What’s the best alternative to CCA treated timber?

Copper Chrome Arsenate or ‘CCA’ timber has been restricted and banned from some uses in Australia because the Australian Pesticides and Veterinary Medicines Authority (APVMA) has determined that it poses dangers to our health, especially to children, and the environment.

CCA consists of three active chemicals – copper, chromium and arsenic. It was initially thought that these chemicals stayed fixed in the timber but research subsequently found the chemicals are dislodged from the timber when it is in use and the public is at risk of exposure to them by absorbing them through the skin or accidentally ingesting them.

CCA timbers have now been restricted and cannot be used in children’s playground equipment, decks, handrails and picnic tables where it is considered there is a high risk that children would be exposed to dislodged chemicals.

For details on reasons why the APVMA has restricted CCA in Australia see www.apvma.gov.au/chemrev/arsenic.shtml

What should I do with existing CCA timbers? 

There is a considerable amount of CCA already in use, including for the uses which have been now been banned. This has led to a lot of confusion amongst the public about what to do with existing timbers – should they be removed? Are they safe? Where should CCA timbers be taken for safe disposal?

The APVMA has no regulatory authority over existing structures constructed of CCA treated timber and has made no recommendation with respect to future action for existing structures. The responsibility in relation to existing timbers belongs with States and Territories, in NSW the agency is the NSW Department of Environment and Climate Change (DECC).

According to DECC “Small quantities of household CCA-treated timber waste (e.g. off cuts from a small DIY job) could be placed in your rubbish bin, with the rest of your household waste. CCA-treated timber waste from larger household building and demolition jobs is classified as inert waste, and can be disposed of to most suburban landfills. You should tell the landfill staff if you have CCA-treated timber in your load. DECC considers that CCA-treated timber waste from industrial sources should only be disposed of to certain landfills, in accordance with DECC requirements. CCA-treated timber waste must not be burned or used as mulch/soil amendment”.

For information on how to dispose of CCA timbers contact the NSW Department of Environment and Conservation Climate Change

Should I paint my existing CCA timber?

According to the APVMA there is no definitive advice at this time on whether there are benefits from painting CCA timber. The APVMA states:  “Information is limited on the possible benefits of painting treated-timber (including existing structures) to reduce possible risks. Some scientific studies indicate that certain penetrating coatings, such as oil-based semi-transparent stains, when used on a regular basis may reduce the potential for CCA exposure. However, there have been some questions raised about the effectiveness of film-forming or non-penetrating stains because of cracking, peeling and flaking”.

One Australian company claims to make a certified organic penetrating oil coating product that helps to seal CCA timbers.

For further information and material safety data sheet see www.cooeeproducts.com.au/web_pages/timbertreat.html

Safer options

Hardwoods and metal are safer options for decks, handrails and playground equipment.There are arsenic-free timber treatment products that are registered for use in Australia. Check with your timber supplier or hardware store to find out what options are currently available.

For further information and discussion of alternatives to CCA see www.uow.edu.au/arts/sts/sbeder/CCAtimber/sitemap.html