Carbon Monoxide Safety

Carbon monoxide (CO) is a serious household danger and one that many people don’t fully understand. It is the #1 cause of unintentional poisoning deaths in North America, with thousands of injuries and hundreds of deaths being reported every year. If you have an attached garage on your home, a wood or gas fireplace, or any gas appliances, then you need to be informed and prepared.

What is CO?

Carbon monoxide is an odorless, colorless gas that is found in combustion fumes and can cause sudden illness and death. It can come from a variety of sources including cars and trucks, small gasoline engines, stoves, lanterns, burning charcoal or wood, gas appliances and heating systems. The toxic fumes from these fuel sources can build-up in enclosed or semi-enclosed spaces if the source is not operated properly, has inadequate venting or is poorly maintained.

Recognizing The Signs

Carbon monoxide prevents your bloodstream from absorbing the oxygen you breathe in. It also poisons your red blood cells, preventing them from carrying oxygen. Without a constant supply of oxygen, your body's tissues and organs (in particular your brain) will stop functioning properly. Carbon monoxide poisoning can be especially dangerous for people who are sleeping or intoxicated, as the fumes may be fatal before anyone realizes there's a problem.

Signs and symptoms of carbon monoxide poisoning may include:

  • Dull headache
  • Weakness
  • Dizziness
  • Nausea
  • Vomiting
  • Shortness of breath
  • Confusion
  • Blurred vision
  • Loss of consciousness

If you are exposed to low concentrations of the gas, you might experience flu-like symptoms such as weakness, headache, dizziness and shortness of breath. At higher concentrations, the headache will likely become more severe and you may have trouble with your vision and hearing. One of the major symptoms at this level is confusion, and it can leave you unable to understand that your life is in danger. At extreme concentrations, you will slip into a coma within a few minutes and die.


Carbon monoxide detectors are as important to home safety as smoke detectors are, and many regions are now making their use mandatory. It is recommended that each home have at least one detector, and preferably one on each level of the building. Target locations around heaters and other equipment, in addition to outside the sleeping areas of your home.

A carbon monoxide detector is designed to sound an alarm if it senses dangerously high CO levels in a short period of time. There are three different types of detectors on the market: plug-in, battery-operated and hardwired (connected to the home's wiring system) and these come in a variety of models. There are also monitored services available through home security systems.

Test your system regularly, and be sure to replace primary and back-up batteries twice per year.

Although all home detectors use an audible alarm signal as the primary indicator, some versions also offer a digital readout of the CO concentration. These models have the advantage of showing the current reading to assess hazard if the alarm sounds, plus peak levels from memory. They may also aid emergency responders in evaluating the level of past or ongoing exposure.

Be aware that CO detectors have a finite lifespan and that the sensors wear out within five to seven years. The newest detectors come equipped with a convenient end-of-life timer.

Maintenance & Prevention

Here are some tips to help prevent a CO incident in your home:

Have your home heating system, water heater and any other gas, oil, wood or coal burning appliances serviced by a qualified technician every year.

Fireplace chimneys and furnace vent pipes should be cleaned annually.

All furnaces, fireplaces, stoves and gas-burning appliances must be properly vented to the outdoors. This helps them to burn fuel properly and prevents the build-up of CO.

Don't try fixing furnaces or fuel-burning appliances yourself, unless you've been trained and certified to do so.

Only purchase gas equipment that carries the seal of a national testing agency, such as the CSA.

Never patch a vent pipe with tape or other material. If damaged, the pipe section should be replaced and jointed properly by a trained professional.

Never burn charcoal or run a gas barbecue indoors or in an enclosed area.

Do not use portable flameless chemical heaters (catalytic) indoors. Although these heaters don't have a flame, they burn gas and can cause CO to build up inside your home.

Never leave a car idling in a garage. The exhaust, which contains CO, can penetrate walls and also get into your home through doorways or vents.

Emergency Procedures & First Aid

The threat of potential harm due to CO poisoning must be taken very seriously, as it can have devastating effects on those that may be exposed.

Never ignore your CO detector if it goes off. Call 911 and get out of the house immediately. The same would apply if you smell natural gas.

As you would with fire safety, be sure that you have a family emergency procedure in-place.

Don’t ever take chances. At high concentrations, CO poisoning can kill within minutes.

At the first sign of any of the symptoms of carbon monoxide poisoning, you need to get out into the fresh air right away. It also helps to open a few windows on your way out if you are able.

Note that all people and animals are at risk for CO poisoning. Pregnant women, infants, the elderly or people with chronic heart disease, anemia, or respiratory problems are more susceptible to its effects.

If you suspect you've been exposed to carbon monoxide, call for emergency assistance or get someone to take you to a hospital. The application of oxygen is usually the first step in treatment, and in some cases, the use of a hyperbaric oxygen chamber may be necessary to help normalize the amount of gas in the body.

If you enter a home and find someone unconscious due to a CO leak, move the person outside. The injured person should be kept lying down and warm until emergency personnel arrive.

If the person has stopped breathing but there is a pulse, begin mouth-to-mouth respiration and continue until the patient begins breathing or help arrives.

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