The U.S. Supreme Court issued a significant pesticide-labeling decision this week in Monsanto Co. v. Durnell, holding that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) expressly preempts state-law failure-to-warn claims seeking to require a cancer warning on EPA-approved Roundup labels. In a 7-2 decision authored by Justice Brett Kavanaugh, the Court reversed a Missouri appellate ruling that had allowed a $1 million-plus verdict against Monsanto to stand. 

The case centered on whether a state tort claim could impose liability on Monsanto for not including a cancer warning on Roundup, even though EPA has repeatedly concluded that glyphosate is “not likely to cause cancer” and has not required such a warning on glyphosate-based pesticide labels. The Court held that it could not.  

Background 

John Durnell sued Monsanto in Missouri state court, alleging that he used Roundup products for approximately 20 years and developed non-Hodgkin’s lymphoma as a result. His failure-to-warn claim asserted that Monsanto should have included a cancer warning on Roundup’s label. A jury agreed, and the Missouri Court of Appeals affirmed the verdict. 

Monsanto argued that FIFRA preempted the claim because pesticide labels are reviewed and approved by EPA, and federal law prohibits states from imposing pesticide labeling requirements “in addition to or different from” those required under FIFRA. The Supreme Court agreed.  

The Court’s Holding 

The Court emphasized that FIFRA gives EPA comprehensive authority over pesticide registration and labeling. Before registering a pesticide, EPA must determine that the product will not generally cause unreasonable adverse effects and that its label complies with FIFRA’s requirements, including necessary warnings. Once EPA approves a label, the manufacturer generally must use that label unless EPA approves or requires a change.  

Because EPA had approved Roundup labels without a cancer warning, the Court concluded that a state-law verdict premised on the absence of that warning would effectively require Monsanto to use a label different from the EPA-approved label. That, the Court held, is exactly what FIFRA’s express preemption provision forbids. 

Justice Kavanaugh wrote that Durnell’s claim would impose a pesticide-labeling requirement “in addition to or different from” federal labeling requirements, and therefore was expressly preempted. Justice Jackson dissented, joined by Justice Gorsuch. 

Why This Matters for Agriculture 

For agricultural employers, applicators, and pesticide users, the decision reinforces the central role of EPA-approved labels in pesticide regulation. The ruling provides important clarity that states may not use tort law to require additional or different label warnings where EPA has not required them under FIFRA. 

However, the decision should not be read as a broad exemption from pesticide compliance obligations. Growers and applicators must still follow all EPA-approved label instructions, including use restrictions, application rates, personal protective equipment requirements, restricted-entry intervals, worker protection requirements, storage and disposal directions, and any applicable state and local pesticide-use rules. 

The decision also does not eliminate other potential claims or enforcement theories. It addresses a specific category of claim: state-law failure-to-warn claims based on the absence of a label warning that EPA has not required. Claims based on alleged misuse, off-label application, drift, exposure, negligence, workplace safety violations, or failure to comply with the label may still present legal risk depending on the facts. 

Practical Takeaways for WG Members 

Employers and agricultural businesses should continue to treat pesticide-label compliance as a core risk-management practice. The ruling makes EPA-approved labels more central, not less. Members should: 

• Review pesticide labels before use and ensure employees and supervisors understand all application restrictions and safety requirements. 

• Maintain records showing that products were used consistently with label instructions and applicable state pesticide regulations. 

• Train handlers and field employees under applicable Worker Protection Standard requirements and state-specific pesticide-safety rules. 

• Avoid modifying, supplementing, or disregarding label directions based on informal guidance or assumptions. 

• Monitor EPA and state regulatory developments, particularly where pesticide registrations, use restrictions, or label language may change. 

Bottom Line 

Monsanto v. Durnell is a major pesticide-preemption decision. For agriculture, it provides greater certainty that EPA-approved pesticide labels cannot be displaced by state-law failure-to-warn verdicts requiring different warnings. But it also underscores the importance of strict label compliance: the EPA-approved label remains the controlling document for lawful pesticide use.