23
Jul
A Wave of Lawsuits Filed that Links the Weed Killer Paraquat to Parkinson’s Disease, Report Charges Coverup
(Beyond Pesticides, July 23, 2025) The pesticide manufacturer Syngenta has settled several lawsuits in federal courts in Pennsylvania and Illinois in recent months and is seeking a global settlement with over 6,000 litigants in order to avoid nationwide trials linking their weed killer paraquat to Parkinson’s Disease, according to reporting by The New Lede and The Guardian, respectively. Internal Syngenta documents released by these news outlets in a report dubbed The Paraquat Papers indicate that the company was aware of scientific evidence linking paraquat to Parkinson’s and attempted to quash research efforts to disclose the evidence.
These lawsuits were filed on behalf of former farmers and agricultural workers who went on to be diagnosed with neurological disorders, including Parkinson’s Disease, after using paraquat-based herbicide products for long periods of time. This litigation comes at a time when pesticide manufacturers across the board are facing increased scrutiny and subsequent financial repercussions. Simultaneously, their allies in Congress are revamping their efforts to shield chemical manufacturers from “failure to warn” lawsuits and establish federal preemption of local state governments’ ability to regulate pesticides more stringently than the U.S. Environmental Protection Agency.
Many of the paraquat lawsuits in federal courts, known as multidistrict litigation (MDL), are being overseen by a federal court in Illinois as of June 2025, while several other federal and state cases are proceeding separately, according to The Guardian. The law firm Miller and Zois, LLC, which maintains the website Lawsuit Information Center, reports the filing of a new lawsuit in Delaware on June 25, 2025, against Syngenta and Chevron for prolonged paraquat exposure linked to Parkinson’s.
Connection to Bayer Litigation, Failure-to-Warn Claims
The public’s ability to sue chemical companies for their “failure to warn” has enshrined in the legal system the ability to hold corporations accountable for the harm that their products cause under weak regulatory standards that they lobbied to create. Bayer has lost almost all of the lawsuits filed against it for compensatory and punitive damages associated with the plaintiffs’ charge that its products caused them harm. The U.S. Supreme Court twice rebuffed the company’s plea to have its appeal heard, as reported by Beyond Pesticides and news outlets. Its legal strategy, pursued through the entire court system, has failed to fend off ongoing litigation for harm associated with its glyphosate-based products (Roundup). As Bayer’s website has touted in a five-point strategy to mitigate the company’s financial “risks” from future litigation, “A favorable ruling by the U.S. Supreme Court on the federal preemption question could largely end the Roundup litigation.”
The main question here is whether state-based “failure-to-warn” claims are preempted by federal law since EPA concluded glyphosate does not cause cancer and approved the Roundup™ label without a warning. Bayer is vigorously pursuing a judicial decision or the adoption of legislation at the federal or state level that preempts, or takes away, plaintiffs’ right to sue the company when they are harmed by the company’s products. For the third time in recent memory, Bayer submitted yet another petition for SCOTUS on April 4, 2025, to “limit legal claims” on Roundup weed killer linkages to cancer, according to reporting by Reuters. The pesticide manufacturer has signaled optimism that the nation’s highest court will move in a different direction, given that there is now a Federal Court Circuit split with the latest decision in the Third Circuit Court of Appeals in Schaffner v. Monsanto. As reported in Progressive Farmer in early May, twelve national agricultural groups filed an amicus brief in support of Bayer’s petition. These groups represent the interests of industrial agriculture, including American Farm Bureau Federation, 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. Legal issues continue to mount for the pesticide manufacturer as the Western District of Missouri Court of Appeals upheld a $611 million judgment against Bayer, as reported by Missouri Independent on May 28.
There were several other significant developments in 2024, including the Oregon Court of Appeals decision on July 10, ruling that FIFRA does not preempt pesticide exposure victims’ claims in state court against pesticide manufacturers, based on reporting from The New Lede. An Appellate court overturned a 2022 local court ruling and remanded the case (for a retrial) in part because the judge had failed to consider the expert witness testimony of Chuck Benbrook, PhD, a scientist specializing in agricultural economics with over 40 peer-reviewed articles, reports, and book chapters on pesticide regulation and risk assessment. (See Daily News here.)
Bayer is not giving up on the current U.S. Supreme Court in seeking to overturn current law, as established by previous court decisions, including Bates v Dow (2005). However, that strategy is not succeeding, at least not yet. The string of Bayer losses includes adjudication decision on February 5, 2024, when the decision by the Eleventh Circuit Court of Appeals came down in favor of the plaintiff in Carson v. Monsanto on Bayer’s claim that FIFRA preempts a “failure-to-warn” claim. (See Daily News here for further analysis.)
Bayer has doubled down on the safety of its weed killer, even though investors are sounding the alarm, and as the company announced that it could pull Roundup from the U.S. market due to ongoing legal risks. With this, Bayer has taken its campaign to the states to strip away people’s (including farmers’) ability to hold corporations accountable through a common law duty to provide warning about the hazards associated with their pesticide products. Most recently, SCOTUS asked the Solicitor General’s office (U.S. Justice Department) “for its views on whether the justices should take up the appeal,” according to Reuters coverage. There are more than 67,000 pending cases in state and federal courts alleging Bayer failed to warn customers of Roundup products’ link to various cancers, including failure to warn through their advertising materials. In May 2025, the Missouri Independent reported that a federal court of appeals (Western District of Missouri Court of Appeals) upheld the decision of a 2023 case in Cole County, Missouri, awarding a $611 million judgment to three cancer victims.
For an in-depth history and related developments for Bayer-Monsanto litigation, see this tracker developed by the Lawsuit Information Center.
Call to Action
The U.S. House of Representatives is taking up legislation, already passed by the Interior and Environment Subcommittee on July 15, that provides total pesticide company immunity from “failure to warn” lawsuits filed by farmers and consumers who faced hazards, but were not warned. Beyond Pesticides and groups nationwide have called for Section 453 of the Appropriations Bill to be removed. The legislation also blocks states from requiring label warning language with information on product harm beyond EPA-approved language.
See Beyond Pesticides’ action, which asks all members of the U.S. House of Representatives to ask members of the Appropriations Committee to remove Section 453 from the bill and uphold the basic right to sue for companies’ failure to warn.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: The New Lede and The Guardian
