Oil and Gas Occupational Safety and Health Regulations

12.6 (1) Where a hazardous substance may be produced by hot work in a confined space,

• (a) the confined space shall be ventilated in accordance with subsection (2); or

• (b) every employee who enters into, exits from and occupies the confined space shall use a respiratory protective device that meets the requirements of section 13.7 of Part XIII.

(2) Where an airborne hazardous substance or oxygen in the atmosphere in a confined space is maintained at the value, level or percentage prescribed in subsection 12.2(1) by the use of ventilation equipment, no person shall be granted access to the confined space unless

• (a) the ventilation equipment is

  • (i) equipped with an alarm that will, if the equipment fails, be activated automatically and be audible or visible to any person in the confined space, or

  • (ii) monitored by an employee who is in constant attendance at the equipment; and

• (b) in the event of failure of the ventilation equipment, sufficient time will be available for the person to escape from the confined space before

  • (i) his exposure to or the concentration of a hazardous substance therein exceeds the value, level or percentage prescribed in paragraph 12.2(1)(a) or (b), or

  • (ii) the percentage of oxygen in the atmosphere ceases to meet the requirements of paragraph 12.2(1)(c).

(3) The employee referred to in subparagraph (2)(a)(ii) shall activate an alarm in the event of faulty operation of the ventilation equipment.