The Supreme Court Rules that FIFRA Preempts State Tort Law Claims Against Monsanto for Roundup
Key Takeaways
- The U.S. Supreme Court ruled 7-2 in Monsanto v. Durnell that FIFRA preempts a Missouri failure-to-warn claim based on Roundup’s lack of a cancer warning. The decision overturned a jury verdict exceeding $1 million.
- The ruling limits state law claims that would require pesticide labels to add warnings beyond EPA-approved labeling under FIFRA. For registrants, it narrows exposure to safety-based failure-to-warn suits challenging federally approved labels.
- Companies with products subject to federal labeling regimes should assess whether pending or threatened warning claims seek requirements beyond federal approvals. Litigation strategy should focus on preemption defenses where claims challenge federally reviewed safety labeling.
More than 100,000 people have sued Monsanto claiming that they developed cancer or other personal injury as a result of using Roundup, a pesticide that contains glyphosate. In 2017 and 2019, the International Agency for Research on Cancer stated that glyphosate is probably carcinogenic to humans. The EPA re-examined the issue but adhered to its position that glyphosate was unlikely to cause cancer and that glyphosate products could be registered without a cancer warning. Nevertheless, the IARC finding, and other research on glyphosate, led to the explosion of lawsuits against Monsanto.
The Missouri Failure-to-Warn Verdict
Mr. Durnell sued Monsanto in Missouri state court claiming that his use of Roundup for about 20 years caused his non-Hodgkin’s lymphoma. He brought a failure-to-warn claim, asserting that the Roundup label should have included a cancer warning. The jury found for Mr. Durnell and awarded over $1 million. The Missouri Court of Appeals confirmed. Monsanto continued to maintain that glyphosate used in Roundup does not cause cancer.
Monsanto petitioned the United States Supreme Court, which accepted the case. Case No. 24-1068. Monsanto’s lawyers argued in their briefing that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) expressly preempted Durnell’s failure-to-warn claim. See 7 U.S.C. §136v(b).
FIFRA Preemption Reaches the Supreme Court
The Supreme Court agreed in a 7-2 decision, in which only Justices Ketanji Brown Jackson and Neil Gorsuch dissented, overturning the jury’s finding of liability based on FIFRA preemption. Monsanto v. Durnell, Case no. 24-1068, 609 U.S. ____ (2026) (Durnell). The majority held that FIFRA’s preemption clause “provides that a ‘State shall not impose or continue in effect any requirements for labeling or packaging in addition to or different from those required under this subchapter’.” The Court stated that “[t]he question, then, is whether the Missouri failure-to-warn claim—which would require a cancer warning on the Roundup label—would impose a labeling requirement that is ‘in addition to or different from’ federal labeling requirements imposed ‘under’ FIFRA. The answer is yes.” Durnell (slip op. at 9).
The Court’s Reasoning on EPA-Approved Labeling
The Court noted that the case concerned safety claims and concluded that EPA’s registration determinations reflect EPA’s considered judgment that a pesticide’s label is not false or misleading and contains all necessary information. It concluded that safety claims, such as Durnell’s failure-to-warn claim, would impose labeling requirements in addition to or different from those required under FIFRA and are preempted. Durnell (slip op. at 12).
Implications for FIFRA-Regulated Products and Beyond
The Court’s ruling effectively precludes state law failure-to-warn claims for products subject to FIFRA registration that would require warnings in addition to or different from the federal labeling requirements. The Court’s analysis may also affect failure-to-warn claims against other industries—such as medical devices—that are subject to at least some federal labeling regulations. Please reach out to your Polsineli attorney with any questions.
