Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is poisonous to humans. It is often referred to as the “silent killer” because humans are unable to see, taste, or smell this deadly gas. The carbon monoxide monitor is a device, like a smoke detector, that can alert you when it detects high concentrations of carbon monoxide in the surrounding air.

At Minnick’s, we help homeowners identify and prevent carbon monoxide from infiltrating their homes, and we have learned a great deal about the CO monitors on the market today.

Not all CO monitors are designed the same nor follow the same safety standards, and there is one big problem with carbon monoxide monitors that could put you and your family at risk. We’ll tell you what you need to know about your carbon monoxide monitors. We’ll also go into what monitors can help protect you and how to avoid carbon monoxide poisoning.

The Problem with Carbon Monoxide Monitors

A carbon monoxide (CO) monitor is a time-weighted alarm. The way a time-weighted alarm works is by measuring the airborne concentration of carbon monoxide in a room. The time before the alarm sounds will vary depending on the concentration level of carbon monoxide in the air. For example, an alarm will sound after eight hours of continuous carbon monoxide exposure at a level of 50 PPM (parts per million), but after only one to four hours of continuous exposure at a level of 70 PPM.

Carbon Monoxide Levels and Risk

This means you and your family could be exposed to 40 PPM of carbon monoxide for up to 10 hours before even being alerted you’re breathing in toxic gas. This time-weighted design was introduced in 2010 by the United States Underwriters Laboratories’ (UL) published standards for carbon monoxide monitors.

These revised standards required manufacturers to perform testing in more realistic conditions and required additional safety features such as end-of-life signaling. One of the goals of the UL was to reduce the number of emergency calls for what they deemed non-threatening levels of carbon monoxide exposure. To accomplish this, a small change in display requirements was placed in UL 2034

No indication shall be given for CO concentrations less than 30 ppm…

This means that you will never be alerted that you’re exposed to carbon monoxide if the concentration levels stay below 30ppm. This one requirement (that’s still in effect today!) is the biggest flaw with most of today’s standard carbon monoxide monitors. Carbon monoxide monitors largely to protect against acute poisoning, but not chronic poisoning.

Acute Carbon Monoxide Poisoning vs. Chronic Poisoning

Basically, the problem with UL certified monitors is that they only offer indication once very high levels of carbon monoxide are already circulating in your home’s air. UL certified CO monitors can potentially save a healthy adult from acute poisoning. Acute poisoning is a single large exposure to carbon monoxide that requires immediate medical attention.  

UL certified monitors ignore how low exposure to carbon monoxide can affect the human body over long periods of time. When inhaled, carbon monoxide is treated just like oxygen and binds with our red blood cells.  Enough of this harmful exposure and you can deprive your body of oxygen. This makes for obvious reasons why’d you want to avoid large concentrations of this gas, but low levels of exposure can be just as damaging.

The damaging effects of carbon monoxide exposure are cumulative and build up over time. Repeated low-level exposure to carbon monoxide is chronic poisoning. This type of exposure can cause long-term damage to our brain and has been linked to an increased risk of birth defects, strokes, and respiratory issues.

What kind of Carbon Monoxide Monitor should I get?

Now that you’re aware of the problems with a standard carbon monoxide monitor, you may be wondering what kind of CO monitor you should invest in to protect you and your family. There’s a surprising amount of variety between carbon monoxide monitors on the market. Here are the elements to consider when deciding between carbon monoxide monitors.

Power Source

One of the first choices you’ll have to consider is the power source. Most models plug into outlets, use batteries, or a combination of both.  Here at Minnick’s, we recommend battery-operated monitors because they are easier to install near the ceiling where carbon monoxide is most likely to be located. Carbon Monoxide (CO) is lighter than both Oxygen (O2) and Carbon Dioxide (CO2), so if you do have any CO in your home, it’s likely to be detected near the ceiling. It’s our recommended best practice to install your CO monitors at least five feet above the ground, and most homes don’t have electrical outlets that high.

Sensor Type

There are three commonly used types of carbon monoxide detecting sensors.

  • Biomimetic sensor: The biomimetic sensor uses a color-changing gel to detect carbon monoxide.  When the gel changes color, this triggers the alarm. Monitors that use this style of sensor can last up to three years.
  • Metal oxide semiconductor: The metal oxide semiconductor sensor uses a wired circuit to monitor carbon monoxide. When the circuit board detects carbon monoxide, it lowers the electrical resistance to trigger the alarm. Most monitors that use this style sensor can last up to 10 years.
  • Electrochemical sensor: The electrochemical sensor is arguably the best style of sensor in terms of lifespan and detecting carbon monoxide. Electrochemical carbon monoxide sensors use electrodes immersed in a chemical solution to detect changes in electrical current from the amount of carbon monoxide in the air. The change in current from these electrodes allows electrochemical sensors to have the best sensitivity and is what also triggers the alarm. Most monitors that use this style sensor can last in excess of 11 years.

Smart Models

You’ll also find smart models that can connect with smart home devices or provide alerts through a mobile app. If you have kids or pets at home, these could be a useful investment for remotely monitoring their safety. An additional benefit is some models combine the functions of a smoke detector and carbon monoxide monitor into one device.

Different Types of Carbon Monoxide Alarms

Bottom Line

Overall, the best carbon monoxide monitor is one that is most sensitive to detecting low concentration levels. Regardless of what type you choose, be sure to test it every month and make sure its power source is reliable and functioning.  It’s also a best practice to install a carbon monoxide monitor on all the levels in your home, including the basement and attic. We also recommend checking to find out if your local laws require any specific install locations.

How to Prevent Carbon Monoxide Poisoning

Now that you’re knowledgeable about how to select the best co monitor, we would like to leave you with some practical tips to keep you and your family safe from carbon monoxide.

  • Install co monitors on each floor of your home and in bedrooms
  • If battery-operated, check the batteries at least every six months.
  • Don’t use a gas stove to heat your home.
  • Don’t warm-up your car in the garage.
  • Don’t run a generator or any gas-powered engines in an unventilated enclosed area.
  • Clear all gas dryer, furnace, stove, and fireplace vents during and after snowstorms.

Lastly, never ignore a beep from your carbon monoxide monitor! Should you hear any noise from your co monitor it is trying to communicate one of three things:

  1. There is carbon monoxide present you should call 9-1-1 after seeking fresh air outdoors.
  2. If battery-operated the batteries could be low and need to be replaced.
  3. Your co monitor has reached the end of its life cycle and needs to be replaced with a new monitor.

Do You Think Your Home Has Carbon Monoxide?

If you’re concerned that you may have questionable levels of carbon monoxide in your home, it is critical that you get help immediately.

Our Minnick’s technicians and comfort advisors are trained to not only identify if you have carbon monoxide in your home but to also identify potential risks that could allow carbon leaks into your home.

Take our free online assessment to find out how your home is affecting your health and receive personalized actionable recommendations with steps you can take to improve the indoor air quality and the overall health of your home.