Congress asks EPA what went wrong with Enlist Duo

Led by Congressmen Earl Blumenauer and Peter DeFazio, thirty five Members of Congress sent a letter to Environmental Protection Agency Administrator Gina McCarthy today asking for an explanation as to what went wrong with EPA's evaluation of Enlist Duo, Dow Chemical Company's next generation herbicide that combines glyphosate (the active ingredient in Roundup) with another powerful herbicide called 2,4-D. EPA approved Enlist Duo in October of 2014, but since then a number of things have occurred that call EPA's approval of this pesticide into question:

  • An investigate article in the Chicago Tribune revealed that the approval involved EPA dismissing a key study linking 2,4-D to kidney abnormalities based on one scientist's analysis. In doing so, EPA effectively paved the way for 41 times more of the chemical to enter the American diet than was previously allowed.
  • The World Health Organization came out with a finding in 2015 that both glyphosate and 2,4-D are probable and possible carcinogens, respectively. EPA registered Enlist Duo without considering this cancer finding, and without looking at any studies on glyphosate's cancer risk that have been published in the last twenty years.
  • The EPA itself asked a court to allow them to vacate the registration of Enlist Duo based on new information that the two herbicides may have synergistic effects that the EPA had not originally considered. The court did not vacate the registration, but did remand it back to EPA for further consideration.

These new developments, combined with the fact that EPA never considered the effect that Enlist Duo would have on the declining monarch butterfly population, have left many people - including many members of Congress - wondering how EPA could have approved this pesticide without a more thorough evaluation of Enlist Duo's likely harms to public health and the environment.

So far the EPA has only indicated that it plans to narrowly look at the issue of synergistic effects of the herbicides on endangered plants. However, they have the ability - and the mandate - to more broadly evaluate all of these problematic issues before issuing a new registration or cancelling it altogether. In their letter, the Members of Congress write, "The public deserves to know how EPA intends to address all of these concerns about the risks posed by Enlist Duo." EPA still has the power to get this right. And Congress will be watching.

About the Authors

Sylvia Fallon

Director, Wildlife Conservation project

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