Carbon Monoxide Frequently Asked Questions

 
What is carbon monoxide?
Carbon monoxide (CO) is a colorless, practically odorless, and tasteless gas or liquid. It results from incomplete oxidation of carbon in combustion. Burns with a violet flame. Slightly soluble in water; soluble in alcohol and benzene.

What are some some sources of carbon monoxide?
Unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves, and fireplaces; gas stoves; generators and other gasoline powered equipment; automobile exhaust from attached garages; and tobacco smoke. Incomplete oxidation during combustion in gas ranges and unvented gas or kerosene heaters may cause high concentrations of CO in indoor air. Worn or poorly adjusted and maintained combustion devices (e.g., boilers, furnaces) can be significant sources, or if the flue is improperly sized, blocked, disconnected, or is leaking. Auto, truck, or bus exhaust from attached garages, nearby roads, or parking areas can also be a source.

What are the symptoms of carbon monoxide poisoning?
At moderate levels, you or your family can get severe headaches, become dizzy, mentally confused, nauseated, or faint. You can even die if these levels persist for a long time. Low levels can cause shortness of breath, mild nausea, and mild headaches, and may have longer term effects on your health. Since many of these symptoms are similar to those of the flu, food poisoning, or other illnesses, you may not think that CO poisoning could be the cause.

How can carbon monoxide poisoning be prevented?

  • DO have your fuel-burning appliances -- including oil and gas furnaces, gas water heaters, gas ranges and ovens, gas dryers, gas or kerosene space heaters, fireplaces, and wood stoves -- inspected by a trained professional at the beginning of every heating season. Make certain that the flues and chimneys are connected, in good condition, and not blocked.

  • DO choose appliances that vent their fumes to the outside whenever possible, have them properly installed, and maintain them according to manufacturers’ instructions.

  • DO read and follow all of the instructions that accompany any fuel-burning device. If you cannot avoid using an unvented gas or kerosene space heater, carefully follow the cautions that come with the device. Use the proper fuel and keep doors to the rest of the house open. Crack a window to ensure enough air for ventilation and proper fuel-burning.

  • DON’T idle the car in a garage -- even if the garage door to the outside is open. Fumes can build up very quickly in the garage and living area of your home.

  • DON’T use a gas oven to heat your home, even for a short time.

  • DON'T sleep in any room with an unvented gas or kerosene space heater.

  • DON’T use any gasoline-powered engines (mowers, weed trimmers, snow blowers, chain saws, small engines or generators) in enclosed spaces.

  • DON’T ignore symptoms, particularly if more than one person is feeling them. You could lose consciousness and die if you do nothing.


    For more information, read the EPA's "Protecting Your Family and Yourself from Carbon Monoxide Poisoning".

    The above information is provided as a public service by the Environmental Protection Agency for educational purposes.