In 2005, the United States Supreme Court decided Bates v. Dow Agrosciences LLC, 544 U.S. 431 (2005), concerning preemption of state law failure to warn claims by the Federal Insecticide, Fungicide and Rodenticide Act, 7 U.S.C. §136 et seq. (“FIFRA”) For more than 10 years before Bates, Federal and State appellate courts nearly unanimously found such claims preempted by 7 U.S.C. §136v(b), which provides that a State “shall not impose or continue in effect any requirements for labeling or packaging in addition to or different from those required under this subchapter.” Because FIFRA requires all pesticide labels to be approved by the EPA, these courts held that an inadequate warning verdict would effectively require labeling “in addition to or different from” Federal requirements.

The Supreme Court rejected this reasoning in Bates. It held that a state law labeling requirement is not preempted “if it is equivalent to, and fully consistent with, FIFRA’s misbranding provisions” because such requirements are equivalent to FIFRA’s requirements that a pesticide label must not contain false or misleading statements.” However, the Court also emphasized that a state-law labeling requirement “must in fact be equivalent to a requirement under FIFRA in order to survive preemption,” and that state law requirements “must also be measured against any relevant EPA regulations that give content to FIFRA’s misbranding standards.” 544 U.S. 431, 453. Accordingly, it remanded the case for the lower courts to determine whether the plaintiffs’ failure to warn claims were in fact preempted. Bates clearly mandates a case-by-case, factual assessment of preemption claims, but offers little guidance about how the “equivalent in fact” test should be applied in practice.

Not surprisingly, post-Bates FIFRA preemption case law has been far from consistent. Some Courts have seemed to consider any failure to warn that passes muster under section 2 of The Restatement (Third) of Torts: Product Liability to be “equivalent” to a FIFRA misbranding claim. See Indian Brand Farms, Inc. v. Novartis Crop Protection, Inc., 617 F.3d 207 (3d Cir. 2010). Others have appeared to treat any failure to warn claim based on inadequate labeling to “impose a labeling requirement not found among FIFRA’s statutory requirements.” See In re Syngenta AG MIR 162 Corn Litigation, 131 F. Supp. 3d 1177 (D. Kansas 2015). This inconsistency leaves pesticide sellers uncertain about whether, and if so, under what circumstances, warning claims against them are preempted.

Proper consideration of FIFRA preemption should include the Supreme Court’s subsequent holding in Riegel v. Medtronic, Inc., 552 U.S.312 (2008), interpreting similar pre-emption language in the Medical Device Amendments of 1976, 21 U.S.C. §360c et seq. In Riegel, the Court reaffirmed that a Federal statutes preempting state law “requirements” include common law tort claims, saying that excluding such claims from the scope of preemption “would make little sense.” It also questioned allowing lay juries to assess the merits of regulated products, saying that a jurysees only the cost of a more dangerous design, and is not concerned with its benefits.” 552 U.S. 312, 325.

As discussed above, the Supreme Court emphasized in Bates that common law warning claims must be measured against relevant EPA regulations that give content to FIFRA’s misbranding standards. EPA regulations state that the agency will only register a pesticide if it has determined that the product is not misbranded as that term is defined in FIFRA and that its labeling and packaging comply with the applicable requirements of the Act and the relevant regulations. 40 CFR §152.112(f). EPA’s pesticide labeling regulations are set forth in 40 CFR Part 156 and elaborated in detail in its published Label Review Manual (available on line at Thus, while EPA’s registration of a pesticide and acceptance of its label is not dispositive, failure to warn litigants should be prepared to address whether the EPA erred in determining that the product was not misbranded.

The lesson for pesticide sellers and practitioners is that failure to warn and inadequate warning claims involving registered pesticides under the Bates “equivalent in fact” standard rarely can be properly decided based solely on the allegations of the pleadings. Rather, a careful analysis of the precise nature of the claim asserted, based on an adequate fact record, will usually be necessary to determine the issue.