1,3-Dichlorobenzene – Evaluation of a biological guidance value (BLW)
Assessment Values in Biological Material – Translation of the German version from 2026
Andrea Kaifie1Wobbeke Weistenhöfer1
Thomas Kraus2
Hans Drexler1 (Head of the working group “Assessment Values in Biological Material” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
Andrea Hartwig3 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
MAK Commission4
1 Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, Germany
2 Institute for Occupational, Social and Environmental Medicine, Uniklinik RWTH, Pauwelsstraße 30, 52074 Aachen, Germany
3 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
4 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
In 2025, the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated a biological guidance value (BLW) for 1,3‑dichlorobenzene [541-73-1]. Relevant publications were identified from a literature search. For the derivation of the BLW, an experimental study was available that demonstrated a good correlation between the concentration of 1,3-dichlorobenzene in the air and 1,3-dichlorobenzene in blood as well as the urinary metabolites 3,5‑dichlorocatechol, 2,4‑dichlorophenol and 3,5-dichlorophenol. The data of the experimental study conducted with resting volunteers for 6-hours were extrapolated to account for an exposure of 8 hours and an increased respiratory volume at the work place. At the level of the MAK value of 2 ml/m3, an average value of 40 mg 3,5-dichlorocatechol (after hydrolysis)/g creatinine can be expected and was set as BLW. Sampling time is at the end of the shift, after several previous shifts.
