US chemical giant ends herbicide manufacturing following safety criticism over hazardous blend
The chemical company Corteva is to cease production of a herbicide containing components linked to cancer and widespread ecological damage, bringing to a close a decade of legal action by environmental groups.
The product, Enlist Duo, is a mixture of glyphosate and a chemical used in the defoliant Agent Orange, which was deployed by the US military during the Vietnam War. Environmentalists have long considered it one of the most dangerous herbicides still in use in the United States.
Both constituent chemicals are banned or heavily restricted in many industrialised nations. The World Health Organization classifies the Agent Orange chemical, 2,4-D, as a “possible” carcinogen, linking it to non-Hodgkin lymphoma, birth defects, respiratory and reproductive issues, and Parkinson’s disease. It is also believed to harm hundreds of endangered species, including butterflies, birds, fish and mammals.
Despite these risks, the US Environmental Protection Agency (EPA) first approved Enlist Duo for use on food crops in 2014 and reapproved it in 2022 for a further seven years. The compound is used on roughly 4.5 million acres of corn, soybean, and genetically engineered cotton fields annually.
Kristina Sinclair, a staff attorney with the non-profit Center for Food Safety (CFS), which led litigation against the product, said advocates were “celebrating it as a win”.
“After over a decade of legal battles, rather than try to rebut our arguments in court, the manufacturer pulled Enlist Duo from the market,” Sinclair stated. “Our food system never should have been doused in this toxic cocktail, and now never will be again.”
The CFS had argued in court that the EPA violated federal law by failing to ensure the herbicide would not cause “unreasonable adverse effects on the environment”. A federal court invalidated the EPA’s approval in 2020, but the agency reapproved it two years later. Advocates contended the EPA’s impact assessments used outdated, lower usage levels that dramatically underestimated the threat.
Nathan Donley, environmental health director with the Center for Biological Diversity, which was involved in the suits, criticised the EPA’s approach. He said the agency’s pesticide division operated on a flawed philosophy, seeking quick “tweaks” and workarounds to reapprove products whenever courts found flaws, rather than reflecting on a faulty process. “Getting pesticides to market is always the goal for the EPA,” Donley said.
Corteva reported over $1bn in sales of Enlist products in 2022 but did not comment on its reason for halting Enlist Duo production. The 2,4-D component will continue to be used in a related product, Enlist One, and a lawsuit seeking to invalidate its approval will proceed.
The litigation also alleged the EPA’s approval of Enlist Duo threatened to increase herbicide-resistant “superweeds” because the agency failed to properly mitigate that risk, as described by The Guardian.
