Mutagenic reaction products of aqueous chlorination of catechol.

Aqueous chlorination of catechol (4 and 8 mM) at varying reagent ratio has been shown to produce high mutagenicity with the Ames Salmonella strain TA100. The mutagenicity peaks at 3 equivalents of chlorine per mole of catechol. But the mutagens are unstable in neutral and alkaline solutions. Substituted catechols produce less mutagenic solutions than catechol on aqueous chlorination. If the chlorine is replaced with equivalent chlorine dioxide very little mutagenicity is produced. Among the reaction products are chlorinated catechols; all of these were synthesized, none was mutagenic but some were toxic. The sample oxidation products, o-benzoquinone and chloro-o-benzoquinone, have been identified and through synthesis were proven to be mutagenic. Some possible ring fracture products also become mutagenic after reaction with aqueous chlorine. Catechol and other simple phenolic substrates are model compounds for the aqueous reaction of chlorine with wood pulp, sewage water and potable water.