Working with and handling treated timber safely

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.

When planning a new project

  • Do your research and choose the safest treated timber for the job with the lowest hazard levels possible.
  • Look at alternatives to timber. There are now new materials such as recycled plastic on the market that look like timber but do not contain as many hazardous chemicals.
  • Make sure you have the right screws, nails, bolts, brackets or other fastening hardware for the job.Some timber treatments, particularly copper based treatments, can corrode steel fasteners. Fasteners in contact with preservative-treated pine should be: hot-dipped galvanised; monel; silicone; bronze or stainless steel. Electroplated fasteners are not suitable due to early break down of the plating.
  • Some treated timber types need cut surfaces resealed to make sure the treatment envelope is maintained. Ask at a hardware store if you are not sure which sealant to use.

Make sure you have the correct personal protective equipment.

Gloves: chemicals used to treat timber may leach out of the timber onto the surface of the wood. To avoid skin contact, always wear gloves which

  • are strong enough to resist tearing
  • will protect you from painful splinters
  • should be cleaned or disposed of after working with treated timber. 

Dust mask: avoid breathing in sawdust from all timbers, whether or not they have been treated.

  • If cutting, drilling or planing timbers treated with light organic solvent preservative, take care because the temperature of the cutting face (the point where the cutting blade and wood meet) can be high enough to give off chemical fumes.
  • Wear dust (P1) or dust and fume (P2 or N95) rated masks. Cheap paper masks are not suitable for working with treated timber.
  • If you are unsure about which mask to use, ask at your local hardware store.

Goggles: all timber sawdust and fragments, especially treated timber sawdust and fragments should be kept out of the eyes.

  • Work outside if possible to minimise the risks of inhaling sawdust and wear goggles to prevent it going into your eyes.
  • Clean up treated timber sawdust as you go. Either damp it down or use a vacuum fitted with a high efficiency particulate air (HEPA) filter to clean it up.
  • If you are working inside, use dust extraction devices if available. Hoods and hoses fitted to saws, drilling rigs and other tools use air under negative pressure to suck sawdust away.
  • If you are working with a lot of treated timber, make sure your dust extraction device or vacuum cleaner is fitted with a HEPA filter. HEPA filters capture particles down to 1 micron in size. Dust sucked through vacuum cleaners without a HEPA filter can come out the other end of the machine and be blown back into the environment you are trying to keep dust free.
  • Clean up as you go.
  • Children and animals should be kept out of areas where treated timber is being worked on.
  • If treated timber is to be used in an area where children play, for example outdoor play equipment or furniture, choose the least toxic suitable alternative.
  • If you want to reduce the risk of contact with treated timbers, paint the structure with an oil-based polyurethane or paint product.
  • Ensure a smooth finish to the structure to prevent splinters.
  • When you are smoothing, use a dust extraction device when working inside, or work outdoors to eliminate or reduce the risk of you or your children inhaling sawdust.
  • If children have been in contact with treated timber, wash their face and hands with soap and water as soon as you can.
  • Children should not put their fingers in their mouths after contact with treated timber.
  • Cover any recent cuts or abrasions to avoid exposure to treated timber or treated timber sawdust.
  • After handling treated timber, wash your hands and face thoroughly with soap and water before and after eating, drinking, smoking or using the toilet.

If you are working with treated timber more frequently than the occasional home or community project, or you are exposed to it in your workplace, you need to take extra precautions to manage the risks.

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