Cabashing the Roundup Litigation

By Barbara Pfeffer Billauer JD MA (Occ. Health) PhD  

A Litigation Boom Over Roundup

The Roundup litigation craze has fed roughly 100,000 plaintiffs and their lawyers over $11 billion in settlements and verdicts since claims surrounding the world’s most widely used and highly profitable weed-killer first surfaced. It all began seven years ago with a California jury awarding a $289 million verdict against the manufacturer, Monsanto, and its parent company, Bayer. The plaintiffs suffered their share of defeats as Monsanto’s lawyers became more skillful in exposing the flaws in the causation claims presented by the plaintiffs.  Some 65,000 Roundup claims remain,  motivating the plaintiffs’ bar to troll for more clients, especially those claiming Roundup exposure caused their Non-Hodgkins Leukemia (NHL). 

But no more. Last week, the plaintiff’s litigation tsunami crashed with a monumental Supreme Court ruling. 

“There are still other claims against Monsanto that do not involve a warning.  But there is no way to spin this.  This is awful news.”

- Plaintiffs’ Lawyers Ronald v. Miller Jr. 

A primer on the litigation trajectory and defense strategy can be found here. In short, rather than proving a lack of causation on a case-by-case basis (i.e., that Roundup doesn’t cause cancer, the prevailing scientific view embraced by most scientists, governmental agencies, and public health departments around the world), Bayer/Monsanto presented its conundrum to the Supreme Court on legal grounds. They argued that the warning sought by plaintiffs was not only scientifically flawed but also illegal under the statute governing pesticide regulation, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). 

The Case Behind the Ruling

The case concerns John Durnell, who brought a “failure-to-warn suit” under state common law against Monsanto for failing to include a cancer warning on Roundup’s label, which he claims caused his non-Hodgkin lymphoma (NHL). Durnell’s lawyers relied on a “problematic” report from IARC, a World Health Organization agency, which classified Roundup’s active ingredient, glyphosate, as a “probable carcinogen.”

Borrowing from similar legislation governing drugs and medical device regulation [1], which preempts certain lawsuits brought under state common-law tort claims, Monsanto/Bayer claimed that compliance with FIFRA preempts state court failure-to-warn cases, thereby preventing the addition of the sought-after warning, and noted that the EPA and most international health agencies dispute the IARC report. 

Why the Label Could Not Simply Be Changed

Seven of the Supremes agreed. Their reasoning was multifaceted. 

• The Act requires that all pesticides be registered with the EPA. To do so, the EPA must approve the pesticide’s label, determining that it contains all warnings “necessary and… adequate to protect health and the environment…” and does not include false or misleading statements. After the EPA approves the label, manufacturers are legally required to use it as is. Any changes (including adding the warning the plaintiffs demanded) would be illegal, and the manufacturer might face liability for misbranding. 
• FIFRA defines “protect health and the environment” to mean “protection against any unreasonable adverse effects on the environment,” including “any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of any pesticide.” [2]
• The statute’s purpose is to promote uniformity by conferring on the EPA comprehensive and exclusive authority to register pesticides and approve labels. Allowing each state to impose its own warning requirements would frustrate this objective and thus preempts state failure-to-warn claims because “FIFRA prohibits states from imposing any requirements for labeling or packaging in addition to or different from those required under FIFRA.”

As a result, this requirement prevents the placement of the warning that the plaintiff sought. The majority ruled that “as a matter of federal law, Monsanto must use a label without a cancer warning unless and until the EPA approves or requires a change.”

The EPA’s Role Was the Point, Not the Problem

The court painstakingly noted the extensive review and evaluation the EPA conducts before approving labels, both generally and for Roundup, to ensure that labels do not omit a necessary warning. The court also noted the “slew of tools” the EPA possesses to monitor subsequent scientific developments and determine whether and when to require additional warnings, including the power to suspend or cancel registration “to prevent an imminent hazard.”

Moreover, the opinion recounts the EPA’s history of evaluating glyphosate-based pesticides, beginning in 1974, when it first approved a label without a cancer warning. Again in 1991 and repeatedly in the more than three decades since, we learn that the EPA has “repeatedly re-evaluated glyphosate and has repeatedly concluded that glyphosate is not likely to cause cancer.” Even following the IARC classification of glyphosate as a probable carcinogen in 2017 and 2019, the EPA re-evaluated the issue “but still adhered to its longstanding position on glyphosate,” and reiterated its position in a 2020 interim registration review. Noting that “EPA’s assessment is shared by many other regulatory bodies around the world that have likewise concluded that glyphosate is not carcinogenic…,” the majority ruled that “as a matter of federal law, Monsanto legally must use a label without a cancer warning unless and until EPA approves or requires a change.”

The Dissent’s Unlikely Duo 

Writing that the majority relied on a medical device case under FDA law and disregarded a Supreme Court precedent on FIFRA, the dissent vigorously objects to the decision. Authored by the ultra-liberal Justice Ketanji Jackson and joined by arch-conservative Justice Neil Gorsuch, the dissent reads, to me, like an apology to the plaintiffs’ bar.

Justice Jackson laments that the decision deprives Mr. Durnell of a remedy for his claim. One wonders whether Justice Jackson forgot first-year law school, where students learn that remedies are available only to address wrongs. Since the majority clearly ruled that no wrong was committed, no remedy exists. 

Next, Justice Jackson proposes a solution for the conundrum faced by Bayer/Monsanto. Given they could not augment the label with a cancer warning without running afoul of federal law, she asserts the company could have chosen not to market the product at all. 

Uniform Labels, Uniform Markets

The dissent’s two-dimensionality also fails to account for the policy rationale behind the legislation. FIFRA specifically emphasizes the importance of uniform rulings, a clearly business-based rationale. Different requirements across states create commercial obstacles and uncertainties that would frustrate business development and insurance planning, which underlie the uniformity requirement.

The EPA is charged not only with balancing product development with human health and environmental safety, but also with the product's overall economics. This additional consideration requires the agency to weigh the agricultural, nutritional, and environmental risks and benefits of glyphosate pesticides, which enable greater cultivation and food production at lower cost.

Further, not only did the majority rule that Monsanto/Bayer had no alternative but to comply with FIFRA’s directive and omit a warning, but they also relied on the EPA’s determination that causality between the product and cancer is unproven and likely doesn’t exist, meaning a warning wasn’t necessary under any decision-making standard. 

Hand Wringing over Chevron’s Demise

Many moons ago, much was written, tears were shed, and worry was wasted when the Supreme Court overruled the Chevron case, which held that deference was due to agencies making technical or scientific decisions, thereby vesting those decisions in judges without proper expertise or training. The fear was that we would have wacky judicial decisions on scientific matters.

Under the Loper Bright decision, which overturned Chevron, the court was free to re-evaluate for itself the scientific basis behind EPA’s decision, i.e., that glyphosate was not a likely human carcinogen, and no cancer warning was needed. They didn’t. Indeed, they proudly touted EPA expertise and diligence in rendering its ruling.

The decision is more than a victory for Monsanto. It reaffirms that federal statutory decisions grounded in science cannot be circumvented by artful lawyers invoking favored-state tort law and junk science. It appears that the Roundup litigation boom and the thousands of similar claims that have sprung up may finally have met their weed killer.

 

[1] The FDA’s Medical Device Amendment of 1976 is nearly identical to FIFRA’s preemption clause. 

[2] While changes are permitted to account for new information, any changes must be approved prior to their inclusion.

https://www.acsh.org/news/2026/06/30/cabashing-roundup-litigation-50207