Mutagenicity assays on fluorescent whitening agents using microorganisms.

Six fluorescent whitening agents (FWAs) have been re-examined for their activity as inducers of cytoplasmic petite mutants and mitotic gene conversion in diploid yeast Saccharomyces cerebisiae and reversion from auxotrophy to prototrophy in Neurospora crassa, Escherichia coli and Salmonella typhimurium. The results provide no indication that the FWAs examinded produce mutagenic changes or any other alterations in the gene material. In a recent re-examination with Salmonella using the method of Ames et al., the four examined compounds failed to elicit a mutagenic response in the presence of rat liver postmitochondrial supernatant and cofactors.