Paraquat: Health Risks, Parkinson’s Disease & Legal Actions

Paraquat is banned in more than 70 countries. In the United States, the Environmental Protection Agency (EPA) classifies it as a restricted-use pesticide. Only certified applicators are allowed to use it.

In March 2026, Syngenta announced it would stop making the active ingredient in paraquat. It plans to completely remove the product from the global market by the end of 2026. The company said this was a business decision and not an admission of liability.

While Syngenta’s predecessor was the first to market paraquat, more than 750 companies now make a generic version of the pesticide. These manufacturers may still supply paraquat to the U.S. market.

Paraquat, also known as paraquat dichloride, is a quick-acting herbicide that kills many types of weeds and grasses on commercial farms. It is sold under brand names like Gramoxone, Firestorm, Helmquat and Parazone.

Farmers use paraquat in no-till farming or before planting seeds. It allows them to clear fields, control weeds and dry out plants before harvest. According to an estimate by the U.S. Geological Survey, about 10 million pounds were applied across the country in 2017.

Paraquat is not allowed for home or public use. Unlike some other restricted pesticides, only a certified applicator can apply paraquat.

Although it works well on farms, paraquat is one of the most toxic herbicides in use. Studies have found that long-term paraquat exposure may be linked to Parkinson’s disease.

Paraquat is a toxic herbicide. Your body can absorb it quickly if you are exposed to it, which could result in damage to your heart, kidneys, liver and lungs. Swallowing just one teaspoon could kill you.

Research also suggests paraquat exposure is linked to an increased risk of developing Parkinson’s disease. Paraquat can start a reaction in the body called redox cycling, which makes unstable molecules known as reactive oxygen species (ROS). Long-term exposure can trigger this process too often, and too many ROS in the body can hurt or destroy cells.

As early as 2005, research has suggested that paraquat may damage brain cells. Researchers have found that immune cells in the brain, called microglia, may also fuel redox cycling and increase chemical stress. Together, these processes can lead to the loss of nerve cells, which is linked to Parkinson’s disease.

Paraquat Exposure Pathways

Swallowing even a small amount of paraquat can be deadly. According to the CDC, there is no specific antidote for paraquat poisoning.

Steve Rosas, President of Omega Environmental, evaluates paraquat exposure through the skin, inhalation and swallowing.

People can also be exposed if the chemical drifts from fields. A UCLA study of Central Valley residents found that people had a higher risk of developing Parkinson’s disease if they lived or worked within 500 meters of fields treated with paraquat. This means that people living nearby could still be affected by exposure.

How Does Paraquat Exposure Immediately Affect Your Health?

The initial symptoms of Paraquat exposure depend on how you came into contact with it. You may experience eye or throat irritation, burning pain in your mouth, skin dryness and more. There is no specific antidote for paraquat poisoning. Treatment is mainly supportive, and outcomes depend on how much you ingested and how quickly you receive care.

Paraquat poisoning can be life-threatening, especially if it affects your vital organs. It can also lead to death.

Get medical help immediately if you think you’ve been exposed to paraquat. The faster you receive care, the better your chances of minimizing the potential harm from exposure.

In addition to poisoning, paraquat exposure can cause damage to your central nervous system. A study in Neurotoxicity used magnetic resonance imaging to examine people who survived acute paraquat poisoning.

Researchers found abnormal signals in the brain, particularly in the areas that regulate movements and control memory, learning and emotion.

Another study in Neurotoxicology found increased oxidative stress in specific brain areas of rats exposed to paraquat. The impacted areas control movement and brain chemistry, and damage to them is linked to the development of Parkinson’s disease.

These effects also impact families and caregivers. Bambi Rattner, Psy.D., points out that exposure can cause lasting emotional stress when a person begins to show early signs of cognitive decline or mood changes.

“The most concerning gap I see is the complete absence of mental health considerations in paraquat risk assessments,” Rattner told Drugwatch. “When someone develops early cognitive decline or mood disorders from toxic exposure, their family system enters a state of chronic hypervigilance that mirrors combat-related trauma patterns.”

Researchers have linked paraquat exposure to a higher risk of Parkinson’s disease, though scientists continue to study whether there is a causal relationship. A 2011 study published in Environmental Health Perspectives found that people exposed to paraquat and another pesticide called rotenone were 2.5 times more likely to develop Parkinson’s.

Researchers believe paraquat can damage dopamine-producing neurons through oxidative stress. This is the same chemical process that makes the herbicide effective at killing plant cells.

Multiple studies have supported the paraquat link to Parkinson’s disease

Based on the latest research, specific groups of people may be more likely to develop paraquat-related Parkinson’s disease in the United States.

In January 2025, the EPA told a federal court that it still needs “at least four years” to study paraquat’s health effects. The European Union has taken a different approach, banning paraquat since 2007.

European countries were the first to ban paraquat, citing its high toxicity, risk of lasting harm and the threat of accidental poisoning.

In 2007, the European Union introduced a ban on paraquat that applied to all 27 member countries. The UK was part of the EU at the time, and still has a paraquat ban today. However, Syngenta continued to manufacture paraquat in the UK for export until the end of June 2026.

Community Impacts of Paraquat Exposure

Rattner also points out that paraquat exposure can have community-wide psychological consequences.

“What regulatory discussions miss entirely is how environmental toxins create what I call ‘invisible trauma communities,’” Rattner said. “These are neighborhoods and families living in constant anticipation of illness, watching for early signs of neurological decline in themselves and loved ones.”

She says the psychological toll of living near agricultural areas with heavy pesticide use can create anxiety disorders that require specialized treatment approaches.

People who developed Parkinson’s disease or lost a loved one after exposure to the herbicide have filed thousands of paraquat lawsuits against its manufacturers. As of September 2026, 6,666 of these lawsuits were combined in a multidistrict litigation (MDL) in a Southern Illinois federal court.

A global settlement announced in April 2025 is still being negotiated.

Three companies are named as defendants in the Paraquat lawsuit. These include two different divisions of Syngenta, which first produced the herbicide.

People who may qualify to file a paraquat lawsuit include those who live or work on a farm or who use or mix herbicides containing paraquat and have developed Parkinson’s disease.

Paraquat Lawsuit Settlements

Paraquat settlements can vary based on how severe your Parkinson’s disease is, how long and how much you were exposed and how strong your proof is. Lawyers estimate payouts from around $20,000 for less serious claims to over $1.5 million for the strongest cases. However, no amounts are guaranteed. As of September 2026, the MDL settlement has not been finalized.

In 2021, Syngenta settled an unknown number of paraquat lawsuits for $187.5 million. This is the only publicly confirmed settlement, though Syngenta denied any liability.

In mass tort cases, payouts are often decided using a tiered or points-based system. This system looks at how serious the disease is, the person’s age at diagnosis, their medical and work records and how long and what kind of exposure happened. Other big herbicide lawsuits, like Roundup, have used similar processes to organize claims.

The Case Against Paraquat Manufacturers

Paraquat lawsuits argue there is strong evidence linking the herbicide to Parkinson’s disease. They point out that paraquat results in Parkinson’s-like conditions in lab animals, similar to what is seen in humans with the disease.

Additionally, people filing lawsuits claim that companies did not provide sufficient warnings, even though manufacturers knew or should have known about the risks of their products.

How Paraquat Lawsuits Compare to Other Toxic Exposure Cases

Paraquat and Roundup lawsuits are examples of current herbicide lawsuits. Each litigation involves different injuries and has moved through the courts in its own way. Paraquat cases are about Parkinson’s disease, while Roundup cases are about non-Hodgkin lymphoma.

Lawsuits and news investigations allege that paraquat manufacturers, including Syngenta and Chevron, knew about the herbicide’s dangers but continued to market and sell it without adequate safety warnings.

Simultaneously, the EPA has been slow to decide whether to ban paraquat.

What Did Paraquat Manufacturers Know About the Risks?

According to court documents reviewed by Investigate Midwest, Syngenta, previously known as ICI, knew as early as 1967 that paraquat could enter the bloodstream of workers handling it.

A study conducted on rodents by ICI in 1973 found that once paraquat entered the body of mice, it could reach the brain and spine.

As early as the 1950s, the company knew paraquat could affect the central nervous system (CNS). An internal memo from ICI’s medical department discussed how paraquat skin exposure could have a toxic effect on the CNS.

Despite this knowledge, the company continued to market the product. Syngenta claims paraquat presents “no risk to human safety” if people follow “basic good agricultural practices.”

The company bases its statement on toxicology studies and “over 60 years of experience in use.”

However, Syngenta announced in March 2026 that it would stop producing paraquat. It promised to stop sales on Dec. 31, 2026, or when stock ran out, whichever came first.

“The decision reflects significant competition from generic producers around the world, which has eroded Syngenta’s competitiveness in the production of this herbicide,” Syngenta said in a statement announcing the closure of its last paraquat factory. It did not suggest the decision was related to international bans or ongoing lawsuits.

The EPA promised to deliver a decision about banning paraquat by Jan. 17, 2025. However, it decided to hold off, citing insufficient evidence about the risks of inhaling the chemical.

The EPA has implemented some safety measures to protect people and the environment, including more explicit product labels and new warning materials. Certified applicators are now required to complete specialized training every three years, and closed-system packaging is mandated for paraquat to prevent accidental exposure.

Rosas says that part of the problem is the EPA’s reliance on voluntary measures in the early stages.

“The EPA’s non-binding guidelines often delay real protection—we’ve seen contamination levels that exceeded safety thresholds for years before mandatory reporting kicked in,” Rosas said.

What Countries Have Banned Paraquat?

While the EPA has spent years weighing a paraquat ban, other countries already prohibit its use. According to the Pesticides Action Network Europe, Norway was the first to withdraw paraquat from its markets in 1981. Sweden was the first to ban paraquat in 1983.

On May 26, 2026, Vermont became the first state to ban paraquat. The law allows apple and other fruit farmers to phase out its uses until the end of 2030. Paraquat use in Vermont was already very limited — only 107.5 gallons of paraquat were used statewide in 2024, according to the state’s agriculture agency.

State and federal lawmakers have taken steps to ban or restrict the use of paraquat. In 2023, Senator Cory Booker (D-NJ) urged the EPA to ban paraquat, citing its links to Parkinson’s disease and cancer. Booker also introduced a bill to ban paraquat, but it hasn’t moved forward in Congress.

In 2024, 47 members of Congress also sent a letter to the EPA asking the agency to ban paraquat.

In 2019, Representative Nydia Velázquez (D-NY) introduced the Protect Against Paraquat Act to get the EPA to ban paraquat and prevent it from being found in food. The bill didn’t advance, stalling in committee later that year.

California Assemblymember Laura Friedman proposed a bill in 2024 to reevaluate paraquat and determine if it should be banned in the state. Governor Gavin Newsom signed the bill, requiring the Department of Pesticide Regulation to reevaluate paraquat usage by January 1, 2029.

In Virginia’s 2026 legislative session, Delegate Nadarius Clark introduced HB1375. This bill seeks to ban the manufacture, distribution, use or sale of any pesticide containing paraquat. However, it stalled when it was sent to the House Agriculture, Chesapeake and Natural Resources Committee. It has been continued into the 2027 session.

If you or a loved one were exposed to paraquat and have developed Parkinson’s disease, taking the appropriate steps can help protect your health and legal rights. Start by documenting your exposure, tracking your symptoms and getting medical care.

You should also gather evidence of paraquat use at your job or near your home. Consider speaking with a lawyer to explore your legal options.

If you’re considering filing a lawsuit, talk to a lawyer with experience in environmental or product safety lawsuits. These cases can be complex and may require medical and scientific proof that paraquat exposure caused your Parkinson’s disease.

Drugwatch works with experienced lawyers specializing in paraquat cases and can help you find the right attorney for your situation.

Depending on your state, you may have 1 to 6 years to file a lawsuit. The clock typically starts when you’re diagnosed or you first discover the connection to paraquat exposure. An attorney experienced in paraquat cases can confirm the exact deadline for your situation. A free case review through Drugwatch can help you determine if you have a case.