Carbon Monoxide Awareness Week

November 1-7 is Carbon Monoxide Awareness Week. Fire and emergency officials, as well as municipal, provincial and federal governments across the country are asking Canadians to brush up on our Carbon Monoxide safety and prevention practices.

What is Carbon Monoxide?

Carbon monoxide (CO) is an invisible, odourless and colourless toxic gas produced by the burning of common fuels – for example, gasoline, diesel, coal, natural gas, propane, heating oil, kerosene or other combustible materials like wood, cloth or paper.

Common sources include things like:

  1. Gas appliances (such as water heaters, ovens and dryers)
  2. Fireplaces or clogged chimney flues
  3. Gas space heaters
  4. Generators
  5. Wood and gas stoves
  6. Furnaces
  7. Vehicle exhaust
  8. Tobacco and cannabis smoke
  9. Charcoal grills

When cars, trucks, or other engines are left running in enclosed spaces, such as garages, carbon monoxide can build up and leak back into the house. Even sitting in an idling car in an open garage or idling a motorboat or jet ski at slow speed can be dangerous.

Dangerous levels of carbon monoxide can also build up in homes or other buildings when fuel-burning appliances or heating systems are not installed, maintained or used properly.

What Makes it So Dangerous?

When carbon monoxide is inhaled, it replaces the oxygen in your blood. This can become deadly within minutes, but it can also cause damage to your organs that could have lasting health impacts.

Preventing carbon monoxide exposure is the most important thing you can to do reduce your risk, but it is also important to know the signs and symptoms of carbon monoxide poisoning and what to do if you have the symptoms.

Signs & Symptoms of Carbon Monoxide Poisoning

CO Blood Concentration

Early symptoms of carbon monoxide poisoning include:

  1. Headache
  2. Dizziness
  3. Fatigue
  4. Nausea

As carbon monoxide builds up in your blood, symptoms get worse and may include:

  1. Confusion and drowsiness
  2. Fast breathing, fast heartbeat, or chest pain
  3. Vision problems
  4. Seizures or convulsions
  5. Abdominal pain, diarrhea, weakness or other flu-like symptoms

If you have symptoms that you think could be caused by carbon monoxide poisoning, leave the area right away, and call 911 or go to the emergency room. If you keep breathing the fumes, you may pass out and die.


Because many of the symptom are similar to those caused by the flu or other carbon monoxide common illnesses, it can be hard to know if you have carbon monoxide poisoning. You can help your doctor determine the cause by noting any symptoms in your housemates, carbon monoxide -workers or even pets.

Long Term Exposure

Carbon monoxide poisoning can occur suddenly or over a long period of time. Prolonged exposure, even at very low levels, can cause severe heart problems, brain damage or other long-term health impacts.

See a doctor if:

  1. You often are short of breath and have mild nausea and headaches when you are indoors.
  2. You feel better when you leave the building and worse when you return.
  3. Other people you work or live with have the same symptoms you do.

In the video below, a survivor of long-term CO exposure talks about the signs and symptoms she originally brushed off, how she eventually figured out what was happening and her advice for how you can protect yourself and your loved ones from this silent killer.

Preventing Carbon Monoxide Poisoning

There are some easy steps you can take to reduce your risk.