Pure and Applied Chemistry

Abstract: This paper discusses the practical implementation of the precautionary principle in the area of management of industrial chemicals in the European Union. An analysis of a number of recent cases where the precautionary principle was invoked shows that the main reason for doing so were the uncertainties in the risk assessment (or the underlying effects or exposure data), which were, according to the scientific experts, so high that the "normal" level of certainty could not be obtained. The challenge for the future is to try to develop general guidance or rules that will support the policymakers in their decision as to whether this uncertainty is so large that action is warranted or whether it is acceptable to wait until further information has become available.