2-Butanethiol
MAK Value Documentation – Translation of the German version from 2021
Andrea Hartwig1 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
2 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 Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated data for 2-butanethiol [513-53-1] considering all toxicological end points. Data from a 90-day inhalation study with rats show that the critical effects are haematotoxicity and histopathological alterations in the nasal olfactory epithelium. On the basis of the NOAEC of 25 ml/m3 for systemic toxicity and taking into account the increased respiratory volume at the workplace, the maximum concentration at the workplace (MAK value) has been set at 2 ml/m3. Local effects in the nose can be ruled out at this concentration. As the critical effect is systemic, Peak Limitation Category II has been assigned with an excursion factor of 2. As data for developmental toxicity are not available, 2-butanethiol has been classified in Pregnancy Risk Group D. According to skin absorption models, percutaneous absorption is expected to contribute significantly to systemic toxicity. Therefore, 2-butanethiol has been designated with an “H”. No studies of the sensitizing, genotoxic or carcinogenic potential of the substance are available.
