Stay safe around copper chrome arsenate treated wood

The three chemicals in CCA – copper, chromium and arsenic – protect wood from dry rot, fungi, mould, termites and other pests.

CCA treated wood was often used outdoors for:

• decks
• garden furniture
• picnic tables
• playground equipment
• landscaping timbers, retaining walls and fences
• gazebos and patios.

Wood that is freshly treated with CCA has a greenish tinge which fades over time. Other wood treatments may also have a green colour.

Unless your structure has been built with hardwood or cedar, it is possible it was built with CCA treated wood.

Children who place their hands in their mouth after playing on CCA treated wooden playground equipment do increase their risk of arsenic exposure. International research has found, however, that it:

• only contributes between 2–8 per cent of the safe daily acceptable limits set by the World Health Organisation
• is within the safe daily acceptable limits set by the Australian Department of Health and Ageing.

This combined arsenic exposure is still less than a third of the amount that a child can be exposed to in their lifetime before it significantly affects their health. Small amounts of arsenic are also commonly found in the environment, our food and drinking water.

Minimise the risk during play

Arsenic exposure through contact with CCA treated wood can be minimised by:

• washing your child’s hands after they use wooden play equipment
• putting food on to plates and napkins rather than directly on the picnic bench.

In March 2005 the national authority that registers pesticide products, the Australian Pesticides and Veterinary Medicines Authority (external link), completed a safety review of the use of CCA.

It determined that CCA treated wood should no longer be used for new garden furniture, picnic tables, exterior seating, children’s play equipment, patio, domestic decking and handrails.

There is no evidence, however, that:

• existing CCA treated timber structures in parks and throughout the community pose a public health risk
• it is necessary to replace or remove existing structures.

While existing CCA structures do not need to replaced, you cannot use CCA treated wood to repair these structures. Such structures should be repaired with other forms of treated wood or replaced.

CCA timber treatment products were declared as Restricted Chemical Products in July 2012. This means their supply and use is restricted to trained authorised persons.

Information on whether painting treated wood reduces arsenic exposure is limited.

Some research indicates that when used regularly, coatings such as oil-based semi-transparent stains that soak into the wood may reduce the risk of arsenic exposure. For maximum protection the coating may need to be repeated every 6 to 12 months.

Arsenic may leach from treated wood into the soil but it generally stays in the area immediately surrounding the wood.

The uptake of arsenic by plants is generally limited due to:

• their distance from the source
• the low amount in the soil
• the limited uptake by vegetables generally.

As an additional precaution, place a plastic liner between the soil and the timber.

Do not:

• use treated wood to make toys or furniture that may be chewed or sucked on by babies and toddlers, for example playpens, cots and wooden blocks
• prepare food on treated wood or store in treated wood containers
• make food utensils from treated wood
• use to make containers for storing drinking water
• use in beehives where it may come in contact with honey
• use for firewood.

Burning of treated wood

Do not burn treated or painted wood in open fires, stoves, fireplaces, or residential boilers. Burning CCA treated wood releases toxic smoke and ash containing copper, chromium and arsenic into the environment.

Ash from timber treated with copper chrome arsenic (CCA) may be harmful.

Safe disposal and handling

• Dispose of CCA treated wood by burying it, taking it to your local tip, or putting it in with your ordinary rubbish.
• Wear a dust mask when sawing and machining treated wood. Whenever possible, perform these operations outdoors to avoid a build up of contaminated sawdust indoors.