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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 barium sulfate. Barium sulfate is a biopersistent granular dust. Therefore, the respirable fraction of barium sulfate dust has been classified in Carcinogen Category 4 and a MAK value of 0.3 mg/m3 × material density was established for the respirable fraction in analogy to the other biopersistent granular dusts. This classification is based on animal data that showed increased tumor incidences in rats exposed to biopersistent granular dusts in the high dose range. These tumors are regarded to be a consequence of the inflammatory mechanism of action, for which thresholds can be defined. Direct genotoxic effects appear to be of subordinate relevance for the carcinogenicity of biopersistent granular dusts. In analogy to biopersistent granular dusts the Peak Limitation Category II was established for barium sulfate with an excursion factor of 8. Since barium sulfate is not systemically distributed and accumulates only locally in the lungs, no developmental effects due to this dust are expected to occur at the MAK value of 0.3 mg/m3 × material density (respirable, R‐fraction). Barium sulfate has accordingly been classified in Pregnancy Risk Group C. Barium sulfate is not designated with either “Sa” or “Sh” or “H”.
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