General Introduction

Over the last few decades there has been considerable activity in the field of risk assessment. This has mainly taken place in international bodies such as the Organization for Economic Co-operation and Development (OECD), the World Health Organization (WHO) - especially in the context of its International Programme on Chemical Safety (IPCS) - the European and Mediterranean Plant Protection Organization (EPPO), the Council of Europe and the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) [1-10]. Various directives and regulations in which risk assessment plays a crucial part have been issued by the European Community [11-14] and similar activities are taking place in other parts of the world, e.g., the U.S., Canada and Japan.