Mutagenic activity of photoreaction products formed from chlorinated ethenes and nitrogen dioxide.

The mutagenicity in Salmonella, strain TA 100, of photoreaction products from chlorinated alkenes and nitrogen dioxide, was studied after a mean reaction time of 40 min with UV-irradiation and an exposure time of 20 hr. Only vinyl chloride (monochloroethene) gave rise to significantly mutagenic photoreaction products. Of the other chloroethenes, 1,1-dichloroethene and tetrachloroethene, but not 1,2-dichloro- or trichloroethene, formed slightly mutagenic products. Bacteriotoxic effects occurred at low doses, especially with tri- and tetrachloroethene.