The Ontario Building Code | Exhaust Ventilation
3.3.1.19. Exhaust ventilation
(1) An exhaust ventilation system designed in conformance with the appropriate requirements of Part 6 shall be provided in a buildingor 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) 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.