Chemical changes of organic compounds in chlorinated water. VII Formation of mutagenic substances by the reactions of phenylphenols with hypochlorite in dilute aqueous solution and their absorbabilities by activated carbon.

The mutagenicity of chlorine-treated phenylphenols (o-, m-, and p-isomers) solutions was tested by the Ames procedure with Salmonella typhimurium TA 98 and TA 100 in the absence and presence of rat liver homogenate (S 9 mix). The Ames tests showed that chlorination of these compounds with an excess of chlorine in water leads to the formation of lipid-soluble and nonvolatile mutagens (positive in strain TA 100 without S 9 mix). Ether extracts of the aqueous p-phenylphenol solutions treated with low chlorine doses were also mutagenic and toxic in both strains TA 98 and TA 100 without S 9 mix. The strongest mutagenic and toxic effects on strain TA 100 without S 9 mix were observed with extracts of the aqueous solutions treated with chlorine under acidic conditions, and there was a pattern of decreasing mutagenicity with increasing pH. In addition, it was found that the mutagenic substances produced in the reactions can be removed from the chlorinated aqueous solutions by activated carbon.