Working with epoxy can be highly rewarding, as well as
safe. Serious health problems associated with epoxy use are uncommon. Most epoxy related
health problems are minor, but they can cause discomfort and diminish the rewards of
working with it. Fortunately, these problems are preventable.
As an epoxy user, you should be concerned about health and
safety, and be well informed of the materials and products you use. This guide covers the
health hazards of working with WEST SYSTEM epoxy, and some related shop hazards. More
importantly, it offers common sense safety practices that will help prevent health
problems and assure your long and productive use of epoxy.
Please read this entire guide. Read and follow all product
label directions and warnings. Refer to the Material Safety Data Sheets
(MSDS) for detailed product safety information.
Health & Safety Department:
989-684-7286 / Fax 989-684-1287
Health Effects from Overexposure to
How to Prevent Overexposure to Epoxy
Other Epoxy Related Hazards
When we select raw ingredients for WEST SYSTEM epoxy
products, we search for a balance between desired physical properties and lowest human and
environmental health risks. Epoxy resins and hardeners are comprised of a number of
chemical ingredients, of varying proportion and toxicity. Fortunately, they contain only a
very small proportion of the more hazardous ingredients.
There is a safe exposure level for most substances. The
more toxic the substance, the lower that level will be. Overexposure occurs when the safe
exposure level is exceeded. When this happens, the substance can cause health problems.
Your immune system and overall health can influence your tolerance of a substance.
Hazardous substances enter the body by skin absorption,
inhalation or ingestion. The route for a particular substance depends on its physical
characteristics and how it is normally used.
Epoxy Resins and Hardeners
The risk of exposure to resin, hardener and mixed epoxy is
greatest when they are liquid. As epoxy cures, the chemical ingredients react to form a
non-hazardous solid. As it solidifies, epoxy and its components are less likely to enter
Skin contact is the most common means of exposure to resins
and hardeners. Even minor skin contact, if repeated often enough, can cause chronic health
problems. In rare cases, with prolonged or repeated contact, the skin can absorb harmful
Exposure by inhaling vapors is unlikely, because epoxy
products evaporate slowly. However, the risk increases when ventilation is inadequate or
when the products are heated.
People rarely ingest epoxy, but it can happen when resin,
hardener or mixed epoxy contaminates food, beverages or eating surfaces.
Partially Cured Epoxy Dust
Sanding partially cured epoxy produces airborne dust, which
increases your risk of exposure by skin contact, inhaling or ingesting. Although epoxy is
firm enough to sand within two hours, it may not cure completely for up to two weeks.
Until then, the dust can contain unreacted hazardous components. Do not overlook or
underestimate this hazard.
We have a long history of working with and around epoxies
daily. As builders and epoxy manufacturers, we've had a much higher risk of exposure
to epoxy than the average builder or casual epoxy user. Through our own experience, and
the experience of other builders, we can estimate the likelihood of health problems from
handling WEST SYSTEM resins and hardeners.
The following are the most common health problems stemming
from epoxy use. Nearly all of us can prevent these problems. The majority of those who do
develop a health problem can continue using epoxy with adequate precautions.
Fewer than 10% of epoxy users react when overexposed to
epoxy resin or hardener. The most common reaction is contact dermatitis, or skin
inflammation. Both epoxy resin and hardener can cause acute contact dermatitis. Discomfort
can be severe, but usually disappears after stopping contact with the irritant. Repeated
skin contact with resins and hardeners may also cause chronic contact dermatitis, which is
usually milder but longer lasting. If left untreated for long periods it can progress to
eczema, a form of dermatitis that can include swelling, blisters and itching. Partially
cured epoxy sanding dust, if allowed to settle on the skin, can also lead to contact
Allergic Dermatitis (Sensitization)
Allergic dermatitis is a more serious problem, but less
than 2% of epoxy users are likely to get it. Allergic dermatitis is when the body
hyperreacts to an allergen. Sensitization is the condition of being allergic to a
substance. Your immune system and the degree and frequency of exposure to epoxy affects
your chance of becoming sensitized. You are most susceptible if you have been grossly
overexposed to epoxy or if you are inherently sensitized or allergic to a component of
epoxy. You are also more susceptible if you have fair skin, if you've already been
exposed to other sensitizing substances, or if you have hay fever, other allergies or are
You may become sensitized to epoxy after many exposures or
just one. It could take ten days of exposure, a month, or even years. It is best to avoid
all exposure because you cannot know ahead of time how much you can tolerate before you
Allergic reactions to epoxy can result in irritated skin or
respiratory problems. Irritated skin is by far the more common of the two. Usually, it
appears much like a reaction to poison ivy and may include swelling, itching and red eyes.
Just as with poison ivy, the irritation can be mild or severe, acute or chronic.
Inhaling concentrated epoxy vapors, if done frequently or
for long periods, can irritate your respiratory tract. Exposing sensitive skin areas, like
the eyelids, to highly concentrated epoxy vapors may cause itching and swelling.
See a physician if irritation persists or worsens after
avoiding epoxy for several days. There is no specific antidote for epoxy sensitization,
but symptoms can sometimes be treated with medicine.
Once sensitized, additional (and sometimes increasingly
severe) reactions become likely upon future exposures, even to tiny amounts of epoxy. It
is difficult, but not impossible to prevent recurrences. Resume epoxy use only after
symptoms disappear, and strictly follow the recommended handling procedures to prevent
exposure. Read the product's material safety data sheets (MSDS) so you can identify
symptoms and employ preventive and first aid measures.
Severe Irritation and Chemical Burns
Hardener burns are uncommon. Mixed epoxy is unlikely to
cause burns. By themselves, WEST SYSTEM and PRO-SET epoxy hardeners are moderately
corrosive. If left in contact with the skin, they can severely irritate it and cause
moderate chemical burns. Chemical burns develop gradually, and first cause irritation and
slight pain. The burn may discolor and slightly scar the skin. The time it takes for a
hardener to cause a chemical burn depends on the area of contact and hardener
concentration. When resin and hardener are mixed, the hardener is diluted and therefore
less corrosive. Although mixed epoxy is less corrosive, never leave it on your skin. It
cures rapidly and is difficult to remove.
Breathing highly concentrated epoxy vapor can irritate the
respiratory system and cause sensitization. At room temperature, epoxy vapors are unlikely
to be highly concentrated. However, if you are already sensitized to epoxy, exposure to
low concentrations of epoxy vapors can trigger an allergic reaction. At warmer
temperatures and in unventilated spaces, the epoxy vapor levels increase.
Never breathe the sanding dust of partially cured epoxy.
Epoxy chemicals remain reactive until they have cured. Serious health problems can result
from sanding epoxy before it is fully cured. When you inhale these dust particles, they
become trapped in the mucus lining of your respiratory system. The reactive material can
cause severe respiratory irritation and/or respiratory allergies.
WEST SYSTEM fillers present few hazards by themselves.
However, breathing any nuisance dust will worsen existing respiratory problems. Smokers
and others whose lungs are under strain are far more likely to develop serious respiratory
You can prevent health problems from the start by limiting
your exposure to hazardous materials. This means more than using respirators, goggles and
While the following guidelines are meant for an industrial
setting, they can be an important guide for casual epoxy users. Consider the following
steps to protect yourself from epoxy or any hazardous product.
Step 1 Make informed decisions about
the products you use. Use the least hazardous product that will do the job. Often you can
find a product with minimal health hazards that is adequate or even superior for the job.
This can reduce or eliminate the hazard source.
Step 2 Set up a safe shop. Install
equipment or use procedures that prevent or reduce exposure. This can include ventilation
or specialized storage for hazardous materials. Effective ventilation can range from
expensive, high-tech air-filtration and exhaust systems to the basic floor or window fans,
and is useful for a wide range of vapors and dusts. A dedicated cabinet or isolated area
for storing hazardous materials can help reduce exposure.
Step 3 Wear protective equipment
(goggles, safety glasses, gloves, respirators, protective clothing, etc.) appropriate for
the job at hand. The recommended minimum for most epoxy users is gloves, eye protection
and protective clothing. Protect yourself from epoxy vapors by using a respirator with an
organic vapor cartridge. The approved respiratory protection against epoxy dust, wood dust
and nuisance dusts is a dust/mist mask or respirator.
Epoxy Resins and Hardeners
The government has not established exposure limits for WEST
SYSTEM or PRO-SET epoxy products. We recommend limiting exposure to the levels approved
for the raw materials used in formulating the product, as shown in the product's
MSDS. Practices the following procedures for the safe use and handling of our epoxy
Avoid contact with resin, hardeners, mixed epoxy and
sanding dust from partially cured epoxy. Wear protective gloves and clothing whenever you
handle epoxies. Barrier skin creams provide added protection. If you do get resin,
hardener or mixed epoxy on your skin, remove it as soon as possible. Resin is not
water-soluble, use a waterless skin cleanser to remove resin or mixed epoxy from your
skin. Hardener is water soluble, wash with soap and warm water to remove hardener or
sanding dust from your skin. Always wash thoroughly with soap and warm water after using
epoxy, removing amine blush or sanding epoxy. If you spill epoxy on your clothes, change
them immediately. Use skin cleanser to remove any epoxy from you and your clothes. If you
cannot completely remove it from your clothes, do not continue to wear them. If it is
mixed epoxy, you may wear the clothes again once the epoxy has completely cured. Never use
solvents to remove epoxy from your skin.
Stop using the product if you develop a reaction. Resume
work only after the symptoms disappear, usually after several days. When you resume work,
improve your safety precautions to prevent exposure to epoxy, its vapors and sanding dust.
If problems persist, discontinue use and consult a physician.
Protect your eyes from contact with resin, hardeners, mixed
epoxy, and sanding dust by wearing appropriate eye protection. If epoxy gets in your eyes,
immediately flush them with water under low pressure for 15 minutes. If discomfort
persists, seek medical attention.
Avoid breathing concentrated vapors and sanding dust. All
of our epoxies have a low volatile organic content (VOC), but vapors can build up in
unvented spaces. Provide ample ventilation when working with epoxy in confined spaces,
such as boat interiors. When you can't adequately ventilate your workspace, wear an
approved respirator with an organic vapor cartridge.
Provide ventilation and wear a dust/mist mask or respirator
when sanding epoxy, especially partially cured epoxy. Breathing partially cured epoxy dust
increases your risk of sensitization. Although epoxy cures quickly to a sandable solid, it
may take over two weeks at room temperature, or elevated-temperature post-curing, to cure
Avoid ingesting epoxy. Wash thoroughly after handling
epoxy, especially before eating or smoking. If you swallow epoxy, drink large quantities
of water, DO NOT induce vomiting. Hardeners are corrosive and can cause additional harm if
vomited. Call a physician immediately. Refer to First Aid procedures on the Material
Safety Data Sheet.
Keep your workshop clean to avoid incidental contact. Avoid
touching door handles, light switches and containers when you have epoxy residue on your
gloves, because you may touch them later without gloves on. Clean up spills with a
scraper, collecting as much material as possible. Follow up with absorbent towels. Use
sand, clay or other inert absorbent material to contain large spills. DO NOT use sawdust
or other fine cellulose materials to absorb hardeners. Clean resin or mixed epoxy residue
with acetone, lacquer thinner, alcohol or WEST SYSTEM 855 Cleaning Solution. Follow all
safety warnings on solvent containers. Clean hardener residue with warm soapy water. You
may reclaim uncontaminated resin or hardener for use. DO NOT dispose of hardener in trash
containing sawdust or other fine cellulose materials, they can spontaneously combust.
Safely dispose of resin, hardener and empty containers.
Puncture a corner of the can and drain residue into the appropriate new container of resin
or hardener. Do not dispose of resin or hardener as liquids. Mix and cure waste resin and
hardener (in small quantities) to make a non-hazardous inert solid. CAUTION! Pots of
curing epoxy can get hot enough to ignite surrounding combustible materials and give off
hazardous fumes. Place pots of mixed epoxy in a safe and ventilated area, away from
workers and combustible materials. Dispose of the solid mass only after it has completely
cured and cooled. Follow federal, state or local disposal regulations.
Uncontrolled curing and burning of epoxy
The chemical reaction that cures mixed epoxy is
*exothermic*, or heat generating. If left to cure in a contained mass, such as in a mixing
pot, it can generate enough heat to melt plastic, burn your skin or ignite surrounding
combustible materials. The larger or thicker the epoxy mass, the more heat generated. A
100-gram mass of mixed epoxy can reach 400°F.
To prevent heat buildup, transfer epoxy from the mixing pot
to a roller pan or other wide, shallow container. Fill large cavities with epoxy in
multiple layers rather than in a single, thick layer. Heat build up and uncontrolled
curing are unlikely in typical bonding and coating jobs, because spreading the epoxy into
thinner layers dissipates heat.
Mixed resin and hardener become hot and frothy as they
thermally decompose, generating toxic vapors. These include carbon monoxide, oxides of
nitrogen, ammonia, and possibly some aldehydes. Cured epoxy can emit similar vapors if you
heat it too much. This can happen when you use a flame to release epoxy-mounted hardware.
To reduce this risk, use just enough heat to release the hardware. Only as a last resort
should you use a flame to burn epoxy from hardware. If you must do so, work in a
While leftover mixed epoxy cures, set the container aside
where you can monitor it. Use a fan to disperse vapors and direct them away. Air purifying
respirators may not be effective against these vapors.
Spontaneous combustion is a danger when hardeners are mixed
with sawdust, wood chips, or other cellulosic materials. When hardener is spilled onto or
mixed with sawdust, the air and moisture react with the amine to generate heat.
<Note>If the heat is not dissipated quickly enough, it can ignite the sawdust. Do not
use sawdust or other cellulosic materials to absorb a hardener spill. Likewise, do not
pour unused hardener into a trashcan with sawdust or other cellulosic materials.