API STD 2015:2001 is applicable to cleaning stationary atmospheric and low-pressure (up to and including 15 psig) aboveground petroleum storage tanks used in all sectors of the petroleum and petrochemical industry, including crude oil and gas production, refineries, petrochemical plants, bulk plants and terminals. This standard provides requirements for safely planning, coordinating and conducting tank cleaning operations from decommissioning (removal from service) through recommissioning (return to service) tanks that have contained flammable or combustible liquids or petroleum related toxic materials. This standard does not and cannot cover every possible unique hazard or situation that may arise during tank cleaning operations. These site specific, product specific and tank specific hazards and situations must be addressed by employers (owner/operators or contractors) using the appropriate principles and considerations provided for by this standard. The ANSI/API Recommended Practice 2016, Guidelines and Procedures for Entering and Cleaning Petroleum Storage Tanks , provides supplemental information applicable to the requirements of this standard.