Do we find relevant parameters for in vitro cytotoxicity testing?

The current strategy for the design of cytotoxicity tests is briefly reviewed in light of goals that need to be reached, and in the capacity of in vitro tests to fulfill the high public expectations for alternative methods to animal testing. Various cytotoxicity tests and parameters used for the assessment of topical toxicity and of neurotoxicity are chosen as examples and their relevance is discussed. Past experience with in vitro and short-term tests for mutagenicity shows not to look for one single supertest. A proposition for reasonable safety testing implies that a combined approach must be developed that integrates the results from a battery of cell tests and from structure-activity analyses as well as from kinetic and metabolic studies. The relevance of such an integrated approach must be aimed directly at the organisms that may be exposed.