What Is the Paraquat Lawsuit?

Official sources: U.S. Judicial Panel on Multidistrict Litigation (JPML) | U.S. District Court for the Southern District of Illinois | U.S. Environmental Protection Agency (EPA) | National Library of Medicine / peer-reviewed research

Litigation status reviewed: August 2026

What is Paraquat?

Paraquat dichloride is a highly toxic herbicide used to control weeds and grasses.

EPA classifies paraquat as a restricted-use pesticide, which means it may be used only by certified applicators who meet federal training requirements. EPA states that paraquat is highly toxic, that even a small accidental ingestion can be fatal, and that there is no antidote. (US EPA)

Paraquat has been used primarily in agricultural settings, including on crops and fields where other vegetation needs to be controlled.

What is the Paraquat lawsuit about?

The Paraquat litigation involves lawsuits alleging that people developed Parkinson’s disease after occupational, agricultural, or other significant exposure to paraquat.

Plaintiffs generally allege that manufacturers and sellers:

• Failed to adequately warn about alleged neurological risks.
• Sold paraquat despite alleged evidence linking exposure to Parkinson’s disease.
• Failed to design or market the product safely.
• Were negligent in connection with the manufacture or sale of paraquat.

The defendants dispute plaintiffs’ allegations and deny that paraquat causes Parkinson’s disease.

That causation question is one of the central scientific and legal issues in the litigation.

Is there a Paraquat MDL?

Yes.

Federal Paraquat cases are centralized in:

In re: Paraquat Products Liability Litigation

MDL No. 3004

U.S. District Court for the Southern District of Illinois

The litigation is overseen by Chief U.S. District Judge Nancy J. Rosenstengel. The Southern District of Illinois maintains the official MDL docket and case-management materials. (Illinois Southern District Court)

As of August 3, 2026, the Judicial Panel on Multidistrict Litigation reported:

• 6,665 pending actions
• 8,487 total actions historically

in MDL 3004. (JPML)

Is the Paraquat lawsuit a class action?

No.

MDL 3004 is a multidistrict litigation, not a class action.

In an MDL:

• Individual lawsuits remain separate claims.
• Similar federal cases are coordinated before one judge.
• Common discovery and scientific issues can be handled together.
• Individual cases may later settle, go to trial, be dismissed, or otherwise resolve.

Each plaintiff still has an individual:

• Exposure history
• Parkinson’s diagnosis
• Medical history
• Work history
• Causation case
• Damages claim
• Applicable state law

Being part of an MDL does not mean every plaintiff automatically receives the same result or payment.

What happened to the first Paraquat bellwether cases?

This is one of the most important developments in the litigation.

The first group of bellwether cases did not proceed to trial.

In April 2024, the federal court excluded the plaintiffs’ general-causation expert testimony under the federal rules governing expert evidence. The first bellwether cases were then dismissed. The court later summarized the history directly, stating that the first bellwether cases “did not survive a Daubert challenge and were dismissed in April 2024.” (Illinois Southern District Court)

This was a significant defense victory.

However, it did not automatically dismiss every Paraquat case in MDL 3004.

What is a Daubert challenge?

A Daubert challenge asks a federal judge to determine whether proposed expert testimony is sufficiently reliable and relevant to be presented to a jury.

In complex product-liability cases, expert testimony can be critical because plaintiffs may need scientific experts to address questions such as:

• Can the product cause the alleged disease?
• What level or type of exposure matters?
• Is there a plausible biological mechanism?
• Did the exposure contribute to the individual plaintiff’s condition?

If a plaintiff cannot present admissible expert testimony on an issue they are required to prove, the claim may not be able to proceed.

That is what made the 2024 Paraquat ruling so consequential.

Did the 2024 dismissals end the Paraquat MDL?

No.

After the first bellwether cases were dismissed, the court selected a new group of cases for case-specific discovery and continued developing the litigation. (Illinois Southern District Court)

The court scheduled a later bellwether trial, but that trial did not proceed because the parties entered settlement discussions.

By October 2025, Judge Rosenstengel explained that the second group of bellwether cases had been stayed so the parties could work toward a global resolution that had been agreed to “in principle.” (Illinois Southern District Court)

The litigation therefore moved from active bellwether preparation into a settlement-focused phase.

Is there a Paraquat settlement?

There is a significant settlement process underway, but it should not be described as a completed universal settlement.

The official federal docket shows that:

• Case-specific deadlines were stayed during settlement discussions.
• A scheduled bellwether trial was vacated.
• The court has supervised a settlement process.
• In April 2026, the court entered Order No. 24, allowing the Special Master access to information concerning the MDL settlement.
• In June 2026, the court issued orders selecting certain opt-out cases for limited discovery and adopted recommendations from the Special Master. (Illinois Southern District Court)

These developments confirm that a structured settlement process exists.

However, the official court page does not publish one universal payout amount or state that all 6,665 pending cases have been resolved.

What are opt-out cases?

An opt-out case generally refers to a plaintiff who does not participate in a settlement program or otherwise continues pursuing the individual claim.

The Paraquat court’s June 2026 orders selected certain opt-out cases for limited discovery. (Illinois Southern District Court)

That matters because it shows that even while settlement proceedings are underway, some claims may continue on an individual litigation track.

The existence of a broad settlement process does not necessarily mean every plaintiff participates.

Has the Paraquat litigation settled completely?

No.

As of the August 2026 review:

• The court is supervising settlement-related proceedings.
• Some cases have been voluntarily dismissed.
• Certain opt-out cases are continuing through limited discovery.
• The JPML still reports 6,665 pending federal actions in MDL 3004. (Illinois Southern District Court)

It is therefore more accurate to say that the litigation is in an advanced settlement phase than to say that every Paraquat lawsuit has settled.

Is there a Paraquat settlement amount?

There is no publicly established universal payout amount for all plaintiffs.

Potential compensation could depend on factors such as:

• Confirmed Parkinson’s disease diagnosis
• Exposure history
• Duration and intensity of exposure
• Work history
• Age at diagnosis
• Severity of disease
• Medical expenses
• Lost income
• Strength of exposure evidence
• Strength of causation evidence
• Settlement-program criteria
• Whether the plaintiff participates in or opts out of a settlement

Consumers should be cautious about websites publishing exact “average Paraquat settlement amounts” when the official court has not published a universal payment schedule.

What is Parkinson’s disease?

Parkinson’s disease is a progressive neurological disorder that primarily affects movement.

Common symptoms can include:

• Tremor
• Slowness of movement
• Muscle stiffness
• Balance problems
• Changes in gait
• Speech changes

Parkinson’s disease can also involve non-movement symptoms such as sleep problems, cognitive changes, depression, and autonomic symptoms.

The condition is believed to involve a combination of genetic and environmental factors.

Does Paraquat cause Parkinson’s disease?

The scientific evidence remains disputed.

EPA states that it has reviewed hundreds of studies involving paraquat and Parkinson’s disease and found that the scientific literature includes mixed and conflicting results. After its review, EPA concluded that it has not found a clear link between paraquat exposure from labeled uses and Parkinson’s disease. (US EPA)

That does not mean no study has reported an association.

Some epidemiological studies have found relationships between pesticide exposure, including paraquat, and Parkinson’s disease.

Others have not.

What did the Agricultural Health Study find?

The Agricultural Health Study is a large long-term research program involving licensed pesticide applicators and their spouses.

An earlier analysis from this cohort suggested a possible relationship between paraquat exposure and Parkinson’s disease.

However, an updated 2020 study using the same cohort did not find an association between paraquat exposure and incident Parkinson’s disease.

EPA specifically notes that the 2020 analysis did not replicate the earlier finding. (US EPA)

This conflicting research is one reason the causation question remains contested.

What does EPA say today?

EPA’s current Paraquat information page states:

> EPA has not found a clear link between paraquat exposure from labeled uses and adverse health outcomes such as Parkinson’s disease and cancer.

EPA also says it evaluated hundreds of human, animal, and laboratory studies as part of its scientific review. (US EPA)

At the same time, EPA continues to evaluate new information about Paraquat.

For example, a new vapor-pressure study submitted in 2024 led EPA to reassess uncertainty about the potential for paraquat to volatilize and move through the air. In November 2025, EPA said it would require additional data from manufacturers and perform an updated analysis as part of the ongoing registration-review process. (US EPA)

Why is Paraquat so tightly regulated?

Regardless of the Parkinson’s disease debate, Paraquat is acutely toxic.

EPA states that:

• A small accidental ingestion can be fatal.
• There is no antidote.
• The pesticide can damage skin and eyes.
• Occupational handlers and bystanders may face exposure risks.

Because of those risks, EPA has imposed safeguards including:

• Restricted use by certified applicators only.
• Specialized training.
• Closed-system packaging.
• Enhanced warnings.
• Personal protective equipment requirements.
• Spray-drift controls.
• Restrictions on some application methods. (US EPA)

Is Paraquat banned in the United States?

No.

Paraquat remains registered for agricultural use in the United States under strict restrictions.

It is a restricted-use pesticide and cannot legally be used by the general public.

EPA continues to review its registration and potential exposure risks. (US EPA)

Who may be affected by the Paraquat litigation?

Potential claims generally involve people who allege meaningful Paraquat exposure and were later diagnosed with Parkinson’s disease.

Relevant factors may include:

• Occupational history
• Agricultural work
• Whether the person mixed or applied Paraquat
• Frequency of exposure
• Years of exposure
• Method of application
• Protective equipment used
• Work near treated fields
• Date of Parkinson’s diagnosis
• Other pesticide exposures
• Family medical history
• Other Parkinson’s disease risk factors
• Applicable filing deadlines

Being diagnosed with Parkinson’s disease alone does not establish a Paraquat claim.

Likewise, having used Paraquat without developing an injury does not automatically establish a personal-injury lawsuit.

How can Paraquat exposure happen?

Potential exposure can occur through:

• Mixing or loading the herbicide
• Applying Paraquat
• Working in treated agricultural areas
• Spray drift
• Accidental spills
• Contact with contaminated equipment

EPA has specifically identified potential occupational risks for workers who mix, load, or apply Paraquat and potential risks to bystanders from spray drift. (US EPA)

The amount, duration, route, and timing of exposure can all matter.

What evidence may matter in a Paraquat claim?

Potential evidence can include:

Exposure evidence

• Employment records
• Agricultural work history
• Pesticide applicator licenses
• Farm records
• Purchase records
• Product records
• Employer pesticide-use records
• Crop-treatment records
• Witness statements
• Protective-equipment history

Medical evidence

• Parkinson’s disease diagnosis
• Neurology records
• Medication records
• Imaging or other diagnostic testing
• Treatment history
• Records showing symptom onset
• Family history
• Other neurological conditions

The quality of exposure evidence is especially important because many alleged exposures happened years before diagnosis.

Do you need proof that you personally applied Paraquat?

Not necessarily, but exposure must generally be supported by evidence.

A person may allege exposure from:

• Personally mixing or applying the product.
• Working near others who used it.
• Agricultural drift or other occupational circumstances.

The strength of a claim depends on whether the exposure can be documented and whether applicable scientific and legal requirements are satisfied.

What is a Plaintiff Assessment Questionnaire?

The Paraquat MDL uses a Plaintiff Assessment Questionnaire (PAQ) to collect standardized information about individual plaintiffs.

The federal court maintains PAQ forms and authorization materials as part of its official MDL case-management system. (Illinois Southern District Court)

These questionnaires can address information such as:

• Exposure history
• Work history
• Product use
• Medical diagnosis
• Treatment
• Other relevant facts

Standardized questionnaires help courts and parties manage thousands of individual claims without turning them into one class action.

What happened with Chevron in the Paraquat litigation?

The litigation has involved both Syngenta-related defendants and Chevron-related entities.

An early MDL order dismissed certain defendants and also dismissed cases against Chevron U.S.A. Inc. alleging exposure occurring after 1990. (Illinois Southern District Court)

That means the identity of the product manufacturer or seller and the timing of alleged exposure can matter significantly in an individual case.

What is the difference between scientific association and legal causation?

This distinction is critical in Paraquat litigation.

A scientific study may identify an association, meaning that one exposure appears more common among people with a disease.

Legal causation asks a different question:

Did this product cause or substantially contribute to this particular plaintiff’s disease under the evidentiary standard required by law?

That may require:

• Reliable epidemiological evidence
• Biological plausibility
• Exposure evidence
• Expert testimony
• Consideration of competing causes

The 2024 dismissal of the first Paraquat bellwether cases demonstrates how important admissible causation evidence can be.

Common misconceptions

Myth: Scientists and EPA have established that Paraquat causes Parkinson’s disease.

Reality: Some studies have reported associations between Paraquat exposure and Parkinson’s disease, but the scientific evidence is mixed. EPA currently states that it has not found a clear cause-and-effect relationship between Paraquat exposure from labeled uses and Parkinson’s disease. The federal court also excluded the causation experts in the first Paraquat bellwether cases in 2024. (Illinois Southern District Court)

Why this matters

Paraquat litigation is a good example of why mass-tort information needs more nuance than an advertisement can provide.

Three things are simultaneously true:

• Paraquat is highly toxic and tightly regulated.
• Some scientific studies have reported associations between Paraquat exposure and Parkinson’s disease.
• EPA’s current scientific review has not found a clear causal link, and the first federal bellwether cases were dismissed after the court excluded plaintiffs’ causation expert testimony.

At the same time, MDL 3004 remains active and is now deep into a court-supervised settlement process.

Understanding all of those facts gives consumers a much more accurate picture than simply saying “Paraquat causes Parkinson’s” or “the lawsuit has settled.”

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• Learn about Parkinson’s Disease
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