3-Chloro-p-toluidine hydrochloride: in vitro mutagenicity studies for human health hazards determinations.

3-Chloro-p-toluidine hydrochloride (CPT-HCl) is an aniline derivative used in the manufacture of the dye palatine fast yellow; it is also registered as a selective, low-volume-use (< 45 kg/yr) avicide. Three in vitro mutagenicity tests of CPT-HCl were performed according to methods recommended by the U.S. Environmental Protection Agency (EPA): the Ames/Salmonella assay, the Chinese hamster ovary/hypoxanthine-guanine phosphoribosyl-transferase (CHO/HPRT) mammalian cell forward gene mutation assay, and the CHO chromosome aberration assay. CPT-HCl did not display mutagenic activity using the Ames/Salmonella or CHO/HPRT assays. However, CPT-HCl induced statistically significant, concentration-dependent, metabolically activated increases in the proportion of aberrant cells and aberrations/cell in cultured CHO cells. Results are suggestive of minimal mutagenicity effects associated with exposure to anilines and their derivatives.