Carbon Monoxide: The Silent Killer

By Bryan McWhorter
Last updated: January 17, 2022
Key Takeaways

The dangers of CO poisoning and how to protect yourself and your family.

It was a lazy winter morning back in 2005 when my wife received a phone call from our daughter, who was also a new mom. Her husband had gone to work and she was feeling like she had come down with the flu. My wife jumped at the chance to go and see our granddaughter and help our daughter out.


About ten minutes after my wife left, I received a phone call from her and I could hear the panic in her voice. Our daughter was barely conscious and the house had a horrible odor.

By the time I got there, all of them were outside of the house, standing in the cold. When I stepped inside their home, I was immediately hit by the smell of carbon monoxide. Carbon monoxide is practically odorless, so being able to smell it meant the exposure levels were high. Everyone got out in time, but the ordeal may have scared a year off my wife's life.


Fast forward a couple of months to January, 2016. My wife and I notice a strange odor in our house. Soon after, our carbon monoxide detector sounded the alarm. The culprit? Our hot water heater had shifted a little due to age and rust, and was no longer venting properly. In addition to supplying us with hot water, it was filling our house with carbon monoxide.

Carbon Monoxide Poisoning

We normally don't think about the fact that our furnaces and hot water heaters are capable of poisoning us to death. Yet, each year about twenty thousand people in the U.S. end up in the emergency room for CO poisoning.

Carbon monoxide poisoning is a serious health topic according to the Center for Disease Control and Prevention (CDC). The U.S. has approximately 400 carbon monoxide related deaths each year, and carbon monoxide is the leading cause of fatal poisonings in North America.

Carbon monoxide poisoning has been attributed to faulty furnaces, hot water heaters, stoves, and portable heaters. Really, almost anything that uses gas as a fuel source can emit dangerous levels of CO. The permissible exposure limit set by OSHA is 35 parts per million over an eight hour time weighted average. And a venting problem with your water heater or furnace can quickly push the levels of CO in your home past that 35 ppm mark.

Carbon monoxide poisoning can manifest as flu-like symptoms: headaches, dizziness, and nausea. CO is colorless and odorless – it's the ninja of common poisonous gases and you may not detect it until it's too late.


Given that, it's easy to understand why someone with carbon monoxide poisoning might simply think "I must have the flu, I'm going to lay down for a while." This, obviously, can have terrible outcomes. Trying to rest in your home while you're experiencing carbon monoxide poisoning will only expose you to more CO.

That's why it's highly advisable to buy a carbon monoxide detector for your home. That's what I did after the close call with my daughter and granddaughter.

(Learn more in Yes, Poor Indoor Air Quality Is Bad for Your Health)

Carbon Monoxide Safe Guards

As with any other recognized hazard, you need control measures in place to keep you and your family safe.

Since CO can invade the atmosphere you're breathing, and do so virtually unnoticed, detection devices are your best safe guard. The CDC recommends that every home has a carbon monoxide alarm. I can second that: when my wife and I noticed the strange odor in our house, neither of us gave it much thought until we heard the CO alarm go off.

Carbon monoxide detectors will run you about $20 or so. Not a bad investment at all, considering it's such an important life-saving device.

If you already own one, good. I commend you for taking this step to protect yourself and the ones you love. But be sure to check it each year before the start of the cold season to make sure it's still in good working shape and the batteries still have enough life in them.

Mount your CO detector near bedrooms or wherever people sleep. That way, you're less likely to sleep through the alarm and more likely to spring into action as soon as it goes off.

Carbon monoxide is lighter than air, which means it will tend to rise rather than pool near ground level. Be sure not to mount your CO monitor too low or the CO may evade detection until airborne concentrations are really high.

Other safety precautions to protect against excessive CO exposure:

  • Make sure any appliance or device that runs on gas is in good working condition and serviced annually (poorly maintained heating systems are the number one cause of CO poisoning)
  • Never use a gas stove to heat your home
  • When using a gas generator, keep it outside, at least 25 feet from the house when in use (but further is better)
  • Never warm up your vehicle while it's sitting in your garage

CO Poisoning Is Completely Preventable!

Any loss of life is tragic. But loss of life from carbon monoxide exposure is 100% preventable.

Unfortunately, it's easy to become complacent with items that we interact with on a daily basis. They blend into the fabric of our lives and we stop giving a thought to the dangers associated with them.

Maintaining safety at work or at home requires attention. It does not take a great deal of time or energy to keep ourselves safe, but it does require making safety something we highly value.

I can remember as a kid speaking to adults I respected who were skilled craftsman. No matter what their field of expertise was, they all seemed to revere safety practices as important. I worked for them after school or on weekends to earn extra cash, and they were unbending on their safety rules, like making me wear goggles to use the belt sander. To them, safety was a constant mindset and you did not take safety for granted.

We need more of that type of thinking.

I don’t want to scare people into creating a safety mindset at work and home. Life can be scary enough as it is. But safety does requires attention and effort – it doesn't happen by accident.

(Learn about 20 Catchy Safety Slogans – And Why They Matter)

Acceptable Risks

Think about what you consider an acceptable risk. Not having a carbon monoxide detector was an acceptable risk for us – until our family had a brush with carbon monoxide poisoning. We were lucky to learn a lesson without actual harm done to anyone we love.

Fastening your seat belt, putting on a helmet before getting on a motorcycle, wearing the right PPE for the job – it all requires some attention but very little effort.

I would never dream of riding my motorcycle without a helmet. It's not an acceptable risk to me. So why would potentially exposing my family to carbon monoxide be?

Err on the side of caution. If your home doesn't have a CO monitor, get one. Encourage your friends and family to do the same. CO is a preventable threat, and all it takes to neutralize it is that one small step.

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Written by Bryan McWhorter | Lead Safety Advisor, Author, Writer, Speaker

Bryan McWhorter

Bryan McWhorter is a safety professional with eight years of experience in driving and teaching safety. Bryan gained his knowledge and experience as the safety officer and Senior Trainer for Philips Lighting. Philips is a strong health and well-being company that promotes a safety first culture.

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