EPA has opened a 30-day public comment period for a proposed regulatory decision to register Enlist Duo, which contains glyphosate and the choline salt of 2,4-D for use in controlling weeds in corn and soybeans genetically-engineered (GE) to tolerate 2,4-D.
According to a news release from EPA, “Weeds are becoming increasingly resistant to glyphosate-based herbicides and are posing a problem for farmers. If finalized, EPA’s action provides an additional tool to reduce the spread of glyphosate resistant weeds.
“To ensure that Enlist Duo successfully manages weed resistance problems, the proposal would impose requirements on the manufacturer including robust monitoring and reporting to EPA, grower education and remediation.”
The proposal would also allow EPA to impose additional restrictions on the manufacturer and the use of the pesticide if resistance develops.
The choline salt of 2,4-D is less prone to drift and volatilization than its other forms, but is not currently registered for these uses. Glyphosate is already registered for several varieties of GE soybeans and corn. Since no new use pattern and no new exposures for glyphosate are being considered with this registration action, no further assessment is needed for glyphosate.
The herbicide 2,4-D is one of the most widely used herbicides to control weeds and has been registered for many years in the United States and is registered in dozens of countries, such as Canada, Mexico, Japan, 26 European Union Members, and many member countries of the Organisation for Economic Co-operation and Development (OECD).
Public comments on the EPA’s proposed regulatory decision must be submitted no later than May 30, 2014. Comments may be submitted to the EPA docket EPA-HQ-OPP-2014-0195 at www.regulations.gov 
After the comment period closes, EPA will review all of the comments and reach a final decision, which the Agency expects to issue in late summer or early fall.
Questions and Answers about this proposal are available at: http://www.epa.gov/pesticides/factsheets/2-4-d-glyphosate.html