Dichloromethane – Addendum: evaluation of a pregnancy risk group for the BAT value
Assessment Values in Biological Material – Translation of the German version from 2023
Wobbeke Weistenhöfer1Sandra Michaelsen2
Gerlinde Schriever-Schwemmer2
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 Hartwig2 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
MAK Commission3
1 Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, Germany
2 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
3 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 2014, the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area re-evaluated the maximum workplace concentration (MAK value) of dichloromethane [75-09-2] and set a MAK value of 50 ml dichloromethane/m3 (180 mg/m3). In humans, exposure to 50 ml/m3 of dichloromethane led to CO-Hb levels in the range of 3%, which is above the endogenous CO-Hb range of 0.4–2.6% in non-smoking pregnant women. There is no information available on the CO-Hb level at which oxygen deficiency occurs in the foetal tissues. As a result, the possibility of prenatal toxicity cannot be excluded even if the MAK value of 50 ml dichloromethane/m3 is observed. Based on this finding, classification in Pregnancy Risk Group B has been confirmed. In 2015, the biological tolerance value (BAT value) of 500 μg dichloromethane/l blood was derived in correlation to the MAK value. Pregnancy Risk Group B is therefore also valid for the BAT value. The possibility of prenatal toxicity cannot be excluded even when adhering to the BAT value of 500 μg dichloromethane/l blood.
