Epoxy Resin and Allergies
This is an edited summary by Franklin Peale of a paper on the safety of epoxies (Occupational Medecine 9:97-112 (1994) R. Jolanki, L. Kanerva, T. Estlander, and K. Tarvainen).
1. Chemical Agents causing Allergy
The chemicals in common two-part epoxy systems which can cause allergic reactions include
- the epoxy resin (usually diglycidyl ether of bisphenol A),
- reactive diluents used to lower the viscosity of the resin (usually glycidyl ethers)
- hardeners (usually polyamines)
The component most commonly causing an allergic reaction is the resin. Between 2-4% of people not employed in the epoxy industry will have a positive skin test to the resin component. A higher percentage of worker in the epoxy industry test positive. "After chromium and rubber chemicals, epoxy resin compounds are the third most frequent cause of occupational allergic dermatoses [skin reactions]."
Some formulations of epoxy acrylates (aka vinyl esters) used in dental work and printing have lead to contact allergies. Unpolymerized resin, diluent and hardener are the offending agents, but measurable amounts of unpolymerized reagents remained in some "cured" resin after 1 week.
As well as causing allergic skin reactions, the polyamine hardeners, being very alkaline (pH 13-14), may cause chemical burns. Diluents and hardeners, being more volatile than resin, may more readily cause allergic reactions from vaporization (as well as by direct contact).
2. Risks
Likelihood of developing an adverse reaction increases with the amount and concentration of epoxy resin used, frequency of skin contact, and area of contaminated skin. Rubber gloves are not completely impermeable to the chemicals involved, but help to minimize contact.
I find no references to fatal allergic reactions, but the usual skin reactions (and respiratory symptoms) are of the "anaphylactic" type. The occasionally fatal allergies to bee stings or seafood are of this type, so it is not out of the question that for a rare person, exposure to epoxy resins would be a life-threatening situation.
3. References
There is a well-illustrated Web site describing the detailed chemistry of many resins and composites (but not vinyl esters) at http://www.psrc.usm.edu/macrog/index.html
A Medline literature search on "epoxy" and "allergy"/ "allergic" yields scores of references. There is a concise review article on epoxy dermatitis in "Occupational Medicine" 9:97-112 (1994). For the cost of reproduction and mailing, I will send a copy to folks who want to read it themselves, but I'll summarize the most relevant points.