An International Reference Chemical Data Bank would Accelerate the Development, Validation and Regulatory Acceptance of Alternative Toxicology Tests

Abstract

Toxicologists involved in safety evaluation have a primary responsibility for ensuring that their results are the best possible for predicting human health effects. Currently, the scientific and regulatory consensus is that animal-based studies provide the best possible evidence. Thus, toxicologists are faced with ethical questions about the use of animals for experimental research. In vitro tests which equal or supersede animal studies, in terms of provision of data for human health assessment, are thus a high priority for toxicologists. There is no shortage of ideas for alternative methods and this emphasises the importance of adequate validation. One critical component of validation studies is the selection, evaluation and provision of appropriate chemicals for assessing the performance of alternative tests. Problems are encountered with poor published toxicology data, the difficulty of ensuring the selection of chemicals to represent a sufficiently wide range of chemical classes, disagreement as to the toxicological classification of chemicals and many other issues in the selection and supply of validation chemicals. Validation studies will be much easier to carry out and will be better received by those involved in human hazard assessment if this aspect of the studies is well planned and controlled. It is proposed, therefore, that an international reference collection of chemicals is assembled which is carefully selected for validation of specific toxicological endpoints, carefully reviewed and classified as to toxicity and made available to research workers interested in validating alternative methods. Additionally, the usefulness of the database could be enhanced if the results of validation studies were to be recorded in a central repository.