Association of the Wall and Ceiling Industry Logo

Carbon Monoxide and Carbon Monoxide Detectors

C arbon monoxide gas is an ever-present fact of life these days. It’s found anywhere combustion occurs, which is pretty much everywhere. In small amounts it presents no threat, but in larger amounts it can be very dangerous—even deadly. According to the Journal of the American Medical Association, carbon monoxide poisoning is the leading cause of death in the United States. Carbon monoxide, or CO, is a colorless, odorless gas that can be deadly in certain concentrations.

Carbon monoxide is produced as a byproduct of the combustion of many different fuel types. Any machinery, equipment or heater that burns coal, wood, charcoal, oil, kerosene, gasoline, propane or natural gas produces small amounts of carbon monoxide. Any types of equipment or machinery that are powered by an internal combustion engine also produce the gas; this includes cars, lawn mowers and power generators. Because of this, it’s important to realize that carbon monoxide can be a hazard on the job as well as at home.

The most direct way to limit your exposure to carbon monoxide is to not operate internal combustion engines inside. Unfortunately, this is not always an option. The amount of carbon monoxide produced by machinery and equipment can be minimized through frequent maintenance and engine tuneups. Another safer option may be to replace carbon monoxide producing equipment and machinery with their electrical counterparts. This will very effectively reduce the amount of carbon monoxide that is produced. However, when carbon monoxide–producing equipment or machinery must be used, it can be helpful to install carbon monoxide detectors in your home or workplace. In many states and local municipalities carbon monoxide detectors/alarms are required to be installed in residences. Be sure to check your state and local building codes to find out the requirements that apply to where you live. Either way, having carbon monoxide detectors installed could save lives.

Three Types

Carbon monoxide detectors are designed to measure carbon monoxide levels over time and trigger an alarm prior to dangerous levels of carbon monoxide being reached. At present there are three types of sensors that are used in the United States:

• A chemical reaction causes a white sensor pad to fade to a brownish or blackish color in the presence of carbon monoxide. These are the least expensive and the original type of sensors used in detectors. When first developed, they only gave a visual warning but as the number of carbon monoxide related deaths increased in the 1990s, audible alarms became the norm.

• An electrochemical sensor is a simple fuel cell that instead of producing power produces a current that is precisely related to the amount of carbon monoxide in the atmosphere. The current is measured to determine the carbon monoxide concentration. The benefits of this type of sensor are that they are very accurate, require minimal power to operate and have a long lifetime (five years or longer). Most carbon monoxide detectors in the United States use an electrochemical sensor.

• A semiconductor sensor measures carbon monoxide concentration through changes in its electrical resistance in the presence of carbon monoxide. Although these sensors last an average of five to 10 years, they must be powered through an electrical main, so they are not as commonly used as electrochemical sensors.

Place It Up High, and Listen

Placement of carbon monoxide detectors can have a large effect on their efficacies. Carbon monoxide is somewhat lighter than air and is often found rising with warm air. This helps to determine detector placement; on a wall about 5 feet from the floor or as high as the ceiling is best. Be certain not to place the detector right next to or over a flame-producing appliance or fireplace as these areas can give an artificially high carbon monoxide count. Each floor of your home, business or job site should have its own detector.

If a carbon monoxide detector should go off, it should be given the same attention and respect as a smoke detector. Although you may feel fine, the key to this type of detector is that it is designed to go off before anyone is experiencing any of the symptoms that indicate carbon monoxide poisoning. Once the alarm sounds, don’t go looking for the source of the carbon monoxide; get out of the building and leave that to the trained professionals. Once outside contact your local emergency services or fire department by calling 911 or the appropriate number in your area. Do a head count to be sure that everyone in the building or at the job site is accounted for. You should never re-enter the building until given the all-clear sign by emergency services.

Should the alarm go off again within a 24-hour period, again leave the building, call emergency services and contact a qualified technician to inspect fuel burning equipment and machinery to locate the source or sources of the carbon monoxide. When the source is located, be sure to have it serviced immediately.

With the availability of affordable, reliable carbon monoxide detectors, the threat of carbon monoxide poisoning can easily be reduced keeping your family, employees and coworkers safe.

Diane Kelly is a safety specialist with INTEC, Waverly, Pa. INTEC is AWCI’s safety consultant.

For additional assistance with safety and OSHA compliance, take advantage of the resources available through AWCI and INTEC, Inc. Contact AWCI at (703) 538.1600 or visit Additional technical information can be obtained by contacting INTEC’s Joe O’Connor at (607) 624.7159 or

Browse Similar Articles

You May Also Like

The ceiling installations at Nurix Therapeutics is Marek’s best job ever. Preserving the artistry evident in the architect’s design proved enormously gratifying.
Rob Aird, C. Brent Allen, Lee Zaretzky, Davis Sprague and Travis Vap share a passion for transforming spaces and structures with an eye for craftsmanship, innovation and historical preservation. You’ll
An exterior photo of the Clovis Community Medical Center (Phase 3) Parex
We will spare you the details of how it was done, but we are happy to tell you about the outcome. This article brings you just some of the many