The government withdrew its approval of Dow’s Enlist Duo herbicide because the combination of two weedkillers is more powerful than originally believed and could endanger “non-target plants.” The EPA acted just over a year after approving the herbicide, a combination of 2,4-D and glyphosate, the most widely used weedkiller in the world. The new herbicide was to be used in conjunction with corn and soybeans genetically engineered to tolerate the chemical, and was expected to be a huge money-maker for Dow and an alternative for farmers faced with emerging resistance by weeds to glyphosate, the main ingredient in Monsanto’s Roundup weedkiller.
The EPA announced its action as part of an ongoing lawsuit by environmental groups who challenged the approval of Enlist Duo on Oct. 15, 2014, for use in six Midwestern states. That approval included a requirement that farmers leave a 30-foot downwind buffer around the edges of fields. On March 31, the EPA said Enlist Duo could be used in an additional nine states in the Midwest, Plains and South.
“EPA is in receipt of new information regarding potential synergistic effects between the two ingredients on non-target plants,” the agency told the U.S. appeals court, so it cannot be sure the 30-foot buffer is adequate or that the herbicide will not cause unreasonable impact on plants. It requested the court to vacate and remand the registration to it.
“Dow had not provided this information to EPA prior to EPA issuing the Enlist Duo application,” the agency said in a statement. “EPA has not yet completed its review of the new information. EPA is seeking a remand because this new information could lead EPA to a different decision on the restrictions for using Enlist Duo. Specifically, this could result in changes to the width around application areas of no-use buffer zones that EPA imposed to protect unintended plants, including those listed as endangered.”
“With this action, EPA confirms the toxic nature of this lethal cocktail of chemicals, and has stepped back from the brink,” said Paul Achitoff, managing attorney for Earthjustice, one of the groups that sued. Earthjustice and six other groups said the agency failed to adequately consider the impact of the new herbicide on endangered plants and animals.
In a statement, Dow said it was working with the EPA for “prompt resolution of all outstanding issues,” said Reuters. The EPA decision means Enlist Duo will not be in wide use for the 2016 spring planting season, said the Associated Press. The Center for Food Safety told AP that EPA has not said if farmers will be allowed to use stocks of the chemical already on hand.