Are Wood Burning Stoves Bad For Your Health?

Who doesn’t like the sounds, sight and smell of a fireplace? I mean, we even have fireplace channels on tv to watch one when we don’t have our own. While wood-burning fireplaces are pleasing to look at and listen to, they produce significant pollution inside the house, known as particulate matter, from the burned wood and other materials.

I decided to do some research to learn if a wood burning stove is better than an open fireplace and was surprised by what I found. While you might think that a wood burning stove with a tightly shut door will eliminate pollution inside the home, you would be wrong.

Wood burning stoves introduce significant particulate matter into the home particularly when lighting and refueling the fire with more wood. Research shows that even normal use of a wood burning stove floods the home with hazardous particles.

Pollution from wood burning stoves

Researchers measure particulate matter (PM) in terms of the size of the particles by diameter. The smaller the particle the harder it is to filter them out and the less visible they are to the naked eye. In that regard:

PM1 refers to particulate matter that has a diameter of less than 1 micrometers (1μm). This includes particles like dust, diesel emissions, bacteria and viruses. It can only be seen with a microscope it is so small and is even difficult for many air filters to remove from the air we breathe.

PM2.5 refers to particulate matter that has a diameter of less than 2.5 micrometers (2.5μm) which is about 3% of the diameter of a human hair. It is so small, it can also only be seen with a microscope. Examples include pollen and spores.

PM10 refers to particulate matter that has a diameter of less than 10 micrometers (10μm). Examples include coarse fine dust and other organic particles.

Air filters used in your furnace are only able to filter out a certain size of particle and the average home does not use a filter capable of filtering out many very small but potentially dangerous particles.

Wood burning stoves produce various levels and sizes of particulate and PM2.5 in particular is noted in various forms of heating specifically along with cooking and particle re-suspension. Research has shown that air pollution may be responsible for up to 7 million deaths around the world per year so exposure to these particles is very dangerous.

What chemicals are produced by wood burning fires?

While the main components of a fire are water and carbon dioxide, other dangerous chemicals may be produced depending on what you burn:

Carbon monoxide (CO)
Carbon dioxide (CO2)

Sulfur oxides (SOx)
Nitrogen oxides (NOx)

While a roaring fire is often referred to as being cozy and relaxing, the truth is that byproducts from burning wood can be very dangerous. These chemicals are even more dangerous if you suffer from asthma, heart disease, lung disease, bronchitis, diabetes or other health conditions.

Wood to avoid burning in a fireplace or wood burning stove

If you burn chemically treated woods or other materials you can also introduce volatile organic chemicals (VOCs) and polycyclic organic matter (POMs) into the environment. In that regard, wood to avoid burning includes:

Wet or freshly cut wood which has not had a chance to dry.
Chemically treated wood.

Driftwood that you found as it may have a high salt content.
Wood that produces sparks such as trees with sap, dried branches or leaves, pine cones or needles (ie. Christmas tree).

Also avoid throwing things into the fire to quickly burn them as they may also release chemicals into the air that are hazardous to your health.

Are wood burning stoves bad for your health?

In a word, yes.

Even a wood burning stove like the one shown above – which has doors that can be tightly shut during use – produces significant particulate matter which is able to enter the home.

Research has shown that use of an indoor wood burning stove increased PM2.5 by 196.23% and PM1 by 227.80% simply through normal stove use.

The State of Washington reports that homes that are heated with wood burning fires have 26% more PM2.5 particles present than homes that don’t. It’s also believed that upwards of 70% of smoke and particles that leave a fireplace and go up through the chimney can reenter the house and neighboring houses. Even modern windows and doors that offer tight seals are often not secure enough to prevent microscopic particles from entering a home for residents to breathe in.

So even if you don’t have a wood burning fire, if your neighbor(s) does, you may be susceptible to breathing in fumes and chemicals that their fire produces.

Are wood burning fireplaces bad for your health?

In a word, yes.

And even more so than a closed wood burning stove since an open fireplace doesn’t have metal and glass doors to limit the spread of smoke and microscopic PM inside the home.

Every time wood is added to the fire it tend to result in ashes from the already-burning wood flying up a bit into the air and while much of it will disappear up the chimney, at least some will enter the house. Open fireplaces tend to use much more wood than closed wood burning stoves, too.

I lived with my grandmother for 6 months at her home in my younger years and love starting and playing around with her open fireplace. I just loved the sight and sound of the fire.

But I also recall the smell of burning wood and paper when I sat near the fire and also remember seeing some black marks on her walls from soot that had entered the house from the fire.

How to reduce your exposure to PM1 and PM2.5 particles

Don’t burn wood inside the home in either open fireplaces or wood burning stoves if you can avoid it.
If you have to burn wood, only burn dry wood not wet wood as it produces more smoke. Freshly cut wood might need to wait up to 1 full year to fully dry out.

A wood burning stove can produce up to 3x more heat while using 1/3 of the wood that an open fireplace uses. It also controls heat better.
The hotter the fire the less smoke is produced.
Use an air purifier(s) inside your home to clean the air from particles produced by the fire.

Use the highest rated air filter allowed by your furnace manufacturer to remove the smallest particles possible.
Keep your windows and doors shut if your neighbors are the ones burning fires as the fumes and burned chemicals can enter your home.
Stay indoors if there is a nearby outdoor fire burning.

Manufactured fire logs

Some people use manufactured fire logs rather than actual wood from trees to burn in their fireplace. There are both pros and cons to using them. Over time there have been new manufactured logs produced that incorporate more materials, last longer and may better mimic real wood.

Here is a comparison between manufactured fire logs and real wood.

NOTE: As you’ll see below, manufactured fire logs may not be usable in wood stoves or wood stove fireplace inserts.

Summary

While a fireplace or wood burning stove can be a fun thing to have in your home to provide heat and even some entertainment with the sights and smells, it also comes with a price. The chemical and fumes introduced into your home can be deadly or at a minimum unhealthy.

If you have a wood burning fireplace or any fireplace for that matter, make sure you have it cleaned and maintained. Also ensure your home insurance company knows that you have any fireplace as it’s important for your ongoing coverage.

And remember, you can always check out a fireplace channel or video if you need to get your fire fix. It’s safer and has a pause and rewind feature.

	Manufactured fire logs	Real wood
Place of use	Generally not used in wood stoves or wood stove fireplace inserts. Newer fireplaces have begun updating labeling to allow fire logs. Check with your fireplace manufacturer and with the log manufacturer to be safe.	Used in any fireplace.
Materials	Typically made with recycled wood, agricultural fibers and wax. Some add coffee grounds or other materials.	Actual wood from a wide variety of sources and types.
Burn time	Manufactured logs common burn for up to 3 hours. 1 log is used at a time.	For 3 hours of burning, you might need up to 25 lbs of wood.
Emissions	Manufactured logs may give off up to 75% less harmful gases and 80% fewer fine particles than real wood and also introduce less particle matter into the home and air.	Burning wood produces dangerous chemicals and produces CO, CO2, SOx and NOx.
Ambiance	Less ambiance as manufactured logs are burned one at a time and don’t produce the same heat or flames.	More ambiance as you can burn more logs at one time which produces more heat and flames.
Heat	Produces far less heat with 1 log than a typical wood-based fire.	Produces more heat with multiple wood logs than 1 manufactured log.
Convenience	More convenient. One log used at a time = less work, less storage of wood, less clean up.	Less convenient. More wood is consumed, more clean up is required and stored to keep a fire burning.
Cost	Individual logs cost $3 – $10 depending on the quality and brand each. Multi-packs of 6 – 9 logs costs $15 – $55. Assuming 3 logs used per day, 6 -10 weeks of fires could cost $378 – $2,100 depending on the price price per log.	A cord of wood may cost $200 – $600 and can last 6 – 10 weeks in the winter.