Although the U.S. Environmental Protection Agency (EPA) said in April that it plans to permit a new weed killer called Enlist Duo onto the market, consumer advocates are attempting to dissuade the agency from doing so before a final decision is made. The herbicide is a combination of 2,4-D and glyphosate and is made by Dow AgroSciences. If approved, it would be used on millions of acres of farm fields in combination with a new type of herbicide-resistant genetically engineered corn and soybean crops and at least triple the use of 2,4-D. Glyphosate is the active ingredient in Roundup, the top-selling weed killer developed by Monsanto. When announcing the agency’s inclination to approve Enlist Duo, EPA added that “the proposal would impose requirements on the manufacturer including robust monitoring and reporting to EPA, grower education and remediation and would allow EPA to take swift action to impose additional restrictions on the manufacturer and the use of the pesticide if resistance develops.” EPA accepted public comments on the decision until June 30 and is expected to issue a final decision in late summer or early fall. The U.S. Department of Agriculture, which must grant approval of the crops genetically engineered to tolerate Enlist Duo, said it was prepared to its grant approval in January. USDA’s comment period closed on March 11. A number of farm, food, health, public interest, consumer, fisheries and environmental organizations submitted comments in opposition to the proposals, and the EPA docket received more than 25,000 comments in total. At the end of June, 35 scientists, medical professionals and researchers also wrote to EPA Administrator Gina McCarthy to urge the agency not to approve Enlist Duo. On Wednesday, the Center for Food Safety and the Environmental Working Group hosted a briefing for congressional staffers to persuade members of Congress to pressure the two agencies to reject the proposals because of the potential negative impacts on the environment and human health. Panelists at the event included Doug Gurian-Sherman, senior scientist at Center for Food Safety; John Wargo, professor of Environmental Health and Politics at Yale University; Dr. Philip Landrigan, dean for global health at Mount Sinai School of Medicine; Dr. Catherine Thomasson, executive director at Physicians for Social Responsibility, and Gary Hirshberg, co-founder of Stonyfield Farm and chairman of Just Label It. The consumer advocates are concerned about the serious health risks associated with 2,4-D exposure, including non-Hodgkin lymphoma, suppressed immune function, lower sperm count, and a greater risk of Parkinson’s disease. When pregnant women are exposed to pesticides of all kinds, their child can sustain learning disabilities, behavioral problems and possibly chronic diseases. Safety advocates are also concerned that 2,4-D and glyphosate have not been tested for combined toxicity. “We’re very concerned that this combination is going to cause not only additive effects, but multiplicative or synergistic effects,” Thomasson said. In terms of environmental effects, critics say that Enlist Duo will increase soils, surface and groundwater contamination and perpetuate the “pesticide treadmill,” which is when farmers use larger amounts of increasingly toxic chemicals to control herbicide-resistant weeds, eventually requiring the use of different chemicals. Hirshberg called the herbicide a “three- to five-year solution, at best” and compared it to the issue of antibiotics overuse contributing to drug resistance. Rep. Chellie Pingree (D-ME), who spoke at the start of Wednesday’s briefing, said that the struggle over Enlist Duo ties into the fight for the labeling of genetically modified food. It’s not just about giving consumers the chance to know the source of their food, but to voice whether they want to support the system. “It’s an issue that 90 percent of the American public thinks that we should move ahead with … but sometimes when I turn around and say to people, ‘So what’s the part that worries you most about it?,’ honestly a lot of people don’t understand the health risks or the concerns or what the implications of it are,” she said. Pingree and Rep. Peter DeFazio (D-OR) are hoping that more members of Congress sign on to their letter to McCarthy and Agriculture Secretary Tom Vilsack urging them not to approve Enlist Duo and 2,4-D-resistant crops.