Carbon Monoxide Awareness Week: test your alarms this fall

November 1 to 7 is Carbon Monoxide (CO) Awareness Week in Ontario. Oshawa Fire Services is reminding residents to change the batteries in their smoke and CO alarms when turning clocks back one hour on Sunday, November 1.

Ontario law requires working CO alarms in all homes with fuel-burning appliances, fireplaces or attached garages. As of January 1, 2026, in addition to CO alarms required outside all sleeping areas, CO alarms are also required on every storey of your home. Removing or tampering with smoke or CO alarms can result in significant fines and penalties.

Smoke and CO alarm safety:

• Install smoke alarms on every storey and outside all sleeping areas. For added protection, install one in every bedroom.
• Install CO alarms on every storey and outside all sleeping areas if your home has a fuel-burning appliance, fireplace or attached garage.
• Test alarms monthly and replace batteries every spring and fall.
• Create and regularly practice a home escape plan.
• Replace alarms according to the manufacturer's recommendations or when they are more than 10 years old.

What is Carbon Monoxide?

Carbon monoxide is a poisonous gas known as the "silent killer" because it cannot be seen or smelled. It is produced when fuels such as natural gas, propane, gasoline, heating oil or wood do not burn completely.

Prevent CO in your home

• Have fuel-burning appliances, chimneys and vents inspected and cleaned annually. Find a registered contractor at COSafety.ca.
• Keep outdoor vents clear of obstructions.
• Use barbecues and generators outdoors only, away from doors, windows and vents. 
• Never use a stove or oven to heat your home.
• Open the fireplace flue before use.
• Never run a vehicle or other fuel-powered engine in a garage, even with the door open. 

Know the signs of CO poisoning

Symptoms can include headaches, nausea, dizziness, confusion, drowsiness and unconsciousness.

If your CO alarm sounds and anyone has symptoms of CO poisoning, leave the home immediately and call 9-1-1 from outside. If no one has symptoms, check the battery and alarm expiry before seeking assistance.

Know your alarm

CO alarms sound different from smoke alarms. Test both monthly and ensure everyone in your home recognizes the difference. Follow the manufacturer's instructions to understand low-battery, end-of-life and CO alert signals.

For more CO safety tips, visit the Office of the Fire Marshall’s carbon monoxide safety page and COsafety.ca.

For more information about Oshawa Fire Services and fire prevention, visit oshawa.ca/Fire or follow @OshawaFire on X.