CO Alarms

Carbon Monoxide Alarms are the Law

Carbon Monoxide (CO) Alarms

Every home with a fuel fired appliance, fireplace or an attached garage must have at least one carbon monoxide alarm installed outside the sleeping areas. Carbon Monoxide alarms will warn you of danger but regular maintenance of all fuel fired appliances and solid fuel burning appliances will minimize the danger of carbon monoxide poisoning.

What is CO?

• CO is known as the silent killer because it is an invisible, tasteless and odourless gas that can be deadly.
• CO is produced when fuels such as propane, gasoline, natural gas, heating oil or wood do not burn completely in fuel-burning appliances and devices such as furnaces, gas or wood fireplaces, hot water heaters, stoves, barbeques, portable fuel-burning heaters and generators and vehicles.

Prevent CO in your home

• Ensure all fuel-burning appliances in your home are inspected annually. 
• Check that all outside appliance vents are not blocked.
• Never use a portable fuel-burning appliance inside (i.e. barbeques, portable heaters and generators).

 Know the symptoms of CO

• Exposure to CO can cause flu-like symptoms such as headaches, nausea, dizziness, as well as confusion, drowsiness, loss of consciousness and death.
• If your CO alarm sounds, and you or other occupants suffer from symptoms of CO poisoning, get everyone out of the home immediately. Then call 9-1-1 from outside the building.
• If your CO alarm sounds, and no one is suffering from symptoms of CO poisoning, check to see if the battery needs replacing, or the alarm has reached its "end-of-life" before calling 9-1-1.

 Know the sound of your CO alarm

• Your CO alarm sounds different than your smoke alarm. Test both alarms monthly and make sure everyone in your home knows the difference between the two alarm sounds.
• Don’t be confused by the sound of your CO alarm’s low-battery warning. Follow your CO alarm manufacturer’s instructions so you know the difference between the low-battery warning, the “end-of-life” warning, and the alarm alerting you to the presence of CO in your home.

New CO alarm requirements

Starting January 1, 2026, new carbon monoxide (CO) alarm requirements are in effect in Ontario. These requirements expand on the existing CO alarm requirements in residential dwellings including houses, multi-unit dwellings, apartments, townhouses, cottages, care occupancies, and other residential accommodations.

In addition to existing CO alarm requirements, CO alarms will now be required if your home is heated by air from a fuel-burning appliance that is not contained within your home and CO alarms must now be installed on every storey of the home, including storeys that do not have sleeping areas.

In apartment or condominium units, the new fire code will require a CO alarm if the unit is heated by air from a fuel-burning appliance that is not contained within the unit, such as air coming from a furnace in a building service room. The new fire code will also require a CO alarm on every storey of your unit, including storeys that do not have sleeping areas, and in public corridors of the building if the corridors are heated by air from a fuel-burning appliance.

Residents can view the requirements in full at the link below, and are encouraged to contact Thorold Fire and Emergency Services with questions.

Click here for more information from the Office of the Ontario Fire Marshal.

Click here for more information on residential home safety.

Click here for more information on apartment and condo safety.

Click here for more information on care occupancy safety.