No matter the time of year, everyone enjoys sitting around a bonfire. While most people know the basics of how to build a fire and maintain a fire pit, there are some lesser-known facts about the wood that can and cannot be burned. For instance, the only wood that should be burned is natural wood and never pressure-treated wood.
When pressure-treated wood is burned, it releases toxins into the air that can cause chronic respiratory issues. If you accidentally burn pressure-treated wood, seek medical attention if you begin to feel ill. If you have a neighbor that burns pressure-treated wood, inform city bylaw services.
It is not always ideal to have to address the problematic behaviors of a neighbor, such as burning pressure-treated wood, but when there are health risks involved to everyone in the surrounding area, it is necessary.
What Is Pressure-Treated Wood?
Pressure-treated wood is wood that has had preservatives forced into it under pressure to make it resistant to decay and insect infestations. You will notice that freshly pressure-treated wood has a green hue and this comes from the preservative, Chromated Copper Arsenate (CCA), which was often used to treat it. Over time, with exposure to outdoor elements and sunlight, the green hue fades to grey making it indistinguishable from untreated wood.
What is Wolmanized Lumber? Check out the full article.
Because of the health risk of burning CCA-treated wood, the sale of it has been limited to commercial use only, though older homes may still contain this type of treated wood in its foundation. If you are unsure of whether or not the wood at your home is pressure-treated or not, it is best to err on the side of caution and dispose of it, only burning wood that you are certain is natural.
Is it Legal to Burn Pressure-Treated Wood?
While it is not technically illegal to burn pressure-treated wood, most cities have bylaws and regulations prohibiting the burning of pressure-treated wood to mitigate the health risks involved. If you see someone burning pressure-treated wood, you can contact your city’s bylaw services.
Are the Fumes from Burning Pressure-Treated Wood Dangerous to Inhale?
When burned, pressure-treated wood releases the chemicals that it was treated with (chromium, copper, and arsenic) into the air. After it is burned, the ashes also possess the toxic remnants of the wood making it hazardous to inhale while cleaning up.
Exposure to fumes from burning pressure-treated wood can result in health issues such as respiratory inflammation, permanent irritation to bronchial tubes, upper respiratory tract infections, and lung cancer.
Read my related guide: Can You Burn Painted, Stained, or Varnished Wood?
Why is Older Pressure-Treated Wood More Dangerous?
Chromated copper arsenate (CCA) treated wood came about in the 1930s and it was not until 2002 that the Consumer Product Safety Commission started to raise concerns over the safety of CCA. At that time, the Environmental Protection Agency restricted the use of CCA-treated wood for commercial construction purposes only.
Pressure-treated wood is now treated using the successor of CAA, ammoniacal copper zinc arsenate or alkaline copper quaternary, free of arsenic. While the newer versions still release harmful substances if burned, the older pressure-treated wood released toxic chemicals in their pure forms like chromium, copper, and arsenic, all of which are hazardous to humans if inhaled or ingested.
Wondering about sanding pressure-treated wood? Read our Sanding Pressure Treated Wood Dangers Safety Tips article here!
What is Arsenic Pressure-Treated Wood?
Prior to 2004, most pressure-treated woods contained arsenic to prevent insects from eating away at and burrowing in the wood. However, when it was found that arsenic was carcinogenic to humans, manufacturers ceased the use of arsenic in its CCA format.
Pressure-treated wood is more commonly treated with alkaline copper quaternary now, which does not contain arsenic and is safer for use according to the Environmental Protection Agency, though it should still never be burned.
How Should You Dispose of Pressure-Treated Wood?
If you have wood or lumber laying around and cannot recall its source or whether or not it has been pressure treated, it is best to dispose of it, only burning wood that is guaranteed natural. Pressure-treated wood can be disposed of at your local landfill. There may be a small fee to dispose of items at the landfill however it is worth it for safety purposes and peace of mind.
Who Should I Contact if my Neighbor is Burning Pressure-Treated Wood?
If you notice your neighbor burning pressure-treated wood and have a good relationship with them, it can be worthwhile to talk to them. Get curious and ensure they know about the safety hazards of burning pressure-treated wood.
If you do not have a comfortable relationship with your neighbor or if they continue to burn pressure-treated wood, reach out to your city bylaw services, as most cities have bylaws against burning this type of wood.
If you need help immediately and bylaw services are unreachable, you can call the non-emergency phone line for the fire department, and perhaps they can deter your neighbor from burning this type of wood.
Final Thoughts
It can be hard to distinguish regular, natural wood from pressure-treated wood especially if it has aged and lost its distinct green or brown color. If you are unsure whether or not wood has been pressure-treated, it is best to avoid burning that wood altogether. Only burn wood that is natural and untreated for the safety of yourself and those around you.
Wondering if you can stain pressure-treated wood? Read our article here for more information.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.