Affordable carbon monoxide detectors have been available since 1993. Manufacturers offer a wide range of sensors, alarms, detectors, and controls for specific applications. Hundreds of people die annually as a result of accidental carbon monoxide poisoning in North America. Knowing the facts can reduce the number of these accidents and save lives. Carbon monoxide detectors send out an alarm signal to homeowners when carbon monoxide levels reach dangerous levels.

What is Carbon Monoxide?

Carbon monoxide is a colourless, odourless, tasteless and toxic gas. It is produced by incomplete combustion of fossil fuels such as coal, natural gas or propane, charcoal, wood and gasoline. Any fuel-burning appliance, vehicle, tool or other device has the potential to produce dangerous levels of carbon monoxide gas. In the home, carbon monoxide-producing devices include: fuel fired furnaces, gas water heaters, space heaters, gas or wood stoves and gas dryers. The problem of malfunctioning equipment is often aggravated by improvements in building construction which limit the amount of fresh air flowing in homes and other structures.


Carbon monoxide poisoning associated with using fuel-burning appliances kills more than 200 people each year and sends about 10,000 to hospital emergency rooms for  treatment.  High concentrations of carbon monoxide can kill in less than five minutes. The Center for Disease Control states that carbon monoxide kills more people than any other cause in the home.

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According to the Consumer Product  Safety Commission, the home heating system is the most common cause. The first symptoms of carbon monoxide poisoning are often mistaken for common illnesses like the flu. Victims of low level carbon monoxide poisoning often experience mild headaches, shortage  of breath, nausea, drowsiness and dizzy spells. At higher levels, carbon  monoxide  causes  severe  headaches,  mental   confusion, impairment of vision or hearing, vomiting, fatigue, loss of consciousness, and coma. Severe carbon monoxide poisoning can cause an irregular heartbeat, amnesia, brain damage, coma, and eventually death. High risk groups include fetuses, children, the elderly and those with heart and lung disorders. When inhaled, carbon monoxide combines with hemoglobin in the red blood cells to form substances that work to decrease oxygen levels and eventually asphyxiate the victim.  Many people are unaware that they are being poisoned until it is too late.


There are hundreds of different types and brands of carbon monoxide detectors on the market today.  They can most easily be characterized by whether they operate on household current or batteries.  The most important component of either is the  type of sensor they house. Hard-wired carbon monoxide detectors using household current typically employ some type  of solid-state sensor which purges itself and resamples for carbon monoxide on a periodic basis. These detectors give a continuous display of carbon monoxide levels and require no maintenance during the life of the product.   They generally have a life expectancy of five to ten years.

Detectors powered by batteries typically use a passive sensor which reacts to the prolonged exposure to carbon monoxide gas. Prices range from around $30.00 for a battery operated model up to $100.00 for more elaborate models that may detect for both smoke and carbon monoxide. Battery operated models are only as reliable as the battery and, like smoke detectors, should be tested regularly and batteries should be replaced annually. The cheaper detectors generally carry a one year warranty and provide minimal protection. More effective detectors with 9 volt batteries have a life expectancy of about 6 years and are often guaranteed for that length of time. Some carbon monoxide detectors sound an alarm similar to a smoke detector when carbon monoxide levels become dangerous. This is often accompanied by a flashing light.

Others have only a flashing light or a digital read-out.  Regardless of the type of sensor used all detectors sold on the market today should conform to minimum sensitivity and alarm characteristics. These standards are defined and verified by the Underwriters Laboratory in the U.S.A. and by the Canadian Standards Association (C.S.A) and the Canadian Fire Association (C.F.A). in Canada. These standards went into effect in 1995. Under no circumstance should one purchase a detector that is not U.L., C.F.A. or C.S.A. approved. This approval is clearly marked on any carbon monoxide detector packaging.


Carbon monoxide detectors are mandatory in new homes and must be hard-wired into the electrical system. According to the Ontario Building Code, they must be installed inside of each bedroom, in the garage and at the top of each staircase. In older homes where hard-wiring may be problematic, battery operated or plug-in models are recommended in the same areas. For maximum security, carbon monoxide detectors should be installed in each room where there is a source of combustion such as locations of fireplaces, gas appliances, etc. Ceiling mounted detectors should be installed in the center of the room. Wall mounted detectors should be installed at least three feet from the door. Avoid installing carbon monoxide detectors near open windows or doors or in damp or very humid areas such as bathrooms as these locations can delay the alarm. Do not install them behind furniture or drapes or in closets or areas that block air flow to the alarm.


  1. Install the carbon monoxide detector according to the manufacturer’s instructions. This will ensure that it works.  As with all detectors, test your carbon monoxide detector regularly according to the manual. Also replace your carbon detector according  to the manual  as  they  tend to wear out in time.
  2. Have furnace, hot water heaters, vents, chimneys and space heaters inspected annually by a qualified service technician.
  3. Have your vent pipe and chimney flues inspected and cleaned once a year by a certified professional. Birds’ nests, twigs and old mortar in chimneys can block proper ventilation and lead to buildup of carbon monoxide gas in the home.
  4. Make regular visual inspections of all fuel burning equipment including gas water heaters, space heaters, gas ranges and gas dryers. The colour of the pilot flame should be blue. A yellow flame means the fuel is not burning completely and hazardous levels of carbon monoxide may be present.
  5. Investigate appliances that emit unusual odours or sounds.
  6. Never heat with a gas range or oven.
  7. Never leave a car running in a garage.
  8. Never use an unvented gas or kerosene space heater in a room where a person is sleeping.
  9. Be aware of the symptoms of carbon monoxide and note if others (including pets) demonstrate them. Also note if you feel better when you leave the building for a day and feel worse after you return.