Paraquat and Parkinson's Claims: What the Record Shows

Paraquat dichloride is a restricted-use herbicide that US regulators allow only certified applicators to use. Epidemiological research has associated paraquat exposure with Parkinson’s disease, a progressive disorder of the nervous system, and federal lawsuits alleging that paraquat caused plaintiffs’ Parkinson’s disease have been consolidated in a multidistrict proceeding in southern Illinois against Syngenta and Chevron. No court has held that paraquat caused any individual plaintiff’s Parkinson’s disease, and the Environmental Protection Agency (EPA) has said it has not found a clear link. Syngenta announced in March 2026 that it will stop producing paraquat, and a settlement framework it disclosed in 2025 remains in progress.

What paraquat is and how it is regulated

Paraquat dichloride, usually called paraquat, is one of the most widely used herbicides in the United States. It is applied to crops including cotton, corn, and soybeans, and it is also used to desiccate certain crops before harvest. Since 1964 paraquat has been used in the United States to kill broadleaf weeds and grasses. There are no homeowner uses and no products registered for application in residential areas; all US paraquat products are Restricted Use Pesticides that only trained certified applicators may use. EPA describes paraquat as highly toxic and has run public safety campaigns aimed at preventing accidental ingestion and skin or eye exposure.

EPA re-evaluated paraquat under registration review and released an interim decision in July 2021, published in the Federal Register on August 2, 2021. The interim decision added enforceable mitigation measures, including limits on aerial applications, residential drift buffers, a ban on human flaggers, a prohibition on pressurized handgun and backpack sprayer applications, a requirement for enclosed cabs or respirators, and longer restricted entry intervals for several crops. In the same action, EPA said it had evaluated hundreds of studies on paraquat and health outcomes including Parkinson’s disease, described the studies as conflicting in quality and result, and stated that it had not found a clear link between paraquat exposure from labeled use and Parkinson’s disease.

What is established vs. what is alleged

Established by agency or court action

• Paraquat is registered in the United States only as a restricted-use pesticide, with no residential or homeowner uses.
• EPA released an interim registration review decision for paraquat in July 2021 and imposed new enforceable mitigation measures to reduce exposure.
• The Judicial Panel on Multidistrict Litigation (JPML) created MDL No. 3004, In re Paraquat Products Liability Litigation, in the US District Court for the Southern District of Illinois on June 7, 2021, and assigned it to Judge Nancy J. Rosenstengel. The named defendants in the transfer order were Syngenta Crop Protection LLC, Syngenta Corporation, and Chevron U.S.A. Inc.
• The court in the MDL has entered case management orders, including Order No. 24 (April 8, 2026), which gave a special master access to information about the MDL settlement, and Order No. 25 (June 12, 2026).
• Syngenta announced on March 3, 2026 that it would cease global production of paraquat by the end of June, citing competition from generic producers.

Alleged, not decided

• That paraquat exposure caused any individual plaintiff’s Parkinson’s disease. Plaintiffs allege failure to warn, asserting that the manufacturers knew of a neurological risk and did not adequately warn users.
• That Syngenta and Chevron are liable for those injuries. Reporting indicates that Syngenta denies that paraquat causes Parkinson’s disease and denies liability, and that a settlement it agreed to is not an admission of liability.

Where the claims stand procedurally

The federal cases are consolidated in In re Paraquat Products Liability Litigation, MDL No. 3004, in the Southern District of Illinois before Judge Rosenstengel. The JPML report for October 1, 2026 lists 6,602 actions pending in the MDL out of 8,495 transferred over the life of the proceeding.

No paraquat case has gone to trial. The New Lede reported that a first bellwether trial, set to open in Philadelphia in January 2026, was settled on its eve, and that Syngenta has settled cases set for trial before they begin. In 2025, according to Syngenta’s interim financial report as reported by SWI swissinfo.ch, the company reached a master settlement agreement with MDL plaintiffs’ co-lead counsel covering a number of pending lawsuits; the company said the settlement is not an admission of liability. The court has stayed the MDL while the settlement process runs and, in 2026, ordered plaintiffs who did not accept settlement terms to meet with a special master and undergo limited discovery. Reporting indicates that hundreds of plaintiffs have declined the offers, though the terms have not been made public. This publication’s product liability coverage also follows the AFFF PFAS foam and Depo-Provera meningioma cases.

Key dates

• 1964: Paraquat begins use in the United States.
• July 2021 (published August 2, 2021): EPA releases the paraquat interim registration review decision with new mitigation measures.
• June 7, 2021: The JPML transfers paraquat actions into MDL No. 3004 in the Southern District of Illinois, assigned to Judge Rosenstengel.
• 2025: Syngenta’s financial statements disclose a master settlement agreement with MDL plaintiffs’ co-lead counsel.
• January 2026: A bellwether trial set in Philadelphia is settled before it opens.
• March 3, 2026: Syngenta announces it will cease global production of paraquat by the end of June.
• April 8, 2026: The court enters Order No. 24, giving a special master access to settlement information.
• June 12, 2026: The court enters Order No. 25 relating to the ongoing litigation.
• October 15, 2026: A status conference is scheduled before Judge Rosenstengel.

What this does not establish

The record does not show that any court has held that paraquat causes Parkinson’s disease in any individual, or that it causes the disease generally. EPA’s decision to keep paraquat registered with added restrictions is not a finding either way on causation, and EPA separately stated that it had not found a clear link from labeled use. Syngenta has said any settlement is not an admission of liability. Because the settlement terms have not been disclosed and no trial has occurred, no individual claim has been tested before a jury.

Frequently asked questions

Has any paraquat case gone to trial?

Not as of this writing. A first bellwether trial was set to open in Philadelphia in January 2026 but was settled before it began, and the MDL has been stayed while the settlement process proceeds. A federal court has scheduled a status conference for October 15, 2026.

Does EPA say paraquat causes Parkinson’s disease?

No. In its July 2021 interim decision, EPA said it reviewed the epidemiology, described the studies as conflicting, and stated that it had not found a clear link between paraquat exposure from labeled use and Parkinson’s disease. EPA kept paraquat registered but added enforceable measures to reduce exposure.

Is paraquat banned in the United States?

No. Paraquat remains a registered restricted-use pesticide that only certified applicators may use. Syngenta, a major producer, announced in March 2026 that it would stop producing paraquat by the end of June, citing competition from generic producers rather than any regulatory ban.

Is there a paraquat settlement?

Syngenta’s financial statements, as reported, disclosed a master settlement agreement reached in 2025 with MDL plaintiffs’ co-lead counsel. The terms have not been made public, and reporting indicates that hundreds of plaintiffs have declined to participate, so no final, court-approved resolution covering all claims is in place.

What does the MDL number mean for an individual case?

An MDL consolidates federal cases for pretrial proceedings such as discovery and pretrial motions; it does not merge the lawsuits into one case. Mass tort coordination works the same way. Individual claims generally remain separate and can return to their home courts for trial if not settled or dismissed.

Sources

1. U.S. Environmental Protection Agency: “Paraquat Dichloride” (link, accessed 2026-10-13)
2. U.S. Environmental Protection Agency: “EPA Finalizes New, Stronger Safety Measures for Pesticide Paraquat” (link, accessed 2026-10-13)
3. Federal Register (U.S. Environmental Protection Agency): “Pesticide Registration Review; Interim Decision for Paraquat Dichloride; Notice of Availability” (link, accessed 2026-10-13)
4. Judicial Panel on Multidistrict Litigation: “In re Paraquat Products Liability Litigation, MDL No. 3004, Transfer Order” (link, accessed 2026-10-13)
5. Judicial Panel on Multidistrict Litigation: “MDL Statistics Report: Docket Summary Listing (October 1, 2026)” (link, accessed 2026-10-13)
6. U.S. District Court for the Southern District of Illinois: “Paraquat Products Liability Litigation (Case No. 3:21-md-3004-njr)” (link, accessed 2026-10-13)
7. Syngenta: “Syngenta to cease paraquat production in the UK in 2026” (link, accessed 2026-10-13)
8. The New Lede: “Syngenta settles bellwether US trial over paraquat links to Parkinson’s” (link, accessed 2026-10-13)
9. SWI swissinfo.ch: “Syngenta’s efforts to settle US herbicide litigation rejected by hundreds of plaintiffs” (link, accessed 2026-10-13)

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