Monsanto v. Durnell

1
(Slip Opinion) OCTOBER TERM, 2025
Syllabus
NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
being done in connection with this case, at the time the opinion is issued.
The syllabus constitutes no part of the opinion of the Court but has been
prepared by the Reporter of Decisions for the convenience of the reader.
See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.
SUPREME COURT OF THE UNITED STATES
Syllabus
MONSANTO CO. v. DURNELL
CERTIORARI TO THE COURT OF APPEALS OF MISSOURI,
EASTERN DISTRICT
No. 24–1068. Argued April 27, 2026—Decided June 25, 2026
Monsanto Company manufactures and distributes Roundup, a glypho-
sate-based herbicide designed to control weeds. The EPA has repeat-
edly evaluated glyphosate and repeatedly concluded that glyphosate is
not likely to cause cancer. EPA’s assessment is shared by many other
regulatory bodies around the world. In accordance with EPA’s view
that glyphosate is not likely to cause cancer in humans, EPA has not
required labels on glyphosate-based pesticides like Roundup to include
a cancer warning.
In 2019, John Durnell sued Monsanto in Missouri state court, alleg-
ing that he had used Monsanto’s Roundup products for about 20 years
and that they had caused his non-Hodgkin’s lymphoma. As relevant
here, Durnell brought a failure-to-warn tort claim, asserting that Mon-
santo should have included a cancer warning on Roundup’s label. A
jury agreed and awarded Durnell more than $1 million on the failure-
to-warn theory. On appeal, the Missouri Court of Appeals affirmed,
707 S. W. 3d 828. The Court of Appeals rejected Monsanto’s argument
that the Federal Insecticide, Fungicide, and Rodenticide Act expressly
preempted Durnell’s failure-to-warn claim, see 7 U. S. C. §136v(b).
This Court granted certiorari.
Held: FIFRA expressly preempts Durnell’s state-law failure-to-warn
claim because the claim would require Monsanto to add a cancer warn-
ing to Roundup’s label. Pp. 9–22.
(a) FIFRA’s preemption clause, entitled “Uniformity,” provides that
a “State shall not impose or continue in effect any requirements for
labeling or packaging in addition to or different from those required
under this subchapter.” 7 U. S. C. §136v(b). FIFRA therefore
preempts a state-law labeling requirement that differs from the

2 MONSANTO v. DURNELL
Syllabus
federal labeling requirements imposed under FIFRA. Pp. 9–14.
(1) To register a pesticide, EPA must approve the pesticide’s label
by determining that the label contains all warnings “necessary and . . .
adequate to protect health and the environment” and that the label
does not include any “false or misleading” statements. §§136a(c)(5)(B),
136(q)(1)(A), (G). After EPA approves a pesticide’s label at registra-
tion, manufacturers are legally required to use that label unless and
until EPA approves or requires a label change and amends the pesti-
cide’s registration. See §136a(f)(1); 40 CFR §§152.44(a), 156.70(c). If
a manufacturer does not use the EPA-approved label, it may be subject
to civil and criminal penalties. See 7 U. S. C. §§136l, 136j(a)(1)(E).
Federal law therefore requires Monsanto to sell Roundup with the
label that EPA approved at the initial registration and that EPA has
subsequently re-approved on multiple occasions—that is, the label
without a cancer warning. Meanwhile, as the Court’s precedents make
clear and as the parties agree, state tort duties constitute state label-
ing requirements. See Bates v. Dow Agrosciences LLC, 544 U. S. 431,
443–444. Durnell’s state tort claim would require Monsanto to add a
cancer warning to its labels, which is “in addition to” and “different
from” Monsanto’s federal-law labeling obligations. Pp. 9–11.
(2) The Court’s decision in Riegel v. Medtronic, Inc., 552 U. S. 312,
further confirms that Durnell’s failure-to-warn claim is expressly
preempted. In Riegel, the Court addressed the preemption clause in
the Medical Device Amendments of 1976, which is nearly identical to
FIFRA’s preemption clause. Id., at 316; see 21 U. S. C. §360k(a). The
Riegel Court concluded that FDA’s premarket approval of devices im-
posed “ ‘requirements’ under” the Act’s preemption clause, 552 U. S.,
at 322, and therefore that FDA’s premarket approval of a medical de-
vice preempted state-law claims premised on additional or contrary
safety requirements. Id., at 323–325. Pp. 11–14.
(b) Durnell’s counterarguments are unpersuasive. Pp. 14–22.
(1) Durnell contends that a Missouri failure-to-warn claim, like
FIFRA itself, simply requires manufacturers to include adequate
warnings to protect human health and not to include false or mislead-
ing statements. But that argument operates at far too high a level of
generality and disregards the central and comprehensive role that
EPA performs in making labeling determinations under FIFRA’s reg-
istration provisions. Pp. 14–15.
(2) Durnell argues that EPA’s regulations and its procedures for
registering pesticides and approving pesticide labels exceed or contra-
vene EPA’s statutory authority under FIFRA. Durnell is incorrect.
FIFRA empowers EPA to “prescribe regulations to carry out the provi-
sions of [FIFRA],” §136w(a)(1), and expressly directs EPA to register
pesticides and “determin[e]” that the pesticide’s “labeling” complies

3 Cite as: 609 U. S. ___ (2026)
Syllabus
with FIFRA’s many specific requirements. §136a(c)(5)(B). During that
extensive registration process, EPA critically evaluates the pesticide’s
label to ensure that the label contains all warnings necessary to pro-
tect human health. And after EPA decides the appropriate warnings
for a pesticide’s label, a manufacturer is legally required to use that
label unless and until EPA subsequently approves or requires a new
label. 40 CFR §§152.44(a), 156.70(c). Pp. 15–16.
(3) Durnell seizes on 7 U. S. C. §136a(f)(2), which provides that
registration shall not be “construed as a defense for the commission of
any offense under [FIFRA],” but that registration is “prima facie” evi-
dence of compliance with the registration provisions. By its text,
§136a(f)(2) does not apply to state tort suits; that provision simply clar-
ifies that registration does not bar EPA enforcement actions against
manufacturers for violating FIFRA. Additionally, Monsanto is not in-
voking the mere fact of “registration” as a complete defense to state
tort suits but rather is relying on EPA’s specific determination that
cancer warnings are not required for glyphosate-based pesticide labels.
This argument also contravenes Riegel, where the possibility that FDA
could withdraw its premarket approval based on new evidence or new
analysis did not preclude the Court from concluding that FDA’s pre-
market approval imposed “requirements” on manufacturers that
preempted state tort suits under the Medical Device Amendments’ ma-
terially identical preemption clause. 552 U. S., at 322–323. Pp. 16–
20.
707 S. W. 3d 828, reversed and remanded.
K
AVANAUGH, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and T
HOMAS, ALITO, SOTOMAYOR, KAGAN, and BARRETT, JJ., joined.
THOMAS, J., filed a concurring opinion. JACKSON, J., filed a dissenting
opinion, in which GORSUCH, J., joined.

_________________
_________________
1 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
NOTICE: This opinion is subject to formal revision before publication in the
United States Reports. Readers are requested to notify the Reporter of
Decisions, Supreme Court of the United States, Washington, D. C. 20543,
pio@supremecourt.gov, of any typographical or other formal errors.
SUPREME COURT OF THE UNITED STATES
No. 24–1068
MONSANTO COMPANY, PETITIONER v.
JOHN L. DURNELL
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF
MISSOURI
, EASTERN DISTRICT
[June 25, 2026]
JUSTICE KAVANAUGH delivered the opinion of the Court.
Under authority granted by the Federal Insecticide,
Fungicide, and Rodenticide Act, the Environmental
Protection Agency regulates pesticides, including pesticide
labels. As relevant here, EPA regulates Roundup, a
glyphosate-based pesticide manufactured by Monsanto.
Because EPA has repeatedly concluded that glyphosate is
not likely to cause cancer, the agency has not required a
cancer warning on Roundup’s label. Importantly, EPA’s
regulations require a pesticide manufacturer such as
Monsanto to use the EPA-approved pesticide label—here,
the Roundup label without a cancer warning—unless and
until EPA approves or requires a different label. Moreover,
to ensure “[u]niformity” in labeling, FIFRA’s preemption
clause prohibits States from imposing any pesticide
labeling requirements that are “in addition to or different
from” the federal labeling requirements “under” FIFRA. 7
U. S. C. §136v(b).
John Durnell brought a failure-to-warn tort suit in
Missouri state court against Monsanto for not including a
cancer warning on Roundup’s label. Durnell alleged that

2 MONSANTO v. DURNELL
Opinion of the Court
Monsanto failed to warn him of Roundup’s cancer risks and
that he developed non-Hodgkin’s lymphoma as a result.
But Durnell’s state tort claim would require Monsanto to
add a cancer warning to Roundup’s label even though
federal law requires Monsanto to use the EPA-approved
label without a cancer warning. Because Durnell’s state
tort claim would impose a pesticide labeling requirement
“in addition to or different from” the label required by EPA,
FIFRA expressly preempts Durnell’s claim.
I
A
In 1947, Congress passed and President Truman signed
the Federal Insecticide, Fungicide, and Rodenticide Act. 61
Stat. 163, as amended, 7 U. S. C. §136 et seq. The 1947 Act
required that pesticides be registered with the Secretary of
Agriculture. But the Act assigned the Secretary a relatively
passive role; the Secretary could not refuse to register a
pesticide. 61 Stat. 167–168.
In 1972, Congress passed and President Nixon signed the
Federal Environmental Pesticide Control Act. 86 Stat. 973.
That Act “transformed” FIFRA “into a comprehensive
regulatory statute” and placed the newly created
Environmental Protection Agency in charge of pesticide
registration and labeling. Bates v. Dow Agrosciences LLC,
544 U. S. 431, 437 (2005) (quotation marks omitted). In
doing so, Congress “significantly strengthened FIFRA’s
registration and labeling standards” and granted
“increased enforcement authority” to EPA. Wisconsin
Public Intervenor v. Mortier, 501 U. S. 597, 601 (1991).
Under that revamped regulatory regime, which still
governs today, pesticides must be registered with EPA.
§§136a(a), 136j(a)(1)(A). Before registering a pesticide,
EPA undertakes an extensive review of the pesticide and
its proposed labeling. Pesticide manufacturers must
submit information about the pesticides’ formulas,

3 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
potential adverse effects, and testing. §§136a(c)(1)(A)–(F),
(2); 40 CFR §152.50(f )(3) (2025). Manufacturers must also
propose a label for their products, which must include any
necessary precautionary statements. 7 U. S. C.
§136a(c)(1)(C); 40 CFR §156.10(a)(1)(vii).
EPA must then review all of that information and data.
To register a pesticide, EPA must conclude that the
pesticide “will not generally cause unreasonable adverse
effects” on human health and the environment, and that its
labeling “compl[ies] with the requirements” of FIFRA. 7
U. S. C. §§136a(c)(5)(B), (D).
As to the label, FIFRA requires that a pesticide not be
“misbranded.” §136j(a)(1)(E). A pesticide is misbranded if
its label contains “any statement” that is “false or
misleading” or if the label does not contain “a warning or
caution statement which may be necessary and . . .
adequate to protect health and the environment.”
§§136(q)(1)(A), (G). FIFRA defines “protect health and the
environment” to mean “protection against any
unreasonable adverse effects on the environment,”
including “any unreasonable risk to man or the
environment, taking into account the economic, social, and
environmental costs and benefits of the use of any
pesticide.” §§136(x), (bb).
FIFRA authorizes EPA to issue regulations to “carry out
the provisions of ” FIFRA. §136w(a)(1). Under that
statutory authority, EPA has promulgated extensive
regulations fleshing out what it means for a pesticide to be
misbranded and dictating what must appear on a
pesticide’s label. See, e.g., 40 CFR §156.10 (Labeling
requirements). As relevant here, those regulations specify
the required content and placement of precautionary
statements such as cancer warnings. See §§156.60–156.70
(Human Hazard and Precautionary Statements).
Putting all of that together, before registering a pesticide,
EPA must evaluate a pesticide and its proposed label—and

4 MONSANTO v. DURNELL
Opinion of the Court
must determine that the proposed label includes all
warnings necessary and adequate to protect human health
and the environment, and is not false or misleading. EPA’s
registration of the pesticide and approval of the pesticide’s
label embodies the agency’s considered judgment that a
pesticide is not misbranded—that is, that the label is not
false or misleading and does not omit a necessary warning.
See 7 U. S. C. §§136a(c)(5)(B), 136(q)(1)(A), (G).
Importantly, after EPA has registered the pesticide and
approved the label, the manufacturer is required to use that
label. Subject to narrow exceptions not relevant here, the
manufacturer may not change the label unless EPA
subsequently approves a manufacturer’s proposed change
or EPA itself requires a change to the label. See 40 CFR
§§152.44(a), 156.70(c). If a manufacturer does not use the
EPA-approved label, it may be subject to civil and criminal
penalties. See 7 U. S. C. §§136j(a)(1)(E) (misbranding
violation), 136l (civil and criminal penalties). In particular,
EPA may bring enforcement actions against a
manufacturer for violating FIFRA’s misbranding
provisions—which could happen, for example, if a
manufacturer sells its pesticide with a different label than
the one EPA approved. If EPA determines that a given
warning is necessary for a pesticide’s label and the
manufacturer then proceeds to sell the pesticide without
that warning, the manufacturer might face liability for
misbranding.
1
EPA’s comprehensive regulatory role does not end with
the pesticide’s initial registration and label approval. If the
manufacturer wants to modify the label, it typically must
——————
1
Registration carries other consequences, too. FIFRA prohibits selling
a pesticide “if any claims made for it . . . substantially differ” from any
claims made in “the statement required in connection with its
registration.” 7 U. S. C. §136j(a)(1)(B). And FIFRA prohibits selling a
pesticide if its “composition” differs from the composition described at
registration. §136j(a)(1)(C).

5 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
go through an amended registration process. FIFRA
provides that if “the labeling . . . for a pesticide is changed,
the registration shall be amended to reflect such change if
the [EPA] Administrator determines that the change will
not violate” FIFRA. §136a(f )(1). EPA regulations further
provide that “any modification” to the “labeling” of a
“registered product must be submitted with an application
for amended registration.” 40 CFR §152.44(a); see §152.50
(listing required contents of registration and amended
registration applications).
EPA also possesses a slew of tools to monitor the pesticide
market and scientific developments, and thereby ensure
that pesticide labels contain appropriate warnings in light
of changed circumstances or new information. After the
initial registration and approval of a label, manufacturers
must continue to inform EPA of “additional factual
information regarding unreasonable adverse effects” of
their pesticides. 7 U. S. C. §136d(a)(2). That obligation is
enforced through civil and criminal penalties. See §136l.
EPA may also “determin[e] that additional data are
required to maintain in effect an existing registration of a
pesticide,” and therefore request more information from
the manufacturers. §§136a(c)(2)(B)(i)–(ii). In that
circumstance, manufacturers must take appropriate steps
to disclose that new evidence or face suspension of their
pesticides’ registration. §136a(c)(2)(B)(iv). In light of new
information or analysis by EPA, the agency at any time may
require “additional labeling language” to “mitigate”
“identified hazard(s).” 40 CFR §152.170(e)(1). EPA also
must formally review a pesticide’s registration every 15
years. 7 U. S. C. §§136a(g)(1)(A)(iii)–(iv).
In addition, EPA may cancel a pesticide’s registration,
and thereby prohibit its continued sale, if “it appears to the
Administrator that a pesticide or its labeling . . . does not
comply with” FIFRA. §136d(b). EPA may also immediately
suspend a pesticide’s registration if “necessary to prevent

6 MONSANTO v. DURNELL
Opinion of the Court
an imminent hazard” while a cancellation is pending.
§136d(c)(1).
On top of EPA’s own authority to monitor a pesticide’s
continued safety and order appropriate changes such as a
new label, any person can petition EPA to modify, suspend,
or cancel a pesticide’s registration based on, for example,
new evidence about the dangers of the pesticide. 40 CFR
§154.10. If EPA refuses to do so, a party may seek judicial
review of EPA’s decision. 7 U. S. C. §§136n(a), 136d(h).
Finally, and crucially for this case, FIFRA includes a
preemption clause that further underscores EPA’s
comprehensive and exclusive authority in registering
pesticides and approving labels. In a provision entitled
“Uniformity”—a title that was added in a public law
enacted by Congress in 1988, not by the codifiers—FIFRA
prohibits States from imposing “any requirements for
labeling or packaging in addition to or different from those
required under” FIFRA. §136v(b); Federal Insecticide,
Fungicide, and Rodenticide Act Amendments of 1988, 102
Stat. 2654, 2687.
2
B
Monsanto Company is a subsidiary of Bayer AG.
Monsanto manufactures and distributes Roundup, a
glyphosate-based herbicide designed to control weeds.
3
In 1974, EPA first registered glyphosate-based pesticides
and approved Roundup’s label without a cancer warning.
In 1991 and for the more than three decades since, EPA has
repeatedly re-evaluated glyphosate and has repeatedly
concluded that glyphosate is not likely to cause cancer. For
——————
2
States remain free to “regulate the sale or use of any federally
registered pesticide.” §136v(a). For example, a State could outright ban
a pesticide within its borders.
3
Pesticide is an umbrella term that covers any substance “intended for
preventing, destroying, repelling, or mitigating any pest.” §136(u). A
herbicide is a kind of pesticide that specifically targets weeds.

7 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
example, in 1991, EPA classified glyphosate as unlikely to
cause cancer in humans. See EPA, Office of Pesticides and
Toxic Substances, Second Peer Review of Glyphosate 1 (Oct.
30, 1991). In 1993, EPA reiterated that conclusion and re-
registered glyphosate products without a cancer warning.
See EPA, Office of Prevention, Pesticides and Toxic
Substances, Reregistration Eligibility Decision: Glyphosate
13–14 (Sept. 1993).
In 2017 and 2019, after the International Agency for
Research on Cancer classified glyphosate as a probable
carcinogen, EPA re-examined the issue but still adhered to
its longstanding position on glyphosate. See EPA, Office of
Pesticide Programs, Revised Glyphosate Issue Paper:
Evaluation of Carcinogenic Potential 12–13, 144 (Dec. 12,
2017); EPA, Glyphosate: Proposed Interim Registration
Review Decision 7–8 (Apr. 2019). In 2020, in an interim
registration review decision, EPA reiterated that same
position. See EPA, Glyphosate: Interim Registration
Review Decision Case No. 0178, p. 10 (Jan. 2020); Natural
Resources Defense Council v. EPA, 38 F. 4th 34, 51 (CA9
2022) (vacating EPA’s 2020 decision regarding glyphosate).
EPA’s assessment of glyphosate is shared by many other
regulatory bodies around the world that have likewise
concluded that glyphosate is not carcinogenic, including
regulators in Canada, Australia, Japan, and the European
Union.
All told, in accordance with EPA’s view that glyphosate
is not likely to cause cancer in humans, EPA has not
required glyphosate-based pesticides like Roundup to
include a cancer warning on their labels.
4
Therefore, as a
matter of federal law, Monsanto legally must use a label
without a cancer warning unless and until EPA approves or
requires a change.
——————
4
Monsanto has phased out residential Roundup products that contain
glyphosate.

8 MONSANTO v. DURNELL
Opinion of the Court
C
In 2019, John Durnell sued Monsanto in Missouri state
court. Durnell alleged that he had used Monsanto’s
Roundup products for about 20 years and that they had
caused his non-Hodgkin’s lymphoma, a form of cancer. As
relevant here, Durnell brought a failure-to-warn tort claim,
claiming that Monsanto should have included a cancer
warning on Roundup’s label. A jury agreed and awarded
Durnell more than $1 million on the failure-to-warn theory.
In Missouri trial court, Monsanto moved on preemption
grounds for judgment notwithstanding the verdict.
Monsanto argued that FIFRA expressly preempted
Durnell’s failure-to-warn claim because FIFRA prohibits
States from imposing labeling requirements that are “in
addition to or different from” those imposed under FIFRA.
7 U. S. C. §136v(b). Monsanto explained that EPA
approved its labels without a cancer warning at registration
and that it was therefore able to (indeed, required to) keep
using that label.
The Missouri trial court rejected Monsanto’s preemption
argument. The Missouri Court of Appeals affirmed. 707
S. W. 3d 828 (2025). The Court of Appeals reasoned that
Missouri failure-to-warn claims are “fully consistent with”
FIFRA’s misbranding provisions because “both require a
pesticide manufacturer to adequately warn users of the
potential dangers of using its product.” Id., at 832–833.
The federal Courts of Appeals and state courts have
divided over whether FIFRA preempts a state tort claim
based on Roundup’s lack of a cancer warning. Compare
Schaffner v. Monsanto Corp., 113 F. 4th 364 (CA3 2024),
with Carson v. Monsanto Co., 92 F. 4th 980 (CA11 2024);
Hardeman v. Monsanto Co., 997 F. 3d 941 (CA9 2021);
Johnson v. Monsanto Co., 333 Ore. App. 678, 554 P. 3d 290
(2024); Pilliod v. Monsanto Co., 67 Cal. App. 5th 591, 282
Cal. Rptr. 3d 679 (2021).

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To resolve that split, this Court granted certiorari. 607
U. S. 1148 (2026).
II
FIFRA’s preemption clause is entitled “Uniformity” and
provides that a “State shall not impose or continue in effect
any requirements for labeling or packaging in addition to
or different from those required under this subchapter.” 7
U. S. C. §136v(b). FIFRA therefore preempts a state-law
labeling requirement that differs from the federal labeling
requirements imposed under FIFRA. “Uniformity” in
labeling—the textually stated objective of FIFRA’s
preemption clause—would otherwise be impossible to
achieve. Ibid.
A
To start, as this Court’s precedents make clear and as the
parties agree, state tort duties constitute state labeling
requirements. See Bates v. Dow Agrosciences LLC, 544
U. S. 431, 443–444 (2005); Riegel v. Medtronic, Inc., 552
U. S. 312, 323–324 (2008); Cipollone v. Liggett Group, Inc.,
505 U. S. 504, 523–524 (1992) (plurality opinion); id., at
548–549 (Scalia, J., concurring in judgment in part and
dissenting in part). Failure-to-warn claims, like Durnell’s
claim here, “are premised on common-law rules that
qualify” as labeling requirements because those “rules set a
standard for a product’s labeling.” Bates, 544 U. S., at 446.
That makes good sense. After all, the heart of Durnell’s
failure-to-warn claim under Missouri tort law is that
Monsanto should have included a cancer warning on its
Roundup labels.
The question, then, is whether the Missouri failure-to-
warn claim—which would require a cancer warning on the
Roundup label—would impose a labeling requirement that
is “in addition to or different from” federal labeling
requirements imposed “under” FIFRA. The answer is yes.

10 MONSANTO v. DURNELL
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As described at length above, to register a pesticide, EPA
must approve the pesticide’s label. And to approve the
label, EPA must determine that the label contains all
warnings “necessary and . . . adequate to protect health and
the environment” and that a label does not include any
“false or misleading” statements. §§136a(c)(5)(B),
136(q)(1)(A), (G).
After EPA approves a pesticide’s label at registration,
manufacturers are legally required to use that label—
unless and until EPA approves or requires a label change
and amends the pesticide’s registration. See §136a(f )(1); 40
CFR §§152.44(a), 156.70(c) (2025). If a manufacturer does
not use the EPA-approved label, it may be subject to civil
and criminal penalties. See 7 U. S. C. §§136l, 136j(a)(1)(E).
It is true that EPA may subsequently change course in
light of new information or new analysis, and require an
amended label and amended registration. As described
above, FIFRA and EPA’s regulations set forth an extensive
process for doing so. But absent such an EPA-approved or
EPA-required label change, the pesticide manufacturers
may—and indeed legally must—use the pesticide label
approved by EPA at registration.
5
——————
5
Of course, a manufacturer may make “minor modifications” by
notification to EPA and without EPA’s approval. 40 CFR §152.46(a)(1).
But EPA’s regulations specifically require EPA approval for
precautionary “statements pertaining to the hazards of the product,”
which would include cancer warnings. §156.70(c); see also Brief for
United States as Amicus Curiae 32–33 (“that exception” for minor
modifications “does not apply to precautionary statements like cancer
warnings”).
The dissent disputes that conclusion, maintaining that precautionary
statements encompass only “acute hazards,” not chronic risks—and thus
do not require EPA approval for cancer warnings. Post, at 6, n. 4 (opinion
of J
ACKSON, J.). The ordinary meaning of “hazards” and “precautionary
statements,” however, covers cancer warnings. Hazards to human
health are hazards. As the U. S. Government has explained,
“precautionary statements” pertain to the hazards of a pesticide and thus

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Opinion of the Court
In sum, federal law requires Monsanto to sell Roundup
with the label that EPA approved at the initial registration
and that EPA has subsequently re-approved on multiple
occasions—that is, the label without a cancer warning.
Durnell’s state tort claim, by contrast, would require
Monsanto to add a cancer warning to its labels. That
Missouri-law requirement is “in addition to” and “different
from” Monsanto’s federal-law labeling obligations.
B
This Court’s precedents reinforce that textual conclusion.
In Bates, the Court explained that the relevant labeling
“requirements” under FIFRA included FIFRA’s
misbranding provision and “any relevant EPA regulations
that give content to FIFRA’s misbranding standards.” 544
U. S., at 453.
And the Bates Court gave a telling example of how
FIFRA’s preemption clause operates. If an EPA regulation
required a “CAUTION” designation for a pesticide and if a
state failure-to-warn claim targeted the pesticide’s label for
including the “CAUTION” designation instead of a
——————
plainly encompass “cancer warning[s].” Brief for United States as
Amicus Curiae 7 (quotation marks omitted); see Tr. Oral Arg. 55 (“[I]f
you are doing something like a hazard warning, which I don’t see any
way of describing a cancer warning as anything other than that, you
must get agency approval. That’s what it says. That’s 156.70”); see also
id., at 43 (“[Section] 156.70 is the clearest. It says, for hazards like
cancer, you have to ask for EPA’s approval”). That is why EPA requires
robust evidence of a pesticide’s potential carcinogenicity as a part of
registration. See, e.g., 40 CFR §§158.34, 158.130(d)(3), 158.500(d) (2025).
And that is why, with respect to Roundup specifically, EPA has
repeatedly evaluated glyphosate’s potential carcinogenicity to ensure
that the pesticide “will not generally cause unreasonable adverse effects”
on human health and the environment. 7 U. S. C. §136a(c)(5)(D); see
supra, at 6–7. Moreover, even if Monsanto could unilaterally add a
cancer warning to its Roundup label as a “minor modification,” EPA has
not required such a warning. Therefore, a state-law requirement
purporting to mandate a cancer warning is necessarily “in addition to”
or “different from” the relevant federal requirements.

12 MONSANTO v. DURNELL
Opinion of the Court
“DANGER” warning, that failure-to-warn claim would be
preempted. See ibid.
Here, just like an EPA regulation providing that a
pesticide need not include a “DANGER” warning on its
label, EPA’s registration determination that Roundup’s
label need not include a cancer warning constitutes a
federal labeling requirement that cannot be altered by state
law, including state tort suits. That is because those
registration determinations, just like EPA’s regulations,
“give content to FIFRA’s misbranding standards.” Ibid.
To be sure, in Bates, the state failure-to-warn claims at
issue targeted a pesticide label’s efficacy claims. See id., at
435, 440. Those state tort claims were not preempted.
Bates distinguished between efficacy claims on the one
hand—which EPA did not review as a part of registration—
and safety claims on the other hand, which EPA does
thoroughly review at registration and are therefore
preempted. See id., at 440 (“EPA’s approval of a pesticide
label does not reflect any determination on the part of EPA
that the pesticide will be efficacious”) (quotation marks
omitted).
This case of course concerns safety claims. And when it
comes to safety claims, EPA’s registration determinations
do reflect EPA’s considered judgment that a pesticide’s
label is not false or misleading and contains all necessary
warnings. So safety claims that would impose labeling
requirements “in addition to” or “different from” those
required under FIFRA are preempted.
The Court’s more recent decision in Riegel further
confirms that Durnell’s failure-to-warn claim is expressly
preempted. In Riegel, the Court addressed the preemption
clause in the Medical Device Amendments of 1976, which is
nearly identical to FIFRA’s preemption clause. 552 U. S.,

13 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
at 316; see 21 U. S. C. §360k(a).
6
The Medical Device
Amendments direct the Food and Drug Administration to
approve medical devices for sale after analyzing their
safety, just as EPA does for pesticides. 552 U. S., at 318.
As part of the premarket approval process, FDA is required
to review the device’s label and to determine that the label
is neither false nor misleading, as EPA does for pesticide
labels. Ibid. And after FDA approves a device, the
manufacturer is required to use that label and is prohibited
from making any changes to the device or label without
additional FDA approval, as is the case with pesticide labels
and EPA. Id., at 319.
The Riegel Court concluded that FDA’s premarket
approval of devices imposed “‘requirements’ under” the
Act’s preemption clause, id., at 322, and therefore that
FDA’s premarket approval of a medical device preempted
state-law claims premised on additional or contrary safety
requirements. Id., at 323–325.
Riegel is dispositive here. If FDA’s premarket approval
of medical devices preempted additional state-law
requirements, so too must EPA’s registration of pesticides
and approval of pesticide labels.
As Riegel indicates, allowing Durnell’s state tort claim to
overcome preemption would affect more than FIFRA. The
Medical Device Amendments and several other federal
statutes across a range of industries contain similar or
identical labeling preemption provisions. See, e.g., 21
U. S. C. §§678; 1052(b); 467e; 379s(a), 379r(a)(2); 343–
1(a)(2)–(4). Those similar labeling preemption clauses
——————
6
The MDA’s express preemption clause provides that “no State . . .
may establish or continue in effect with respect to a device intended for
human use any requirement—(1) which is different from, or in addition
to, any requirement applicable under this chapter to the device, and
(2) which relates to the safety or effectiveness of the device or to any
other matter included in a requirement applicable to the device under
this chapter.” 21 U. S. C. §360k(a) (emphasis added).

14 MONSANTO v. DURNELL
Opinion of the Court
reflect Congress’s judgment that the ability to sell a product
throughout the country with a single label can be important
to maintaining an efficient nationwide market.
In short, under federal law, Monsanto was required (i) to
obtain EPA’s approval for its Roundup label at registration;
and (ii) to use the EPA-approved Roundup label unless, in
the future, EPA approved or required changes to the label.
Those are the relevant federal labeling requirements
“under” FIFRA. Durnell’s failure-to-warn claim,
meanwhile, would require Monsanto to place a cancer
warning on Roundup’s label. That state labeling
requirement is “in addition to or different from” EPA’s
labeling determinations that do not mandate a cancer
warning. Durnell’s failure-to-warn claim is expressly
preempted.
7
III
Durnell counters with four overlapping arguments, none
of which is persuasive.
First, Durnell (echoed by the dissent) contends that a
Missouri failure-to-warn claim, like FIFRA itself, simply
requires manufacturers to include adequate warnings to
protect human health, and not to include false or
misleading statements. Compare Moore v. Ford Motor Co.,
332 S. W. 3d 749, 756 (Mo. 2011), with 7 U. S. C.
§§136(q)(1)(A), (G), 136j(a)(1)(E). But that argument
operates at far too high a level of generality and disregards
the central and comprehensive role that EPA performs in
making labeling determinations under FIFRA’s
registration provisions. Looking at only FIFRA’s general
standard for misbranding rather than the specific
requirements imposed under federal law would nullify
——————
7
Because we conclude that Durnell’s failure-to-warn claim is expressly
preempted, we need not consider Monsanto’s implied preemption
argument.

15 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
FIFRA’s preemption clause and the uniformity that
Congress sought for safety warnings on pesticide labels.
Durnell’s argument implausibly maintains that EPA’s
registration and labeling determinations do not have
preemptive force. But by its text, FIFRA affords
preemptive force to federal requirements imposed “under”
FIFRA, not merely those imposed “by” the actual statute
itself. §136v(b). And FIFRA authorizes EPA to “prescribe
regulations to carry out the provisions of [FIFRA],” and
requires EPA to make registration and labeling
determinations. §§136w(a)(1), 136a(c)(5)(B). EPA’s
regulations require manufacturers to use the label
approved by EPA, or face potential civil or criminal
penalties. See 40 CFR §§152.44(a), 156.70(c) (2025); 7
U. S. C. §§136j(a)(1)(E), 136l. So EPA’s registration
determinations as to the appropriate level of warning on a
pesticide’s label impose “requirements” “under” FIFRA.
Durnell’s argument also contravenes Riegel v. Medtronic,
Inc., 552 U. S. 312 (2008). There, as explained above, the
Court held that FDA’s determinations in the premarket
approval process imposed federal “‘requirements’” “under”
the Medical Device Amendments and thereby displaced
additional or different state-law requirements imposed
through state tort suits. Id., at 322–323. There is no good
argument for treating FDA’s premarket approval as
“requirements” “under” the Medical Device Amendments,
but not treating EPA’s regulations and registration
determinations as requirements under FIFRA’s materially
identical preemption clause.
Second, Durnell claims that EPA’s regulations—and its
procedures for registering pesticides and approving
pesticide labels—exceed or contravene EPA’s statutory
authority under FIFRA. See Brief for Respondent 21–25,
39–40 (citing Loper Bright Enterprises v. Raimondo, 603
U. S. 369 (2024)).

16 MONSANTO v. DURNELL
Opinion of the Court
Durnell is incorrect. Again, FIFRA empowers EPA to
“prescribe regulations to carry out the provisions of
[FIFRA].” 7 U. S. C. §136w(a)(1). And FIFRA expressly
directs EPA to register pesticides and “determin[e]” that
the pesticide’s “labeling” complies with FIFRA’s many
specific requirements. §136a(c)(5)(B). During that
extensive registration process, EPA critically evaluates the
pesticide’s label to ensure that the label contains all
warnings necessary to protect human health. After EPA
makes a determination about the appropriate warnings for
a pesticide’s label, a manufacturer is legally required to use
that label unless and until EPA subsequently approves or
requires a new label. See 40 CFR §§152.44(a), 156.70(c).
Under FIFRA’s preemption provision, those federal
labeling requirements displace any additional or different
state-law requirements.
Third, Durnell (also echoed by the dissent) seizes on one
of FIFRA’s self-described “[m]iscellaneous” provisions, 7
U. S. C. §136a(f )(2), which provides that “[i]n no event shall
registration . . . be construed as a defense for the
commission of any offense under this subchapter,” but that
registration is “prima facie” evidence of compliance with the
registration provisions. Durnell argues that the fact of
“registration” of a pesticide like Roundup could not serve as
a defense to an EPA enforcement action for misbranding
and therefore cannot serve as a defense in a state tort suit
that parallels a federal misbranding action.
That argument would effectively erase FIFRA’s express
preemption clause. And the argument fails for multiple
independent reasons.
To begin, §136a(f )(2), by its text, does not apply to state
tort suits. That provision simply clarifies that registration
does not bar EPA enforcement actions against
manufacturers for violating FIFRA.
Moreover, the premise of Durnell’s §136a(f )(2) argument
is flawed. It is highly doubtful that EPA would bring an

17 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
enforcement action for misbranding against a
manufacturer for using the EPA-approved and EPA-
required label. Rather, a manufacturer’s label might
constitute a misbranding violation if the label (i) included
information that was not on the EPA-approved label, or
(ii) omitted information that was on the EPA-approved
label. Under those circumstances, the mere fact of
registration obviously may not serve as a complete defense
to an EPA enforcement action, as §136a(f )(2) indicates. In
that context, §136a(f )(2) makes complete sense.
But Durnell’s failure-to-warn claim does not fault
Monsanto for using a label different from the EPA-approved
labeling. Durnell instead faults Monsanto for not using a
label different from the EPA-approved label. But FIFRA’s
preemption clause expressly preempts any state tort claim
that would require a pesticide manufacturer to use a label
“in addition to” or “different from” federal requirements
imposed under FIFRA, which, as explained above, include
the EPA-approved label.
And even more problematic for Durnell, EPA regulations
promulgated under FIFRA require a manufacturer to use
the EPA-approved label and prohibit the manufacturer
from unilaterally changing the label without EPA’s
approval. See 40 CFR §§152.44(a), 156.70(c). Indeed, if the
manufacturer unilaterally changed the label, as Durnell
says Monsanto should have done, the manufacturer would
be flouting EPA’s regulations and exposing itself to
potentially severe federal penalties. See 7 U. S. C.
§§136j(a)(1)(E), 136l. So Durnell’s argument also triggers
potential retroactivity and estoppel questions. The law is
not ordinarily read to retroactively penalize persons for
doing what the Government had required them to do. Cf.
Landgraf v. USI Film Products, 511 U. S. 244 (1994).
Not surprisingly, therefore, the United States explicitly
represented at oral argument that EPA does not bring a
misbranding action when the manufacturer was using an

18 MONSANTO v. DURNELL
Opinion of the Court
EPA-approved label. See Tr. of Oral Arg. 44 (“EPA doesn’t
go after people for . . . not changing your label even though
EPA doesn’t let you . . . . We don’t bring that kind of
enforcement action”). Instead, as described at length above,
if new safety information comes to light, EPA may gather
more information from the manufacturer; ask the
manufacturer to change its label; pursue registration
cancellation, suspension, or modification proceedings; or
seek civil or criminal penalties if a manufacturer failed to
inform EPA of important new safety-related information.
See 7 U. S. C. §§136a(d), 136d, 136l; 40 CFR §152.170(e)(1);
Tr. of Oral Arg. 51–52 (United States: “if EPA also thought
that there was some sort of misbranding risk,” “as a
practical matter, what happens is EPA gets information
and might ask the manufacturer . . . can you please try to
amend your registration and change it?”).
But suppose (contrary to the United States’ express
representation to this Court) that EPA someday did charge
a manufacturer with misbranding for using the EPA-
approved and EPA-required label. Even in that unlikely
scenario, Durnell’s §136a(f )(2) argument would falter in
light of the statutory text and context. To reiterate,
§136a(f )(2)’s proviso that registration is not a defense is
limited to EPA enforcement actions for “any offense under
this subchapter.” And it would be rather bizarre to read a
provision entitled “[m]iscellaneous” and dealing only with a
defense to an EPA enforcement action to upend FIFRA’s
carefully calibrated and EPA-centric regulatory scheme.
Make no mistake: Durnell’s §136a(f )(2) argument would
negate FIFRA’s express preemption clause, expose
manufacturers to potentially massive tort liability for doing
what EPA required them to do, and eviscerate the

Cite as: 609 U. S. ____ (2026) 19
Opinion of the Court
“uniformity” of EPA’s labeling determinations.
§§136a(f )(2), 136v(b).
8
See
In addition, Durnell’s §136a(f )(2) argument does not
work for yet another reason. Monsanto is not invoking the
mere fact of “registration” as a complete defense to state
tort suits. Rather, Monsanto is relying on EPA’s specific
determination that cancer warnings are not required for
glyphosate-based pesticide labels. So even by its own
terms, §136a(f )(2) would not apply here.
Last, Durnell’s §136a(f )(2) argument contravenes this
Court’s decision in Riegel. In that case, FDA was
statutorily authorized to withdraw premarket approval for
a medical device based on “newly reported data or existing
information.” 552 U. S., at 319. And FDA was obligated to
withdraw approval if it “determine[d] that a device is
unsafe or ineffective.” Id., at 319–320. But the possibility
that FDA could withdraw its premarket approval based on
new evidence or new analysis did not preclude this Court
from concluding that FDA’s premarket approval imposed
“requirements” on manufacturers that preempted state tort
suits under the Medical Device Amendments’ materially
identical preemption clause. Id., at 322–323.
9
——————
8
Durnell’s §136a(f )(2) argument also runs up against the Act’s history.
Under the initial 1947 Act, manufacturers would apply to register their
pesticides with the Secretary of Agriculture, and the Secretary’s decision
to grant registration was essentially mandatory. See 61 Stat. 163, 168;
Bates v. Dow Agrosciences LLC, 544 U. S. 431, 437, n. 8 (2005). At that
time, registration did not indicate compliance with the Act. So
§136a(f )(2) is a vestige of that earlier regulatory approach, which is
another contextual reason not to interpret it so broadly as to erase
FIFRA’s later-added preemption clause.
9
The dissent advances two further arguments for distinguishing
Riegel. Neither works. First, the dissent contends that the Medical
Device Amendments lack an equivalent to FIFRA’s §136a(f )(2). See post,
at 19–20. But as explained above, premarket approval of a medical
device did not prevent the FDA from later withdrawing its approval, just
as §136a(f )(2) and other statutory provisions indicate that the mere fact

20 MONSANTO v. DURNELL
Opinion of the Court
So too here. The theoretical possibility that EPA could
(despite its representation otherwise) try to bring a
misbranding enforcement action against a pesticide
manufacturer on the theory that the EPA-approved and
EPA-required label had in essence become misbranded over
time due to new evidence does not deprive EPA’s
registration decisions of their preemptive force.
Fourth, and relatedly, Durnell raises concerns about the
scenario in which new safety information arises after EPA’s
initial registration determination and labeling approval.
As described at length above, however, Durnell’s policy
concern about regulatory lag is amply addressed by the
extensive processes that FIFRA and EPA’s implementing
regulations have established to respond to new or evolving
safety information. For example, manufacturers must
apprise EPA of new information “regarding unreasonable
adverse effects” of their pesticides. §136d(a)(2). That
obligation is backed by civil and criminal penalties. §136l.
EPA, meanwhile, also has many ways of ensuring a
pesticide’s continued compliance with FIFRA. EPA does
not sit in an information-free silo. It keeps abreast of new
safety developments. EPA may request additional
——————
of registration does not foreclose EPA from later changing its labeling
requirements.
Second, the dissent points out that Riegel did not consider state-law
claims that were parallel to “an applicable federal requirement, apart
from the FDA’s premarket approval process.” Post, at 20. From that,
the dissent concludes that Riegel does not control this case, which
involves state-law claims that are allegedly parallel to an applicable
federal requirement—FIFRA’s misbranding prohibition. See post, at 20.
But that conclusion does not follow. It is true that Riegel did not assess
whether the state-law claims at issue were “different from, or in addition
to” the relevant federal-law requirements. 552 U. S., at 330 (quotation
marks omitted). But Riegel indisputably did resolve the question of
whether premarket approval constituted a “requirement” for preemption
purposes. See id., at 322–323. That is the portion of Riegel that controls
here: It establishes that EPA’s analogous registration and label approval
determinations are “requirements” under FIFRA.

21 Cite as: 609 U. S. ____ (2026)
Opinion of the Court
information from manufacturers whenever the Agency
“determines that additional data are required to maintain”
a pesticide’s registration. §136a(c)(2)(B)(i). And EPA
possesses ample resources to evaluate that information.
EPA may solicit “comments, evaluations, and
recommendations” to “improve the effectiveness and
quality” of EPA’s “scientific analyses” from scientific
advisory panels. §136w(d)(1).
For example, in the aftermath of the International
Agency for Research on Cancer’s classification of glyphosate
as probably carcinogenic, EPA commissioned multiple
reports about glyphosate’s potential carcinogenicity from
its Cancer Assessment Review Committee and Office of
Pesticide Programs. See EPA, Office of Chemical Safety
and Pollution Prevention, Glyphosate: Report of the Cancer
Assessment Review Committee 7–8 (Oct. 1, 2015); EPA,
Office of Pesticide Programs, Revised Glyphosate Issue
Paper: Evaluation of Carcinogenic Potential 13 (Dec. 12,
2017).
Moreover, if third parties (like Durnell) want to bring
new information to EPA’s attention or if they believe that
EPA has failed to consider relevant information, those third
parties are free to petition EPA to modify, suspend, or
cancel a pesticide’s registration. See 40 CFR §154.10. And
EPA’s decision in response to such a petition is subject to
judicial review. See 7 U. S. C. §§136n(a), 136d(h).
10
As demonstrated by that comprehensive regulatory
regime, EPA possesses a variety of tools to learn of and
address new safety information. And as a matter of law,
state tort law may not impose labeling requirements “in
——————
10
If a citizen becomes aware of new safety concerns that arise after
registration, the citizen is free to bring the information to EPA’s
attention and ask EPA to cancel or suspend the pesticide’s registration,
or require a labeling change. But that is quite different from seeking to
retroactively penalize a manufacturer for doing what it was legally
required to do at the time.

22 MONSANTO v. DURNELL
Opinion of the Court
addition to” or “different from” federal requirements
imposed under FIFRA.
***
With respect to pesticide labels, FIFRA demands
“[u]niformity” and expressly preempts state labeling
requirements that are “in addition to” or “different from”
federal labeling requirements. §136v(b). Durnell’s state-
law failure-to-warn claim would require a cancer warning
on Roundup’s label—a requirement “in addition to” and
“different from” the label required by EPA under FIFRA.
FIFRA therefore expressly preempts Durnell’s claim. We
reverse the judgment of the Missouri Court of Appeals and
remand the case for further proceedings not inconsistent
with this opinion.
It is so ordered.

_________________
_________________
1 Cite as: 609 U. S. ____ (2026)
T
HOMAS, J., concurring
SUPREME COURT OF THE UNITED STATES
No. 24–1068
MONSANTO COMPANY, PETITIONER v.
JOHN L. DURNELL
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF
MISSOURI
, EASTERN DISTRICT
[June 25, 2026]
JUSTICE THOMAS, concurring.
I agree with the Court’s interpretation of the Federal In-
secticide, Fungicide, and Rodenticide Act and its applica-
tion of our preemption precedents. I therefore join its opin-
ion in full. I write separately to call attention to some of the
underlying constitutional infirmities in the Act.
First, the Act likely exceeds Congress’s authority under
the Commerce Clause, which authorizes Congress to regu-
late “Commerce . . . among the several States.” Art. I, §8,
cl. 3. This power allows Congress to regulate “selling, buy-
ing, and bartering” across state lines. United States v.
Lopez, 514 U. S. 549, 585 (1995) (T
HOMAS, J., concurring).
It does not allow Congress to regulate “agriculture” or
“manufacturing,” activities entirely “separate” from “com-
merce.” Id., at 586.
The Act is a “comprehensive regulatory statute” that ap-
pears to regulate more than the Commerce Clause allows.
Ruckelshaus v. Monsanto Co., 467 U. S. 986, 991 (1984). As
this Court has acknowledged, the Act “regulate[s] the use,
as well as the sale” of pesticides and “regulate[s] pesticides
produced and sold in . . . intrastate . . . commerce.” Id., at
991–992. The Act, among other things, requires pesticide
manufacturers to register their pesticides with the Envi-
ronmental Protection Agency, submit information about
them, and use EPA-approved labels before selling the

2 MONSANTO v. DURNELL
T
HOMAS, J., concurring
pesticides anywhere. Ante, at 2–4. A manufacturer that
does not use the approved label may be subject to civil and
criminal penalties, regardless of whether the goods are sold
in interstate commerce. Ante, at 4. And, the Act goes even
further, making it illegal for consumers to use registered
pesticides in ways inconsistent with their label. 7 U. S. C.
§§136j(a)(2)(G), 136l(b)(2). The Act thereby purports to reg-
ulate how an individual who owns pesticide products such
as Roundup can use those products, even if he bought them
at a locally owned store down the street, and even if he
seeks to use them in his own backyard. Accordingly, the
Act is likely unconstitutional in many applications.
Second, the Act raises questions about Congress’s ability
to delegate core legislative power to the EPA. As the Court
explains, ante, at 3, Congress granted the EPA the author-
ity to issue regulations for carrying out the Act.
§136w(a)(1). The EPA has thereby issued “extensive regu-
lations . . . dictating what must appear on a pesticide’s la-
bel.” Ante, at 3. Through these label regulations, the EPA
exercises immense power over private businesses and indi-
viduals. Violating certain regulations is a federal offense.
§136j(a)(2)(S). The EPA thus appears to “make substantive
rules . . . punishable with fines or imprisonment,” a core
legislative power that cannot be delegated. Learning Re-
sources, Inc. v. Trump, 607 U. S. 229, 318 (2026) (T
HOMAS,
J., dissenting).*
——————
*Such delegations of broad regulatory authority often benefit large in-
cumbent companies at the expense of smaller competitors and consum-
ers. Incumbent companies “exercise considerable sway over agency
rules,” S. Prakash, The Sky Will Not Fall, in The Administrative State
Before the Supreme Court 293 (P. Wallison & J. Yoo eds. 2022), which
they use to lobby for more “favorable regulations” that “protect the exist-
ing regulated firms from threats arising from new firms,” T. Sowell,
Basic Economics: A Citizen’s Guide to the Economy 107–108 (2004).
Those regulations often enable a “profitable alliance” between corpora-
tions and government, as the corporations look “for government to

3 Cite as: 609 U. S. ____ (2026)
T
HOMAS, J., concurring
Third, and relatedly, the Act raises questions about the
extent to which federal agency action can preempt state
law, a form of preemption taken for granted by the parties
in this case. See Brief for Respondent 37, 39, 43, 49. The
Supremacy Clause makes “[t]his Constitution, and the
Laws of the United States which shall be made in Pursu-
ance thereof; and all Treaties . . . the supreme Law of the
Land.” Art. VI, cl. 2. The Constitution, federal law, and
treaties thus preempt any conflicting state law. See, e.g.,
Wyeth v. Levine, 555 U. S. 555, 584–588 (2009) (T
HOMAS, J.,
concurring in judgment). Administrative action appears
difficult to fit under the Supremacy Clause. Agency action
is not the Constitution. Nor is it a treaty. And, “Laws” are
made by Congress and the President through bicameralism
and presentment. See Art. I, §7, cl. 2. So, if “agency action
qualifies as ‘supreme Law,’” then it arguably “violates the
Constitution’s separation of powers.” D. Rubenstein, The
Paradox of Administrative Preemption, 38 Harv. J. L. &
Pub. Pol’y 267, 334 (2015). On the other hand, if agencies
cannot make “Law” their actions seem to fall “beyond the
Supremacy Clause’s purview” and cannot preempt state
law. Ibid.
Of course, to the extent that federal agency action is
treated with the force of law, regulated parties should likely
not be compelled by state law to take contradictory actions.
See Wyeth, 555 U. S., at 588 (opinion of T
HOMAS, J.) (agree-
ing that valid federal regulations can preempt conflicting
state laws). But, the difficulty illustrates the consequences
of the modern administrative state and our mistaken
——————
cartelize their industry after private efforts for cartels and monopoly
ha[ve] failed.” M. Rothbard, The Progressive Era 318 (2017).
This scheme is a perfect example. As the Court explains, EPA ap-
proval entails onerous registration requirements, imposing a formidable
barrier to entry for any company that, unlike a worldwide chemical con-
glomerate, lacks the capacity to commission scientific safety and efficacy
studies. See ante, at 2–6.

4 MONSANTO v. DURNELL
T
HOMAS, J., concurring
separation-of-powers jurisprudence. If agencies were not
exercising core legislative power, especially through
schemes that exceed even Congress’s powers, there would
be far less occasion to address conflicts between agency ac-
tions and state law that the Constitution’s Framers would
not have envisioned.

_________________
_________________
1 Cite as: 609 U. S. ____ (2026)
J
ACKSON, J., dissenting
SUPREME COURT OF THE UNITED STATES
No. 24–1068
MONSANTO COMPANY, PETITIONER v.
JOHN L. DURNELL
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF
MISSOURI
, EASTERN DISTRICT
[June 25, 2026]
JUSTICE JACKSON, with whom JUSTICE GORSUCH joins,
dissenting.
In 2019, John Durnell brought a state-law failure-to-
warn claim against Monsanto, an agrochemical company
that manufactures and distributes a widely used pesticide
called Roundup. Durnell claimed that he had developed
non-Hodgkin’s lymphoma, a type of blood cancer, due to his
two-decade-long use of Roundup. Roundup’s label did not
(and still does not) include any warning about the risk of
developing cancer. Durnell thus sued Monsanto in Mis-
souri state court, alleging that Roundup’s label lacked a
necessary warning. After a 9-day trial, the jury agreed and
awarded Durnell $1.25 million in compensatory damages.
Monsanto argues that 7 U. S. C. §136v(b)—a provision of
the Federal Insecticide, Fungicide, and Rodenticide Act
(FIFRA)—expressly preempts Durnell’s failure-to-warn
claim. See ibid. (providing that state labeling “require-
ments” that are “in addition to or different from those re-
quired under” FIFRA are preempted). Today, the Court
agrees. The majority emphasizes that the Environmental
Protection Agency (EPA) has consistently registered
Roundup—a precondition to Monsanto’s ability to sell that
product—and has thus approved Roundup’s label without a
cancer warning. Ante, at 6–7. According to the majority,
the EPA’s registration decision and approval of Roundup’s

2 MONSANTO v. DURNELL
J
ACKSON, J., dissenting
label created a labeling “requirement” under FIFRA:
namely, that Monsanto sell Roundup with the label exactly
as the EPA approved it. Ante, at 10–11. Thus, the majority
concludes, Durnell’s lawsuit added a labeling requirement
that federal law did not require, triggering preemption per
§136v(b). Ante, at 11.
In so holding, the Court departs from the near-
unanimous view of the many state and federal courts that
have rejected this preemption argument.
1
In my view, the
majority should have joined that chorus. Durnell’s failure-
to-warn claim is not “in addition to or different from”
FIFRA’s mandates; it is equivalent to FIFRA’s key labeling
requirement—the misbranding prohibition. And Durnell’s
claim does not conflict with any other FIFRA “requirement”
for §136v(b) purposes because the EPA’s registration of a
pesticide and approval of its label does not create a labeling
requirement under FIFRA.
So, I respectfully dissent. In accepting Monsanto’s argu-
ment and holding that Durnell’s failure-to-warn claim is
preempted, the Court misunderstands FIFRA’s require-
ments, misinterprets the scope of FIFRA’s preemption, and
ultimately leaves Durnell without a remedy for the signifi-
cant harms he has suffered.
I
Congress has the power to preempt state law. It can do
so expressly through the text of a federal statute or im-
pliedly. Regardless of the method, federal preemption is
——————
1
See, e.g., 707 S. W. 3d 828, 835 (Mo. App. 2025) (case below); Carson
v. Monsanto Co., 92 F. 4th 980, 986 (CA11 2024); Hardeman v. Monsanto
Co., 997 F. 3d 941, 954 (CA9 2021); Anderson v. Monsanto Co., 719
S. W. 3d 755, 798 (Mo. App. 2025); Caranci v. Monsanto Co., 338 A. 3d
151, 170 (Pa. Super. 2025); Dennis v. Monsanto Co., 116 Cal. App. 5th
322, 342, 339 Cal. Rptr. 175, 188 (2025); Johnson v. Monsanto Co., 333
Ore. App. 678, 699–701, 554 P. 3d 290, 306–308 (2024); Pilliod v. Mon-
santo Co., 67 Cal. App. 5th 591, 613, 282 Cal. Rptr. 3d 679, 698 (2021);
but see Schaffner v. Monsanto Corp., 113 F. 4th 364, 399 (CA3 2024).

3 Cite as: 609 U. S. ____ (2026)
J
ACKSON, J., dissenting
typically premised on a conflict between federal and state
law. See Murphy v. National Collegiate Athletic Assn., 584
U. S. 453, 477 (2018). Under the Constitution’s Supremacy
Clause, Art. VI, cl. 2, “federal law takes precedence” over
conflicting state law “and [thus] the state law is
preempted.” Murphy, 584 U. S., at 477.
Importantly, however, there is not always a complete con-
flict between a federal statute and state law, even if they
address the same subject matter. That is, federal law does
not necessarily box out all state regulation on a particular
issue. Congress can and does enact statutory provisions
that specifically define the preemptive scope of the federal
law. See, e.g., Montgomery v. Caribe Transport II, LLC, 608
U. S. ___, ___–___ (2026) (slip op., at 2–3) (describing
preemption provision that carves out state safety regula-
tions); cf. Cipollone v. Liggett Group, Inc., 505 U. S. 504, 517
(1992) (“Congress’ enactment of a provision defining the
pre-emptive reach of a statute implies that matters beyond
that reach are not pre-empted”). And federal preemption
provisions often permit parallel state laws—i.e., those that
“merely duplicate federal requirements.” Bates v. Dow
Agrosciences LLC, 544 U. S. 431, 442, 453 (2005). When al-
lowing state-law versions of a federal mandate, Congress
displaces state law only “to the extent of th[e] difference”
from federal law. Id., at 453. Thus, state law can still “pro-
vide a traditional damages remedy for violations of com-
mon-law duties when those duties parallel federal require-
ments.” Medtronic, Inc. v. Lohr, 518 U. S. 470, 495 (1996).
FIFRA fits this mold. It is a federal statute that regulates
the sale and use of pesticides, and among other things, re-
quires that pesticides bear detailed labels providing con-
sumers with information about how to use them and what
risks they pose. FIFRA expressly limits States’ authority
to regulate pesticide labels, but it does not eliminate that
authority. Instead, FIFRA preempts only those state “re-
quirements for labeling or packaging in addition to or

4 MONSANTO v. DURNELL
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ACKSON, J., dissenting
different from” the requirements under FIFRA. §136v(b).
2
This means that state labeling requirements “equivalent
to” FIFRA’s requirements are not preempted. Bates, 544
U. S., at 447. In other words, FIFRA’s preemption clause
does not block state-law claims where the violation of state
law is also a violation of FIFRA. Id., at 454.
II
To analyze the reach of FIFRA’s preemption provision, I
begin, per usual, with the statute’s text. See Chamber of
Commerce of United States of America v. Whiting, 563 U. S.
582, 594 (2011). To repeat: §136v(b) provides that a “State
shall not impose or continue in effect any requirements for
labeling or packaging in addition to or different from those
required under” FIFRA. To distinguish the state laws this
provision preempts from those that can continue unabated,
one must, first, identify the “requirements” under FIFRA,
and, second, determine whether the state law imposes re-
quirements that are “in addition to or different from” (as
opposed to the equivalent of ) those FIFRA requirements.
Here, the majority falters on both tasks. FIFRA’s label-
ing requirements are established by statute and regulation,
and those requirements are no different than the labeling
duties imposed by Missouri via its failure-to-warn tort. The
state-law claim at issue reflects a parallel requirement that
is fully consistent with FIFRA’s primary labeling duty—its
misbranding prohibition—and makes no additional asks of
those who are subject to it.
A
“A requirement is a rule of law that must be obeyed.”
Bates, 544 U. S., at 445. In interpretating FIFRA, this
Court has previously held that the term “requirements” in-
cludes “positive enactments, such as statutes and
——————
2
As the majority points out, many federal statutes contain similarly
limited express preemption clauses. Ante, at 13–14 (collecting statutes).

5 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
regulations,” as well as “common-law duties.” Id., at 443.
Thus, the “requirements” under FIFRA that can preempt
state labeling requirements are those directives “set out in
FIFRA and its implementing regulations.” Id., at 452.
FIFRA’s principal labeling requirement is its prohibition
on selling or distributing “misbranded” pesticides.
§136j(a)(1)(E). The statutory definition of “misbranded” is
extensive, establishing many detailed supplementary label-
ing requirements. See §136(q). For example, a pesticide
that contains a highly toxic substance but does not have the
“skull and crossbones” and the word “‘poison’” on its label
is misbranded. §136(q)(2)(D). So too is a pesticide that does
not bear an ingredient statement. §136(q)(2)(A). And so is
a pesticide that has “false or misleading” statements on its
label. §136(q)(1)(A).
Another type of prohibited misbranding is relevant to to-
day’s dispute: A pesticide is misbranded if “the label does
not contain a warning or caution statement which may be
necessary and . . . is adequate to protect health and the en-
vironment.” §136(q)(1)(G). Adequate warnings must,
among other things, protect against “any unreasonable risk
to [humans] or the environment, taking into account the
economic, social, and environmental costs and benefits of
the use of any pesticide.” §136(bb); see §136(x). Conse-
quently—and this is important to remember—one require-
ment under FIFRA is that a pesticide’s label must contain
“adequate” and “necessary” warnings. §136(q)(1)(G).
FIFRA does not specify the particular warnings that are
adequate and necessary (and thus comply with the mis-
branding prohibition). But the EPA has started to fill in
that gap by promulgating regulations to “give content to”
FIFRA’s misbranding prohibition in certain contexts.
Bates, 544 U. S., at 453. For the adequate-and-necessary-
warnings requirement, EPA regulations require labels to
contain specific precautionary statements in a certain cir-
cumstance: where the pesticide may cause particularly

6 MONSANTO v. DURNELL
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ACKSON, J., dissenting
acute hazards. See 40 CFR §§156.60–156.70 (2025); see
also §156.10(a)(1)(vii). The regulations dictate that, for cer-
tain categories of toxins, a pesticide manufacturer must add
to the product label different “signal word[s]”: “‘DANGER,’”
“ ‘WARNING,’” and “‘CAUTION.’” §156.64.
To date, the EPA has not promulgated any other regula-
tions pertaining to FIFRA’s adequate-and-necessary-warn-
ing requirement.
3
Critically for present purposes, the
EPA’s regulations do not set specific requirements for label
warnings relating to chronic risks, like cancer.
4
FIFRA’s
misbranding prohibition establishes the broad requirement
that a pesticide’s label contain necessary and adequate
warnings for any chronic risks, but neither the statute nor
——————
3
The EPA has promulgated regulations that give content to a different
aspect of FIFRA’s misbranding prohibition: the false-or-misleading-
statement element. Those regulations provide a nonexhaustive list of
statements that qualify as false or misleading and therefore would ren-
der the pesticide misbranded. See 40 CFR §156.10(a)(5) (2025) (prohib-
iting, for example, “[c]laims as to the safety of the pesticide” such as
“ ‘safe’” or “‘nontoxic to humans and pets’”).
4
The majority asserts that cancer warnings are a type of precautionary
statement covered by the EPA’s regulations, relying on its unsupported
view of the “ordinary meaning of ‘hazards’ and ‘precautionary state-
ments.’ ” Ante, at 10–11, n. 5. That is mistaken. Whatever the ordinary
meaning of the term (and whatever the United States’ litigation-created
interpretation), the “[p]recautionary statements” regulations are ex-
pressly directed at only acute hazards. §156.70. The regulations require
that, if the pesticide may pose “an acute hazard” to “humans or domestic
animals,” then the pesticide’s label “must bear precautionary statements
describing the particular hazard.” §156.70(b) (emphasis added). The
regulations then list the “typical hazard and precautionary statements”:
warnings that the pesticide is or may be “[f]atal” or “[h]armful” if swal-
lowed or that it could cause eye or skin irritation. §156.70(c). The risk
of developing cancer is not listed as an “acute” hazard. Nor could it be;
cancer is a long-term or chronic risk. While the EPA does, as part of its
registration decision, evaluate the chronic risks a pesticide may pose, see
ante, at 11, n. 5, the EPA has not promulgated regulations addressing
when a cancer warning must be included on a label or what a cancer
warning must say. The precautionary-statements regulations simply
have nothing to do with cancer warnings.

7 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
the EPA’s regulations dictate more specific requirements
for such warnings.
B
All this has implications for the meaning of FIFRA’s
preemption provision. The provision’s language establishes
that when FIFRA itself or the EPA’s regulations require
specific statements on a pesticide’s label—such as the skull
and crossbones or a particular “signal word”—a state law
that requires additional or different statements is
preempted. But, absent such federal-law requirements, a
state-law duty that simply parallels FIFRA’s misbranding
prohibition is not preempted.
Suppose, for example, a State mandates that pesticides
causing moderate skin irritation bear the word
“WARNING.” That state law would be preempted by
FIFRA because the EPA’s regulations require that the label
for pesticides causing moderate skin irritation bear the sig-
nal word “CAUTION.” 40 CFR §§156.62, 156.64(a)(3). The
State’s labeling requirement is different from (and indeed
conflicts with) the EPA’s regulations. By contrast, if a State
seeks to hold a manufacturer liable under state law for fail-
ing to label a pesticide with the same warning words that
federal regulations require, application of the state law
would not be preempted under 7 U. S. C. §136v(b). In that
situation, the State is not requiring anything “in addition
to or different from” FIFRA’s requirements.
Consider another example. A State wants to ensure that
the pesticides its residents use are properly labeled and
contain all warnings necessary and adequate to protect
against unreasonable risks to its residents and the environ-
ment. So it either enacts a statute that makes liable any
pesticide manufacturer that fails to provide adequate and
necessary warnings, or relies on the existing tort regime to
accomplish this same result. In either case, the state-law
scheme merely “duplicate[s]” FIFRA’s adequate-and-

8 MONSANTO v. DURNELL
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ACKSON, J., dissenting
necessary-warnings requirement—and is therefore not
preempted. Bates, 544 U. S., at 442. Why not? Because
the State is not requiring anything “in addition to or differ-
ent from” what FIFRA’s own misbranding prohibition re-
quires.
With that background, it is easy to see that Durnell’s
failure-to-warn claim—which faults Monsanto for not in-
cluding cancer warnings on the Roundup label—does not
trigger preemption under FIFRA. Missouri’s failure-to-
warn tort punishes the sale of unreasonably dangerous
products, like pesticides, without “adequate warning of the
danger.” Moore v. Ford Motor Co., 332 S. W. 3d 749, 756
(Mo. 2011) (en banc). As the Missouri Court of Appeals ex-
plained, Durnell’s claim has the same “practical effect” as
FIFRA’s misbranding prohibition: “[B]oth require a pesti-
cide manufacturer to adequately warn users of the poten-
tial dangers of using its product.” 707 S. W. 3d 828, 833
(2025) (internal quotation marks omitted). Durnell’s claim
does not impose any labeling requirement that is “in addi-
tion to or different from” what FIFRA itself requires,
§136v(b); instead, the standards prescribed by federal and
state law are equivalent.
5
——————
5
To be clear, Missouri’s failure-to-warn claim is equivalent to FIFRA’s
misbranding prohibition at least as presented to us. Monsanto argues
that Missouri’s tort is not equivalent because it permits, but does not
require, a jury to conduct the cost-benefit analysis that FIFRA’s ade-
quate-and-necessary-warnings requirement appears to mandate. See
Rodriguez v. Suzuki Motor Corp., 996 S. W. 2d 47, 65 (Mo. 1999) (en
banc) (leaving the decision of what it means to be “unreasonably danger-
ous” to the jury (internal quotation marks omitted)); 7 U. S. C. §136(bb)
(incorporating the “costs and benefits of the use of any pesticide” into the
definition of “misbranded”).
But any potential difference does not doom Durnell’s claim. Recall that
preemption displaces state law only “to the extent of th[e] difference” be-
tween state and federal law. Bates v. Dow Agrosciences LLC, 544 U. S.
431, 453 (2005). Monsanto has not properly presented any argument
that Durnell’s claim in fact imposes a requirement that differs from

9 Cite as: 609 U. S. ____ (2026)
J
ACKSON, J., dissenting
Why might a federal law that expressly seeks “[u]ni-
formity” in labeling, §136v(b), leave room for parallel state
tort suits like Durnell’s? As we have previously explained,
“FIFRA contemplates that pesticide labels will evolve over
time.” Bates, 544 U. S., at 451. To that end, “tort suits can
serve as a catalyst”—encouraging pesticide manufacturers
to “keep abreast of all possible injuries stemming from use
of their product” and to maintain labels with the necessary
and adequate warnings. Ibid. (internal quotation marks
omitted). Parallel state tort liability is an enforcement tool
that can have a salutary information-forcing effect, and
that, in turn, helps ensure the effectiveness of FIFRA’s mis-
branding prohibition.
III
The majority does not view FIFRA’s misbranding prohi-
bition as the relevant federal “requirement” for preemption
purposes. Instead, it ventures far beyond FIFRA and its
regulations, purporting to identify the relevant labeling re-
quirement in the EPA’s approval of Roundup’s label. Ante,
at 10–11, 14. The argument goes like this: A manufacturer
must register its pesticide with the EPA before selling or
distributing it. §136a(a). As part of the registration
——————
FIFRA’s misbranding prohibition. Monsanto did not seek a jury instruc-
tion at trial directing the jury to find for Durnell only if his evidence met
the requirements for FIFRA’s misbranding standard. See id., at 454.
Since it declined to present that argument to the jury, Monsanto cannot
now complain that Durnell’s claim is actually broader than the federal
requirement. Nor does Monsanto argue before us that the evidence at
trial was insufficient to support a jury verdict for a failure-to-warn claim
that was equivalent to FIFRA’s misbranding standard. Cf. Boyle v.
United Technologies Corp., 487 U. S. 500, 513 (1988) (holding that a
plaintiff would not be entitled to a new trial, even after the Court of Ap-
peals reformulated the relevant defense, “[i]f the evidence presented in
the first trial [still] would not suffice . . . to support a jury verdict under
the properly formulated defense”). Accordingly, we cannot address
whether Durnell’s failure-to-warn claim, in light of the evidence pre-
sented, is different than FIFRA’s misbranding standard.

10 MONSANTO v. DURNELL
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ACKSON, J., dissenting
process, the EPA reviews and approves the pesticide’s label,
confirming that the label complies with FIFRA’s require-
ments. §136a(c)(5)(B). Furthermore, the EPA generally re-
quires a manufacturer to get the agency’s approval before
changing its product’s label. 40 CFR §152.44.
As the majority sees it, the EPA’s registration of a pesti-
cide and approval of its label creates a federal requirement
that the manufacturer use the label exactly as the EPA ap-
proved it. Ante, at 11. Here, the majority says, because the
EPA approved Roundup’s label without a cancer warning,
state law cannot require Roundup’s label to include one.
Ante, at 11, 14.
This theory has some intuitive appeal—federal approval
should count for something, after all. But, in reality, the
majority’s view is unmoored from the statute’s text and ir-
reconcilable with our precedents.
A
1
Start with the text. In the same section of FIFRA that
lays out the pesticide registration process, the statute con-
tains a crucial caveat: “In no event shall registration of [a
pesticide] be construed as a defense for the commission of
any offense under” FIFRA, 7 U. S. C. §136a(f )(2)—includ-
ing misbranding, §136j(a)(1)(E). Rather, per the terms of
the statute, registration is merely “prima facie evidence
that the pesticide [and] its labeling . . . comply with the reg-
istration provisions of ” FIFRA. §136a(f )(2).
These two parts of §136a(f )(2) work in tandem. Registra-
tion is prima facie evidence that the pesticide’s label com-
plies with FIFRA’s requirements, meaning that the EPA’s
approval reflects the agency’s best judgment that the label
satisfies FIFRA. See §136a(c)(5)(B). But prima facie evi-
dence is not conclusive evidence. Thus, the statute clarifies
that, in the face of a misbranding charge, the EPA’s regis-
tration is not a defense. This means that the EPA’s

11 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
approval of a pesticide’s label cannot conclusively establish
that the pesticide is not misbranded. The statute, in other
words, does not treat as infallible the EPA’s judgment as to
whether FIFRA’s misbranding provision has been violated.
For that reason, a pesticide may be “registered but never-
theless misbranded.” Bates, 544 U. S., at 438.
This, in turn, must mean that the EPA’s (not infallible)
approval of a pesticide’s label does not establish a “rule of
law that must be obeyed” when it comes to the pesticide’s
label. Id., at 445. Because the EPA’s registration decision
is not conclusive of the label’s compliance with the statute,
that registration decision itself cannot carry the force of
law, much less capture the universe of requirements with
which a manufacturer must comply to prevent its product
from being misbranded in violation of FIFRA. To conclude
otherwise would turn the registration decision from “prima
facie evidence” of compliance with FIFRA into conclusive
proof of such compliance. It defies logic to treat the EPA’s
approval of a pesticide’s label as creating a legal require-
ment under FIFRA when that approved label may not com-
ply with the law.
The majority fails to grapple with any of this. Nor does
it address the internal tension its theory produces. The ma-
jority says that the registration process creates a require-
ment because a pesticide manufacturer must use the label
exactly as the EPA approved it, with no additions or
changes. But the statutory misbranding prohibition might
well require a different or additional warning on the label
than what the EPA approved, since approval is merely
prima facie evidence of compliance. The majority’s theory
thus cannot be squared with what FIFRA plainly requires.
That is, notwithstanding the EPA’s approval of its label, a
manufacturer has “a continuing obligation to adhere to
FIFRA’s labeling requirements,” including the misbranding
prohibition. Id., at 438.

12 MONSANTO v. DURNELL
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ACKSON, J., dissenting
In short, the EPA’s approval of the label cannot set a “re-
quirement” for §136v(b) purposes. Instead, the require-
ments of FIFRA—the misbranding prohibition and the im-
plementing regulations—dictate the contents of the label.
This is so because §136a(f )(2) makes clear that FIFRA’s
misbranding prohibition continues to apply to pesticides
even after they have been registered. The upshot here is
that, even though the EPA approved Roundup’s label, that
label could still lack a necessary warning.
A real-world example illustrates the interplay between
registration and misbranding. In 1999, the EPA approved
a label for a Roundup product distributed by Monsanto that
did not include any statements warning the user that the
pesticide could leak.
6
But the EPA itself soon determined
that the approved label did not meet the requirements of
FIFRA because, “[w]hen used in accordance with its label
directions,” the pesticide could “leak or spray onto the user.”
In re: The Monsanto Co., 2000 WL 1886918, *2 (EAB, Sept.
29, 2000). Accordingly, the EPA imposed civil penalties on
Monsanto for “distributing or selling misbranded pesti-
cides.” Ibid.
This example rebuts the majority’s claim that a regis-
tered pesticide can be misbranded only if the label contains
information that was not on the label that the EPA ap-
proved or omits information that was. Ante, at 16–17. Far
from creating a new requirement under FIFRA, the EPA’s
approval of the label did not suffice to establish compliance
with the statutory requirement that a pesticide not be mis-
branded, nor did it shield Monsanto from liability for
——————
6
See Roundup® L & G READY-TO-USE Fast Acting Formula Grass &
Weed Killer, EPA Reg. No. 239–2638, pp. 11–12 (June 8, 1999), https://
www3.epa.gov/pesticides/chem_search/ppls/071995-00008-19990608.pdf
(archived at https://perma.cc/7EkZ-SPFW).

13 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
violating the misbranding requirement.
7
And if a state-
tort duty, akin to Durnell’s failure-to-warn claim, had like-
wise required Monsanto to include a leak warning on the
label, the State’s requirement would have been identical to
FIFRA’s and therefore would not have been preempted—
regardless of the fact that the EPA had previously approved
the label without that warning.
The continuing force of FIFRA’s misbranding prohibition,
even after the EPA’s registration of a pesticide, thus re-
solves today’s preemption dispute. Since FIFRA’s mis-
branding prohibition remains a requirement with which
registered pesticides must comply, state-law duties that are
equivalent to the misbranding prohibition add nothing new
or different that would trigger preemption. If an additional
warning is necessary to comply with FIFRA’s misbranding
prohibition, then a state-law duty can require that warning,
even if the EPA approved the label without it.
2
The majority tries valiantly to discount the relevance of
§136a(f )(2)—the provision clarifying that the EPA’s regis-
tration decision is not conclusive of a pesticide manufac-
turer’s compliance with FIFRA’s misbranding prohibition.
Its efforts fail.
——————
7
For a similar example, see In re: Ecolab Inc., 2009 WL 10729367
(EPA, June 22, 2009) (imposing civil penalties for misbranding on man-
ufacturer whose three pesticides were ineffective against certain bacte-
ria even though the EPA-approved labels stated that the pesticides were
effective against those bacteria). See also A–33, EPA Reg. No. 42964–5,
pp. 2, 4 (Aug. 24, 2004), https://www3.epa.gov/pesticides/chem_search/
ppls/042964-00005-20040824.pdf (archived at https://perma.cc/2JPG-
NXYA) (first label); A–33 Dry, EPA Reg. No. 42964–25, p. 3 (May 17,
2002), https://www3.epa.gov/pesticides/chem_search/ppls/042964-00025-
20050517 (archived at https://perma.cc/T6LJ-ZUZB) (second label);
Omega, EPA Reg. No. 42964–14, p. 2 (May 24, 2001), https://www3.epa.
gov/pesticides/chem_search/ppls/042964-00014-20010524.pdf (archived
at https://perma.cc/27XH-WMJZ) (third label).

14 MONSANTO v. DURNELL
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ACKSON, J., dissenting
The majority notes, for example, that §136a(f )(2) is in the
portion of the registration statute titled “[m]iscellaneous,”
and reasons that “it would be rather bizarre” for a miscel-
laneous provision to “upend” the statute’s preemption pro-
vision. Ante, at 18. But the policy concern about exposing
manufacturers to disruptive tort liability is no basis for ig-
noring the statute’s text. And the argument is also substan-
tively faulty. It assumes the conclusion that the EPA’s ap-
proval of a label creates a “requirement” with preemptive
force (hence the bizarreness of housing this consequential
provision in a “miscellaneous” section of the statute). Un-
der a correct interpretation of §136a(f )(2), however, the
EPA’s approval of the label does not create requirements.
So registration does not preempt different or additional
state-law requirements, §136a(f )(2) does not upend any-
thing, and the “miscellaneous” placement of this provision
makes sense.
The majority also tries to cast doubt on §136a(f )(2)’s rel-
evance to the preemption provision. In particular, the ma-
jority argues that §136a(f )(2) does not apply to state tort
lawsuits as a general matter, and that it would not apply
here because Monsanto did not invoke the fact of registra-
tion as a defense to Durnell’s claim. Ante, at 16, 19. But
this framing misses the point. Section 136a(f )(2)’s rele-
vance to the preemption question is not whether Monsanto
intends to, or can, invoke registration as a defense to Dur-
nell’s failure-to-warn suit. Instead, §136a(f )(2) clarifies
that a “no misbranding” conclusion cannot be based on the
fact of registration alone, thus demonstrating that registra-
tion itself does not create a labeling requirement under
FIFRA—in any context.
In addition to its attempt to downplay §136a(f )(2), the
majority also insists that the EPA’s registration of a pesti-
cide must create a labeling requirement because the manu-
facturer cannot change its pesticide’s label without the
EPA’s approval, on pain of civil or criminal penalties. Ante,

15 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
at 10, 15, 17. But the majority’s analysis—which errone-
ously treats the EPA-approved label as a requirement un-
der FIFRA—misstates FIFRA and the EPA’s implementing
regulations, and it also misunderstands the nature of
FIFRA’s express preemption clause.
First of all, it is wrong to say that FIFRA establishes that
a manufacturer can face civil or criminal penalties solely for
using a label that differs from what the EPA approved. The
closest FIFRA comes to this is the provision that makes it
unlawful for any person to “alter . . . any labeling required
under” FIFRA. §136j(a)(2)(A). Notably, this provision does
not say that it is unlawful to alter the label that the EPA
approved. Instead, it protects only the “labeling required
under” FIFRA. And given §136a(f )(2), we know that the
EPA-approved label is not coextensive with the “labeling re-
quired under” FIFRA because FIFRA’s ongoing misbrand-
ing prohibition could require that the EPA-approved label
be amended.
Another variation of this argument is the majority’s con-
tention that it is a violation of FIFRA’s misbranding provi-
sion “if a manufacturer sells its pesticide with a different
label than the one [the] EPA approved.” Ante, at 4. The
majority offers no support for this assertion—and there is
none. The statutory definition of misbranding does not say
that a pesticide sold with a label different from the EPA-
approved label is necessarily misbranded. See generally
§136(q).
Second, the fact that a pesticide manufacturer must seek
the EPA’s approval for most labeling changes does not
change the express preemption calculus. Whatever the
manufacturer must do procedurally to get its product ap-
proved for marketing, FIFRA requires the manufacturer
not to sell a misbranded pesticide. The majority implicitly
acknowledges this when it notes that the EPA can require
changes to a pesticide’s label in light of new information or
analysis. Ante, at 10. The agency mandates such changes

16 MONSANTO v. DURNELL
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ACKSON, J., dissenting
to ensure continued compliance with FIFRA’s require-
ments, including the misbranding prohibition. See
§136d(b) (providing that the EPA can cancel a pesticide’s
registration or change its classification “[i]f it appears to the
Administrator that a pesticide or its labeling . . . does not
comply with” FIFRA); §136d(d) (authorizing the EPA Ad-
ministrator to “requir[e] modification of the labeling”). So
FIFRA’s misbranding prohibition continues to apply to reg-
istered pesticides. And state-law requirements that paral-
lel FIFRA’s misbranding prohibition add nothing new.
Therefore, such state-law requirements can likewise apply
to registered pesticides.
At the end of the day, then, the majority’s theory of ex-
press preemption rests on a misinterpretation of FIFRA.
The EPA’s approval of a pesticide’s label does not create a
labeling requirement under FIFRA. Instead, FIFRA’s key
labeling requirement—the statutory prohibition on mis-
branding—continues to apply to registered pesticides even
though the EPA has approved their labels. State-law
claims that parallel the misbranding prohibition are not
preempted, even if the claim requires a warning that was
absent from the EPA-approved label. The majority thinks
it “implausibl[e]” that the “EPA’s registration and labeling
determinations do not have preemptive force.” Ante, at 15.
But, at bottom, the majority’s quibble is with the text of
FIFRA’s misbranding requirement and preemption provi-
sion, not with Durnell’s claim.
B
Perhaps recognizing all this, Monsanto embraces a more
extreme position: that a registered pesticide can never be
misbranded. Tr. of Oral Arg. 10–11. That argument is eas-
ily disposed of because it cannot be squared with our deci-
sion in Bates, 544 U. S. 431, which recognized that a pesti-
cide can be “registered but nevertheless misbranded,” id.,
at 438. Indeed, Bates—the only prior case in which we

17 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
interpreted FIFRA’s preemption provision—not only re-
quires flat rejection of this view; it also confirms that the
majority’s interpretation of §136v(b) is wrong.
The plaintiffs in Bates brought state tort claims against
Dow Agrosciences for failing to warn them that the use of
its pesticide in a particular type of soil would stunt crop
growth. Id., at 435. We held that States could impose label-
based requirements that were equivalent to FIFRA’s mis-
branding prohibition. Id., at 452–453. And we remanded
for the lower courts to decide in the first instance whether
the particular failure-to-warn claim at issue in Bates im-
posed a requirement equivalent to FIFRA’s misbranding
prohibition. Id., at 453–454.
That disposition is critical. Had Bates accepted the the-
ory the majority adopts today, there would have been no
need to remand the case. That is, if the EPA’s approval of
a label preempted States from requiring any different or ad-
ditional warnings, then a failure-to-warn claim would be
impossible. Our remand in Bates thus necessarily rejected
the theory that the EPA’s approval of the label creates a
labeling requirement that can preempt a state failure-to-
warn claim.
The majority tries unsuccessfully to rewrite Bates to sup-
port its view. It focuses principally on an example Bates
gave of the type of EPA regulation that could preempt a
failure-to-warn claim: the precautionary-statements regu-
lations that require a “CAUTION” designation or a
“DANGER” designation depending on the pesticide’s tox-
icity. Ante, at 11–12 (citing Bates, 544 U. S., at 453). The
EPA’s registration determination, the majority says, is “just
like” those EPA regulations. Ante, at 12.
But the majority provides no justification for this compar-
ison. For good reason: It is only the EPA’s duly promul-
gated regulations that can prescribe the content of a pesti-
cide’s label, not the individualized registration decision.
Indeed, Bates made clear that the EPA’s registration

18 MONSANTO v. DURNELL
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ACKSON, J., dissenting
decision and the regulation providing for certain designa-
tions are not alike. Bates explained that the relevant fed-
eral requirements could be found in FIFRA’s misbranding
prohibition and “any relevant EPA regulations that give
content” to the misbranding standards. 544 U. S., at 453.
Bates also noted that “there appear to be relatively few reg-
ulations that refine or elaborate upon FIFRA’s broadly
phrased misbranding standards.” Ibid., n. 28. Thus, Bates
gave no suggestion that the EPA’s registration of a particu-
lar pesticide (and corresponding approval of its label) also
created requirements under FIFRA.
Nor could it. Because registration of a pesticide is not
conclusive of FIFRA compliance, the registration decision
cannot give content to FIFRA’s misbranding standard. In-
stead, Bates’s reference to the EPA regulations means just
that—the regulations that the EPA promulgated pursuant
to its statutory authority. See §136w(a).
The majority also points out that the Bates plaintiffs’
failure-to-warn claim concerned a pesticide’s lack of effi-
cacy, while Durnell’s claim here relates to the pesticide’s
safety. Ante, at 12; see also Brief for Petitioner 31–34. That
matters to Bates’s outcome, the majority says, because the
EPA had not reviewed the pesticide’s efficacy as part of the
registration process, so the EPA-approved label would of
course not preempt state-required statements related to ef-
ficacy. See §136a(c)(5).
The problem with this argument is that it is irrelevant to
our actual holding in Bates. Our decision did not rely on
the fact that the EPA had waived review of the pesticide’s
efficacy in its registration determination. Indeed, outside
of our discussion of the case’s factual background, we men-
tioned the agency’s decision to waive efficacy review only
once: when explaining why it was particularly important to
allow tort litigation in those circumstances. 544 U. S., at
450. But this was in the context of discussing an alterna-
tive ground for our holding, namely, applying a

19 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
presumption against preemption. Id., at 449–450. It was
not support for our primary holding, grounded in the text of
the statute, that FIFRA does not preempt state tort claims
that parallel its requirements.
8
Instead of relying on our precedent about FIFRA, the ma-
jority points to our decision in Riegel v. Medtronic, Inc., 552
U. S. 312 (2008). See ante, at 12–13. Riegel involved an
entirely separate statute: the Medical Device Amendments
of 1976 (MDA). Similar to FIFRA, the MDA established a
premarket registration scheme for medical devices that in-
cluded review and approval of the devices’ labeling by the
Food and Drug Administration (FDA). 21 U. S. C.
§360e(d)(1)(A). The MDA also has an express preemption
provision similar to FIFRA’s. Specifically, the MDA
preempts state requirements “with respect to a device in-
tended for human use” that are “different from, or in addi-
tion to, any requirement applicable under [the MDA] to the
device.” §360k(a). We held in Riegel that “[p]remarket ap-
proval . . . imposes ‘requirements’” specific to medical de-
vices under the MDA. 552 U. S., at 322–323. So, the ma-
jority says, if premarket approval under the MDA creates
labeling requirements, then the EPA’s registration and ap-
proval of pesticide labels under FIFRA does too. Ante, at
13–14.
But in treating Riegel as dispositive, the majority ignores
a key difference between the MDA and FIFRA: The MDA
has nothing analogous to 7 U. S. C. §136a(f )(2). This mat-
ters because, again, §136a(f )(2) establishes that the EPA’s
——————
8
Confirming the irrelevance of the EPA’s waiver of efficacy review to
our holding in Bates, we granted, vacated, and remanded—in light of
Bates—a case holding that FIFRA preempted a safety-based failure-to-
warn claim. Oken v. Monsanto Co., 544 U. S. 1012 (2005); see Oken v.
Monsanto Co., 371 F. 3d 1312, 1314–1315 (CA11 2004) (per curiam).
Had Bates concluded that the EPA’s approval of a label did not preempt
a failure-to-warn claim only because the EPA did not review the label’s
statements related to efficacy, vacating and remanding a safety-based
case would have been unnecessary.

20 MONSANTO v. DURNELL
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ACKSON, J., dissenting
approval of a pesticide’s label is not conclusive of the label’s
compliance with FIFRA and therefore cannot establish a re-
quirement under FIFRA. Because the MDA lacks an
analogous provision, it might well be that the FDA’s ap-
proval of a medical device’s label does create labeling re-
quirements under the MDA.
9
There is another reason that the right outcome in today’s
case differs from Riegel: Riegel did not involve “parallel
claims.” 552 U. S., at 330. The litigation in Riegel pro-
ceeded on the assumption that the medical device “violated
state tort law notwithstanding compliance with the rele-
vant federal requirements.” Ibid. So this Court had no oc-
casion to consider whether there was an applicable federal
requirement, apart from the FDA’s premarket approval
process, that might be equivalent to the plaintiffs’ tort
claim. Here, by contrast, it is precisely because FIFRA’s
misbranding prohibition parallels Missouri’s failure-to-
warn claim that Durnell’s claim is not preempted.
Thus, it is Bates, not Riegel, that is dispositive here. Con-
tra, ante, at 13. Bates confirms what FIFRA’s text makes
clear: The EPA’s approval of a label does not create a re-
quirement under FIFRA.
IV
Having rejected Monsanto’s express preemption argu-
ment, I conclude by addressing its alternative contention
that Durnell’s failure-to-warn claim is impliedly
——————
9
The majority tries to wave away the MDA’s lack of a provision analo-
gous to §136a(f )(2), arguing that, in any event, the FDA could withdraw
premarket approval from a medical device that it had previously ap-
proved. Ante, at 19–20, n. 9. But the statutory caveat in §136a(f )(2) is
broader than the FDA’s withdrawal authority in the MDA. Specifically,
§136a(f )(2) makes clear that registration does not preclude a pesticide
from being misbranded—regardless of who makes the misbranding de-
termination. By contrast, the MDA gives authority only to the FDA to
withdraw premarket approval from a medical device if it determines that
device is misbranded. 21 U. S. C. §360e(e)(1)(F); see §352(a).

21 Cite as: 609 U. S. ____ (2026)
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ACKSON, J., dissenting
preempted. Specifically, Monsanto argues that it is impos-
sible to comply with both the labeling requirements of Mis-
souri law and the labeling requirements of FIFRA. See Mu-
tual Pharmaceutical Co. v. Bartlett, 570 U. S. 472, 480
(2013).
Monsanto is wrong. It can easily comply with both fed-
eral and state law by stopping sales of Roundup. Under
FIFRA, it is unlawful to sell a misbranded pesticide.
§136j(a)(1)(E). Under Missouri failure-to-warn law, manu-
facturers have a duty not to sell products made unreasona-
bly dangerous by inadequate warnings. See Racer v. Utter-
man, 629 S. W. 2d 387, 395 (Mo. App. 1981). Far from being
incompatible, both federal and state law require Monsanto
to stop selling its pesticide if the label lacks adequate warn-
ings.
To be sure, our decision in Bartlett largely rejected a
“stop-selling rationale” as “incompatible with our pre-
emption jurisprudence.” 570 U. S., at 488 (internal quota-
tion marks omitted). But we also expressly left open the
possibility that a manufacturer could avoid state and fed-
eral liability if the state claim “parallel[ed] the federal mis-
branding statute” at issue in that case. Id., at 487, n. 4.
This was because the relevant misbranding statute could
require the manufacturer to pull the product from the mar-
ket. Ibid. As support for this conclusion, we cited Bates,
implying that we were not deciding whether a “stop-selling
rationale” would (or would not) work to avoid implied
preemption where the federal and state standards are
equivalent and impose a duty not to sell misbranded prod-
ucts. This case thus falls squarely into the exception seem-
ingly left open by Bartlett.
In any event, Monsanto’s implied preemption argument
fails on its own terms. The premise of Monsanto’s conten-
tion is that Missouri law requires it to add a cancer warn-
ing, but FIFRA prohibits Monsanto from adding such a

22 MONSANTO v. DURNELL
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ACKSON, J., dissenting
warning without approval from the EPA. Monsanto says it
thus cannot do under federal law what state law requires.
But Monsanto overstates the difficulty of adding a cancer
warning to Roundup’s label. In PLIVA, Inc. v. Mensing, 564
U. S. 604 (2011), we explained how true impossibility works
in the labeling context. There, a plaintiff alleged that a ge-
neric drug manufacturer had failed to include adequate
warnings on its label. Id., at 610. Federal law, however,
required the label on a generic drug to match exactly the
label on the brand-name drug. Id., at 612–613. So, for a
generic manufacturer to add a warning, it would have to
ask the FDA to ask the brand-name manufacturer to add
the warning. Id., at 616. We explained that the state-law
claim was preempted because it was impossible for the ge-
neric manufacturer to add the required warning without
the “special permission and assistance” of the Government.
Id., at 623–624.
Here, by contrast, Monsanto does not need the EPA’s
“special permission and assistance” to add a cancer warn-
ing. Like all pesticide manufacturers, Monsanto bears pri-
mary responsibility for maintaining the warnings on its la-
bel. See Bates, 544 U. S., at 438 (“[M]anufacturers have a
continuing obligation to adhere to FIFRA’s labeling require-
ments”). To the extent it needs the EPA’s approval at all
(more on that below), all it must do is submit an application
for an amended registration that reflects the labeling
change, which the EPA “shall” approve as long as the
change does not violate FIFRA. §136a(f )(1); see 40 CFR
§152.44(a). This is a far cry from the contingent chain of
approvals a generic drug manufacturer was required to se-
cure in PLIVA.
But there is no need for Monsanto to undertake this
amended-registration path here. Monsanto can add a can-
cer warning without the EPA’s approval. The EPA’s regu-
lations permit pesticide manufacturers to make “minor
modifications” to their labels without getting prior approval

23 Cite as: 609 U. S. ____ (2026)
J
ACKSON, J., dissenting
from the agency. §152.46. Instead, the manufacturer need
only notify the EPA of the change (and in some cases, noti-
fication is not even required). Ibid.
The majority claims that adding a cancer warning would
not be a “minor” modification. Ante, at 10–11, n. 5. For
support, it relies on the regulation that requires the EPA’s
approval for “‘statements pertaining to the hazards of the
product.’” Ibid. (quoting §156.70(c)). But that regulation
does not apply to chronic conditions like cancer. See supra,
at 6, and n. 4. The prior-approval requirement for hazard
and precautionary statements says nothing about whether
cancer warnings also need prior approval from the EPA.
While a cancer warning may not seem like a minor mod-
ification, facts on the ground belie that appearance. On at
least six occasions, the EPA has permitted manufacturers
to add state-specific cancer warnings as minor modifica-
tions without the agency’s prior approval.
10
Among the
manufacturers that have previously added a cancer
——————
10
See, e.g., Letter from K. Montague, EPA, Office of Pesticide
Programs, to L. Zahigian, Lawn and Garden Products, Inc. (Sept. 14,
2017), https://www3.epa.gov/pesticides/chem_search/ppls/054705-00006-
20170914.pdf (archived at https://perma.cc/9Y47-RGPK); Letter from K.
Davis, EPA, Office of Pesticide Programs, to L. Radevski, Chase Products
Co. (June 21, 2017), https://www3.epa.gov/pesticides/chem_search/ppls/
000498-000156-20170621.pdf (archived at https://perma.cc/46KX-
U46D); Letter from M. Walsh, EPA, Office of Pesticide Programs, to E.
Smith, PBI/Gordon Corporation (May 30, 2017), https://www3.epa.
gov/pesticides/chem_search/ppls/033955-000394-20170530.pdf (archived
at https://perma.cc/6469-9D7S); Letter from M. Walsh, EPA, Office of
Pesticide Programs, to C. Zemanek, The Scotts Company LLC (Mar. 1,
2017), https://www3.epa.gov/pesticides/chem_search/ppls/000239-00739-
20170301.pdf (archived at https://perma.cc/P9SH-74HV); Letter from J.
Urbanski, EPA, Office of Pesticide Programs, to V. Lawless, Wellmark
International (Apr. 21, 2015), https://www3.epa.gov/pesticides/
chem_search/ppls/002724-00702-20150421.pdf (archived at https://
perma.cc/GJR9-FRQ2); Letter from J. Gaines, EPA, Office of Pesticide
Programs, to L. Hodges, Bayer CropScience (Dec. 17, 2012), https://
www3.epa.gov/pesticides/chem_search/ppls/000264-00343-20131217.pdf
(archived at https://perma.cc/P4RU-6X2W).

24 MONSANTO v. DURNELL
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ACKSON, J., dissenting
warning without prior approval is a subsidiary of Mon-
santo’s parent company, Bayer.
***
The majority reads into FIFRA a labeling requirement
that does not exist, and it reads out of FIFRA the statute’s
ongoing prohibition on misbranding. This interpretation
cannot be squared with the text of FIFRA or our precedents.
Ultimately, the effect of the majority’s interpretation is
both remarkable and regrettable, for it unjustifiably closes
the courthouse doors to state tort plaintiffs like Durnell.