Consumer Safety Information Sheet


Copper Azole Treated Wood

The primary active ingredient in copper azole is copper, which has long been established as an effective biocide in timber preservation. Tebuconazole acts as the co-biocide in the copper azole preservative, providing additional protection from fungi that copper alone would not control. Tebuconazole is commonly used for protection from fungi on food crops.

Copper azole preservative penetrates into and remains in pressure-treated wood for a long time. However, some preservative may migrate from the preserved wood into surrounding soil over time and there may be incidental contact with skin during construction or use.

Follow the safe practices listed below when working with pressure-treated wood. Specific work practices may vary depending on the environment and safety requirements of individual jobs.


Wood pressure-treated with copper azole preservatives may be used inside residences as long as all sawdust and construction debris are cleaned up and disposed of after construction.

Do not use treated wood under circumstances where the preservative may become a component of food or animal feed. Examples of such sites would be structures or containers for storing silage or food.

Do not use treated wood for cutting boards or countertops.

Only use treated wood that's visibly clean and free from surface residue for patios, decks and walkways.

Do not use treated wood for construction of those portions of beehives that may come in contact with honey.

Do not use treated wood where it may come in direct or indirect contact with public drinking water, except for uses involving incidental contact such as docks and bridges.

Do not use treated wood for mulch.


Wear gloves to protect against splinters.

Wear a dust mask when machining any wood to reduce the inhalation of wood dusts. Avoid frequent or prolonged inhalation of sawdust. Machining operations should be performed outdoors whenever possible to avoid indoor accumulations of airborne sawdust.

Wear appropriate eye protection to reduce the potential for eye injury from wood particles and flying debris during machining.

Wash exposed areas thoroughly with mild soap and water after working with treated wood.

If preservative or sawdust accumulates on clothes, launder before reuse. Wash work clothes separately from other household clothing.

Installation and Maintenance

All cuts and holes that expose untreated wood should be liberally brush-coated with an end cut preservative before wood is installed.

For best results, hot dipped galvanized or stainless steel fasteners and fittings are recommended. Direct contact of copper azole treated wood with aluminum is not recommended.

Copper azole treated lumber can be painted or stained with any high quality oil or latex based paint or stain. Water repellent coatings can be applied to improve the weathering performance. It is important to ensure the wood is dry and free from surface deposits prior to applying any film-forming coating. Always use products in accordance with manufacturers instructions.


Do not burn treated wood. Preserved wood should not be burned in open fires or in stoves or fireplaces.

Residential users may dispose of treated wood scraps and cut offs by ordinary trash collection or burial. Commercial and industrial users of treated wood should dispose of copper azole treated wood scraps and cut offs in accordance with local, provincial and federal regulations.

Revised: October, 2003.