California Air Resources Board

SACRAMENTO – The California Air Resources Board (ARB) today announced its annual winter months' carbon monoxide warning. On average each year, 45 Californians die and many more experience flu-like symptoms from accidental carbon monoxide (CO) poisoning. These are easily preventable tragedies.

"Carbon monoxide is an insidious poison. It's a colorless, odorless gas that lulls a person to complacency," said Alan Lloyd, Chairman of ARB. "It aggressively removes the capacity of blood to transport oxygen, making the person tired and sleepy. If the person is not removed and treated quickly suffocation ensues. An otherwise perfectly healthy person can die in very little time."

Each winter, tragic accidents occur when people are exposed to toxic levels of indoor CO from improperly vented or leaking furnaces, ovens and fireplaces. Burning fuel produces CO and with extended exposure, can have a lethal effect on humans. Even at below-toxic levels, exposure to CO may cause headaches, nausea, fatigue, or heart pain.

CO adheres to red blood cells blocking their ability to carry oxygen and thereby denying the body's sensitive organs, the heart and brain, of an adequate supply. The deprivation of oxygen from the body leaves a person feeling sleepy and tired. If the person is not removed from the area and treated, suffocation may result. Those most susceptible include infants, young children, fetuses, the elderly and patients with pre-existing heart or respiratory conditions.

More than half of CO poisoning deaths are from malfunctioning or improperly vented combustion appliances. Proper use and maintenance of any appliances that produce a flame such as gas furnaces, gas and propane space heaters and small barbecues can prevent exposure to lethal levels of CO. Because of the danger from poor ventilation, kerosene or propane space heaters, charcoal grills and unvented gas logs cannot be used legally indoors in California. Gas ovens should not be used for heating the home.

Care should also be taken not to operate cars or other internal combustion engines in enclosed spaces or attached garages. A third of CO poisoning deaths are the result of accidental exposure from vehicles running in closed garages.

The ARB encourages annual furnace check-ups by a qualified professional and the use of Underwriters Laboratory (UL) approved CO detectors that sound an alarm when dangerous carbon monoxide levels are detected. Some detectors also have warning signals or digital readouts to indicate lower levels of CO.

People who heat with propane appliances, older wall or floor gas furnaces and fireplaces should be especially careful. Fireplaces and wood stoves should be checked for damage and cleaned each year before use. If you are concerned about the safety of your gas furnace or oven, contact your local utility provider or utility-certified heating contractor immediately and request a Combustion Appliance Safety Test. Some utility companies will inspect home equipment for little or no charge.

ARB data show that outdoor CO levels rise throughout California between the months of November and March because of stagnant weather conditions. These outdoor levels of CO have been measured in covered garages and at busy intersections. Rising levels of outdoor CO may generate health complaints in sensitive people. Cars should be tuned and muffler systems checked regularly for exhaust leaks.

Free booklets, "Combustion Pollutants in Your Home" and "Woodburning Handbook" (1.4 MB PDF) is available from ARB by calling (916) 322-8282 or by writing to: Air Resources Board, Indoor Air Quality Program, Research Division, P.O. Box 2815, Sacramento, CA 95812.