Carbon monoxide is an odorless, colorless and toxic gas. Because it is impossible to see, taste or smell the toxic fumes, CO can kill you before you are aware it is in your home. At lower levels of exposure, CO causes mild effects that are often mistaken for the flu. These symptoms include headaches, dizziness, disorientation, nausea and fatigue. The effects of CO exposure can vary greatly from person to person depending on age, overall health and the concentration and length of exposure.

If you think you are experiencing symptoms of CO exposure go outside or to a well ventilated area with plenty of fresh air. If symptoms worsen or if you pass out seek immediate attention from a health care provider.

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.

Health Effects Associated with Carbon Monoxide

At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination; headaches; dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after leaving home. Fatal at very high concentrations. Acute effects are due to the formation of carboxyhemoglobin in the blood, which inhibits oxygen intake. At moderate concentrations, angina, impaired vision, and reduced brain function may result. At higher concentrations, CO exposure can be fatal.

Steps to Reduce Exposure to Carbon Monoxide

It is most important to be sure combustion equipment is maintained and properly adjusted. Vehicular use should be carefully managed adjacent to buildings and in vocational programs. Additional ventilation can be used as a temporary measure when high levels of CO are expected for short periods of time.

  • Keep gas appliances properly adjusted.
  • Consider purchasing a vented space heater when replacing an unvented one.
  • Use proper fuel in kerosene space heaters.
  • Install and use an exhaust fan vented to outdoors over gas stoves.
  • Open flues when fireplaces are in use.
  • Choose properly sized wood stoves that are certified to meet EPA emission standards. Make certain that doors on all wood stoves fit tightly.
  • Have a trained professional inspect, clean, and tune-up central heating system (furnaces, flues, and chimneys) annually. Repair any leaks promptly.
  • Do not idle the car inside garage.

Carbon Monoxide Detectors

The U.S. Consumer Product Safety Commission (CPSC) recommends that every home should have a CO alarm. CPSC also urges consumers to have a professional inspection of all fuel- burning appliances -- including furnaces, stoves, fireplaces, clothes dryers, water heaters, and space heaters -- to detect deadly carbon monoxide leaks. CPSC recommends that every home should have at least one CO alarm that meets the requirements of the most recent Underwriters Laboratories (UL) 2034 standard or International Approval Services 6-96 standard.

Reporting Carbon Monoxide Poisoning

CO poisoning is reportable to the Iowa Department of Health and Human Services.

Who should report?

  • Healthcare providers or facilities

What should be reported?

  • A blood carbon monoxide level equal to or greater than 10 percent carboxyhemoglobin or its equivalent with a breath analyzer test or;
  • A clinical diagnosis of carbon monoxide poisoning regardless of any test result.

How to report?

  • The Iowa Statewide Poison Control Center (1-800-222-1222) offers 24/7 consultation to the public and physicians on CO treatment and forwards reports of CO exposures and poisonings to Iowa HHS.

How to report to the Division of Environmental Health

  • Phone (Mon-Fri 8 am-4:30 pm): 800-972-2026
  • Fax: 515-281-4529
  • Address:
    Iowa Department of Health and Human Services
    Division of Environmental Health
    Lucas State Office Building
    321 E. 12th St.
    Des Moines, Iowa 50319-0075
  • 24-hour Disease Reporting Hotline: 800-362-2736 (For use outside of EH office hours)

For More Information

The EPA website has information on Indoor Air Quality in Ice Arenas which includes information on potential carbon monoxide exposures.