NRDC v. E. Scott Pruitt, et al. (Enlist Duo)

In January 2017, the U.S. Environmental Protection Agency approved a new pesticide called Enlist Duo—despite its serious risks to people and certain animal species—to be used on three major crops (corn, soy, cotton) across 34 states. NRDC is challenging the EPA’s reckless decision in federal court.

Formulated by Dow AgroSciences, Enlist Duo combines the active ingredients glyphosate and 2,4-D. In 2015, the International Agency for Research on Cancer, the cancer-evaluation branch of the World Health Organization, concluded that glyphosate and 2,4-D are, respectively, “probably” and “possibly” carcinogenic to humans. Yet, in deciding whether to approve Enlist Duo, the EPA discounted evidence of the cancer risk posed by glyphosate. The agency also used an outdated cancer assessment for 2,4-D—conducted more than 20 years ago—and ignored recent, mounting evidence that 2,4-D may cause cancer in humans. Furthermore, the EPA disregarded more than two decades of science on non-cancer health risks posed by glyphosate, including studies linking it to increased risk of kidney toxicity and birth defects.

It’s not just human health that may be in danger. Enlist Duo also threatens the North American monarch butterfly, an iconic species famed for its annual migration across the continent. After undergoing a precipitous population decline in recent years, the monarch is suffering from numbers so precariously small that experts—including those at the U.S. Department of Agriculture—have warned that the monarch migration may be coming to an end. Milkweed, the monarch caterpillar’s sole food source, has been decimated by the sharp increase in the use of herbicides on herbicide-resistant crops. Enlist Duo is specifically designed to kill milkweed, among other target plants. The pesticide is also intended to be used on crops genetically engineered to resist it, meaning that farmers can apply more of this toxic pesticide across a longer portion of the growing season. Its ongoing destruction of milkweed habitat across the monarch’s breeding grounds puts the species at further risk of eradication.  

After hearing oral arguments, the U.S. Court of Appeals for the Ninth Circuit granted a partial victory to NRDC in May 2019, as the court asserted its power to review EPA’s approval of Enlist Duo across all 34 states, and not just some. The court will decide on the remaining issues after reviewing the parties’ supplemental briefs, which were submitted in November 2019.

Last Updated

January 17, 2020



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