Sources of Carbon Monoxide

- Charcoal grills generate 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 or during a power outage.

- Gas clothes 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.

- Electric clothes dryers may be responsible for CO in the home when it competes in an enclosed unvented space with a furnace or water heater. This is called "reverse stacking". If a furnace or hot water heater is operating at the same time and there is a lack of fresh air, the clothes dryer will draw air down the chimney and thus prevent the exhaust of CO from the furnace or hot water heater. Rooms that contain both a clothes dryer and furnace or hot water heater should have adequate outside ventilation (i.e. through a window) or slats in the door.

- Furnaces that are 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 that falls into an uncapped chimney. Animals may make their nests in unused chimneys during the summer months. Furnaces should be serviced regularly.

-The household 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 that 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!

- Gas 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 mixes 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 gas 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.

- A fireplace that is properly adjusted with a proper flue and a clean chimney, 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. A competent professional should check flues and chimneys every heating season.

- Before closing a wood burning stove or fireplace flue, ash should be removed from the fireplace or stove and placed outside in a fireproof bucket away from the house. Do not push burning embers or warm ash into a fireplace cleanout (usually found in the back of the fireplace).

- Wood burning stoves turn firewood into ash. The ash that is left behind may be cool on top, but still warm underneath. We have found that this is one of the most common causes of CO in the home when associated with a wood-burning stove.

- 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.

- 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! Be sure not to close the garage door immediately. Allow the CO to escape.

- Natural air inversions have been known to cause elevated CO levels in homes. In 1994, Chicago experienced an air inversion that caused 10 PPM of CO throughout the city setting detectors off throughout the city.