Carbon Monoxide: Just the Facts

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What is carbon monoxide?

Carbon monoxide or CO, is a colorless, odorless, gas which is slightly lighter than air. It is produced whenever something is burned incompletely, or in a closed environment. It is toxic to all animals. It is the most commonly inhaled poisonous substance.

How can it effect my living space?

Charcoal grill: the smoke from burning charcoal contains high levels of CO. Each year several people die from exposure to burning charcoal in enclosed spaces. This happens when someone uses charcoal, incorrectly, as a space heater or brings the charcoal grill inside when the barbecue is rained out.

Clothes dryer: gas dryers are a potential source of CO when their exhaust hose becomes disconnected or when someone uses the heated exhaust to warm a living area. A dryer may shift position during its function thereby loosening the exhaust hose resulting in venting of toxic gases into the air.

Furnace: an incorrectly adjusted or vented furnace may spread deadly CO within the living space. The chimney to which a furnace is vented may become obstructed by debris which falls into an uncapped chimney. Furnaces should be serviced regularly.

Water heater: every water heater should be vented into a chimney. There is usually a space between the bottom of the tube leading to the chimney and the heater. This exhaust must be properly lined up and the exhaust pipe and chimney kept clear to insure that all toxic gases are vented out and do not escape into the air.

Space heaters: space heaters which burn any fuel (except electric) are potential sources of CO and should be vented into the outside air. No unvented space heater should ever be used inside!

Stoves: stoves are considered exempt equipment, meaning, they do not have to be vented. This implies that they are not a risk, but they are. The exhaust from stoves mix with the air in the living space and is thus diluted. When a stove is used to heat the environment, excess quantity of CO may leak out and pose a threat. A stove or a cooktop should be used to cook and never to heat the room. When used, a window should be opened to provide fresh air to help dilute the potentially toxic gases.

Fireplace: properly adjusted with a proper flue and a clean chimney, a fireplace is a thing of beauty. If the chimney is blocked by debris or if the flue does not produce enough of an updraft to pull toxic CO up and out, then CO may leech into the living space posing a serious health risk. Flues and chimneys should be checked every heating season by a competent professional.

Gas-Powered Equipment: lawnmowers, leaf blowers, and other small gasoline powered equipment produce CO in use. They should never be used inside. These devices can be repaired inside, but should be tested by starting them ONLY outside.

Automobile: winter startup of cars in a closed garage to "warm the engine" is a potential disaster. Each year there are reports of illness and deaths from such a practice. It is not even good for the car. The garage door should be opened BEFORE starting the car. The motor should be off anytime the car is in the garage!

Pets: miners used to take canaries with them into mines as poison gas detectors. If the birds became sick or died while in the mines, the miners knew that poison gas was present, and escaped unharmed. Thus, the canary became the first poison gas (CO) detector.
Birds breathe faster than man and have faster metabolic rates thus show effects earlier than we do. If a pet suddenly becomes ill or dies, think of the possibility of a toxic exposure and have the house checked.

What precautions can be taken against the effects of CO?

CO detectors: provide protection from exposure to potentially lethal concentrations of CO. Every home should have CO detectors installed. But, only those meeting UL standard 2034 or IAS 696 should be used. One should be located near every potential source of CO and in the living areas. They should be checked regularly for functionality.

©1999, NJ Poison Information & Education System.