Carbon Monoxide

Policy April 02, 2008


Carbon monoxide (CO) is a poisonous gas that is odorless, colorless, tasteless and nonirritating. CO results from the incomplete combustion of organic materials such as gasoline, kerosene, natural gas, propane, coal, wood, charcoal, diesel fuel, heating oil and almost any other combustible material, such as tobacco and paper. When inhaled, CO combines with the body s blood and prevents it from absorbing oxygen. A person exposed to high levels of CO may complain of dizziness, headache, nausea, sleepiness and similar symptoms. In extreme cases, CO poisoning can be fatal. Stationary vehicles (such as cars idling in garages) are the largest source of unintentional, nonfire-related fatalities, according to the U.S. Consumer Product Safety Commission (CPSC).

According to statistics published by CPSC in 2005, unintentional, nonfire carbon monoxide (CO) fatalities due to natural gas appliances have continued to decline over the past 50 years. Average annual CO fatalities involving natural gas heating systems declined from 35 per year during 1994-1998 to 27 per year during 1999-2002, a 23 percent decline. Fatalities involving gas water heaters declined from seven per year for 1994-1998 to one per year for 1999-2002. Fatalities involving gas ranges and ovens remained relatively unchanged at seven per year for 1994-1998 to eight per year for 1999-2002. Overall, fatalities associated with all fuel-burning consumer appliances declined from 200 per year to 141 per year over these time periods, a 30 percent decline. While CPSC has not published statistics for more recent years, AGA's analysis of data records used for these reports by CPSC indicates that the overall trend of declining fatalities continued for 2003 and 2004.

These declines are consistent with the historical trend for declines in CO fatalities since World War II and appear to be the result of replacement of older combustion equipment, newer housing stock, and increased awareness of combustion appliance safety. The primary cause of CO problems in natural gas appliances is space-heating equipment, in which vents and chimneys are not properly installed or maintained. Other causes include misuse of appliances, such as improper use of ranges and ovens for space heating.

AGA Viewpoint

Education is the best way to prevent CO poisoning in the home. Utilities recommend that consumers arrange for a regular inspection of home heating systems and other natural gas equipment by qualified professionals. Because stationary vehicles are the largest source of CO poisoning, consumers should not idle cars in garages.

AGA Contact: Ted Williams, (202) 824-7313,