On June 25, 2026, the Supreme Court of the United States decided Monsanto v. Durnell, No. 24-1068, holding that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) expressly preempts a failure-to-warn tort claim contending that a pesticide label should have included a warning for cancer in addition to or different from the label approved by the Environmental Protection Agency (EPA).
Under FIFRA, the EPA regulates pesticide registration and labeling. Before registering a pesticide, the EPA undertakes an extensive review process, requiring manufacturers to submit information about a pesticide's formulas, potential adverse effects, and testing. A manufacturer must also propose a pesticide label that includes any necessary precautionary statements and may not contain any false or misleading statements. The EPA has promulgated regulations specifying the required content and placement of precautionary statements, such as cancer warnings. Under FIFRA, the EPA may not register a pesticide unless it concludes the pesticide "will not generally cause unreasonable adverse effects" on human health or the environment and its labeling complies with FIFRA's requirements. A manufacturer that does not use the EPA-approved label may be subject to civil and criminal penalties.
After registration, the manufacturer may not change the EPA-approved label unless the EPA requires or approves the change and must continue to inform EPA of "additional factual information regarding unreasonable adverse effects" of the pesticide. The EPA also monitors developments and must formally review a registration every 15 years. Additional labeling may be required at any time to mitigate newly identified hazards. FIFRA includes a preemption clause prohibiting states from imposing "any requirements for labeling or packaging in addition to or different from those required under FIFRA."
Monsanto manufactures Roundup, a glyphosate-based herbicide. The EPA first registered glyphosate-based pesticides and approved Roundup's label without a cancer warning in 1974. It re-evaluated and reapproved Roundup's label in 1991 and has repeatedly concluded since then, including as recently as 2019, that glyphosate is not likely to cause cancer. Many other regulatory bodies around the world have likewise concluded that glyphosate is not carcinogenic. The EPA has therefore not required the Roundup label to include a cancer warning.
In 2019, John Durnell sued Monsanto in Missouri state court alleging he had used Roundup products for about 20 years and they had caused him to develop cancer. Among other causes of action, he asserted a failure-to-warn tort claim, contending that Monsanto should have included a cancer warning on Roundup's label. A jury agreed and awarded him more than $1 million. Monsanto moved for a judgment notwithstanding the verdict arguing that FIFRA expressly preempted Durnell's failure-to-warn claim, but the trial court denied that motion. The Missouri Court of Appeals affirmed, after which Monsanto sought — and was granted — a writ of certiorari.
The Supreme Court reversed, framing the question as whether including a cancer warning would impose a labeling requirement that is "in addition to or different from" the federal labeling requirements "under" FIFRA. If so, then the failure-to-warn claim would fall within the scope of FIFRA's preemption provision. Under federal law, the Court concluded, "EPA's registration determination that Roundup's label need not include a cancer warning constitutes a federal labeling requirement" imposed "under" FIFRA "that cannot be altered by state law, including state tort suits." Because Durnell's state law failure-to-warn claim would require Monsanto to include a cancer warning on Roundup's label, it would constitute a requirement that is "in addition to or different from" the federal labeling requirement imposed by the EPA's registration determination. Durnell's failure-to-warn claim was therefore expressly preempted by FIFRA.
Justice Kavanaugh delivered the opinion of the Court, joined by Chief Justice Roberts and Justices Thomas, Alito, Sotomayor, Kagan, and Barrett. Justice Thomas filed a concurring opinion. Justice Jackson filed a dissenting opinion, joined by Justice Gorsuch.
