CCA Treated Timber (Copper
Chrome Arsenic)
June 06 Press Release from the Croydon Conservation Society
Arsenic
based timber treatments will be phased out in the US by the
end of this year.The use of CCA
in Australia has been reviewed because of new evidence that
it is unsafe.
But what about the existing decks, cubby-houses, schools &
public playgrounds?
For
60 years, wood treated with copper, chromium and arsenic has
been the preferred solution for a long-lasting, low-cost wooden
structure around the home. The timber has also been extensively
utilised in park benches, tables, and climbing structures. Evidence
against using these products has been mounting, and a review
has been conducted by the Australian
Pesticides and Veterinary Medicines Authority. The use of
CCA treated timber has been restricted in certain domestic situations,
such as children’s play equipment, picnic tables, decking
and handrails.
Sharon
Beder, Professor of Science and Technology at Wollongong University,
has analysed the international research on CCA timber and its
possible impact on human health. The problem is that over time,
as particularly the arsenic leaches out onto the surface of
the wood, anyone who touches the wood gets arsenic on their
hands. This leaching can go on for up to 20 years, with no reduction
in toxicity.
The
Croydon Conservation Society in Victoria tested some CCA treated
playground equipment in June this year. Their tests revealed
staggering levels of not only arsenic, but also chromium and
copper. The highest levels wiped from the surface of the timber
were 710 micrograms of arsenic, 630 micrograms of chromium and
670 micrograms of copper. To put that into perspective, the
level of arsenic available to children on the surface of the
timber far exceeds the maximum amount of arsenic allowed in
a glass of drinking water. 
Arsenic
is a known carcinogen, an endocrine system disruptor and can
be toxic to the skin and internal organs. Chromium accumulates
in tissues, is a strong skin irritant and a potent skin allergen.
There is no data on the effects of ingesting chromium, arsenic
and copper together. Burning CCA treated timber releases toxic
amounts of arsenic gas. Gloves are recommended to be used when
handling CCA treated timber.
A
study by the US Consumer Product Safety Commission has found
that children between two years and six years old who regularly
play on CCA treated playground equipment have a significantly
increased lung or bladder cancer risk over their lifetimes.
Professor
Beder told Earthbeat (13/09/2003) that some countries have banned
treated timber outright. For example, Switzerland, Vietnam and
Indonesia. Some countries have severely restricted it, for example
Japan, Sweden and Germany. The European Commission has issued
a directive that treated timber should not be marketed except
for selected industrial purpose. In the US there’s a voluntary
phase-out of CCA treated timber for residential uses.
What
will be done to deal with the problem of existing CCA treated
timber structures?
Paints
and varnishes have been shown to be temporary fixes only. Alternative
wood preservatives are available, without the chromium or the
arsenic, but are not widely available. LOSP, or Light Organic
Solvent Preservative, is a combination of a solvent and a preservative,
such as linseed and kerosene. It is suitable for decks and for
house framing, and is quite widely available in Sydney and through
a number of outlets in Melbourne, and Brisbane.
CCA-treated
timber currently goes to landfill in Australia, but is treated
as hazardous waste elsewhere in the world.
As consumers and parents, we can demand a national strategy
to deal with this problem.
Some ideas that spring to mind are:
1. A set of guidelines for schools and childcare centres on
existing CCA structures
2. Warning signs on all public structures
3. Promotion of solutions and safer alternatives through the
media and all relevant organisations and departments.
Further
Information
Arsenic
Based Timber Treatments FAQ
Australian Pesticides and Veterinary Medicines Authority (APVMA)
http://www.apvma.gov.au/chemrev/arsenic_faq.pdf
Ecospecifier
A guide to sourcing environmentally preferable materials.
http://ecospecifier.org
PINETEC
Major West Australian based supplier of Copper Azole
treated timber (sold under the trade name Tanalith-E)
http://www.pinetec.net/
