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 dermatitis.
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 under stress.
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 become allergic.
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.
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 problems.