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Contact allergy to epoxy resin based on diglycidyl ether of bisphenol F

2001; Wiley; Volume: 44; Issue: 2 Linguagem: Inglês

10.1034/j.1600-0536.2001.4402092.x

1600-0536

Ann Pontén, Magnus Bruze,

Contact Dermatitis and Allergies

Epoxy resins based on diglycidyl ether of bisphenol A (DGEBA-R) (Fig. 1) are well-known causes of occupational allergic contact dermatitis (1–3). Besides bisphenol A, epoxy resins can be based on other substances, including bisphenol F (BF) (4). Epoxy resins based on BF (DGEBF-R) or phenolic novolac both contain diglycidyl ether of bisphenol F (DGEBF), which has 3 isomers (Fig. 2). DGEBF-R is less viscous than DGEBA-R, and is used when greater resistance is needed. Diglycidyl ether of bisphenol A. (a) p,p′-diglycidyl ether of bisphenol F. (b) o,p′-diglycidyl ether of bisphenol F. (c) o,o′-diglycidyl ether of bisphenol F. There have been several reports of contact allergy to epoxy resins other than DGEBA-R (5–11). In a Swedish aircraft plant, of 3 cases of contact allergy to a novolac-based epoxy resin, only 1 showed positivity to DGEBA-R (11). Contact allergy to DGEBF-R has also been acquired from epoxy resins in flooring materials and putty (12). A DGEBF-R was added to our standard series in 1997. The results from 1997 and 1998 in consecutively patch tested dermatitis patients are described here. A DGEBF-R (Rütapox 0161) provided by Bakelite Gesellschaft mbH, Duisburg, Germany, was used as test substance. 1299 patients tested with the standard series in our department were included, 40% of whom were male. DGEBF-R 1% w/w in pet., the same concentration as DGEBA-R in the standard series, was applied in Finn Chambers® attached to the back with Scanpor® for 2 days (D), and read according to ICDRG criteria on D3 and D7. The DGEBF-R added to the standard series contained 0.6% DGEBA (and the test preparation, accordingly, 0.006%). The DGEBA-R in the standard series (Chemotechnique, Malmö) contained less than 0.01% of any of the 3 DGEBF isomers (Fig. 2). A total of 23/1299 (1.8%) patients reacted to either of the epoxy resins (Table 1). 22/1299 (1.7%) reacted to DGEBF-R, 16 of whom had suspected occupational contact dermatitis. 9 patients reacted to DGEBF-R without reacting to DGEBA-R. 4 patients were positive to DGEBF-R on D7 but not on D3. 1 patient (no. 14) was positive only to DGEBA-R and not to DGEBF-R, but she was read only on D3 and therefore a reaction by D7 to DGEBF-R cannot be excluded. 7 patients who reacted only to DGEBF-R had weak reactions, 1 of whom was not read on D7. 12 of the patients who reacted to DGEBF-R had equal or almost equal intensity of reaction to DGEBA-R, scored as +, ++ or +++. 18 patients had concomitant reactions to other substances in the standard series. A clear occupational relevance was found in 6 of the patients allergic to epoxy resins. 1 of these (no. 15) worked with composite material, which, according to the material safety data sheet, was impregnated with epoxy novolac resin. Among our patients, contact allergy to DGEBF-R may be more common than to DGEBA-R. Patients with contact allergy to DGEBF-R, but not to DGEBA-R, had weak reactions in most cases. In a recent report, 9/178 (5.1%) patients reacted to an epoxy resin based on novolac, all of whom also reacted to DGEBA-R in the standard series (13). It has been suggested that reactions to DGEBF-R could be explained by its content of DGEBA. In our study, there were more patients reacting to DGEBF-R than to DGEBA-R, which excludes that interpretation. Furthermore, the concomitant reactions to DGEBA-R ought then to be stronger, which they were not. The 3 patients who did not react to DGEBF-R until D7 and had a reaction to DGEBA-R on D3 may have metabolized a substance present in DGEBF-R into an allergen present or cross-reacting with an allergen in DGEBA-R. In addition to the 22 patients reacting to DGEBF-R in this study, 3 patients reacted to DGEBF-R, but not to DGEBA-R, after more than 10 days. When retested with DGEBF-R, they reacted on D3. Patch-test sensitization was suspected and therefore patch testing with DGEBF-R 1% pet. cannot be recommended. At present, the test preparation in our department is 0.25% pet. No suspected patch test sensitizations have so far been reported (905 patients tested). Further studies are required to elucidate contact allergy to the 3 isomers of DGEBF-R and its relationship to contact allergy to DGEBA-R. The study was supported by grants from the Swedish Council of Work Life Research and the Swedish Foundation for Health Care and Allergy Research.