Determination of Dimethyl Fumarate and Other Fumaric and Maleic Acid Diesters in Desiccants and Consumer Products in Japan

Abstract

Recently, many contact dermatitis cases related to leather furniture and footwear containing dimethyl fumarate (DMF) as an anti-mold agent have been reported in European countries. We investigated the concentrations of DMF and several fumaric and maleic acid diesters in desiccants and household products (footwear and rack) enclosed with a desiccant sachet in Japan. We sorted the product samples by material, and analyzed the product parts that can come into contact with the skin of consumers. Twenty-one desiccant samples and eighteen product samples (seven footwear products and one rack product) were analyzed. DMF was detected in the range of 0.11-2.3 mg/kg in two desiccant samples and three product samples (different parts of one product). The DMF concentrations detected in this study exceeded the value regulated by the European Union (0.1 mg/kg); the concentration of one desiccant sample was exceeded 1.0 mg/kg which showed a strong reaction in the patch tests in a precious study. The notes printed on the sachets of the desiccant samples containing DMF read “mold-proof desiccant” and “do not eat” in one case and merely “do not eat” in the other case. DMF has strong sensitization and irritation activities; hence, it is necessary to analyze more samples to prevent DMF-related contact dermatitis in Japan. Dibutyl maleate (DBM) was detected in the rack product and enclosed desiccant; its concentration ranged from 29 to 720 mg/kg. DBM may be a constituent of the adhesive used for the rack. Further investigation is necessary to verify the cross-reaction of DBM with DMF.