This second comprehensive edition of these Principles is to help public authorities, industry and communities worldwide anticipate accidents involving hazardous substances resulting from technological and natural disasters, as well as sabotage. It addresses the following issues: preventing the occurrence of chemical accidents and near-misses, preparing for accidents through emergency planning, public communication, etc., responding to accidents and minimising their adverse effects, and following-up to accidents, regarding clean-up, reporting and investigation.The first edition was published in 1992 under the same title.