Updated July 19, 2019 by Daniel Imperiale

The 8 Best Carbon Monoxide Detectors

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We spent 45 hours on research, videography, and editing, to review the top choices for this wiki. Being odorless and colorless, carbon monoxide is a potentially lethal danger in any home, office, or workplace. But with today's technology, it's pretty easy to keep your employees, colleagues, and family safe from this silent killer. One of these CO detectors will quickly warn you at the first sign of dangerous levels in the air. When users buy our independently chosen editorial picks, we may earn commissions to support our work. Skip to the best carbon monoxide detector on Amazon.

8. First Alert Combination

7. Honeywell Ademco Wireless

6. Pyle Handheld PCMM05

5. Kidde Digital C3010D

4. Kidde COPP-B-LPM

3. Nest Protect 2

2. BRK Electronics CO5120BN

1. First Alert CO615

What Is Carbon Monoxide?

When carbon monoxide levels rise above 35 ppm, the gas poses a potentially lethal danger to humans and other animals.

A lot have things have been referred to as the silent killer in our vernacular, but few of those killers are as utterly undetectable to the human senses as carbon monoxide. The gas is colorless, odorless, tasteless, and ruthless in its ability to destroy human life. But what exactly is it?

Carbon monoxide consists of equal parts of two building blocks that are essential to life as we know it: carbon and oxygen. Comprised of a single oxygen atom and a single carbon atom, it’s a natural part animal metabolism in the majority of vertebrates and invertebrates alike. And, yet, it’s toxic to those life forms in a high enough concentration.

When carbon monoxide levels rise above 35 ppm, the gas poses a potentially lethal danger to humans and other animals. When you inhale carbon monoxide, you won’t feel it initially. It isn’t like helium, which can immediately alter your voice, or nitrous oxide, which dentists serve up to make you feel giddy while they drill holes in your face. With enough carbon monoxide taking up toxic portions of your breath, you’re liable to feel a little lightheaded and eventually fall asleep. Then, you die. Bummer, right?

The problem begins in the lungs, through which blood flows to drop of carbon dioxide and pick up oxygen. That oxygen binds to your hemoglobin and travels all around the body, invigorating everything from your brain to the muscles that require oxygen to function.

When carbon monoxide enters the lungs, it binds to your hemoglobin in place of oxygen. That means that your blood cells can’t carry that vital oxygen wherever it’s needed. You might not feel this in your muscles as much, but the effects of oxygen deprivation on your brain will be gradual and devastating.

In high enough concentrations, as when you run your car in an enclosed space, the effects are more swift. A smaller, but still toxic concentration, can be even more dangerous, as long-term exposure will usually manifest itself in symptoms akin to the flu, including nausea and mild headaches. Without a functional carbon monoxide detector, not only can these symptoms slowly turn into permanent damage to brain and lung tissue, but others in the vicinity will be susceptible to the toxic gas, as well.

This is why it’s so important to own and regularly check your carbon monoxide detector. It’s a small investment to make in the safety and health of everyone who enters your home.

How Do Carbon Monoxide Detectors Work?

Given the fact that carbon monoxide, even at lethal levels, is undetectable to the human senses, it’s a very good idea to employ a device that can detect it for you. When there’s a fire in the home, you can usually smell or see the smoke just as quickly as your smoke detector can. The advantage of a smoke detector is that it can wake you from sleep in the event of a fire, when your senses are too muted to notice the presence of danger.

When carbon monoxide interacts with silica, it alters the substance’s electrical impedance, which is monitored by the device’s circuit board.

A carbon monoxide detector has to be sensitive enough to detect a much less visible agent, and to do so without creating too many false alarms. After all, the boy who cried wolf eventually asphyxiated on CO2.

Fortunately, carbon monoxide’s propensity to interact with other chemicals and substances (including your hemoglobin) can actually be used to protect you from it. Carbon monoxide detectors usually function in one of three ways. They either utilize silica, chemical solutions, or a reactive gel to register the presence of the gas.

When carbon monoxide comes into contact with a chemical gel substance, the gel’s color changes. Detectors that use gel also often employ photo sensors akin to those found in photoelectric fire alarms. These simple sensors can register the change in gel color, and when they do, they sound the alarm.

Detectors that employ chemical solutions and silica-based detectors both rely on changes to electrical resistance as their triggers. When carbon monoxide interacts with silica, it alters the substance’s electrical impedance, which is monitored by the device’s circuit board. Large enough changes in impedance trigger the alarm. Similarly, small amounts of certain chemical solutions can respond to the presence of carbon monoxide with changes in the flow of electricity through them. Electrodes dipped in the chemical solution detect this change and sound the alarm.

Tips To Maximize Your Safety

In order to keep you and your family as safe as possible, owning a carbon monoxide alarm isn’t quite enough. You should be familiar with how your alarm is installed, as well as what to do if it needs any kind of maintenance. There are also a few additional purchases that can help ensure your safety.

You should routinely test these batteries to make sure you’ll remain safe no matter the power conditions.

Carbon monoxide alarms are either plug-in or battery-operated. Detectors that have to be plugged in are dependent on the placement of the outlets in your home for their efficacy. They often also have batteries inside them to act as backups should the power fail. You should routinely test these batteries to make sure you’ll remain safe no matter the power conditions.

Battery-operated carbon monoxide alarms require a little more attention, as you’ll want to keep their batteries as fresh as possible. The benefit of these is that you can install them anywhere, including in a garage that doesn’t have power running to it, to ensure your air is safe to breathe.

If you’re also worried about fire safety, there are combination alarms on the market that can serve both to detect smoke and carbon monoxide. It would also be a good idea to invest in a couple of high-quality fire extinguishers and to keep them in the most effective places, such as the kitchen, or by a fireplace.

Lastly, make sure you and your family have an escape plan in case of a fire or gas leak. This may necessitate the purchase of an escape ladder, as well as the development of a detailed evacuation plan. It may take a little up-front cost and planning, but you’ll be grateful if you ever need to use the tools and tactics you’ve acquired.

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Daniel Imperiale
Last updated on July 19, 2019 by Daniel Imperiale

Daniel Imperiale holds a bachelor’s degree in writing, and proudly fled his graduate program in poetry to pursue a quiet life at a remote Alaskan fishery. After returning to the contiguous states, he took up a position as an editor and photographer of the prestigious geek culture magazine “Unwinnable” before turning his attention to the field of health and wellness. In recent years, he has worked extensively in film and music production, making him something of a know-it-all when it comes to camera equipment, musical instruments, recording devices, and other audio-visual hardware. Daniel’s recent obsessions include horology (making him a pro when it comes to all things timekeeping) and Uranium mining and enrichment (which hasn’t proven useful just yet).

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