Carbon Monoxide

The presence of carbon monoxide (CO) in our homes is dangerous. So, how can you protect your family from carbon monoxide? How do you choose the right CO detector for your home? The first step is to make sure that carbon monoxide never enters your home. The second step is to install at least one CO detector in your home.

This About Your House answers often-asked questions about carbon monoxide to help you make the right decision to make your home safe.

What Is Carbon Monoxide?

Carbon monoxide (CO) is a colourless and odourless gas. Because you can't see, taste or smell it, it can affect you or your family before you even know it's there. Even at low levels of exposure, carbon monoxide can cause serious health problems. CO is harmful because it will rapidly accumulate in the blood, depleting the ability of blood to carry oxygen. ( Exposure Guidelines for Residential Indoor Air Quality, Health Canada, 1989).

Where Does Carbon Monoxide Come From?

Carbon monoxide is a common by-product of the combustion (burning) of fossil fuels. Most fuel-burning equipment (natural gas, propane and oil), if properly installed and maintained, produces little CO. The by-products of combustion are usually safely vented to the outside. However, if anything disrupts the venting process (such as a bird's nest in the chimney) or results in a shortage of oxygen to the burner, CO production can quickly rise to dangerous levels.

The burning of wood, kerosene, coal and charcoal produce CO. Gasoline engines produce CO. CO production is at a maximum during the startup of a cold engine. Starting, then idling, your car or gas mower in the garage can be dangerous.The fumes that contain CO can enter a home through connecting walls or doorways and can quickly rise to dangerous levels.

How Can I Eliminate Sources of CO in My Home?

The most important step you can take to eliminate the possibility of CO poisoning is to ensure that CO never has an opportunity to enter your home. This is your first line of defence. Review this list to minimize the risk of CO in your home.

•  Have a qualified technician inspect and clean fuel-burning appliances yearly, before the cold weather sets in, to ensure they are in good working order.

•  Have a qualified technician inspect chimneys and vents yearly for cracks, blockages (e.g., bird's nests, twigs, old mortar), corrosion or holes.

•  Check fireplaces for closed or blocked flues.

•  Check with a qualified technician before enclosing heating and hot water equipment in a smaller room, to ensure there is adequate air for proper combustion.

•  If you have a powerful kitchen exhaust fan or downdraft cooktop, have a qualified technician check that its operation does not pull fumes back down the chimney.

•  Never use propane or natural gas stove tops or ovens to heat your home.

•  Never start a vehicle in a closed garage; open the garage doors first. Pull the car out immediately onto the driveway, then close the garage door to prevent exhaust fumes from being drawn into the house.

•  Do not use a remote automobile starter when the car is in the garage; even if the garage doors are open.

•  Never operate propane, natural gas or charcoal barbecue grills indoors or in an attached garage.

•  Avoid the use of a kerosene space heater indoors or in a garage. If its use is unavoidable provide combustion air by opening a window while operating. Refuel outside after the unit has cooled.

•  Never run a lawnmower, snowblower, or any gasoline-powered tool such as a whipper-snipper or pressure washer inside a garage or house.

•  The use of fossil fuels for refrigeration, cooking, heat, and light inside tents, trailers, and motorhomes can be very dangerous. Be sure that all equipment is properly vented to the outside and use electric or battery-powered equipment where possible.

•  Regularly clean the clothes dryer ductwork and outside vent cover for blockages such as lint, snow, or overgrown outdoor plants.

•  Reduce or eliminate the use of fondue heaters indoors.

•  If you live close to a road with heavy traffic, outdoor carbon monoxide levels can affect your indoor air quality, especially during rush hour. Such levels should not set off a CO alarm, but slightly elevated CO levels might be observable on some types of CO detectors with a digital display.

Carbon Monoxide Detectors: Is One Really Necessary?

If you take the actions above, you greatly reduce your risk of CO poisoning. But unanticipated dangerous incidents may still occur despite your best efforts to avoid CO. The installation of at least one CO detector in your home is a good safety precaution and in some municipalities it is the law. A detector might be your second line of defence, but it is necessary. You should have one in your home today.