Evaluation of the genotoxicity of lac dye.

Red lac dye, a by-product of the shellac industry, has the potential for use in foods, drugs and cosmetics as a colouring agent. As part of a series of tests of the suitability of lac dye for this purpose an evaluation of its genotoxicity was carried out. Lac dye was non-mutagenic in Ames tests using five strains of Salmonella typhimurium with or without metabolic activation. No cytotoxicity or mutagenicity was observed in Chinese hamster lung (V79) cells exposed to lac dye in vitro. A clastogenic effect was observed in the bone-marrow cells of mice that had been treated with lac dye ip or orally.