Pentachlorophenol

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

Registration Review of Pentachlorophenol

Use of PCP is being phased out over five years beginning in 2022. Until February 29, 2024, registrants may continue to produce, sell, and distribute wood preservatives containing PCP while wood treatment facilities transition from PCP to alternatives. After that time, wood treatment facilities will be allowed to use their existing stocks of PCP to produce treated wood until February 28, 2027.

On February 4, 2022, EPA issued a final registration review decision requiring the cancellation of PCP, a wood preservative used primarily on utility poles. During the registration review process, EPA found that given the emergence of viable alternatives, the risks PCP poses to workers’ health outweigh the benefits of its use. To read EPA’s registration review 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.
• PCP is very highly toxic to aquatic non-target organisms and honey bees, and slightly toxic to avian species. However, these species’ exposure to PCP 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.
  • For treated wood being disposed by non-households, it is the responsibility of the persons generating PCP-treated wood wastes to make a determination if it is hazardous waste.
  • Learn more about making a hazardous waste determination 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 pentachlorophenol (EPA risk assessments, decisions, and other documents)