Mutagenicity of a new hair dye ingredient: 4-ethoxy-m-phenylenediamine.

An ingredient recently introduced in hair dyes, 4-ethoxy-m-phenylenediamine, is mutagenic in histidine-requiring strains of Salmonella typhimurium. Its mutagenic activity is similar to that of the hair dye ingredient is apparently replaced, 4-methoxy-m-phenylenediamine.