Pesticide exposure lawsuits in California have included some of the largest toxic tort verdicts in American history, along with civil rights complaints against state regulators and enforcement actions against applicators who let chemicals drift onto schools and neighborhoods. Plaintiffs have included cancer patients, farmworker families whose children suffered brain damage, teachers’ unions, and the state itself. The claims rest mostly on negligence and strict liability, and the chemicals at the center of the fight are Roundup (glyphosate), chlorpyrifos, paraquat, and the fumigants chloropicrin and 1,3-dichloropropene.
Roundup Cancer Lawsuits
California has been the center of Roundup litigation. The first case to go to trial, Johnson v. Monsanto, was brought by a San Francisco school groundskeeper who said years of spraying the glyphosate-based herbicide caused his non-Hodgkin lymphoma. A jury awarded $289 million in 2018. The trial court cut it to $78.5 million, and the California Court of Appeal upheld liability in 2020 while reducing the judgment to $20.5 million. Bayer did not seek Supreme Court review.1Wisner Baum. Roundup Settlement
In Pilliod v. Monsanto, a jury awarded a married couple $2 billion, reduced by the trial judge to $87 million. The First Appellate District denied Monsanto’s appeal in August 2021, the California Supreme Court declined review in November 2021, and the U.S. Supreme Court denied certiorari in June 2022.1Wisner Baum. Roundup Settlement
Roundup litigation has grown into one of the largest mass torts in history. As of early 2025, roughly 4,414 actions were pending in the federal multidistrict litigation in the Northern District of California, and Bayer reported about 114,000 Roundup-related claims had been settled or resolved.2Motley Rice. Pesticide Lawsuits In February 2026, Bayer announced a proposed $7.25 billion class-action settlement to resolve tens of thousands of remaining claims in Missouri state court. Objectors filed papers in May 2026 calling the deal unconstitutional, arguing it delivers $675 million in attorney fees while offering minimal payments to cancer sufferers and is designed to make opting out nearly impossible. U.S. District Judge Vince Chhabria, who has overseen the federal Roundup litigation since 2016, previously described an earlier proposed settlement as “filthy” and “legally problematic.” A final approval hearing is scheduled for July 2026.3Investigate Midwest. Bayer’s Proposed Roundup Settlement Violates Constitution, New Legal Filing Claims
Everything above sits under a shadow. In Monsanto Company v. Durnell, the U.S. Supreme Court is deciding whether the federal pesticide labeling law preempts state failure-to-warn claims when the EPA has not required the warning at issue. Oral arguments took place on April 27, 2026, and a decision is expected by early July 2026.4SCOTUSblog. Justices Debate Who Gets to Decide That Pesticide Labels Need a Cancer Warning A ruling for Monsanto could shut down many state-court Roundup claims nationwide.
Chlorpyrifos Brain Injury Cases
Chlorpyrifos, an organophosphate insecticide once applied to more than two million pounds of California crops a year, is now banned in the state. California designated it a restricted material in 2015 and a toxic air contaminant in 2018, and in 2019 the Department of Pesticide Regulation reached a settlement with manufacturers including Dow AgroSciences to withdraw it. Sales to growers ended in February 2020, and all remaining use was prohibited after December 31, 2020.5California Department of Pesticide Regulation. Agreement Reached to End Sale of Chlorpyrifos in California
In the Central Valley, two Kings County farmworker families, the Avilas and the Calderon de Cerdas, sued Corteva Agrisciences (the successor to the Dow-DuPont merger), alleging chlorpyrifos exposure caused lifelong brain damage to their children. The families claimed the chemical reached their homes through pesticide drift and contaminated drinking water, and that mothers were exposed while working in fields and packing houses during pregnancy. The lawsuits also named the towns of Huron and Avenal for failing to protect their water supplies. Lead attorney Stuart Calwell described the cases as a precursor to broader class action litigation.6Fresno Alliance. Valley Farmworker Families Sue Chemical Giant Dow
A February 2026 lawsuit filed by Californians for Pesticide Reform, the Pesticide Action and Agroecology Network, and two individual plaintiffs targets the Department of Pesticide Regulation’s rules for the fumigant 1,3-dichloropropene. The plaintiffs argue the department created two conflicting rules, one for residential bystanders and one for occupational bystanders, that apply different safety thresholds to the same populations. They want both regulations invalidated and a single health-protective standard adopted.7California Rural Legal Assistance. Farmworker Advocates Sue California Over Conflicting Regulations for Cancer-Causing Fumigant
Paraquat and Parkinson’s Disease
Paraquat litigation alleges that chronic exposure to the herbicide causes Parkinson’s disease. The main cases are consolidated outside California: as of June 2026, 6,651 cases are pending in a federal multidistrict litigation in the Southern District of Illinois before Chief Judge Nancy J. Rosenstengel, and another 1,843 cases are pending in Pennsylvania’s Philadelphia Court of Common Pleas.8MDL Update. Paraquat Parkinson’s Disease Lawsuit MDL 30049Motley Rice. Paraquat Lawsuit Defendants are primarily Syngenta, Chevron, and FMC Corporation. Paraquat remains legal in the United States as a restricted-use pesticide but is banned in more than 30 countries, including the European Union.
In October 2025, the Supreme Court declined to review a jurisdictional challenge by Syngenta, allowing the Pennsylvania mass tort to proceed. A bellwether trial there settled on January 27, 2026, the night before it was scheduled to begin. No global settlement or major trial verdict has come out of the federal MDL yet.9Motley Rice. Paraquat Lawsuit
Lawsuits Over Pesticide Spraying Near Schools
A coalition of teachers’ unions and environmental groups, represented by Earthjustice, sought judicial review of six permits that the Monterey County Agricultural Commissioner issued in 2023 authorizing twelve applications of the fumigants chloropicrin and 1,3-dichloropropene within one mile of Ohlone Elementary, Pajaro Middle School, and Hall District Elementary. The petitioners argued regulators approved the permits without evaluating cumulative health impacts on students or considering safer alternatives, in violation of the California Environmental Quality Act, the Food and Agricultural Code, and civil rights laws protecting the predominantly Latino student population. An air monitoring station at Ohlone Elementary had recorded fumigant levels deemed unsafe for human health every year for the twelve years it had operated.10Earthjustice. Protecting Schoolchildren in Monterey County From Toxic Pesticide Exposure11KSBW. Lawsuit Over Pesticides Near Central Coast Schoolchildren
On September 11, 2025, the Monterey County Superior Court ruled against the coalition and upheld all six permits. The court found a state law exempts county agricultural commissioners from CEQA’s formal documentation requirements, requiring only that they consider impacts and alternatives rather than produce written findings. It also concluded regulators had adequately assessed cumulative impacts, and noted that University of California research showed no effective alternatives currently exist for Central Coast strawberry production.12KSC Lawyers. Monterey Court Upholds DPR and County Ag Commissioner Authority in Pesticide Permit Dispute
The Monterey case has a long backdrop. In 1999, Latino parents including Marcia Garcia filed a Title VI complaint with the EPA alleging the California Department of Pesticide Regulation discriminated against Latino schoolchildren in Oxnard by renewing methyl bromide’s registration without accounting for health impacts on nearby schools. In April 2011, the EPA issued a preliminary finding of an “unintentional adverse and disparate impact” on Latino children between 1995 and 2001.13Pesticide Action Network North America. Justice Delayed for Latino Schoolchildren14EPA. Title VI Settlements and Decisions The case ended in a negotiated settlement in which the state agreed to maintain air monitoring in Salinas, Oxnard, Santa Maria, and Watsonville; hold outreach events in the five counties with the highest methyl bromide use; distribute bilingual pesticide guides to schools; and fund an $850,000 contract to train community health liaisons. The agreement stated it was not an admission of a Title VI violation.15EPA. Title VI Settlement Agreement
Pesticide Drift Enforcement Cases
Not every pesticide suit targets a manufacturer. The state Attorney General and the San Joaquin County District Attorney sued Alpine Helicopter Service and several of its pilots over five drift incidents between 2014 and 2020, including applications that contaminated Turner Academy, a special education school in Lodi, and a Stockton sports complex while children and families were present. The San Joaquin County Superior Court established liability in March 2022, with penalty proceedings continuing.16California Department of Pesticide Regulation. Court Decision Against Alpine Helicopter for Illegal Pesticide Drift
How Pesticide Exposure Claims Work
Private plaintiffs in California typically sue under negligence or strict liability. A negligence claim requires showing the defendant owed a duty of care, breached it, caused harm, and that the harm resulted directly from the breach. Common allegations include failure to test a product’s effects, failure to warn of known dangers, and marketing a pesticide as safe when evidence suggested otherwise.17National Agricultural Law Center. Plaintiffs’ Pesticides Negligence Claims in Pesticide Injury Lawsuits Causation is widely recognized as the hardest element, particularly where a plaintiff was exposed to multiple products over years.18FindLaw. Product Liability Claims Arising From Pesticides
The statute of limitations for toxic exposure claims is two years under California Code of Civil Procedure Section 340.8, but the clock does not start at the moment of exposure. Under the discovery rule, it begins when the plaintiff knows or reasonably should know three things: that a physical injury exists, that a toxic substance caused it, and that another party’s wrongful conduct may be responsible. Media coverage of contamination alone is not enough to trigger the deadline. Claims against government entities carry a much shorter six-month filing window.19JNY Law. Toxic Exposure
If you believe pesticide exposure caused injury to you or your family, the deadline is the first thing to check, and the diagnosis date, not the spraying date, is usually what counts.