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1000
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Abstract/Summary
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The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated chromium(VI) compounds. Chromium(VI) compounds are associated with lung cancer in humans as shown in several epidemiological studies of workers at chromate production and chrome‐plating plants. Animal studies confirm the carcinogenic effects of several/different chromium(VI) compounds in the lung. After subcutaneous and intramuscular administration of lead chromate, malignant tumours are formed at the site of injection, and, in one study, renal tumours were induced in rats. As the results of kinetic, genotoxicity and carcinogenicity studies were similar for lead chromate and other chromium(VI) compounds, carcinogenic effects of lead chromate in the lung of humans are to be expected. There are no carcinogenicity studies available for barium chromate. As a result of the higher water solubility of barium chromate, better absorption and bioavailability compared with that of lead chromate can be assumed. Therefore, all chromium(VI) compounds must be considered as carcinogenic in humans and are classified in Carcinogen Category 1. Chromium(VI) compounds were found to be genotoxic in numerous studies with bacteria and mammalian cells. In mice, intraperitoneal injection produces micronuclei in the bone marrow and dominant lethal mutations in the germ cells. As the poorly soluble lead chromate and barium chromate can be absorbed into the cells, and the results of in vitro and in vivo genotoxicity studies with somatic cells were similar for all chromium(VI) compounds, they must be regarded as genotoxic. Chromium(VI) compounds are thus classified in Category 2 for Germ Cell Mutagens. In humans and in animal studies, chromium(VI) compounds, with the exception of lead and barium chromate, can induce skin sensitization. Asthma is very rare in persons exposed to chromium(VI). With the exception of barium chromate and lead chromate, chromium(VI) compounds thus continue to be designated with “Sh”, but not with “Sa”. The absorption of chromium(VI) compounds through the skin is possible. As lead chromate, barium chromate, strontium chromate and zinc chromates are poorly soluble and only lead to low chromium concentrations, these compounds are not designated with an “H”. In the case of the soluble chromium(VI) compounds, however, there is a danger of dermal penetration with exposure to more highly concentrated solutions, and they therefore continue to be designated with an “H”. No MAK value has been derived and thus also no peak limitation has been established, and classification in one of the Pregnancy Risk Groups is not possible.
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