In Vitro Methods in Regulatory Toxicology: The Crucial Significance of Validation

Abstract

Regulatory toxicity testing in animals raises a number of scientific, humanitarian, legislative, practical and economic questions and conflicts. For example, while the use of animal procedures in identifying the potential hazards represented by chemicals and products of many kinds is required by various specific and general laws and regulations, there are other laws of no less importance (e.g. European Union [EU] Directive 86I609IEEC [Anon, 1986]), which are intended to protect laboratory animals from unnecessary pain, suffering, distress or lasting harm. They stipulate that the use of laboratory animals in potentially harmful procedures should only be permitted when such use can be justified as necessary on strong scientific grounds. However, the scientific basis of many animal tests themselves and, in particular, of the ways whereby the data they provide are currently applied in human risk assessment, is weak. In addition, the present dependence of hazard prediction on animal tests requires considerable human and economic resources, as a result of which only a very small proportion of the chemicals which might threaten the wellbeing of humans, or be hazardous to the environment in general, have been subjected to anything approaching a scientifically-satisfactory evaluation.