What is Preemption and How Might it Affect Glyphosate Litigation

Lawsuits involving plaintiffs who have alleged that exposure to glyphosate caused their non-Hodgkin’s lymphoma continue to make their way through the court system. Over the past year, the issue of preemption has become a focus of these lawsuits. Preemption occurs when a “higher” level of government reduces the authority of a “lower” level of government and may occur when a federal law and a state law conflict. In glyphosate lawsuits, the defendant Bayer has argued that the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”), the federal law governing pesticide regulation, preempts the state law failure-to-warn claims raised by most glyphosate plaintiffs.

FIFRA regulates the labeling of pesticides. A pesticide may not be distributed or sold in the United States until it has a label approved under FIFRA. Additionally, states may not impose any labeling or packaging requirements that are “in addition to or different from” those required by FIFRA. Plaintiffs bringing state law failure-to-warn claims are arguing that had the label included adequate warnings about the risks of glyphosate, then their injuries would not have occurred. So far, juries have found in favor of plaintiffs on these claims.

Bayer has appealed these jury findings, arguing that FIFRA’s prohibition on states imposing additional or different pesticide labeling requirements preempts failure-to-warn claims. If the state law claims are preempted by FIFRA, then Bayer argues that those claims should never have been raised in court.

Courts have split on the issue. A state court in California dismissed a plaintiff’s failure-to-warm claims, finding that the claims were preempted because the approved label for glyphosate does not require a carcinogen warning. However, both a California state appellate court and the Ninth Circuit have ruled the opposite. Those courts found that the failure-to-warn claims were not preempted because FIFRA prohibits pesticides from being “misbranded.” A pesticide is misbranded if its label does not contain a warning which may be necessary to protect human health. The Ninth Circuit concluded that FIFRA’s prohibition on misbranding was broader than the state law failure-to-warn and that such claims were therefore not preempted.

Bayer has appealed the Ninth Circuit’s decision to the Supreme Court. If the Court takes up the case, a ruling could impact not just glyphosate lawsuits, but any pesticide lawsuit where a plaintiff raises a state law failure-to-warn claim.


Rollins, Brigit. “What is Preemption and How Might it Affect Glyphosate Litigation.” Southern Ag Today 1(51.5). December 17, 2021. Permalink