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Carbon Monoxide (CO)

Carbon monoxide (CO) is a serious danger and one that many people do not understand. It is the #1 cause of unintentional poisoning deaths in North America. It kills about 50 people every year in Canada with an average of 11 deaths in Ontario.

What is Carbon Monoxide?

Carbon Monoxide (aka "CO")  is a colourless, odourless, tasteless, toxic gas that enters the body through the lungs during the normal breathing process.  It replaces oxygen in the blood and prevents the flow of oxygen to the heart, brain and other vital organs. Check out our Carbon Monoxide FAQ.

What are its sources?

Sources of CO include furnaces, gas water heaters/boilers, wood stoves, and other appliances that run on fuels. If these devices are improperly installed or malfunction, they can release CO into your home.

Other sources of CO include:

  • exhaust fumes from vehicles or other gas-powered equipment, like lawnmowers, snow blowers, and power generators, used indoors or in your attached garage
  • chimneys that are blocked or dirty
  • fuel-burning cooking appliances, like gas stoves, propane, natural gas or charcoal grills
  • tobacco smoke

Why should I care about Carbon Monoxide?

When you inhale carbon monoxide, it reduces your body's ability to carry oxygen in your blood. The health effects can be very serious.

  • Exposure to CO may cause:
    • headaches
    • fatigue
    • shortness of breath
    • flu-like symptoms
    • impaired motor functions (like difficulty walking or problems with balance)
    • dizziness
    • chest pain
    • poor vision
    • difficulty thinking
    • convulsions
    • coma
    • death

When does the new Carbon Monoxide law apply to my home?

The CO alarm regulation came into force on October 15, 2014. Buildings with six suites of residential occupancy or less are required to comply with the installation and replacement requirements within 6 months of the in-force date (April 15, 2015, at the latest).

Buildings with more than six suites of residential occupancy are required to comply with the installation and replacement requirements by October 15, 2015.

The maintenance and testing requirements for existing CO alarms (e.g. those devices previously installed to comply with the OBC or a municipal by-law) take effect on the in-force date (October 15, 2014).

How do I find out about the requirements of the law and where the alarms need to be installed?

View the Ministry's CO Alarm Questions & Answers to read about Carbon Monoxide, how CO alarms work, when & where alarms should be installed, whose responsibility it is to ensure alarms are installed, and information on the replacement, testing and enforcement of CO alarms.