Lawsuit Information Center
Chlorpyrifos lawsuits allege that repeated exposure to this widely used insecticide can contribute to Parkinson’s disease. The people most likely to bring these claims are farmers, pesticide applicators, pest control workers, groundskeepers, greenhouse employees, and others who personally mixed, loaded, sprayed, or cleaned up chlorpyrifos products over months or years.
Chlorpyrifos was sold under trade names that include Dursban, Lorsban, Cobalt, Nufos, Bolton, Stallion, Pilot, Warhawk, and Hatchet. It was used on farms, golf courses, ornamental plants, and residential and commercial properties. Many workers remember the trade name but not the active ingredient. Product identification is therefore one of the first and most important parts of investigating a claim.
Quick answers
- Who may have a case? People with Parkinson’s disease or qualifying Parkinsonism who personally handled a chlorpyrifos pesticide product. Our complete screening criteria appear below.
- Which products are involved? Brands include Lorsban, Dursban, Cobalt, Nufos, Bolton, Stallion, Pilot, Warhawk, and Hatchet, although the product and formulation must be confirmed.
- What might a case be worth? No resolved cases have established an average. Our preliminary range and the evidence that may drive future values are discussed in the settlement section.
If you have Parkinson’s disease after years of working with pesticides, you may have wondered whether that exposure played a role. A December 2025 study gives lawyers and scientists a serious reason to investigate chlorpyrifos. Researchers associated estimated long-term residential exposure near agricultural applications with more than 2.5 times the risk of Parkinson’s disease. They also found Parkinson’s-related brain damage in mice that inhaled chlorpyrifos.
Our lawyers are investigating claims for people who directly handled chlorpyrifos and were later diagnosed with Parkinson’s disease or qualifying Parkinsonism. These cases are new, and difficult questions about exposure and medical causation remain. But people who spent years working with these products deserve a careful investigation of what they used, what the manufacturers knew, and whether the exposure contributed to their disease.
Our lawyers are reviewing these claims. Call 800-553-8082 or contact Miller & Zois online for a free consultation.
Latest Chlorpyrifos Lawsuit Updates
October 12, 2026
These Cases Are About Failure to Warn
There are two big pieces to these cases: causation and what the defendants knew about these chemicals’ ability to cause Parkinson’s disease. The newer chlorpyrifos research gives plaintiffs more to work with on causation and we expect more studies will continue to be produced as we move along.
When workers were spraying Dursban in the 1980s or Lorsban in the 1990s, what did the defendants know? Studies published decades later cannot, at least by themselves, establish that an earlier warning was inadequate.
If we get to a jury, it will boil down to what the jury thinks about whether these companies had earlier evidence that would have prompted them to investigate a chronic neurological risk and tell workers about it. The key will be the documents produced in pretrial discovery.
August 13, 2026
Ramos Plaintiff Asks to Return the Case to State Court
The plaintiff in Ramos v. Corteva, Inc., et al. filed a motion to remand on August 13, asking that the chlorpyrifos Parkinson’s case return to state court. Dow filed its opposition on August 27.
A July 24 order had stayed the defendants’ deadline to respond to the complaint pending a ruling on remand and vacated the scheduled preliminary pretrial conference. That changes the picture presented by the initial removal: the parties were first litigating where the case belongs. These docket entries do not resolve whether chlorpyrifos caused the plaintiff’s Parkinson’s disease.
If you directly handled chlorpyrifos and were later diagnosed with Parkinson’s disease, call our lawyers at 800-553-8082 or contact us online. The consultation is free.
Do You Qualify?
A strong case begins with evidence that you personally handled chlorpyrifos and later received a qualifying diagnosis. You may not remember every product name or date today. That would be an impossible hill to climb, and no one expects you to climb it. We track down employment records, pesticide logs, invoices, labels, and former coworkers to identify what you used and how often you used it.
Exposure histories vary. A farmer who mixed Lorsban during several planting seasons has a different history from a person who walked through a treated field once. A pest control technician who filled tanks with Dursban, worked around leaking hoses, and cleaned application equipment may have a strong factual account even if old purchase records are gone.
We are not accepting indirect exposure cases. Given where the science stands today, these cases are too hard to link scientifically. The new epidemiological study estimated exposure from agricultural applications near homes and workplaces. That research is useful for deciding whether chlorpyrifos deserves serious attention as a Parkinson’s risk factor. But a lawsuit presents a narrower question. Can this plaintiff prove meaningful exposure to a product sold by this defendant? Direct handling gives the case a much firmer foundation.
Parkinson’s Disease and Parkinsonism Are Not Identical
Parkinson’s disease is a progressive neurological disorder. Common symptoms include tremor, muscle rigidity, slow movement, impaired balance, changes in speech and handwriting, sleep problems, and eventually cognitive impairment. The diagnosis is clinical. A neurologist considers the pattern and progression of symptoms, the examination, treatment response, and whether another condition better explains the problems.
Parkinsonism describes a group of movement symptoms rather than one disease. It can result from Parkinson’s disease, another neurological disorder, certain medications, strokes, or other causes. Our firm may review a Parkinsonism case when a physician has prescribed Parkinson’s medication and the records show that the medication is helping. Treatment response is part of our intake criteria, while a neurologist’s diagnosis and the complete medical record remain essential.
Exposure and Diagnosis May Be Decades Apart
Parkinson’s disease does not ordinarily appear the day after pesticide exposure. The disease process may develop quietly for years before tremor, stiffness, or slow movement sends someone to a doctor. That makes latency a central issue. A long interval between exposure and diagnosis does not automatically defeat a claim, but the timeline must make medical sense.
There is no court-approved chlorpyrifos latency rule. Experts will have to consider when exposure began, how long it continued, when early symptoms appeared, when the diagnosis was made, and whether age, genetics, other pesticides, head trauma, medications, or another condition offer a stronger explanation.
Lorsban, Dursban, and Other Chlorpyrifos Products
Chlorpyrifos is the active ingredient. It may not be the name you remember seeing in large letters on a jug, bag, drum, or invoice. Dow introduced the chemical commercially in 1965 and sold it under different names for agricultural and residential markets. Other formulators and registrants later sold chlorpyrifos products of their own.
| Product Name | Reported Market or Use | Historical Company Connection |
|---|---|---|
| Lorsban | Agricultural applications | Dow entities |
| Dursban | Residential and structural pest control, turf, and other applications | Dow entities |
| Cobalt | Agricultural insect control | Dow entities |
| Nufos and Bolton | Agricultural and commercial applications | Cheminova, later acquired by FMC |
| Stallion | Agricultural insect control | FMC |
Other chlorpyrifos trade names have included Pilot, Warhawk, Hatchet, Lock On, and additional regional or specialized products. That list is not proof that a particular container contained chlorpyrifos in the year you used it. Product formulations, registrations, distributors, and corporate ownership changed. The label and EPA registration number are better evidence than a product name alone.
Raid alone does not meet our criteria. Raid is a brand used for many products containing different active ingredients. A person who remembers only “Raid” cannot assume it was chlorpyrifos. If Raid was one of several products and you also handled an identifiable chlorpyrifos product, the separate chlorpyrifos exposure can still be evaluated.
Jobs With Potential Chlorpyrifos Exposure
Direct exposure may have occurred among people who worked as:
- Farm owners, farmworkers, crop consultants, and licensed pesticide applicators
- Orchard, vineyard, citrus, cotton, corn, soybean, wheat, and alfalfa workers
- Pest control technicians and termite treatment workers
- Golf course superintendents, groundskeepers, and turf management employees
- Greenhouse, nursery, landscaping, and ornamental plant workers
- Workers who mixed pesticides, filled tanks, repaired sprayers, or cleaned equipment
- Mosquito control and public health pesticide workers
- Homeowners who personally applied an identifiable residential chlorpyrifos product before 2000
What Direct Handling Looks Like
The strongest exposure histories will involve opening concentrate, measuring it, pouring it into a tank, stirring mixtures, carrying a backpack sprayer… people who had real hands on contact with the chemical.
Chlorpyrifos can enter the body through breathing, swallowing, or skin contact. Protective equipment can reduce exposure, but only so much. Gloves tear, respirators fit poorly, and workers sometimes remove them in hot weather. Concentrate can also splash during mixing. Every case specific investigation will focus on the equipment actually used and what happened during the work.
What Does the Science Show?
Pesticide exposure has been associated with Parkinson’s disease for years. The harder scientific job is identifying which chemical contributes to the risk. Farmworkers rarely encounter only one pesticide. Exposure may have occurred decades before diagnosis, and researchers ordinarily cannot measure a chemical in someone’s body after that much time.
Earlier studies supplied clues rather than a complete case for chlorpyrifos. A 2014 study of ambient organophosphate exposure in California reported an association between Parkinson’s disease and estimated exposure to organophosphates near homes and workplaces. Laboratory studies also examined whether chlorpyrifos could injure dopamine systems, altering genes connected to Parkinson’s pathways. The study is helpful. But we can see the defense argument coming if that was all we had: an association involving a pesticide class does not prove that one product causes one disease. And they are right about that.
The December 2025 study really ignited this litigation because it focused on chlorpyrifos and used human, mouse, and zebrafish evidence in the same project. The UCLA Parkinson’s Environment and Genes cohort included 829 people with Parkinson’s disease and 824 controls from Kern, Fresno, and Tulare counties in California. Researchers geocoded lifetime residential and workplace addresses and compared them with state pesticide use reports for chlorpyrifos applications within 500 meters.
The study adjusted for estimated exposure to Paraquat, diazinon, and glyphosate. That is key because the argument that they could cause Parkinson’s is not far-fetched.
What did they find? Long-term residential chlorpyrifos exposure remained associated with more than 2.5 times the risk of developing Parkinson’s disease. This adjustment helps because it reduces the chance that the reported association merely reflects exposure to another commonly used pesticide. It does not eliminate every possible confounding factor.
The researchers estimated ambient exposure from reported agricultural applications. They did not measure the amount of chlorpyrifos absorbed into each participant’s body. A 500-meter model cannot recreate the wind on a particular day, whether a window was open, whether a worker wore gloves, whether concentrate spilled, or whether the same person used other pesticides that were not fully captured.
The reported 2.5-fold association applies to the population studied. It cannot predict whether a directly exposed worker will develop Parkinson’s disease or prevail in a lawsuit.
Why the Animal Findings Help Plaintiffs
Researchers exposed mice to aerosolized chlorpyrifos for six hours per day, five days per week, for eleven weeks. The animals developed impaired movement, loss of dopamine neurons, activation of brain immune cells, and abnormal alpha-synuclein. Each finding is relevant to the biology of Parkinson’s disease.
The zebrafish experiments helped show how the chemical may damage cells. Chlorpyrifos interfered with the cells’ ability to clear damaged material and toxic proteins, a process connected to Parkinson’s disease. When researchers restored that cleanup system or reduced the troublesome proteins, the neurons became less vulnerable.
What Manufacturers and Regulators Knew
The history matters because a failure to warn case is not limited to what scientists know today. Plaintiffs will ask what manufacturers knew or should have known while people were mixing and spraying their products. They will also ask whether companies reported adverse events, conducted adequate chronic neurotoxicity research, and changed warnings as evidence accumulated.
1965: Chlorpyrifos products entered the United States market. The active ingredient later appeared in agricultural, residential, structural pest control, turf, and other products.
1995: EPA assessed a $732,000 penalty against DowElanco for failing to timely report information about adverse health effects involving pesticides, including Dursban. EPA said much of the information came from personal injury claims and included reports of peripheral neuropathy and other chronic neurological effects. Those reports did not establish Parkinson’s causation, but they are certainly relevant to the history of neurological safety signals. This is also a healthy reminder that pesticide manufacturers have a long history of covering up the harm their products cause.
2000: Chlorpyrifos registrants reached a voluntary agreement with EPA to eliminate most homeowner uses, phase out termiticide uses, and modify additional uses. This is why our residential exposure criteria generally require use before 2000. EPA’s chlorpyrifos page summarizes the agency’s later regulatory actions.
2002 through 2012: EPA required or obtained changes involving protective equipment, application rates, and spray drift buffers. The restrictions addressed worker, environmental, dietary, and child exposure concerns. They were not an EPA finding that chlorpyrifos caused Parkinson’s disease.
2020: Corteva announced that it would stop producing chlorpyrifos because of declining demand. That commercial decision did not resolve whether earlier exposure caused Parkinson’s disease.
2021 through the present: EPA revoked food tolerances in 2021. The Eighth Circuit vacated that rule in 2023 and returned the issue to EPA, which continued regulatory action involving remaining uses. Food tolerance proceedings primarily concern residues and statutory safety standards. They are not a judicial or agency decision on Parkinson’s causation.
The 1995 penalty will get a lot of focus in this litigation. The EPA stated that DowElanco submitted 249 incident reports late and failed to report certain incidents it learned about through personal injury claims and lawsuits. We will push the narrative that the episode shows why adverse event reporting is critical and how these companies are motivated by profit, not safety.
How Can You Prove Exposure Decades Later?
Most people do not save pesticide receipts for thirty years. Many workers did not choose the products or see the invoice. The employer bought the chemicals, a supervisor handed out the work, and everyone went home. Missing receipts make the investigation harder, although other records and witnesses may still identify the product.
| Evidence | What It May Establish |
|---|---|
| Employment and union records | Employer, job title, work location, and years in a pesticide handling position |
| Applicator licenses and training records | Authority and training to mix or apply commercial pesticides |
| Farm and pesticide use records | Products used on particular crops, properties, and dates |
| Invoices, purchase records, and tax records | Purchase of chlorpyrifos products or application supplies |
| Labels, photographs, and containers | Trade name, active ingredient, formulation, EPA registration number, and seller |
| Coworker and family testimony | Frequency, mixing practices, spills, protective equipment, and product appearance |
| Medical and occupational histories | Earlier reports of pesticide work, acute symptoms, and progression of neurological problems |
Do not worry if you cannot remember every detail right now. Start with what you do remember: employers, properties, crops or buildings treated, container colors, product names, equipment, protective gear, spills, and the people who worked beside you. Our investigators can review old employment records, purchase invoices, pesticide-use reports, applicator files, and spraying logs.
A recognizable trade name, repeated hands-on use, consistent dates, witnesses, and records from the employer or application site can make the exposure history much stronger. Even a partial memory may give an investigator a useful place to begin.
Legal Claims Against the Manufacturers
Corporate buyouts mean the company responsible today may have a different name from the one printed on a bottle decades ago. Dow sold products that included Dursban, Lorsban, and Cobalt, and its agricultural business later became Corteva. FMC acquired Cheminova, which had sold products including Nufos and Bolton. Our lawyers handle the work of tracing the product and identifying the company that may be financially responsible.
Failure to Warn About Parkinson’s Risk
A worker can understand that swallowing pesticide will make him sick and still have no idea that years of mixing and spraying it might contribute to Parkinson’s disease. Those are different warnings about different decisions. One tells you to keep the chemical out of your mouth. The other might make you question whether you want to spend the next twenty years working with it.
Plaintiffs allege that chlorpyrifos manufacturers never gave workers that second warning. These were people filling tanks, clearing clogged sprayers, and washing concentrate off their hands before lunch. They were doing their jobs. They were not reading neurological research after their shifts or checking whether the company selling the pesticide had adequately investigated its long-term effects. They depended on the manufacturer to tell them what they needed to know.
Our lawyers want to reconstruct what the companies knew while those workers were still using the products. Which studies raised concerns? Who read them? What additional testing was proposed, and did anyone pay for it? The important documents may be ordinary emails and meeting notes recording a decision that seemed small inside the company but carried enormous consequences for someone holding a spray wand.
Design Defect and Negligence
If the warnings case does not work, design defect might. Chlorpyrifos was sold to kill insects. Nobody disputes that it had a useful function. But what wereworkers were being asked to risk to get that benefit? Was there a safer product or version of the product that could have done the job? So we need to dig into the particular use and the alternatives available at the time. A farmer treating a crop and a technician spraying around a house were not making the same choice.
Negligence also puts the company’s actual work under scrutiny. Did its testing address repeated exposure over years? Did it follow up on neurological complaints? When evidence raised a concern, did the company investigate it or leave the question unanswered while sales continued? After the Supreme Court’s Roundup ruling, this claim could become a focus.
Concealment and Punitive Damages
A worker cannot protect himself against information that never leaves the company’s files. If the evidence shows that a manufacturer understood a substantial neurological danger and deliberately kept users in the dark, there will be a real possibility of huge punitive damages.
The 1995 reporting penalty gives us a concrete place to start asking questions. What information arrived at the company? Who was responsible for reporting it? Why was it late? We need to trace those reports and the response to them. A fine is a number on a corporate ledger. The documents behind it may tell us whether warnings from injured people prompted a meaningful investigation or simply accumulated while other workers kept using the product.
Chlorpyrifos Lawsuit Settlement Amounts
At this stage, it is hard to get specific about chlorpyrifos settlement amount ranges. We do know that Parkinson’s disease can cause havoc and the medical expenses, lost income, and pain and suffering that come with it. But we do not know whether these cases will be successful. You need to know that up front before we start talking about chlorphrifos.
If they are as successful as our lawyers believe they will be, we would estimate settlement ranges would eventually fall between $300,000 and $800,000. That is our preliminary projection based on the seriousness and long-term cost of Parkinson’s disease. It is not an average drawn from resolved chlorpyrifos cases or anything other than our estimate based on experience in these types of cases.
What will be the best cases? Claims where the plaintiff was diagnosed at a younger age, can document heavy exposure, has major wage loss, and needs extensive future care.
Keep in mind we are talking about settlement. The sky is the limit if one of these cases goes to trial. If a jury finds for a plaintiff in this litigation, the verdict is likely to be in the millions.
The Paraquat Parkinson’s litigation provides general lessons about expert battles, exposure proof, and Parkinson’s damages. It is not a settlement calculator for chlorpyrifos because Paraquat is a different chemical with different manufacturers, scientific literature, labels, and defenses. Still, those cases will likely resolve before these cases and those values will be a marker for this litigation.
Filing Deadlines and Statutes of Limitations
Every state limits the time available to file a product liability lawsuit. The difficult question is when that period began. Sometimes that is easy to figure out, but it can also be very complicated in some cases. A person may have been diagnosed with Parkinson’s disease years before learning that chlorpyrifos was a possible cause. We are confident that a court will find that the deadline did not begin until they knew or reasonably should have known of a potential connection between the product and the disease, but it will depend on the jurisdiction.
Manufacturers will press for an earlier date. They may rely on the diagnosis, older pesticide research, medical records mentioning chemical exposure, regulatory publicity, or earlier lawyer advertising. Some states also have statutes of repose that can bar a claim after a fixed period measured from sale or exposure, even if the disease and its possible cause were discovered later.
The December 2025 study does not automatically restart every limitations period. If you have Parkinson’s disease and directly handled chlorpyrifos, waiting for an MDL or settlement announcement may jeopardize a claim. A lawyer can examine the deadline under the law that applies to your case.
Frequently Asked Questions
Contact Our Chlorpyrifos Lawyers
If this page describes your exposure and diagnosis, tell us what you remember. We can investigate the product and work history while records and witnesses are still available.
Call 800-553-8082 or contact Miller & Zois online for a free consultation.