“…For instance, 2-naphthylamine, 4-aminobiphenyl, 4,4/-diaminobiphenyl (benzidine) (4), and Acid Red 27 (FD&C Red 2, a food, drug, and cosmetic colorant) have been identified as actual or potential carcinogens, although evidence suggests that metabolites of some of the azo compounds are the actual genotoxic agents (5). Also, certain aromatic amines used in the past as precursors of synthetic dyes pose a potential risk to the health of man (6,7). This point was initially thought to be important only if workers were exposed to a genotoxic precursor during dye manufacture or when handling an impure dye containing the unreacted genotoxic parent arylamine.…”