Mutagenicity of para-nitroso-dimethyl- and diethyl-anilines

Low concentrations of para-nitroso-dimethylaniline (NdMA) were mutagenic to Salmonella typhimurium TA100 with optimal effect at 1.5 microM in fluctuation assays, without activating enzymes. The diethyl homologue (NdEA) had little or no mutagenic effect at low concentrations, although the bacteriocidal effects of NdMA and NdEA were similar. At higher bacteriocidal concentrations (approximately LC55-LC80) both NdMA and NdEA were mutagenic. NdMA and some other C-nitroso compounds proved carcinogenic in animal bioassays, and further research is needed to assess the human hazard from exposure to C-nitroso compounds in food, medicines or industry.