(1) Except as provided in Sentence (2), an exhaust ventilation system designed in conformance with the appropriate requirements of Part 6 shall be provided in a building or part of a building in which dust, fumes, gases, vapour or other impurities or contaminants have the potential to create a fire or explosion hazard.
(2) Where a fire separation required to have a fire-resistance rating is penetrated by a ventilation system required by Sentence (1) for power-ventilated enclosures in laboratories, the ducts shall be continuously enclosed from the first penetrated fire separation to any subsequent fire separations or concealed spaces and to the outdoors so that the highest fire-resistance rating of all the penetrated fire separations is maintained.
(3) Ducts described in Sentence (2) need not be equipped with a fire damper, a smoke damper or a combination smoke and fire damper.
(4) Explosion relief devices, vents or other protective measures conforming to Subsection 6.2.2. shall be provided for a space in which substances or conditions that have the potential to create an explosion hazard are present as a result of the principal use of a building.