Paraquat Lawsuits Over Parkinson’s Disease Risk Set for Trial in October 2025, April 2026

Bellwether trials will test allegations likely to be repeated throughout thousands of Paraquat lawsuits being pursued by individuals who developed Parkinson’s disease following exposure to the herbicide.

The U.S. District Judge presiding over thousands of federal Paraquat lawsuits, which involve allegations that the toxic weedkiller caused users to develop Parkinson’s disease, has ordered the parties to prepare six cases for potential bellwether trials, indicating that the first two claims will go before juries on October 14, 2025 and April 6, 2026.

Paraquat was originally developed in the 1950s by Imperial Chemical Industries, PLC (ICI), which is a legacy company of Syngenta, and the weed killer was first marketed under the brand name Gramoxone in the 1960s. However, over the subsequent decades Syngenta and Chevron sold Paraquat formulations under a variety of names. However, agricultural workers say the manufacturers promoted the weed killer despite knowledge that it may cause Parkinson’s disease.

Syngenta and Chevron currently face more than 5,800 product liability lawsuits in the federal court system, each of which involve claims that the manufacturers failed to adequately disclose the link between use of Paraquat and Parkinson’s disease.

Given the common questions of fact and law raised in the litigation, all federal Paraquat lawsuits over Parkinson’s disease have been centralized before U.S. District Judge Nancy J. Rosenstengel in the Southern District of Illinois since June 2021, as part of a multidistrict litigation, or MDL.

To help the parties gauge how juries may respond to certain evidence and testimony that is likely to be repeated throughout the claims, Judge Rosenstengal has established a bellwether process, where a small group of representative Paraquat lawsuits are being prepared for early test trials.

The process was delayed last year, after the judge dismissed the first batch of potential bellwether cases, after excluding the plaintiffs’ expert witness from testifying at trial. However, the Judge selected 10 new Paraquat bellwether candidates in August 2024, which have been fast-tracked for trial.

Over the past six months, plaintiffs and defendants have conducted case-specific discovery on six potential bellwether cases, and submitted competing proposals to the court last month about how the cases should move forward.

New Paraquat Lawsuit Bellwether Candidates Selected

In a court order (PDF) issued on January 23, Judge Rosenstengal announced that the parties will continue with full case-specific discovery on all six Paraquat bellwether lawsuits, and they will later select two specific claims to go before juries later this year.

The order identified three of the bellwether lawsuits, including complaints filed by Donald Tucker, Paul Scibilia and Marshall Bork, as candidates for the first bellwether trial, which will begin on October 14, 2025. The three other lawsuits, including claims filed by Michael Peek, Russel Okerlund and Douglas Malish, will be eligible for the second bellwether trial, slated to begin on April 6, 2026.

In addition, the judge issued a series of deadlines for the two Paraquat bellwether trials. Summary judgement and Daubert briefings are due for the first trial by August 15, 2025. The order indicates the court will set a hearing date for oral arguments on summary judgment and Daubert motions in a future order.

While the outcome of these trials will not have any binding impact on other plaintiffs, they are likely to have a substantial influence on average Paraquat settlement amounts the manufacturers may offer to avoid each individual claim being remanded back to U.S. District Courts nationwide for separate trial dates in the coming years.