Companies can produce, distribute, and sell the wood preservative pentachlorophenol in the US for only 2 more years, the US Environmental Protection Agency announced Feb. 4. Wood treatment facilities, however, have until 2027 to use up their existing stocks of the chemical. The National Toxicology Program lists pentachlorophenol as a “reasonably anticipated” human carcinogen. It is banned under the United Nations’ Stockholm Convention on Persistent Organic Pollutants, an international treaty the US signed but has not ratified. The EPA claims that pentachlorophenol poses health risks to workers. Alternative wood preservatives—including chromated arsenicals, copper naphthenate, creosote, and dichloro-octyl-isothiazolinone—are available, the EPA says. Environmental groups have been urging the EPA for decades to ban pentachlorophenol. The chemical is persistent in the environment and contaminates about 250 Superfund hazardous waste sites where it was made, according to the advocacy group Beyond Pesticides.
C&EN, 11 February 2022