RoNoMar - This course has been developed under Romanian Norwegian Maritime Project

RoNoMar - This course has been developed under Romanian Norwegian Maritime Project
This course has been developed under
RoNoMar - Romanian Norwegian
Maritime Project
Supported by a grant from Norway through the
Norwegian Cooperation Programme for Economic
Growth and Sustainable Development with Romania.
Dangerous, Hazardous and Harmful Cargoes
Dangerous, Hazardous and Harmful Cargoes
Purpose of the course
The objective of this manual is to give a brief guide to the rules covering the
carriage of dangerous goods at sea - as contained in the International Maritime
Dangerous Goods (IMDG) Code 2008 with amendment 34-08.
The manual is directed to those personnel responsible for the handling and
transport of dangerous goods and to government officials who have to enforce the rules.
The regulations themselves run to several thousand pages and this manual should not
be seen as a replacement for the Code but rather as a short guide to how it works.
1.1 Main issues
Why have dangerous goods transport rules? Over the years there have been
some serious accidents, and it is not acceptable for innocent people to be hurt or for
damage to be caused to the environment.
Road accidents account for far more deaths and injury than accidents involving
dangerous goods in transport. Nevertheless, even quite small quantities of dangerous
goods can cause significant damage, and when accidents do happen they can be very
serious. Listed below are some examples of the consequences of accidents involving
dangerous goods. Many relate to sea journeys:
in 1974, unknown to the crew, a number of arsine cylinders were loaded inside a
container being shipped across the Atlantic. One of the cylinders leaked because
it was incorrectly stowed. Some twenty years later, crew members who went to
investigate were still unable to work because of the effects; in 1984 the Mont St
Louis, a cargo vessel, sank in the North Sea after colliding with a ro-ro ferry. Part
of the cargo contained uranium hexafluoride. Although there was no leakage, the
fact that nuclear material sank in one of the busiest shipping lanes in the world
caused an outcry;
in 1985 the East African port of Mogadishu (Somalia) was put on alert for
possible evacuation when the Ariadne ran aground and began to break up. The
ship's manifest showed that there were dangerous goods from six of the nine
classes on board. As the ship broke up and the containers washed overboard the
population had to be warned not to eat fish and dead fish began to be washed up
on the shore;
in 1987 the Cason ran aground in bad weather off the Spanish coast. On board
here were dangerous goods from six of the nine classes, amounting to over
1,000 tonnes. Large quantities of dangerous goods were spilt into the sea. The
incident raised questions regarding the adequacy of packaging, stowage and on
board documentation;
in 1993 the Santa Clara I lost two containers overboard on arrival in Baltimore,
USA. Another container was dangling precariously over the side and the deck
was awash with arsenic thoxide, a highly toxic substance. It was also discovered
that the ship was carrying magnesium phosphide which had also spilt. The worry
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here was the casual approach to the cargo by the crew, the ship's owners and
the longshoremen. The US government took action against the owners to
recover the $5 million costs of the cleanup operation.
It is estimated that more than 50% of packaged goods and bulk cargoes
transported by sea today can be regarded as dangerous, hazardous or harmful to the
environment according to IMO criteria. The cargoes concerned include products which
are transported in bulk - such as solid or liquid chemicals and other materials, gases
and products for and of the oil refinery industry, and wastes.
Many chemicals are dangerous but we take them for granted in our everyday
lives. There is no published comprehensive list of the dangerous goods which are sold
or transported; estimates range from 60,000 to 200,000.
Dangerous goods can be substances or articles: e.g. gunpowder is a substance
but if it is put into a firework it is an article; lithium is a substance but a battery
containing lithium is an article.
Dangerous goods are sometimes called hazardous materials (mainly in the
USA). Examples of dangerous goods in the home include: paint, camping gas, petrol,
perfumes, aftershave, bleach, aerosols, nail varnish, fireworks, fibreglass kits, safetytype matches, firelighters. Examples of dangerous goods in the workplace include:
acetylene, propane, sulphuric acid, solvents, sodium, gas cylinders.
1.2 Personal objectives
At the end of this course, the student should be familiar with:
the reasons for the IMDG Code's existence;
the layout of the Code;
the procedures for classifying and identifying dangerous substances and articles;
safe packaging methods and the procedures for ensuring the safety of tank
containment systems;
the requirements for marking, labelling and documentation;
the requirements for stowage and segregation;
the procedures to be adopted in an emergency on board a ship.
Dangerous, Hazardous and Harmful Cargoes
Background and general introduction
2.1 Need for international agreements
Although international maritime trade had been carried on for thousands of years,
the need for international agreements to regulate it was not generally recognized until
stimulated by the loss of the Titanic ocean liner in April 1912, when more than 1,500
passengers and crew died. Two years later an International Conference adopted the
first International Convention for the Safety of Life at Sea (SOLAS), which included
chapters on navigation, construction, radiotelegraphy, life-saving appliances etc.
Mainly because of the First World War, SOLAS 1914 never came into force and
the maritime community had to wait until 1933, when SOLAS 1929 came into operation.
By the time of SOLAS 1948, many aspects were dealt with in much more detail.
However, a basic problem was that there was no international organization which could
coordinate the practical working out of detail necessitated by these Conventions.
Further, the differing national regulations imposed by individual governments created
increasing problems for the rapidly-growing international trade by sea. For example, the
labels identifying different dangerous goods varied from country to country, as did the
permitted packagings.
2.2 Establishment of IMO
The formation of the United Nations organization and its specialized agencies
provided the opportunity for creating a suitable marine agency and the InterGovernmental Maritime Consultative Organization (IMCO) - as IMO was originally
known - came into being in January 1959. One of its first tasks was to arrange a
Conference to revise SOLAS 1948, and SOLAS 1960 duly came into force in 1965, in
which year the first edition of the IMDG Code was adopted. In 1982, IMCO's name was
changed to International Maritime Organization (IMO).
2.3 IMO's dangerous goods codes
As well as the IMDG Code (see chapter 4), IMO is also responsible for keeping
up to date a number of other Codes dealing with dangerous goods, including:
Code of Safe Practice for Solid Bulk Cargoes (BC Code).
Internationa] Code for the Construction and Equipment of Ships Carrying
Dangerous Chemicals in Bulk (IBC Code).
Code for the Construction and Equipment of Ships Carrying Dangerous
Chemicals in Bulk (BCH Code).
International Code for the Construction and Equipment of Ships Carrying
Liquefied Gases in Bulk (IGC Code).
Dangerous, Hazardous and Harmful Cargoes
3.1 International Convention for the Safety of Life at Sea, 1974
(SOLAS 74)
The current SOLAS Convention and came into force in 1980. Because of
improved amendment procedures it is unlikely that it will need to be replaced; instead is
amended when necessary. Chapter VII of SOLAS 74 deals with dangerous goods and
refers to the IMDG Code. In 2008 the Maritime Safety Committee confirmed its earlier
decision to make the Code mandatory with the issue of Amendment 34. Amendment 31
was published in 2008, became available for use from 1 January 2009 and mandatory
from 1 January 2010. Chapter VII is reproduced in full in chapter 1.1 of the IMDG Code.
The revised Chapter VII, as amended in 1994, now applies to all ships covered
by SOLAS and also to cargo ships of less than 500 tons gross tonnage. The 1974
SOLAS Convention has been ratified by 128 countries and applies to some 98% of the
world merchant gross tonnage.
Regulation 1 of part A of chapter VII prohibits the carriage of dangerous goods by
sea except when they are carried in accordance with the provisions of the SOLAS
Convention, and requires each Contracting Government to issue, or cause to be issued,
detailed instructions on safe packing and stowage of dangerous goods which shall
include the precautions necessary in relation to other cargo. In a footnote, reference is
made to the more detailed provisions of the International Maritime Dangerous Goods
(IMDG) Code.
Regulation 2 divides dangerous goods into nine classes which are described
later in this paper. In the IMDG Code, classes 2, 4, 5 and 6 are further divided into two
or three sub-classes.
The other six regulations of part A deal with the packing, identification, marking,
labeling and placarding of dangerous goods, the documents which are to be provided,
stowage and segregation requirements, the carriage of explosives on board passenger
ships, and reporting of incidents involving dangerous goods.
Since 1974, revisions and amendments to chapter VII adopted by the MSC
entered into force in 1986, 1992,1994, 1996, 2001, 2003, 2004 and 2006. Although
invoked by a footnote reference in regulation 1 of chapter VII, the IMDG Code itself had
only recommendatory status until 31 December 2003.
3.2 International Convention for the Prevention of Pollution from
Ships, 1973/78 (MARPOL 73/78)
Although concern for safety of life at sea was addressed early in the 20th
century, it was not until much later that the task of protecting the marine environment
was tackled, following tanker accidents (notably the Torrey Canyon in 1967) which
caused extensive oil pollution. An international convention was drawn up in 1973, but
the complications were such that additional work was required, and a modifying
Protocol had to be produced in 1978 - hence the usual abbreviation of "MARPOL
Dangerous, Hazardous and Harmful Cargoes
There are 6 Annexes to MARPOL 73/78, containing regulations for the
prevention of various forms of pollution, as follows:
Entry into force
Annex I
Pollution by oil
2 October 1983
Annex II
Pollution by noxious liquid substances
6 April 1987
carried in bulk
Annex III
Pollution by harmful substances carried in
1 July 1992
packages, portable tanks, freight
containers, or road or rail tank wagons,
Annex IV
Pollution by sewage from ships
Not yet in force
Annex V
Pollution by garbage from ships
31 December 1988
Annex VI
Air pollution from ships
Not yet in force
The Marine Environment Protection Committee (MEPC) decided in 1985 that
Annex III should be implemented through the IMDG Code. This decision was also
endorsed by the MSC in 1985. Amendments agreed by the MEPC and MSC to Annex
III to MARPOL 73/78 entered into force in 1994, 1996 and 2002.
Annex III, like chapter VII of SOLAS 74, comprises short regulations crossreferenced to the IMDG Code which, as mentioned above, contains detailed
information. Annex III is reproduced in full in chapter 1.1 of the IMDG Code.
3.3 Dangerous goods and harmful substances
The use of the terms "dangerous goods" (SOLAS) and "harmful substances"
(MARPOL) tends to cause confusion, especially as they originate in two completely
separate conventions.
Although, MARPOL Annex III defines "harmful substances" as "those substances
which are identified as marine pollutants in the IMDG Code", so that references in the
IMDG Code to marine pollutants relate to the MARPOL Convention.
Many dangerous goods are of course also harmful to the marine environment
and in such cases the requirements of both conventions must be met, although SOLAS
takes precedence in the event of conflict (e.g. MARPOL prefers marine pollutants to be
stowed under deck, but SOLAS requires certain particularly dangerous items to be
stowed on deck only).
However, some marine pollutants do not meet the criteria of any class of
dangerous goods, and special entries in the IMDG Code ensure these are controlled in
a similar way to dangerous goods i.e. by proper classification, packing, labeling,
marking, documentation and stowage etc., as described in later parts.
Dangerous, Hazardous and Harmful Cargoes
IMO and dangerous goods
The SOLAS and MARPOL Conventions (see chapter 3) include chapters on the
carriage of dangerous goods in ships. These chapters set down guidelines and IMO is
requested to make detailed provisions. This is carried out within IMO's Committee
structure and has led to the publication of the IMDG Code.
4.1 The Committee structure
The chart below does not show all of IMO's Committee structure, only those
committees which impact on the IMDG Code.
The day to day work of developing the IMDG Code rests with DSC which is made
up of members of IMO that have adopted the IMDG Code along with non-governmental
organizations accredited to IMO with consultative status. Any of the delegations can
submit proposals to the Committee for consideration. If it is necessary to vote then only
government delegations may do so. Having discussed and adopted proposals the DSC
has an Editorial and Technical Group of about 8 Member States which, following each
DSC meeting, reviews the adopted proposals and ensures they are embodied in the
correct parts of the Code with appropriate cross references. On completion of a
particular amendment the report is submitted to the MSC which has the opportunity to
reject, amend or accept its contents. If the MSC agrees to the changes then the
amendment is published and comes into force on a date specified by the MSC. The FAL
Committee provides input on certain documentation issues. The MEPC also has an
input into the IMDG Code. When MARPOL Annex III was adopted (see chapter 3) it was
decided that, as most pollutants were also dangerous goods, rather than publish a
separate set of regulations they would incorporate the provisions of Annex III into the
IMDG Code. This means that some of the work of the MEPC is included in the IMDG
4.2 UN Committee of Experts on the Transport of Dangerous Goods
In 1953 the United Nations Economic and Social Council (ECOSOC) adopted a
resolution that created the UN Committee of Experts on the Transport of Dangerous
Goods and it held its first meeting in Geneva in 1954. The first meeting did not start its
work without the Knowledge that there were already in existence and at various stages
of development rules on the transport of dangerous goods, including: SOLAS, RID
(railways) and IATA (air).
That first meeting established the class numbers and recognized that labels
should be applied to packagings. The Committee circulated some recommendations
which were considered two years later in 1956. The work of the UN progressed and
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when IMO began to develop a Code the UN Recommendations provided a helpful guide
which from the outset had taken account of the requirements of SOLAS.
The UN Committee of Experts has continued to meet until the present day and its
published ``Recommendations on the Transport of Dangerous Goods'' (``Orange Book'')
are updated biennially. In 1996, the MSC agreed that the IMDG Code shall be
reformatted consistent with the format of the UN Recommendations on the Transport of
Dangerous Goods. The consistency in format of the UN Recommendations, the IMDG
Code and other dangerous goods transport regulations is intended to enhance userfriendliness, compliance with the regulations, and the safe transport of dangerous
The UN Committee broadly considers common multi-modal issues:
Dangerous Goods List (identification) and Limited Quantities
Transport operations
The results are published as the United Nations Recommendations on the
Transport of Dangerous Goods every 2 years; provisions in the current (15th) edition,
published in 2009, are included in Amendment 34 to the IMDG Code in 2009.
4.3 The UN Recommendations and IMO
Although in the early years of the IMDG Code there were significant deviations
from the UN Recommendations, in the last decade IMO has taken the majority of the
UN Recommendations and incorporated them into the Code. This makes multi-modal
transport much easier.
The UN Recommendations are not written in isolation: representatives of the
IMO Secretariat and some DSC delegations attend the UN meetings. IMO also provides
a useful feedback to the UN Committee - they often find inconsistencies in the text from
the UN and they can propose appropriate changes.
Dangerous, Hazardous and Harmful Cargoes
The IMDG Code
5.1 Introduction
The International Maritime Dangerous Goods (IMDG) Code is an international
agreement for the transport of dangerous goods by sea. It is published by IMO.
Resolution 56, adopted at the 1960 SOLAS Conference, recommended that
Governments should adopt a uniform international code for the carriage of dangerous
goods by sea which should supplement the SOLAS regulations and cover such matters
as packing, container traffic and stowage, with particular reference to the segregation of
incompatible substances. It further recommended that IMO, in co-operation with the
United Nations Committee of Experts on the Transport of Dangerous Goods, should
pursue its studies on such an international code, especially in respect of classification,
description, labelling, a list of dangerous goods and shipping documents.
To carry out this mandate, in January 1961, IMO's Maritime Safety Committee
(MSC) established a Working Group on the Carriage of Dangerous Goods (CDG).
Governments with considerable experience in the carriage of dangerous goods were
invited to nominate experts.
The Group met for the first time from 29 to 31 May 1961 and set about preparing
the "unified international maritime code" as envisaged by the 1960 SOLAS Conference.
Preliminary drafts for each class were compiled by individual national delegations
and then considered by the Group which took into account the practices and procedures
of numerous maritime countries in order to make such a code as widely acceptable as
possible. Close co-operation was established with the United Nations Committee of
Experts on the Transport of Dangerous Goods, which had prepared its 1956 report in
which it established the minimum requirements for the transport of dangerous goods by
all modes of transport. The CDG
Working Group met 10 times, the final meeting being held in November 1965,
after which it became the Sub-Committee on the Carriage of Dangerous Goods,
meeting 45 times. In May 1995 the sub-committee was combined with the SubCommittee on Containers and Cargoes (BC), to become the Sub-Committee on
Dangerous Goods, Solid Cargoes and Containers (DSC).
By November 1965, good progress had been made in preparing such a code and
the resulting document became known as the International Maritime Dangerous Goods
(IMDG) Code . It was adopted by the fourth IMO Assembly in 1965. Although designed
primarily for mariners, the provisions of the IMDG Code affect a number of industries as
well as storage, handling and transport services from manufacturers to consumers.
Chemical and packaging manufacturers, packers, shippers, forwarders, carriers
and terminal operators are guided by its provisions on classification, terminology,
identification, packing and packagings, marking, labelling and placarding,
documentation and marine pollution aspects. Feeder services, such as road, rail,
harbour and inland water craft are guided by its provisions. Port authorities, terminal
and warehousing companies consult the IMDG Code to segregate and separate
dangerous cargoes in loading, discharge and storage areas. Although the Code only
applies to ships covered by the SOLAS Convention, IMO considers it highly desirable
that its provisions should be observed by all ships.
Since its introduction in 1965, the IMDG Code has undergone many changes,
both in appearance and content to keep pace with the ever-changing needs of industry.
Amendments which do not affect the principles upon which the Code is based may be
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adopted by the Maritime Safety Committee alone. Thus IMO can respond to transport
developments in reasonable time.
Requirements relating to the carriage by sea of marine pollutants - arising from
Annex III of MARPOL 73/78 - are also encompassed within the provisions of the Code.
The latest edition of the Code incorporates the 34th Amendment, adopted in
2008 (Amendment 34-08) and comes into effect on 1 January 2009.
The guidance contained in the Code is intended for use by all personnel involved
in the shipment of dangerous goods by sea: mariners, manufacturers, consignors,
agents and any associated feeder or support industries and services, competent
authorities. The various parts of the Code contain advice on dangerous goods
classification, identification, containment, labeling, stowage, segregation, handling and
emergency response procedures.
5.2 Application of the Code
The IMDG Code has until Amendment 31 no binding force; it has simply been
recommended to governments for adoption. Of the 130 members of the International
Maritime Organization, 51 countries have currently adopted the IMDG Code. These
countries account for 80% of world shipping tonnage.
From 1 January 2004 the IMDG Code becomes mandatory and member of IMO
are required to put in place legislation to enforce the provisions. However it should be
noted that some parts of the Code cannot be mandatory and chapter 1.1 (1.1.5) lists
those parts of the Code that remain recommendations, notably training, determination of
flashpoint, Emergency Schedule and the MFAG. Some national governments also apply
variations to, and exemptions from, the standard provisions of the Code.
5.3 Content and layout of the Code
The IMDG Code comprises two volumes and a Supplement, the contents and
layout of which are described below. The structure of the IMDG Code is based on the
UN structure:
General provisions, definitions and training
Dangerous Goods List and Limited Quantity exceptions
Packing and tank provisions
Consignment procedures
Construction and testing of packagings, intermediate bulk
containers (IBCs), large packagings, portable tanks and road tank
Provisions concerning transport operations
Appendix A List of Generic and N.O.S proper shipping names
Appendix B Glossary of terms
Alphabetical index
Supplement Emergency Procedures (EmS), Medical First Aid Guide (MFAG),
reporting Procedures, Packing Cargo Transport Units, Safe Use o
Pesticides, International Code for the Safe Carriage of Packaged
Irradiated Nuclear Fuel, Plutonium and High Level Radioactive
Wastes on Board ships (INF Code), Appendix
Dangerous, Hazardous and Harmful Cargoes
Part 1 of the IMDG Code, which consists of general provisions e.g. definitions,
conversion tables etc is not dealt with in this manual, but the remaining parts are
covered. For most day-to-day shipment procedures, shore personnel and seafarers will
normally use part 3 of the Code as the key to identifying information and duties. The
contents of this part, in particular the Dangerous Goods List, are explained in 5.4.
Each part of the Code is divided into chapters which are in turn subdivided into
sections and sub-sections. A sequential numbering system applies to the paragraphs
within each subsection. For example, a reference to means that the
information concerned will be found in part 6, chapter 5, section 1, sub-section 4,
paragraph 1.
5.4 The Dangerous Goods List
Most of volume two of the Code consists of a Dangerous Goods List (DGL). This
comprises in a list of UN Numbers allocated to dangerous goods of different classes.
The list has 18columns (as shown below) spread across two pages. The list is in UN
Number order. There is an alphabetical list of chemical names in the index at the back
of volume 2.
Subsidiary Packing
Name (PSN)
Portable tanks and bulk
(12) (13)
Limited and excepted
provisions quantities provisions
Excepted Instruc Provisi Instruc Provi
quantities quantities tions
tions sions
Stowage and segregation No.
Properties and observations
Below the number of the column eg “(4)” we find the direct reference to the IMDG
Code where we can find information about that column. The Introduction to the DGL in
chapter 3.2 provides guidance to the purpose of each column, The notes below are to
supplement those notes:
Column 1 – UN No. – To identify the consignment requirements for a particular
substance or article, it is necessary to know the UN Number. This is allocated by the UN
Committee of Experts on the Transport of Dangerous Goods. It is common to all modes
of transport. It is unique to the name in column 2.
Column 2 – Proper shipping name – The name in CAPITALS (upper case) is
the one allocated by the UN to the number shown in column 1. Lower case text is
optional information and is not required on packages or documentation Although the
name is shown in capitals there is no requirement to use this style on packages or
Column 3 – Class or division – All substances are allocated to one of nine
Column 4 – Subsidiary risk(s) – Many substances have more than one hazard.
Any secondary hazards are known as subsidiary risks. The UN generally allocates
these but IMO includes information concerning marine pollutants in this column.
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Column 5 – Packing group – Packing groups indicate a level of danger within a
class. The level can determine the type of packaging or tank to be used. Where more
than one packing group is listed for a particular entry, the rules of classification for the
primary hazard must be used to determine which group is applicable. Packing groups
are not allocated in classes 1, 2, 6.2 or 7 although the concept is used when
determining some types of packaging.
Column 6 – Special provision – These are very important. They can give criteria
for: exempting the substance from the Code, clarifying classification detail, changing
labeling requirements etc. There are two types of SP:
UN special provisions (numbered 15 - 310). These are common
across the modes.
IMDG special provisions (numbered from 900 upwards). These are
unique to maritime shipments.
Column 7a – Limited quantities – These are dangerous goods consignments
that can be carried without full compliance with the Code subject to certain conditions
being met with respect to package quantity limitations and markings.
Column 7b – Excepted quantities – These are small amounts, up to 30g or
30ml per inner package, 1kg per outer package. An entry E0 in column 7b indicates that
a substance may not be transported in excepted quantities. Codes E1 to E5 indicate
different quantity limits according to a table in chapter 3.5. The total number of excepted
quantity packages in a CTU shall not exceed 1000.
Columns 8 - 9 – Packing – Columns 8 and 9 are linked. Column 8 identifies the
applicable packing instruction, prefixed with the code "P" for a packaging or "LP" for a
large packaging from the options available under the instructions for the substance
concerned. If in column 9 a number prefixed with the code "PP" for packagings or "L" for
large packagings appears in this column, it is an additional condition concerning the use
of that packaging. It will usually add restrictions to use but occasionally relaxations are
Columns 10-11 – IBC – Columns 10 and 11 are linked. Column 10 identifies the
applicable IBC instruction, prefixed with the code "IBC" for a packaging from the options
available under the instructions for the substance concerned. If in column 11 a number
prefixed with the code "B" for IBCs appears in this column it is an additional condition
concerning the use of that IBC. It will usually add restrictions to use but occasionally
relaxations are provided.
Column 12 – – [reserved]
Column 13 – Tank and bulk containers instructions – these apply for portable
tanks and road tanks if the letter T appears in it. The code BK2 refers to closed bulk
containers, also the code “MEGC” are for gases authorized for transportation in MEGCs
Column 14 – Tank and bulk containers provisions – These Provisions are
additional conditions applicable to the tank or bulk container used for the substance.
Column 15 – EmS – This column indicates the relevant Emergency Schedule
number in the emergency procedures. These are explained in the Supplement to the
Code. There are two Schedules shown: "F-" for fire and "S-" for spillaqe.
Column 16 – Stowage and segregation – This column indicates a stowage
category for the substance and identifies any special segregation instructions.
Column 17 – Properties and observations – This column provides background
information about the properties and nature of the substance.
Column 18 – UN No. – Identical with column 1.
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Classification - physics and chemistry
6.1 Introduction
The purpose of this training module is to give sea-going and shore personnel
involved in handling dangerous goods a basic knowledge of chemistry so that they are
able to understand the terms used in the IMDG Code and to appreciate the hazards
associated with the dangerous goods they are dealing with. It is not the intention of the
module to turn non-chemists into chemists and it must be stressed at the outset that
expert advice must always be sought if there is any doubt.
Also, names for the same chemical will often be different in different languages.
To avoid misunderstandings, the United Nations Number given in column 1 of the DGL
must always additionally be quoted, preceded by the letters "UN". UN Numbers are only
assigned to substances and articles which meet the classification criteria.
6.2 Physics and chemistry – Basic Terms
Physics is the study of the basic laws that govern our universe, including the
forces that exist between objects and the interrelationship between energy and matter.
Chemistry is defined as the science of elements and compounds and their laws
of combination and behaviour under various conditions. For study purposes, chemistry
is divided into a number of major branches including physical, inorganic, organic and
polymer chemistry.
Physical chemistry - This branch of chemistry is concerned with the effect of a
chemical's structure on its physical properties such as shape, colour, odour, solubility,
melting point etc.
Organic chemistry - This is the chemistry of carbon compounds apart from
some of the most simple ones such as carbon monoxide, carbon dioxide and
carbonates. There are over a million organic substances, some natural, some man
made (synthetic), some both, with new ones being found every day. Many substances
are familiar: sugar and crude oil, which are produced naturally, plastics such as
polyethylene, which are produced synthetically, and alcohol, which can be made
through both natural fermentation or by synthesis, are examples of organic substances.
Our organs and tissues are composed of organic compounds including carbohydrates,
proteins and fats. All living things are organic but not all organic substances are not
found in living organisms.
Inorganic chemistry - This branch of chemistry is devoted to those substances
which are not considered to be organic. Many of these are derived from minerals: iron
ore and common salt are inorganic naturally occurring substances, as is water. They all
have a characteristic chemical composition.
Polymer chemistry - This is really a sub-branch of organic chemistry but is so
important that it is treated as a specialized subject. It is the study of large or macro
molecules which consist of repeating units of small molecules (monomers). These may
be naturally occurring, such as proteins, or manufactured synthetically, such as
A number of terms commonly used in chemistry, some of which have been used
in the above definitions, are found in the Code and these are explained as follows:
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Elements - These are the basic building block blocks from which all chemical
structures are made. They cannot be broken down into simpler substances and are
composed of identical atoms which are the smallest particles of an element that can
chemically exist. An atom consists of a dense nucleus containing positively charged
protons and uncharged neutrons. In orbits surrounding this nucleus are small negatively
charged electrons, the number of which equals the number of protons so that the overall
atomic charge is neutral. There are over 100 elements, most of which are easily divided
into two main classes, metals which conduct electric current and heat and non metals
which do not.
Materials - a material is defined as having some general properties but these
may vary depending upon the composition. For example, wood has some general
properties that we all recognize but different kinds of wood have different colours and
Substances - the IMDG Code refers to the term "substance". This is a generic
term covering chemicals the chemical composition of which do not vary significantly
from one sample to another. Many substances are compounds, some are elements.
Examples of substances are common salt (sodium chloride), iron and cane sugar.
Articles - the IMDG Code also refers to the term "article". An article is a device
that contains a dangerous substance or mixture of substances. Examples of articles are
fireworks, aerosols, lighters, bombs etc.
Mixtures - if the elements iron and sulphur are blended together in powder form,
then a mixture is formed. The two components retain their individual chemical and
physical characteristics and can be separated from each other again, in this instance by
applying a magnetic field which will separate the metallic iron from the sulphur. Mixtures
may be either solid, such as gunpowder (carbon, sulphur and saltpetre), liquid (whisky
and water), solid/liquid (sugar in tea) or gaseous such as air (oxygen and nitrogen).
Each component within the mixture is called a constituent.
Compounds - if the mixture of iron and sulphur powders is heated together their
atoms combine to form molecules (fundamental units) of a new substance called a
chemical compound, in this instance iron or ferrous sulphide.
6.3 Physical chemistry
Matter exists in three states, solid, liquid or gas. The physical state of many
substances will vary depending upon the temperature and pressure applied to them.
Solids - have a regular shape and are crystalline (the atoms or molecules
composing the substance are arranged in a regular pattern). Solids, which have no
particular structure, are said to be amorphous. Glass, rubber and many plastics are
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amorphous. Some solids take water from the air and become damp. These are called
hygroscopic. Common salt is an example of a hygroscopic solid. Some crystals actually
dissolve in the water from the atmosphere to become concentrated solutions. Such
solids are called deliquescent. It is difficult to compress solids.
Liquids - have a definite mass and volume but no shape; they take up the
shape of the container into which they are poured. Some liquids, like water, flow easily
and are said to be mobile whilst others like treacle are said to be viscous. The Code
recognizes that increasing viscosity can reduce hazard (chapter 2.3) and affect packing
(chapter 4.1 - Liquids are difficult to compress.
Gases - like air, have a definite mass but no defined volume and will expand to
fill the volume of the containment vessel. Gases are much less dense than solids or
liquids and whilst some gases like chlorine are heavier than air, others like hydrogen are
lighter than air. Gases are easily compressed and are available in pressure resistant
gas cylinders.
Physical properties:
Chemicals are identified and characterized by their properties. Physical
properties are used to assist in the classification of substances and articles within the
Code and some important physical properties are also specified in the Code on the
individual schedules.
Boiling point - is is the temperature at which a liquid boils and begins to turn into
a vapour. The boiling noint will vary depending upon the pressure applied. The
atmospheric pressure (the pressure exerted by the mass of air in the atmosphere at any
one point on the Earth's surface) will determine the boiling point. At sea level the
atmospheric pressure is 1 atmosphere = 101.13 kPa = 14.7 pounds per square inch
gauge (psig) = 760 mm mercury (mmHg) and the boiling point of water is 100°C. If the
pressure is decreased (e.g. at the top of a high mountain), the boiling point will be less
and will be increased if the pressure is raised. Boiling point criteria are used together
with flashpoint to allocate flammable liquids into packing groups (see chapter 2.3 of the
Code). The IMDG Code uses kPa to define pressure and degrees Celsius (°C) to
specify temperature. Tables to convert degrees Fahrenheit (°F) into "C are included in
chapter 1.2.
Vapour pressure - all solids and liquids give off vapour consisting of atoms or
molecules of the substance that have evaporated from the surface. The pressure which
the vapour exerts under specified conditions is known as the vapour pressure. Vapour
pressure increases with temperature and a liquid boils when its vapour pressure is
equal to the atmospheric pressure. In general, the higher the substance's vapour
pressure, the lower the boiling point and the more volatile (likely to vaporize) it is likely
to be. Vapour pressure is an important consideration in defining whether a particular
substance should be classified as a gas (see chapter 2.2 of the Code) and also in
determining the toxicity of a substance if inhaled. In the IMDG Code, the unit used to
describe pressure is the kiloPascal (kPa). For conversion, Standard Atmospheric
Pressure = 1 atmosphere = 14.7 psig (0 psig) = 101.13 kPa = 760 mmHg.
Flashpoint - This is the lowest temperature at which a volatile liquid gives off
sufficient vapour to form a combustible liquid in air and in the presence of a naked flame
gives a momentary flash but not a sustained fire under controlled conditions. It is an
indication of the flammability of a substance. Standardized open cup (o.c.) or closed cup
(c.c.) test methods are used to determine the flashpoint. In view of the importance of
flashpoint in the classification of flammable substances (see below), further details on
the test methodology may be found in chapter 2.3 of the Code. A liquid cannot be
ignited at a temperature below its flashpoint. Some liquids have flashpoints at very low
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temperatures. Petrol, for instance, has a flashpoint of below -18°C which enables cars
to start even in arctic conditions. A flashpoint criterion of 61 °C c.c. is used to determine
if a substance should be classified within class 3 - Flammable Liquids. Along with the
boiling point, the flashpoint is used to assign flammable liquids within packing groups.
Autoignition point - This is the temperature to which a liquid must be raised to
cause a sustained fire or explosion when touched by a flame or hot object or by the heat
generated during the reaction or by friction. There is no relationship between flashpoint
and ignition temperature.
Explosive limits - This is the percentage by volume vapour/air concentration of
a substance which is ignitable. Below the lower explosive limit (LEL), the mixture is too
"lean" to ignite and above the upper explosive limit (UEL) the mixture is too rich.
Schedules for flammable gases and liquids give the explosive limits for each substance.
Melting point - The melting point is the lowest temperature at which a solid will
change into a liquid when heated e.g. ice turning to water. Chemists measure melting
points for two reasons. Each substance has its own specific melting point which can
assist in its identification and also to determine its purity, as impure substances may
have a lower melting point than their pure form or may melt over a temperature range.
Some solids not normally classified as hazardous will become so if they are transported
molten and the melting point is at or above 240°C (see chapter 2.9 of the] Code). Care
must be exercised in the selection of packaging materials for solids which have a
relatively low melting point since changes in climatic temperatures during export
shipments from a temperate to a tropical climate can change a solid into a liquid.
Density - The density of a sample of a substance is determined by dividing its
mass by the volume it occupies. The resulting number is expressed as kilograms per
cubic meter (kg/m3): the higher the number the more dense and heavy is the substance.
For example, mild steel has a density of 7.9 kg/m3 whereas balsa wood has a density of
0.2 kg/m3. To compare densities of different substances, relative density (r.d.) is used.
For liquids and solids, it is the ratio of the density (usually at 20°C) of the substance to
that of water at its maximum density of 1.000 at 4°C. For gases, the Code compares the
density of the gas to that of dry air and is known as the relative vapour density. Relative
densities have no units assigned to them. Relative density is used to determine the net
mass of different substances packed into e.g. drums of the same volumetric capacity.
For instance the net mass of 200 litres of ethanol (r.d. 0.61) = 122 kg whereas the same
drum filled with 200 litres of carbon tetrachloride (r.d. 1.586) = 317 kg. The United
Nations Package Performance Tests recognize that product r.d. can affect container
performance, particularly impact strength, and therefore the drop height for packagings
destined to carry substances with a relative density exceeding 1.2 must be increased
over the standard heights for packing groups I, II, and III (see chapter 6.1 of the Code).
Relative vapour density is important in stowage planning. For example, the toxic gas
arsine, which has a relative vapour density of 2.8 compared to air would not be stowed
below deck where it could not easily disperse. For gases, the Code defines the terms
"much lighter than", "lighter than", "heavier than" and "much heavier than" air based on
the vapour density of the gas compared to air (see chapter 3.2 - Structure of the
Dangerous Goods List - explanation of column 17).
Solubility/Miscibility - When a solid or a gas (a "solute") dissolves in a liquid (a
"solvent") a homogeneous mixture or solution is formed. Eventually as more and more
solute is added, the solution cannot dissolve any more and is said to be saturated. For
example, common salt will dissolve in water forming a clear solution. By adding more
and more salt the solution will become cloudy regardless of how much it is stirred. The
only way of increasing the solubility of the salt is by heating the solution. Generally, for a
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solid in a liquid, solubility will increase with temperature rise; for a gas in a liquid the
reverse is true. If a liquid mixes completely with another liquid then it is said to be
miscible (e.g. alcohol is completely miscible with water). Some liquids will only partially
mix with other liquids and these are said to be partially miscible, whilst others such as
petrol and water will not mix and are immiscible. In this instance the liquid with the lower
relative density (petrol) will float on water as a separate layer. Miscibility and relative
density are important criteria used in determining what medium should be used in
fighting fires involving chemicals. For example water would not be suitable for fighting
fires involving petrol which would merely float on the water and spread the fire. Water is
the main solvent used in chemistry and solutions in water are called aqueous solutions
after the Latin name for water (aqua). Water is a good solvent for gases and aquatic life
depends upon the solubility of oxygen dissolved in water for its very existence. If water
is not used as the solvent then the name of the solvent must be specified.
The IMDG Code classifies a solution of a hazardous chemical as though it were
the pure substance unless the dilution is such that the chemical no longer meets the
hazard criteria tor the pure substance or has been changed by the nature of the diluent.
Odour - Many substances have a characteristic smell which may be the first
indication of product escape. Any unusual odour should be treated as a warning and
appropriate emergency action taken. The Code uses a number of words (see column 17
of the DGL) to assist in identification of the odour, such as:
Causes drowsiness
EtherealEther-like, an anaesthetic
IrritatingSmell which is unpleasant to the senses
LachrymatoryBrings tears to the eyes
NarcoticCauses drowsiness
PhenolicSmells like creosote
PungentHas a strong effect on the senses
It must be emphasized that many chemicals are odourless and some of these
(e.g. carbon monoxide) are highly toxic and therefore odour must not be relied upon to
detect if chemicals are present.
6.4 Hazardous chemicals and chemical reactions
All chemicals are to a greater or lesser extent hazardous to human health or to
the environment. An iron bar dropped onto somebody's head can maim or kill and even
water can, under certain circumstances, be highly dangerous: probably more people
have died by drowning than from exposure to any other chemical. However the United
Nations Committee of Experts on the Transport of Dangerous Goods have recognized
that certain families or classes of substances and articles present particular and
significant hazards from which the general public and those involved in their transport
need to be protected.
The hazard posed arises from either the substances or article itself, often caused
by a change in its storage or transport conditions (e.g. cylinders of compressed air can
explode if involved in a fire due to the increased pressure formed within the cylinder as
the temperature is raised) or by reaction of the substance or article with other
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substances either in the surrounding environment such as oxygen or water or those
chemicals which make up living tissues.
A chemical reaction is a process in which a new substance is formed and which
either requires energy to initiate it usually in the form of heat (endothermic) (e.g. the
formation of acetylene gas from carbon and hydrogen) or generates heat energy during
the reaction (exothermic) (e.g. the reaction of calcium carbide with water, which not only
generates heat but the gas acetylene).
There are many examples of hazardous reactions:
flammable substances react with oxygen in the air and in the presence of an
ignition source to generate heat, light and new substances. Some oxygencontaining substances decompose when heated in a fire, liberating their
oxygen and therefore making a fire more intense;
many toxic (poisonous) substances act by reacting with substances in the
body, thus interfering with the normal life processes;
some substances react exothermically with water, generating gases which
may be flammable or toxic;
some substances, such as metal alkyls, react so violently with air that
spontaneous ignition occurs. Such reactions are said to be pyrophoric;
some substances, e.g. radioactives, can alter genetic material, causing
cancer and birth abnormalities.
The rate at which a chemical reaction occurs normally increases as the
temperature rises, which is why thermally unstable substances such as many organic
peroxides are stored and transported at low temperatures; however, some substances,
often in very small amounts, can also promote chemical reactions without themselves
undergoing any chemical change. These are called catalysts and an example is the use
of finely divided platinum in car exhaust systems, which assists the conversion of some
hazardous by-products of combustion into carbon and sulphur dioxides before they
leave the exhaust system. Some impurities can act as catalysts promoting the
exothermic decomposition of unstable chemicals such as organic peroxides.
More recently, IMO has also recognized that some substances, if accidentally
released into the sea, will pollute the marine environment.
For convenience, the UN has divided these families of hazardous substances
and articles amongst nine classes based on the type of hazard that they represent and
criteria have been developed to enable science-based decisions to be made on the
assignment of substances or articles to these classes. A basic knowledge of the
chemistry of these families will assist in understanding the hazards they present.
Chemical hazard classes:
Explosives (class 1) - Chemical explosions are usually caused by very rapid
burning of a substance or mixture of substances in the presence of oxygen in the air
("deflagration"). The rapidly expanding gaseous products of this reaction cause damage
by the propulsion of fragments of its container and other nearby material at high velocity
and also by disturbance of the surrounding air ("blast").
Explosives may be classified in a number of different ways:
• Primary and secondary explosives
A primary explosive is easily initiated; a secondary explosive requires a primary
explosive for initiation but, when initiated, tends to be more powerful. An example
of a primary explosive is mercury fulminate. TNT is a secondary explosive whilst
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nitroglycerine has the initiation properties of a primary explosive and the power of
a secondary explosive, hence the problems in handling this substance.
High and low explosives
A high explosive such as nitro-glycerine will burn at such a rate that detonation
occurs. A low explosive such as gunpowder will not detonate. In detonation a
shock wave is generated which provides the energy not only to initiate the
oxidation reaction but also cause much more damage to the surroundings.
The UN system
Explosives are classified within class 1 into six sub-divisions depending upon the
type of explosive hazard (mass, projection, fire) and how sensitive the explosive is to
initiation. For stowage purposes explosives are also assigned to one of 13 compatibility
groups. The combination of class, hazard division and compatibility group is known as
the hazard classification code which provides the key to identify the provisions for safe
storage and transport of explosive substances and articles assigned to class 1.
Gases (class 2) - The IMDG Code defines a gas as a substance that has a
vapour pressure greater than 300 kPa at 50°C or is completely gaseous at 20°C at
atmospheric pressure.
Gases are stored and transported in one of four states:
refrigerated liquefied
in solution
The state in which a particular gas is transported depends primarily upon the
minimum temperature required in order to liquefy the gas by pressure. This is known as
the critical temperature, above which a gas cannot be liquefied by pressure alone.
Some gases such as hydrogen, nitrogen and oxygen - known collectively as permanent
gases - need to be cooled to a very low temperature before pressure can liquefy them
(e.g. oxygen has a critical temperature of -119°C). Such gases are either transported in
high-pressure cylinders or in refrigerated gas tanks. Other gases such as butane have
much higher critical temperatures and are therefore relatively easy to liquefy. These
gases are transported in lower pressure cylinders or non refrigerated gas tanks. Some
gases such as butane are used as propellants and are transported in aerosols. A few
gases (e.g. acetylene) do not liquefy and are transported dissolved in a solvent under
Gases can present a variety of hazards:
all gases in pressure cylinders/tanks could explode if involved in a fire;
"inert" gases such as nitrogen, neon, xenon, etc. are asphyxiant and can cause
suffocation by reducing the oxygen content in the air if released in confined
some gases such as oxygen are strong oxidizers that could enhance the effects
of a fire;
some gases such as methane are highly flammable;
some gases are highly toxic (arsine) or corrosive (sulphur dioxide).
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Flammable liquids (class 3) - This class comprises liquids that have a
flashpoint of 61 °C c.c. or below. Also included are any substance that is transported as
a liquid at an elevated temperature at or above its flashpoint even if the flashpoint is
above 61 °C. This class is composed almost entirely of liquids which are organic and
the major hazard is the potential for their vapours to catch fire. Fire is the result of a
chemical oxidation reaction involving three components:
A fuel
Oxygen (normally air)
A source of ignition
The fuel reacts with the oxygen to produce reaction products, heat and light
energy. If one of the components is removed then combustion will not occur or will stop.
Petrol will not spontaneously ignite when exposed to air at ambient temperatures. Car
engines stop when the ignition is turned off and fires can be put out by removing the
oxygen with C02 or foam extinguishers.
Not all organic liquids are flammable. In fact, some chlorinated organic liquids are
used to extinguish fires, although for environmental reasons such products are now
being phased out. All flammable liquids have a narcotic effect if inhaled.
Flammable solids (class 4) - This class comprises both inorganic and organic
substances and is divided into three classes:
Class 4.1 - Flammable solids This class includes:
readily combustible solids which if ignited can rapidly spread the resulting fire
(e.g. celluloid);
solids which may catch fire through friction which can produce sufficient heat
energy to ignite the substance (e.g. matches);
self-reactive solids and liquids and substances related to them. These are
thermally unstable molecules which if heated will undergo a strongly
exothermic decomposition reaction and some will burn vigorously. Typical
self-reactive substances contain nitrogen. Some self-reactive substances
need to be temperature controlled during storage and transport;
desensitized explosives. These are explosives which are wetted with water or
alcohol or diluted with other substances to suppress their explosive properties
(e.g. mixtures containing between 2% and 10% nitro-glycerine).
Class 4.2- Substances liable to spontaneous combustion
The IMDG Code defines two types of spontaneously combustible substances:
Pyrophoric substances. These are substances (including mixtures and
solutions) which even in small quantities will spontaneously ignite due to the
rate of heat produced during the reaction with oxygen in the air exceeding the
rate at which heat can be removed. The overall effect is that the substance is
raised to its auto-ignition temperature and thus catches fire. Ignition occurs
within five minutes of exposure. Typical examples of spontaneously
combustible substances are some finely divided metal powders and metal
Self-heating substances. These are substances which will only auto-ignite
when stored for long periods of time (hours or days) in large (kg) amounts.
Carbon powder and some vegetable fibres are liable to self-heating and are
therefore classified as class 4.2.
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Class 4.3- Substances which, in contact with water, emit flammable gases
(water-reactive)- Many of the substances involved are inorganic, including the metals
caesium, lithium, potassium and sodium, which form part of the alkali metal family, and
some of their compounds. Some compounds of the alkaline earth metals (calcium,
lithium, magnesium and strontium) are also water-reactive. The major gas produced in
the reaction with water is hydrogen. However, depending upon the substance involved,
other flammable gases such as methane, acetylene and ammonia and/or toxic gases
such as phosphine and arsine are produced.
Oxidizing substances and organic peroxides (class 5) - Class 5 is divided
into two:
Class 5.1 - Oxidizing substances - This class contains mainly inorganic
compounds which have in common their ability during thermal decomposition to liberate
oxygen contained within the molecule, which is then available to react with other
substances to form oxides. This process is called oxidation. As previously discussed,
burning is also a form of oxidation in which, for example, organic substances such as
petrol, paraffin, alcohol, paper, sugar, coal, etc., react with oxygen in a fire to form
oxides of carbon. It is for this reason that oxidizing substances are considered so
dangerous: they increase the risk and intensity of fire in combustible materials and
make fires involving them difficult to extinguish. Many inorganic compounds end with
the suffix "-ate" (e.g. nitrate, bromate, borate) indicating the presence of oxygen. These
are oxidizers. The prefix "per-" also indicates the presence of additional oxygen (as in
permanganate, perchlorate and peroxide). Chlorine is also a strong oxidizer and is
found in compounds such as chlorates and hypochlorites (bleach).
Class 5.2 - Organic peroxides - These compounds are related to the oxidizer
hydrogen peroxide (H202), but one or both hydrogen atoms have been replaced by
organic molecules. The resulting compounds are not only very strong oxidizers but
many are thermally unstable some even at normal transport temperatures.
Decomposition is initiated not only by temperature rise but sometimes by the presence
of impurities. The reaction is exothermic, sometimes explosively so, and may result in
the evolution of harmful or flammable gases. In this respect this sub-class is similar to
the self-reactive substances in class 4.1. Organic peroxides burn vigorously and attack
eyes and skin. Depending upon their reactivity, organic peroxides are assigned to one
of seven generic types within class 5.2.
Toxic and infectious substances (class 6) - Class 6 is divided into two:
Class 6.1 - Toxic substances - Toxicology is the science of poisons and their
effects on the body. Substances (both inorganic and organic) and articles assigned to
class 6.1 are either known from experience to cause death or serious injury to humans
by poisoning or, based on the results of testing the chemical on animals under strictly
controlled conditions, are strongly suspected of causing harm to human health. The
IMDG Code is concerned with the effects of a single dose of short duration (known as
an acute exposure) that a transport worker or member of the public may be exposed to
in the event of a spillage or fire. Unlike safety in the workplace regulations, the Code is
not concerned with the effects on health of long-duration (days, months or years)
repeated exposure (known as subchronic and chronic exposures).
Usually exposure can occur through one or more of three routes:
oral route = gastrointestinal absorption via the mouth
dermal route
= absorption through the skin
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inhalational route = absorption via the lungs through breathing in
contaminated air
Of these, the dermal and inhalation routes are the most important in accidental
poisonings, and chemicals absorbed by these routes tend to be more serious as they
pass directly into the blood stream and only a small proportion is detoxified by the liver
(unlike ingested materials, which pass totally through that organ before dispersion).
Mercury and lead alkyls in particular are much more toxic if inhaled or absorbed through
the skin than if they are swallowed.
Dosage is the most important factor in determining if a particular chemical will
produce an acute toxic effect and this is measured by the median lethal dose (LD50) for
oral and dermal exposure or median lethal concentration (LC50) for inhalation exposure
for dusts, mists and vapours. This is a statistical estimate of the amount of chemical
required to kill 50% of a given population of test animals. To be meaningful the test
must specify the species of animal used, their sex and age and the time of the
measurement. For oral and dermal routes, the results are expressed in terms of
milligrams of chemical required per kilogram of body mass (mg/kg). For the inhalational
route results are expressed either in milligrams/litre (mg/l) for dusts and mists or
millilitres/cubic metre (ml/m3) = parts per million (ppm) for vapours. The details for LDso
and LC50 determinations are given in the chapter 2.6 of the Code.
Class 6.2 - Infectious substances - This class controls the transport of cultures of
biological micro-organisms that are known or reasonably expected to cause infectious
disease in humans or in animals. The class includes clinical waste.
Radioactive materials (class 7) - As mentioned in 6.2, atoms are composed of
protons, neutrons and electrons. Not all atoms in the same element have the same
atomic mass because a few have a different number of neutrons. These are called
isotopes or nuclides. For example, hydrogen has three isotopes with masses 1
(hydrogen 1), 2 (hydrogen 2 - called deuterium) and 3 (hydrogen 3 - called tritium). They
all contain the same number of protons and electrons and have the same chemical
properties but differ in the number of neutrons. Naturally occurring hydrogen contains
99.9% of hydrogen 1; the remaining 0.1% is composed of the other two isotopes.
Isotopes are identified by their chemical symbol followed by a number denoting their
atomic mass: e.g. cobalt (Co)-60, uranium (U)-235.
If the number of neutrons greatly exceeds the number of protons, as is common
in heavy elements like uranium, radium and thorium, the isotopes become unstable and
eject particles from their nuclei to make them more stable. These are called radioactive
isotopes, radioisotopes or radionuclides because the particles ejected can be detected
using a Geiger counter. Two types of particles are emitted, alpha particles, which only
travel a few centimetres in air, and beta particles, which may travel several metres.
They are often accompanied by energy in the form of gamma radiation. As a radioactive
element decays a new element is formed which may also decay, and the process is
repeated until a stable isotope is reached.
When large atoms split vast amounts of energy are released. This is called
nuclear fission and elements which are capable of undergoing this process are called
fissile. These are uranium-233, uranium-235, plutonium-238, plutonium-239, plutonium241 and any combination of these radioisotopes. When the nucleus of a fissile isotope
is irradiated by neutrons it can absorb a neutron, becoming unstable in the process and
splitting into approximately two halves releasing energy and neutrons. These cause
more atoms to split releasing more energy and neutrons. A chain reaction ensues
releasing a vast amount of energy in a fraction of a second.
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The major hazard of radioactive materials is the damage which may be caused to
external or internal body tissues by the effect of invisible radiation. Also heat emission
and liability to criticality are potential hazards.
The international unit used to express the activity of a radioisotope is the
becquerel (Bq) named after the discoverer of radioactivity A.H. Becquerel (1852-1908).
The becquerel is the rate at which a radioactive isotope decays and relates to the
contents of the package. This is replacing the former unit, the curie (Ci).
In the past the IMDG Code required that any material with a specific activity of
greater than 70 kBq/kg had to be declared as a radioactive material. The 2001 edition of
the Code introduces a new definition of radioactivity: "Radioactive material means any
material containing radionuclides where both the activity concentration and the total
activity in the consignment exceed the values specified in -".
The effect is that if a substance is listed in the table (see part 7 of this book) and
exceeds two values it is dangerous. If the radionuclide is not listed then a Competent
Authority would have to approve the classification.
The sievert (Sv), formerly known as the "rem" is the dose equivalent and
measures the relative effects of different types of emitted radiation: 1 Sv = 100 rem.
Sieverts are used in the calculation of the Transport Index which is given on each
package containing a radionuclide. The figure assigned (normally between 1 and 10)
depends on the maximum radiation detectable at a distance of 1 m from any point on
the package.
Corrosives (class 8) - This class comprises both organic and inorganic
substances and articles which contain them. All have the common property of causing
damage to living tissue such as burns to skin, eyes and mucous membranes and/or
corrosion to the metal structures of ships.
Many of the substances in this class are either acidic (e.g. sulphuric acid), will
form acids on contact with moisture or are basic (alkaline).
Acids - Acids are substances which contain hydrogen and when dissolved in
water dissociate to form hydrogen ions: atoms or groups of atoms that have lost one or
more electrons making the atom positively charged. The easiest way to recognize an
acid in water is to test the solution with litmus paper which turns red. The degree to
which ionization takes place is measured by its pH (potential of hydrogen) meter which
has a range of 0 to 14. A pH of 7 is neutral; below 7 is acidic and above 7 is alkaline.
Inorganic acids such as sulphuric, nitric and hydrochloric acids (known
collectively as the mineral acids) are almost completely dissociated in water, have a pH
approaching 0 and are known as strong acids, whereas organic acids, the most
important of which are the carboxylic acids having the structure COOH (e.g. acetic acid
- the main ingredient of vinegar), are generally much weaker, having pH values in the
range 2 to 5. In general, the stronger the acid the more corrosive to skin, eyes and
metal it is likely to be.
Bases (alkalis) - Metal oxides and hydroxides are bases and most are insoluble
in water. Alkalis are bases which will dissolve in water, turning litmus indicator paper
blue, and have a pH above 7. Common alkalis are sodium hydroxide, potassium
hydroxide, ammonia and sodium carbonate. Bases will neutralize acids to form a salt
and water. Such reactions can be strongly exothermic, which is why some acids and
bases must be stowed at least away from each other, an example of stowage
incompatibility within the same class. Sodium and potassium hydroxides, even in dilute
solutions, will attack skin and eyes and are said to be caustic. If you rub dilute sodium
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hydroxide between two fingertips they will soon feel soapy as the alkali emulsifies the
natural oils in the skin.
The determination of whether a particular material should be included within
class 8 depends upon human experience or on the time taken for the product to cause
full-thickness destruction of skin. Also account is taken of its potential to corrode metals.
Mercury metal is included in class 8 because of its corrosivity to aluminium.
Miscellaneous dangerous substances and articles (class 9) - Substances
and articles in this class do not meet the criteria for the other eight classes but
nevertheless are considered sufficiently dangerous to warrant inclusion in the Code.
This class includes substances likely to cause cancer (carcinogens) after even a single
exposure (asbestos, PCBs), irritants and allergens (benzaldehyde, castor beans), fire
risk (substances carried at elevated temperatures), asphyxiants (dry ice, containers
under fumigation) and environmentally hazardous substances (marine pollutants).
The inclusion of such substances has added significantly to the number of
substances in class 9 that have been identified as marine pollutants by GESAMP (Joint
Group of Experts on the Scientific Aspects of Marine Environmental Protection). For
packaged goods, marine pollutants are defined using criteria such as the potential for
bioaccumulation (concentration of the substance in the food chain), tainting of seafood
or high toxicity to aquatic life (defined as having an LC50/96 hour of less than 1 mg/l
(ppm)). The Code differentiates between marine pollutants, which meet the GESAMP
criteria, and severe marine pollutants, which are bioaccumulated or extremely toxic to
aquatic life, having an LC50 /96 hour of 0.001 mg/l or less. Substances meeting these
criteria are classified as marine pollutants and if they have no other hazard are
classified under the liquid or solid entry for Environmentally Hazardous Substance in
class 9. The criteria used by IMO to define the environmental hazard of marine
pollutants differs from that used to classify substances "dangerous to the environment"
by user classifications and also by international road and rail transport regulations
(RID/ADR). Consequently, a substance can be a marine pollutant as defined by IMO but
not dangerous to the environment as defined by other authorities and vice versa.
Dangerous, Hazardous and Harmful Cargoes
Classification - the UN system as used by IMO
7.1 United Nations classes
The purpose of the United Nations dangerous goods classification system is
twofold: firstly, to draw out boundary lines to determine which goods are dangerous and
which goods are not dangerous in the transport environment; secondly, to show in
broad terms what kind(s) of danger are to be found in a particular substance or article.
There are a series of standard tests for deciding if a substance or article presents risks
that make it dangerous to transport.
Dangerous goods are split into nine broad groups or classes dependent upon the
major kind of danger that the substance presents; other risks may be present in a
product and these are known as sub-risks or secondary risks whilst the main risk is
referred to as the class risk. Some classes are further split into divisions which
categorize risk more finely. Each class or division has a diamond-shaped label assigned
to it; these have broadly universal acceptance by all transport controls. The nine UN
classes and divisions of dangerous goods are:
2.1 - Flammable gases
2.2 - Non-flammable, non-toxic gases
2.3 - Toxic gases
Flammable liquids
Other flammable substances
4.1 - Flammable solids
4.2 - Spontaneously combustible substances
4.3 - Water-reactive substances
Oxidizers and organic peroxides
5.1 - Oxidizers
5.2 - Organic peroxides
Toxic and infectious substances
6.1 - Toxic substances
6.2 - Infectious substances
Radioactive materials
Miscellaneous items
The chemical and physical nature of these various items was considered in part
6. Articles and substances that are not specifically identified in the alphabetical index to
the IMDG Code must be placed in the class that corresponds with the kind of risk known
to be in the product. If necessary, chemical analysis should be undertaken to determine
If the substance has more than one risk there is a set procedure for determining
the classification: a product that is a flammable liquid which gives off toxic fumes could
be a flammable liquid with a toxic sub-risk, i.e. class 3, sub-risk 6.1; it could also be a
toxic liquid with a flammable sub-risk, i.e. class 6.1, sub-risk 3. Only one classification
can be correct. The class will be the one indicated by use of the precedence of hazard
table in chapter 2.0 of the Code. By checking one risk factor from the horizontal rows
Dangerous, Hazardous and Harmful Cargoes
and the other risk factor from the vertical columns, the precedence of risk is given at the
point of intersection. The classes and divisions not included in the table always take
Extract from - Precedence of hazards
Class and
3 1*
3 II*
3 III*
4.1 II*
4.1 III*
4.2 II
4.2 III
4.3 I
4.3 II
4.3 III
6.1, I
6.1, I
8, I
8, I
precedence over the featured classes and divisions.
• substances of class 4.1 other than self-reactive substances and solid
desensitized explosives and substances of class 3 other than liquid desensitized
• 6.1 for pesticides
• - denotes an impossible combination
The table above shows a section of the precedence of hazard table. A substance
presenting risks associated with a flammable liquid of PG II and a toxic liquid of PG III
may be classified as a flammable liquid with a toxic sub-risk because there is a figure 3
for class 3 (flammable liquid) at the point of intersection of the reference row and
7.2 Packing groups
Dangerous goods present wide ranging levels of danger as well as wide ranging
kinds of danger. As shown above, the kinds of danger are revealed by the classification
of the substance; the level of danger is usually shown by a simple measure known as
the packing group (PG) of the substance.
There are three levels of danger, always indicated by the use of roman numerals,
PG I - High danger
PG II - Medium danger
PG III - Low danger
The packing group of a substance determines the quality of packaging required
for safe and acceptable transport. PG I items require the highest standard of UN
specification packaging; PG II materials may be safely transported in slightly less
substantial containment systems whilst PG III represents a range of items where a
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further reduction in packaging standards can safely be permitted. Parts 9 and 10 of this
Compendium explain further the link between packing groups and packaging selection.
Packing groups are allocated to substances on the basis of the test criteria used
for each class (e.g. a substance with a flashpoint not exceeding 61 °C which boils below
35°C is allocated to PG I in class 3 (flammable liquids) whilst a substance which causes
full-thickness destruction of intact skin tissue within 10 minutes after 2 minutes exposure
is allocated to PG I in class 8 (corrosives)). There are some classes (1, 2, 5.2, 6.2 and 7)
where the packing group concept is not used: there are no specific criteria and special
packaging requirements apply.
In the case of substances/articles in classes 1 and 5.2, the UN
Recommendations indicate that any packagings used must be to PG II standards so as
to avoid over-confinement in the event of a fire or explosion.
Infectious substances are not allocated to packing groups but clinical or medical
waste for the [purposes of packaging is allocated to PG II.
In the Code, the Damaged Goods List (see part 5.4 of this Compendium) to the
IMDG Code lists the packing groups of all substances entered, with the exception of the
classes/divisions referred to above.
7.3 Proper shipping names and United Nations Numbers
Identification of dangerous goods for shipment by sea means using a name
recognized by the IMDG Code together with the linked UN Number for the substance.
These methods of identification are then used on the documentation prepared to
accompany the goods and they are also marked on packages or tanks that contain the
goods. The procedures for documentation and for package or tank marking will be
considered later in this manual (part 11). Chapter 2.0 and chapter 3.1 of the Code detail
the procedures for identifying dangerous goods for transport by sea.
Identification is straightforward for products that can be found in the DGL of the
IMDG Code. A name printed in capital letters in column 2 of the DGL that has no
qualification placed upon it is known as a proper shipping name (PSN); this is the
proper name to use. A qualification would normally appear in either:
a qualification to the name in column 2 (e.g. 'With not less than 20% water by
a Special Provision in column 6; or
Notes in column 17 of the DGL.
To find the name of a substance when the UN Number is not known there is an
alphabetical index at the back of volume 2 (an extract is shown below). If the name is
printed in lower case and qualified by the word "see" it is a synonym that is not
acceptable as a PSN. The correct PSN is found by cross referencing the DGL entry for
the UN Number shown in the right hand column against such entries.
Dangerous, Hazardous and Harmful Cargoes
Substance, material or article
2-ethylbutyl alcohol, see
UN No.
In the table above, 2-ethylbutyl alcohol is not a PSN. The reader is referred to UN
2275 and in column 2 of the DGL entries for this UN Number, 2-ETHYLBUTANOL is
listed as the PSN. For certain Explosives after the word "see" there is an alternative
name offered e.g. "Explosive Articles N.O.S., see ARTICLES, EXPLOSIVE, N.O.S."
Unnumbered/Unlisted substances and articles
If the UN Number is not known and a substance PSN cannot be found in the
alphabetical index then a little more work is required.
In addition to specific substance names (e.g. acetone), the alphabetical index
also contains generic entries for groups of substances/articles (e.g. Adhesives), general
entries which relate to a particular family of substances (e.g. BARIUM COMPOUNDS
N.O.S), and entries which describe a particular type of risk or risks (e.g. FLAMMABLE
LIQUID, TOXIC N.O.S). The letters N.O.S. stand for "not otherwise specified", meaning
the substance has not been directly named elsewhere in the alphabetical index. If both
a family and a descriptive N.O.S. entry effectively describe the substance, the generic
entry should be used.
The nature of the risk(s) "family" associated with the substance must be
determined by the classification procedures as described in part 7.1 and 7.2; the most
appropriate "family" or descriptive PSN must then be chosen. For a flammable liquid
with no other risks the most appropriate PSN may well be UN 1993 FLAMMABLE
LIQUID N.O.S. However it should be noted that use of this number is a last resort.
Where a person is classifying a ketone for which there is no UN Number the procedure
should be that UN 1224 KETONES, LIQUID N.O.S takes precedence over UN 1993
If the substance has more than one risk then at least two PSNs will present
themselves: a product that is a flammable liquid which gives off toxic fumes could be
described as a FLAMMABLE LIQUID, TOXIC N.O.S. but an entry will also be found in
the index for TOXIC LIQUID, FLAMMABLE N.O.S. Only one entry is correct. The PSN
must reflect the hazard precedence procedure referred to in 7.1. For example, a
substance presenting risks associated with a flammable liquid of PG II and a toxic liquid
of PG III should be identified as a FLAMMABLE LIQUID, TOXIC N.O.S. because at the
point of intersection of the reference row and column there is a figure 3 for class 3,
flammable liquid. This PSN has a UN Number of UN 1992.
To complete the identification process for a PSN that ends with the letters N.O.S.
(and some others e.g. many generic pesticide entries) it is generally necessary to
undertake one further task.
Following the N.O.S. letters a bracket is opened and the chemical name of the
risk substance is entered, the brackets are then closed. If there are several constituents
contributing to the risk only the two major substances are listed. Similarly, if there are
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two risks present then the major generator of each risk is listed and nothing further.
Thus, FLAMMABLE LIQUID, TOXIC N.O.S. (contains acetone and phenol) would be a
complete PSN.The bracketed information is reproduced in the same sequence as the
risks are described in the first part of the name, i.e. the flammable risk is from the
acetone and the toxic risk is from the phenol. If appropriate, the word "contains" should
precede the chemical name. Names requiring this extra detail have SP274 listed
column 6 of the DGL. A complete list of N.O.S. shipping names can be found in
Appendix A towards the back of volume 2 of the IMDG Code.
Solutions, mixtures, preparations etc.
Many of the substances that will be identified by the foregoing procedures will be
solutions, mixtures or preparations. That is to say, they will not be pure chemicals but
pure chemicals mixed with other substances, dangerous or otherwise. The identification
of such a product is subject to three different possibilities. Using diethyl ether as an
example, the possibilities will be addressed.
Pure diethyl ether is a rare commodity, as are all truly pure chemicals.
Commercial grades of a substance will be in the order of 97% pure; these are the
substances that will be shipped. According to the details shown in the DGL, diethyl
ether is a flammable liquid (class 3.1, PG I, with no sub-risk), and has the UN Number
UN 1155.
Combining pure diethyl ether with other substances to produce a new product
may create a solution, mixture or preparation. The item is no longer pure diethyl ether
and it is no longer correct to identify it as such. The correct form of identification
depends upon the hazard criteria exhibited by the newly made substance.
If analysis shows the new substance to be of class 3, PG I, with no sub-risk, the
new product will share the same hazard characteristics as its parent material. In this
situation, when there is no variation of hazard rating by class, physical state or packing
group between the chemical and the preparation, identification proceeds as for the
original substance but with the addition of "solution" or "mixture" immediately after the
Thus, a preparation consisting largely of diethyl ether and presenting exactly the
same hazard icharacteristics as diethyl ether would be identified as diethyl ether 75%
solution, UN 1155. The percentage concentration is required (chapter 3.1 of the Code
If the preparation contains a rather smaller proportion of diethyl ether and a
greater proportion of the other substances it may well be that the hazard characteristics
of the new preparation |are not exactly the same as those of the commercially pure
If upon analysis the new substance is determined to be of class 3, PG III, then it
is not diethyl ether, nor is it diethyl ether solution. It must now be shipped under the
most appropriate '-family" or descriptive PSN which in this case, because diethyl ether
is an ether, would be ETHERS N.O.S. (contains diethyl ether), UN 3271.
Yet further dilution of the preparation with other materials could eventually
produce a substance that no longer possesses the hazard characteristics of a
flammable liquid; it is no longer to be considered to be dangerous for transport.
Dangerous, Hazardous and Harmful Cargoes
Marine pollutants
Substances of all classes may be classified as marine pollutants; as such they
are dangerous goods which also pollute the marine environment. A distinction is made
between substances which are marine pollutants and those which are severe marine
pollutants. Substances which possess this pollution risk are identified as marine
pollutants or severe marine pollutants in ithe DGL by a "P" in column 4.
The IMDG Code also encompasses substances, articles and materials which do
not fall within the criteria of any of the hazard classes but which are pollutants in the
marine environment. These are shipped under class 9 (miscellaneous dangerous
substances and articles) using the following PSN and UN Number as appropriate:
Explosive substances/articles require the provision of one extra piece of
information before classification and identification of the goods is complete. In the
nature of these materials it is possible for one explosive item to provide the appropriate
circumstances to bring about activation of another explosive material (e.g. detonator
and explosive charge).
To prevent such circumstances from arising during transport all explosives are
allocated to compatibility groups designed to distinguish between those that may
explode and those that may bring about such an explosion. These compatibility groups
are indicated by the use of a capital letter code ranging through the letters A to H, J to L,
N and S (see chapter 2.1 of the Code).
Classification is not complete until the correct compatibility group letter has been
determined for any explosive item. This information is recorded immediately after the
class/division designation (e.g. class 1.4S).
Note: In most countries it is a requirement that the classification of an explosive
is approved by the Competent Authority or another government agency.
Radioactive materials
There are seven groups of radioactive material (RAM) in the transport rules:
special form; other form; low specific activity (LSA); surface contaminated object (SCO);
low dispersible; fissile material; fissile excepted. Materials may meet the criteria of more
than one of these groups. Chapter 2.7 of the IMDG Code contains definitions in sections
2.7.2, 2.7.3, 2.7.4, 2.7.5 and 2.7.10 - from which the following explanations are drawn.
Special form - RAM that is prepared in such a way that contamination is a most
unlikely transport occurrence is called "special form" material. At least one surface of
such material must have a dimension of 5 mm or more. It may be in sealed capsules or
in a solid mass such that dust etc. will not be generated. Sealed capsules must be such
that they can only be opened by destroying them. Generally, larger quantities of special
form material may be carried compared to non-special form material. Unilateral approval
is needed for special form material. There are a range of performance tests that must
be complied with before a Competent Authority can classify material as special form.
Dangerous, Hazardous and Harmful Cargoes
Other form - RAM that is not special form is referred to as "other form" material.
Low specific activity material (LSA) - These are materials that present a low
level of radiation activity compared to the bulk quantity of the material involved. They
tend to be ores and waste materials in a low hazard state or they are materials that
effectively bind the source into a matrix, such as bitumen. Varying degrees of activity
and material are covered by this description; these variations are catered for by splitting
the classification into three sub-groups, LSA-I, LSA-II, LSA-III.
Surface contaminated objects (SCO) - SCO are non-radioactive items that
have their surfaces contaminated by radioactive materials. Such a classification may be
applied to a pipework system that has been used to conduct radioactive materials. The
pipes themselves are not radioactive but they do contain quantities of harmful RAM.
This classification falls into two groupings, SCO-I and SCO-II dependent upon the
nature and level of the contamination.
Low dispersible material - These are materials that possess similar qualities to
special form material in that they are of a sufficient mass or are engineered in capsules
to ensure that they will not spread over a wide area in a transport incident. They cannot
be in powder form. The grouping may be advantageous in arranging air transport of
RAM but may also be encountered by those involved in maritime movements.
Fissile material - Fissile material is a range of RAM that have the capability,
when gathered into a large enough mass, to create high levels of heat and radiation.
The result of this high activity can be the creation of even higher levels of heat and
activity; this is known as a chain reaction where each action causes yet greater activity.
It is a little like running fast downhill: at first you are in control but there comes a point at
which your legs are beyond your control and the descent proceeds at a faster and faster
speed. The descent has to end in disaster in the form of some crash to the ground as all
control is finally lost. The consequence of a chain reaction in fissile material is loss of
control and eventual major explosion or melt down. The mass of a particular material
that will cause a chain reaction is known as the critical mass; ensuring that such a
situation cannot arise during the transportation of fissile material is a function called
criticality control.
Fissile excepted - Consignments of fissile material that are made in defined
ways relative to quantities and presentation may be moved as fissile excepted items.
Such fissile material is deemed not to warrant the full level of criticality control normally
afforded to fissile material because as presented for transport it does not possess
sufficient mass to reach criticality. Fissile excepted items are regulated in the same
manner as non-fissile RAM.
RAM identification - Radioactive material is identified following the normal
routines of the IMDG Code. The choice of an appropriate name is determined by the
nature of the material being moved and the manner of its packaging, in line with the
groupings indicated above. Excepted packages contain materials as described above
but they present such minor transport hazards that significant concessions are given to
them within the Code.
Within chapter 3.5 of the IMDG Code the various radioactive material UN
Number/PSN combinations are each allocated to one of 14 schedules. These schedules
reflect a system developed by the International Atomic Energy Agency (IAEA). They are
offered as an aid to the user of the IMDG Code to the extent that they summarize
consignment and transport duties in a single location; they are not, however, part of the
IMDG Code procedural system and the preface to chapter 3.5 makes it clear that if
there is any conflict between schedule statements and duties listed elsewhere in the
Code then the latter must prevail.
Dangerous, Hazardous and Harmful Cargoes
As explained in part 6, the new system of classification is based on a knowledge
of the radionuclide values. The table below is extracted from the table in chapter 2.7 of
the Code.
Table - Basic radionuclide values
Radionuclide (atomic
i Actinium (89)
Ac-225 (a)
Ac-227 (a)
Ai (TBq)
Activity limit for an
concentration for exempt consignment
A2 (TBq)
exempt material
1 x10"1
1 x101
1 X10-4
1 X10"3
Notes to table
The activity value of special form. Special form is either an
indispersible solid or a sealed capsule that can only be opened by destruction.
A2 The activity of material which is not special form.
(a) A1 and/or A2 values include contributions from daughter nuclides with half
lives less than 10 days.
(b) Once it is determined that a consignment is not exempt then there will be a
need to calculate the Transport Index (Tl), which is a measure of the
radiation at a distance of 1 metre from the package. There is a numbering
system relating to the level of activity similar to that for packing groups, i.e. I,
II, and III that will be seen on labels: however, for class 7, "I" indicates low
activity and "III" high activity (i.e. the reverse of PGs).
If the substance is fissile (certain types of uranium and plutonium), a criticality
safety index has to be calculated. If a radionuclide is not listed a consignor has two
choices. There is a default value in chapter 2.7 of the Code that can be used but it is
very restrictive. The alternative is to approach a Competent Authority to provide a
classification and make a special arrangement with the receiving country's Competent
Authority to permit transport.
Infectious substances
The classification of infectious substances is based on rules set down by the
World Heath Organization (WHO). Infectious substances can fall into one of four risk
groups which are described in chapter 2.6 of the Code.
In addition, the class includes genetically modified micro-organisms, biological
products, diagnostic specimens and clinical waste.
A new provision appearing for the first time in Amendment 31 concerns
diagnostic specimens. These are samples, usually taken from patients who are not
suspected as having an infectious disease, and a specimen is being sent for analysis.
Special packaging has been established to deal with these samples.
Classification of samples
This is a new procedure for the UN and the IMDG Code and will be found in
chapter 2.0. .Substance identification and allocation to a UN class for a newly
developed product is dependant in principle on product testing. Industry has had a
Dangerous, Hazardous and Harmful Cargoes
problem with this concept given jthat facilities for testing are often not available at the
product development site.
Under the provisions for samples is a belief that a substance is dangerous but it
has to be sent to another laboratory for testing. A consignor can provide a classification
and UN [Number based on the knowledge available. The most severe packing group
has to be applied. Where this provision is used the PSN will be supplemented by the
word "sample". Where the consignor uses an N.O.S entry for a sample the name need
not be supplemented by a technical name (which is generally required under special
provision 274 for N.O.S entries -see unnumbered/unlisted substances and articles in
The sample must be transported in a combination packaging with a net mass not
exceeding 2.5 kg and must not be packed with other goods.
Dangerous, Hazardous and Harmful Cargoes
Classification - the IMDG Code classes
Presentation and use of information
Part 2 of the Code addresses classification and follows the UN system as
described in part 7. Part 2 of the Code consists of an introductory chapter (2.0) that
describes the UN principles:
The nine classes
Marine pollutants and wastes
UN Numbers and Proper Shipping Names
Classification of:
- substances
- mixtures and solutions
- multiple hazards
This chapter is followed by nine chapters (one for each class - 2.1 to 2.9). The
procedures are aligned to the UN provisions. There is an additional chapter (2.1.0) for
marine pollutants, a subject unique to sea transport.
Classification of unusual items
Certain items are of a very particular nature and do not readily conform to the
standard pattern for any given class. Such items are given individual classification
procedures within their appropriate schedules. The following is an example:
The alphabetical index to the IMDG Code (volume 2) contains six separate
entries related to batteries; each entry represents a variation upon the formation or
nature of the item in question. The first task must be to identify the correct entry for the
item being shipped. If the batteries to be shipped are known to contain acid then it can
be determined that two entries may be appropriate: BATTERIES, WET, FILLED WITH
ACID, electric storage or BATTERIES, WET, NON-SPILLABLE, electric storage. It is
necessary to check the detail of the respective entries in the DGL to determine which of
these options is correct.
The key difference between the two entries is revealed in the content of Special
Provision 238 which applies to BATTERIES, WET, NON-Spillable, electric storage.
Special Provisions are explained in chapter 3.3 of the Code. This one applies to
performance standards (by testing) for the batteries. Quite simply, if the items to be
shipped meet the demands of the listed vibration and pressure tests, they may be
shipped under this PSN; if they do not, then the entry BATTERIES, WET, FILLED WITH
ACID, electric storage is the correct PSN to use.
Note: the above example deals with acid/alkaline batteries. Sodium or lithium
batteries have separate entries.
Waste materials
All waste materials shipped across international boundaries are subject to
stringent controls derived from the decisions of the Basel Convention on the Control of
Transboundary Movements of Hazardous Wastes and their Disposal, 1989. Any waste
carried by sea that presents any of the hazards controlled by the IMDG Code, i.e. the
nine UN classes of danger, is subject to the IMDG Code in addition to any controls
placed upon it by virtue of it being Waste material. As such, the waste is classified and
Dangerous, Hazardous and Harmful Cargoes
identified in the manner outlined in parts 6 and 7 of this Compendium. Chapter 7.8 of
the Code describes the provisions as they apply to sea shipments.
Single-substance wastes that present the same hazards as the pure material
should be shipped as that material, e.g. waste methanol, class 3.2, UN 1230, PG II.
Materials containing more than one constituent dangerous substance should be
classified and identified according to the procedures outlined in part 7 of this manual. If
this is impracticable, they should be classified according to the "predominant hazard"
based on the class of the constituents or, where they fall under more than one class, the
outcome of the multiple hazard precedence procedures.
Dangerous, Hazardous and Harmful Cargoes
Packing and tank requirements
9.1 Introduction
All cargo carried on ships, whether dangerous or not, is being sent by one party
to another for some reward - usually money - and it is therefore not in the interests of
the consignor to dispatch goods that will not arrive in a safe condition. However, goods
have different market values and the type of packaging may reflect this. Once a
substance or article has been classified as dangerous, there is an additional regulatory
reason for ensuring it is contained safely - whether in a box, drum, intermediate bulk
container (IBC), large packaging or tank - whilst in transit to the customer.
All containment systems face potential dangers during distribution and it is a
requirement of the IMDG Code that the consignor considers these and selects a
containment method that will survive the entire journey. In addition, there is often a need
to have the package/IBC tested, approved and marked in accordance with UN
This part of the course deals with the general principles which apply to all
packagings (including IBCs and large packagings) and tanks. Part 10 considers the
detailed testing and approval requirements.
A number of terms appear in this section. These include:
Cylinders: these are transportable pressure receptacles of a water capacity not
exceeding 150 litres;
Packages', these are the complete product of the packing operation, including
the packaging (e.g. the box or drum) and its contents (the chemical). They are
generally limited to 400 kg or 450 litres. Packages can be divided into two broad
o single packagings - these provide a safe containment system without any
special overpacking (e.g. steel drums)
o combination packagings - these usually consist of an outer packaging with
the chemical contained in an inner packaging (e.g. plastics bottle in a
fibreboard box).
Intermediate bulk container (IBC): a packaging designed for bulk product (e.g. a
liquid or solid). IBCs do not carry inner packagings (e.g. bottles). There is no
lower size/capacity limit but an IBC must be designed for mechanical handling
and must not exceed 3 m3 (3000 litres) capacity.
Large packagings: these are intended for the carriage of inner packagings or
articles. They are designed for mechanical handling. They exceed the normal
packaging threshold of 400 kg net or 450 litres but must not exceed 3 m3.
Bulk packagings: these are cargo transport units loaded with solid dangerous
goods without any intermediate form of containment (see 9.15).
Tank: the definition of a tank covers a portable tank or a road tank vehicle - it
must have a capacity exceeding 450 litres or more and the shell must be fitted
with items of service equipment.
Dangerous, Hazardous and Harmful Cargoes
Distribution hazards for packages
The distribution hazards begin at the point of filling and in the case of sea
transport this will rarely be at the port but somewhere inland. Chapter 4.1 of the Code
list a number of requirements with which the shipper must comply. •These requirements
apply to all packagings and some are relevant to tanks although the general provisions
for tanks are set out in chapter 4.2.
Packages must be of good quality. They do not have to be new (in fact the UN
system recognizes reconditioning, reuse, repair and maintenance of different packaging
types -'definitions can be found in chapter 1.2), and when closed for the transport
journey they must not leak as a result of:
Vibration: there is vibration during all forms of transport and it can be particularly
serious during sea voyages. Leakage can occur if the product is not effectively
contained. One of the most common effects of vibration is to loosen closures. In
more extreme circumstances the vibration can lead to leakage through package
seams and welds.
Handling: no packaging gets from a filling point to a ship without involving some
other means of transport (e.g truck, train and sometimes an air journey).
Packages will be handled on several occasions and the consignor is required to
take this into account in selecting a packaging.
Changes in temperature, humidity or pressure: a container loaded in January in
Rotterdam for shipment to Australia will encounter significant variations in
temperature. Temperature changes could cause expansion of liquids sufficient to
deform and ultimately damage packages, leading to leakages. The same voyage
will pass through areas of high humidity near the equator. As a result, packages
such as fibreboard boxes could be weakened and made ineffective, whilst steel
drums could rust. Changes in pressure are somewhat less important in sea
transport than in the air but they could lead to leakage especially if a package
has been overfilled.
Compatibility: most chemicals can affect other materials. It is therefore necessary
to know whether the chemical will attack the material from which the intended
packaging or tank is constructed.
Ullage: It is also important to ensure that sufficient ullage is provided in
packagings intended for liquids: this is an amount of space left in the top of
packagings to allow for the liquid to expand.
These principles have to be taken into account for all packagings
(including tanks and IBCs).
An additional provision requires that packages are closed in accordance with the
manufacturer's instructions. This involves having the correct information on closure
torques for drums etc. and the method of taping for boxes and bags. The provision
applies equally to inner packagings of combination packagings.
It is worth noting here that packages are usually placed in cargo transport units
(CTUs) for their journey. These units can affect package design and package designers
should be aware of the stresses that will be applied during a journey (CTUs are
considered in more detail in parts 13 and 14 of this Compendium). Advice on packing
CTUs can be found in the Supplement to the Code.
Dangerous, Hazardous and Harmful Cargoes
It is the responsibility of the consignor to select a packaging that meets the above
parameters and, except in the case of tanks, the UN testing requirements for
packagings (as outlined in part 10 of this Compendium).
Tanks and most IBCs are recognized as being reusable and they are subject to
2.5 and 5 year inspection programmes. These are explained in part 10 of the
Compendium. The person responsible for filling a tank or IBC must ensure, prior to
commencing the filling operation, that the vessel is within the inspection period.
Further details of the requirements applicable to the selection and use of IBCs
and tanks are given in 9.8-9.12 of this Compendium.
The relevance of packing groups (PG)
The PG concept was introduced to grade the danger of a substance which in turn
would affect:
the packaging to be used
the performance level to be achieved in testing and
the quantity permitted per package.
The instructions can also be further identified as follows: for packagings:
pOXX are general packing instructions (e.g P001) applicable to
substances in any class except 1, 2 and 7. These general
instructions cover over 1800 UN Numbers. P099, P101, IBC99 and
LP99 require the packaging to be approved by the Competent
P1XX are for class 1
P2XX are for class 2
P3XX are for class 3 etc.
These are class specific. It should be noted that there are a few substances,
notably in classes 4, 6.1 and 8, where the class number and the packing instruction are
different (e.g. Bromine UN 1744 is in class 8 but is allocated to P601).This was done
because the packing arrangements are similar to those for substances in class 6.1. It
affects about 20 very dangerous substances (all PG I and toxic by inhalation). It was
agreed that repeating the same instruction in each class was unnecessary.
For IBCs: The system is slightly different. The main IBC instructions are
numbered IBC01-IBC08. IBC01 Js the most restrictive packing instruction while IBC08
is the most liberal. There are [instructions for class 1 (IBC100), class 5.2 (IBC520) and
class 6.2 (IBC620). IBC099 requires 'the IBC to be approved by the Competent
For large packagings: At present large packagings are limited to substances in
PG III without any subsidiary risk, iexcept for certain class 1 articles and clinical waste
(UN 3291). There are two general [instructions, LP01 for liquids and LP02 for solids.
There are three other packing instructions, ifor class 1 (LP101 and 102) and class 6.2
(for clinical waste) (LP621). LP99 requires the [packaging to be approved by the
Competent Authority.
Dangerous, Hazardous and Harmful Cargoes
Packagings for all classes (except class 7)
With the exception of class 7, all packaging (including IBCs and large
packagings) are listed in a series of packing instructions. They appear in columns 8 and
10 of the DGL. The type of instruction can be identified as follows:
PXXX Packagings
IBCXXX Intermediate bulk containers
LPXXX Large packagings
The packing instructions generally follow a standard format:
Title - P= packaging, IBC = PXXX
intermediate bulk container,
LP = large packaging
General provisions (for
The following packagings are authorized, provided the general
certain classes there are
packing provisions of 4.1.1 and 4.1.3 are met
other references e.g. 4.1.5
for class 1). Also some
packing instructions are
specific to UN Numbers and
these are shown here.
Packaging options.
This is a list of packagings authorized for use under the
Specific additional general Additional provisions
provisions (not all
Example: "Matches should be packed tightly"
Specific requirements for
Special packing provision
certain substances
(optional). UN Numbers
"PP31 For UN 1381, packagings shall be hermetically sealed"
generally appear in the
B3 Only flexible IBCs fitted with a coating or liner are
provision (not all
9.6 Packagings for classes 1,2,4.1 (self-reactive substances), 5.2,6.2,
and 7
For certain classes the Code adds particular general requirements. With the
exception of class 7 these additional requirements are referred to at the beginning of the
packing instruction. For example, in class 1, the following statement appears in the
packing instructions: “The following packagings are authorized, provided the general
packing provisions of 4.1.1, 4.1.3 and special packing provisions of 4.1.5 are met". 4.1.1
and 4.1.3 are common to all packing instructions except P200 but 4.1.5 are additional
requirements for explosives.
The following paragraphs provide similar additional requirements for the classes
4.1.6 Class 2
4.1.7 Class 4.1 and 5.2
4.1.8 Class 6.2
4.1.9 Class 7
Dangerous, Hazardous and Harmful Cargoes
Class 7 (radioactive material)
The design, testing, selection and use of packaging systems for radioactive
material (RAM) follows a radically different procedure to that for packagings for other
hazardous materials. Because RAM cannot be entirely contained, the overriding
principle applied to other substances cannot be applied to RAM. Protection of the
material, protection of persons within the vicinity of the material and the limitation of
emissions to acceptably safe levels are the functions of RAM packaging.
The range of packagings in use for class 7 substances is unique to the class and
is intertwined with the classification and identification of the material for transport
packaging controls are not employed for the selection of RAM shipments. The general
requirements and the product-specific requirements are all contained within section
4.1.9 of the Code; the DGL makes this distinct reference in the packing and IBC
instructions columns.
In very general terms it may be said that the most efficient packaging selection
decisions will be made if the following list of RAM packaging types is considered to be a
league table of options, with the first type (excepted) representing the cheapest and
easiest option whilst the final type (Type C) represents the most expensive and complex
packaging available. Given this presumption, it makes sense for the consignor to use
the least demanding option, consistent with such factors as acceptability, suitability,
company policy, availability, etc.
The statements which follow are only intended as a very general guide to
packaging types. For detailed descriptions reference should be made to section 4.1.9
and chapter 6.4 of the Code.
Excepted packages - RAM within these packages have low activity levels.
Surface radiation levels cannot be in excess of 5 mSv/h. They must be of good quality
with smooth external surfaces.
Industrial packages - There are three types which are appropriate for varying
levels of RAM, referred to as IP-1, IP-2, IP-3. They are intended for the transport of
LSA/SCO material. Part 7 of this Compendium identifies the nature of such items.
Maximum activity limits are laid down. One face on every package must have minimum
dimensions of at least 100 mm x 100 mm. In addition, IP-2 must be UN packs rated as
PG l/ll (X/Y) or they must meet equivalent RAM-based performance criteria. IP-3
packages must be type A test competent. Type A package tests establish competence
in normal transport conditions.
Mixed packing
The assumption to this point has been that there will be one package for one
chemical. This is not always practical or necessary. Sometimes a number of small
quantities of different chemicals have to be sent to the same destination. The Code
does not prevent different chemicals being contained within one outer packaging but
certain rules must be followed:
the chemicals must not be required to be "away from" each other or require more
strict segregation in the segregation table of chapter 7.2;
there must not be any adverse chemical reaction if the chemicals become mixed
following a leakage. Such reactions would include the evolution of excessive
heat, toxic gases etc. as described in of the Code.
Dangerous, Hazardous and Harmful Cargoes
Selecting a suitable IBC
Selecting an IBC follows precisely the same procedure described for packagings
except that the IBC packing instruction is found in column 10 of the DGL and any IBC
special provision (an alphanumeric code prefixed with the letter "B" e.g. B3) in column
Large packagings
An IBC is for the carriage of bulk solids or liquids while a large packaging is
intended to carry large articles (e.g. bombs and missiles) or a large number of inner
packagings. The selection procedures for large packagings are broadly the same as for
other packagings except that the large packaging packing instruction found in column 8
of the DGL is prefixed "LP". Any large packaging special provision (an alphanumeric
code prefixed with the letter "L", e.g. L1) is found in column 8. The inner packaging
quantities are the same as those in P001 and P002. The large packaging was
developed originally for large explosive articles that exceeded the parameters for
ordinary packaging and during development it was recognized that the concept could
also be applied to wastes and other goods that could be distributed in larger quantities.
9.10 Unpackaged articles
The provisions of the Code provide for the carriage of unpackaged articles with
the approval of the Competent Authority. The conditions are set out in for
classes 2-6, 8 and 9 and for class 1 in Generally the Competent Authority will
have to be satisfied that the item cannot be packaged in accordance with the provisions,
either because of the size or shape, and that in an unpackaged state it is strong enough
to withstand the normal rigours of transport without constituting a danger. There is no
exemption from other consignment procedures.
Tank systems
9.11 General requirements
The 2000 edition of the Code introduced a new concept for tank transport and it
led to some complications that will exist for a very long time, possibly up to 25 years.
The previous edition of the IMDG Code listed permitted tanks as IMO tanks (see below).
Now the UN has developed the concept of multimodal "UN tanks" and these will
gradually replace IMO tanks. Tanks, unlike most packagings, have very long lives
(decades) and to build new tanks takes a long time. It would be impossible to make a
change from IMO to UN overnight and the IMO therefore agreed to permit a long
transition. This can be summarized as follows:
IMO tanks can be manufactured until 31 December 2002; thereafter only UN
tanks can be manufactured.
At the same time the UN decided to apply a more rational approach to tank
selection for different substances and this affects the use of IMO tanks as follows:
IMO tanks can be used for substances even when the IMO specification is
inferior to the new UN specification until 31 December 2009.
IMO tanks can continue in use indefinitely after 31 December 2009 so long as
they remain safe and their specification is the equivalent of a UN tank.
Dangerous, Hazardous and Harmful Cargoes
There are probably tens of thousands of IMO tanks in existence and they will
remain so well into the 21st century. Therefore DO NOT DISPOSE OF THE LAST
EDITION OF THE LOOSE-LEAF CODE until you have made a complete change to UN
9.12 IMO tanks (pre-2000)
Tank information is found in section 13 of the General Introduction in volume I of
the loose-leaf edition of the Code (Amendment 29). Tanks tend to be operated by tank
container companies on behalf of chemical companies. The selection of the tank is
ultimately the responsibility of the consignor but he will place a great deal of reliance on
the operator's expertise for identifying the type to be used.
Section 13 is in three parts:
13.1 liquid dangerous goods (tank types 1, 2 and 4)
13.100 non-refrigerated liquefied gases (tank types 5 and 6)
13.200 refrigerated liquefied gases (tank types 7 and 8)
Within the Code, tanks are allocated to one of the following tank "types":
Type 1 portable tank with pressure relief devices having a maximum
allowable working pressure of 1.75 bar or above
Type 2 portable tank with pressure relief devices having a maximum
allowable workingpressure equal to or above 1.0 bar but below 1.75 bar
Type 4 a road tank permanently attached to a chassis or with at least four
ISO twistlocks, having a capacity of more than 450 litres. It need not
comply fully with all the requirements for a Type 1 or 2 tank. It should only
be used on short international voyages.
Type 5 a portable tank for non-refrigerated liquefied gases designed for a
particular gas Type 6 a road tanker for non-refrigerated liquefied gases
which should only be used on short international voyages
Type 7 a thermally insulated portable tank for refrigerated liquefied gases
Type 8 a road tanker for refrigerated liquefied gases which should only be
used on short international voyages
A short international voyage is defined as follows - one where the ship is no more
than 200 miles from a port or place of safety. Neither the distance between the last port
of call in the country in which the voyage begins and the final port of destination nor the
return voyage shall exceed 600 miles. Constructional requirements for tanks are
considered in part 10.
9.13 UN tanks (2000 onwards)
Chapter 4.2 of Amendment 30 of the Code relates to the use of UN portable
tanks (most of the provisions apply to IMO tanks, but the requirements are of
Amendment 29). The chapter contains general provisions for the use of tanks for
substances in classes 3 to 9 (4.2.1); non-refrigerated liquefied gases of class 2 (4.2.2);
refrigerated liquefied gases of class 2 (4.2.3); and a list of tank instructions (4.2.4).
Instead of 7 tank types the UN system consists of 25 types as follows:
Types 1-22 for substances of classes 3-9
Dangerous, Hazardous and Harmful Cargoes
Type 23
For self-reactive substances of class 4.1 and for organic
peroxides of class 5.2
Type 50
For gases of class 2
Type 75
For non-refrigerated gases of class 2
The applicable UN tank type code (tank instructions) is listed in column 13 of the
DGL. The tank instructions are simpler than the packing instructions because there are
limited alternatives. An extract from the table for classes 3 - 9 is shown below.
T1 -T22
T1 - T22
These portable tank Instructions apply to liquid and solid substances of classes 3 to fl. The general provisions of 6.7.2 should be
Portable tank
Minimum shell thickness (In
Bottom opening
Minimum test
provisions (see
mm - reference steel) (see
'previsions (see
pressure (bar)
Until 31.12.2009 the lower pressure tank corresponding to the T10 requirements
may be used but from 1.1.2010 a tank meeting the specifications forT14 must be used.
If a substance is allocated to type T1 then any tank from 1 - 2 2 may be used but
if the substance is allocated to T4 then types 1 - 3 are not permitted. The instruction for
T2 is the single line of information i.e. a 1.5 bar tank with a minimum shell thickness in
accordance with, normal pressure relief devices in accordance with and
the option of bottom openings in accordance with
For the special instructions for class 4.1 (self-reactive substances) and classes
5.2 and 2 the instructions have different requirements depending on UN Numbers.
Note: Although the T10 will no longer be permitted for this substance it may still
be used for other substances provided it is still safe.
9.14 Selecting a suitable tank
As explained in 9.11 and 9.12 above, there are potentially two choices of tank: a
tank meeting the pre-2000 IMO standards (referenced in column 12 of the DGL) or a
tank meeting the new UN provisions (column 13 of the DGL).
The procedure for selecting a tank can be explained using two example
substances. The applicable instructions (the T codes shown in columns 12/13 and any
“TP" tank special provisions in column 14) are decoded in 4.2.4 of the IMDG Code.
UN 1664 nitrotoluenes, liquid: for UN 1664 there is no tank number in
column 12 - IMO, but T7 appears in column 13 - UN. This means that
the same standard of tank is required whether it is an IMO or UN tank.
AT7 tank has to have a minimum test pressure of 4 bar. In addition, in
column 14 there is TP2. This is explained in and states that the
filling limits in shall be met; this section provides a formula for
a degree of filling.
Dangerous, Hazardous and Harmful Cargoes
UN 1595 dimethyl sulphate: column 12 indicates IMO T10 and column
13 UN T14. T100 requires a minimum of 4 bar pressure while T14
requires 6 bar.
TP2 and TP13 apply in either case. TP2 is explained above while TP13 states that
self-contained breathing apparatus must be carried.
9.15 Solids in tanks
The concept of tanks carrying solid dangerous goods is relatively new. The
requirements are found in 4.2.6 and chapter 6.9 of the Code. The provisions are very
short - there is a set of constructional and testing general requirements and in some
instances Competent Authority approval is needed.
9.16 Solids in bulk packagings
Certain solid substances may be carried in bulk packagings. This is permitted in
the Code. "BP" appears in column 8 of the DGL e.g. UN 1495 sodium chlorate. The
provisions relating to the use and transport of bulk packagings are laid down in chapter
4.3 of the Code.
Dangerous, Hazardous and Harmful Cargoes
10. Construction and testing of packagings, IBCs
and portable tanks
10.1 Introduction
Part 9 of this manual sets out the procedure for selecting a suitable packaging or
tank for a particular dangerous goods consignment. For many dangerous goods, initial
selection is only one step towards compliance with the regulations. Generally the
dangerous goods have to be placed in a package or tank that has been tested to show
that it should remain safe during normal transport journeys (the exception is radioactive
materials where the package must be safe in all conditions). This part of the manual is
divided into sub-sections covering the construction and testing requirements for:
large packagings
gas cylinders
infectious substances packagings
radioactive materials packagings
tanks and portable tanks (tank containers)
10.2 Packaging definitions
Packagings are described in part 9 of this manual and the requirements for
packaging selection are set out in part 4 of the Code. The provisions concerning testing
and certification are set down in detail in part 6 of the Code: it is these provisions which
are considered here. Chapter 6.1 reproduces text from the UN Recommendations and
the requirements are therefore common to all modes of transport. It is often referred to
as the UN packaging system. In the majority of cases, a package tested in accordance
with chapter 6.1 of the IMDG Code is acceptable for all modes of transport.
The UN system requires that every package (including IBCs and large
packagings) design type is tested, that the tests are carried out on the package as
prepared for transport, that the package is manufactured in accordance with a quality
control system approved by the Competent Authority and that a mark is issued in
accordance with a scheme approved by the Competent Authority.
combination packagings (see part 9);
the term Package means the complete product of the packing operation,
consisting of the packaging(s) and the contents as prepared for transport;
packagings are receptacles and any other components or materials
necessary for the receptacle to perform its containment function.
Chapter 4.1 permits the use of reconditioning, reuse and remanufacture of
packagings. Chapter 6.1 provides guidance on the marking of reconditioned
packagings. In part 9 it was stated that the IMDG Code does not require new
packagings to be used for chemicals and these definitions underline that provision.
Packages must be safe.
6.1.4 gives detailed specifications for particular packaging types, including:
Dangerous, Hazardous and Harmful Cargoes
steel or aluminium drums
steel or aluminium jerricans
wooden boxes
fibreboard boxes
textile bags
plastics film bags etc.
Performance tests for packagings
10.3 Preparation for testing
Having selected a suitable packaging (see part 9) the consignor must ensure that
it has been tested in accordance with the Code - unless it is exempt for some reason
(e.g. it is being consigned under special "Limited Quantity" provisions) (see part 12).
Every design type must be tested. A design type is defined by the material, thickness
and manner of construction. The UN text leaves some discretion to the Competent
Authority to interpret this provision. If a steel drum which has a metal thickness of 1.00
mm throughout is subsequently made from 0.9 mm steel this would be regarded as a
design change. The use of glue instead of metal stitches to secure the side seams of a
fibreboard box would be regarded as a design change. The tests must be carried out on
the package as prepared for transport. This means that if a liquid is to be put into a steel
drum then a liquid should be used for the test. If a glass bottle is to be carried inside a
fibreboard box then a glass bottle should be used in the test. The test contents need not
be the actual substance but must reflect it: in the case of liquids water is normally used.
The density may be adjusted by the addition of lead weights. Where a solid is to be
transported the substance used in the testing procedure must reflect the physical
characteristics of the actual substance to be carried.
There are five tests:
Hydraulic pressure
Drop test
The normal height for a drop test is 1.2 m and this is applied to substances in PG
II, explosives, certain self-reactive substances, organic peroxides and clinical wastes of
class 6.2 (see 10.19).
Packagings for substances and articles of PG I normally undergo a drop test
from 1.8 m, whilst those for PG III undergo a drop from 0.8 m.
These are the normal drop heights for liquid substances with a relative density
(specific gravity) not exceeding 1.2. Where the density exceeds 1.2 and the test
substance is water, provides a formula to increase the height.
The drop test is normally carried out at ambient temperatures but the one
exception is that plastics materials are dropped when the temperature of the test
sample and contents have been conditioned to -18°C or lower to test the effects of
embrittlement on the plastics material.Following the drop the package must not leak.
Dangerous, Hazardous and Harmful Cargoes
Stack test
The stack test involves applying a force to the top surface of the test sample
equivalent to the total weight of identical packages which might be stacked on it during
transport. The minimum height for the stack test (including the test sample) is 3 metres.
The test is normally carried out with dead weights and the load is applied for 24 hours at
ambient temperatures. The exception to this is that plastics packagings intended for
liquids must be stack tested for 28 days at 40°C in order to check the strength of the
plastics material.
Hydraulic pressure test
Single packagings for liquids must be capable of withstanding a build-up of
pressure which may come about because of heat. The tester must know the vapour
pressure of the substance at 50°C or 55°C, using the formula in, to determine
the pressure the package must be able to withstand. This equates in general terms to a
50% safety factor. A table in illustrates the effect of this formula with certain
Leakproof test
This test only applies to single packagings intended to contain liquids (e.g. drums
and jerricans). The package is connected to an air supply and placed under water. The
pressure applied is 20 kPa for PG II and PG 111 and 30 kPa for PG I.
Every single packaging intended to contain liquids is subjected to a leakproof test
before it is filled with a chemical. This is production testing and it is not necessary to
carry out the test under water as long as an equivalent test is used.
There is a requirement in the Code for some packagings to be hermetically
sealed (i.e. vapour tight), but there is no recognized test for this: testing authorities often
recommend a leakproof test even for packagings intended for solids.
Cooperage test
This is an additional test for wooden barrels.
10.5 Packaging test reports
Following testing, a report must be prepared and made available to the
packaging manufacturer, the user of the packaging and the Competent Authority. The
test report does not have to be produced to the ship's master or his agent.
The report must contain information which will enable:
the manufacturer to produce packagings in accordance with the specification
of the design type which was tested
the user to identify the design type and understand how the packaging should
be used (e.g the closure torque on drums or the method of taping boxes)
the Competent Authority to enforce the regulations.
The report must state who carried out the tests and it must contain a statement
that the package was tested in accordance with the provisions of the Code.
Dangerous, Hazardous and Harmful Cargoes
10.6 UN packaging mark
Following successful testing and the issue of a satisfactory test report, a UN
mark can be allocated to the packaging. The procedure varies from country to country
{see 10.15).
The UN mark consists of a number of elements of information. These elements
can vary slightly according to the packaging type.
Example 1
UN symbol Drum
1 Material of manufacture: steel Drum type:
A non-removable head Suitable for packing
1 groups II or III
Y Suitable for a product with a relative density of 1.8 (single packagings only)
1.8 Pressure tested to 200 kPa
20 Year of manufacture - if the drum was plastics the month of manufacture would also
0 need to marked on the drum. This is because plastics drums have a maximum five98
year life. Country authorizing the mark
Identification of the packaging, as specified by the Competent Authority
Example 2
4G/X16/S/98 NL/23897
UN symbol
Suitable for packing groups I, II or III
Maximum gross mass in kilograms
Solids or inner packagings. The box may be designed for solids, inner
packagings or articles: there is no way to identify this information from the
Year of manufacture
Country authorizing the mark
Identification of the packaging specified by the Competent Authority
It can be seen that the mark does not give complete explanations of the uses to
which the package may be put - notes in 6.1.3 of the Code warn of this fact.
6.1.3 also shows a number of examples of packaging marks, including those for
reconditioned packagings.
Dangerous, Hazardous and Harmful Cargoes
10.7 Intermediate bulk container (IBC) definitions
Intermediate bulk containers (IBCs) are packagings as described in part 9 of this
Compendium. They are intended for bulk substances such as powders and liquids.
There are six types of IBC which may be used and chapter 6.5 of the Code
contains specific provisions relating to the design, construction and testing of each type:
metal IBCs
flexible IBCs
rigid plastics IBCs
composite IBCs with plastics inner receptacles
fibreboard IBCs
wooden IBCs - (see 6.5.3)
IBCs are restricted by the UN to:
solids of packing group I, II or III
liquids of packing group II or III
A designator/ code system has been developed which is similar to that used for
conventional packagings. A two-digit code indicates the type and purpose of the IBC;
this is followed by a letter or letters indicating the material(s) of construction and, where
necessary, a further numeral indicating the category of IBC. These are explained in of the Code.
10.8 Performance tests for IBCs
The tests for different IBC types are as follows:
bottom lift
top lift
hydraulic pressure
The tests are sequential and are carried out in the above sequence. The actual
tests carried out on any particular IBC vary according to the design type and its
intended use. For example, an IBC not capable of being top lifted does not have to
undergo the top lift test. The tear, topple and righting tests are unique to flexible IBCs.
Full details are given in 6.5.4 of the Code.
10.9 IBC test reports
The IBC test report has the same requirements as the packaging test report
described in 10.5 above ( of the Code refers).
Dangerous, Hazardous and Harmful Cargoes
10.10 UN mark for IBCs
Having undergone testing, the IBC has to be UN marked in a similar way to
conventional packagings. A typical mark for a composite IBC might be:
Metal Rigid
Composite Flexible Fibreboard/
Capacity in litres of water
Tare mass (kg)
Date of last leak test
Date of last inspection
Max. loading/discharge pressure
Body material and thickness
Manufacturers serial no.
Test (gauge) pressure
Pictograms indicating lifting position
31HA1/Y/04 97
04 97
UN symbol
Plastics material
Steel frame
Rigid inner receptacle
Packing group II or III
Month and year of manufacture
Country authorizing the mark
Identification as given by the Competent Authority
Stacking load in kilograms
Maximum permissible gross mass in kilograms
10.11 Periodic inspections of IBCs
Every metal, rigid plastics and composite IBC must be inspected:
before being put into service
every 2.5 years regarding external condition and service equipment, and
every 5 years for conformity to a design type, internal and external condition and
the proper functioning of equipment (
Those intended for liquids or for solids filled or discharged under pressure must
also be leakproof tested, before use and then very 2.5 years (6.5.4).
IBCs must be marked with the date of the last inspection and last leak test.
A report must be kept and be available to the Competent Authority.
Like testing and certification arrangements, these inspections are left to
Competent Authorities and vary from country to country.
Dangerous, Hazardous and Harmful Cargoes
10.12 Large packagings
Large packagings are described in part 9 of this Compendium. They are intended
for the carriage of a large number of inner packagings or large articles. There are five
types of large packagings:
flexible material
wooden large packagings
Large packagings are restricted to:
certain articles of class 1
clinical waste (UN 3291) and
substances of PG III, with no subsidiary risk
A designatory code system has been developed which is similar to that for other
packagings and IBCs.
A two-digit Code (50 for rigid and 51 for flexible materials), followed by a letter
indicating the material of manufacture, is used. The full text describing the codes and
testing procedures is in chapter 6.6 of the Code.
The majority of countries have a single organization which allocates the marks
and usually carries out the UN tests for all modes of transport. Others allow testing at
many testing facilities but issue the final mark centrally. Some allow companies to do
their own testing and allocate their own UN marks. All of these systems are mutually
recognized as long as they are enforceable by the national authorities.
10.13 Performance tests for large packagings
The tests for large packagings are:
bottom lift test*
top lift test*
stacking test*
drop test
* Only required when the large packaging is designed for that purpose (see 6.6.5).
10.14 Test reports for large packagings
The large packaging test report has the same requirements as the packaging test report
in 10.5 above
10.15 UN marks for large packagings
The mark allocated is similar to that for IBCs and can be found in 6.6.3:
Dangerous, Hazardous and Harmful Cargoes
50H/Z/07 01/AUS/ABCpty 2000/800
07 01
Rigid large packaging
Plastics material
Date of manufacture (month and year)
State authorizing the allocation of the mark
Stacking load capacity in kilograms
Maximum gross mass in kilograms
10.16 National procedures for packaging: IBC and large packagings
There is no standard method for the allocation of marks. The system is
multimodal and it is left to competent authorities to establish a procedure which enables
them to identify packagings in response to enquiries from any interested party, including
other Competent Authorities.
Gas cylinders
10.17 Receptacles for gases
Receptacles for gases are generally designed to hold a gas under some
pressure and in some cases in a liquid state. To achieve these two objectives the
package will tend to be a gas cylinder of some description.
The IMDG Code states that cylinders should be either:
UN cylinders in accordance with chapter 6.2 of the Code or
approved by the Competent Authority in countries of transport and use.
Gas cylinders tend to have very long service lives - up to 50 years is not
unknown - and therefore cylinders currently in use will continue to be so for a
considerable period of time. UN cylinders are a new concept appearing for the first time
in Amendment 31 to the Code and it is unlikely that such cylinders will be generally on
the market, particularly for international transport, for several years.
Amendment 31 to the Code now permits either type of cylinder. However, nonUN cylinders are subject to Competent Authority approval.
10.18 Testing and marking of gas cylinders
The construction and testing requirements are specified in chapter 6.2 of the
Code. Gas cylinders are subject to an initial inspection. Sample batches of cylinders
must be checked for metal thickness and quality whilst every cylinder must be
hydraulically tested. The general provisions apply to both UN and existing cylinders.
UN cylinders must generally be constructed to an ISO standard and approved by
an inspection body approved by the Competent Authority. Such a body must comply
with written procedures and be able to show independence from the manufacturer.
Similarly a manufacturer must have a documented quality inspection scheme.
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Physical testing, unlike packaging, is rather less although a hydraulic pressure
test is required. To get an approval for a design type of cylinder the manufacturer's
quality system must be approved. Once approved the manufacturer is permitted, under
a scheme approved by the Competent Authority, to apply a UN mark.
the UN packaging symbol
the technical standard used for design, manufacture and testing
the character(s) identifying the country of approval
the identity mark or stamp of the inspection body
the date of the initial inspection, the year (four digits) followed by the month (two
digits) separated by a slash (i.e. "/")
(f) the test pressure in bar, preceded by the letters "PH" and followed by the letters
(g) the empty mass of the pressure receptacle including all permanently attached
integral parts (e.g. neck ring, foot ring, etc.) in kilograms
(h) the minimum guaranteed wall thickness of the pressure receptacle in millimetres
(i) in the case of pressure receptacles intended for the transport of compressed
acetylene, dissolved, and UN 3374 acetylene, solvent free, the working pressure
in bar, preceded by the letters "PW"
(j) in the case of liquefied gases, the water capacity in litres
(k) in the case of UN 1001 acetylene, dissolved, the total of the mass of the empty
(I) in the case of UN 3374 acetylene, solvent free, the total of the mass of the empty
receptacle (m) identification of
the cylinder thread
(n) the manufacturer's mark registered by the Competent Authority
(o) the serial number assigned by the manufacturer
(p) in the case of steel pressure receptacles and composite pressure receptacles with
steel liner intended for the transport of gases with a risk of hydrogen
embrittlement, the letter "H" showing compatibility of the steel
10.19 Packagings for infectious substances (class 6.2)
This part deals with two broad categories of infectious substance packagings:
packagings for clinical waste and those for infectious substances.
Clinical waste
Clinical waste includes dressings, needles and blades which have a low
probability of containing infectious substances. These items may be packaged in rigid
UN-certified packagings that meet the PG II performance level (see 10.3-4).
Infectious substances
These will usually be laboratory samples in vials, slides, test tubes etc. These
substances must be packaged in accordance with the provisions set down in chapter
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The vial/test tube is considered the primary packaging and this must be placed
inside a secondary packaging. Both must be watertight. There must be absorbent
material between the primary and secondary packagings. The outer package must be of
adequate strength.
Packagings for infectious substances are subject to the following requirements:
a 9 m drop test (fibreboard outers must be subjected to a water spray test
before dropping and plastics packagings must be conditioned at -18°C prior to
being drop tested;
if any packaging is to carry dry ice then it must be used in the test;
a puncture test with a steel rod of defined mass is required for packagings of
7 kg or less;
an impact test onto a steel rod from a height of 1 m is required for packagings
which exceed 7 kg.
As with standard UN packagings, the testing system leads to the allocation of
a UN mark similar to that shown below:
4G/Class 6.2/98 S/SP - 9989 - ERIKSSON
The mark is similar to those applied to conventional packagings but instead of
showing mass and packing group it states "Class 6.2".
10.20 Packagings for radioactive materials (class 7)
A range of general requirements are applied to all RAM packaging selections but
they are not entirely the same demands as those laid upon packages for the other
classes. The basic requirements take into account ease and safety of transport handling
and securing plus the provision of smooth external surfaces to ease decontamination.
These general requirements together with package type specific demands can
be found in chapter 6.4 of the Code. They are based on the construction, testing,
certification and authorization systems contained in the IAEA publication Regulations for
the Safe Transport of Radioactive Material No ST-1 but this section of the Code is freestanding. It does not relate back to ST-1 and provides full operational details in the
Code text.
Excepted packages
The quality requirements for excepted packages are less demanding than those
for other package types. The basic criteria for the acceptability of a shipment within an
excepted package is that the radiation level must not exceed 5 mSv/h at any point on
the external surface.
The packagings must be able to retain their contents under the conditions likely
to be encountered in transport. Typically, a stout outer packaging might contain
cushioning material shielding a plastic bag that holds the low activity material; other
RAM package types may be classed as excepted packages when they are being
returned as empties with a low level of residual activity.
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Industrial packagings
LSA and SCO would normally be carried in industrial packages of varying types
designated IP-1, IP-2, IP-3. The construction and test standards for IP-1, IP-2 and IP-3
packs are of increasing severity through the various types. IP-2 packs are broadly
equivalent to UN-specification packages of PG l/l I and may indeed be such packs.
Tanks, tank containers and ISO freight containers may be IP-3 packs if they are
constructed in conformity with UN or other specified standards.
Type A packages
These packages must meet the general requirements together with those
identified in 6.4.7. Liquids and gas carrying type A packages are subjected to enhanced
drop and penetration tests; liquids packs have also to satisfy substantial demands for
liquid retention performance.
Type A packages must have suitable physical capabilities for the RAM to be
shipped and the activity of the material to be packaged must be within the A1 limit for
special form RAM, or the A2 limit for other form RAM. The activity limits for the various
radionuclides are listed in table
In many ways Type A packs may be compared to UN-specification packs for
other hazardous materials: they are of proven competence in normal transport
As well as boxes, drums, etc., freight containers may be type A packages for
radioactive material.
Type B packages
These packagings have to meet test criteria that emulate accident conditions in
addition to those of the normal conditions of transport applicable to type A packs. They
take two forms: type B(U) packs have unilateral approval for use granted by their
country of origin; type B(M) packs are authorized for use within one country or between
specified countries and under specified conditions. All fissile shipments must be in type
B{M) packages.
Type B packs are authorized for use in the carriage of designated radioactive
material at activity levels above the A1 and A2 levels appropriate for type A packs.
These items must comply with the demands of 6.4.8, which supplement provisions for
type A packages. The supplementary requirements centre on an ability to withstand
accident conditions and to limit heat transfer from the RAM to the packaging outer
surfaces. Accident conditions are simulated by three means: an enhanced drop test
sequence, a fire test and a water immersion test. Each test is carried out on each
sample submitted for testing; the cumulative demands thus made on the packagings are
Further criteria for type B(U) packages
Type B(U) packages are required to achieve their test competence without
depending upon filters, mechanical cooling or venting.
Criteria for type B(M) packages
The requirements listed above for type B(U) packages have to be met as far as is
practicable by type B(M) packs. However, venting/mechanical cooling of these
packages may be permitted by the Competent Authorities concerned.
All Type B packages are Competent Authority-registered and carry serial
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Type C packages
These packagings are required to prove themselves competent in extreme
impact conditions representative of a descent from operating height when being
transported by air as well as an ability to survive effectively if buried in the earth. They
are Competent Authority-registered and carry serial numbers.
Fissile material packaging
The requirements for industrial packages and for either type A, type B or type C
packages as appropriate must be fulfilled by packages for fissile material. In addition,
the need to ensure the maintenance of sub-criticality under transport and accident
conditions has to be taken into account.
Uranium hexafluoride packagings
This material must be packaged to the ISO standard 7195:1993(E) which takes
account of the high pressures that can be generated in transport by such materials.
Section 6.4.6 provides details.
10.21 Tank construction and testing
There are three broad categories of tank listed in the IMDG Code for construction
tanks for all classes other than class 2;
non-refrigerated gas tanks for class 2;
refrigerated gas tanks for class 2.
As explained in part 9 of the Compendium there are now two types of portable
tank (tank container) in existence: the IMO tank and the UN tank. Many of the principles
of construction are common but the details are different. Those wishing to construct
IMO tanks up to 31 December 2002 are referred to Amendment 29 of the Code and the
following sections:
section 13.1.3 - 13.1.18 tanks for all classes other than class 2;
section 13.103 - 13.115 non-refrigerated gas tanks for class 2;
section 13.203 - 13.212 refrigerated gas tanks for class 2.
In future, tanks will have to be constructed to new UN standards in accordance
with chapter 6.7 of the 2000 edition of the Code (Amendment 30). Road tanks carried
on ships are subject to the provisions of chapter 6.8 of the Code.
The Code lays down strict design guidelines, many of which are similar to the
rules for packagings: e.g. the tank and its components must be compatible with the
substances which will be carried in them and they must be capable of withstanding a
build-up of pressure.
Tanks must be designed so that they can be safely secured on board ship.
In addition to these general points, the tank must be capable of absorbing certain
dynamic forces:
in the direction of travel: twice the mass;
horizontally at right angles to the direction of travel: the total mass;
vertically upwards: the total mass; and
vertically downwards: twice the total mass.
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These factors, along with a number of others, lead to the strict definition of the
types of metal (usually steel) that must be used and criteria for ancillary equipment such
as valves, pressure relief devices, frameworks and lifting and tie-down devices.
All tanks must be fitted with pressure relief devices and the type of devices
required are shown against the entries in the relevant tank instuctions (see part 9). The
pressure relief devices must discharge at five sixths of the test pressure. The capacity
of relief devices is defined.
10.22 Approval of tanks
Like packagings, tanks must be approved. However, the approval system is
different. The Competent Authority must make arrangements to approve tanks or it must
appoint an authorized body(ies) to undertake this work. In many countries this has been
the responsibility of the ship classification societies or insurance companies (e.g. Lloyds
Register, Bureau Veritas, DNV).
A test report and certificate must be issued and every tank must be fitted with a
corrosion-resistant metal plate. The information on the plate is extensive and includes:
the tank type
approval country
test pressures
date of last inspection.
10.23 Periodic inspections
Every tank must undergo a 2.5 and 5 year inspection. The 5 year inspection must
be carried out by the Competent Authority or his agent.
The 2.5 year (midway) inspection consists of:
leak testing the service equipment;
an internal and external inspection of the tanks.
The 5 year inspection requires the same checks as the mid-term inspection, plus
a more detailed engineering inspection.
In both cases, the date of the last test should be marked on the plate on the tank.
Dangerous, Hazardous and Harmful Cargoes
11. Consignment procedures
11.1 Introduction
In order to ensure that safe transport and handling is maintained throughout the
journey and, in particular, that appropriate actions are taken in the event of an
emergency, it is essential that everyone involved in the movement of dangerous goods
is aware of the danger(s) they present.
When dangerous goods are offered for transport by sea they must therefore be
properly marked, labelled and placarded, and be accurately described and certified on a
transport document. Part 5 of the Code addresses these procedures.
Chapter 5.1 is concerned with general provisions. Chapters 5.2 and 5.3 of the
Code contain specific provisions relating to both the marking and labelling of packages
(including IBCs and large packagings) and the placarding of any cargo transport unit
containing dangerous goods.
If the package (including IBCs and large packagings) or cargo transport unit is
capable of surviving three months immersion in the sea, the method of applying all the
marks, labels, placards and other signs identified in this part must be such that they also
survive for this period.
In addition, with respect to documentation, particular requirements are laid down
in chapter 5.4 concerning the detail and manner of presentation of information about the
goods being consigned and the completion of declarations confirming compliance with
the requirements of the Code. Chapter 5.5 considers special provisions for infectious
substances and cargo transport units under fumigation.
Marking and labelling of packages (including IBCs and large
11.2 Marking of packages
Except where otherwise specified in the Code, every package, IBC and large
packaging must be durably marked with the following two items of information - both as
determined by the identification procedures detailed in part 7 of this Compendium:
Proper shipping name (PSN) of the contents and UN Number (preceded by the
letters "UN"). There are no particular specifications with respect to the dimensions of
these marks.
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Marine pollutants
The marine pollutant mark must be durably marked on the following packages:
single packagings containing marine pol.lutants or severe marine pollutants;
packages containing marine pollutants in inner packagings with contents of
more than 5 litres or 5 kg;
packages containing severe marine pollutants in inner packagings with
contents of more than 0.5 litre or 500 g.
This mark must be in a contrasting colour to the outside of the package or, when
applied by means of a sticker, coloured black and white. It must have sides of at least
100 mm except in the case of a package which, because of its size, can only bear
smaller marks. It should be located adjacent to any label(s) required to be displayed on
the package (see 11.3).
Salvage packagings
In addition to the above markings, salvage packagings must be marked
For explosives in division 1.4S, the division and compatibility group letter must
also be shown unless the 1.4S label is displayed.
Overpacks and unit loads
Where dangerous goods are consigned in an overpack or unit load, any package
markings which are not visible must be displayed on the outside of the overpack or unit
Empty uncleaned packagings
Other than for radioactive materials (class 7) the marking requirements identified
above apply equally to any packaging which previously contained dangerous goods
unless it has been sufficiently cleaned of residue or vapour so as to nullify any danger
or filled with a non-dangerous substance.
Mixed dangerous goods
Where two or more dangerous goods are contained in the same outer package,
the markings required for each substance must be displayed.
Limited quantity consignments
Different marking requirements apply to packages consigned in accordance with
the "Limited Quantity" provisions of chapter 3.4 of the Code (see part 12 of this
UN packaging approval marking
Most packagings also need to bear a UN packaging approval mark confirming
that the packaging has been tested and approved to the relevant United Nations
performance standards (see parts 9 and 10).
Dangerous, Hazardous and Harmful Cargoes
11.3 Labelling of packages
Except where otherwise specified in the Code, every package and IBC must bear
a diamond label or stencil of the label indicating the danger class of the substance it
contains. Where the substance has a subsidiary risk or risks, the appropriate subsidiary
risk label(s) must also be displayed.
The appropriate danger class and subsidiary risk labels can be identified by
reference to the substance entries (column 3 and 4) in the DGL (chapter 3.2) of the
Examples of the labels and signs are shown in chapter 5.2.
The class number must be shown in the bottom corner of all labels. In the case of
labels for class 5 substances, the appropriate division must be indicated (i.e. 5.1 or 5.2).
The use of text on labels (e.g. 'Toxic" or "Flashpoint") is optional, except for class
7 (radioactive) labels when specified text must be shown.
Labels must be not be less than 100 mm x 100 mm except in the case of a
package which, because of its size, can only bear smaller labels.
Each IBC with a capacity greater than 450 litres must bear all the required
markings on two opposite sides.
If a substance is exempt from the package labelling requirements this is indicated
by a special provision (column 6 of the DGL).
For explosives of division 1.4S a label is not generally required. However each
package should be marked "1.4S".
Gas cylinders
Gas cylinders for class 2 substances may bear reduced-size shoulder labels (i.e.
labels affixed to the non-cylindrical part of the cylinder), provided that they are clearly
visible from a distance.
Other supplementary labelling instructions
A number of supplementary instructions and/or variations apply to the labelling of
certain consignments. Full details are provided in chapter 5.2 of the Code.
Overpacks and unit loads
Where dangerous goods are consigned in an overpack or unit load, any package
labels which are not visible must be displayed on the outside of the overpack or unit
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Empty uncleaned packagings
Other than for radioactive materials, the labelling requirements identified above
apply equally to any packaging which previously contained dangerous goods unless it
has been sufficiently cleaned of residue or vapour so as to nullify any danger or filled
with a non-dangerous substance.
Mixed dangerous goods
Where two or more dangerous goods are contained in the same outer package,
the labels required for each substance must be displayed but subsidiary risk labels need
not be applied where a hazard is already represented by a danger class label.
Limited quantity consignments
Different labelling requirements apply to packages consigned in accordance with
the "Limited Quantity" provisions of chapter 3.4 of the Code (see part 12).
Marking and placarding of cargo transport units
11.4 General provisions
Cargo transport units carrying dangerous goods must display appropriate marks,
placards and, in certain circumstances, other signs, indicating the dangers of the load.
The term "cargo transport unit" (CTU) encompasses road freight vehicles, freight
containers, road tanker vehicles and portable tanks (tank containers) and rail freight or
tank wagons.
The person responsible for the final loading of the CTU must ensure that all the
necessary marks, placards and signs have been applied. The person responsible for
offloading a CTU must ensure that all marks, placards and signs have been removed or
masked once the CTU is empty and that it has, where necessary, been adequately
The requirements identified in this section do not apply to CTUs loaded with
solely packaged dangerous goods carried under the "Limited Quantity" provisions of
chapter 3.4 of the Code. There are different requirements for such consignments (see
part 12).
11.5 Marks and signs
Proper shipping name
The full proper shipping name (PSN), as determined by the identification
procedures detailed in part 7 of this Compendium, must be durably marked on at least
both sides of: all tank transport units; all loads of bulk packagings; and any semi-trailer,
vehicle, freight container or rail wagon carrying a full load of packages of a single
substance for which no label (and hence placard) or marine pollutant mark (see below)
is required.
Marine pollutant mark
Where the substance being carried is identified as a marine pollutant, a marine
pollutant mark with sides of at least 250 mm must be applied to the CTU as follows: on
at least both sides of a rail wagon; on each compartment side of a multi60
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compartment tank carrying more than one substance;on both sides and the rear of a
road vehicle; all four sides of a semi-trailer, freight container or portable tank.
Elevated temperature mark
A red "elevated temperature" mark, with sides of at least 250 mm, must be
displayed on all four sides of any CTU carrying such a substance(s).
Fumigant warning sign
Where a closed CTU is loaded with cargoes under fumigation, a fumigation
warning sign must be displayed on the access doors in a location where it will be easily
seen by anyone attempting to enter the unit.
The sign, which is rectangular, must be at least 300 mm wide and 250 mm high,
with black lettering (of not less than 25 mm height) on a white background. The sign
must show the date and time of fumigation and the type of fumigant used.
Limited Quantities
Cargo transport units must be marked "LIMITED QUANTITIES" or "LTD QTY" in
at least 65 mm high letters. They must be placed in the same position as placards (see
11.6 Placards
The basic principle is that any danger class diamond labels (including subsidiary
risk labels) relevant to the substance(s) being carried must be reproduced in large
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format on the outside of the cargo transport unit (CTU) in which the goods are loaded
unless, in the case of packaged goods, the marks and labels affixed to the packages
are clearly visible from outside the CTU. '
These enlarged labels, which must be at least 250 mm x 250 mm in size, are
known as placards.
Where a CTU contains goods of different classes, subsidiary risk placards are
not required if the risk concerned is already indicated by a primary class placard.
Number and location
The number and location requirements for placards vary according to the type of
CTU in which the dangerous goods are being carried. Rail wagons must be placarded
on at least both sides. Multiple compartment tanks carrying more than one substance
need appropriate placards on each compartment side. Road vehicles carrying
packaged dangerous goods must display appropriate placards on both sides and the
rear. Semi-trailers, freight containers and portable tanks must be placarded on all four
UN Numbers
In certain circumstances the UN Number of the substance being carried must be
indicated (in black digits not less than 65 mm high) either in a white panel in the lower
half of the class placard or, alternatively, in an orange rectangular panel (not less than
120 mm high and 300 mm wide and with a 10 mm black border) placed immediately
adjacent to the class placard or marine pollutant mark.
This requirement applies to the following CTUs:
all tank traffics;
packaged goods loads comprising goods of a single UN Number in
quantities exceeding 4000 kg;
unpackaged LSA-1 or SCO-1 class 7 radioactive loads;
packaged radioactive material consignments comprising a single UN
Number being moved under "exclusive use";
the movement of bulk packagings.
Where no placard is required - because no danger labels are specified for the
substance -and the substance is not a marine pollutant, the UN Number must be
displayed immediately adjacent to the proper shipping name (PSN) (see 11.5).
Placards are not required on CTUs carrying 1.4S explosives, dangerous goods in
"Limited Quantities" (as defined in chapter 3.4 of the Code) or excepted packages of
class 7 radioactive material. Where danger labels are not required on a package,
placards are not required on CTUs.
Dangerous, Hazardous and Harmful Cargoes
Placards indicating the highest explosive risk only need be affixed to CTUs
carrying explosives of more than one division in class 1.
11.7 Dangerous goods note
When dangerous goods are offered for shipment by sea the consignor must
complete a dangerous goods document (often referred to as a dangerous goods note DGN) and declaration of compliance with the provisions of the Code. This
documentation must be provided to the operator of the ship which is to carry the goods.
No particular format is specified for this documentation but the Code contains
very detailed instructions with respect to the content of the information which must be
provided and manner of its presentation.
Chapter 5.4 of the Code details the information which must be included on the
DGN.This falls into two categories: information which is necessary for all dangerous
goods consignments and information which is only required for particular shipments.
Standard information requirements
The basic items of information required for all dangerous goods consignments
a) the UN Number (preceded by the letters "UN"); the proper shipping name
(PSN); the UN class (division) and, when assigned, the subsidiary risk; the packing
group (if applicable).
These items of information may appear in either order as follows and nothing
should be interspersed in the sequence (e.g. flashpoint - see below).
UN 1230, Methanol, 3, (6.1),
PG II or
Methanol, 3, (6.1), UN 1230, PG II
The word "class" may be inserted (e.g. UN 1230, Methanol, class 3, (6.1), PG II)
Note: there is no requirement that the name should be in capital letters or upper
and lower case.
b) a description of the manner in which the consignment has been packed: i.e. the
number and kind of packages/IBCs/large packagings/tanks, and the total quantity
of dangerous goods covered by the description (by volume or mass).
This information may precede or follow the information required under (a) above.
There is no restriction on the number of individual consignment descriptions
which may appear on a single transport document (DGN).
Dangerous, Hazardous and Harmful Cargoes
Additional information
Where applicable, the following additional items of information must also be
the technical name where required when SP 274 appears in column 7;
the minimum flashpoint if 61 °C (c.c) or below;
or after the PSN where the packages, IBCs or tanks concerned contain the
residue of the dangerous goods;
the word "WASTE" before the PSN where waste dangerous goods are being
transported for disposal, or for processing for disposal;
the identification of the goods as "MARINE POLLUTANT', if applicable;
for class 1 explosives, the net explosives mass of the contents should be
included in the description of the consignment;
in the case of a class 4.1 self-reactive substance or a class 5.2 organic
peroxide, the control and emergency temperatures, if applicable;
for dangerous goods consigned in salvage packagings, the words "SALVAGE
PACKAGING" should be included.
Limited quantity consignments
For these consignments, the phrase "Dangerous goods in Limited Quantities of
class/classes..." may be used instead of the proper shipping name (PSN) in accordance
with the provisions of chapter 3.4 of the Code (see part 12) but all other documentation
entries are required. The words "Limited Quantity" or "Ltd Qty" must be added to
standard entries.
Special requirements
Special additional information is required on the documentation for certain
consignments (e.g. class 1 explosives, self-reactive substances in class 4.1, organic
peroxides in class 5.2, class 6.2 infectious substances, class 7 radioactive materials
and elevated temperature loads). Full details are provided in chapter 5.4 of the Code.
Where a vehicle/container is being transported under fumigation the documentation
must show the date of fumigation and the type and amount of the fumigant used.
Instructions for the disposal of a residual fumigant, including fumigation devices (if used)
must also be provided.
11.8 Compliance declaration
The DGN must incorporate, or be accompanied by, a certificate or declaration by
the consignor confirming that the shipment is properly classified, packaged, marked and
labelled, and in proper condition for carriage in accordance with the applicable
regulations. This declaration must be signed on behalf of the consignor.
11.10 Special certificates
Where indicated for the substance concerned in the DGL, the following
certificates must also be provided: a weathering certificate; a certificate exempting a
substance, material or article from the provisions of the Code.
For new self-reactive substances and organic peroxides or new formulations of
currently assigned self-reactive substances and organic peroxides, a statement by the
Competent Authority (see part 13) of the country of origin confirming the approved
Dangerous, Hazardous and Harmful Cargoes
classification and conditions of carriage for the goods must be provided with the
11.9 Container/vehicle packing certification
Where packaged dangerous goods are being consigned in a freight container or
vehicle, a certificate must be completed by the party responsible for the packing/loading
operation, confirming that it has been properly carried out. The identification number of
the freight container/vehicle must be indicated. A container packing certificate is not
required for tanks.
The certificate provides confirmation that a number of actions or checks have
been carried out, including:
the freight container or vehicle was clean, dry and apparently fit to receive the
any goods which need to be segregated have not been loaded together in the
freight container or vehicle unless Competent Authority approval has been
obtained (see part 13);
all packages have been externally inspected for damage and only sound
packages loaded;
all packages have been properly packed and secured;
drums have been stowed in an upright position unless otherwise authorized
by the Competent Authority (see part 13);
the freight container or vehicle and any packages therein are properly
marked, labelled and placarded.
Chapter 5.4 provides a fully itemized checklist for this certificate. The importance
of the certificate is highlighted in a circular (MSC/Circ.506/Rev.1) issued in 1990 by the
IMO Maritime Safety Committee (see part 14).
This particular aspect of documentation can cause some significant problems
about its completion. The duty for completion lies with the person who fills the container
or vehicle. This will quite often be someone who is not the consignor. The container
packing certificate is intended to make the person who is filling the transport unit check
that it appears to be fit for the journey and that incompatible goods are not carried in the
same unit. This is not intended as an engineering inspection. Consignors with groupage
consignments will very often not see the transport unit that will travel the oceans.
11.11 Documentation required on board the ship
Each ship carrying dangerous goods or marine pollutants should have a special
list or manifest providing full details of the goods being carried and their location on the
ship. This list or manifest should be based on the contents of the dangerous goods
transport documents and certificates required by the Code and should include details of
stowage locations.
Appropriate emergency response information must be available at all times for
use in the event of an accident or incident involving dangerous goods. This information
must be held in a location away from packages containing dangerous goods and
immediately accessible in the event of an incident.
Dangerous, Hazardous and Harmful Cargoes
12. Limited and Excepted Quantities
12.1 Limited Quantities
Chapter 3.4 of the Code provides concessions from a number of the duties
normally placed on the consignor when dangerous goods are being shipped in small
packages which qualify for "Limited Quantities" status.
The "Limited Quantities" section comprises:
the general packing requirements for Limited Quantity consignments;
directions relating to the mixed packing, stowage and segregation of different
dangerous goods shipped as Limited Quantities;
details of the concessions which apply to Limited Quantities consignments.
12.2 Permitted consignments
For dangerous goods which may be sent as Limited Quantities, an entry in
column 7 of the DGL shows the quantities permitted in any inner packaging. For goods
which are not permitted under these provisions the word "None" appears in column 7. In
a few instances the Limited Quantity provision is controlled by a Special Provision (e.g.
UN 1950). Marine pollutants can change the quantity that can be carried. 3.4.8 limits
inner packagings of marine pollutants to 5 litres for liquids or 5 kg for solids. Severe
marine pollutants are limited to 500 ml for liquids or 500 gm for solids. These quantities
override the limits in column 7 where the substance meets the marine pollutant criteria.
12.3 Packaging requirements
In all cases, dangerous goods shipped as Limited Quantities must be packed in
inner packagings placed inside a suitable outer packaging: i.e. in combination packs.
The packagings must meet the general packing requirements of chapter 4.1 of
the Code (see part 9 of this Compendium)(e.g. quality, product compatibility, ullage (for
liquids) and venting) but they do not have to be tested and approved to the UNspecification standards (see part 10): i.e. they do not have to be UN-approved
The total gross weight of any package must not exceed 30 kg (or the maximum
gross weight permitted in the individual schedule for the goods concerned, if lower).
Shrink-wrapped or stretch-wrapped trays are acceptable as outer packagings for
Limited Quantities, but only up to a maximum gross weight of 20 kg.
There is no limit on the number of Limited Quantities packages that may be
consigned together.
Dangerous, Hazardous and Harmful Cargoes
12.4 Mixed packing, segregation and stowage
Different dangerous goods may be packed together in the same outer packaging
provided that they do not require segregation and will not interact dangerously in the
event of leakage (see also part 9).
No segregation is required between packages containing Limited Quantities or in
relation to other dangerous goods. All dangerous goods carried as Limited Quantities
are allocated to stowage category A (see part 13).
12.5 Consignment concessions
Limited Quantities packages do not have to be:
bear the marine pollutant mark
show the proper shipping name.
However, packages must show the UN Number inside a diamond shape. For a
single substance
The UN Number must be at least 6 mm high
The line must be at least 2 mm thick
For a mixed package
The diamond must be big enough to include each number.
Limited Quantities consignments for personal or household use that are packed
and distributed in a form or suitable for sale through retail agencies do not require any
marks on the packages. Cargo transport units (freight containers, vehicles, trailers, rail
wagons) packed only with Limited Quantities do not have to be placarded. However,
they must be marked with the words "LIMITED QUANTITIES" or "LTD QTY".
The standard documentation requirements apply to Limited Quantities
consignments - see part 11. In addition to the other information required, the description
of the consignment must include the words "Limited Quantity".
For aerosols (UN 1950) not exceeding 1000 cm3 no division is assigned and the
class can be shown as 2 on the dangerous goods transport document.
Dangerous, Hazardous and Harmful Cargoes
13. Transport operations
13.1 Introduction
Part 7 of the IMDG Code concerns transport operations. The provisions mainly
affect the ship operator and members of the crew, but they are not for their exclusive
use. There are a number of safety-related operational issues which need to be taken
into account by consignors, shipborne staff and others (e.g. container base staff) when
dangerous goods are transported by sea.
Chapter 7.1 of the Code details restrictions relating to stowage by the type of
vessel ("cargo" or "passenger") which may be used and any particular requirements
with respect to the location on board the vessel where the goods may be stowed, whilst
chapter 7.2 sets out procedures designed to ensure that adequate separation
(segregation) is maintained between incompatible dangerous goods.
Measures which need to be taken in the event of an incident involving dangerous
goods or to minimize the risk of fire on board the vessel are highlighted in chapter 7.3.
Chapter 7.4 of the Code deals specifically with the transport of cargo transport
units (including freight containers) on board ships, whilst chapter 7.5 addresses the
packing of cargo transport units (generally the consignor's or his agent's responsibility)
and identifies particular procedures which must be followed in order to ensure that any
such movements are carried out safely.
Chapter 7.6 outlines a number of operational special or additional provisions
relevant to the carriage of dangerous goods on shipborne barges and barge-carrying
Chapter 7.7 addresses temperature control. Some substances, particularly in
class 4.1 and 5.2, have to be carried at specific temperatures otherwise they can cause
Chapter 7.8 deals with wastes. This issue has been covered in part 8 of this
Chapter 7.9 of the Code deals with Competent Authority approvals and provides
details of appropriate contact points in individual countries.
13.2 Stowage principles
Chapter 7.1 of the Code contains provisions for the stowage of dangerous goods.
These provisions impose restrictions with respect to the type of ship on which goods
may be transported and also the location on board the ship where the goods must be
stowed during the voyage.
Whilst stowage procedures on board a ship are primarily the concern of the
ship's master and crew, failure to take account of any relevant constraints, particularly
where the dangerous goods are being shipped in a cargo transport unit such as a road
vehicle or freight container, could result in the shipment being delayed.
For the purposes of stowage (except for the carriage of explosives in class 1 see 13.5), the Code distinguishes between two types of ship: ships carrying not more
than 25 passengers or 1 passenger per 3 metres of overall length, whichever is the
Dangerous, Hazardous and Harmful Cargoes
greater, are deemed to be "cargo ships"; ships on which this limitation on passenger
numbers is exceeded are designated as "passenger ships".
Column 16 of the DGL in volume 2 of the Code identifies a stowage category for
the goods concerned; these categories range through the letters A to E. The letter code
is fully explained in chapter 7.1.
The various categories determine, according to the type of ship, whether the
goods should be stowed on deck or under deck; in some cases, consignment on a
passenger ship is prohibited.
There are special stowage categories for class 1 (explosives) - see 13.5 below.
Further guidance on the procedures which should be followed to ensure the safe
stowage and securing of cargo transport units on board ships is provided in three IMO
Assembly Resolutions. These may be found in the Appendix to the Supplement (see
part 14).
13.3 General stowage requirements
Stowage under deck is recommended wherever possible because of the
advantages it offers in terms of protection, whilst on deck stowage is prescribed in
cases where constant supervision and/or ready accessibility is required or there is a
significant risk of the formation of explosive gas mixtures, the development of highly
toxic vapours or unobserved corrosion of the ship.
Packages susceptible to water damage should be stowed under deck unless
they can be stowed on deck in a manner that ensures that they are protected at all
times from exposure to weather or seawater.
There are guidelines on stacking methods and procedures for packaged
dangerous goods -generally a 3 metre maximum stack height is recommended,
although this may be increased at the discretion of the ship's master.
Drums should always be stowed upright unless otherwise authorized by the
Competent Authority.
Goods must be stowed so that walkways and access routes to facilities
necessary for the safe operation of the ship, such as hydrants and sounding pipes, are
kept clear at all times.
13.4 Specific stowage requirements
In addition to identifying a general stowage category (A, B, C, D or E), column 16
of the DGL may indicate one or more specific additional stowage requirements which
must be observed by the master and crew of the ship when determining appropriate
stowage arrangements. Note that additional stowage guidance sometimes appears in
column 17 - "Properties and Observations". Specific guidance on stowage
arrangements for each class of dangerous goods is given in 7.1.7 to 7.1.16. Some of
these provisions are summarized below. In some instances the stowage requirements
will be subject to the approval of the Competent Authority (e.g. UN 2814).
Stowage in relation to living quarters (7.1.2)
Special requirements apply to goods of classes 1 (explosives), 5.2 (organic
peroxides) and 7 (radioactive materials), and substances of class 3 (flammable liquids)
with a flashpoint of 23°C or less when carried in portable tanks.
Dangerous, Hazardous and Harmful Cargoes
Where an instruction to stow goods clear of living quarters is listed, it means that
consideration should be given to the possibility of leaking vapours penetrating
accommodation, work areas or machinery spaces through entrances, bulkhead
openings or ventilation ducts.
Stowage in relation to undeveloped films and plates, and mailbags (7.1.3)
Radioactive material (class 7) must be stowed away from undeveloped films and
plates, as well as mailbags (which should be assumed to contain them), in accordance
with the provisions outlined in, and
Stowage of marine pollutants (7.1.4)
Where stowage on deck or under deck is permitted, the goods should preferably
be stowed under deck unless there is a weather deck that provides equivalent
protection. Where on deck only stowage is required, preference should be given to
stowage on well-protected decks or inboard in sheltered areas of exposed decks.
Stowage in relation to foodstuffs (7.1.5)
In order to avoid the possibility of contamination, toxic (class 6.1, PG I or II, or
class 2.3), infectious (class 6.2), corrosive (class 8), radioactive (class 7) and corrosive
(class 8) substances, materials and articles must be stowed so that they are adequately
separated from any foodstuffs (e.g. Minimum separation distances are
specified according to circumstances. These are explained in chapter 7.2 of the Code.
Stowage of solutions and mixtures (7.1.6)
Solutions or mixtures shipped under a generic or N.O.S. entry must be stowed in
accordance with the stowage instructions assigned to that entry, as identified on the
schedule page for the goods concerned in the DGL.
Stowage of containers
Particular requirements apply to the stowage and securing of containers loaded
with dangerous goods on different types of vessel. Full details are provided in chapter
7.4 of the Code (see 13.10). These cover matters such as:
restrictions on the stowage of containers loaded with flammable gases or
liquids, or temperature-controlled CTUs in the same cargo spaces as
refrigerated or heated CTUs, the heating equipment or coolant of which could
provide a potential source of ignition;
safe stowage directions for CTUs loaded with marine pollutants;
procedures for ensuring the safe stowage of dangerous goods on open-top
Full details are provided in chapters 7.2 and 7.4 of the Code.
13.5 Stowage of explosives
Special stowage requirements apply to the carriage of explosives (class 1).
With the exception of explosives in division 1.4, compatibility group S, there are
strict limitations on the type and quantity of explosives which may be carried on different
categories of vessel. On deck stowage is usually preferred.
Dangerous, Hazardous and Harmful Cargoes
A number of specific special stowage requirements are set down in part 7.1.7 for
class 1 explosives consignments and these must always be taken into account in
addition to any other requirements on the schedules.
For class 1 stowage purposes, ships with up to 12 passengers are classed as
"cargo ships" and ships on which this limitation on passenger numbers is exceeded are
designated as "passenger ships".
There is a separate set of stowage categories for explosives - numbered 01 to 15.
These categories are explained in The applicable stowage category for any
particular explosive substance or article appears in of the Code, where the
categories are numbered (e.g. "Stowage category 01") and this number appears in
column 16. Having identified the category, the list explains what it means in relation to
cargo and passenger ships.
It should also be noted that, with the exception of explosives in division 1.4,
compatibility group S, there are strict limitations on the type and quantity of explosives
that may be carried on passenger ships. These are explained in
13.6 Segregation principles
Chapter 7.2 of the Code sets out procedures designed to ensure that adequate
separation (segregation) is maintained between incompatible dangerous goods.
Different dangerous goods are considered incompatible if their stowage together
may result in undue hazards in the case of leakage, spillage or any other accident.
Whilst segregation requirements are often based on incompatibility problems
between different hazard classes (e.g. flammable liquids (class 3) and oxidizing
substances (class 5.1)), there are circumstances where substances, materials or
articles in the same hazard class need to be segregated from each other.
The segregation provisions in 7.2 apply to all cargo spaces on deck or under
deck in all types of ships and to cargo transport units (CTUs).
Segregation is achieved by maintaining minimum separation distances between
incompatible dangerous goods or by requiring one or more bulkheads or decks between
them, or a combination thereof.
The following standard segregation terms are used for the purposes of
determining segregation requirements when dangerous goods are being transported by
"Away from";
"Separated from";
"Separated by a complete compartment or hold from";
"Separated longitudinally by an intervening complete compartment or hold from".
However, different interpretations are applied to these terms according to the
context in which segregation decisions are being made. For example, the term "Away
from" has a different meaning when applied to the segregation of packaged goods
stowed in the hold of a vessel than when applied to the segregation of freight containers
loaded on board a containership.
These interpretations are fully explained in the sub-sections of chapter 7.2, which
detail the segregation requirements applicable to the various modes of carriage by sea.
These sub-sections cover:
Dangerous, Hazardous and Harmful Cargoes
Segregation of packages (7.2.2);
Segregation of cargo transport units on board containerships (7.2.3);
Segregation of cargo transport units on board ro-ro ships (7.2.4);
Segregation in shipborne barges and on board barge-carrying ships (7.2.5);
Segregation between bulk materials possessing chemical hazards and
packaged dangerous goods (7.2.6);
Segregation of goods of class 1 (7.2.7), classes 4.1 and 5.2 (7.2.8) and class
7 (7.2.9).
Further guidance on the general procedures to be followed when determining
segregation needs is provided in 13.7 and specific interpretations in 13.8.
13.7 General segregation requirements
When determining segregation requirements, there are three important points to
address from the DGL:
The class of the substance and any subsidiary risk (columns 3 and 4)
The primary rule that applies to segregation is that incompatible classes are not
placed together. It is therefore necessary to know the primary risk. Chapter 7.2
also requires that subsidiary risks are taken into account.
Any additional comments contained in column 16 of the DGL (stowage and
segregation) Column 16 contains "Stowage and Segregation" information. The
main part of this column identifies the stowage category (see 13.2), and any
additional instructions relevant to segregation decisions. In many instances
additional information is included. For example, "Away from acids". There can be a
problem identifying other acids. In order to help many users of the Code who will
not be chemists and do not have the chemical knowledge to determine whether a
particular substance is an acid the IMO have introduced "Segregation Groups".
These sixteen segregation groups (e.g. acids, azides, bromates etc.) are listed in Chapter 3 (3.1.4) (in volume 2 of the Code) provides a detailed list of
substances falling under each group; thus the list for "acids" includes not only
common acids such as hydrochloric acid but other less common acids like
octyltrichlorosilane.The list only includes pure substances with UN Numbers (i.e.
not N.O.S or generic entries).
UN 1504 sodium peroxide. In column 16 it states that the substance must be
"separated from powdered metals and permanganates". A consignor wishes to
send titanium sponge powders (UN 2878) with UN 1504 and he is not be sure
whether UN 2878 is a metal powder; reference to the list in 3.1.4 of the Code will
confirm that it is a metal powder.
Any comments in column 17 of the DGL (Properties and observations)
Under properties and observations will be found information regarding the
chemical properties that may influence segregation e.g. "reacts vigorously with
sulphuric acid".
For class 1 (explosives) particular segregation instructions exist for:
substances and articles within class 1
between class 1 items and dangerous goods in other classes; and
between class 1 items and non-dangerous goods.
Dangerous, Hazardous and Harmful Cargoes
For class 4.1 (flammable solids) and class 5.2 (organic peroxides) there are
specific instructions for calculating segregation requirements for dangerous goods with
an explosive subsidiary risk. For class 7 (radioactive materials) these are specific
segregation directions for class 7 items.
Segregation table
Once any specific segregation directions found in the DGL have been taken into
account, the segregation table in chapter of the Code provides the basis for
segregation decisions.
By reference to the hazard class and, where applicable, subsidiary risk of each of
the dangerous goods, the table identifies any relevant segregation requirements.
The segregation decision must be based on the most stringent requirements for
any of the dangerous goods concerned.
"X" in the table in the box where the column and row for the classes being
compared intersect indicates (in the absence of any instructions to the contrary in
columns 16 and 17 of the DGL) that no segregation is required between the goods
concerned, whilst a number code 1, 2, 3 or 4 indicates a particular level of segregation,
as follows:
= "Away from"
= "Separated from"
= "Separated by a complete compartment or hold from"
= "Separated longitudinally by an intervening complete compartment or hold from"
Dangerous, Hazardous and Harmful Cargoes
As explained above, any specific requirements identified in the DGL for the
goods concerned take precedence over instructions in the table.
The extent of the segregation identified by the number code varies according to
the mode of carriage for which the calculation is being made (e.g. whether it concerns
the separation of packaged goods in the hold of a vessel, the distance required between
containers on a containership or the separation of vehicles on a ro-ro ferry).
Consequently, once the applicable number code has been established, reference must
be made to the appropriate modal carriage section of chapter 7.2 in order to interpret
the exact implications - see 13.8.
An example of the segregation procedure for a sample consignment is provided
at the end of 13.8.
Subsidiary risks
Where the Code requires packages to bear a single subsidiary risk label, the
segregation appropriate to this subsidiary risk must be applied when it is more stringent
than that required for the class (primary) hazard: i.e. the calculation explained above
must be done twice.
Segregation requirements for packages bearing more than one subsidiary risk
label are always highlighted in the DGL.
However, dangerous goods of the same hazard class may be stowed together
without regard to any segregation required by subsidiary hazards, provided that the
goods concerned are compatible.
13.8 Specific segregation procedures
The manner in which segregation directions are interpreted for different shipment
methods is explained below.
Segregation of packages
Chapter 7.2.2 of the Code identifies how segregation directions are to be
interpreted and applied where packaged dangerous goods are carried in the hold of a
vessel or in a cargo transport unit (see part 11) (or a combination thereof, both on the
same ship).
Whilst the basic procedure for determining segregation is as outlined under 13.7,
there are variations in the manner in which the standard segregation directions are
interpreted for such cargoes; these are explained in detail and illustrated in diagramatic
form in 7.2.2 of the Code.
For the purposes of determining segregation distances between packaged
dangerous goods stowed conventionally in the hold and those packed in a cargo
transport unit, a distinction is made between closed (contents totally enclosed by
permanent structures) and open cargo transport units. More stringent requirements
apply where the cargo transport unit is of an open design.
If any level of segregation is required between particular dangerous goods, the
goods concerned must not be loaded in the same cargo transport unit. The only
exception to this rule is where the minimum segregation level of "Away from" is
specified, in which case the goods may be carried together with the prior approval of the
Competent Authority (see 13.10).
Dangerous, Hazardous and Harmful Cargoes
Segregation of freight containers on board containerships
7.2.3 of the Code identifies how segregation directions are to be interpreted and
applied in the case of freight containers carried on board containerships, or on the
decks or in holds and compartments of other types of ships fitted with permanent
container stowage facilities.
Whilst the basic procedure for determining segregation is as outlined under 13.7
above, there are variations in the manner in which the standard segregation directions
are interpreted and applied for such cargoes.
Their practical application is based on a number of factors: the type of vessel; the type
of containers - whether they are of a closed (with permanent structures totally enclosing
the contents) or open design type; their location on the vessel - on deck or under deck;
and the nature of the segregation being considered - vertical or horizontal, "fore and aft"
or "athwartships".
Segregation of cargo transport units on board ro-ro ships
7.2.4 of the Code identifies how segregation directions are to be interpreted and
applied where cargo transport units loaded with dangerous goods are carried on ro-ro
ships or in ro-ro cargo spaces, either on deck or under deck.
Whilst the basic procedure for determining segregation is as outlined under 13.7
above, there are variations in the manner in which the standard segregation directions
are interpreted and applies for such cargoes. Their practical application is based on a
number of factors: the type of units - whether they are of a closed (with permanent
structures totally enclosing the contents) or open design type; their location on the
vessel - on deck or under deck; and the nature of the segregation being considered "fore and aft" or "athwartships".
Segregation in shipborne barges and on board barge-carrying ships
7.2.5 of the Code identifies how segregation directions are to be interpreted and
applied where dangerous goods are carried in a shipborne barge or a number of such
barges are conveyed on a ship specially designed and equipped for their carriage.
Whilst the basic procedure for determining segregation is as outlined under 13.7
above, there are variations in the manner in which the standard segregation directions
are interpreted for such cargoes.
Segregation between bulk materials possessing chemical hazards and
packaged dangerous goods
The segregation requirements on ships loaded with both bulk hazardous
chemicals and packaged dangerous goods are identified in 7.2.6.
Segregation decisions for such cargoes are based on the use of the special
segregation table in sub-section 7.2.6 of the Code, taking account of any specific
segregation directions in the DGL.
Dangerous, Hazardous and Harmful Cargoes
13.9 Actions to be taken in the event of incidents involving
dangerous goods and fire precautions
Chapter 7.3 deals with emergency action procedures and fire prevention. It
contains some general emergency procedures and some specific directions for
incidents involving class 6.2 (infectious) and class 7 (radioactive) cargoes.
With respect to fire prevention, there is a list of eight general precautions
applicable in all circumstances. In addition, the seafarer is advised to study the
individual class sections of 7.3 and applicable instructions in the DGL, especially the
Emergency Schedule (EmS) in column 15. The practical application of the EmS
instructions is explained in the section headed "Emergency Procedures for Ships
Carrying Dangerous Goods" in the Supplement to the Code.
13.10 Cargo transport units
Chapter 7.4 identifies a number of specific requirements which must be met
when dangerous goods are to be transported by sea in a cargo transport unit (CTU).
The term "cargo transport unit (CTU)" covers freight containers used for the
transport of packaged dangerous goods, bulk packagings used for solid dangerous
goods, road freight vehicles, railway freight wagons, road tank vehicles, rail tank
wagons or portable tanks. Portable tanks are dealt with in more detail in part 9.
A freight container is defined as an article of transport equipment that is of
permanent character, strong enough to be suitable for repeated use, specially designed
to be transported by one or more modes of transport without intermediate reloading and
designed and fitted to enable proper securing and ready handling. Vehicles or
packagings are not regarded as freight containers.
Freight containers and road or rail vehicles into which solid dangerous goods are
loaded without any intermediate form of containment are regarded as bulk packagings.
CTUs used for the transport of packaged goods or as bulk packagings for solid
dangerous goods must be strong enough to meet the normal conditions of transport
under which they will be used and, with the exception of those used for offshore
operations, "containers" must be approved in accordance with the International
Convention for Safe Containers (CSC).
Competent Authority approval is required for offshore containers. The approval
plate on such containers must be clearly marked with the words "Offshore Container".
Permitted shipments
Dangerous goods which require segregation from each other must not be carried
in the same CTU. The only exception to this rule is where the minimum segregation
level of "Away from" is specified, in which case the goods may only be carried together
with the prior approval of the Competent Authority.
Containers carried under fumigation
Special preparation and carriage conditions apply to the transport of containers
under fumigation: measures must be taken to minimize the escape of fumigant; a
minimum time period of 24 hours (or any shorter period specified by the Competent
Authority) is required between the application of the fumigant and the loading of the
Dangerous, Hazardous and Harmful Cargoes
container onto the ship; prior notification must be given to the ship's master; fumigant
detection equipment and instructions for its use must be carried.
DATE __________
TIME _________
Ro-ro ships
There are some alternative and/or additional provisions which must be met when
dangerous goods are transported on ro-ro vessels. These arise mainly because of
structural differences between ro-ro and conventional vessels.
A ro-ro (roll-on/roll-off) ship means a ship which has one or more decks, either
closed or open, which are not sub-divided in any way and normally run the entire length
of the vessel, carrying goods which are normally loaded and unloaded in a horizontal
13.11 General handling, stowage and segregation
Due to the very particular nature of ro-ro operations, a number of specific
provisons apply to the loading, carriage and unloading of ro-ro traffics. These
provisions, which are fully detailed in section 17 of the Code, relate to matters such as:
loading/unloading operations: all such operations must carried out under the
surveillance of officers/crew members or responsible persons appointed by the
master of the ship
prevention of access to decks: passengers and other unauthorized persons
must be excluded from vehicle decks where dangerous goods have been loaded;
access doors to such decks must be securely closed and notices prohibiting
access must be clearly displayed; an authorized crew member must accompany
any unauthorized person requiring access to such a deck during the voyage
prevention of vapour spread: the closing arrangements for doors or openings
between cargo spaces and machinery and accommodation spaces must be such
that the risk of vapours entering such areas is minimized
Dangerous, Hazardous and Harmful Cargoes
The requirements are detailed in full in chapter 7.4 of the Code.
safefy of electrical systems: where there is a possibility of flammable vapours
being released, electrical systems on vehicle decks must be designed so as to
preclude the possibility of explosion
ventilation systems: closed ro-ro cargo spaces and special category cargo
spaces intended for the carriage of vehicles with fuel in their tanks must be
mechanically ventilated where dangerous goods which require such ventilation
are being carried
temperature-controlled containers or vehicles: there are restrictions on the
operation of mechanically or electrically operated temperature-controlled
containers or vehicles on ro-ro vessels
safefy inspections: vehicle decks must be regularly inspected by an authorized
crew member during the voyage
Units loaded with dangerous goods must be stowed so as to be accessible at all
times, especially for fire fighting.
A unit is defined as a vehicle, container, tank, intermediate bulk container (IBC),
unit load or receptacle.
Particular stowage directions apply to containers (both freight containers and
portable tanks) - see 13.3 - and to any units loaded with marine pollutants - see 13.4.
Details of the segregation requirements both within and between units carrying
dangerous goods are provided in 13.8.
All units carrying dangerous goods must be securely fastened to the ship with
lashings or other suitable means which ensure that they cannot shift during the voyage.
13.12 Container packing of cargo transport units (CTUs)
Where packages are carried in a CTU, there are a number of measures which
should be taken to ensure safety during the journey. These are set down in chapter 7.5
of the Code.
For example, both the CTU and the packages should be visually examined to
ensure that there is no damage likely to affect safety; packages should be tightly packed
or adequately braced or secured so as to prevent their movement and minimize the
possibility of damage; where possible, dangerous goods consigned as a part load
should be packed so as to be accessible from the doors; any locking system must be
designed so that the doors can be opened without delay in an emergency; any
irrelevant markings or placards etc., must be removed from the container before
loading. Further detailed guidelines on safe loading procedures are contained in the
IMO/ILO/UN ECE Guidelines for Packing Cargo Transport Units which are reproduced
in the Supplement to the Code (see part 14).
Containers carried under fumigation: special preparation and carriage conditions
apply to the transport of containers under fumigation: measures must be taken to
minimize the escape of fumigant; a minimum time period of 24 hours (or any shorter
period specified by the Competent Authority) is required between the aplication of the
fumigant and the loading of the container onto the ship; prior notification must be given
to the ship's master; fumigant detection equipment and instructions for its use must be
Dangerous, Hazardous and Harmful Cargoes
13.13 Shipborne barges
Chapter 7.6 of the Code identifies the procedures which must be followed when
packaged dangerous goods or solid bulk materials possessing chemical hazards are
being transported on a barge-carrying ship or being transferred to or from such a ship
on a barge feeder vessel.
A barge-carrying ship is a vessel specially designed and equipped to carry
shipborne barges.
A shipborne barge or barge is an independent, non-self-propelled vessel which is
specially designed and equipped to be lifted in a loaded condition and stowed aboard a
barge-carrying ship or barge feeder vessel.
A barge feeder vessel is one which is specially designed and equipped to
transfer shipborne barges to or from a barge-carrying vessel/ship.
The design and construction of shipborne barges is subject to Competent
Authority approval.
Permitted shipments
The standard requirements relating to the design, construction and approval of
packages and portable tanks (see parts 9 and 10) apply equally when dangerous goods
are transported on barge-carrying vessels.
There are restrictions on the carriage of certain commodities in shipborne
barges, and these are indicated as appropriate, on the individual schedule pages; other
commodities may only be carried with Competent Authority approval under specified
13.14 Barge loading, stowage and segregation
Packages, portable tanks, freight containers and any other goods within a
shipborne barge must be properly immobilized by stowage and adequately braced so as
to prevent their movement and minimize the possibility of damage.
Shipborne barges should be visually examined for hull or hatch cover damage
which could impair watertight integrity. If there is evidence of such damage, the barge
should not be loaded.
Packages should be examined and any found to be damaged, leaking or sifting
should not be loaded.
Where solid bulk materials possessing chemical hazards are carried in shipborne
barges, the cargo must at all times be evenly distributed, properly trimmed and secured.
The DGL or manifest and stowage plan (see part 11) should clearly identify all
shipborne barges loaded with dangerous goods and show their location on board the
ship. The total quantity of each dangerous substance should also be shown.
Stowage decisions must be based on the direction given on the individual
schedule page in the DGL for the dangerous goods concerned.
When a shipborne barge is loaded with more than one substance and the
individual schedule pages for the substances relevant entries in the DGL indicate
different stowage locations -i.e. some require on deck stowage and others under deck
stowage - the barge should be stowed on deck
Dangerous, Hazardous and Harmful Cargoes
Particular stowage directions apply to barges loaded with marine pollutants - see
13.4. Shipborne barges should be securely fastened to the ship with lashings or other
suitable means so as to prevent shifting during the voyage.
Details of segregation requirements in shipborne barges and on barge-carrying
ships are provided in 13.8.
The following safety issues should be taken into account when dangerous goods
are transported on shipborne barges:
ventilation: where specific ventilation requirements apply to the goods
concerned, measures must be taken to ensure that the barge is adequately
condensation: account must be taken of potential condensation problems
where barges are loaded with substances in class 4.3 (dangerous when wet),
materials hazardous only in bulk (MHB) having similar properties or
substances liable to spontaneous heating;
leakage of vapours or fumes: when removing hatch covers, the possibility
that leakage may have caused an unsafe concentration of toxic or flammable
vapours or produced an oxygen-rich or oxygen-depleted atmosphere should
be taken into consideration;
fire protection: shipborne barges loaded with significant quantities of
dangerous goods should be stowed as far as practicable from
accommodation and navigational areas.
Where barge-carrying ships are fitted with fixed fire-fighting systems or fire
detection systems which can be linked to individual barges, care should be taken to
ensure that these systems are attached and operational.
barges loaded with goods under fumigation: special preparation and carriage
conditions apply where barges are loaded with goods under fumigation:
measures must be taken to minimize the escape of fumigant; a minimum time
period of 24 hours (or any shorter period specified by the Competent
Authority) is required between the application of the fumigant and the loading
of the barge onto the ship; prior notification must be given to the ship's
master; fumigant detection equipment and instructions for its use must be
13.15 Temperature control
Chapter 7.7 of the Code details how the temperatures should be controlled and
particular requirements to be followed, including stowage requirements, where several
substances with different self-accelerating decomposition temperatures (SADT) are
loaded into the same containers cargo transport unit.
Certain substances, mainly organic peroxides of class 5.2 and self-reactive
substances of class 4.1, must be carried at low temperatures.
Chapter 7.7 also addresses substances that must be stabilized by means of
temperature control.
The DGL identifies such substances with their UN Number (e.g UN 3114: organic
peroxide Type C, solid, temperature controlled).
Where applicable, the entries in column 17 identify the need to check table of the Code (for self-reactive substances) or (for organic peroxides)
in order to ascertain full details of the temperature requirements.
Dangerous, Hazardous and Harmful Cargoes
Where a substance has to be temperature controlled, there are three
temperatures levels to be established:
control temperature: the maximum temperature at which the substance
should be carried
emergency temperature: the temperature at which emergency procedures
should be implemented
self-accelerating decomposition temperature (SADT): the lowest temperature
at which self-accelerating decomposition occurs
If a substance has an SADT of 30°C the control temperature would be 15°C and
the emergency temperature 20°C. If the SADT is not provided or known, it must be
ascertained by testing in accordance with the latest edition of the UN Manual of Tests
and Criteria. The other temperatures can be determined once this is known. The
procedure is explained in 7.7.2. Ships' masters must have instructions for the operation
of the refrigeration system.
13.16 Transport of wastes
Chapter 7.8 of the Code explains the relationship between the IMDG Code and
the Basel Convention on the Control of Transboundary Movements of Hazardous
Wastes and their Disposal. The Convention sets down the rules for the international
movements of all wastes (not only dangerous goods). Notifications and approvals from
and to Competent Authorities (these are not usually the maritime authorities) are
required. The classification procedures for dangerous wastes follow the UN system.
13.17 Competent Authorities
Chapter 7.9 lists the names and addresses of designated national "Competent
Authorities". The term "Competent Authority" means the national government
department responsible for interpreting and enforcing the provisions of the IMDG Code
in a particular country, or any agency or organization which has been delegated by that
government department to carry out certain functions e.g. the testing and approval of
packagings. Where applicable, details of any such agencies or organizations are
included in the above mentioned list of national Competent Authorities.
13.18 Competent Authority approvals
Where there is a reference in the provisions of the Code to "Competent Authority
approval" or an indication that a particular action or procedure is "subject to the
approval of the Competent Authority", an application must be made to the appropriate
Competent Authority for the necessary authorization. Any such authorizations - which
will be in the form of written approvals, permits or certificates - issued by a Competent
Authority, or by duly authorized organization acting under its responsibility, should be
recognized by all other countries. Approvals, permits or certificates should at least
comply with the requirements of the International Convention for the Safety of Life at
Sea, 1974 (SOLAS); the International Convention for the Prevention of Pollution from
Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78); and
the standards of the IMDG Code.
Dangerous, Hazardous and Harmful Cargoes
14. IMDG Supplement
14.1 Supplement contents
The Supplement to the IMDG Code contains seven distinct sections each
containing guidance on specific issues and procedures relevant to the safe transport of
dangerous goods by sea. Its contents comprise a number of separate annexes and
supplements which relate to the Code.
These concern:
Emergency response procedures on board ships - EmS Guide
First aid procedures on board ships - Medical First Aid Guide (MFAG)
Reporting procedures following incidents
Safe packing procedures for cargo transport units
Safe use of pesticides in ships
Carriage of nuclear materials (INF Code)
Appendix of relevant resolutions and circulars
Emergency procedures
14.2 Emergency response procedures (EmS Guide)
The use of emergency procedures involves a course in its own right. The
following notes are intended to explain the purpose of the emergency response
procedures and how they should be used.
For consignors of dangerous goods there is no requirement to provide this
information to the shipping line or to the ship, which will have a Code and will be able to
determine the correct schedule to use in the circumstances from column 15.
In order to assist vessels with advice regarding the actions to be taken on board
in emergencies involving dangerous goods (fire or spillage), IMO has published a guide,
Emergency Response Procedures for Ships Carrying Dangerous Goods (EmS Guide).
This document has been completely revised from Amendment 31 to the Code.
The EmS Guide is divided into two sections:
This style is reflected in the DGL where column 15 shows two codes:
"F-?" indicates the schedule for firefighting (e.g. F-H which deals with fires
involving substances which are oxidizers with explosive potential). There are 10
firefighting schedules.
"S-?" indicates the schedule for spillages (e.g. S-P concerns spills involving
substances which are dangerous when wet (class 4.3)). There are 26 spillage
Dangerous, Hazardous and Harmful Cargoes
Each part of the Guide has a general introduction dealing with common issues. In
the introduction to the firefighting schedules there are sections concerning:
identification of the goods;
general effects of fire and chemicals;
firefighting media - types of extinguishants;
personal protection and first aid.
These general sections are followed by some guidance on the effects of fire with
chemicals of the nine classes: e.g. for class 1 they explain that divisions 1.2, 1.3,1.4 and
1.6 are unlikely to explode en masse, while for class 3 the guide warns against directing
jets of water on to flammable liquids as this can lead to the spread of fire.
A similar introduction applies to spillages. It should be noted that at the bottom of
each schedule there is space for special cases where additional information is required.
Where special cases are shown in the schedule the entry in column 15 of the
DGL has the schedule underlined to indicate that special additional rules appear in the
Schedule (e.g. UN 2447 in column 15 will show F-A).
The following conditions are of particular importance when using the guide:
Detailed knowledge of dangerous goods carried on board is, of course, essential
and this is covered by the following stipulation in the SOLAS Convention (chapter VII,
regulation 5, item 5).
"Each ship carrying dangerous goods shall have a special list or manifest setting
forth, in accordance with the classification set out in regulation 2, the dangerous
goods on board and the location thereof. A detailed stowage plan, which identifies
by class and sets out the location of ail dangerous goods on board, may be used
in place of such a special list or manifest. A copy of one of these documents shall
be made available before departure to the person or organization designated by
the port state authority"
In a number of schedules under "spillage - on deck", the recommended action is
to wash overboard with copious quantities of water; in certain cases the jettisoning of
packages is considered necessary. For marine pollutants and other goods which may
have a harmful effect on the marine environment this may seem odd, but regulation 7,
item 1 of Annex III of MARPOL states:
"Jettisoning of harmful substances carried in a packaged form shall be prohibited
except where necessary for the purpose of securing the safety of the ship or
saving life at sea."
Emergency equipment
The use of the Guide implies that the vessel carries emergency equipment as
required in SOLAS chapter II-2, regulation 54 (special requirements for ships carrying
dangerous goods) and also as instructed in the Emergency Schedules concerned,
under the heading "Special Emergency Equipment to be Carried".
Whenever the use of an inert absorbent material has been recommended,
diatomaceous earth has been mentioned as an example. In practice a number of very
efficient commercial absorbents exist, which could not be mentioned in the Guide.
Dangerous, Hazardous and Harmful Cargoes
It should be noted that whenever "full protective clothing" is recommended, this
includes boots, coveralls, gloves, headgear and goggles. In cases where protection of
the respiratory tract is necessary, "self-contained breathing apparatus" is
recommended, which excludes the use of goggles. In such cases additional "protective
clothing" may be recommended, comprising boots, coveralls, gloves and headgear.
A person wearing self-contained breathing apparatus and protective clothing
when working will rapidly become exhausted, and therefore regular training is of great
importance. Furthermore, a person should not work alone in an emergency situation,
particularly not in enclosed spaces, and a relieving force should always be prepared to
take over.
Stowage on board
When planning the stowage of the vessel, the possible need for emergency
actions during the voyage should be kept in mind. Stowage of water-reactive
substances under deck in vessels where only water-based firefighting media are
available may be unsuitable, even if such stowage is allowed according to the IMDG
In an emergency situation, the jettisoning of some commodities may have to be
considered. The cargo should be stowed in such a way that it is accessible for such
A number of commodities may cause structural damage to the vessel in case of
leakage and it may be unsuitable to use the bilge pumping system. For such
commodities stowage on deck may be preferable, even if stowage under deck is
The possible entrance of toxic gases or fumes into living quarters through
ventilation systems etc. should be considered and avoided when planning stowage.
Such gases or fumes may also be formed when the substance concerned comes into
contact with water.
14.3 General procedures for using the Guide
Once the name of the substance concerned has been verified, the appropriate
EmS No. can be determined by reference to the appropriate entry in the General Index
in volume 1 of the IMDG Code.
Tank instructions
(12) (13)
T3 T4
Stowage and
Properties and observations
Category E
Colourless, volatile liquid with 1088
an agreeable odour.
Flashpoint: below-18°C c.c.
Explosive limits: 1.6% to
10.4%. Miscible with water.
(The use of the correct Proper Shipping Name in the dangerous goods
transport document (see part 11) is essential if delays in taking
appropriate actions are to be avoided.)
Dangerous, Hazardous and Harmful Cargoes
The procedure to be followed will depend on the incident, either the appropriate
fire schedule or the spillage schedule. It should be noted that some fire schedules refer
also to the spillage schedule when dealing with the clear-up.
Medical First Aid Guide
14.4 Medical First Aid Guide
A general guide for medical treatment on board ships, the International Medical
Guide for Ships (IMGS), has been published by the World Health Organization (WHO)
in Geneva; the MFAG is regarded as the chemicals supplement to the IMGS.
The transport of dangerous goods is very specialized and in order to be able to
take the proper actions in the event of accidents or incidents the ship's officers and crew
must at all times know the identity of the commodities being carried and their stowage
location on the vessel.
This is covered by the following stipulation in the SOLAS Convention (chapter
VII, regulation 5, item 5):
"Each ship carrying dangerous goods shall have a special list or manifest setting
forth, in accordance with the classification set out in regulation 2, the dangerous
goods on board and the location thereof. A detailed stowage plan, which identifies
by class and sets out the location of all dangerous goods on board, may be used
in place of such a special list or manifest. A copy of one of these documents shall
be made available before departure to the person or organization designated by
the port state authority."
An important condition for the use of the MFAG is that the ship carries the proper
medical equipment and the medicines referred to in the Guide (see section 11) in
addition to corresponding requirements in the IMGS. These requirements are normally
covered by national legislation.
It is also essential that officers and crew on board vessels which normally carry
dangerous goods should be properly trained and continuously informed about the
hazards involved and the procedures to be used in the event of an accident.
Modern communication methods also allow vessels to obtain assistance from various
emergency response centres, shipowners, shippers, etc.
14.5 Structure of the MFAG
The MFAG for the 2000 edition of the Code has undergone fundamental changes
from previous editions. In the past there were tables, similar to those in the EmS Guide,
that provided first aid guidance for different substances. These were available in the
IMDG Code and it was not unusual to see the relevant table quoted on the dangerous
goods transport document.
There is now a new approach. IMO experts decided that ships' crews should deal
with medical emergencies on the basis of the incident and the symptoms shown by the
patient and that direct relationships between the substance and the medical emergency
were only necessary in a limited number of cases.
Dangerous, Hazardous and Harmful Cargoes
Thus there are no tables and no means of referencing the MFAG.
The MFAG assumes that the ship's master and crew are in compliance with the
International Convention on Standards of Training, Certification and Watchkeeping for
Seafarers (STCW) and that they have qualified first aiders in the crew. The MFAG takes
a three-step approach:
1. Emergency actions and diagnosis
2. Having determined from each table the symptoms and diagnosis, the tables
provide the basic instructions, whilst
3. The appendices provide detailed information.
There are a few substances that need specific treatment and these are
highlighted in the Diagnosis table.
Reporting incidents
14.6 General principles
The reporting of incidents involving harmful substances and/or marine pollutants
is regulated under Protocol I of the International Convention for the Prevention of
Pollution from Ships 1973, as modified by the Protocol of 1978 relating thereto
(MARPOL 73/78). This Protocol entered into force on 6 April 1987.
Recognizing that incidents at sea may give rise to the accidental discharge of
substances which cause pollution, MARPOL 73/78 identifies the need for any such
incidents to be reported to the appropriate coastal authorities as quickly and as fully as
Resolution A.851(20), which supplements the requirements of Protocol I, outlines
the general principles for ship reporting systems and contains detailed guidelines for
reporting incidents involving dangerous goods, harmful substances and/or marine
14.7 Guidelines for reporting incidents
Annexes 1 to 3 of Reporting Procedures contain detailed guidelines relating to
the manner in which reports of incidents involving dangerous goods, harmful
substances and/or marine pollutants should be made to coastal authorities and other
interested parties.
Annex 1
- Procedures
This annex identifies the need for standard reports both prior to and during a
voyage and allocates a coding system for their transmission.
Annex 2 - Standard reporting format and procedures
In addition to providing the format, this annex also indicates that where language
difficulties may exist, the Standard Marine Communication Phrases or, alternatively, the
International Code of Signals should be utilized for reports.
Dangerous, Hazardous and Harmful Cargoes
Annex 3
Guidelines for detailed reporting requirements
This annex contains three sub-sections which specify the details that should be
provided, respectively, in reports relating to incidents involving dangerous goods,
harmful substances and marine pollutants. These cover matters such as: the proper
shipping name, class and UN Number for the substance(s) involved; the name of the
manufacturer, if known (or the consignor or consignee); details of the type of packages,
tank, vehicle or freight container concerned; an estimate of the quantity involved;
whether the lost goods floated or sank; whether the loss is continuing; the cause of the
A fourth sub-section deals with circumstances where the probable discharge of a
substance(s) is anticipated as a result of damage to a vessel. This identifies the factors
which should be taken into account by the ship's master when deciding whether the
submission of a report is required.
14.8 Appendices
There are three appendices to Reporting Procedures.
Appendix 1 reproduces Protocol I to MARPOL 73/78. The five articles of this
protocol deal with: the general duty to report incidents, the type of incidents for which
reports are required, the basic content of reports, the need for supplementary update
reports and the manner in which reports should be submitted.
Appendix 2 reproduces resolution A.851(20), which supplements the
requirements of Protocol I. This resolution identifies the need for the introduction of
standardized incident reporting procedures and contains a recommendation to IMO
Member Governments to introduce reporting systems in line with the general principles
contained in the annex to the resolution.
Appendix 3 contains a list by country of the national operational contact points
responsible for the receipt, transmission and processing of incident reports.
Packing cargo and freight
IMO/ILO/UN ECE Guidelines for Packing Cargo Transport Units
14.9 Scope and general conditions
This section of the Supplement contains extensive guidance on the procedures
which should be followed by personnel responsible for packing and securing dangerous
goods cargo in freight containers or vehicles (referred to as cargo transport units CTUs) which are to be carried by sea. Guidance is also provided on the actions which
should be taken on receipt of a CTU.
Dangerous, Hazardous and Harmful Cargoes
The transport of CTUs by sea may occur in a variety of circumstances leading to
rough handling and disturbance involving pitching, rolling and other similar actions of
the vessel which can exert very significant forces on the cargo; it should always be
assumed that the weather will never be calm nor the sea smooth and that securing
methods used for land transport may be inadequate at sea.
This guide is multimodal and comprehensive, incorporating illustrations and
detailed explanations of the stresses that affect CTUs in transport journeys. It was
developed by the IMO, UN Economic Commission for Europe and International Labour
14.10 Visual inspections prior to packing
The CTU should be inspected inside and outside before it is packed with cargo.
Basic procedures for such inspections should ensure that the following actions are
carried out:
Exterior inspections: checks should be carried out to ensure that the CTU is
structurally sound and that there is no damage or distortion to walls, floor, roof, doors,
corner posts and other fittings which could adversely affect its safety during transport. It
should be capable of being securely closed and sealed.
A freight container should bear a current International Convention for Safe
Containers (CSC) Safety Approval Plate.
All irrelevant labels, marks and placards should be removed or masked.
Interior inspections: the CTU should be weatherproof unless its construction is
such that this is not possible. Previous patches or repairs should be checked for
possible leakage. Potential leakage points may be detected by checking whether any
light enters a closed CTU (ensuring when carrying out any such operation that nobody
becomes locked inside).
There should be no major damage to the floor and no protrusions such as nails,
bolts etc. which could cause injuries to people or damage to the cargo. Tie-down points
and rings should be in good condition and well anchored. A vehicle should be fitted with
points for securing it aboard ship.
The CTU should be clean, dry and free of residue and persistent odours from
previous cargoes.
14.11 Stowage planning and packing/securing of cargo
The following checks, issues and procedures are of particular importance when
CTUs are to be packed in preparation for transport by sea:
Packing location: the CTU to be packed should rest on level and firm ground
and, in the case of a vehicle/trailer, the brakes should be securely applied and the
wheels chocked.
Pre-planning: the packing operation and load configuration should be planned in
advance, taking account of the nature and strength of packages and any compatibility
It is essential to ensure that the load is tightly packed or well braced. When
planning the packing of a CTU, account should be taken of potential problems which
may be created when it is unpacked. Whenever possible, goods should be tightly
Dangerous, Hazardous and Harmful Cargoes
packed from wall to wall, special care being taken when open-sided vehicles are
concerned. Alternatively, consideration should be given to the use of dunnaging, folded
cardboard, air bags or other suitable means to fill spaces and reinforce load stability.
Examination of packages: packages should be examined before being packed
into the CTU; any damaged, leaking or sifting packages should not be packed.
Packages showing evidence of staining etc. should not be packed without first
determining that it is safe to do so. Water, snow, ice or other matter adhering to
packages should be removed before packing. Liquids that have accumulated on drum
heads should initially be treated with caution in case they are the result of leakage of the
Part loads and palletized consignments: dangerous-goods consignments
which form only part of the load of a CTU should, whenever possible, be packed
adjacent to the doors with markings and labels visible. If dangerous goods are palletized
or otherwise unitized they should be compacted and secured in a manner unlikely to
damage the individual packages. The materials used to bond a unit load should be
compatible with the unitized substances and retain their efficiency when exposed to
moisture, extremes of temperature and sunlight.
Fire prevention: suitable measures should be taken to prevent fires, including
the prohibition of smoking in the vicinity of dangerous goods.
Condensation: temperature and humidity changes can give rise to
condensation, which may cause damage such as rust, discoloration, dislodging of
labels, collapse of fibreboard packages or mould formation.
In order to minimize the risk of condensation, every effort must be made to
ensure that the moisture content of packaging and securing materials within a CTU is
kept as low as possible.
Weight factors and load distribution: the planned load should not exceed the
maximum payload of the CTU. In the case of a freight container, this will ensure that the
permitted maximum gross weight (which includes the payload) marked on the
International Convention for Safe Containers (CSC) Safety Approval Plate will never be
The load should be evenly distributed over the entire floor area of the CTU. In
cases where a CTU is only part loaded, it may be necessary to utilize timber baulks or
other methods to achieve an even weight distribution. The centre of the weight of the
packed cargo should be at or near the mid-length of the CTU and in no case should
more than 60% of the load be concentrated in less than half the length of the unit
measured from one end.
Heavy goods should not be placed on top of lighter goods and liquids should not
be placed on top of solids. The centre of gravity should be below the half-height of the
cargo space of the unit.
Prevention of overloading: potential overloading problems should be properly
addressed prior to commencing CTU packing operations. Packing should be carried out
under the supervision of trained competent personnel who have adequate information
Dangerous, Hazardous and Harmful Cargoes
about the cargo to be packed and sufficient authority to control the operation and
prevent overloading.
To prevent overloading, measures must be taken to ensure that:
the cargo is properly packed, blocked, braced and secured;
the load is arranged and distributed so that the centre of gravity is reasonably
central to the length, breadth and height of the CTU;
the maximum gross weight of the CTU is not exceeded.
Where possible, a weight declaration or weighbridge certificate should be
included in or with the container documentation. Where practicable, load detection
devices should be fitted to CTU handling equipment (e.g. fork-lift trucks).
Checks on completion of packing: during the final stages of packing, care
should be taken to ensure that the cargo is secure enough to prevent "fall-out" when the
doors are opened. Where necessary, additional strapping or timber braces should be
Checks should be made to ensure that any timber within the CTU (e.g. that used
for securing the load or in the packages comprising the load) complies with any wood
treatment quarantine regulations in the country of destination. Ideally, a wood treatment
certificate should be secured in a conspicuous place on the CTU.
After closing the doors, all closures should be fully engaged and secure and any
sealing procedures properly carried out.
When dry ice or any other expendable refrigerant is used for cooling purposes, a
warning label should be posted on the outside of the doors - see also Marking and
Placarding of CTUs below.
Marking and placarding of CTUs: the CTU must display appropriate marks,
placards and, in certain circumstances, other signs indicating the dangers of the load.
Full details are provided in part 11.
Container/Vehicle packing certificate: the person responsible for the CTU
packing operation must complete a certificate or declaration confirming that the
procedure has been properly carried out. Full details are provided in part 11.
Actions on receipt of CTUs
Persons opening a freight container or vehicle should be aware of the risk of
cargo falling out. Doors, when opened, should be secured in the fully opened position.
Where expendable refrigerants or fumigants have been used in a CTU, there is a
potential risk of a dangerous atmosphere (e.g. asphyxiant or toxic), and the CTU should
be ventilated by leaving the doors open for a sufficient time before allowing personnel to
enter. Where flammable goods are concerned, there should be no sources of ignition in
the vicinity.
If there is a particular reason to suspect danger, for example because of damage
to packages or the presence of fumigants, expert advice should be sought before the
unpacking operation commences.
After a CTU has been unpacked, particular care should be taken to ensure that
no hazard remains. Special cleaning may be required, particularly if a toxic spillage has
occurred or is suspected. When the CTU offers no further hazard, the dangerous goods
Dangerous, Hazardous and Harmful Cargoes
placards, orange plates, marks and signs should be removed, masked or otherwise
Recommendations on the Safe Use of Pesticides in Ships
The Recommendations on the Safe Use of Pesticides in Ships were first issued
by the IMO Maritime Safety Committee in 1971. Subsequent revisions have been
issued in 1984, 1993, 1995 and 1996.
The Recommendations provide guidance on the measures which should be
taken on board ships and in cargo units loaded on ships to control and eradicate pests
(insects and rodents) and thus prevent damage to equipment or cargo, food
contamination, or the spread of disease and infection.
The guidance contained in the Recommendations covers the following issues:
Prevention of infestation: the importance of adequate maintenance and
sanitation in the prevention of infestation is highlighted, as are the main sites where
infestation may be anticipated.
Chemical control of insect infestation: this section identifies the need for some
form of chemical toxicant to control pests and the factors which should be taken into
account with respect to both the choice of appropriate chemical agents and the manner
of their application; appropriate disinfestation methods for different areas of the ship
and/or cargo spaces and the cargo itself; the conditions under which fumigants should
be used and the manner of their use both prior to loading and during a voyage.
Control of rodent pests: this section covers the use of fumigants, poisoned
baits (acute or chronic) or trapping as means of controlling rodents, and identifies the
safety precautions which should be taken when such methods are being employed.
Regulations for the use of pesticides: this section highlights the need to
ensure that pesticides are used in accordance with both the manufacturer's instructions
and any national regulations applicable in the countries of loading, destination and
registration of the ship. A number of commonly used pesticides are also identified (see
Annexes below).
Safety precautions - general: the potential dangers of pesticides for humans
are highlighted in this section, as are the general safety precautions which should be
taken with respect to their storage and use and the actions which should be taken in the
event of exposure.
Annexes: there are five annexes to the Recommendations: annex 1 lists a
number of common pesticides suitable for shipboard use; annex 2 explains the
application of the Threshold Limit Value (TLV) for vapours in air - a formula used to
determine recommended maximum exposure levels for workers in contaminated
environments; annex 3 illustrates the standard fumigation warning sign to be used on
the outside of cargo units; annex 4 reproduces the class 9 schedule for cargo units
under fumigation; and annex 5 comprises a model checklist for in-transit fumigation with
Dangerous, Hazardous and Harmful Cargoes
Irradiated nuclear fuel
14.14 Carriage of nuclear materials (INF Code)
The INF Code is fully titled "International Code for the Safe Carriage of Packaged
Irradiated Nuclear Fuel, Plutonium and High-Level Radioactive Wastes on Board
Nuclear fuel is essentially the range of both fissile and non-fissile radioactive
material used to generate electricity in power stations. Irradiated nuclear fuel is such
material after it has been employed in the process of power generation. It is highly
radioactive. Such used fuels are valuable items that can be reprocessed to provide
further fresh fuel stocks for the nuclear power generation industry.
Plutonium is part of the non-waste element resulting from the reprocessing
operation. During the course of reprocessing, waste materials are separated from the
fuel source. Some of these waste materials are highly radioactive and are known as
high-level radioactive wastes. These materials are capable of generating extremely high
levels of heat.
All ships carrying such materials are subject to the constraints of the INF Code in
addition to the demands of the IMDG Code. The INF Code encompasses such matters
as vessel construction and stability, on-board safety equipment, fire protection
standards, temperature control systems, electrical systems, securing systems,
radiological protection, emergency procedures, accident notification and crew training.
The degree of competency and performance in each of these areas is varied in relation
to the aggregate radioactivity of the load being carried. The activity levels are split into
three groups in ascending order of aggregate activity: class INF 1, class INF 2, class
INF 3.
Class INF 3 covers ships which have no restriction upon the aggregate level of
activity permitted. These would be vessels constructed to the highest control levels and
could be effectively dedicated to the task of transporting nuclear material. Passengers
are not permitted on such ships.
The appropriate level of control for each of the three INF levels is indicated in
table 1 of the INF Code.
14.15 Appendix to the Supplement
The Appendix to the Supplement comprises four separate but associated
resolutions adopted by the IMO Assembly, two circulars issued by the Maritime Safety
Committee and one circular issued by the Facilitation Committee. The four resolutions
are concerned with cargo stowage and securing measures on board ships.
Resolution A.489(XII), which was adopted in November 1991, provides
guidelines on the safe stowage of cargo units and other entities in ships other than
cellular containerships. The guidelines cover wheeled cargo, containers, flats, pallets,
portable tanks, packaged units, vehicles etc., and any parts of loading equipment which
Dangerous, Hazardous and Harmful Cargoes
belong to but are not fixed to the ship. The resolution recommends that IMO Member
Governments should issue the guidelines to all relevant ships entitled to fly their
respective State flags and ascertain that any such vessel is provided with a Cargo
Securing Manual which outlines safe procedures appropriate to the characteristics and
dimensions of the ship, its intended service, anticipated weather and sea conditions in
its trading area and the cargo composition (see also MSC/Circ.385 below).
Resolution A.533(13), which was adopted in November 1983, invites IMO
Member Governments to issue recommendations on the elements which should be
taken into account when considering the safe stowage and securing of cargo units and
vehicles in ships. These recommendations are intended for the information and
guidance of all parties involved in the transport chain: shipbuilders, shipowners,
shipmasters, port authorities, shippers, forwarding agents, road hauliers, stevedores,
cargo unit and vehicle manufacturers, insurers, railway operators, and packers of
containers at inland depots. With respect to shipowners and shipbuilders, the
recommendations cover matters such as the number, location and strength of securing
points, the provision of securing equipment and the preparation of the Cargo Securing
Manual (see Resolution A.489(XII) above).
The recommendations for shipmasters highlight the importance of ensuring that
decks and cargo units are in a satisfactory condition, that the securing gear on board
the vessel is adequate and properly maintained, that both cargo units and the cargoes
within are adequately stowed and secured, and that cargo spaces and securing
arrangements are regularly inspected throughout the voyage.
Shippers, forwarding agents, road hauliers, stevedores and, where appropriate,
port authorities are advised to ensure that the significant forces likely to be encountered
during the voyage are properly taken into account when determining the suitability of
cargo units, the adequacy of their securing points and the methods used to secure
cargo within cargo units or vehicles. The need to ensure that a cargo unit or vehicle is
clearly marked and that there is proper documentation indicating its gross weight and
any necessary safety precautions, is also highlighted.
Resolution A.581(14), adopted on 20 November 1985, contains guidelines for
the securing of road vehicles on ro-ro ships. The guidelines are intended to apply to roro vessels which regularly carry road vehicles on either long or short international
voyages in unsheltered waters. The guidelines are aimed at shipowners and shipyards
involved in designing and constructing ro-ro ships and at manufacturers, owners and
operators of road vehicles which may be transported on such vessels. The term road
vehicle encompasses all vehicles primarily intended for the carriage of goods, from 3.5
to 45 tonnes maximum permissible weight, and any type of trailer (semi-trailer or drawbar design).
The guidelines cover matters such as:
the provision of a Cargo Securing Manual (see also Resolution A.489(XII)
the number, location and strength of securing points on both ship's decks and
road vehicles;
the design and strength of lashings used for securing vehicles and the
manner in which they should be attached;
Dangerous, Hazardous and Harmful Cargoes
the procedures which should be followed to ensure that road vehicles are
safely and securely stowed, taking account of the particular characteristics of
both the vehicle and the ship, the length of the voyage and the predominant
weather conditions.
Resolution A.854(20) of 27 November 1997 is concerned with the INF Code
(see 14.4 above) and provides guidelines for developing shipboard emergency plans for
ships carrying materials subject to the INF Code. The objective is to assist shipowners
preparing plans for carrying INF materials and to assist responders to emergencies by
providing information.
In addition to the above resolutions, the Appendix to the Supplement contains
two circulars issued by the IMO Maritime Safety Committee.
MSC/Circ.385 of 8 January 1985 is concerned with the Cargo Securing Manual
recommended under Resolution A.489(XH) (see above). The circular aims to ensure a
uniform approach to the preparation, layout and content of such manuals. The manual
should provide: details of fixed securing arrangements and their locations; an inventory
of portable securing equipment and details of its location and stowage; examples of
correct application procedures for portable securing gear on different types of cargo
units, vehicles etc.; and an indication of the various transverse, longitudinal and vertical
forces to which cargo is likely to be subjected in different parts of the ship.
MSC/Circ.506/Rev.1 of 10 January 1990 is concerned with the provision of
container packing certificates/vehicle packing declarations. It highlights the dangers that
can arise when such a certificate/declaration is not issued and, as a consequence, the
cargo unit is not placarded to indicate the danger(s) of its contents. The circular
emphasizes the threat to safety that unmarked cargo units can pose on board ships,
during inland transport movements and at container terminals and ports. IMO Member
Governments are urged to ensure that their national legislation requires container
packing certificates/vehicle packing declarations to be provided by the packer of the
cargo unit.
FAL 2/Circ.51 of 15 March 1999 supplements the information in part 5 of the
Code (part 11 of this Compendium). Ships' masters need summaries of the information
contained in the dangerous goods transport document and SOLAS and MARPOL
require the ship to have a manifest of dangerous goods. This resolution provides a
suggested format.
Dangerous, Hazardous and Harmful Cargoes
15. Recommendations on the safe transport of
dangerous cargoes and related activities in port
15.1 Introduction
The port area is the interface between modes of transport; it is where cargoes
are placed on board ship or removed. These movements may involve straightforward
transfers on/off a ship of a truck or rail wagon and its cargo, or at the other extreme the
removal of cargo from a ship's hold and its loading onto a truck.
Irrespective of the nature of the operation, the port has to store a range of
cargoes on a temporary basis. In the case of dangerous goods this may involve a
number of different classes. The storage period may be as short as a few minutes or up
to several days pending the arrival of the vessel or even longer if there are warehouses
in the port area.
This short storage of dangerous goods can present a range of problems - ports
are not only an interface for dangerous goods but also for general freight and very often
passengers. This means that dangerous goods entering port areas must be subject to
some control to protect everyone in the port.
To assist ports with this interface the IMO have published "Recommendations on
the Safe Transport of Dangerous Cargoes and Related Activities in Port Areas". These
Recommendations provide advice to countries on how to address the problems which
arise when dangerous cargoes are transiting port areas. The Recommendations have
been aligned as far as possible with the requirements of the IMDG Code.
The recommendations include a number of definitions including "cargo interests",
a term which does not appear in the IMDG Code itself. Cargo interests are those people
or companies who are involved in classification, packaging, marking, labelling and
documentation. They might include a shipper, carrier, forwarder or consolidator.
15.2 Warehouses, terminal areas and infrastructure
Port areas have to be defined: they usually extend beyond the docks and jetties
where ships tie up. They often cover large areas of land, some parts of which may be
utilized for activities not directly associated with the port (e.g. factories and chemical
plants). Some parts of factories or plants may be within the port area whilst others may
Having defined the port area subject to control, the authority must decide the
effect of allowing access for dangerous goods. To decide this, they will take into account
matters such as the main activities of the port, its accessibility in the event of an
emergency and the surrounding population. For example, some ports which can only be
accessed through populated areas or which are located within a heavily populated area
may restrict or prohibit explosives and other substances which have an explosive
potential; alternatively, they may limit the quantity permitted within the port at any one
Where possible there should be designated areas for the parking/stowage of
transport units containing dangerous goods.
Dangerous, Hazardous and Harmful Cargoes
15.3 Responsibility and training
The port authority will make bye-laws to deal with all aspects of the port
operation, including specific rules concerning dangerous goods. The bye-laws or
regulations will define specific responsibilities for the port, berth operators, cargo
interests and ship operators. Responsibilities will cover the control of ships in the
harbour area and the control of incoming and outgoing ships, vehicles and rail wagons
carrying dangerous goods.
For example, port authorities must be given prior notification of the impending
arrival of dangerous goods, whether by road or rail from an inland location or by sea.
Notifications must be provided in writing (e.g. by fax or e-mail). The port regulations will
define the period of notice. In some ports it might be at least 24 hours, but it could be as
short as a few minutes. Prior knowledge of the arrival of dangerous goods is essential: it
enables the port authorities to determine how the goods should be handled (e.g.
whether the vehicle concerned can safely be parked near other vehicles or whether it
should be taken straight onto the vessel). A port operation is complex and for reasons of
general safety and smooth operation the authorities need to know what is arriving and
In line with the above notification requirements, berth operators must ensure that
they have procedures in place to handle and move the goods safely when they arrive.
This will involve the carrying out of risk assessments and the establishment of
emergency plans to deal with incidents. The Recommendations require that personnel
working in the port area should have relevant training in their responsibilities. Such
training should include: dangerous goods general awareness/familiarization training,
safety training and function-specific training.
15.4 General recommendations
The port authority, along with the regulators, must ensure they have in place a
regulatory regime that will deal with all eventualities. In this respect the guide offers
outline solutions on controlling dangerous goods in port areas.
Port authorities, along with regulatory authorities, should set down in their
details of the dangerous goods which they will accept and the quantities - with
the exception of classes 1, 6.2 and 7 there are no detailed recommendations;
an overriding authority to prohibit or remove dangerous goods. In this respect
a system of adequate communications is required along with defined areas
for the loading and offloading of dangerous cargo;
the period of notification which they require before the arrival of dangerous
goods at the port;
powers to direct where a ship should berth for dangerous goods;
outline emergency procedures including the maintenance of safety
equipment. There should be procedures to be followed in relation to fire
prevention and hot work. There should be a system for reporting incidents.
The port controls are not only applicable to the person on the berth. They are
also to be applied to the master of the ship, the crew and other cargo interests.
Dangerous, Hazardous and Harmful Cargoes
The master is required to have a suitable watch scheme whilst dangerous goods
are on board and there must be suitable emergency procedures in place including
firefighting. Cargo interests must ensure they provide the correct documentation and
they must ensure that the dangerous cargoes are properly classified, identified,
packaged and labelled where necessary.
Specific recommendations for certain dangerous cargoes
15.5 Packaged dangerous goods
Ships built after 1 September 1984 must have a document of compliance and
this will define the types of dangerous goods that can be carried on deck and in each
compartment. The master should appoint responsible persons to oversee the loading
and unloading of the ship and the master should be in possession of documentation
relating to the dangerous goods.
15.6 National port regulations
Most ports have been in existence for hundreds of years. They may not always
have been formal docks but natural harbours. The recommendations described above
represent a set of principles which can be adopted by a government or a port authority
which is writing or rewriting their ort regulations. Many ports have had regulations for a
long time and they may have different rules until IMO Recommendations are adopted.
Dangerous, Hazardous and Harmful Cargoes
16. Updating the IMDG Code
16.1 Introduction
The 2000 edition of the IMDG Code was the first to be produced in two volumes.
This was the first major revision since its first publication in 1965. Most of the editions
had been in loose-leaf format and at least three and usually four or five volumes. In
1995/96 the UN Committee of Experts decided, recognizing that transport was
multimodal, that their recommendations should be made into a "model regulation" for
modal agencies and national governments to adopt into international or national law.
IMO was asked to align its rules with the UN structure.
This monumental task took five years, but it now means that many users,
particularly the chemical producers, can easily compare the requirements of land, sea
and air transport. The European land regulations have been aligned and the air rules
are largely aligned.
The Code is normally amended at two-year intervals and an edition is expected
to be published in 2004 for implementation in 2005. This will be a replacement book.
16.2 Reasons for updating the IMDG Code
The Code needs to be updated to take account of:
Industry's changes in technology
The provisions of the Code need to reflect technological advances (e.g. new
types of ships and handling methods); the "invention" by the chemical industry of new
chemicals and mixtures which require classification to determine whether they can be
carried safely; the development of new packaging methods.
Regulators' needs
Governments are required to enforce the Code. From time to time they may find
that certain parts of the Code cannot be enforced. Occasionally there are accidents and
incidents which lead to a need to change the provisions of the Code.
Developments in other modal regulations
Chemicals rarely move from a chemical plant to a ship without moving on other
modes of transport (e.g. road, rail or air). The distribution of goods is a complex process
and it is essential that the various modal rules should, as far as is practicable, be
harmonized. Amendments to the Code therefore need to reflect changes to the
ADR/RID and ICAO rules.
UN Committee of Experts on the Transport of Dangerous Goods
At the beginning of the Compendium it was explained that the UN would now
normally consider issues concerning classification, packaging, marking and labelling
before the modes. The UN have decided at present to make amendments at two-year
intervals; to ensure that IMO remains aligned, IMO has to keep to these intervals.
Dangerous, Hazardous and Harmful Cargoes
16.3 IMDG Code amendments
IMO usually publishes amendments to the Code about three months before they
are due to take effect. The amendment process takes two years through the IMO
Committee structure. Industry can normally obtain information from national
governments or trade associations on the main changes under consideration long
before the text is published. There are a number of magazines which deal with shipping,
cargo handling and dangerous goods, all of which report the changes that are likely to
take place. Regular users of the Code should use as many of these sources as possible
to ensure that they remain up to date. Like many technical and complex documents it is
often the case that errors and omissions are identified within the text and IMO issues
errata sheets. Users of the Code should watch through the trade press and trade
associations for notices of correction.
16.4 The importance of keeping up to date
Using out-of-date versions of the IMDG Code can in extreme cases be a
dangerous practice. It is more likely, however, that goods will not be moved. If there is a
discrepancy between what the shipper has said about his consignment and what the
current version of the Code says, the agent and shipping line will not move the goods.
Normally the change is on 1 January of each year but there is often agreement
that there should be a six-month transitional period during which either the old version
or the new can be used. National governments occasionally set implementation dates in
advance of those set by IMO but generally they are later, particularly where there is a
need to translate the book into a national language.
Like all legislation, it can be difficult to keep up to date with all the changes.
Trade associations, specialist magazines and attendance at training courses can help
make personnel aware of current developments.
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