Despite the steady increase in the number of cases of HIV infection in the community there are dangers of complacency and lowering of standards for worker protection. This guidance seeks to reinforce important messages to ensure that the small risk of occupational infection continues to be controlled. This publication supersedes the earlier guidance entitled HIV - The Causative Agents of AIDS and Related Conditions - Second Revision of Guidelines which appeared in 1990. It explains relevant aspects of health and safety law in simple terms and indicates ways in which the law may be upheld. This new edition also includes full reference to hepatitis and certain other blood-borne viruses which are transmitted in the same way.