Chemical Safety Manual for Small Businesses

Chemical Safety Manual for Small Businesses
Chemical Safety
Manual for
Small Businesses
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American Chemical Society
American Conference of Governmental Industrial Hygienists
American Industrial Hygiene Association
Chemical Safety
Manual for
Small Businesses
Third Edition
Compressed Gas Association
National Institute for Occupational Safety and Health
Occupational Safety & Health Administration
U.S. Department of Energy
U.S. Environmental Protection Agency
U.S. Small Business Administration
The Small Business Act (SBA) was established to aid, counsel, assist, and protect the interests of
small business concerns; to preserve free competitive enterprise; to insure that a fair portion of total
purchases by the government is placed with small business enterprises; and to maintain and strengthen
the overall economy of the nation. SBA also defines a small business concern as “one that is
independently owned and operated and which is not dominant in its field of operation.” Finally, the
act also states that in determining what is a small business, the definition shall vary from industry to
industry to the extent necessary to properly reflect industry differences.
A Publication of the American Chemical Society
Committee on Chemical Safety
Division of Small Chemical Businesses
Copyright ©2007
American Chemical Society
Washington, DC
All rights reserved
During the fourteen years since the publication of the second edition, several
new topics have developed that are relevant to small businesses. The Occupational
Safety & Health Administration’s Laboratory Standard and its resulting Chemical
Hygiene Plan are a regular part of every laboratory in the United States. The science
of ergonomics continues to evolve, as do strategies for improving workstations
and equipment. Safety professionals need to be skilled in conducting exposure
assessments. Laboratories and manufacturing areas must be designed to
accommodate qualified persons who may have a disability. The Internet provides
access to a wealth of safety information, although sources must be evaluated for
reliability. Plant and laboratory security must be assured. The Division of Chemical
Health and Safety of the American Chemical Society (ACS) now publishes the
Journal of Chemical Health & Safety to keep chemists and safety professionals aware
of the best practices and latest developments in chemical safety. All division
members receive this journal as a benefit of membership.
The Chemical Safety Manual for Small Businesses serves as only a brief outline
of the most basic guidelines in chemical safety. Appendix I contains many
recommended sources of additional information that is supplementary to the
contents of this booklet. Small businesses have a continuing challenge to keep up
with new regulations while protecting employees and maintaining efficient
I am pleased to introduce the third edition of this important communication
of the ACS Committee on Chemical Safety (CCS). The committee wishes to thank
the many individuals who generously contributed their time and wisdom to this
and the previous editions. Their efforts have helped to make small businesses that
make or use chemicals safer places with fewer accidents and injuries. Jay Young has
contributed to most of the CCS publications, including both earlier editions of
this booklet; his influence continues to touch our readers. Eileen Segal updated the
appendices and several sections of the text. Erik Talley suggested several new topics
and drafted the resulting sections. Other reviewers included Barbara Foster, Russ
Phifer, Harry Elston, Wayne Wolsey, Doug Walters, Kevin Edgar, Dan McDonald,
Pat Redden, Art Marcinkowsky, Cherlyn Bradley, Paul Schickedantz, and Al Hazari.
Bob Gates and Jim Landis contributed the perspective of the ACS Committee on
Chemists with Disabilities. Both Larry Funke and Bob Rich coordinated the efforts
of those ACS staff members involved in the production and distribution activities.
All comments are welcome. Please direct them to the Committee on Chemical
Safety, American Chemical Society, 1155 Sixteenth Street, NW, Washington, DC
Kenneth P. Fivizzani
Past Chair (2002-2004), ACS
Committee on Chemical Safety
January 2006
ISBN 0-8412-6984-X
Printed in the United States of America
Preface to the First Edition
Safety in the use of chemicals has become the theme of a great deal of public
concern and legislative activity. Recent federal, state, and local legislation has
included many small businesses in hazardous materials management regulations.
The American Chemical Society Committee on Chemical Safety has developed
this manual for all of those who work with chemicals and particularly for small
businesses that may not have specialized expertise in chemical safety. This manual
will be of broad benefit to chemists and non-chemists alike.
Information presented in the manual is of two types: i) suggestions for
working safely following generally accepted practices, and ii) specific regulations
resulting from legislative actions. The first pages of text are directed to management;
they relate mainly to philosophy, facilities, practices, and policies. The remainder
of the manual is directed to employees and may be interpreted or modified to fit
particular requirements.
This is not a text or a “cookbook”, but a point of departure for responsible
actions when chemicals are handled. Safety is affirmative action, based on
awareness of personal responsibilities, on knowledge of the hazards and other
properties of materials, and on a constructive attitude in the application of that
awareness and knowledge.
Completion of this manual resulted from the dedicated efforts of members
and friends of the Committee on Chemical Safety who read and critiqued the early
manuscripts. Lyle Phifer initiated the project and served as the subcommittee
chairman. He was enthusiastically supported in the writing effort by Leonard Gray,
Kenneth Greenlee, Ellen Mimnaugh, and Jay Young. Maureen Matkovich, the
committee liaison, provided invaluable technical assistance. Earl Peters, Stanley
Pine, and Maureen Matkovich proofread the final manuscript. The American
Chemical Society Divisions of Chemical Health and Safety and of Small Chemical
Businesses endorsed the manual, and the Corporation Associates provided a grant
in partial support of the project.
All comments are welcome. Please direct them to the Committee on Chemical
Safety, American Chemical Society, 1155 Sixteenth Street, NW, Washington, DC
The materials contained in this manual have been compiled by recognized
authorities from sources believed to be reliable and to represent the best opinions
on the subject. This manual is intended to serve only as a starting point for good
practices and does not purport to specify minimal legal standards or to represent
the policy of the American Chemical Society. No warranty, guarantee, or
representation is made by the American Chemical Society as to the accuracy or
sufficiency of the information contained herein, and the society assumes no
responsibility in connection therewith. This manual is intended to provide basic
guidelines for safe practices. Therefore, it cannot be assumed that all necessary
warning and precautionary measures are contained in this document and that
other or additional information or measures may not be required. Users of this
manual should consult pertinent local, state, and federal laws and legal counsel
prior to initiating any safety program.
Stanley H. Pine
Chairman, ACS Committee on
Chemical Safety
[October 1988]
List of Abbreviations and Acronyms
ac - alternating current
ACGIH - American Conference of Governmental Industrial Hygienists
ACS - American Chemical Society
ADA - Americans with Disabilities Act
AEDs - automatic external defibrillators
ALARA - as low as reasonably achievable
ANSI - American National Standards Institute
ASHRAE - American Society of Heating, Refrigerating, and Air-Conditioning Engineers
BHT - 2,6-ditertiary-4-methylphenol
CAS - Chemical Abstracts Service
CCS - ACS Committee on Chemical Safety
CD-ROM - compact disc read-only memory
CEO - chief executive officer
CERCLA - Comprehensive Environmental Response, Compensation, and Liability Act
CFR - Code of Federal Regulations
CPR - cardiopulmonary resuscitation
CWD - ACS Committee on Chemists with Disabilities
DART/ETIC - Developmental and Reproductive Toxicology/Environmental Teratology
Information Center
dc - direct current
DHHS - Department of Health and Human Services
DOT - Department of Transportation
EEOC - Equal Employment Opportunity Commission
EPA - Environmental Protection Agency
IUPAC - International Union of Pure and Applied Chemistry
MSDS - material safety data sheet
NaK - sodium-potassium alloys
NEC - National Electrical Code
NFPA - National Fire Protection Association
NIOSH - National Institute for Occupational Safety and Health
OSHA - Occupational Safety & Health Administration
PEL - Permissible Exposure Limit
RCRA - Resource Conservation and Recovery Act
SARA - Superfund Amendments and Reauthorization Act
SBA - Small Business Act
TBC - 4-tertiary-butylcatechol
TCLP - Toxicity Characteristic Leaching Procedure
THF - tetrahydrofuran
TLC - thin-layer chromatography
TLV - Threshold Limit Value
TOXNET - National Library of Medicine Toxicology Data Network
TSDF - treatment, storage, or disposal facility
UV - ultraviolet
WEEL - workplace environmental exposure level
Preface ........................................................................................................................iii
Preface to the First Edition ............................................................................................iv
Disclaimer ......................................................................................................................v
List of Abbreviations and Acronyms
PART I: Guide for Managers and Administrators..................................................1
1. Introduction ..........................................................................................................3
2. Responsibility for Safety ......................................................................................3
3. Safety Rules for the Chemical Workplace ..........................................................4
4. Safety Facilities and Design..................................................................................5
4.1 General ......................................................................................................5
4.2 Protective Clothing....................................................................................6
4.3 Laboratory Chemical Hoods (Formerly Called Fume Hoods) ............6
4.4 Sinks ..........................................................................................................8
Safety Showers ..........................................................................................8
4.6 Eyewashes ..................................................................................................8
4.7 Respirators and Self-Contained Breathing Apparatuses ........................8
4.8 Storage ........................................................................................................9
4.9 Labeling ....................................................................................................10
4.10 Electrical Hazards ....................................................................................10
4.11 Hearing Protection and Noise Control ................................................10
4.12 Eye Protection ..........................................................................................11
4.13 Ergonomics..............................................................................................12
5. Waste Disposal....................................................................................................12
5.1 Introduction ............................................................................................12
5.2 Proper Planning ......................................................................................12
5.3 Waste Definitions ....................................................................................15
5.3.1 Waste Classification ................................................................................16
5.3.2 Mixed Waste ............................................................................................17
5.3.3 Universal Waste ......................................................................................17
5.3.4 Biohazard Waste, or Regulated Medical Waste ....................................17
5.3.5 Electronics................................................................................................17
5.4 Getting Help ............................................................................................17
5.4.1 Regulators ................................................................................................17
5.4.2 Consultants..............................................................................................18
5.4.3 Waste Brokers ..........................................................................................18
5.4.4 Transporters ............................................................................................18
5.4.5 Environmental Training ........................................................................18
5.4.6 Disposal Facilities ..................................................................................18
5.4.7 Trade Associations ..................................................................................18
5.4.8 Large Local Businesses............................................................................19
5.4.9 Books and Other References ..................................................................19
5.5 Summary..................................................................................................19
6. Preparation for Medical Emergencies ..............................................................19
6.1 Chemical Toxicity....................................................................................20
6.2 Material Safety Data Sheets....................................................................22
6.3 Technical Guidance ................................................................................22
6.4 Accident Reporting..................................................................................24
6.5 Safety Inspections and Audits................................................................24
6.6 Employee Training..................................................................................25
6.7 OSHA and EPA Requirements ..............................................................25
7. Americans with Disabilities Act ........................................................................26
8. Visitors ................................................................................................................27
9. Security ................................................................................................................27
PART II: Employee Guide to Safety ...................................................................... 29
1. Safe Work Practices ............................................................................................31
1.1 Introduction ............................................................................................31
1.2 Eye Protection ..........................................................................................31
1.3 Clothing ..................................................................................................32
1.4 Food and Beverages ................................................................................32
1.5 Smoking ..................................................................................................32
1.6 Personal Hygiene ....................................................................................32
1.7 Unattended Operation of Equipment ..................................................33
1.8 Working Alone ........................................................................................33
1.9 Workers’ Responsibility ..........................................................................33
2. Safety Training ....................................................................................................33
2.1 Chemical Hazards Orientation ............................................................33
2.2 Reading and Understanding a Material Safety Data Sheet ................33
2.3 Evacuation and Fire Drills......................................................................37
2.4 Use of Fire Extinguishers ........................................................................37
2.5 Safety Showers and Eyewashes ..............................................................37
3. Emergency Action ..............................................................................................37
3.1 Dealing with an Emergency ..................................................................37
3.2 Protecting Life..........................................................................................38
4. Handling Chemicals ..........................................................................................39
4.1 General Precautions................................................................................39
4.2 Safe Laboratory Techniques ..................................................................39
4.3 Adequate Ventilation ..............................................................................40
4.4 Separations ..............................................................................................40
4.4.1 Extractions....................................................................................41
4.4.2 Distillations..................................................................................41
Hazard Evaluation, Risk Assessment, and Hazardous Chemicals ....42
5. Assembling Apparatuses ....................................................................................42
5.1 Working with Chemicals and Apparatuses ..........................................42
5.2 Preparation of Glass Tubing and Stoppers ..........................................44
5.3 Insertion of Glass Tubes or Rods into Stoppers or Flexible Tubing ..44
5.4 Glassware ................................................................................................45
5.5 Working with Reduced Pressure ............................................................45
5.6 Centrifuges ..............................................................................................46
5.7 Oil and Sand Baths ................................................................................46
5.8 Cooling Baths, Cold Traps, and Temperature Control........................46
5.8.1 Cooling Baths ..........................................................................................46
5.8.2 Cold Traps................................................................................................47
5.8.3 Temperature Control ..............................................................................47
5.9 Compressed Gases ..................................................................................48
Chemical Spills ..................................................................................................49
6.1 General Procedures ................................................................................49
6.2 Spills of Specific Types of Chemicals ....................................................50
6.3 Chemicals on the Skin............................................................................50
6.4 Chemicals in the Eyes ............................................................................51
6.5 Releases of Acutely Toxic Vapors and Gases..........................................51
Some Other Hazardous Chemicals ..................................................................51
7.1 Inorganic Peroxides ................................................................................51
7.2 Organic Peroxides and Hydroperoxides ..............................................52
7.2.1 General Considerations ..............................................................52
7.2.2 Disposal of Organic Peroxides ..................................................53
7.3 Peroxide-Forming Compounds ............................................................53
7.3.1 General Considerations ..............................................................53
7.3.2 Detection and Determination of Peroxides..............................54
7.3.3 Some Uncommon Peroxy Compounds ..................................54
7.4 Perchloric Acid ........................................................................................55
7.5 Solvents ....................................................................................................55
7.5.1 Flammable Liquids ....................................................................55
7.5.2 Toxicity of Solvents......................................................................56
7.6 Cryogenic Hazards ..................................................................................56
Housekeeping and Disposal of Laboratory Wastes ........................................57
8.1 Housekeeping..........................................................................................57
8.2 Cleaning Glassware ................................................................................58
8.3 Laboratory Storage of Chemicals ..........................................................58
8.4 Disposal of Chemicals............................................................................58
Safety Equipment and Clothing ......................................................................59
9.1 Safety Showers and Eyewash Fountains................................................59
9.2 Fire Extinguishers ....................................................................................60
9.3 Laboratory Chemical Hoods (Formerly Called Fume Hoods) ..........61
9.4 Refrigerators ............................................................................................61
9.5 Gloves ......................................................................................................62
Fires and Explosions ..........................................................................................62
10.1 Fires ..........................................................................................................62
10.2 Runaway Reactions ................................................................................63
10.3 Explosions................................................................................................63
Electrical Hazards................................................................................................64
11.1 Precautions for Using Electrical Equipment ........................................64
11.2 Static Electricity and Spark Hazards ......................................................65
12. Radiation Hazards ..............................................................................................65
12.1 Radioactive Materials ..............................................................................65
12.2 X-ray Generators and Particle Accelerators ..........................................65
12.3 Lasers ........................................................................................................66
12.4 Ultraviolet Lamps....................................................................................66
APPENDICES ....................................................................................................67
Appendix I
Sources of Additional Information ........................................69
Appendix II OSHA Regional Offices............................................................74
Appendix III EPA Regional Offices................................................................75
Appendix IV Checklist of Minimum Requirements for Chemical
Laboratory and Workplace Design ........................................76
Appendix V Properties of Protective Clothing Materials ..........................77
Appendix VI Incompatible Chemicals ........................................................78
Appendix VII Facilities Safety and Housekeeping Inspection Report ........80
Index ....................................................................................................................81
Guide for
Managers and
The American Chemical Society (ACS) Committee on Chemical Safety (CCS)
has prepared these guidelines for prudent practice in small businesses. However,
the guidelines can be adapted to practices in all operations using chemicals,
including large research, clinical, quality control, and development laboratories.
These general recommendations can serve as a basis for more detailed instructions
prepared for each chemical facility by those directly responsible for the operation
of that facility.
There is a preferred way to perform all work with chemicals that can both
reduce the probability of an accident to a negligible level and minimize its
consequences, should one occur. Risk minimization depends on safe work
practices; the use of personal protective equipment; appropriate engineering
controls; and, when possible, the substitution of a less hazardous chemical for a
more hazardous one. A question to ask before beginning an operation or
performing an experiment is, “What would happen if...?” Answers to this question
require an understanding of the hazards associated with the chemicals and
equipment involved. The reactivity, flammability, corrosiveness, and toxicity of
chemicals used will dictate the precautions to be taken. Such information might
well form an introductory section to all written procedures.
An effective and mandatory safety program will have strong support from the
chief executive officer (CEO) and will have the active participation of all employees.
Without the enthusiastic support of the CEO, who is ultimately responsible for
safety within any facility, an effective safety program is rarely achieved. An
appropriately trained and qualified safety officer is essential. Laboratories meeting
the criteria in the Occupational Safety & Health Administration’s (OSHA’s)
Laboratory Standard are required to have a designated chemical hygiene officer.
However, even the best safety coordinator cannot relieve the CEO, the
administrative and technical staff, and each employee of the responsibility for the
safety of operations under their jurisdiction. A good safety program includes
constant training and reminders of the common hazards that workers may face
and attention to the equipment and facilities that workers use.
Good practice requires mandatory safety rules. The following are
recommended parts of a program that establishes safe conditions for the
a. Regular safety inspections at intervals of no more than 3 months (and at
shorter intervals for certain types of equipment, such as eyewash fountains)
b. Procedures that ensure proper disposal of waste chemicals at regular intervals
c. Formal and regular safety training that ensures that a sufficient number of fulltime personnel are knowledgeable in the proper use of emergency equipment
and procedures
d. Regular monitoring of the performance of ventilation systems
The CEO, line organization, and staff are responsible for the administration
of the safety program. Each individual is responsible for performing his or her job
safely following an appropriate training program. Untrained technicians, operators,
or visitors should not be permitted to work with laboratory or plant chemicals.
Every supervisor should do the following:
a. Set a good example by
• observing all rules and recommendations,
• wearing protective equipment where recommended, and
• being enthusiastic about safety.
b. Be alert for unsafe conditions.
c. Conduct frequent and thorough inspections.
d. Take effective corrective action promptly.
e. Maintain discipline and enforce rules.
f. Assume responsibility for visitors and require that they follow the same rules
as the employees and are escorted or supervised at all times.
g. Carefully review all procedures for possible health, safety, and environmental
concerns before the work is begun. Provide training to ensure that workers
can perform each task safely.
h. Maintain a file of publications on chemical safety that is readily available to
employees, visitors, and others, and encourage its use.
i. Obtain or generate a material safety data sheet (MSDS) for each chemical,
mixture, or other hazardous material. Ensure that the employees have access
to and understand the information on these sheets.
In addition to a growing awareness of the need for adequate safety precautions
and training, there has been increased recognition of the health effects of
prolonged, low-level exposure to many chemicals. However, the latter subject is
beyond the purpose and scope of this manual, and you are urged to seek specific
guidance from appropriate federal and state agencies and specialized textbooks in
this field. See Appendix I, “Sources of Additional Information”; Appendix II,
“OSHA Regional Offices”; and Appendix III, “EPA Regional Offices”.
Under OSHA regulations, a specific set of safety rules must be developed
and communicated clearly to employees. Each employee should attest by
signature that he or she has read and understands the safety rules. These rules
must be rigidly and impartially enforced. Willful noncompliance can result in
dismissal or suspension from the workplace. On the other hand, supervisors
should encourage and seriously consider suggestions from the employees for
improvements in safety rules, practices, and equipment. Safety meetings should
be held with all employees at regular intervals.
The following are suggested as rules for persons in all chemical workplaces:
a. Immediately notify your supervisor if you are injured or experience an illness
in the workplace.
b. Wear proper eye protection-American National Standards Institute (ANSI)approved glasses or goggles-at all times in chemical work, handling, and
storage areas.
c. Always know the hazards and physicochemical properties of the chemicals
used (e.g., corrosiveness, flammability, reactivity, and toxicity). Read the label
and the MSDS for each unfamiliar or extremely hazardous chemical in the
d. Always wear appropriate protective clothing. To minimize exposure to
hazardous chemicals, wear clothing that covers the torso, arms, and legs.
Confine long hair and loose clothing. Wear shoes that completely cover the
feet. Do not wear high-heeled shoes, open-toed shoes, sandals, or shoes made
of woven material. Wash work clothes separately from personal laundry.
e. Never perform any work with hazardous materials when alone in the
f. Do not eat, drink, smoke, or apply cosmetics in work areas where laboratory
or industrial chemicals are handled or stored.
g. Do not perform unauthorized work, preparations, or experiments with
hazardous materials.
h. Always wash your face, hands, and arms with soap and water before leaving the
work area. This applies even if you have been wearing gloves.
i. Never engage in horseplay, pranks, or other acts of mischief in chemical work
j. Never remove chemicals or equipment from the facility without proper
All chemical work areas should be provided with safety showers, eyewash
fountains, approved fire extinguishers, proper ventilation, wash sinks, and
appropriate waste disposal facilities. All of these should be conveniently located,
properly maintained, and frequently tested. There should be two or more wellmarked and unobstructed exits for evacuating the workroom. Aisles and exits must
be kept clear at all times. Safety equipment such as showers, eyewash fountains, fire
extinguishers, and unrestricted telephones should be readily available, located
strategically, and in working order. All employees should be trained in how to use
all safety equipment. Special consideration should be given to ensure accessibility
to safety equipment by, and ease of evacuation of, workers with disabilities. New
construction and renovation of existing facilities should meet the Americans with
Disabilities Act (ADA) Accessibility Guidelines. Appendix IV lists minimum design
considerations for construction of laboratories and pilot plants.
A general alarm system, which alerts a facility’s emergency and security services,
should be provided. This alarm system should have both audible and visual
warnings, such as a bell with a flashing light, so that visually or hearing-impaired
people are also warned. Automatic smoke and fire alarms are now commonly used
and are highly recommended. In some cases, they are legally required, especially
in the absence of automatic water sprinklers. Such systems must be properly
maintained and monitored, with the results documented on a regular basis to
ensure their proper operation. Emergency telephone numbers must be clearly
Highly visible signs, temporary or permanent as appropriate, should be posted
in areas where hazardous operations are being carried out or where hazardous
chemicals are being used. Exit signs should be tactile (i.e., one should be able to
run one’s hand along a wall and find the exit sign). The signs should be at an
appropriate height for workers who use wheelchairs and those who don’t.
Storage of chemicals in laboratories should be minimized. Suitable stockroom
or chemical storage space should be used. Laboratory chemical hoods should never
be used for long-term storage of any chemicals. NFPA 45: Standard on Fire Protection
for Laboratories Using Chemicals, published by the National Fire Protection
Association (NFPA), gives maximum quantities of flammable and combustible
liquids that may be stored as well as maximum container sizes.
Emergency fire drills are essential. In case of general evacuation, employees
should be required to go to a designated safe area and remain there until further
direction has been given. Establish a safe area of refuge for workers with disabilities;
this is simply a designated safe area where workers with disabilities can gather if
they need assistance to exit. Discussions with local fire officials should be held to
review the special problems of fire containment and handling in the chemical
work environment, and such discussions may be mandated by law if the facility
must comply with the requirements of Title III of the Superfund Amendments and
Reauthorization Act (SARA).
cutting operations (e.g., using a razor knife to trim a polymer sample). Note that
some of these products are open weave and offer no protection against liquid
chemicals; these need to be worn under the appropriate chemical-resistant gloves
when chemical protection is needed. Cut-resistant gloves also tend to offer little
protection against sticking injuries, such as by a hypodermic needle. Gloves must
provide sufficient arm protection to minimize the chance of spilled chemicals
making contact with the skin. Selection of proper glove materials is important
because most gloves are permeable to some types of chemicals. Contaminated
gloves must not be reused. Protection for legs and feet should be provided by a lab
coat and shoes and, in some cases, boots. Where necessary, employees should wear
other protective equipment such as safety shoes and hard hats.
Laboratory Chemical Hoods (Formerly Called Fume Hoods)
Aprons, lab coats, gloves, safety glasses and goggles, and other protective
clothing, preferably made of chemically inert material, should be readily available
and used. For further information, see Appendix V. Note that most lab coats and
aprons are made of substances that will burn. Experiments or processes involving
corrosive or reactive materials, such as strong acids or bases, require the use of
goggles and face shields. In the chemical industry, common injuries are cuts to the
hands and arms caused by broken glass or mishaps with cutting tools, for example.
Cut-resistant gloves are now available that are comfortable to wear and that offer
very significantly increased protection against slicing-type injuries, in comparison
with cotton or rubber gloves. Cut-resistant gloves should be worn in any situation
where a cutting injury is likely. Some examples include cleaning glassware,
handling wet and slippery glassware, handling broken glassware, handling glass
under stress (e.g., putting a thermometer through a rubber stopper), or performing
One key to safe handling of chemicals in enclosed areas is a good, properly
installed hood system. The National Research Council’s Prudent Practices in the
Laboratory: Handling and Disposal of Chemicals and ACS’s Handbook of
Chemical Health and Safety provide extensive discussions of laboratory ventilation
problems. The ANSI Standard Z9.5, Laboratory Ventilation (periodically revised),
contains the current recommended guidelines for laboratory chemical hoods. By
definition, a hood is any opening that exhausts air. A laboratory chemical hood is
different from a biological safety cabinet, laminar flow hood, glove box, or vented
enclosure. This manual addresses laboratory chemical hoods and vented
enclosures. The same criteria apply to chemical workplaces other than laboratories.
Operations where flammable gases, toxic vapors, or noxious odors are given off
should be performed in these hoods.
There are a few basic rules about ventilation design. Incoming (i.e., supply or
makeup) air must be sufficient to replace and compensate for the exhausted air;
otherwise, hood containment will be compromised and contaminants will escape.
Exhaust fans should be outside the building to ensure that hood ductwork is under
negative pressure. This is done so that if a leak develops in the ductwork, the
exhaust will not escape back into the building. Exhaust fans should be as far as
possible downwind from all air intakes. Hood exhaust air should not be
recirculated. Hoods should not be located in aisles where there is major traffic
flow, near open windows and doorways, next to desks, or near sources of crossdrafts. Locate hoods as far to the rear as possible in a laboratory to ensure
emergency escape routes. Where possible, locate hoods at the dead end of aisles
to minimize traffic flow in front of the hoods.
Careful selection, installation, maintenance, and evaluation of laboratory
chemical hoods and vented enclosures are imperative. Many hoods have specific
functions. For example, canopy hoods (like those over a kitchen stove) should
only be used when the effluents from the operation are forced (e.g., by heating)
upward toward the hood. Otherwise, the exhaust is drawn across the worker and
his or her breathing zone, no matter how careful the work practices. Slot hoods at
the back of laboratory benches are of very limited usefulness.
There are several reasons why face velocity and exhaust rate by themselves
Protective Clothing
should not be used to determine performance. These parameters are influenced
dramatically by cross-drafts caused by operator movements, laboratory traffic flow,
location of room doors, nature of the equipment and processes being enclosed,
location and type of room air supply, and exhaust air diffusers. In addition, use of
higher exhaust rates than necessary is expensive. Active hoods should always be left
running, even after hours; otherwise, the materials used in the hood will diffuse
back into the work area. Airflows that are too high can also cause turbulence at the
face and compromise containment. A higher exhaust rate than is needed for
protection is uneconomical as well.
Vented enclosures are intended as alternatives and complements to traditional
laboratory chemical hoods. Vented enclosures are less expensive to buy, install,
and maintain than traditional hoods. Because they use less air, they are cheaper to
operate. Vented enclosures can be custom designed for specific operations (e.g.,
balance enclosures, microscopes, high-throughput robotic and automatic
equipment enclosures, and histopathology operations). When properly designed,
they have demonstrated excellent containment. In addition, they usually can be
installed or removed in a matter of hours-an important advantage in today’s
rapidly changing corporate world.
Actual containment tests of installed hoods under conditions of use are
recommended. See ANSI/ASHRAE (American Society of Heating, Refrigerating,
and Air-Conditioning Engineers) 110-1995 (or current revision), Method of Testing
Performance of Laboratory Fume Hoods, for specific details of installation and
containment testing. Velometers should be used to survey hoods on a regular
schedule, at least semiannually, to ensure uniformity of airflow over the face of
the hood and to detect any changes. Periodic inspections should be made to
determine whether the hood is overcrowded and to check the air tightness of the
ducts and exhaust system.
Canopy-style hoods can do more harm than good, for they often draw
dangerous vapors from the work area across the head of the worker. Their location,
relative to the worker and work area, should be considered carefully. Where
appropriate, consider the use of “elephant trunks” (flexible ductwork) as a means
of providing local exhaust ventilation.
Once a hood is installed, the responsibility shifts to the users. Periodic and
routine maintenance and inspection should be established. This includes
inspection of motors, fans, pulleys, and belts, as well as routine lubrication. Always
have an emergency plan for hood or electrical failure. The safety department or
chemical hygiene officer should establish a routine hood monitoring and
evaluation program. Safety personnel should use separate airflow monitors, or
anemometers, that are calibrated each year and visually inspect and evaluate all
hoods at least annually. Each hood should be marked with a date of inspection,
the face velocity, and the proper operating sash height.
All hood users should receive proper training before they ever use a hood.
Except for gloved hands and protected arms, no part of the worker’s body should
ever enter a hood, especially the head. Always wear proper personal clothing,
including appropriate eye protection. Always lower the sash whenever the hands6
on operation is completed. Keep the sash fully closed when the hood is
unattended. Never shut off a hood unless the hood is clean and decontaminated.
Avoid clutter in hoods, and don’t use them to store unwanted or unused materials
or equipment. Keep light fixtures clean, ground electrical outlets, and keep the
outlets free from corrosion and in proper working order. Inspect baffles to ensure
they have not slipped shut. Malfunctioning sashes and broken glass should be
repaired before the hood is used. Routinely inspect the hood immediately before
it is used.
The water supply for laboratory sinks must be separate from that used for
toilets, drinking water, and emergency showers or eyewashes. This is necessary to
prevent possible contamination of the potable water supply. Back-siphoning or
back-pressure can suck sink water into the potable water system through hoses or
other apparatuses. Most building codes require a check-valve system that must be
tested periodically.
It is advantageous to separate laboratory sink drainage from the sanitary
drainage to facilitate independent treatment of each type of waste where this is
Safety Showers
Safety showers should be clearly labeled. ANSI-Z358.1 requires that emergency
showers be located no more than a 10-second walk from the hazard. The shower
area must be readily accessible and be kept clear of obstructions. Chain pulls
should be provided with a large ring. Even better, a double ring at right angles can
be installed. The chain should extend down to 48 in. so that short or seated people
can reach it easily. The valve should open readily and remain open until
intentionally closed. Water flow must be sufficient to drench the subject rapidly
and to accommodate more than one person, if necessary. ANSI-Z358.1 requires a
minimum flow of 75.7 L/minute (20 gal/minute) of potable water. The water may
be tempered. Although an associated floor drain is desirable, its absence should not
prohibit installation of a safety shower. The shower should be tested on a regular
basis, and a record should be kept of such tests. The shower’s location should be
clearly labeled.
Eyewash fountains should provide a copious and gentle flow of tempered,
aerated, potable water for a period of at least 15 minutes (15 minutes of cold water
is intolerable). Use of the hands should not be required to maintain the water
flow. Eyewash fountains should be tested on a regular basis (activate plumbed
installation once a week to flush the lines), and a record should be kept of such
tests. ANSI-Z358.1 requires that eyewash units be located no more than a 10second walk from the hazard. The location should be clearly labeled. A handheld
spray wand is an inexpensive and effective adaptation for washing the eyes of
people in wheelchairs or those of short stature who are not able to reach a wall7
mounted unit. Portable eyewash units provide an inadequate supply of water,
require strict attention to maintenance, and may provide an environment for the
growth of microorganisms. Their use should be discouraged except as an interim
wash until the injured party can reach a plumbed fixture or in circumstances when
running water is not available.
Respirators and Self-Contained Breathing Apparatuses
Rather than relying on respirators, most workplaces should rely instead on
engineering controls, administrative controls, and work practices to limit exposures
to hazardous vapors, dusts, and mists.
At least two 30-minute self-contained breathing devices (not cartridge or filter
gas masks) should be available for emergency control where high concentrations
of toxic vapors, gases, smoke, or oxygen-deficient atmospheres are frequently or
potentially present. This equipment should be set in permanent cabinets outside
of the danger area. OSHA regulations state that before workers can use a respirator,
they must be physically able to. Training (including fit testing) and practice in the
use and limitations of all respirators must be given to those who are expected to
use them. See the current edition of ANSI-Z88.2, Respiratory Protection, and OSHA’s
Code of Federal Regulations (CFR), Title 29, Part 1910.134. Individuals without
current certification must not use air-purifying or air-supplied respirators, even
during an emergency.
Cleanup of a medium to large toxic spill may require using cartridge or airlinesupplied respirators. The requirements of 29 CFR 1910.134 apply. Depending on
the situation, you may want to call off-site contractors when the complex degree
of service mandated by 29 CFR 1910.134 is required.
extinguishing system. When a flammable liquid is withdrawn from a drum, or
when a drum is filled, both the drum and other equipment must be electrically
grounded and bonded to each other.
Never store containers of chemicals on the floor, even temporarily. Keep all
stored chemicals, especially flammable liquids, away from heat and direct sunlight.
Peroxide-forming chemicals deserve special consideration at all times and
particularly in storage. Peroxide formation is accelerated by the presence of UV
light and elevated temperature. Maintain careful storage records of compounds
that form peroxides upon standing, and periodically review those records. Write
the date of receipt of every chemical container on the label.
Chemical storage rooms and buildings must be adequately ventilated, with a
recommended air change of at least six turnovers per hour; they must have vents
and intakes at both ceiling and floor levels. Every storage room should have at
least two exits. Automatic water sprinklers are strongly recommended-except, of
course, for spaces where water-reactive materials are stored. Large containers of
corrosives should be transported from central storage in a chemically resistant
bucket or other container designed for this purpose. When transferring from a
metal container to a nonelectrically conductive container, ground the metal
container. Only small quantities should be transferred to glass, plastic, or other
nonelectrically conductive containers. For additional protection for the eyes, never
store corrosives above chin level.
ANSI Z129.1-2000, Hazardous Industrial Chemicals-Precautionary Labeling,
should be consulted. The OSHA booklet 3084, Chemical Hazard Communication,
summarizes the federal regulatory requirements for the labeling of containers in
the workplace. Because state regulations may vary, consult them also.
All chemicals should be labeled with the date received and expected shelf life.
Chemicals that are repackaged should have secure, waterproof labels, marked with
waterproof ink, that contain information about hazards as well as the chemical
name, date packaged, and strength or purity.
Keep the number and quantity of stored chemicals to a reasonable minimum.
Classify the chemicals by hazard. Separate incompatible materials. Unauthorized
access to storage areas must be prevented. Storage equipment must be stable and
secure against sliding, tilting, and collapse. In regions subject to earthquakes,
restraints should be installed on every shelf. Storage should not be in an area likely
to be flooded. In addition, housekeeping in the storage area must be neat and
orderly. Storage for large containers of reagents should be provided on a low shelf,
preferably in a tray adequate to contain spills or leakage. Chemicals should be
arranged in compatible hazard classes (see Appendix VI), not in alphabetical order.
Store flammable liquids in a manner that prevents accidental contact with strong
oxidizing agents. NFPA 30: Flammable and Combustible Liquids Code specifies
requirements for flammable liquid storage rooms and storage cabinets.
Keep only minimum quantities of flammable liquids in the workplace, as
required by OSHA guidelines and NFPA 45: Standard on Fire Protection for
Laboratories Using Chemicals. Store larger quantities in approved safety containers
or in fire-resistant, properly ventilated solvent cabinets away from ignition sources.
Maintain storage for current work only. Large amounts of flammable liquids
should be stored in a separate storage building with an automatic fire-
OSHA regulations require that all electrical outlets have a grounding
connection for use only with three-pronged plugs. If equipment is not equipped
with a three-pronged plug, follow the requirements of the National Electrical Code
(NEC), and replace the cord and plug with a three-wire cord and three-pronged
plug. Protect all electrical outlets with ground-fault interrupters; note that the NEC
requires that all outlets within 6 feet of any source of water be so protected.
Polarity of outlet wiring and continuity of grounding connections, including
leads to the building ground system itself, should be checked regularly by an
authorized inspector. The NEC should be followed in all installations. This
includes proper grounding as well as proper equipment for hazardous areas.
The condition of wiring, plugs, cords, and related equipment should be
frequently inspected. Wiring that is frayed or worn should be replaced. Wiring
Electrical Hazards
should never be stretched across the floor where someone could trip over it.
Eliminate obstructed switchgear and panel boards, unlabeled panel boards,
electrical outlets with open (or missing) cover plates, and excessive use of extension
All personnel should know the location of circuit breakers and how to cut off
all electrical service in case of a fire or accident. All circuit breakers should be
labeled properly.
The OSHA Standard 29 CFR 1910.147, The Control of Hazardous Energy
(Lockout/Tagout), covers the servicing and maintenance of machines and
equipment in which the unexpected energizing or start-up of the machines or
equipment, or release of stored energy, could cause injury to employees. This
standard establishes minimum performance requirements for the control of such
hazardous energy.
Hearing Protection and Noise Control
Hearing conservation should be practiced through proper design,
modifications of existing sources of noise, and the use of ear protection. Ear
protection includes earmuffs and earplugs. Generally, earmuffs have a greater
attenuation factor than earplugs.
OSHA-allowable occupational noise exposure limits contained in 29 CFR
1926.52 are listed in Table I. Exposure to impact noise should not exceed a 140dB peak sound pressure level.
OSHA Occupational Noise Exposure Limits
Duration Per Day, h
0.25 or less
Sound Level, dBA Slow Response*
*Decibels when measured on the A-scale of a standard sound level meter at slow response
Eye Protection
The use of proper eye protection is a minimum requirement for everyone who
enters a chemical work area. The type of eye protection needed depends on the
circumstances. There is always a danger of splashing chemicals or flying particles.
Therefore, goggles or other forms of eye protection that protect both the front and
sides of the eyes are mandatory. Side shields offer some protection from objects
that approach from the side, but they do not provide adequate protection from
chemical splashes, which can drip behind glasses. Face shields and goggles may be
appropriate when working with glassware under reduced or elevated pressure and
with glass apparatuses used in combustion or other high-temperature operations.
Face shields alone are not considered adequate eye protection, according to ANSI
Z87.1-2003, and must be used in conjunction with other eye protection. The
current ANSI standard, ANSI-Z87.1-2003, Occupational and Educational Personal
Eye and Face Protection Devices, should be considered the minimum protection.
Goggles should be worn when working with compressed gases.
There is no published evidence to support the traditional belief that wearing
contact lenses in a chemical environment increases the risk of eye injuries. A careful
study of the literature by knowledgeable consultants has refuted the perceived
risks. Because of the ever-increasing use of contact lenses and the benefits they
provide, the CCS members, having studied and reviewed the issue, are of the
consensus that contact lenses can be worn in most work environments, provided
that the same approved eye protection is worn that is required of other workers in
the area. Contact lenses by themselves do not offer adequate eye protection in any
environment in which the chance of an accidental chemical splash can reasonably
be anticipated. Appropriate eye protection should always be worn in such
situations, in accordance with OSHA’s Personal Protective Equipment Standard
(29 CFR 1910.132 and 133) and ANSI Z87.1-2003, Occupational and Educational
Personal Eye and Face Protection Devices. The National Institute for Occupational
Safety and Health (NIOSH) Publication No. 2005-139, Contact Lens Use in a
Chemical Environment, can be viewed at
(accessed Aug. 25, 2005).
Before working with chemicals, have an action plan in case of a chemical
splash near the face or eyes. For splashes, immediately flush the eyes with tempered
potable water from a gently flowing source for at least 15 minutes. Hold the eyes
open to wash thoroughly behind the eyelids. An eyewash fountain should be used,
but if one is not available, injured persons should be placed on their backs and
water gently poured into their eyes. This must be followed by prompt treatment
by a member of a medical staff or an ophthalmologist specializing in chemical
injuries to the eyes. Emergency response planning should include arrangement
with an ophthalmologist who may issue standing instructions to staff medical
personnel. All injuries, especially eye injuries, should be treated and reported to
ensure maximum attention and feedback to be used in programs designed to
prevent future accidents.
Considerable discomfort and damage to the eyes can result from exposure to
ultraviolet (UV) light. Absorption of this radiation by the outer layers of the eyes
(cornea and conjunctiva) produces conjunctivitis that gives the sensation of sand
in the eyes. All personnel should wear protective glasses whenever they may be
exposed to UV radiation. Use of lasers requires special care. (See Part II, Section
Proper planning is required to minimize the cost of disposal and the potential
liabilities. First and foremost is a clear understanding of the nature of the waste
generated. A “waste determination” is the first step in proper planning; the waste
“stream” must be evaluated to determine whether or not it is regulated as
hazardous. Several sources of information are helpful in completing this
evaluation, including 40 CFR 260-399, which is available online at (accessed Aug. 26, 2005). These parts are
in two volumes. Because the regulations that apply to your business are usually
state specific, it will also be helpful to call the state environmental agency (listed
in the blue pages of most phone books) to request a copy of the state’s hazardous
waste regulations. These publications are usually free and may be available
electronically from the agency’s website. See (accessed Aug. 26, 2005) for state agencies.
A crucial aspect of planning is a clearly defined line of responsibility for
chemical waste management. This means that one employee should be assigned
responsibility for coordinating the management program. This person should
become familiar with regulatory requirements, develop internal handling
procedures, and work with contractors. The employer must provide support for
the program, particularly with respect to adequate space for storage and handling
with suitable safety features. This should include secondary containment in the
event of leaking containers.
All employees must recognize the value of good housekeeping practices,
especially in terms of identification and labeling of waste materials. In any
operation where waste is generated, chemicals should be segregated. When mixed
together, hazardous waste and nonhazardous waste are usually regulated as
hazardous, thereby increasing the volume of material and the cost for disposal. If
waste chemicals are to be disposed of off-site, good segregation will result in more
disposal options.
Pollution prevention and waste minimization strategies should be employed
whenever possible to reduce costs and liability. Some strategies include the
a. Training: Each individual must choose to minimize chemical waste for the
program to work successfully. Personnel should be trained when they are first
hired, yearly thereafter, and when procedures change.
b. Chemical Redistribution: Unopened or unused portions of chemicals may be
redistributed within the organization. If a chemical is needed, especially an
exotic, high-hazard, or single-use chemical, check with other personnel and
colleagues for availability before ordering.
c. End of Process Treatment: Write end of process treatment procedures into
standard operating procedures and use them. An example would be to conduct
“in container” neutralization of an acid with a base and to flush the mixture
to the local sewer with excess water.
d. Process Modification: Encourage the modification of processes to decrease the
quantity of hazardous chemicals used and generated. Where possible, use
micro and semi-micro techniques to reduce the volumes of waste generated.
e. Product Substitution: Substitute nonhazardous or less toxic materials in your
chemical processes and experiments. Some examples include the following:
• High-flashpoint scintillation fluids (e.g., Ecoscint)
• Non-mercury thermometers (e.g., Enviro-SafeTM)
• Detergents and enzymatic cleaners in place of sulfuric acid and potassium
dichromate (Chromerge) cleaning solutions and ethanol and potassium
hydroxide cleaning solutions
Avoid the use of known carcinogens, reproductive toxins, or extremely
hazardous chemicals where possible.
f. Recycling: Some precious metals and valuable chemicals may be collected for
recycling by outside contractors to reduce waste disposal costs. Examples
include the following:
• Reclamation of silver from photo-fixing chemicals
• Collection of mercury (e.g., thermometers and lamps) for distillation by an
outside recycler
• Collection of surplus electronics (e.g., computers) for recycling by an outside
g. Segregation and Characterization: Do not consolidate various process or
experiment wastes into the same container unless the wastes contain similar
constituents or you are otherwise authorized to do so. Accurately label waste
containers, including all chemical contents and approximate percentages.
Ergonomics is the science of fitting workplace conditions and job demands to
the capabilities of the working population. Effective and successful “fits” assure
high productivity, avoidance of illness and injury risks, and increased satisfaction
among the workforce. Although the science of ergonomics is broad, the term most
commonly refers to those work-related factors that may pose a risk of
musculoskeletal disorders and recommendations to alleviate them. For a good
introduction to this area, see NIOSH Publication No. 97-117, Elements of Ergonomic
Programs: A Primer Based on Evaluations of Musculoskeletal Disorders.
The management of industrial waste in the United States, especially hazardous
waste, is highly regulated at the federal and state levels. Waste disposal costs have
steadily risen, and the civil and criminal liabilities associated with improper
management present numerous concerns to small businesses. Liabilities for proper
packaging, transportation, paperwork, and disposal all rest primarily with the waste
generator. While all waste is of concern, this discussion will focus primarily on
hazardous waste, which represents both the greatest cost and the greatest potential
liability to small businesses.
Proper Planning
Segregation and characterization simplifies the waste stream, facilitating
treatment and disposal.
h. Inventory Control: It is important to audit chemical supplies and use inventory
control measures. Purchase only the quantity of chemical required for a
specific project, and do not stockpile chemicals unnecessarily. Chemicals in
storage should be examined periodically for changes in the condition of the
chemical, the container holding the chemical, and the storage area. Signs of
degradation-such as split caps, the accretion of deposits on the bottles or on
shelf surfaces in the storage area, and the formation of two phases or a change
in the physical state or the formation of crystalline structures within liquidsshould be corrected immediately or else the chemical should be disposed of.
Some changes in the chemical may not be readily visible (e.g., formation of
peroxides in ether). Before using or storing chemicals, become familiar with
their physical and chemical hazards.
i. Storage Practices: Chemical containers should be stored and segregated
according to their hazards (e.g., flammables, acids, bases, oxidizers, reactives,
poisons) and incompatibilities. Measures such as secondary containers to
protect the stock container may be required to safely store a particular
chemical. Information on the specific hazards is available on the chemical’s
MSDS. Caution must be taken to ensure that chemicals are stored in a safe
manner. Examples include the following:
• Water-reactive chemicals are not to be stored under sinks.
• Acids are not to be stored under sinks.
• Flammable chemicals are not to be stored near ignition sources.
All containers must have an appropriate container label that is intact and
legible at all times. Any defaced, faded, or separating labels should be addressed
immediately. Proper labeling practices by all personnel will eliminate unknown
chemicals being passed on to future personnel responsible for maintaining the
workspace. Expiration dates should be clearly marked for chemicals that are in
reactive groups or that develop hazardous functional groups upon long-term
storage (e.g., peroxide-forming chemicals).
In general, it is prudent to consider all waste chemicals to be hazardous waste
unless there are good reasons to consider a specific material to be nonhazardous.
Before shipping hazardous waste off-site for disposal, the company will need a
generator identification number from the U.S. Environmental Protection Agency
(EPA) or your state environmental agency. There is no cost to acquire an
identification number; call your state environmental agency to obtain the proper
form. It can also be obtained online from EPA at (accessed Aug. 26, 2005). In addition to
properly classifying chemical waste, companies are obligated to meet requirements
within designated generator categories based on the quantity of hazardous waste
on the premises. For example, large companies are typically required to remove
accumulated waste every 90 days, whereas smaller companies that generate smaller
quantities may be able to store waste for longer periods. Facilities designated as
“small-quantity generators”-those that generate 100-1,000 kg of hazardous waste
in any given month-may store their waste for 180 or 270 days, depending on the
location of their designated disposal facility. Still smaller generators (those that
generate less than 100 kg in any given month) may store their waste indefinitely
under some conditions.
All generators must ship waste off-site by using a hazardous waste manifest
that tracks waste from “cradle to grave”-from the time the waste is first generated
until its ultimate destruction. Appropriate labeling, marking, and placarding
requirements also apply.
A material is usually defined as a waste when it is determined that the material
should no longer be used and it is time to discard it. In the past, the laboratory or
plant worker was often the one who determined when an unwanted material was
to be declared a waste; more recently, federal and state regulations have expanded
our understanding of what constitutes a waste. Thus, according to federal
regulations, a material is also a waste, for example, if it has been abandoned or if
it is considered to be “inherently wastelike”. This means that a material that has
been spilled, degraded, or obviously contaminated is often considered to be a
waste, according to the regulations.
In the United States, disposal of certain chemical wastes is governed by the
requirements of the Resource Conservation and Recovery Act (RCRA) of 1976 and
the Hazardous and Solid Waste Amendments of 1984. RCRA is administered by
EPA and authorized state environmental agencies. Note that regulations
promulgated by state and local jurisdictions take precedence over federal
regulations and may be different or more restrictive. Obtain detailed, up-to-date
information from state environmental agency offices. For details on the federal
RCRA regulations, consult 40 CFR 260-268 (available online at (accessed Aug. 26, 2005).
Under federal regulations, any material that is discarded or intended to be
discarded is considered a solid waste (regardless of its physical state). A subset of
solid waste is hazardous waste, which must meet certain criteria defined in RCRA
in two categories: characteristic waste and listed waste. (See Section 5.4.)
Most companies that generate hazardous waste work with a disposal
contractor or consultant to arrange for off-site disposal. Competent contractors
can provide a number of valuable services, but it is important to understand that
the waste generator retains virtually all liability for the proper packaging,
transportation, and disposal of waste. Great care should be taken in the process of
selecting a contractor, including a review of references, qualifications, capabilities,
insurance, and permits, as applicable.
A competent contractor must be able to do all of the following:
a. Properly package waste according to U.S. Department of Transportation
(DOT) requirements
b. Label waste according to EPA and DOT requirements
c. Prepare necessary forms, including disposal facility approval documents and
the waste manifest used for transportation
Waste Definitions
d. Transport waste to a permitted treatment, storage, or disposal facility (TSDF)
Although contractors may assert that they “take title to” hazardous waste or
otherwise claim responsibility for its proper disposal, it is important to understand
that the generator, not the contractor, always maintains responsibility for the waste,
from cradle to grave.
Under another federal law, the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) of 1980, frequently referred to as
Superfund, generators may be held liable for cleanup costs if their hazardous waste
or other waste from other generators, all located in the same disposal location
unit, poses a threat to human health or the environment. This concept, referred to
as joint and several liability, emphasizes the importance of choosing good
contractors and facilities for waste disposal.
Waste Classification
EPA waste classification terminology is quite specific and cannot necessarily
be inferred from a general knowledge of chemistry. This section is helpful in
determining the status of various wastes based on their characteristics or listing.
The status of a material as a hazardous or nonhazardous waste depends on its
identification as possessing one or more of four characteristics and/or on its
identification as a material named in one or more of the listed wastes. All waste
determinations are based on evaluating the material against these standards.
Sending a representative sample to a properly accredited environmental
laboratory for a determination of toxicity is advisable. Wastes from a number
of industrial processes are also regulated as hazardous, as are many common
commercial products. There are four characteristics of hazardous wastes:
ignitability, corrosivity, reactivity, and toxicity. The four characteristics are
defined as follows:
a. Ignitability. A waste material is classified as ignitable (EPA Waste Number
D001) if it is
• A liquid (other than an aqueous solution containing less than 24% alcohol
by volume) and has a flash point of less than 60 oC (140 oF);
• Not a liquid and is capable under standard temperature and pressure of
causing fire through friction, absorption of moisture, or spontaneous
chemical changes and, when ignited, burns so vigorously and persistently
that it creates a hazard;
• An ignitable compressed gas (as defined in 49 CFR 173.300); or
• An oxidizer (as defined in 49 CFR 173.151).
b. Corrosivity. A waste material is classified as corrosive (EPA Waste Number
D002) if it has either of the following properties:
• It is aqueous and has a pH equal to or less than 2 or greater than or equal
to 12.5 using EPA test methods, or
• It is liquid and corrodes steel (SAE 1020) at a rate greater that 6.35 mm (0.25
in.) per year at a test temperature of 55 oC (130 oF).
c. Reactivity. A waste material is classified as reactive (EPA Waste Number D003)
if it has any of the following properties:
• It is normally unstable and readily undergoes violent change without
• It reacts violently with water;
• It generates toxic gases, vapors, or fumes when mixed with water;
• It is a cyanide- or sulfide-bearing waste that generates toxic gases, vapors, or
fumes at a pH between 2 and 12.5;
• It is capable of detonating or exploding when it is subjected to a strong
initiating course or if it is heated under confinement; or
• It is a forbidden Class A or Class B explosive as defined by DOT.
d. Toxicity. A waste is classified as toxic by RCRA (EPA Waste Numbers D004D043) if an extract from the Toxicity Characteristic Leaching Procedure (TCLP)
test results in a waste leachate above certain concentration levels. The TCLP
list includes a number of toxic metals, pesticides, and solvents that are
regulated as hazardous if the leaching test indicates they may leach in sufficient
concentrations to pose a threat to groundwater. Included on the list are 8
common metals (As, Ba, Cd, Cr, Hg, Pb, Se, Ag), 20 solvents, and 12 pesticides.
The list and the levels are provided in 40 CFR 261.24.
Wastes are named in lists found in 40 CFR 261.31-261.33. These wastes are
materials generated through either specific or nonspecific processes and include
materials such as spent solvents, which are frequently generated by both laboratory
and manufacturing facilities. The lists also include numerous commercial products
that are regulated as hazardous wastes when they are discarded, such as many
common laboratory reagents.
Mixed Waste
Some waste generated by companies may present a combination of chemical,
radioactive, and/or biological hazards; this is generally referred to as mixed waste.
Although much of the previous discussion on chemical hazardous waste may
apply, this waste may require special management considerations because the
treatment method for one of the hazards may be inappropriate for the treatment
of one or more of the others.
The management of mixed waste is further complicated by legal
requirements that may not be consistent with the risks of each of the different
hazards present. Thus, chemical waste is regulated by RCRA, and radioactive
waste is regulated by the U.S. Nuclear Regulatory Commission. Various states
also regulate medical/infectious waste. There are currently few options for
disposal of mixed RCRA-defined wastes and radioactive wastes; such wastes are
mostly stored on-site, pending the permitting of facilities designed to treat
multiple hazards. More information is available at the following Web page: (accessed Aug. 26, 2005).
If the chemical waste contains biological waste (e.g., human blood in dental
amalgam waste), the chemical waste contractor may allow the biological
component to be treated prior to collecting the material. Check with your
disposal company and state environmental agency to determine what options
are available.
Universal Waste
Universal waste includes fluorescent bulbs, batteries, and pesticides. While
this waste may be considered RCRA-defined hazardous waste, federal regulations
were created to allow longer on-site storage and expanded disposal options, with
a goal of increasing the amount of recycling of this waste. More information is
available at the following EPA website:
(accessed Feb. 1, 2007).
Biohazard Waste, or Regulated Medical Waste
Waste containing biological materials is regulated by each state. More
information is available at (accessed Aug.
26, 2005).
The average cathode ray tube computer monitor contains 4 lb of lead and
may be regulated as RCRA-defined hazardous waste. However, when recycling
options are used, this material may be allowed to go to a recycling facility. More
website: (accessed Aug. 26, 2005).
Unlike consultants, brokers usually pay the transporter and disposal facility directly
and mark up these rates. The generator may not be aware of all the arrangements
made on its behalf and should take steps to verify proper transportation and
disposal. References should be requested.
Getting Help
There are a number of resources that are available to help small businesses
make waste determinations and properly manage waste. These different options are
described below.
State and federal regulators can be helpful both in supplying copies of
applicable regulations and in giving interpretations as required. In addition, lists
of permitted transporters and disposal facilities are usually available. It is also
possible in many cases to obtain regulatory compliance information on potential
Disposal Facilities
Permitted TSDFs, which may include incinerators, treatment plants, waste
consolidation facilities, and landfills, can provide information on acceptance of
wastes at their location. In many cases, permits are more restrictive than the
regulations for wastes accepted, packaging methods, analysis required, and other
factors. Copies of permits and insurance certificates should be requested. Many
TSDFs also offer consulting, transportation, packaging, and cleanup services. The
generator should be aware of the final disposal method and location for all
shipments, as well as the long-term liability for the waste materials. For this reason,
financial stability and a good regulatory complaint record are requirements for
the TSDFs.
Environmental Training
If facility personnel are available to take a more active role in the off-site
shipments of waste, there are a variety of commercial training programs offered.
Commercial environmental magazines (many of which are free) can give details
on upcoming courses. The National Environmental Training Association certifies
trainers and can also provide information on available courses. Federal regulations
require training of individuals who handle hazardous waste.
Transporters frequently act as waste brokers, arranging shipments directly with
the disposal facility and billing for these services. Costs may be lower because there
are no markups on transportation. Proper permitting and insurance should be
Trade Associations
Trade associations can frequently allow a company to combine with other
firms to share resources. This might include joint training sessions, shared
transportation, competitive contracts for multiple facilities, references, and general
Qualified consultants may be helpful in providing unbiased opinions on
vendor qualifications, and can often provide regulatory interpretations, waste
determinations, packaging advice, and an interface with regulators. In the event of
a reportable spill involving contamination of the environment, most government
agencies will require the company to hire an independent consultant to develop
a remediation plan and oversee the cleanup. Consultants typically charge an hourly
or project fee for their services. Qualifications vary considerably; certifications may
be helpful in determining competence. References may also be requested.
Large industrial firms are a good source of references because they usually
have the resources to verify proper handling. It may also be possible to arrange for
shared transportation in certain circumstances.
Waste Brokers
Large Local Businesses
Books and Other References
Waste brokers can provide many of the same services as consulting firms, but
they usually specialize in arranging shipments of waste into disposal facilities.
There are many reference materials available to help; some of these are free of
charge. The EPA manual entitled Managing Your Hazardous Waste: A Guide for Small
Businesses is particularly recommended. Request this title online at (accessed Aug. 26, 2005).
EPA’s Office of Small Business Ombudsman is an extremely useful resource for
both regulatory information and documents. For additional titles and sources, see
the inside front cover of this manual and Appendix I. Scientific equipment
distributors are another source of information.
Economic and liability concerns dictate careful management of hazardous
waste. The following are some general do’s and don’ts for businesses that generate
hazardous waste:
a. DO keep accurate records of all shipments of hazardous waste, preferably
forever, as Superfund liability may be mitigated by accurate record keeping.
b. DON’T pour any hazardous waste onto the ground, into the sewer, or into
municipal waste containers. Don’t burn any waste at the site without a permit.
c. DO determine the final disposition of the waste materials. Request certificates
of destruction or disposal from TSDFs.
d. DON’T mix wastes together except for compatible flammable solvents or other
clearly compatible wastes.
e. DO look at all processes that generate chemical waste to see if less hazardous
materials can be substituted, and minimize all waste generated by poor
housekeeping practices.
f. DON’T automatically hire the cheapest contractor without concern for the
liability of proper disposal of your waste. Always check references, insurance,
and permits when applicable.
g. DO attend seminars, training sessions, or workshops to learn more about the
regulations and your disposal options.
h. DON’T ignore spills or releases of hazardous materials. Investigate the need to
report these releases, and clean up all small spills promptly.
i. DO investigate working with other companies in the area to share
transportation costs. Communicate with other companies in the same industry
to find out how they handle waste materials.
j. DON’T accept samples of chemicals that will not be used. Don’t give away
surplus chemicals unless you know they are going to someone who will
actually use them. You may have liability if someone else improperly disposes
of your chemicals.
k. DO select a key employee to manage the hazardous waste, and make sure this
employee receives the needed support.
workplace, both the MSDSs and competent medical authorities be consulted in
advance regarding first aid treatment. First aid supplies approved by a consulting
physician should be readily available. For specific guidelines on appropriate first
aid training, see OSHA’s Guidelines for First Aid Training Programs, Directive CPL 22.53, January 7, 1991, available at (accessed Aug. 26, 2005).
In planning for potential emergencies, consult with local emergency personnel
in advance and establish plans for the handling of chemical emergencies. At a
minimum, make the following preparations:
a. Always have first aid equipment readily available.
b. Post in obvious places the locations and phone numbers of the local
physicians qualified to handle chemical emergency cases and the locations
and phone numbers of local medical facilities. Also post the telephone
number of the local poison control center and the location of the MSDS file.
c. Train sufficient staff in basic first aid and cardiopulmonary resuscitation (CPR).
If automatic external defibrillators (AEDs) are part of the emergency
equipment, staff members should be trained in how to use them. American
Red Cross certification or its equivalent should be encouraged for all
d. Develop procedures to ensure that someone knowledgeable about the accident
always accompanies the injured person and that copies of the appropriate
MSDSs are sent with the injured person.
e. Establish procedures to ensure that, following any first aid, only a nurse or
physician qualified to handle chemical emergencies provides further
examination and treatment.
There are other preparations to be made in advance for medical handling of
emergencies involving the chemicals used in the workplace. For example, if first aid
treatment is not described in the MSDS, a recommended practice is to add this
information to the MSDS with minimum delay. Examples of emergencies that you
should anticipate follow:
a. Thermal, cryogenic, and chemical burns
b. Cuts and puncture wounds from glass or metal that is contaminated with
c. Chemicals (liquid, dust, glass) in the eye
d. Skin irritation by chemicals
e. Poisoning by ingestion, inhalation, skin absorption, or injection
f. Asphyxiation (chemical or electrical)
g. Lachrymatory vapor irritations
Chemical Toxicity
This manual does not address specific first aid treatment. In Part II, proper
handling techniques are discussed, as well as symptoms of overexposure to certain
selected chemicals. We strongly recommend that, for all chemicals used in the
Almost all of the chemicals in the workplace and laboratory are toxic to some
degree. The two most likely routes of exposure to a toxic chemical are by inhalation
and by absorption through the intact skin. Injection (e.g., from a contaminated
needle or broken glass fragment) and ingestion are also possible. Accordingly,
protection from all four routes of exposure is necessary.
Toxic effects can be immediate or delayed, reversible or irreversible, local or
systemic. The toxic effects of chemicals can vary from mild and reversible, such as
a headache from a single episode of inhaling the vapors of petroleum naphtha
that disappears when the injured person gets fresh air, to serious and irreversible,
such as birth defects from excessive exposure to certain materials during pregnancy
or perhaps cancer from extended chemical exposure.
The toxic effects from exposure to a chemical depend on the severity of the
exposure. Generally, the greater the exposure (quantity, frequency, and duration),
the more severe the result. There are the concepts known as the Threshold Limit
Value (TLV) and OSHA’s Permissible Exposure Limit (PEL). For example, the TLV,
and PEL, for phenol is 5 ppm. According to the definitions for these terms, a
normal person can inhale in his or her breathing air 5 ppm of phenol vapor for 8
hours a day, 40 hours a week, for a working lifetime without harmful effects. Since
some people may not be “normal” in their reaction to phenol, any person’s
exposure to phenol vapor should always be as low as possible-and never exceed for
even a very short time the limit of 5 ppm.
MSDSs for hazardous chemicals and mixtures of hazardous chemicals cite the
TLVs or PELs for the chemicals or mixtures. Employers should insure by
appropriate measurements of the breathing air that all persons who work with
hazardous chemicals are exposed at concentrations less than the TLV or PEL. Most
certified industrial hygienists are qualified to make the appropriate measurements
and to suggest ways to improve the ventilation or to recommend appropriate
respirators when the limits are exceeded. However, respirators are uncomfortable
to wear for long periods and cannot be used by persons with beards or persons
who suffer from respiratory difficulties. Engineering controls to prevent the escape
of hazardous vapors, mists, and dusts are preferable.
An MSDS cannot cite a TLV or PEL if the limit has not been established. In rare
cases, the chemical is not harmful to inhale, and no limit is necessary. More often,
the chemical will be harmful when inhaled, and employees must be protected. In
such instances, an industrial hygienist can offer advice.
An MSDS also describes other hazardous characteristics of a chemical or
mixture. Thus, if a chemical can be absorbed through the intact skin, the MSDS will
so state and will also prescribe the use of protective equipment, such as gloves or
full protective clothing, as appropriate. If the MSDS does not specify the material
(e.g., rubber, neoprene, or polyethylene) for the protective equipment and the
supplier cannot suggest a suitable material, an industrial hygienist can assist in the
selection of the proper material.
Reproductive toxins adversely affect the reproductive process. Examples are
mutagens, which can cause damage to chromosomes in males and females, and
teratogens, which can affect fetal development or cause birth defects, including
fetal death. For the best available and up-to-date information, refer to DART/ETIC
(Developmental and Reproductive Toxicology/Environmental Teratology
Information Center), a bibliographic database on TOXNET (National Library of
Medicine Toxicology Data Network). Go to and click on
“TOXNET” under “Environmental Health and Toxicology”. NIOSH has a website
that contains information on female and male reproductive health issues,
including chemicals and radiation. See (both
sites accessed Aug. 26, 2005). Two useful and recommended books are Reproductive
Hazards of the Workplace and Catalog of Teratogenic Agents, 10th edition.
A variety of allergens (agents that can produce an immunologic reaction) may
be encountered in the workplace when suitable precautions are not enforced.
Further, some chemicals evoke nonimmunologic reactions in individuals who are
sensitive to them. Typical responses include dermatitis or asthma. The special
problem is one of sensitization, and difficulties also arise because the allergic
response may not be readily identifiable. Thus, there is usually no physical reaction
at the time of initial exposure, although this is the point at which sensitization
may have occurred. The physical reaction then takes place after the next or some
subsequent exposure. There is no comprehensive list of substances causing these
There are many factors influencing the toxicity of chemicals, some known,
some not yet fully understood. Hence all chemicals should be handled with respect
for their known or potential hazards. Employers should ensure that workplace
exposures to chemicals are always maintained at the lowest possible levels. The
skin, eyes, and respiratory tract should always be protected from possible exposure
by use of engineering controls, appropriate protective equipment, ventilation
controls, and safe work practices, including personal hygiene practices. Eating,
drinking, smoking, and the application of cosmetics should be strictly prohibited
in all work areas where lab or industrial chemicals are handled. Thorough washing
with soap and water should be mandatory at the end of a workday and before
leaving the area during a break. These precautions can go a long way toward
preventing undesirable toxic consequences.
MSDSs are references intended primarily to train workers in the hazards of
and precautions for chemicals that they will use in an industrial workplace. OSHA
defines a hazardous substance as any chemical that presents a hazard under
normal-use conditions or in a foreseeable emergency. OSHA requires that all
hazardous chemical suppliers furnish MSDSs to their customers and that
employers make them readily available to their employees for every hazardous
chemical on the premises. MSDSs can be stored in databases, provided that
workers can readily access them.
OSHA has prepared a suggested format for MSDSs, but any format that
supplies the information required by 29 CFR 1910.1200 is acceptable. Regardless
of format, the principal topics required in an MSDS include physical data, fire and
explosion hazards, toxicity hazards, other health hazards, propensity to react
vigorously (often called an incompatible chemicals list or reactivity description),
spill cleanup procedures, and precautionary measures that will materially reduce
the probability of harm. OSHA requires that known and suspected carcinogens
recognized by relevant authorities be identified in MSDSs. A properly prepared
MSDS is a useful tool to train employees in descriptive and theoretical chemistry
Material Safety Data Sheets
as well as accident prevention. Part II, Section 2.2, contains an explanation of how
to read and understand MSDSs. Many employers use MSDSs as part of the
employee training required by OSHA. (See next section.)
Technical Guidance
Both EPA and OSHA rules state that most businesses handling chemicals in
any way must designate a person or persons in the organization to be responsible
for emergency response measures and for the safe use of hazardous chemicals in
the workplace and in the laboratory.
Under EPA rules, the designated person is called an emergency coordinator.
This person must either be on the premises of the facility or on call at all times. The
responsibilities of, and need for, the coordinator are spelled out in detail in 40
CFR 265.55 and 265.56. In general, this individual has the responsibility for
coordinating the necessary emergency response measures. The person must be
thoroughly familiar with the entire facility and must have authority to act on behalf
of the management in all respects.
Under OSHA, two separate regulations apply: one to the industrial workplace,
called the Hazard Communication (or Right-to-Know) Standard, 29 CFR
1910.1200, and the other to most laboratory work, called the Laboratory Standard,
29 CFR 1910.1450.
The designated person under the Hazard Communication Standard is not
identified by a specific name. Here, we will use the term safety officer. This
individual may also function as the emergency coordinator and as the chemical
hygiene officer.
Under the Hazard Communication Standard, the employer is required to
prepare and implement a written hazard communication program describing the
procedures for the safe use of chemicals and the training of employees. See 29 CFR
1910.1200 for details. The safety officer might be charged with the responsibility
for preparing the hazard communication program and the training program, as
well as supervising the implementation of the hazard communication program.
In a large facility, a safety committee may be desirable to assist the safety officer.
Hazardous conditions should be reported and corrected. Giving a serial number
and date for each hazardous condition is helpful in keeping track of such
conditions until they can be corrected.
In practice, a revolving safety committee membership is preferable because it
brings the judgment of more individuals into the system. The person responsible
for an area in which a hazard is identified should be formally advised of the hazard
and should be given suggestions and deadlines for corrections. After corrective
measures have been completed, the person responsible for the corrective action
should report to the safety officer. Periodically, the safety officer should review past
reports for recurring hazards and act to eliminate them after consulting with
management and others for suggestions. It is normally helpful to carry out such
review procedures in the manner of a formal safety audit. Appendix VII suggests
some areas and operations that should be reviewed. Refer to the references in
Appendix I for further information concerning safety audits.
Usually, the safety officer has the responsibility for reviewing the safety rules
with all new employees, and periodically, with all employees. The safety officer
also participates in revising these rules.
A Chemical Hygiene Plan is required for laboratories where multiple chemical
procedures with hazardous chemicals are carried out using containers that can be
easily and safely manipulated by one person and where protective laboratory
equipment and practices are available and used, provided that the laboratory work
does not include the production of commercial quantities of materials.
(Laboratories whose function is to produce commercial quantities of materials are
guided by the provisions of the Hazard Communication Standard.)
The written Chemical Hygiene Plan, which must be annually reviewed and
updated if necessary, must be capable of protecting employees from health hazards
associated with the chemicals used, as well as keeping exposures below the PELs
that are specified in 29 CFR 1910, Subpart Z.
Specifically, the Chemical Hygiene Plan includes the following:
a. Designation of a chemical hygiene officer
b. Standard operating procedures for the laboratory
c. Provision for establishing “designated areas” for working with and storing
select carcinogens, reproductive toxins, and highly toxic substances
d. Criteria used to insure that control measures keep exposures below the PELs
e. A requirement for properly functioning and maintained hoods
f. Provisions for employee information and training
g. A description of circumstances under which a laboratory operation requires
prior approval from the employer
h. Provision for medical consultation for employees
Refer to 29 CFR 1910.1450 for details.
Accident Reporting
All accidents should be reported. Accidents resulting in even minor medical
treatment or observation must be recorded. A formal, written report stating the
causes and consequences of each accident should be made to the designated
authorities, including the insurance carrier. Recommendations for the prevention
of recurrences should be discussed with the safety officer.
A written report of each accident should be submitted to management and to
the safety officer, who should take appropriate measures to prevent recurrence. A
periodic review of accident reports will often reveal problem areas that need special
attention. If the accident causes a lost time condition, it must be reported on OSHA
Form 200. Unusual or unexplainable chemical accidents should be reported in
the Letters to the Editor column of Chemical & Engineering News to alert others.
Safety Inspections and Audits
Accidents are caused by mistakes. Clearly, even though regular inspections
and audits cannot prevent every accident-causing mistake, it is worth the
expenditure of some time and effort to conduct more than just occasional
inspections and audits. The following discussion is introductory; for a detailed
treatment of this topic, including a suggested checklist of specific items, see the
ACS Safety Audit/Inspection Manual available at (accessed Aug. 26, 2005).
A safety audit is a systematic review of operations intended to ensure that what
should be done is, in fact, being done, both in spirit and to the letter. A safety audit
has two parts: acquiring information and then evaluating it. Several governmental
regulations identify the details of the information to be acquired: OSHA
regulations, particularly in 29 CFR 1910 but elsewhere in 29 CFR as well; EPA
regulations in 40 CFR; DOT regulations in 49 CFR; and corresponding state and
local regulations. Details can also be found in company policies and rules.
A safety audit should reveal current defects and weaknesses in the operation
of a company facility; however, perhaps more important, it should also identify its
strengths. Audit data are acquired by reviewing records and procedures, identifying
records that should be available but are not, and conducting interviews. Data are
collected from management and operations. Too often, in these latter collections,
maintenance and janitorial operations are overlooked. Remember to review the
mailroom, the shipping department, and the personnel in other service operations.
A proper safety inspection is a monitoring function with a positive purpose:
to identify existing and potential accident-causing hazards, actions, and failures
to act, which, once identified, can be corrected. Safety inspections are usually
conducted by teams, not by the safety committee. The team gives copies of its
report to the safety committee, which is responsible to top management. At least
one member of the inspection team should have some knowledge of safety
principles. Equally important is the presence on the team or committee of a person
with practical knowledge that has been obtained from personal work experience;
a janitor, a maintenance person, or a facility manager could fill this role.
Safety inspections are time-consuming; it is often practical to inspect only a
limited area for safety one week-for example, electrical safety-and to cover another
area, perhaps the frequency of toxic exposures, or hazards of a physical nature, on
a following week. Guided by the decisions of an active committee, eventually the
entire company will be thoroughly safety-inspected by one team or another-and
then the time will come to begin all over again.
Employee Training
Employee training is required under the Hazard Communication Standard
and under the Laboratory Standard. The following comments may be helpful in
designing and implementing a training program.
The purpose of training is to help employees perform tasks safely when they
work with chemicals. When proper precautions are taken, hazardous chemicals
cannot cause harm. These precautions must be learned because they are not
obvious to an untrained person. Common experience teaches that a sharp knife
can cut, so most people know to exercise care when using this tool. But the dangers
of many chemicals are not as obvious. Phenol, for example, has killed careless
workers; n-hexane has caused permanent peripheral neuropathy; and borax has
caused long-lasting respiratory disease. Although phenol has a somewhat
unpleasant odor, the odor of hexane is considered by many to be almost pleasant,
and borax is a white, innocent-appearing powder. To an untrained person, none
of these three indicate the severity of the hazards they present. Only workers who
know the hazards and how to take the proper precautions can be assured of safety
from the harm that these three, or any other chemical, can cause when used
improperly. It is essential for employees to be trained in the hazards and
appropriate precautions for the chemicals they will use.
The MSDS for a chemical is a useful source of information. It identifies the
hazards and describes the precautions to be taken. However, because of the style
in which it is written, an MSDS is not a suitable source of information for most
employees. It must be interpreted for them. Training can change employee
behavior, and during training, employees will have the MSDSs for the chemicals
they use explained to them. Other sources of information include the label on the
container and a variety of reference works, such as those identified in Appendix I.
There are many ways to conduct the training, such as the following:
a. Lecturing in a classroom-like environment
b. Telling small groups or single employees about the hazards and precautions
in the work area
c. Showing employees how to handle a hazardous chemical by personal example
d. Preparing a videotape that demonstrates in detail how to handle a hazardous
chemical in the employee’s workplace
e. Using purchased or prepared presentations and audio/visual material for
Frequent and very brief, informal reviews of what has been learned can be
combined with new or changed information. No single way is best for everyone,
and usually a variety of techniques is the most effective.
Evaluation of the effectiveness of the training is the final step in the process.
Because the purpose of safety training is to insure proper employee behavior, safety
training can be evaluated by observing an employee’s behavior in handling
hazardous chemicals. When incorrect procedures are noticed, they should be
corrected as soon as possible. Avoid describing corrections in terms of errors by the
worker. The trainer may not have explained the correct procedure clearly or the
trainee may not have understood the training.
Retraining will be necessary, perhaps every 6 to 12 months. If employees are
not performing chemical handling satisfactorily, the training program should be
reevaluated, planned, and conducted more effectively.
Training records should be signed, should describe the content and date of
each training session, and should identify the trainees. These records should be
kept permanently.
OSHA and EPA Requirements
Two OSHA regulations have been discussed in Section 6.6. Many other OSHA
regulations, all found in 29 CFR, are applicable to small chemical businesses. Some
of these are not well-known and are identified here; the section identification refers
to the section, or subpart, of 29 CFR:
a. The employer’s safety and health protection policy must be posted. See Section
b. Employers must maintain a log and summary of occupational injuries and
illnesses on OSHA Form 200. There are posting requirements and records that
must be retained. See Section 1904.
c. A written emergency action plan and a written fire protection plan must be
prepared. See Sections 1910.38(a) and 1910.38(b).
d. Portable fire extinguishers must be inspected monthly. See Section
1910.156(d). Hands-on training in the use of fire extinguishers must be
provided annually for employees whose job requires the use of fire
extinguishers. See Section 1910.157(g).
e. Safety shower and eyewash facilities must meet the requirements of Section
1910.151(c). See also ANSI Z358.1.
f. Respirators must be inspected, and records must be maintained. See Section
In addition to the requirement for an emergency coordinator, other EPA
requirements include plans for spill prevention; controls and countermeasures for
fires, explosions, or accidental releases; and hazardous waste management. Details
are given in 40 CFR 265.50-265.56 and 265.112.
SARA Title III, the Community Right-to-Know Act, addresses emergency
planning and emissions of hazardous materials, and it introduces the Toxic Release
Inventory Form. This report requires an evaluation, or “mass balance” accounting
and reporting, of specific chemicals manufactured or used in the workplace above
certain threshold levels. Copies of 29 CFR and 40 CFR should be obtained from
the U.S. Government Printing Office and studied thoroughly. Further information
can be obtained from the regional OSHA and EPA offices. Refer to Appendices II
and III.
A number of states have regulations that require written plans or other reports.
Check with the state authorities or agencies for information. Regional OSHA and
EPA offices will be able to direct you appropriately.
access by workers with disabilities.
The ACS Committee on Chemists with Disabilities (CWD) has published
Teaching Chemistry to Physically Handicapped Students, with suggestions on training
and evaluation of employees with physical disabilities. The March 1981 issue of the
Journal of Chemical Education featured several articles on teaching chemistry and
chemical safety to people with physical disabilities. Additional information can
be found in the November 12, 2001, issue of Chemical & Engineering News in the
article “Approaching a Workplace for All”, which can be found at the CWD Web
page under “ACS/CWD Publications”:
(accessed Aug. 26, 2005).
Visitors should be escorted at all times. While in laboratories, process areas,
pilot plants, or manufacturing plants, visitors should wear safety glasses with side
shields. Small children should not be allowed to enter a laboratory, warehouse, or
plant where hazardous chemicals are being used or are available on open shelves.
The federal ADA prohibits employment discrimination against a qualified
person with a disability. This covers private employers with 25 or more employees
after July 26, 1992; the act is enforced by the Equal Employment Opportunity
Commission (EEOC). Employees protected under the act are those who have a
substantial impairment and are qualified to perform the essential duties of the
job, with or without reasonable accommodation. The pertinent regulations are
published in the Federal Register, July 26, 1991, and A Guide to Disability Rights Laws,
available at (accessed March 13, 2007). EEOC
has established a technical assistance program separate from its enforcement
activities to help employers comply with the law. ADA resulted in new
commercially available hood designs and new advances in laboratory design for
An unfortunate development in recent history has been a higher level of
concern about security issues in light of the increase in acts of terrorism. Hazardous
materials at a small chemical business may become the target of terrorist action.
Here are some issues to be reviewed by the staff:
a. Evaluate access and egress to the facility, and identify any potential weak points
(e.g., shipping and receiving areas, garbage and waste pickup zones, etc.).
b. Does the facility have security cameras? Where are they located? Are they
monitored? What type of security is there for the cameras?
c. Do employees all have photo identification, and are they required to wear
them? Are the photo badges color-coded for access to specific areas?
d. Is there a perimeter fence? Is it secure? How is it guarded? Is it inspected on a
regular basis?
e. For smaller facilities with a skeleton staff on certain shifts, is there adequate
security at entrance areas?
f. What type of emergency communication is available in the event of an attack
on the facility?
g. What hazardous materials are present at the facility that are susceptible (fuels,
flammable and corrosive materials), and is there extra security for those areas?
h. What is the worst-case scenario in the event of (a) a terrorist attack, (b)
vandalism, (c) violent weather, (d) a power failure, (e) a fire, and (f) a major
release of hazardous material?
i. What types of backup power are available?
j. If you are hosting a meeting involving outside personnel, what are your specific
responsibilities? Do you know exactly who is coming? Do your guests know
where they are allowed to go, and what are the limits on their movement
through the facility?
k. What evacuation procedures are in place in the event of an attack?
l. What personal protective equipment is readily available in the event of an
m. Who owns the surrounding property, and what is the access? Are there
residential properties that might be vulnerable in the event your facility is
n. What federal, state, and local agencies are available to assist you in case of an
emergency? Do they know about the materials and activities at your facility?
Employee Guide
to Safety
Safe work practices require alertness and a knowledgeable awareness of
potential hazards. The first and most important rule is this:
Do not use or handle any chemical until YOU have read and understand the label
and the material safety data sheet (MSDS) for that chemical.
The second rule states that safety is the collective responsibility of everyone. It
requires the full cooperation of all concerned. This means that each person must
observe safety precautions and procedures and should do the following:
a. Follow all safety instructions carefully.
b. Become thoroughly acquainted with the location and use of safety facilities
such as fire extinguishers, showers, exits, and eyewash fountains.
c. Ensure that necessary safety equipment is readily available and in usable
d. Before undertaking any work, become familiar with the hazards of the
chemicals being used and the safety precautions and emergency procedures.
e. Before beginning an operation, become familiar with the chemical operations
and all hazards involved, including the precautions both on the labels and on
the MSDSs. In addition, pay attention to potentially hazardous reactions such
as those described in Bretherick’s Handbook of Reactive Chemical Hazards, sixth
edition; the Letters column of Chemical & Engineering News; the American
Chemical Society (ACS) Committee on Chemical Safety (CCS) website,; and NFPA 491M: Fire Protection Guide to Hazardous
Materials, 2001 edition, published by the National Fire Protection Association
Many accidents have resulted from an indifferent attitude, failure to use
common sense, or failure to follow instructions. Be aware of what your co-workers
are doing because you can be a victim of their mistakes. Do not hesitate to point
out to other employees that they are engaging in unsafe practices or operations. If
necessary, report unsafe practices or unsafe conditions to management.
Horseplay cannot be tolerated. Variations in procedures, including changes
in quantities or reagents, may be dangerous. Never leave unattended a reaction
that is in progress.
Anticipate sudden backing up or changes in direction from others. If you
stumble or fall while carrying glassware or chemicals, try to project them away from
yourself and others. Use a proper transport device, such as a rubber pail or a cart
with side rails and secondary containment trays, for transporting chemicals and
apparatuses. Shield chemicals and equipment from shock during any disruption of
movement. Stairs must be negotiated carefully. Elevators, unless specifically indicated
and so designated, should not be used for carrying chemicals. Do not smoke around
chemicals and apparatuses in transit as well as inside or outside the work area itself.
Eye Protection
All persons in the work area, including visitors, must wear eye protection
at all times, even when not performing a chemical operation. Safety glasses
with side shields are the minimum recommended level of eye protection.
Descriptions of suitable safety glasses and goggles are found in the current
edition of the American National Standards Institute (ANSI) Z-87.1 standard.
In many workplaces where hazardous chemicals are used or handled, the
wearing of contact lenses is prohibited or discouraged. Contrary to the widely
held belief that there are dangers associated with wearing contact lenses in an
industrial chemical environment, there is no published evidence to support
that belief. Because of the increasing use of contact lenses and the benefits they
provide in improving vision, the CCS members, having studied and reviewed
the issue, are of the consensus that contact lenses can be worn in most work
environments, provided that the same approved eye protection is worn that is
required of other workers in the area. It should be emphasized that contact
lenses by themselves do not provide adequate protection in any environment
in which there is a chance of an accidental chemical splash or exposure to
harmful vapors. In addition, face shields that protect the neck and ears as well
as the face, along with approved standing shields, should be available as
appropriate for vacuum work or where there is a potential for explosions,
implosions, or splashing. Face shields alone are not considered adequate eye
protection and should always be worn in addition to safety goggles.
To avoid exposure to hazardous materials, wear clothing that completely
covers the torso and legs. Open-backed or sleeveless shirts, shorts, or short skirts
are inappropriate apparel in a chemical workplace. Laboratory jackets or coats
worn to protect clothing should be fastened only with snap fasteners so that they
can be readily ripped off if necessary. Wash laboratory coats separately from
personal laundry. Nonflammable, nonporous aprons are the most satisfactory.
Wear shoes that completely cover the feet. Do not wear high-heeled shoes,
open-toed shoes, open-backed shoes, sandals, or shoes made of woven material.
Steel-tipped shoes should be worn where heavy objects or large equipment is
handled. Inspect gloves for holes or tears before wearing them.
For your protection, neckties and jewelry (rings, bracelets, and watches) should
not be worn in an industrial chemical workplace. Dangling neckties and jewelry
can become entangled in equipment, and jewelry can conduct electricity.
Chemicals can seep under jewelry and cause serious injury to the skin. Chemicals
can ruin jewelry by changing its composition.
Do not smoke inside or outside any chemical work area.
Personal Hygiene
The following basic work practices are essential:
a. Before leaving any chemical work area, wash hands and arms thoroughly, even
if gloves have been worn.
b. Do not apply cosmetics in a chemical work area.
c. Use only the respirator equipment that has been personally assigned for your
use. Respirator training, medical certification, and fit testing are all required.
d. Do not use a mouth suction when pipeting or for starting a siphon.
e. If you must smell a chemical, gently waft the odor toward your nose using
some type of fan or your hand. Do not place the container directly under your
nose and inhale the chemical.
Unattended Operation of Equipment
Reactions that are left to run unattended overnight or at other times are prime
sources of fires, floods, and explosions. Do not let equipment such as power
stirrers, hot plates, heating mantles, and water condensers run overnight without
fail-safe provisions and the consent of management. Check unattended reactions
periodically. Always leave a note plainly posted with a phone number where you
can be reached in case of an emergency. Remember that in the middle of the night,
emergency personnel are entirely dependent on accurate instructions and
Working Alone
Do not work alone with chemicals. Work should be absolutely forbidden
unless there are at least two people present.
Workers’ Responsibility
Employees must learn, understand, and follow all safety rules and regulations
that apply to their work areas. Workers must use personal protective equipment as
appropriate for each procedure that involves hazardous materials. Workers have the
responsibility to seek advice and guidance whenever they are in doubt about safety
procedures or potential hazards in their work and to inform their supervisors of
unsafe conditions. Workers must notify their supervisors immediately if they
experience an injury or illness in the chemical workplace.
Chemical Hazards Orientation
Food and Beverages
Do not prepare, store, or consume food or beverages in any chemical work
area. Industrial chemicals must not be placed in refrigerators used for storing food
and beverages. Never use laboratory glassware or apparatuses for eating or drinking
Employers are required to provide instructions regarding hazards of the
chemicals being used and the manner in which these chemicals are to be handled
and disposed of safely. The information provided by the container labels and by
the MSDSs, which are now required under the Occupational Safety & Health
Administration (OSHA) Hazard Communication Standard as well as other local
and state right-to-know laws, should be understood. Document all safety training.
Additional information is available from the references provided in Appendix I.
Reading and Understanding a Material Safety Data Sheet
There is a specific list of items that are required to be on an MSDS. Each such
item, with an explanation of its meaning, follows:
a. Chemical Name—usually the IUPAC (International Union of Pure and
Applied Chemistry) or Chemical Abstracts Service (CAS) chemical name is
given, but it also may be a common name for the chemical (e.g., ethylene
glycol is acceptable instead of 1,2-ethanediol). Trade names may be supplied,
but the chemical name is also required unless it is considered a trade secret.
b. CAS Registry Number—This number is not required by OSHA, but most state
right-to-know laws require it. This number is assigned to each chemical by
CAS. There are a few instances where a chemical has several different numbers.
A few chemicals have no assigned number, and most mixtures do not have
assigned numbers.
c. Date Prepared-OSHA requires that the date of preparation or latest update
be on the MSDS.
d. Composition of Mixtures—This includes all hazardous materials in
concentrations greater than 1% and all carcinogens in concentrations greater
than 0.1%. Trade names can be used, but chemical names must also be
included unless this information is considered a trade secret.
e. OSHA Permissible Exposure Limit (PEL)—A time-weighted average limit for
an 8-hour day and, for some chemicals, also includes a maximum
concentration exposure limit. The figures may be in parts per million or
milligrams per cubic meter.
f. American Conference of Governmental Industrial Hygienists (ACGIH)
Threshold Limit Value (TLV)—An exposure limit, similar to the PEL,
recommended by ACGIH. The measuring units specified in the OSHA PEL are
applicable. The ACGIH TLV list is updated each year. TLVs are considered
guidelines, not regulated exposure limits.
g. Health Effects—This section identifies target organs or systems adversely
affected by overexposure, as well as chronic effects and any existing condition
that would be aggravated by exposure.
h. Physical and Chemical Characteristics—This section usually includes the
following items where applicable:
• Boiling point—the value may be at reduced pressure and either in degrees
Celsius or Fahrenheit.
• Melting point.
• Vapor density—relative to air.
• Vapor pressure—usually in millimeters of Hg; the temperature must be
specified (usually in the range of normal room temperature).
• Specific gravity—density with respect to water at a specified temperature.
Solubility in water—approximate values are acceptable.
Appearance and odor.
Evaporation rate—usually relative to butyl acetate.
Fire and Explosion Hazard Data—This section usually includes the following
• Flash point—the temperature at which vapors from a liquid can be ignited.
Open or closed cup should be specified.
• Flammability limits—lower and upper concentrations in air (percent) below
and above which volatile flammable chemicals cannot be ignited.
• Auto-ignition temperature—the minimum temperature at which a chemical
ignites spontaneously in the air.
• Recommended extinguishing media.
• Unusual fire and explosion hazards.
j. Reactivity Hazard Data—Information should include whether the material is
unstable and under what conditions instability exists, incompatibilities, and
whether hazardous decomposition products can be produced.
k. Health Hazard Data—This topic includes one or more of the following:
• LD50 (Lethal Dose 50)—the lethal single dose (usually oral), in milligrams
of chemical per kilogram of animal body weight, that is expected to kill
50% of a test animal population. The animal should be specified. Because
some animals react differently to some chemicals, this is not necessarily an
indication of the hazard of the chemical to humans.
• LC50 (Lethal Concentration 50)—a concentration dose, expressed as parts
per million for gases and vapors or as micrograms of material per liter of air
for dusts and mists, that is expected to kill 50% of a test animal population
in one exposure.
In the Health Hazard Data Section of MSDSs, often words or phrases such as
avoid contact and flammable are used. Generalized descriptions of many of these
phrases and the precautions to be practiced follow. The general rule for all
chemicals, even if they are considered nonhazardous, is to avoid contact.
ALLERGIC REACTION: Some individuals may develop severe allergic reactions to
even undetectable quantities of certain types of chemicals (e.g., amines,
organosulfur compounds).
PRECAUTIONS: For the susceptible individual, virtually total isolation from the
chemical is necessary. Allergy studies by a qualified physician may be necessary.
CARCINOGEN: A substance that may possibly, is suspected to, or is known to
cause cancer. Some may have threshold limits of exposure.
PRECAUTIONS: Exercise extreme care when handling! Do not breathe vapors,
and avoid all contact with skin, eyes, and clothing by wearing suitable
protective equipment and using appropriate confining apparatuses. OSHA has
specific rules for handling known carcinogens. Refer to 29 CFR 1910, Subpart
CORROSIVE: A chemical that destroys living tissue on contact and can cause a
severe corrosion rate in steel or aluminum.
PRECAUTIONS: Do not breathe vapors, and avoid contact with skin, eyes, and
clothing. Use suitable protective equipment.
highly reactive material to a reaction.
PRECAUTIONS: Do not open or handle the material without thoroughly
understanding the potential reactions that the substance can undergo. This
information should be in the reactivity section of the MSDS.
DANGER: Applies to substances that have known harmful effects. Also applies to
substances whose properties are unknown but that may have harmful effects,
based on their similarity to compounds with known harmful effects.
PRECAUTIONS: Treat these chemicals as if these are the most dangerous chemicals
that exist. There may or may not be serious hazards associated with them.
PEROXIDE FORMER: A substance that forms peroxides or hydroperoxides upon
standing or when in contact with air.
PRECAUTIONS: Many peroxides are explosive! Do not open bottle if a residue is
present on the outside of the cap or inside the bottle! For more details, see
Sections 7.1-7.3.
EXPLOSIVE: A substance known to explode under some conditions.
PRECAUTIONS: Avoid shock (dropping), friction, sparks, and heat. Isolate from
other chemicals that become hazardous when spilled.
POISON: A substance that has very serious and often irreversible harmful effects
on the body. Hazardous when breathed, swallowed, or in contact with the
skin. In sufficient quantity, leads to death. DOT regulations classify many
poisons for transportation.
PRECAUTIONS: Avoid all contact with the body. When handling, use suitable
protective equipment.
FLAMMABLE: A substance that gives off vapors that ignite easily and burn rapidly
under usual working conditions; the flash point is less than 100 oF (140 oF for
materials regulated by the U.S. Department of Transportation, or DOT).
PRECAUTIONS: Keep away from heat, sparks, or flames. Be aware that materials
with a high vapor density tend to creep along the floor or ground until an
ignition source is found. For more details, see Section 7.5.1.
HIGHLY REACTIVE: A substance that reacts vigorously with water, air, or any other
substance to which it may be exposed in the working environment.
PRECAUTIONS: Use extreme care in opening and handling the substance.
Examine the reactivity section of the MSDS for additional details.
IRRITANT: A substance that causes a reversible inflammatory effect on the skin,
eyes, or respiratory tract.
PRECAUTIONS: Do not breathe vapors, and avoid contact with skin and eyes. The
effect may be evident at an extremely low concentration.
LACHRYMATOR: A substance that has an irritant or burning effect on the skin,
eyes, or respiratory tract. A lachrymator is dangerous in very small quantities.
(Opening the cap has an immediate effect on eyes.) Causes tears upon
PRECAUTIONS: Only open in an operating, fully tested laboratory chemical hood!
Do not breathe vapors. Avoid heating. Avoid contact with skin, eyes, and
MUTAGEN: A chemical or physical agent that causes genetic alterations.
PRECAUTIONS: Handle with extreme care! Do not breathe vapors, and avoid
contact with skin, eyes, and clothing.
OXIDIZER: A substance capable of supplying its own source of oxygen or other
STENCH: A foul smell that many substances have or generate.
PRECAUTIONS: If substances have a stench, open them only in a properly
operating laboratory chemical hood equipped with an adequate absorbing
TERATOGEN: A substance that causes the production of physical defects in a
developing fetus or embryo.
PRECAUTIONS: Handle with extreme care! Do not breathe vapors, and avoid
contact with skin, eyes, and clothing. Use suitable protective equipment when
TOXIC MATERIAL: A substance that is hazardous to health when breathed,
swallowed, or in contact with the skin. Prolonged exposure brings the danger
of serious damage to health.
PRECAUTIONS: Avoid all contact with the body. When handling, use suitable
protective equipment.
First Aid—Appropriate procedures for emergency first aid should be given in
the MSDS, identifying antidotes, if known.
m. Precautions for Spills and Cleanup—Appropriate steps for safe cleanup of a
spill or release should be given. An appropriate waste disposal method, including
whether the material can be put in a landfill or other Environmental Protection
Agency (EPA)-approved disposal facility, should be supplied in the MSDS.
n. Control Measures—Types of protective clothing, gloves, and respiratory
protection should be listed. If the material should always be handled in a
hood, in a glove box, or with extra ventilation, it should be listed under this
o. Storage—This section should indicate whether refrigeration or special storage
conditions are necessary. It should also indicate incompatibilities in storage
Evacuation and Fire Drills
Every employee should be aware of the location of the fire exits, alarms (and
their operation), and telephones. Emergency drills should be scheduled on a
regular basis. Employees should be instructed to go to a prearranged place outside
the danger area and remain in that place until accounted for.
Use of Fire Extinguishers
Every person should be aware of the location of fire extinguishers and should
be given annual hands-on training in the proper manner of operating them. Any
use of a fire extinguisher must be reported so the extinguisher can be refilled and
replaced promptly.
Safety Showers and Eyewashes
Every person should know the location of the nearest safety shower and
eyewash fountain and how to operate them.
Dealing with an Emergency
When an emergency occurs, determine the nature of the emergency, whether
it is safe to remain on the scene, and whether somebody has been injured. The
following steps should then be taken:
a. Follow local procedures for initiating an emergency alarm.
b. Report the nature and location of the emergency to the appropriate fire or
medical facility; give your name, telephone number, and address. Tell where
you will meet the emergency vehicle. If individuals are involved, report how
many; whether they are unconscious, burned, or trapped; whether an
explosion has occurred; and whether there is or has been a chemical or
electrical fire.
c. Tell others in the area about the nature of the emergency.
d. Meet the ambulance or fire crews at the place you indicated. Send someone
else if you cannot go.
e. Do not make any other telephone calls unless they directly relate to the control
of the emergency.
Protecting Life
Do what is necessary to protect life while waiting for assistance. Keep calm. The
following suggestions are currently acceptable practices for emergency action:
a. Do not move any injured persons unless they are in immediate danger from
chemical exposure or fire. Keep them warm. Unnecessary movement can
severely complicate neck injuries and fractures.
If chemicals have been spilled on a person, wash the affected area thoroughly
(at least 15 minutes) using a safety shower, hose, or eyewash fountain as
appropriate. See Sections 6.3 and 6.4 for full details.
Use a blanket in shock cases and for the protection of an injured person from
exposure en route to medical aid.
If a person’s clothing is on fire, use the safety shower. If the shower is not
readily available, douse the individual with water. Get him or her to stop, drop,
and roll; that is, to lie down and roll to put out the fire. Then try to extinguish
any small flames by patting them out. Beat out the flames around the head and
shoulders, then work down toward the feet. Next, cover the injured person
with a coat, blanket, or whatever is available, but leave the head uncovered. Do
not use fire blankets until the fire is extinguished. While wearing gloves if
necessary, remove any clothing contaminated with chemicals. Use caution
when removing pullover shirts or sweaters to prevent contamination of the
eyes. It may be better to cut the garments off. Douse with water to remove
heat, and place clean, wet, ice-packed cloths on burned areas. Wrap the injured
person to avoid shock and exposure. Get medical attention promptly.
If there is a fire and there is little personal risk, use the appropriate extinguisher
if you have been trained in its proper use. If the fire is very small, it may be
extinguished by smothering it with a nonflammable material such as an
inverted beaker, watch glass, or metal sheet. Fight the fire from a position of
escape. Understand that it is easy to underestimate a fire. Turn off electrical
circuits and gas lines. Close fire doors. Do not use elevators to leave the
building; use the stairs. Keep the lights on.
Anyone overcome with smoke or fumes should be moved to uncontaminated
air and treated for shock. Provide oxygen for inhalation, if possible.
If hazardous chemicals are ingested, follow the first aid treatment shown on
the label or the MSDS. Never give anything by mouth to an unconscious
person. Determine exactly what substances were ingested, and inform the
medical staff (while the injured person is en route to a hospital, if possible).
The nearest poison control center can give advice.
If the injured person is not breathing, the Red Cross recommends the
following procedure: Place the person face up, clear the mouth of any
obstruction, and loosen tight clothing. Lift the neck and tilt the head back so
that the chin is pointing upward. Insert your thumb in the mouth, grasp the
lower jaw, and lift it forcibly upward and forward. Pinch the nose and blow
vigorously through the mouth to make the chest expand. Repeat every 4 to 5
seconds. If the injured person’s chest does not expand, recheck the mouth for
any obstruction, tilt the head back farther, and resume blowing into the
If an individual is bleeding severely, the Red Cross recommends the following
procedures: Control the bleeding by compressing the wound with a cloth or
whatever is available. Elevate the injury above the level of the heart. If blood
is spurting, place a pad directly on the cut and apply firm pressure. Wrap the
injured person to avoid shock, and get immediate medical attention. In the
case of a less severe cut, wash the cut and remove any pieces of glass, wrap the
injured person to avoid shock (except in the case of a trivial cut), and get
medical attention. A pressure pad may be applied firmly on the wound.
Pressure points should be tried before using tourniquets. Tourniquets should
be used only by persons trained in first aid.
Do not touch a person who is in contact with a live electrical circuit.
Disconnect the power first or you may be seriously injured.
General Precautions
All chemicals are potentially harmful. Avoid direct contact with any chemical.
Some substances now considered “safe” may in the future be found to cause longterm disorders. It is especially important to keep chemicals from the hands; the
face; and clothing, including shoes or other foot coverings. Many substances are
readily absorbed into the body through the intact skin and through inhalation.
Chemicals can also enter the body through the mouth by contamination of the
hands, and chemicals can be transferred to the eyes from the hands. Therefore, the
following precautions are recommended:
a. Do not use or handle any chemical until you have read the label and you
understand the hazards of that chemical.
b. Keep your hands and face clean. Wash thoroughly with soap and warm water
whenever a chemical contacts your skin. Always wash your hands and arms
before leaving the work area.
c. Never taste a chemical. If it is necessary to smell a chemical, cautiously waft the
vapor toward the nose. Smoking, drinking, eating, or applying cosmetics is
forbidden in chemical work or storage areas.
d. Some solvents, such as dimethyl sulfoxide, serve as vehicles for the rapid
transport of dissolved toxic substances through the skin into the body. Always
wear suitable gloves when handling such materials.
e. All containers of chemicals must be labeled clearly. Do not use any substance
from an unlabeled or improperly labeled container.
f. Safe handling and storage procedures for compressed gases are discussed in
Section 5.9.
or powders. Use a funnel if you are pouring into a small opening. If a stopper
or lid is stuck, use extreme caution in opening the bottle.
Always add a reagent slowly; never dump it in. Observe what happens when
the first small amount is added, and wait a few moments before adding more;
some reactions take time to start.
Before pouring a liquid into an addition or separatory funnel, make sure the
stopcock is closed, firmly seated, and freshly lubricated (if glass). Use a stirring
rod to direct the flow of the liquid being poured. Keep a beaker under the
funnel in the event the stopcock opens unexpectedly.
To avoid a violent reaction and spattering while diluting solutions, always pour
concentrated solutions slowly into water or into less concentrated solutions
while stirring. The more concentrated solution is usually more dense, and any
heat evolved is better distributed. This applies especially when preparing dilute
acids. Always wear goggles and use the laboratory chemical hood when
diluting concentrated solutions.
Support a small beaker by holding it around the side with one hand. If the
beaker is 500 mL or larger, support it from the bottom with the other hand,
and consider using heavy-duty beakers. When setting the beaker down, first
remove your hand from the base, and then place the beaker slowly on the
clean surface of the bench. A small piece of grit can make a “star” crack in the
thin, flat bottom of a beaker or flask. If the beaker is hot, use beaker forceps
or heavy gloves and place the beaker on a ceramic-centered gauze pad.
Grasp multinecked flasks by the center neck, never by one of the side necks. If
the flask is round bottomed, it should rest on a proper-sized cork ring when
it is not assembled for a reaction. Large flasks must always be supported at the
base during use.
Never look down the opening of a vessel.
Never use mouth suction to fill a pipet. Use an aspirator bulb or a loose-fitting
hose attached to an aspirator. Constantly watch the tip of the pipet, and do not
allow it to draw air.
Flasks and beakers containing hot or boiling liquids should always be cooled
before any additional chemical is added.
When carrying large bottles of corrosive, toxic, or flammable liquids, use
impact-resistant transport containers.
Adequate Ventilation
There are a number of generally accepted laboratory techniques that will make
working with chemicals safer. Some of these are discussed below.
a. When opening bottles, hold the bottle with its label toward your palm to
protect the label (and also the hand of the next user) in case some reagent
drains down the side of the bottle. Stoppers that cannot stand upside down on
the bench top should be held at the base and pointed outward between two
fingers of the pouring hand. Do not pour toward yourself when adding liquids
Hazardous chemicals should be dispensed and handled only where there is
adequate ventilation, such as in a hood or vented enclosure. A large number of
common substances present acute respiratory hazards and should not be used on
the open bench where dispersion into the surrounding air is possible. Adequate
ventilation is defined as ventilation that is sufficient to prevent excessive exposure
to those chemicals for which exposure values have been established. Chemical
exposures should always be below the OSHA PEL, the ACGIH TLV, or the American
Industrial Hygiene Association’s workplace environmental exposure level (WEEL).
If you smell a chemical, you are inhaling it. Also, remember that the vapors
Safe Laboratory Techniques
of many chemicals can be at hazardous concentrations without any noticeable
odor. The same applies to dusts, mists, and smokes. A chemical that has an odor
may not be hazardous, aside from the nuisance of the odor.
Chemicals can be broken down by the body into hazardous metabolites.
Similarly, byproducts of chemical reactions can be extremely hazardous. Planning
for the handling and control of these toxic metabolites and byproducts should be
part of the experimental procedure.
Extractions can present a hazard because of the potential buildup of pressure
from a volatile solvent and an immiscible aqueous phase. Glass separatory funnels
used in laboratory operations are particularly susceptible to problems because
their stoppers or stopcocks can be forced out, resulting in a spill of the contained
liquid. It is even possible for pressure to burst the vessel. The following is an
accepted procedure for accomplishing such a separation.
Do not attempt to extract a solution until it is cooler than the boiling point
of the extractant. When a volatile solvent is used, the unstoppered separatory
funnel should first be swirled to allow some solvent to vaporize and to expel some
air. Close the funnel and invert it with the stopper held in place, and immediately
open the stopcock to release more air plus vapor. This should be done with the
stopcock handle and funnel drain turned away from you and others, with the hand
encompassing the barrel to keep the stopcock plug securely seated. (Note: Glass
stopcocks should be lubricated.) Do not vent the separatory funnel near a flame
or other ignition source. Then close the stopcock, shake with a swirl, and
immediately open the stopcock with the funnel in the inverted position to again
vent the vapors. If it is necessary to use a separatory funnel larger than 1 L for an
extraction with a volatile solvent, the force on the stopper may be too great and
cause the stopper to be expelled. Consider performing the extraction in several
smaller batches.
Distillations are probably the most common method of separation and
purification used in laboratory and industrial operations. Potential dangers arise
from pressure buildup, the common use of flammable materials, and the necessity
for heat to vaporize the chemicals involved. A variety of apparatus designs are used
to accomplish distillations at atmospheric pressure, under inert atmospheres, at
reduced pressure (vacuum distillation), and by the addition of steam to the
distillation mixture (steam distillation).
Careful design and construction of the distillation system is required to
accomplish effective separation and to avoid leaks that can lead to fires or
contamination of the work area. It is necessary to ensure smooth boiling during
the separation process and to avoid bumping, which can blow apart the distillation
apparatus. Stirring the distillation mixture is the best method to avoid bumping.
The use of boiling chips is effective for distillations carried out at atmospheric
The source of heat is an important factor in the distillation process. Even
heating can best be done by using an electric mantle heater, a ceramic cavity heater,
steam coils, or a nonflammable liquid bath. Silicon oil or another suitable highboiling oil can be used if heated on a hot plate. Hot water or steam may be used
where practical. An additional thermometer may be inserted very near the center
bottom of the distilling flask to warn of dangerous, exothermic decomposition.
Always avoid heating above the temperature directed in the procedure.
Superheating and sudden boiling (bumping) frequently occur during
distillation under reduced pressure. Therefore, it is important that the assembly
be secure and the heat be distributed more evenly than is possible with a flame.
Evacuate the assembly gradually to minimize the possibility of bumping. A
standing shield should be in place for protection in the event of an implosion.
Boiling chips are of little value in a distillation under reduced pressure. Liquids
needing vacuum distillation are usually of high molecular weight and somewhat
viscous at the distillation temperatures. Best results are obtained when the liquid
being distilled is whipped into a fine spray of droplets using a motor-driven stirrer.
This provides good vaporization without overheating and decomposition. After
finishing a reduced-pressure distillation, cool the system before slowly bleeding in
air, because air may induce an explosion in a hot system. Pure nitrogen is always
preferred to air and can be used even before cooling the system. Refer to Section
5.8.2 for the safe use of cold traps during a vacuum distillation.
When carrying out a steam distillation, take care not to run the steam in at too
great a rate for the condenser. Remember that the heat of condensation of steam
is very high. Overfilling the flask is less likely if condensation from the entering
steam line is trapped and if the flask is heated or insulated to prevent excessive
Organic compounds must never be distilled or evaporated to dryness unless
they are known to be free of peroxides. Most ethers, including cyclic ethers, form
dangerously explosive peroxides upon exposure to air and light. Unsaturated
hydrocarbons, potassium metal, and other reagents can also form peroxides. See
Sections 7.1-7.3 for further discussion.
Hazard Evaluation, Risk Assessment, and Hazardous Chemicals
A hazard is the danger that can result when an unwanted event occurs. Hazards
are evaluated according to their potential, based on an analysis of their properties
and their conditions necessary to produce an unwanted activity. Risk is a measure
of the probability and the consequences of the hazards resulting from an activity
or condition. Risk assessment is an evaluation of the probability that an
undesirable event could happen and the extent of the impact it could have on the
health and welfare of humans and the environment.
Chemicals often present biological, chemical, environmental, or physical
hazards. A hazardous chemical or chemical mixture is one that can fit into one of
three categories:
a. It has undesirable biological effects, either acute or chronic, depending on the
size and duration of the dose, the type of exposure, and the physical state of
the material needed to produce such effects.
b. Its toxicity information is not available, but the material is highly suspect
because of its structural or functional similarity to known toxic agents.
c. It is combustible, flammable, explosive, corrosive, or highly reactive.
Many organizations, such as OSHA, NFPA, EPA, DOT, have specific definitions for
hazardous chemical classifications.
Working with Chemicals and Apparatuses
Following these recommendations will help make your work easier and
equipment use safer:
a. Plan your work before starting a procedure. Be sure you know what to do if you
or another worker has an accident.
b. Keep workspace free of clutter.
c. Set up clean, dry apparatuses, firmly clamped and away from the edge of the
bench. Be careful to place reagent bottles away from burners and other workers
and their equipment. Choose sizes that can properly accommodate the
operation to be performed, allowing at least 20% free space.
d. Except for glass tubing, stirring rods, and graduated cylinders, use borosilicate
glassware (e.g., Pyrex). Examine your glassware closely for flaws such as cracks
and chips. Damaged glassware should be repaired (see your supervisor) or
discarded in a properly labeled glassware waste container.
e. All equipment should be free from flaws such as cracks, chips, frayed wire, and
obvious defects. Check with your supervisor if you have questions.
f. A properly placed pan under a reaction vessel or container will act as a
secondary containment device to confine spilled liquids in the event of glass
g. Use shields when working with reactive mixtures. Place the shields in suitable
positions to protect yourself and others. Stabilize the shields with weights or
fasteners so that they cannot be knocked over. Wear both eye and face
protection when using shields.
ventilating motors (if present) do not spark.
Whenever possible, use an enclosed, nonsparking electric heater or hot plate
or use steam in place of a gas burner. Use only nonsparking motors (e.g., air
motors) in the work area when flammables are present.
Support and orient large separatory funnels so that the stopcock will not be
loosened by gravity. Use retainer rings on the stopcock plugs.
Use securely positioned clamps to support condensers; secure attached water
hoses with wire or clamps.
Secure stirrer motors and vessels firmly to maintain proper alignment.
Magnetic stirring is preferable, except for viscous materials.
Position an apparatus that is attached to a ring stand so that the center of
gravity of the system is over the base and not to one side. Arrange the apparatus
so that burners and baths can be removed quickly. Stands bearing heavy loads
should be firmly attached to the bench top. Anchor equipment racks at both
the top and the bottom.
Never place any apparatuses, equipment, boxes (empty or filled), containers
of chemicals, or any other objects on the floor.
Never heat a closed container. Make sure the heating apparatus has a vent.
Before you heat more than a few milliliters of a liquid in an unstirred vessel,
add some boiling stones or a short glass tube with one end closed. If, as in
some distillations, there is the possibility of a dangerous exothermic reaction
or decomposition, use a thermometer during the procedure to monitor the
temperature of the liquid. This will provide a warning and may allow time to
remove the heat and apply external cooling.
Use an appropriate gas trap whenever evolution of hazardous gases or fumes
is possible.
Chemical hoods are recommended for all operations in which toxic or
flammable vapors are evolved. Most flammable vapors have a density greater
than that of air and will settle on a bench top or floor, where they may diffuse
to a distant burner or other ignition source and flash back. These vapors will
roll out over astonishingly long distances, and any ignition can flash back to
the source. However, once diluted with significant amounts of air, the vapors
will move in air essentially as air itself.
When working with quantities of flammable liquids or gases that are too great
to be conveniently handled in an enclosed hood, make sure that the
procedures to be carried out have been thoroughly reviewed by a competent
safety expert.
Use a hood when working with a system under reduced pressure (which may
implode). Close the sash of the hood to provide a shield. Note that unless
designed and built for the purpose, hoods are not to be relied on for protection
in case of an explosion.
When working with flammable gases or liquids:
a. Do not allow burners or other ignition sources in the vicinity unless your
supervisor directs otherwise.
b. Use appropriate traps, condensers, or scrubbers to minimize release of material
to the environment.
c. If you will be using a hot plate or heating mantle, do not proceed with your
work until you know the autoignition temperature of the chemicals likely to
be released and can ensure that the temperatures of all exposed surfaces are less
than those autoignition temperatures.
d. Make certain that the temperature-control device and the stirring and
To cut glass tubing, hold the tubing against a firm support and make one
quick, firm stroke with a sharp triangular file or glass cutter, rocking the file to
Preparation of Glass Tubing and Stoppers
extend the deep nick one-third around the circumference. Cover the tubing with
cloth, and hold the tubing in both hands away from your body, with the nick
centered between your hands and turned away from your body. Place your thumbs
on the tubing opposite the nick about 1 in. apart and extended toward each other.
Push out on the tubing with your thumbs as you pull the sections apart, but do
not deliberately bend the glass with your hands. Avoid accidental contact of the
tubing with a nearby person by standing with your back toward a wall or the lab
bench. If the tubing does not readily pull apart, the nick probably is too shallow
or rounded; make a fresh, sharp file scratch in the same place and repeat the
operation. Be careful when cutting a short piece from a long piece of tubing,
because the long end may whip and injure a nearby person.
All glass tubing and rods, including stirring rods, should be fire polished
before use. Unpolished cut glass has a razorlike edge, which not only will lacerate
the skin but will cut into a stopper or rubber hose, making it difficult to insert the
glass properly. After polishing or bending glass, allow ample time for it to cool;
then touch it gingerly before grasping it to be certain it is not too warm.
When drilling a stopper, use only a sharp borer that is one size smaller than
what would just slip over the tube to be inserted. For rubber stoppers, lubricate
with water or glycerol. Bore holes by slicing through the stopper, twisting with
moderate forward pressure, grasping the stopper only with the fingers, and keeping
the hand away from the back of the stopper. Keep the index finger of the drilling
hand against the barrel of the borer and close to the stopper to stop the borer
when it breaks through. Drill only partway through, and then finish by drilling
from the opposite side. Discard a stopper if a hole is irregular or does not fit the
inserted tube snugly, if it is cracked, or if it leaks.
When available, ground glassware is preferable. Glass stoppers and joints
should be clean, dry, and lightly lubricated. Rubber or cork stoppers should fit so
that one-third to one-half of the stopper is inserted into the joint. Corks should
have been previously softened by rolling and kneading.
h. Often a cork borer can be used as a sleeve for the insertion of glass tubes.
Borosilicate glassware is recommended for all laboratory glassware except for
special experiments that use UV or other light sources. The only soft glassware that
should be used are some reagent bottles, measuring equipment, stirring rods, and
tubing. Any sizable nonspherical glass equipment to be evacuated, such as suction
flasks, should be specially designed with heavy walls. Dewar flasks and large
vacuum vessels should be taped or otherwise screened or contained in a metal
jacket to prevent flying glass caused by an implosion. Thermos bottles with thin
walls are not adequate substitutes for Dewar flasks. Bottles, jars, and other
containers of acids, alkalies, flammable or combustible substances, or corrosive
chemicals should be transported in carriers to protect them from breakage, as well
as to limit the spread in case of leaks. Note that even plastic containers can cause
similar problems because plastic can be punctured, fail under pressure or heat, or
crack as a result of age.
Working with Reduced Pressure
Frequently a short piece of metal tubing can be substituted for glass tubing.
The following practices will help to prevent accidents:
a. Make sure the diameter of the tube or rod is compatible with the diameter of
the hose or stopper.
b. Fire polish the end of the glass to be inserted.
c. Lubricate the glass. Water may be sufficient; glycerol is a good lubricant.
d. Wear leather gloves or wrap a cloth around the glass and protect the other
hand by holding the hose or stopper with a cloth.
e. Hold the glass not more than 5 cm from the end to be inserted.
f. Insert the glass with a slight twisting motion, avoiding too much pressure and
g. A tube that has become stuck in a hose or stopper may be removed by slitting
the hose or stopper with a sharp knife.
Protect vacuum desiccators by covering them with cloth-backed friction or
duct tape or by enclosing them in a sturdy box or in an approved shielding device
to restrict flying fragments in case of an implosion. Store only chemicals being
dehydrated or protected from moisture in a desiccator. Before opening a desiccator
that is under reduced pressure, make sure that atmospheric pressure has been
restored. Occasionally, a vacuum desiccator lid will be found to be frozen after
atmospheric pressure has been restored. Try using a single-edge razor blade as a
wedge; tap it gently with a wooden block to loosen the lid.
Surround an apparatus that is under reduced pressure with shielding. If you
use vacuum pumps, place a cold trap between the apparatus and the vacuum
pump so that volatiles from a reaction or distillation neither mix with the pump
oil nor escape into the atmosphere of the work area. When possible, vent exhausts
from pumps to a properly functioning hood. Vacuum pumps with belt drives must
be equipped with belt guards.
Water aspirators for reduced pressure are used for filtration purposes and for
some rotary evaporations. Use only equipment that is approved for these purposes.
For example, use only a heavy-walled filter flask designed for the purpose; never
apply reduced pressure to other flat-bottomed flasks. When you use a water
aspirator for reduced pressure, place a trap and a check valve between the aspirator
and the apparatus so that water cannot be sucked back into the system if the water
pressure should fall unexpectedly during filtering.
Superheating and consequent bumping (sudden boiling) frequently occur
when you use reduced pressure for distilling. Therefore, it is important that the
assembled apparatus is secure and that heat is distributed more evenly than is
possible with a flame. Use a heating mantle whenever possible. Evacuate the
assembly gradually to minimize the possibility of bumping. Stirring or using a
nitrogen or other inert gas (never use air) bleed tube often can provide good
Insertion of Glass Tubes or Rods into Stoppers or Flexible
vaporization while preventing bumping or overheating and decomposition. Use
standing shields to surround the apparatus for protection in the event of an
implosion. After you finish a reduced-pressure distillation, allow the system to
cool before slowly bleeding in air; the oxygen in air that is introduced into a hot
apparatus may induce an explosion in the hot system. Pure nitrogen or another
inert gas is preferable to air during distillation and for cooling the system.
Bench-top centrifuges should be anchored securely so that if vibration occurs,
they will not “walk” off the edge of the bench or knock over bottles and equipment.
These rules apply to the safe operation of centrifuges:
a. If vibration occurs, stop the centrifuge immediately and check the
counterbalance load. If swing-out buckets are present, check them for clearance
and support.
b. Always close the centrifuge lid before operating the centrifuge; keep it closed
while the centrifuge is running.
c. Do not leave the centrifuge until full operating speed is attained and the
machine appears to be running safely without vibration.
d. If the centrifuge has no brake, allow the centrifuge to coast to a stop. If it has
a brake, use the brake, not your hand, to stop the centrifuge.
e. If requested by your supervisor, thoroughly clean the centrifuge and buckets
regularly using a noncorrosive cleaning solution.
c. Nonflammability
d. Low volatility
e. Suitable freezing point
Acetone and butanone are volatile and flammable and should not be used.
Isopar L, a mixture of long-chain isoparaffins that has a boiling point of 188 °C
and a flash point of 60 °C, is an excellent substitute. When Isopar L is mixed with
dry ice, temperatures of about -75 °C can be achieved. Therefore, Isopar L is
suggested instead of acetone in combination with dry ice for cold traps and cooling
The final choice of a liquid will also depend on the temperature requirements.
Although no substance works in all situations, these liquids are suggested:
a. Isopar L
b. Ethylene glycol or propylene glycol in a 3:2 ratio with water and thinned with
isopropyl alcohol (CAUTION: becomes viscous)
c. Some glycol ethers (CAUTION: become viscous)
d. Isopropyl alcohol (CAUTION: flammable)
Add the dry ice to the liquid, or the liquid to the dry ice, in small increments.
Wait for the foaming to stop before proceeding with the addition. The rate of
addition can be increased gradually as the liquid cools.
Do not lower your head into a dry ice chest. No oxygen is present, and
suffocation can result. Do not handle dry ice with bare hands; if the skin is even
slightly moist, a severe burn can result. Wear dry leather or suitable cryogloves,
safety goggles, and a lab coat when handling dry ice.
Oil and Sand Baths
When you use hot oil or sand for heating, take care to avoid hazardous
spattering if water or an organic liquid falls into the hot oil or sand.
Avoid overheating an oil bath. Watch for smoking of the oil; oil that is
smoking is too hot and may burst into flames at any moment. Do not leave an
operating sand or oil bath unattended unless it is equipped with a hightemperature shutoff and a warning label (Hot Oil or Hot Sand).
Ensure that glassware that is to be used in an oil or sand bath is free of cracks
and other imperfections. Do not use a sand or oil bath unless it is equipped with
a thermometer or other temperature-indicating device. In addition, an oil bath
must be labeled with the name of the oil and its maximum safe working
temperature. Take precautions to contain any spills of hot oil or hot sand caused
by breakage or overturning of the baths.
Cold Traps
When ice water is not cool enough as a bath or cold trap, salt and ice may be
used. For lower temperatures, dry ice or dry ice with an organic liquid may be used.
To be used safely with dry ice, an organic liquid should have the following five
a. Nontoxic vapor
b. Low viscosity
Cold traps that are used in reduced-pressure systems should be wrapped with
cloth-backed friction tape or duct tape so that, in the event of an implosion, the
tape will reduce flying glass. A better alternative is to place the cold trap in a
vermiculite-filled metal can.
Special attention should be directed to the boiling points of the components
and the possible products of materials in the system. Even an inert atmospheric gas
must be considered. For example, argon, a common inert gas, has a boiling point
of -186 °C, which is very close to that of liquid nitrogen (with a boiling point of
-195 °C), a common coolant for cold traps. Argon is condensed into traps cooled
with liquid nitrogen. When the cooling bath is removed, the argon rapidly
vaporizes and the rate of pressure buildup may be too great to be vented or
pumped down. A potentially dangerous explosion can occur.
Exercise caution when using liquid cryogenic coolants. Follow the precautions
described in the MSDS for the cryogenic liquid you will be using. Be aware that very
low temperature coolants, such as liquid nitrogen, will condense oxygen from the
air upon standing and then cause an explosion if they come in contact with
combustible materials. These precautions are essential:
a. Wear gloves, a lab coat, and a face shield. Immerse the object to be cooled
slowly to avoid too vigorous boiling and overflow of the coolant.
b. Use only properly vented containers when handling cryogenic liquids.
Cooling Baths, Cold Traps, and Temperature Control
Cooling Baths
Glass Dewar flasks should be made of borosilicate glass. Protect them by
covering them with cloth-backed friction tape or duct tape or by encasing them
in a metal sheath to contain flying pieces in the event of an implosion.
d. The edge of a glass Dewar flask is fragile. Avoid pouring cold liquid onto the
edge of a glass Dewar flask when filling because the flask may break and
implode. For the same reason, do not pour a cryogenic liquid out of a glass
Dewar flask; use a siphon. Consider using a metal or plastic Dewar flask to
eliminate this problem.
e. Never use a household thermos bottle or other insulated container in place of
a Dewar flask. Thermos bottles and other insulated containers are designed to
keep consumable liquids cold; they are not sturdy enough for laboratory use.
Temperature Control
Many reactions must be initiated by heating. Because the rates of most
chemical reactions increase as the temperature increases, highly exothermic
reactions can become dangerously violent unless provisions are made for adequate
cooling. Some exothermic reactions have an induction period. In such reactions,
if too much reagent was added initially, the reaction can become too vigorous for
effective condensation of vapors once the induction period is completed. A cooling
bath must be prepared in advance and be ready to be applied promptly to the
reaction vessel. Remember that viscous liquids transfer heat poorly and require
special precautions.
Many reactions require some temperature control. Assemble your apparatus
in such a way that both heating and cooling can be controlled-that is, readily
applied and withdrawn. For example, when you are heating the contents of a test
tube in a burner flame, it is easy to overheat the test tube and cause the contents
to boil up and out. To prevent this, hold the test tube with a test tube holder and
heat it gently along the side, not at the bottom. Or heat the contents of a test tube
by placing it in a hot water bath. Never point a heated test tube toward yourself or
any other person.
Compressed Gases
When ordering hazardous gases, consider factors such as handling and storage,
eye and skin absorption, proper gas regulators, and chemical properties. The
publications of the Compressed Gas Association and of major suppliers should be
consulted before using compressed gases. The rules for proper use of compressed
gases include the following:
a. Handle cylinders of compressed gases as high-energy sources and therefore as
potential explosives.
b. Restrain cylinders of all sizes, empty or full, individually by straps, chains, or
a suitable stand to prevent them from falling.
c. Store cylinders in appropriately ventilated cabinets or in an open storage area.
d. When storing or moving cylinders, secure the protective caps in place over the
valves in order to protect the valve stems.
e. When moving cylinders, use only properly designed wheeled carts, and before
moving, strap the cylinders securely in place on the cart.
Do not expose cylinders to temperatures higher than about 50 °C. The rupture
devices on some cylinders will release at about 65 °C. Some small cylinders,
such as lecture bottles, are not fitted with rupture devices and may explode if
exposed to high temperatures.
Never use cylinders if their contents cannot be identified positively.
Never lubricate, modify, force, or tamper with cylinder valves.
Use toxic, flammable, or reactive gases only in laboratory hoods that are
known to be operating properly.
Never direct compressed air or high-pressure gases at a person.
Do not use compressed gas or compressed air to blow away dust or dirt; the
resultant flying particles are dangerous.
Be aware that rapid release of a compressed gas will cause an unsecured gas
hose to whip around dangerously.
Rapid release of a compressed gas builds up a static charge that could ignite the
gas if it is flammable or combustible.
Do not extinguish a flame involving a highly combustible or flammable gas
until the source of gas has been shut off; otherwise, it can reignite and burn or
even explode.
Close main cylinder valves tightly when they are not in use.
Promptly remove the regulators from empty cylinders, and replace the
protective caps at once. Label the cylinder to show that it is empty.
Never bleed cylinders completely. Leave a slight pressure to keep out
Use the appropriate regulator on each gas cylinder. The threads on the
regulators are designed to prevent improper use. Adapters and homemade
modifications can be dangerous. Do not use them.
Do not put oil or grease on the high-pressure side of a cylinder of oxygen,
chlorine, or any other gaseous oxidizing agent. A fire or explosion can result.
Never put oil or grease in, on, or near a regulator for the same reason.
Always wear safety glasses or goggles when handling and using compressed
Observe the following special rules when working with acetylene cylinders:
• Always store acetylene cylinders upright. They are partially filled with liquid
acetone, which can be discharged instead of or along with acetylene if the
cylinder is not upright.
• Do not use an acetylene cylinder that has been stored or handled in a nonupright position until it has remained in an upright position for at least 30
• Ensure that the outlet line of an acetylene cylinder is protected with a flash
• Never exceed the pressure limit indicated by the warning red line of an
acetylene pressure gauge. Acetylene polymerizes rapidly and spontaneously
when under “red line pressures”. The polymerization reaction is rapid,
violent, and exothermic.
• Use the correct kind of non-cuprous tubing to transport gaseous acetylene.
Tubing made of copper or high-copper brass will form copper acetylides,
which are explosively unstable and shock- and impact-sensitive.
General Procedures
The following steps are generally applicable:
a. Immediately alert fellow workers and the supervisor.
b. For all spills, all contaminated clothing must be removed immediately and
the skin washed with soap and water. Flush the skin with water for no less
than 15 minutes. Clothes must be laundered before reuse. (Do not wash with
other clothing.) See also Section 6.3.
c. If there is no fire hazard and the material is not particularly volatile or toxic,
proceed to clean it up as directed in the MSDS. To facilitate cleaning up liquids,
use an absorbent material that will neutralize the liquids if possible (trisodium
phosphate, sand followed by sodium bicarbonate solution or powder for acids,
sodium thiosulfate solution for bromine, etc.). Various commercial absorbents
packaged individually (spill kits) or in bulk are available. Vermiculite and clay
absorbents such as cat litter can be more economical substitutes, but they will
not control hazardous vapors. Dry sand is even less effective. A dustpan and
brush should be used, and protective gloves should be worn. While wearing
gloves, clean the contaminated area with soap and water and mop it dry. If
the spill is on the floor, some absorbent should be sprinkled on the spot to
prevent slipping. Dispose of the residue properly. CAUTION: Vermiculite and
some other absorbents create a slipping hazard when wet.
d. If a volatile, flammable, or toxic material is spilled, immediately warn everyone
to extinguish flames and turn off spark-producing equipment such as brushtype motors. Shut down all equipment, and vacate the area until it is
decontaminated. The supervisor or management will be responsible for
designating the extent of evacuation and the proper cleanup procedure. Avoid
skin contact and, to prevent inhalation, wear an appropriate breathing
apparatus. Clothing contaminated by spills or splashes should be removed
immediately to prevent skin penetration.
e. Many small liquid spills (less than 100 mL) can be absorbed with paper towels,
sand, or an absorbent. However, paper towels can increase the surface area
and evaporation, increasing the fire hazard. Most solid spills can be brushed
up and disposed of in appropriate solid-waste containers, but care must be
exercised to avoid reactive combinations. Don’t leave paper towels or other
materials used to clean up a spill in open trash cans in the work area. Dispose
of them properly.
or Zorball. Avoid contact with skin.
b. Mercury. Because of the high toxicity of mercury vapor, spilled mercury should
be immediately and thoroughly cleaned up using an aspirator bulb or a
vacuum device. If a mercury cleanup unit is available, become familiar with its
location and proper use. Mercury spilled into floor cracks can be made
nonvolatile by amalgamation with zinc dust. Domestic vacuum cleaners must
not be used because they will only redisperse mercury aerosols and spread the
contamination. A mercury vapor monitoring instrument should be available
for determining the effectiveness of the cleanup.
c. Alkali metals. A spill of an alkali metal should be smothered with powdered
graphite or Met-L-X extinguisher and moved to a safe location where it can be
disposed of by reaction with a long-chain primary alcohol (n-butyl alcohol is
acceptable). Sodium-potassium alloys (NaK) present even greater hazards than
either sodium or potassium alone; observe the suppliers’ recommendations
strictly. Particles of alkali metal splattered on the skin should be rapidly
removed, and the skin should be flushed quickly with water. If any metal on
the skin becomes ignited, deluge it with cold water immediately.
d. White (yellow) phosphorus. A spill of white (yellow) phosphorus should be
blanketed with wet sand or wet absorbent and disposed of by controlled
burning outdoors, but first consult the regulations. If any white phosphorus
is splattered on the skin, flush the skin with cold water and remove any
adhering phosphorus.
Chemicals on the Skin
For spills covering small amounts of skin, immediately flush with water for no
less than 15 minutes. If there is no visible burn, wash with warm water and soap,
removing jewelry to facilitate removal of any residual materials. Check the MSDS
to see if delayed effects should be expected. If a delayed reaction is noted, seek
medical attention immediately and explain carefully what chemicals were
For larger spills, quickly remove all contaminated clothing, shoes, jewelry, etc.,
while using the safety shower. Do not attempt to wash chemicals off clothing.
Instead, remove the clothing. Seconds count, and no time should be wasted
because of modesty. Be careful not to spread the chemical on the skin or especially
into the eyes. Unless the eyes are affected, do not remove safety goggles until all
chemicals are washed from the hair and face. Use caution when removing pullover
shirts or sweaters to prevent contamination of the eyes. It may be better to cut the
garments off. Immediately flood the affected body area with tempered water for
at least 15 minutes. Resume if pain returns. Do not use creams, lotions, or salves.
Get medical attention as soon as possible.
Chemicals in the Eyes
a. Acids and other acid materials. Use calcined absorbent products, such as Oil-Dri
For chemical splashes, at least a 15-minute flush is recommended.
Immediately flush the eyes with a copious amount of water under gentle pressure,
checking for and removing contact lenses at once. However, contact lenses may
Spills of Specific Types of Chemicals
be difficult to remove, and the essential irrigation must not be delayed. Forcibly
hold the eyes open to wash thoroughly behind the eyelids. Eyeballs should be
rotated so that all surfaces are rinsed. In the absence of some type of eyewash
device, the injured person should be placed on his or her back and water gently
poured into the eyes. The injured eyes must be held open. After flushing, the
injured person must be given prompt medical attention, regardless of the severity
(or apparent lack of severity) of the injury. Keep the eyes immobilized with clean,
wet, soft, cold pads while transporting the injured to medical attention.
sodium bisulfite (NaHSO3) solution; larger spills should be absorbed with inert
solids such as vermiculite, sand, or salt and then reacted with sodium bisulfite in
a safe area. Skin that has been burned by these peroxides should be washed gently
but thoroughly, and the injured person should be given prompt medical attention.
Organic Peroxides and Hydroperoxides
General Considerations
Peroxides all contain the -OO- group; hydroperoxides, the -OOH group.
Inorganic peroxides are known for the alkali metals, calcium, strontium, and
barium. Such compounds are generally stable, but they produce hydrogen peroxide
when reacted with water or dilute acids. When in contact with organic compounds,
inorganic peroxides will form carbonate. Inorganic peroxides must be stored,
handled, and used with caution. Peroxides of alkali metals are not sensitive to
shock but are decomposed by moisture. The most common inorganic peroxides
are sodium peroxide (Na2O2), hydrogen peroxide, sodium perborate, and sodium
persulfate (Na2S2O7).
Small spills of inorganic peroxides can be reacted cautiously with aqueous
Most organic peroxides, R-O-O-R, and hydroperoxides, R-O-O-H, are unstable
to some degree and can be difficult to handle. The hazard is greater with shortchain (low-carbon-number) peroxides. Many lower molecular weight peroxides
can explode violently.
Organic peroxides and hydroperoxides are sensitive to heat, mechanical shock,
friction, impact, and contact with oxidizing and reducing agents. All organic
peroxides are flammable, and fires involving bulk quantities should be approached
with extreme caution. Peroxides can burn vigorously, and putting out such fires is
difficult. Even peroxides of moderate flammability can present fire hazards because
they decompose to form highly flammable products. The oxygen formed by
peroxide decomposition supports the ignition.
Organic peroxides are generally more stable when water is present to lower the
shock and heat sensitivity of the peroxide. For example, benzoyl peroxide is a solid
(with a melting point of 104-106 °C) that can ignite or explode from heat, impact,
or friction, and that must be kept moist in storage. Unscrewing a container that has
dry benzoyl peroxide or other peroxide crystals caught in the lid threads can cause
the entire contents of the container to explode. Keep on hand no more than a
short-term supply of any peroxide, and check the container at regular intervals. If
in doubt, call an expert for disposal of these dangerous chemicals.
The following precautions should be followed when handling organic
peroxides and hydroperoxides:
a. Study and follow all precautions specified by the manufacturer of the
substance before using it.
b. Store the peroxides at the minimum safe temperatures to minimize the rate of
decomposition. CAUTION: Do not refrigerate liquid or solutions of peroxides
at or below the temperature at which the peroxides freeze or precipitate.
Peroxides in these forms are extra sensitive to shock and heat.
c. Limit the quantity of peroxide handled to the minimum amount required.
Do not return unused peroxide to the container.
d. Clean up all spills immediately using the procedures recommended in the
MSDS. The first step is usually to dilute or disperse the peroxide with an inert
e. Remember that the sensitivity of most peroxides to shock and heat can be
reduced by dilution with inert solvents such as aliphatic hydrocarbons (e.g.,
mineral oil) but NEVER with acetone or other oxidizable materials.
f. Avoid using solutions of peroxides in volatile solvents when it is possible that
the solvent will vaporize and thereby increase the peroxide concentration.
g. Never use a metal spatula with organic peroxides. Contamination by metals
Releases of Acutely Toxic Vapors and Gases
Some vapors and gases can be permanently disabling or lethal when inhaled
even at low concentrations. These include the following:
a. Fluorine
b. Chlorine
c. Bromine
d. Iodine
e. Phosgene
f. Hydrogen cyanide and other cyanides
g. Hydrogen sulfide
h. Hydrogen selenide
i. Hydrogen fluoride
j. Arsine
k. Stibine
l. Phosphorus trichloride
m. Phosphorus oxychloride
n. Phosphorus tribromide
o. Methyl isocyanate
If you plan to work with any of these chemicals, you should not only consult
the MSDS but seek additional guidance on evacuation steps, first aid, and handling
procedures before you begin working with the chemical.
Inorganic Peroxides
can cause explosive decomposition. Use ceramic or plastic spatulas instead.
h. Do not permit smoking, open flames, sparking equipment, or any other source
of intense heat near peroxides.
i. Avoid friction, grinding, and all forms of impact, especially with solid organic
peroxides. NEVER use glass containers with screw-cap lids or glass stoppers.
Instead, use plastic (e.g., polyethylene) bottles and sealers.
j. Because peroxides are generally irritants, avoid ingestion, inhalation, and skin
contact. Flush with water. Treat any areas of contact for burns, and get medical
Disposal of Organic Peroxides
CAUTION: Only an expert or a bomb squad should dispose of highly
concentrated peroxides of 25 g or more.
a. Disposal of smaller quantities of peroxides can be done by diluting with water
or another inert substance to a concentration of 2% or less and then
transferring the mixture to a polyethylene disposal vessel containing an
aqueous solution of a reducing agent (e.g., sodium bisulfite or acidified ferrous
sulfate). Stir the mixture gently, then vigorously to complete the chemical
reaction. Do not mix the resultant material with other waste chemicals for
disposal. Spilled peroxides should be absorbed on vermiculite as quickly as
possible. The mixture may then be burned directly or may be stirred with a
suitable solvent to form a slurry that can be treated according to company
procedures. Never flush organic peroxides down the drain.
b. Large quantities (more than 25 g) of dilute peroxide solutions may require
expert assistance. Consider each case individually for handling, storage, and
disposal. Refer to the manufacturer’s recommendations, and comply with
applicable regulations.
Peroxide-Forming Compounds
General Considerations
d. Saturated hydrocarbons with exposed tertiary hydrogens
Some specific and typical examples are diethyl ether, diisopropyl ether,
tetrahydrofuran (THF), p-dioxane, cyclohexene, isopropylbenzene (cumene),
tetrahydronaphthalene (tetralin), divinylacetylene, decahydronaphthalene, and
Peroxide-forming compounds cannot form peroxide or hydroperoxide
compounds without exposure to oxygen or other oxidizers. Therefore, their
containers should always be tightly sealed. Air should always be flushed out of the
free space with an inert gas (usually nitrogen) before sealing. Plastic caps, stoppers,
and plugs should be used to reduce corrosion and friction.
Peroxidation is generally a problem of the liquid state. Solid peroxide-forming
compounds present little problem except when finely divided because the reaction,
if any, will occur only at the surface. Peroxidation seems to be no problem within
gases and vapors. For liquids, the peroxidation typically occurs when containers are
not completely sealed and “blanketed” with inert gas. Breathing then occurs with
changes in temperature and barometric pressure, and oxygen gets into the
containers. Peroxide buildup is usually slow because the exchange of air is usually
If abundant oxygen is supplied to a fast peroxide-forming compound, typically
there is an induction period, followed by a relatively fast accumulation of
hydroperoxide, which tapers off at a maximum level. Then the concentration
stabilizes or even decreases because the hydroperoxide itself undergoes
decomposition, forming byproducts such as alcohols and water that interfere with
the free-radical chain reaction of peroxidation. The byproduct content may
continue to grow, but the peroxide content does not. CAUTION: This scenario
does not apply when peroxides separate in solid form. Then the peroxide is
undiluted by solvents or byproducts and is an immediate threat.
Detection and Determination of Peroxides
Peroxide-forming compounds react with oxygen even at low concentrations
and ordinary temperatures to form peroxide compounds that are usually
hydroperoxides. In addition to any other hazards that they have, they pose a
“peroxide threat”, especially if the oxygenated product crystallizes when the
material is cooled or becomes concentrated by evaporation or distillation of the
unoxidized part. Peroxide crystals may form on the ground glass or other surfaces
of a sealing plug or within the threads of a cap. Removing the plug, unscrewing,
or otherwise removing the cap has caused detonations with serious, and in some
cases fatal, consequences.
There are four main groups that are known to be peroxide-forming
a. Ethers with primary and/or secondary alkyl groups, including open-chain and
cyclic ethers, acetals, and ketals
b. Hydrocarbons with allylic, benzylic, or propargylic hydrogens
c. Conjugated dienes, eneynes, and diynes
A test for peroxides should only be attempted if it is clear that no danger will
result from moving or opening the container. Solids observed in the liquid or
around the cap can indicate dangerous peroxide buildup. The presence of most
peroxy compounds, including all hydroperoxides, can be detected by the following
test: Mix 1-3 mL of the liquid to be tested with an equal volume of glacial acetic
acid in a test tube, add a few drops of 5% aqueous potassium iodide solution, and
shake. The appearance of a yellow-to-brown color indicates the presence of
peroxide. If the color is faint, run a blank to make sure the test is really positive. A
semiquantitative testing kit using treated paper strips is available from chemical
suppliers. Quantitative titration procedures are known.
However, in order to test for the presence of peroxide in a peroxide-forming
compound, it is necessary to open the container. Test peroxide-forming
compounds for the presence of peroxide immediately on receipt from the supplier,
and repeat the testing frequently. If the peroxide test is positive, take the appropriate
steps; if negative, record the date and the result (e.g., on a tag or label affixed to the
container) and return the container to its proper place in storage.
Some Uncommon Peroxy Compounds
Expect surprises when dealing with peroxy compounds. Two paraffinic
hydrocarbons, 2,5-dimethylhexane and 2,6-dimethylheptane, have been found to
deposit crystalline dihydroperoxides upon long exposure to air. The liquid phase
always contains a low concentration of the corresponding monohydroperoxide.
Caution is recommended.
1,4-Cyclohexadiene has been found to react with oxygen and generate
hydrogen peroxide. When exposed to air, the clear liquid becomes cloudy and
slowly forms a bottom layer that proves to be hydrogen peroxide in 60-80%
concentration. This is capable of inflicting severe burns. Dilution or washing
with water easily removes the immediate hazard. An organic hydroperoxide is
formed, but it immediately decomposes into hydrogen peroxide and benzene.
Some alkyl derivatives of this hydrocarbon behave similarly.
Most ketones, especially when they are water-free and exposed to sunlight,
can peroxidize slowly. They form peroxides rapidly when in contact with peroxy
reagents. Acetone can form an explosive crystalline peroxide when treated with
hydrogen peroxide. Other ketones may yield peroxides, which may not be
crystalline products, by similar treatment. Do not mix peroxy compounds with
ketones unless literature reports or cautious experiments prove that the exact
procedure is safe.
Follow these precautions for storing and handling peroxide-forming
a. Label the chemicals as peroxide-forming or (in some cases) as possible
peroxide-forming materials.
b. In laboratory use, limit the stock of any item to a supply of 3 months or less,
and discard the remaining stock unless it is found to be essentially peroxidefree.
c. In plant use, monitor drum and tank supplies at regular intervals (1-3
months). If peroxide starts to accumulate, use the lot promptly only if the
peroxide level is considered safe. If not within safe limits, destroy or remove
the peroxide.
d. In both laboratory and plant storage, always maintain an inert atmosphere
(nitrogen or argon) in the “free” space of each container. Either flush with a
stream of the gas or use pressure siphoning with the gas when withdrawals
are made.
e. Unless it would compromise the material’s usefulness, add an oxidation
inhibitor to it. The recommended amount is from 0.001 to 0.01% of inhibitors
such as hydroquinone, 4-tertiary-butylcatechol (TBC), or 2,6-ditertiary-4methylphenol (BHT).
f. Before distilling any known or suspected peroxide-forming compound,
check it carefully for peroxide. If any is present, eliminate it by chemical
treatment or percolation through a suitable adsorbent, or add a highboiling aliphatic hydrocarbon (such as mineral oil) to prevent the peroxide
from concentrating to a dangerous level. Never distill a peroxide-forming
material to dryness.
Perchloric Acid
Under some very specific conditions, perchloric acid is a powerful oxidizing
agent that may react explosively with organic compounds and other reducing
agents. Room temperature perchloric acid solutions can oxidize at
concentrations above 73%. When heated to temperatures greater than 60 oC,
perchloric acid begins to exhibit oxidizing potential at concentrations of about
50%. Under these conditions, perchloric acid must be used only in a water
wash-down laboratory chemical hood of noncombustible construction.
Frequent inspections should be made to prevent perchloric acid and perchlorate
accumulation in the exhaust system of the hood. Do not use perchloric acid
around wooden tables or benches. Keep perchloric acid bottles on glass or
ceramic trays that have enough volume to hold all the acid, should the bottle
break. Organic matter should be digested with nitric acid before the addition
of perchloric acid. Never heat perchloric acid with sulfuric acid because
dehydration may produce anhydrous perchloric acid. Transition-metal
perchlorates are capable of exploding.
Many of the commonly used solvents are volatile and can be harmful even
upon exposure to relatively small amounts. Some are readily absorbed through
the skin. Most are flammable or combustible. Organic solvents should be regarded
as potentially hazardous unless definitely known to be innocuous.
Flammable Liquids
A flammable liquid itself does not burn; it is the vapor from the liquid that
burns. The vapors are often denser than air. The vapors can travel long distances
and also accumulate in pits and other low areas. The vaporization rate increases
as the temperature increases; therefore, a flammable liquid is more hazardous at
elevated temperatures than at normal temperatures. Minimize fire and explosion
hazards associated with flammable liquids by observing the following precautions:
a. Keep flammable liquids away from heat, direct sunlight, and sources of static
electrical charge. See Section 11.2.
b. Do not heat flammable liquids directly over a flame or other source of heat
that can generate sparks or that has a surface temperature approaching the
autoignition temperature of the liquid.
c. Before using equipment that produces a spark, a flame, or a hot surface (e.g.,
motors, hot plates, and open heaters), verify that no flammable vapors are
present. The turning on of a light, a timer, or an actuated relay switch-or the
ringing of a telephone-can ignite flammable vapors, even when the source of
the vapor, a flammable liquid, is not nearby.
d. Do not dispose of flammable liquids in sinks or drains.
e. Use a laboratory chemical hood or equivalent ventilation when appreciable
quantities of flammable materials are transferred from one container to
another, allowed to stand in open containers, or heated in open containers.
Toxicity of Solvents
The toxicity of common solvents must be recognized. Some common solvents
that require special care are the following:
a. Benzene
b. Carbon disulfide
c. Glycol esters and glycol ethers
d. Halogenated hydrocarbons
e. Nitrogen bases, such as amines
Many halogenated hydrocarbons are suspected human carcinogens. Avoid
exposure to the liquids and their vapors. High concentrations in the air also can
rapidly lead to death from respiratory failure. Less severe exposure can lead to
kidney and liver damage. Halogenated hydrocarbons can also be absorbed through
the skin.
Benzene is a human carcinogen. Chronic poisoning can occur by inhalation
of relatively small amounts of benzene over a long period of time. The toxic action
is primarily on the blood-forming organs. Contact with the skin should be avoided
because of potential skin absorption. Also, like other solvents, benzene causes
dryness and cracking of the skin, which opens the way to infection and allergic
responses. Benzene is also a flammable solvent and should be handled and
disposed of with extreme care in accordance with all prevailing regulations.
Whenever possible, toluene or xylene should be substituted for benzene.
Cryogenic Hazards
without outside pockets or wear a laboratory apron. Wear cuffless pants and
high-topped leather shoes to deflect any spills; the bottoms of the pants should
cover the tops of the shoes. Do not wear watches, rings, and other jewelry.
e. The eyes are particularly vulnerable to harm from exposure to cryogenic
liquids. Wear both safety goggles (Type G, H, or K) and a Type N face shield
when working with cryogenic liquids.
f. If it is necessary to handle chilled parts of the apparatus, consider wearing
insulating gloves. If the gloves become contaminated with an oxidizing
cryogenic liquid, handle the gloves as though they are flammable for at least
24 hours.
g. Avoid skin contact with cryogenic liquids. Even very brief contact can result in
severe frostbite and/or torn flesh.
h. Employees who use, handle, or store toxic cryogenic liquids and all co-workers
in the area should wear appropriate respiratory equipment.
i. Avoid inhaling air that has been cooled to near-cryogenic temperatures.
j. The chilled vapors from evaporated cryogenic liquids tend to accumulate in
pits and low-lying areas. These gases are invisible and have partially or
completely displaced oxygen from the area they occupy. Do not enter such
areas without wearing an oxygen-supplying respirator.
k. Never transport cryogenic liquids in an elevator. In the event of elevator
malfunction, the resulting collection of evaporated gas in the elevator shaft
from the cryogenic liquid could displace oxygen in the elevator. Even a socalled Dewar has a pressure-relief valve that can release evaporating vapors.
l. Many solids become brittle and fragile at cryogenic temperatures. Before
allowing an unfamiliar solid to be chilled to cryogenic temperatures, learn its
properties at such temperatures.
m. Immediately evacuate any area in which there is an uncontrolled release of a
cryogenic liquid or vapor.
For more information, see ACS’s Handbook of Chemical Health and Safety
and the Compressed Gas Association’s CGA P-12, Safe Handling of Cryogenic
Cryogenic conditions are generally agreed to include the temperature range
from the temperature of dry ice downward to temperatures approaching absolute
zero. All cryogenic liquids are liquefied gases. The liquefied gases combine the
hazards of flammability, reactivity, corrosivity, toxicity, and asphyxiation, and they
vigorously support combustion. Even liquid nitrogen, ordinarily considered to be
chemically inert, will condense oxygen from the air when allowed to stand exposed
in an open container. The resulting liquid mixture should be handled as though
it is as hazardous as pure liquid oxygen.
For example, when either liquid oxygen or oxygen-contaminated liquid
nitrogen is spilled on a flammable or combustible solid (e.g., clothing, asphalt,
wood), the oxygen, now a gas, tends to remain on and around the surface of the
solid for several hours. If a source of energy (e.g., an ignition source) is brought
near, a violent explosion can occur. Thus, asphalt on which liquid oxygen has
recently been spilled can explode violently when struck with a hammer.
Follow these necessary precautions:
a. Know the first aid procedures for frostbite before using, handling, or storing
a cryogenic liquid.
b. Keep flammables and combustibles well away from liquefied oxidizing gases.
For example, under suitable conditions, steel burns when in liquid oxygen.
c. Avoid pouring a cryogenic liquid into a household thermos bottle or other
insulated container ordinarily used to keep food or drinks cold.
d. When using, handling, or storing cryogenic liquids, wear a laboratory coat
In the laboratory and elsewhere, keeping things clean and neat generally leads
to a safer environment. Avoid unnecessary hazards by keeping drawers and
cabinets closed while you are working. Never store materials, especially chemicals,
on the floor-even temporarily. Workspaces and storage areas should be kept clear
of broken glassware, leftover chemicals, and even scraps of paper. Do not store
chemicals in the laboratory chemical hoods. Keep aisles and paths of egress free
of obstructions such as chairs, boxes, and waste receptacles. Do not block access
to emergency equipment or utilities. Do not use hallways and stairs as storage
spaces. Avoid slipping hazards by keeping the floor clear of ice, stoppers, glass
beads, glass rods, other small items, and spilled liquids. Use the required
procedures for the proper disposal of chemical and other wastes.
Cleaning Glassware
Clean glassware at the laboratory sink or in laboratory dishwashers. Use hot
water, if available, and soap or another detergent and mild scouring powder, if
necessary. Wear impervious gloves that have been checked to ensure that no holes
are present. Use brushes of suitable stiffness and size. Avoid accumulating too
many articles in the cleanup area. Usually the workspace around a sink is limited,
and piling up dirty or cleaned glassware leads to breakage. Remember that the
turbid water in a sink may hide a jagged edge on a piece of broken glassware that
was intact when put into the water. A pair of loose-fitting, coarse leather gloves
may be useful for removing broken glass, but care must be exercised to prevent
glove contamination. To minimize breakage of glassware, use sinks with rubber or
plastic mats on their bottoms but not over the drains.
Avoid the use of chemical cleaning agents such as nitric acid, chromic acid,
sulfuric acid, strong oxidizers, or any chemical with a “per” in its name (such as
perchloric acid, ammonium persulfate, etc.) unless specifically instructed to do so,
and then only when wearing proper protective equipment. A number of explosions
involving strong oxidizing cleaning solutions, such as chromic-sulfuric acid
mixtures, have been reported. The use of flammable solvents should be minimal,
and when they are used, appropriate precautions must be observed.
Laboratory Storage of Chemicals
All chemicals should be labeled properly and dated upon receipt. Peroxideforming chemicals should have the date the container was first opened on the
label. Do not expose chemicals to direct sunlight or heat. Store toxic materials in
a secure cabinet. Do not store chemicals on the floor or inside hoods. Laboratory
storage of large containers of reagents should be kept to a minimum. They should
be placed on a low shelf, preferably in a tray adequate to contain spills or leakage.
Incompatible materials should not be stored together or in close proximity. See the
list of incompatible chemicals in Appendix VI. Water-reactive chemicals should
not be stored near a water source such as a faucet or sprinkler. Corrosives should
never be stored above chin level. Safety cans must be provided for 1-gal or larger
quantities of flammable solvents. If chemical purity requirements preclude the use
of metal containers, an alternative is to place the glass container inside a metal
chemical wastes:
a. To minimize disposal problems, always specify the smallest amount that will
suffice when ordering chemicals.
b. Obtain directions for disposal from the supervisor.
c. Do not let surplus chemicals accumulate indefinitely; if there is no likelihood
of their use within the facility, they should be designated for disposal.
d. When disposing of chemicals, one basic principle applies: Keep each different
class of waste chemical in a separate disposal container.
Put ordinary wastepaper in a wastepaper basket separate from the chemical
wastes. If a piece of paper is contaminated, such as paper toweling used to clean
up a spill, put the contaminated paper in the special container that is marked for
this use. It must be treated as a chemical waste.
Broken glass belongs in its own marked waste container. Place broken plastic
apparatuses in a different marked waste container. Broken thermometers may
contain mercury in the fragments, and these belong in their own special “broken
thermometer” container. See Section 6.2 for instructions on cleaning up mercury
spills from broken thermometers.
For leftover and unused chemicals, put each solid and liquid in its own
specially marked container, based on hazard class compatibility, and close the
container. Never deliberately put solid chemicals into the sink or down a drain. If
it happens accidentally, notify your supervisor. CAUTION: Liquid chemicals may
be put down the drain only if they are clearly nonhazardous or if permission is
secured from the sewer authority. Flammable materials should never be poured
down the drain.
Safety Showers and Eyewash Fountains
Careless disposal can cause problems. Incompatible chemicals that are
inadvertently mixed together on a bench or put into the same disposal container
can produce toxic gases, catch fire spontaneously, or explode. Solid or liquid
chemicals put into the sink drain can harm the environment. Broken glass in a
wastepaper basket can injure the person who empties that basket.
Promote safety by following these commonsense practices when disposing of
Safety showers and eyewash fountains should be located at least 5 feet apart.
Often an employee who needs either of these facilities also will need help from one
or two co-workers. If an accident involves two injured people, one who needs the
shower and the other the eyewash, it would be very difficult to use both facilities
properly if they were closer than 5 feet.
The water supply lines to eyewashes and safety showers should be valve-free
in order to supply an uninterruptible water flow. If it is necessary to install a shutoff
valve, a lock should be attached to keep the valve in the open position, with a tag
affixed stating that the valve must be kept open during normal operation of the
All employees must know the locations of the safety showers and how to
operate them. Each work area where hazardous chemicals are used should be
equipped with at least one safety shower. ANSI Z358.1 requires that safety showers
be located no more than 10 seconds from any location in the room. The shower
area must be kept clear of obstructions and be clearly labeled by highly visible
signage on the wall. Chain pulls to activate the shower should be provided with a
Disposal of Chemicals
large ring. The valve should open readily when the chain is pulled and remain
open until intentionally closed. Water flow must be sufficient to drench the subject
rapidly. ANSI Z358.1 requires a 30-gal/minute minimum flow of potable water.
Provide temperate water for all safety showers; it is impossible to remain under a
drenching shower for 15 minutes if the water is cold. Although a nearby floor drain
is desirable, its absence should not prohibit installation of a safety shower.
The ANSI standard requires that safety showers be activated weekly to ensure
that they are working properly. Keep a record of such tests, for example, on a tag
affixed to the shower plumbing.
ANSI Z358.1 mandates a minimum 3-gal/minute water flow for handheld
drench hoses and states that, although drench hoses are well-adapted for flushing
when a safety shower or eyewash fountain cannot be used to flush a hazardous
chemical from the eyes or skin, drench hoses are not a substitute for safety showers
or eyewash fountains. When drench hoses are installed in a work area, every
employee should know their locations, their limitations, and how to operate them.
When feasible, employees should practice the procedure.
Employees should also know the locations of the eyewash fountains and how
to operate them. Eyewash fountains should provide a copious and gentle flow of
temperate, aerated, potable water at 0.4 gal/minute for a period of at least 15
minutes. Plumbed installations are strongly recommended. Use of the hands
should not be required to maintain the water flow.
Small, handheld, portable eyewash units cannot provide a supply of water
sufficient to copiously flush two eyes for at least 15 minutes. Also, the small units,
the multigallon portable units, and the nonplumbed wall-mounted units provide
an environment for the growth of microorganisms. All require strict attention in
order to maintain sterility of the contained water. The small bottle-sized units
should not be used. The use of multigallon portable units and nonplumbed wallmounted units is strongly discouraged unless the sterility of the contents can be
ensured and testing shows that a unit will flush both eyes simultaneously and will
deliver at least 0.4 gal/minute of temperate water for at least 15 minutes.
As with safety showers, ANSI Z358.1 requires that eyewashes be flushed
weekly. Such flushing reduces the risk of eye infections from contaminated
standing water. Keep a record of these test flushes (e.g., on a tag affixed to the
eyewash fountain plumbing). ANSI Z358.1 requires that eyewash units be located
no more than 10 seconds from any workstations.
Always follow up every first aid treatment for the eyes with proper treatment
by a member of the company’s medical staff or an ophthalmologist who is
qualified to treat chemical injuries to the eyes. Finally, all employees should
understand that proper eye protection is much more effective than eyewashes in
preventing eye injuries.
be recharged promptly after use and should be sealed and clearly marked to ensure
their utility. At least one large backup fire extinguisher of the dry chemical powder
type should be conveniently located. Dry chemical fire extinguishers may be
preferred for certain areas, but carbon dioxide is satisfactory for most small fires
(with the notable exception of fires from alkali, alkaline earth, and certain other
metals) and is cleaner to use around most equipment. Conventional dry chemical
extinguishers expel a stream of sodium or potassium bicarbonate or other powder
and are not recommended for Class A fires (wood, paper). Multipurpose dry
chemical extinguishers release a stream of monoammonium phosphate as the
extinguishing agent and are often preferred. Under OSHA rules, a person not
trained in the use of fire extinguishers is prohibited from using them.
Laboratory Chemical Hoods (Formerly Called Fume Hoods)
Laboratory chemical hoods control hazardous chemicals (e.g., toxic, offensive,
flammable, or reactive vapors). Apparatuses used in hoods should be fitted with
condensers, traps, or scrubbers to contain or collect hazardous effluents. The hood
should never be used as a means for disposing of chemicals.
The effective operation of a hood depends on many factors, including the face
airflow velocity, the overall ventilation pattern of the room, the adequacy of the
room air supply, and the methods of working at the hood. Before each use, be
sure that the hood exhaust system is functioning properly. Adequate airflow and
the absence of excessive turbulence are necessary for safe operation. All work in a
hood should be carried out at least 15 cm (6 in.) from the front edge of the hood.
A yellow line 15 cm from the edge can serve to indicate the limit of usage. Ensure
that equipment does not block the hood baffles. It may be necessary to place large
pieces of equipment on 2-in. blocks to permit adequate and uniform airflow.
Always keep your head outside of the hood face. Specialized vented
workstations, such as vented balance safety enclosures, are available for many
operations like weighing, microscopy, and pipeting. Flexible ductwork (or
“elephant trunk”) hoods should be used over the exit ports of equipment like gas
chromatographs and atomic absorption spectrometers to remove toxic effluents
from the work environment.
Hoods should never be used for the storage of chemicals. Chemicals should
be stored in appropriate locations, as described in Part I, Section 4.8. Remember
that in the event of an accident or fire, every item in the hood may be involved,
including chemicals that are improperly stored in the hood.
Fire extinguishers in the workplace should be a convenient size for rapid use
and should be the appropriate type for the expected fire emergency. There should
be at least one extinguisher easily accessible to each work area. Extinguishers must
Storage of chemicals in refrigerators constitutes a unique hazard because the
various control switches and defroster heaters can spark and ignite flammable
materials. Explosions and fires may occur. Refrigerators used for low-temperature
storage of industrial chemicals should be labeled for such use and must be
explosion-proof. Never use household refrigerators for chemical storage. Most
household refrigerators can be modified by a trained technician to remove internal
sources of spark. However, the motor and other electrical parts on the exterior of
Fire Extinguishers
a modified household refrigerator can still ignite flammable vapors that are leaking
out of the refrigerator or vapors that are already present in the room. In explosionproof refrigerators, the internal wiring has been modified to eliminate ignition
sources and the external motor and switches are sealed.
Industrial chemicals stored in refrigerators should be placed on a spill tray
with edges sufficiently high to contain the spilled contents of any containers that
are placed in the tray. Always seal and, if possible, double-package all chemicals to
be stored in refrigerators; label each container legibly with the name of the
material, the date placed in the refrigerator, and the name of the person who stored
the material. Dispose of old chemicals after a specified storage period.
Store radioactive materials only in a designated refrigerator that can be locked
and is properly labeled for such storage.
Never under any circumstances store food or beverages in a refrigerator that
is used for industrial or laboratory chemicals or radioactive materials. Store food
and beverages in a refrigerator that is labeled “Food and Beverages Only”. Locate
the food and beverage refrigerators in areas outside of the chemical laboratory or
Gloves are an important part of personal protection. They may be required for
certain procedures. Gloves come in a variety of materials: latex, nitrile, neoprene,
butyl rubber, and many others. Different types of gloves have different gauntlet
lengths; some cover the entire arm, some cover the forearm, and some are only
wrist-length. Although cloth or leather gloves may protect against hot or cold
objects, do not rely on them for protection against hazardous chemicals. Cloth
gloves are porous; leather gloves may be contaminated from prior use.
Use gloves correctly. Always check gloves before each use to ensure the absence
of cracks and small holes. To avoid unintentionally spreading chemicals, remove
your gloves before leaving the work area and before handling telephones,
doorknobs, writing instruments, computers, laboratory notebooks, and reference
Be aware that no glove material can provide permanent protection. Eventually,
liquids will permeate the glove. When certain glove materials are used with some
liquids, permeation can take only a few minutes. Because the permeability of
gloves made of the same or a similar material can vary by manufacturer, refer to
the information provided by the manufacturer of the gloves for specific guidance.
Use gloves only under the conditions and with the chemicals for which they are
intended. If a chemical diffuses through a glove, that chemical is held against your
skin; you could receive more exposure than if you had not worn a glove at all.
If gloves are clean, they may be reused. Do not reuse gloves if they previously
have been permeated by a harmful chemical; they cannot be reused safely because
the chemical cannot be totally removed. Gloves permeated by a hazardous material
are themselves hazardous waste material and must be properly disposed of via the
institution’s waste policies.
The best way to fight a fire is to prevent it. You can prevent fires and reduce
their severity considerably through proper housekeeping and thoughtful reflection
about what you are doing. Proper housekeeping includes the following:
a. Maintaining unobstructed aisles and exits
b. Storing only limited quantities of flammable material
c. Promptly disposing of waste
d. Separating flammable liquids from combustible materials, such as cardboard
boxes and paper towels
Stand back, take a look, and ask these questions:
Are there any frayed wires?
Is a stirrer with a sparking motor being used to stir a flammable liquid?
Are bottles too close to the edge of the bench?
Is the workspace cluttered?
Do I understand each of the potential hazards in what I am about to do?
Am I prepared in advance to take preventive steps?
If a fire occurs, the following actions are recommended:
a. A fire contained in a small vessel can often be suffocated. For example, use a
watch glass to suffocate a fire in a beaker by covering the mouth of the beaker.
Do not pick up a vessel that is on fire. Do not cover it with dry towels or cloth;
use a wet material. Remove nearby flammable materials to avoid spreading
the fire.
b. Activate the fire alarm. Notify co-workers and your supervisor. Call the fire
c. If the fire is burning over an area too large for the fire to be suffocated quickly
and simply, everyone should evacuate the area except those trained and
equipped to fight fires. Use the stairs to leave the building; do not use the
elevators. Follow evacuation procedures that have been established and that
you have practiced during prior fire drills.
d. It is easy to underestimate a fire. Never attempt to use a fire extinguisher unless
you have been trained in its use and know that it is likely to extinguish the fire.
If you have been trained in the use of a fire extinguisher, position yourself
between the fire and an escape route (e.g., a door) and fight the fire from this
location, but be sure that you can escape. Small fires that have just started often
can be extinguished, but not always. If not extinguished, a fire can quickly
threaten your life and those of your co-workers.
When a person’s clothing is on fire, you may need to lead him or her to the
safety shower. Some people instinctively run randomly if their clothes are on fire,
which fans the flames and increases their injuries. If possible, stop an individual
from running.
If the shower is not readily available, douse the individual with water. Get him
or her to stop, drop, and roll; that is, to lie down and roll to put out the fire. Then
try to extinguish any small, still-burning flames by patting them out. Beat out the
flames around the head and shoulders, and then work downward toward the feet.
Next, cover the injured person with a coat, blanket, or whatever is available, but
leave the head uncovered. Do not use fire blankets until the fire is extinguished.
While wearing gloves, if necessary, remove any clothing contaminated with
chemicals. To prevent contamination of the eyes, use scissors when removing
pullover shirts or sweaters. Wrap the injured person to avoid shock and exposure.
Get medical attention promptly.
Runaway Reactions
A sudden, rapid rise in the temperature of a liquid that is being heated is
evidence of a reaction that may become violent. Immediately remove heat, stop
adding reagents, alert all persons nearby, and quickly move away. Do not return
until the temperature has dropped to a safe level. Advanced knowledge of the
reaction and the reaction potential will decrease hazards from these situations.
Explosions result from the rapid expansion or evolution of gases, often in a
closed or restricted system. One should ensure that a system has sufficient venting
capability, including plenty of blowout panels. If the nature of the process involves
a particular danger of explosion, always use adequate shielding and other
appropriate safety devices. Special monitoring devices may also be advisable.
Particularly dangerous reactions should be carried out in isolated areas, often using
remote controls.
Employees in industrial laboratories or plants do not ordinarily work with
very many substances that are explosive. Picric acid is rarely used; other nitrated
organic compounds are used only occasionally. Perchloric acid is rarely used for
oxidations involved in analytical work or other oxidative procedures. Organic
peroxides (e.g., benzoyl peroxide) might be used now and then as polymerization
initiators. Occasionally, unstable compounds (e.g., diazo derivatives) are used in
some research projects, but this is rare.
These functional groups pose an explosion hazard: azide, ozonide, nitro,
nitroso, diazo, halogen-substituted amine, and peroxide.
Some unstable compounds explode in the presence of a catalyst; others tend
to explode at high temperatures. Some mixtures are shock-sensitive and will
explode if impacted. Examples include carbon disulfide and potassium
perchlorate; aluminum dust, magnesium dust, and sodium nitrate; many diazo
compounds; and some organic nitrates.
Suspensions of oxidizable dust (e.g., magnesium, sulfur, or aluminum) in the
air explode when ignited by a static electrical spark, flame, or other ignition source.
Keep explosive substances and mixtures well away from co-workers. Both in
use and in storage, keep such substances well-separated from other unstable
compounds, flammables, and toxins. For explosion hazard information, refer to
the MSDS and Bretherick’s Handbook of Reactive Chemical Hazards.
Distillation of peroxide formers presents an explosion hazard, even if tests
indicate that no peroxide is present. When you conduct these distillations, always
protect yourself with shielding on all sides and wear both a Type N face shield and
Type G, H, or K safety goggles. Have a fire extinguisher ready, along with someone
who has been trained to use it. Do not distill these liquids to dryness. Stop the
distillation while there is a considerable amount of liquid remaining in the
distillation flask.
If an ignition source is present, any flammable gas or vapor can explode when
mixed in suitable proportion with air, oxygen, chlorine, or other gaseous oxidizers.
Acetylene and hydrogen are particularly hazardous in this respect because of their
very wide flammability limits. Liquid oxygen is particularly dangerous. Liquid
nitrogen that has been standing open to the air for some time becomes a mixture
of liquid nitrogen and oxygen, which is also particularly dangerous; see Section 7.6.
It is prudent to run reactions on the smallest scale possible. When an explosion
is a possibility, use less than 1 g total of all materials involved. Wear a Type N face
shield; Type G, H, or K safety goggles; and a buttoned-up, thick, quilted lab coat.
Cover any glass apparatus with a fabric-not plastic-tape (e.g., use duct tape), and
surround the work with shatterproof shielding. Do not rely on an ordinary hood
to provide protection. If it is considered necessary to work with or produce more
than 1 g of an explosive compound or mixture, the work should be performed in
a setting that is designed for such potentially dangerous activities.
Precautions for Using Electrical Equipment
Electrical currents of low amperage and voltage under certain circumstances
may result in fatal shock. Voltages as low as 24-V alternating current (ac) can be
dangerous and present a lethal threat. Comparably low-voltage direct current (dc)
circuits do not normally present a hazard to human life, although severe burns
are possible. The longer that contact with a live circuit lasts, the worse the damage,
especially for burns. Follow these recommendations:
a. Only individuals qualified by training or experience should maintain or repair
electric or electronic equipment.
b. Do not use electric wires as supports. Never pull on live wires.
c. Immediately report any electrical failure or any evidence of equipment
d. Inspect all electrical equipment periodically to be certain the insulation on
the cords is not frazzled, tattered, cracked, or damaged. Inspect the plugs; make
sure they are not bent or damaged. Make sure that only three-wire grounded,
double-insulated, or isolated wiring is used for 110-115-V ac applications.
Static Electricity and Spark Hazards
When handling flammable liquids, you can obtain some protection from
static electricity and sparks by properly grounding and bonding containers and
equipment. The risk of static charge buildup is increased under conditions of low
humidity (e.g., cold weather). For details, refer to NFPA 77: Recommended Practice
on Static Electricity.
Common potential sources of electrical sparks and electrostatic discharges
include the following:
a. Ungrounded metal tanks and containers
b. Clothing or containers made of plastic or synthetic materials
c. An electric circuit that is made or broken while the circuit, or part of it, is
d. Exposed hot nichrome wires (e.g., in hot air dryers, damaged heating mantles)
e. Temperature-control systems and brush/commutator motors in some hot
f. Discharge of gas from high-pressure gas cylinders
g. Brush/commutator motors, often used in hot air dryers, stirrer motors, and
air-moving fans
Radioactive Materials
Before you start any work, check with your state or federal agency (Nuclear
Regulatory Commission) to determine which regulations regarding radioactive
materials apply to your company. Coordinate all work requiring the use of radioactive
materials with the person responsible for the laboratory or plant and under the
direction of the company’s radiation safety officer. Clearly label all radioactive
materials, the vessels in which they are used, and the work area itself as a radioactive
material use area. Always have the appropriate radiation measurement equipment
in good working order while working with radioactive materials.
Anyone considering the use of radioactive materials should consult the
radiation safety officer for advice on the regulations concerning procurement,
handling, and disposal. All contaminated materials must be thoroughly cleaned
or properly disposed of. These materials ordinarily would include glassware, wipes,
gloves, spill pads, thin-layer chromatography (TLC) plates, pipets, and so forth.
All employees planning to work with radioactive materials must first be trained in
their safe handling. Worker protection requires good practices, adequate
supervision, and control of exposure levels.
The ALARA (as low as reasonably achievable) exposure premise must be the
guiding principle behind all radioactive work. This requires that the exposure to
radiation or radioactive materials be kept to a minimum and that any associated
radiation doses be decreased by reducing duration, increasing distance, and
providing shielding when possible. Personal exposure monitoring may be required
for users of radioactive materials. Such monitoring includes personal film badges,
bioassay testing, and other scanning methods. The company’s radiation safety
officer is responsible for providing appropriate guidance on personal monitoring.
X-ray Generators and Particle Accelerators
These instruments can be dangerous because of the radiation they generate
and the high voltages produced by their power supplies. Follow all the regulations
of the Nuclear Regulatory Commission, your state department of public health,
and your local radiological health service. Post warning signs in the area and on
or near the main power switch of the instrument.
Where lasers are used, the company may be required to have a laser safety
officer who is knowledgeable in evaluating and controlling laser hazards and who
is authorized and responsible for supervising their safe operation. Lasers and laser
systems must be classified (I-IV) and appropriately labeled in accordance with the
current edition of ANSI Z136.1. Class I lasers are of low intensity and pose little
or no risk of physiological harm. Under certain conditions, Class II lasers can cause
eye injury in people who lack a normal eye-aversion response to bright light. Class
III and IV lasers are high-powered and can do considerable physiological damage,
especially to the eyes; a medical professional should review the use and operation
of Class III and IV lasers. Even reflected beams from a Class III or IV laser can cause
eye injury.
Higher power lasers present additional hazards. The power density of the
beam can be sufficient to ignite combustible materials. The high voltages involved
present shock hazards. Some of the dyes used in dye lasers are reproductive toxins
or are carcinogenic.
Only authorized individuals with specific training should use lasers. Everyone
should obey all warning signs posted at the entrances to laser areas.
Ultraviolet Lamps
The use of UV lamps presents two types of hazards: those inherent in the
radiation itself and those associated with operation of the lamps.
All radiation of wavelengths shorter than 250 nm should be considered
dangerous. Wear protective safety glasses or goggles with UV-absorbing lenses
whenever the eyes may be accidentally exposed to light in this wavelength region.
It is advisable to operate such UV irradiation systems only in a completely closed
radiation box. Wear slacks and a long-sleeved shirt to protect your skin. Skin areas
exposed to illumination from UV lamps can be painfully burned in a way that is
similar to severe sunburn.
Mercury arc lamps should be adequately cooled and operated within an
enclosure designed to prevent damage by explosion of glass fragments and leakage
of mercury vapor; make sure that the lamp you use is so equipped.
Do not handle mercury arc lamps with your bare hands. Deposits of oils from
your skin damage the outer glass surface. If these oily residues are not thoroughly
removed, they will burn into the glass, causing localized buildup of heat during the
operation of the lamp. The lamp may then overheat, and the outer envelope may
At the end of the useful life of a mercury arc lamp, buildup of UV-absorbing
films on the interior glass walls may cause the temperature to rise above the safe
operating point. Therefore, make sure the running-time meter on the lamp works
so that you can know the total time the lamp has been operated.
APPENDIX I - Sources of Additional Information
All books, even the best ones, may rapidly become outdated after they are
published. Readers must make continual efforts to update their knowledge in the
quickly changing field of chemical safety. The titles in the following bibliography
that are regularly updated are marked by an asterisk.
ACS Task Force on Laboratory Waste Management. Laboratory Waste Management:
A Guidebook; American Chemical Society: Washington, DC, 1994.
Armour, M. A. Hazardous Laboratory Chemicals Disposal Guide, 3rd ed.; CRC: Boca
Raton, FL, 2003.
Ashford, N. A.; Miller, C. S. Chemical Exposures: Low Levels and High Stakes, 2nd ed.;
John Wiley & Sons: New York, 1998.
Basic Environmental Toxicology; Cockerham, L. G.; Shane, B. S., Eds.; CRC: Boca
Raton, FL, 1993.
*Best’s Safety Directory: Industrial Safety, Hygiene, and Security 1995; A. M. Best:
Oldwick, NJ, 1994.
Bretherick, L., et al. Bretherick’s Handbook of Reactive Chemical Hazards, 6th
ed.; Urben, P. G., Ed.; Butterworth-Heinemann: Newton, MA, 1999; available
on CD-ROM.
“Chemical Storage Resources”; Committee on Chemical Safety. American
Chemical Society: Washington, DC, 2005;
“Chemistry Laboratory Information Profiles (CLIPs)”; Courtesy of J. Chem. Ed.
Division of Chemical Education. American Chemical Society: Washington,
DC, 2001-2004;
Cheremisinoff, N. P., et al. Dangerous Properties of Industrial and Consumer Chemicals;
Marcel Dekker: New York, 1994.
CRC Handbook of Laboratory Safety, 5th ed.; Furr, A. K., Ed.; CRC: Boca Raton, FL,
DiBerardinis, L. J., et al. Guidelines for Laboratory Design: Health and Safety
Considerations, 3rd ed.; John Wiley & Sons: New York, 2001.
Eyewash and Shower Equipment, Emergency; Standard No. ANSI-Z358.1; American
National Standards Institute: Washington, DC.
Filskov, P., et al. Substitutes for Hazardous Chemicals in the Workplace; CRC: Boca
Raton, FL, 1996.
Fire Protection Guide to Hazardous Materials, 2001 ed.; National Fire Protection
Association: Quincy, MA, 2001.
Forsberg, K.; Mansdorf, S. Z. Quick Selection Guide to Chemical Protective Clothing,
4th ed.; John Wiley & Sons: New York, 2002.
Frazier, L. M.; Hage, M. L. Reproductive Hazards of the Workplace; John Wiley & Sons:
New York, 1998.
Guideline for the Development of Personal Protective Equipment Programs for Small
Business Owners; Stock No. EPCG05-688; American Industrial Hygiene
Association: Fairfax, VA, 2005.
Handbook of Chemical Health and Safety; Alaimo, R. J., Ed.; Oxford University
Press/American Chemical Society: New York/Washington, DC, 2001.
Handbook of Compressed Gases, 4th ed.; Compressed Gas Association: Arlington,
VA, 1999.
Handbook of Occupational Safety and Health, 2nd ed.; DiBerardinis, L. J., Ed.; John
Wiley & Sons: New York, 1999.
Hathaway, G. J.; Proctor, N. H. Proctor and Hughes’ Chemical Hazards of the
Workplace, 5th ed.; John Wiley & Sons: New York, 2004.
*Hawley’s Condensed Chemical Dictionary, 14th ed.; Lewis, R. J., Ed.; John Wiley &
Sons: New York, 2001; available on CD-ROM.
Hazardous Industrial Chemicals—Material Safety Data Sheets-Preparation; Standard
No. Z400.1-2004; American National Standards Institute: Washington, DC.
Hazardous Industrial Chemicals-Precautionary Labeling; Standard No. Z129.1-2000;
American National Standards Institute: Washington, DC.
Improving Safety in the Chemical Laboratory: A Practical Guide, 2nd ed.; Young, J. A.,
Ed.; John Wiley & Sons: New York, 1991.
Industrial Ventilation: A Manual of Recommended Practice; American Conference of
Governmental Industrial Hygienists: Cincinnati, OH, 2001.
Johnson, R. W., et al. Essential Practices for Managing Chemical Reactivity Hazards;
Wiley/American Institute of Chemical Engineers: New York, 2003;
Laboratory Ventilation; Standard No. ANSI/AIHA Z9.5-2003; American National
Standards Institute/American Industrial Hygiene Association: Washington,
DC/Fairfax, VA.
Langerman, N. Precautionary Labels for Chemical Containers; Lewis: Boca Raton, FL,
Lewis, R. J. Hazardous Chemicals Desk Reference, 5th ed.; John Wiley & Sons: New
York, 2002.
Lewis, R. J. Sax’s Dangerous Properties of Industrial Materials, 11th ed.; John Wiley &
Sons: New York, 2005; available on CD-ROM.
Lunn, G.; Sansone, E. B. Destruction of Hazardous Chemicals in the Laboratory, 2nd
ed.; John Wiley & Sons: New York, 1994.
Method of Testing Performance of Laboratory Fume Hoods; Standard No.
ANSI/ASHRAE 110-1995; American National Standards Institute: Washington,
National Institute for Occupational Safety and Health. “Reproductive Hazards in
the Workplace: Bibliography”; Report No. 550-147/00003; U.S. Government
Printing Office: Washington, DC.
National Research Council. Prudent Practices in the Laboratory: Handling and Disposal
of Chemicals; National Academy: Washington, DC, 1995.
*NFPA 30: Flammable and Combustible Liquids Code, 2003 ed.; National Fire
Protection Association: Quincy, MA, 2003.
*NFPA 45: Standard on Fire Protection for Laboratories Using Chemicals, 2004 ed;
National Fire Protection Association: Quincy, MA, 2004.
NFPA 70: National Electric Code, 2005 ed.; National Fire Protection Association:
Quincy, MA, 2005.
*NFPA 491M: Hazardous Chemical Combustible Liquids Code; National Fire
Protection Association: Quincy, MA.
NIOSH Pocket Guide to Chemical Hazards; DHHS (NIOSH) Publication No. 2005149; U.S. Department of Health and Human Services. Centers for Disease
Control and Prevention. National Institute for Occupational Safety and
Health: Washington, DC, 2005; available on CD-ROM.
Occupational and Educational Personal Eye and Face Protection Devices; Standard No.
Z87.1-2003; American National Standards Institute: Washington, DC.
OSHA Handbook for Small Businesses; OSHA 2209; U.S. Department of Labor.
Occupational Safety & Health Administration. U.S. Government Printing
Office: Washington, DC, 1996 (Revised).
Ottoboni, M. A. The Dose Makes the Poison: A Plain-Language Guide to Toxicology,
2nd ed.; John Wiley & Sons: New York, 1997.
Patnaik, P. A Comprehensive Guide to the Hazardous Properties of Chemical Substances,
2nd ed.; John Wiley & Sons: New York, 1999.
Personal Protective Equipment; OSHA 3151-12R; U.S. Department of Labor.
Occupational Safety & Health Administration: Washington, DC, 2003.
“Practicing Safe Science”; free video; Howard Hughes Medical Institute: Chevy
Chase, MD;
“Questions and Answers for Small Business Employers”; OSHA 3163; U.S.
Department of Labor. Occupational Safety & Health Administration:
Washington, DC, 2002 (Revised).
Rapid Guide to Hazardous Chemicals in the Workplace, 4th ed.; Lewis, R. J., Ed.; John
Wiley & Sons: New York, 2000.
Report on Carcinogens, 11th ed.; U.S. Department of Health and Human Services.
Public Health Service. National Toxicology Program: Research Triangle Park,
NC, 2005;
Risk Factors for Cancer in the Workplace; Siemiatycki, J., Ed.; CRC: Boca Raton, FL,
Safe Storage of Laboratory Chemicals, 2nd ed.; Pipitone, D. A., Ed.; John Wiley &
Sons: New York, 1991.
Safety and Compliance Directory; Pub. No. 20494; Lab Safety Supply: Janesville,
Safety Audit/Inspection Manual; Committee on Chemical Safety. American
Chemical Society: Washington, DC, 2000;
Safety in the Research Laboratory Set 1: “Chemical Hazards”, “Emergency
Response”, and “Radionuclide Hazards”; free videos; Howard Hughes Medical
Institute: Chevy Chase, MD;
Safety in the Research Laboratory Set 2: “Centrifugation Hazards”, “Chemical
Storage Hazards”, and “Glassware Washing Hazards”; free videos; Howard
Hughes Medical Institute: Chevy Chase, MD;
Safety in the Research Laboratory Set 3: “Mammalian Cell Culture Hazards”, “Xray Diffraction Hazards”, and “Assessing Risks of Toxic Chemicals”; free videos;
Howard Hughes Medical Institute: Chevy Chase, MD;
Safety Listserve; Subscribe or unsubscribe,; Archives,
Saunders, G. T. Laboratory Fume Hoods: A User’s Manual; John Wiley & Sons: New
York, 1993.
Shepard, T. H.; Lemire, R. J. Catalog of Teratogenic Agents, 11th ed.; Johns Hopkins
University: Baltimore, MD, 2004.
Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, 4th ed.;
Pohanish, R. P., Ed.; Noyes: Park Ridge, NJ, 2002.
Stricoff, R. S.; Walters, D. B. Handbook of Laboratory Health and Safety, 2nd ed.; John
Wiley & Sons: New York, 1995.
Task Force on Laboratory Environment, Health, and Safety. “Less is Better: Guide
to Minimizing Waste in Laboratories”; Committee on Chemical Safety.
*The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 13th ed.;
Merck: Whitehouse Station, NJ, 2001.
The Occupational Environment: Its Evaluation, Control, and Management, 2nd ed.;
DiNardi, S. R., Ed.; American Industrial Hygiene Association: Fairfax, VA, 2003.
Waldo, A. B.; Hinds, R. D. Chemical Hazard Communication Guidebook: OSHA, EPA,
and DOT Requirements, 2nd ed.; McGraw-Hill: New York, 1994.
Organizations (accessed March 21, 2007)
American Chemical Society, 1155 Sixteenth St., N.W., Washington, DC 20036;
Committee on Chemical Safety (; Division of
Chemical Health and Safety (; Chemical Health
and Safety Referral Service (800-227-5558);
American Chemistry Council (formerly Chemical Manufacturers Association),
American Conference of Governmental Industrial Hygienists, 1330 Kemper
Meadow Dr., Cincinnati, OH 45240. 513-742-2020;
American Industrial Hygiene Association, 2700 Prosperity Ave., Suite 250, Fairfax,
VA 22031. 703-849-8888;
American National Standards Institute, 1819 L St., N.W., 6th Floor, Washington,
DC 20036. 202-293-8020;
ASTM International (formerly American Society for Testing and Materials), 100
Barr Harbor Dr., West Conshohocken, PA 19428-2959. 610-832-9585;
Canadian Centre for Occupational Health and Safety, 135 Hunter St. East,
Hamilton, Ontario, Canada L8N 1M5. 800-668-4284;
Chemical Abstracts Service, 2540 Olentangy River Rd., P.O. Box 3012, Columbus,
OH 43210. 614-447-3600;
Interactive Learning Paradigms Inc., 4905 Waynes Blvd., Lexington, KY 405131469. 859-396-5218;
International Agency for Research on Cancer, 150 Cours Albert-Thomas, 69372
Lyon Cedex 08, France. +33 (0)4 72 73 84 85;
Laboratory Safety Institute, 192 Worcester Rd., Natick, MA 01760. 508-647-1900;
MSDS Online, 350 North Orleans, Suite 950, Chicago, IL 60654. 888-362-2007;
National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 021697471. 617-770-3000;
National Institute for Occupational Safety and Health (NIOSH), Hubert H.
Humphrey Bldg., 200 Independence Ave., S.W., Room 715H, Washington, DC
20201. 800-356-4674;
National Safety Council, 1121 Spring Lake Dr., Itasca, IL 60143-3201. 800-6217619;
National Toxicology Program, Department of Health and Human Services, P.O.
Box 12233, MD A3-01, Research Triangle Park, NC 27709. 919-541-0530;
Occupational Safety & Health Administration, 200 Constitution Ave., N.W.,
Washington, DC 20210. 800-321-6742;
U.S. Environmental Protection Agency, Ariel Rios Building, 1200 Pennsylvania
Ave., N.W., Washington, DC 20460. 202-272-0167;
U.S. Government Printing Office, 732 North Capitol St., N.W., Washington, DC
20401. 202-512-0000;
U.S. Nuclear Regulatory Commission, One White Flint North,11555 Rockville
Pike, Rockville, MD 20852-2738. 800-368-5642;
Electronic Media
Chemical toxicity, as well as much regulatory and emergency response
information, can be handled in electronic files. Until the mid-1980s, electronic
files were most commonly available as online databases to which access was
measured and sold by database vendors based on the number of hours connected.
This is still a good option in many circumstances, particularly for bibliographic
files. Database users need computer terminals and modems as well as vendorassigned passwords to access these databases. Front-end software, when installed
on a personal computer, will make searching the electronic files easier.
Nevertheless, attendance at a user-training workshop offered by the database
vendor and the willingness to maintain the appropriate documentation are also
recommended. As an alternative, almost all academic and many public libraries
offer database search services. Finally, the database vendors themselves will
perform searches for customers.
In the past several years, more and more electronic databases have become
available as CD-ROM (compact disc read-only memory) products. In the most
commonly available format, the discs store approximately 550 MB of information.
The services are usually sold by subscription with at least quarterly updates. For the
CD-ROM discs to be used, a personal computer with a monitor and (optional)
printer and a CD-ROM player are required. CD-ROM products should be
considered when there is potentially high use of the data files, when it is desirable
not to depend on telecommunication links, or when the files themselves (such as
collections of MSDSs) are well-adapted to the format. Perhaps they should not be
used when it is essential to have the most current information. In this case, access
to online databases may be better. However, online databases will only be as
current as the updating policies of the vendors, and many files are updated as rarely
as quarterly.
Many databases are available in both online and CD-ROM formats or even
additional ones such as floppy disks or magnetic tapes. In addition to the many
collections of MSDSs, some of the potentially more useful databases are the
Chemical Hazards Response Information System (CHRIS). U.S. Coast Guard
hazard response.
CHEMLIST. Regulatory activities such as premanufacture notices and EPA rule
Hazardous Substances Data Bank (HSDB). Reviewed data on environmental and
regulatory issues as well as toxicological information.
NIOSHTIC. searchable bibliographic database of occupational safety and health
publications, documents, grant reports, and other communication products
supported in whole or in part by the National Institute for Occupational Safety
and Health (NIOSH).
Oil and Hazardous Material Technical Assistance Data System (OHMTADS).
Information from EPA.
Registry of Toxic Effects of Chemical Substances (RTECS). Acute and chronic
toxicity information.
Toxicology Literature Online (TOXLINE). Bibliographic database covering the
toxicological and physiological effects of drugs and other chemicals.
Occupational Safety & Health Administration Regional Offices
Environmental Protection Agency Regional Offices
Region 1
(CT, #* MA, ME, NH, RI, VT*)
JFK Federal Building, Room E340
Boston, MA 02203
Telephone: 617-565-9860
Region 6
(AR, LA, NM,* OK, TX)
525 Griffin St., Room 602
Dallas, TX 75202
Telephone: 972-850-4145
Region 2
(NJ,# NY,# Puerto Rico,*
Virgin Islands#)
201 Varick St., Room 670
New York, NY 10014
Telephone: 212-337-2378
Region 7
(IA,* KS, MO, NE)
City Center Square
1100 Main St., Suite 800
Kansas City, MO 64105
Telephone: 816-426-5861
Region 1
(CT, MA, ME, NH, RI, VT)
1 Congress St., Suite 1100
Boston, MA 02114-2023
Telephone: 617-918-1111
Toll-free: 888-372-7341
Fax: 617-918-0101
Region 6
(AR, LA, NM, OK, TX)
1445 Ross Ave., Suite 1200
Dallas, TX 75202
Telephone: 214-665-6444
Toll-free: 800-887-6063
Fax: 214-665-7113
Region 3
(DC, DE, MD,* PA, VA,* WV)
The Curtis Center, Suite 740 West
170 South Independence Mall West
Philadelphia, PA 19106-3309
Telephone: 215-861-4900
Region 8
(CO, MT, ND, SD, UT,* WY*)
1999 Broadway, Suite 1690
Denver, CO 80202
Telephone: 720-264-6550
Region 2
(NJ, NY, Puerto Rico, Virgin Islands)
290 Broadway
New York, NY 10007-1866
Telephone: 212-637-3660
Fax: 212-637-3526
Fax: 913-551-7066
Region 7
(IA, KS, MO, NE)
901 North 5th St.
Kansas City, KS 66101
Telephone: 913-551-7003
Toll-free: 800-223-0425
Region 4
(AL, FL, GA, KY,* MS, NC,*
SC,* TN*)
61 Forsyth St., S.W.
Atlanta, GA 30303
Telephone: 404-562-2300
Region 9+
(AZ,* CA,* Guam, HI,* NV*)
71 Stevenson St., Room 420
San Francisco, CA 94105
Telephone: 415-975-4310
Region 3
(DC, DE, MD, PA, VA, WV)
1650 Arch St. (3PM52)
Philadelphia, PA 19103-2029
Telephone: 215-814-5000
Toll-free: 800-438-2474
Fax: 215-814-5103
E-mail: [email protected]
Region 8
(CO, MT, ND, SD, UT, WY)
1595 Wynkoop St., 80C-EISC
Denver, CO 80202-1129
Telephone: 303-312-6312
Toll-free: 800-227-8917
Fax: 303-312-6961
E-mail: [email protected]
Region 5
(IL, IN,* MI,* MN,* OH, WI)
230 South Dearborn St., Room 3244
Chicago, IL 60604
Telephone: 312-353-2220
Region 10
(AK,* ID, OR,* WA*)
1111 Third Ave., Suite 715
Seattle, WA 98101-3212
Telephone: 206-553-5930
Region 4
(AL, FL, GA, KY, MS, NC, SC, TN)
Sam Nunn Atlanta Federal Center
61 Forsyth St., S.W.
Atlanta, GA 30303-8960
Telephone: 404-562-9900
Toll-free: 800-241-1754
Fax: 404-562-8174
Region 9
(AZ, CA, HI, NV)
75 Hawthorne St.
San Francisco, CA 94105
Telephone: 415-947-8000
Toll-free: 866-EPA-WEST
Fax: 415-947-3553
E-mail: [email protected]
Region 5
(IL, IN, MI, MN, OH, WI)
77 West Jackson Blvd.
Chicago, IL 60604
Telephone: 312-353-2000
Toll-free: 800-621-8431
Fax: 206-553-0149
Region 10
(AK, ID, OR, WA)
1200 Sixth Ave.
Seattle, WA 98101
Telephone: 206-553-1200
Toll-free: 800-424-4372
# CT, NJ, NY, and Virgin Islands plans cover public sector (state and local government) employment
* State with approved state plan.
+ Region 9 has three types of offices: (1) state, (2) federal, and (3) consultation project offices.
Checklist of Minimum Requirements for Chemical Laboratory and
Workplace Design
Properties of Protective Clothing Materials*
For additional information, refer to
Guidelines for Laboratory Design: Health
and Safety Considerations, third edition,
and Improving Safety in the Chemical
Laboratory: A Practical Guide, second
6. Appropriate fire extinguishers are
dispersed throughout the laboratory
and near the exits.
2. Aisles are at least 4 feet wide.
3. Laboratory chemical hoods are
sufficient and have adequate
ventilation. Employees should be
able to use laboratory chemical
hoods without crowding. The hoods
should be located so that they are
not near desks or areas in which
employees congregate.
Fairly durable
8. Provision has been made for gas
cylinders to be located out of the
main traffic flow and properly
strapped or chained.
Resistant to
rips and tears,
but less so
than polyamide
fibers; abrasion resistant,
but less so
than nylon or
Not water
strong and abra- absorbant
sion resistant
Melts when
heated; requires
Lab coats
9. Tops of benches and tables are
impervious to chemical spills.
possible; requires
antistatic agent
Usually reinforced at
points of
strain; will
stick together,
peel, crack,
or stiffen
to corrosive
Can be ignited
by flammable
solvents and
others in event
of static
charge of
static electricity
Aprons, sleeve
protectors, boots
Resistant to
Excellent chem- High melting
rips and tears
ical resistance;
low binding
for chemicals
point; flame
Bouffant caps
good permeability; limited
moisture absorbtion; may be
if the wearer is
Resistant to
Low melting
most chemicals; point; requires
oxygen and light flame-retardant
Fairly durable
Degraded by
acids; binds
some chemicals
10. Adequate storage space is available
for flammables.
11. The shelving units or cabinets are
sufficient. No chemicals or supplies
should be stored on the floor.
7. Grounded (three-prong) electrical
receptacles are sufficient and make
extension cords unnecessary. No
cords should be on the floor or
across aisles.
1. At least two exits are in place, with
doors opening outward, preferably
into an offset. (Direct openings
partially block passages and
corridors.) Exits should be at
opposite ends of the facility and
easily accessible from all locations.
For the most current information in this area, consult the NIOSH protective
equipment program.
Degraded by
Requires special No static
acids; binds
treatment for
some chemicals flame-retardancy
Lab coats
Resistant to
In direct flame,
most chemicals fabric shrinks
and to flame
will not melt
or drip; selfextinguishing;
rapidly dissipates when
source of ignition is removed
soft, and resilient; easy to
clean and has
Lab coats
Has antistatic
12. Lighting is adequate.
4. Desks are located so that spills or
other accidents do not endanger
employees sitting at the desks.
13. Pipes and conduits have been
installed so as not to block aisles.
They should allow for adequate
5. Safety showers and eyewash
fountains are at easily accessible
locations for all employees. These
locations should not tempt
employees to restrict access to
showers or eyewashes by placing
boxes in front of the emergency
14. New construction and renovation
of existing facilities should meet
the ADA Accessibility Guidelines.
Lab coats
*Based on manufacturers’ claims
The following list is to be used only as a guide. Specific incompatibilities are
listed in the MSDSs. You may also wish to consult Bretherick’s Handbook of Reactive
Chemical Hazards.
Ammonia, acetylene, butadiene,
butane, methane, propane (or other
petroleum gases), hydrogen, sodium
carbine, benzene, finely divided metals,
Chlorine dioxide
Ammonia, methane,
hydrogen sulfide
Incompatible With
Chromic acid and chromium
Acetic acid
Chromic acid, nitric acid, hydroxyl
compounds, ethylene glycol, perchloric
acid, peroxides, permanganates
Acetic acid, naphthalene, camphor,
glycerol, trioxide alcohol, flammable
liquids in general
Acetylene, hydrogen peroxide
Incompatible Chemicals
Concentrated nitric and sulfuric acid
Cumene hydroperoxide
Acids (organic or inorganic)
Chlorine, bromine, copper, fluorine,
silver, mercury
Flammable liquids
Alkali and alkaline earth
Water, carbon tetrachloride or other
metals (such as powdered
chlorinated hydrocarbons, carbon
dioxide, aluminum or magnesium,
halogens calcium, lithium, sodium,
Ammonium nitrate, chromic acid,
hydrogen peroxide, nitric acid, sodium
peroxide, halogens
All other chemicals
Hydrocarbons (such as butane,
Fluorine, chlorine, bromine, chromic
acid, propane, benzene) sodium
Hydrocyanic acid
Nitric acid, alkali
Hydrofluoric acid (anhydrous)
Ammonia (aqueous or anhydrous)
Hydrogen sulfide
Fuming nitric acid, oxidizing gases
Acids, powdered metals, flammable
liquids, chlorates, nitrites, sulfur, finely
divided organic combustible materials
Acids, activated carbon
Acetylene, ammonia (aqueous or
anhydrous), hydrogen
Ammonia (anhydrous)
Mercury (e.g., in manometers),
chlorine, calcium hypochlorite, iodine,
bromine, hydrofluoric acid (anhydrous)
Ammonium nitrate
Nitric acid, hydrogen peroxide
Acetylene, fulminic acid, ammonia
Arsenical materials
Any reducing agent
Nitric acid (concentrated)
See Chlorine
Calcium oxide
Carbon (activated)
Calcium hypochlorite, all oxidizing
Acetic acid, aniline, chromic acid,
hydrocyanic acid, hydrogen sulfide,
flammable liquids and gases, copper,
brass, any heavy metals
Inorganic bases, amines
Oxalic acid
Silver, mercury
Oils; grease; hydrogen; flammable
liquids, solids, and gases
Perchloric acid
Acetic anhydride, bismuth and its
alloys, alcohol, paper, wood, grease,
Ammonium salts, acids, powdered
metals, sulfur, finely divided organic or
combustible materials
Peroxides, organic
Acids (organic or mineral)
Phosphorus (white)
Air, oxygen, alkalies, reducing agents
Carbon tetrachloride, carbon dioxide,
Potassium chlorate
Sulfuric and other acids
Potassium perchlorate
See also Chlorates
Potassium permanganate
Glycerol, ethylene glycol, benzaldehyde,
sulfuric acid
Reducing agents
Acetylene, oxalic acid, tartaric acid,
ammonium compounds, fulminic add
Carbon tetrachloride, carbon dioxide,
Sodium nitrite
Ammonium nitrate
ammonium salts
Sodium peroxide
Ethyl or methyl alcohol, glacial acetic
acid, acetic anhydride, benzaldehyde,
carbon disulfide, glycerin, ethylene
glycol, ethyl acetate, methyl acetate,
Sulfuric acid
perchlorate; potassium permanganate;
similar compounds of light metals,
such as sodium, lithium
Reducing agents
Facilities Safety and Housekeeping Inspection Report
This listing is not intended to be complete. Use it as a guide when preparing
a similar list for your use that applies to your situation.
Facility No. ______________________________Bldg. ______________________________
Comments and
Areas of Inspection
Bench tops
Areas under sinks
Cabinets, drawers, shelves
(chemicals properly stored)
Hoods and other ventilation
Window ledges
Walls and floors
Chairs, stools, upholstery, casters
Safety glasses, face shields,
protective clothing
Fire extinguishers
Compressed gas cylinders
Broken glassware: Destroy? Repair?
“No Smoking” and “No Eating” signs
Tubing and hoses: Condition?
Proper use?
Guards on moving equipment
Condition of equipment
Electric cords, other wiring
Eyewashes and safety showers
Storage of peroxide-forming chemicals
Storage of chemicals in work area
Storage of chemicals in storage area
Evaluation of amount of supplies
and equipment
Laboratory desks, bookshelves
Office housekeeping
Actions taken and other recommendations: ______________________________________
Inspection made by____________________________ Date: ______________
*Please use additional sheets if necessary.
Accident reporting 24
ADA 5, 26, 77
Air masks 9
Allergens 21
Americans with Disabilities See ADA
Carcinogens 13, 22, 23, 35, 36, 57, 67, 72
Cardiopulmonary resuscitation See CPR
CAS Registry numbers 34, 73
Centrifuges 46
Chemical emergencies 15-16, 31-33, 44-46
Chemical Hygiene Plan 19
Chemical incompatibility 72-73
Chemical toxicity 16-18
Cold traps 42
Compressed gases 42-44
Cooling baths 41-42
CPR 20, 39
Distillations 35-36
Electrical hazards 9-10, 58-59
Emergencies 31-33
See also Chemical emergencies,
Fires, Medical emergencies
Employee training 20-21, 27-31
Environmental Protection Agency
See EPA requirements
EPA requirements 11-14, 18
Equipment 26, 36-38
Explosions 58
Extractions 35
Eye protection 10-11, 26
Eyewashes 8, 25, 31, 55
Fire drills 6, 31, 22, 31, 55
Fire extinguishers 22, 31, 55
Fires 57-58
First aid 32-33
Flammable liquids 52-53
Food in the laboratory 5, 33, 56
Fume hoods See Laboratory chemical hoods
Gases 46
See also Compressed gases
Glass tubing 38-39
Glassware 39, 53-54
Gloves 6, 56-57
Health hazard data 27-31
Incompatible chemicals 72-73
Ingestion of chemicals 32-33
Inorganic peroxides 46-47
Labeling 9
Laboratory chemical hoods 6-7, 55-56
Laboratory techniques 34
Lasers 60
Material safety data sheets See MSDS
Medical emergencies 15-16, 31-33, 45-46
MSDS 16-18, 27-31
Mutagens 17, 31
Noise control 10
Occupational Safety and Health
Administration See OSHA requirements
Organic peroxides 47-48, 50-51
OSHA requirements 10, 18-22
PEL 16-17, 27
Perchloric acid 51-52
Permissible exposure limit See PEL
Peroxide formers 48-51
Peroxides See Inorganic peroxides,
organic peroxides, peroxide formers
Personal hygiene 5, 26
Personal protective equipment
See Safety equipment
Protective clothing 6, 26, 56-57, 71
Radiation hazards 59-60
Record keeping 14, 21
Reduced-pressure operations 39-41
Refrigerators 56
Responsibility for safety 3, 4, 25
Safety equipment 5-7
Safety glasses See Eye protection
Safety inspection 19, 74
Safety literature 62-67
Safety rules 4-5, 25
Safety showers 7-8, 31
Separations 35-36
Sinks 7
Smoking 5, 26
Solvents 52-53
Spills 44-46
Storage 6, 48, 54
Temperature control 40-42
Teratogens 17, 30
Threshold Limit Value See TLV
TLV 16-17, 27
Training See Employee training
Ultraviolet lamps 60
Vacuum operations See Reducedpressure operations
Ventilation 34-35
See also Laboratory chemical hoods
Waste disposal 11-14
X-ray generators 59-60
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