Abstract
The International Programme on Chemical Safety (IPCS) is a cooperative program of the World Health Organization, the International Labour Organization, and the United Nations Environment Programme. The main objectives of its risk assessment work are to provide, on a global basis, consensus assessments of priority chemicals (including pesticides) and to promote the development, validation, use, and harmonization of sound methodologies for risk assessment. The IPCS provides a number of comprehensive risk assessment documents, the most prominent of which are the Environmental Health Criteria monographs. In addition, evaluations of chemicals in food, air, and drinking water are conducted, and health-and environment-based guidelines for exposure are developed. In deriving guidance values for exposure to chemicals, the risk assessment paradigm of the National Academy of Sciences is followed. The development of guidance values for exposure is based on the calculation of a total intake from all sources. The process involves the identification of the critical effects and the pivotal studies, the derivation of a no (or lowest) observed adverse effect level, the application of (preferably data-derived) uncertainty factors, and the partitioning of the overall tolerable intake among all possible routes of exposure. Work on risk assessment methodologies is directed toward the promotion of scientifically sound approaches to evaluating risks to human health and the environment from exposure to chemicals. Special focus is placed on a project of harmonization of risk assessment methodologies.