1,1-Dichloroethane

Autor: Hartwig, Andrea, MAK Commission
Jazyk: angličtina
Rok vydání: 2022
Předmět:
DOI: 10.34865/mb7534e7_1ad
Popis: The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re-evaluated 1,1-dichloroethane [75-34-3] considering all toxicological end points. The critical effect is kidney toxicity. Inhalation of 1000 ml/m3 led to histopathologic injury to the kidneys, increased serum urea and creatinine after 3-month exposure of cats. A NOAEL of 500 mg/kg body weight and day for changes in the urinary excretion of acid phosphatase and N-acetylglucosaminidase was found in rats after 13-week oral exposure. Based on the NOAEC of 500 ml/m3, the maximum concentration at the workplace (MAK value) has now been lowered to 50 ml/m3 taking into account the increased respiratory volume at the workplace because the blood:air partition coefficient of 1,1-dichloroethane is > 5 (see List of MAK and BAT Values, Sections I b and I c). The same MAK value is obtained based on the oral NOAEL of 500 mg/kg body weight and day. As a systemic effect is critical, Peak Limitation Category II and the default excursion factor of 2 are retained. The margins between the MAK value and the NOAECs for developmental toxicity in rats are sufficient even taking into account the increased respiratory volume at the workplace. Therefore, damage to the embryo or foetus is unlikely when the MAK value is not exceeded and 1,1-dichloroethane remains assigned to Pregnancy Risk Group C. 1,1-Dichloroethane is genotoxic in vitro but the findings are not quite consistent. A carcinogenicity study was performed, which is of limited validity because of high mortality. In female rats, a few haemangiosarcomas and mammary gland adenomas developed which are identical to the tumour types induced by 1,2-dichloroethane. Therefore, 1,1-dichloroethane is classified in Carcinogen Category 3 B for suspected carcinogens. The substance is not regarded as a germ cell mutagen. Skin contact is suspected to contribute to systemic toxicity and the substance is designated with “H”. Studies of the sensitization potential are not available.
Databáze: OpenAIRE