Toxic Types of Wood to Avoid Burning in Your Fire Pit

You may be tempted to burn any random wood lying around just because it’s convenient. But since you’re here, I assume you have an idea that not all kinds of timber are fit to burn in a fireplace.

Your instincts are right. In this article, I’ll tell you what wood you shouldn’t burn in your fire pit.

Can Pressure Treated Wood Be Burned in a Fire Pit?

You should avoid burning pressure-treated wood in a fire pit. All furniture products made with pressure-treated wood are labeled with a sticker that warns against burning it.

The reason is that lighting up pressure-treated wood can release arsenate fumes into the air, which is a poisonous odorless gas. The US Environmental Protection Agency considers remains of this wood as hazardous waste.

Also known as CCA wood, this timber owes its name to how it’s treated under high pressure with copper, chrome, and arsenic to lock the chemicals in. The purpose was to create timber that’s resistant to mold, rotting and insects.

These chemicals are hazardous to humans and production of this kind of wood stopped in 2000. Did you know that only one teaspoon of ash from CCA-treated wood contains lethal amounts of arsenic?

Pressure-treated wood can be found in old furniture and garden fencing. So, you should avoid burning any of those in your fire pit.

Can You Burn Rotted Wood in a Fire Pit?

It’s not a good idea to burn rotted wood in a fire pit. First of all, rotting logs are less dense than healthy ones so they won’t burn well, hence producing less heat.

If you notice green or yellowish patches on timber, it means it has mold on it. Burning moldy wood will produce foul-smelling smoke that can irritate when inhaled.

Also, rotten wood contains some water which creates lots of smoke when burned. So, it’s better to leave decomposing logs in the garden for the fungi and insects to feast on.

Can You Burn Stained Wood in a Fire Pit?

When you burn stained wood, the paint turns into potentially dangerous fumes. If the painted wood is old, there’s a chance the dye contains some lead.

Lead is a poisonous element responsible for many deaths in the past centuries when used in paint, makeup, and children’s toys.

Even if the gloss doesn’t contain lead, burning it will release other chemicals into the air.

Can You Burn Wet Wood in a Fire Pit?

When you burn wet wood, it crackles and pops. Although the noises aren’t harmful, they can zap you out of your zen state when enjoying your evening with loved ones.

Now, the reason you should avoid burning wet wood is because it creates soot that will cling to your fireplace. It’s sticky, flammable, and hard to clean.

Also, burning wet wood produces less heat than dry timber making it inefficient to keep us warm.

You should aim for wood with a moisture of 20% or less. Anything more than this is too soggy for clean flames.

If your logs look dry on the outside but you’re not sure what’s happening on the inside, you can measure the dampness level of your wood with a moisture meter. Investing in one is a good idea if you have a fire pit or a wood stove.

To measure the moisture level of the wood, you can split the log along the middle and test the innermost part.

Can You Burn Wood With Nails in It in a Fire Pit?

It’s not advisable to burn wood with nails in it in a fire pit for several reasons. Let’s first discuss the source of the timber. It may come from construction sites, old furniture, or wood pellets.

As discussed earlier, wood from such sources could be pressure-treated or painted. Both of these produce harmful fumes when burned.

Similarly, burning wood pellets can produce toxic vapors if they contain methyl bromide. You can tell if wood pellets have the substance if they’re labeled with MB.

If the wood with nails is damp, burning it in a fire pit poses the danger of flying nails. Once the wood pops, as characteristic of wet wood, lodged nails can be thrown out of the fire.

Sharp and hot nails can pose a danger for people sitting around the fire.

Finally, the nails in the wood could be galvanized. Burning wood with galvanized nails produces ash containing cadmium.

When you dispose of the ashes, you can introduce cadmium into the soil. This metal is harmful to plants and microorganisms.

Can You Burn Driftwood in a Fire Pit?

Driftwoods are pieces of trees coming from the ocean, river, or other water bodies. They’ve probably been floating around for a long time.

Driftwood from the ocean soaks up with salt water containing sodium chloride. When you burn salty driftwood, chlorine evaporates into the air.

Although it burns in colorful flames, chlorine gas is irritating if inhaled.

Sadly, even freshwater driftwood is a poor choice to burn in a fire pit because it may have absorbed other pollutants and a lot of moisture. As discussed above, wet wood doesn’t produce a clean fire.

Can You Burn Plywood in a Fire Pit?

Carpenters use plywood to make affordable furniture items. Sad to say, these pieces are short-lived. You may think, why toss a broken desk if you can burn it instead? Let me explain why that’s not such a good idea:

Plywood contains lots of glue and resin to hold it together. When burned, resin produces thick soot called creosote.

This tar stains the objects it comes in contact with. Also, the black fumes are both a nuisance and harmful when inhaled.

In chimneys, creosote buildup can restrict airflow and is a fire hazard because it’s flammable. Sadly, clogged flues are responsible for many house fires in the winter.

Can You Burn Your Christmas Tree in a Fire Pit?

We’re all in for the zero-waste lifestyle and repurposing what we already have. So, once the festive season is over, you may be thinking of putting your Christmas tree to use keeping you warm for the rest of winter.

Unfortunately, Christmas tree branches contain water which needs to evaporate over six months up to a year before they can be used.

More importantly, fir trees aren’t fit to burn in a fire pit because they contain lots of resin. Burning wood with resin produces creosote soot which can throw off the mood with its black smoke.

Additionally, the pins of a Christmas tree can catch fire quickly and send sparks flying all around. Although it sounds fun, these sparks can potentially cause a fire when they land on grass or upholstery.

Lastly, if your tree is decorated with whitish flecks to resemble snow, burning it will release harmful chemical vapors into the air.

Final Thoughts

To sum up, not all woods are suitable to burn in a fire pit. You should avoid burning pressure-treated, stained, or wet wood. It’s also a bad idea to burn driftwood, plywood, and wood with nails in it.

Rotten logs and branches of an old Christmas tree are poor choices for a fire pit as well. Using any of these woods can harm your health and the environment.