(1) Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose flammability is not known, a test must be made by a competent person to determine its flammability. You must consider preservative coatings to be highly flammable when scrapings burn with extreme rapidity.

(2) You must take precautions to prevent ignition of highly flammable hardened preservative coatings. When coatings are determined to be highly flammable, you must strip them from the area to be heated to prevent ignition.

(3) Protection against toxic preservative coatings:

(a) In enclosed spaces, you must strip all surfaces covered with toxic preservatives of all toxic coatings for a distance of at least 4 inches from the area of heat application, or you must protect the employees by air line respirators, meeting the requirements of Part C of this chapter.

(b) In the open air, you must protect employees by a respirator, in accordance with requirements of Part C of this chapter.

(4) You must remove the preservative coatings 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.