EPA finds toxic compounds in mosquito spray used in Mass.; maker will change packaging

Mosquito spraying in Southeastern Massachusetts in 2006.David L Ryan/Globe staff/file

The Environmental Protection Agency has acknowledged that a controversial pesticide used to kill mosquitoes in Massachusetts contains toxic chemicals that leach into the product from its container, and the manufacturer has agreed to change its packaging, officials said Thursday.

The state Department of Environmental Protection began testing the pesticide, known as Anvil 10+10, in the fall, after earlier testing by a Washington advocacy group found it contained elevated levels of toxic compounds known as PFAS. The federal EPA said separately it would conduct its own testing.

The so-called “forever chemicals,” which are present in a variety of commercial products and never fully degrade, have been linked to cancer, low infant birth weight, and a range of diseases.

The EPA said Thursday it had determined that fluorinated “containers that are used to store and transport a mosquito control pesticide product contain PFAS compounds that are leaching into the pesticide product.” It did not give details on the level of the compounds found in the pesticide.

Clarke, the Illinois-based manufacturer of Anvil 10 + 10, said in a separate statement that it had investigated and found none of the toxic chemicals in its products or the raw materials used to make them. The company has stopped “all sales and shipments to customers of Anvil 10+10 packaged in plastic containers” and is committed to using only PFAS-free plastic in the future, it said.

“Fluorinated packaging is widely used by the agricultural industry for finished goods, including pesticides,” the company said. “The potential for PFAS chemistry from the fluorinated packaging to leach into finished goods was unknown to Clarke.”

The EPA is still early in its investigation of Anvil 10+10 and has requested information from the company that fluorinates the plastic containers used by Clarke and other pesticide manufacturers, it said.

Public Employees for Environmental Responsibility, the advocacy group that initially tested the pesticide samples, prompting the state’s investigation, said in a statement Thursday that the EPA’s announcement “raises big new public health concerns.”

“EPA’s discovery has opened a Pandora’s Box of health risks,” Kyla Bennett, the organization’s science policy director, who led the initial testing of the pesticide, said in the statement. “Shipping containers may be a significant source of PFAS exposure through the entire U.S. agricultural sector.”

An unknown number of other products may be shipped in similarly contaminated containers, and untold acres of land may have been sprayed with pesticides containing PFAS, the organization said. It estimates that nearly 30 states, including Massachusetts, use Anvil 10+10 for aerial mosquito spraying.