This introductory document first gives some information on the nature of the documentation provided for the IPCS/UNEP/WHO/OECD Workshop on Health Aspects of Chemical Accidents, to be held in Utrecht on 13th-16th April 1993. Next, this document briefly describes the activities, related to chemical accidents, of the four international organizations that have collaborated in organising the Workshop. Finally, the document sets the scene for discussion by presenting a brief overview of chemical accidents, including a list of some of the major chemical accidents that have accurred worldwide