Lindan [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 the maximum concentration at the workplace (MAK value) of lindane [ 58‐89‐9 ] and its classification in category 4 for carcinogenic substances considering all toxicological endpoints. In several studies an increased risk of non‐Hodgkin lymphoma for lindane users in agriculture is described. After controlling for other pesticides, the risk decreased. Exposure or biomonitoring data are not available from these studies. From the viewpoint of the Commission, the studies are not sufficient to classify lindane as a human carcinogen. Because of its tumour‐promoting effects on the liver of the rat and the liver carcinogenicity in the mouse, lindane is still classified in category 4 for carcinogenic substances. The critical toxic effects of lindane are immunotoxic and immunomodulating effects. After inhalation exposure, NOAECs of 0.6 mg/m 3 (rat) and 1 mg/m 3 (mouse) can be derived for histological changes of the spleen, thymus and bone marrow and NOAELs of 0.45 mg/kg body weight for rats and 2 mg/kg body weight for mice for immunological effects. Excluding skin contact, exposure to the MAK value of 0.1 mg/m 3 for the inhalable fraction results in a daily intake of 0.014 mg/kg body weight (100 % absorption, 70 kg body weight and 10 m 3 respiratory volume) for humans. In this low concentration range, an inhibition of immunological responses is not likely and the MAK value is confirmed. Damage to the embryo or foetus is unlikely when the MAK value is not exceeded; therefore, the assignment to Pregnancy Risk Group C is confirmed as well. Skin contact may contribute significantly to systemic toxicity and the “H” notation is confirmed. Sensitization is not expected from the available data.