Patch testing with low molecular oligomers of epoxy resins in humans.

Thirty-four patients sensitive to epoxy resin were patch tested with oligomers of epoxy resin. All reacted when tested with MW 340 oligomer. Twenty-three were tested with MW 624 and MW 908 oligomers and seven with MW 1192 oligomer; none reacted. Eight patients tested with commercial mixtures of epoxy resins with an average MW 1280 and MW 1850 reacted to these resin mixtures which contained the MW 340 oligomer. The MW 340 oligomer seems to be the main ingredient responsible for contact allergy to epoxy resins in humans.