The Environmental Health Criteria (EHC) documents produced by the International Programme on Chemical Safety, include an assessment of the effects on the environment and on human health of exposure to a chemical or combination of chemicals, or physical or biological agents. They also provide guidelines for setting exposure limits. The purpose of a Health and Safety Guide is to facilitate the application of these guidelines in national chemical safety programmes. The first three sections of a Health and Safety Guide highlight the relevant technical information in the corresponding EHC. Section 4 includes advice on preventive and protective measures and emergency action; health workers should be thoroughly familiar with the medical information to ensure that they can act efficiently in an emergency. Within the Guide is an International Chemical Safety Card which should be readily available, and should be clearly explained, to all who could come into contact with the chemical. The section on Regulatory information has been extracted from the legal file of the International Register of Potentially Toxic Chemicals (IRPTC) and from other United Nations sources. The target readership includes occupational health services, those in ministries, governmental agencies, industry,a nd trade unions, who are involved in the safe use of chemicals and the avoidance of environmental health hazards and those wanting more information on this topic. An attempt has been made to use only terms that will be familiar to the intended user. However, it is inevitable that sections 1 and 2 contain technical terms. A bibliography has been included for readers who require further background information. Revision of the information in this guide will take place in due course, and the eventual aim is to use standardized terminology.