We know open fires are romantic. We know about fire danger. Hopefully, we also know about the importance of clear, well-functioning chimneys and flues to remove indoor air polluting combustion gases. But did you know some fire fuels can also be a source of dangerous toxins?

The fuel I’m talking about is treated wood.

While I’m all for reducing the amount of waste we send to landfill, you should never burn old or waste timber if you don’t know its history. It may have been treated with copper chrome arsenate (aka “CCA”).

CCA is a wood preservative, applied to timber to protect it against fungi and bacteria-driven decay and insect attack – the arsenic is the insecticide component. Yes – THAT arsenic! The one made (in)famous by the Borgias and Agatha Christie novels.

Burning wood makes a highly toxic ash, concentrating the arsenic. But don’t just take my word for it! Here’s the advice from the Copper chrome arsenic (CCA) treated timber factsheet on the Victorian Government’s Better Health Channel website:

“CCA-treated timber and fire

Do not burn CCA-treated timber in fireplaces, barbecues, wood stoves or any wood fire.
In the event of a bushfire, the ash from burnt CCA-treated timber can contain up to 10 per cent (by weight) arsenic, chromium and copper.

Swallowing only a few grams of this ash can be harmful. Symptoms can include nausea, vomiting, diarrhoea and a ‘pins and needles’ feeling in the skin. Keep children and pets away from CCA-treated ash until it is removed, and see a doctor if you or anyone in your family shows signs of having eaten CCA-treated ash.

Ash from CCA-treated timber can be double-bagged, sealed and taken directly to your local landfill. When removing CCA treated timber ash, wear protective gloves, disposable overalls, and a P1 or P2 face mask (P2 masks are sometimes referred to as N95 masks) to minimise exposure to dust. Do not bury CCA treated timber ash.”

Serious stuff! Remember this when you see a pile of waste timber on the side of the road with a sign next to it saying “Free firewood”. This can be tempting, particularly given rising electricity and gas prices and the effects they have on heating bills. But it’s important to keep your family’s health in mind, as well as the household budget.

Useful resources:

EPA Victoria’s Wood burning and air quality information.

Forest Stewardship Council (Australia) – remember fire wood is a forestry product – look for FSC certified!

My fabulous book* Greeniology 2020 has great tips on saving money on heating bills (*shameless self promotion).