3.3.6.3.Indoor Storage of Compressed Gases

(1) Except as provided by Sentence (3), where required by the Fire Code made under the Fire Protection and Prevention Act, 1997, a room intended for the indoor storage of cylinders containing flammable compressed gases shall meet the following requirements: (a) it is separated from the remainder of the building by a gas-tight fire separation having a fire-resistance rating of not less than 2 h, (b) it is located on an exterior wall of the building, (c) it can be entered from the exterior, (d) it is ventilated in conformance with Sentence (4), (e) it is constructed so that an exterior wall provides explosion venting (i) in the ratio of 0.2 m2 for each cubic metre of room volume, or (ii) in the ratio computed in accordance with NFPA 68, “Standard on Explosion Protection by Deflagration Venting,” but in no case less than 0.065 m2 of vent area for each cubic metre of room volume, (f) it is not intended to contain fuel-fired equipment or high temperature heating elements, and (g) it is not intended to be used for a purpose other than the storage of compressed gas. (2) Where a closure is installed in the fire separation separating the room from the remainder of the building in accordance with Clause (1)(a), it shall be (a) equipped with a self-closing device that keeps the closure closed when not in use, and (b) constructed so as to prevent the migration of gases from the room into other parts of the building. (3) Where required by the Fire Code made under the Fire Protection and Prevention Act, 1997, a room intended for the storage of not more than three cylinders of flammable compressed gases that are heavier than air and that have an aggregate capacity not exceeding 100 kg shall be (a) separated from the remainder of the building by a gas-tight fire separation having a fire-resistance rating of not less than 45 min, (b) located at or above grade, and (c) ventilated in conformance with Sentence (4). (4) A room described in Sentence (1) or (3) shall be (a) mechanically vented to the outside so as to ensure at least one air change per hour, or (b) naturally vented to the outside so as to ensure cross ventilation through non-closable louvered openings with (i) at least one opening having an aggregate free opening area of at least 0.2 m 2 per 100 m2 of the floor area located not more than 300 mm from the ceiling, and (ii) at least one opening having an aggregate free opening area of at least 0.2 m 2 per 100 m2 of the floor area located not more than 300 mm from the floor. (5) Except as permitted by Sentences (6) and (7), where required by the Fire Code made under the Fire Protection and Prevention Act, 1997, an area intended for the storage of cylinders containing compressed gases that may react with one another shall be divided into separate fire compartments having a fire-resistance rating of not less than 1 h. (6) Separate fire compartments required by Sentence (5) need not be provided, if the area intended for the storage of cylinders containing compressed gases that are lighter than air is separated by a concrete or masonry wall having a height of at least 2.0 m and projecting at least 1.0 m, measured horizontally, beyond the cylinders. (7) Separate fire compartments required by Sentence (5) need not be provided, if the area intended for the storage of cylinders containing compressed gases that are heavier than air is separated by a concrete or masonry wall having a height of at least 1.5 m and projecting such that the minimum distance that vapour can travel between two cylinders of gas that may react with each other is not less than 15 m, measured horizontally.