Roundup MDL Preemption Fight: Judge Chhabria Asks Amici Whether Durnell Bars Design and Negligence Claims

The Roundup MDL preemption question moves to six states

The Roundup MDL preemption fight has a new front: Judge Vince Chhabria of the Northern District of California has invited amicus briefs on whether the Supreme Court's June 25, 2026 decision in Monsanto Co. v. Durnell also preempts Roundup negligence, design defect, and express or implied warranty claims under the law of Florida, Ohio, North Carolina, Mississippi, Georgia and Arizona, according to Law.com's report of the order on October 20, 2026. The answer will determine whether the 1,104 cases still pending in In re Roundup Products Liability Litigation, MDL No. 2741, are dismissed in bulk or sorted claim by claim, state by state.

The order matters because it is the first time the federal judge who has run the Roundup Multidistrict Litigation (MDL) since 2016 has framed the post-Durnell question not as a single federal issue but as a series of state-law questions. Durnell held that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) bars state failure-to-warn claims that would require a cancer warning missing from the EPA-approved label. Monsanto and its parent Bayer have argued that the ruling knocks out the theory on which the MDL was built. Plaintiffs say it reached only labeling. By asking outside parties to brief specific states' product liability law, Judge Chhabria has signaled that the answer may differ depending on how each state defines a defective product and what each state's tort duty actually demands of a manufacturer.

For practitioners, the order is the federal counterpart to what Missouri, Idaho and Massachusetts courts have been doing since June: deciding which Roundup claims are "warnings in disguise" and which stand on their own. It also arrives while the $7.25 billion King v. Monsanto class settlement awaits final approval in St. Louis and while the MDL's docket has shrunk by more than two thirds in a single month.

What did Judge Chhabria order in the Roundup MDL?

Judge Chhabria ordered briefing from amici, meaning non-parties with an interest or expertise in the question, on whether Durnell reaches beyond failure-to-warn claims. As reported by Law.com and repeated in The Legal Intelligencer on October 21, the order asks whether federal law also preempts other claims, "primarily, negligence, design defect or express or implied warranty," in the six named states. Law.com framed the overarching issue as whether the June 25 ruling "wiped out all lawsuits over Monsanto's Roundup."

Three features of the order stand out from the reporting:

• It is claim-specific. The question is not whether the MDL survives but whether three named categories of claim (negligence, design defect, warranty) survive. That tracks the structure of Durnell, which addressed one theory and left the others undecided.
• It is state-specific. Preemption under FIFRA turns on whether a state-law duty amounts to a "requirement for labeling or packaging" that is "in addition to or different from" federal requirements. Whether a given state's design defect or negligence duty is really a labeling duty depends on how that state's law defines the duty, so the analysis has to be done one jurisdiction at a time.
• It invites outside voices. Courts typically decide preemption on the parties' briefs. Opening the record to amici suggests the court expects the ruling to be cited well beyond MDL 2741, including by state courts in Missouri, Pennsylvania and California, where most remaining Roundup claims sit.

The order's filing deadline, page limits and any list of invited amici were not included in the reporting available as of October 21, 2026, and the order's text had not been widely circulated. No amicus filer had been publicly identified.

Does Monsanto v. Durnell end all Roundup lawsuits?

No. Durnell ended Roundup failure-to-warn claims that depend on the label, but it did not decide whether design defect, negligence, or warranty claims are preempted, and no court has dismissed the Roundup MDL wholesale on the strength of it. That is exactly the gap Judge Chhabria's order targets.

The Supreme Court ruled 7-2. Justice Brett Kavanaugh wrote for the majority, joined by Chief Justice Roberts and Justices Thomas, Alito, Sotomayor, Kagan and Barrett. Justice Thomas also concurred separately to raise constitutional concerns about FIFRA. Justice Ketanji Brown Jackson dissented, joined by Justice Neil Gorsuch, arguing that EPA's approval of a registration does not create a "requirement" within the meaning of the statute.

The holding is narrow on its face. FIFRA's express preemption clause, 7 U.S.C. § 136v(b), forbids states from imposing "any requirements for labeling or packaging in addition to or different from" those required under the Act. A jury verdict that Monsanto should have printed a cancer warning that EPA never required is such a requirement, so John Durnell's Missouri failure-to-warn claim was preempted. Durnell's jury had awarded him $1.25 million on strict liability failure to warn, and the Missouri Court of Appeals had affirmed before the Supreme Court reversed. His jury had not found for him on his other theories, so those theories were never before the Court.

That procedural posture is why the post-Durnell litigation is now about characterization. Monsanto's position is that negligence and design defect claims, as pleaded in most Roundup complaints, are repackaged warning claims: the alleged defect is that users were not told about a cancer risk. Plaintiffs' position is that a claim about how glyphosate formulations were designed or tested is not a claim about the label at all. Judge Chhabria's order puts that dispute to six bodies of state law.

Which states' laws are covered by the Roundup MDL preemption briefing?

The briefing covers Florida, Ohio, North Carolina, Mississippi, Georgia and Arizona. The order as reported did not explain why those six were chosen, and nothing in the available reporting ties them to particular plaintiffs. What can be said is that the six states define product defects in materially different ways, which is likely to matter to a preemption analysis that asks whether a state duty is "really" a labeling duty.

State	Product liability framework	Design defect test	Why it may matter to FIFRA preemption
Florida	Common law strict liability and negligence	Consumer expectations test as primary standard (Aubin v. Union Carbide, Fla. 2015)	A test built on what an ordinary consumer expects can blur into what the consumer was told, inviting a "warning in disguise" argument
Ohio	Ohio Product Liability Act, R.C. 2307.71 et seq., which abrogates common-law product liability claims	Statutory risk-benefit test; plaintiff must show a practical and technically feasible alternative design	Statutory, design-focused framework; warranty and negligence theories must fit inside the Act
North Carolina	Chapter 99B; no strict liability in tort for product liability claims (N.C. Gen. Stat. § 99B-1.1)	Negligence-based; reasonable alternative design or design so unreasonable no reasonable person would market it (§ 99B-6)	Design claims proceed as negligence, so the negligence question and the design question largely merge
Mississippi	Mississippi Products Liability Act, Miss. Code Ann. § 11-1-63	Feasible alternative design that would have prevented the harm without impairing utility	Requires proof of a safer formulation, which Monsanto may argue EPA would have had to approve
Georgia	Strict liability under O.C.G.A. § 51-1-11 plus negligence	Risk-utility balancing (Banks v. ICI Americas, Ga. 1994), with alternative safer design a central factor	Risk-utility tests often weigh the adequacy of warnings among other factors
Arizona	Common law strict liability and negligence	Consumer expectation and risk-benefit tests both recognized	Dual tests mean some design theories are label-free and others are not

The table summarizes settled published state law and is offered as background; how the court or amici will apply these frameworks to Roundup has not been briefed publicly. The point for readers is that "design defect" is not one claim. In a state that asks whether a safer, feasible formulation existed, the claim is about chemistry. In a state that asks what an ordinary consumer expected, the claim can look like a complaint about information, and information is what Durnell says only EPA may require on the label.

Are Roundup design defect and negligence claims preempted after Durnell?

Not automatically. Under the Supreme Court's earlier decision in Bates v. Dow Agrosciences LLC, 544 U.S. 431 (2005), FIFRA's express preemption clause reaches only state "requirements for labeling or packaging," and the Court there said claims for defective design, defective manufacture, negligent testing and breach of express warranty are not such requirements. Durnell did not overrule Bates. The live questions are whether particular state-law versions of those claims are labeling requirements in substance, and whether some other preemption doctrine reaches them.

There are three distinct arguments Monsanto can make, and each plays differently across the six states:

1. Express preemption through characterization. If a state's design defect or negligence duty is, in practice, satisfied by a better warning, Monsanto will say it is a labeling requirement under § 136v(b) regardless of its name. The Idaho federal court in Merril Hoge's case accepted a version of that argument for a "label-adjacent" warning claim while letting negligence go forward. A consumer-expectations design standard, like Florida's, is the most exposed to this argument.

2. Implied impossibility preemption. In Mutual Pharmaceutical Co. v. Bartlett, 570 U.S. 472 (2013), the Supreme Court held a New Hampshire design defect claim against a generic drug maker preempted because the manufacturer could not lawfully change the drug's composition and could comply with state law only by changing its labeling or leaving the market. Monsanto can argue an analogous point: a glyphosate formulation is registered with EPA, and a materially different formulation would need a new or amended registration. Plaintiffs answer that FIFRA does not prohibit a manufacturer from developing and seeking registration of a safer product, that Bartlett turned on the unique "sameness" rules for generic drugs, and that the Missouri trial courts that have ruled so far rejected implied preemption of design claims. States that require proof of a feasible alternative design, such as Mississippi and Ohio, sharpen this debate because the plaintiff's own burden puts the alternative formulation at the center of the case.

3. Warranty claims and voluntary undertakings. Bates held that express warranty claims are not preempted because a warranty is a duty the manufacturer voluntarily assumes, not one imposed by the state. That reasoning should protect an express warranty claim based on Monsanto's statements, unless the "warranty" is simply the label's own text, which EPA approved. Implied warranty of merchantability is less clear: a product's fitness for ordinary use may be judged partly by its warnings, and Monsanto will argue that an implied warranty claim premised on undisclosed cancer risk is a failure-to-warn claim by another name.

No federal appellate court has yet resolved any of these questions for Roundup after Durnell. Judge Chhabria's order is the first step toward a federal answer that covers more than one plaintiff.

Why did the Roundup MDL judge ask for amicus briefs?

The reporting does not quote the order's stated reasons, so the following is analysis rather than the court's explanation. Three features of the litigation make outside briefing useful.

First, the parties' earlier submissions apparently did not satisfy the court. Coverage of the post-Durnell proceedings in MDL 2741 reported that Judge Chhabria had criticized both sides' initial briefing on the ruling's effect as insufficient. A state-by-state analysis of six bodies of product liability law is the kind of work that benefits from scholars and specialists who are not advocating for a particular client.

Second, the ruling will travel. The MDL's federal decision on how Durnell applies to Ohio or Georgia design defect law will be cited by state courts deciding the same question for the thousands of Roundup claimants who opted out of the class settlement or who sit outside it. More than 450 Roundup cases remain pending in the Philadelphia Court of Common Pleas alone, according to The Legal Intelligencer; the Philadelphia Inquirer counted 462 active cases there in June 2026.

Third, the question has a federal-state dimension the parties may not fully represent. The United States, a group of states, and the MDL's court-appointed plaintiffs' leadership all filed amicus briefs at the Supreme Court in Durnell. Similar voices could address the MDL court on whether recognizing state design duties interferes with EPA's registration program. Whether any of them will do so is not yet known.

How many Roundup cases are left in the MDL?

The Judicial Panel on Multidistrict Litigation (JPML) reported 1,104 actions pending in MDL 2741 as of October 1, 2026, out of 5,324 actions that have been part of the MDL since its creation in 2016. One month earlier, on September 1, 2026, the Panel's report listed 3,925 pending actions. That is a drop of 2,821 cases, or about 72 percent, in one reporting period.

The JPML report does not explain the decline. Secondary trackers note that total filings barely moved, which suggests closures rather than reclassification, and one reported that Monsanto has been filing stipulated dismissals and seeking to clear an inactive docket of resolved cases. That explanation could not be independently confirmed from court records. What is clear is that the remaining 1,104 cases are the ones the six-state preemption ruling will act upon, and that the MDL is now a fraction of the 3,900-case docket that dominated coverage earlier in 2026.

Date	MDL 2741 pending actions	Event
May 1, 2026	about 3,903	Pre-Durnell
June 25, 2026	—	Monsanto Co. v. Durnell decided, 7-2
September 1, 2026	3,925	JPML monthly report
September 22, 2026	—	Reported minute entry setting Category 3 and 4 dismissal schedule
October 1, 2026	1,104	JPML monthly report
October 20, 2026	—	Amicus order reported
March 19, 2027	—	Reported argument date on Monsanto's Category 3 and 4 motions

How the Roundup MDL got here

MDL 2741 was created by the JPML in 2016 and assigned to Judge Chhabria in San Francisco, where it became the federal hub for claims that glyphosate-based Roundup causes non-Hodgkin lymphoma. Its first bellwether, Hardeman v. Monsanto, produced an $80 million verdict in March 2019 that the court later reduced to about $25 million. On May 14, 2021, the Ninth Circuit affirmed and rejected Monsanto's argument that FIFRA preempted Edwin Hardeman's failure-to-warn claim. Durnell has now displaced that holding on the warning question, which is why the MDL's remaining inventory must be re-examined.

Bayer's 2020 global resolution, valued at roughly $10 billion, settled most of the MDL's pending claims at the time but failed to resolve future claims, and new filings continued for years afterward. The 2026 King class settlement was Bayer's second attempt to reach future claimants, this time through a Missouri state court. The six-state order is therefore the third chapter of the same problem: what to do with the claims that neither settlement captures.

The post-Durnell scorecard: where courts have landed

The six-state order joins a short but consistent run of trial-court decisions that have refused to read Durnell as ending every Roundup claim while enforcing it strictly against warning theories.

Case	Court	Date	Warning claims	Design / negligence / other
Monsanto Co. v. Durnell	U.S. Supreme Court	June 25, 2026	Label-based claim preempted	Not decided
Rubin v. Monsanto	D. Mass.	July 2026	Off-label warning theory left open; leave to amend	Other state claims left open
Shull	Boone County, Mo. Circuit Court	Aug. 31, 2026	Not the focus	Summary judgment denied; no implied preemption
Aretino v. Monsanto	St. Louis County, Mo. Circuit Court	Trial opened Sept. 29, 2026	Not tried	Design defect tried to a jury
Hoge v. Monsanto	D. Idaho	Reported Oct. 7, 2026	Barred, including "label-adjacent" theory	Negligence survives
Dennis v. Monsanto	U.S. Supreme Court (GVR)	Oct. 13, 2026	$28 million verdict vacated and remanded for reconsideration in light of Durnell	Jury had rejected design and negligence
In re Roundup (MDL 2741)	N.D. Cal.	Order reported Oct. 20, 2026	—	Amicus briefing on negligence, design defect and warranty under six states' law

The pattern so far: courts treat warning claims as gone, including warnings relocated off the label, and treat design and negligence claims as surviving at least the pleadings and summary judgment. Judge Chhabria's order is the first to ask whether that consensus holds up when the state-law elements are examined one jurisdiction at a time. No verdict in Aretino had been reported as of October 21, 2026.

How does the Roundup MDL order affect the $7.25 billion settlement?

Directly, it does not. The $7.25 billion class settlement in King v. Monsanto is pending in the Circuit Court of the City of St. Louis, outside the MDL. Judge Timothy Boyer granted preliminary approval on March 4, 2026, heard objections at a final fairness hearing on September 14, 2026, and reserved decision. Reports through early October said he had not ruled. The court heard from 135 objectors, and class counsel have requested $675 million in fees, about 9.3 percent of the fund. (Law.com's October 20 report describes the Missouri deal as $7.5 billion; the figure used in the settlement papers and in most coverage is $7.25 billion.)

Indirectly, the order matters to the settlement in two ways. First, the value of opting out depends on what claims remain triable after Durnell. If a federal court holds that design defect and negligence claims survive under most states' law, opt-out claimants have more leverage; if the court finds them preempted in some states, the class deal looks better by comparison for claimants from those states. Second, Judge Chhabria has already said the MDL court will have its own say on the settlement's reach. In a May 6, 2026 order denying a request to enjoin the Missouri deal, he wrote that "current or future plaintiffs in this MDL will be free to contend that the settlement does not bind them," and said he could not imagine ruling that a future claimant would be bound. A preemption ruling that keeps design and negligence claims alive would make that question practically significant for MDL plaintiffs.

When will the Roundup MDL judge rule on preemption?

No ruling date has been set publicly for the six-state Roundup MDL preemption question, and the amicus deadline was not reported. Separately, reporting on a September 22, 2026 minute entry (Dkt. 22664) says the court divided the remaining MDL cases into categories and set a schedule for Monsanto to move to dismiss the cases in Categories 3 and 4 under Durnell, with argument on March 19, 2027. If the six-state briefing feeds into those motions, a ruling before spring 2027 would be unlikely; if it concerns an earlier category, a decision could come sooner. The available reporting does not say which categories correspond to which states.

What it means for plaintiffs' firms, Monsanto and opt-out claimants

Plaintiffs' firms with MDL inventory. The Roundup MDL preemption order rewards complaints that plead design and negligence theories on their own terms: identify the alternative formulation, the testing failures, and the conduct alleged, without relying on what consumers were or were not told. Firms with clients whose claims are governed by Florida law, with its consumer-expectations design standard, face the sharpest characterization risk. Firms with clients governed by Ohio law must fit every theory, including warranty and negligence, inside the Ohio Product Liability Act's statutory claims. Choice-of-law analysis for each remaining client, not just each complaint, is now central to case valuation.

Monsanto and Bayer. A state-by-state Roundup MDL preemption ruling may produce a split result. A defense win in one or two states would support targeted motions elsewhere; a loss across all six would leave the MDL's surviving claims headed toward remand and trial on design theories, the same posture as Aretino in St. Louis County. The impossibility argument modeled on Bartlett is Monsanto's best tool against feasible-alternative-design states, and it is untested in the Roundup context at the appellate level.

Opt-out and future claimants. Claimants who rejected the King settlement, and people with later non-Hodgkin lymphoma diagnoses who may argue they are not bound by it, have a direct stake. The six-state ruling will be the most detailed federal statement yet of which theories they can bring. It will also bear on the statute-of-limitations calculus for new filers, since a claimant who cannot plead failure to warn must decide quickly whether a design or negligence case is viable under the governing state's law.

State courts. Missouri, Pennsylvania and California courts are not bound by an MDL judge's reading of their sister states' law, and the federal ruling will not cover their own states unless the six-state analysis extends by analogy. But a reasoned federal opinion on how Bates and Durnell interact will be persuasive authority in every remaining Roundup forum, which is presumably why the court wants the question fully briefed.

What remains unknown

Several facts that matter were not available from the reporting as of October 21, 2026: the order's docket number and exact entry date; the deadline for amicus briefs; whether specific organizations or government entities were invited; why these six states were chosen; and whether the parties will file supplemental state-law briefs alongside the amici. The cause of the September-to-October drop in pending MDL cases also has not been explained on the record. This article will not speculate on those points; each should be checked against the MDL 2741 docket.

Frequently asked questions

What did Judge Chhabria order in the Roundup MDL?

He invited amicus briefs on whether Monsanto v. Durnell also preempts Roundup negligence, design defect, and express or implied warranty claims under the laws of Florida, Ohio, North Carolina, Mississippi, Georgia and Arizona, according to Law.com's October 20, 2026 report.

Does Monsanto v. Durnell end all Roundup lawsuits?

No. Durnell preempted label-based failure-to-warn claims only; the Supreme Court did not decide design defect, negligence or warranty claims, and courts in Missouri, Idaho and Massachusetts have allowed some of those theories to proceed.

Are Roundup design defect and negligence claims preempted?

Not as a category. Bates v. Dow Agrosciences (2005) treats design, testing and express warranty claims as outside FIFRA's labeling preemption clause, but Monsanto argues particular state-law versions are disguised warning claims or are impliedly preempted, which is what the six-state briefing will test.

How many Roundup cases are left in the MDL?

The JPML listed 1,104 actions pending in MDL 2741 as of October 1, 2026, down from 3,925 on September 1, 2026.

When will the Roundup MDL judge rule on preemption?

No date has been announced for the six-state question; separately, argument on Monsanto's motions to dismiss Category 3 and 4 cases under Durnell has been reported for March 19, 2027.

Can you still file a Roundup lawsuit after Durnell?

Yes, but a new case cannot rest on a claim that Roundup's EPA-approved label should have carried a cancer warning; it must plead theories such as design defect or negligence that the governing state's law recognizes and that courts find are not preempted, and it must be filed within that state's limitations period.