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Can You Burn Old Pressure Treated Wood? (Explained)

Generally, we burn different types of wood in our day-to-day life. Either we burn wood for warmth or for other useful purposes. So, whenever it comes to burning wood, you might take any wood available close to you. 

Even you might take Pressure-treated wood to burn because it looks pretty similar to the traditional wood.

So, you might be confused about whether you can burn old Pressure-treated wood or not. Well, if you want to burn Pressure-treated wood, you have to know the consequences. Moreover, you have to know whether it is safe to burn old Pressure-treated wood or not.

Can you burn old Pressure-treated wood?

You should not burn old Pressure-treated wood. Because it is not safe to burn old Pressure-treated wood. Generally, when wood gets Pressure-treated, chemicals are used. So, while burning these wood, these chemicals will make toxic fumes that are highly toxic to humans, animals, and the environment.

So, burning Pressure-treated wood is not safe in general. Especially, if you burn new pressure-treated ones. But if you burn older ones, it is less harmful. So, you might think about how much old Pressure-treated wood is harmful. 

So, let’s see which Pressure-treated wood is too old to be toxic.

10 year old:

You should not burn any type of Pressure-treated wood. Because when the treated wood is manufactured with toxic chemicals, the chemicals don’t go away on their own. These chemicals can remain on the wood for decades. 

So, if you burn 10 years old Pressure-treated wood, the wood will still release toxic chemicals.

15 year old:

You should also not burn 15 years old Pressure-treated wood. Because you are not sure whether the chemicals of the wood are dissipated or not. Sometimes, the wood requires decades to dissipate the chemicals.

20 year old:

While burning Pressure-treated wood, the wood must be older. Even you can’t burn 10 years old ones. You need to choose Pressure-treated wood that is at least 20 or more years old. Though it might be safe to burn 20-year-old treated wood, you should ensure high safety.

25 year old:

You can burn 25 years old Pressure-treated wood because at this stage the wood has released most of its chemicals. So, the toxicity is lower when you burn this wood.

30 year old:

You can burn Pressure-treated wood if the wood is 30 years old. Because after three decades, the chemicals have been dissipated from the wood. Moreover, the wood will have fungus and other microorganisms that will help to dissipate the chemicals. So, you can burn it.

Can you burn old Pressure-treated wood in a fire pit?

You can burn old Pressure-treated wood in a fire pit if the wood is some decades old. But generally, you should not burn Pressure-treated wood in a pit. Because Pressure-treated wood will pollute the environment with toxic chemicals and fumes.

It’s often considered that older Pressure-treated wood is safe to burn. But it is might not be possible to guess the age of the Pressure-treated wood. So, it will also be unwise to burn Pressure-treated burn whether the wood is new or old.

Moreover, when you burn old Pressure-treated wood in a fire pit, the fumes will release into the environment. Pressure-treated wood contains chemicals that are harmful for humans and animals to inhale. So, don’t try to burn old Pressure-treated wood in a fire pit.

Why is Pressure-treated wood not safe to burn?

You might know that Pressure-treated wood is not safe to burn. But knowing the reasons behind it will make you more conscious about burning the Pressure-treated wood.

Releases toxic chemicals:

Generally, if you keep Pressure-treated wood for other reasons, it might not harm you. But when you burn Pressure-treated wood, the toxic chemicals will come out. These chemicals are used while manufacturing the Pressure-treated wood. 

So, there is no way to escape from the toxic chemicals.

These chemicals include Alkaline Copper Quaternary (ACQ), arsenic, and other toxic elements. So, it will be highly toxic to burn Pressure-treated wood.

Releases toxic fumes:

It is predictable that when you burn Pressure-treated wood, the chemicals will make the fumes toxic. Even the chemicals will release carcinogenic byproducts into the air. So, Pressure-treated wood will release toxic fumes into the environment.

Causes health issues:

Pressure-treated wood burning can cause instant health problems. Especially when you directly inhale the fumes. Even both short and long-term health problems can arise. 

For example, you can face respiratory inflammation, breathing problem, lung cancer, etc., dangerous health issues.

Causes pollution:

Another big issue that can arise from burning Pressure-treated wood is environmental pollution. Both air and water can be polluted from burning Pressure-treated wood.

For example, if you burn Pressure-treated wood, the toxic fume will pollute the air. Besides, if the leached-out chemicals from Pressure-treated wood get mixed with water, the water will be contaminated.

What happens if you accidentally burn Pressure-treated wood?

What will happen if you accidentally burn Pressure-treated wood depends on the age of the wood. If you burn a newer Pressure-treated wood or a Pressure-treated wood that is 10 to 20 years old, it might cause several problems.

For example, if you burn Pressure-treated wood that is not so older, it will release toxic chemicals and fumes into the environment. If you inhale the smoke, it can cause instant or long-term health problems. Moreover, toxic smoke is highly harmful for the environment.

But the Pressure-treated wood is older, for example, 20 or more years old, it will not cause any harm to you and the environment. Because the chemicals of the wood have already been dissipated. 

So, if you accidentally burn a Pressure-treated wood that is newer, the following problems might arise.

  • Air and water pollution
  • Highly toxic chemical release
  • Highly toxic smoke release
  • Short and long term health issues
  • Release of harmful carcinogenic byproducts

What do you do with old pressure-treated wood? How to get rid of Pressure-treated wood?

Now you might be confused about what you can do with old Pressure-treated wood. If you can’t burn them, you have to find a way to get rid of Pressure-treated wood. Let’s see what you can do with old Pressure-treated wood.

Contact to local authorities:

You have to find out whether your local authorities can take care of the old Pressure-treated wood. You must not throw out the Pressure-treated wood in the compost or waste bin. You can contact the local authorities to know whether they can take away the wood or not.


You can also recycle the Pressure-treated wood for other purposes. But make sure that the recycling process doesn’t use any heat that can leach the chemicals out of the wood.


You can also reuse the wood somewhere else in your house. For example, you can use wood for decorative purposes. Moreover, you can also modify the wood by painting and using it for different purposes.


You can also sell the old Pressure-treated wood. Selling is a wiser decision than burning the old Pressure-treated wood. But you must inform the buyer about the Pressure-treated wood while selling it. Otherwise, the buyer might use the pressure-treated wood wrongly.

How to tell if the wood is Pressure treated?

It is pretty difficult to tell if the wood is Pressure-treated. Because the wood looks pretty the same as the traditional wood. Moreover, this wood is available around us. So, it is pretty difficult to make difference between woods. 

But you can identify a Pressure-treated wood by following some processes.


You can identify the Pressure-treated wood by visual inspection. Generally, the Pressure-treated wood has a greenish outlook for using chemicals on it. Sometimes, the Pressure-treated wood can have a brown hue also.


Sometimes, you can identify the Pressure-treated wood by smelling it. Generally, the treated wood has an oily smell that the normal wood might don’t have.


Pressure-treated wood has tags or stamps that might inform you about the wood type. For example, sometimes the chemical names are mentioned in the tags or stamps. Besides, where you can use the wood is often mentioned. Thus you can identify a Pressure-treated wood.

Final Thoughts

Burning old Pressure-treated wood can be dangerous. Because Pressure-treated wood contains different toxic chemicals. So, when you burn it, the wood will leach out chemicals and release toxic fume into the air. But if the Pressure-treated wood is more than 20 years old, you can burn it.