International harmonization for the risk assessment of pesticides: results of an IPCS survey.

Risk assessment harmonization has become an important issue on the environmental agendas of numerous countries. The benefits of an international consensus on risk assessment methodologies include decreased duplication of toxicity testing through the sharing of experimental data, decreased barriers to trade, and more consistency and cooperation within the scientific community. This paper presents the findings of an international survey of regulatory scientists in OECD and select non-OECD countries. The survey was sponsored by the International Programme on Chemical Safety (IPCS), which itself was formed by a cooperative agreement between the World Health Organization, the International Labor Organization, and the United Nations Environment Program. The survey results represent the first step in a project initiated by the IPCS to harmonize risk assessment methodologies used worldwide for the toxicological evaluation of chemicals. In this phase, the primary focus was on the health risk assessment of pesticides. Participants responded to questions regarding: (1) the support or review documents relied on for performing risk assessments; (2) procedures used and criteria applied when evaluating carcinogenicity data, including issues relating to mechanism of action, the maximum tolerated dose, and doses used in carcinogenicity bioassays; (3) risk assessment methodologies, such as the use no effect levels with safety factors or risk assessment models; (4) methods for assessing occupational and dietary exposure to pesticides; and (5) the primary areas of interest for the commencement of international harmonization efforts. There was significant consensus on specific issues relating to risk assessment methods and carcinogenicity assessment, as well as strong positive support for international harmonization activities. Differences existed with respect to the doses used in bioassays and data interpretation.