Chlorophenols have been used primarily as intermediates in the manufacture of chlorophenoxy herbicides. Commercial formulations of chlorophenols contain polychlorinated dibenzodioxins and polychlorinated dibenzofurans and other substances as impurities. Pentachlorophenol has been used primarily as a fungicide. Alkali salts of 2,3,4,6-tetrachlorophenol have also been used as fungicides in wood preservation. Occupational exposures to chlorophenols and their polychlorinated dibenzodioxins and polychlorinated dibenzofuran impurities have been extensive.
Skin absorption is thought to be the major route of exposure.
Incineration of chlorophenol containing materials may result in polychlorinated dibenzodioxins and polychlorinated dibenzofurans forming. Analytical methods for determining chlorophenols were summarized. Biological data relevant to evaluating the carcinogenic risk to humans were reviewed. Studies of cytogenetic effects gave conflicting results. Case control and epidemiologic studies of exposure to chlorophenols and the incidence of the soft tissue sarcomas, malignant lymphomas, the nasal and nasopharyngeal cancers have also yielded conflicting results.