Evaluation of the ECETOC TRA model for workplace inhalation exposure to ethylbenzene in Japan

The European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) that is positioned as a Tier 1 model for screening assessment in Europe can contribute to improvement of the independent work environment of workers if utilized in Japanese workplaces. In this study, estimated values of ethylbenzene obtained using ECETOC TRA were compared to measured values, and applicability of ECETOC TRA to the Japanese workplace was studied. Measured values and the work content collected from exposure field surveys conducted by the Japanese government in FY 2009 and FY 2010 were utilized for this study. The 137 tasks in 17 companies evaluated were related to manufacturing and painting. The process categories (PROCs) related to ECETOC TRA were selected for manufacturing (PROC 2, 3, 4, 5, 8a, 8b, 9, 13, 14 or 15) and painting (PROC 7 or 10). The results showed that most of the estimated values of manufacturing work were above the measured values, and just 3 of 52 tasks were below the measured values. On the other hand, the estimated values of painting work below the measured values were observed in 27 of 85 tasks. In particular, it was observed that the estimated values were below the measured values in 22 of 38 tasks for roller painting work (PROC 10). The 24 tasks for which 20 ppm was exceeded were related to painting work, and 4 of 10 tasks for PROC 7 and 13 of 14 tasks for PROC 10 were below the estimated values. All of the work for which the estimated values were below the measured values consisted of the hull block painting in ship building work. Though the painting work performed at indoor workplaces in Japan was subject to regulations for ethylbenzene in 2013 and reduction measures are being developed, independent risk assessment and management by workers is required continuously at workplaces engaged in the production of ethylbenzene. ECETOC TRA can be adequately utilized as a Tier 1 model for screening assessment to perform independent risk assessment at Japanese workplaces engaged in the production of ethylbenzene.