Today’s carbon monoxide detection devices are effective, trustworthy, and the only means to detect the odorless, tasteless, and deadly carbon monoxide gas.

68,316  Number of unintentional, non-fire related CO incidents reported to poison
centers during 2000-2009

15,000 Approximate number of people treated for accidental CO exposure at emergency rooms each year (Does not include incidents that were managed at the site of exposure)

439 Average number of CO deaths per year*

Potential sources of carbon monoxide can be found in most homes, including furnaces, gas ranges or cook tops, camp stoves, generators, clothes dryers and vehicles. Carbon Monoxide alarms/detectors are designed to activate before potentially life-threatening levels of CO are reached and are based on two factors: time and amount. If low levels of carbon monoxide are detected, the alarm will not signal until the levels are consistently detected for a period of time – indicating the CO levels are appearing at a level and duration that is harmful. This prevents the number of nuisance alarms which can occur based on naturally occurring CO level fluctuations.

Who is Required to have CO Detectors?

Ohio: Single family and buildings up to 3 stories in multiple family properties, publicly funded child care centers.

Kentucky: Newly constructed one- and two-family dwellings, townhomes not more than 3

stories, apartment buildings, dormitories, adult/child care facilities and assisted living facilities which contain a fuel-burning-appliance or an attached garage.

Indiana: No requirements at this time.

Types of CO Detectors

There are three types of CO detection technologies: biomimetic, MOS, and electrochemical. The difference in these is in how they detect CO levels, but each is reliable. The advantages and disadvantages for each is outlined below.

Low cost sensor
Capable of a long life span (10 years)
Reliable; few field defects
Long recovery after alarm
  • High current draw
  • Expensive
High sensitivity to ammonia-based cleaners

Regardless of the sensing technology, all CO detectors have a limited-life CO sensor and will need to be replaced at the end of their life span. This is generally 10 years, but check your manufacturers’ instructions for your detectors, as this may vary and some detectors will need to be replaced if the alarm is activated.

Placement requirements

Contrary to popular belief, CO does not layer on the floor. In a 2012 study by the Center for Hyperbaric Medicine, Virginia Mason Medical Center, Seattle, WA, it was shown that Carbon Monoxide diffused until it was of equal concentration through the local environment. This would occur quickly in a home where drafts due to motion and temperature exist to move the carbon monoxide. This means that it is reasonable to place a residential CO alarm at any height within a room, but always check your manufacturer’s instructions.

NFPA 720 ( requires that Carbon Monoxide alarms be placed in the immediate vicinity of each bedroom, and centrally located on each habitable level including basements, but not including attics and crawl spaces. It also requires that CO detectors be placed on the ceiling in the same room as permanently installed fuel-burning appliances, and in every HVAC zone of a building.

When wall mounting a system-connected CO detector, it should be at least as high as a light switch, and at least six inches from the ceiling. The detector should not be mounted near the floor, as studies show that CO gas rises from the point of production and then mixes evenly throughout the air as it cools. Higher placement also protects CO detectors from potential damage caused by pets and tampering. When ceiling mounting a system-connected CO detector, the detector should be located at least 12 inches from any wall.

Where do I mount CO Detectors?

Wall mounted, at least 6 inches from the ceiling but at least as high as a light switch

or Ceiling mounted, at least 12 inches from any wall

How many do I need?

1 outside each bedroom

1 centrally located on each level of the building, including the basement but not the attic or crawl space

1 on the ceiling of any room with a fuel-burning appliance (gas furnace, fire place, etc)

1 in each HVAC zone of the building

* Always check the manufacturer’s instructions on your carbon monoxide detectors.

Benefits of combining your CO detectors with your fire alarm

Integrating your Carbon Monoxide detectors with your fire alarm system allows you to have all the functionality of independent CO devices including the alarm signals and maintenance signals, while additionally having your CO detectors monitored by a central monitoring station. Monitoring your CO detectors will provide an additional assurance that your detectors are working properly and will allow the proper first responders to be notified if an alarm is triggered.

Testing, Inspection and Maintenance

Immediately after installation and annually thereafter, CO detectors should be inspected visually and for functionality by the introduction of carbon monoxide into the sensing chamber. This inspection and testing ensures that each detector remains in good condition and performs correctly. Carbon monoxide detectors are designed to be as maintenance free as possible; however, dust, dirt, and other foreign matter can accumulate inside a detector’s sensing elements and change its sensitivity. They can become either more sensitive, which may cause unwanted alarms, or less sensitive, which could reduce the amount of warning time given if CO reaches a dangerous level. CO detectors also need to be tested due to the limited life span of the sensing cell, to ensure the sensing cell is still working and has not reached its end of life earlier than the manufactured intent. Always follow the manufacturer’s specific instructions for testing and maintenance of CO detectors.

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