Chromated Arsenicals (CCA)

Chromated arsenicals, which include chromated copper arsenate (CCA), are a group of pesticides containing chromium, copper, and/or arsenic that protect wood against termites, fungi and other pests that can degrade or threaten the integrity of wood products. Chromated arsenicals-treated wood is used to produce commercial wood poles, posts, shakes, shingles, permanent foundation support beams, pilings, and other wood products permitted by approved labeling. EPA-HQ-OPP-2015-0349 at  https://www.regulations.gov).

Registration Review of Chromated Arsenicals

Chromated arsenicals are currently undergoing registration review, a process EPA conducts for all pesticides every 15 years to ensure that products can carry out their intended function without creating unreasonable risks to human health and the environment. In its Interim Decision (ID), EPA implemented additional mitigation measures to protect workers who apply chromated arsenicals. To read the ID and other documents, see docket at EPA-OPP-2015-0349 at  https://www.regulations.gov.

Basic Information

• Chromated arsenicals have been used as wood preservative pesticides since the 1940s.
• Chromated arsenicals pesticides are applied using specialized high-pressure equipment in wood treatment facilities by certified pesticide applicators only.
• Chromated arsenicals pose cancer and non-cancer health risks of concern to workers in wood treatment facilities. EPA did not find health risks of concern for the general public.
• Chromated arsenicals pose risks to aquatic invertebrates and plants.
• Prior to 2004, wood treated with chromated arsenicals was used in residential structures such as decks and playsets.
  • In December 2003, chromated arsenicals manufacturers voluntarily discontinued manufacturing chromated arsenicals-treated wood products for homeowner uses.
  • However, EPA does not require the removal of existing structures made with wood treated with chromated arsenicals or the surrounding soil.
  • If you have an older deck or other structure made with chromated arsenicals-treated wood, applying a penetrating protective coating (such as oil- or water-based stains) on a regular basis may reduce the leaching of chemicals.
• Alternatives to chromated arsenicals-treated wood include the following:
  • Wood treated with other preservatives approved by EPA;
  • Wood-alternative and composite materials (including steel, fiberglass-reinforced concrete, laminated wood); and
  • Species of wood that are resistant to pests.

Disposing of Items Treated with Chromated Arsenicals Safely

• Although chromated arsenicals pesticide products are not available to homeowners, individuals may encounter wood treated with chromated arsenicals in a residential setting (e.g., existing treated structures).
• Reuse of chromated arsenicals-treated wood is not subject to regulation by EPA under pesticide laws.
• If homeowners need to dispose of chromated arsenicals-treated wood, it can usually be disposed of by ordinary trash collection (i.e., as municipal solid waste)
• However, state and local governments may have specific guidance or instructions for disposing of treated wood, so please check with your state or local waste management program.
• Wood treated with chromated arsenicals should not be reused in products such as mulch.
• Do not burn CCA or other preservative-treated wood in a residential setting to avoid possible inhalation of toxic chemicals in the smoke and ash.
• Wear goggles and a dust mask when sawing wood treated with chromated arsenicals and wash your hands after handling.
• The Resource Conservation and Recovery Act (RCRA) is the federal law that creates the framework for the proper management and disposal of hazardous and nonhazardous solid waste.
• For treated wood being disposed of by non-households, it is the responsibility of the persons generating the chromated arsenicals-treated wood wastes to make a determination if it is hazardous waste.
• Learn more about making a hazardous waste determination, visit https://www.epa.gov/hwgenerators/steps-complying-regulations-hazardous-waste.
• State and local governments may have specific guidance or instructions for disposing of treated wood, so please check with your state or local waste management program.

Additional Information

• Learn more about chromated arsenicals (EPA risk assessments, decisions, and other documents)
• CCA Pressure-Treated Wood: Guidance for Outdoor Wooden Structures (PDF) (Consumer Product Safety Commission)(2 pp, 630 K, About PDF)