Acetylcholinesterase inhibitors – Addendum: withdrawal of BAT value and continuation as BLW

Assessment Values in Biological Material – Translation of the German version from 2024

Wobbeke Weistenhöfer¹
  Hans Drexler² (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 Commission<sup>4

1</sup> Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, Germany
² Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, 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

The German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) re-evaluated the biological tolerance value (BAT value) of acetylcholinesterase inhibitors, defined as a reduction in activity of no less than 70% of the reference value in erythrocytes. The BAT value is defined as a concentration at which the health of an employee generally is not adversely affected. However, it is not always clear whether the inhibition of acetylcholinesterase is the most sensitive toxicological endpoint of a substance or this has usually not been explicitly tested. The BAT value for the activity of acetylcholinesterase in erythrocytes is therefore suspended and continued as a biological guidance value (BLW). For substances for which it has been conclusively demonstrated that acetylcholinesterase inhibition in erythrocytes is the most sensitive endpoint, 70% of the reference value continues to be the BAT value.

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