On October 15, 2014, the U.S. Environmental Protection Agency (EPA) granted a Dow AgroSciences’ petition to register “Enlist Duo” as a new pesticide product pursuant to the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). FIFRA requires the EPA to determine that the registration will not cause unreasonable effects to the environment. Enlist Duo contains and mixes two previously registered pesticides 2,4-D and glyphosate. The EPA’s registration allowed use of the new pesticide in six states on new types of genetically engineered corn and soy bean varieties bearing the trade name “Enlist,” which Dow genetically engineered specifically to be immune to those two pesticides.
In March 2015, the EPA amended the registration to allow Enlist for use in nine additional states. Enlist Duo addresses an agricultural and environmental concern that itself arose from a prior generation of genetically engineered crops, specifically, herbicide-resistant “super weeds.” Such super weeds developed in response to proliferation of earlier genetically modified organisms (GMOs), and the ability of the weeds to compete for space with those organisms also rendered the weeds resistant to traditional pesticides and herbicides. Glyphosate-resistant crops allow growers to saturate fields with amounts of glyphosate and 2,4-D in excess of what had traditionally been used, killing super weeds without killing the crop.
Agricultural companies sell both the patented genetically modified seed and the herbicide used on it as a crop system. The crop system allows a grower to cover a field with a product like Roundup, which will result in killing of all of the weeds, including the new super weeds, but allowing the growth of the genetically modified resistant plants.
Environmentalists immediately filed suit to challenge the registration, arguing that the EPA failed to assess adequately the new products’ health and ecological risks, violating both the FIFRA and the Endangered Species Act. The environmentalists argued that runoff from fields doused with Enlist Duo could affect endangered species or endangered species’ habitats. The environmentalists allege that the EPA failed to consult the all expert wildlife agencies before registering the new product.
In November, the EPA actually joined with the environmentalists to urge the court to vacate the EPA’s registration of the herbicide after the EPA discovered new data in Dow’s patent application suggesting that the registration application might have underestimated the product’s “synergistic” risks to endangered non-target plants. The EPA told the court that Dow did not submit to the EPA during the registration process the extensive information relating to potential synergies Dow cited to the patent office. Previously, the EPA claimed that Enlist Duo combines two well-studied herbicides and that the EPA’s assessment of 2,4-D exposures are far below levels of concern. The EPA had said that it was not required to review potential effects of glyphosate prior to registering Enlist Duo, since that ingredient is already commonly used on genetically modified crops. The EPA now states that it has become aware of previously existing information about possible synergistic effects that it did not consider and can no longer represent that its conclusions were correct regarding whether issuance of the registration met the standard required by FIFRA and whether the buffer zones included in the registration support the finding that the registration will have no affect upon threatened or endangered plant species.
This process is interesting because the EPA has gone beyond the application materials submitted by Dow to review the side effects of chemicals related to production of genetically modified plants. It raises the question of whether other agencies should be taking those effects into account or should be automatically referring questions to the EPA when they arise in the course of the work of those other agencies. That is, should the Patent Agency as a matter of course forward to the EPA all materials it receives relating to patented biological processes? Should the Department of Justice or courts forward to the EPA all filings in patent or contract disputes regarding GMOs?
It is still possible that the EPA will ultimately approve registration of Enlist Duo in some form based on greater restrictions than were included in the initial registration. The fate of Enlist Duo will most likely not resolve the issues relating to proper registration and use of GMOs, but it may provide some guidance as to the proper process to determine where and how such products may be used.
A frequent lecturer and author on diverse environmental issues, 
