Can Candles Cause Carbon Monoxide Poisoning?

carbon monoxide

Carbon monoxide poisoning is dangerous. It is colorless, odorless, tasteless and it can be building up right now and you would never know it. Carbon monoxide is produced by candles, but is it enough to be dangerous?

Can candles cause carbon monoxide poisoning? Yes, candles can cause carbon monoxide poisoning. Candles produce a small but measurable amount of carbon monoxide and in a small enclosed space with poor ventilation carbon monoxide poisoning can happen. You should never leave candles burning in a small enclosed space.

Carbon monoxide is sometimes referred to as the “silent killer”. This is a title it has earned as an estimated 50,000 people per year visit emergency rooms due to carbon monoxide poisoning. Our choice carbon monoxide and smoke detector on Amazon.

Candles produce a very small, but measurable amount of carbon monoxide. Let’s take a look at some of the risk factors.

Carbon Monoxide Risk Factors

candles carbon monoxide

What Are Carbon Monoxide Risk Factors?

  • Poorly vented fuel-burning appliances
  • Poorly vented rooms
  • Enclosed spaces
  • Car running in a closed garage

Poorly vented fuel-burning appliances

Causes Of Carbon Monoxide Poisoning

  • Gas heaters
  • Fireplaces
  • Gas cookstoves
  • Gas water heaters
  • Furnaces
  • Charcoal grills
  • Wood burning stoves

Some of these appliances are not meant to be used as a main source of heat while others should be properly vented.

If you have an open floor plan and a ventless gas heater it is likely you will be okay, but if you try to use a ventless heater in your bedroom then you could be asking for trouble.

If an appliance is designed to be ventless it will be marketed as such, never use an alliance that is supposed to be vented without venting it.

Wood burning stoves and fireplaces are also a leading cause of carbon monoxide exposure. If you use a fireplace it is important to make sure that your chimney is complete with no leaks and is unobstructed.

A reverse air flow is a risk when using a fireplace because in this situation the air actually flows through the chimney back in to your house. This happens when your house is too tightly sealed, not allowing proper air flow through your house and out the chimney.

Poorly vented rooms

Poorly ventilated rooms can be risk factors, particularly if it has a ventless heater or a fuel-burning heating source such as a fireplace or gas heater.

A candle can also contribute to carbon monoxide poisoning in this situation. However, it may take multiple candles over the course of a certain amount of time.

Enclosed spaces

Enclosed spaces are also risky, particularly if it is one with a few or several people sleeping. Imagine a bedroom with a ventless gas heater and a few beds or bunk beds.

Carbon monoxide could slowly build up in this room over time if a detector is not in place and if the room is not adequately ventilated. This is a situation in which candles can also contribute to carbon monoxide poisoning.

Car running in a closed garage

This is a situation in which carbon monoxide poisoning can happen and a car running in a closed garage can be dangerous for people to enter and work in up to 10 hours later.

Sadly this is also a common form of suicide.

This is the number for the suicide prevention lifeline: 1-800-273-8255

Who is most susceptible?

Who Is Most Susceptible To Carbon Monoxide?

  • Elderly
  • Children
  • People with respiratory conditions


Elderly people who experience any form of carbon monoxide poisoning may be more likely to develop brain damage.


Children breathe more shallow and more rapidly than adults which may make them more susceptible to carbon monoxide poisoning.

People with respiratory conditions

Respiratory conditions that may exacerbate carbon monoxide exposure.

Respiratory Conditions That Many Exacerbate Carbon Monoxide Exposure

  • Asthma
  • COPD
  • Bronchitis
  • Lung Cancer
  • Pneumonia
  • COVID-19
  • Black lung
  • Silicosis

Symptoms of Carbon Monoxide Poisoning

According to the Mayo Clinic, carbon monoxide poisoning happens when carbon monoxide builds up in your blood stream. Your body can replace oxygen in your blood cells with carbon monoxide when too much is in the air.

Symptoms Of Carbon Monoxide Poisoning

  • Blurred Vision
  • Confusion
  • Weakness
  • Nausea
  • Dizziness
  • Dull headache
  • Shortness of breath
  • Loss of consciousness

The danger is paticularly elevated to those that may be intoxicated or sleeping.

Find out more by visiting the Mayo Clinic at the link below.

Here is an article from the Mayo Clinic on carbon monoxide poisoning

Preventing Carbon Monoxide Exposure

carbon monoxide detector

How To Prevent Carbon Monoxide Poisoning

  • Use Candles In Well Ventilated Areas
  • Have fuel-burning appliances serviced by a professional
  • Install a CO detector in your home
  • Leave your home if you experience dizziness, light-headedness, or nausea.

Serviced by a professional

While we all like to save a little money, if you are not confident that you know absolutely what you are doing, it is a lot safer to hire a qualified professional.

This is particularly true when it comes to gas furnaces, stoves, and other gas-burning appliances.

In addition to it being safer, in some municipalities, you are required to hire a licensed professional when it comes to things such as installing a gas water heater or a gas furnace.

Install CO detector in your home

Having a battery-operated CO detector in your home can act as an early warning system giving you the opportunity to get out or ventilate your home.

If your CO detector goes off, immediately turn off any fuel-burning appliances and begin opening doors and windows. Have your appliances inspected by a professional before turning them back on.

CO detectors should be placed at the same height of your bed. The risk with CO is that you may go to sleep and never wake-up.

Leave your home if you experience CO exposure symptoms

Above all, if you experience any symptoms of carbon monoxide poisoning please leave your home immediately. You can call 911 and the fire department will come and help assess your situation.

You can find out more about prevention from the CDC at the link below.

Here is an article from the CDC on carbon monoxide prevention.

Frequently Asked Questions

Can candle fumes harm you?

Candle fumes can be harmful if you are using candles made of paraffin wax. Paraffin wax candles are oil byproducts and are known to release carcinogens as they burn. In addition, all candles release carbon monoxide that can be dangerous in small and poorly ventilated areas.

Where should you not put a candle?

Candles should not be accessible to pets or children. In addition, candles should be kept away from drafty areas, curtains, showers, sinks, beds and should always be used with a heat-resistant surface.

How much carbon monoxide does a candle produce?

Candles produce a small but measurable amount of carbon monoxide. However, the amount is so small that it should not concern you unless you plan to burn dozens of candles for several hours in a small enclosed space.

Do soy candles emit carbon monoxide?

Yes, soy candles do emit carbon monoxide. It is a very small amount. Through the normal use of a single candle, you should never have to worry about carbon monoxide poisoning. However, you should always install a carbon monoxide detector in your home.

Can a candle set off a carbon monoxide detector?

Candles do not usually produce enough carbon monoxide to set off a carbon monoxide detector. If your carbon monoxide detector is going off, immediately blow out the candle and turn off all appliances that have a flame. Open your windows and doors and then check the appliances one by one.


In conclusion, carbon monoxide poisoning from a candle is not likely, but not entirely impossible. The greatest threat a candle can pose is that it may cause a house fire, not that it can cause carbon monoxide poisoning.

With that said, carbon monoxide is a real threat and can come from several sources other than candles.

Have your appliances professionally inspected, circulate air through your home with open windows and fans, buy and install a carbon monoxide protector, and give yourself some peace of mind.

Lastly, do not hesitate to leave your home and call for help if you suspect carbon monoxide poisoning. It is not worth the risk and it is always better to be safe than sorry.

What precautions do you take to keep carbon monoxide in check? Let us know in the comments.

Carl Adamson

Hi, I'm Carl Adamson, one of the founders here at Candleers. A few years ago I got really into the art and craft of candle making, initially with soy wax container candles. My friends started asking me to make candles for them and pretty soon it turned into a nice side-business. I started this website as a way to document what I've learned over the past few years and hopefully help others in the process. I still love candle making but I'm learning that what I enjoy even more is the business side of things - and for this reason I've started consulting others on how to start and grow their own candle-making businesses and side-hustles.

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