Working with treated timber

When working with treated timber, there is a risk of inhalation of noxious fumes and dust. Guidelines have been put together by the New Zealand Timber Industry Federation for people working with Light Organic Solvent Preservatives (LOSP) or copper, chromium and arsenic (CCA) treated timber.

These guidelines can be found on the New Zealand Timber Preservation Council's website. The guidelines recommend waiting for the preservatives to dry off before using the treated timber, but if this is not an option, wear protective goggles and use a respirator when cutting or sanding treated timber.

You should also wash your clothes separately from other household clothing and wash your hands before eating, drinking or smoking. Any off-cuts should be disposed of in a proper landfill not be burnt nor used in barbecues.

Ensure that any dust and residue on the surface of the wood is washed off prior to use.
 

Using Treated Timber for Vegetable Gardens

A number of studies have shown that CCA is not absorbed into above-ground food crops such as grapes, tomatoes and cucumbers There are, however, some reports of a slight increase in arsenic content in root crops such as carrots and beets grown against treated timber, although the arsenic is in a safe organic form and most of it is removed with peeling. Any possible concern can be eliminated by growing these vegetables more than 100 mm from treated-timber garden edgings, or by lining the edgings with plastic. This has the additional useful effect of reducing soil contact with the wood, which could further extend the wood's life.
 

Technical Advice

For technical advice about construction methods and materials such as treated timber; contact:

Building Research Association of New Zealand Ltd (BRANZ). If you are a home or building owner or a member of the public requiring advice, there is a public helpline, phone               0900 590 90         0900 590 90, or visit their website: www.branz.co.nz.

Department of Building and Housing (DBH) for help understanding your obligations under the Building Act and Building Code, visit their website: www.dbh.govt.nz, or phone               0800 242 243         0800 242 243.

Osmose guide to the Hazard Class System and Timber Preservation options in New Zealand, phone customer support               0800 787 070         0800 787 070 or visit their website www.osmose.co.nz