Carbon Monoxide in Homes and Workshops

DANA O. PORTER P.E.
Agricultural Engineering Specialis
t
WVU Extension Service

Note: this information is adapted from "Carbon Monoxide in the Home," an instructional module from the Healthy Indoor Air for America's Homes handbook. The handbook was developed through a partnership of the United States Environmental Protection Agency, the United States Department of Agriculture, and the Montana State University Cooperative Extension Service.

The "Carbon Monoxide in the Home" module was prepared by Joseph T. Ponessa, Ph.D., associate professor/housing and energy specialist, of Rutgers Cooperative Extension Service.

What is Carbon Monoxide?

Carbon monoxide (CO) is a toxic gas produced when any carbon-based fuel is burned. It is colorless and odorless; therefore, you may not be aware of its presence. CO can collect in enclosed spaces (including homes, offices, and workshops) without the awareness of the occupants.

According to the National Safety Council and the Center for Disease Control, approximately 500 to 1000 people are killed in the home each year by CO. Nearly 5,000 people in the United States are treated in emergency rooms for carbon monoxide poisoning. It is believed that many other people are made ill by exposure to elevated CO levels, but are either misdiagnosed or untreated.

What are some common sources of carbon monoxide in the home or workshop?

Most carbon monoxide produced in homes comes from combustion of fuel for heating and cooking. CO may accumulate in the home when a blocked chimney, broken chimney flue, or damaged furnace heat exchanger allows gases to enter the home. It can also enter the home from the garage when an automobile, lawn mower, or other engine is in operation. Backdrafting chimneys and flues (common when ventilation fans are used in tightly sealed homes) may allow combustion gases, including carbon monoxide, to enter the home.

Gas stoves and ranges can produce CO, which can present problems if the appliances are used for prolonged periods or if they are not operated properly. Gas ranges are not intended to be used to heat the home. Some other common sources of carbon monoxide include unvented fuel burning space heaters and indoor use of charcoal for heating or cooking. (Note: charcoal should NEVER be burned indoors.)

What are symptoms of carbon monoxide poisoning?

Carbon monoxide bonds to hemoglobin in red blood cells, interfering with the capacity of the hemoglobin to transport oxygen throughout the body. Common symptoms of CO poisoning include nausea, dizziness, weakness, muscle aches, vomiting, and a general weakness or sleepiness. Because the symptoms may resemble the "flu" or food poisoning, carbon monoxide exposure may be mistaken for these common illnesses. Carbon monoxide usually affects all occupants of a household at the same time (which may help distinguish carbon monoxide poisoning from the flu.) Higher dosages of CO can cause impaired judgment, confusion, paralysis, coma, and death.

Victims of CO poisoning must be removed from exposure as quickly as possible. They require prompt medical attention. Symptoms may not disappear immediately after the victim is removed from exposure to the gas; in some cases symptoms may recur days or weeks later.

How can you protect yourself from carbon monoxide poisoning?

Regular inspection and maintenance of all fuel-burning appliances (stoves, furnaces, water heaters, dryers, etc.) should be conducted by a qualified technician. Metal flues and heat exchangers should be inspected for signs of rust or cracking. Follow recommendations in owners' manuals to ensure proper use of all appliances. Gas ranges, ovens, and clothes dryers are not intended to be used to heat the home.

Do not use "outdoor" appliances (such as barbeque grills or construction space heaters) indoors. Garages and workshops are "indoors"; they are enclosed spaces in which combustion gases may accumulate.

Carbon monoxide detectors carrying the Underwriters Laboratories (UL) listing are recommended. CO detectors meeting UL standard 2034 can detect long-term, high-level CO concentrations and short-term, low-level CO concentrations. CO detectors should be installed on a wall or ceiling near a sleeping area.

For More Information

For more information about carbon monoxide or other indoor air pollutants, please contact the WVU Cooperative Extension Service, the Healthy Indoor Air for America's Homes handbook, or the following references.

U.S. Consumer Product Safety Commision. Cabon Monoxide Fact Sheet, Publication #466. Washington, DC 20207.

US EPA. 1996. Protect Your Family and Yourself from Carbon Monoxide Poisoning. United States Environmental Protection Agency Indoor Environments Division.