Carbon monoxide, or CO, is a gas that can be produced by incomplete combustion when carbon-based materials are burned such as wood, propane, charcoal, natural gas, oil, gasoline and kerosene. CO mixes freely with the air we breathe.

It has no odor or color, however some components of combustion do have an odor and may indicate a potential carbon monoxide problem.

Your first line of defense against CO is to make sure your system is properly installed and vented, in good working order, and inspected every year by a licensed heating contractor.

Click here to see a graphic of potential CO hazards (reprinted with permission from the Omaha World-Herald).

When does carbon monoxide become a problem?
According to the U.S. Office of Safety and Health Administration, CO becomes a problem when it builds up in your home and the concentration rises to more than 50 parts per million for eight hours or more.

At high levels, CO is deadly. It combines with hemoglobin -- the red component of your blood which transports oxygen to your cells -- and prevents oxygen from being circulated. Older people, young children, people with heart and respiratory problems and small pets are particularly susceptible.

Symptoms of carbon monoxide
Symptoms are like the flu: headaches, dizziness, vomiting or nausea, weakness and tightness of the chest.

Be suspicious if all members of your family share the same symptoms and the symptoms clear up when you're outside the house.

If symptoms persist, see a doctor. If anyone is overcome by CO, call 911.

If you suspect carbon monoxide:

1. Check to see if anyone is experiencing symptoms of carbon monoxide. If anyone is overcome by CO, call 911.
2. Do not panic. Get everyone out of the building.
3. Get help for anyone who is in need of medical care.
4. Open doors and windows to let in fresh air.
5. Turn the thermostat to the lowest setting.
6. Turn off all unvented appliances (range, auxiliary heater).
7. Turn the water heater to the lowest setting.
8. Check flues for obstructions.
9. Check for soot around the water heater and furnace.
10. Check for a vehicle or small engine operating in an attached garage or basement.
11. If you are unable to determine the cause, call a licensed heating contractor or our emergency number, 402.554.7777.

Prevent carbon monoxide:
Any fuel-burning appliance using coal, oil, wood, propane or natural gas can produce CO if not working properly. Follow these maintenance and inspection tips:

1. Don't use temporary heating systems. Never use a gas or propane range to heat your home.
2. Make sure your permanent heating system and appliances are operating and vented properly. Have the heating system and appliances inspected every year by a licensed heating contractor.
3. Keep flues and chimneys clean and free of debris.
4. Check for rusted or pitted flue pipes from your furnace and water heater. Don't patch or repair these pipes; have them replaced immediately.
5. Check the flames. All gas flames should be crisp and blue. If flames are white or yellow, appear "soft" or wavy, or if you see soot or carbon deposits, shut off the furnace and call your heating contractor.
6. Hold your hand under the vent pipe on the furnace. If you notice hot air backing out of the vent, turn off the furnace and call your heating contractor. Hot air can mean blockage in the vent or chimney.
7. Use a clean filter -- your furnace will run smoother and more efficiently. Standard air filters need to be changed once a month. Newer filters may be washable or require less frequent changing. Check the owner's manual.
8. Be sure a fire is completely out before closing the fireplace damper.
9. Do not operate a barbecue grill in a closed area.
10. Don't start or run gasoline-powered equipment in a closed area.

Should I buy a CO detector? Is one enough?
Your first line of defense is regular maintenance of your heating system, appliances and venting system. If you buy a detector, be sure it has the Underwriters' Laboratories (UL) label and a loud alarm. Experts suggest there should be one alarm near a primary bedroom and another in a primary living area. If bedroom areas are widely separated, you may need additional detectors.

Do not place detectors near open windows or doors as weather conditions may affect the sensors. Prolonged rain and dense fog or high levels of humidity may cause detectors to alarm. Heavy smoke, cleaning agents or aerosol sprays used near the detector also may cause it to sound.

Click here for information about carbon monoxide detectors