On May 14, 2021, the United States Court of Appeals for the Ninth Circuit, issued a decision upholding a $25 million award to a plaintiff who claimed that he contracted non-Hodgkin’s Lymphoma (“NHL”) after being exposed to Roundup, a glyphosate-based pesticide. In its opinion, the court considered whether the plaintiff’s state law claims were preempted by federal pesticide law, and whether the evidence introduced by the plaintiff at trial had been properly admitted by the court. Because the case is the first one to reach a federal appeals court, the conclusions reached by the Ninth Circuit will likely affect other glyphosate cases brought in that jurisdiction where the plaintiffs are making similar arguments or bringing similar evidence.


Hardeman v. Monsanto Co., No. 19-16636 (9th Cir. 2021) was originally filed in a federal court in California on February 12, 2016. At the time, the case was one of hundreds that was filed against Monsanto Corporation (“Monsanto”) alleging that the company’s glyphosate pesticide, Roundup, had caused the plaintiffs to develop NHL. Many of the cases were ultimately consolidated into a multidistrict litigation (“MDL”), a type of legal proceeding that allows federal cases from around the country that have questions of fact in common to be consolidated into one court. Of all the cases that were consolidated into the Monsanto Roundup MDL, the Hardeman case was the first one selected to go before a jury, making it the “bellwether” trial. In the federal court system, a bellwether trial is a case that the court and parties select to test their arguments. Bellwether trials are typically used in mass tort actions where hundreds or thousands of people are injured by the same product, and are bringing similar claims. The outcome of a bellwether trial will generally impact similar cases going forward.

The plaintiff Hardeman v. Monsanto Co. brought a variety of tort claims against Monsanto, including negligence, design defect, failure to warn, and breach of implied warranties. In essence, the plaintiffs argued that Monsanto either knew or should have known that the glyphosate in Roundup was dangerous to human health, and failed to properly warn the public of those dangers. The jury who heard the case returned an $80 million verdict in favor of the plaintiff in March, 2019. Of that $80 million, $5 million were for compensatory damages to cover the actual harm done to the plaintiff, and $75 million were for punitive damages. Ultimately, the judge reduced the punitive damages to $20 million, bringing the total award to $25 million.

In late 2019, Monsanto, which had since been bought by Bayer, appealed the verdict to the Ninth Circuit Court of Appeals. It was the first time a verdict in a glyphosate case had been appealed in federal court. In the appeal, Monsanto raised two main arguments.

First, it claimed that that the pesticide labeling requirements under the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”) preempted any state requirement to place cancer warnings on pesticide labels. One of the claims the plaintiff had brought in the lower court was that Monsanto had failed to warn consumers of the risks of glyphosate by putting a warning label on Roundup products. Under FIFRA, states are not permitted to enact any labeling or packaging standards for pesticides that are “in addition to,” or “different from” federal standards. 7 U.S.C. § 136v(b). In Bates v. Dow Agrosciences LLC, 544 U.S. 431 (2005), the United States Supreme Court interpreted the preemption language in FIFRA to mean that states may only enact labeling and packaging standards for pesticides that are “equivalent to,” or “consistent with” federal standards. In its appeal, Monsanto argued that the plaintiff’s failure to warn claims were preempted by FIFRA because the Environmental Protection Agency (“EPA”) has consistently registered Roundup labels, and approved sale and use of Roundup without cancer warnings.

Monsanto’s second main argument on appeal was that the lower court improperly admitted the plaintiff’s expert testimony on the alleged link between glyphosate and NHL. According to Monsanto, the lower court improperly applied what is known as “the Daubert standard,” a legal standard that is used by trial judges to determine whether an expert witness’s scientific testimony is based on scientifically valid reasoning that can be properly applied to the facts of the case. Monsanto claims that the lower court misapplied the Daubert standard in such a way that it allowed the plaintiff to rely on flawed findings with an “analytical gap” between the data and conclusions of the expert witnesses. Had the court applied the standard correctly, Monsanto argues that the case never would have been allowed to go to trial because none of the evidence linking glyphosate exposure to cancer would have been admitted.

Ninth Circuit Decision

The decision issued by the Ninth Circuit on May 14 rejected both of Monsanto’s main arguments. According to the court, FIFRA did not preempt the plaintiff’s failure to warn claims, nor had the lower court improperly allowed testimony from the plaintiff’s expert witnesses. Therefore, the Ninth Circuit upheld the lower court’s verdict and the award of $20 million.

The court first considered whether FIFRA preempted the plaintiff’s state law failure to warn claims. In order to determine whether the claims were preempted, the court applied the two-part test adopted by the Supreme Court in Bates v. Dow Agrosciences, LLC. Under that test, a state law will only be preempted by FIFRA if it is (1) a requirement for pesticide labeling or packaging, and (2) is also in addition to or different from FIFRA requirements. A state requirement for pesticide labeling or packaging that is equivalent to, or consistent with FIFRA requirements will not be preempted.

According to the Ninth Circuit, the plaintiff’s failure to warn claims satisfied the first step of the Bates test because the claims were based on Monsanto’s failure to provide a warning label under California law. Next, the court considered whether a warning label would be consistent with FIFRA requirements. State law is consistent with FIFRA when both impose “parallel requirements,” meaning that a violation of the state law is also a violation of FIFRA. Therefore, if a violation of the California state law duty to warn would also be a violation of the FIFRA. Under FIFRA, a pesticide may not be “misbranded.” 7 U.S.C. § 136j(a)(1)(E). A pesticide will be considered “misbranded” if “the label does not contain a warning or caution statement which may be necessary … to protect health and the environment.” 7 U.S.C. § 136(q)(1)(G). Under California common law, the duty to warn requires a manufacturer to warn consumers of any health risk that is “known or knowable” or of risks that “a reasonable prudent manufacturer would have known and warned about.” According to the court, the FIFRA requirements and the California requirements are parallel because the FIFRA requirement to provide any “necessary” warning to protect human health is broader than the California requirement to warn against any “known or knowable” risks. Therefore, the plaintiff’s failure to warn claims were not preempted by FIFRA.

Next, the Ninth Circuit considered whether the lower court had improperly applied the Daubert standard by admitting the plaintiff’s expert witness testimony. Ultimately, the court found that the Daubert standard had been applied correctly according to precedent within the Ninth Circuit.

Under the Daubert standard, judges can consider the following non-exclusive factors when determining an expert witness’s reliability: (1) whether the theory or technique employed by the expert is generally accepted in the scientific community; (2) whether it has been subject to peer review; (3) whether it can be or has been tested; and (4) whether the known or potential rate of error is acceptable. Monsanto argued that the lower court improperly allowed expert witnesses to make assumptions in violation of how the Daubert standard is usually applied in Ninth Circuit cases.  The court rejected this argument, noting that in the Ninth Circuit, the guiding principle when applying the Daubert standard is to exclude expert evidence when the flaws in theory or methodology are so large that the expert lacks “good grounds” for their conclusions. Because the lower court concluded that the plaintiff’s expert witnesses were relying on theories and methodologies that could reasonably support their conclusions that glyphosate exposure is linked to NHL, the Ninth Circuit concluded that the Daubert standard had been correctly applied.


Because Hardeman v. Monsanto Co. is a bellwether case, the court’s conclusions are indicative of how future courts in the Ninth Circuit may rule in similar lawsuits. While the court noted that many of its holdings were fact-specific, and would not necessarily be the same if the facts of the case were different, there are still important takeaways that may be applicable in other glyphosate lawsuits. At least in the state of California, it seems likely that additional claims that Monsanto failed to warn consumers that glyphosate may cause cancer will not be preempted by FIFRA. Additionally, expert witnesses in other glyphosate cases that rely on the same theories and methodologies as the expert witnesses in Hardeman v. Monsanto Co. will likely be able to testify in Ninth Circuit courts without violating the Daubert standard.

Currently, settlement negotiations for the glyphosate MDL are on-going. If the negotiations are successful, many plaintiffs in the MDL and in the Ninth Circuit will settle their claims and drop their lawsuits. However, some plaintiffs may choose to continue with litigation, and may rely on the decisions reached by the Ninth Circuit.

Going forward, Bayer has said that it intends to pursue all available legal options, including petitioning the Supreme Court to review the case. Should the Supreme Court take the case, it would likely have an impact on future glyphosate cases, regardless of the outcome.


To read the Ninth Circuit’s opinion in Hardeman v. Monsanto Co., click here.

To read Monsanto’s appellate brief, click here.

To read the plaintiff’s initial complaint, click here.

To read the text of FIFRA, click here.

For more information on FIFRA preemption, click here.

For more pesticide resources from the National Agricultural Law Center, click here.