Cases & Deals

Chevron secures significant wins in paraquat multidistrict litigation

Client(s) Chevron Corporation

Jones Day secured two important wins for client Chevron in the paraquat multidistrict litigation (MDL). The MDL involves thousands of plaintiffs who have filed claims related to the manufacture or distribution of paraquat. Plaintiffs allege that they developed Parkinson's disease from exposure to paraquat. In April 2024, the federal court overseeing the MDL granted a motion by Chevron and co-defendant Syngenta, excluding the testimony of plaintiffs' epidemiology expert, Dr. Martin Wells, the lone expert backing plaintiffs' theory that exposure to paraquat causes Parkinson's disease. In a detailed 97-page opinion, the court criticized the "blatant … methodological shape-shifting" of Plaintiffs' expert and deemed his opinions "a textbook example of the standardless presentation of evidence that courts have cautioned against." The court further observed that Dr. Wells's conclusions lie "in direct conflict" with a "consensus" among the scientific community "that the available evidence does not warrant a claim that paraquat causes Parkinson's disease." After excluding Dr. Wells, the court dismissed plaintiffs' four trial-ready bellwether cases.

The court's opinion heavily cited the recent amendments to Federal Rule of Evidence 702, which are intended to keep unreliable expert testimony out of courtrooms. The advisory committee's notes that accompanied the 2023 amendments make clear that expert testimony may not be admitted unless the proponent demonstrates to the court that it is more likely than not that the proffered testimony meets the admissibility requirements set forth in Rule 702. The Rule 702 amendments and Judge Rosenstengel's opinion send a clear message that litigation-driven junk science does not meet that bar.

This significant win comes two years after Jones Day secured dismissal of all public nuisance claims in the paraquat MDL. In response to Chevron's motion to dismiss, the court dismissed all public nuisance claims, holding that the cause of action was not appropriate because Plaintiffs' allegations regarding the manufacture, advertising and sale of paraquat sounded in product liability.

These decisions follow a series of successful motions filed in paraquat litigation on Chevron's behalf in jurisdictions across the country, including state courts in California, Pennsylvania, Florida, and elsewhere.

In Re: Paraquat Products Liability Litigation v. Syngenta Crop Protection, LLC et al., No. 3-21-MD-03004-NJR (S.D. Ill.)