Carbon monoxide (CO) is an odorless, colorless and toxic gas that causes hundreds of unintentional deaths a year, according to the Centers for Disease Control and Prevention (CDC). The gas is invisible to our eyes and CO poisoning symptoms are flu-like, which is why it can sometimes go unnoticed. That’s why a carbon monoxide detector is essential for any living space. We collected CO guidance from government agencies like the CDC and U.S. Environmental Protection Agency (EPA), and recommend top-rated CO detectors below.
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What is carbon monoxide?
Carbon monoxide is an odorless, colorless and toxic gas. Common household sources of carbon monoxide include fuel-fired heating and cooking appliances like gas space heaters, gas stoves, gas grills, gas water heaters and improperly vented fireplaces, to name a few. CO can accumulate to dangerous levels when any fuel-fired combustion source is used improperly and not adequately vented to the outdoors, says Carolyn Holran, the press secretary at the EPA.
Inhaling CO can cause a variety of symptoms (more on those later), but inhaling a lot of CO can cause you to pass out and may kill you, according to the EPA and CDC.
How we picked top-rated carbon monoxide detectors
Carbon monoxide detectors tend to look similar to each other and often don’t have specific product names, just model numbers like CO615 or C05120BN, which makes buying one even more confusing. We picked CO detectors based on the following criteria:
- Certifications: All of our picks are certified to UL 2034, a recognized safety standard from Underwriters Laboratories, an independent global safety science company.
- Power supply: We include carbon monoxide detectors that can be powered by different kinds of sources, including plug-in and battery-powered models.
- Extra features: We also noted useful extra features like an LED screen and battery backups in our selection.
Top-rated carbon monoxide detectors
Most of our top picks come from two well-known safety brands: First Alert and Kidde. We selected models with at least a 4.5-star average rating from hundreds of reviews on online storefronts like Amazon.
Plug-in pick
Plug-in CO detectors are convenient because you can place them wherever you have a wall outlet. This model also has a battery backup (powered by two AA batteries), so it will keep running even during a power outage. The LED screen indicates backup battery level as well as CO levels. The brand also makes a lower-priced version without a screen.
Travel pick
If you are a frequent traveler and often find yourself staying in short-term lodging, consider bringing this portable CO detector with you. In the US, only 14 states require CO detectors in temporary lodging, and a lack of CO detectors has led to hospitalization and deaths locally and abroad. It has a built-in lithium battery with up to 10 years of battery life.
Battery-powered pick
If you need a CO detector for an area of your home that does not have a wall outlet or hardwire option, consider a battery-powered model like this one from First Alert. It runs off of two AA batteries, included in the box.
For hardwiring
If you prefer hardwiring your CO detector, this model is a good fit, plus it has a battery backup through a regular 9V alkaline battery. It doesn’t have a screen — push and hold the single button to test the alarm, or push it once to silence the low-battery chirp.
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Frequently asked questions
Kidde and First Alert are two of the biggest brands in the CO detector space. Kidde, however, has a much more extensive history of product recalls with its fire extinguishers, smoke detectors and carbon monoxide detectors than First Alert. In 2021, a federal judge ordered the brand to pay a $12 million civil penalty in connection with allegations that the company “failed to timely inform the Consumer Product Safety Commission (CPSC) about problems with fire extinguishers manufactured by the company.”
First Alert has had recalls too, but not as many as Kidde, and not for as many units.
What are symptoms of carbon monoxide poisoning?
Carbon monoxide poisoning can seem like flu-like symptoms without a fever, says Holran. Carbon monoxide exposure can cause headaches, dizziness, weakness, nausea, shortness of breath, confusion and fainting. High levels of CO exposure can cause death.
Carbon monoxide detectors should be installed:
- Near every sleeping area in your home
- On every level of your home
- In central locations of your home
Some carbon monoxide detectors can be connected to each other wirelessly, meaning if one alarm goes off, all of them go off. This can be especially useful in large homes.
There are multiple ways to prevent a carbon monoxide incident from occurring in your home. Most prevention methods revolve around fuel-fired appliances and ventilation.
- Vent fuel-fired, combustion appliances to the outdoors — think stoves, heaters, furnaces and fireplaces. Avoid the use of unvented appliances (or fireplaces) indoors.
- Run vehicles outside your garage. If you need to warm up a vehicle, start it inside your garage and remove it immediately after starting.
- Run fuel-powered portable generators outdoors, at least 20 feet away from buildings and structures. If you need a generator for indoor use, consider a battery or solar powered station instead.
- Test all CO detectors monthly, and replace them according to manufacturer instructions.
- Have a professional inspect, clean and tune central heating systems like furnaces, flutes and chimneys annually.
Meet our expert
At NBC Select, we work with experts who have specialized knowledge and authority based on relevant training and/or experience. We also take steps to ensure all expert advice and recommendations are made independently and without undisclosed financial conflicts of interest.
- Carolyn Holran is the press secretary at the Environmental Protection Agency (EPA).
Why trust NBC Select?
I’m a reporter at NBC Select who covers technology and fitness including recent stories on air purifiers, wireless earbuds, and walking shoes. For this piece, I researched carbon monoxide and pulled information from reputable agencies like the Centers for Disease Control and Prevention (CDC) and Environmental Protection Agency (EPA).
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