Supreme Court: FIFRA Preempts State Failure-to-Warn Claims Contrary to EPA-Approved Labeling

This Holland & Knight alert analyzes the U.S. Supreme Court's reasoning for its 7-2 ruling in Monsanto Co. v. Durnell, No. 24-1068, and its interpretation of the Federal Insecticide, Fungicide, and Rodenticide Act's (FIFRA) preemption provision as applied to U.S. Environmental Protection Agency (EPA)-approved pesticide labeling. It also examines how the June 25, 2026, decision reinforces the legal significance of EPA's labeling determinations, considers its implications for pending and future state-law failure-to-warn claims, and offers practical guidance for strengthening preemption defenses through strategic regulatory engagement and record development.

FIFRA Background

FIFRA authorizes EPA to regulate the registration, distribution, sale and use of pesticides, including the content of pesticide labels. A manufacturer must obtain EPA registration before marketing, selling or distributing a product, a process that includes EPA's review and approval of the label. Under FIFRA, "the label is the law": It must include all warnings EPA determines are "necessary and … adequate to protect health and environment" and not include "false or misleading" statements. 7 U.S.C. Sections 136a(c)(5)(B), 136(q)(1)(A). Once approved, the label must be used unless and until EPA authorizes a change and amends the product's registration. Id. Section 136a(f)(1); 40 C.F.R. Sections 152.44(a), 156.70(c). A failure to use the EPA-approved label may result in civil and criminal penalties. 7 U.S.C. Sections 136l, 136j(a)(1)(E).

FIFRA's preemption provision, 7 U.S.C. Section 136v(b), ensures "uniformity" in labeling by prohibiting states from imposing "any requirements for labeling or packaging in addition to or different from those required under this subchapter." As the Court emphasized, the preemption clause is expressly titled "Uniformity," reflecting the U.S. Congress' intent to establish a single, nationwide labeling standard. Accordingly, though a state may ban a pesticide outright, it may not impose additional or different labeling requirements beyond those approved by EPA. Because FIFRA seeks uniform labeling nationwide, any state-law requirement that diverges from federal labeling requirements is preempted.

Case Background and Procedural Posture

Monsanto Company (now a subsidiary of Bayer AG) manufactures Roundup, a glyphosate-based herbicide and one of the most widely used pesticide products in the U.S. EPA has repeatedly evaluated glyphosate and consistently determined that it is "not likely to be carcinogenic to humans" and, accordingly, has never required a cancer warning on Roundup's label.

In January 2019, plaintiff John Durnell filed suit in Missouri state court alleging that he developed non-Hodgkin's lymphoma after approximately 20 years of Roundup use. His complaint asserted state-law claims for failure to warn, defective design and negligence. As relevant before the Supreme Court, the failure-to-warn claim alleged that Monsanto should have included a cancer warning on Roundup's EPA-approved label. A jury found for Durnell on that claim and awarded $1.25 million in damages.

Monsanto moved for judgment notwithstanding the verdict on the ground that FIFRA preempted the state-law failure-to-warn claim. The trial court denied the motion, and the Missouri Court of Appeals affirmed, holding that FIFRA did not preempt the claim. The Supreme Court granted certiorari on January 16, 2026.

The Supreme Court's Holding

In its 7-2 decision, authored by Justice Brett Kavanaugh, the Court reversed and remanded the judgment of the Missouri Court of Appeals, holding that "FIFRA expressly preempts Durnell's state-law failure-to-warn claim because the claim would require Monsanto to add a cancer warning to Roundup's label" – a requirement "in addition to or different from" those imposed under FIFRA, in violation of the statute's preemption clause. 7 U.S.C. Section 136v(b).

Justice Clarence Thomas filed a concurring opinion. Justice Ketanji Brown Jackson dissented, joined by Justice Neil Gorsuch.

The Majority Opinion

The Court's analysis proceeded in two steps. First, relying on Bates v. Dow Agrosciences LLC, 544 U.S. 431 (2005), the Court reaffirmed that "state tort duties constitute state labeling requirements." Failure-to-warn claims, including Durnell's, "are premised on common-law rules that qualify" as labeling requirements because those rules "set a standard for a product's labeling." A successful failure-to-warn claim would require Monsanto to add a cancer warning to its label to avoid liability – a paradigmatic labeling requirement.

Second, the Court concluded that such a state-law duty would impose requirements "in addition to or different from" those "required under FIFRA." The majority drew a critical analogy to Riegel v. Medtronic, Inc., 552 U.S. 312 (2008), which interpreted a materially similar preemption clause in the Medical Device Amendments of 1976 to bar state-law claims imposing additional or conflicting safety requirements following U.S. Food and Drug Administration (FDA) premarket approval. Finding Riegel dispositive, the Court reasoned that "[i]f FDA's premarket approval of medical devices preempted additional state-law requirements, so too must EPA's registration of pesticides and approval of pesticide labels." The Court emphasized that allowing Durnell's claim to proceed would have implications beyond FIFRA, as "similar labeling preemption clauses reflect Congress's judgment that the ability to sell a product throughout the country with a single label can be important to maintaining an efficient nationwide market."

The Court also held that EPA's labeling determination that glyphosate-based labels do not require a cancer warning, combined with regulations requiring manufacturers to use the approved label, 40 C.F.R. Sections 152.44(a), 156.70(c), establishes a federal labeling requirement for preemption purposes.

Finally, the Court addressed 7 U.S.C. Section 136a(f)(2), which provides that "[i]n no event shall registration of [a pesticide] be construed as a defense for the commission of any offense under" FIFRA. The Court clarified that this provision does not limit the preemptive effect of EPA's labeling determinations. Rather, Section 136a(f)(2) prevents a manufacturer from relying on registration as a defense to its own violations of FIFRA but does not undermine the separate question whether EPA's label-approval decisions establish binding federal requirements that preempt conflicting state-law standards.

The Thomas Concurrence

Justice Thomas joined the majority in full but wrote separately to raise constitutional concerns with FIFRA's regulatory framework. His concurrence flagged potential commerce clause issues and expressed broader skepticism of expansive federal regulatory regimes that vest significant authority in federal agencies and may burden market participants. Though not affecting the Court's holding, the concurrence signals potential receptiveness to future structural challenges to federal regulatory schemes.

The Jackson Dissent

Justice Jackson, joined by Justice Gorsuch, dissented on the ground that Durnell's failure-to-warn claim paralleled – rather than "added to" – FIFRA's misbranding prohibition, which requires labels to include adequate warnings. In the dissent's view, the claim was not "in addition to or different from" FIFRA's requirements, but instead "equivalent to FIFRA's key labeling requirement – the misbranding prohibition."

The dissent further argued that EPA registration and label approval do not constitute the sole labeling requirements under FIFRA for purposes of Section 136v(b) because the statute's misbranding prohibition continues to apply after registration. Accordingly, the dissent concluded that the majority's approach improperly forecloses state-law remedies.

Finally, responding to Monsanto's impossibility argument, the dissent asserted that a manufacturer "can easily comply with both federal and state law by stopping sales of [the product]," rejecting the premise that dual compliance is unattainable.

Implications for Regulated Industry

The Court's decision in Monsanto Co. v. Durnell has significant practical implications for pesticide manufacturers and, more broadly, regulated entities that rely on federal agency approvals to limit state tort liability:

• Enhanced Preemptive Force of EPA Label Approvals. The decision confirms that EPA's labeling determinations – including decisions that particular warnings are not required – carry preemptive force under FIFRA. Registrants can rely on EPA-approved labels as a defense to state failure-to-warn claims, significantly strengthening preemption defenses in pending Roundup litigation and similar cases involving EPA-registered products.
• Importance of EPA Engagement and Record Development. Because the majority relied on EPA's specific determination regarding cancer warnings and glyphosate, registrants should consider strengthening their engagement with EPA during the registration and label-review process. Developing a clear administrative record documenting EPA's evaluation of risks and labeling decisions will be key to establishing and defending preemption.
• Limits of Preemption/Surviving State-Law Theories. The decision does not eliminate all state-law exposure. Claims that do not impose additional or different labeling requirements – such as those based on manufacturing defects, express warranties, fraud not tied to label content or off-label conduct (e.g., application, discharge or disposal) – may remain viable, depending on the facts. States also retain authority under Section 136v(a) to regulate the sale or use of pesticides, though not their label content.
• Broader Implications Beyond Pesticides. The Court's reliance on Riegel v. Medtronic signals that similar reasoning may apply to other statutes with comparable preemption language and federal regulatory regimes. Though the analysis will remain statute-specific, particularly where the statute contains a savings clause or product-liability carve-out, Durnell strengthens arguments that federal approvals can define the operative federal requirement for preemption.
• Post-Loper Bright Implications. The Court's rejection of Durnell's argument that EPA's label-approval regulations lack statutory authority, even in the post-Loper Bright environment, suggests that clear statutory authority coupled with concrete agency determinations will continue to support strong preemption defenses.

Conclusion

The Supreme Court's decision in Monsanto Co. v. Durnell is a landmark ruling, reaffirming that where EPA has made a specific labeling determination, state-law claims requiring different, supplemental or contradictory warnings are expressly preempted.

Regulated entities should reassess the strength of their preemption defenses and importance of proactive EPA engagement throughout the registration and label-review process. Maintaining a robust administrative record and closely monitoring registration reviews, label amendments and related proceedings will be critical. Companies should also track state efforts to regulate pesticide use under Section 136v(a), which remains a viable avenue for state action, and evaluate how state-law claims may be reframed to avoid direct challenges to labeling.

More broadly, companies operating under federal labeling, warning, safety or approval regimes other than FIFRA should consider how Durnell enhances the preemptive effect of agency determinations while preparing for continued evolution in state tort theories.

How Holland & Knight Can Help

Holland & Knight's Environmental and Regulatory team is monitoring how courts apply Durnell across environmental, product liability and regulatory contexts. Please contact the authors with any questions regarding how this decision may affect your operations, compliance strategy or anticipated litigation.

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