Mutagenicity and toxicity of chromyl chloride and its vapours

Chromyl chloride (CC), a liquid Cr6+ compound suspected of carcinogenic activity, was assayed for mutagenicity in the Ames reversion test. Due to its high volatility and toxic and corrosive properties, handling of CC required particular precautions. The liquid phase of CC elicited dose-related mutations in Salmonella typhimurium, strain TA100, although it had a limited range of activity because of its toxicity to the bacteria. The mutagenic potency and the toxic activity were of the same order of magnitude as all the water-soluble Cr6+ compounds so far tested. Toxic and mutagenic activities could also be clearly detected by using a variety of modifications of the Ames test in CC vapours which indicates the particular danger of this chromium compound. In analogy with the other Cr6+ compounds previously tested in this laboratory, all the effects observed were decreased in the presence of S-9 mix containing rat liver post-mitochondrial fractions.