In a striking reversal, the EPA has asked a court to revoke the agency's registration of Enlist Duo, the next generation herbicide that poses threats to both monarch butterflies and human health. EPA initially approved Enlist Duo for uses in six states in October of 2014, and NRDC and other groups promptly challenged the decision in court. Enlist Duo is a combination herbicide that contains both glyphosate (the same active ingredient as in Roundup) and 2,4-D. In making its decision, the EPA says that further consideration of Enlist Duo revealed that the synergistic effects of the two chemicals may be more potent than it had initially realized and therefore, the instructions for use that EPA had previously approved may not be protective enough.
This decision is good news for monarch butterflies as well as public health. NRDC has argued that Enlist Duo will continue to eliminate milkweed, a native wildflower that is the sole food source for monarch caterpillars, and that the pesticide poses health risks to people. In fact, shortly before EPA expanded its registration of Enlist Duo to nine addition states, an international panel of experts classified glyphosate and 2,4-D as probable and possible carcinogens respectively. Furthermore, Enlist Duo, which was created because several varieties of superweeds have developed resistance to glyphosate alone, just escalates a never ending chemical arms race that only leads us towards a more toxic and unsustainable future.
It is troubling that EPA did not adequately assess the toxicity of Enlist Duo before approving its use, which raises major concerns about the agency's regulatory process. For EPA to abandon its defense of the pesticide and ask the court to invalidate the agency's earlier decision is a striking admission of error. Also troubling is that it's possible the EPA will simply impose different buffer requirements on Enlist Duo and then re-issue a new registration. The agency has not indicated that it will address Enlist Duo's impact on monarch butterflies or reconsider the health impacts of the combination pesticide, but if the court grants EPA's request to vacate the registration, the agency will have the ability to do both. And, in fact, if EPA doesn't address the effects of Enlist Duo on monarchs and human health, then it knows that it may simply be facing another lawsuit. This will be EPA's chance to get it right.
In re-evaluating Enlist Duo, the EPA is facing a clear choice: do we want a future of increasingly toxic pesticide use? Or do we want to reject the pesticide treadmill and encourage sustainable solutions that will benefit farms, people, and the environment?