Note to Table 3.13.4.5.:
3.16.1.7. Exits and Means of Egress  (1) Except as permitted in Sentences (2) and (3), every walkway or platform level shall be provided with no fewer than two exits conforming to Section 3.4. (2) An access to exit from an elevated platform level may be provided by means of open unenclosed stairs serving, (a) not more than four platform levels, the highest of which shall be not more than 12 m above the main floor, where the shelf and rack storage system is intended for the storage of Class I, II, III and IV commodities, as defined in NFPA 13, “Installation of Sprinkler Systems”, and (b) not more than two platform levels, where the shelf and rack storage system is intended for the storage of Group A, B and C plastics and rubber tires, as defined in NFPA 13, “Installation of Sprinkler Systems”. (3) Any single platform or walkway in a shelf and rack storage system may be served by a single unenclosed stair leading to the platform or walkway level immediately below provided, (a) the platform or walkway does not exceed 200 m2 in area, (b) the travel distance on the platform or walkway to the level below, including the travel distance along the single unenclosed egress stair, does not exceed 25 m, and (c) the platform or walkway below is provided with two separate egress stairs or exits. (4) The maximum travel distance on an elevated platform to the ground floor level, including the travel distance along unenclosed stairs, shall not exceed 45 m. (5) The maximum travel distance on an elevated platform to an exit serving that platform shall not exceed 45 m. (6) Except as permitted in Sentence (7), the maximum travel distance from the bottom of an unenclosed stair to an exit along a main aisle on the ground floor level shall not exceed 45 m. (7) Where the travel distance in Sentence (6) exceeds 45 m, (a) an egress system serving the shelf and rack storage system shall be designed on the basis of a time-based egress analysis using the following criteria: (i) occupant egress speed of 1 m/sec shall be used for horizontal egress routes within the shelf and rack storage system, (ii) occupant egress speed of 0.6 m/sec shall be used for vertical egress routes within the shelf and rack storage system, measured on the diagonal along the nosing of the stairs, (iii) occupant egress speed of 1.3 m/sec shall be used for horizontal egress routes along a main aisle on the ground floor level, (iv) each lift-gate shall be accorded an egress time of 10 seconds, (v) each at-level conveyor cross-over shall be accorded a time of 5 seconds, (vi) a safety factor of 1.5 shall be used in calculating the total egress time (b) the total egress time shall be calculated using the following formula: Total Egress Time = (Hp + Vp/0.6 + Hm/1.3 + 10Nlg + 5Nlc ) · 1.5 (in seconds) where: Hp = horizontal travel distance on the shelf and rack storage system, in metres, Vp = vertical travel distance on the shelf and rack storage system, in metres, Hm = horizontal travel distance on the main floor, in metres, Nlg = number of lift gates in the means of egress, Nlc = number of at-level cross overs in the means of egress, (c) the total egress time from any point in the shelf and rack storage system shall be a maximum of 4 minutes, (d) a fire alarm and detection system conforming to Subsection 3.2.4. shall be installed in the building, (e) smoke detectors shall be provided under all solid decking and walkways, (f) clearly identified and easily accessible pull stations shall be provided at egress stairs, conveyor cross-overs or lift-gates located along egress paths, and (g) the occupant load on each level of the shelf and rack storage system shall not exceed 10 persons per egress stair. (8) A dead end aisle shall not exceed 9 m where the platform or walkway is provided with 2 or more egress facilities. (9) An aisle serving a shelf and rack storage system shall have a clear-aisle width of not less than 760 mm. (10) Conveyors, trolleys, tracks or any other similar mode of product transportation within the aisle or walkway shall not reduce the clear-aisle width required in Sentence (9). (11) Where exits are provided to comply with Sentence 3.4.2.5.(2), main aisles serving the shelf and rack storage system on the ground floor, leading from egress stairs directly to an exit, shall be clearly demarcated and have a minimum unobstructed, clear-aisle width of 2.4 m. (12) Where a lift-gate is incorporated along an egress route, (a) a maximum of two lift-gates may be within a single egress route, (b) each lift-gate shall be equipped with a positive lock when open, and (c) it shall be designed to automatically stop the conveyor belt that it serves when the lift-gate is open. (13) Where an at-level conveyor cross-over is incorporated along an egress route, (a) not more than two at-level conveyor cross-overs shall be within a single egress route, (b) handrails spaced not more than 1 m apart and parallel to the direction of egress shall be provided on both sides of the at-level cross-over, (c) flat, metal inserts shall be placed between each roller over the required egress width at each at-level conveyor cross-over to provide a walking surface, (d) at least two inserts not less than 100 mm wide shall be arranged symmetrically between the handrails serving the at-level cross-over, (e) inserts shall be sized to support loads specified in Part 4, (f) a clearly identified and easily accessible switch that will stop the conveyor shall be located at each at-level cross-over, and (g) stairs approaching at-level conveyor cross-overs shall be marked to indicate that they are readily identifiable as part of the egress route. 3.16.2. Storage of Class I, II, III and IV Commodities