Copper-based preservatives penetrate into and remain 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.

1. Use
2. Handling
3. InstallAndMaintenance
4. Disposal

Introduction

Copper-based preservatives penetrate into and remain 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.

Use

• Wood pressure-treated with copper-based 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.

Handling

• 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 from treated wood. 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 two applications of an end-cut preservative (copper naphthenate in ground contact or zinc naphthenate above ground) before the wood is installed. Always follow the manufacturers’ recommendations.
• For long-term performance in outdoor applications use high quality hot dip galvanized or stainless steel fasteners and hardware that are in compliance with building codes for the intended use.
• Do not use pressure treated wood in direct contact with aluminum – When using pressure treated wood in close proximity to aluminum products, such as aluminum siding, flashing, and door and window frames, a 1/4" minimum space must be allowed for between the pressure treated wood and the aluminum products. Polyethylene or nylon spacers can be used to maintain the 1/4" spacing. Another option is to use a polyethylene barrier, with a minimum thickness of 10 mils, between the pressure treated wood and the aluminum product to prevent direct contact of the wood and the aluminum.
• Treated wood can be stained with a high quality penetrating finish. 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 coating. Always use products in accordance with manufacturers’ instructions.

Disposal

• Do not burn treated wood. Preserved wood should not be burned in open fires, 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 treated wood scraps and cut offs in accordance with local, provincial and federal regulations.