California Air Resources Board

SACRAMENTO– On average, 45 Californians die each year from accidental carbon monoxide (CO) poisoning and many more experience flu-like symptoms from moderate CO exposure, according to Air Resources Board (ARB) and Department of Health Services data.

     ARB Chairman Alan C. Lloyd said, "Carbon monoxide poisoning is a serious health threat, but preventive steps such as basic maintenance of indoor heating equipment, can possibly avert tragedy later."

    Carbon monoxide is a colorless, odorless gas that is produced by burning fuel.  Each winter, tragic accidents occur when people are exposed to lethal levels of indoor CO from improperly vented or leaking furnaces, ovens and fireplaces.  Even at below-lethal levels, exposure to CO may cause headaches, nausea, fatigue, or heart pain.

    Carbon monoxide causes toxic effects in humans by replacing oxygen in red blood cells, thereby depriving heart and brain tissue of enough oxygen to function properly.  Extended exposure to high levels of CO can result in permanent heart or brain damage and even death.  Those most susceptible include infants, young children, fetuses, the elderly, and patients with heart or respiratory diseases.

    More than half of CO poisoning deaths are from malfunctioning or improperly vented combustion appliances such as gas furnaces, gas and propane space heaters and small barbecues.  Gas ovens should not be used for heating the home.

    CO poisoning can be prevented by proper use, maintenance and venting of any appliances that produce a flame.  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.

    Care should also be taken not to operate car engines 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.

    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.

    The ARB also 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.

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

    Free booklets, "Combustion Pollutants in Your Home" and 'Woodburning Handbook" is available from ARB by calling (916) 322-8282, by visiting our Web site at www.arb.ca.gov/research/indoor/combustf.htm, or by writing to: Air Resources Board, Indoor Air Quality Program, Research Division, P.O. Box 2815, Sacramento, CA 95812.