50-204.72—Safe practices for welding and cutting on containers which have held combustibles.
Welding or cutting, or both, on containers which have held flammable or combustible solids, liquids, or gases, or have contained substances which may produce flammable vapors or gases will not be attempted until the containers have been thoroughly cleaned, purged, or inerted in strict accordance with the rules and procedures embodied in American Welding Society Pamphlet A-6.0-65, edition of 1965.