Addendum to Benzene

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has derived biological reference values (BAR) and re‐evaluated the exposure equivalents for carcinogenic substances (EKA) for the urinary benzene metabolites S‐phenylmercapturic acid, t,t‐muconic acid and benzene in 2016. Available publications are described in detail. The existing exposure equivalents for carcinogenic substances (EKA) for the benzene metabolites were re‐evaluated and extended especially to the low‐exposure range. For the parameter benzene in urine, new EKA were established. Taking results of studies into consideration with persons of the general population not occupationally exposed to benzene, with sufficient number of cases and current biomonitoring methods, biological reference values (BAR) of 0.3 µg S‐phenylmercapturic acid/g creatinine, 150 µg t,t‐muconic acid/g creatinine and 0.3 µg benzene/l urine were established. Sampling time is at the end of exposure or the end of the working shift.