David Schaffner, Jr. v. Monsanto Corp

                                      PRECEDENTIAL

      UNITED STATES COURT OF APPEALS
           FOR THE THIRD CIRCUIT
                _____________

                    No. 22-3075
                   _____________

DAVID SCHAFFNER, JR.; THERESA SUE SCHAFFNER

                          v.

           MONSANTO CORPORATION
                                            Appellant
                   _____________

    On Appeal from the United States District Court
       for the Western District of Pennsylvania
            (D.C. Civil No. 2:19-cv-01270)
    Magistrate Judge: Honorable Cynthia R. Eddy
                   _____________

               Argued October 19, 2023
                  ______________

Before: CHAGARES, Chief Judge, PHIPPS and CHUNG,
                Circuit Judges

               (Filed August 15, 2024)
                   _____________
Michael X. Imbroscio
David M. Zionts [ARGUED]
Covington & Burling
850 10th Street NW
One City Center
Washington, DC 20001

Kenneth L. Marshall
Bryan Cave Leighton Paisner
Three Embarcadero Center
7th Floor
San Francisco, CA 94111

      Counsel for Appellant

Shannen W. Coffin
Sara Beth Watson
Mark C. Savignac
Steptoe & Johnson
1330 Connecticut Avenue NW
Washington, DC 20036

      Counsel for Amicus Curiae Croplife America in
      Support of Appellant

William R. Stein
Alex Bedrosyan
Hughes Hubbard & Reed
1775 I Street NW
Suite 600
Washington, DC 20006




                              2
      Counsel for Amici Curiae Chamber of
      Commerce of the United States of America,
      Pharmaceutical Research and Manufacturers of
      America, and Products Liability Advisory
      Council Inc. in Support of Appellant

Charles L. Becker [ARGUED]
Ruxandra M. Laidacker
Tobias L. Milrood
Kline & Specter
1525 Locust Street
19th Floor
Philadelphia, PA 19102

Adrian N. Roe
First Floor
428 Boulevard of the Allies
Pittsburgh, PA 15219

Michael D. Simon
Law Office of Michael D. Simon
2520 Mosside Boulevard
Monroeville, PA 15146

      Counsel for Appellees

Patti A. Goldman
Earthjustice Legal Defense Fund
810 Third Avenue
Suite 610
Seattle, WA 98104




                              3
Alexis Andiman
Peter Lehner
Earthjustice
48 Wall Street, 19th Fl.
New York, NY 10043

Carrie Apfel
Earthjustice
1001 G Street NW, Suite 1000
Washington, DC 20001

Alisa Coe
Earthjustice
111 S Martin Luther King Jr. Blvd
Tallahassee, FL 32301

       Counsel for Amici Curiae Farmworker
       Association of Florida, Farmworker Justice,
       Migrant Clinicians Network, Pesticide Action
       Network, United Farm Workers, and UFW
       Foundation in Support of Appellees

Leah M. Nicholls
Public Justice
1620 L Street NW
Suite 360
Washington, DC 20036

Jeffrey R. White
American Association for Justice
777 6th Street NW
Suite 200
Washington, DC 20001




                             4
      Counsel for Amici Curiae Public Justice and the
      American Association for Justice in Support of
      Appellees


Adina H. Rosenbaum
Allison M. Zieve
Public Citizen Litigation Group
1600 20th Street NW
Washington, DC 20009

      Counsel for Amicus Curiae Public Citizen in
      Support of Appellees

Robin L. Greenwald
James J. Bilsborrow
Weitz & Luxenberg
700 Broadway
New York, NY 10003

      Counsel for Amicus Curiae Roundup MLD Co-
      Lead Counsel in Support of Appellees

                      _____________

                OPINION OF THE COURT
                    _____________

CHAGARES, Chief Judge.

      This appeal presents the question of whether, once the
Environmental Protection Agency (“EPA”) registers and
approves a pesticide label that omits a particular health




                             5
warning, a state-law duty to include that warning is preempted
by a federal statute expressly preempting any state-law
pesticide labeling requirement that differs from or adds to the
requirements imposed under federal law. Plaintiffs David
Schaffner, Jr. and Theresa Sue Schaffner allege that defendant
Monsanto Company (“Monsanto”)1 violated Pennsylvania law
by omitting a cancer warning from the label of its weed-killer,
Roundup (the “Cancer Warning”). But the Federal Insecticide,
Fungicide, and Rodenticide Act (“FIFRA”), 

 et
seq., the federal statute that regulates pesticides such as
Roundup, mandates nationwide uniformity in pesticide
labeling by prohibiting states from imposing labeling
requirements that are in addition to or different from the
requirements imposed under FIFRA itself. This provision,
Monsanto argues, preempts the Pennsylvania duty to warn that
it allegedly breached. Because regulations promulgated to
implement FIFRA require the health warnings on a pesticide’s
label to conform to the proposed label approved by the EPA
during the registration process (the “Preapproved Label”), and
because during Roundup’s registration process the EPA
approved proposed labels omitting a cancer warning following
an extensive review of scientific evidence concerning
Roundup’s possible carcinogenicity, we conclude that the
alleged state-law duty to include the Cancer Warning on
Roundup’s label (the “Pa. Duty to Warn”) imposes
requirements that are different from those imposed under
FIFRA, and that it is therefore preempted by FIFRA. The

1
  Although Monsanto was sued under the name “Monsanto
Corporation,” it is in fact named “Monsanto Company.” See,
e.g., Bayer, Bayer Closes Monsanto Acquisition (June 7,
2018),     https://www.bayer.com/media/en-us/bayer-closes-
monsanto-acquisition [https://perma.cc/XVX7-R69B].




                              6
judgment in the Schaffners’ favor that was stipulated to by the
parties and entered by the District Court reflected a prior
ruling, issued during consolidated multi-district pretrial
proceedings held in an out-of-circuit judicial district, that
FIFRA did not preempt state-law tort duties to include the
Cancer Warning on the Roundup label. We will therefore
reverse the judgment of the District Court.

        We first provide background in Part I, addressing
pesticide regulation under FIFRA, the dispute over Roundup’s
carcinogenicity, and the Schaffners’ claims in this case, then
we discuss our jurisdiction and the standard of review in Part
II. In Part III, we consider and reject the Schaffners’ arguments
that certain doctrines require our decision in this case to
conform to the prior rejection of Monsanto’s preemption
theory by other courts in other litigation. Instead, we conclude
that we must independently interpret FIFRA’s express
preemption scheme ourselves. We present our interpretation
in Part IV, applying it to conclude that the Schaffners’ claims
are expressly preempted by FIFRA. An EPA regulation
promulgated pursuant to FIFRA (the “Preapproval
Regulation”) prohibits modifying the health warnings included
on a pesticide’s Preapproved Label, see 

(a),
and the exceptions to the Preapproval Regulation would not
permit the addition of the Cancer Warning to the Roundup
label. This prohibition, we hold, imposes a “requirement” for
the purposes of FIFRA’s preemption provision. Because the
Pa. Duty to Warn is not equivalent to that federal regulatory
requirement, it is expressly preempted. Lastly, we explain in
Part V why we are unpersuaded by the Schaffners’ arguments
that FIFRA cannot preempt a state-law duty to include a
particular health warning on a pesticide’s label by virtue of the
omission of that warning on the pesticide’s Preapproved Label.




                               7
                       I.    Background2

                            A.   FIFRA

         FIFRA is a “comprehensive regulatory statute” that
governs “the use, as well as the sale and labeling, of pesticides;
regulate[s] pesticides produced and sold in both intrastate and
interstate commerce; provide[s] for review, cancellation, and
suspension        of     registration;    and     [gives      the]
EPA . . . enforcement authority.” Ruckelshaus v. Monsanto
Co., 

 (1984). FIFRA both regulates
pesticides directly and grants the EPA additional authority to
supervise the pesticide industry. One such direct regulation is
FIFRA’s prohibition on distributing or selling “any pesticide
which is . . . misbranded.” 7 U.S.C. § 136j(a)(1)(E). And one
of the many ways in which a pesticide may be misbranded is
for its label to omit “a warning or caution statement which may
be necessary and if complied with . . . is adequate to protect
health and the environment.” Id. § 136(q)(1)(G). FIFRA
thereby directly prohibits the distribution of pesticides whose
labels fail to include warnings necessary to protect human
health.

       The pesticide registration process is among the methods
through which FIFRA authorizes the EPA to supervise the
pesticide industry. FIFRA prohibits the distribution or sale of
any pesticide that has not been registered, id. § 136a(a), and it
establishes procedures by which pesticides may be registered

2
 These facts, which are not materially disputed by the parties,
are drawn from allegations in the complaint, as well as from
documents issued by the EPA and other relevant public
agencies.




                                 8
with the EPA, see generally id. § 136a(c). An applicant for
registration must first file with the EPA a statement containing
information about the pesticide to be registered, including its
formula and a complete copy of its proposed labeling, the
“claims to be made for it,” and the directions for its use. Id.
§ 136a(c)(1)(C)-(D). That statement must be accompanied by
supporting data, as required by the EPA and by guidelines that
FIFRA authorizes the EPA to promulgate. Id. § 136a(c)(2).
The EPA registers the pesticide upon determining that it
satisfies a number of conditions, including that its labeling
complies with FIFRA’s requirements. Id. § 136a(c)(5). The
EPA further determines whether to classify the pesticide for
general use or whether instead to restrict its use. Id. § 136a(d).

       The information submitted to the EPA during a
pesticide’s registration process under FIFRA determines in part
how the pesticide may be marketed following its registration.
For example, when it is distributed or sold, a registered
pesticide’s composition may not differ from the composition
described in the statement submitted as part of its application
for registration. Id. § 136j(a)(1)(C). Similarly, the claims
made for the pesticide as part of its distribution or sale may not
differ substantially from the claims made for it in its
registration statement. Id. § 136j(a)(1)(B). Most relevant here,
unless certain exceptions apply, the Preapproval Regulation
requires that an application for an amended registration be
submitted when a registered pesticide’s labeling is modified
from its Preapproved Label. See 

(a)
(“[A]ny modification in the . . . labeling . . . of a registered
product must be submitted with an application for amended
registration.”). And the pesticide may not be distributed or sold
with the modified label until the EPA approves the amended
registration. See 

 (“If an application for amended




                                9
registration is required, the application must be approved by
the Agency before the product, as modified, may legally be
distributed or sold.”).

       The EPA’s supervision of a pesticide does not end once
it approves an application to register that pesticide. In the 1988
amendments to FIFRA, see generally Federal Insecticide,
Fungicide, and Rodenticide Act Amendments of 1988, 

 Stat. 2654, Congress required the EPA to
reregister any pesticide (save for those falling within certain
exceptions not relevant here) with an active ingredient
contained in a pesticide first registered before November 1984.
See 7 U.S.C. § 136a-1(a). And in the 2007 amendments to
FIFRA, see generally Pesticide Registration Improvement
Renewal Act, 

 Stat. 1000 (2007),
Congress required the EPA to conduct a registration review for
each pesticide every fifteen years. See 7 U.S.C. § 136a(g). In
addition, FIFRA obligates a registrant to inform the EPA if,
following registration, it learns of new information concerning
a pesticide’s environmental risks. Id. § 136d(a)(2). The EPA
may, on its own initiative, revisit its decision to register a
pesticide should it conclude at any time that the pesticide can
no longer meet the requirements for registration. See generally
id. § 136d(b).

                         B.   Roundup

       In 1974, Monsanto introduced the pesticide Roundup, a
weed-killer that employs glyphosate as its active ingredient.
Since then, the EPA has repeatedly evaluated the health risks
posed by glyphosate. It first assessed the carcinogenicity of
glyphosate in 1985, when it classified the chemical as
“possibly carcinogenic to humans.” Joint Appendix (“JA”) 43,




                               10
954. The following year, a scientific advisory panel concluded
that glyphosate’s human carcinogenicity could not yet be
classified and suggested a review of additional data. Following
the submission of further studies, in 1991 the EPA reclassified
glyphosate as a chemical for which there exists “evidence of
non-carcinogenicity for humans.” JA 955. It has not altered
that conclusion since. More recently, its Cancer Assessment
Review Committee reviewed scientific data about glyphosate
in 2015 and concluded that the pesticide was “not likely to be
carcinogenic to humans.” Id. And in January 2020, it issued
an interim decision in its review of glyphosate’s registration,
finding once again that glyphosate is not likely to be
carcinogenic to humans. That portion of the EPA’s interim
decision has since been vacated by the Court of Appeals for the
Ninth Circuit. Nat. Res. Def. Council v. U.S. Env’t Prot.
Agency, 

, 45 (9th Cir. 2022).

       Others have disagreed with the EPA’s view that
glyphosate is not carcinogenic, however. The International
Agency for Research on Cancer (“IARC”), which forms part
of the World Health Organization, concluded in 2015 than
glyphosate is probably carcinogenic to humans. See Kathryn
Z. Guyton et al., Carcinogenicity of Tetrachlorvinphos,
Malathion, Palathion, Diazinon, and Glyphosate, 16 Lancet
Oncology 490 (2015) (announcing the IARC’s conclusion);
Int’l Agency for Rsch. on Cancer, World Health Org., IARC
Monographs on the Evaluation of Carcinogenic Risks to
Humans No. 112: Some Organophosphate Insecticides and
Herbicides 321-99 (2017). The IARC further noted that non-
Hodgkin’s lymphoma is among the types of cancer most
closely associated with glyphosate.




                              11
        Following the IARC’s announcement of its findings,
plaintiffs across the United States began filing lawsuits against
Monsanto to seek compensation for cancers allegedly caused
by their use of Roundup. See In re Roundup Prods. Liab.
Litig., 

 (J.P.M.L. 2016) (listing
actions filed as of October 3, 2016). In 2016, Monsanto moved
to dismiss in one such case on the theory that any state-law
duty to warn of Roundup’s carcinogenicity was expressly
preempted by FIFRA’s preemption provision. See Mot. to
Dismiss at 5-10, Hardeman v. Monsanto Co., No. 16 Civ. 525
(VC) (N.D. Cal. Mar. 1, 2016). The motion was denied in
April of 2016. Hardeman v. Monsanto Co. (Hardeman I), 

 (N.D. Cal. 2016).

        In October 2016, the Judicial Panel on Multi-District
Litigation (“JPML”) responded to the growing wave of
Roundup litigation by centralizing pretrial proceedings for
lawsuits alleging that Roundup can cause non-Hodgkin’s
lymphoma and that Monsanto had failed to warn adequately of
that risk. In re Roundup Prods. Liab. Litig., 

. As the venue for the MDL, the JPML chose the
United States District Court for the Northern District of
California (the “MDL Court”) — the same court that had
already heard, and rejected, Monsanto’s express preemption
argument.3 

. The first bellwether trial was later held

3
 In addition to the argument described here, which was raised
by Monsanto and rejected by the MDL Court in 2016,
Monsanto raised a second express preemption argument in its
January 2019 motion for summary judgment, which the MDL
Court denied in March 2019. In re Roundup Prods. Liab.
Litig., 

 (N.D. Cal. 2019). That
argument relied on details of California products liability law.




                               12
before the MDL Court featuring the same plaintiff, Edwin
Hardeman, against whom Monsanto had first raised its express
preemption arguments in 2016. See Hardeman v. Monsanto
Co. (Hardeman II), 

 (9th Cir. 2021). At that
trial, a jury found Monsanto liable for failing to warn of
Roundup’s carcinogenicity. 

 It awarded compensatory
damages of over $5 million and punitive damages of $75
million, the latter of which were reduced to $20 million by the
MDL Court. 

 Monsanto appealed that judgment on multiple
grounds, including by challenging the MDL Court’s rejection
of its preemption arguments. 

 The Court of Appeals for the
Ninth Circuit affirmed, holding that FIFRA did not preempt the
California duty to warn that Monsanto was found liable for
violating. 

 The Supreme Court denied Monsanto’s petition
for certiorari. Monsanto Co. v. Hardeman, 

(2022).

        While the JPML centralized pretrial proceedings for
Roundup cases involving non-Hodgkin’s lymphoma, cases
involving other types of cancer remained in the districts in
which they were filed. Among them is Carson v. Monsanto
Co., which was filed in the Southern District of Georgia in
December 2015, and which involves malignant fibrous
histiocytoma rather than non-Hodgkin’s lymphoma. See
Carson v. Monsanto Co., (Carson I), 

,
1373 (S.D. Ga. 2020). In Carson I, Monsanto moved for
judgment on the pleadings using the same express-preemption
arguments that the MDL Court had rejected in Hardeman I, and
the district court dismissed the plaintiff’s failure-to-warn claim
on the grounds that it was expressly preempted by FIFRA. 

As the present case does not concern California law, Monsanto
unsurprisingly has not raised that argument before this Court.




                               13
at 1375-76. The plaintiff appealed after amending his
complaint to withdraw the claims that remained. See Carson
v. Monsanto Co. (Carson II), 

 (11th Cir.
2022).4 A panel of the Court of Appeals for the Eleventh
Circuit reversed, holding that the district court had
misapprehended the types of agency action that can preempt
state law pursuant to FIFRA’s express preemption provision.

. Sitting en banc, that court then vacated and
remanded Carson II, holding that the panel had improperly
relied on the law of implied preemption to analyze Monsanto’s
doctrinally distinct express-preemption arguments. Carson v.
Monsanto Co. (Carson III), 

 (11th Cir.
2023) (en banc). The original panel then held, on remand, that
the doctrines it had derived from implied-preemption
precedents in Carson II also apply, independently, to express
preemption under FIFRA. Carson v. Monsanto Co. (Carson
IV), 

 (11th Cir. 2024). On that basis, the
court reversed Carson I’s holding that FIFRA expressly
preempts failure-to-warn claims premised on Monsanto’s
failure to include the Cancer Warning on the Roundup label.

.

                     C.   The Schaffners

     David Schaffner, Jr. was diagnosed with non-Hodgkin’s
lymphoma in 2006. Prior to his diagnosis, he was exposed to
Roundup both in his work as a professional landscaper and in

4
  Carson II vacated and superseded an earlier opinion issued by
the same panel in the same year. See Carson II, 

, vacating Carson v. Monsanto Co., 

 (11th
Cir. 2022). Because the two opinions differ only in minor
ways, we will not further discuss the panel’s initial opinion.




                              14
his capacity as a property owner. Theresa Sue Schaffner, his
wife, suffered loss of consortium due to Mr. Schaffner’s
illness. In May 2019, the Schaffners filed a lawsuit against
Monsanto in the Court of Common Pleas of Allegheny County,
Pennsylvania, asserting six state-law causes of action,
including one for failure to warn. Monsanto removed the case
to the United States District Court for the Western District of
Pennsylvania in October 2019, and the following month the
JPML transferred the case to the Northern District of
California. Because the MDL court had instructed the parties
not to relitigate issues that it had already decided, Monsanto
moved for summary judgment on preemption grounds merely
by incorporating its earlier briefing before the MDL Court on
that question, and the Schaffners opposed the motion on the
same basis. The MDL Court denied the motion for the same
reasons that it had relied upon in its earlier rejection of
Monsanto’s arguments. It then filed a suggestion of remand to
the Western District of Pennsylvania, and the case was
remanded to that court in March 2022.

        Following the remand, the parties consented for all
further proceedings in the District Court to be held before Chief
Magistrate Judge Cynthia Reed Eddy pursuant to 

(c).5 The Schaffners moved with Monsanto’s consent to
amend their complaint by removing all causes of action besides
their claim for failure to warn, and the District Court granted
that motion. The parties then jointly stipulated to the entry of
judgment against Monsanto, with the express understanding
that Monsanto reserved the right to appeal from — and
intended to appeal from — the MDL Court’s orders rejecting
its preemption arguments. As the stipulation explained, while

5
    For ease of reference, we refer simply to the District Court.




                                 15
the parties remained adverse and in disagreement with respect
to those orders, they had reached a settlement with respect to
all other aspects of the suit, and Monsanto had agreed to pay
the Schaffners an amount that would depend on the ultimate
result of the appeal. Pursuant to that stipulation, the District
Court entered judgment in favor of the Schaffners. This timely
appeal followed.

           II.   Jurisdiction and Standard of Review

        The District Court had jurisdiction over the Schaffners’
claims under 

, and we have jurisdiction over
Monsanto’s appeal from the judgment entered against it under

. While that judgment was stipulated to by
the parties, we held in Keefe v. Prudential Property & Casualty
Insurance Co., 

 (3d Cir. 2000), that we may
exercise jurisdiction over an appeal from a stipulated judgment
so long as the parties “are truly adverse with respect to the
critical legal issue that they ask us to resolve, . . . the dispute
between them is not feigned[,] . . . [and] both parties have a
significant stake in the outcome.” 

. We have
reviewed the confidential settlement agreement between the
parties to this case to verify that those conditions are met, and
we are satisfied that we have jurisdiction.

        In an appeal taken once “final judgment has been
entered, . . . claims of district court error at any stage of the
litigation may be ventilated.” Dupree v. Younger, 

 (2023) (quoting Quackenbush v. Allstate Ins. Co., 

 (1996)). Monsanto’s appeal therefore draws in
question the MDL Court’s order denying its motion for
summary judgment on preclusion grounds. That order, in turn,
incorporated by reference the MDL Court’s prior order




                                16
rejecting certain of Monsanto’s preclusion arguments with
respect to other cases that also formed part of the MDL. And
that earlier order itself incorporated by reference an even
earlier order also rejecting Monsanto’s preemption arguments,
which the MDL Court issued in Hardeman before pre-trial
proceedings in that case were centralized with others in the
MDL. Consequently, the MDL Court’s rulings on preemption
are properly before us in this appeal. We review questions of
preemption de novo. Sikkelee v. Precision Airmotive Corp.,

 (3d Cir. 2016).

                III. The Effect of Hardeman II

       Before considering Monsanto’s contention that FIFRA
preempts the Pa. Duty to Warn, however, we first address the
Schaffners’ two arguments that the Court of Appeals for the
Ninth Circuit’s rejection of Monsanto’s position in Hardeman
II binds us in this case. Schaffner Br. 47-55. Neither argument
is compelling.

       We begin with the law-of-the-case doctrine, under
which “one panel of an appellate court generally will not
reconsider questions that another panel has decided on a prior
appeal in the same case.” In re Phila. Litig., 

(3d Cir. 1998). The Court of Appeals for the Ninth Circuit
decided in Hardeman II that FIFRA does not preempt a state-
law failure-to-warn claim premised on the omission of the
Cancer Warning from Roundup’s label. 

.
The Schaffners therefore conclude that this Court should not
reconsider the question. Schaffner Br. 53-54. The law-of-the-
case doctrine, however, applies only when a question has been
decided in “a prior appeal in the same case.” In re Phila. Litig.,

 (emphasis added). As we recently held in




                               17
Home Depot USA, Inc. v. Lafarge North America, Inc., 

 (3d Cir. 2022), “[c]ases centralized in an MDL ‘retain
their separate identities’ unless they choose to proceed on a
consolidated ‘master’ complaint,” and the law-of-the-case
doctrine therefore cannot be applied across distinct actions in
an MDL. 

 at 61 (quoting Gelboim v. Bank of Am. Corp.,

, 413 & n.3 (2015)). Because Hardeman and the
present case remain distinct despite having been centralized in
the same MDL, a holding issued in the former is not binding as
the law of the case upon this Court.

        We next turn to issue preclusion, which “prevents
parties from relitigating an issue that has already been actually
litigated.” Peloro v. United States, 

 (3d Cir.
2007).6 There are four general “prerequisites for the

6
   “[T]he law of the issuing court — here, federal law —
determines the preclusive effects of a prior judgment.” Peloro,

 n.11 (quotation marks omitted). Nonetheless,
in some contexts federal law provides that the preclusive effect
of a federal-court judgment must follow state law rather than
being determined independently as a matter of federal common
law. In particular, the Supreme Court has held that the law of
the state in which a federal court sits determines the claim-
preclusive effect of the judgments that court issues pursuant to
its diversity jurisdiction. Semtek Int’l Inc. v. Lockheed Martin
Corp., 

 (2001). That principle could
conceivably be extended to require state law also to determine
the issue-preclusive effect of judgments issued by a federal
court sitting in diversity, such as the judgment issued in
Hardeman II. See, e.g., CSX Transp., Inc. v. Gen. Mills, Inc.,

 (11th Cir. 2017). But because the parties
have each framed their arguments concerning issue preclusion




                               18
application of issue preclusion”: “(1) the issue sought to be
precluded is the same as that involved in the prior action; (2)
that issue was actually litigated; (3) it was determined by a final
and valid judgment; and (4) the determination was essential to
the prior judgment.” Nat’l R.R. Passenger Corp. v. Pa. Pub.
Util. Comm’n, 

, 525 (3d Cir. 2002) (cleaned up).
The Schaffners argue that each of these four is met, Schaffner
Br. 49-52, and Monsanto does not appear to dispute the point,
see Monsanto Reply 21-26.

       Even when those four prerequisites are met, however,
issue preclusion “is subject to a number of equitable exceptions
designed to assure that the doctrine is applied in a manner that
will serve the twin goals of fairness and efficient use of private
and public litigation resources.” Nat’l R.R. Passenger Corp.,
288 F.3d at 525. The scope of a court’s equitable discretion
depends on whether all parties to the subsequent case were also
parties to the prior one, which is referred to as mutuality, and
on whether preclusion favors the plaintiff or the defendant in


using this Court’s own precedents, not California law, see
Schaffner Br. 48-49; Monsanto Reply 21-26, we decline to
consider whether California law should govern. See Williams
v. BASF Catalysts LLC, 

 (3d Cir. 2014)
(holding that by briefing and relying on one sovereign’s law, a
party waives any argument that the law of a different sovereign
should apply, as while “litigants may not waive issues that go
to the power of the courts to hear a case,” “choice-of-law
questions do not go to the court’s jurisdiction”); Hammersmith
v. TIG Ins. Co., 

, 227 n.2 (3d Cir. 2007) (“Because
the parties only argued the choice-of-law issue with respect to
New York and Pennsylvania, we will not consider Texas in our
choice-of-law analysis.”).




                                19
the second suit, which distinguishes offensive uses of
preclusion from defensive ones. 

 The application of issue
preclusion in favor of the Schaffners would be offensive and
non-mutual, as the Schaffners are the plaintiffs, and they were
not parties in Hardeman. Courts enjoy particularly broad
discretion in deciding whether to employ issue preclusion in
offensive, non-mutual contexts. Jean Alexander Cosmetics,
Inc. v. L’Oreal USA, Inc., 

 (3d Cir. 2006)
(citing Parklane Hosiery Co. v. Shore, 

(1979)).

        To identify which equitable factors should guide a
court’s application of issue preclusion in general, we have
relied upon the relevant provisions of the Restatement
(Second) of Judgments (“Second Restatement”), see, e.g.,
Nat’l R.R. Passenger Corp., 288 F.3d at 525, as has the
Supreme Court, see, e.g., Standefer v. United States, 

, 23 & n.17, 25 (1980). The specific factors to be applied in
cases of non-mutual issue preclusion, offensive or defensive,
are identified in section 29 of the Second Restatement.
Monsanto argues that one such factor weighs decisively
against applying issue preclusion to its preemption arguments.
Whether FIFRA preempts a state-law duty to provide a health
warning given the omission of that warning from a pesticide’s
Preapproved Label is a pure question of law. And in cases of
non-mutual issue preclusion one of the “circumstances [that]
justify affording [a party] an opportunity to relitigate the issue”
sought to be precluded is that “[t]he issue is one of law and
treating it as conclusively determined would inappropriately
foreclose opportunity for obtaining reconsideration of the legal
rule upon which it was based.” Restatement (Second) of
Judgments § 29(7) (Am. L. Inst. 1982). Applying issue
preclusion to a pure question of law, the Second Restatement




                                20
reasons, risks impeding a court from discharging “its function
of developing the law.” Id. cmt. i. Furthermore,

       This consideration is especially pertinent
       when . . . the issue was determined in an
       appellate court whose jurisdiction is coordinate
       with or subordinate to that of an appellate court
       to which the second action can be taken; or when
       the issue is of general interest and has not been
       resolved by the highest appellate court that can
       resolve it.

Id. The Second Restatement therefore advises that “the rule of
preclusion should ordinarily be superseded” when either of
those circumstances is present. Id.

       These principles have been applied by multiple other
United States Courts of Appeals, see, e.g., In re Westmoreland
Coal Co., 

 (5th Cir. 2020); Pharm. Care
Mgmt. Ass’n v. District of Columbia, 

(D.C. Cir. 2008); Af-Cap, Inc. v. Chevron Overseas (Congo)
Ltd., 

 (9th Cir. 2007); Chi. Truck Drivers,
Helpers, & Warehouse Union (Indep.) Pension Fund v.
Century Motor Freight, Inc., 

, 531 (7th Cir. 1997),
as well as by the highest courts of multiple states, see Planned
Parenthood of the Heartland, Inc. v. Reynolds ex rel. State, 

, 729-30 (Iowa 2022); NIPSCO Indus. Grp. v. N.
Ind. Pub. Serv. Co., 

 (Ind. 2018);
Bowen ex rel. Doe v. Arnold, 

 (Tenn.
2016). And we are unaware of any decision of such a court
that has considered these principles and either rejected them as
invalid or expressly declined to apply them to facts analogous
to those before us now. We join this consensus and hold that




                              21
section 29(7) of the Second Restatement, along with its
elaboration in comment i to that section, identifies an equitable
factor that courts may consider in deciding whether to apply
issue preclusion non-mutually. Applying the principles
articulated in that section, we conclude that both circumstances
requiring that “the rule of preclusion should ordinarily be
superseded,” Restatement (Second) of Judgments § 29 cmt. i,
are present. The appellate courts to which appeals were taken
in Hardeman and in this case — respectively, the Court of
Appeals for the Ninth Circuit and this Court — have coordinate
jurisdiction. See Hoffman v. Blaski, 

, 340 n.9
(1960). And the issue presented by this case, which is clearly
of general interest, has yet to be decided by the highest court
capable of resolving it — the United States Supreme Court.
We therefore follow the Second Restatement in exercising our
“broad discretion to determine when to apply non-mutual
offensive [issue preclusion].” Jean Alexander Cosmetics, 

. We decline to apply issue preclusion and instead
develop the law of express preemption under FIFRA
ourselves.7

           IV. Express Preemption Under FIFRA

       The provision of FIFRA governing “uniformity”
provides that no state shall “impose or continue in effect any
requirements for labeling or packaging in addition to or
different from those required under this subchapter.” 7 U.S.C.

7
  In addition, one Justice of the Supreme Court has expressed
“serious doubts about the application of nonmutual offensive
[issue preclusion] in the MDL context.” See E.I. du Pont de
Nemours & Co. v. Abbott, 

, 16 (2023) (Thomas,
J., dissenting from denial of petition for writ of certiorari).




                               22
§ 136v(b).      Monsanto argues that because Roundup’s
Preapproved Label omitted the Cancer Warning, any state-law
requirement to include it on the Roundup label is “in addition
to or different from” the labeling requirements imposed under
FIFRA, and thus is preempted.8 Monsanto Br. 25-47. We
begin our analysis by discussing the principles the Supreme
Court has articulated to govern whether a suit under state law
is preempted by section 136v(b).

       In Bates v. Dow Agrosciences LLC, 

(2005), the Supreme Court held that a requirement imposed
under state law must meet two conditions to be preempted by
section 136v(b). 

. “First, it must be a requirement
‘for labeling or packaging,’” and “[s]econd, it must impose a
labeling or packaging requirement that is ‘in addition to or
different from those required under this subchapter.’” 

(quoting 7 U.S.C. § 136v(b)). The Court further held that a
common-law duty to warn satisfies the first of these two
conditions, constituting a requirement for labeling or
packaging because it “set[s] a standard for a product’s labeling
that the . . . label is alleged to have violated by
containing . . . inadequate warnings.” Id. at 446. Although the
Schaffners argued otherwise in their briefing, see Schaffner Br.
28-29, at oral argument they conceded that under this principle
the Pa. Duty to Warn constitutes a “requirement for labeling or
packaging,” Oral Arg. at 18:00-18:46. The first of the two

8
 Monsanto also argues that the Pa. Duty to Warn is preempted
under the doctrine of impossibility preemption, which applies
when state and federal law impose inconsistent obligations that
cannot be jointly discharged. Monsanto Br. 47-57. Because
we conclude that FIFRA expressly preempts the Pa. Duty to
Warn, we need not consider this alternative theory.




                              23
conditions required for section 136v(b) to apply is therefore
met. The sole question that remains is whether the second is
met as well — that is, whether the Pa. Duty to Warn is in
addition to or different from the requirements imposed under
FIFRA itself.

        To answer that question, we follow the approach
outlined in Bates, where the Supreme Court explained how
courts must determine whether a state-law requirement is
preempted under section 136v(b) because it is “in addition to
or different from” the requirements imposed under FIFRA.

. That language, the Court held, imposes a
“parallel requirements” test. 

 Under that test, a state-law
labeling requirement is not preempted if it is “equivalent to a
requirement under FIFRA,” while it is preempted if it
“diverges from those set out in FIFRA and its implementing
regulations.” 

. Section 136v(b) does not preclude
states from awarding remedies — such as monetary damages
— against those whose conduct breaches a requirement
imposed under FIFRA, even if FIFRA does not itself authorize
such remedies. 

. But it does not allow states to
impose liability on those who would not otherwise be liable for
violating a requirement under FIFRA.              

.
Consequently, to apply the parallel-requirements test, a court
must identify the labeling requirements imposed under state
law and under FIFRA, then compare the two to determine
whether a pesticide label that violates the state requirement
would also violate the federal one. 

 If so, the state-law
requirement is equivalent to the federal one and is not
preempted. 

 If not, the requirements are not equivalent, and
the federal requirement preempts the state one. 

                              24
       The parties’ primary disagreement in this case lies in
how they identify the federal requirement that must be
compared with the Pa. Duty to Warn in applying the parallel-
requirements test (the “Federal Comparator”). The parties do
not challenge each other’s interpretation of the Pa. Duty to
Warn, nor do they analyze equivalence differently between it
and the Federal Comparator once the latter is identified. See
Monsanto Br. 37-39; Schaffner Br. 30-31. To decide this case,
then, we must first determine the content of the Federal
Comparator, then apply the parallel-requirements test by
comparing it with the Pa. Duty to Warn.

       According to the Schaffners, the Federal Comparator
incorporates only FIFRA’s statutory prohibition on
misbranding. Schaffner Br. 29. FIFRA prohibits the
distribution or sale of a pesticide that is “misbranded,” 7 U.S.C.
§ 136j(a)(1)(E), and it defines a pesticide as misbranded if its
label “does not contain a warning or caution statement which
may be necessary and if complied with . . . is adequate to
protect health and the environment.” Id. § 136(q)(1)(G).
Pennsylvania products liability law deems a product
“defective,” in turn, if it “was distributed without sufficient
warnings to notify the ultimate user of the dangers inherent in
the product.” Phillips v. A-Best Prods. Co., 

,
1171 (Pa. 1995). The Schaffners argue that FIFRA does not
preempt the Pa. Duty to Warn because Pennsylvania’s standard
for defective products is equivalent to FIFRA’s statutory
misbranding standard. Schaffner Br. 29-31. Crediting the
allegation that the omission of the Cancer Warning from
Roundup’s label rendered the pesticide defective, its label
arguably lacked a warning “necessary . . . to protect health”
and thereby satisfied the statutory definition of misbranding,
see 

(q)(1)(G); Schaffner Br. 29-31. Applying




                               25
the parallel-requirements test in this fashion, the Courts of
Appeals for the Ninth and Eleventh Circuits each held that
section 136v(b) does not preempt the similar duties to warn
imposed by California and Georgia law. See Carson IV, 

; Hardeman II, 

.

       Monsanto argues instead that the Federal Comparator
must incorporate the Preapproval Regulation, 

(a), and through it the EPA’s repeated approvals of
proposed Roundup labels omitting the Cancer Warning.
Monsanto Br. 28-30. As set forth above, FIFRA both prohibits
the distribution or sale of unregistered pesticides and institutes
a process through which the EPA registers individual
pesticides once it has determined that those pesticides, and
their proposed labels, comply with FIFRA. See generally 7
U.S.C. § 136a. The EPA established that federal law requires
Roundup’s label to omit the Cancer Warning, in Monsanto’s
view, since its Preapproved Label omits the Cancer Warning.
Monsanto Br. 28-30. And if FIFRA requires the Cancer
Warning to be omitted, a Roundup label that complies with
FIFRA must violate the Pa. Duty to Warn. Monsanto therefore
concludes that the Pa. Duty to Warn is not equivalent to the
Federal Comparator, that the parallel-requirements test is not
met, and that the Pa. Duty to Warn is preempted under section
136v(b). Id. at 37-38.

       Must the Pa. Duty to Warn be equivalent to a Federal
Comparator incorporating only the requirement that pesticides
not be misbranded under the statutory definition of that term,
as the Schaffners claim? Or must it be equivalent to a Federal
Comparator also incorporating the omission of the Cancer
Warning from Roundup’s Preapproved Label, as Monsanto
claims? This dispute, which lies at the core of the parties’




                               26
disagreement, forms the focus of our analysis in this opinion.
EPA regulations govern different parts of a pesticide label
differently, so our holding does not generalize to all state-law
claims involving pesticide labeling. But with respect to the
Cancer Warning, we hold that Monsanto is correct.

      Our analysis proceeds in three steps. First, in Part
IV(A), we examine “EPA regulations that give content to
FIFRA’s misbranding standards.”9 Bates, 

. We

9
  The Supreme Court has recently overruled its decision in
Chevron U.S.A., Inc. v. National Resources Defense Council,

 (1984), holding that “[c]ourts must exercise their
independent judgment in deciding whether an agency has acted
within its statutory authority.” Loper Bright Enters. v.
Raimondo, 

, 2273 (2024). Prior to Loper
Bright, courts might have owed deference to the EPA’s
interpretation of the statutory term “misbranding,” but no
more. Nonetheless, while Loper Bright requires courts, not
agencies, to determine the meaning of statutory terms such as
“misbranding,” we do not read the decision to undermine the
EPA’s authority to promulgate the regulations that implement
FIFRA. As the Court explained in Loper Bright, while courts
alone must ascertain a statute’s meaning, “the statute’s
meaning may well be that the agency is authorized to exercise
a degree of discretion.” 

. And one way for statutes
to express that meaning is when they “empower an agency to
prescribe rules to ‘fill up the details’ of a statutory scheme.”

 (quoting Wayman v. Southard, 

(1825)). FIFRA is such a statute: it expressly authorizes the
EPA Administrator “to prescribe regulations to carry out the
provisions” of the statute. 7 U.S.C. § 136w(a)(1). We
therefore conclude that Loper Bright does not undermine the




                              27
conclude that the Preapproval Regulation, 

,
prohibited Monsanto from modifying Roundup’s Preapproved
Label in order to add the Cancer Warning. Second, in Part
IV(B), we consider whether the Preapproval Regulation
establishes a “requirement” for the purposes of preemption
under section 136v(b), and we conclude that it does. Third, in
Part IV(C), we return to the parallel-requirements test. Having
held that the Preapproval Regulation constitutes a
“requirement” under section 136v(b), we must decide whether
to apply the parallel-requirements test by comparing the Pa.
Duty to Warn with a Federal Comparator that incorporates that
regulatory requirement, or whether instead to compare the Pa.
Duty to Warn with a Federal Comparator that incorporates the
requirement that pesticides not be misbranded solely under the
statutory definition of that term.        Under the parallel-
requirements test, state-law requirements must “be measured
against any relevant EPA regulations that give content to
FIFRA’s misbranding standards.” Bates, 

. We
therefore hold that the parallel-requirements test must involve
a comparison to the Preapproval Regulation, and having so
held we apply the test. While the Cancer Warning was
allegedly required by the Pa. Duty to Warn, it was omitted from
Roundup’s Preapproved Label and could not have been added
to the Roundup label without violating the Preapproval
Regulation. Accordingly, the Pa. Duty to Warn is not
equivalent to the Federal Comparator, and it is thus preempted
under section 136v(b).




validity of the EPA regulations that govern pesticide labeling
and that we consider in analyzing preemption under FIFRA in
this opinion.




                              28
            A.   Modifications to Pesticide Labels

       FIFRA “pre-empts any statutory or common-law rule
that would impose a labeling requirement that diverges from
those set out in FIFRA and its implementing regulations.”
Bates, 

 (emphasis added). We thus first
examine the EPA regulations that govern pesticide labeling
under FIFRA. FIFRA authorizes the EPA Administrator “to
prescribe regulations to carry out the provisions of this
subchapter.” 7 U.S.C. § 136w(a)(1). Pursuant to that
authority, the EPA has promulgated regulations that govern
both the process of initially registering a pesticide and the
process of subsequently amending its registration. See
generally 40 C.F.R. pt. 152, subpt. C. As noted above, the
Preapproval Regulation mandates that “[e]xcept as provided by
§ 152.46, any modification in the . . . labeling . . . of a
registered product must be submitted with an application for
amended registration.” Id. § 152.44(a). And “[i]f an
application for amended registration is required, the
application must be approved by the Agency before the
product, as modified, may legally be distributed or sold.” Id.
Once a pesticide is registered and its proposed label is
approved by the EPA, then, the Preapproval Regulation
prohibits the distribution or sale of the pesticide with a
modified label, unless and until an application for amended
registration is submitted and approved.

       The Preapproval Regulation contains an exception,
however. Only “[i]f an application for amended registration is
required” must an application for amended registration be
approved before the modified pesticide may be sold or
distributed. Id. And such an application is not always required.




                              29
Modifications may be made without an application for
amended registration “as provided by § 152.46.” Id. That
section governs the modification of a pesticide or its label “by
notification,” a procedure under which the registrant must
inform the EPA of the modification but need not receive
approval before selling or distributing the modified pesticide.10
Id. § 152.46(a). The Schaffners argue that adding the Cancer
Warning to the Roundup label would be a permissible
modification by notification under section 152.46. Schaffner
Br. 46-47. Were they correct, no application for amended
registration would be required, and the Preapproval Regulation
would by its own terms have permitted Monsanto to add the
Cancer Warning.

       The Schaffners rely on section 152.46’s provision that
“a manufacturer can make minor modifications to labeling that
have ‘no potential to cause unreasonable adverse effects to the
environment’ without prior EPA approval if EPA is notified of
the change.”        Schaffner Br. 46 (quoting 

(a)(1)).      Monsanto could have relied on this
authorization, they suggest, to add the Cancer Warning to the
Roundup label using modification by notification. 

 The
Schaffners quote the phrase out of context, however. Section
152.46 does not itself directly permit the modification by
notification of a registered pesticide in any manner that has “no

10
  Section 152.46 also governs the modification of a pesticide
“without notification,” in which case the label may be changed
without any EPA involvement. 

(b).
Because the Schaffners do not argue that the Roundup label
could have been modified without notification, however, see
Schaffner Br. 46-47, we focus only upon modification by
notification.




                               30
potential to cause unreasonable adverse effects to the
environment.” 

(a)(1). Rather, it merely
authorizes the EPA, at its discretion, to permit registrants to
modify pesticides by notification in some such circumstances:

       EPA may determine that certain minor
       modifications to registration having no potential
       to cause unreasonable adverse effects to the
       environment may be accomplished by
       notification to the Agency, without requiring that
       the registrant obtain Agency approval. If EPA
       so determines, it will issue procedures following
       an opportunity for public comment describing
       the types of modifications permitted by
       notification and any conditions and procedures
       for submitting notifications.

(a)(1) (emphasis added). Thus, section
152.46(a) does not of its own force permit Monsanto to add the
Cancer Warning to the Roundup label by notification. At most,
it could authorize the EPA to permit that modification to be
made by notification. Whether Monsanto in fact could have
added the Cancer Warning by notification depends on how the
EPA has exercised the authority conferred upon it by section
152.46(a).

       We therefore turn to the policies that the EPA has issued
pursuant to its authority under section 152.46(a)(1). Following
the opportunity for public comment required by section
152.46(a), see Proposed Pesticide Amendment Reinvention
Measures, 

 (Oct. 1, 1997), in 1998 the EPA
issued Pesticide Registration Notice 98-10 (“PRN 98-10”), see
generally JA 142-64, on the subject of “Notifications, Non-




                              31
Notifications and Minor Formulation Amendments,” JA 142.
Pursuant to the EPA’s authority under section 152.46, PRN 98-
10 specifies which “registration amendments may be
accomplished by notification” as pertains to “labeling.” JA
144. But PRN 98-10 does not allow the Cancer Warning to be
added by notification. PRN 98-10 explicitly enumerates what
types of modifications may be made by notification, and that
list includes no category that might encompass the addition of
the Cancer Warning to a pesticide label. See JA 144-50, 162-
64. Instead, the final item on that list — a catch-all provision
encompassing minor label changes that do not fall under any
earlier item — expressly provides that modification by
notification must “involve no change in . . . precautionary
statements.” JA 150. The Cancer Warning would constitute a
precautionary statement because it would at a minimum
“describe[e] the particular hazard,” along with whatever other
information it might contain.11 

(b); see also

11
  In certain contexts, the EPA distinguishes between a “hazard
statement” and a “precautionary statement,” though in others it
uses “precautionary statement” in a manner that reaches across
that distinction. See 

 (“Hazard statements
describe the type of hazard that may occur, while precautionary
statements will either direct or inform the user of actions to
take to avoid the hazard or mitigate its effects.”); but see 

§ 156.70(b) (discussing “precautionary statements describing
the particular hazard”); Office of Pesticide Programs, U.S.
Env’t Prot. Agency, Label Review Manual § 7.I, at 7-2 (2018)
(“[P]recautionary statements provide the pesticide user with
information regarding the toxicity, irritation, and dermal
sensitization hazards associated with the use of the
pesticide . . . .”). Because the EPA also employs the term
“precautionary statements” as a heading for the section of the




                              32
Office of Pesticide Programs, U.S. Env’t Prot. Agency, Label
Review Manual § 7.I, at 7-2 (2018) (“[P]recautionary
statements provide the pesticide user with information
regarding the toxicity, irritation, and dermal sensitization
hazards associated with the use of the pesticide . . . .”).
Because adding the Cancer Warning would involve “a change
. . . in precautionary statements,” PRN 98-10 does not permit
it to be added through modification by notification.12



label that must contain all hazard and precautionary statements
together, 

(a) (“Human hazard and
precautionary statements as required must appear together on
the label or labeling under the general heading ‘Precautionary
Statements’ . . . .”), we understand PRN 98-10’s reference to
“precautionary statements” to encompass any label contents
properly placed under the heading “Precautionary Statements,”
regardless of whether those contents might be more precisely
categorized as hazard statements or precautionary statements.
12
   Citing an instance in which the EPA condoned the addition
of a cancer warning by notification, the Hardeman II court
concluded that PRN 98-10 permits similar such warnings to be
added by notification. 

, 959 n.10 (quoting
Letter from Jennifer Gaines, EPA, Office of Pesticide
Programs, to Larry Hodges, Bayer CropScience (Dec. 17,
2012)). But on that occasion, the warning, which read, “This
product contains a chemical known to the state of California to
cause cancer,” was not placed beneath the heading
“Precautionary Statements.” Bayer CropScience, Proposed
Larvin         Label       2       (Nov.        29,       2012),
https://www3.epa.gov/pesticides/chem_search/ppls/000264-
00343-20131217.pdf            [https://perma.cc/5U8W-Y6QW].
Instead, it was included with legal information such as




                              33
warranty disclaimers, limitations of liability, and trademark
registrations. Id. at 3.

        The EPA understandably accepted the proposed
modification as non-precautionary legal information, since the
substance of that modification was to provide pesticide users
with information about a determination made under California
law. That is readily distinguishable from the Cancer Warning
here, the substance of which is the finding of carcinogenicity
itself. Put more simply, the Schaffners conflate the legal
information that a state has made a particular determination
with the non-legal substance of that determination, which, in
our view, is clearly precautionary. Thus, unlike the notice
considered by the court in Hardeman II, the Cancer Warning is
not “minor” information that may be added by notification
under PRN 98-10, and Monsanto could not have added it
without running afoul of the Preapproval Regulation.

       More generally, we also do not believe that courts may
avoid the task of interpreting sources of law such as section
152.46 and PRN 98-10 based on the reasoning that actions
must be permissible if the agency that administers that law has
permitted them. See Hardeman II, 

. As the
Supreme Court has recently reminded us, “[i]t is emphatically
the province and duty of the judicial department to say what
the law is.” Loper Bright, 144 S. Ct. at 2257 (alteration in
original) (quoting Marbury v. Madison, 

 (1803)). And while courts may sometimes defer to an
agency’s interpretation of its own regulations, the Court has
“cabined” the scope of that deference “in varied and critical
ways.” Kisor v. Wilkie, 

 (2019). Agency
interpretations are not entitled to deference unless they




                              34
       This interpretation of PRN 98-10 is further reinforced
by the EPA regulation governing “[p]recautionary statements
for human hazards,” which provides that “[s]pecific statements
pertaining to the hazards of the product and its uses must be
approved by the Agency.” 

 § 156.70(c). As the Cancer
Warning would warn that Roundup risks causing a particular
disease, it constitutes a “[s]pecific statement pertaining to the
hazards of [Roundup] and its uses.” It thus “must be approved
by the Agency.” See also JA 1045 (identifying a cancer
warning for glyphosate-based pesticides that “could be
approved, if requested by a pesticide registrant, for inclusion
on pesticide labels” (emphasis added)). Label modifications
made by notification, however, are accomplished “without
requiring that the registrant obtain Agency approval.” Id.


emanate “from those actors, using those vehicles, understood
to make authoritative policy in the relevant context.” Id. at
577. Similarly, “an agency’s reading of a rule must reflect ‘fair
and considered judgment’ to receive . . . deference” from
courts. Id. at 579 (quoting Christopher v. SmithKline Beecham
Corp., 

 (2012)). The EPA letter cited in
Hardeman II satisfies neither condition. Rather than being a
statement of “authoritative policy,” it merely condones a single
registrant’s modification by notification of the label of a single
pesticide. See Letter from Jennifer Gaines. And rather than
reflecting the EPA’s “fair and considered judgment,” it
consists entirely of a single, boilerplate, three-sentence
paragraph that omits any substantive analysis of PRN 98-10 or
the relevant regulations. 

 Such a letter is not entitled to
deference in the face of our conclusion, based on our own
substantive legal analysis, that the Cancer Warning could not
have been added to the Roundup label via modification by
notification.




                               35
§ 152.46(a)(1). Because the EPA does not approve label
contents added through modification by notification, that
procedure cannot be used to add contents, such as the Cancer
Warning, that “must be approved by the Agency.” Section
156.70 therefore provides an additional basis, besides the
express terms of PRN 98-10 itself, for our conclusion that the
Cancer Warning could not have been added to the Roundup
label through modification by notification.

         The present version of section 152.46 was enacted in
1996. See Notification Procedures for Pesticide Registration
Modifications, 

, 33041 (June 26, 1996)
(codified at 

). The Schaffners’ earliest
allegation of Mr. Schaffner’s Roundup use dates to 1988,
however, so the present version of section 152.46 did not apply
during part of the period when the omission of the Cancer
Warning allegedly caused Mr. Schaffner’s illness — namely,
the time prior to 1996. But the EPA regulations that applied
prior to 1996 similarly prohibited Monsanto from adding the
Cancer Warning to the Roundup label. While the present
version of section 152.46 was enacted in 1996, the relevant
portion of the Preapproval Regulation has been in force since
1988, prohibiting modifications to a registered pesticide
without an approved application for amended registration
unless the exception under section 152.46 applies. See
Pesticide      Registration   Procedures;     Pesticide    Data
Requirements, 

, 15978 (May 4, 1988)
(codified at 

(a)); accord 

(a) (1996). And the earlier version of section 152.46,
which was also promulgated in 1988, provided that
modification by notification could be used for “[a] revision of
the label language” only if it “involve[ed] no change in
the . . . precautionary statements.”    Pesticide Registration




                              36
Procedures, 53 Fed. Reg. at 15978 (codified at 

(a)(1)); accord 

(a)(1) (1996)
(superseded text); see also supra note 11. Before those
regulations took effect, label changes could not be made absent
EPA approval. See 

(b)(3) (1988) (“(i)
General. Applications for amended registration shall be
submitted if: (A) Changes are proposed in the labeling . . . .
(iv) Distribution under amended labeling. (A) Approval of
amendments authorizes distribution under such amended
labeling . . . .”).

       Because the addition of the Cancer Warning to
Roundup’s label would involve a change in the precautionary
statements on its Preapproved Label, modification by
notification was unavailable under section 152.46 and PRN 98-
10. The Preapproval Regulation therefore prohibited the
addition of the Cancer Warning to the Roundup label without
further EPA approval.

               B. Requirements Under FIFRA

      Roundup’s Preapproved Label omitted the Cancer
Warning, and the Preapproval Regulation prohibited Monsanto
from modifying Roundup’s label to include it.13 Section

13
    Monsanto has not claimed that it ever submitted an
application for amended registration or sought EPA approval
for a modified Roundup label that included the Cancer
Warning. A plaintiff might conceivably argue that FIFRA
required Monsanto to submit such an application and that a
state-law claim for breach of the duty to warn could satisfy the
parallel-requirements test because it is equivalent to that
federal requirement. Because the Schaffners advanced no such




                              37
136v(b) preempts only those state-law requirements that are
not parallel to any “requirement” imposed under FIFRA,
however. The Preapproval Regulation could be relevant to the
parallel-requirements test, and thereby to preemption under
section 136v(b), only if it establishes a “requirement” under
FIFRA. We next consider whether it establishes such a
requirement, and we hold that it does.

       First, the Preapproval Regulation satisfies the definition
of “requirement” that the Supreme Court adopted in Bates. “A
requirement is a rule of law that must be obeyed.” Bates, 

. And “[r]ules issued through the notice-and-
comment process,” such as section 152.44(a), “have the force
and effect of law.” Perez v. Mortg. Bankers Ass’n, 

 (2015) (quotation marks omitted); see also Pesticide
Regulation Procedures; Pesticide Data Requirements, 

, 15952-53 (May 4, 1988) (describing notice-and-
comment proceedings undertaken prior to the promulgation of
the Preapproval Regulation). The Preapproval Regulation is a
rule of law that must be obeyed, so it establishes a
“requirement” that a pesticide’s label must conform to its
Preapproved Label. Furthermore, because the Preapproval
Regulation was enacted to “revise[] procedures for the
registration of pesticide products under section 3 of [FIFRA],”
Pesticide Regulation Procedures, 53 Fed. Reg. at 15952, it was
promulgated under the EPA Administrator’s authority “to
prescribe regulations to carry out the provisions of [FIFRA],”
7 U.S.C. § 136w(a)(1). The regulatory prohibition on
modifying a pesticide’s Preapproved Label therefore
constitutes a “require[ment] under [FIFRA].” Id. § 136v(b).


argument here, however, we do not consider it, and we express
no opinion as to whether it could succeed.




                               38
Indeed, in Bates the Supreme Court expressly identified EPA
regulations as a source of “requirements” for the purposes of
preemption under FIFRA. 

.

        To be sure, while some EPA regulations directly
identify the contents that labels must contain, the Preapproval
Regulation instead only requires a pesticide’s label to bear the
contents contained in its Preapproved Label, whatever those
contents may be. The regulation itself does not directly
identify any particular label contents as permitted, prohibited,
or required. In Bates, the Court’s analysis suggested that a
“requirement” under section 136v(b) must substantively
restrict the content of pesticide labels. A state-law claim for
breach of an express warranty that was included on a
pesticide’s label, it held, would not be preempted under
FIFRA. 

. The duty to honor an express
warranty placed on a pesticide label “does not impose a
requirement ‘for labeling or packaging’” because it “does not
require the manufacturer to make an express warranty” on its
label or “to say anything in particular in that warranty.” 

 It
might be argued, then, that the Preapproval Regulation fails to
substantively restrict the content of pesticide labels, like the
claim discussed in Bates, such that it fails to impose a
“requirement” for the purposes of section 136v(b).

       A state-law duty to honor an express warranty included
on a pesticide label fails to impose a “requirement” for the
purposes of section 136v(b), on the Court’s reasoning, because
that duty allows a registrant to include any language it wishes
on a pesticide’s label. In theory, the same could be true of the
Preapproval Regulation. If the EPA automatically approved
any proposed pesticide label without reviewing its contents in
whole or in part, then the Preapproval Regulation would fail to




                               39
restrict substantively the contents of pesticide labels. A
registrant could include any language it wished on a pesticide
label simply by submitting a proposed label containing that
language, then including it on the label following the
proposal’s automatic approval. But the EPA does not approve
proposed labels automatically. Rather, it reviews the substance
of proposed labels and approves them only if they “comply
with the requirements of [FIFRA],” 7 U.S.C. § 136a(c)(5)(B),
which requires the EPA to have “determined that the product
is not misbranded as that term is defined in FIFRA,” 

(f). Unlike the contractual obligation to honor an
express warranty, the Preapproval Regulation does not permit
a registrant to include whatever language it wishes on a
pesticide label. Instead, because the EPA will approve only
labels that it deems compliant with federal law, the prohibition
on modifying a pesticide’s Preapproved Label does “require
the manufacturer . . . to say [some]thing in particular” on the
pesticide label, Bates, 

 — namely, to include
only content that the EPA deems compliant with federal law.
The Preapproval Regulation therefore does impose a
“requirement” under the principles articulated in Bates.

       Our holding that the Preapproval Regulation imposes a
“requirement” for purposes of preemption receives further
support from the Supreme Court’s preemption analysis in
Riegel v. Medtronic, Inc., 

 (2008). Riegel did not
directly concern FIFRA or any of its provisions, including
section 136v(b). Instead, in Riegel the Court analyzed
preemption under the Medical Device Amendments of 1976
(the “MDA”), 

 Stat. 539. 

. But FIFRA resembles the MDA in two respects that were
central to the Court’s preemption analysis in Riegel. First, the
MDA’s preemption provision prohibits states from imposing a




                              40
requirement for a medical device “which is different from, or
in addition to, any requirement applicable under this chapter to
the device,” 21 U.S.C. § 360k(a)(1); see Riegel, 

, closely echoing the language employed by FIFRA’s
preemption provision, see 7 U.S.C. § 136v(b) (prohibiting
states from imposing “requirements for labeling or packaging
in addition to or different from those required under this
subchapter”). Second, the defendant in Riegel argued that state
law was preempted by a federal regulatory scheme — the
MDA’s system of premarket approval — that operates very
similarly to pesticide registration under FIFRA. 

. A medical device cannot enter the market, unless
certain exceptions apply, until it has received premarket
approval, 21 U.S.C. § 360e(a), which must be denied unless
the FDA concludes there is reasonable assurance of the
device’s safety, id. § 360e(d)(2)(A). Then, once premarket
approval has been granted, a supplemental application for
premarket approval is required before the device may be
modified. Id. § 360e(d)(5)(A)(i). Like pesticides, medical
devices must be reviewed and approved before being
marketed, and once approved they cannot be modified unless
the proposed modification is itself reviewed and approved.

       Because the Court’s decision in Riegel turned on the
preemptive effect of a regulatory scheme similar to the system
of pesticide registration created by FIFRA, and because the
two statutes’ preemption provisions themselves are so similar,
the Court’s analysis in that case sheds light on how we should
analyze preemption under FIFRA. In Riegel, the Court applied
the parallel-requirements test (in substance if not in name), just
as we must do here, by separately identifying federal and state
“requirements,” then comparing them to determine whether
they were equivalent. 

; see also Bates, 544




                               41
U.S. at 447-48 (relying on precedents interpreting the MDA in
holding that the parallel-requirements test governs preemption
under FIFRA).        To “determine whether the Federal
Government ha[d] established requirements applicable to” the
challenged device, Riegel, 

, the Court focused
on the MDA’s system for premarket approval, analyzing in
particular whether the prohibition on modifying a medical
device once the FDA had reviewed and approved it for safety
established a “requirement” for the purposes of preemption
under the MDA. 

. And its conclusions and
reasoning shed light on whether, in general, a “requirement”
exists within the meaning of a similar preemption provision,
such as FIFRA’s, where an agency reviews regulated products
for safety before they may be marketed, then prohibits
modifications of those products absent an additional safety
review.

        The Court held in Riegel that premarket approval does
establish “requirements” for purposes of the MDA’s
preemption provision.            

 (“Premarket
approval . . . imposes ‘requirements’ under the MDA . . . .”).
Its holding rested squarely on the two regulatory elements
common to both premarket approval under the MDA and
pesticide registration under FIFRA — namely, the safety
review that regulated products must undergo before they are
marketed, and the prohibition on subsequent modifications of
such products once they are reviewed and approved. As the
Court explained, “the FDA may grant premarket approval only
after it determines that a device offers a reasonable assurance
of safety and effectiveness,” and “the FDA requires a device
that has received premarket approval to be made with almost
no deviations from the specifications in its approval
application, for the reason that the FDA has determined that




                              42
the approved form provides a reasonable assurance of safety
and effectiveness.” 

. The process of premarket
approval substantively restricts which medical devices may be
sold by requiring a reasonable assurance of safety and
effectiveness, the Court reasoned, and therefore the
preapproval regulations limiting modifications to a medical
device that has received premarket approval also substantively
restrict which medical devices may be sold. No requirement
would have existed were medical devices permitted to “take
any particular form for any particular reason.” 

 (quoting
Medtronic, Inc. v. Lohr, 

 (1996)); see also
Lohr, 

. But a requirement existed for
purposes of preemption because a medical device must take a
certain specific form following premarket approval.

        The analysis of “requirements” adopted in Riegel
carries over to FIFRA. If the prohibition on modifying medical
devices following their approval for safety establishes
“requirements” for medical devices, then FIFRA’s regulatory
approach, which employs the same two elements, should
likewise establish “requirements” under a similar preemption
provision, such as section 136v(b) of FIFRA. Laws fail to
establish requirements if they do not require registered
products to “take any particular form for any particular
reason.” Riegel, 522 U.S. at 323 (quoting Lohr, 

). The contractual obligation to honor an express warranty
included on a pesticide label, for example, “does not require
the manufacturer . . . to say anything particular in that
warranty,” and thus establishes no requirement. Bates, 

. But in approving applications for a new or
amended pesticide registration, the EPA substantively restricts
what precautionary statements may appear on a pesticide’s
label, and the Preapproval Regulation thereby requires labels




                              43
to take a particular form consistent with those substantive
restrictions. By virtue of the Preapproval Regulation, the
EPA’s approval determinations impose “requirements” as that
term is employed in section 136v(b).14

        C. Applying the Parallel-Requirements Test

       As we have explained, the Supreme Court in Bates held
that lower courts should apply section 136v(b) using the
parallel-requirements test, identifying the relevant state and

14
   The Court of Appeals for the Eleventh Circuit distinguished
FIFRA from the MDA in the course of holding that the EPA’s
preapproval determinations do not establish any requirement
for the purposes of preemption under section 136v(b). Carson
IV, 

. But in its analysis of “[t]he statutes’
distinct approval processes,” 

, we believe the court
overlooked a crucial similarity between the two regulatory
schemes. Although it recognized that a pesticide’s label may
not be modified once the EPA has approved it, see 

,
its discussion of the differences between each statute’s
approval processes did not consider the similarity between that
prohibition and the analogous one established under the MDA,
see 

. And because that prohibition under the MDA
was central to the Supreme Court’s explanation for why
premarket approval does impose requirements for the purposes
of preemption, see Riegel, 

 (“[T]he FDA
requires a device that has received premarket approval to be
made with almost no deviations from the specifications in its
approval application . . . .”), the existence of an analogous
prohibition under FIFRA strikes us as a crucial similarity that
outweighs the differences between FIFRA and the MDA cited
in Carson IV.




                              44
federal labeling requirements then comparing the two to
determine whether they are equivalent. But our analysis of
FIFRA and its implementing regulations has revealed that
FIFRA’s labeling requirements are articulated at two distinct
levels of generality. On the one hand, under the broad statutory
definition of misbranding, a pesticide is misbranded simply if
its label omits a warning necessary for safe use; no specifically
identified warning is required to be included or omitted. See 

(q)(1)(G). The Schaffners apply the parallel-
requirements test using a Federal Comparator that incorporates
this standard alone, directly comparing the Pa. Duty to Warn
with the statutory definition of misbranding. Schaffner Br. 29-
30. So did the Courts of Appeals for the Ninth and Eleventh
Circuits in holding that section 136v(b) does not preempt
duties to warn imposed by California and Georgia law.15 See
Carson IV, 

; Hardeman II, 

-
56. On the other hand, the Preapproval Regulation requires
pesticide labels to contain certain specific contents, including
the precautionary statements contained on the pesticide’s
Preapproved Label.          Monsanto applies the parallel-
requirements test using a Federal Comparator that incorporates
this specific regulatory requirement, not just the broad
statutory misbranding standard. Monsanto Br. 30.




15
  While the Court of Appeals for the Eleventh Circuit appeared
to recognize that the Preapproval Regulation generally
prohibits modifications to pesticide labels absent an
application for amended registration, Carson IV, 

, it considered only the statutory definition of misbranding
when applying the parallel-requirements test, giving no
explanation for that choice, 

.




                               45
       When state tort law and a federal statute seem to impose
equivalent requirements, but a federal regulation gives
different content to that apparently equivalent requirement,
should a court articulate the Federal Comparator at the broader
statutory level of generality or the more specific regulatory
level of generality? That question determines what Federal
Comparator we must employ when applying the parallel-
requirements test in this case. Should we ask whether the Pa.
Duty to Warn is equivalent to FIFRA’s broad statutory
requirement that labels contain all necessary warnings, or
whether it is equivalent to the specific regulatory requirement
that a pesticide’s label must contain particular contents
included on its Preapproved Label, including the precautionary
statements?

        We hold that under both Bates and section 136v(b) itself
federal requirements must be articulated at the more specific
level when identifying the Federal Comparator in applying the
parallel-requirements test. If EPA regulations specifically
identify the contents required to be included on a pesticide
label, a state-law requirement is preempted unless it is
equivalent to that specific regulatory requirement. The state-
law duty cannot survive preemption simply because its
standard of liability is equivalent to the broad statutory
definition of misbranding. We therefore apply the parallel-
requirements test in this case by comparing the Pa. Duty to
Warn with a Federal Comparator that incorporates the
Preapproval Regulation.

       The principal holding articulated in Bates was that the
parallel-requirements test governs preemption under section
136v(b). The Supreme Court did not itself apply that test to
the plaintiffs’ claims, but rather remanded for the Court of




                              46
Appeals to do so. Bates, 

. Nonetheless, the
Court provided guidance concerning how the parallel-
requirements test was to be applied on remand. After
explaining that “a state-law labeling requirement must in fact
be equivalent to a requirement under FIFRA in order to survive
pre-emption,” 

, the Court provided two illustrations
of state failure-to-warn claims that would not be equivalent to
the relevant Federal Comparator and would therefore be
preempted. One example involved a “failure-to-warn claim
alleging that a given pesticide’s label should have stated
‘DANGER’ instead of the more subdued ‘CAUTION.’” 

 In
order to apply the parallel-requirements test to such a claim,
the Court explained, “[s]tate-law requirements must also be
measured against any relevant EPA regulations that give
content to FIFRA’s misbranding standards.” 

 A state-law
requirement to employ ‘DANGER’ on a pesticide label would
thus be preempted were it “inconsistent with 

(2004), which specifically assigns [‘DANGER’ and
‘CAUTION’] to particular classes of pesticides based on their
toxicity.” 

        The Court’s analysis of section 156.64 in Bates
indicates that the parallel-requirements test should be applied
using more specific EPA regulations requiring pesticide labels
to bear particular contents, where such regulations exist, rather
than using the broad statutory definition of misbranding.
Under the latter approach, which the Schaffners adopt, alleged
liability under state law for using ‘CAUTION’ on a pesticide
label would not be preempted so long as the label satisfies the
statutory definition of misbranding by omitting “a warning . . .
which may be necessary and if complied with . . . is adequate




                               47
to protect health and the environment.”16             

(q)(1)(G). But when the Court analyzed this example in
Bates, it did not consider or even mention the statutory
definition of misbranding. See 

. Instead, it
compared the state-law duty with only the specific regulatory
requirement to include certain identified contents on the
pesticide label. 

 And it explained that the hypothetical state-
law duty was preempted simply because it was not equivalent
to the federal regulatory requirement: “a failure-to-warn claim
alleging that a given pesticide’s label should have stated
‘DANGER’ instead of the more subdued ‘CAUTION’ would

16
  Indeed, a plaintiff bringing the hypothetical claim discussed
in Bates almost surely could allege that the label violated not
only state law but also the federal prohibition on misbranding,
as that term is defined in FIFRA. A plaintiff who sues to
recover damages for any alleged failure to warn, such as for the
use of “CAUTION” rather than “DANGER” on a pesticide
label, must allege that the label’s inadequate warnings caused
her to be injured. Crediting those allegations, the pesticide’s
label would likely satisfy the statutory definition of
misbranding: if the use of “CAUTION” caused the plaintiff’s
injuries, then a warning using “DANGER” (or some other
signal word) instead was “necessary . . . to protect health.” 

(q)(1)(G). The same facts establishing the
defendant’s liability for the failure to warn would also establish
that the pesticide violated the statutory prohibition on
misbranding. If the parallel-requirements test were applied
using the statutory definition, as the Schaffners urge, then there
would be no preemption in these circumstances, despite the
Court’s unambiguous conclusion to the contrary. The
hypothetical thus weighs against our adopting the Schaffners’
approach.




                               48
be pre-empted because it is inconsistent with 

(2004), which specifically assigns these warnings to particular
classes of pesticides based on their toxicity.” 

 This
discussion indicates that a state-law duty is preempted if
“relevant EPA regulations that give content to FIFRA’s
misbranding standards,” 

 would prohibit adding the
warning that state law requires. If so, any equivalence between
the state-law duty and the statutory definition of misbranding
does not prevent the preemption of state law.

        Like the regulation the Court discussed in Bates, which
requires specific signal words such as “CAUTION” or
“DANGER” to appear on labels for different types of
pesticides, see 

, the Preapproval Regulation
also gives content to FIFRA’s misbranding standards. Section
156.64 does not explicitly define “misbranded,” a word that it
does not even use. See 

 Instead, it gives content to the
misbranding standard by prohibiting one type of label that the
EPA believes would constitute misbranding — namely, labels
that do not bear the requisite signal words. The Preapproval
Regulation gives content to FIFRA’s misbranding standards in
the same sense. Because the EPA approves a pesticide label
only if it “has determined that the product is not misbranded as
that term is defined in FIFRA,” 

(f), the
requirement not to modify the Preapproved Label likewise
prohibits pesticides from bearing particular labels that, in the
EPA’s view, constitute misbranding. Each regulation requires
pesticide labels to conform to the EPA’s opinion as to whether
specific labels would constitute misbranding, and thus each
“give[s] content to” the broad requirement that such labels not
be misbranded. Bates, 

.




                              49
        The Court explained in Bates that whether a state-law
duty allegedly requiring the use of ‘DANGER’ rather than
‘CAUTION’ would be preempted depends on a comparison
between that duty and the regulation requiring that
‘CAUTION’ be used, regardless of whether the plaintiff
plausibly alleges the label to satisfy the statutory definition of
misbranding. 

 So too, whether the Pa. Duty to Warn is
preempted depends on a comparison between it and the
Preapproval Regulation, regardless of whether the label is
alleged to satisfy the statutory definition of misbranding.
Because the Preapproval Regulation gives content to FIFRA’s
prohibition on misbranding, Bates requires us to incorporate
that regulation into the Federal Comparator when applying the
parallel-requirements test here. See 

 (Breyer, J.,
concurring) (emphasizing “the practical importance of the
Court’s statement that state-law requirements must ‘be
measured against’ relevant Environmental Protection Agency
(EPA) regulations ‘that give content to [FIFRA’s] misbranding
standards’” (quoting 

)).

        Even were we not bound by Bates, section 136v(b) itself
indicates that the parallel-requirements test should be applied
by comparing state-law requirements to a Federal Comparator
that incorporates content-giving regulations rather than to one
based solely upon the broad statutory definition of
misbranding. The Supreme Court has “oft-repeated” its
comment that “‘[t]he purpose of Congress is the ultimate
touchstone’ in every pre-emption case.” Lohr, 

(alteration in original) (quoting Retail Clerks v. Schermerhorn,

 (1963)). Thus, our “understanding of the
scope of a pre-emption statute,” such as section 136v(b), “must
rest primarily on a fair understanding of congressional
purpose.” Id. at 485-86 (quotation marks omitted). We draw




                               50
that understanding of congressional purpose primarily from the
text of the statute and from its surrounding framework. Id. at
486

         Here, Congress has made the purpose of section 136v(b)
transparent by titling it “Uniformity.” 7 U.S.C. § 136v(b); see
Merit Mgmt. Grp., LP v. FTI Consulting, Inc., 

 (2018) (explaining that “section headings . . . supply cues
as to what Congress intended” (quotation marks omitted)).
Congress enacted section 136v(b) to ensure that pesticide
labeling requirements would be uniform across the nation.
Accord Schoenhofer v. McClaskey, 

 (10th
Cir. 2017) (“For labeling . . . the statute requires national
uniformity.”). We must interpret that provision to realize the
purpose that animates it while remaining consistent with its
text. See Merit Mgmt. Grp., 538 U.S. at 380 (“[S]ection
headings cannot limit the plan meaning of a statutory
text . . . .”).

        The level of generality at which a rule is framed often
affects the degree of uniformity in how it will be applied on
different occasions. Different interpreters may apply a vague,
broad rule differently given the same facts, while they are
likely to apply a specific, precise rule more consistently.
Because misbranding is defined by statute as the omission of
warnings “necessary . . . to protect health,” 

(q)(1)(G), that standard cannot be applied without
determining which warnings are in fact necessary to protect
health, a challenging question about which reasonable
individuals may disagree. This very case provides a suggestive
illustration, as disagreement has persisted for decades over
whether the Cancer Warning is necessary to protect Roundup
users’ health. By contrast, the Preapproval Regulation may be




                              51
applied by comparing the label a pesticide actually bears with
its Preapproved Label, a straightforward matter about which
disagreement is unlikely. The broad statutory definition of
misbranding is likely to be applied less uniformly in practice
than a regulatory requirement to include specific contents on
pesticide labels.

        The parallel-requirements test affects the uniformity of
state-law labeling requirements by determining which state-
law duties FIFRA preempts. If state-law duties to warn can
survive preemption so long as they are equivalent to the broad
statutory definition of misbranding, then FIFRA would not
preempt state-law duties to warn that simply require the
inclusion of all warnings necessary to protect health. State-law
duties framed in these vague and broad terms would produce
considerable heterogeneity, not uniformity, in the labels that
pesticides are required to bear, for different factfinders
deciding different individual cases might reasonably disagree
about whether a particular warning was necessary to protect
health. But if the parallel-requirements test were applied to
preempt any state-law duty that is not equivalent to EPA
regulations requiring pesticide labels to bear certain specific
contents, then state-law duties to warn would likely be
considerably more uniform, for different factfinders are
unlikely to disagree about whether a pesticide label bears the
specific contents required by regulation.

       Congress’s aim of instituting uniform rules for pesticide
labeling would thus be realized more effectively were state-law
requirements “measured against any relevant EPA regulations
that give content to FIFRA’s misbranding standards,” Bates,

, rather than against the statutory definition of
misbranding itself. Where no such regulations exist, of course




                              52
the parallel-requirements test can only be applied using the
statutory definition, despite any consequent risk of
heterogeneous state-law labeling requirements. But the
Preapproval Regulation gives content to the broad misbranding
standard by specifically requiring a pesticide’s label to bear the
particular precautionary statements on its Preapproved Label.
We therefore apply the parallel-requirements test using a
Federal Comparator that incorporates that specific regulatory
requirement.

                           * * * * *

       The parties reach different conclusions as to whether
section 136v(b) preempts the Pa. Duty to Warn because they
identify the Federal Comparator differently in applying the
parallel-requirements test. We have concluded that the test
must be applied by comparing the Pa. Duty to Warn with a
Federal Comparator that incorporates the Preapproval
Regulation. That question having been resolved, only the
straightforward task of making the comparison remains.
Monsanto’s omission of the Cancer Warning from the
Roundup label allegedly violated the Pa. Duty to Warn. But it
did not breach the Preapproval Regulation — and thus the
Federal Comparator — because Roundup’s Preapproved Label
omitted the Cancer Warning. As Monsanto’s alleged violation
of the Pa. Duty to Warn did not constitute a violation of the
Federal Comparator, the two requirements are not equivalent,
the parallel-requirements test is not satisfied, and the
Schaffners’ claim for failure to warn is preempted under
section 136v(b).




                               53
              V. The Schaffners’ Counterarguments

      The Schaffners’ counterarguments ultimately fail to
persuade us of their claim that the Pa. Duty to Warn cannot be
preempted by virtue of the omission of the Cancer Warning
from Roundup’s Preapproved Label.

                    A. Indian Brand Farms

       The Schaffners first cite the discussion of Bates found
in Indian Brand Farms, Inc. v. Novartis Crop Protection Inc.,

 (3d Cir. 2010), one of our few precedents
addressing preemption under FIFRA. The pesticide label
alleged in Bates to violate state law conformed to that
pesticide’s Preapproved Label. See Bates, 

.
When interpreting Bates in Indian Brand Farms, therefore, we
commented that the Supreme Court’s decision to remand that
case to the Court of Appeals rather than to reverse “established
that mere inconsistency between the duty imposed by state law
and the content of a manufacturer’s labeling approved by the
EPA at registration did not necessarily mean that the state law
duty was preempted.” Indian Brand Farms, 

.
Citing that statement, the Schaffners argue that a state-law duty
cannot be preempted simply because it requires a warning that
was not included on a pesticide’s Preapproved Label.
Schaffner Br. 33.

        Our comment in Indian Brand Farms is consistent with
our holding today and with the reasoning that supports it. As
we explained in Indian Brand Farms, the fact that a pesticide’s
Preapproved Label differs from the label allegedly required by
state law “[does] not necessarily mean that the state law duty
was preempted.” 

 (emphasis added). As a result, state law




                               54
may, in some circumstances, require a pesticide’s label to bear
particular contents that were excluded from its Preapproved
Label. Our reasoning in this opinion fully respects that
principle. We do not hold that FIFRA necessarily preempts
any state-law duty requiring modification to a pesticide’s
Preapproved Label. Rather, we hold only that such duties may
sometimes be preempted, including in the circumstances of this
case.

        First, given the Supreme Court’s explicit explanation in
Bates for its choice to vacate rather than reverse, we read that
disposition — and our commentary on it in Indian Brand Farms
— to address only the preemptive effect of 7 U.S.C. § 136v(b)
when considered on its own. By contrast, our holding today
that the Pa. Duty to Warn is preempted rests not on that section
alone but rather on its effect when considered jointly with the
Preapproval Regulation, which was not examined in Bates. As
discussed, the primary question addressed in Bates was only
whether the parallel-requirements test governs the preemption
of state law under section 136v(b). See Bates, 

-
37. In its briefing, the respondent “chose[] to mount a broader
attack on the ‘parallel requirements’ interpretation” of section
136v(b). 

 at 453 n.27. And while the Court “settled on [its]
interpretation of” that provision, it declined to decide the
remaining question of “whether that provision pre-empts
petitioners’ . . . failure-to-warn claims.” 

. The parties
debated — and the Court decided — what standard governs
whether a state requirement is preempted under section
136v(b) without further applying that standard to the state-law
duty allegedly violated in Bates. And the Court vacated the
decision below rather than reversing it so that the respondent
could “address these matters on remand.” 

                                55
        The Court’s choice to vacate rather than reverse in Bates
plausibly indicates that section 136v(b) does not on its own
preempt all state-law duties to include a warning that was
omitted from a pesticide’s Preapproved Label. But the Court
expressly did not consider whether state law would be
preempted under section 136v(b) in light of requirements
imposed through EPA regulation: it “ha[d] not received
sufficient briefing on this issue” because the parties had not
“identified any EPA regulations that further refine [FIFRA’s]
general [misbranding] standards in any way that is relevant to
petitioners’ allegations.” 

 at 453 & n.27. Because the Court
did not analyze the preemptive effects of EPA regulations
under section 136v(b), we do not understand its disposition of
Bates to express any view on what those effects are. While the
remand may be relevant to our interpretation of section
136v(b), it does not constrain our analysis of whether state-law
duties are preempted by EPA regulations, such as the
Preapproval Regulation, that were expressly not considered in
Bates. The remand in Bates therefore does not undermine our
conclusion in this opinion that FIFRA preempts the Pa. Duty
to Warn in light of the Preapproval Regulation.

       In turn, our discussion of Bates in Indian Brand Farms
was consistent with the Court’s express explanation for its
disposition in Bates. The discrepancy between a pesticide’s
Preapproved Label and the label allegedly required by state law
does not “necessarily” result in the state law’s being
preempted, as we explained in Indian Brand Farms, see 

, in that section 136v(b) does not of its own force
preempt all such state-law duties. Instead, to quote the very
next sentence of our opinion in Indian Brand Farms, “[w]e
must look to the requirements imposed by FIFRA.” 

 And,
of course, those requirements may depend on the regulations




                               56
the EPA has promulgated: whether FIFRA preempts state-law
duties to modify a pesticide’s Preapproved Label will depend
on whether those state-law requirements are in addition to or
different from the content-giving regulatory requirements that
the EPA has promulgated. By noting that FIFRA does not
“necessarily” preempt state-law duties requiring modification
to a pesticide’s Preapproved Label, our opinion in Indian Brand
Farms merely recognized the possibility that such duties would
not be preempted — a possibility that may or may not be
realized depending on what regulations the EPA enacts. Our
FIFRA preemption analysis in this case thus is consistent with
Indian Brand Farms, as it rests specifically on the Preapproval
Regulation. We do not take section 136v(b) automatically to
preempt any state-law duty that would require modification of
a pesticide’s Preapproved Label, regardless of what regulatory
requirements actually have been imposed under FIFRA.

       Furthermore, our holding today would be consistent
with our comment in Indian Brand Farms even were we to
interpret it as addressing the preemptive effect of the
regulations promulgated pursuant to FIFRA, not just of section
136v(b) on its own. We do not today endorse the claim,
rejected in Indian Brand Farms, that any state-law duty
requiring modification of a pesticide’s Preapproved Label is
preempted. See 

. The Pa. Duty to Warn, we
have held, is preempted by virtue of the Preapproval
Regulation. And the Preapproval Regulation does not prohibit
all modifications to a pesticide’s Preapproved Label; rather, as
discussed above, it carves out an exception for modifications
by notification (and without notification) authorized under 

. See 

(a). There is
consequently no per se requirement under FIFRA that a
pesticide’s label conform to its Preapproved Label with respect




                              57
to the label contents that may be modified by notification or
without notification. See generally PRN 98-10. And absent
such a regulatory requirement, no federal requirement would
necessarily preempt a state-law duty requiring a modification
to those contents on the Preapproved Label. With respect to
such duties, “inconsistency between the duty imposed by state
law and the content of a manufacturer’s labeling approved by
the EPA at registration [would] not necessarily mean that the
state law duty was preempted,” just as we explained in Indian
Brand Farms. 

.

       We do not hold the Schaffners’ claim for failure to warn
to be preempted on the grounds, properly rejected in Indian
Brand Farms, that any such claim is “necessarily” preempted
if it would require a modification to the pesticide’s
Preapproved Label. Rather, as we explained in Indian Brand
Farms, when applying section 136v(b) “[w]e must look to the
requirements imposed by FIFRA.” 

. The
opinion in Indian Brand Farms thus continues its analysis by
examining the text of the statute and of applicable agency
actions in order to identify the relevant requirements, just as
we have done here. We conclude that the Schaffners’ claim is
preempted because of the specific requirement imposed
through the Preapproval Regulation, which prohibits the
modification of a pesticide’s Preapproved Label without
further approval unless the exception for modification by
notification (or without notification) applies.

                  B. 7 U.S.C. § 136a(f)(2)

      The Schaffners next claim that FIFRA itself does not
allow the EPA’s registration of a pesticide to affect the




                              58
preemption of state-law duties under that statute.         Under
FIFRA,

       [i]n no event shall registration of an article be
       construed as a defense for the commission of any
       offense under this subchapter. As long as no
       cancellation proceedings are in effect
       registration of a pesticide shall be prima facie
       evidence that the pesticide, its labeling and
       packaging comply with the registration
       provisions of the subchapter.

7 U.S.C. § 136a(f)(2).           The Schaffners contend that
Monsanto’s preemption argument in essence raises registration
as a defense to misbranding, as Monsanto cites the omission of
the Cancer Warning from Roundup’s Preapproved Label as a
basis for denying that it has violated any requirement imposed
under FIFRA. Schaffner Br. 32-33. Because section
136a(f)(2) makes clear that a pesticide may be misbranded
even if it is registered, the Schaffners conclude that the Federal
Comparator must incorporate only the broad statutory
definition of misbranding, not the determinations made by the
EPA during the registration process. Id. 32-34, 37-39. The
Courts of Appeals for the Ninth and Eleventh Circuits each
agreed, citing this provision as one basis for their holdings that
FIFRA does not preempt similar state-law failure-to-warn
claims. See Carson IV, 

; Hardeman II, 

.

      We agree with the Schaffners that EPA registration
cannot be “dispositive of FIFRA compliance.” Schaffner Br.
33. Because section 136a(f)(2) provides that registration
cannot constitute a defense to a violation of FIFRA, a pesticide




                               59
otherwise liable for violating FIFRA cannot defeat liability
simply because it is registered.17 We therefore cannot interpret
any regulation promulgated under FIFRA to implement a rule
under which the mere fact of registration would entail,
dispositively, that a pesticide was not misbranded. But we have
adopted no such interpretation in this opinion. We have instead

17
    This provision predates the modern system of pesticide
registration under FIFRA and is instead a vestige of an earlier
system, enacted in 1947, that mandated pesticides be registered
even if the government deemed their labels non-compliant with
FIFRA. See Federal Insecticide, Fungicide, and Rodenticide
Act § 4(c), 

 Stat. 163, 168 (1947) (“If .
. . the registrant insists that such corrections [to the label] are
not necessary and requests in writing that [the article] be
registered, the Secretary shall register the article . . . . In no
event shall registration of an article . . . be construed as a
defense for the commission of any offense prohibited under . .
. this Act.” (emphasis added)). Congress later amended FIFRA
to prohibit the registration of pesticides with non-compliant
labels while retaining the provision that registration was not a
defense to FIFRA violations, perhaps to address non-compliant
products already on the market. See Federal Insecticide,
Fungicide, and Rodenticide Act Amendments of 1964 § 3,

 Stat. 190, 190, 192 (“If . . . the applicant
for registration does not make the corrections [to the label], the
Secretary shall refuse to register the article . . . . In no event
shall registration of an article be construed as a defense for
commission of any offense prohibited . . . under this Act.”
(emphasis added)). Given the passage of time and the
introduction of re-registration requirements, see, e.g., 7 U.S.C.
§§ 136a(g), 136a-1(a), this provision may have simply lost
some vitality.




                                60
concluded that under the Preapproval Regulation the EPA’s
approval of a proposed label “give[s] content to FIFRA’s
misbranding standards,” Bates, 

, as the
pesticide’s label must conform to its Preapproved Label with
respect to precautionary statements. A pesticide can still be
misbranded despite being registered.18 The EPA’s registration
of a pesticide is therefore not dispositive as to whether it is
misbranded, as section 136a(f)(2) would forbid. Rather,
registration affects the content of the requirements imposed
under FIFRA, as registration determines what label the
pesticide must bear (at least in certain respects). And while
section 136a(f)(2) indicates that registration cannot itself be a
defense to a charge of misbranding, we do not understand it to
indicate that the registration process cannot play any role in
determining the content of a requirement imposed under
FIFRA, the only role we have assigned it in this opinion.

                  C. Mead and the Force of Law

       The Schaffners’ final argument begins with the claim
that only EPA actions with the “force of law” may exert
preemptive force under section 136v(b) by giving content to a
Federal Comparator used in applying the parallel-requirements
test. Schaffner Br. 37, 39. Relying on the Supreme Court’s
analysis of the “force of law” in United States v. Mead Corp.,

18
   Most obviously, a registered pesticide may be misbranded if
it bears a label that differs from its Preapproved Label. And
we have explicitly left unresolved how FIFRA would apply
following the discovery of information rendering a pesticide’s
Preapproved Label inaccurate were the use of that label
continued without applying for amended registration or
otherwise notifying the EPA. See supra note 13.




                               61


 (2001),19 they then conclude — as did
our colleagues on the Courts of Appeals for the Ninth and
Eleventh Circuits — that because the EPA actions Monsanto
relies upon in its preemption arguments lacked the force of law,
they cannot affect the content of the Federal Comparator we
must compare to the Pa. Duty to Warn. Schaffner Br. 35-37,
39; Carson IV, 

; Carson II, 

;
Hardeman II, 

.

       In Carson II and Hardeman II, the key premise in these
arguments — that section 136v(b) bestows preemptive force
only on agency action with the force of law, as that concept is
understood in Mead — was supported only with a citation to
the Supreme Court’s decision in Wyeth v. Levine, 

(2009). See Carson II, 

 (citing Wyeth, 

); Hardeman II, 

 (citing Wyeth, 

); see also Schaffner Br. 32 (quoting Hardeman
II, 

). The opinion in Wyeth, however, did not
interpret a statutory provision that expressly preempted state
law, as section 136v(b) does. Instead, it addressed the distinct
doctrine of implied preemption, under which state law is
preempted if it either conflicts directly with federal law or
poses an obstacle to achieving the aims of federal law. Wyeth,

. For that reason, the Court of Appeals for
the Eleventh Circuit, sitting en banc, vacated Carson II’s
holding that agency action must possess the force of law to

19
  The Court in Mead employed the notion of the “force of law”
in order to identify the appropriate scope of Chevron
deference. 

. Because the Supreme Court
has since overruled Chevron, see Loper Bright, 144 S. Ct. at
2273, the reliance on Mead in Hardeman II and Carson II might
no longer be appropriate today.




                              62
preempt state law pursuant to an express preemption provision.
Carson III, 74 F.4th at 1267-68. Instead, when Congress has
expressly authorized the preemption of state law by statute,
“the meaning of the express-preemption provision . . . triggers
preemption.” Id. at 1268. Thus, “[o]ur role when confronted
with an express-preemption provision is to apply the text that
embodies Congress’s decision.” Id. We have already
concluded that the Preapproval Regulation establishes a
“requirement” under FIFRA’s express preemption provision, 7
U.S.C. § 136v(b).20 See supra Part IV(B). And as Congress

20
  On remand following Carson III’s vacatur of Carson II, the
Court of Appeals for the Eleventh Circuit held that agency
action constitutes a “requirement” for the purposes of section
136v(b) only if it possesses the force of law, as that concept is
used in Mead. Carson IV, 

. It then declined
to “conflate FIFRA’s broad prohibition on misbranding—
indisputably a ‘requirement’—or even generally applicable
agency regulations, with an individualized finding that a
particular pesticide is not misbranded,” concluding that the
EPA’s registration of a pesticide lacks the force of law and
cannot preempt state law. 

. But while a “finding that
a particular pesticide is not misbranded,” 

 may not
constitute a requirement for the purpose of section 136v(b), the
EPA has done more than merely issuing such a finding. As the
court itself recognized in Carson IV, the Preapproval
Regulation prohibits the modification of a pesticide’s
Preapproved Label. See 

; see also 

(a). In Carson IV, the court did not consider the
Preapproval Regulation before concluding that the EPA’s
actions with respect to Roundup lacked the force of law and
therefore established no “requirement” for the purposes of
section 136v(b). 

. We have explained,




                               63
has decreed in the text of that provision that federal
“requirements” have preemptive force, see 

 no further
analysis is necessary.


                          VI. Conclusion

        We conclude that neither issue preclusion nor
administrative law provides a basis upon which to affirm the
MDL Court’s ruling that the Schaffners’ failure-to-warn claim
is not preempted under FIFRA. As to issue preclusion, we
adopt section 29(7) of the Second Restatement. A court has
discretion to decline to apply issue preclusion if the “issue is
one of law and treating it as conclusively determined would
inappropriately foreclose opportunity for obtaining
reconsideration of the legal rule upon which it was based.”
Restatement (Second) of Judgments § 29(7) (Am. L. Inst.
1982). For that reason, we do not apply issue preclusion in this
case. The complex subject of preemption under FIFRA has not
been comprehensively analyzed in prior caselaw, and the
Supreme Court has yet to address FIFRA preemption in the
specific circumstances presented by this case. Independently
evaluating the merits of Monsanto’s preemption arguments
therefore advances our “function of developing the law.” Id.
cmt. i.

       As to those preemption arguments, our analysis differs
from that of the MDL Court — and of our colleagues in other


however, that in our view the Preapproval Regulation does
impose a “requirement.” See supra Part IV(B). As a legislative
rule promulgated following notice and comment, it is “a rule
of law that must be obeyed.” Bates, 

.




                              64
courts who have agreed with its conclusion — chiefly in how
we define the Federal Comparator that must be employed in
applying the parallel-requirements test. We hold that the
Preapproval Regulation prohibits modifying the health
warnings on a pesticide’s Preapproved Label, including by
adding the Cancer Warning; that this prohibition constitutes a
“requirement” for the purposes of section 136v(b); and that
when we apply the parallel-requirements test the Federal
Comparator must incorporate this regulatory requirement
rather than incorporating only the statutory definition of
misbranding. This approach best achieves Congress’s stated
aim of uniformity in pesticide labeling. And the parallel-
requirements test is not satisfied when the Pa. Duty to Warn
and the Federal Comparator are compared under this approach:
they are not equivalent because Monsanto’s alleged violation
of the Pa. Duty to Warn does not constitute a violation of the
Preapproval Regulation. We thus conclude that the Schaffners’
failure-to-warn claim is preempted under section 136v(b).

       For these reasons, we will reverse the judgment of the
District Court.




                             65