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Carbon monoxide safety

CO detector

CO Awareness Week

The Calgary Fire Department joins Alberta’s Office of the Fire Commissioner, ATCO Gas and partners across the province and country to promote CO Awareness Week during the first week of November every year.

Please review the information on this page about CO alarms and what you can do to keep your family safe from CO gas.

CO alarms

Carbon monoxide (CO) is a poisonous gas that has no colour, smell or taste. If you are exposed to a high amount of CO gas for a long time you may become sick, unconscious, suffer brain damage, or in very severe cases, even die.

CO alarms provide the only warning of dangerous CO gases in your home. Most commonly, the main source of CO gas in your home is your furnace, but of course you should monitor any household appliances which run on fossil fuels.

If you are exposure to CO gas, you may get flu-like symptoms such as headaches, nausea and dizziness, as well as become confused, tired and lose consciousness. Other warning signs that you might have CO gas in your house include stale or stuffy air, a lot of moisture on your windows and walls, soot build-up around appliances and vents, or a pilot light that keeps going out.
If you or anyone in your house experiences the symptoms of CO poisoning or your CO alarm goes off, you should leave your house and call 9-1-1. Do not go back into the house until the Fire Department tells you it is safe to do so.

What you should do

Install  least one carbon monoxide alarm on every level of your home, including the basement. The most important location for a CO alarm is in or near your bedrooms.

Test CO alarms once a month by pressing the alarm’s test button to hear if the alarm will sound. Replace the batteries of your CO alarms once a year.

Replace CO alarms at the end of their life span, which will be noted on its packaging. If you no longer have the packaging, you should be able to find the information by searching your CO alarm online. The life span of CO alarms is typically three to seven years. Regardless of the type of CO alarm or how it is powered, either hard-wired, battery or electric, alarms must be replaced at the end of their life span.


When buying a CO alarm, look for a product that has been made and properly tested by looking for a marking by the Underwriters Laboratories of Canada (ULC), or Underwriters Laboratories Incorporated (cUL).

Sleep with your bedroom doors closed, and then test your CO alarm to make sure you and your family can hear and wake-up at the sound of the alarm. If you can't hear it, then install CO alarms inside bedrooms so that you will hear it when sleeping.

How to prevent CO build-up in your home

  • Make sure fuel-burning appliances, chimneys and vents are cleaned and inspected by professionals every year before you start to use them, usually when the weather gets cold.
  • Make sure your vents for the dryer, furnace, stove, fireplace and other fuel-burning appliances are always clear of snow and other debris.
  • Only use gas and charcoal barbeques outdoors, away from all doors, windows, vents and other building openings. Never use barbeques inside a garage, even if the garage door is open.
  • Only use portable fuel-burning generators outdoors in well-ventilated areas away from windows, doors, vents and other building openings.
  • Make sure portable fuel-burning heaters are vented properly, according to their instructions.
  • Never use the stove or oven to heat your home.
  • Make sure to open the flu of your fireplace before you use it. 
  • Never run a car, vehicle or other motor inside a garage, even if the garage door is open. Always drive your car or vehicle out of the garage right after starting it.
  • Every year, check all the fuel-burning appliances in your house; make sure they are working properly and used properly.
  • Check the outside and inside walls of your house for cracks, holes, separations, and check for rust, stains or carbon deposits on heating ducts or pipes.
  • Check the flame on fuel-burning appliances – it should be clear blue with occasional yellow tips.
  • Install CO alarms according to the directions on its packaging and pay attention to the clearance requirements.