Characterization of patients with occupational allergy to two new epoxy hardener compounds

The practical importance of two recently described epoxy hardener allergens-1,3-benzenedimethanamine, N-(2-phenylethyl) derivatives (1,3-BDMA-D) and hydrogenated formaldehyde benzenamine polymer (FBAP)-as occupational allergens remains to be defined.To describe patients diagnosed at the Finnish Institute of Occupational Health (FIOH) with positive reactions to 1,3-BDMA-D or FBAP.We searched FIOH's patch-test files from January 2017 to December 2020 for patients examined due to suspected occupational contact allergy to epoxy compounds. We analyzed the patch-test results and sources of exposure to various epoxy hardeners and focused on occupations, symptoms, and the sources of exposure to 1,3-BDMA-D and FBAP.During the study period, 102 patients were examined at FIOH for suspected occupational contact allergy to epoxy compounds. Of these, 19 (19%) were diagnosed with contact allergy to 1,3-BDMA-D (n = 10) or FBAP (n = 12). The largest occupational group was sewage pipe reliners (n = 8). Seven different hardener products contained FBAP, whereas 1,3-BDMA-D was present in only one hardener used by spray painters.A substantial number of patients with suspected occupational epoxy resin system allergy tested positive to in-house test substances of 1,3-BDMA-D and/or FBAP.