Carbon Monoxide Detectors for the Home

Carbon Monoxide Detectors for the Home

What is Carbon Monoxide?

Carbon monoxide (CO) is a poisonous, colorless, odorless and tasteless gas. Although it has no detectable odor, CO is often mixed with other gases that do have an odor. So, you can inhale carbon monoxide right along with gases that you can smell and not even know that CO is present. When too much carbon monoxide is in the air, your body replaces the oxygen in your red blood cells with carbon monoxide. This can lead to serious tissue damage, or even death. Source: OSHA

Is Carbon Monoxide Dangerous? 

About 430 people die in the U.S. from accidental CO poisoning. Approximately 50,000 people in the U.S. visit the emergency department each year due to accidental CO poisoning. Source: CDC 

What are the Carbon Monoxide Symptoms?

Signs and symptoms of carbon monoxide poisoning may include:

  • Dull headache
  • Weakness
  • Dizziness
  • Nausea or vomiting
  • Shortness of breath
  • Confusion
  • Blurred vision
  • Loss of consciousness

Carbon monoxide poisoning can be particularly dangerous for people who are sleeping or intoxicated. People may have irreversible brain damage or even die before anyone realizes there's a problem. Source: Mayo Clinic 

What produces Carbon Monoxide?

Carbon monoxide is typically found exhaust and flue gases produced during any form of combustion. Examples include:

  • Car and truck engines.
  • Small gasoline engines.
  • Fuel-burning space heaters (not electric).
  • Gas stoves.
  • Lanterns.
  • Heating systems, including home furnaces.
  • Burning charcoal, kerosene, propane or wood.

Source: Cleveland Clinic

How does one reduce the risk of Carbon Monoxide in the Home? 

The Office of the State Fire Marshal encourages residents to have their furnaces checked, change furnace filters and to make sure carbon monoxide and smoke detectors are functioning properly. Also, ensure you have carbon monoxide detectors per your city, state and county code, and in addition, ensure you have early warning devices like a low level carbon monoxide detector.

Shall I take my CO detector alarm serious?

Absolutely. For example, in 2019, according to National Fire Incident Reporting System, Illinois fire departments responded to 23,000 calls about carbon monoxide and were able to determine a CO leak at nearly 11,000 of those locations.

What shall I do if I suspect carbon monoxide is in my Home?

If you suspect you may be experiencing these symptoms, smell natural gas leaking in your home, or if your CO alarm activates, if you can evacuate the building, do so immediately. Only open windows on your way out if they are easily accessible. If someone is unable to leave the building, or is unconscious, open doors and windows to the outside in the area the person is located and stay as near to the open window or door as possible until first responders arrive. Close any doors that open to other areas of the building to isolate the room the person is in. Turn on any exhaust fans that may be present. Once you evacuate, call 9-1-1 from outside your home or a neighbor's house.

What shall one do to prevent a Carbon Monoxide leak in a Home? 

  • Have a qualified professional install stationary space heating equipment, water heaters or central heating equipment according to the local codes and manufacturers' instructions. 
  • Keep interior and exterior air vents clear of blockages or obstructions.
  • Keep anything that can burn at least 3 feet away from heating equipment, like a furnace, fireplace, wood stove, or portable space heater.
  • Make sure the fireplace has a sturdy screen to stop sparks from flying into the room. Ashes should be cool before being placed into a metal container. Keep the container a safe distance away from your home.
  • Create a 3-foot "kid-free zone" around open fires and space heaters.
  • Test smoke and CO alarms at least once a month and be familiar with the sounds they make.
  • Never use an oven or range to heat your home.
  • Remember to turn off portable or space heaters when leaving the room or going to bed.
  • Install carbon monoxide and smoke detectors on each floor of your home and within 15 feet of each sleeping area.
  • CO detectors have a limited life span; check the manufacturer's instructions for information on replacement.

Do Carbon Monoxide alarms operate differently than smoke alarms?

Although they may look and sound similar, CO alarms and smoke alarms are designed and intended to detect two separate, distinct hazards. Therefore, to help protect your family from both hazards, it's important to install both UL Listed CO alarms and smoke detectors. Source: EPA

How do I install my Carbon Monoxide Alarm?

Follow the installation instructions found in the manufacturer's use and care booklet that accompanies the product. Proper installation is an important factor in receiving optimum performance. It's important to follow these instructions exactly. Source: EPA

How do I take care of my Carbon Monoxide Alarm?

Like smoke detectors, CO alarms need to be tested regularly and cleaned as indicated in the manufacturer's use and care booklet. If the unit operates off a battery, test the detector weekly and replace the battery at least once a year. Source: EPA

Should I follow any safety tips for using and or maintaining my Carbon Monoxide Alarm?

As with any product, read the manufacturer's use and care booklet for installation and maintenance guidelines. If your unit operates off the battery, never allow anyone to "borrow" the battery. Like any appliance or power tool, a CO alarm can't work unless it has a functioning power source. Source: EPA

What about breathing Fresh Air?

If you think you're suffering from CO exposure, breathe some fresh air as soon as you can. Open doors and windows — or better yet, leave the house. If you have time, turn off the stove, furnace, or anything that is burning.

If you're pretty sure you have a CO problem, call the fire department to be on the safe side. At the very least, get a service person to check out your appliances and furnace before you turn anything back on.

In high concentrations, the gas can kill in minutes. Lower levels are also dangerous because the typical symptoms — headache, dizziness, nausea, shortness of breath — could indicate so many illnesses. People think they have some kind of low-grade infection or the flu, not a serious poisoning problem.

Even if it's not fatal, CO poisoning can have devastating effects, including brain damage. If someone is mentally impaired from an exposure for more than two weeks, the odds of a complete recovery are slim.

Source: Harvard University

Any other tips regarding Carbon Monoxide in the home?

  • Have your home heating systems (including chimneys and vents) inspected and serviced annually by a trained service technician.
  • Never use portable generators inside homes or garages, even if doors and windows are open. Use generators outside only, far away from the home.
  • Never bring a charcoal grill into the house for heating or cooking. Do not barbeque in the garage.
  • Never use a gas range or oven for heating.
  • Open the fireplace damper before lighting a fire and keep it open until the ashes are cool. An open damper may help prevent build-up of poisonous gases inside the home.
  • Install battery-operated CO alarms or CO alarms with battery backup in your home outside separate sleeping areas.
  • Know the symptoms of carbon monoxide poisoning: headache, dizziness, weakness, nausea, vomiting, sleepiness, and confusion. If you suspect CO poisoning, get outside to fresh air immediately, and then call 911. Source: CPSC

What are the standards and Guidelines for indoor carbon monoxide in my home?

No standards for CO have been agreed upon for indoor air. This is the reason why various agencies, department and organization are quoted and each has difference recommended exposure levels. Here are some examples:





9ppm average over 8 hours



9ppm average over 8 hours



9ppm average over 8 hours



35ppm average over 10 hours

200ppm ceiling value


50ppm average over 8 hours



25ppm average over 8 hours


UL2034 (USA) >70ppm (60 to 240 minutes)
>200ppm (10 to 50 minutes)
>400ppm (4 to15 minutes)
USA Carbon Monoxide Detectors
EN 50291:2001 (Europe)

>50ppm (60 to 90 minutes)
>100ppm (10 to 40 minutes)
>300ppm (3 minutes)

Europe Carbon Monoxide Detectors

Low Level Detector

>25ppm (1 minute)

Forensics Detectors Low Level Detector

The World Health Organization (WHO)

The WHO is a specialized agency of the United Nations that is concerned with international public health. To protect public health from risks due chemical exposure, WHO has published guidelines for toxic chemicals in indoor air. The guideline for carbon monoxide exposure is 9ppm over a time weighted average over an 8 hour period. (Reference: WHO. (2010). "WHO guidelines for indoor air quality: selected pollutants” ISBN 978 92 890 0213

The United States Environmental Protection Agency (EPA)

The EPA is a Federal agency concerned with air quality standards, and has set maximum standards for pollutants considered harmful to public health.   The Table Of Historical Carbon Monoxide National Ambient Air Quality Standards establishes a concentration of 9 ppm carbon monoxide time weighted average over an 8 hour period since 1971.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

ASHRAE has created maximum standards for pollutants considered harmful to public health, and also establishes a concentration of 9 ppm carbon monoxide time weighted average over an 8 hour period. Source:

The National Institute for Occupational Safety and Health (NIOSH)

NIOSH is a Federal agency under the Department of Health and Human Services published a Recommended Exposure Limit of no more than 35ppm at a 10 hour time weighted average per day and a ceiling value of 200pm, where the ceiling value should not be exceeded at any time (Source:

The Occupational Health and Safety Administration (OSHA) 

OSHA is a Federal agency under the Department of Labor that develops and enforces federal standards for health and safety in the work place recommend a permissible exposure limit (PEL) of carbon monoxide to no more than 50ppm time weighted over an 8 hour work day.  Source:

The American Conference of Governmental Industrial Hygienists (ACGIH) 

ACGIH has assigned carbon monoxide a threshold limit value (TLV) of 25 ppm (29 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour work week [ACGIH 1994, p. 15]