Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose
flammability is not known, a test shall be made by a competent person to determine its flammability. Preservative coatings shall be considered to be
highly flammable when scrapings burn with extreme rapidity.
Precautions shall be taken to prevent ignition of highly flammable hardened preservative coatings. When
coatings are determined to be highly flammable, they shall be stripped from the area to be heated to prevent ignition.
Protection against toxic preservative coatings:
In enclosed spaces, all surfaces covered with toxic preservatives shall be stripped of all toxic
coatings for a distance of at least 4 inches from the area of heat application, or the employees shall be protected by air line respirators, meeting
the requirements of Subpart E of this part.
In the open air, employees shall be protected by a respirator, in accordance with requirements of
Subpart E of this part.
The preservative coatings shall be removed a sufficient distance from the area to be heated to ensure
that the temperature of the unstripped metal will not be appreciably raised. Artificial cooling of the metal surrounding the heating area may be used
to limit the size of the area required to be cleaned.