This publication contains two parts: Part 1 contains internationally harmonized generic terms used in hazard/risk assessment. This set of harmonized terms was developed by the International Programme on Chemical Safety after an extensive survey of the terms used by chemical risk assessment professionals. Implementation of these harmonized terms will help facilitate the mutual use and acceptance of assessments of chemicals between countries saving resources for both governments and industry. It will also facilitate increased public understanding of risk assessment reports. Part 2 the glossary of key exposure assessment terminology is intended to help facilitate communication and consistency of language used in the exposure sciences in particular.This publication will be useful for hazard exposure and risk assessment practitioners in government industry research institutions and other non-government organizations with an interest in chemicals risk assessment. It will also be useful for others including users of chemicals who wish to interpret chemical risk assessment information.