DNA-damaging properties and cytotoxicity in human fibroblasts of tetrachlorohydroquinone, a pentachlorophenol metabolite.

The DNA-damaging potential of pentachlorophenol (PCP) and its metabolite tetrachlorohydroquinone (TCH) was investigated. TCH was found to bind covalently to calf-thymus DNA and to cause single-strand breaks in PM2 DNA. No DNA-damaging effects were observed for PCP. Exposure of human fibroblasts to PCP and TCH showed that TCH is more toxic, when colony-forming ability after exposure to the agent is used as a measure of toxicity. In the evaluation of the mutagenic and carcinogenic potential of PCP the metabolite TCH should be taken into consideration.