Setback For Dow’s Duo Herbicide

Abstract

New information about the synergistic effects of glyphosate and 2,4-dichlorophenoxyacetic acid, also known as 2,4-D—the two active ingredients in Dow AgroSciences’ Enlist Duo herbicide—has prompted the Environmental Protection Agency to ask a federal court to rescind EPA’s approval of the controversial mixture. In a motion filed on Nov. 24 with the U.S. Court of Appeals for the 9th Circuit, EPA says that it may have understated the toxicity of Enlist Duo to plants. “The 30-foot [9-meter] buffer on the approved label may not be adequate to protect nontarget plant species located outside the treated fields,” the agency says. EPA recently discovered a Dow patent application showing that the two active ingredients in Enlist Duo “are more effective in combination than when applied individually.” The agency told the court that it did not have this information when it approved the herbicide last year for use in a handful of states on ...