Facts About Carbon Monoxide

In the winter, the risk for carbon monoxide poisoning is at its highest, because it’s almost always related to the heating systems. 

Although some governments in Canada have taken regulatory actions on carbon monoxide, fatal accidents still occur, that is why it is extremely important to understand some facts about carbon monoxide (CO).

CO is an odourless, colourless and tasteless gas that can cause sudden illness and death.

CO is found in combustion fumes, such as those produced by cars and trucks, small gasoline engines, stoves, lanterns, burning charcoal and wood, and gas ranges and heating systems. CO from these sources can build up in enclosed or semi-enclosed spaces. Breathing it can poison people and animals in these spaces.

Because CO is basically undetectable to the human senses, people may not know that they are being exposed. The initial symptoms of low to moderate CO poisoning are similar to the flu (but without the fever). They include: headache, fatigue, shortness of breath, nausea and dizziness. High levels of CO inhalation can cause: mental confusion, vomiting, loss of muscular coordination, loss of consciousness and ultimately death. Symptom severity is related to both the CO level and the duration of exposure. Unless suspected, CO poisoning can be difficult to diagnose because the symptoms mimic other illnesses. People who are sleeping or intoxicated can die from CO poisoning before ever experiencing symptoms.

How does CO poisoning work? Red blood cells pick up CO quicker than they pick up oxygen. If there is a lot of CO in the air, the body may replace oxygen in blood with CO. This blocks oxygen from getting into the body, which can damage tissues and result in death. CO can also combine with proteins in tissues, destroying the tissues and causing injury and death.

All people and animals are at risk for CO poisoning. Certain groups — unborn babies, infants, and people with chronic heart disease, anemia, or respiratory problems — are more susceptible to its effects.

Carbon monoxide (CO) can only be detected with an alarm (detector). You should have at least one carbon monoxide detector in your home, in addition to a smoke alarm. Smoke alarms alert you to fires, not carbon monoxide. Carbon monoxide detectors can be purchased at any hardware or home equipment store.

Install a Canadian Standards Association (CSA) certified carbon monoxide detector. The CSA certified product will have the CSA mark on the product. This will have an alarm you can hear to warn you of high carbon monoxide levels in your home.

Make sure to follow the manufacturer's suggestions for:

• Installation
• Testing
• Use
• Replacement

The most important place to install a detector is in hallways, outside of sleeping areas.

Test your detectors regularly. Replace batteries and the detector itself as recommended by the manufacturer. Write on the battery or device to remind yourself when it was installed and when it should be replaced.


Contact your municipal or provincial government office for more information on the use and installation of carbon monoxide detectors in your area. Your local fire department may also be able to assist you.

Keep your home and cottage air clean and free of carbon monoxide by:

• Preventing indoor smoking
• Keeping the door between your house and the garage closed
• Not idling vehicles in the garage, even when the garage door is open

Never use:

1. Gas-powered machines in the garage, such as:

• trimmers
• generators
• lawnmowers
• snowblowers

2. A barbecue or portable fuel-burning camping equipment inside a:

• home
• garage
• vehicle
• camper
• tent

3. Kerosene or oil space heaters and lamps in enclosed areas unless they're specifically designed for indoor use