treated wood safety

Treated Wood Safety

Common Sense Safety Precautions

The following precautions should be taken both when handling preservative treated wood and in determining where to use and dispose of it. Many of these precautions also apply to untreated wood and other building materials.

California Proposition 65 Warnings

⚠️ WARNING: Drilling, sawing, sanding or machining wood products can expose you to wood dust, a substance known to the State of California to cause cancer. Avoid inhaling wood dust or use a dust mask or other safeguards for personal protection. For more information go to

⚠️ WARNING: This product can expose you to chemicals, including Titanium Dioxide, which is known to the State of California to cause cancer, and Methanol, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to

Use Site Precautions

  • All sawdust and construction debris should be cleaned up and disposed of after construction.
  • Do not use preservative treated wood under circumstances where the preservative may become a component of food or animal feed. Examples are mulch from recycled treated wood, cutting boards, counter tops, animal bedding, and structures or containers for storing animal feed or human food.
  • Only preservative treated wood that is visibly clean and free of surface residue should be used where contact is likely.
  • Do not use preservative treated wood for construction of those portions of beehives which may come into contact with honey.
  • Preservative treated wood should not be used where it may come into direct or indirect contact with drinking water, except for uses involving incidental contact such as docks or bridges.

Handling Precautions

  • Preservative treated lumber and plywood should not be burned in open fires or in stoves, fireplaces or residential boilers because toxic substances may be produced as part of the smoke and ashes. Preservative treated wood may be disposed of by complying with local landfill rules or burned in commercial or industrial incinerators or boilers when done in accordance with state and federal regulations. Check with your local Waste Management Agency for proper disposal requirements.
  • Avoid frequent or prolonged inhalation of sawdust from wood, treated or untreated. When sawing, sanding, and machining wood, wear a dust mask. Whenever possible, these operations should be performed outdoors to avoid indoor accumulations or airborne sawdust. See California Proposition 65 Warning for additional details.
  • When power-sawing and machining, wear goggles to protect eyes from flying particles.
  • Wear gloves when working with wood. Use proper techniques when lifting.
  • After working with wood, and before eating, drinking, toileting, and using tobacco products, wash exposed areas thoroughly.
  • Because preservatives or sawdust may accumulate on clothes, they should be laundered before reuse. Wash work clothes separately from other household clothing.
  • Review Resources/SDS information for preservative specific health warnings and usage precautions.

Safety Study

A comprehensive study of occupational, residential, and playground uses of pressure preserved wood with copper azole preservative has concluded, “no adverse health effects are expected.” The study was commissioned by Bayer Chemicals Corporation (now Lanxess Corporation) and conducted by Gradient Corporation, a noted environmental and toxicological consulting firm. Lanxess manufactures Preventol® A8, which is an azole fungicide used in the copper azole preservative. A number of different exposures (e.g., inhalation, incidental ingestion, exposure to the skin) were assessed and aggregated in each of these scenarios. The highest potential risk was estimated to be 17 times lower than the level that the EPA uses as a safety benchmark, thus demonstrating the safety of copper azole-treated wood. Read the report summary (PDF).