Carbon Monoxide in a House: 14 Things (2024) You Ought to Know

Carbon monoxide in your home is a very real danger.

This odorless and colorless gas has dozens of sources in a home where families and pets live.

Without proper preparation, you could be at risk of illness or death.

If you’re interested in learning how to reduce the potential for carbon monoxide in a house, here’s what you should know.

1. What is carbon monoxide?

Carbon monoxide (CO) is an odorless gas that results from the burning of fuel in cars, trucks, small engines, stoves, lanterns, grills, furnaces, etc.

Because you can’t see it or smell it, it’s sometimes called the invisible killer.

2. What is the problem with carbon monoxide in a house?

Carbon monoxide replaces the oxygen in your blood when you breathe it in.

This produces a variety of symptoms including headaches, dizziness, nausea, weakness, and potentially death.

CO can build up in homes because of incorrectly installed or poorly maintained/ventilated appliances.

This is why it’s important to have an alarm installed.

The alarm will help to notify you if the colorless, odorless gas is present because it’s impossible to notice otherwise.

3. What are the sources of carbon monoxide in a house?

Whenever a material is burned, CO is produced.

So, the common sources of CO in homes include fuel-burning appliances and devices, including:

bulletClothes dryers

bulletWater heaters

bulletFurnaces or boilers

bulletFireplaces, both gas and wood burning

bulletGas stoves and ovens

bulletMotor vehicles

bulletGrills, generators, power tools, lawn equipment

bulletWood stoves

bulletTobacco smoke

4. What are the signs of carbon monoxide leakage or buildup in your home?

Carbon monoxide is a silent killer.

You have to be on your guard against this issue in your home.

It could pop up when you least expect it, and since the stakes are so high, you don’t want to be caught unprepared.

Here are the most common signs that you could have a carbon monoxide issue with one of your appliances.

bulletYou see black soot marks on the cover of gas fires

bulletYou see heavy condensation building up at the windowpane where an appliance is installed

bulletYou see soot or yellow/brown stains on or around boilers, stoves, or fires

bulletYou have smoke building up in rooms of your house

bulletYou see yellow flames coming out from gas appliances (except natural gas fireplaces)

bulletYou have pilot lights blow out frequently

bulletYou have solid-fuel fires burn a lot slower than usual

bulletYou or someone in your house has symptoms like breathlessness, chest pains, fits, loss of consciousness, headaches, nausea, and confusion while at home but the symptoms disappear when you are away

bulletYou get seasonal headaches during the winter when central heating is used

bulletYou have pets that become ill

bulletYou notice that your symptoms correlate when using fuel-burning equipment

5. What is the ideal concentration of carbon monoxide in a house?

In a best-case scenario, the indoor CO levels will be the same as the outdoor CO levels.

The outdoor CO levels will change depending on where you are.

However, the federal standard is 9 ppm of CO in outdoor air.

Generally speaking, the concentrations of carbon monoxide will be higher in urban settings and lower in rural settings.

If you test your CO levels and find that the indoors are higher than outdoors, then you have sources of CO either inside or close to your home.

Take this seriously and find these sources as they can negatively affect your health.

6. How do you protect your family?

Here’s a straightforward guide to lowering the risk of CO poisoning in your home.

bulletCorrectly vent and maintain fuel-burning appliances

Start by digging a little deeper into your home and learning about the appliances that you use every day.

“Fuel-burning” appliances are the ones that emit carbon monoxide.

Make sure you know which appliances fall into this category.

Are they properly maintained?

Are they vented to the outside?

Have you had them checked annually by a qualified heating contractor for any potential problems?

If you notice any signs (see #4) of a potential CO problem, you should call a technician out sooner to ensure you’re not at risk.

bulletUnderstand the symptoms of CO poisoning

Many people brush off the symptoms of carbon monoxide poisoning because they are similar to the flu.

It starts with headaches, fatigue, and nausea.

However, as time moves on, you may notice irritability, impaired judgment, coordination, and loss of consciousness as well.

If you’re starting to put the clues together, but you’re still unsure if it’s a virus or something more serious like CO poisoning, here are some helpful clues.

  • Everyone gets sick simultaneously (instead of having the sickness spread from person to person)
  • Your symptoms improve when you leave the home
  • The individuals most impacted are those who spend the most time at home
  • You don’t have symptoms like fever, body aches, or swollen lymph nodes which are common with the flu and other infections
  • Any pets in the home are also ill
  • Symptoms either appear or worsen when fuel-burning equipment is used

bulletInstall and maintain CO alarms in your home

Get carbon monoxide alarms installed in your home if they aren’t already present.

Many states will require that homes have them in certain areas of the house (for example, within a certain number of feet of rooms used for sleeping).

Please take note of how to install the alarm correctly, how to maintain it, and when to replace it.

7. Is carbon monoxide more dangerous to some people than others?

Yes, some people are more susceptible to this danger.

If you or someone in your family falls into the following categories, you should take additional caution.

bulletRespiratory conditions (ex: asthma or emphysema)

bulletCardiovascular disease

bulletAnemia or sickle cell anemia


bulletYoung children

bulletIndividuals engaging in strenuous activities

That said, anyone can get sick (or even die) from carbon monoxide poisoning.

Even if you’re not included in the above list, you must still be careful.

8. When does carbon monoxide pose a bigger threat?

Interestingly, though CO poisoning cases are higher in the winter months, people are more likely to be exposed to high levels of carbon monoxide during the summer.

This is because vehicles like boats as well as devices like grills, camp stoves, and non-electric heaters all produce carbon monoxide.

So, regardless of the time of year, it’s important to be vigilant about carbon monoxide in a house.

You can prevent instances of carbon monoxide poisoning by having an alarm in your home and being wary of power generators.

While generators can be a great resource during power outages, they can produce more CO than cars, killing people in a short amount of time.

For safety, make sure you place generators at least 25 feet away from and downwind of your house.

Additionally, be mindful of where the generator is in relation to vents or openings of your home, so no exhaust enters.

9. How can you guard your house against carbon monoxide?

As noted above, the best way to protect you and your family again carbon monoxide in a house is to get a CO alarm.

These alarms last between 5 and 7 years.

You should check the manufacturer’s guidelines for replacement when you purchase it.

If your carbon monoxide alarm goes off, then you should address the issue immediately.

If people in the home are exhibiting symptoms of CO poisoning, then the safest route is to leave the building and call your local fire department.

If there are no signs of CO poisoning, it’s okay to call your local gas utility company or a qualified technician to figure out the problem at hand.

Just make sure you don’t ignore the issue!

It’s not the same as an irritating fire alarm that needs its battery replaced.

Another important factor in keeping yourself safe is using appliances for their intended purpose.

For example, it’s NEVER a good idea to use appliances like barbeque grills, camp stoves, portable generators, or gas-powered lawn equipment inside.

All these items are intended for outdoor use.

Whether you’re trying to cook or use it for heat, it is both a fire and carbon monoxide hazard.

This also extends to running or idling your vehicle in an attached garage.

You must always open the door and back the vehicle out as soon as possible.

Additionally, always check to make sure the exhaust pipe isn’t blocked.

For instance, this can sometimes occur in the winter with snow, and vehicle owners won’t notice.

10. My CO detector just went off…now what?

 If your CO detector just went off, follow these steps.

These can help you troubleshoot the issue.

bulletDouble-check that it is indeed your carbon monoxide detector and not your smoke detector that is sounding

bulletSee if you or anyone in your household is experiencing CO poisoning

bulletIf symptoms are present, evacuate the house and seek medical attention

bulletIf symptoms are not present, ventilate your house with fresh air and turn off all sources of carbon monoxide

The most common sources are your gas or oil furnace, gas water heater, gas range and oven, gas dryer, gas or kerosene space heater, and any vehicle or appliance with a small engine

bulletHave a qualified technician come out to your house and check your appliances and chimney to ensure everything is functioning properly

In some cases, you could be experiencing a blockage that is causing carbon monoxide to build up in the home

11. How long does it take to get carbon monoxide poisoning?

Numerous factors impact how long it takes to get carbon monoxide poisoning.

The most relevant of these factors include age, gender, and general health.

The EPA says that the national ambient air quality standard (NAAQS) for CO is 9 ppm over 8 hours.

This threshold must not be exceeded more than once a year.

When carbon monoxide concentration in the air is higher than this, signs of CO poisoning can occur within 1 to 2 hours.

However, if there’s an extreme CO concentration, then it can kill an exposed individual within 5 minutes.

This is why it’s important not to ignore any signs of carbon monoxide poisoning and reach out for help immediately.

12. Can you survive carbon monoxide poisoning?

Yes, carbon monoxide poisoning can be treated, but you must seek medical attention immediately.

If you suspect you or someone in your home is suffering from carbon monoxide poisoning, then you should move them to fresh air.

Next, go to an emergency room or call the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the U.S. to seek counsel on the next steps.

If you take an individual who is suspected to have CO poisoning to the hospital, medical staff will be able to administer a simple blood test to determine if CO poisoning has occurred.

13. What are the measurement tools?

Are you interested in measuring carbon monoxide levels in your home?

You have a few options if you want to do it yourself in your home.

bulletRelatively high-cost infrared radiation absorption and electrochemical instruments

bulletModerately priced real-time measuring devices

bulletPassive monitors (still in development)

These tools (as well as detectors) are available in stores.

However, they are not a replacement for properly maintaining and using fuel-burning appliances.

14. What are the top tips for preventing carbon monoxide poisoning?

bulletDon’t cover the bottom of natural gas or propane ovens with aluminum foil as this can block airflow and cause CO build-up

bulletDon’t leave a car or truck running in a garage (even if it has remote start)

bulletDon’t use a charcoal grill, oil lantern, or portable camping stove inside

bulletDon’t use a portable generator or any gas-powered engine in your home or garage (even if doors and windows are open)

bulletDon’t use a stove or clothes dryer to heat your home

bulletDo make sure the flu is open when using a fireplace

bulletDo make sure your vents for your dryer, heating system, stove, and fireplace are clear of snow build-up during and after a winter storm

bulletDo have your heating system inspected every year and follow all recommended maintenance for appliances

bulletDo instruct your family on the hazards, signs, and symptoms of CO exposure

bulletDo have an evacuation plan in the case of CO exposure and poisoning

bulletDo consider switching from fossil fuel-powered to electrical or battery-powered equipment 

Final Thoughts

Carbon monoxide poisoning is a serious issue that causes more than 400 Americans to die unintentionally each year.

More than 100,000 visit the emergency room annually for symptoms and 14,000 are hospitalized.

Fortunately, there are many steps you can take to protect both yourself and your family from carbon monoxide in a house.

If your home doesn’t have a carbon monoxide detector, install one today.

Furthermore, follow the other tips above regarding proper maintenance and use of fuel-burning appliances to ensure everyone in your household stays healthy.

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Erika Gokce Capital

Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.


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