API RP 2207 provides information to assist safe performance of hot work on the bottoms of storage tanks that have been in service to store flammable products. This work activity has specific precautions and work practices. It also addresses the safety aspects of hot work performed on petroleum storage tank bottoms. It discusses safety precautions for preventing fires, explosions, and associated injuries. The term "hot work," as used in this publication, is defined as an operation that can produce a spark or flame hot enough to ignite flammable vapors. This recommended practice does not contain all safety precautions and procedures that may be required prior to, during, or after a specific hot-work activity. All hot work should be performed in compliance with applicable federal, state, and local regulatory requirements and recognized industry practices. Work practices of concern for working on tank bottoms include, but are not limited to, confined space entry, lockout/tagout, atmospheric testing, ventilation, and requirements for use of personal protective equipment (PPE).