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Carbon monoxide

What is carbon monoxide?

Carbon monoxide (CO) is a colourless, odourless, toxic gas that interferes with the blood's ability to absorb and transport oxygen. Carbon monoxide causes flu-like symptoms of headaches, drowsiness, nausea and loss of muscle control.
Carbon monoxide is produced when fuels are burned incompletely. Tobacco smoking, idling gasoline-powered vehicles and the burning of oil, coal, wood, charcoal, kerosene, propane or natural gas can all produce carbon monoxide.

Carbon monoxide poisoning

If carbon monoxide is inhaled, it depletes the amount of oxygen in your red blood cells, resulting in specific symptoms. Depending on the amount inhaled and the length of time you have been exposed, symptoms could include the following:

  • chronic headaches
  • nausea
  • drowsiness
  • impaired judgment
  • loss of coordination

Signs that carbon monoxide may be present include:

  • an unidentified chronic odour inside the building
  • condensation on cool, indoor surfaces

Exposure to high amounts of carbon monoxide can lead to unconsciousness, brain damage and death.

The risk of carbon monoxide poisoning from natural gas appliances is extremely low. A very small percentage of carbon monoxide deaths are actually caused by natural gas appliances. Most are caused by fires and car exhaust.

If you suspect carbon monoxide poisoning

  • move the person to fresh air right away
  • call for medical assistance

Carbon monoxide alarm buying tips

Avoid problems with CO

While carbon monoxide alarms are an added safety measure, the best solution is regular appliance maintenance. You can easily reduce the risk of carbon monoxide poisoning by following some simple guidelines:

  • Always have a licensed gas contractor who is registered with the BC Safety Authority, install, inspect and service your natural gas appliances and check vents regularly to make sure that they are not disconnected, blocked or corroded. Licensed contractors are required to maintain a performance bond.
  • Make sure your contractor uses a licensed gas fitter (ask to see the gas fitter license). Also ask if the gas fitter knows how to check heat exchangers —companies that only clean furnaces and ducting may not be qualified to do this kind of inspection.
  • ALWAYS keep furnace fan compartment doors and/or the filter access panel in place.
  • Check that outside air ducts are clear. Be sure to clean bug screens before every heating season.
  • Open the damper of your wood-burning fireplace. If you have an open wood-burning fireplace, open the damper and partially open a window or door at or below the level of the fireplace when the fireplace is in use; close the damper after each fire, but only after the ashes are cool.
  • Remove vehicles from the garage immediately after starting the engine.
    Be sure that all vent hoods and pipes from fuel-burning equipment are in place and secure.
  • Ensure that an external vent is used for all gas appliances that are designed to be vented.
  • Never operate a barbecue, camp stove or lantern in an enclosed space.
  • Buy equipment that bears the seal of an approved certification agency such as the Canadian Gas Association or the Canadian Standards Association.
  • Keep the area around your furnace clear for proper air circulation.
  • Install a carbon monoxide alarm.

If you suspect the presence of carbon monoxide in your home

  • Open all doors and windows.
  • Get fresh air immediately outside.
  • Seek medical attention if needed.
  • Turn off any appliances that you suspect are faulty.
  • Have a qualified gas contractor inspect your appliances or contact FortisBC.

Energy upgrades and CO problems

Energy conservation saves energy and money — as you caulk and weatherproof, smaller amounts of cold, fresh air enter the house and less heat loss occurs. But too much weatherproofing can be bad for indoor air quality and appliance and vent operation.

If you are planning to do a lot of caulking, draftproofing or insulating, or add a high-volume kitchen or bathroom exhaust fan, talk to a qualified gas or ventilation contractor first.


 Read more about carbon monoxide


What are the properties of carbon monoxide? The safety measures?
The dangers?