The mutagenicity and carcinogenicity of hair dyes

Synopsis A number of the constituents of semi-permanent and permanent hair dyes have been shown to be mutagenic in bacteria, to induce mutation, chromosome breakage, sister chromatid exchanges and malignant transformation in mammalian cells, to cause mutation in Drosophila, to induce mitotic recombination in yeast and to induce tumours in rodents. Some hair dye ingredients and commercial dyes have been shown to give rise, in the urine of treated rats, to metabolites which are also mutagenic in bacteria. The test systems used are briefly described and the data generated are reviewed. In addition, attempts to identify whether the hazards predicted from the laboratory studies present a risk to man either by epidemiological studies or monitoring of exposed populations are also discussed.