In recent years many developments have taken place in promote co-operation between governments and other the field of risk assessment of chemicals. Many reports parties involved in chemical safety and to provide policy have been published by national authorities, industries guidance with emphasis on regional and subregional co and scientific researchers as well as by international bod operation. The Inter-Organization Programme for the ies such as the European Union, the Organization of Sound Management of Chemicals (IOMC) was estab Economic Cooperation and Development (OECD) and lished in 1995 and provides a mechanism for the six par the joint International Programme on Chemical Safety ticipating organizations (UNEP, ILO, FAO, UNIDO,WHO (IPCS) of the World Health Organization (WHO), the and OECD) to better co-ordinate policies and activities in International Labour Organization (lLO), and the United the field of chemical risk management. Nations Environment Programme (UNEP). The present book is an introduction to risk assessment of The development and international harmonization of risk chemicals. It contains basic background information on assessment methods is an important challenge. In sources, emissions, distribution and fate processes for Agenda 21 of the United Nations Conference on exposure estimation. It includes dose-effects estimation Environment and Development (UNCED), chapter 19 is for both human health related toxicology and ecotoxicol entirely devoted to the management of chemicals. For ogy as well as information on estimation methodologies. one of its recommendations, i. e.