Paraquat is a widely used herbicide that has been linked to Parkinson’s disease in those who were exposed to it. Some claim that long-term exposure to paraquat is related to health conditions like Parkinson’s disease and the companies that produce and use the chemical, including Chevron and Syngenta, have known about the connection between paraquat and Parkinson’s disease for years. Although they supposedly knew about these detrimental effects, paraquat manufacturers did nothing to warn regular users of the toxic herbicide about the potential harm that could result from its extended use.

Despite the fact that paraquat is banned in many countries, the United States still allows commercial paraquat use. Countries and areas that no longer allow the use of paraquat include Brazil, Syria, Kuwait, Austria, Finland, Slovenia, Sweden, Denmark, Malaysia, Cambodia, Germany, Ivory Coast, Switzerland, United Kingdom, European Union, United Arab Emirates.

Many people with Parkinson’s disease or its beginning symptoms who used paraquat or lived in an area where paraquat was widely used, have filed lawsuits against Chevron, Syngenta, and other manufacturers of the herbicide. Claimants include farmers and agricultural workers, as well as those living with them, who now have Parkinson’s disease or are showing symptoms indicative of Parkinson’s disease.

Paraquat Lawsuit Updates

Is there a paraquat lawsuit?

Yes, there are several active lawsuits surrounding paraquat. In 2017, several early lawsuits were filed against Syngenta for herbicide paraquat and the link the herbicide has to early-onset Parkinson’s disease. Since then, more people have filed suits claiming a link between their exposure to paraquat and their development of Parkinson’s disease and other health conditions. This resulted in the formation of a multidistrict litigation (MDL) suit where a large number of the cases were consolidated into an Illinois federal Court. As of May 1, 2023, there were over 3,400 claimants involved in the Illinois MDL case. This number will continue to grow as more people become aware of the lawsuit and the potential negative impact of exposure to paraquat.

In addition to the MDL, paraquat lawsuits have been filed in several states, including:

  • Pennsylvania
  • California
  • Washington
  • Florida

The first bellwether trial has been rescheduled to take place in October 2023. Judge Nancy Rosenstengel, who oversees the paraquat MDL case in the Southern District of Illinois, issued an order for Daubert and summary motions to help determine the validity and use of expert testimony. The judge will hear the first oral arguments on these issues starting in August 2023.

In early settlement news, Syngenta reached a master settlement agreement with certain paraquat claimants in June 2021. In order for the settlement to take place, counsel for the claimants had to agree to dismiss all pending cases and give Syngenta a broad release from accusations made by covered claimants. Upon settlement, Syngenta put $187.5 million into a settlement fund before distribution to impacted claimants. While Syngenta asserts the claims and cases have no merit, Syngenta believed it was better to put an end to the risk of ongoing litigation.

This has been the only settlement related to paraquat so far. The upcoming bellwether trial should give attorneys a better understanding of what to expect with future cases and settlements. Those suffering from Parkinson’s disease or paraquat related injuries should contact an attorney to find out if they can join the MDL along with thousands of others who have may have been injured by long-term exposure to paraquat-containing herbicides.

Paraquat linked to injuries

Paraquat is a chemical used in the manufacture of herbicides that kills weeds. It was first introduced in the 1960s and has since been applied to agricultural land in many developed countries. Although the chemical is currently banned in more than 30 countries, the U.S. and some other developed nations continue to use it commercially. Even though Paraquat requires agricultural workers to have special certification and safety equipment to apply it in the US; however, it is routinely sprayed on millions of farm acres around the world without such precautions and training.

Plaintiffs in the paraquat MDL lawsuit claim that their long-term exposure to the substance caused their Parkinson’s disease, and there are some studies that back up this claim. However, not all studies have been conclusive, and there are uncertainties about the causal links between some of the evidence in the case and the injuries suffered by those exposed to the herbicide. Farmers and agricultural workers often spray the fields in which they work with herbicides, some of which contain paraquat. This herbicide also goes by numerous brand names, including:

  • Agroquat
  • Agroxone
  • Almoxone
  • Blanco
  • Bonedry
  • Cekuquat
  • Crisquat
  • Cyclone SL 2.0
  • Devour
  • Dextrone
  • Dexuron
  • Drexel Quik-Quat
  • Dynaquat
  • Esgram
  • Firestorm
  • Gramixel
  • Gramuron
  • Gramoxone
  • Halexone
  • Helmquat 3SL
  • Herbaxon
  • Herbikill
  • Inferno
  • LPI 6620 Paraquat 3SL
  • Methyl Viologen Dichloride
  • Ortho Paraquat CL
  • Para-col
  • Para-Shot 3.0
  • Parakill
  • Parazone
  • Parazone 3SL
  • Pillarquat
  • Pillarxone
  • PP148
  • Quick-Quat
  • Secaquat
  • Sunquat
  • Totacol
  • Toxer Total
  • Weedol

Although methods of application for toxic herbicides like paraquat have become stricter in recent years, lack of historical guidance on risks and the need to wear protective equipment have negatively impacted the long-term health of workers who are required to regularly use paraquat. Studies that link paraquat use to Parkinson’s disease are on the rise, which should help shed light on how the two are connected and what can be done to protect people who are exposed to paraquat and other toxic herbicides in their daily lives.

Herbicides and Parkinson’s Disease – Is There a Link?

A study published in February 2006 by Environmental Health Perspectives states that “the weight of evidence is sufficient to conclude that a generic association between herbicide exposure and Parkinson’s disease exists.” However, the study also indicates that Parkinson’s disease could be related to exposure to a variety of herbicides or their ingredients and that more data is necessary to understand the role paraquat plays in causing or increasing the likelihood of developing Parkinson’s disease.

The research also relates that in two other studies Hertzman et al. 1990 and Liou et al. 1997 paraquat exposure was shown to be significantly associated with Parkinson’s disease, especially if exposure spanned more than 20 years. It concludes that paraquat may have neurotoxic actions that could potentially play a role in the development of Parkinson’s disease. An increased risk of developing the neurological disorder could be associated with rural living, well-water consumption, and farming in addition to long-term use of herbicides and insecticides, but it is important to note that Parkinson’s disease is caused by both genetic and environmental factors.

Epidemiological studies

In Taiwan, where herbicides like paraquat are widely used on rice fields, a study with 120 patients found a strong correlation between exposure to paraquat and developing Parkinson’s disease. The research indicates that exposure to paraquat for more than 20 years increases the chance of developing Parkinson’s disease by nearly six times. Longer durations of herbicide use increased its effects on agricultural workers. When combined with data from a door-to-door survey of Taiwanese residents that concluded environmental factors may play a more important role in Parkinson’s disease than other factors, these findings present strong evidence that even general exposure to paraquat increases the risk of Parkinson’s disease.

Of course, there is some debate as to the validity of the methodology used in the Taiwan study. It can be difficult to separate the use of various herbicides and insecticides that might be used in the daily work of someone in the agriculture industry, which makes it difficult to conclusively prove that paraquat alone is the cause of Parkinson’s disease in humans. However, there is no doubt that prolonged use of certain chemicals, including paraquat, is linked to early-onset Parkinson’s disease, non-Hodgkins lymphoma, and other cancers and diseases with negative long-term effects on health.

Neurotoxicity of PQ, MPTP and other dopamine congeners

Paraquat has a chemical similarity to other compounds known to cause parkinsonian syndrome, and it has been shown that the systemic administration of paraquat to animals causes neuronal damage and a parkinsonian-like syndrome. Although paraquat is not transported by the dopamine carrier, like compounds of similar makeup, it can still exert neurotoxic effects on the brain, which are linked to an increased risk of Parkinson’s disease. The scientific community recognizes that paraquat causes cellular toxicity through oxidative stress. However, the intracellular targets of the oxidative stress caused by paraquat are presently unknown.

Occupation and Risk of Parkinson: A Multicenter Case-Control Study

The Journal of the American Medical Association (JAMA) conducted a case-control study “to investigate occupations, specific job tasks, or exposures and risk of parkinsonism and clinical subtypes.” In this study, researchers found that occupational use of herbicides, such as in agricultural work, was associated with an almost 80% greater risk of parkinsonism. Several herbicides and insecticides, including paraquat, were associated with a more than three-fold increase in the risk of developing Parkinson’s disease. This study included cases that demonstrated atypical symptoms, as this may be a factor of toxicant-induced parkinsonism, something which may have been overlooked in other studies.

Paraquat and Parkinson’s disease: a systematic review protocol according to the OHAT approach for hazard identification

Due to the suggestion that paraquat could be linked to Parkinson’s disease, there have been several studies on the topic recently, although much more research needs to be conducted to ensure accurate results and findings. The evidence to support a link between herbicide use and Parkinson’s disease is strong, but more research and investigation are necessary to determine what role paraquat plays on the development of these injuries. In the Paraquat and Parkinson’s disease: a systematic review protocol according to the OHAT approach for hazard identification study, paraquat was associated with the production of reactive oxygen species, oxidative stress, and aggregation of ±synucleins in dopaminergic neurons.

Each of these factors is related to an increased risk of developing Parkinson’s disease. However, the mechanism that paraquat uses to access dopaminergic neurons is not fully understood. The findings of this study suggest that multiple factors can contribute to developing Parkinson’s disease and causality between paraquat exposure and the disease cannot be determined by epidemiological studies on their own. In fact, linking a specific herbicide to Parkinson’s disease has proven difficult, and many of the studies to date have methodology flaws.

The goal of this study was to determine “the real human levels of exposure and the relevance of paraquat’s mechanisms of neurotoxicity.” This can help regulatory agencies understand what the exposure limits are and how to mitigate risk for those who use herbicides regularly.

Projected paraquat settlement amounts

Other than the June 1, 2021, settlement, where Syngenta put nearly $200 million into a settlement fund, no paraquat lawsuits have settled or reached verdict in Court. This makes it difficult for attorneys to quote an exact settlement amount for their clients who are involved in this MDL. Settlement amounts for this litigation will depend on what tier you fall into.

Those in tier I are people who have suffered significant losses due to their deteriorating health condition they allege was caused by long-term use of paraquat. Tier II plaintiffs are awarded the next highest amount, with tier III plaintiffs getting the lowest payout.

Estimates for possible settlement terms for the paraquat lawsuit are in part based on the recent Roundup lawsuit, where the company’s product, which contains an ingredient that has been linked to non-Hodgkins lymphoma, was the subject of major litigation. The settlement for this case as of January 2023 is $10 billion. Like paraquat cases, claimants were separated into tiers based on the severity of their condition and other factors, making it difficult to know the exact amounts awarded to each individual. Some estimate that the average payout was around $160,000 per claimant.

However, attorneys are estimating that those in tier I for the paraquat MDL could receive as much as $1 million, with lower estimates still reaching as much as $400,000 to $500,000. Those in tier II plaintiffs could see settlement amounts in the $150,000 to $300,000 range, while tier III may receive anywhere from $20,000 to $150,00. These estimates are not definitive and will vary frequently depending on a variety of factors, including how many claimants are involved in the case, evidence that arises in the MDL, and the results of bellwether trials.

Do you qualify for the paraquat lawsuit?

Agricultural workers and farmers are the most common plaintiffs in the paraquat MDL case because the herbicide has wide usage in the agricultural industry. People who lived in an area where paraquat was used frequently and those who lived with someone who regularly used paraquat are also at risk of developing Parkinson’s disease. If you were exposed to paraquat in your daily work or you lived with someone who was or in an area where paraquat use was common, then you or a loved one could qualify to join thousands of others who suffer from tremors, loss of motor functions, and other symptoms related to the disease in seeking relief through the paraquat litigation.

People who applied paraquat as part of their regular work and those who may have been exposed to paraquat because of drift when the chemical was sprayed over fields by aircraft could qualify to join the paraquat litigation if they have developed Parkinson’s disease or have any of its symptoms. Those suffering from Parkinson’s disease often show symptoms such as:

  • Tremors (unilateral shaking when muscles relaxed)
  • Stiffness/slowing of movement
  • Gait issues
  • Impaired posture and balance
  • Loss of balance
  • Speech changes
  • Writing changes
  • Muscle rigidity

Other signs of the disease include cognitive impairment, depression, and sleep disorders, among others. Paraquat can also affect the kidneys and could lead to other medical conditions like multiple system atrophy and progressive supranuclear palsy. Parkinson’s disease is incurable and those who have the condition struggle to complete simple daily tasks. Manufacturers of paraquat allegedly knew the herbicide had side effects that could lead to Parkinson’s disease but failed to inform users of the product. If you believe your Parkinson’s disease could be caused by exposure to paraquat, contact an attorney to find out how to join the paraquat litigation and get the compensation you deserve.

Long-term exposure to paraquat seems to pose the highest risk, but the herbicide is poisonous even through a brief encounter, especially if accidentally ingested. If you ever suffered from paraquat poisoning through a brief exposure, you may remember experiencing these symptoms:

  • Difficulty breathing
  • Muscle weakness
  • Nausea, diarrhea, or vomiting
  • Confusion
  • Coma
  • Dehydration
  • Seizures
  • Swelling of the mouth or throat
  • Death

It is important to include these details when you speak to someone about joining the paraquat litigation or filing a claim on behalf of a loved one.

The paraquat litigation could help thousands of people who used the chemical receive a settlement to cover the costs of medical bills, treatments, care, and loss of wages for those who can no longer work but still require an income. An attorney can help you understand more about the paraquat MDL lawsuit and whether you qualify. This litigation is ongoing but with the upcoming bellwether trial, some clarity should be provided for plaintiffs about settlement amounts and future trial dates.

Paraquat Lawsuit Timeline 


August 19 – Initial conference held by MDL Judge Nancy Rosenstengel. First bellwether trial is set for November 15, 2022. 

October 1 – Despite calls for a ban, the EPA re-approved paraquat in July. A petition filed in the 9th Circuit Court of Appeals seeks to overturn this decision. 

November 11 – Plaintiffs’ response due to Defendants’ motions to dismiss certain cases based on statutes of limitation and repose. 

December 4 – 319 lawsuits pending in the MDL. Plaintiffs required to complete a Plaintiff’s Assessment Questionnaire (PAQ). 

December 20 – Case management order issued for selecting bellwether trial cases. 


January 15 – Confidential settlement in Hoffmann v. Syngenta Crop Protection, LLC. Plaintiffs seek court order for deposition transcripts. 

January 21 – 589 Paraquat lawsuits in the MDL, an increase of 107 since December. 

February 1 – 16 cases selected for the first round of bellwether trials beginning in November. 

February 4 – Over a dozen new lawsuits filed in the Southern District of Illinois. 

February 10 – Judge orders production of Syngenta corporate witness depositions from a prior case. 

March 3 – Judge rules on motions to dismiss; key plaintiffs’ claims move forward. 

March 16 – 875 Paraquat lawsuits now in the MDL. 

March 21 – Pool of 16 cases identified for first round of bellwether trials. 

April 1 – Monthly status conference discussing bellwether trial selection process. 

April 14 – 44 new Paraquat lawsuits transferred into the MDL. 

May 2 – Six lawsuits selected for the first round of bellwether trials. 

May 6 – Concerns over maintaining the November 2022 trial date. 

May 11 – Impact of Bayer’s loss in Roundup cases on Paraquat lawsuit. 

May 16 – MDL grows to 1,153 claims, with 57 new lawsuits added in the first week of May. 

June 10 – Discovery schedule extended for bellwether trial cases. 

August 1 – 1,292 plaintiffs in the MDL; consistent influx of new cases. 

August 15 – Total number of cases in the MDL reaches 1,703. 

August 29 – First bellwether test trial rescheduled for July 2023. 

September 1 – 20 additional cases selected for limited fact discovery. 

September 15 – MDL grows to 1,925 cases. 

October 1 – EPA seeks voluntary remand to reconsider Paraquat risk-benefit analysis. 

November 1 – Bellwether trials pushed to July 2023 amid a surge in new lawsuits. 

December 17 – Explosive growth in 2022 with 2,352 pending cases in the MDL. 


January 2 – Paraquat class action lawsuit increased significantly in 2022, averaging over 200 new cases per month. 

January 17 – Only 69 new cases added to the MDL, bringing the total to 2,352. 

February 2 – Motion filed to compel Exponent Inc. to produce documents related to Syngenta and Paraquat. 

February 17 – A spike with 300 new Paraquat cases, total in MDL reaches 2,721. 

March 1 – Disputes over the admissibility of expert witness testimony begin as bellwether trial approaches. 

March 16 – 277 new cases added to the MDL, total now at 2,998. 

March 27 – Syngenta seeks to exclude testimony from plaintiffs’ expert Martin Wells. 

April 10 – Over 200 Paraquat lawsuits in Pennsylvania state courts consolidated into a state MDL. 

April 27 – Court denies motion to strike Martin T. Wells’ rebuttal expert report. 

April 29 – New deadlines set for the first Paraquat lawsuit trial. 

May 2 – Defendants’ Motion to Strike Dr. David A. Mortensen’s Supplemental Expert Report denied. 

May 3 – Explanation of the Daubert hearing’s significance. 

May 5 – New Paraquat lawsuit filed directly in the MDL class action in Connecticut. 

May 15 – 511 new cases added to the MDL, totaling 3,730. 

May 20 – Judge Rosenstengel issues mandate regarding actions involving deceased plaintiffs. 

June 1 – Record high of 511 new cases filed in May, indicating continued growth of the MDL. 

June 12 – Chevron and Syngenta AG move for summary judgment in the MDL. 

June 16 – 353 new Paraquat lawsuits added to the MDL. 

July 1 – Defendants identify 611 questionable claims in the MDL. 

July 18 – 223 new Paraquat lawsuits transferred into the MDL, total at 4,306. 

August 1 – Judge in Paraquat MDL to rule on scientific causation evidence admissibility. 

August 4 – State court Paraquat lawsuit in Pennsylvania involves over 300 plaintiffs. 

August 15 – MDL case count reaches 4,454. 

August 16 – Hearing on Daubert motions scheduled for August 21-24. 

August 21 – Daubert hearing begins, focusing on expert epidemiologist Dr. Martin Wells. 

August 31 – First bellwether test trial in the MDL postponed. 

September 6 – Judge orders parties to present closing briefs by September 8. 

September 18 – Pending cases in the MDL reach 4,752. 

September 27 – Closing Daubert briefs submitted, indicating potential challenges for plaintiffs. 

October 2 – Future of litigation uncertain as Judge Rosenstengel weighs Daubert challenges. 

October 17 – Only 30 new cases added to the MDL in the past month. 

November 1 – Dr. Douglas Weed files a motion to dismiss a subpoena concerning his article on paraquat and Parkinson’s disease.