The Ontario Building Code | Self-Closing Devices
3.4.6.13. Self-Closing Devices
(1) An exit door that is normally required to be kept closed,
(a) shall be provided with a self-closing mechanism, and
(b) shall not be secured in an open position except as permitted by Sentence 3.1.8.12.(1).
In Plain Language
An exit door normally required to stay closed must have a self-closing mechanism and generally can't be propped open, so the fire separation the door is part of isn't defeated by convenience.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.