CCA Treated Timber
Process, Uses and Health and Safety Implications.
CCA-treated wood is specially pressure-treated with a preservative containing copper, chromium, and arsenic (CCA) to enhance its durability and resistance to decay and insect damage.
Why Treat Timber?
Timber treatment is essential for extending the life of wood, ensuring it can withstand the elements and resist decay and insect damage.
There are various methods to treat timber, with CCA (Copper, Chromium, and Arsenate) treatment being one of the most effective and widely used for outdoor applications. By treating timber, we enhance its durability and suitability for various structural and decorative uses.
By treating timber and extending its lifespan, we significantly reduce the need for frequent harvesting, contributing to the conservation of our forest resources.
CCA Treated Wood
What is CCA Treatment?
CCA-treated wood is created through a pressure treatment process where the timber is infused with a preservative mixture of copper and arsenate, the two main active ingredients.
Copper acts as a fungicide, protecting the wood from decay, while arsenate works as an insecticide, safeguarding it from wood-boring insects.
This deep penetration of preservatives ensures that the wood is robust and long-lasting, making it ideal for outdoor projects like fences, decks, landscaping, playground structures, and other structural and decorative uses where durability is essential.
Health, Safety, and Environmental Considerations
While CCA-treated timber is generally safe to use, it’s important to understand the precautions necessary to minimise potential risks associated with the treatment chemicals:
Protective Gear
Always wear protective gear, such as goggles and a dust mask, when cutting or machining CCA treated timber to prevent inhalation of dust and protect your eyes from particles.
Hygiene
After handling CCA treated wood, especially when cutting or sanding, wash your hands thoroughly before eating, drinking, or touching your face. If sawdust accumulates on your clothing, launder the clothes separately from other household laundry.
Disposal
The greatest risk from CCA treated wood comes from exposure to smoke and ash, which is why you should never burn CCA treated wood. Offcuts and sawdust should be disposed of in a designated landfill, not used in barbecues or fireplaces.
When using CCA treated wood, it's important to be aware of specific restrictions to ensure safety and effectiveness:
Food Safety
Avoid using CCA treated wood for projects that involve direct contact with food, such as cutting boards, countertops, or food storage containers.
Water Contact
CCA treated wood should not be used in applications where it may come into direct or indirect contact with public drinking water, except for incidental uses like freshwater docks and bridges.
Child Safety
CCA treated timber isn’t recommended for making toys for young children; however, it is suitable for building playgrounds, as studies have confirmed that the arsenic levels in treated wood used in these settings are safe and not harmful.
Animal Safety
Wood shavings from CCA treated timber should never be used as animal litter or mulch, as the chemicals could be harmful to pets and livestock.
Make Sure You Know Your Requirements
The Hazardous Substances & New Organisms (HSNO) documents outline the compliance requirements for the treated timber industry. If you run or work in a treatment plant, it's a great idea to familiarise yourself with these requirements.
Other Timber Treatment Methods
CCA is just one of several effective methods used to treat timber and enhance its durability. Other popular treatments include Light Organic Solvent Preservatives (LOSP) and Boron treatments, each offering unique benefits for different applications.
The Role of the NZTPC and WOODmark®
The NZ Timber Preservation Council (NZTPC) plays a crucial role in ensuring that timber treated in New Zealand, regardless of the treatment method, meets the highest standards of quality and safety. Treatment plants that adhere to these rigorous standards can become licensees of the WOODmark® brand, a recognised sign of quality timber.
Guidelines and Health and Safety
To qualify as a WOODmark® licensee, treatment plants must follow strict guidelines for treatment quality, ensuring that the timber is treated effectively to protect against decay, insects, and other environmental factors. Additionally, these facilities must comply with stringent health and safety regulations, protecting both workers and the environment during the treatment process.
Compliance
Licensees and operators of treatment plants can find more information about compliance with the Hazardous Substances & New Organisms (HSNO) Act here, ensuring that they meet all legal and safety requirements.
Always Look for the WOODmark ®
By choosing WOODmark® branded timber, you can be confident that the wood you’re using has been treated to the highest standards, providing long-lasting durability and safety for your projects.
Become a WOODmark® Licensee
NZTPC welcomes new WOODmark® licensees and is dedicated to supporting and nurturing the community.