Healthy Environment, Healthy Community, Healthy Business

Environment Protection Authority

Environmental Issues

Chemicals and pesticides

Building and renovating with treated timber

Timber is treated with pesticides to protect it from insects such as borers and termites, as well as fungi that cause rot and decay. However, these pesticides can harm people and the environment, so it is important to use and dispose of treated timber safely and legally.

Most treated timber in Australia is softwood, usually plantation pine. Softwood grows more quickly and is cheaper to produce than hardwood but is not naturally resistant to pests. Treating softwood makes it more durable and versatile. Some hardwoods are also treated.

This 8-minute video contains practical information for treated timber users.

If you don't have time to watch the video, view one or two sections of the 'Learn more' program.

Using treated timber

Treated timber has many uses, including house and deck framing, flooring, building poles, interior and exterior joinery, cladding, garden furniture, trellises, pergolas, picnic tables, exterior seating, patios, decking, lattice, handrails, stairs, retaining walls, poles, stumps, fences and more. It can also be used in fresh water and seawater environments.

Is treated timber dangerous?

People may be exposed to chemicals in treated timber when

  • using it in their workplaces or homes
  • coming into contact with ash or smoke after treated timber has been burnt 
  • inhaling sawdust when using power tools on treated timber
  • having contact with soil which has been mulched with treated timber woodchips or sawdust

Copper chrome arsenate

One preservative, copper chrome arsenate (CCA), may harm people or the environment if not handled or disposed of properly. CCA contains arsenic, which causes cancer. Timber treated with CCA must be labelled correctly and not used in

  • playgrounds
  • picnic areas
  • areas where people may regularly come into contact with treated surfaces

Alternatives to copper chrome arsenate

Treated timber that is less toxic than CCA includes

There are also timber alternatives which are naturally resistant to pests and decay. These include

  • some hardwoods
  • cypress pine
  • plastic, aluminium, concrete or other composite ‘wood-look’ products, although these have a larger carbon footprint than timber

Using the right timber safely

Before you buy, handle or work with treated timber

Properly dispose of any waste treated timber.

Page last updated: 26 April 2017