Epoxies & Resins

Epoxy and other resins are used for floors, coatings, adhesives, repairs, anchoring, countertops, boat work and composites. They make strong, durable results. They are also a top cause of skin allergies among workers, because uncured epoxy and its hardeners can sensitize skin and lungs. Once you’re sensitized, even tiny exposures can cause a reaction for life, so prevention is essential.

• Flooring
• Coatings
• Construction

What epoxy is

• Most epoxy products have two parts: a resin (often based on bisphenol A and epichlorohydrin) and a hardener (often an amine or an anhydride). When mixed, they react and cure into a hard plastic.
• Related materials include polyester and vinyl ester resins (used with fiberglass, containing styrene), polyurethane resins (see Isocyanates), and acrylics.
• Products come as coatings, putties, adhesives, grouts, anchoring systems, injection resins and kits. Some are solvent-free, and some contain solvents.
• Always read the label and Safety Data Sheet (SDS) for both parts. See Safety Data Sheets and Hazard Communication.

Main hazards

• Skin sensitization and dermatitis: uncured epoxy resin and many hardeners can cause allergic contact dermatitis: red, itchy, blistering rashes that usually appear a day or two after contact and can spread. Once you’ve developed an allergy, any further exposure, even to small amounts, can trigger it. Hardeners can also cause chemical burns. See Skin Disease & Dermatitis.
• Respiratory sensitization: vapors and aerosols from hardeners, and dust from sanding, can cause asthma-like symptoms in some people. See Work-Related Asthma.
• Eye damage: splashes can burn or injure the eyes. See Eye Injuries.
• Vapors and solvents: some products contain solvents that cause headaches and dizziness and are flammable. Polyester resins contain styrene, which irritates the eyes, nose and throat and can affect the nervous system. See Solvents.
• Heat and fire: the curing reaction gives off heat (an exotherm). Large batches, or batches left in a mixing container, can get very hot, smoke, burn skin and even catch fire.
• Dust: sanding or grinding cured epoxy makes fine dust that can irritate and may contain fillers such as silica. See Silica.
• Slips: wet epoxy floors are slippery. See Slips, Trips & Falls.

Preventing skin contact: the key rule

• Wear the right gloves. Many common gloves don’t protect well. Thin latex and some thin nitrile can be penetrated by epoxy resin in minutes. Choose gloves recommended by the product maker or the glove maker for epoxy, such as laminated film (for example, polyethylene-EVOH) or butyl gloves for long contact, and thicker nitrile for short tasks. Change gloves often, and right away if they’re contaminated, torn or soaked. Check the SDS and the glove chemical resistance charts. See Hand Protection and Chemical-Protective Clothing.
• Remove gloves carefully without touching the outside with bare hands, and wash hands afterward.
• Cover your skin: long sleeves, disposable coveralls and sleeves, and cuffs that fit over gloves. Don’t roll up sleeves. Wear boots or shoe covers when working in wet epoxy.
• Protect your eyes and face with splash goggles and a face shield when mixing and pouring. See Eye & Face Protection.
• Use barrier creams only as a back-up. They don’t replace gloves.
• Never use solvents (acetone, thinner, gasoline) to clean epoxy off your skin. They drive the resin into the skin and add their own hazards. Use soap and water, or a waterless cleaner made for epoxy, and wash thoroughly. Wipe off with disposable paper towels first.
• Don’t touch your face, eat, drink or smoke with contaminated hands. See Sanitation.

Mixing and applying safely

• Measure exactly. Follow the mix ratio, since too much hardener or resin leaves uncured material that stays sticky and hazardous.
• Mix thoroughly in small batches in a container made for the job, and use up the mix within its pot life. Don’t leave a large batch in a bucket. Spread large amounts out, or pour the batch out to reduce heat build-up. Watch for smoking or a hot container: if it overheats, move it outdoors, away from combustibles, and let it cool.
• Ventilate. Work with good airflow, such as open doors, fans moving air away from you and local exhaust. Solvent-based, styrene and amine products give off vapors. See Ventilation.
• Use a respirator when the SDS or an exposure assessment calls for it: usually an organic vapor cartridge respirator for vapors, with a particulate filter for dusts and mists, with fit testing and medical clearance. See Respiratory Protection and Respirator Filters.
• Keep ignition sources away from solvent-containing products. See Flammable Liquids.
• Protect the work area: use drop cloths, keep children and pets out, and keep people who aren’t protected away.
• In flooring work, keep fresh epoxy off bare skin and shoes, and mark wet floors.

Sanding and cured epoxy

• Fully cured epoxy is much less hazardous, but sanding or grinding makes dust that can irritate skin, eyes and lungs, and trap uncured material and fillers. Use dust collection and a respirator, and wear gloves and eye protection. See Dust Extractors.
• A product may seem hard but still be “green” and unfinished. Follow the cure time on the label before sanding.
• If the surface stays tacky, it may be undercured, and it should be handled as uncured resin.

Cleanup, storage and disposal

• Wipe up spills with absorbent pads, not bare hands. Dispose of contaminated materials as the SDS says.
• Let small leftover amounts cure in the container before disposal, if the label allows, spreading them in a thin layer to avoid heat. Hazardous waste rules may apply to liquid resin and hardener.
• Store both parts in tightly closed, labeled containers, in a cool place away from heat, sunlight and incompatible materials, and out of reach of children.
• Wash reusable PPE and clothing separately, and dispose of contaminated gloves and coveralls. See Take-Home Contamination.

If exposed

• Skin: remove contaminated clothing and gloves, wash with soap and plenty of water for at least 15 minutes. Don’t use solvents. Get medical help for burns or a developing rash. See Chemical Exposure First Aid.
• Eyes: flush with water for at least 15 minutes and get medical care. See Eyewash & Showers.
• Breathing: move to fresh air. See a doctor for wheezing, coughing or trouble breathing. Tell the doctor what you work with.
• Report rashes and breathing symptoms early. A work-related allergy may be covered by workers’ compensation. See Filing a Workers’ Comp Claim.

Epoxy work checklist

• I read the label and the SDS for both the resin and the hardener
• I wear gloves rated for epoxy, long sleeves and eye protection, and I change gloves often
• I never use solvents on my skin; I wash with soap and water
• I mix small, measured batches and watch for heat build-up
• Ventilation, a suitable respirator and dust control are in place
• I know to report rashes or breathing symptoms early

Last updated: October 4, 2026