John Carson v. Monsanto Company

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[PUBLISH]
In the
United States Court of Appeals
For the Eleventh Circuit

____________________

No. 21-10994
____________________

JOHN D. CARSON,
Plaintiff-Appellant,
versus
MONSANTO COMPANY,

Defendant-Appellee.

____________________

Appeal from the United States District Court
for the Southern District of Georgia
D.C. Docket No. 4:17-cv-00237-RSB-CLR
____________________
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2 Opinion of the Court 21-10994

Before ROSENBAUM, TJOFLAT, Circuit Judges, and MOODY,∗ District
Judge.
ROSENBAUM, Circuit Judge:
State tort litigation plays an important role in protecting
consumers from dangerous products. But the federal government,
through legislation and regulation, exercises its own authority over
those products. And when the two conflict, federal law is supreme.
This case requires us to decide whether the Federal Insecticide,
Fungicide, and Rodenticide Act (“FIFRA”) preempts a state failure-
to-warn tort claim.
Plaintiff-Appellant John D. Carson, Sr., used the popular
weedkiller Roundup for decades before he developed cancer. Car-
son alleges that Roundup caused his cancer and sued Monsanto
(Roundup’s manufacturer) for failure to warn of the product’s can-
cerous effects, among other claims. Monsanto moved for judg-
ment on the pleadings based on FIFRA’s preemption provision, 7
U.S.C. § 136v(b). Specifically, Monsanto argued that FIFRA
preempted Carson’s state-law claims because the Environmental
Protection Agency (“Agency”) approved Roundup’s label without
a cancer warning and classified Roundup’s main ingredient as “not
likely to be carcinogenic.”
The district court agreed and found that FIFRA preempted
Carson’s claims regarding Roundup’s packaging or labeling. We

∗ The Honorable James S. Moody Jr., U.S. District Judge for the Middle Dis-
trict of Florida, sitting by designation.
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21-10994 Opinion of the Court 3

reversed the district court’s dismissal of Carson’s failure-to-warn
claim. But sitting en banc, this Court vacated the opinion and clar-
ified the relevant express-preemption inquiry. Now, on remand,
we reconsider whether Carson’s failure-to-warn claim is
preempted, either expressly or impliedly.
We conclude that FIFRA does not expressly preempt Car-
son’s failure-to-warn claim. FIFRA’s preemption provision applies
to only those state requirements that are “in addition to or different
from” federal requirements. And Georgia common law does not
impose duties “in addition to or different from” FIFRA’s require-
ments; rather, Georgia common law is less demanding than the
federal requirements.
We also conclude that implied preemption does not bar Car-
son’s failure-to-warn claim. Monsanto has not met its burden to
show that, in an action that carried the force of law, the Agency
would not have approved the warning label that Carson proposes.
So Monsanto has not established that it could not have complied
with both state and FIFRA requirements. And as a result, Mon-
santo has failed to show that FIFRA impliedly preempts Carson’s
state-law claim.
I. BACKGROUND
A. FIFRA

The Federal Insecticide, Fungicide, and Rodenticide Act
(“FIFRA”) regulates the use, sale, and labeling of pesticides. 7
U.S.C. § 136 et seq. FIFRA requires all pesticide manufacturers to
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4 Opinion of the Court 21-10994

register their pesticides with the Environmental Protection Agency
(“Agency”) before they can be sold. See 7 U.S.C. § 136a(a). A man-
ufacturer seeking to register a pesticide must submit a proposed
label, as well as certain supporting data, to the Agency. 7 U.S.C.
§§ 136a(c)(1)(C), (F). The Agency will register the pesticide if it de-
termines that the pesticide is efficacious, § 136a(c)(5)(A); that the
pesticide will not cause unreasonable adverse effects on humans
and the environment, §§ 136a(c)(5)(C), (D); and that the pesticide’s
label complies with the statute’s prohibition on misbranding,
§ 136a(c)(5)(B).
FIFRA also prohibits pesticide manufacturers from selling a
pesticide that is “misbranded.” 7 U.S.C. § 136j(a)(1)(E). A pesticide
is “misbranded” if its label contains a statement that is “false or
misleading in any particular” or omits adequate instructions for
use, necessary warnings, or cautionary statements. Id.
§§ 136(q)(1)(A), (F), (G).
During the registration process, the Agency will consider
whether a pesticide’s label is misbranded. The Agency’s initial re-
view does not absolve the registrant’s liability if the pesticide is mis-
branded. Pesticide manufacturers have a continuing obligation to
adhere to FIFRA’s labeling requirements and must report any ad-
verse effects of the pesticide to the Agency. See id. §§ 136a(f )(1);
136d(a)(2).
Similarly, the registration process does not establish a safe
harbor for pesticide manufacturers. FIFRA declares that, “[i]n no
event shall registration of an article be construed as a defense for
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21-10994 Opinion of the Court 5

the commission of any offense under [FIFRA].” Id. § 136a(f )(2).
Rather, registration serves merely as “prima facie evidence that the
pesticide, its labeling and packaging comply with the registration
provisions.” Id.
FIFRA also addresses a state’s role in pesticide regulation. In
this respect, FIFRA provides that “[a] State may regulate the sale or
use of any federally registered pesticide or device in the State, but
only if and to the extent the regulation does not permit any sale or
use prohibited by this subchapter.” Id. § 136v(a). In line with this
qualification, a preemption provision immediately follows: states
may “not impose or continue in effect any requirements for label-
ing or packaging in addition to or different from those required
under this subchapter.” Id. § 136v(b).
B. Factual Background

Plaintiff-Appellant John D. Carson, Sr., used Roundup on his
lawn for over thirty years. But when he was diagnosed with malig-
nant fibrous histiocytoma, a form of cancer, he stopped using the
product.
Carson filed suit against Monsanto, Roundup’s manufac-
turer, alleging that Roundup contained a dangerous carcinogen,
glyphosate, and that Monsanto was aware of Roundup’s harmful
effects but failed to warn customers of the dangers. In his com-
plaint, Carson alleged four causes of action under Georgia law:
strict liability for a design defect (Count I); strict liability for failure
to warn (Count II); negligence (Count III); and breach of implied
warranties (Count IV).
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C. Procedural History

Monsanto moved for judgment on the pleadings on the
ground that FIFRA’s preemption provision, 7 U.S.C. § 136v(b), ex-
pressly preempted Carson’s suit. In the alternative, Monsanto
claimed that the Agency’s previous approval of Roundup’s labeling
and continued adherence to the reasoning for that decision im-
pliedly preempted Carson’s suit. Monsanto argued that because
the Agency declined to require a cancer warning when it registered
and continued to approve Roundup for sale, requiring a label with
such a warning would be “in addition to or different from” FIFRA’s
requirements, in violation of 7 U.S.C. § 136v(b).
The district court granted Monsanto’s motion in part. Spe-
cifically, the court ruled that FIFRA expressly preempted Carson’s
failure-to-warn and breach-of-implied-warranty claims. Carson v.
Monsanto Co., 508 F. Supp. 3d 1369, 1376–77 (S.D. Ga. 2020) (“Carson
I”). So the district court dismissed Counts II and IV of Carson’s
complaint. Id. at 1377–78. The court also dismissed Counts I (de-
sign defect) and III (negligence) as preempted to the extent that
those claims related to Roundup’s labeling or packaging. Id. at
1378.
Because it ruled on express-preemption grounds, the district
court did not address Monsanto’s alternative claim that Counts II
and IV were impliedly preempted. See id. But it did address and
reject implied preemption with respect to Counts I and III. Id. at
1378–79. The court reasoned that, because FIFRA gives states the
authority to regulate pesticides, it would not be impossible for
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Monsanto to comply with both state-law and FIFRA requirements
for manufacturing and design. See id. at 1379.
The parties subsequently settled. In accordance with that
“high-low” settlement agreement, Carson moved to amend his
complaint to dismiss Counts I and III but preserved his right to ap-
peal Count II, the failure-to-warn claim. The district court granted
that motion, eliminating Counts I and III from Carson’s complaint.
Carson timely appealed the district court’s grant of judgment on
the pleadings as to Count II.
On appeal, this panel determined that FIFRA did not
preempt Carson’s failure-to-warn claim. Carson v. Monsanto Co., 51
F.4th 1358, 1363 (11th Cir. 2022), reh’g en banc granted, opinion va-
cated, No. 21-10994, 2022 WL 17813843 (11th Cir. Dec. 19, 2022)
(“Carson II”). We concluded that Georgia’s common-law standard
for product-safety warnings “imposes less of a duty” than FIFRA’s
prohibition against marketing “misbranded” pesticides. Id. And
we held that the Agency’s approval of Roundup’s labels without a
cancer warning did not preempt the Georgia cause of action be-
cause “only federal action with the force of law has the capacity to
preempt state law.” Id. at 1362–65. We analyzed whether the
Agency’s registration process carried the force of law allowing it to
preempt Carson’s state-law claim and determined that it did not.
Id. at 1364.
Before the mandate issued, though, the en banc Court va-
cated the opinion and granted rehearing on the role of a “force-of-
law” analysis in the context of express preemption. Carson v.
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8 Opinion of the Court 21-10994

Monsanto Co., No. 21-10994, 2022 WL 17813843 (11th Cir. Dec. 19,
2022). Sitting en banc, the Court held that a “force-of-law” inquiry
is “usually irrelevant where Congress has enacted an express
preemption provision.” Carson v. Monsanto Co., 72 F.4th 1261, 1267
(11th Cir. 2023) (en banc) (“Carson III”). Rather, an express-preemp-
tion analysis applies the text of the preemption provision in line
with “ordinary principles of statutory interpretation.” Id.
The en banc Court remanded to this panel to address
whether Carson’s failure-to-warn claim was preempted, whether
expressly or impliedly. Id. at 1268. The Court also left for our con-
sideration “Carson’s argument that section 136v(b)’s reference to
‘requirements’ compels a force-of-law inquiry as a matter of statu-
tory interpretation.” Id. We now address those issues.

II. STANDARD OF REVIEW
We review de novo a district court’s order granting judg-
ment on the pleadings, treating the facts alleged in the complaint
as true and viewing the record in the light most favorable to the
nonmovant. Horsley v. Feldt, 304 F.3d 1125, 1131 (11th Cir. 2002).
We review de novo the affirmative defense of preemption. Irving v.
Mazda Motor Corp., 136 F.3d 764, 767 (11th Cir. 1998). Judgment on
the pleadings is proper when no issues of material fact exist and the
moving party is entitled to judgment as a matter of law. Ortega v.
Christian, 85 F.3d 1521, 1524 (11th Cir. 1996) (citing Fed. R. Civ. P.
12(c)).
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III. DISCUSSION
Our analysis proceeds in two parts. In Part A, we consider
Monsanto’s express-preemption defense and conclude that FIFRA
does not expressly preempt Carson’s failure-to-warn claim. Then,
in Part B, we address Monsanto’s implied-preemption defense and
conclude that Monsanto has not met its burden to show impossi-
bility preemption.
A. FIFRA does not expressly preempt Carson’s failure-to-warn
claim.

The Supremacy Clause of the Constitution provides that the
laws of the United States “shall be the supreme Law of the Land.”
U.S. Const. art. VI, cl. 2. Consistent with that command, the Su-
preme Court has long recognized that state laws that conflict with
federal law are “without effect.” Altria Grp., Inc. v. Good, 555 U.S.
70, 76 (2008) (quoting Maryland v. Louisiana, 451 U.S. 725, 746
(1981)). Express preemption occurs when, explicitly in statutory
text, Congress manifests its intent to preempt state law. See Med-
tronic, Inc. v. Lohr, 518 U.S. 470, 485–86 (1996). To be sure, “we have
long presumed that Congress does not cavalierly preempt state-law
causes of action.” Id. at 485. But when a statute’s terms clearly
reflect Congress’s intent to preempt, that statute bars any state-law
claims that fall within its purview.
Indeed, sitting en banc, we have clarified that “[e]xpress
preemption turns primarily on ‘the language of the preemption
statute and the statutory framework surrounding it.’” Carson III,
72 F.4th at 1267 (quoting Lohr, 518 U.S. at 486). So when we
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10 Opinion of the Court 21-10994

consider “an express-preemption provision, we identify the state
law that it preempts according to ordinary principles of statutory
interpretation, and no presumption against preemption applies.”
Id. That is our starting point here.
As we’ve mentioned, FIFRA includes an express-preemption
provision. That provision 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. 7
U.S.C. § 136v(b). We must determine the scope of that provision’s
state-law displacement.
The Supreme Court has explained that FIFRA is not “a suf-
ficiently comprehensive statute to justify an inference that Con-
gress had occupied the field to the exclusion of the States.” Bates v.
Dow Agrosciences LLC, 544 U.S. 431, 441–42 (2005) (quoting Wis. Pub.
Intervenor v. Mortier, 501 U.S. 597, 607 (1991)). “To the contrary,
[FIFRA] leaves ample room for States and localities to supplement
federal efforts.” Mortier, 501 U.S. at 613. For instance, “[n]othing
in the text of FIFRA would prevent a State from making the viola-
tion of a federal labeling or packaging requirement a state offense,
thereby imposing its own sanctions on pesticide manufacturers
who violate federal law.” Bates, 544 U.S. at 442. So at a minimum,
state requirements “that merely duplicate” FIFRA’s requirements
do not violate FIFRA’s preemption provision. See id.
To determine whether FIFRA preempts state requirements
that go beyond “mere[] duplication” of FIFRA’s requirements, we
turn to Bates. There, the Supreme Court clarified the reach of
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FIFRA’s preemption provision. FIFRA preempts a state require-
ment if it (1) is a “requirement ‘for labeling or packaging’”; and (2)
that requirement “is ‘in addition to or different from those required
under’” FIFRA. Id. at 444 (quoting 7 U.S.C. § 136v(b)). In other
words, FIFRA preempts any state-law labeling or packaging re-
quirement that is not “fully consistent” with FIFRA’s requirements.
Id. at 447. But FIFRA does not preempt state-law requirements that
do not relate to labeling or packaging—for example, those that con-
cern only product design or manufacture. See id. at 444.
We now apply Bates’s two-step framework to Carson’s fail-
ure-to-warn claim.
1. FIFRA establishes at least three requirements for labeling.

We begin by identifying FIFRA’s labeling requirements for
pesticide manufacturers. A “requirement is a rule of law that must
be obeyed; an event . . . that merely motivates an optional decision
is not a requirement.” Bates, 544 U.S. at 445. Starting with the stat-
utory text, FIFRA prescribes at least three relevant requirements.
First, FIFRA prohibits misbranding, including on a pesti-
cide’s label. See 7 U.S.C. § 136j(a)(1)(E). A pesticide may be mis-
branded if its label contains a “false or misleading statement,”
“does not contain adequate directions for use,” or “omits necessary
warnings or caution statements.” Bates, 544 U.S. at 438. If the
Agency determines that a pesticide is misbranded, it may institute
cancellation proceedings, see 7 U.S.C. § 136d(b), or impose other
civil or criminal penalties, id. § 136l.
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12 Opinion of the Court 21-10994

Second, FIFRA mandates pesticide registration with the
Agency. Id. § 136a(a). To register, the manufacturer must submit
a proposed label to the Agency along with certain supporting data.
Id. §§ 136a(c)(1)(C), (F). Once the Agency approves a label during
the registration process, manufacturers cannot change the label’s
contents without the Agency’s prior approval and a new registra-
tion application, except for “minor modifications.” 40 C.F.R.
§§ 152.44, 152.46. The Agency reviews a pesticide’s registration,
including its effects on human health, every 15 years. Id.
§ 136a(g)(1)(A). Manufacturers must also re-register certain pesti-
cides after a certain amount of time has passed. Id. § 136a-1(a). Re-
registration involves five “phases,” including data gathering and
analysis and the Agency’s independent verification of that data’s
adequacy. Id. § 136a-1(b).
Third, FIFRA imposes an ongoing reporting requirement.
Under that requirement, manufacturers must report to the Agency
(1) “additional factual information regarding unreasonable adverse
effects on the environment,” 7 U.S.C. § 136d(a)(2), and (2) incidents
involving a pesticide’s toxic effects on humans that may not be ad-
equately reflected in its label’s warnings, see 40 C.F.R. § 159.184(a).
This reporting alerts the Agency to any developments that may ren-
der a previously approved label misbranded.
To sum up, FIFRA’s labeling “requirements” that bear on our
preemption analysis are its (1) prohibition on misbranding, (2) re-
quired registration of pesticides and their labels, and (3) ongoing
reporting requirements.
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2. Georgia state law does not impose duties in addition to or different
from FIFRA’s requirements.

Next, we consider the state-law requirements that Carson’s
failure-to-warn suit, if successful, would impose. Under Georgia
law, “the duty to warn arises whenever the manufacturer knows or
reasonably should know of the danger arising from the use of its
product.” Chrysler Corp. v. Batten, 450 S.E.2d 208, 211 (Ga. 1994).
That includes the duty to warn of “nonobvious foreseeable dangers
from the normal use of its product.” Thornton v. E.I. Du Pont De
Nemours & Co., Inc., 22 F.3d 284, 289 (11th Cir. 1994). A manufac-
turer breaches that duty to warn “if it fails to ‘[(1)] adequately com-
municate the warning to the ultimate user or (2) fail[s] to provide
an adequate warning of the product’s potential risks.’” Watkins v.
Ford Motor Co., 190 F.3d 1213, 1219 (11th Cir. 1999) (quoting
Thornton, 22 F.3d at 289). At bottom, breach occurs when the warn-
ing does not advise “the user of the dangers associated with the use
of the product.” Id.
Carson claims that Monsanto breached its state-law duty to
warn. He alleges that Roundup’s warning “failed to contain rele-
vant warnings, hazards, and precautions,” and instead, Monsanto
“disseminated information that was inaccurate, false and mislead-
ing and which failed to communicate accurately . . . [the] extent of
the risk of injuries with use and/or exposure to Roundup.” In Car-
son’s view, Monsanto should have included a warning about
glyphosate’s potentially carcinogenic effects on its label.
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On their face, Carson’s claims concern labeling and packag-
ing. And in Bates, the Supreme Court held that a common-law duty
constitutes a state-law “requirement” within the scope of FIFRA’s
preemption provision in section 136v(b). 544 U.S. at 446. Indeed,
“[t]he parties agree that Carson’s suit relies on a Georgia ‘require-
ment[] for labeling or packaging.’” Carson III, 72 F.4th at 1267
(quoting Bates, 544 U.S. at 443). So we must determine whether
Carson’s failure-to-warn claim would impose any duties “in addi-
tion to or different from” FIFRA’s requirements. See Bates, 544 U.S.
at 447.
As we’ve noted, FIFRA does not preempt state-law duties,
including common-law claims, that “parallel” or “are fully con-
sistent with” federal requirements. Bates, 544 U.S. at 447. So while
FIFRA may preempt additional state “requirements,” it does not
preempt additional state “remedies” for violations of federal law.
Id.; cf. Lohr, 518 U.S. at 513 (O’Connor, J., concurring in part and
dissenting in part). Rather, FIFRA “authorizes a relatively decen-
tralized scheme that preserves a broad role for state regulation.”
Bates, 544 U.S. at 450. As long as Carson’s state-law claim “paral-
lel[s]” FIFRA’s requirements, section 136v(b) does not expressly
preempt that claim. See id. at 447.
With that in mind, we revisit FIFRA’s “requirements.” Un-
der FIFRA, a pesticide is misbranded if, for example, its “label does
not contain a warning or caution statement which may be neces-
sary and if complied with . . . is adequate to protect health and the
environment.” 7 U.S.C. § 136(q)(1)(G). FIFRA’s prohibition on
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misbranding effectively imposes a strict-liability standard, as it con-
tains no element of knowledge or intent. So long as the pesticide’s
label omits a “necessary” warning “to protect health and the envi-
ronment,” the manufacturer is liable under FIFRA. See id.
By comparison, under Georgia common law, a pesticide
manufacturer breaches its duty to warn if it “fail[s] to provide an
adequate warning of the product’s potential risks.” Watkins, 190
F.3d at 1219 (quoting Thornton, 22 F.3d at 289). But this is not a
limitless standard—the manufacturer is liable only if it “knows or
reasonably should know of the danger arising from the use of its
product.” Chrysler Corp., 450 S.E.2d at 211. And that duty extends
to only “nonobvious foreseeable dangers from the normal use of
its products.” CertainTeed Corp. v. Fletcher, 794 S.E.2d 641, 645 (Ga.
2016) (quoting Thornton, 22 F.3d at 289).
True, Georgia common law does not exactly track FIFRA’s
requirements. But the Supreme Court has explained that “state law
need not explicitly incorporate FIFRA’s standards as an element of
a cause of action in order to survive pre-emption.” Bates, 544 U.S.
at 447. Rather, so long as the state-law duty parallels or is “fully
consistent” with FIFRA, FIFRA does not preempt it. Id. And here,
the practical effect is the same: both FIFRA and Georgia common
law require pesticide manufacturers to warn users of potential risks
to health and safety.
If anything, Georgia common law about failure-to-warn
claims imposes less of a duty on pesticide manufacturers than
FIFRA. Georgia common law requires manufacturers to warn of
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16 Opinion of the Court 21-10994

nonobvious and foreseeable dangers of which they know or rea-
sonably should know. See, e.g., Thornton, 22 F.3d at 289. By con-
trast, FIFRA imposes a blanket duty on pesticide manufacturers,
regardless of knowledge or foreseeability. Because Carson’s state
failure-to-warn claim is “fully consistent with” or even narrower
than federal requirements, FIFRA does not expressly preempt that
claim. See Bates, 544 U.S. at 447; Hardeman v. Monsanto Co., 997 F.3d
941, 955 (9th Cir. 2021) (“Because FIFRA’s misbranding require-
ments parallel those of [the state’s] common law duty, [the plain-
tiff’s] failure-to-warn claims effectively enforce FIFRA’s require-
ment against misbranding and are thus not expressly preempted.”),
cert. denied, 142 S. Ct. 2834 (2022). After all, as the Supreme Court
has reasoned, “[w]hile such a narrower requirement might be ‘dif-
ferent from’” FIFRA’s requirements “in a literal sense,” that would
be “a strange reason for finding pre-emption of a state rule insofar
as it duplicates” FIFRA. Bates, 544 U.S. at 547 (quoting Lohr, 518
U.S. at 495). So FIFRA does not expressly preempt “narrower” state
requirements.
3. FIFRA’s registration process does not preempt Carson’s state-law fail-
ure-to-warn claim.

Monsanto argues that FIFRA’s “requirements” sweep far
more broadly—namely, that FIFRA’s registration process itself car-
ries preemptive effect. In Monsanto’s view, the Agency’s approval
of individual pesticide registrations and corresponding labels also
qualify as “requirements” under FIFRA. In other words, Monsanto
contends, because the Agency approved Roundup’s registration
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and re-registration, all state-law claims related to the registered la-
bel are preempted. Carson responds that the Agency’s individual
approvals are not “requirements” because they do not carry the
force of law.
We agree with Carson. As the en banc Court clarified, we
do not undertake a force-of-law analysis before interpreting an ex-
press-preemption provision. See Carson III, 72 F.4th at 1267. As a
congressionally enacted statute, FIFRA of course carries the force
of law, and its plain text preempts state labeling requirements that
are “in addition to or different from” federal requirements. See 7
U.S.C. § 136v(b).
But the en banc Court left for us to consider whether “sec-
tion 136v(b)’s reference to ‘requirements’ compels a force-of-law
inquiry as a matter of statutory interpretation.” Carson III, 72 F.4th
at 1268. To establish whether a particular Agency action amounts
to a “requirement” under FIFRA, we must determine whether that
Agency action carries the force of law. If it is not “a rule of law
that must be obeyed,” then as the Supreme Court has directed, it is
not a “requirement.” Bates, 544 U.S. at 445. So though we need not
perform a threshold force-of-law analysis before defining the scope
of FIFRA’s preemption, we must do that analysis to determine
whether an Agency action qualifies as a “requirement.”
We “assume . . . that Congress contemplates administrative
action with the effect of law when it provides for a relatively formal
administrative procedure[.]” United States v. Mead Corp., 533 U.S.
218, 230 (2001). That category includes “notice-and-comment
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18 Opinion of the Court 21-10994

rulemaking or formal adjudication,” id., but may extend to other
processes, like cancellation proceedings, as well. Our analysis,
then, turns on whether the FIFRA registration process is “relatively
formal,” id., and creates “a rule of law that must be obeyed,” Bates,
544 U.S. at 445. If it is not, it does not carry the force of law and
cannot preempt state-law duties.
On the record before us, we have little trouble concluding
that the Agency’s individual approvals are not “requirements” un-
der FIFRA. FIFRA sets forth “broadly phrased misbranding stand-
ards.” Bates, 544 U.S. at 453 n.28. Agency regulations, promulgated
after notice and comment, “give content to” those standards. Id. at
453. And Congress has given the Agency the authority to deter-
mine whether a particular pesticide’s label complies with those
broad standards. But we cannot conflate FIFRA’s broad prohibition
on misbranding—indisputably a “requirement”—or even generally
applicable agency regulations, with an individualized finding that a
particular pesticide is not misbranded.
This is especially true because Agency approvals provide
only “prima facie evidence,” not conclusive proof, that a pesticide
is not misbranded. See 7 U.S.C. § 136a(f )(2); Hardeman, 997 F.3d at
956. Indeed, FIFRA specifies that “[i]n no event shall registration .
. . be construed as a defense for the commission of any offense un-
der” its provisions. 7 U.S.C. § 136a(f )(2). By approving a pesticide’s
registration, the Agency signals that the pesticide “compl[ies] with”
FIFRA’s “requirements,” 7 U.S.C. § 136a(c)(5)(B), but it does not im-
pose any new requirements beyond FIFRA’s. And significantly, the
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21-10994 Opinion of the Court 19

Agency can later retract its approval. Since the Agency’s determi-
nation is neither conclusive nor irrevocable, it would make little
sense to deem it a “requirement” on equal footing with FIFRA’s
prohibition on misbranding. See Hardeman, 997 F.3d at 956
(“[B]ecause EPA’s labeling determinations are not dispositive of
FIFRA compliance, they similarly are not conclusive as to which
common law requirements are ‘in addition to or different from’ the
requirements imposed by FIFRA.”).
Still, though, Monsanto argues that registration under
FIFRA preempts state-law claims. For support, Monsanto relies on
Riegel v. Medtronic, Inc., 552 U.S. 312 (2008).
Riegel concerned the “rigorous” pre-market approval process
for medical devices under the Medical Device Amendments
(“Amendments”) to the Federal Food, Drug, and Cosmetic Act—a
statute that the Federal Food and Drug Administration (“FDA”) ad-
ministers. Id. at 317. To initiate the pre-market approval process
under the Amendments, a medical-device “manufacturer must sub-
mit what is typically a multivolume application,” including “full re-
ports of all studies and investigations of the device’s safety and ef-
fectiveness that have been published or should reasonably be
known to the applicant.” Id. at 318 (citing 21 U.S.C. § 360e(c)(1)).
The FDA “spends an average of 1,200 hours reviewing each appli-
cation,” id., and grants premarket approval only if it finds a “rea-
sonable assurance” of the device’s “safety and effectiveness,” 21
U.S.C. § 360e(d). As part of that process, the FDA must determine
that the device’s proposed label is not false or misleading. Id.
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20 Opinion of the Court 21-10994

§ 360e(d)(1)(A). Once a device has received premarket approval,
the manufacturer cannot change its label (or anything else that
would affect the device’s safety or effectiveness) without the FDA’s
permission. Id. § 360e(d)(5)(A)(i).
In Riegel, the plaintiffs brought common-law strict-liability,
breach-of-implied-warranty, and negligence claims against a cathe-
ter manufacturer, including over the device’s labeling. 552 U.S. at
320. The Supreme Court concluded that the Amendments ex-
pressly preempted those state-law claims. Like FIFRA, the Amend-
ments to the Federal Food, Drug, and Cosmetic Act contain an ex-
press-preemption clause: no State “may establish or continue in ef-
fect with respect to a device . . . any requirement—(1) which is dif-
ferent from, or in addition to, any requirement applicable under
[the Amendments] to the device, and (2) which relates to the safety
or effectiveness of the device . . . .” 21 U.S.C. § 360k(a).
As we do here, the Supreme Court interpreted the term “re-
quirement” within the Amendments’ preemption provision. The
Court concluded that the premarket approval process imposed “re-
quirement[s] relating to safety [and] effectiveness” because, after
the FDA grants premarket approval, the manufacturer can make
“almost no deviations” (including labeling) from its application.
Riegel, 552 U.S. at 323, 328. And, the Court reasoned, because the
plaintiffs’ tort claims concerned the device’s “safety and effective-
ness,” they fell within the scope of the Amendments’ preemption
provision. Id. at 327–29. But because the plaintiffs had not fully
briefed it, the Court declined to address whether the plaintiffs’
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21-10994 Opinion of the Court 21

state-law claims imposed “parallel” requirements to those of the
Amendments. Id. at 330.
We think the differences between Riegel and the circum-
stances here show why the Agency’s individualized determinations
about a particular pesticide do not qualify as “requirement[s].”
First, the Riegel Court expressly declined to consider whether state
tort law imposed parallel requirements to the Amendments’ fed-
eral requirements. Id. Here, that question is before us, and, as
we’ve explained, Georgia common law parallels FIFRA’s labeling
requirements.
Second, and more importantly, FIFRA’s statutory scheme
differs from the Amendments’. Again, FIFRA “authorizes a rela-
tively decentralized scheme that preserves a broad role for state
regulation.” Bates, 544 U.S. at 450. By contrast, the Amendments’
scheme is decidedly centralized: the Federal Food, Drug, and Cos-
metics Act Amendments “swept back . . . state obligations and im-
posed a regime of detailed federal oversight.” Riegel, 552 U.S. at
316. So while the preemption provisions are similar, we must read
them in context.
The statutes’ distinct approval processes confirm this signif-
icant difference. Premarket approval under the Amendments rep-
resents a “rigorous” conclusion that a device is safe and effective.
See id. at 317–18. Once the FDA has approved a device, manufac-
turers cannot change a device’s label (or design, etc.) without the
FDA’s permission. See 21 U.S.C. § 360e(d)(5)(A)(i). By contrast, the
Agency’s approval of a pesticide’s registration serves as only “prima
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22 Opinion of the Court 21-10994

facie evidence” that the pesticide complies with FIFRA’s require-
ments. 7 U.S.C. § 136a(f )(2). And through its ongoing reporting
requirements, “FIFRA contemplates that pesticide labels will
evolve over time, as manufacturers gain more information about
their products’ performance in diverse settings.” Bates, 544 U.S. at
451. As the Supreme Court has reasoned, state tort litigation “may
lead manufacturers to petition [the] [Agency] to allow more de-
tailed labelling of their products,” or the Agency “itself may decide
that revised labels are required in light of ” the litigation. Id. at 451
(quoting Ferebee v. Chevron Chem. Co., 736 F.2d 1529, 1541 (D.C. Cir.
1984)).
What’s more, the Amendments’ preemption provision ex-
pressly contemplates device-specific application, as it preempts re-
quirements “with respect to a device.” 21 U.S.C. § 360k(a). FIFRA,
on the other hand, contains no such limitation—it imposes only
“general standards.” Bates, 544 U.S. at 453 n.27. And “different fed-
eral statutes and regulations may . . . lead to different preemption
results.” PLIVA, Inc. v. Mensing, 564 U.S. 604, 626 (2011).
Given the differences between FIFRA and the Amendments’
statutory schemes, Riegel does not control here. And we conclude
that neither FIFRA’s labeling requirements nor the Agency’s regis-
tration process preempts Carson’s state-law failure-to-warn claim.
After all, given “the long history of tort litigation,” it “seems un-
likely that Congress considered a relatively obscure provision like
[section] 136v(b) to give pesticide manufacturers virtual immunity
from certain forms of tort liability.” Bates, 544 U.S. at 449–50.
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21-10994 Opinion of the Court 23

Rather, FIFRA expressly contemplates a role for states in pesticide
regulation, and that role includes common-law claims that parallel
FIFRA’s requirements. See id. at 447.
At bottom, we conclude that FIFRA does not expressly
preempt Carson’s state-law failure-to-warn claim, so Monsanto was
not entitled to judgment on the pleadings on this ground.
4. No other Agency action preempts Carson’s failure-to-warn claim.

Monsanto also points to other Agency actions that it claims
have preemptive effect. We are not convinced.
For instance, Monsanto cites the Agency’s interim registra-
tion reviews and re-registration eligibility decision for glyphosate-
containing pesticides (“Agency’s 2020 Interim Decision”), as well as
accompanying comments. See, e.g., EPA, Reregistration Eligibility
Decision (RED) – Glyphosate (Sept. 1993); EPA, Glyphosate: In-
terim Registration Review Decision Case No. 0178 ( Jan. 2020);
EPA, Response from the Pesticide Re-evaluation Division (PRD) to
Comments on the Glyphosate Proposed Interim Decision ( Jan. 16,
2020).
But the Ninth Circuit vacated the human-health portion of
the Agency’s 2020 Interim Decision as arbitrary and “not supported
by substantial evidence.” Nat. Res. Def. Council v. U.S. Env’t Prot.
Agency, 38 F.4th 34, 51–52 (9th Cir. 2022). And the Agency with-
drew “all remaining portions of the interim registration review de-
cision for glyphosate” in 2022. EPA, EPA Withdraws Glyphosate
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24 Opinion of the Court 21-10994

Interim Decision (Sept. 23, 2022). 1 So, that 2020 determination can-
not carry the force of law or any preemptive effect. See, e.g., Kia-
kombua v. Wolf, 498 F. Supp. 3d 1, 50 (D.D.C. 2020) ( Jackson, J.) (“In
essence, a vacatur order takes the unlawful agency action off the
books[.]” (citation and internal quotation marks omitted)).
Monsanto also relies on a 2019 Agency letter concluding that
glyphosate is “not likely to be carcinogenic to humans” and that
California’s warning of glyphosate’s potential carcinogenic effects
was “false or misleading.” EPA, Letter to Glyphosate Registrants
Regarding Labeling Requirements (Aug. 7, 2019). We note that the
Agency issued the 2019 letter after Carson was diagnosed with can-
cer and filed this lawsuit. And while the letter rejected California’s
specific Proposition 65 warning, it did not foreclose any and all
warnings related to glyphosate’s potentially harmful effects.
In any event, the 2019 letter did not carry the force of law
because it neither reflected sufficient formality, Mead, 533 U.S. at
230, nor created “a rule of law that must be obeyed.” Bates, 544
U.S. at 445. Rather, the Agency issued the letter “without any writ-
ten notice, gave no hearing or opportunity to respond, and lacked
any sort of dispute-resolution process.” Hardeman, 997 F.3d at 957;
cf. Fellner v. Tri-Union Seafoods, L.L.C., 539 F.3d 237, 255 (3d Cir. 2008)
(finding, in the implied-preemption context, no preemptive effect

1 In its announcement of the withdrawal, the EPA nonetheless reiterated “its

finding that glyphosate is not likely to be carcinogenic to humans” but noted
that it “intends to revisit and better explain its evaluation of the carcinogenic
potential of glyphosate.” Id.
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21-10994 Opinion of the Court 25

where the agency “merely expressed an informal policy opinion in
a letter, and it did so only after [the plaintiff’s] injuries were alleg-
edly suffered”). So the 2019 letter does not expressly preempt Car-
son’s state-law failure-to-warn claims.
For similar reasons, we reject Monsanto’s arguments that
Agency scientific papers or letters from Agency officials about
glyphosate’s potentially carcinogenic effects (or lack thereof ) carry
preemptive effect. See, e.g., EPA, Health Effects Div., Second Peer
Review of Glyphosate (Oct. 30, 1991); EPA, Office of Pesticide Pro-
grams, Revised Glyphosate Issue Paper: Evaluation of Carcino-
genic Potential (Dec. 12, 2017). In short, we conclude that neither
FIFRA nor any other Agency action imposes “requirements” that
would preempt Carson’s state-law failure-to-warn claim.
B. Carson’s failure-to-warn claim is not impliedly preempted.

Though we find no express preemption, our preemption in-
quiry does not end there. Monsanto contends that Carson’s claims
are “independently barred by impossibility preemption” because
Monsanto “could not have added a cancer warning to the Roundup
label over [the] [Agency’s] objection.” In fact, Monsanto claims, the
Agency would not have approved a warning label stating that
glyphosate may be carcinogenic to humans, so Monsanto could not
comply with both federal directives and Georgia common-law du-
ties.
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26 Opinion of the Court 21-10994

The district court did not rule on Monsanto’s implied-
preemption defense to Carson’s failure-to-warn claim,2 as it con-
cluded that Monsanto prevailed on its express-preemption argu-
ment. See Carson I, 508 F. Supp. 3d at 1377–78. But as we’ve noted,
we reach a different answer on the express-preemption issue. And
as it turns out, the parties have briefed the implied-preemption is-
sue before us. Because the resolution of that issue is clear, we de-
cide it. See LaCroix v. Town of Fort Myers Beach, 38 F.4th 941, 954
(11th Cir. 2022).

Implied preemption occurs when “it is ‘impossible for a pri-
vate party to comply with both state and federal requirements.’”
Mensing, 564 U.S. at 618 (quoting Freightliner Corp. v. Myrick, 514 U.S.
280, 287 (1995)). The mere “possibility of impossibility [is] not
enough.” Merck Sharp & Dohme Corp. v. Albrecht, 139 S. Ct. 1668,
1678 (2019) (alteration in original) (quoting Mensing, 564 U.S. at 625
n.8). Rather, the state and federal laws must “irreconcilably con-
flic[t].” Id. at 1679 (alteration in original) (citation omitted).

To show an “irreconcilabl[e] conflict” that would bar Car-
son’s failure-to-warn claim, Monsanto must present “clear evi-
dence” that (1) Monsanto “fully informed” the Agency of “the jus-
tifications for the warning” that Georgia state law would impose;
(2) the Agency “informed [Monsanto] that [it] would not approve

2 The district court considered only whether impossibility preemption barred

Carson’s remaining design-defect (Count I) and negligence (Count III) claims.
See Carson I, 508 F. Supp. 3d at 1378.
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21-10994 Opinion of the Court 27

changing the . . . label to include that warning”; and (3) the Agency
undertook its action “pursuant to . . . congressionally delegated au-
thority” in a way that “carr[ies] the force of law.” Id. at 1678–79
(citation and internal quotation marks omitted). The Supreme
Court has characterized this burden as “demanding.” Wyeth v. Lev-
ine, 555 U.S. 555, 573 (2009).

As a threshold matter, Carson argues that implied preemp-
tion is not an available defense given FIFRA’s express-preemption
provision. Cf. Mortier, 501 U.S. at 613 (1991) (finding that FIFRA
does not “otherwise imply pre-emption” beyond section 136v(b));
Graham v. R.J. Reynolds Tobacco Co., 857 F.3d 1169, 1189 (11th Cir.
2017) (reasoning that the fact that “the express-preemption provi-
sion” at issue “does not cover the” substance of the plaintiffs’ claims
“supports an inference that there is no implied preemption of
those” claims). But we need not resolve that question, because
even if implied preemption is available, Monsanto has not satisfied
its burden here.

Monsanto relies on the Agency actions we’ve already
noted—chiefly, the Agency’s 1993 determination that glyphosate
met FIFRA’s requirements for re-registration and its 2019 letter say-
ing that California’s cancer warning for glyphosate would be a
“false and misleading statement” in violation of FIFRA. These ac-
tions don’t meet the “demanding” standard for impossibility
preemption.
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28 Opinion of the Court 21-10994

First, the Agency’s registration, interim registration review,
and re-registration of glyphosate without a cancer warning do not
show that a cancer warning would be impossible. Put differently,
the Agency’s repeated approvals of a label without a cancer warn-
ing do not mean the Agency necessarily would have rejected a label
with a cancer warning.

Nor does the Agency’s concurrent classification of glypho-
sate as not likely to be carcinogenic to humans alter this conclusion.
Based on the record before us, Monsanto did not request—and the
Agency did not consider, much less reject—a cancer warning at all.
So Monsanto cannot meet its burden to show that the Agency “in-
formed [Monsanto] that [it] would not approve changing the . . . la-
bel to include that warning,” and impossibility preemption does
not apply. See Merck, 139 S. Ct. at 1678.

Our conclusion is the same for the Agency’s 2019 letter: the
Agency action does not meet the “demanding” requirements for
impossibility preemption. Of course, the Agency issued the 2019
letter after Carson was diagnosed with cancer and filed this lawsuit,
so it does not necessarily reflect the Agency’s position during the
time Carson used Roundup. But even if it did, the 2019 letter was
directed at California’s specific Proposition 65 warning and did not
conclude that any and all warnings related to glyphosate’s potential
cancerous effects would render a pesticide “misbranded.” That is
not enough for impossibility preemption. See Merck, 139 S. Ct. at
1678 (“The underlying question for this type of impossibility pre-
emption defense is whether federal law . . . prohibited the [product]
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21-10994 Opinion of the Court 29

manufacturer from adding any and all warnings to the [product]
label that would satisfy state law.”).

Monsanto also can’t point to caselaw from the Supreme
Court or this Court that compels preemption. To be sure, in Mens-
ing, the Supreme Court found that impossibility preemption barred
the plaintiffs’ state-law claims. 564 U.S. at 618. But Mensing is ma-
terially distinguishable from this case.

In Mensing, the prescription-drug manufacturers could not
change their labels in the way the plaintiffs sought because the drug
was a generic version of a name-brand drug. See id. at 612, 618.
And under federal law, generic drugs must carry the same labels as
their name-brand equivalents, so the generic-brand manufacturers
could not unilaterally change their labels if the name-brand label
stayed the same. Id. at 618; see also 21 U.S.C. § 355(j)(4)(G); 21
C.F.R. § 314.150(b)(10). If, in fact, the generic-brand manufacturers
“independently changed their labels to satisfy their state-law duty,
they would have violated federal law.” Id. As a result, the generic-
brand manufacturers in Mensing could not comply with both fed-
eral and state-common-law requirements. Id. This conflict trans-
cended the mere “possibility of impossibility.” See id. at 625 n.8.
And that required the Court to find implied preemption. Id. at 618.
But here, Roundup’s label was not dependent on that of any other
pesticide. And Monsanto cannot show that a cancer warning
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30 Opinion of the Court 21-10994

“would have violated federal law.” See id. So Mensing does not lend
any support to Monsanto’s claims.3

What’s more, in 2022, the Agency publicly stated that it
“could approve” warning language that “[t]he International
Agency for Research on Cancer classified glyphosate as probably
carcinogenic to humans,” and products with that warning “would
not be considered misbranded.” EPA, Response to California’s Of-
fice of Environmental Health Hazard Assessment on California’s
Proposition 65 (Apr. 8, 2022). To be sure, the Agency expressed this
position years after Carson filed his lawsuit. But it still undercuts
Monsanto’s claim of impossibility. If, in the Agency’s own words,
it “could approve” a warning similar to the one Carson seeks, and
products with a warning like that would not be “misbranded” un-
der FIFRA, Monsanto could comply with both state and federal la-
beling requirements. See also Hardeman, 997 F.3d at 959 (noting that
the Agency “has repeatedly permitted pesticide manufacturers to
use the notification procedure to add notices related to cancer to
their products’ labels”). And no “irreconcilabl[e] conflict” exists.
As a result, FIFRA does not impliedly preempt the warning that
Georgia law would require. See Merck, 139 S. Ct. at 1679.
Finally, and in any event, as we’ve explained, none of the
Agency’s actions on which Monsanto relies carry the force of law.

3 We note also that Mensing did not involve express preemption, as Congress

has “declined to enact [an express-preemption] provision for prescription
drugs.” Wyeth, 555 at 567.
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21-10994 Opinion of the Court 31

See Mead, 533 U.S. at 230; Hardeman, 997 F.3d at 960. So even if the
Agency’s actions satisfied the first two requirements for impossibil-
ity preemption—and as we’ve explained, they do not—they fail to
meet this third requirement. See Merck, 139 S. Ct. at 1679. Because
Monsanto has not carried its burden of proving impossibility, we
conclude that implied preemption does not bar Carson’s state-law
failure-to-warn claim.

IV. CONCLUSION
For the reasons we’ve explained, we vacate the district
court’s conclusion that FIFRA expressly preempts Carson’s failure-
to-warn claim, hold that neither FIFRA nor any Agency action im-
pliedly preempts Carson’s failure-to-warn claim, and remand for
further proceedings consistent with this opinion.
VACATED AND REMANDED.