In early February 2022 the U.S. Environmental Protection Agency announced a five-year phaseout of all uses of the wood preservative pentachlorophenol. Commonly called “penta,” the chemical is primarily used to treat wooden utility poles. It’s estimated there are approximately 60 million penta-treated wood poles in service in the United States.

During the registration review process, EPA found that the risks pentachlorophenol poses to workers’ health outweigh the benefits of its use—especially given the emergence of viable alternatives. Other wood preservatives that can be used instead of penta include copper naphthenate, dichlorooctylisothiazolinone (DCOIT), chromated arsenicals, and creosote.

The EPA said this action aligns the United States with the United Nations’ Stockholm Convention on Persistent Organic Pollutants, which lists pentachlorophenol as one chemical to eliminate.

For the next two years, manufacturers of pentachlorophenol products can continue to produce, sell, and distribute wood preservatives containing the pesticide. The complete phase-out of pentachlorophenol will be conducted over five years and is intended to ensure stability within the utility pole industry by giving wood treaters time to switch to alternative wood preservatives. After February 2024, wood treatment facilities will be allowed to use their existing stocks of pentachlorophenol to produce treated wood for an additional three years.

For an EPA press release about this cancellation, see https://tinyurl.com/4m4ww674

For two alternative views of this action, see the links below:

North American Wood Pole Council: https://tinyurl.com/ymmws6y7

Beyond Pesticides: https://tinyurl.com/bddw4ee6