Mutagenicity of Chemicals Added to Foods
Among the chemically defined substances that can be found in food are microbial toxins, natural toxicants, environmental contaminants, food additives, color additives, and pesticide residues. The substances classified as food additives by the US Food and Drug Administration (FDA) in the Code of Federal Regulations fall into a number of categories. The US FDA has studied the mutagenicity of a number of food additives and can request mutagenicity data on proposed new food additives, there is no published compilation of these mutagenicity results. The Salmonella mutagenicity assay measures reversion from histidine dependence to histidine independence in a series of tester strains of Salmonella typhimurium. Mutagenicity test information is available for a greater proportion of indirect additives. The majority of chemicals that are mutagenic in Salmonella and clastogenic in mammalian cells have been shown to be rodent carcinogens. A high proportion of the chemicals detected as positive in in vitro chromosomal aberration tests are often noncarcinogens.