During the past decade, important position statements on mutagenicity testing have been issued by industrial organizations such as CEFIC (the European Council of Chemical Industry Federations) and ECETOC (the European Chemical Industry Ecology and Toxicology Centre). Mutagenicity testing is of potential value as a research tool for screening new compounds, as a probe for the identification of harmful substances and as a diagnostic tool for monitoring the health of individuals exposed to certain chemicals. The problems inherent in mutagenicity testing include specificity and sensitivity, and meaningful interpretation of test data will depend on the strict maintenance of accepted quality standards.