March 02, 2003
CCA - Treated Timber
Statement by the Environmental Risk Management Authority Chair
In November 2002 our attention was drawn to a report published by U.S. scientist Dr Richard Maas, which raised new concerns about the use of Copper Chromium Arsenic (CCA) as a timber treatment.
The Environmental Risk Management Authority immediately undertook an investigation into public health issues surrounding the use of CCA-treated timber in playgrounds and residential buildings in New Zealand.
The report on this investigation, conducted by a recognised public health specialist - Dr Deborah Read - was completed last month. It was the subject of peer review by three independent medical and scientific authorities. It has also been examined by ERMA New Zealand experts and considered by the Authority's Standing Committee on Hazardous Substances.
The report's key findings are that research to date is inconclusive as to whether exposure to arsenic from CCA-treated timber poses a significant health risk to children, and that the low-level exposure that most of the general population of New Zealand will experience is unlikely to result in increased health risks.
The Authority accepts the findings of Dr Read's report. Our conclusion is that the weight of current evidence does not support measures such as banning all future use of CCA-treated timber or replacing structures in current use. On the basis of this review, we do not currently propose to undertake a formal reassessment under the Hazardous Substances and New Organisms Act.
There is however no question that CCA is a toxic chemical and that, in general terms, it is desirable to reduce human exposure to arsenic. The Authority is accordingly of the view that a range of actions recommended by Dr Read as prudent public health policy should be taken. These include:
- enhanced monitoring of treatment plants to ensure that CCA fixation is complete and relevant Codes of Practice and industry best practice standards are being observed;
- improved public health information for consumers, including labelling of CCA-treated timber;
- close attention paid to the occupational health and safety of those who are directly involved in timber treatment and the use of treated timber;
- additional safeguards in public parks and playgrounds; and
- ensuring that the appropriate authorities are aware of the availability of alternative materials or treatment methods for dealing with structures such as playground equipment.
The Authority is also of the view that more extensive studies into the environmental effects of CCA and the availability and comparative merits of alternatives to CCA should be commissioned. Options for achieving this are currently under discussion.
For the reports and questions and answers view CCA focus page.