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Preventing Carbon Monoxide Poisoning

Carbon monoxide (CO) is an odorless, colorless, tasteless gas. It is a common byproduct of incomplete combustion, produced when fuels (oil, gas, coal or wood) burn. Because you can't see, taste or smell it, carbon monoxide can make you sick—or even kill you—before you know it's there.

Carbon monoxide robs the body of oxygen. When you inhale CO, it bonds with the hemoglobin in your blood and displaces oxygen, producing a toxic compound called carboxyhemoglobin (COHb).

We're all at risk for carbon monoxide poisoning but some groups are especially vulnerable: children, the elderly and people with heart and lung problems. Poorly maintained homes or apartments are susceptible to CO problems.

Where Does CO Come From?

Carbon monoxide is a poisonous gas produced by the incomplete burning of solid, liquid or gaseous fuels such as oil, kerosene, coal and wood. It can be produced by gas or oil appliances such as furnaces, clothes dryers, water heaters, ranges, ovens or space heaters. It is also produced by fireplaces and wood burning stoves.

If appliances are working properly and your house is vented correctly, CO should not be a problem. But a clogged chimney, improper venting or an appliance malfunction can cause a buildup of CO. In some cases, problems arise even if appliances are working properly due to problems such as the re-circulation of exhaust, backdrafting and lack of fresh air in the home.

The National Fire Protection Association provides detailed information on carbon monoxide poisoning in the U.S.

Carbon monoxide infographic

Symptoms of CO Poisoning

One of the problems with CO poisoning is that initial symptoms are not serious enough to signal a life-threatening issue. The symptoms are often flu-like and include headaches, dizziness, weakness and fatigue, shortness of breath, nausea, confusion and irritability.

CO is measured in parts per million (ppm). At low levels, victims experience mild, flu-like symptoms. Symptoms become more serious as the level of CO increases or if the time of exposure lengthens. Victims may experience vomiting and unconsciousness and, eventually, death. Exposure of 400 ppm for three hours can kill you; so can longer exposures to lower concentrations of CO.

If you experience any of these symptoms and suspect CO may be a factor, open the windows and doors to let in fresh air, turn off combustion appliances, get out of the house and call 911. First responders will try to pinpoint the problem; if CO is the culprit, the problem must be fixed before you can return.

About CO Alarms

To protect your family, install carbon monoxide alarms. These devices save lives. They sound an alarm before the average adult normally would experience symptoms of CO poisoning. They are designed to sound an alert based on exposure to gas over time.

County law requires carbon monoxide alarms in all rental housing. BCoFD strongly recommends carbon monoxide alarms in every home.

CO detectors are relatively inexpensive and can be purchased at home supply stores. They are easy to install following the manufacturer’s guidelines.


Fire officials recommend the following regarding CO alarm placement:

  • Place the alarms high on the walls of the house since CO, if present, will be fairly well-mixed with the existing air in a house.
  • Install one alarm in the hallway outside of each sleeping area
  • Install alarms in rooms with fireplaces and fuel-burning appliances.


Test your alarm monthly by pushing the test button. If your alarm goes off, never ignore it; instead: 

  • Call 911 immediately.
  • Open the doors and windows to ventilate the house, then leave the house.
  • Do not re-enter until experts have investigated the problem and declared it safe to return.

Information about these laws and regulations regarding CO alarms is available online.

Tips for Preventing CO

Proper maintenance of fuel-burning appliances is essential to protect against CO. Every homeowner and landlord should:

  • Ensure that household appliances are installed and running correctly. Have a professional technician check fuel-burning appliances, furnaces, chimneys and vents at least annually for blockages, corrosion, debris and faulty connections.
  • Check appliances that use natural gas, oil, wood and kerosene. These include water heaters, clothes dryers, ranges, ovens, gas-powered refrigerators and pilot lights.
  • Never operate unvented fuel-burning appliances in a room with closed doors or windows or in rooms where people are sleeping.
  • Use a professional to service fuel-burning appliances.
  • Check venting systems—such as flues, chimneys and fireplaces—to the outside for cracks and blockages.
  • Make sure space heaters are vented properly.
  • Never operate generators indoors.
  • Never burn charcoal inside a home, garage, vehicle or tent.
  • Never use gasoline-powered tools and engines indoors.
  • Never use gas-powered appliances such as an oven or clothes dryer for heating a home.
  • Never leave a car running in an attached garage, even if the garage door is open.

Additional information about carbon monoxide poisoning is available through the Environmental Protection Agency and the National Fire Protection Association.

Revised February 24, 2020         


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