Can You Burn Pressure-Treated Wood? (Hazards & Effects)

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If you have a pile of pressured-treated lumber in your backyard, you have ways to get rid of it or recycle it for other purposes. But did you know that not all wood types are safe to burn? 

When disposing of it, you may probably ask yourself if you can burn pressure-treated wood or not. So, in this piece, I’ll guide you through the available and safe disposal options. Let’s get started!

What is Pressure-Treated Wood?

Pressure-treated wood is lumber that has undergone a preservation process using pressurized chemicals. The treatment involves placing the wood in a sealed chamber and subjecting it to high pressure. It will force the preservatives deep into its fibers.

Woodworkers prefer to treat lumber to prevent natural decay and to increase its resistance to water, corrosion, and UV rays.

pressure treated lumbers

Pressure-Treated Wood vs. Traditional Wood: Advantages

So why do woodworkers prefer using pressure treated lumbers? 

It is because pressure-treated wood has a longer lifespan than regular lumber. It means it will be more cost-effective than the traditional one.

Some craftsmen choose pressure-treated wood as a versatile and more convenient material than regular lumber. According to studies, new formulations are identified to be safer for the environment and need a minimal amount of maintenance.

Another advantage of pressure-treated wood is its resistance to fungi and insects burrowing into the wood. 

As part of the pressurized treatment process, manufacturers used copper-based chemical compounds to protect the wood surface from fungi and insects. 

milling lumber

In addition, to make it fire-resistant, chemicals such as insecticides and fungicides are sprayed over the outdoor furniture. Some manufacturers added fire-retardant compounds to keep treated wood for outdoor projects from burning.

You can also find treated wood with the standard nominal size of lumber. You can purchase it in a plank, poles, or post variations. You can also easily cut and drill it because you can maneuver it instantly.

Read Next: Lumber Dimensions and Sizing

Is Burning Wood That’s Pressure-Treated Hazardous?

Technically, you can burn wood except pressure-treated wood. This lumber is highly combustible and can cause extreme danger because of the pressure treatment. 

Why It’s Not Safe for Burning

The burning of pressure-treated wood is hazardous because of the preservatives and other chemicals. The burnt lumber emits arsenic that can harm people and the environment.

If you believe that fire eliminates chemicals by burning, it does not. Incinerating it will not get rid of the pile-treated lumber in an instant.

pressure treated lumber

The American Medical Association warns that exposure to ash dust and smoke from burnt lumber is harmful and potentially lethal due to its poisonous nature. Ingesting these carcinogenic compounds, specifically arsenic, can lead to acute intoxication.

To put it in perspective, a lethal dose is about 10 lbs relative to your body weight, and it can cause harm instantaneously.

And according to the Environmental Protection Agency, burning wood is illegal. Therefore, if you want to dispose of it, you should look for the local government’s proper wood disposal options in your community.

What Will Happen if You Burn Treated Wood Accidentally?

Given that wood is often preserved with copper-based compounds, burning it can lead to serious health issues. After exposure to such toxic environments, you can experience symptoms like extreme fatigue, hair loss, persistent headaches, and nosebleeds.

A family reported that they suffered from these conditions after accidentally using pressured-treated lumber in a wood stove. 

lumber pressure treated

According to reports, all the family members experienced hair falls, blackouts, and extreme disorientation for a long time. And what is alarming, parents complained about the frequent seizures of children because of the toxic fumes from a wood stove.

So if you accidentally burn pressure-treated lumber, you can call 911 or apply first aid medication. Take off your clothes and use water and soap to wash your skin thoroughly. 

If the irritations in your eyes and skin persist, you seek medical attention.

New Wood Preservatives

Traditionally, treating wood includes oil-borne, water-borne, and fumigation chemicals. 

Manufacturers used oil-borne preservatives for treating the wood by dissolving it with petroleum and other natural solvents. Chromated copper arsenate (CCA), Penta, and Copper naphthenate solution (COP-R-NAP) are some available oil-borne preservatives.

cutting lumber with table saw

You can use oil-borne with your fences and utility poles. If you want clean treated lumber, you can use water-borne preservatives as well.

Water-based preservatives are mainly composed of ammoniacal copper zinc arsenate, arsenic, fluoride, and chromium. Other metallic salts and compounds are also ingredients of this preservative.

But if you want potent wood preservatives, you can use fumigants for a longer life span and prevent future problems with your lumber. The fumigant’s primary active ingredient is methyl-isothiocyanate (mitc). 

Other than those wood-decay preventive chemicals, you can opt for these new wood preservatives:

ACQ (Alkaline Copper Quat)

The Alkaline Copper Quat or ACQ has two types— A and B. Type A or CBA-A has copper, boric acid, and tebuconazole, whereas type B or CA-B contains higher concentrations of copper and tebuconazole. But the latter has no boric acid. 

lumber at a Home Depot

You can use ACQ for wood underwater or below ground. 

CA (Copper Azole)

Commonly used in the United States and Canada, Copper Azole or CA is a water-based and reliable all-around lumber preservative. CA is considered a fungicide and insecticide that you can apply to wood products for water and ground.

Borates

Borates or DOT (disodium octaborate tetrahydrate) is an EPA-registered water-based wood treatment. It is common around Asia, North America, and Europe for interior and indoor furnishing.

Copper Naphthenate

If you are looking for another option to prevent insect damage, you must use copper naphthenate. You can apply it with a brush or spray by dipping or pressure to treat lumber. It is one of the oldest wood preservatives, registered in 1951.

Copper-HDO (N-Cyclohexyl Diazonium Deoxy-Copper)

Not as oldest as copper naphthenate, copper-HDO or N-Cyclohexyl deoxy-copper was first used in 2005. You can use this for rails, gazebos, fences, and posts. However, you should not use it with copper-HDO for food-related buildings and packaging areas.

lumber sorted according to species

Polymeric Betaine

If the lumber is for forest goods, you will need to apply polymeric betaine. It is good for pressure-treated wood for forest goods. Polymeric betaine converts to didecyl dimethyl ammonium chloride or DDAC and boric acid.

Effects of Burning Pressure-Treated Wood on the Environment

Burning pressure-treated lumber has adverse effects on the environment. If you burn pressure-treated lumber, the chemicals used as preservatives to the wood are released as toxic gas in the air. Treated wood contains arsenic and other highly hazardous chemicals that are lethal.

Burning is also illegal, as I have mentioned earlier in this article. The government prohibited it because of the contamination in the water source for drinking and irrigation of farmlands [1].

Effects of Ingesting Dust from Burnt Treated Wood

Dust from burning treated lumber poses a significant threat to us because arsenic is poisonous. If you accidentally ingest dust from it, you can feel mild to serious negative effects on your health.

How to Tell if the Wood is Pressure-Treated?

So how would you tell if lumber is treated or not? Pro woodworkers can easily identify treated lumber, especially those pressurized with chemical preservatives. 

deck built with pressure treated wood

But, just like them, you can identify if your waste lumber has been treated or just regular with these straightforward measures that we have.

Color

Treated lumber comes in a greenish, blue, or dark brown color. The change of wood color depends on the chemicals used during treatment. But for long periods, the lumber will return to its more natural color as the chemicals remain in the wood.

Chemical Injections Areas

If there are half-inch-long splits on the surfaces, you can tell if it has been pressure treated. 

These markings result from placing the lumber inside a pressurized chamber full of liquid preservatives. This process also removes the air from it.

See Also: Is Pressure-Treated Wood Sealer Required for Cut Ends?

Burning Old Treated Wood: Is it Advisable?

Can you burn pressure-treated wood regardless oif it’s excess from your woodwork or waste from previous building construction? Can you simply burn it? The answer is simply no. I strongly advise against burning waste-treated wood as a disposal method.

indoor seating bench

Is it Okay to Burn a 20-Year-Old Treated Wood?

A 20-year-old treated wood is as good as new, so you should not burn it. The chemicals can be as toxic as the 5-year-old treated lumber.

How About a 25-Year-Old Pressure-Treated Wood?

Incinerating 25-year-old pressure-treated lumber is not advisable by our experts. A block of older pressure-treated wood has a life span of as long as 40 years. 

Is it Fine to Burn Treated Wood Outdoors?

Burning it outdoors is illegal. There are rules regulating the proper disposal of it, except burning it. If you need to dispose of it, there are different options you can get as you read along in this article.

Can You Burn Green Pressure-Treated Wood?

Either green, blue, or brown, you should not burn it. It is safe depending on the chemicals used and if it’s cured. On the contrary, burning pressured treated lumber is highly risky to both public health and the environment.

How About Burning Wolmanized Wood?

Burning wolmanized wood is illegal and extremely toxic. The latter is CCA wood or pressure-treated lumber using CCA chemicals. 

wolmanized wooden floor deck

How to Dispose of Pressure-Treated Wood

So to properly dispose of your excess wood, I’d suggest looking into the disposal options I’ve outlined here to handle your excess wood responsibly.

Keep in Specialized Bins

To prevent mixing treated lumber or any hazardous waste with other trash or regular lumber, you should prepare a disposal bin with a protective layer. 

Reach Out to Your Local Landfill

Another option you have is to reach out to your local dumpsite. Treated wood can fill your disposal bin, or your backyard can be hazardous if you leave it in with regular lumber. 

Most disposal areas have enough space for treated wood or any hazardous waste. But it should be approved by your local authorities. 

What Wood Type Can You Burn?

On a side note, you can burn wood as a fire-lighter and firewood during winter. You can use hardwood and softwood as long as it’s untreated wood or has no harmful chemicals. 

quarter sawn Red Oak

But the most common wood you can burn is oak, elm, or birch. You can use the birch bark as a fire-lighter. Oak and elm wood are good sources of heat and little smoke. 

Learn more about pressure-treated wood here

FAQ

Can I burn pressure-treated wood that's new?

No, you cannot burn pressure-treated lumber, old or new. The wood absorbs the chemicals used to extend its life span. Therefore, if you burn them, the public health and environmental risks will be extreme if you burn them.

Will pressure-treated wood burn?

Yes, pressure-treated wood can burn, but you should not burn it. But the toxic chemicals used to preserve the wood delay the spread of flames because wood releases water and carbon dioxide.

Conclusion

So, can you burn pressure-treated wood? Now, you’re pretty sure that no one should burn treated lumber. No matter the circumstances, burning treated wood is prohibited by law and extremely dangerous to everyone and your community. 

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Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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