The Environmental Protection Agency withdrew its approval of a new weed killer which combines glyphosate and 2,4-D that Dow AgroSciences developed for the use on the next generation of genetically engineered crops.
It has been over a year since the agency approved the herbicide, saying at the time the decision to approve the pesticide would help manage the problem of resistant weeds and their decision “reflects a large body of science and an understanding of the risk of pesticides to human health and the environment.”
Following the approval in October 2014, several environmental groups sued EPA in the Ninth Circuit Court of Appeals on EPA’s decision to register the Enlist Duo pesticide product for use on corn and soybean genetically modified to be tolerant of this pesticide.
On Nov. 25, EPA asked the court to vacate and remand the registration of the pesticide Enlist Duo “because the agency has received new information from Dow AgroSciences – the registrant of Enlist Duo – that suggests two active ingredients could result in greater toxicity to non-target plants. Dow had not provided this information to EPA prior to EPA issuing the Enlist Duo registration. EPA has not yet completed its review of the new information,” EPA said in a statement.
EPA said it 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,” EPA added.
Initially in 2014 EPA put in place restrictions to avoid pesticide drift, including a 30-foot in-field “no spray” buffer zone around the application area, no pesticide application when the wind speed is over 15 mph, and only ground applications are permitted.
Dow said in a statement that it had only heard about the issue the night before but remains confident in the extensive data supporting Enlist Due herbicide. “We are working with EPA to quickly provide further assurances that our product’s conditions of registered use will continue to protect the environment, including threatened and endangered plant species,” Dow said.
“Recognizing the pressing needs of U.S. farmers for access to Enlist Duo to counter the rapidly increasing spread of resistant weeds – and in light of the comprehensive nature of the regulatory assessments already conducted to support the Enlist Duo registration – we expect that these new evaluations will result in a prompt resolution of all outstanding issues,” Dow said.
The herbicides 2,4-D and glyphosate are two of the most widely used herbicides in the world for controlling weeds. Dozens of other countries including Canada, Mexico, Japan and 26 European Union Members have approved these pesticides for use on numerous crops and residential lawns. In 2013, Canada approved the use of Enlist Duo for the same uses that EPA is authorizing.
Enlist Duo is a combination of two herbicides - 2,4-D and glyphosate - designed for use in herbicide resistant corn and soybeans. Glyphosate was already widely used on those plants before Enlist Duo was registered; 2,4-D was not.