Present and future uses of mutagenicity tests for assessment of the safety of food additives.

The tier approach has been employed for the past 3 years for investigating the potential mutagenicity of food additives and generally recognized as safe (GRAS) substances. This approach is used to set testing priorities, since a large number of substances must be investigated. Three tiers or testing levels are used. The first tier is a pre-screen to determine whether a chemical has the potential to cause genetic damage. The second tier is designed to ascertain whether mutagenic activity detected at tier one can be confirmed in the tests which are a part of tier two. The third tier is used for risk assessment and, as such, attempts to define the genetic risk to humans that is associated with use of a substance which is a confirmed mutagen as defined by one or more test methods in tier two. The future uses of mutagenicity test methods will probably be in the area of short-term tests for carcinogenicity and as a means of assessing the risk associated with the use of gentically active chemicals.