Monsanto Company v. Durnell

Justia · Docket · oyez.org

Argued on Apr 27, 2026.

Petitioner: Monsanto Company.
Respondent: John L. Durnell.

Advocates:

• Paul D. Clement (for the Petitioner)

Facts of the case (from oyez.org)

John L. Durnell used Monsanto’s product Roundup, a herbicide containing the active ingredient glyphosate. Durnell subsequently developed non-Hodgkin’s lymphoma, which he alleged was caused by his exposure to Roundup and glyphosate. In January 2019, Durnell sued Monsanto, asserting claims for strict liability defective design, strict liability failure to warn, and negligence. Durnell claimed that Monsanto should have included a cancer warning on Roundup’s label to alert users to the risk of developing non-Hodgkin's lymphoma from glyphosate exposure.

After a jury trial in September 2023 in the Circuit Court of the City of St. Louis, the jury found in favor of Durnell on his strict liability failure to warn claim and awarded him $1.25 million in compensatory damages, but ruled for Monsanto on the defective design and negligence claims. Monsanto moved for judgment notwithstanding the verdict, arguing that federal law—specifically the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)—both expressly and impliedly preempted Durnell’s failure to warn claim. The trial court denied the motion, and Monsanto appealed to the Missouri Court of Appeals, Eastern District, which affirmed the judgment.

Question

Does the Federal Insecticide, Fungicide, and Rodenticide Act preempt a label-based failure-to-warn claim where EPA has not required the warning?