Paraquat Lawsuit (2026): Claims, Status & Who May Qualify

Paraquat is a powerful herbicide used in agriculture, and thousands of people allege that occupational exposure to it caused them to develop Parkinson's disease. These claims are centralized in a federal multidistrict litigation, and as of June 2026 the litigation remains active but has faced a significant adverse ruling on the scientific evidence. This page explains the claims, the science, and the current status neutrally.

This page is part of our Mass Tort & Product Liability overview.

What paraquat is and the alleged harm

Paraquat, often sold under the brand name Gramoxone, is a fast-acting herbicide used to control weeds and grasses, primarily in agriculture. In the United States all paraquat products are Restricted Use Pesticides, meaning they may only be applied by trained, certified applicators; there are no homeowner uses and no products registered for residential areas, according to the EPA. The lawsuits allege that occupational or agricultural exposure to paraquat, through mixing, loading, applying, drifting spray, or working near treated fields, caused users to develop Parkinson's disease, a progressive neurological disorder that affects movement, and that the companies that made and sold paraquat knew or should have known of a potential risk yet failed to warn. Parkinson's disease involves the loss of dopamine-producing nerve cells in the brain and commonly causes tremor, rigidity, slowed movement, and balance problems that worsen over time. The claims are typically framed as failure to warn and design defect under state product liability law, and many also allege negligence. This is a description of the allegations, not a finding that paraquat caused any individual person's Parkinson's disease.

Note: These are allegations being tested in court. A lawsuit reflects what a plaintiff claims, not a final determination of liability, and the court has not found that paraquat causes Parkinson's disease.

What the science and regulators say

The evidence on paraquat and Parkinson's disease is genuinely mixed. Some peer-reviewed research has reported an association: a 2011 study in Environmental Health Perspectives by Tanner and colleagues, drawn from the federally supported Agricultural Health Study, reported that Parkinson's disease was about two and a half times more likely among those who used paraquat (odds ratio 2.5; 95 percent confidence interval 1.4 to 4.7). The National Institute of Environmental Health Sciences has identified paraquat among pesticides studied in connection with Parkinson's risk, and some laboratory research has examined how paraquat can promote oxidative stress in nerve cells, a mechanism researchers have proposed could be relevant to the disease. The U.S. Environmental Protection Agency, however, reviewed the literature during its registration review and stated that it has not found a clear link between paraquat exposure from labeled uses and adverse health outcomes such as Parkinson's disease, noting an updated 2020 Agricultural Health Study analysis that reported no association, which contrasted with earlier findings the agency had previously considered. This disagreement matters in the litigation because plaintiffs must prove general causation, meaning that paraquat is capable of causing Parkinson's disease at all, before they can prove that it caused a particular person's illness. An association reported in some studies is not the same as proof that paraquat causes Parkinson's disease in any individual, and scientists and regulators do not fully agree.

Note: Nothing here establishes that paraquat causes Parkinson's disease or that any product caused any individual's illness. The scientific record is contested and may evolve.

The status of the paraquat litigation (as of June 2026)

Most federal paraquat cases are consolidated in In re: Paraquat Products Liability Litigation, MDL No. 3004, in the U.S. District Court for the Southern District of Illinois (docket 3:21-md-03004-NJR) before Chief Judge Nancy J. Rosenstengel. The litigation experienced a major setback in 2024. On April 17, 2024, the court excluded the testimony of the plaintiffs' sole general-causation expert, Dr. Martin Wells, under Federal Rule of Evidence 702 and the Daubert standard, finding his methodology unreliable, and the same day it dismissed the four trial-selection bellwether cases. The plaintiffs had acknowledged that excluding their expert was fatal to those cases, because Dr. Wells was their sole general-causation expert and without admissible expert testimony they could not establish that paraquat is capable of causing Parkinson's disease. That ruling cast serious doubt on the MDL's path forward, since it went to whether the plaintiffs could prove general causation at all rather than the facts of any one person's case. Following the 2024 ruling, the litigation entered a period of further motion practice and procedural steps rather than trials. The MDL remains on file with cases pending, and the court entered an order extending a stay and vacating a trial date in September 2025. Because of the 2024 expert ruling, the outlook for the litigation is genuinely uncertain. The parties reached a proposed settlement framework in 2025 and a court-approved qualified settlement fund in 2026, but it is not finalized, opt-out rates have been high, and plaintiffs have appealed the expert ruling to the Seventh Circuit while working to develop new causation experts, so nothing here suggests that recovery is likely. Anyone reading about this litigation should treat the current posture cautiously and verify the latest status, because the situation can change as the court rules on outstanding matters.

Note: Litigation status changes. The 2024 exclusion of the plaintiffs' causation expert was a significant adverse development; nothing here suggests the cases are strong or that any recovery is likely.

Regulatory background

Paraquat has long drawn regulatory attention because it is highly toxic if swallowed. EPA began its current registration review of paraquat in 2011, released draft human-health and ecological risk assessments in 2019, and finalized an interim decision in July 2021. On August 2, 2021, EPA announced new, stronger safety measures, including limits on aerial application, residential buffer requirements, a prohibition on pressurized handgun and backpack-sprayer application, and enclosed-cab or respirator requirements for some uses, while keeping paraquat a restricted-use product limited to certified applicators. EPA's review has continued; after a manufacturer submitted a new vapor-pressure study, the agency revisited the question of how readily paraquat moves through the air, and in a November 2025 memorandum it acknowledged greater uncertainty about paraquat's potential to volatilize and said it planned to request additional data from manufacturers. Paraquat also remains banned or restricted in a number of other countries, though regulatory decisions abroad reflect different legal standards and do not control U.S. litigation. These regulatory actions concern product safety, labeling, and exposure limits, and they are separate from the question of liability in the lawsuits; an agency restricting a product is not the same as a court or agency finding that the product caused a particular disease.

Who may be involved

The people generally involved in this litigation are individuals who had meaningful occupational or agricultural exposure to paraquat and were later diagnosed with Parkinson's disease. Because paraquat is a restricted-use pesticide, that group most often includes licensed applicators, farmers, farmworkers, mixers and loaders, tank fillers, and others who worked with or near the product over time. Whether any particular person may have a claim depends on the specific facts, including the extent and duration of exposure, the diagnosis and its timing, the law of the relevant state, and, importantly, the current state of the litigation after the 2024 causation ruling. Exposure and a diagnosis alone do not establish a claim, and many people exposed to paraquat never develop Parkinson's disease. Family members who lived on or near farms where paraquat was used have sometimes also been part of the broader discussion, but proximity by itself does not create a claim. Nothing here suggests that every exposed person has a claim or that any outcome is assured, and the 2024 ruling on the plaintiffs' causation evidence makes it especially important not to assume eligibility.

Deadlines and why they matter

Claims like these are subject to statutes of limitations, which are legal deadlines to file suit. These deadlines vary by state and by the type of claim, and many states measure the deadline from when a person knew or reasonably should have known that an injury may be linked to the product, a concept sometimes called the discovery rule. Because the deadline depends on your state and your facts, there is no single national filing deadline, and this page does not state any individual's deadline. Missing a deadline can permanently bar a claim, so people who believe they may be affected often act promptly rather than waiting. A licensed attorney in the relevant state can evaluate which deadline applies to a specific situation.

How to evaluate your options

If you are trying to understand your legal options, the appropriate step is to speak with a licensed attorney who handles this type of case. An attorney can assess the facts, explain the applicable law in your state, account for the current posture of the MDL after the 2024 expert ruling, and advise whether you may have a claim; this page cannot do that. It can help to gather any records you have, such as proof of which products you used or were exposed to and when, employment or licensing history showing exposure, and your medical records confirming a Parkinson's diagnosis and its date. Most mass tort and personal injury attorneys offer a free, confidential consultation, and many work on a contingency basis, meaning a fee is generally owed only if there is a recovery. A consultation creates no obligation to file.