Treated wood generally refers to wood that has been treated with a chemical preservative to protect it from wood-degrading insects and fungi (decay and rot). The wood preservatives are registered pursuant to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and with the state Department of Pesticide Regulation.
Surface-applied coatings, such as paint, varnish and oil stain, are not considered wood preservatives. Under federal hazardous waste regulations, most wood product wastes are nonhazardous or are exempted from hazardous waste designation.
The first step in proper disposal of treated wood is to determine if your wood waste is indeed treated with a preservative. The following information can help you determine if your waste wood has been treated. For utility-produced treated wood waste, see HSC § 25150.7.
- The wood may be identified by a grade stamp or an end tag indicating treatment.
- If the wood has been incised to enhance treatment, it is likely to have been preservative-treated. This wood is easily identified by the presence of small, closely spaced indentations on the surface of the wood.
- If the material has not been stained or painted, some preservative treatments will cause the wood to appear greenish in color. Materials used in industrial or transportation systems may be dark brown in color with a slight petroleum odor.
- A crosscut section of the wood may reveal the preservative treatment as a darker color in the outer ¼ to 1 inch.
- The location of the wood within a project and the project type may also suggest the presence of treated wood. If the wood was in contact with the ground or water, or exposed to the elements, it is likely treated material.
- As a generator you can determine if your waste is nonhazardous or choose to manage the material as treated wood waste in accordance with HSC §25150.7.
- If doubt remains after applying the above evaluation tools, laboratory testing can make a positive evaluation.
Certain additional standards may apply to treated wood once it is under the authority of the disposal operator or facility. Parties needing to dispose of treated wood material are cautioned to be sure they are aware of any state or local requirements that may exceed the federal standards. The handler of the treated wood waste is responsible for legal compliance and should review the laws applicable to treated wood material and discuss any handling concerns with the appropriate agency.
Treated wood waste in any form (waste or not) cannot be open burned. The Health and Safety Code requires that treated wood waste be managed in a specified manner. Some of the requirements are:
- The treated wood waste should be kept separate and not mixed with other waste.
- Scavenging is not allowed.
- Store the waste for no longer than 90 days.
- Stored treated wood waste should be protected from run on and run off of water and placed on a surface sufficiently impervious to prevent, to the extent practical, contact with, and any leaching to soil or water. For example, the material could be stacked on skids and covered with an impervious plastic tarp secured to keep water off.
- Do not burn treated wood in a fireplace.
DISCLAIMER: The LSU AgCenter believes this guidance to be based on current information and is intended for general informational purposes. The information contained herein should not be construed as a recommendation to violate any federal, state or municipal law, rule or regulation, and any party using or disposing of pressure treated wood products should review all such laws, rules or regulations prior to using or disposing of treated wood. As with any pesticide product, the label is the law.