Safe handling of Entropy Epoxy Resins

These epoxy resin safety precautions will help make working with epoxy fun, satisfying, and safe. Most health problems associated with epoxy are minor, but our goal for you is no problems at all. The good news is, with a few precautions it’s easy to prevent these problems.

We’ll cover the hazards of working with Entropy Resins epoxy products and a few common shop hazards. Use these common-sense practices to ensure your safety, productivity, and enjoyment of the unique and wonderful things you can create with Entropy Resins.

It begins with following the directions and heeding the warnings on our product labels. Our Safety Data Sheets are a great resource for detailed epoxy safety information.


Why you must avoid overexposure | Preventing overexposure | 
Working clean |
Disposing of epoxy safely |
Epoxy-related hazards

Why you must avoid overexposure

Most substances have a safe level of exposure. The more toxic a substance, the less it takes to reach its overexposure threshold. Exceeding safe exposure levels is what causes health problems. Your immune system and overall health can also affect your tolerance of a substance.

When formulating the epoxy resins and hardeners in the Entropy Resins product line, we go for the best physical properties possible with the lowest risk to people and the planet. This keeps the proportion of hazardous ingredients in our products small enough that, with good work habits, you can easily avoid overexposure.

Hazardous substances can enter the body by being absorbed through the skin, inhaled, or ingested. The usual route for a given substance depends on its physical characteristics and how it is normally used.

Epoxy Resins and Hardeners

Exposure to resin, hardener, and mixed epoxy is most likely when they are liquid. As epoxy cures, its chemical ingredients react to form a non-hazardous solid. Solidified epoxy is unlikely to enter the body except in the form of sanding dust, which we’ll discuss shortly.

Skin contact is the most common route of exposure to resins and hardeners. Even minor skin contact, repeated often, can cause chronic health problems. In rare cases, with prolonged or repeated skin contact, harmful ingredients may be absorbed.

Exposure by inhaling vapors is unlikely because epoxy products evaporate slowly. But this risk increases when you are working in a small or confined workspace, don’t have good ventilation in your workspace, or if you’re heating the epoxy.

People rarely ingest epoxy but it can happen when resin, hardener, or mixed epoxy contaminate food, beverages, or eating surfaces.

Partially Cured Epoxy Dust

When you sand partially cured epoxy, it produces airborne dust that can get on your skin, be inhaled, or even ingested. Although epoxy may be firm enough to sand within a few hours, it may not cure completely for up to two weeks. Until then, the epoxy dust can contain unreacted hazardous components. Never overlook or underestimate this sanding hazard.

Health Effects from Overexposure to Epoxy

Let’s explore the most common health problems stemming from epoxy use. Nearly all of us can prevent these issues. Even those who do develop a health problem can usually resume using epoxy with additional precautions.


Fewer than 10% of people react when overexposed to epoxy resin or hardener. Usually, the reaction is a rash, medically known as acute contact dermatitis. Either epoxy resin or hardener can cause a rash. Discomfort may be severe, but the symptoms usually go away after stopping contact with the epoxy. However, repeated contact may cause chronic contact dermatitis. This is usually milder but longer lasting. Left untreated for long periods, it can progress to eczema and may include swelling, blisters, and itching. Partially cured epoxy sanding dust that settles on the skin can also lead to contact dermatitis.

Allergic Dermatitis (Sensitization)

While allergic dermatitis―the body hyper-reacting to an allergen―is more serious, less than 2% of epoxy users are likely to get it. This sensitization is an allergy that results from repeated exposures. Your chance of developing allergic dermatitis depends on your immune system and the degree and frequency of your exposure to epoxy. You’ll be more susceptible if you’ve had a massive overexposure to epoxy or if you’re already allergic to an epoxy ingredient. Your risk is also higher if you have fair skin, have already been exposed to other sensitizing substances, have hay fever or other allergies, or are under stress.

You can become sensitized to epoxy after many exposures or just one. Some people get sensitized over a matter of days, for others, it can take years. The best approach is to avoid all exposure because there is no way to predict how much exposure you can take before becoming allergic.

Allergic reactions to epoxy result in skin irritation or respiratory problems. Irritated skin is by far the more common reaction. It usually looks like poison ivy and may include swelling, itching, and red eyes. The symptoms can range from mild to severe, and be acute or chronic.

Inhaling epoxy vapors frequently or for long periods can irritate your respiratory tract. Sensitive skin areas like the eyelids may itch and swell after exposure to highly concentrated epoxy vapors.

See your doctor if irritation persists or worsens after avoiding epoxy for several days. There is no antidote for epoxy sensitization, but some symptoms can be treated with medicine.

Once you’ve become sensitized, additional (and sometimes increasingly severe) reactions are more likely with future exposures, even to tiny amounts of epoxy. It’s difficult, but not impossible, to prevent recurrences. Don’t resume epoxy use until all symptoms are gone. Strictly follow all handling procedures. Review the product’s Safety Data Sheets (SDS) for preventative measures, symptoms, and first aid.

Severe Irritation and Chemical Burns

By themselves, our epoxy hardeners are moderately corrosive. Hardener burns are uncommon, and burns from mixed epoxy are even less common. Left in contact with skin, hardener can severely irritate it and cause moderate chemical burns. These develop gradually, beginning with irritation and slight pain. The burn may discolor skin or slightly scar it. The time it takes for epoxy hardener to burn the skin depends on the skin area and the hardener concentration. Mixing resin with hardener dilutes the hardener, making it less corrosive. Although mixed epoxy is less corrosive, never leave it on your skin as it cures rapidly and is hard to remove.

Respiratory Irritation

Breathing highly concentrated epoxy vapor risks respiratory irritation and sensitization. Epoxy vapors aren’t likely to be highly concentrated at room temperatures. But if you’re already sensitized to epoxy, exposure to low vapor concentrations can trigger an allergic reaction. At warmer temperatures and in unventilated spaces, epoxy vapor levels increase.

Sanding epoxy before it has fully cured can cause serious health problems. Epoxy chemicals remain reactive until they have cured, and when inhaled these particles get trapped in the mucus lining of your respiratory system where they can cause severe irritation and/or respiratory allergies.

If you’re a smoker or your lungs are otherwise strained, you’re far more likely to develop serious respiratory problems from epoxy.
Return to Epoxy Safety Topics

Preventing overexposure to epoxy


General Guidelines & Precautions for Epoxy Resin Safety

These guidelines address both industrial and casual epoxy use. If followed, they’ll protect you from epoxy and other hazardous materials.

  • Use the least hazardous product that will do the job. This reduces or even eliminates hazard sources.
  • Set up a safe shop. Install equipment and follow procedures that prevent or reduce exposure. This includes effective ventilation which, depending on your workshop, can range from high-tech air-filtration and exhaust systems to basic floor or window fans. This can address a wide range of vapors and dust. A dedicated cabinet or isolated area for storing hazardous materials can also reduce exposure.
  • Wear goggles, safety glasses, gloves, a respirator, and protective clothing appropriate for the project. The bare minimum for working with epoxy is gloves, eye protection, and protective clothing. You can 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 dust is a dust/mist mask or respirator.

Limiting Exposure to Epoxy Resins and Hardeners

The US government hasn’t established exposure limits for Entropy Resins epoxy products. Our guidelines are based on the levels approved for the raw materials used in our formulations, as shown in each product’s SDS.

Protect Your Skin From Epoxy Products
  • Avoid contact with resin, hardeners, mixed epoxy, and sanding dust from partially cured epoxy. Wear protective gloves and clothing whenever you handle epoxies. If you get resin, hardener, or mixed epoxy on your skin, remove it immediately. 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 working with epoxy, including sanding.
  • If you get epoxy on your clothes, change them immediately. Use skin cleaners to remove any epoxy from your skin and clothing. Do not continue to wear clothing with epoxy on it. If it’s mixed epoxy, you can wear the item again once the epoxy has fully cured.
  • Never use solvents to remove epoxy from your skin. Solvents, even mild ones like vinegar, can drive the epoxy’s ingredients into your skin, making overexposure more likely.
  • Stop using epoxy if you develop a reaction. Resume work only after symptoms disappear, usually after several days. When you resume work, improve your epoxy safety precautions to prevent overexposure to epoxy, its vapors, and sanding dust. If problems persist, discontinue use and see your doctor.
Protect Your Eyes and Vision
  • Wear safety glasses or goggles to protect your eyes from contact with resin, hardeners, mixed epoxy, and sanding dust.
  • If you get epoxy in your eyes, flush them immediately with water under low pressure for 15 minutes. Seek medical attention.
Protect Your Lungs and Respiratory Tract
  • Avoid breathing epoxy vapors and sanding dust. Our epoxies have low volatile organic content (VOC) but vapors can build up in unvented spaces. Provide ample ventilation in small workshops or other confined spaces.
  • When you can’t adequately ventilate your workspace, wear an approved respirator with an organic vapor cartridge.
  • When sanding epoxy―especially partially cured epoxy―provide ventilation and wear a dust/mist mask or respirator. Breathing partially cured epoxy dust increases your risk of sensitization. Even when the epoxy has cured to a sandable solid, a complete cure may require over two weeks at room temperature.
Never Ingest Epoxy
  • After handling epoxy, wash thoroughly, especially before you eat or smoke.
  • 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 doctor or contact Poison Control immediately. Refer to First Aid procedures on the products SDS.

Return to Epoxy Safety Topics

Work clean

  • Maintain a clean workshop to avoid incidental contact with the epoxy resin. If you have epoxy residue on your gloves, don’t touch door handles, light switches, or epoxy containers because you’ll probably touch them again when you’re not wearing gloves.
  • Clean up epoxy spills with a scraper, collecting as much material as possible. Follow up with paper towels.
  • Contain large spills with sand, clay, or other inert, absorbent material. DO NOT use sawdust or other fine cellulose materials to absorb hardeners. You may reclaim uncontaminated resin or hardener for use.
  • Clean up resin or mix epoxy with acetone, lacquer thinner, or alcohol. Follow all safety warnings on solvent containers.
  • DO NOT dispose of hardeners in the trash containing sawdust or other fine cellulose materials―they can spontaneously combust.
  • Clean hardener residue with warm, soapy water.

Disposing of Epoxy Resin Safety Precautions

  • Puncture a corner of the resin or hardener can and drain the residue into a new container.
  • Do not dispose of resins or hardeners as liquids. Mix small quantities of waste resin and hardener and allow them to cure to an inert solid.

CAUTION! Pots of curing epoxy can get hot enough to emit hazardous fumes and ignite combustible materials nearby. Place pots of mixed epoxy in a safe and ventilated area, away from works and combustible materials. Dispose of the solid epoxy mass only after it has completely cured and cooled. Follow federal, state, or local disposal regulations.

Return to Epoxy Safety Topics

Epoxy-related hazards


Uncontrolled Curing of Epoxy

Epoxy cures by an exothermic chemical reaction that generates heat. Left to cure in a contained mass, such as a mixing pot, epoxy can get hot enough to melt plastic, burn your skin, or ignite combustible materials nearby. The larger or thicker an epoxy mass, the more heat it generates. A 100-gram mass of mixed epoxy can reach 400

To prevent heat buildup, pour mixed resin and hardener from the mixing pot to a roller pan or other wide, shallow container. Fill large cavities with epoxy in multiple layers rather than a single, thick layer. Heat buildup and uncontrolled curing are unlikely in 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 including carbon monoxide, oxides of nitrogen, ammonia, and possibly some aldehydes. Cured epoxy can emit these vapors when overheated, such as when using a flame to release a casted or embedded object. Use a flame to do this only as a last resort, and work in a well-ventilated area.

While leftover mixed epoxy is curing, set the container aside where you can monitor it. Use a fan to disperse vapors, directing them away from people. Air-purifying respirators may not be adequate for these vapors and fumes.

Combining hardeners with sawdust, woodchips or other cellulose can cause a fire. When hardener is spilled onto or mixed with sawdust, the air and moisture react with the amine, generating heat. If not dissipated quickly, this can ignite the sawdust. Never use sawdust or other types of cellulose to absorb a hardener spill. Do not pour unused hardener into a trash can with sawdust or other cellulose materials.

Entropy Resins epoxy resins and hardeners are classified as non-flammable because their flash points are greater than 200°F (93 and they evaporate slowly. Furnaces, wood stoves, and other heat sources do not pose a serious fire hazard in the presence of epoxy vapors.

Spraying Epoxy

The health and safety risks of spraying epoxy are enormous and we never recommend it. Epoxy leaving a spray gun nozzle is reduced to a fine mist that is too easily inhaled. This can cause serious lung damage and other health problems. This mist can settle on your skin, causing sensitization and allergic reaction. It can settle on your eyes, injuring them.

Spraying increases the amount of hazardous volatile components released compared to other application methods. Thinning the epoxy with solvents adds to health and safety risks. The health and flammability hazards are similar to any spray painting operation. If you must spray epoxy, control hazardous vapor and spray mist with isolation and enclosure such as a ventilated and filtered spray booth. Always use an air-supplied respirator and full-body protective clothing.

Return to Epoxy Safety Topics

Disposal of leftover resin and hardener

Use these guidelines for disposing of unused resin and hardeners.

  • Minimize waste by saving unused resin and hardeners for future projects. Entropy Resins epoxy products have a 1 year long shelf life when stored in sealed containers.
  • Mix unwanted resin and hardener and allow it to cure and cool to a non-hazardous solid for disposal.
  • Warm containers are easier to drain.
  • When disposing of empty resin and hardener containers, make every attempt to empty the container. No more than 3% by weight of the total capacity of the container should remain inside of it at the time of disposal.
  • Reclaim spilled or leaked epoxy that is uncontaminated. If it’s contaminated, it’s waste. If you’ve used solvent to clean up a spill, the contaminated epoxy-solvent mixture may be a regulated hazardous waste.
  • Never release hazardous wastes directly to the land, air, or water. Many communities organize periodic waste collections where they accept household wastes for safe disposal.
  • The disposal guidelines above may not comply with the laws and regulations in your area. If you are uncertain, refer to your local, state, and federal regulations.

Return to Epoxy Safety Topics

Epoxy Safety Summary

Your health and safety are in your own hands. Staying informed about the products you use and following epoxy resin safety precautions and shop safety practices will protect your health and safety while using Entropy Resins epoxy products.

All Entropy Resins product labels provide basic safety information and appropriate hazard warnings. For specific information, download the SDS for the product in question or contact [email protected].

Return to Epoxy Safety Topics