Scientific validation: a crucial and unavoidable prerequisite to the acceptability of new tests and testing strategies

By Balls, M.

The use of in vitro techniques in fundamental pharmacotoxicological research is widespread, but relatively little progress has been made in applying the knowledge and experience gained to regulatory toxicity testing. This is largely because specific tests of various kinds are required by national and international laws and regulations, before chemicals and products of many types can be manufactured, transported or marketed. These requirements have led to the publication of standardised test guidelines by various regulatory authorities. Although there is an increasing willingness to accept, in principle, the incorporation of non-animal tests and testing strategies into regulatory practice, their relevance and reliability must first be established in recognised validation studies, the outcomes of which must be assessed by independent groups of experts. The formal validation of alternative methods is not progressing satisfactorily. The reasons for this are discussed and some suggestions for improvements are made.