Amicus Curiae Brief — Monsanto Company, Petitioner v. John L. Durnell

Supreme Court briefMay 7, 2025

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No. 24-1068

IN THE

Supreme Court of the United States

MONSANTO COMPANY,

JOHN L. DURNELL

Petitioner,

Respondent.

On Petition for Writ of Certiorari to the

Missouri Court of Appeals—Eastern District

BRIEF OF CROPLIFE AMERICA

AS AMICUS CURIAE IN SUPPORT OF

PETITIONER MONSANTO COMPANY

SHANNEN W. COFFIN

Counsel of Record

STEPTOE LLP

1330 Connecticut Ave., N.W.

Washington, D.C. 20036

(202) 429-3000

scoffin@steptoe.com

Counsel for Amicus Curiae

TABLE OF CONTENTS

INTEREST OF AMICUS CURIAE ............................. 1

SUMMARY OF ARGUMENT ..................................... 3

BACKGROUND .......................................................... 8

FIFRA Requires Comprehensive EPA

Review of Pesticide Safety and Health

Effects as Part of Product Registration 8

FIFRA Grants EPA Primacy in

Determining

Pesticide

Labeling

Requirements ....................................... 10

FIFRA Bars States from Imposing

Different Labeling Requirements ....... 12

ARGUMENT ............................................................. 13

REVIEW IS NEEDED TO RESOLVE A CLEAR

CONFLICT AMONG STATE AND FEDERAL COURTS

OF APPEALS ...................................................... 13

II.

THE MISSOURI COURT’S HOLDING, LIKE THOSE

OF THE CIRCUIT COURTS THAT IT FOLLOWS,

MISAPPLIES CONTROLLING AUTHORITY AND

MISCONSTRUES THE EFFECT OF EPA’S LABELING

DETERMINATIONS ............................................. 19

III.

THE PETITION PRESENTS AN EXCEPTIONALLY

IMPORTANT QUESTION ..................................... 24

CONCLUSION .......................................................... 27

TABLE OF AUTHORITIES

Page(s)

Cases

Bates v. Dow Agrosciences LLC,

544 U.S. 431 (2005) ..................... 9, 12, 13, 15-16,

..................................................................... 19, 27

Carson v. Monsanto Co.,

92 F.4th 980 (11th Cir. 2024) ................ 4, 14, 16,

............................................................... 17-18, 19

Hardeman v. Monsanto Co.,

997 F.3d 941 (9th Cir. 2021) ................. 4, 14, 16,

......................................................... 17-18, 19, 24

Johnson v. Monsanto Co.,

554 P.3d 290 (Or. App. 2024), appeal

denied, 562 P.3d 237 (Or. Dec. 19, 2024) ........... 4

MacDonald v. Monsanto Co.,

27 F.3d 1021 (5th Cir. 1994) ............................. 17

Nat. Res. Def. Council v. U.S.

EPA, 38 F.4th 34 (9th Cir. 2022) ...................... 24

Ruckelshaus v. Monsanto Co.,

467 U.S. 987 (1984) ............................................. 8

Schaffner v. Monsanto Corp.,

113 F.4th 364 (3d Cir. 2024) .................... 4, 5, 12,

......................................................... 13-18, 19, 20

iii

Statutes

7 U.S.C. § 136 ......................................... 2, 5, 8, 9, 11

7 U.S.C. § 136a ......................................... 8, 9, 10, 17

7 U.S.C. § 136j .................................................. 11, 14

7 U.S.C. § 136v ........................... 5, 13, 14, 15, 16, 17

Rules and Regulations

40 C.F.R. pt. 158 ....................................................... 9

40 C.F.R. § 142.56 .................................................. 16

40 C.F.R. § 152.44 .............................. 5, 6, 12, 15, 20

40 C.F.R. § 152.46 .................................................. 12

40 C.F.R. § 152.112 ................................................ 11

40 C.F.R. § 155.40 .................................................. 10

40 C.F.R. § 155.50 .................................................. 10

40 C.F.R. § 156.10 .................................................. 11

40 C.F.R. § 156.60 .................................................. 11

40 C.F.R. § 156.70 ............................ 5, 11, 12, 19, 20

40 C.F.R. § 158.500 .................................................. 9

Final Rule: Glyphosate; Pesticide

Tolerances, 62 Fed. Reg. 17,723, 17,724

(Apr. 11, 1997) ................................................... 21

Final Rule: Glyphosate; Pesticide

Tolerances, 67 Fed. Reg. 60,934, 60,936

(Sept. 27, 2002) ................................................. 21

Final Rule: Glyphosate; Pesticide

Tolerances, 73 Fed. Reg. 73,586, 73,589

(Dec. 3, 2008) ..................................................... 21

Other Authorities

AgbioInvestor, “Time and Cost of New

Agrochemical Product Discovery,

Development, and Registration,” A

Study on Behalf of Crop Life

International (Feb. 2024).................................... 2

Associated Press, “Georgia jury orders

Monsanto parent to pay nearly $2.1

billion in Roundup weedkiller lawsuit,”

(Mar. 27, 2025) .................................................... 7

Bayer, “Bayer announces agreements to

resolve major legacy Monsanto

litigation” (June 24, 2020). ............................... 25

CNN.com, “Bayer ordered to pay $2.25

billion after jury concludes Roundup

weed killer caused a man's cancer,

attorneys say,” (Jan. 30, 2024) ........................... 7

EPA, Glyphosate: Draft Human Health

Risk Assessment in Support of

Registration Review, Case No. 0178

(Dec. 12, 2017) ................................................... 22

EPA, Glyphosate: Interim Registration

Review Decision, Case No. 0178 (Jan.

2020) .................................................................. 23

EPA, Glyphosate: Proposed Interim

Registration Review Decision, Case No.

0178 (Apr. 2019) .......................................... 22, 26

EPA, Ingredients Used in Pesticide

Products: Glyphosate ........................................ 20

EPA, Letter to Glyphosate Registrants on

California Proposition 65 (Aug. 7, 2019) .......... 23

EPA, Office of Pesticide Programs, Label

Review Manual ........................................... 10, 11

EPA, Office of Pesticide Programs, Pesticide

Registration Notice 98-10: Notifications,

Non-Notifications and Minor

Formulation Amendments................................ 12

EPA, Office of Pesticide Programs, Revised

Glyphosate Issue Paper: Evaluation of

Carcinogenic Potential (Dec. 12, 2017) ...... 21, 22

EPA Pesticide Registration Manual:

Introduction......................................................... 9

EPA, R.E.D. Facts, Glyphosate (Sept. 1993) ......... 21

EPA, Reregistration Eligibility Decision

(RED): Glyphosate (Sept. 1993) ....................... 20

European Chemicals Agency, Glyphosate:

no change proposed to hazard

classification (May 30, 2022) ............................ 23

European Food Safety Authority,

Glyphosate: no critical areas of concern;

data gaps identified (July 6, 2023) ................... 23

U.S. Environmental Protection Agency,

“Cost Estimates of Studies Required for

Pesticide Registration” (April 2025) ................... 2

U.S. Environmental Protection Agency,

“Introduction to Pesticide Labels” (April

2025) .................................................................... 6

U.S. EPA, Office of Chem. Safety &

Pollution Prevention, “Glyphosate:

Response to Comments, Usage, and

Benefits” (April 18, 2019) ................................. 26

INTEREST OF AMICUS CURIAE

Established in 1933, CropLife America is the

national trade association for the pesticide industry,

representing developers, manufacturers, formulators,

and distributors of pesticides and plant science

solutions. CropLife America’s member companies

produce, sell, and distribute pesticides, including

herbicides, insecticides, and fungicides, that

American farmers use to provide consumers with

abundant food and fiber.

CropLife America is

committed to safe and responsible use of the

industry’s products. 1

CropLife America’s members are deeply invested

in the discovery and development of new pesticide

products and product uses. The Environmental

Protection Agency (“EPA”) makes its pesticide

registration decisions based on a thorough review of

current scientific and technical information provided

pesticide

manufacturers—including

many

CropLife America member companies—at significant

cost to the manufacturer. EPA publishes a list of more

than 300 possible scientific tests that may be required

as part of a single pesticide’s registration, with dozens

1 CropLife America provided timely notice of its intention to

file this brief to the parties. No counsel for either party authored

this brief in whole or in part, nor did any party or other person

or entity other than amicus curiae, its members, and its counsel

make a monetary contribution intended to fund its preparation

or submission. Monsanto Company’s parent company, Bayer

Corp., is a member of CropLife America, but apart from the dues

it pays as a member, did not contribute money intended to fund

preparation or submission of this brief.

of those tests each costing in the hundreds of

thousands of dollars and some tests costing in the

millions. 2 Pesticide manufacturers spend, on average,

$301 million and more than 12 years on research,

development, and registration to bring each new

active ingredient for crop protection products to the

marketplace. 3

Given that investment, CropLife America’s

members are intimately familiar with the

comprehensive regulation of pesticides under the

Federal Insecticide, Fungicide, and Rodenticide Act

(“FIFRA”). 7 U.S.C. § 136 et seq. CropLife America

member companies have a keen interest in FIFRA’s

legal framework, especially the interrelationship

between federal and state pesticide regulation.

In light of its extensive experience with FIFRA’s

regulatory system—and its substantial interest in the

outcome of the preemption questions presented—

2 For instance, EPA estimates the average cost of “Combined

Chronic Toxicity/Carcinogenicity Testing of Respirable Fibrous

Particles (inhalation route),” just one of the myriad tests

required by EPA regulations, to exceed $5 million. U.S.

Environmental Protection Agency, “Cost Estimates of Studies

Required

for

Pesticide

Registration,”

April

2025,

https://www.epa.gov/system/files/documents/2025-04/test-costestimates-2025-04-25.pdf.

3 See AgbioInvestor, “Time and Cost of New Agrochemical

Product Discovery, Development, and Registration,” A Study on

Behalf of Crop Life International (Feb. 2024), Executive

Summary

5-6,

https://agbioinvestor.com/wpcontent/uploads/2024/02/AgbioInvestor-CropLife-The-Cost-ofNew-Agrochemical-Product-Discovery-Development-andRegistration.pdf.

CropLife America files this brief amicus curiae to

assist the Court’s understanding of FIFRA’s pesticide

registration and the registration review process. A

comprehensive understanding of that process—which

has resulted in EPA’s repeated determinations that

glyphosate-based pesticides are unlikely to cause

cancer and that a cancer warning should not be

included on the product labels—supports granting the

Petition to review the important federal question

presented.

SUMMARY OF ARGUMENT

CropLife America urges the Court to grant

Monsanto Company’s Petition without delay.

Expeditious review is needed to resolve a clear and

deepening conflict of authority, which is unlikely to go

away without this Court’s intervention. This Court’s

review is also needed to correct the persistent

misinterpretation of FIFRA and its implementing

regulations reflected in the Missouri Court of Appeals’

decision. The decision below—and the federal court of

appeals’ decisions on which the Missouri court rested

its preemption holding—have the potential to subject

pesticide manufacturers to millions if not billions of

dollars in unwarranted liability, imposed by lay juries

acting contrary to EPA’s expert scientific judgment

and Congress’s statutory design.

The fundamental question presented by the

Petition is whether juries acting under state law can

override EPA’s determination that glyphosate product

labels should not contain a cancer warning—a

determination based on EPA’s expert judgment that

the scientific evidence does not support a link between

glyphosate and cancer. An acknowledged conflict of

authority on this question has emerged among the

federal courts of appeals and with the decisions of

state courts. Compare Schaffner v. Monsanto Corp.,

113 F.4th 364 (3d Cir. 2024) (FIFRA preempts state

law failure-to-warn claims involving glyphosate

cancer risk warning) with Pet. App. 11 (“we do not find

Schaffner persuasive”); Hardeman v. Monsanto Co.,

997 F.3d 941, 950 (9th Cir. 2021) (rejecting FIFRA

preemption); Carson v. Monsanto Co., 92 F.4th 980,

992-93 (11th Cir. 2024) (same). 4 That division of

authority is well defined and will not benefit from

further development. It invites this Court’s prompt

resolution.

The Missouri court’s decision—like the Ninth and

Eleventh Circuit decisions that it follows—is also

manifestly wrong on a legal question of substantial

public importance. Because EPA has repeatedly

determined that glyphosate-based pesticides do not

cause cancer and thus regularly approves glyphosatebased product labels without requiring a cancer

warning, FIFRA prohibits a contrary state-mandated

warning label.

This follows from the interplay of two relevant

statutory and regulatory provisions. First, FIFRA’s

“Uniformity” provision commands that States “shall

As the Petition notes, state appellate courts in two

additional states—California and Oregon—have similarly

concluded, contrary to the Third Circuit’s Schaffner decision,

that FIFRA does not preempt state failure-to-warn claims. See

Pet. 2 (citing Pilliod v. Monsanto Co., 282 Cal Rptr. 3d 679 (Ct.

App. 2021), appeal denied, No. S270967 (Cal. Nov. 17, 2021);

Johnson v. Monsanto Co., 554 P.3d 290 (Or. App. 2024), appeal

denied, 562 P.3d 237 (Or. Dec. 19, 2024).

not impose or continue in effect any requirements for

labeling or packaging in addition to or different from

those required under” that statute.

7 U.S.C.

§ 136v(b). Second, among the “requirements” of

federal law guarded by FIFRA’s Uniformity provision

is EPA’s label preapproval regulation, which provides

that, once approved by EPA, a pesticide label

generally may not be modified without EPA’s review

and approval. 40 C.F.R. § 152.44(a); see also 40 C.F.R.

§ 156.70(b). Read together, as the Third Circuit

correctly did in Schaffner, those provisions prohibit a

state from imposing liability for a pesticide

manufacturer’s refusal to provide a warning label

different from the label approved by EPA. See

Schaffner, 113 F.4th at 386-88.

The decision below nevertheless upheld a sevenfigure jury verdict imposing liability on Monsanto

under Missouri law for selling its glyphosate-based

pesticide without a warning that EPA has explicitly

and repeatedly found scientifically unsupported and

unnecessary. The Missouri court’s holding is based on

its erroneous view that the only relevant federal

“requirement” for purposes of applying FIFRA’s

Uniformity provision is the statute’s command that a

pesticide not be misbranded.

See 7 U.S.C. §

136(q)(1)(G) (“[a] pesticide is misbranded if . . . the

label does not contain a warning or caution statement

which may be necessary and if complied with . . . is

adequate to protect health and the environment”).

Under the Missouri court’s view, FIFRA’s Uniformity

provision permits a state labeling requirement where

the state law’s purpose is also to protect public health

and the environment through adequate labeling.

But this broad, generalized reading of FIFRA’s

Uniformity provision overlooks the critical scientific

conclusions made by EPA in approving the contents of

the label in the first instance. Where EPA determined

that the science did not support a cancer warning and

approved a label without such a warning, FIFRA’s

preapproval requirement explicitly prohibits a state

from varying that label with a contradictory warning

absent EPA approval. 40 C.F.R. § 152.44(a).

In short, a high-level consistency between the

general purposes of EPA’s misbranding provision and

state label requirements is insufficient to overcome

federal preemption.

FIFRA’s requirements also

include the regulation’s specific label preapproval

requirement and forbid state law modifications absent

EPA approval. As EPA itself often tells the public,

once approved by EPA, “the label is the law.” 5 40

C.F.R. § 152.44(a). FIFRA thus preempts state-law

requirements that seek to vary the label warnings

approved by EPA after its own careful evaluation of

the scientific evidence.

The preemption issues raised in the Petition are

both legally and socially important. Monsanto alone

faces tens of thousands of claims like this one. The

multi-district litigation currently pending in the U.S.

District Court for the Northern District of California

has more than 4,300 active cases raising issues

identical to those presented here. In its home state of

Missouri, Monsanto is a defendant in tens of

thousands of cases seeking relief for a failure to warn

U.S. Environmental Protection Agency, “Introduction to

Pesticide Labels” (April 2025), https://tinyurl.com/5n8kdeh2.

of the very cancer risk that EPA has found does not

require a label warning. Pet. 17.

Pesticide manufacturers have been successful in

defeating many of the dozens of cases that have gone

to trial. But in a handful of those cases where a jury

has been allowed to second-guess EPA’s expert

science-based labeling judgment, the awards have

been staggering—with two recent jury verdicts

exceeding $2 billion. 6

The potential for such

astronomical verdicts puts enormous financial

pressure on the pesticide industry. The legal and

financial crisis facing the manufacturers of products

that EPA has found safe and effective for widespread

use calls for immediate review.

6 See, e.g., Associated Press, “Georgia jury orders Monsanto

parent to pay nearly $2.1 billion in Roundup weedkiller lawsuit,”

(Mar. 27, 2025) (compensatory damages award of $65 million and

punitive damages of $2 billion), https://tinyurl.com/n5fx57y9;

CNN.com, “Bayer ordered to pay $2.25 billion after jury

concludes Roundup weed killer caused a man’s cancer, attorneys

say,” (Jan. 30, 2024) (Pennsylvania jury award included $2

billion in punitive damages), https://tinyurl.com/yc6x867r.

BACKGROUND

FIFRA is a “comprehensive regulatory statute”

governing the sale, use, and labeling of “pesticides.”

Ruckelshaus v. Monsanto Co., 467 U.S. 987, 991

(1984). FIFRA defines “pesticide” to include “any

substance or mixture of substances intended for use

as a plant regulator, defoliant, or desiccant,” 7 U.S.C.

§ 136(u), and encompasses glyphosate-based

herbicides like Monsanto’s Roundup products.

CropLife America explains below the provisions of

FIFRA relevant to pesticide registration and labeling.

FIFRA Requires Comprehensive EPA

Review of Pesticide Safety and Health

Effects as Part of Product Registration

FIFRA prohibits the sale of “any pesticide that is

not registered.” 7 U.S.C. § 136a(a). EPA “shall

considered with any restrictions imposed,” the

pesticide meets four general requirements: 1) its

composition is such as to warrant the proposed claims

for it; 2) its labeling complies with FIFRA’s

requirements; 3) it will perform its intended function

without unreasonable adverse effects on the

environment; and 4) when used in accordance with

widespread and commonly recognized practice it will

not generally cause unreasonable adverse effects on

the environment. 7 U.S.C. § 136a(c)(5).

FIFRA defines “unreasonable adverse effects on

the environment” to mean “any unreasonable risk to

man or the environment,” a calculus that requires

EPA to balance the “economic, social, and

environmental costs and benefits of the use of any

pesticide.”

Id. § 136(bb).

It also includes

consideration of any “human dietary risk from

residues that result from a use of a pesticide” on food

inconsistent with Food, Drug & Cosmetic Act

standards. See id.

EPA’s Pesticide Registration Manual explains that

“[b]efore any pesticide product that EPA has not

exempted from registration requirements can be

lawfully sold or distributed, EPA performs a rigorous,

comprehensive scientific assessment of the product,

resulting in a registration decision.” 7 FIFRA and its

implementing regulations require registrants to

provide substantial scientific data to support a

pesticide’s safety and health effects.

7 U.S.C.

§§ 136a(c)(1)(F) & (c)(2)(A); 40 C.F.R. § 158.500(d); see

40 C.F.R. pt. 158.

A registrant must submit

substantial data addressing the toxicology of the

pesticide, including studies relating to the likelihood

that a particular pesticide could cause cancer in

laboratory rodents. 40 C.F.R. § 158.500(d).

FIFRA allows EPA to waive data requirements

pertaining to—and register a pesticide without

reviewing—product efficacy. Id. § 136a(c)(5)(D); see

Bates v. Dow Agrosciences LLC, 544 U.S. 431, 440

(2005). But EPA cannot similarly waive review for

adverse human health and environmental effects; it

must conduct this searching review in every

registration.

See EPA Pesticide Registration Manual: Introduction,

https://www.epa.gov/system/files/documents/2021-08/pesticideregistration-manual-introduction.pdf.

EPA must reevaluate a pesticide at least once

every 15 years to determine whether it continues to

satisfy registration standards. See 7 U.S.C. § 136a(g);

40 C.F.R. § 155.40 et seq. This process involves a

review of the applicable science under public notice

and comment procedures. See 40 C.F.R. § 155.50.

FIFRA

Grants

EPA

Primacy

Determining

Pesticide

Labeling

Requirements

A central focus of EPA’s registration and

registration review is the product’s label. “Pesticide

product labels provide critical information about how

to safely and legally handle and apply pesticides.” 8 A

“critical function of the label is to translate the results

of the science evaluations into a set of conditions,

directions, precautions, and restrictions that define

who may use a pesticide, as well as where, how, how

much, and how often it may be used.” 9

EPA’s Label Review Manual notes that the

accuracy of the label is “vital” to EPA’s (and other

governmental agencies’) management and mitigation

of pesticide risks; to these agencies’ enforcement of

pesticide

production,

distribution,

and

use

requirements;

registrants,

including

manufacturers and distributors; to applicators, who

8 EPA, Office of Pesticide Programs, Label Review Manual 1-

https://www.epa.gov/system/files/documents/202412/label_review_manual_12122024.pdf.

9 Id.

rely on the label for use instructions and hazard and

safety information; and to the general public. 10

FIFRA’s regulations provide that a product label

“shall include” any “pertinent information which the

[EPA] Administrator determines to be necessary for

the protection of man and the environment.” 40

C.F.R. § 156.10(i)(2)(x)(F).

A product label “is

required to bear hazard and precautionary

statements for humans and domestic animals.” Id.

§ 156.60; id. § 156.70(b). Critically, any “[s]pecific

statements pertaining to the hazards of the product

and its uses must be approved” by EPA. Id. §

156.70(c).

It is unlawful to distribute or sell any misbranded

pesticide. 7 U.S.C. § 136j(a)(1)(E). EPA will not

product is not misbranded . . . and its labeling and

packaging comply with the applicable requirements”

of FIFRA and its regulations. 40 C.F.R. § 152.112(f).

A pesticide is misbranded if its labeling “bears any

statement, design, or graphic representation relative

thereto or to its ingredients which is false or

misleading in any particular.” 7 U.S.C. § 136(q)(1)(A);

see also 40 C.F.R. § 156.10(a)(5). A pesticide is also

misbranded if its label “does not contain a warning or

caution statement which may be necessary and . . . is

adequate to protect health and the environment.” 7

U.S.C. § 136(q)(1)(G).

Once approved, a label must accompany the sale of

the pesticide, 7 U.S.C. § 136j(a)(2)(A), and may

10 Id.

generally be amended only with express EPA

approval. 40 C.F.R. § 152.44(a) (“any modification in

the composition, labeling, or packaging of a registered

product must be submitted with an application for

amended registration”). EPA’s regulations permit it

to allow “minor modifications to registration having

no potential to cause unreasonable adverse effects to

the environment” by notification, without advance

approval. 40 C.F.R. § 152.46(b). Those “minor

modifications” cannot involve “change in the

ingredients statement, signal word, use classification,

precautionary statements, statements of practical

treatment (First Aid), physical/chemical/biological

properties, storage and disposal, or directions for

use.” 11 Consistent with 40 C.F.R. §§ 152.44(a) and

156.70(c), a registrant thus cannot add a new health

hazard to the approved “precautionary statement” of

the label without EPA approval. See Schaffner, 113

F.4th at 385; id. at 383 n.11.

FIFRA Bars States from Imposing

Different Labeling Requirements

Congress addressed the States’ role in pesticide

regulation in the 1972 FIFRA amendments. See

Bates, 544 U.S. at 439. While FIFRA provides the

States certain leeway to regulate the sale and use of

pesticides within their borders, it preserves the

primacy of EPA’s role and federal law. FIFRA grants

11 EPA, Office of Pesticide Programs, Pesticide Registration

Notice 98-10: Notifications, Non-Notifications and Minor

Formulation

Amendments,

(Oct.

22,

1998),

https://www.epa.gov/sites/default/files/2014-04/documents/pr9810.pdf.

the States authority to “regulate the sale or use of any

federally registered pesticide or device in the State,”

but “only if and to the extent the [state] regulation

does not permit any sale or use prohibited by this

subchapter.” 7 U.S.C. § 136v(a).

The States’ role is even more circumscribed with

respect to product labeling. States may enforce only

requirements that are fully consistent with EPA’s

labeling requirements: “Such 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.” Id. § 136v(b). As

this Court reasoned in Bates, FIFRA’s “requirements”

include both the provisions of the statute and “its

implementing regulations.” Bates, 544 U.S. at 452.

ARGUMENT

REVIEW IS NEEDED TO RESOLVE A CLEAR

CONFLICT AMONG STATE AND FEDERAL COURTS

OF APPEALS

The conflict in the lower courts is fully developed,

well defined and otherwise unlikely to be resolved

without this Court’s intervention.

In a thorough and thoughtful opinion, the Third

Circuit recently held that, where EPA has approved

labels that omit cancer warnings on glyphosate-based

pesticides after its extensive review of the scientific

evidence, FIFRA’s Uniformity provision preempts

state failure-to-warn claims seeking damages based

on the failure to include such a warning on the EPAapproved label. See Schaffner, 113 F.4th at 370-71.

Schaffner explicitly acknowledged that its decision

conflicted with those of two sister circuits holding that

FIFRA does not preempt such state law claims. Id. at

389-90; id. at 399 (noting “our analysis differs

from . . . our colleagues in other courts who have

agreed with [the MDL court’s] conclusion”). The

Missouri Court of Appeals’ decision adopts the holding

of those other federal circuit courts and those of two

other state courts, thus deepening a pre-existing split

of authority. See Pet. App. 10-11; see Hardeman, 997

F.3d at 950; Carson, 92 F.4th at 992-93; see also supra,

n.4. There is little reason to allow this conflict to

percolate further. It stems from fundamentally

differing interpretations of a number of relevant

FIFRA provisions that have been fully aired in the

lower courts.

The most basic difference between the approach

adopted by the Missouri Court of Appeals (following

the holdings of Hardeman and Carson) and the Third

Circuit in Schaffner is their differing identification of

the relevant federal “requirements” under FIFRA’s

Uniformity provision, 7 U.S.C. § 136v(b). Hardeman

and Carson both concluded that the only relevant

“requirement” of federal law for purposes of § 136v(b)

was the statute’s misbranding provision, 7 U.S.C.

§ 136j(a)(1)(E), which provides that a product is

misbranded if it does not contain a warning necessary

to protect human health and the environment. The

Ninth and Eleventh Circuits thus held that, because

state law merely sought to determine whether a

missing warning was necessary to protect human

health, the state cause of action was consistent with

§ 136j(a)(1)(E) and not preempted. Hardeman, 997

F.3d at 955-56; Carson, 92 F.4th at 991-92.

The Third Circuit disagreed that FIFRA’s

misbranding statute provided the only relevant

federal requirement. While acknowledging that, at a

high level of generality, the statute’s misbranding

standard and a state law duty-to-warn claim both

seek to accomplish the same objective, the Third

Circuit reasoned that § 136v(b) requires an

examination of federal requirements at “the more

specific level” of the regulations implementing FIFRA.

Schaffner, 113 F.4th at 390. “The state-law duty

cannot survive preemption simply because its

standard of liability is equivalent to the broad

statutory definition of misbranding.” Id.

Instead, the Third Circuit reasoned that, under

Bates, courts must also “examine ‘EPA regulations

that give content to FIFRA’s misbranding standards.’”

Schaffner, 113 F.4th at 381 (quoting Bates, 544 U.S.

at 453).

Those regulations, the Third Circuit

concluded, include 40 C.F.R. § 152.44, the

“Preapproval Regulation.” Schaffner, 113 F.4th at

381. Like the labeling regulations discussed in Bates,

“the Preapproval Regulation also gives content to

FIFRA’s misbranding standards.” Id. at 391; see

Bates, 544 U.S. at 453 (discussing example of FIFRA’s

“DANGER” and “CAUTION” labeling requirements).

Schaffner concluded the Preapproval Regulation

“prohibited Monsanto from modifying Roundup’s

Preapproved Label” to add a state-compelled cancer

warning because the regulation prohibits the sale of a

pesticide with a label different from that approved by

EPA, absent an amended registration and EPA

approval. Id. at 381, 382-85.

Because Bates requires courts applying FIFRA’s

express preemption provision to measure state-law

requirements “against any relevant EPA regulations”

that give content to the statute’s misbranding

requirement (Bates, 544 U.S. at 453), the Third

Circuit held that the preemption provision’s parallelrequirements test “must involve a comparison to the

Preapproval regulation.” Schaffner, 113 F.4th at 38182. Concluding that EPA’s omission of a cancer

warning meant that such a warning could not be

added under state law “without violating the

Preapproval Regulation,” the Third Circuit, expressly

disagreeing with its sister circuits, held that “the Pa.

Duty to Warn is not equivalent to the Federal

Comparator, and it is thus preempted under section

136v(b).” Id. at 382. 12

12 The Ninth and Third Circuits also differed in their reading

of the Preapproval Regulation, which allows EPA to permit

“minor modifications” to a label by notice without EPA approval.

40 C.F.R. § 142.56(a). Citing that provision, the Ninth Circuit

noted that “EPA has repeatedly permitted pesticide

manufacturers to use the notification procedure to add notices

related to cancer to their products’ labels.” Hardeman, 997 F.3d

at 959. The Third Circuit disagreed with the Ninth Circuit’s

suggestion, reasoning that the minor modifications regulation

was not self-executing. Based on subsequent guidance by EPA,

Schaffner concluded that the minor modifications provision

would not permit a registrant to add an actual cancer warning

without EPA approval. Schaffner, 113 F.4th at 385; id. at 384

n.11 (disagreeing with Hardeman’s analysis of the minor

modifications provision).

The Eleventh Circuit noted the

Preapproval Regulation (see Carson, 92 F.4th at 990, but did not

consider it in its “requirements” analysis. See Schaffner, 113

F.4th at 389 n.15 (noting that Carson “[gave] no explanation for

that choice.”).

The disagreement among lower courts also

stemmed from their different treatment of 7 U.S.C.

§ 136a(f)(2).

That subsection provides that the

registration of a pesticide shall not “be construed as a

defense for the commission of any offense under this

subchapter,” but serves as “prima facie evidence” that

the pesticide and its labeling comply with FIFRA’s

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

Both the Ninth and Eleventh Circuits relied on

this statutory provision in concluding that FIFRA

does not preempt state failure-to-warn laws. See

Hardeman, 997 F.3d at 956; Carson, 92 F.4th at 993.

But Schaffner reasoned that § 136a(f)(2) did not affect

the express preemption analysis. While recognizing

that “the mere fact of registration” cannot serve as a

defense to a misbranding action, the Third Circuit

reasoned that the registration of a pesticide also

“affects the content of the requirements imposed

under FIFRA, as registration determines what label

the pesticide must bear.” Schaffner, 113 F.4th at 397.

Unlike its sister circuits, the Third Circuit did not

read § 136a(f)(2) “to indicate that the registration

process cannot play any role in determining the

content of a requirement imposed under FIFRA.” Id.

In that respect, the Third Circuit’s decision was

consistent with an earlier decision of the Fifth Circuit,

which concluded that § 136a(f)(2) “has no bearing” on

federal preemption. MacDonald v. Monsanto Co., 27

F.3d 1021, 1027 n.4 (5th Cir. 1994).

Finally, there is disagreement among the federal

circuit courts on whether EPA’s action must have the

“force of law” to have preemptive effect under §

136v(b). The Ninth Circuit and Eleventh Circuit

concluded that only those EPA actions having the

“force of law” fall within the preemptive scope of

FIFRA’s Uniformity provision. Hardeman, 997 F.3d

at 956; Carson, 92 F.4th at 993. Schaffner disagreed,

reasoning that, when Congress has expressly

authorized the preemption of state law by statute,

“the meaning of the express-preemption provision …

triggers preemption.” 113 F.4th at 398. Because

“Congress has decreed in the text of that provision

that federal ‘requirements’ have preemptive force, no

further analysis is necessary.” Id.

By contrast, in finding no preemption here, the

Missouri Court of Appeals relied upon Hardeman and

Carson and expressly rejected the Third Circuit’s

analysis in Schaffner. The court concluded that “we

do not find Schaffner persuasive and choose to follow

the weight of the authority in holding that Plaintiff’s

failure to warn claim is not expressly preempted by

federal law.” Pet. App. 11. This decision deepens the

pre-existing conflict of authority on both the main

holding of express preemption and the subsidiary

questions on which the federal courts of appeals have

differed. This Court should grant the Petition to

resolve this conflict of authority and the uncertainty

that it has engendered in courts throughout the

country.

II.

THE MISSOURI COURT’S HOLDING, LIKE

THOSE OF THE CIRCUIT COURTS THAT IT

FOLLOWS,

MISAPPLIES

CONTROLLING

AUTHORITY AND MISCONSTRUES THE EFFECT

OF EPA’S LABELING DETERMINATIONS

This Court should grant the Petition because the

decision below, like that in Hardeman and Carson,

misapplies this Court’s decision in Bates. As the

Schaffner court correctly recognized, Bates holds that

FIFRA “pre-empts any statutory or common-law rule

that would impose a labeling requirement that

diverges from those set out in FIFRA and its

implementing regulations.” 544 U.S. at 443-44, 452

(emphasis added). Thus, state labeling requirements

must “be measured against any relevant EPA

regulations that give content to FIFRA’s misbranding

standards.” 544 U.S. at 453. But Hardeman and

Carson—and the Missouri Court of Appeals in

adopting the holding of those decisions—did not

adequately examine FIFRA’s regulations in their

preemption analysis. Had they done so, those courts

would have been required to find the state causes of

action preempted.

In several places, EPA’s FIFRA regulations set

requirements for EPA approval of health warnings

and changes to health warnings on product labels.

For instance, 40 C.F.R. § 156.70, sets out

requirements for human hazard and related

precautionary statement on pesticide labels,

prescribing both the content and location for these

required statements.

Critically, the regulation

requires EPA pre-approval of any statement

pertaining to the hazards of a product or its uses. 40

C.F.R. § 156.70(c).

Once the EPA approves a pesticide label, the label

generally may not be changed without express EPA

approval.

Under 40 C.F.R. § 152.44(a), “any

modification in the composition, labeling, or

packaging of a registered product must be submitted

with an application for amended registration.” As

Schaffner properly held, this provision means EPA

must approve in advance any change to existing

health warnings on pesticides. See 113 F. 4th at 399.

A state-imposed warning is necessarily inconsistent

with this requirement.

In this case, EPA’s decision not to require a cancer

warning was no accident. It was the result of decades

of evaluation of the relevant scientific evidence. The

label reflects EPA’s repeated conclusion that

glyphosate-based pesticides do not cause cancer. EPA

issued its initial glyphosate registration in 1974 and

issued a Reregistration Eligibility Decision for the

active ingredient glyphosate, after a thorough

examination of the underlying data, in 1993. 13 In the

50 years since the original registration, EPA has

concluded again and again that glyphosate does not

pose a cancer risk. Acting on the recommendation of

a scientific peer review committee in the early 1990s,

EPA found “evidence of non-carcinogenicity for

See EPA, Ingredients Used in Pesticide Products:

Glyphosate,

https://www.epa.gov/ingredients-used-pesticideproducts/glyphosate; EPA, Reregistration Eligibility Decision

(RED): Glyphosate (Sept. 1993), https://tinyurl.com/4rewtdnp.

humans.” 14 It reiterated that finding in a formal rule

in 1997 and again in subsequent rulemakings. 15

In 2009, EPA opened its most recent registration

review, which has entailed extensive review of

glyphosate’s environmental safety and toxicology data

after numerous rounds of public notice and comment.

After review by both EPA’s Cancer Assessment

Review Committee and a Scientific Advisory Panel,

EPA published a Revised Glyphosate Issue Paper

evaluating the pesticide’s carcinogenic potential. 16

This extensive review of “new science” included

assessment of “63 epidemiological studies, 14 animal

carcinogenicity studies, and nearly 90 genotoxicity

studies for the active ingredient glyphosate.” 17 EPA

concluded that “available data and weight-of-evidence

clearly do not support the descriptors ‘carcinogenic to

humans’” or “‘likely to be carcinogenic to humans.’” 18

Instead, the scientific evidence most strongly supports

the description “not likely to be carcinogenic to

14 See EPA, R.E.D. Facts, Glyphosate, at 2 (Sept. 1993),

https://archive.epa.gov/pesticides/reregistration/web/pdf/0178fac

t.pdf.

15 Final Rule: Glyphosate; Pesticide Tolerances, 62 Fed. Reg.

17,723, 17,724 (Apr. 11, 1997); see also Final Rule: Glyphosate;

Pesticide Tolerances, 67 Fed. Reg. 60,934, 60,936 (Sept. 27,

2002); Final Rule: Glyphosate; Pesticide Tolerances, 73 Fed. Reg.

73,586, 73,589 (Dec. 3, 2008).

16 See EPA, Office of Pesticide Programs, Revised Glyphosate

Issue Paper: Evaluation of Carcinogenic Potential (Dec. 12,

2017),

https://cfpub.epa.gov/si/si_public_file_download.cfm?p_downloa

d_id=534487&Lab=OPP.

17 Id. at 144.

18 Id.

humans.” 19 EPA concluded this assessment after the

International Agency for Research of Cancer (IARC)

announced its view, upon which glyphosate plaintiffs

nationwide base their claims, that glyphosate was a

probable carcinogen.

EPA’s scientific review led to its Draft Human

Health Risk Assessment, which, after notice and

comment, concluded that glyphosate was not likely to

cause cancer. 20 After considering thousands of public

comments, EPA issued its “Proposed Interim

Registration Review Decision,” reaffirming that its

“independent evaluation of the carcinogenic potential

of glyphosate . . . has determined that glyphosate is

‘not likely to be carcinogenic to humans.’” 21 EPA

expressly rejected IARC’s cancer conclusion,

explaining that EPA’s “cancer evaluation is more

robust than IARC’s evaluation,” which “only

considered a subset of the studies included in the

EPA’s evaluation” and included “some studies that

were not appropriate for determining the human

carcinogenic potential of glyphosate.” 22

After this extensive process, EPA’s Office of

Pesticide Programs sent an August 2019 letter to all

19 Id.

20 See EPA, Glyphosate: Draft Human Health Risk

Assessment in Support of Registration Review, Case No. 0178

(Dec. 12, 2017), https://www.regulations.gov/document/EPA-HQOPP-2009-0361-0068.

21 See EPA, Glyphosate: Proposed Interim Registration

Review Decision, Case No. 0178, at 7 (Apr. 2019),

https://www.regulations.gov/document?D=EPA-HQ-OPP-20090361-2344.

22 Id.

glyphosate registrants, reiterating that it “disagrees

with IARC’s assessment of glyphosate.” 23 EPA noted

that its cancer classification is “consistent with other

international

expert

panels

and

regulatory

authorities,” including government regulators in

Canada, Australia, and New Zealand, as well as the

European Food Safety Authority and European

Chemical Agency. 24 EPA notified registrants that

glyphosate products that do bear a cancer warning

would be “misbranded pursuant to” FIFRA. 25

In January 2020, following another comment

period, EPA issued its interim registration review

decision, reaffirming its longstanding conclusion that

that glyphosate does not cause cancer in humans. 26 It

is currently reviewing that determination in light of a

EPA, Letter to Glyphosate Registrants on California

Proposition 65, at 1 (Aug. 7, 2019) (“EPA Letter”),

https://tinyurl.com/53eb7685.

24 Id.; see, e.g., European Food Safety Authority, Glyphosate:

no critical areas of concern; data gaps identified (July 6, 2023)

(“In 2022, the European Chemicals Agency (ECHA) carried out a

hazard assessment of glyphosate and concluded that it did not

meet the scientific criteria to be classified as a carcinogenic,

mutagenic

reprotoxic

substance.”),

https://tinyurl.com/ywbkvdus; European Chemicals Agency,

Glyphosate: no change proposed to hazard classification (May 30,

2022) (“the committee again concludes that classifying

glyphosate

carcinogen

not

justified”),

https://tinyurl.com/yeywmrfz.

25 EPA Letter 1.

26 See EPA, Glyphosate: Interim Registration Review

Decision,

Case

No.

0178,

(Jan.

2020),

www.epa.gov/sites/production/files/202001/documents/glyphosate-interim-reg-review-decision-casenum-0178.pdf.

subsequent Ninth Circuit decision vacating the

interim decision. See Nat. Res. Def. Council v. U.S.

EPA, 38 F.4th 34, 52 (9th Cir. 2022). But even after

the Ninth Circuit decision, EPA continues to maintain

that its “longstanding finding that glyphosate is not

likely to be carcinogenic to humans” may be used to

support future decisions. 27

As the Petition notes, EPA continues to approve

glyphosate-based pesticide labels without including

cancer warnings. Pet. 11-12. And it has not approved

any relevant amendment to accommodate the

contrary jury determination applying Missouri law in

this case. Under FIFRA’s Uniformity provision,

Missouri state law cannot require a cancer warning

not approved for inclusion on the label by EPA. The

Missouri Court of Appeals’ determination that state

law survives FIFRA preemption is fatally flawed.

This Court should grant the Petition. 28

III.

THE PETITION PRESENTS AN EXCEPTIONALLY

IMPORTANT QUESTION

“Since 2015, thousands of cancer victims have sued

Monsanto in state and federal court, alleging that

EPA

website

https://www.epa.gov/ingredients-used-pesticideproducts/glyphosate.

“Glyphosate,”

28 CropLife America agrees with Petitioner’s suggestion that

the Court should also review the Missouri court’s determination

that FIFRA does not impliedly preempt state law. Application of

state law where EPA has made a clear determination on the

content of the label creates insoluble conflicts with EPA’s label

approval and its amendment regulations. See Pet. 28-31.

Roundup caused their” cancer. Hardeman, 997 F.3d

at 950. Monsanto has faced more than 125,000 filed

and unfiled claims. 29 While it has settled many of

those claims, thousands more persist, with more than

4,400 MDL cases currently pending and tens of

thousands more in state courts throughout the

country. See Pet. 10, 32.

The jury in this case awarded $1.25 million in

damages, but even that sizeable award is eclipsed by

massive jury awards in other glyphosate cases. In the

last two years, two different plaintiffs have been

awarded more than $2 billion in compensatory and

punitive damages. 30 Though Monsanto has prevailed

in the majority of cases that have gone to trial, it does

not take many multi-billion-dollar awards to

endanger a company’s—and an industry’s—existence.

The threat of such immense liability multiplied

across so many cases could easily drive an

economically vital product off the market, despite

EPA’s repeated findings that it poses no cancer risk

and is safe and effective for widespread use. Indeed,

Bayer, Monsanto’s parent company, has already

removed glyphosate-based products from residential

lawn and garden applications.

Should the continued risk of large verdicts based

on flawed legal theories lead to similar decisions for

29 See Bayer, “Bayer announces agreements to resolve major

legacy

Monsanto

litigation”

(June

24,

2020),

https://www.bayer.com/media/en-us/bayer-announcesagreements-to-resolve-major-legacy-monsanto-litigation/.

30 See supra, n.6.

commercial applications, the result would be

devastating to U.S. agricultural production. EPA has

repeatedly found glyphosate to be a highly effective

herbicide with a broad spectrum of “use in agriculture,

including horticulture, viticulture, and silviculture, as

well as non-agricultural sites including commercial,

Increased

industrial and residential areas.” 31

agricultural use has resulted in corresponding

increases in crop yield. Glyphosate is also the leading

active ingredient used to control noxious and invasive

weeds in aquatic systems, pastures and range lands,

forestry, and rights-of-way. 32 These applications are

“critical to maintaining vital infrastructure and safety

for transportation, distribution of goods and services

(railways and roadways) and utilities (electric and

gas).” 33

Imposing a state-law warning requirement where

EPA has found that glyphosate does not cause cancer

would thus discourage socially and economically

useful applications. Unsupported warnings may lead

consumers to avoid buying useful products that do not

pose a risk. A cancer risk warning would discourage

the widespread use of glyphosate with a resulting loss

of crop yields and other benefits from use.

See U.S. EPA, Office of Chem. Safety & Pollution

Prevention, “Glyphosate: Response to Comments, Usage, and

Benefits,”

(April

18,

2019),

https://www.epa.gov/sites/default/files/2019-04/documents/

glyphosate-response-comments-usage-benefits-final.pdf.

32 Id. at 2.

33 Id.

Dissonant state and federal requirements also

place manufacturers in an untenable position. It is

difficult to imagine, for instance, how a manufacturer

could thread the needle between EPA’s and Missouri’s

warning requirements, given that EPA has

specifically rejected any cancer warning for

glyphosate as mislabeling. See Bates, 544 U.S. at 452

(warning against “50 different labeling regimes

prescribing the color, font size, and wording of

warnings” and the “significant inefficiencies for

manufacturers” such a legal regime would entail).

Congress designed FIFRA’s Uniformity provision

to avoid conflicting state and federal labeling

standards. The holding below, like the decisions it

follows, results in disharmony rather than uniformity.

This Court should grant review to harmonize state

and federal law and to resolve the growing conflict on

the important federal question presented.

CONCLUSION

This Court should grant the petition.

Respectfully submitted,

SHANNEN W. COFFIN

Counsel of Record

STEPTOE LLP

1330 Connecticut Ave., N.W.

Washington, D.C. 20036

(202) 429-3000

scoffin@steptoe.com

May 7, 2025

Counsel for Amicus Curiae

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.