Vinylchlorid [MAK value documentation in German language, 2019]

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated vinyl chloride [ 75‐01‐4 ] considering all toxicological endpoints. Vinyl chloride is a genotoxic liver carcinogen in humans and animals. The re‐evaluation showed that a maximum concentration at the workplace (MAK value) cannot be derived and vinyl chloride remains classified in Carcinogen Category 1. However, the Commission has, for the first time, established an exposure‐risk relationship for a carcinogen using an approach similar to that of the Dutch Expert Committee on Occupational Safety. Pre‐defined excess risks for hepatic angiosarcomas after occupational exposure to vinyl chloride were calculated from two large epidemiological studies. The exposure‐risk relationships for both studies were similar. Concentrations of 40, 4, and 0.4 ml/m 3 for a 40‐year exposure correspond to risks of 4:1000, 4:10 000, and 4:100 000, respectively. A 40‐year exposure to 1 ml/m 3 thus results in a risk of 1:10 000. These risk values also cover the risks for hepatocellular carcinomas. Vinyl chloride is a mutagen in vitro and in vivo. It can reach the testes of animals, but does not lead to dominant lethal mutations in mice and rats and is therefore not classified as a germ cell mutagen. Vinyl chloride from the gas phase is not taken up via the skin in toxicologically relevant amounts. Studies on sensitization are not available and there are no reports on sensitization in humans.