2‐Butoxyethanol (Ethylene glycol monobutyl ether)

MAK Value Documentation, addendum – Translation of the German version from 2018

  Andrea Hartwig¹ (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
  MAK Commission<sup>2

1</sup> 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 re‐evaluated the carcinogenicity classification of 2‐butoxyethanol [111‐76‐2]. In long‐term studies, 2‐butoxyethanol resulted in hepatocellular carcinomas, haemangiosarcomas and forestomach tumours in mice and phaeochromocytomas in rats and was classified in Carcinogen Category 4.

New studies indicate that the hepatic tumours and the phaeochromocytomas are consequences of the haemolysis which is caused by the metabolite butoxyacetic acid. The forestomach tumours in mice are judged to be irrelevant for humans. There are differences between rats and humans concerning the formation and the haemolytic potency of butoxyacetic acid, which renders humans much less susceptible for haemolysis than rats, although humans can develop signs of haemolysis after severe oral intoxication. However, the CNS‐depression and the irritation caused by 2‐butoxyethanol precludes that humans are exposed regularly to 2‐butoxyethanol concentrations at the workplace which might result in significant haemolysis. Therefore, the Commission has removed 2‐butoxyethanol from the Carcinogen Category 4.

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