Monsanto was involved in several well-known legal cases, both as the one being sued and the one filing lawsuits. It was often the defendant in cases related to health and environmental concerns about its products. Monsanto also used the courts to protect its patents, especially in farming technology. After Bayer bought Monsanto in 2018, Bayer became involved in legal disputes about former Monsanto products, including glyphosate, PCBs, and dicamba. In 2020, Bayer agreed to pay over $10 billion to end lawsuits related to the herbicide called Roundup that contains glyphosate.
Patent litigation
Monsanto was one of the first companies to use the business model from the biotechnology industry in agriculture. This model was based on techniques developed by companies like Genentech in the late 1970s in California. In this model, companies spend a lot of money on research and development, and they get their money back by using and protecting biological patents.
In 1969, Monsanto sued Rohm and Haas for using Monsanto’s patent for the herbicide propanil. In the case Monsanto Co. v. Rohm and Haas Co., the Third Circuit Court of Appeals ruled against Monsanto because the company had obtained the patent dishonestly.
Since the mid-1990s, Monsanto has sued 145 U.S. farmers for breaking patents or contracts related to genetically engineered seeds. However, it has only taken these cases to trial against 11 farmers, all of whom Monsanto won. The Center for Food Safety reported that Monsanto had filed 90 lawsuits against farmers by 2004 for seed patent violations. Monsanto explains that patents are needed to ensure it is paid for its products and the money it spends on development.
Monsanto says the idea behind seed contracts is simple: businesses must be paid for their products, and only a small number of farmers break these agreements. Many lawsuits involve farmers breaking Monsanto’s Technology Agreement, but even farmers who do not sign this agreement can be held responsible if they use patented seeds. Monsanto says it will not use its patent rights against farmers if only a small amount of patented seed or traits is found in their fields by accident. A court ruled that this rule is legally binding, meaning farmers who do not harvest more than a small amount of patented crops cannot challenge Monsanto’s patents.
Monsanto often claims that farmers break patents by intentionally replanting patented seeds. The U.S. Supreme Court agreed in Bowman v. Monsanto Co. (2013) that this is patent infringement. The case began in 2007 when Monsanto sued Indiana farmer Vernon Hugh Bowman. Bowman had bought seed from a grain elevator, where he and others sold their transgenic crops. The elevator sold the soybeans as commodities, not as seeds for planting. Bowman tested the seeds and found they were resistant to glyphosate. He replanted his harvest of genetically modified seeds in later years, using soybeans he bought from the elevator. Monsanto said Bowman broke its patents because the soybeans he bought were not licensed for replanting. Bowman argued that the first sale of seed allowed him to use it freely. A court ruled in favor of Monsanto, and the Supreme Court upheld this decision in 2013.
In 2004, the Supreme Court of Canada ruled in Monsanto Canada Inc. v. Schmeiser that a farmer named Percy Schmeiser had broken Monsanto’s patent by planting seeds he had saved from a crop that had been contaminated by pollen from neighboring fields. Schmeiser claimed the contamination was accidental, but the court found that the 1998 crop was mostly made up of patented plants, which meant he had intentionally used them. The court said Schmeiser did not have to pay damages or legal fees because he did not profit from the infringement.
Monsanto has also sued grain elevators that clean seeds for farmers to replant. For example, Monsanto sued the Pilot Grove Cooperative Elevator in Missouri and Maurice Parr, a seed cleaner in Indiana, for encouraging farmers to save patented seeds. Parr agreed to stop this practice after a settlement.
In one case, a farmer faced criminal penalties for misconduct during a lawsuit with Monsanto. In 2003, the farmer was sentenced to four months in prison and ordered to pay $165,649 in restitution after pleading guilty to conspiracy to commit mail fraud. The farmer also had to pay nearly $3 million in a civil case because of willful infringement. These damages could not be erased through bankruptcy.
Monsanto has faced criticism for a mistaken lawsuit. In 2002, Monsanto incorrectly sued Gary Rinehart of Eagleville, Mississippi.
Chemical products and related harms
Monsanto began as a chemical company in 1901 and later became an agricultural company. In 1997, it separated its chemical business into a new company called Solutia Inc. In 2008, Monsanto agreed to take financial responsibility for legal cases involving harm from chemicals like asbestos, PCB, dioxin, and others made before Solutia became an independent company.
In 1980, a group of U.S. military personnel who served in Vietnam filed a class-action lawsuit, claiming injuries from exposure to dioxins in Agent Orange. The chemical companies involved denied a link between Agent Orange and the veterans’ health problems. In 1984, seven companies settled the case out of court, offering $180 million to veterans if they dropped all claims. Monsanto alone paid about 45% of this amount.
In 2004, a group of Vietnamese people sued Monsanto and other companies in a U.S. court over the effects of Agent Orange used during the Vietnam War. The case was dismissed, and the Supreme Court rejected the appeal.
In 2013, Monsanto reached a settlement with the town of Nitro, West Virginia, agreeing to pay $93 million for damages, cleanup, and ongoing monitoring of dioxin contamination near a plant where Agent Orange was made.
From 1984 to 1987, Monsanto was the defendant in the longest civil jury trial in U.S. history, Kemner v. Monsanto. The case involved people who claimed to have been poisoned by dioxin after a train derailment in Missouri. The jury found that Monsanto had not caused physical harm to the plaintiffs but had failed to eliminate dioxin from its manufacturing process or warn the public about its dangers. Most plaintiffs received only $1 each for actual losses but were awarded $16.2 million in punitive damages. Monsanto appealed and won the case.
In the early 1990s, Monsanto faced lawsuits over harm caused by PCBs. Workers at companies like Westinghouse, which used PCBs in electrical equipment, and scrap yard workers who handled used equipment, sued Monsanto and its customers. Monsanto settled some cases and won others, arguing it had warned customers about PCB dangers.
In 2003, Monsanto and Solutia Inc. reached a $700 million settlement with residents of West Anniston, Alabama, who were affected by PCBs from manufacturing and dumping. A jury found Monsanto guilty of "outrageous behavior" and held it responsible for multiple charges, including negligence and suppression of the truth.
In 2014, a Los Angeles Superior Court ruled that Monsanto was not responsible for cancers linked to PCBs in the food supply of three plaintiffs with non-Hodgkin’s lymphoma. The jury found that Monsanto’s production of PCBs before 1977 was not a major cause of the cancer.
In 2015, cities like Spokane, San Diego, and San Jose sued Monsanto to recover cleanup costs for PCB-contaminated sites, claiming Monsanto sold PCBs without proper warnings. Monsanto stated that improper use or disposal by third parties was not its responsibility.
In 2015, a Missouri court ruled that Monsanto, Solutia, Pharmacia, and Pfizer were not liable for deaths and injuries caused by PCBs made before 1977. A jury found in favor of the companies after a month-long trial.
In 2016, a Missouri jury ordered Monsanto to pay $46.5 million to three plaintiffs who claimed PCB exposure caused non-Hodgkin lymphoma.
In 2016, the state of Washington sued Monsanto over PCB-related cleanup costs. In 2018, Ohio’s attorney general also filed a lawsuit against Monsanto over health risks from PCBs.
In 2019, a federal judge denied Monsanto’s request to dismiss a lawsuit by Los Angeles County, which asked the company to clean up PCBs from waterways and storm sewer pipelines. The lawsuit seeks cleanup of PCBs in areas like the LA River and Dominguez Watershed.
In 2020, Bayer agreed to pay $650 million to settle lawsuits related to Monsanto’s PCB pollution in the U.S. However, a U.S. judge rejected this settlement and allowed the lawsuits to continue. In 2024, a Washington state appeals court overturned a $185 million verdict against Bayer.
In 2025, North Carolina State University sued Monsanto over PCBs used in the construction of Poe Hall on campus in 1971. Health risks are currently being evaluated by the National Institute for Occupational Safety and Health.
Alachlor is the second most widely used herbicide in the U.S., but it is banned in the European Union.
In 2012, a French court found Monsanto guilty of poisoning a farmer who used the herbicide Lasso, a brand name for alachlor. This was the first such case in France and may support other health claims against pesticides. In 2015, a French appeals court upheld the ruling and ordered full compensation for the farmer.
The active ingredient in Roundup, the most widely used herbicide, is glyphosate. As of October 2019, over 40,000 plaintiffs claimed glyphosate-based herbicides caused their cancer. Most lawsuits were filed after 2015, when the World Health Organization linked glyphosate to cancer. Monsanto denies that Roundup is carcinogenic.
There is limited evidence that occupational exposure to large amounts of glyphosate, such as in farming, might increase cancer risk, but no strong evidence of such a risk from home use, like gardening. Regulatory agencies and scientific groups, including the U.S. Environmental Protection Agency and the European Commission, agree that glyphosate used as labeled is unlikely to be carcinogenic to humans.
In 2016, Monsanto sued to prevent glyphosate from being classified as a carcinogen in California.
Other legal actions
In 2005, the U.S. Department of Justice (DOJ) reached a legal agreement with Monsanto. Monsanto admitted to breaking the Foreign Corrupt Practices Act and making false entries in its financial records. The company agreed to pay a $1.5 million fine.
The case involved bribes given to an Indonesian official. A senior Monsanto manager told an Indonesian consulting firm to pay $50,000 to a high-ranking Indonesian government official in 2002. This was related to a review of Monsanto’s genetically modified cotton. Monsanto instructed the firm to hide the bribe by labeling it as "consulting fees."
The U.S. Securities and Exchange Commission (SEC) found that Monsanto’s Indonesian offices made illegal payments to at least 140 Indonesian officials and their families, totaling at least $700,000. Some of these payments were funded through sales of pesticide products in Indonesia that were not properly documented and priced higher than they should have been. In 2008, a court dismissed the legal agreement against Monsanto, stating the company had met all its requirements.
In 2014, Monsanto settled a dispute with soft wheat farmers after experimental glyphosate-resistant wheat was found in Oregon in 2013. This discovery caused South Korea and Japan to temporarily stop importing U.S. wheat. The settlement included a $2.125 million fund to help farmers affected economically.
In 2019, French news outlets Le Monde and France 2 revealed that a public relations firm had created a database in 2016 listing private information about journalists, scientists, and politicians. The database included evaluations of their views on topics like agriculture, pesticides, and health. Seven individuals listed in the database complained to a French privacy agency, which fined Monsanto €400,000 for secretly collecting the data.
In 2003, Monsanto sued Oakhurst Dairy over a label on its milk cartons that stated, "Our farmer's pledge: no artificial hormones." Monsanto claimed the label suggested Oakhurst milk was better than milk from cows treated with a hormone called rBST, which hurt Monsanto’s business. The companies reached a settlement, and Oakhurst agreed to add the word "used" to its label and note that the U.S. Food and Drug Administration (FDA) found no major differences between milk from rBST-treated and non-rBST-treated cows.
In 2010, the U.S. Supreme Court ruled in Monsanto Co. v. Geertson Seed Farms. The case involved a court order blocking the planting of Monsanto’s genetically engineered Roundup Ready alfalfa (RRA). In 2005, the U.S. Department of Agriculture (USDA) had allowed RRA to be planted after a basic environmental review. In 2006, a court blocked this decision, requiring a more detailed environmental study before RRA could be planted. The Supreme Court later overturned this ruling, stating that plaintiffs must prove they would suffer lasting harm if RRA was planted. The court did not address whether RRA should be fully deregulated, and the crop remained under regulation until USDA completed a full environmental review in 2012.
In 2008, the Center for Food Safety and other groups sued USDA over its decision to allow planting of glyphosate-resistant sugar beets developed by Monsanto. They worried the beets could cross-pollinate with regular sugar beets. A court ruled in 2009 that USDA had broken the law by deregulating the beets. In 2010, the court banned planting the beets in 2011. However, in 2011, a higher court overturned this decision, citing the Supreme Court’s earlier ruling. USDA then created rules for handling the beets while they remained regulated. In 2012, USDA fully deregulated the beets after completing environmental reviews.
In 2018, Monsanto asked the activist group Avaaz to hand over documents related to glyphosate safety. Monsanto planned to use the documents in a court case involving two Missouri residents who claimed their cancer was caused by exposure to Monsanto’s Roundup herbicide. A New York judge ruled in favor of Avaaz, stating that the request could harm free speech and political activity.
Investigations
In 2009, Monsanto faced an investigation by the U.S. Department of Justice to determine if the company’s actions in soybean markets violated anti-trust rules. In 2010, the Department of Justice created a website for people to share comments on "Agriculture and Antitrust Enforcement Issues in Our 21st Century Economy." Over 15,000 comments were submitted, including a letter from 14 State Attorneys General. These comments are available to the public. On November 16, 2012, Monsanto announced it had received a written notice from the U.S. Department of Justice stating the Antitrust Division had finished its inquiry and decided not to take any enforcement action. People who opposed Monsanto’s seed patenting and licensing practices were upset that the Department of Justice did not share details about the inquiry’s findings.
Brofiscin Quarry was used as a waste site from about 1965 to 1972 and received waste from BP, Veolia, and Monsanto. A 2005 report by the Environment Agency Wales found the quarry contained up to 75 toxic substances, including heavy metals, Agent Orange, and polychlorinated biphenyls (PCBs). The UK’s Environment Agency investigated which companies were responsible for cleanup costs. In February 2011, the Guardian reported that Monsanto agreed to help with cleanup costs but did not admit responsibility for the pollution. A webpage on the Environment Agency’s site stated: "We have completed our investigations to identify companies responsible for the pollution under contaminated land laws. We are consulting with BP, Veolia, and Monsanto to allow them to voluntarily help clean up the site. If this effort fails, we can carry out the work ourselves and recover costs. These companies are legally responsible for the pollution caused by earlier companies that deposited waste at the quarry." In July 2015, Natural Resources Wales announced that the three companies reached agreements to cover cleanup costs.
Uncertainty remains about whether full disclosure and responsibility have been fully addressed for other sites linked to waste from Monsanto’s Newport works. Other sites of interest include Maendy and Sutton Walls.
In February 2016, Monsanto agreed to pay an $80 million settlement after a U.S. Securities and Exchange Commission investigation found the company had incorrectly reported earnings in filings over a three-year period. The misleading reports were tied to Monsanto’s failure to fully account for costs related to its Roundup rebate programs.
Disputes
In 1997, the news team at WTVT (Channel 13), a Fox-owned station in Tampa, Florida, planned to broadcast an investigative report by reporters Steve Wilson and Jane Akre about possible health risks linked to Monsanto’s bovine growth hormone product, Posilac. Before the report was scheduled to air, Monsanto sent a threatening letter to Fox, claiming the reporters were biased and that the story would harm the company. Fox attempted to resolve the issue with the reporters, but discussions failed. Both reporters were later fired. Wilson and Akre claimed they were fired as punishment for their actions, while WTVT stated they were fired for refusing to follow instructions. The reporters then filed a lawsuit against Fox/WTVT in Florida state court under the state’s whistleblower law. In 2000, a Florida jury ruled that there was no proof Fox/WTVT had changed the story due to pressure from Monsanto. However, the jury found that Akre, but not Wilson, was a whistleblower and had been unfairly fired. Fox appealed the decision, arguing that Florida law requires a whistleblower to report a violation of a law, rule, or regulation, and that the FCC’s news distortion policy did not meet this standard. The appeals court overturned the verdict, stating that Akre was not a whistleblower because Florida law requires rules to be officially adopted, not developed through legal processes. The court also said treating uncodified policies as official rules would expand the scope of employer liability beyond what the Florida legislature intended.
In 1981, three senior employees of Industrial Bio-Test Laboratories (IBT) and one from Monsanto were charged with federal crimes, including mail fraud and lying to the government. Three were convicted in 1983, while one case was dismissed due to medical reasons. IBT conducted toxicology tests for many chemical companies, including Monsanto, whose products used falsified data from IBT. One of the convicted individuals, Paul Wright, a toxicologist, had previously worked for Monsanto before joining IBT, where he oversaw studies on an antimicrobial product, triclocarban (TCC), that Monsanto was developing. After completing the studies, Wright returned to Monsanto. Court records and investigations showed that Monsanto used IBT’s flawed data for regulatory submissions, even though Monsanto employees knew the data was unreliable. These discoveries led to the creation of Good Laboratory Practice standards for industrial testing.
In 1991, Philip Smith, a former assistant toxicologist at IBT, testified in a trial where Monsanto was being sued by workers at Westinghouse over PCBs. Smith stated that final toxicology reports on PCBs provided to Monsanto by IBT contained false information.
In late 2006, the Correctional Tribunal of Carcassonne, France, ordered two directors of Monsanto’s subsidiary Asgrow to pay a €15,000 fine for knowing about the presence of unauthorized genetically modified organisms (GMOs) in seed bags imported by Asgrow on April 13, 2000.
False advertising
In 1996, the New York Times reported that Dennis C. Vacco, the Attorney General of New York, told the company to remove advertisements that claimed Roundup was "safer than table salt" and "practically nontoxic" to mammals, birds, and fish. The company removed the ads but stated that the phrases were allowed by EPA rules.
In 1999, Monsanto was criticized by the UK Advertising Standards Authority (ASA) for making "confusing, misleading, unproven, and wrong" claims in a £1 million advertising campaign. The ASA said Monsanto presented its opinions as if they were facts and included "wrong" and "unproven" scientific statements. Monsanto apologized and explained that it did not intend to deceive but had not considered cultural differences between the UK and the US in how information was shared.
In 2001, French environmental and consumer rights groups filed a lawsuit against Monsanto for misleading the public about the environmental effects of Roundup. They argued that glyphosate, Roundup’s main ingredient, was considered "dangerous for the environment" and "toxic for aquatic organisms" by the European Union. Monsanto’s advertisements claimed Roundup was biodegradable and left soil clean after use. In 2007, Monsanto was found guilty of false advertising and fined 15,000 euros. Its French distributor, Scotts France, was also fined 15,000 euros. Both companies were ordered to pay 5,000 euros to the Brittany Water and Rivers Association and 3,000 euros to the CLCV, a major consumer group in France. Monsanto appealed the decision, but courts agreed with the original ruling.
In August 2012, a Brazilian Regional Federal Court ordered Monsanto to pay a $250,000 fine for false advertising. In 2004, advertisements about genetically modified soybean seeds and the herbicide glyphosate used in their cultivation claimed the products were beneficial for the environment. A federal prosecutor said Monsanto incorrectly stated that less herbicide was needed and noted that "there is no scientific certainty that soybeans marketed by Monsanto use less herbicide." The judge called the advertisements "abusive and misleading propaganda." The prosecutor said the goal was to promote the sale of genetically modified soybean seeds (which were banned at the time) and the herbicide used on them, during a period when a Brazilian biosafety law was being debated.
In March 2014, the South African Advertising Standards Authority (ASA) agreed with a complaint from the African Centre for Biosafety that Monsanto made "unproven" claims about genetically modified crops in radio advertisements and ordered the ads to be removed. In March 2015, after reviewing more information from Monsanto, the ASA changed its decision.