On June 25, 2026, the U.S. Supreme Court ruled in Monsanto Co. v. Durnell, No. 24-1068, that federal pesticide law preempts state tort claims over missing cancer warnings on Roundup labels.
The 7-2 opinion, written by Justice Kavanaugh, held that the Federal Insecticide, Fungicide, and Rodenticide Act expressly bars states from imposing labeling requirements beyond those approved by the U.S. Environmental Protection Agency.
The Court reversed a Missouri Court of Appeals decision that had upheld a jury verdict against Monsanto based on its alleged failure to include a cancer warning on Roundup’s EPA-approved label.
FIFRA’s preemption provision, codified at 7 U.S.C. ยง 136v(b), prohibits states from imposing labeling requirements “in addition to or different from” those required under federal law.
The majority held that allowing failure-to-warn claims to proceed “would require [a manufacturer]…to add a warning to its labels” that the EPA has neither approved nor required.
Roundup is a glyphosate-based herbicide first registered by the EPA in 1974, and the agency has repeatedly reviewed glyphosate, most recently in 2020, concluding it is “not likely to be carcinogenic to humans.”
Despite those determinations, plaintiffs in Durnell and in other cases across the country have alleged that long-term Roundup use caused cancer and that Monsanto failed to adequately warn users of that risk.
The Supreme Court granted certiorari in January 2026 to resolve a deepening split among state and federal appellate courts over whether FIFRA preempts such failure-to-warn claims.
The Court distinguished the earlier ruling in Bates v. Dow Agrosciences LLC, 544 U.S. 431 (2005), explaining that the prior case concerned efficacy labeling rather than the precautionary warnings at issue in Durnell.
The majority placed considerable weight on the EPA’s extensive scientific review process, its authority to approve pesticide label language, and its ongoing power to require labeling changes when new safety information emerges.
The Court also noted that the EPA must review each pesticide registration at least every 15 years, reinforcing the view that federal oversight provides a continuous and adequate mechanism for updating product warnings.
For pesticide registrants, the decision significantly strengthens preemption defences in failure-to-warn product liability suits where plaintiffs seek warnings inconsistent with EPA-approved labelling.
The ruling does not eliminate all litigation risk, however, as the Court confirmed that states retain authority under 7 U.S.C. ยง 136v(a) to regulate the sale or use of registered pesticides, including by banning them outright within state borders.
Legal experts at Beveridge and Diamond PC advise that pesticide registrants and other stakeholders should review pending product liability claims for potential preemption defences in light of the Durnell decision.
Companies are also encouraged to assess whether state-required label language, point-of-sale warnings, website statements, or marketing materials could be characterised as pesticide labelling inconsistent with EPA-approved requirements.