S-2.1, r. 4 - Safety Code for the construction industry
3.14.3. No cutting, welding or other work requiring an open flame shall be performed on a vessel, reservoir, pipe or other container where a flammable or explosive substance may be present, unless:
(a) air samples have been taken to indicate that the work may be done without danger; or
(b) procedures have been taken in accordance with subdivision 9.8 of CAN/CSA Standard W117.2-M87 Safety in Welding, Cutting, and Allied Processes.
R.R.Q., 1981, c. S-2.1, r. 6, s. 3.14.3; O.C. 1413-98, s. 22.