The Center for Food Safety and Earthjustice filed a lawsuit on Wednesday against the U.S. Environmental Protection Agency (EPA) challenging the approval of Dow Chemical’s Enlist Duo herbicide, a blend of 2,4-D and glyphosate. The suit was filed in the U.S. Ninth Circuit Court of Appeals on behalf of Beyond Pesticides, Center for Biological Diversity, Center for Food Safety, Environmental Working Group, the National Family Farm Coalition, and Pesticide Action Network North America. The groups are challenging the approval under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), arguing that EPA did not adequately analyze the impacts of 2,4-D on human health. They also argue that the approval violated the Endangered Species Act. EPA has proposed to restrict the use of Enlist Duo to Illinois, Indiana, Iowa, Ohio, South Dakota, and Wisconsin, but the agency is currently accepting comments on whether to register it for use in an additional 10 states. The product is intended for use on Dow’s Enlist genetically engineered corn and soybeans, which were approved by the U.S. Department of Agriculture last month. A number of farm, food, health, public interest, consumer, fisheries, and environmental organizations submitted comments in opposition to both proposals, arguing that the use of Enlist Duo on millions of acres of farm fields could negatively impact both environmental and human health. Members of Congress and prominent doctors, scientists, and researchers also urged the agencies not to approve the system. The Natural Resources Defense Council filed a petition in the U.S. Court of Appeals for the District of Columbia Circuit immediately after EPA approved Enlist Duo’s registration on Oct. 15, asking that the court block Enlist Duo’s unconditional registration.