Epoxy resin is a chemical that is part of an epoxy resin system. Epoxy resin systems are used widely in industry because of their strong adhesive properties, chemical resistance and toughness. Common two-part epoxy resin systems contain epoxy resin, catalysts/curing agents, and diluents and/or other additives. Any of these chemicals on their own may cause irritant and/or allergic contact dermatitis. Cured epoxy resin (the fully hardened combination of the epoxy resin system chemicals) should be non-irritating and non-sensitising.
Epoxy-resin system component
Features
Epoxy resin (uncured)
Common epoxy resin is bisphenol A (made by the condensation of a mixture of polyglycidyl ethers)
Little use on its own. Must be further polymerized or cured with agents listed below before becoming useful
Bisphenol A cross-reacts with diethylstilbestrol (a hormone present in some pharmaceutical and medical preparations)
Catalysts/curing agents
Chemicals that speed the polymerization of epoxy resin to form hard, insoluble products
Although there are several chemical groups of curing agents, the amine hardeners appear to be the most potent sensitisers
Amine hardeners are particularly useful for curing epoxy resin at room temperature
Amine hardeners are highly alkaline solutions and may cause caustic burns on skin contact
Diluents/additives
Include epoxy resin diluents, plasticizers, solvents, fillers, pigments and blends of other resins
All potential irritants and sensitisers
Where is epoxy resin found?
Most people associate epoxy resin with glues and adhesives. Epoxy glues such as Araldite® are often used by home DIY'ers and hobbyists. These glues usually come in two parts, the hardener and the resin. When mixed, it is claimed that the resulting compound can stick almost anything together. The table below shows other uses of epoxy resin.
Uses of epoxy resin
Surface coatings (provide a hard, durable and rustproof surface)
Paint for ships and other marine uses — a danger to boat builders
Primers for cars
Steel pipes
Electrical insulation materials (to prevent conduction of electricity)
Enclosing transformers, condensers, capacitors and other electrical components
Adhesives and glues
Widely used across many industries for its strong bonding properties, e.g. aircraft, flooring, road and bridge surfacing, concrete bonding, automobile manufacturers, wind-turbine industry, carbon fibre products
Home DIY, hobbyist, artist, sculptors all find many uses for epoxy glues
Used in some dental bonding agents
PVC production
Some vinyl, plastic and PVC products contain epoxy resins, e.g. eyeglass frames, vinyl gloves, handbags, plastic necklaces
What are the reactions to epoxy resin allergy?
Typical allergic contact dermatitis reactions may occur in individuals allergic to epoxy resin or other components of an epoxy resin system. The uncured epoxy resin, hardener and diluent are powerful irritants and potent sensitisers. Skin contact with the hardening agent may cause severe burns. They can also cause a severe allergic contact dermatitis characterised by redness, swelling and itching. Skin should be washed with soap and water if any contact occurs. In addition, hardeners and diluents are more volatile than resin and may cause allergic reactions from breathing in fumes.
Cured epoxy resins are seldom a problem but it has been found that measurable amounts of uncured reagents may remain in the "cured" resin after 1 week.
Standard patch testing with test epoxy resin material 1% in acetone or petrolatum will usually find 75% of those allergic to epoxy, even though not every epoxy resin has the same chemical structure. The standard test does not test to the hardener, but most individuals allergic to hardeners are also allergic to the resin. Thus screening for epoxy allergy is done using the epoxy resin.
Chances of developing an allergic reaction increase with the amount and concentration of epoxy resin exposure. There is a small risk of causing allergy to develop from patch testing so the tests should only be done in at risk individuals.
Treatment of contact dermatitis due to epoxy resin exposure
If you are diagnosed with epoxy resin allergy then avoid exposure to epoxy containing products, otherwise take means to reduce potential exposure.
Washing the area immediately with soap and water should treat accidental exposure from glue or paints. Sometimes, solvents (acetone, alcohol, or methyl-ethyl ketone) can be used to reduce the exposure. However, routine use of these chemicals is not recommended, as they tend to dry and irritate the skin.
When using epoxy glues at home, avoid touching the glue and breathing in fumes.
In the workplace try to avoid exposure to epoxy resins, however, this may not be practicable. Identify potential sources of exposure using Material Safety Data Sheets; these are required for all chemicals and substances that you may come into contact with in the workplace. To reduce exposure, use special gloves (nitrile rubber or nitrile butatoluene gloves) to protect the hands. Rubber gloves do not help as the resin penetrates through the glove in 30 seconds. Vinyl and neoprene rubber are not totally protective.
Allergy is more likely to liquid (low molecular weight) epoxy resin systems used in paints and coating material than to the those used primarily for structural bonding, which have a higher molecular weight.
If you are highly sensitive to epoxy resin be aware of products that may contain it. Apart from obvious sources such as two-part glues and paints, be wary of items such as vinyl or plastic handbags, gloves and jewellery.
Alert your doctor or dentist to the fact that you have an allergy to epoxy resin. Your dermatologist may have further specific advice, particularly if you are highly sensitive to epoxy resin.
Alternative names for epoxy resin
Epoxy resin is also known by several other names. These include:
Bisphenol A [2,2-bis(4-hydroxyphenyl)propane] (diphenylpropane)
Christiansen AG, Kinnerup MB, et al. Occupational exposure to epoxy components and risk of dermatitis: A registry-based follow-up study of the wind turbine industry. Contact Dermatitis. 2024;90(1):32-40. doi:10.1111/cod.14431 Journal
Lejding T, Källberg K, Bergendorff O, et al. Epoxy allergy, investigation of a modern industry. Contact Dermatitis. 2023;88(5):383-388. Journal
Prodi A, Rui F, Fortina AB, et al. Occupational sensitization to epoxy resins in Northeastern Italy (1996-2010). Int J Occup Environ Health. 2015;21(1):82-87. Journal