Supreme Court of the United States

Monsanto v. Durnell

June 25, 2026

Summary

The Supreme Court held that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) expressly preempts John Durnell's state‑law failure‑to‑warn claim because the claim would require Monsanto to add a cancer warning to Roundup's label, which is "in addition to or different from" the EPA‑approved federal label. The Court reasoned that EPA's registration and label approval constitute a federal labeling requirement that triggers FIFRA's preemption clause, and that §136a(f)(2) does not defeat that preemptive effect. The judgment of the Missouri Court of Appeals was reversed and the case remanded.