In recognition of the growing importance of hazardous waste generation and disposal to environmental protection and economic development and considering that international cooperation could contribute effectively to a better understanding of the complex nature of the problems involved, the Pilot Study 'Disposal of Hazardous Wastes' was originally proposed by the Federal Republic of Germany at the 1973 CCMS Plenary. The proposal was made at a time when numerous environmentally unsound hazardous waste disposal activities were reported in most industrialized countries. There was an obvious need to improve the situation in that area. Governments of nearly all NATO countries recognized this challenge and responded by preparing or reviewing legislation and regulations to control the flow of hazardous wastes into the environment and to avoid further mismanagement. In this respect the proposed pilot study met special interest among NATO allies.