By Michael Ruttinger

On June 25, 2026, the Supreme Court of the United States issued its decision in Monsanto Co. v. Durnell, No. 24-1068, holding a plaintiff’s state-law claim premised on a failure to warn about a cancer risk preempted under the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”). Writing for a 7-2 Court, Justice Kavanaugh concluded that because the Environmental Protection Agency (“EPA”) approved Roundup’s label without a cancer warning, and federal law required it to use the EPA-approved label, a state tort claim demanding a different label imposed a requirement “in addition to or different from” federal law.

The decision’s significance reaches well beyond pesticides. The Court’s reasoning establishes that an agency’s individualized label-approval decision can constitute a federal “requirement” that displaces state tort duties. That holding has implications across the many federally regulated, label-bearing product markets.

Background

John Durnell sued Monsanto in Missouri state court alleging that Monsanto should have warned of a cancer risk on the Roundup label. A jury awarded him more than $1 million, and the state appellate court affirmed, rejecting Monsanto’s argument that FIFRA expressly barred Durnell’s failure-to-warn claim. Specifically, Monsanto argued that because FIFRA requires the EPA to approve a pesticide’s label, any state-law claim alleging an inadequate label imposes labeling requirements “in addition to or different from” those imposed under FIFRA.

The Decision

The Court reversed. It is well-settled that state tort duties can constitute labeling “requirements,” so the question turned on whether Missouri’s failure-to-warn duty was “in addition to or different from” federal requirements imposed under FIFRA. The Court held that it was.

The Court began by identifying the operative federal requirement. The majority did not rest on FIFRA’s general misbranding standard. Instead, it held that EPA’s registration determination—its approval of the label without a cancer warning—was a federal requirement with preemptive force because federal law obligated Monsanto to use that approved label. A state claim requiring a cancer warning therefore demanded something “in addition to” and “different from” the federal requirement.

The Court found Riegel v. Medtronic, Inc., 552 U.S. 312 (2008), “dispositive.” In Riegel, the Court held that the Food and Drug Administration’s premarket approval of a medical device imposed “requirements” under the Medical Device Amendments’ nearly identical preemption clause. The same logic, the majority reasoned, applies to EPA’s approval of pesticide labels. The Court underscored that the point is not confined to FIFRA: numerous federal statutes contain “similar or identical” preemption provisions.

The majority rejected the plaintiff’s counterargument that Missouri failure-to-warn claims merely impose a duty “parallel” to FIFRA’s prohibition against “misbranding,” and are therefore not “different from” or “in addition to” federal law, as operating “at far too high a level of generality.” The Court also emphasized a textual point with broad application: the statute gives preemptive force to requirements imposed “under” FIFRA, not merely those imposed “by” the statute.

The Concurrence and Dissent

Justice Thomas joined the majority in full but wrote separately to question, on structural grounds, whether federal agency action can preempt state law at all under the Supremacy Clause.

Justice Jackson, joined by Justice Gorsuch, dissented. In her view, FIFRA’s labeling “requirements” are set by the statute (the misbranding prohibition) and EPA’s duly promulgated regulations—not by EPA’s individualized approval of a particular label. On her reading, Durnell’s claim simply paralleled FIFRA’s misbranding prohibition and was therefore not preempted.

Implications

Durnell meaningfully affects the preemption strategies for manufacturers of products carrying federally approved labels:

• Agency approvals carry preemptive force. The decision broadens the scope of what can constitute a federal “requirement” for purposes of federal preemption to encompass labeling approvals. Defendants should identify the specific agency determination at issue and frame the preemption analysis around it.
• The reasoning travels beyond FIFRA. Because the Court relied on Reigel and noted that many statutes contain “similar or identical” preemption clauses, the decision’s logic is likely to be invoked in other regimes that feature federal premarket approval and express preemption provisions. Companies in these spaces should expect Durnell to feature in preemption briefing.
• Frame the comparison narrowly. The Court’s rejection of the plaintiff’s “level of generality” argument instructs courts to measure a state-law duty against the specific federal determination, not a general statutory command. The practical lesson for defendants is to anchor the analysis to the specific agency determination, not an open-ended standard.
• Express, not implied. The Court resolved the case on express preemption and did not reach Monsanto’s implied (impossibility) argument. Impossibility-preemption questions therefore remain open where an express clause does not control.

This Client Alert has been prepared by Tucker Ellis LLP for the use of our clients. Although prepared by professionals, it should not be used as a substitute for legal counseling in specific situations. Readers should not act upon the information contained herein without professional guidance.