A colourless, odourless, and highly toxic gas, carbon monoxide (CO) is produced by the incomplete combustion of carbon-based fuels, sometimes called fossil fuels, such as coal, wood, natural gas and oil. In fact, this invisible killer has been around as long as there has been fire.

Detecting CO was a technical challenge. But, just a few years ago, modern electronics delivered an easy, cost-effective solution. Consumers can now purchase CO detectors at many retail outlets, take them home and install them as easily as smoke detectors.

Installation location is critical. Placement should be in the sleeping area. The recommendation is to buy two detectors, and install the second one in the probable source area of carbon monoxide gas.

CO is measured as a percentage and referred to as parts per million, or ppm. While exposure to low levels will make you slightly sick — like having the flu — as the ppm increases, so do the symptoms. Heavy exposure can lead to unconsciousness and death.

With about the same density as the air we breathe, CO competes with oxygen in the air and the blood stream. The human body absorbs CO about 200 times faster than oxygen. As gruesome as it may sound, a person exposed to this poisonous gas is suffocating internally.

There are many sources of CO in our dwellings, and the trend towards energy conservation has created yet another, the air exchange in older buildings has virtually been eliminated. The most critical time is at night, when the house is

closed up and people are asleep. That’s because, if there is any CO present in the building, sleepers just go into a deeper sleep. This is the reason for installing a detector in or near bedrooms. Should a detector be placed near a furnace room, the less likely it will be heard by a sleeping family.

While people are becoming more aware of CO detectors, less than 10 percent of homes have a unit installed. Market penetration is at about the level of smoke detectors 15 years ago. CO detectors come in various shapes and designs, with prices ranging from $40 to over $100. Installation methods can be as simple as plugging a unit into a wall receptacle. Detectors can also be interfaced with a security panel.