2022/12/18 by Hartwig, Andrea, MAK Commission
#1 #2 #2-Pentachlorethan #2-Pentachloroethane #Hautresorption #Lebertumorpromotor #Luft #MAK value #MAK-Wert #Pentachlorethan #Pentachloroethane #Spitzenbegrenzung #Toxizität #air #alpha-2u-Globulin #alpha-2u-globulin #hepatocellular carcinoma #hepatozelluläre Karzinome #liver tumor promotor #maximale Arbeitsplatzkonzentration #maximum workplace concentration #peak limitation #skin absorption #toxicity
paper · doi:10.34865/mb7601e7_4or
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated pentachloroethane [76-01-7] considering all toxicological end points. In a carcinogenicity study with pentachloroethane, male rats showed a non-significantly increased incidence of kidney tumours induced by the alpha-2u-globulin mechanism. This mechanism is specific to male rats and not relevant for humans. Pentachloroethane leads to hepatocellular carcinomas in B6C3F1 mice. As pentachloroethane is not considered to be genotoxic in vivo, these tumours are assumed to have been caused by tumour promotion. Although no corresponding studies are available, pentachloroethane is assumed to be a liver tumour promotor like the related compounds hexachloroethane and 1,1,2-trichloroethane for which this has been confirmed experimentally. B6C3F1 mice are known for a high incidence of spontaneously initiated liver cells and are therefore very susceptible for liver carcinogenesis via the stimulation of proliferation. Pentachloroethane may induce cytotoxic effects in the liver, probably arising from metabolically formed radicals. This effect is relevant also for humans and pentachloroethane is classified in Carcinogen Category 3 B. Pentachloroethane is neither a mutagen in vitro nor a clastogen in vivo. In a 13-week toxicity study with rats, the body weight gain was reduced at 125 mg/kg body weight and day. Based on the NOAEL of 50 mg/kg body weight and day, a maximum concentration at the workplace (MAK value) of 2 ml/m3 has been established. By analogy with the related compounds hexachloroethane and 1,1,2,2-tetrachloroethane, no irritation is expected at this concentration. As the critical effect is systemic, pentachloroethane has been assigned to Peak Limitation Category II. The default excursion factor of 2 has been set because the half-life is not known. There are no developmental toxicity studies of pentachloroethane and the substance has therefore been assigned to Pregnancy Risk Group D. Model calculations predict that pentachloroethane can be taken up via the skin in toxicologically relevant amounts and the substance is therefore designated with “H”. There are no data that show that pentachloroethane is a skin or airway sensitizer.