What is carbon monoxide (CO)?

Carbon monoxide is a poisonous gas that can kill you when breathed. You can’t see it, smell it or taste it.  It is sometimes called the “silent killer” because it sneaks up on you and takes your life without warning.

Why is carbon monoxide so deadly?

Carbon Monoxide robs you of what you need most-Oxygen. When we breathe air containing CO it is absorbed through the bloodstream; it displaces oxygen; and it inhibits the blood’s ability to carry oxygen to vital organs such as the heart and brain.

Who is at risk from CO poisoning?

Everyone:  because everyone needs oxygen to survive.  Medical experts believe some people are more vulnerable to poisoning, like unborn babies, infants, children, seniors, and people with heart and lung problems.

Where does CO come from?

CO is a by-product on incomplete combustion. Any fuel-burning device has the potential to produce dangerous levels of CO gas. Examples of devices commonly used around the house include: Fuel fire furnaces (non- electric), gas water heaters, gas clothes dryers, gas stoves, fireplaces and wood stoves, charcoal grills, lawnmowers-snow blowers etc., automobiles.


Problems arise when something goes wrong. An appliance can malfunction; a furnace heat exchanger can crack; vents can clog, or debris may block a chimney or flue. Fireplaces, wood burning stoves, charcoal grills, or gas logs can produce unsafe levels of CO if they are unvented or not properly vented. Exhaust can seep into the home from vehicles left running in an attached garage. All these sources can contribute to a CO problem in the home.

In some cases even when appliances are working correctly problems may still arise. The following conditions are dangerous because they can trap exhaust in your home, and are hard to recreate during a CO investigation.

  • Incomplete combustion. Fuel-burning alliances need fresh air for complete combustion. If several appliances run at the same time in a well-insulated home, they “compete” for the available fresh air. If the fresh air supply gets low, appliances recirculate each other’s exhaust instead of venting CO outside.
  • Negative indoor air pressure. When exhaust fans run, they lower the indoor air pressure. If the indoor air pressure gets lower than the outdoor air pressure, the air f low in chimneys and vents can reverse, pulling exhaust containing CO back into the home
  • Loose vent pipes. Vibrations can sake vent pipes loose from gas dryers, furnaces, or water heaters, preventing CO from being vented outside properly.

What are symptoms of carbon monoxide poisoning?

CO poisoning produces flu-like symptoms, such as headaches, fatigue, nausea, dizzy spells, confusion, and irritability. Since symptoms are similar to the flue, CO poisoning can be misdiagnosed. Prolonged exposure can result in vomiting, blackouts and eventually brain damage and death.

What can be done to prevent carbon monoxide poisoning?

  • Make sure appliances are installed according to the manufacturer’s instructions and by professionals
  • Have your heating system inspected and serviced at least once a year
  • Make sure chimneys and vents are checked for blockages, corrosion, and loose connections
  • During and after a snowstorm, make sure vents for the dryer, furnace, stove, and fireplaces are clear of snow build-up.
  • Open flues completely when fireplaces are in use
  • Use proper fuel in kerosene space heaters
  • Never burn charcoal or a barbecue grill inside a home or enclosed area
  • Never use portable fuel-burning camping equipment inside a home, garage, vehicle or tent
  • Never leave a car or mower running in an attached garage, even with the garage door open. If you need to warm a vehicle, remove it from the garage immediately after starting it. Make sure the exhaust pipe of a running vehicle is not covered with snow.
  • Never operate unvented fuel-burning appliances in any room where people are sleeping
  • Never use the kitchen range for heating the house


How can I tell if CO is present in my home?

Early warning is important!

Since CO is colorless, odorless and tasteless, the best way to alert your family is to install a CO detector/alarm to warn you of gas build-up. The Consumer Product Safety Commission recommends that every home have at least one CO detector with an audible warning signal installed near the sleeping area.

What kind of CO detector/alarm should I get?

There are a variety of CO detectors available. When choosing a detector, you should consider the location, the ease of installation, and the power source of the alarm. CO detectors are available in plug-in and battery-operated models. Choose a CO detector that is Underwriters Laboratories Inc. (UL) Listed. Look for the UL logo on the package.  

Each type of CO detectors has different benefits:

  • Battery-operated alarms are ideal for areas where outlets are not handy or are already in use. These alarms keep on working if the electricity fails. They can be mounted on the wall or ceiling, out of reach of children or pets.
  • Plug-in alarms are easy to install. They plug directly into a standard electrical outlet, and don’t need to be mounted on the ceiling or wall. Most plug-in detector can’t work if the electricity fails, so homeowners should consider installing a combination of plug-in and battery powered alarms throughout their home.

How does a CO detector/alarm work?

CO detectors are NOT like a smoke alarm. A smoke alarm triggers an alarm immediately when it detects smoke. In a fire, the danger is immediate.  A CO detector is NOT designed to detect smoke or heat.

A CO detector/alarm triggers an alarm based on exposure to CO over time. It is designed to sound an alarm before an average, healthy adult would experience symptoms.

Remember, with carbon monoxide, it is the concentration of CO over time that poses a threat. Since carbon monoxide displaces oxygen in your blood, it can harm you if you are exposed to high levels of CO in a short period of time, or to lower levels of CO over a long period of time.

What should I do if my CO alarm sounds?

NEVER ignore your alarm!!

It is possible that you won’t be experiencing symptoms of CO poisoning when the alarm sounds. That doesn’t mean that you do not have CO present in your home.

Don’t panic, stay calm. Press the Test/Silence button to temporarily silence the alarm. Call 911. Immediately move everyone to a source of fresh air. Failure to evacuate immediately may result in prolonged exposure and worsening effect from possible CO gas.

Leave the CO detector where it is and don’t ventilate your home. The emergency responders will want to check the detector and measure the air quality to determine if there is CO present. Do not re-enter your home until the emergency responders have ventilated your home and given you the OK to re-enter. If there is a problem, immediately have a qualified technician inspect your fuel-burning appliances and chimneys to make sure they are operating correctly and that there is nothing blocking the fumes from being vented out of the house.


For additional information on Carbon Monoxide you may visit the US Environmental Protection Agency (EPA) at http://www.epa.gov/iaq/co.html

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