Differing degrees of coal-tar shampoo-induced mutagenesis in the Salmonella/liver test system in vitro.

Hexane extracts of four commercial preparations of coal tar shampoos were studied for their mutagenic properties in the Salmonella/liver test system in vitro. Three of the four shampoos were highly mutagenic, whereas the fourth was not - under our experimental conditions. By high-performance liquid chromatographic, gas-liquid chromatographic, and gas-liquid chromatography-mass spectrometric analyses, more than 35 distinct fractions could be resolved; seven polycyclic aromatic chemicals believed to be present in coal tar were tentatively assigned as the major component of some of these fractions. The shampoo extract that was most mutagenic had a greater number of distinct fractions and contained approximately 50 times more benzo[a]pyrene, compared with the one shampoo extract that was not mutagenic under our experimental conditions. The possible clinical hazards of this observed mutagenicity of certain coal tar shampoos are presently not known.