The Ontario Building Code | Combustible Piping Materials
184.108.40.206. Combustible Piping Materials
(1) Except as permitted by Sentences (2) and (3) and by Clause 220.127.116.11.(1)(d) and Article 18.104.22.168., combustiblepiping and tubing and associated adhesives are permitted to be used in a building required to be of noncombustible construction provided that, except when concealed in a wall or concrete floor slab, they,
(a) have a flame-spread rating not more than 25, and
(b) if used in a buildingdescribed in Subsection 3.2.6., have a smoke developed classification not more than 50.
(2) Combustiblesprinkler piping is permitted to be used within a sprinkleredfloor area in a buildingrequired to be of noncombustible construction.
(3) Polypropylene pipes and fittings are permitted to be used for drain, waste and vent piping for the conveyance of highly corrosive materials and for piping used to distribute distilled or dialyzed water in laboratory and hospital facilities in a building required to be ofnoncombustible construction, provided,
(a) the buildingis sprinklered,
(b) the piping is not located in a vertical shaft, and
(c) piping that penetrates a fire separation is sealed at the penetration by a fire stop that has an FT rating not less than the fire-resistance rating of the fire separation when subjected to the fire test method in CAN/ULC-S115, "Fire Tests of Firestop Systems", with a pressure differential of 50 Pa between the exposed and unexposed sides, with the higher pressure on the exposed side.