Contact Allergy to the Isomers of Diglycidyl Ether of Bisphenol F

Diglycidyl ether of bisphenol A (DGEBA) is the monomer and main allergen in the most common epoxy resin, DGEBA-R. Epoxy resin(s) based on bisphenol F (DGEBF-R) contains the 3 isomers of the diglycidyl ether of bisphenol F. Contact allergy to these isomers (p,p'-DGEBF, o,p'-DGEBF and o,o'-DGEBF) has not previously been described in humans. To investigate contact allergies to the DGEBF isomers in patients with contact allergy to DGEBF-R, 9 patients were patch-tested with dilution series of the isomers. All 9 were found to have contact allergy to p,p'-DGEBF and 7/9 to o,p'-DGEBF. Additionally, of 20 workers employed in epoxy-based manufacture and with contact allergy to DGEBA-R and DGEBF-R, 18 reacted to p,p'-DGEBF and 15/20 to o,p'-DGEBF. According to a guinea pig maximization test, all 3 DGEBF isomers are strong sensitizers. Still, o,o'-DGEBF elicited only 3 positive reactions in all participants.