Beginning January 1, 2026, the Ontario Fire Code (OFC) will be updated to expand the areas in residential buildings where carbon-monoxide (CO) alarms are required. The update will require additional carbon-monoxide alarms in more parts of residential buildings to reduce the risk of CO poisoning and fatalities.
Carbon-monoxide is an odourless, colourless, and tasteless gas produced when fuels are burned incompletely.
The Ontario Office of the Fire Marshal notes that stricter requirements have been placed on residential buildings, where homes with fuel-burning appliances will now need carbon-monoxide alarms on each storey, not just in or near sleeping areas. Fuel-burning appliances include gas or wood furnaces, boilers, water heaters, ovens, dryers, and similar equipment. The updated rules also apply to homes with attached garages.
In apartment and condo buildings, carbon-monoxide alarms must also be installed in public corridors if the building is heated by fuel-burning equipment.
Landlords must purchase, install, and provide usage guidelines for tenants, while tenants are responsible for reporting any problems and testing the units monthly.
Carbon-monoxide alarms are not required in homes that are fully electric and have no fuel-burning appliances or attached garages.
Carbon-monoxide alarms should be mounted on ceilings or high on walls, away from corners and vents, and within 10 metres of sleeping areas. There are three types of alarms available, depending on installation: hardwired, battery-operated, and plug-in models.
All carbon-monoxide alarms must carry the Canadian Standards Association (CSA 6.19), Underwriters Laboratories of Canada (ULC 218), and Electrical Testing Laboratories (ETL) or equivalent certifications.
Carbon-monoxide units should also be tested monthly to verify auditory alarms, batteries replaced annually, and complete unit replacement every 5-10 years, depending on the manufacturer’s requirements.