Relates to precautions to be taken prior to and during welding and allied processes to avoid the possibility of fire or explosion. It specifies general precautions for hot work carried out at any location and additional requirements for hot work in hazardous areas. Requirements for hot work equipment, and precautions after occurrence of fire are also included. Guidelines for hot work in hazardous areas are given in an appendix, and a second appendix provides recommended procedures for the preparation for hot work on equipment which has held flammable or explosive substances.