EPA Reconsidering Enlist Duo Registration; Dow Responds

EPA Reconsidering Enlist Duo Registration; Dow Responds

Citing “new information regarding potential synergistic effects between the two ingredients on non-target plants,” EPA is reconsidering the registration of Dow AgroSciences’ Enlist Duo herbicide.

Enlist Duo – a mixture of glyphosate and a new formulation of 2,4-D – received EPA registration in a limited number of corn and soybean producing states in late 2014 and in nine additional states in April 2015, bringing the total to 15 states.


The genetically-engineered trait package that gives crops resistance to those two herbicides was approved for corn and soybeans in September 2014, and for cotton in July 2015.

In a court document filed with the U.S. Ninth Circuit Court of Appeals on November 24, EPA stated that the agency “cannot be sure, without a full analysis of the new information, that the current registration does not cause unreasonable effects to the environment, which is a requirement of the registration standard under FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act).”

In a statement released following the ruling, Dow AgroSciences expressed confidence in the extensive data supporting the Enlist Duo technology and is working quickly with EPA “to provide assurances that the product’s conditions of registered use will continue to protect the environment, including threatened and endangered plant species.”

“We believe the questions that have been raised about any potential synergy between 2,4-D choline and glyphosate can be promptly resolved in the next few months, in time for the 2016 crop use season,” said Tim Hassinger, Dow AgroSciences President and CEO.

“EPA now has all of the data developed by Dow AgroSciences on observed potential synergies between 2,4-D choline and glyphosate in Enlist Duo,” Hassinger added. “From these data, EPA will readily see – after evaluating all of the efficacy data on the final formulation – why these data support the registration of Enlist Duo.”

The Dow statement pointed out that evaluations of potential synergy from herbicide mixtures are common within the crop protection industry and are not unique to Enlist Duo. EPA has not used observations of potential synergy in mixtures as a basis for regulatory action. Technology providers have commonly filed patent applications on mixtures without any connection to EPA’s regulatory processes.

“It’s possible that we could see some changes to use conditions on the existing Enlist Duo label,” Hassinger stated. “However, based on the ongoing dialogue with EPA, we do not expect these issues to result in the long-term cancellation of the Enlist Duo product registration. We continue to prepare for commercial sales of Enlist Duo for the 2016 growing season with enthusiastic grower adoption.”