Carbon Monoxide

Carbon Monoxide (CO) is an odorless, colorless gas that is a by-product of the incomplete burning of fuels (1). Carbon monoxide is produced from cigarette smoke, from human and animal respiration, and when fossil fuels are burned (2). Industrial processes also contribute to CO pollution levels, but the principal source of CO pollution in most large urban areas is the automobile. It adversely affects human health at only a few parts per million and causes death at 250 parts per million (250 ppm)(2). The Centers for Disease Control estimates that each year, 1,500 Americans die from carbon monoxide (CO) poisoning. About 900 of these deaths occur in homes and are preventable (3).

Carbon Monoxide is inhaled and enters the blood stream where it binds chemically to hemoglobin. Hemoglobin carries oxygen to the cells, but when CO binds to it, hemoglobin is unable to bind with oxygen, thereby reducing the amount of oxygen delivered to all tissues of the body. The percentage of hemoglobin inactivated by CO depends on the amount of air breathed, the concentration of CO in air, and length of exposure(1). The initial symptoms of CO poisoning are similar to the flu. They include fatigue, dizziness, irregular breathing, cherry red lips, nausea, headache, paleness, and coughing.

There are many sources of CO around the home. These sources include poorly installed and maintained heating systems, charcoal grills and hibachi pots that are used indoors, gas kitchen stoves that are used for heating, water heaters, and automobile exhaust (3). Carbon monoxide can be easily reduced from all of these sources and CO poisoning is easily preventable. Here are some precautions that can be taken (3):

• Do not use the oven of a gas kitchen stove for heating.
• Avoid use of charcoal grills and hibachi pots indoors for cooking or to eliminate the chill in a room or closed garage. They give off CO fumes, even when no glow is visible in the coals.
• Make sure that fuel-burning equipment is installed by qualified, licensed or trained persons. Such installation should conform to all local codes and standards.
• Provide a constant supply of fresh air for safe burning of fuels. This can be done by leaving a window slightly open.
• Provide for the positive venting of combustion gases to the outside. This can be accomplished by vent or flue pipes, exhaust systems, etc.
• Heating systems, water heaters, kitchen stoves and other fuel-burning devices should be thoroughly inspected and maintained at least once a year by a qualified person (professional service representative).
• Never convert a particular unit from one type of fuel to another without having necessary burner changes and adjustments made by a trained and experienced person. (Example: Changing from liquefied petroleum fuel [L.P.] to natural gas.)
• Never run any internal combustion engine equipment, such as a power lawnmower or snowblower, in an enclosed space such as a closed garage. Always start it outside or with the door open. Automobile exhaust systems also can be hazardous, especially in the winter when cars ale operated with the windows closed. A noisy engine may indicate a faulty exhaust system. Check the system and have it repaired if there is a blown-out gasket, loose exhaust manifold, leaking exhaust pipe connections or holes in the muffler. Be sure the doors are open in the garage or enclosure where an automobile motor is running(3).

The following are some very informative external links that pertain to Carbon Monoxide:

• Carbon Monoxide Headquarters
• Facts About Carbon Monoxide
• American Lung Association Fact Sheet - Carbon Monoxide
• NJPIES Carbon Monoxide Learning Site
• NIOSH Criteria for a Recommended Standard: Occupational Exposure to Carbon Monoxide
• NIOSH ALERT Preventing Carbon Monoxide Poisoning from Small Gasoline-Powered Engines and Tools
• NIOSH Update Safeguards Against Carbon Monoxide Risk from Small Gasoline-Powered Engines

References

1. Measuring Air Quality: The Pollutant Standards Index; Office of Air Quality Planning and Standards, US EPA; EPA 451/K-94-001; February 1994. URL: http://air.linn.ea.us/ambientair/carbon_monoxide.html

2. Greiner, T. Indoor Air Quality: Carbon Monoxide and Carbon Dioxide, ISU Extension Pub # AEN-125, Iowa State University. December 1991. URL: http://www.ae.iastate.edu/housing/aen125.txt

3. Linn, R. Carbon Monoxide and You. MT 8315, Montana State University Extension. February 1983. URL: http://www.cdc.gov/niosh/nasd/docs2/as60300.html

This Page prepared by B.T. Johnson, November 1997 UCD EXTOXNET FAQ Team.