Burning wood in a fire can create warmth, cook food and create ambience among other benefits. But while fire carries the normal dangers we know about including safety aspects related to smoke, CO and CO2 emissions, there’s another danger that we need to be wary of.
Not all wood should be burned as some species are toxic and can create additional hazards. Manufactured and treated woods and wood species with the word poison in it should be avoided.
Below we’ll look at manufactured woods who can have toxins in them as a result of the manufacturing process, wood that simply has toxins in their natural state due to aging and environmental reasons as well as specific wood species to avoid burning due to natural toxins.
What wood should you not burn?
While certain species of wood shouldn’t be burned, there are types of wood in more general terms that shouldn’t be burned either.
They include:
Pressure-treated lumber – Often used in outdoor applications like wood decks and playgrounds, pressure-treated lumber has been coated in a liquid chemical and then highly pressurized to help it withstand whatever mother nature can throw at it. As such, it’s unsuited for burning given the toxins that can be released. This typically includes many wood fence panels.
Green wood – Wood that is still green hasn’t been allowed to season (age) to make it suitable for burning. It may not burn well to start with but can also still have liquid sap inside that when heated can start popping and sizzling which isn’t desirable. Green wood can also cause significant smoke. A tree typically needs 6 – 9 months after being chopped down to season before it’s ready to burn.
Driftwood – Driftwood is wood that has washed ashore on a lake or other body of water. It can be loaded with salt and possibly other chemicals that can cause toxins when burned. It may also be infested with pests that if brought inside your home, could create another problem.
Painted and finished wood – Wood that has been painted or treated with a finish can release harmful chemicals in the air that can be dangerous for your health.
Wood with manufactured material on it – Wood that has rubber, plastic, glue, metal or other man made materials should be avoided as they can give off dangerous toxins when lit.
Rotting wood – Rotting, dead wood can harbor insects and pests and if damp, may also contain mold. Avoid burning it as a result.
Engineered sheet wood – Avoid manufactured woods like particleboard, plywood and MDF among others. Also avoid wood used in pallets (skids).
Softwood – Softwood is commonly grown in Canada and is great for building wood-framed homes in North America. But softwoods like pine, fir and cypress generate significant smoke when burned and thus should be avoid in fires.
Endangered species – Some tree species are endangered and may be illegal to cut down as a result. You can view various lists of endangered tree species but also be wary of protected trees or forests that simply can’t be cut down from, regardless of tree species.
Aromatic woods – If you suffer from allergies, you’ll want to avoid woods such as aromatic cedar, fir, pine, rosewood, camphor, and agarwood among others.
Wood from an unknown source – Is the wood you’re looking at burning non-local or from an otherwise unknown source? Wood – particularly dead wood – can house termites
, Asian long horned beetles and other pests that you can not only introduce into your home area in general but more specifically to your home. Avoid wood that comes from an unknown or non-local source when possible. The risk of bringing termites and other pests into your home with firewood is low but better to eliminate the chance it happens regardless.
What wood species are toxic to burn?
While there are many types of woods to avoid burning as we just saw above, there are a number of common wood species have natural toxins and should also not be burned.
They include:
Trees with the word poison in them – Poison ivy, poison oak, poison sumac and pretty much all woods with the word poison in it should be avoided both literally and in terms of burning.
Oleander – All parts of the oleander are poisonous and it is in fact used as a poison for rodents such as rats. Oleander is toxic when dry and even touching the leaves can cause irritation. Not only is there the toxic aspect of burning oleander that is a problem but the fact it can be problematic to simply touch makes it a wood to avoid.
Cone-bearing trees – Any tree that produces fresh pine cones should be avoided as the cones have sap which can smoke and release the sap that can flare up. Dry pine cones can make great kindling but aren’t a great source of heat if you already have a fire going.
Christmas trees – These are typical fir, pine, cypress, spruce or certain cedars. The problem with burning a Christmas tree are the dried needles and sap inside the tree that when heated will pop and sizzle and can be a fire hazard inside a chimney. Even in an outdoor fire, these trees will burn quickly and can get out of control.
Summary
While most wood species that you may come across in the wild may ultimately be burned in a fire outdoors with no trouble, it’s still best to avoid certain wood species and types for your safety.
This is more critical when burning wood inside a home in a fireplace as deadly toxins can be released for certain types of wood that can endanger your health. Even if you have a wood-burning stove with a tightly sealed door, you do open the door from time to time and that will release toxins inside the home.
And if you’re planning on setting a fire to cook food, you might be interested to know the best types of woods for smoking that aren‘t toxic!
What are the best woods for smoking foods? Click here to find out.
