Supreme Court Hears Arguments in Case on Glyphosate Labeling Regulations

The U.S. Supreme Court heard oral arguments on April 27, 2026, in Monsanto Company v. Durnell, a case examining whether state failure-to-warn claims under Missouri law are preempted by federal regulations under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) regarding health risk labels for glyphosate, the active ingredient in the herbicide Roundup produced by Bayer subsidiary Monsanto.

The case stems from a lawsuit filed by Edwin Durnell, a St. Louis resident who alleged he developed non-Hodgkin's lymphoma after using Roundup to spray weeds on sidewalks and public spaces in his neighborhood. A Missouri state court jury awarded Durnell $25 million in 2023, finding Monsanto liable for failing to warn of cancer risks associated with glyphosate.

According to the EPA's 2017 risk assessment and subsequent reviews, including a 2020 interim decision, the agency has concluded that "glyphosate is not likely to be carcinogenic to humans" based on available scientific data. The EPA's position is that FIFRA requires pesticide labels to conform to federal standards, and states cannot impose additional requirements that differ from those approved by the agency.

The Supreme Court's decision, expected later in 2026, could affect thousands of similar lawsuits against Monsanto alleging that Roundup causes cancer. As of April 2026, federal court records indicate over 100,000 such cases have been filed, with many consolidated in multidistrict litigation in the U.S. District Court for the Northern District of California.

" Justice Ketanji Brown Jackson asked about handling emerging science that might cast "doubt on the efficacy or the safety of this product," potentially resulting in "a product that is misbranded" despite initial registration.

Sarah Harris, deputy solicitor general for the Justice Department, argued in support of Monsanto that allowing state claims would undermine FIFRA's uniformity: "It would be problematic to have each state jumping the gun and arriving at its own conclusions about whether a product can directly cause cancer." The Justice Department's brief stated that FIFRA "vests EPA with responsibility" over necessary warnings, and if states could compel additional labels contrary to EPA judgments, they "could drown EPA's approved warnings in a sea of local health and environmental concerns."