Background 

            On Monday April 27 the U.S. Supreme Court will hear oral argument in Monsanto v. Durnell[1].  The case is a key component the campaign by Bayer AG, the owner of Monsanto, to put an end to the wave of pesticide tort litigation premised on the failure of Monsanto to adequately warn users of the risks of the herbicide glyphosate and its alleged carcinogenicity. The matter is not only the most significant pesticide related case since Bates v. Dow Agrosciences was decided in 2005 but holds potential implications for other regulatory regimes.

            The Federal Insecticide, Fungicide and Rodenticide Act (“FIFRA”) states that “[A] state shall not impose or continue in effect any requirements for labeling or packaging in addition to or different from those required under FIFRA.[2] This provision was addressed by the U.S. Supreme Court in Bates v. Dow Agrosciences.[3] The Court clarified that state requirements include state tort common law. Nonetheless it held that while state labeling or packaging requirements that differed from those imposed by FIFRA are preempted, additional requirements that did not differ from FIFRA requirements were not preempted. It also held that other types of claims, such  defective design or breach of express warranty, were not labeling and thus not preempted.

            Since Bates Monsanto has faced tens of thousands of suits in state and Federal courts over the glyphosate lymphoma claims. Estimates are that Bayer has paid out in the range of $10 billion in the last five years. In February, 2026, Monsanto proposed a settlement of the majority of remaining cases for $725 billion. While proceedings related to the settlement offer are underway Monsanto continues to pursue the Durnell matter.   

            Monsanto lost the Durnell v. Monsanto[4]case in Missouri state court. Prior to that decision a split between the 3^rd and 9^thFederal Courts of Appeal laid the groundwork for Monsanto’s Petition for Certiorari, citing the Circuit split as justification for the Court to grant the petition.  In Hardeman v Monsanto Company[5] the 9^th Circuit Court of Appeals held that Hardeman’s failure to warn claim imposed duties consistent with FIFRA. In Schaffner v. Monsanto[6] the 3^rd Circuit Court of Appeals held that failure to warn claims are expressly preempted by FIFRA. With the encouragement of the U.S. Solicitor General the Court granted the Petition. In a recent order the Court allowed the U.S. to participate in the oral argument in support of Monsanto.

Broad Array of Parties Filing Amicus Briefs Anticipate Impacts of Decision Beyond FIFRA

            The wide range of parties filing amicus briefs in this case attest to the intensity of interest not only from the pesticide industry but other parties concerned with the broader issue of preemption by Federal law in other regulatory schemes.

            Monsanto has attracted support from a wide array of pesticide and agricultural organizations. These include CropLife America, the major agricultural chemical trade association, as well as the American Chemistry Council, a broad-based chemical trade association which includes a focus on antimicrobial pesticides.  The American Farm Bureau Federation, the largest agricultural trade association, joined a brief, as did eleven individual state Farm Bureau organizations[7]. Eleven other crop-based agricultural trade associations[8]also joined briefs.

            Other major trade associations not related to the pesticide industry have also filed briefs. These include the Chamber of Commerce and Pharmaceutical Research and Manufacturers of America, the trade association of major pharmaceutical manufacturers. This case is a rare instance of the Chamber of Commerce supporting rather than attacking EPA. A number of other lesser-known parties focused on “tort reform” have also filed in support of Monsanto, anticipating that a Monsanto victory would have an impact beyond the pesticide industry.

            The case has prompted competing briefs from collections of states both in support of preemption and opposed to it. Fifteen states, led by Missouri[9], filed in support of preemption. Fifteen other states and the District of Columbia filed in opposition to preemption.[10]  A separate brief opposing preemption was also filed by Texas, Florida and Ohio. It is noteworthy that the decision for a state to file an amicus brief is almost universally a decision of the state attorney general. That fact can lead to the anomalous circumstance wherein the attorney general is a member of one party and the governor is a member of another party and would likely take different positions. Pennsylvania is such an example, where the Democratic governor would be unlikely to support preemption but the Republican Attorney General does.

            A number of environmental and health advocacy organizations have filed briefs opposing preemption.  These include the Consumer Federation of America, the National League of Cities, the National Association of Counties, the Center for Biological Diversity, Public Citizen and Veterans of Foreign Wars, along with many other lesser-known entities. The lead law firms representing the plaintiffs in the multidistrict glyphosate and paraquat litigation also filed a brief.

            Glyphosate has played a key role in the “Make America Healthy Again” (“MAHA”) movement. Children’s Health Defense, the organization formerly led by Health and Human Service Secretary Kennedy, has filed a brief opposing preemption. This issue has caused friction within the MAHA movement, as Secretary Kennedy has supported EPA’s position supporting preemption.

            Several other briefs present unique insights into the controversy surrounding glyphosate. In a brief filed by Naomi Oreskes, PhD, and Alexander Kaurov, PhD, of Harvard University, the authors focus on their journal recent article[11] describing the undisclosed ghost writing by Monsanto of a 2000 article[12] long touted as a key support for the assertion that glyphosate is not a carcinogen.

            Another unusual brief opposing preemption was filed by eight former EPA senior staff involved for many years in administering the EPA FIFRA program. This group includes Lynn Goldman, a former Assistant Administrator overseeing FIFRA and Jonothan Cannon, a former EPA General Counsel. Their brief asserts based upon their years of managing the program that EPA never considered additional state warnings as violative of FIFRA.  This position of course contradicts the EPA’s present posture in the case.

Outlook

            The highly anticipated oral argument will be divided three ways. Monsanto is allotted twenty minutes, having conceded ten minutes to the U.S. Solicitor General at his request. Respondent Durnell’s counsel is allotted thirty minutes. The lead law firms representing the plaintiffs in the multidistrict glyphosate and paraquat litigation also sought to participate in the argument but the Court denied their motion.

            If Monsanto prevails, there is a strong likelihood that all the failure to warn suits will be dismissed, although not without a fight depending on the clarity of the opinion. Such an outcome could also prompt Monsanto to revoke the pending settlement offer. The scope of such an opinion will also reveal the precedential importance of the decision to other regulatory issues.

            If Mr. Durnell prevails, the tort litigation will continue if not expand, although not in the limited number of states that have passed legislation annulling failure to warn claims.

[1] Docket No. 24-1068

[2] 7 USC §136v(b)

[3] 544 U.S. 431 (2005)

[4] 707 SW 3d 828 (Missouri Supreme Court)

[5] 997 F.3d 9419^th (Cir. 2021)

[6] 113 F.4 364 (2024)

[7] Farm Bureau Organizations of California, Florida, Kansas, Ohio, Oklahoma, Oregon, Missouri, North Carolina, Tennessee, Texas, and Virginia

[8] American Soybean Association, American Sugarbeet Growers, Association, Cherry Marketing Institute, Florida Fruit and Vegetable Association, International Fresh Produce Association, National Association of Wheat Growers, National Corn Growers Association, National Cotton Council of America, National Sorghum Producers, North American Blueberry Council and Western Growers.

[9]Alabama, Georgia, Iowa, Kansas, Kentucky, Louisiana, Missouri, Montana, Nebraska, North Dakota, Oklahoma, Pennsylvania, South Carolina, South Dakota and Utah.

[10] Arizona, California, Colorado, Delaware, Illinois, Massachusetts, Maine, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon and Wisconsin

[11] The Afterlife of Ghost-written Paper: How Corporate Authorship Shaped Two Decades of Glyphosate Safety Discourse ENVT.SCI & Policy 171 (2025).

[12] Safety Evaluation and Risk Assessment of the Herbicide RoundUp and Its Active Ingredient Glyphosate for humans REG. TOXICOLOGY & PHARM 31 (2000.)