Fay Engineering

Carbon Monoxide Investigation - Has Your Carbon Monoxide Detector Expired?

Carbon monoxide alarms have a limited life, typically 5 to 7 years (some even less). Most people don’t realize they need to replace a $25 - $75 item after several years. Many manufacturers will state the limited life span somewhere in their manual; however, it’s usually not prominent.  The presence of a CO alarm may give you a false sense of security. It could even lead to unsafe combustion practices, thinking that if the air becomes poisonous, the alarm will warn you. Check the manufacturer’s instructions. If your CO detector was put into use before 2007, it probably needs to be replaced.

Like a smoke detector, carbon monoxide alarms are an important safety feature in your home. But unlike most smoke detectors, carbon monoxide detectors contain limited life components. If you utilize fuel burning equipment in your home (gas appliances, oil, wood, etc.) a malfunction can cause dangerous levels of CO to accumulate inside. Since carbon monoxide cannot be detected without an operational alarm, it is imperative that a functional device be present.

Depending on the concentration and time of exposure, carbon monoxide can lead to mental deficiencies and possibly death. A CO alarm will alert you before the CO concentration reaches an acute level. But CO alarms do not last forever. The detecting components will lose their effectiveness after 5 to 7 years and may no longer detect carbon monoxide. First Alerts website states: “After 5 years any detector should be replaced with a new CO alarm.” COSTAR recommends replacing their CO alarms every 6 years or sooner.

Your CO alarm may give no indication that it’s no longer functional. Pushing the test button (usually) only tests the battery, horn and circuitry. The test button does not test whether the gas sensing element is still functional.

On Aug. 1, 2009, UL (Underwriter Laboratories, an independent testing laboratory) required that CO alarms provide an ‘End Of Life’ signal, (EOL). However, alarms manufactured before August 2009 may not contain this EOL feature. Even newer CO alarms can malfunction due to chemical exposure, damage, misuse and various other reasons. If there is any doubt, replace it.

In March 2009, the Colorado state legislature signed into law the requirement to install carbon monoxide alarms in new and resold homes, as well as rented apartments and homes. In July 2011, California required installation of CO alarms in existing single-family homes with multifamily homes to follow in 2013. CO alarms are also required in new construction in Alaska, Connecticut, Florida, Georgia, Illinois, Maryland, Massachusetts, Minnesota, New Jersey, New York, Oregon, Rhode Island, Texas, Vermont, Virginia, Wisconsin and West Virginia.

The standards as of 2010 prohibit showing CO levels of less than 30 ppm (parts per million) on digital displays. This was meant to reduce the calls to fire stations, emergency responders and utilities when the levels of CO are not life threatening or because of inaccurate alarms. Thus, many new alarms will not sound at CO concentrations up to 70 ppm.  These concentrations are above the OSHA standard. This leaves room for a victim to be exposed to dangerous levels of carbon monoxide, even with a functioning CO alarm being present. Babies, children, pregnant women, people with circulatory or respiratory ailments, and the elderly are more sensitive to carbon monoxide than healthy adults.

Today’s carbon monoxide Safety Tips:

  • If burning wood in a fireplace; Do not close the flue damper prematurely! Even though the fire may appear to be out, smoldering coals can still emit large amounts of CO. If the damper is closed before the fire is completely extinguished, the carbon monoxide has no other path but to enter the living quarters.
  • Make sure to provide adequate combustion air when burning in a fireplace. A fireplace will exhaust large amounts of air from the home. If your home was not properly tested/evaluated (most homes), this can starve your other fuel burning appliances of needed oxygen and cause CO to enter your home from these other appliances. 

Randolph Harris is a Chemical Engineer and has been a carbon monoxide Expert for 27 years. He has investigated more than 100 CO poisoning incidents. He has been qualified as a CO expert in many courts in several states.

If you are ever involved in a CO Poisoning Incident; Do not alter anything!

The home and appliances must be properly tested and evaluated to determine all factors which led to the poisoning. CO incidents are usually more complicated than first perceived. Usually multiple factors are present. A qualified and experienced forensic investigator should be consulted before anything changes.