Skip to Main Content

Start of main content

Causes and Prevention for Carbon Monoxide Poisoning

Carbon monoxide is poisonous to humans and animals. Learn the warning signs to prevent CO poisoning.

A clear and odorless gas, carbon monoxide (CO) is poisonous to humans and animals. 

Carbon monoxide is both naturally occurring and a byproduct of manmade combustion. Defective furnaces, fireplaces, flues, and oil heaters are most frequently responsible for accidental carbon monoxide (CO) poisonings. When improperly vented, malfunctioning home appliances like furnaces and air-conditioners can slowly fill your home with CO.

In the United States, CO leaks are responsible for an estimated 400 deaths a year and more than 20,000 trips to the emergency room, according to the Centers for Disease Control and Prevention (CDC). However, as CO poisoning often goes unreported, the number of instances is most likely much higher.

How to spot carbon monoxide buildup

  • decreased hot water supply
  • increased moisture on windows
  • loose or disconnected chimney
  • fireplace or appliance
  • black soot on appliances and vents
  • rust or water on vents or chimney
  • loose or missing furnace panel

What are some signs of carbon monoxide poisoning

CO is dangerous because there tend to be no noticeable symptoms if an individual's CO levels are at less than 10% in the bloodstream. Above 10%, CO poisoning symptoms may mimic the flu or a cold. At that level, according to the Mayo Clinic, symptoms may include:

  • Low to moderate poisoning: 
    • headache
    • fatigue
    • shortness of breath
    • nausea
    • dizziness
  • Severe poisoning: 
    • confusion
    • vomiting
    • loss of muscle coordination
    • unconsciousness

How might you prevent carbon monoxide poisoning?

Taking a small amount of time to manage your home's risks will greatly protect you and your family.

  • Have your furnace inspected and maintained by a qualified contractor once a year. This should be done before the start of the heating months.
  • Have your gas appliances inspected at the same time as your furnace to ensure they are operating correctly.
  • Keep in mind that space heaters, ovens, portable generators, and other gasoline-powered engines can cause a buildup of carbon monoxide.

If you suspect the appliance or tool you're using might be causing a buildup of CO, play it safe and open a window. If you're working in the garage, open the door. Ventilation is a sure way to disperse a buildup of the gas.

Carbon monoxide detector placement in your home

In addition to smoke detectors, install a CO detector on each level of your home, and in or near each sleeping area. You can also hook them up to a smart home system to send a message to your smartphone if it is detected when you're not at home. While you shouldn't rely solely on CO detectors, having them properly placed throughout your home can serve as a good fail-safe.

Try to keep the detectors at least 20 feet from any fuel-burning appliances and at least 10 feet from high humidity locations like bathrooms and kitchens, as moisture can sometimes trigger faulty readings. Test the batteries of your detector regularly, and if an alarm sounds, call a professional to check your gas-burning appliances.

What do I do if my carbon monoxide detector goes off?

  1. Exit the house.
  2. Check everyone for signs of carbon monoxide poisoning.
  3. Call 911.
  4. Do not re-enter your home until authorities have cleared it.

Visit the CDC website for more information about carbon monoxide poisoning.

Enlarge infographic .

State Farm® (including State Farm Mutual Automobile Insurance Company and its subsidiaries and affiliates) is not responsible for, and does not endorse or approve, either implicitly or explicitly, the content of any third party sites hyperlinked from this page. State Farm has no discretion to alter, update, or control the content on the hyperlinked, third party site. Access to third party sites is at the user's own risk, is being provided for informational purposes only and is not a solicitation to buy or sell any of the products which may be referenced on such third party sites.

The information in this article was obtained from various sources not associated with State Farm®. While we believe it to be reliable and accurate, we do not warrant the accuracy or reliability of the information. These suggestions are not a complete list of every loss control measure. The information is not intended to replace manuals or instructions provided by the manufacturer or the advice of a qualified professional. Nor is it intended to effect coverage under our policy. State Farm makes no guarantees of results from use of this information.


Get a Quote

Select a product to start a quote.


Contact Us

844-373-0003 844-373-0003

Also Important

Is Lead Lurking in Your Tap Water?

Is Lead Lurking in Your Tap Water?

Corrosion in your water-supply system can expose your family to health risks.

Tips and Information About Tools for Detecting Radon Gas

Tips and Information About Tools for Detecting Radon Gas

How to test for and treat your home for this colorless, odorless and dangerous gas.

Related Articles

Hidden Home Fire Hazards and How to Eliminate Them

Hidden Home Fire Hazards and How to Eliminate Them

Most house fires are preventable, so take a minute to learn these less obvious causes.

Buying, Installing, and Maintaining a Gas Fire Pit

Buying, Installing, and Maintaining a Gas Fire Pit

The proper placement and power, plus dos and don'ts for your outdoor fire feature.

Possible tips to deal with home emergencies

Possible tips to deal with home emergencies

You can't predict when they will occur, but you can have a home emergency plan.