Buying a detector
- Look for a recognized Canadian certification mark such as CSA, ULC, cULus, or cETLus.
- Choose a CO alarm that meets CSA 6.19 and a smoke alarm that meets CAN/ULC-S531.
- Avoid uncertified products from online marketplaces; several recent Health Canada recalls involve these alarms.
- Consider a combination smoke/CO alarm only if it is certified for both hazards.
Smoke alarm placement
- Install smoke alarms on every storey of the home, including the basement.
- Place one outside each sleeping area and, where possible, inside every bedroom.
- Keep alarms at least 3 m from cooking appliances to reduce false alarms.
- For the best coverage, choose photoelectric or dual-sensor alarms.
CO alarm placement
- Inside each bedroom, or outside each bedroom within 5 m of the bedroom door.
- On every storey of the home, especially near sleeping areas.
- Follow the manufacturer’s recommended mounting height — CO mixes with air, so height matters.
- Keep alarms away from windows, vents, bathrooms, and dusty areas.
Maintenance
- Test every alarm monthly by pressing the test button.
- Replace batteries at least once a year, or when the low-battery chirp sounds.
- Replace smoke alarms every 10 years and CO alarms every 7–10 years (follow the manufacturer’s date stamp).
- Never paint over or disable a smoke or CO alarm.
If the alarm sounds
- Leave the building immediately and get fresh air.
- Call 911 or your local emergency number from outside.
- Do not re-enter until emergency responders clear the building.
- Have all fuel-burning appliances inspected by a qualified technician before using them again.
Frequently asked questions
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Emergency? If you suspect carbon monoxide poisoning, leave immediately and call 911. This website is for reference only and is not a substitute for professional advice or emergency services.