A guest post from Ministry for the Environment about the safe burning of treated wood.

Winter is coming (or it’s already here)… and our thoughts turn to keeping warm, and stocking up on wood for our fires and wood burners.

If you will be using an open fire or wood burner there a couple of things you need to know.

Firstly, burning wood releases tiny particles that affect our health.

PM₁₀ is the collective term for very small airborne particles that 10 micrometres or less in diameter – or about one-fifth of the width of a strand of hair.

These tiny particles are associated with respiratory irritation, heart disease and cancer. Poor air quality can also cause damage to the natural environment including soils, vegetation and waterways, as well as buildings, or structures like statues.

Treated timber and wet wood (ie, with a moisture content greater than 25 percent) are especially polluting and should not be used as fuel at all.

Aside from risking your health, in some regions it breaches local body bylaws to burn treated timber, and the council could undertake compliance action ranging from abatement notices to fines.

Check the rules with your regional council or unitary authority.

It was recently brought to the Ministry for the Environment’s attention that people have been selling treated demolition timber for firewood, but it’s a practice we strongly discourage.

We’re delighted that Trade Me is supporting safer wood burning practices and better health by banning people from selling treated timber as firewood.

Of course treated timber can continue to be sold, but will be listed elsewhere on their website for other purposes, such as repairs or building projects.

Secondly, if you want to install a second-hand wood burner, including ones bought on Trade Me – buyer beware: there are rules in place that prohibit the installation of domestic wood burners that don’t meet national environmental standards which are specified by the Ministry for the Environment and enforced by councils.

These standards ensure all new domestic wood burners burn efficiently to minimise health and environmental risks from poor air quality.

In technical terms, wood burners must have emissions of less than 1.5 grams of particles per kilogram of dry wood burnt and a thermal efficiency of not less than 65 per cent. Authorised wood burners that meet these standards are listed here.

We recommend you discuss your plans with your local council. As well as the national environmental standards, your council might have region-specific rules or guidelines you need to know about before you buy.

For more information about wood burners and fuels contact your regional council/unitary authority or the New Zealand Home Heating Association.

For more information about New Zealand’s air quality and environmental or health risks see the Ministry for the Environment’s website.

Please note:

Trade Me is banning the sale of treated timber in the firewood category from 16 August. Any listings of treated timber offered for firewood will be removed.

All sellers listing wood burners or wood fuel types will need to continue to meet the existing standards for their intended use. Sellers may be asked for evidence of compliance.

A big thanks for MfE for putting this advice together.

Do not list treated timber as firewood on Trade Me