Monsanto v. Durnell
The Supreme Court ruled that federal pesticide law blocks a Missouri man's lawsuit claiming Monsanto should have put a cancer warning on Roundup, because the EPA has repeatedly reviewed and approved Roundup's label without that warning.
The decision means federal approval of a pesticide label can override conflicting state jury verdicts, cutting off a major legal avenue that thousands of Roundup users have used to seek damages for cancer they blame on the weedkiller.
“Durnell’s state tort claim, by contrast, would require Monsanto to add a cancer warning to its labels. That Missouri-law requirement is “in addition to” and “different from” Monsanto’s federal-law labeling obligations.”
The majority's core reasoning for why the state tort claim is preempted by federal pesticide law.
How it got here: A Missouri jury ruled for Durnell; the Missouri Court of Appeals affirmed, rejecting Monsanto's preemption defense; Monsanto sought Supreme Court review to resolve a circuit split.
The Case in Depth
What happened
John Durnell used Monsanto's Roundup weedkiller for about 20 years and developed non-Hodgkin's lymphoma, a form of cancer. He sued Monsanto in Missouri state court, arguing the company should have warned users on the product label that Roundup could cause cancer. A jury sided with him and awarded over $1 million.
The question before the Court
Can a state jury require Monsanto to put a cancer warning on Roundup's label when the EPA has repeatedly approved that label without one?
The Court's answer
No — the Court ruled that federal pesticide law preempts Durnell's Missouri failure-to-warn claim. Because the EPA has repeatedly reviewed glyphosate and approved Roundup's label without a cancer warning, and because federal regulations require Monsanto to keep using that exact approved label until EPA says otherwise, a state jury cannot force Monsanto to add a warning EPA has not required.
The Court found this outcome dictated by FIFRA's text, which bars states from imposing labeling rules "in addition to or different from" federal requirements, and by its earlier decision in Riegel v. Medtronic, which held that a federal agency's approval of a product's label counts as a binding federal requirement capable of blocking conflicting state lawsuits. The Court rejected Durnell's arguments that FIFRA's registration provisions leave room for parallel state tort suits.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Thousands of pending Roundup lawsuits nationwide rely on the same failure-to-warn theory that the Court just rejected, so this ruling could block many plaintiffs from recovering damages. It also signals to other companies regulated under similar federal labeling laws that EPA or FDA approval of a label may shield them from state tort suits demanding different warnings.
What changes now
The case is sent back to the Missouri Court of Appeals for further proceedings consistent with the Supreme Court's ruling, which will likely mean the jury's $1 million-plus verdict cannot stand on the failure-to-warn theory. The decision is a final ruling on the preemption question and is expected to affect other pending Roundup lawsuits raising the same failure-to-warn argument, though implied-preemption and other theories were not addressed.
What this does not decide
The Court decided only that Durnell's specific failure-to-warn claim is expressly preempted; it expressly did not address Monsanto's separate implied-preemption argument. The ruling does not resolve every possible Roundup-related claim, such as design-defect or manufacturing claims not tied to the cancer-warning label dispute.
Concurrences and dissents
How the Justices voted
Majority (7). Justice Kavanaugh (author), joined by Justice Roberts, Justice Thomas, Justice Alito, Justice Sotomayor, Justice Kagan, and Justice Barrett.
Dissent (2). Justice Jackson (author), joined by Justice Gorsuch.
Concurrence — Justice Thomas
Justice Thomas joined the majority in full but wrote separately to flag broader constitutional doubts about FIFRA itself. He argued the law likely exceeds Congress's Commerce Clause power by regulating purely local activities like backyard pesticide use, raises unconstitutional-delegation concerns by letting EPA make rules punishable by fines or imprisonment, and creates uncertainty about whether agency action can ever count as 'supreme law' capable of preempting state law under the Supremacy Clause.
Dissent — Justice Jackson
“The majority reads into FIFRA a labeling requirement that does not exist, and it reads out of FIFRA the statute’s ongoing prohibition on misbranding.”Jackson's central objection that the majority invented a federal requirement not found in the statute.
Justice Jackson argued that Durnell's Missouri failure-to-warn claim simply duplicates FIFRA's own misbranding prohibition rather than adding any new requirement, so it should not be preempted. She contended that EPA's approval of a label is only 'prima facie' evidence of legal compliance, not a conclusive federal requirement, meaning a pesticide can be registered yet still misbranded under ongoing federal law. She would have distinguished Riegel because FIFRA, unlike the medical device law, has no equivalent provision, and would have found Bates controlling instead, allowing Durnell's suit to proceed. Read the full dissent →
How the Court got there
The legal reasoning, step by step
- The Court read FIFRA's preemption clause, titled 'Uniformity,' to block any state labeling requirement that is 'in addition to or different from' the federal labeling requirements imposed under the statute.
- Because EPA must review and approve a pesticide's label before registration, and a manufacturer is legally required to keep using that approved label unless EPA later approves or orders a change, the Court treated EPA's approval itself as a federal labeling requirement.
- Since state tort duties count as labeling requirements under the Court's precedent in Bates v. Dow Agrosciences, a Missouri jury verdict demanding a cancer warning would impose a requirement 'in addition to or different from' the no-cancer-warning label EPA had approved.
- The Court leaned heavily on Riegel v. Medtronic, Inc., a case interpreting a nearly identical preemption clause for medical devices, where the Court held that an agency's premarket approval of a product's label counts as a federal 'requirement' that displaces conflicting state-law claims.
- The Court rejected Durnell's argument that a 1988 FIFRA provision stating registration is not a 'defense' to enforcement actions undermines this analysis, reasoning that provision only concerns EPA's own enforcement suits, not private state tort claims.
- Applying this framework, the Court concluded that Monsanto's federally required label without a cancer warning could not be overridden by a state jury's contrary demand, so the failure-to-warn claim was expressly preempted.
Doctrinal impact
Cases affected by this decision
Reaffirms Riegel v. Medtronic, Inc. (552 U. S. 312)
The Court relies on Riegel's rule that premarket agency approval counts as a federal requirement that can preempt state tort suits.
Distinguishes Bates v. Dow Agrosciences LLC (544 U. S. 431)
The Court says Bates involved efficacy claims EPA never reviewed, unlike this safety-based claim, so it does not control.