"Foreword: The safe cleaning of tanks requires that@ so far as practicable@ all hazards be removed@ or that they be guarded against with suitable protective devices or equipment; and that adequate means of exit for any emergency be provided. The purpose of this manual is to assist supervisors@ foremen@ and others responsible for the cleaning of crude-oil and unfinished-products tanks to fulfill these requirements. Accident-Prevention Manual No. 1 B: ""Cleaning Petroleum Storage Tanks: Section B??Gasoline Tanks"" (2nd edition@ October 1950) deals with similar problems related to the cleaning of tanks which have contained gasoline or light products. Because of the numerous methods employed and because of the differ-ent types of available equipment for cleaning tanks@ the mechanical problems in connection with the actual removal of solid and liquid residues are not covered in this manual. This manual was prepared under the auspices of the Committee on Tank Cleaning of the American Petroleum Institute's Central Committees on Accident Prevention and Fire Protection@ and has been approved for publication by the API Board of Directors."