The infamous Ferebee decision is certainly a contender to be a Dred Scott decision involving scientific evidence,[1] by declaring that science has no validity issues that the law is bound to respect.[2] The decision is often cited for its dictum, written with impressive rhetorical flourish, about how courts should not interfere with expert witness opinion testimony. The dictum, when written in 1984, was contrary to the law of Federal Rule of Evidence 702, and was relegated in 1993 to the trash bin of jurisprudential history by the Supreme Court’s 1993 decision in Daubert.[3]

Since 1993, scofflaw judges continued to cite Ferebee’s discredited dictum, without looking at the specific facts of the case. Indeed, even after Rule 702 was amended to clarify its meaning, courts have cited Ferebee as precedential for a let-it-all-in approach to expert witness testimony. As recently as February 2026, the Chief Judge of the Federal Circuit, of the United States Court of Appeals, cited Ferebee in derogation of Federal Rule of Evidence 702.[4] This recrudenscence of Ferebee warrants revisiting the case, what was actually decided, and whether it has any continuing jurisprudential relevance.

The Ferebee case was a personal injury case against the manufacturer of paraquat, a herbicide, for damages for severe pulmonary fibrosis. Interestingly, the case is sometimes erroneously cited as a cancer causation case, which may explain why some commentators criticize its dismissal of epidemiology and statistical significance.

Critics of Ferebee, as well as its acolytes, rarely describe the factual context of the case. The facts of a case are always germane to its holding, and Ferebee cannot be cited appropriately without a sane appreciation of its facts.

1. Ferebee is a government negligence case.

The plaintiff worked for the federal government when he was exposed to paraquat. Richard Ferebee began working for the Department of Agriculture’s Beltsville Agricultural Research Center (BARC), in Beltsville, Maryland. He started spraying paraquat in the summer of 1977, and used the herbicide regularly through the time he was diagnosed with pulmonary fibrosis, in November 1979.[5] Mr. Ferebee sued Chevron Chemical Company, the supplier of the paraquat, for failing to warn. The important failure to warn, however, was committed by the federal governmental, which had actual knowledge of the hazard, and which owned the BARC facility, employed Ferebee, controlled and supervised his use of paraquat, and failed to comply with Chevron’s instructions. The federal government itself further regulated the sale and use of paraquat extensively, first by the Department of Agriculture, and later by the Environmental Protection Agency. [6]

2. The exposure.

Ferebee filed his lawsuit in 1981; he died in 1982. His case was tried twice. In the first trial, the jury deadlocked. In the second trial, the jury returned a verdict in favor of his estate, and for his family, for $60,000. In his deposition testimony, Ferebee described how he sprayed paraquat, in the summer of 1977. The chemical was diluted for use, per Chevron’s instructions. There was no evidence that Ferebee ever had direct contact with undiluted paraquat, or that the paraquat he was exposed to was not diluted according to the proportions recommended on Chevron’s label.[7]

Crediting Ferebee’s testimony, the federal government was at best grossly negligent; at worst, the government was an intentional tortfeasor. In flagrant disregard of Chevron’s written instructions (as required by federal regulation), Ferebee frequently had the chemical on his ungloved hands.[8] Ferebee further described an occasion when he was drenched with paraquat as he walked behind a tractor that was spraying the chemical, and another incident when he used a defective sprayer that leaked paraquat “all over his pants.”[9]

On the occasions of Ferebee’s being exposed to paraquat without appropriate protective gear, the federal government deviated from its employer common law, statutory, and regulatory duties. Ferebee did not wash when he was dermally exposed to paraquat, and he went home contaminated, where he fell asleep, tired and dizzy, without showering.[10]  The exposure that Ferebee described would not have occurred had his federal employer followed the instructions on the label that the government itself mandated. In 1978, the federal Occupational Health & Safety Administration published Guidelines on the need for protective clothing, respirators, immediate washing of contaminated skin. Ferebee’s federal governmental employer recklessly disregarded the guidelines it mandated that Chevron provide.

3. The warnings.

Paraquat could be sold in the United States only when labeled in accordance with EPA regulations, promulgated pursuant to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).[11] The statute bars EPA from allowing sale of regulated herbicides, such as paraquat, unless the chemicals, as labeled, will not cause “unreasonable adverse effects on the environment.”[12] Such effects are in turn defined as any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of [the] pesticide.[13] FIFRA further requires the EPA to require labeling that is “adequate to protect health and the environment” and that is “likely to be read and understood.”[14]

In the Ferebee case, both the district and the circuit courts failed to provide the complete warning label and the material data safety sheets that Chevron supplied to the federal government employer, as required by the federal government. There are “snippets” of the warning communications in the published opinions, which make clear that the government was largely if not entirely to blame for failing to comply with the directions required under FIFRA. For instance, the district court, in a footnote, acknowledged:

“For example, the label advised the user spraying paraquat to wear waterproof clothing and goggles, to avoid working in spray mist, and to wash splashes on the skin or eyes immediately with water.”[15]

The Court of Appeals Ferebee opinion described the label,[16] as stating a warning in large bold letters:

DANGER

CAN KILL IF SWALLOWED

HARMFUL TO THE EYES AND SKIN

The label also informed users to wash any exposed areas immediately, and to remove contaminated clothing.[17]

4. The Stipulation.

Essential to understanding the holding in Ferebee are the facts of the case, including the parties’ stipulation:

“that Mr. Ferebee’s only significant exposure to paraquat was on his intact skin; i.e., there was no evidence that Mr. Ferebee swallowed or inhaled paraquat, or that he spilled or sprayed it on an area of his skin upon which he had any apparent cuts or scrapes. The jury was not, of course, precluded from concluding that a person engaged in Mr. Ferebee’s line of work could have had some, or even many, minor cuts or abrasions not readily discernible to the naked eye or likely to be remembered some time later.”[18]

Why did the plaintiffs try to present their case solely as a dermal exposure cases? As we will see, this stratagem made their medical causation case a little more difficult, but it avoided defenses of serious misuse and lack of proximate cause. Ferebee had been instructed by his co-workers and supervisors that paraquat was extremely dangerous if swallowed or inhaled. The warning label was unequivocal in detailing the dangers and the need to avoid ingestion. (Without the full label, it is difficult to evaluate how well the label warned against inhalation, but the 1978 OSHA guidelines address the use of a proper respirator for situations in which paraquat may be inhaled.) On the other hand, the label had a weakness, which could be exploited, as long as the preemption defense could be held at bay: the label urged protective clothing, goggles, and immediate washing of contaminated skin, but it failed to describe the consequence of dermal exposure other than irritation. Ferebee could thus try to avoid his own culpable conduct, as well as a sophisticated intermediary defense, by claiming that his exposure was only dermal.

Why did Chevron agree to the stipulation? Ferebee surely had some inhalational exposure when he walking behind applicators and when he was drenched in paraquat. The Chevron warning label, per government-employer regulations, did not specify respirator usage for ordinary work exposures of applicators (as opposed to workers who handled undiluted paraquat, or who worked in confined spaces). The defendant probably felt sanguine about its preemption defense, and thus also about the adequacy of its warnings overall. The stipulation limited the plaintiff’s medical causation case to a route of exposure that put it into an arguable “first instance” case report. Chevron stood to gain a claim of “lack of notice,” and thus lack of actual or constructive knowledge of the risk of lung disease from dilute dermal exposure. The clinical presentation itself differed from many of the cases of known paraquat poisoning, and Chevron probably believed that it could deal with the medical causation claim better if exposure was limited to transdermal absorption on unbroken skin.

5. Medical causation

Chevron stridently argued that there had been no previous documented cases of pulmonary fibrosis in workers exposed to diluted paraquat on unbroken skin. The manufacturer’s argument was clever by halves.  The following facts were uncontroverted as known at the time of Chevron’s sale of the product:

• Paraquat causes pulmonary fibrosis in humans.
• The evidence that established paraquat as a cause of pulmonary fibrosis was largely case series of acute onset of pulmonary fibrosis after ingestion.
• Paraquat induces pulmonary fibrosis relatively rapidly.
• Paraquat can be absorbed through the skin.
• The parties agreed that any type of exposure – ingestion, inhalation, or dermal absorption – could cause lung damage.[19]
• Once paraquat is ingested, inhaled, or absorbed, it can travel to the lungs.
• Lung fibrosis caused by dermal absorption of paraquat had been described previously only with skin lesions before or after the injury.[20]
• The lungs are the target organ for paraquat, regardless of route of administration.
• There are numerous causes of pulmonary fibrosis (such as asbestosis, scleroderma, rheumatoid arthritis, etc.).
• The variants of pulmonary fibrosis do not all look alike clinically or pathologically, present alike, or progress alike.
• Ferebee had no known other disease or exposure that could account for his pulmonary fibrosis.
• There are cases of pulmonary fibrosis with no identifiable cause, known as idiopathic pulmonary fibrosis (IPF).
• IPF is relatively rare; it too has a rapid onset and progression, although arguably not as fast as the cases described after exposure to undiluted paraquat.
• Ferebee’s medical history was largely unhelpful in explaining his clinical course.
• Ferebee had some shortness of breath before starting to use paraquat.[21]
• Ferebee used or was exposed to paraquat occasionally over three years before he was diagnosed with pulmonary fibrosis.

These stipulated facts are rarely acknowledged in the discussion of the Ferebee case. The legal implications of these facts are far reaching. General causation in a sense was not contested. Paraquat causes pulmonary fibrosis. The issue was whether diluted paraquat through dermal exposure over three years causes pulmonary fibrosis, and whether this exposure caused Ferebee’s pulmonary fibrosis. Chevron stridently asserted that the “scientific method” required controlled experimental or observational (epidemiologic) studies. The problem with Chevron’s position was that general causation had already been established, and not by analytical epidemiologic studies. General causation between paraquat exposure of any kind and pulmonary fibrosis had been established by case reports, based upon close temporal proximity between exposure and pulmonary toxicity and fibrosis. Animal toxicology and mechanistic studies confirmed the toxicity observed in clinical studies.[22]

Because idiopathic pulmonary fibrosis is rare, the appearance of this disease in a series of exposed workers soon after they were exposed to a specific toxic chemical really did not require the rigors of analytical epidemiology. The causal analysis between paraquat and lung fibrosis was more akin to the analysis that is used to attribute liver failure to herbal exposure than the epidemiologic approach to the relationship between smoking and lung cancer. At the time of Ferebee’s exposure and his litigation, there was no serious dispute that paraquat caused pulmonary fibrosis when inhaled or swallowed, or that paraquat was absorbed dermally, or that the lung was a target organ of paraquat exposure of any sort.

6. The expert witnesses.

Ferebee was initially treated by Dr. Muhammed Yusuf, a pulmonary specialist, who diagnosed pulmonary fibrosis. Dr. Yusef referred Ferebee to the National Institutes of Health (NIH), where he came under the care of Dr. Ronald G. Crystal of the Heart, Lung, and Blood Institute. (Dr. Crystal is now Chairman of Genetic Medicine at Weill-Cornell Medical College, where he continues to practice pulmonary medicine.)

In the litigation, Chevron called Dr. Carrington, who diagnosed Ferebee with idiopathic pulmonary fibrosis. Dr. Carrington challenged the plaintiffs’ expert witnesses’ opinions for lacking reliance upon controlled observational or experimental studies.[23] Dr. Carrington, however, acknowledged that dermal cases are too rare for observational epidemiologic analysis, but emphasized that no animal studies of sufficient size had been done to support plaintiffs’ hypothesis. Chevron also called a Dr. Fisher, who presented a toxicokinetic (TK) analysis of Ferebee’s dermal absorption. Based upon his TK analysis, Dr. Fisher concluded that the maximal amount of paraquat absorbed by Ferebee was too small, based upon known cases and animal studies, to have caused paraquat toxicity with lung fibrosis.[24]

7. Chevron’s challenge to plaintiffs’ expert witnesses’ causation opinion.

None of the defendant’s expert witnesses examined Ferebee. The courts thought this was relevant, but the judicial opinions never articulated what would have been observed on physical examination that was important to resolving the differential diagnosis of paraquat toxicity versus IPF. There was no dispute that Ferebee had rapidly progressing pulmonary fibrosis. The expert witnesses on both sides evaluated Ferebee’s clinical data, presentation, clinical course, and arrived at different diagnoses, either paraquat-induced lung fibrosis or IPF. The plaintiffs’ expert witnesses’ diagnosis involved a causal attribution to paraquat exposure; the defendant’s expert witness’s diagnosis of IPF ruled out any causal toxic exposure.

The Ferebee case was litigated under Maryland law because federal statutory law requires state law to control in a wrongful death action arising out of the neglect or wrongful act of another on a federal enclave.[25] The choice of law had implications both for procedural and substantive law. Chevron appears to have relied upon Maryland’s articulation of the Frye general acceptance doctrine, and the courts analyzed Chevron’s arguments as a Frye challenge.[26] Under the Erie doctrine, a federal court should have applied its own procedural law to the case at hand, including Rule 702 of the Federal Rules of Evidence.[27] The use of Maryland law to determine an evidentiary issue in federal court was error.

Chevron pressed its challenge in terms of Maryland’s version of Frye, and not under Federal Rule of Evidence 702. The oft-repeated infamous language used by both the district and the circuit courts was, therefore, not an interpretation of federal law. Rule 702 was never cited or discussed in either the trial or the appellate court’s opinion. This oddity has profound implications for how we evaluate the Ferebee decision, and how it can be cited. Before the Supreme Court decided the Daubert case, the epistemic implications of Rule 702 were largely ignored. Defendants sometimes attempted to press the Frye twilight-zone general acceptance test into a rule of decision that would reject an expert witness’s opinion testimony.[28] The Frye case was decided by a federal appellate court, but superseded by the enactment of Rule 702, in 1975. Ferebee was, of course, decided before the Supreme Court breathed life into Rule 702, but Rule 702 was nonetheless the law when the Ferebee case was litigated.

8. The judicial resolution of  Chevron’s Frye challenge

The district court insightfully recognized that Chevron was demanding a level of evidence, which had never been required to establish paraquat’s generally accepted ability to cause pulmonary fibrosis. This recognition led to the district court’s rhetorical language:

“It is true that medical expert testimony must be grounded in proper scientific methodology, but the extremely stringent standard that defendant suggests is beyond reason. Product liability law, especially as it relates to relatively new products or those with a relatively rare yet significant danger, would be rendered next to meaningless if a plaintiff could prove he was injured by a product only after a ‘statistically significant’ number of other people were also injured. A civilized legal system does not require that much human sacrifice before it can intervene. The fact that this is the first case of this exact type – or at least the first of its exact type in which the involvement of paraquat was discovered by alert doctors – cannot be enough by itself to shield defendant from liability. Defendant’s experts were not able to fault Dr. Crystal for his basic diagnostic methodology; in fact, they used the same kinds of test results, consultations, and other tools that he did. What they disagreed with chiefly were his conclusions.”[29]

The important observation is that general causation had been established case series and reports of human exposure. There never was statistical evidence that had been evaluated for “significance,” to establish general causation for undiluted paraquat, and the trial court refused, under Maryland law, to require such evidence for general causation for diluted paraquat. In this context, we can see that the trial court’s suggestion that statistical significance was not required has little bearing upon cases in which general causation could only be established using epidemiologic evidence, with its attendant statistical inferences.

Of course, the matter only became worse when Chevron persisted in its argument and presented it to a panel of the D.C. Circuit. The litigants pulled a panel of what can be described as activist judges not known for their scientific acumen. Judge Mikva wrote the opinion for a panel that included Judge Wald, and Senior Judge Bazelon. The panel’s decision ratcheted up the district court’s rhetoric:

“Thus, a cause-effect relationship need not be clearly established by animal or epidemiological studies before a doctor can testify that, in his opinion, such a relationship exists. As long as the basic methodology employed to reach such a conclusion is sound, such as use of tissue samples, standard tests, and patient examination, product liability does not preclude recovery until a ‘statistically significant’ number of people have been injured or until science has had the time and resources to complete sophisticated laboratory studies of the chemical. In a courtroom, the test for allowing a plaintiff to recover is not scientific certainty, but legal sufficiency; if reasonable jurors could conclude from the expert testimony that paraquat more likely than not caused Ferebee’s injury, the fact that another jury might reach the opposite conclusion or that science would require more evidence before conclusively considering the causation question resolved is irrelevant. That Ferebee’s case may have been the first of its exact type, or that his doctors may have been the first alert enough to recognize such a case, does not mean that the testimony of those doctors, who are concededly well qualified in their fields, should not have been admitted.”[30]

Judge Mikva’s dichotomy between levels of certainty needed in science and in the law was false. On behalf of the plaintiff, Dr. Crystal had done much more than give a clinical diagnosis. His assessment of causality was informed by case series of exposure and lung fibrosis, along with physiological evidence of oral, inhalational, and dermal absorption and distribution to the lungs, with toxic effect soon after exposure.

The appellate court’s dismissive attitude towards statistically significant evidence is severely limited to the factual context of a causal analysis that had been made by scientists, to everyone’s satisfaction, for undiluted paraquat, without the need for epidemiologic, statistical evidence. Statistical significance was never really at issue. In this way, Ferebee resembles the untoward dictum on statistical significance from Matrixx Initiatives Inc. v. Siracusano,[31] where the Court held that causation was not at issue.

In Ferebee, causation was very much at issue, but it had been well established – and the subject of warnings – based upon clinical case reports of paraquat exposure and rapid development of lung fibrosis. Dermal absorption and systemic distribution with toxic effects in the lungs were well established, and not the stuff of epidemiologic proofs.

In both Ferebee and Matrixx Initiatives, statistical significance was never really at issue. In Ferebee, there was no statistical evidence needed or used to reach causal conclusions about paraquat’s ability to induce pulmonary fibrosis. In Matrixx Initiatives, allegations of statistical significance and causation were not necessary because the plaintiffs needed only to allege materiality of the facts suppressed by the company in order to plead a securities fraud case. The FDA could impose warnings or require a product recall on evidence that fell well short of establishing causality. Materiality thus could be established without causation, and neither causation nor statistical significance needed to be alleged.

As for Chevron’s Frye challenge, the district court rejected the implied call for a vote on the general acceptance of Dr. Crystal’s reasoning. Frye may require “vote counting” of some sort, but the process becomes irrelevant when virtually no one has registered to vote. Otherwise, both the defense and plaintiffs’ expert witnesses were indeed using the same technique of arguing by analogy to accepted cases of paraquat poisoning or IPF. Dr. Crystal opined that Ferebee’s case was “similar” to three other cases he had identified. Dr. Carrington argued that Ferebee’s case was more like IPF cases, although IPF cases themselves have some clinical heterogeneity as well. Most reported paraquat cases described onset of toxicity to death as a very rapid process. Ferebee did not present with significant symptoms for three years after his first exposure, and then he survived for another two plus years. Ferebee did not report skin lesions, which had been reported in previous cases of dermal exposure leading up to pulmonary fibrosis. On the other hand, there was no precise exposure assessment for Ferebee’s absorption of paraquat. The case presented, on the diagnostic level, with the implied causality, a difficult call, but it is easy to understand the courts’ impatience with the defendant’s insistence upon more stringent criteria and evidence than was used to establish the causal connection with undiluted paraquat. The ability of paraquat to cause pulmonary fibrosis had been well established based upon case reports, including case reports of dermal exposure to open sores, with documented systemic distribution with specific toxicity to the lung, regardless of the route of administration.

9. Expert witness qualifications.

Chevron never challenged Dr. Yusuf’s or Dr. Crystal’s qualifications, both of whom were highly accomplished and respected clinicians and scientists. Neither was a “hired gun.” The oft-quoted comments about expert witness qualifications were made in the context of describing the appellate court’s standard of review, and the court’s role in not assessing credibility or weighing the evidence:

“These admonitions apply with special force in the context of the present action, in which an admittedly dangerous chemical is alleged through long-term exposure to have caused disease. Judges, both trial and appellate, have no special competence to resolve the complex and refractory causal issues raised by the attempt to link low-level exposure to toxic chemicals with human disease. On questions such as these, which stand at the frontier of current medical and epidemiological inquiry, if experts are willing to testify that such a link exists, it is for the jury to decide whether to credit such testimony.”[32]

Remarkably, this language has been mistakenly invoked as a standard for trial courts to use in determining the admissibility of expert witness opinion testimony. It is no such thing. Some other observations are in order. Although Ferebee worked with diluted paraquat, his exposures were hardly low level. He described himself as drenched in the herbicide, without protective gear, and without his governmental supervisors ever directing him to shower and change clothing.

10. Preemption and Warnings Causation.

Ultimately, Chevron’s preemption defense was rejected by both the district and the circuit court. The defense’s claim of FIFRA preemption might have gone very differently today, after the Supreme Court’s decisive application of preemption to FIFRA labeling of glyphosate.[33]

Even more important in evaluating liability is the emphasis that both the district and the appellate courts gave to the important role of the employer in the case. The evidence showed that there was indeed a warning label that Ferebee had never read. The plaintiff’s case was thus in jeopardy of failing to show proximate causation between an allegedly inadequate warning and harm. The courts, however, emphasized the role that the employer, through its supervisors and responsible co-workers, play in the complex organizational situation of a modern workplace:

“Mr. Ferebee’s situation was quite different, however. He did not purchase paraquat for his personal use; rather, it was provided to him by his employer for use on the job. The evidence showed that his principal source of information about paraquat was the oral instructions of his supervisors and co-workers, not the written label. He learned from them how to mix the product and how to spray it. It was also from this source that he learned of the danger of getting the product in his mouth: one of his co-workers warned him that if he accidently swallowed paraquat, it would ‘get in his blood’ and poison him. This is a common pattern of instruction and use of occupational materials in the workplace. Learning by doing and learning by oral instruction are tried and true methods of educating manual workers in their jobs. Therefore, although it is crucial to plaintiff’s case that someone would have read the label, it was not necessary for Mr. Ferebee to have done so. And it is obvious that one or more employees at BARC did read the label, since information did reach Mr. Ferebee about the proportions for diluting the product and about the dangers about which the label did warn. It was appropriate for the jury to infer that a warning about the danger of fatal lung disease from dermal exposure would also have been communicated to Mr. Ferebee. See Restatement (Second) of Torts § 388 comment n (seller normally entitled to assume that adequate warning will be passed on by purchaser to ultimate user); cf. Chambers v. G.D. Searle & Co., 441 F.Supp. at 381 (in product liability case involving prescription drug, relevant warning is the one given to doctor, not patient).”[34]

There is significant irony in that the Ferebee case has been the subject of serious criticism from defense counsel, and yet it embraced Section 388, comment n, as well as applied the learned or sophisticated intermediary principles to a case not involving prescription drugs. The appellate court waxed enthusiastic about the principles of Section 388, and went so far as to cite the late Victor Schwartz in support:

“We live in an organizational society in which traditional common-law limitations on an actor’s duty must give way to the realities of society. *** In this case, Mr. Ferebee did not purchase the paraquat for his personal use, and there was substantial evidence that workplace communication about the dangers associated with various chemicals usually took the form of oral instructions from supervisors to workers, the latter of whom then retransmitted the information to co-workers. This, rather than individual reading of product warnings, is a typical method by which information is disseminated in the modern workplace. See Schwartz & Driver, “Warnings in the Workplace: The Need for a Synthesis of Law and Communication Theory,” 52 U. Cinn. L. Rev. 38, 66-83 (1983). The requirement that an improper warning proximately ‘cause’ the injury should be elaborated against this background. We believe Maryland would construe its tort law in this case to require only that someone in the workplace have read the label, not that Mr. Ferebee personally have read it. Because there is no dispute that one or more employees at BARC did read the label, we hold that the jury could properly have inferred that, had a warning about the danger of disease from dermal exposure been included on the label, that warning would have been communicated to Mr. Ferebee and that he would as a result have acted differently. Alternatively, the jury could have inferred that an adequate warning would have led Ferebee’s employers to undertake steps that would have protected him from paraquat poisoning-for example, provision of showers for use after spraying.”[35]

Judge Mikva’s prediction, of course, was accurate; Maryland tort law did, soon thereafter, embrace the sophisticated intermediary defense to exculpate the defendant in such remote supplier situations.[36] The principle invoked to excuse plaintiff from reading the warning label also works to exculpate the defendant when that warning label is otherwise adequate, or when the intermediary knows of the hazard in any event. Given that the employer was the federal government, including the scientists at EPA, OSHA, the National Institutes of Health, and the Public Health Service, as well as the plaintiff’s principal expert witness (Dr. Crystal), the employer had complete and superior knowledge to the seller about the known or knowable effects of diluted paraquat.[37]

---

[1]  Nathan Schachtman, Wells v. Ortho Pharmaceutical Corporation -A Dred Scott Case in Science Jurisprudence, ResearchGate (June 2026); DOI: 10.13140/RG.2.2.30242.18880

[2] Ferebee v. Chevron Chem. Co., 552 F. Supp. 1297 (D.D.C. 1982), aff’d, 736 F.2d 529 (D.C. Cir.), cert. denied, 469 U.S. 1062 (1984).

[3] Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).

[4] Willis Electric Co., Ltd. v. Polygroup Ltd., 166 F. 4th 1363, 1379, 1380-81 (Fed. Cir. 2026) (citing Ferebee, and declaring that the validity of assumptions underlying an expert witness’s methodology were fact questions for the jury, and not a a proper basis for excluding the challenged expert witness testimony). See also Barry v. DePuy Synthes Cos., 164 F.4th 896, 912 (Fed. Cir. 2026) (characterizing expert witness challenges to “purported flaws” in methodology as objections that “go to the weight the jury might accord to that evidence and not to its admissibility.”)

[5] Ferebee, 736 F.2d at 1531-32.

[6] Id. at 1532.

[7] 552 F. Supp. at 1295 & n. 3.

[8] Ferebee, 552 F. Supp. at 1294-95

[9] Ferebee, 736 F.2d at 1532.

[10] Id.

[11] 7 U.S.C. § 136, et seq.

[12] 7 U.S.C. § 136a(c)(5)(C).

[13] 7 U.S.C. § 136(bb).

[14] 7 U.S.C. § 136(q)(1)(E). See Ferebee 736 F.2d at 1539-40.

[15] 552. F. Supp. at 1304 n.40.

[16] Ferebee, 736 F.2d at 1536.

[17] Id.

[18] 552. F. Supp. at 1295 & n. 3.

[19] Ferebee, 552. F. Supp. at 1300 & n.28.

[20] Ferebee, 736 F.2d at 1538.

[21] Ferebee, 552. F. Supp. at 1295.

[22] See generally Leah Utyasheva, Prabath Amarasinghe & Michael Eddleston, Paraquat at 63 – the story of a controversial herbicide and its regulations: It is time  to put people and public health first when regulating paraquat, 25 BMC PUB. HEALTH 3089 (2025).

[23]  Ferebee, 552. F. Supp. at 1301.

[24] Id.

[25] 16 U.S.C. § 457; Ferebee, 736 F.2d at 1533.

[26] Ferebee, 552 F. Supp. at 1301; 736 F.2d at 1535.

[27] Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 589 & n.6 (1993). See also Cavallo v. Star Enterprise, 100 F.3d 1150, 1157-58 (4th Cir. 1996); Amorgianos v. National Railroad Passenger Corp., 303 F.3d 256 (2d Cir. 2002); Legg v. Chopra, 286 F.3d 286, 289-92 (6th Cir. 2002). See Erie R.R. Co. v. Tompkins, 304 U.S. 64 (1938); Hanna v. Plumer, 380 U.S. 460, 470 (1965) (Erie does not displace the application of federal procedural rules in federal courts).

[28] Frye v. United States, 293 F. 1013, 1014 (D.C.Cir.1923).

[29] Ferebee, 552 F. Supp. at 1301.

[30] Ferebee, 736 F.2d at 1535-36 (emphasis in original).

[31] 563 U.S. 27 (2011). See Nathan Schachtman & David Venderbush, Matrixx Unbounded:  High Court’s Ruling Needlessly Complicates Scientific Evidence Principles, 26(4) WASH. LEG. FDTN. LEG. BACKGROUNDER (2011).

[32] Ferebee, 736 F.2d at 1534.

[33] Monsanto v. Durnell, ___ U.S. ___, Slip op. (June 25, 2026), available at https://www.supremecourt.gov/opinions/25pdf/24-1068_n7ip.pdf

[34] Ferebee, 552 F. Supp. at 1303-04 (internal citations omitted).

[35] Ferebee, 736 F.2d at 1539 (emphasis in original; internal citation omitted).

[36] See, e.g., Kennedy v. Mobay Corp., 84 Md. App. 397 (1990) (applying sophisticated user defense to bar claims against manufacturers of toluene diisocyanate), aff’d, 325 Md. 385 (1992); Higgins v. E.I. DuPont de Nemours, Inc., 671 F. Supp. 1055 (D. Md. 1987) (Maryland law; holding that manufacturer of paint was in better position than bulk supplier to communicate warnings to customers’ employees), aff’d, 863 F.2d 1162 (4th Cir. 1988).

[37] See Miller v. Diamond Shamrock Co., 275 F.3d 414, 422-23 (5th Cir. 2001) (“There can be no reasonable dispute that knowledge possessed by the United States Public Health Service, … [and] the Navy’s Bureau of Medicine and Surgery is the knowledge of the military.”).