Epoxy Resin Systems
Revised June 1989
Fact Sheet
Hazard Evaluation System and Information Service
850 Marina Bay Parkway
Building P, 3rd Floor
Richmond, CA 94804
(866) 282-5516
Epoxy Resin Systems
(two or more chemicals combined to form
epoxy paint, plastic, or adhesive products)
TABLE OF CONTENTS
Are You Working With An Epoxy Resin System?
What Is In An Epoxy Resin System?
How Do Epoxies Enter And Affect Your Body?
Tests For Exposure And Medical Effects
Legal Exposure Limits
Reducing Your Exposure
Where Can You Get More Information
Health Hazard Summary: The most common effects of overexposure to the chemicals
used in epoxy resin systems are eye, nose, throat, and skin irritation, skin allergies, and
asthma. Chemicals in some epoxy resin systems have additional health effects. Finished,
hardened epoxy products are practically non-toxic unless they are cut, sanded, or
burned.
Are You Working With an
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Epoxy Resin System?
Epoxy products are used for paints and other surface coatings, molded and reinforced
plastics, electronic component potting resins, and adhesives ranging from spray foams to
dental cement. They are often used in jobs where tough, durable coatings or adhesives are
needed. This factsheet is for workers who use epoxy products in a variety of workplaces,
including shipyards, auto body shops, and the electronics, aerospace and construction
industries.
What Is In an Epoxy Resin System?
Epoxy resin systems are made up of an epoxy resin and a curing agent (also called a
hardener or catalyst). Many epoxy products also contain additives such as organic
solvents, fillers such as fiberglass or sand, and pigments. See the box on page 2.
When epoxy resin systems are used, single molecules (monomers) of the epoxy resin
chemical and the curing agent combine to form long chains of molecules (polymers). As
the mixture "cures," it becomes a hard polymer. Some epoxies cure in a few minutes at
room temperature. Others need additional time or heat to harden. The characteristics of
hardened epoxies (such as whether they are firm or flexible, or resistant to heat or
chemicals) depend on which epoxy monomers, curing agents, solvents, and fillers are
added.
The hardened, finished polymers are almost non-toxic; it is exposure to the uncured resin
components that can be harmful. In a two-component epoxy product, the epoxy resin and
the curing agent are packaged separately and must be mixed together just before being
used. Each component can be hazardous. In a single-component product, the resin and the
curing agent are supplied in a pre-mixed form. Single-component systems are usually
safer, because the hazardous chemicals are already partly combined into less toxic
polymers and because they do not evaporate into the air as easily.
You Have the Right to Know: Under California's Hazard Communication Standard
(GISO 5194), your employer must tell you if you are working with any hazardous
substances, including epoxies, and must train you to use them safely.
Because different additives to epoxy resin systems can affect your health in different
ways, you should find out what chemicals are in the products you use. Ask to see the
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Material Safety Data Sheets (MSDSs) for the products in your work area. An MSDS lists
the hazardous chemical contents of a product, describes its health and safety hazards, and
gives methods for its safe use, storage, and disposal. The MSDS should also include
information on fire and explosion hazards, reactivity, first aid, and procedures for handling
leaks and spills. Your employer must have an MSDS for any workplace product that
contains a hazardous substance, and must make the MSDS available to employees on
request.
This Fact Sheet is an aid for worker training programs. It does not take the place of
Material Safety Data Sheets. HESIS Fact Sheets are available for several of the chemicals
commonly added to epoxy resin systems; see page 6.
Examples of Epoxy Resin System Chemicals
Epoxy Resins (monomers or oligomers) can be powders, or they can be thick, clear or
yellow liquids. Some common epoxy resins are: the diglycidyl ether of bisphenol A
(DGEBA), novolac resins, cycloaliphatic epoxy resins, brominated resins, epoxidized
olefins, EponR and EpikoteR.
Curing Agents react with epoxy resin monomers to form epoxy products. They are
usually liquids with strong, unpleasant odors. There are several categories of curing
agents. Examples include:
Aliphatic amines such as triethylenetetramine (TETA) and diethylenetriamine
(DETA);
Aromatic amines, including diaminodiphenyl sulfone (DDS) and dimethylaniline
(DMA);
Anhydrides such as phthalic anhydride and nadic methyl anhydride (NMA);
Amine/phenol formaldehydes such as urea formaldehyde and melamine
formaldehyde;
Catalytic curing agents such as tertiary amines and boron trifluoride complexes.
Diluents and solvents are used to dilute or thin epoxy resins. Diluents are usually
clear liquids. Some examples are:
Glycidyl ethers (reactive diluents) such as n-butyl glycidyl ether (BGE),
isopropyl glycidyl ether (IGE) and phenyl glycidyl ether (PGE);
Organic solvents such as toluene (toluol), xylene (xylenol), acetone, methyl ethyl
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ketone (MEK), 1,1,1-trichloroethane (TCA), and glycol ethers.
Fillers add bulk and body to epoxy products. They are usually powders or fibers
such as sand, clay, calcium carbonate, fiberglass, asbestos, or silica.
HOW DO EPOXIES ENTER AND
AFFECT YOUR BODY?
The chemicals in epoxy resin systems can affect your health when they come in contact
with your skin, or if they evaporate or form a mist or dust in the air you breathe. The main
effects of overexposure are irritation of the eyes, nose, throat, and skin, skin allergies, and
asthma. The solvent additives can cause other effects such as headaches, dizziness, and
confusion.
Lungs: Vapors and spray mists of most epoxy resin system chemicals can irritate your
lungs. Some people develop asthma from the curing agents. Symptoms of asthma include
chest tightness, shortness of breath, wheezing, and coughing. These symptoms may occur
after work or at night. Once a person becomes allergic to curing agents, even the dusts
from sanding or grinding the hardened plastics can cause an asthma attack.
Skin: Epoxy resins can cause skin irritation. Symptoms include redness, swelling, flaking,
and itching on the hands, face, or other areas of contact. Some people develop a skin
allergy or sensitivity to epoxy liquids or mists. Skin allergies may develop after just a few
days of contact or after many years of exposure to epoxies. Sensitized skin may become
red, inflamed, blistered, and itchy even from brief contact with epoxy resins.
Eyes, Nose, and Throat: Most epoxy resin system chemicals and their vapors (especially
the curing agents and solvents) can irritate your eyes, nose, and throat. Some people
develop headaches as a result of this irritation. If the liquids are splashed into your eye
they will sting, and they can severely damage the eye. In case of eye contact, immediately
rinse the eyes with water. Continue rinsing for 15 minutes and then seek medical attention.
Nervous System: Solvents inhaled or absorbed through your skin can affect your central
nervous system (your brain) the same way drinking alcohol does. Symptoms of solvent
overexposure include headache, nausea, dizziness, slurred speech, confusion, and loss of
consciousness. For more information, ask for the HESIS Guide to Industrial Solvents.
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Cancer: Older epoxy resins caused skin cancer in laboratory animals. This may have been
due to epichlorohydrin, a contaminant that can probably cause cancer in humans. Most
newer epoxy resins, which contain less epichlorohydrin, do not seem to cause cancer in
animals.
Diaminodiphenyl sulfone (DDS), a curing agent in some epoxy resin systems, is
carcinogenic in laboratory animals. Certain glycidyl ethers used in epoxy products cause
genetic mutations in laboratory animals. This suggests that they may be cancer-causing
agents. It is not known if glycidyl ethers cause mutations or cancer in humans. Most other
components of epoxy resin systems have not been adequately tested to determine if they
can cause cancer.
Reproductive System: Epoxy resins and curing agents themselves probably do not affect
pregnancy and reproduction in humans. However, some of the diluents and solvents in
epoxy resin systems may affect reproduction. Two solvents sometimes found in epoxy
resin systems (2-ethoxyethanol and 2-methoxyethanol) cause birth defects in laboratory
animals and reduced sperm counts in men. Some glycidyl ethers also damage the testes
and cause birth defects in test animals. It is not known whether they have the same effects
in humans.
Most other solvent additives have not been adequately tested to determine if they affect
reproduction. However, we do know that solvents inhaled by a woman can reach a
developing fetus and may contaminate the woman's breast milk. They may affect the fetus
just as they affect the mother. We recommend that pregnant and nursing women minimize
their exposure to solvents, just as they should minimize their exposure to alcohol.
Find out which chemicals are in the epoxy resin system you use. Epoxy resin systems that
contain hazardous solvents and diluents can be replaced with safer ones. See the section
on "Reducing Your Exposure" on page 5.
TESTS FOR EXPOSURE
AND MEDICAL EFFECTS
There is no medical or laboratory test that can accurately measure the amount of epoxies
in your body. Most of the chemicals found in epoxy resin systems are not stored in the
body. However, it is generally recommended that workers who are frequently exposed to
epoxy resin systems receive a complete physical examination, including an occupational
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and medical history and a pulmonary function test (spirometry), at the beginning of their
employment. A spirometry test measures how well your lungs work. Spirometry can be
performed before and after the same work shift to determine whether lung function is
affected by work activities. Spirometry is also a recommended part of the medical
evaluation before respirator assignment. A spirometry factsheet for workers is available
from HESIS.
People who work with epoxies on a regular basis should also have annual follow-up
examinations, including skin examinations and spirometry. A doctor or other health care
provider can choose other specific tests on a case-by-case basis to evaluate effects of
chemical exposure. Patch testing can be performed for the diagnosis of skin allergies. If
you are sensitized to a chemical, the doctor will see a reaction on your skin within a few
days of the test.
You have the right to see and copy your own medical records and records of your
exposure to toxic substances. These records are important in determining whether your
health has been affected by your work. Employers who have such records must store them
and make them available to you for at least 30 years after the end of your employment.
LEGAL EXPOSURE LIMITS
California's Division of Occupational Safety and Health (Cal/OSHA) sets and enforces
workplace chemical exposure limits. Cal/OSHA has adopted Permissible Exposure Limits
(PELs) for the amounts of some, but not all, of the epoxy resin system chemicals that may
be in the air you breathe.
Legally, your exposure may be above the PEL value at times, but only if it is below the
PEL value at other times, so that your average exposure for any 8-hour workshift is not
greater than the PEL for that chemical. See the box below.
If you work with epoxy resin systems and think you may be overexposed, talk to your
supervisor and/or your union. If any worker might be exposed to a substance at more than
the legal exposure limit, the employer must measure the amount of the chemical in the air
in the work area (Cal/OSHA regulation GISO 5155). You have the right to see the results
of such monitoring relevant to your work (GISO 3204).
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Legal Exposure Limits for Some
Cal/OSHA
Epoxy Resin System Chemicals*
PEL
Chemical Name
n-butyl glycidyl ether (BGE) 25 ppm
isopropyl glycidyl ether (IGE) 50 ppm
phenyl glycidyl ether (PGE) 1 ppm
diethylenetriamine (DETA) 1 ppm
toluene 100 ppm
xylene 100 ppm
2-ethoxyethanol 5 ppm
2-methoxyethanol 5 ppm
methyl ethyl ketone 200 ppm
phthalic anhydride
1 ppm
* PELs are measured as parts of
chemical
per million parts of air ("ppm").
REDUCING YOUR EXPOSURE
Your employer is required to protect you from being exposed to any chemical at levels
that are above the PEL. For information about how Cal/OSHA and Cal/OSHA
Consultation Service can help you and your employer, see the "Resources" section on
page 6.
Substitution: The most effective way to reduce hazardous chemical exposures is to use a
safer chemical, if one is available. For example, you or your employer may be able to
choose an epoxy resin system that:
contains little or no residual epichlorohydrin (a contaminant that causes cancer in
experimental animals and possibly in humans). Check the MSDS to see how much
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epichlorohydrin is in the resin you use.
is hardened with curing agents that are less irritating than the simpler aliphatic
chemicals. For example, polyamides and cycloaliphatic amines are generally less
irritating than other curing agents. (Your supervisor or the manufacturer or supplier
of the product can tell you which type is contained in the epoxy system you use).
contains high-molecular-weight resins. Resins with higher molecular weights are
less likely to sensitize the skin. (Ask your supervisor or chemical supplier about
molecular weights.)
has a reduced-solvent content or is solvent-free, to minimize health effects due to
solvents.
is a single-component epoxy system. These are usually safer than two-part products
because the hazardous monomers are already partly reacted.
does not contain asbestos, fiberglass, or silica fillers in a dry form. These substances
can cause severe lung diseases if you breathe their dusts. Do not sand or grind
hardened epoxies that contain these substances. Avoid products that contain
asbestos.
The health and safety hazards of substitutes must be carefully considered to ensure that
they are actually safer.
Engineering Controls: When feasible, employers must use engineering controls rather
than personal protective equipment to prevent overexposures. Engineering control
methods include installing ventilation, changing the work process, and changing work
practices.
Containers and vats of epoxy resins and solvents should be tightly covered to
prevent evaporation.
Local exhaust ventilation systems ("hoods") are the most effective type of
ventilation control. These systems capture contaminated air at its source before it
reaches your breathing zone.
Heating epoxies during curing or any other process can cause chemicals to
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evaporate (turn into gases) more quickly. The higher the temperature, the greater the
amount of chemical released into the air you breathe. Use the lowest possible curing
temperatures, avoid heating epoxies unnecessarily, and be sure that adequate
ventilation is used when epoxies must be heated or when the curing reaction
generates heat.
Certain work processes, such as heat-curing of epoxy resin systems, can be isolated,
enclosed, or automated to reduce exposures.
Electrostatic spray systems can reduce the amount of workplace contamination and
waste from spray-on epoxy resin system chemicals.
Personal Protective Equipment: When engineering controls cannot sufficiently reduce
exposures, a respirator must be worn and a respiratory protection program must be
developed, as outlined by Cal/OSHA regulations (GISO 5144). An industrial hygienist or
other knowledgeable person should be consulted to ensure that the equipment is
appropriate and is used correctly. In some cases a supplied-air respirator may be required.
If frequent or prolonged skin contact with epoxy resin systems is unavoidable or if
splashing may occur, protective equipment such as gloves, goggles, or faceshields should
be worn. Protective clothing should be made of a material that will protect you from the
chemicals in the epoxy resin system you use. Butyl rubber is resistant to some of the
chemicals commonly used in epoxy resin systems, while polyvinyl alcohol is resistant to
others. Glove materials must be evaluated on an individual basis for each specific product.
Personal Hygiene: Remove clothing contaminated with epoxy resin system chemicals
and immediately wash off any epoxies that get on your skin. Pay particular attention to
your fingernails and the area around the nail bed.
Dry or irritated skin can absorb chemicals and become sensitized to epoxies more easily
than healthy skin. Use soap and water or a commercial hand cleaner. Don't use solvents to
clean your hands; they remove the natural protective oils from your skin and leave your
skin dry and irritated. After washing, use a skin conditioner or lotion to help keep the skin
on your hands in good condition.
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