FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

MIGRANT CLINICIANS 

NETWORK; BEYOND 

PESTICIDES; CENTER FOR 

BIOLOGICAL DIVERSITY; 

ENVIRONMENTAL 

CONFEDERATION OF 

SOUTHWEST FLORIDA; 

FARMWORKER ASSOCIATION OF 

FLORIDA; FARMWORKER 

JUSTICE; NATURAL RESOURCES 

DEFENSE COUNCIL; UNITED 

STATES PUBLIC INTEREST 

RESEARCH GROUP, 

Petitioners, 

 v. 

U.S. ENVIRONMENTAL 

PROTECTION AGENCY; 

MICHAEL REGAN, in his official 

capacity as Administrator of the 

United States Environmental 

Protection Agency, 

Respondents.

No. 21-70719 

OPINION
2 MIGRANT CLINICIANS NETWORK V. USEPA

On Petition for Review of an Order of the

Environmental Protection Agency

Argued and Submitted January 23, 2023

San Francisco, California

Filed December 13, 2023

Before: Ronald M. Gould, Johnnie B. Rawlinson, and 

Daniel A. Bress, Circuit Judges.

Opinion by Judge Bress

SUMMARY*

Federal Insecticide, Fungicide, and Rodenticide Act / 

Endangered Species Act

The panel granted in part and denied in part a petition for 

review of the Environmental Protection Agency’s amended 

pesticide registrations of streptomycin sulfate for use in 

combating citrus diseases, vacated the EPA’s amended 

registrations, and remanded to the agency to comply with its 

statutory obligations.

Before a pesticide can be distributed and sold in the 

United States, the EPA must satisfy the requirements of the 

Federal Insecticide, Fungicide, and Rodenticide Act 

(FIFRA) and the Endangered Species Act (ESA). On 

* This summary constitutes no part of the opinion of the court. It has 

been prepared by court staff for the convenience of the reader.
MIGRANT CLINICIANS NETWORK V. USEPA 3

January 11, 2021, the EPA issued a Final Registration 

Decision, which unconditionally amended the registration of 

streptomycin for use on citrus crop group 10-10.

Petitioners argued that substantial evidence did not 

support the EPA’s determination, as required by FIFRA, that 

registration of streptomycin for use on citrus would not 

cause “unreasonable adverse effects on the environment.” 

See 7 U.S.C. § 136a(c)(5)(C), (D).

The panel held that substantial evidence supported the 

EPA’s assessment of the risk that the registration of 

streptomycin, which is used as a human antibiotic drug, 

would lead to antibiotic resistance. However, the EPA’s 

assessment of the risk that the registration poses to 

pollinators (bees) was incomplete—or, at the very least, 

inadequately explained. Further, although substantial 

evidence supported the EPA’s determination that 

streptomycin was effective at treating Huanglongbing 

disease and citrus canker, the EPA failed to provide a 

sufficient explanation for the registration labels’ suggestion 

that streptomycin could be used to prevent either disease. 

Accordingly, the panel granted the petition for review as to 

the pollinator and disease prevention issues so that the EPA 

could provide either additional support or a more cogent 

explanation of why the current record was adequate to 

support the registration, or both.

The EPA conceded that its amended registrations failed 

to comply with the ESA but argued that the equities weighed 

against vacatur. Given the seriousness of the EPA’s failure 

to comply with the ESA, as well as its failure to fully comply 

with FIFRA, the panel held that remand without vacatur 

would not be an appropriate remedy. Accordingly, the panel 

vacated the EPA’s amended registration of streptomycin for 
4 MIGRANT CLINICIANS NETWORK V. USEPA

use on citrus group 10-10, and remanded so that the agency 

could address the defects in its FIFRA analysis and conduct 

an ESA effects determination.

COUNSEL

Margaret T. Hsieh (argued), Natural Resources Defense 

Council, San Francisco, California; Sarah V. Fort, Natural 

Resources Defense Council, Washington, D.C.; Francis W. 

Sturges, Jr., Natural Resources Defense Council, Chicago, 

Illinois; Hannah Connor, Center for Biological Diversity, 

Washington, D.C.; Carrie Apfel, Earthjustice, Washington, 

D.C.; Dominique Burkhardt, Earthjustice, Miami, Florida; 

for Petitioners.

Daniel R. Dertke (argued) and Robert M. Norway, 

Attorneys, Environmental Enforcement Section; Todd Kim, 

Assistant Attorney General, Environment and Natural 

Resources Division; United States Department of Justice, 

Washington, D.C.; Erin S. Koch, Assistant General Counsel; 

Jori Reilly-Diakun, Attorney-Advisor; United States 

Environmental Protection Agency, Washington, D.C.; for 

Respondents.
MIGRANT CLINICIANS NETWORK V. USEPA 5

OPINION

BRESS, Circuit Judge:

We consider a petition for review of the Environmental 

Protection Agency’s amended pesticide registrations of

streptomycin sulfate for use in combating citrus diseases. 

The EPA concedes that its amended registrations failed to 

comply with the Endangered Species Act (ESA). We also 

conclude that some aspects of the EPA’s registration

decision contravene the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA). We grant the petition for review 

in part, vacate the EPA’s amended registrations, and remand 

to the agency so that it can comply with its statutory 

obligations. Although we do not vacate EPA’s amended 

registrations lightly, the EPA’s statutory violations coupled 

with its own concessions make this the required course.

I

A

Before a pesticide can be distributed and sold in the 

United States, the EPA must satisfy the requirements of 

FIFRA and the ESA. See, e.g., Ctr. for Food Safety v. 

Regan, 56 F.4th 648, 652–53 (9th Cir. 2022).

FIFRA “is a comprehensive regulatory scheme”

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

Kimmel, Inc. v. DowElanco, 275 F.3d 1199, 1204 (9th Cir. 

2002). Under this scheme, manufacturers are required to 

“register a pesticide with the EPA before introducing it into 

the market.” Id. The registration, once granted, “functions 

as a license setting forth the conditions under which the 

pesticide may be sold, distributed, and used.” Nat’l Res. Def. 
6 MIGRANT CLINICIANS NETWORK V. USEPA

Council v. EPA, 38 F.4th 34, 40 (9th Cir. 2022); see also 7 

U.S.C. § 136a(a).

Under FIFRA, the EPA may not register a pesticide (or, 

as here, amend an existing pesticide registration) unless the 

pesticide, “when used in accordance with widespread and 

commonly recognized practice,” will perform its intended 

function without causing “unreasonable adverse effects on 

the environment.” 7 U.S.C. § 136a(c)(5)(C), (D); 40 C.F.R. 

§ 152.44. FIFRA defines “unreasonable adverse effects on 

the environment” to include “any unreasonable risk to man 

or the environment, taking into account the economic, social, 

and environmental costs and benefits of the use of any 

pesticide.” Id. § 136(bb). When the EPA grants an 

unconditional registration, as it did here, it must “review[] 

all relevant data in [its] possession n” and “determine[] that 

no additional data are necessary to make the determinations 

required by FIFRA.” 40 C.F.R. § 152.112(b)–(c); see also 7 

U.S.C. § 136a(c)(5); Pollinator Stewardship Council v. 

EPA, 806 F.3d 520, 523 (9th Cir. 2015) (“Unconditional 

registration necessarily requires sufficient data to evaluate 

the environmental risks.”).

Once the EPA grants a pesticide registration, the 

pesticide must undergo a broader registration review at least 

every 15 years “to determine whether the pesticide continues

to meet the statutory standard for registration under FIFRA

section 3(c)(5)”—i.e., that it will not “generally cause 

unreasonable adverse effects on the environment.” 

Pesticides; Procedural Regulations for Registration Review, 

65 Fed. Reg. 24586, 24587 (EPA 2000) (to be codified at 40 

C.F.R. pt. 152); see also 7 U.S.C. § 136a(g)(1)(A)(i). If the 

EPA determines upon review that the pesticide no longer 

satisfies this standard, it can cancel the registration or take 

other appropriate action. 7 U.S.C. § 136d(b).
MIGRANT CLINICIANS NETWORK V. USEPA 7

In addition to FIFRA, the EPA’s pesticide registration 

decisions must also comply with the ESA. See Ctr. for Food 

Safety, 56 F.4th at 657. The ESA requires federal agencies

to ensure “that any action authorized, funded, or carried out 

by such agency . . . is not likely to jeopardize the continued 

existence of any endangered species or threatened species” 

or damage its habitat. 16 U.S.C. § 1536(a)(2). Thus, “at the 

earliest possible time,” the EPA must determine whether its

proposed pesticide registration decisions “may affect listed 

species or critical habitat.” 50 C.F.R. § 402.14(a). This 

process is generally called an “effects determination.” Ctr. 

for Food Safety, 56 F.4th at 657. 

Should the EPA determine that a pesticide registration 

will have no effect, “further action is unnecessary.” Id. 

(citing 50 C.F.R. § 402.14(b)(1)). But if the EPA determines 

that a pesticide registration “may affect” an endangered 

species or critical habitat, it then must consult the 

appropriate wildlife agency to analyze the potential impacts 

of the proposed action. 50 C.F.R. §§ 402.14(a), 402.40; see 

also Ctr. for Food Safety, 56 F.4th at 657; Ctr. for Biological 

Diversity v. EPA, 861 F.3d 174, 178 (D.C. Cir. 2017). The 

consulted agency must then provide a written statement 

setting forth its opinion. 16 U.S.C. § 1536(b)(3). “The 

threshold for triggering” this consultation requirement is 

“relatively low.” California ex rel. Lockyer v. U.S. Dep’t of 

Agric., 575 F.3d 999, 1018 (9th Cir. 2009).

B

Streptomycin sulfate (streptomycin) is an antibiotic that

has been used in agriculture, animal husbandry, and human 

medicine for several decades. It has been used commercially 

to control bacterial plant diseases in the United States since 

the 1950s. Streptomycin has been approved for use on,
8 MIGRANT CLINICIANS NETWORK V. USEPA

among other things, apples, pears, beans, peppers, celery,

and tomatoes, as well as in residential ornamental gardens. 

Streptomycin is also considered “highly important” in 

human and veterinary medicine. The Food and Drug 

Administration (FDA) has approved streptomycin for use on

humans and animals to treat various ailments, ranging from 

urinary tract infections to tuberculosis to plague. For several 

decades, streptomycin has been used as a human antibiotic 

drug “without significant incidents” raising concerns for 

human health. More recently, though, clinical use of 

streptomycin has diminished due to the development of 

resistance in many human pathogenic species and its higher 

toxicity relative to other antibiotics. For these reasons, 

streptomycin is typically prescribed as a “second line agent” 

in combination with other antibiotics.

In 2015, pesticide manufacturers proposed another use 

for streptomycin: the management of Huanglongbing

disease and citrus canker in oranges and other citrus crops.

Huanglongbing or “HLB,” also known as “citrus greening,” 

is an incurable and often fatal plant disease spread by the 

Asian citrus psyllid, an invasive insect. Since it was first 

detected in the United States in 2005, HLB has devastated 

domestic citrus production. In Florida, which contains most

of the citrus crop in the United States, HLB affects over 90% 

of citrus acres, and the disease has led to a 42% reduction in 

citrus acreage in the state. Researchers have estimated that 

HLB cost Florida citrus growers $4.5 billion in lost revenues 

and led to the loss of 8,000 jobs. HLB has also affected 

citrus operations in Texas and California.

American citrus groves have also suffered from citrus 

canker disease. Citrus canker is caused by the bacterium 

Xanthomonus citri subsp. Citri (Xcc), and is spread by wind, 
MIGRANT CLINICIANS NETWORK V. USEPA 9

rain, irrigation, and human contact. Despite citrus growers’

considerable eradication efforts, the U.S. Department of 

Agriculture (USDA) determined in 2006 that citrus canker 

had spread in Florida citrus groves to such a degree that 

eradication was not possible. The consequences for growers 

have been severe. Between 2004 and 2016, it is claimed that 

citrus canker reduced citrus acreage in Florida by 30%. 

Together, citrus greening and citrus canker have seriously 

harmed citrus crops, affecting fruit size, health, and 

numbers, and leading to premature tree death.

Citrus growers historically struggled to find effective 

treatment methods for citrus greening and citrus canker. 

There is currently only one registered pesticide that targets 

the specific bacteria that causes HLB disease. And although 

there are other pesticides designed to manage infestations 

from the insects that spread HLB, they have not proven 

successful at preventing HLB transmission. Citrus canker, 

meanwhile, has been managed using copper-based 

pesticides, but these can be harmful to citrus fruits when

applied frequently. As these two citrus diseases continued 

to spread, pesticide manufacturers and citrus farmers sought

alternative treatment methods.

C

In November 2015, Geo Logic Corporation and 

AgroSource Inc. submitted applications to the EPA to amend 

the pesticide registrations of streptomycin for use on citrus 

crop group 10-10, which consists of lemons, limes, oranges, 

and grapefruits, as well as other less common citrus fruits,

such as the pummelo. See 40 C.F.R. § 180.41. While these 

applications were pending, the EPA granted several 

emergency exemptions for use of streptomycin on citrus in 

California and Florida. See 7 U.S.C. § 136p; 40 C.F.R. 
10 MIGRANT CLINICIANS NETWORK V. USEPA

§ 166.2. In December 2018, the EPA submitted for public 

comment its proposed decision to grant the amended 

registrations. After receiving over 4,700 unique substantive 

comments, the EPA addressed concerns raised by 

stakeholders, but it did not alter its proposed decision.

On January 11, 2021, the EPA issued a Final 

Registration Decision, which unconditionally amended the 

registration of streptomycin for use on citrus crop group 10-

10. The registration amendments—set for a 7-year term—

will expire automatically in January 2028, thus “allow[ing]

for an additional reevaluation of the resistance risk” for the 

expanded use of the antibiotic. The EPA’s decision also

required the manufacturers to submit yearly reports 

describing the implementation of plans to monitor soil and 

citrus for incidents of antibiotic resistance.

In amending the streptomycin registration, the EPA 

attempted to comply with FIFRA. But it admits it did not

comply with the ESA. Indeed, the EPA acknowledged that 

in the thousands of pesticide registrations it has approved in 

the past decades under FIFRA, it has met its ESA obligations 

for less than 5% of those actions. The EPA attributes this

“multifold” failure to the high volume of pesticide 

applications, “the unusual complexity” of ESA pesticide 

reviews, and the proliferation of lawsuits challenging 

pesticide products. See also In re Ctr. for Biological 

Diversity, 53 F.4th 665, 668 (D.C. Cir. 2022) (describing the 

EPA’s “fraught relationship with the ESA”). To right the 

ship, the EPA has promulgated a workplan to “improve the 

efficiency and timeliness of the ESA-FIFRA process.” Still, 

the EPA faces a considerable backlog of other ESA effects 

determinations (some court-ordered) which it represents it

must complete before it can perform an effects determination 

for streptomycin. Even under the new workplan, the EPA 
MIGRANT CLINICIANS NETWORK V. USEPA 11

does not anticipate being able to complete the effects 

determination for streptomycin any sooner than fall 2026.

In March 2021, petitioners—a consortium of 

environmental advocacy groups and other public interest 

organizations (including those representing agricultural 

workers)—filed a petition for review asking us to set aside 

EPA’s amended registrations of streptomycin for use on 

citrus. In February 2022, the EPA filed a motion to remand

to the agency without vacatur of the pesticide registrations. 

The EPA acknowledged that it had violated the ESA by 

failing to make an ESA effects determination before 

approving the new uses of streptomycin, but argued that the 

equities weighed against vacatur. Petitioners cross-moved 

for remand with vacatur. A motions panel of this court 

denied both motions without prejudice and set a briefing

schedule.

II

We have jurisdiction to review the EPA’s registration 

decision under 7 U.S.C. § 136n(b). See Nat’l Fam. Farm 

Coal. v. EPA, 960 F.3d 1120, 1131 (9th Cir. 2020). 

Petitioners have Article III standing based on their 

organizational purposes and because their members would 

have standing to sue in their individual capacities. See, e.g., 

Nat’l Fam. Farm Coal. v. EPA, 966 F.3d 893, 908–910 (9th 

Cir. 2020) (holding that environmental groups satisfied 

Article III standing requirements for FIFRA and ESA

challenges to EPA pesticide registrations); Nat’l Res. Def. 

Council, 38 F.4th at 54–55 (same).

We review the EPA’s compliance with FIFRA for 

“substantial evidence when considered on the record as a 

whole.” 7 U.S.C. § 136n(b); Nat’l Fam. Farm Coal., 966 

F.3d at 914. Under this deferential standard, we will affirm 
12 MIGRANT CLINICIANS NETWORK V. USEPA

the EPA’s decision when there is “‘such relevant evidence 

as a reasonable mind might accept as adequate to support a 

conclusion’ even if it is possible to draw two inconsistent 

conclusions from the evidence.” Nat. Res. Def. Council v. 

EPA, 857 F.3d 1030, 1036 (9th Cir. 2017) (quoting Nat. Res. 

Def. Council v. EPA, 735 F.3d 873, 877 (9th Cir. 2013)). As 

for the ESA, that statute “does not specify a standard of 

review,” so “we review EPA’s compliance under the 

[Administrative Procedure Act] and uphold agency action 

unless it is arbitrary, capricious, an abuse of discretion, or 

contrary to law.” Nat’l Fam. Farm Coal., 966 F.3d at 923. 

Although an agency decision may be upheld even if it is of 

“less than ideal clarity,” it does not pass muster if the 

agency’s path cannot “reasonably be discerned.” Bowman 

Transp., Inc. v. Arkansas-Best Freight Sys., Inc., 419 U.S. 

281, 286 (1974).

Because the EPA concedes that it failed to comply with 

the ESA, we will address the ESA only in the context of 

determining the appropriate remedy. Before we do that, 

however, we address whether EPA complied with FIFRA.

III

As FIFRA requires, the EPA determined that registration 

of streptomycin for use on citrus would not cause 

“unreasonable adverse effects on the environment.” 7 

U.S.C. § 136a(c)(5)(C), (D). Petitioners argue that this 

determination was not supported by substantial evidence. 

Specifically, they contend that the EPA (1) did not fully 

assess the risk that the streptomycin registration would lead 

to antibiotic resistance, posing a threat to human health; (2) 

failed to evaluate the risk that the registration poses to 

pollinators (bees); and (3) credited streptomycin with 

providing benefits absent evidentiary support.
MIGRANT CLINICIANS NETWORK V. USEPA 13

We agree with the EPA on Point 1, with petitioners on 

Point 2, and with a little from both sides on Point 3. We 

conclude that substantial evidence supports the EPA’s 

assessment of the risk of antibiotic resistance and deny the 

petition of review as to this issue. The EPA’s assessment of 

the amended registrations’ risk to pollinators, however, is

incomplete—or, at the very least, inadequately explained. 

We also conclude that although substantial evidence 

supports the EPA’s determination that streptomycin is 

effective at treating HLB disease and citrus canker, the EPA 

failed to provide a sufficient explanation for the registration 

labels’ suggestion that streptomycin can be used to prevent

either disease. 

We therefore grant the petition for review as to the 

pollinator and disease prevention issues so that the EPA can

provide either additional support or a more cogent 

explanation of why the current record is adequate to support 

the registration, or both. In the sections that follow, we 

explain our reasoning as to each of petitioners’ three 

challenges under FIFRA.

A

In its Final Registration Decision, the EPA concluded 

that streptomycin is not toxic to humans—unsurprisingly so, 

considering that streptomycin has long been prescribed for 

use in humans as an antibiotic drug. Petitioners do not 

dispute this conclusion. Rather, their marquee argument is 

that the widespread use of streptomycin on citrus crops will 

increase antibiotic resistance, thereby undermining the 

effectiveness of streptomycin and other antibiotics in the 

same class.

The EPA did specifically evaluate the risk of antibiotic 

resistance as part of the registration process and concluded 
14 MIGRANT CLINICIANS NETWORK V. USEPA

that the risk was not unreasonable. But petitioners argue that 

the EPA’s analysis was defective in failing to account fully 

for all the potential vectors by which antibiotic resistance 

could spread. We conclude, however, that substantial 

evidence supports the EPA’s assessment of the risk of 

antibiotic resistance. EPA sufficiently evaluated this risk 

and put in place measures to mitigate it.

To evaluate the risk of antibiotic resistance, EPA adapted 

the analytical approach from FDA Guidance for Industry

#152. See U.S. Food & Drug Admin., Guidance For 

Industry #152: Evaluating the Safety of Antimicrobial New 

Animal Drugs with Regard to Their Microbiological Effects 

on Bacteria of Human Health Concern (2003). The FDA 

uses this framework to assess “the effect of the transmission 

of foodborne bacteria of human health concern through the 

consumption of animal derived food products.” FDA 

Guidance for Industry #152 assesses the risk of antibiotic 

resistance by evaluating the probability of resistance 

developing in the target organism (here, citrus fruit), the 

exposure of antibiotic resistant bacteria to humans through 

consumption of treated food products, and the importance of 

the antibiotic to human health. Applying a modified version 

of this risk analysis methodology, the EPA determined that 

the risk of adverse human health effects from streptomycin 

resistance resulting from its use on citrus was “medium.”

Petitioners argue that FDA Guidance for Industry #152, 

as adapted by EPA, does not fully account for the risks posed 

by the amended registration because it was designed to 

evaluate the spread of resistance through farm animals fed 

or injected with antibiotics, which, petitioners allege, has a 

lower risk profile than spraying the antibiotic on crops. 

According to petitioners, agricultural use of streptomycin is 

more likely to expose the antibiotic to human pathogens 
MIGRANT CLINICIANS NETWORK V. USEPA 15

through either direct contact with farm workers or indirect 

exposure through air, soil, or groundwater. Because the risk 

of antibiotic resistance increases with exposure of the 

antibiotic to human pathogens, petitioners maintain that the

EPA underestimated the risk of antibiotic resistance by 

applying a framework that did not sufficiently account for 

significant vectors of exposure.

The record shows, however, that the EPA adequately 

accounted for the various pathways by which antibiotic 

resistance might spread following streptomycin’s

application to citrus groves. And the agency sufficiently 

explained why the risk of increased resistance was not 

unreasonable based on defined mitigation measures.

First, the EPA explicitly recognized that the 

“agricultural use [of streptomycin] has a much greater 

environmental exposure due to the application by air blast or 

other spray technologies,” and it took into account that the 

registration would likely lead to an 18-fold increase in the 

use of streptomycin in agriculture. Though this increase in 

use is not without risk from an antibiotic resistance 

standpoint, the EPA explained that overall exposure of the 

antibiotic to the environment is only one piece of the puzzle. 

For human bacteria to develop resistance to streptomycin, 

they must first be exposed to it. When antibiotics are used 

on livestock meant for human consumption, there is likely a 

more direct effect on potential antibiotic resistance in human 

pathogens because bacteria of human health concern are

often present in the treated animals.

In plant agriculture, however, the EPA explained that the 

risk of exposing human bacteria to streptomycin is lower

because “human pathogens are a relatively minor component 

of the general agricultural environment.” Indeed, the EPA 
16 MIGRANT CLINICIANS NETWORK V. USEPA

emphasized that “there is no data that antibiotic use in 

agriculture leads to the presence of antibiotic resistance in 

bacteria of human health concern,” and that “[a]t the present 

time, there is little evidence for or against the presence of 

microbes of human health concern in the plant agricultural 

environment.” Under these circumstances, and in 

combination with the mitigation measures that we discuss 

below, the EPA could reasonably rely on the fact that after 

many decades of using streptomycin in agricultural 

applications, there is no indication it has led to antibiotic 

resistance that poses a concern to human health.

Petitioners argue that the EPA’s focus on human bacteria 

within the agricultural environment ignores the potential 

that, through the “air blasting” of streptomycin onto citrus 

groves, humans (and human pathogens) may be exposed to 

streptomycin through drinking water, “off-field” spray drift, 

and contact with workers’ boots, clothes, and tools. But the 

EPA adequately addressed these vectors of contamination. 

See Nat’l Fam. Farm Coal., 966 F.3d at 922 (holding that 

EPA’s registration decisions were “supported by substantial 

evidence because the record evidence was of the type that ‘a 

reasonable mind might accept as adequate’” (quoting Nat. 

Res. Def. Council, 857 F.3d at 1036)).

As part of its decision-making process, the EPA 

consulted with the Center for Disease Control (CDC), FDA, 

and USDA on how to protect the public from streptomycin 

residues on food or in water. Based on these discussions, 

EPA developed several mitigation requirements to reduce

off-field exposure to streptomycin. These requirements are 

not merely pro forma. Pesticide registrants are obligated to 

educate growers on mitigating antibiotic resistance and to 

monitor soil and citrus fruit for any incidence of resistance. 

The EPA’s registration label also requires applicators to 
MIGRANT CLINICIANS NETWORK V. USEPA 17

spray the streptomycin pesticide directly into the orchard

canopy and to “turn off outward pointing nozzles at row 

ends” “to help reduce off-target drift.” The EPA’s 

registration further prohibits using the product through “any 

type of irrigation system” or through “aerial application.”

The record thus demonstrates that the EPA considered

the risk of antibiotic resistance spreading through

environmental pathways, and that it took steps to mitigate it. 

Petitioners’ theory that these measures are insufficient lacks 

factual support. See Ctr. for Cmty. Action & Env’t Just. v. 

FAA, 61 F.4th 633, 640 (9th Cir. 2023) (“[T]he burden is on 

petitioners to demonstrate that the [agency’s] ultimate 

conclusions are unreasonable.” (quoting City of Olmsted 

Falls v. FAA, 292 F.3d 261, 271 (D.C. Cir. 2002))).

Second, substantial evidence supports the EPA’s 

determination that human bacteria exposure to streptomycin 

can be reduced through mandatory use of personal protective 

equipment (PPE) by agricultural workers. As part of its 

Final Registration Decision, the EPA instituted requirements 

for PPE. At a minimum, workers applying streptomycin—

who cannot reenter treated areas at all for 12 hours—must 

wear protective eyewear, coveralls, chemical-resistant

headgear and gloves, socks and shoes, and an approved 

respirator. According to the EPA, this PPE use “will reduce 

the contribution of occupational exposure to the overall risk 

estimations.”

Petitioners are not satisfied that these PPE requirements 

will mitigate the development of antibiotic resistance in 

human pathogens. Because FIFRA requires the EPA to 

evaluate risks posed by a pesticide “when used in accordance 

with widespread and commonly recognized practice,” 7 

U.S.C. § 136a(c)(5)(D), petitioners argue that the agency
18 MIGRANT CLINICIANS NETWORK V. USEPA

must account for “real-world” (i.e., non-compliant) PPE use 

by workers handling streptomycin. According to petitioners, 

the fact that PPE is costly and cumbersome will discourage 

full compliance among workers. Petitioners also argue that 

the PPE requirements, even when followed, do not go far 

enough because they only apply when workers are actively 

spraying the pesticide and not when they reenter previously 

sprayed groves.

The EPA acknowledged that it did not account for noncompliance with PPE requirements in its risk assessment. It 

emphasized, however, that the PPE requirements were not 

mere suggestions. Pesticide labels are legally enforceable 

and carry the statement: “It is a violation of Federal law to 

use this product in a manner inconsistent with its labeling.” 

Cf. 7 U.S.C. § 136j(a)(2)(G). Petitioners correctly note that, 

in certain circumstances, the EPA must account for noncompliance with pesticide labels in conducting its risk 

assessments. See Nat’l Fam. Farm Coal., 960 F.3d at 1139–

41. They rely in particular on National Family Farm 

Coalition, in which we held that the EPA erred in failing to 

account for regulatory non-compliance because there was 

“substantial evidence that even conscientious applicators 

had not been able consistently to adhere to the label 

requirements,” which in that instance were “complex and 

onerous.” Id. at 1140. 

Here, there is no evidence that it is “difficult or 

impossible to comply with” the labels’ PPE requirements, id. 

at 1141, which include such standard measures as wearing 

gloves, coveralls, and respirators. Petitioners cite surveys 

indicating that non-compliance with PPE requirements is 

common. But these surveys are not specific to the PPE 

requirements for streptomycin or citrus growers, nor do they 

involve use labels akin to the one here. Petitioners have not 
MIGRANT CLINICIANS NETWORK V. USEPA 19

demonstrated material flaws in the EPA’s determination that 

mandatory PPE use will reduce direct contact between 

streptomycin and human bacteria.1

In sum, in its risk assessment, the EPA acknowledged 

that resistance to antibiotic pesticides “can be spread by 

resistant species in or on food, the skin of workers, or 

indirectly through the environment or clothing.” For the 

reasons we have explained, we conclude that the EPA’s 

antibiotic resistance assessment was based on “reasonable 

inferences,” and that petitioners have presented us with 

insufficient reason to “question the agency’s wellconsidered conclusions.” Protect Our Communities Found. 

v. Jewell, 825 F.3d 571, 583–84 (9th Cir. 2016). To the 

extent petitioners disagree with the EPA on the merits of its 

scientific analysis, “[m]ere differences in opinion . . . are not 

sufficient grounds for rejecting the analysis of agency 

experts.” Ctr. for Biological Diversity v. Bureau of Land 

Mgmt., 833 F.3d 1136, 1148 (9th Cir. 2016).

B

We turn next to petitioners’ argument that EPA failed to 

evaluate the risk that streptomycin will pose to pollinators—

e.g., bees. FIFRA’s implementing regulations set forth 

requirements for how the EPA must evaluate the effect of 

any pesticide registration on pollinators. See 40 C.F.R. 

1 Petitioners argue that the registration labels’ requirement that 

agricultural workers not reenter sprayed groves for 12 hours does not 

reduce the risk of exposure, especially if workers are not wearing PPE. 

This argument was not raised before the agency during the notice and 

comment period and is therefore forfeited. See Exxon Mobil Corp. v. 

EPA, 217 F.3d 1246, 1249 (9th Cir. 2000). Regardless, for the reasons 

discussed above, we conclude that the EPA adequately addressed the risk 

of streptomycin exposure through human and environmental pathways.
20 MIGRANT CLINICIANS NETWORK V. USEPA

§ 158.630(d). We have previously recognized that bees in 

particular are “essential to pollinate important crops” but “in 

recent years have been dying at alarming rates.” Pollinator 

Stewardship Council, 806 F.3d at 532 (vacating pesticide 

registration due to “the absence of sufficient data 

documenting the risk to bees” and noting the “precariousness 

of bee populations”). As the EPA has said in its own internal 

pollinator guidance, “[t]he scientific community is in general 

agreement that a multitude of factors contribute to potential 

adverse impacts on bees, including . . . pesticides.”

Under FIFRA, the EPA may approve a registration only 

if it has “reviewed all relevant data in [its] possession” and 

“has determined that no additional data are necessary” to 

assess whether the pesticide will perform its intended 

function without “unreasonable adverse effects on the 

environment.” 40 C.F.R. § 152.112(b)–(c) (emphasis 

added); 7 U.S.C. § 136a(c)(5). In addition to these general 

requirements, EPA regulations require applicants to provide 

specific data on the pesticide’s effects on pollinators. 40 

C.F.R. § 158.630(d). For any pesticide registration or 

registration amendment, EPA requires at a minimum that 

applicants submit a honeybee acute contact toxicity study, 

though other studies may be conditionally required. Id. 

Furthermore, under the EPA’s current internal guidance, 

additional studies can be required to “identify whether 

potential risks to bees exist.” Pollinator Stewardship 

Council, 806 F.3d at 524.

Under its internal guidelines, if the EPA identifies any 

concerns based on these studies, it will further evaluate the 

likelihood and extent of the potential exposure to bees, 

focusing on “whether the registered uses involve beeattractive crops,” whether the pesticide would be applied 

“when bees may be present,” and whether “measures can be 
MIGRANT CLINICIANS NETWORK V. USEPA 21

identified to mitigate exposure.” The EPA’s own guidance 

makes clear that when the required data “are not available to 

evaluate potential exposure and effects to bees, it may be 

difficult to develop suitable mitigation measures for some 

[pesticides].” In such cases where the studies specifically 

required by the regulations are “not sufficient to evaluate the 

potential of the product to cause unreasonable adverse 

effects on man or the environment, additional data 

requirements will be imposed.” 40 C.F.R. § 158.75.

In this case, and as part of its FIFRA analysis, the EPA 

was thus required to analyze whether the amended 

registration of streptomycin would have an unreasonable

adverse effect on pollinators. Based on our review of the 

record, we conclude that the EPA’s evaluation of 

streptomycin’s effects on bees does not pass muster. The 

EPA’s own statements indicate that it lacked “sufficient data 

to evaluate the environmental risks” of streptomycin 

registration for use on citrus. Pollinator Stewardship 

Council, 806 F.3d at 523. Further, the EPA’s statements on 

this issue point in different directions, and its path thus 

cannot be reasonably discerned. See, e.g., Crickon v. 

Thomas, 579 F.3d 978, 982 (9th Cir. 2009) (citing Motor 

Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto 

Ins., 463 U.S. 29, 43 (1983)).

Here, there is no dispute that the EPA received and 

reviewed the pollinator acute toxicity data required by 40 

C.F.R. § 158.630(d). That honeybee contact study reported 

“no effects.” The EPA in its Final Registration Decision 

therefore classified streptomycin as “‘practically nontoxic’

to honey bees on an acute exposure basis.” And overall, the 

EPA considered the streptomycin database “to be complete 

to assess risk to the environment and human health, when 

using the Agency’s standard processes.”
22 MIGRANT CLINICIANS NETWORK V. USEPA

But the EPA also stated in its Final Registration Decision 

that its “pollinator data are incomplete” and that

“[a]dditional pollinator data, in accordance with the recent 

pollinator guidance . . . [,] are not available for streptomycin 

at this time.” Moreover, the EPA conceded elsewhere that it 

based its risk assessment on “limited pollinator data” since 

“the full suite of data now being required for pollinators is 

not available for streptomycin.” These statements suggest 

that the EPA has not, in fact, concluded that “no additional 

data are necessary to make the determinations required by 

FIFRA.” 40 C.F.R. § 152.112(c).

On this point, the EPA in its Answering Brief concedes

that some of the language in the Final Registration Decision 

is “admittedly unclear.” That is an understatement. On its 

face, the Final Registration Decision confusingly states both 

that the streptomycin database is “complete” (and thus 

sufficient to conduct a pollinator risk assessment) yet that its 

“pollinator data are incomplete.” These statements stand in 

apparent opposition to each other. The EPA nevertheless 

argues that these Janus-like pronouncements are 

reconcilable: in its view, the Final Registration Decision’s 

statement that “pollinator data are incomplete” refers to data 

the EPA might require as part of its ongoing registration 

review process for all streptomycin products and uses, but 

for the purposes of the amended registration at issue here, 

the pollinator data are “complete.”

We recognize that, as part of the broader registration

review process, the EPA may evaluate additional data to 

ensure that a pesticide registration “reflect[s] advances in the 

science of hazard characterization or exposure assessment.” 

Procedural Regulations for Registration Review, 65 Fed. 

Reg. at 24588; see also 7 U.S.C. § 136a(g)(2). Here, 

however, the Final Registration Decision does not limit its 
MIGRANT CLINICIANS NETWORK V. USEPA 23

statement that “pollinator data are incomplete” to only the 

data required for registration review. As petitioners note, the 

statement comes from a section discussing the risk of the 

registration for citrus group 10-10. Absent a better 

explanation (or any explanation) in the Final Registration

Decision, we must take the Final Registration Decision at its 

word: the pollinator data are “incomplete” with respect to 

this amended registration. The EPA’s FIFRA analysis was 

therefore deficient, for “[w]ithout sufficient data, the EPA 

has no real idea whether [streptomycin] will cause 

unreasonable adverse effects on bees.” Pollinator 

Stewardship Council, 806 F.3d at 532.

But even if we were to brush aside this confusion and 

assume that the EPA never intended to suggest that the 

pollinator data was incomplete for the purposes of this 

amended registration, the EPA fails to explain why the

specific data it has identified as necessary for registration 

review is not also necessary here. Under FIFRA, the EPA 

cannot unconditionally approve or amend a registration until 

it has “reviewed all relevant data” and “determined that no 

additional data are necessary.” 40 C.F.R. § 152.112(b)–(c); 

see also Nat’l Fam. Farm Coal., 966 F.3d at 912. EPA 

regulations also provide that “[r]egistration review is the 

periodic review of a pesticide’s registration to ensure that 

each pesticide registration continues to satisfy the FIFRA 

standard for registration.” 40 C.F.R. § 155.40(a) (emphasis 

added).

Here, the Final Registration Decision explained that 

“[a]dditional pollinator data” from studies that would

“examine potential toxicity to larval and adult honey bees” 

could be “necessary to help make a final registration review 

decision for streptomycin.” In its guidelines for assessing 

pollinator risk, the EPA explains that these studies “are 
24 MIGRANT CLINICIANS NETWORK V. USEPA

necessary to more fully evaluate the potential exposure and 

effects to bees for various pesticide use patterns,” and that

without these additional data, “risk assessors may not be able 

to fully determine the potential for exposure and effects to 

bees.” But in its final decision approving the amended 

registration of streptomycin, the EPA admitted that such

“[a]dditional pollinator data, in accordance with the recent 

pollinator guidance . . . are not available for streptomycin at 

this time.”

The EPA argues that, although its own internal 

guidelines emphasize the general importance of these 

additional pollinator studies, the guidelines do not require 

any additional data for this registration because it involved 

an “existing pesticide” with a “new outdoor use.” In such 

cases, the guidelines recommend that the EPA conduct its 

review “with existing data,” with additional data to “be 

called in under registration review criteria.” But the EPA’s 

claimed compliance with its own internal non-binding 

guidelines does not absolve it of its obligation to provide a 

“reasoned explanation” for its decision. Ass’n of Irritated 

Residents v. EPA, 10 F.4th 937, 945 (9th Cir. 2021) (quoting 

Judulang v. Holder, 565 U.S. 42, 45 (2011)). Because the 

EPA never explained how it complied with its internal 

guidelines in its registration decision, or how compliance 

with the guidelines would be sufficient for present purposes, 

the EPA cannot rely on these guidelines to justify its 

conclusion that no additional pollinator data was necessary.

After all, “judicial review of agency action is limited to ‘the 

grounds that the agency invoked when it took the action.’”

Dep’t of Homeland Sec. v. Regents of the Univ. of Cal., 140 

S. Ct. 1891, 1907 (2020) (quoting Michigan v. EPA, 576 

U.S. 743, 758 (2015)).
MIGRANT CLINICIANS NETWORK V. USEPA 25

As it stands, the EPA has not explained how additional 

data that it has deemed essential for assessing the risk of 

streptomycin on registration review are not also necessary to 

conclude, under this amended registration, that streptomycin 

poses no unreasonable risks to pollinators. See Nat. Res. 

Def. Council, 38 F.4th at 46 (granting petition for review 

when agency’s conclusion was “in tension with parts of [its] 

own analysis and with the guidelines it purports to follow”). 

And even if the EPA’s conflicting statements are

reconcilable, we are not permitted to make a “best guess as 

to what reasoning truly motivated” the agency’s decision. 

Williams Gas Processing-Gulf Coast Co., L.P. v. FERC, 475 

F.3d 319, 329 (D.C. Cir. 2006); see also State Farm, 463 

U.S. at 43 (“We may not supply a reasoned basis for the 

agency’s action that the agency itself has not given.”

(quotation omitted)). 

For these reasons, we grant the petition for review with 

respect to this issue so that the agency can either solicit the 

additional pollinator data necessary to evaluate whether use 

of streptomycin on citrus poses any unreasonable adverse 

effects to bees, or else sufficiently explain why no further 

data are needed at this time.

C

We now turn to petitioners’ final argument under 

FIFRA. FIFRA requires the EPA to determine whether 

registration of a pesticide would pose any “unreasonable 

adverse effects on the environment,” “taking into account 

the economic, social, and environmental costs and benefits

of the use of any pesticide.” 7 U.S.C. § 136(bb) (emphasis 

added). Though the EPA’s Final Registration Decision 

described how streptomycin would benefit citrus growers 

struggling with HLB disease and citrus canker, petitioners 
26 MIGRANT CLINICIANS NETWORK V. USEPA

argue that the EPA’s benefits assessment was not supported 

by substantial evidence. We agree with the petitioners in 

part.

As previously discussed, HLB disease and citrus canker 

have devastated citrus crops, resulting in substantial 

reductions in the overall citrus acreage in the United States. 

Citrus growers currently have few options for mitigating 

damage from either disease. The EPA concluded, based on 

evidence from expert reports and scientific studies, that 

applying streptomycin to citrus trees infected with HLB 

disease increased tree height and fruit load and reduced 

branch dieback and fruit drop. It further found that, when 

used alongside existing copper treatments, streptomycin 

reduces the incidence of citrus canker and associated 

defoliation and fruit drop. Studies indicate that using 

streptomycin to treat citrus canker can also reduce the 

amount of copper spray that needs to be applied, which 

ultimately results in healthier trees because copper itself has 

adverse effects.

Petitioners contend the EPA’s benefits assessment was 

not supported by substantial evidence, for three reasons:

First, petitioners argue that the studies finding 

streptomycin to be an effective treatment for citrus canker 

were flawed because they lacked a proper control group. We 

disagree. The EPA’s conclusion that streptomycin is an 

effective treatment for citrus canker is reasonable, 

notwithstanding the fact that the studies it relied upon

compared trees treated with streptomycin and a “low rate of 

copper” to “untreated” trees, without using a streptomycinonly or copper-only control group. Petitioners view the lack 

of a single-chemical control group as significant because 

they believe it means the EPA could not discern which 
MIGRANT CLINICIANS NETWORK V. USEPA 27

chemical—streptomycin or copper—was producing the 

observed benefits. But the lack of a control group that tested

streptomycin or copper on their own does not undermine the 

EPA’s registration decision because EPA expects 

streptomycin to be used in a mixture with other currently 

registered products, including copper.

When copper is used alone, it typically requires several 

sprays throughout the season. Because copper is phytotoxic 

(poisonous to plants), heavy spraying can cause blemishing

on the fruit and ultimately lead to the development of copper 

resistance in bacteria. Data submitted by the applicants 

indicate, however, that streptomycin combined with copper 

reduces the number of copper sprays needed to improve 

yields. The absence of a streptomycin or copper-only 

control therefore does not detract from the EPA’s conclusion 

that streptomycin is a beneficial treatment for citrus canker.

Second, petitioners contend that the EPA ignored 

scientific evidence in the record suggesting that 

streptomycin is ineffective at treating HLB disease. 

Specifically, they allege that the agency failed adequately to 

address a single study (the “Zhang study”) that the Center 

for Biological Diversity (CBD) cited with limited

elaboration in a footnote to a public comment that CBD

submitted during the notice and comment period. The Zhang

study evaluated 31 antibiotics for effectiveness in managing

HLB disease. It found that streptomycin, along with several 

other antibiotics, was “not effective in eliminating or 

suppressing” the HLB-causing bacteria. In its response to 

comments, the EPA briefly addressed the study, noting that 

it was conducted on “newly grafted citrus scion on root stock 

under laboratory conditions.” The EPA did not comment

more broadly on the study’s claim regarding the supposed 

ineffectiveness of streptomycin.
28 MIGRANT CLINICIANS NETWORK V. USEPA

Though the EPA is obligated to “respond to comments 

received on the notice of application,” 40 C.F.R. § 152.102, 

it is expected to focus its consideration and response on 

“significant comments.” Perez v. Mortg. Bankers Ass’n, 575 

U.S. 92, 96 (2015). This does not necessarily include every 

minute point, however obliquely raised. Cf. Altera Corp. & 

Subsidiaries v. Comm’r of Internal Revenue, 926 F.3d 1061, 

1081 (9th Cir. 2019) (“[A]n agency need only respond to . . .

comments . . . which raise relevant points and which, if 

adopted, would require a change in the agency’s proposed 

rule.” (quotations omitted)); Covad Commc’ns Co. v. FCC, 

450 F.3d 528, 550 (D.C. Cir. 2006) (explaining that the 

agency “need not address every comment, but it must 

respond in a reasoned manner to those that raise significant 

problems.” (quoting Reytblatt v. Nuclear Regul. Comm’n, 

105 F.3d 715, 722 (D.C. Cir. 1997))). Since the Zhang study 

was raised in a footnote, with minimal elaboration, the 

EPA’s brief response to that study was commensurate. The 

EPA did not ignore the study, but instead explained that the 

study was based on laboratory conditions. This was a 

sufficient response.

Third, petitioners argue that the EPA registered 

streptomycin for “use[] to treat or prevent infection” without 

providing any evidence in support of streptomycin’s 

preventative capacity. At the outset, we question whether 

petitioners have correctly characterized the Final 

Registration Decision. Taken in context, it is not clear that 

the EPA is, in fact, recommending that streptomycin be used 

to “prevent” infection in the full sense of that term. Rather,

in the final decision EPA is cautioning applicators that to 

“delay antibiotic . . . resistance,” “[t]his product should be 

used to treat or prevent infection that are proven or strongly 

suspected to be caused by the indicated target bacteria.” In 
MIGRANT CLINICIANS NETWORK V. USEPA 29

context, “prevent infection” could simply mean “prevent the 

further spread of infection” or its harmful effects.

But the EPA does not make these arguments and instead 

appears to concur in petitioners’ reading of the relevant 

language. Indeed, the EPA in its Answering Brief “agrees 

that the registrants did not submit any data to support a claim 

that streptomycin prevents infection,” but argues it 

committed no error since it did not itself consider disease 

prevention as a benefit of streptomycin during its review 

process. The EPA suggests that it would need to determine 

if streptomycin prevented HLB or citrus canker only if a 

manufacturer made such a claim on its registration label. 

But the EPA does not cite any authority for the proposition

that it could include an unsupported use in a registration 

decision and then police the issue on a back-end review of 

pesticide labels.

Thus, to the extent that the Final Registration Decision 

determined that streptomycin can be used to prevent 

infection, we grant the petition for review so that the EPA 

can provide a more coherent and detailed explanation of 

whether it understands disease prevention to be a benefit of 

streptomycin, and, if so, to provide sufficient support for that 

conclusion. We note, however, that our determination here 

does not materially undermine the EPA’s bottom-line 

conclusion about the benefits that streptomycin will 

otherwise provide in treating trees infected with citrus 

greening and citrus canker.

IV

At this point in our analysis, we have now concluded that 

the EPA did not fully comply with FIFRA because it (1) 

failed to include additional data in its pollinator risk 

assessment or explain why such data was not necessary and 
30 MIGRANT CLINICIANS NETWORK V. USEPA

(2) suggested that streptomycin could be used to prevent 

disease without providing evidentiary support for such a 

claim. 

We have not discussed the Endangered Species Act in 

any measure because there is little to say: the EPA admits it 

failed to abide by that statute. We have previously found 

“troubling” the “EPA’s apparent habit of ignoring ESA’s 

effect determination and consultation requirements” in its 

pesticide registration decisions. Ctr. for Food Safety, 56 

F.4th at 658. And we have explained that the EPA may not 

avoid compliance with the ESA merely because of its own

internal regulatory priorities. See id. It is Congress that 

required the EPA to comply with the ESA when making 

pesticide registration decisions, and it is our duty to enforce 

Congress’s command. Id. at 658–59.

This brings us to the question of the appropriate remedy 

given the EPA’s several statutory violations. Specifically, 

we must determine whether to vacate the registration 

amendments or remand to the agency to address the above 

errors while leaving the registrations in place (so-called 

“remand without vacatur”). The traditional remedy for 

erroneous administrative decisions is vacatur, but we will 

“leave invalid agency action in place ‘when equity demands’

that we do so.’” Id. at 663 (quoting Pollinator Stewardship 

Council, 806 F.3d at 532). 

To determine whether an agency’s action should remain 

in effect on remand, we apply a two-factor balancing test: 

“We weigh the seriousness of the agency’s errors against 

‘the disruptive consequences of an interim change that may 

itself be changed.’” Id. (quoting Cal. Cmties. Against Toxics 

v. EPA, 688 F.3d 989, 992 (9th Cir. 2012)). When weighing 

the seriousness of the agency’s errors, we look to whether 
MIGRANT CLINICIANS NETWORK V. USEPA 31

the agency could, “by complying with procedural rules, . . . 

adopt the same rule on remand,” and whether “vacating [the] 

faulty rule could result in possible environmental harm.” 

Pollinator Stewardship Council, 806 F.3d at 532.

In balancing these equitable considerations, we are not 

working off a blank slate. In Centerfor Food Safety, decided 

in late 2022, we held that remand without vacatur was 

appropriate even though there, as here, the EPA failed to 

comply with FIFRA in some respects and failed entirely to 

conduct an ESA effects determination for a pesticide 

registration. 56 F.4th at 663–64. Though we expressed 

“serious concern that EPA has continued to flout the ESA,

we ultimately conclude[d] that EPA could maintain the same 

registration decision once it makes an effects determination

and engages in any required consultation.” Id. at 664. We

thus “reluctantly remand[ed] without vacatur” of the 

pesticide registration. Id. at 668. And we did so in part

“because a vacatur would likely harm the environment more 

and disrupt the agricultural industry,” facts that we 

characterized as “unique.” Id. at 668 & n.15. However, 

based on our concern that the EPA on remand would not, as 

required by the ESA, make its effects determination “at the 

earliest possible time,” we directed the EPA to “act 

immediately” and “to address the[] deficiencies” in its 

FIFRA analysis and abide by its ESA obligations “within 

180 days of the mandate being issued.” Id. at 657, 669.

As in Center for Food Safety, the EPA contends that the 

balance of equities in this case favors remand without 

vacatur. The EPA attempts to downplay the seriousness of 

its wholesale failure to comply with the ESA by arguing that 

its FIFRA analysis was sufficient to demonstrate that 

streptomycin use on citrus is unlikely to threaten any 

endangered species or its habitat. The EPA thus maintains 
32 MIGRANT CLINICIANS NETWORK V. USEPA

that it would, after complying with the ESA, still be able to 

“adopt the same rule on remand.” Pollinator Stewardship 

Council, 806 F.3d at 532. The EPA also argues that vacatur 

would have considerable disruptive consequences for citrus 

growers who have few alternatives for managing HLB and 

citrus canker.

We are sympathetic to the EPA’s equitable concerns and

to the plight of citrus growers, whose products contribute to 

our food supply. But under our decision in Center for Food 

Safety, a blank check remand without vacatur would not be 

an appropriate remedy in this case. Given the seriousness of 

the EPA’s failure to comply with its congressionally 

mandated ESA obligations, Ctr. For Food Safety, 56 F.4th

at 657, as well as its failure to comply fully with FIFRA, any 

remand without vacatur would at least require as a condition 

a mandatory timetable for compliance similar to the 180-day 

deadline that we imposed in Center for Food Safety. See id.

at 669. The EPA has not explained how the equities here 

would justify a more lenient remand than we ordered in 

Center for Food Safety. 

But we do not need to decide whether to impose any

timing requirement here. When asked at oral argument 

whether it would prefer a time-limited remand to outright

vacatur of the amended pesticide registration, counsel for 

EPA explained that the agency would request the latter. The 

reason: the EPA knows it cannot complete an ESA effects 

determination for streptomycin until at least the fall of 2026. 

In other words, the EPA does not want a court-ordered 

deadline that it recognizes it cannot meet. 

Although the EPA’s assertion that it cannot complete an 

ESA effects determination until the fall of 2026 is itself 

troubling, we appreciate the agency’s candor in alerting us 
MIGRANT CLINICIANS NETWORK V. USEPA 33

that a time-limited remand without vacatur would not be a 

sensible remedy. Between our governing law and the EPA’s 

concessions, we thus have no choice other than to vacate the 

EPA’s amended registration of streptomycin. The EPA has 

provided no argument as to why we should be willing to 

allow a longer timeframe to complete the ESA analysis (and 

revised FIFRA analysis) when we only permitted the EPA 

180 days in Center for Food Safety. And since the EPA has 

acknowledged that any deadline sooner than the fall of 2026 

would be unworkable, the tighter leash that we imposed for 

remand without vacatur in Center for Food Safety is simply 

not available in this case. 

We therefore vacate the EPA’s amended registrations of 

streptomycin for use on citrus group 10-10 and remand to 

the agency so that it can address the above-noted defects in 

its FIFRA analysis and conduct an ESA effects 

determination.

PETITION FOR REVIEW GRANTED IN PART 

AND DENIED IN PART; VACATED AND 

REMANDED.