Laboratory Safety Rules

Laboratory Safety Rules
The following general standards should be followed by employees for all
laboratory work with chemicals and hazardous materials. These general
guidelines can be modified based on a written laboratory-specific evaluation of
hazards and risks which lead to a laboratory-specific operation and protective
equipment program.
Employees should:
Know the safety rules and procedures that apply to the work that is being done.
Determine the potential hazards and appropriate safety precautions before
beginning any new operation.
Know the location of and how to use the emergency equipment in the work area, as
well as how to obtain additional help in an emergency, and be familiar with
emergency procedures.
Be alert to unsafe conditions and actions and call attention to them so that
corrections can be made as soon as possible.
Use equipment only for its designed purpose.
Use only those chemicals for which appropriate safety controls and protective
equipment are available.
Eating, drinking, smoking, gum chewing, or application of cosmetics should not
occur in areas where laboratory chemicals are present.
Employees should wash their hands prior to leaving the laboratory after using
chemicals, even if gloves or other similar PPE was employed.
Do not store, handle, or consume food or beverages in storage areas, refrigerators,
glassware, or areas that are also used for laboratory operations.
Refrain from using personal electronics such as cell phones and iPods in the
Handle and store laboratory glassware with care to avoid damage; do not use
damaged glassware.
Use extra care with Dewar flasks and other evacuated glass apparatus; shield or
wrap them to contain chemicals and fragments should implosion occur.
Wash areas of exposed skin well before leaving the laboratory. It is especially
important to wash hands routinely before leaving.
Leave all protective equipment in the lab when exiting including lab coats and
protective gloves.
Avoid practical jokes or other behavior that might confuse, startle, or distract other
Do not use mouth suction for pipetting or starting a siphon.
Confine long hair and loose clothing.
Wear closed-toed shoes at all times in the laboratory; NO SANDALS ARE
Safety goggles or alternative eyewear that was designated through the hazard
review process must be worn in the lab at all times when chemicals are present and
in use.
Appropriate protective clothing (e.g., gloves, lab coats, etc.) should be kept in the
laboratory and worn routinely. Bare midriff, legs, or shoulders are not allowed in the
laboratory as directed by the laboratory supervisor
Dispose of chemicals properly at the end of the experiment. Never put hazardous
chemicals down the drain unless specific authorization has been granted.
Hazardous experiments should not be unattended
Be alert to unsafe conditions and see that they are corrected when detected.
All new procedures must be evaluated for potential hazards associated with the work
by the laboratory supervisor.
Report incidents following the Injury and Illness Protection Program.
The following resources are available from EHS for an employee who wishes to explore
alternative controls:
Material Safety Data Sheet (MSDS) for the materials in question.
“Safety in Academic Chemistry Laboratories” American Chemical Society.
“Working Safely With Chemicals in the Laboratory – A Student Guide” Genium
Standard Operating Procedures (SOPs)
The California OSHA Laboratory Standard (Title 8) defines a hazardous chemical as
chemical for which there is statistically significant evidence based on at least one study
conducted in accordance with established scientific principles that acute or chronic
health effects may occur in exposed employees.
The use of toxic gases, pyrophoric substances, and the 13 specific carcinogens that
require OSHA notice 1 must be pre-approved by the CHO due to the likelihood of
specific permitting requirements (see Attachment 8 of the SCU Chemical Hygiene Plan,
Restricted Substances).
As per 8 CCR 5203, the chemicals that require approval include Methylenedianiline, 1,3 Butadiene, Methylene
Chloride, Chromium VI, Cadmium, Vinyl Chloride, DBCP, Acyrlonitrile, Inorganic Arsenic, 4,4’Mehtylenebis (2Chloroaniline), Formaldehyde, Benzene, Ethylene Dibromide, Ethylene Oxide, 2-Acetylaminofluorene, 4Aminodiphenyl, Benzidine (and its salts),3,3'-Dichlorobenzidine (and its salts),4-Dimethylaminoazobenzene, alphaNapthylamine, beta-Naphthylamine, 4-Nitrobiphenyl, N-Nitrosodimethylamine,Propiolactone, bis-Chloromethyl
ether, Methyl chloromethyl ether, Ethyleneimine
The special precautions described in the following sections are to be used in
conjunction with the information detailed in the Attachment 1 - General Laboratory
Standards of the SCU Chemical Hygiene Plan. The special precautions sections and
any other relevant instructions in this Chemical Hygiene Plan may be used as part of
the written standard operating procedures required by the OSHA Laboratory Standard.
Project-specific and/or area-specific standard operating procedures must be
written by departments, work units, Laboratory Supervisors or Supervisors for
hazardous chemical and hazardous operations work not covered by the following
special precautions sections.
Physical & Chemical Hazards
"Physical hazard" refers to a chemical for which there is evidence that it is a
combustible liquid, a compressed gas, explosive, flammable, an organic peroxide, an
oxidizer, pyrophoric, unstable (reactive), corrosive, or water-reactive. Materials which
present a physical hazard can be safely used if the specific hazard(s) are understood,
and measures are taken to address the hazards. If appropriate precautions are not
taken, a fire, an explosion, unwanted corrosion, personal injury, or property damage
could occur. Certain chemicals cannot be safely mixed or stored with other chemicals
because a severe reaction can take place or an extremely toxic reaction product can
An eyewash and safety shower must be readily accessible to areas where injurious
materials are used and stored. In the event of skin or eye contact with an injurious
material, immediately flush the area of contact with cool water for 15 minutes. Remove
all affected clothing. Get medical help. Additional information concerning eyewash and
safety shower requirements is available in SCU’s Emergency Eyewash and Shower
Program located on the EHS website.
Laboratories present special challenges in the prevention of repetitive stress injuries.
Laboratory employees are urged to contact EHS to request an ergonomic workstation
evaluation if they have any concerns regarding the setup of their workstations.
Special Precautions for Working with Flammables and Combustibles:
Flammable/combustible materials are materials which under standard conditions can
generate sufficient vapor to cause a fire in the presence of an ignition source.
Flammable materials can generate sufficient vapors at temperatures below 100oF
(38oC); combustibles, at temperatures at or above 100oF (38oC) and below 140oF
(60oC). The vapors of these materials are invisible, and a vapor trail to an ignition
source away from the immediate area can result in a flashback. Flammables are more
hazardous at elevated temperatures due to more rapid vaporization. In addition,
flammable and combustible materials react with oxidizers which can result in a fire.
Employees must observe the following special precautions:
1. Eliminate ignition sources such as open flames, smoking materials, hot surfaces,
sparks from welding or cutting, operation of electrical equipment, and static
electricity. Post conspicuous "No Smoking" signs in areas where flammable
materials are used or stored.
2. Minimize the quantity kept in the work area.
3. Store in approved flammable liquid containers (original containers or safety cans)
and storage cabinets, or in a special storage room designed for that purpose. Store
away from oxidizers.
4. Flammable liquids stored in glass containers shall not exceed 1 quart. Exception:
For conditions where chemical purity must be protected, flammable liquids stored in
glass containers shall not exceed 1 gallon unless specific permission for such use
has been granted.
5. Refrigerators and freezers used for the storage of flammable or combustible liquids
must have no internal sources of ignition (“lab-safe” or “flammable rated”).
6. Ensure that there is proper bonding and grounding when it is required, such as
when transferring or dispensing a flammable liquid from a large container or drum.
Bonding and grounding must be checked regularly.
7. Ensure that appropriate fire control systems or extinguishers are available.
Special Precautions for Working with Corrosives:
Corrosives are materials that can react with the skin causing burns similar to thermal
burns, and/or which can react with metal causing deterioration of the metal surface.
Acids and bases are corrosives. Observe the following special precautions.
1. Containers and equipment used for storage and processing of corrosive materials
should be corrosion resistant.
2. Eye protection (safety glasses or splash goggles, as appropriate) and rubber gloves
should always be used when handling corrosive materials. A face shield, rubber
apron, and rubber boots may also be appropriate, depending on the work
3. When mixing concentrated acids (caustics) with water, add the acid (caustic) slowly
to water. Never add water to acid (caustic).
4. Acids and bases should be stored separately from each other. Organic acids
should be stored with flammable materials, separate from oxidizers and oxidizing
Special Precautions for Working with Oxidizers
Oxidizers are materials that readily yield oxygen or another oxidizing gas, or that readily
react to promote or initiate combustion of flammable/combustible materials. Oxidation
reactions are a frequent cause of chemical accidents. Observe these precautions
to reduce risk when storing or handling oxidizers.
1. Know the reactivity of the materials involved in experiment or process. Make sure
that there are no extraneous materials in the area which could become involved in a
2. If the reaction can be violent or explosive, use shields or other methods for isolating
the materials or the process.
3. Use the minimum amounts necessary for the procedure. Do not keep excessive
amounts of the material in the vicinity of the process.
4. Store properly, away from organic materials, flammable materials and other
reducing agents.
5. Perchloric acid should be used only in specially-designed perchloric acid fume
hoods equipped with wash-down systems to prevent deposition of shock-sensitive
perchlorates in the ductwork and machinery. Before purchasing perchloric acid, the
laboratory supervisor should arrange for use of an approved perchloric acid hood.
Special Precautions for Working with Water-Reactive Materials
Materials that react with water to produce a flammable or toxic gas, or other hazardous
condition are said to be water-reactive. Fire and explosion are serious concerns when
working with these materials. Special precautions for safe handling of water-reactive
materials will depend on the specific material, and the conditions of use and storage.
Contact CHO for information on the safe use of a specific material. Examples of waterreactives include alkali and alkaline earth metals (e.g. Li, Na, K, Ca, Mg), metal
hydrides, some metal and nonmetal chlorides (e.g. SiCl4, PCl3, AlCl3), calcium carbide,
and acid halides.
Special Precautions for Working with Pyrophoric Materials
Pyrophoric materials ignite spontaneously upon contact with air. The flame may or may
not be visible. Examples include butyllithium, silane, and yellow phosphorous.
Store and use all pyrophorics in an inert atmosphere.
Special Precautions for Working with Peroxidizables
Peroxidizables are substances or mixtures that react with oxygen to form peroxides.
Some peroxides can explode with impact, heat, or friction such as that caused by
removing a lid. Peroxides form inside the containers of some materials even if they
have not been opened. Examples include ethyl ether, tetrahydrofuran, liquid paraffins
(alkanes), and olefins (alkenes).
1. Date all peroxidizables upon receipt and upon opening. Unless an inhibitor has
been added by the manufacturer, materials should be properly disposed of after 18
months from date of receipt or 3 months from date of opening.
2. Do not open any container having obvious crystal formation around the lid.
3. Other special precautions are similar to those used for flammables.
Special Precautions for Working with Light-Sensitive Materials
Light-sensitive materials are unstable with respect to light energy. They tend to
degrade in the presence of light, forming new compounds that can be hazardous, or
resulting in conditions such as pressure build-up inside a container which may be
hazardous. Observe the following precautions.
1. Store light-sensitive materials in a cool, dark place in amber colored bottles or other
containers that reduce or eliminate penetration of light.
2. Date containers on receipt and upon opening, and dispose of surplus material after
one year if unopened or 6 months if opened.
Special Precautions for Working with Shock-Sensitive or Explosive Materials
Shock-sensitive/explosive materials are substances or mixtures which can
spontaneously release large amounts of energy under normal conditions, or when
struck, vibrated, or otherwise agitated. Some materials become increasingly shocksensitive with age and/or loss of moisture. The inadvertent formation of shocksensitive/explosive materials such as peroxides, perchlorates, picrates, and azides is of
great concern in the laboratory.
1. Contact the Chemical Hygiene Officer when work with shock-sensitive or explosive
materials is planned or when it is suspected that the inadvertent formation of shocksensitive materials in ductwork, piping, or chemicals being stored has occurred.
2. Date all containers of explosive or shock-sensitive materials upon receipt and when
opened. Unless an inhibitor has been added, unopened shock-sensitive materials
should be discarded within 12 months after receipt. Open containers of shocksensitive materials should be discarded within 6 months of the date opened.
3. Use the minimum amount of materials necessary for a procedure. Keep a minimum
amount of material on hand.
4. If there is a chance of explosion, use barriers or other methods for isolating the
materials or the process.
Special Precautions for Working with Compressed Gases
Special systems are needed for handling materials under pressure. Toxic and corrosive
gases present special problems in designing engineering controls. The physical and
health hazards of any material are typically compounded by the pressure hazard.
Carefully observe special precautions.
1. Signs shall be provided by the CHO and posted by the Laboratory Supervisor
identifying type of cylinders to be stored and identifying any potential hazard.
2. Compressed gas cylinders shall be stored and secured in an upright position. Gas
cylinders in storage and in use shall be kept tightly secured with chains. City of
Santa Clara Fire Department requirements for gas cylinder restraints are ¼ inch
thick steel welded link chain secured around the cylinder at 1/3 the height of the
cylinder and 2/3 the height of the cylinder. The restraints shall be secured to the
wall or counter in such a manner to prevent demounting due to a moderate
earthquake. Lecture bottles shall be supported in a lecture bottle tube support to
provide upright support.
3. Always use the smallest size cylinder required to perform the work.
4. Cylinders of compressed gases must be handled as high energy sources.
5. Cylinders on wheeled carts must be capped and secured by an approved (either UL
or FM listed) cylinder support strap or chain. The cart must be an approved cylinder
cart. Do not attempt to take a loaded cylinder cart up or down a stairway.
6. Close the gas cylinder at the top of the tank when not in use and remove the
regulator if the cylinder is not to be used for a period over a month. Lecture size
gas cylinders are too small to have valve protective caps.
7. Cylinders shall be stored and transported with the protective valve cap in place to
prevent damage to the cylinder valve in the event the cylinder falls or the valve
sustains impact. No cylinder shall be stored or transported with the regulator still
All uncapped cylinders must be secured independently (not ganged behind a single
chain) to a solid element of the lab structure. Carts are not acceptable for
supporting uncapped or in-use cylinders.
Never bleed a cylinder completely empty. Leave a slight pressure to keep
contaminants out.
Oil or grease on the high pressure side of an oxygen cylinder can cause an
explosion. Do not lubricate an oxygen regulator or use a fuel gas regulator on an
oxygen cylinder.
Always wear goggles or safety glasses with side shields when handling compressed
Always use appropriate gauges, fittings, and materials compatible with the particular
gas being handled. Regulators must be compatible with gas cylinders (do not use
All compressed gas cylinders and chemical containers should be stored away from
heat sources and direct sunlight.
Wherever carbon monoxide or hydrogen sulfide is present in quantities greater than
one standard lecture bottle size, detection alarms must be present and properly
tested and maintained.
Wherever hydrogen is present, all tubing must be of braided stainless steel hose.
Alternative tubing materials shall be reviewed by CHO on a case-by-case basis, to
ensure that the alternative materials meet fire protection requirements.
When work with other toxic, corrosive, or reactive gases is planned, the CHO
should be contacted for information concerning specific handling requirements for
the gas involved. (see Attachment 8, Restricted Substances) Generally, these
gases will need to be used and stored with local exhaust ventilation such as a lab
hood or a gas cabinet and a formal registration with the Santa Clara Fire
Department may be required as per City Ordinance.
Special Precautions for Working with Cryogens
Some of the hazards associated with cryogens (fluids used to maintain extremely low
temperatures such as liquid nitrogen and dry ice) are fire, pressure, embrittlement of
materials, and skin or eye burns upon contact with the liquid. Cryogens can condense
nearly pure liquid oxygen from the air, creating a severe fire risk. A pressure hazard
exists because of the large expansion ratio from liquid to gas, causing pressure build up
in containers. Many materials become brittle at extreme low temperatures. Brief
contact with materials at extreme low temperatures can cause burns similar to thermal
burns. Carefully observe all special precautions.
1. Equipment should be kept clean, especially when working with liquid or gaseous
2. Mixtures of gases or fluids should be strictly controlled to prevent formation of
flammable or explosive mixtures.
3. For flammable cryogens the precautions provided in the "Flammable/Combustible
Materials" section of this booklet should be used.
4. Always wear goggles when handling cryogens. If there is a splash or spray hazard,
a face shield over the goggles, an impervious apron or coat, cuff less trousers, and
fully-covering, non-lacing shoes should be worn. Watches, rings, and other jewelry
should not be worn. Gloves should be impervious and sufficiently large to be
readily thrown off should a cryogen be spilled. Cryo-gloves or pot holders should
also be used. Respirators or oxygen monitors may be required if the cryogen is
toxic and sufficient local exhaust ventilation is not available. Contact EHS to
determine if exposure monitoring is necessary.
Containers and systems containing cryogens should have pressure relief
Containers and systems should be capable of withstanding extreme cold without
becoming brittle. Glass containers should be taped solidly around the outside or
encased in plastic mesh.
Neither liquid nitrogen nor liquid air should be used to cool a flammable mixture in
the presence of air because oxygen can condense from the air, which could lead to
an explosion hazard.
Funnels should not be used for pouring liquid nitrogen or any other cryogen.
Large mobile dewars or LN2 refrigerators (or the trolleys carrying these) used for
transporting cryogens within a building or between buildings should be equipped
with a braking mechanism.
Large mobile dewars at risk for tipping should be transported on appropriate carts.
Wheeled trolleys may not be used if the vessel must pass over elevator thresholds
or other slots/crevasses wider than 25% of the wheel width.
Dispensing stations designed to allow research staff to fill smaller vessels from a
larger self-pressurizing Dewar must be located in non-public areas, and should be
posted with standard operating procedures.
Smaller vessels of liquid nitrogen or other cryogens transported by hand within or
between buildings must have a handle or bail, and must be covered.
Health Hazards
"Health hazard" refers to chemicals for which there is statistically significant evidence
based on at least one study conducted in accordance with established scientific
principles that acute or chronic health effects may occur in exposed employees. This
term includes chemicals which are carcinogens, toxic or highly toxic agents,
reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins,
neurotoxins, agents which act on the hematopoietic system and agents which damage
the lungs, skin, eyes, or mucous membranes.
For many toxic materials, hygienic standards have been established and action must be
taken to prevent personnel from receiving exposures in excess of these standards.
These standards may be referred to as threshold limit values (TLVs) or permissible
exposure limits (PELs).
The MSDS will list the hygienic standard for the hazardous chemical or each component
of a mixture. In addition, the CHO has a complete listing of published TLVs and PELs
and other works concerning the subject of industrial toxicology. If you would like to
conduct a more thorough review of a particular compound, or if you would like an
evaluation of the exposure to a specific material used in your work area, contact the
Protection from health hazards is provided by ensuring that exposure to such hazards is
minimized or eliminated. To minimize the exposure, it is necessary to determine the
route by which the exposure may occur, i.e. inhalation, skin contact, puncture, ingestion,
or a combination of exposure routes.
Special Precautions for Working with Allergens
The term allergens describe a wide variety of substances that can produce skin and
lung hypersensitivity. Examples include diazomethane, chromium, nickel dichromates,
formaldehyde, isocyanates, and certain phenols. Wear suitable gloves to prevent hand
contact with allergens or substances of unknown allergenic activity. Conduct aerosol
producing procedures in a fume hood.
Special Precautions for Working with Embryotoxins and Reproductive Toxins
Substances that act during pregnancy to cause adverse effects on the fetus are referred
to as embryotoxins. These effects include embryolethality (death of the fertilized egg,
the embryo, or the fetus), malformation (teratologic effects), retard growth, and
postnatal functional deficits. Examples include organo-mercurials, lead compounds,
and formamide. Because the period of greatest susceptibility to embryotoxins is the first
8-12 weeks of pregnancy, which includes a period when a woman may not know she is
pregnant, women of child-bearing potential should take care to avoid skin contact with
all chemicals. The term "reproductive toxins" is used to describe substances that cause
harmful effects on the male or female reproductive system or the developing embryo
and fetus. These effects include but are not limited to menstrual irregularity, lowered
fertility, testicular atrophy, and birth defects. Special precautions when working with
these substances include:
1. A review must take place for each use of embryotoxins between the Laboratory
Supervisor and Chemical Hygiene Officer. Review continuing uses annually or
whenever a procedural change is made.
2. Label embryotoxins as follows: EMBRYOTOXIN: READ SPECIFIC PROCEDURES
3. Store embryotoxins and reproductive toxins in unbreakable containers or
unbreakable secondary containers in a well ventilated area.
4. Guard against spills and splashes. Appropriate safety apparel, especially gloves,
should be worn. All hoods, glove boxes, or other essential engineering controls
should be known to be operating properly before work is started.
5. Report of all incidents of exposure or spills.
Special Precautions for Working with Chemicals of Moderate Chronic or High
Acute Toxicity:
Examples of chemicals of moderate chronic toxicity or high acute toxicity include
diisopropylfluorophosphate, hydrofluoric acid, and hydrogen cyanide. Observe the
following precautions:
1. Consult one of the standard compilations that list toxic properties of known
substances and learn what is known about the substance that will be used. Follow
the specific precautions and procedures for the chemical.
2. Use and store these substances only in designated (restricted access) areas
placarded with appropriate warning signs.
3. Use a hood or other containment device for procedures that may result in the
generation of aerosols or vapors; trap released vapors to prevent their discharge
with fume hood exhaust.
4. Avoid skin contact by use of gloves and long sleeves and other protective apparel
as appropriate.
5. Maintain records of the amounts of materials on hand, amounts used, and the
names of the workers involved.
6. Be prepared for accidents and spills. At least two people should be present at all
times if compounds in use are highly toxic or of unknown toxicity.
7. Store breakable containers in chemically resistant trays; also work and mount
apparatus above such trays or cover work and storage surfaces with removable,
absorbent, plastic backed paper.
8. If a major spill occurs outside the hood, evacuate the area and call for assistance
9. Thoroughly decontaminate or dispose of contaminated clothing or shoes. If
possible, chemically decontaminate by chemical conversion to a less toxic product.
10. Store contaminated waste in closed, suitably labeled, impervious containers.
Special Precautions for Working with Chemicals of High Chronic Toxicity
Examples of chemicals exhibiting high chronic toxicity include dimethylmercury, nickel
carbonyl, benzo-a-pyrene, N-nitrosodiethylamine, and other human carcinogens or
substances with high carcinogenic potency in animals
1. Conduct all transfers and work in designated (restricted access) areas: a restricted
access hood, glove box, or portion of a lab, designated for use of highly toxic
substances, for which all persons with access are aware of the substances being
used and necessary precautions.
2. Protect vacuum pumps against contamination with scrubbers or HEPA filters and
vent effluent into the hood.
3. Decontaminate vacuum pumps or other contaminated equipment, including
glassware, before removing them from the designated area. Decontaminate the
designated area before normal work is resumed there.
4. On leaving the area, remove protective apparel (placing it in an appropriate, labeled
container) and thoroughly wash hands, forearms, face, and neck.
5. Use a wet mop or a vacuum cleaner equipped with a HEPA filter to decontaminate
6. If using toxicologically significant quantities of a substance on a regular basis (in
quantities above a few milligrams to a few grams, depending on the substance, 3 or
more times per week), contact the CHO.
7. Keep accurate records of the amounts of these substances stored and used, the
dates of use, and names of users.
8. The designated area must be conspicuously marked with warning and restricted
access signs and all containers should be appropriately labeled with identity and
warning labels (e.g., CANCER-SUSPECT AGENT).
9. Ensure that contingency plans, equipment, and materials to minimize exposures of
people and property in case of accident are available.
10. For a negative pressure glove box, ventilation rate must be at least 2 volume
changes/hour and at a pressure of at least 0.5 inches of water gauge. For a
positive pressure glove box, thoroughly test for leaks before each use. In either
case, trap the exit gases or filter them through a HEPA filter and then release them
into a fume hood.
11. Use chemical decontamination whenever possible; ensure that containers of
contaminated wasted are transferred from the designated area under the
supervision of the CHO.
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