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Pentachlorophenol

Pentachlorophenol (PCP) is an industrial wood preservative used mainly to treat utility poles and cross arms.

Registration Review of Pentachlorophenol

Pentachlorophenol is 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 January 2021 Proposed Interim Decision (PID), EPA proposed canceling the registration of pentachlorophenol. To read the PID and other documents, see Docket EPA-HQ-OPP-2014-0653 at https://www.regulations.gov.

Basic Information

  • PCP has been used as a wood preservative since 1936.
  • PCP is applied using pressure and high temperatures in specialized treatment cylinders. As a restricted-use pesticide, PCP is for sale and use by certified pesticide applicators only or under the supervision of a certified applicator.
  • PCP poses cancer and non-cancer health risks of concern to workers in wood treatment facilities. For EPA’s full assessment of human health and ecological risks, see the draft risk assessment at docket at regulations.gov.
  • Exposure (and therefore risk) to individuals living near PCP-treated utility poles is expected to be minimal.
  • Pentachlorophenol is very highly toxic to aquatic non-target organisms and honey bees, and slightly toxic to avian species. However, these species’ exposure to pentachlorophenol and its degradates is expected to be limited. Therefore, EPA does not expect risks to aquatic and terrestrial organisms, including pollinators.
  • Wood treated with PCP may be installed in a variety of outdoor settings, but it is not approved to treat wood for residential use. Application to wood intended for use indoors is prohibited except for a few low exposure uses for wood that is subject to decay or insect infestation, including supporting structures in contact with the soil in barns, stables, and similar sites.
    • Alternatives to PCP-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 PCP Safely 

  • Although PCP pesticide products are not available to homeowners, individuals may encounter reused PCP-treated wood in a residential setting.
    • Reuse of PCP-treated wood is not subject to regulation by EPA under pesticide laws.
    • If homeowners need to dispose of PCP-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 agency.
    • Do not burn PCP or other preservative-treated wood in a residential setting to avoid possible inhalation of toxic chemicals in the smoke and ash.
  • 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.

Additional Information

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