Vinyl Institute, Inc . v. Environmental Protection Agency

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued December 1, 2023 Decided July 5, 2024
No. 22-1089
VINYL I NSTITUTE, I NC .,
P ETITIONER
v.
E NVIRONMENTAL PROTECTION AGENCY,
RESPONDENT
On Petition for Review of a Final Action
of the Environmental Protection Agency
Eric P. Gotting argued the cause for petitioner. With him
on the briefs were Peter L. de la Cruz and Gregory A. Clark.
Jonathan R. Mook and M. Jarrad Wright were on the brief
for amici curiae Physicians Committee for Responsible
Medicine and People for the Ethical Treatment of Animals in
support of petitioner.
Ryan J. Carra was on the brief for amicus curiae
American Chemistry Council in support of petitioner.
Laura J. Brown, Attorney, U.S. Department of Justice,
argued the cause for respondent. With her on the brief was
Todd S. Kim, Assistant Attorney General.

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Samantha Liskow and James Murphy were on the brief for
amici curiae Environmental Defense Fund and National
Wildlife Federation in support of respondent.
Before: HENDERSON, WALKER and PAN, Circuit Judges.
Opinion for the Court filed by Circuit Judge HENDERSON.*
KAREN LECRAFT HENDERSON , Circuit Judge: In March
2022, the Environmental Protection Agency (EPA) issued an
order directed to seven chemical manufacturers/processors
(hereafter “targeted entities”),1 requiring them to test the
chronic toxicity of 1,1,2-Trichloroethane (1,1,2-TCA) pursuant
to the Toxic Substances Control Act (TSCA), 15 U.S.C.
§§ 2601–2629. Vinyl Institute, a trade organization that
manages a consortium of the seven targeted entities, challenged
the order based on the EPA’s failure to comply with several
statutory requirements.2 See 15 U.S.C. § 2603. Vinyl Institute
also moved to supplement the administrative record with a
scientific consultant’s report. See 15 U.S.C. § 2618(b).
* Judge Walker concurs in the judgment and concurs in the
opinion except as to Parts II.B.4 and .5.
1 We use “targeted entities” to describe the chemical
manufacturers/processors that are required to respond to a test
order—including the seven targeted entities to which the March 2022
Test Order was directed. Those seven targeted entities formed a
consortium, managed by Vinyl Institute, to respond to the order.
2 Several amici have participated in this case. The
Environmental Defense Fund (EDF) and National Wildlife
Federation filed a brief in support of the EPA. The American
Chemistry Council (ACC) filed a brief in support of Vinyl Institute,
as did the Physicians Committee for Responsible Medicine (PCRM)
and People for the Ethical Treatment of Animals (PETA).

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As detailed infra, we grant Vinyl Institute’s petition for
review. The EPA’s non-public part of the administrative record
is not part of “the record taken as a whole” subject to our
heightened substantial evidence review of TSCA test orders.
15 U.S.C. § 2618(c)(1)(B)(i)(II). To the extent it relies on non-
public portions of the administrative record, the EPA has failed
to provide substantial evidence that meets its statutory
mandate. We vacate and remand to the EPA to satisfy that
mandate with “substantial evidence in the record taken as a
whole.” Id. We also deny Vinyl Institute’s motion to
supplement the record with scientific information it could
have—and should have—submitted earlier. See 15 U.S.C.
§ 2618(b).
I. BACKGROUND
A. TSCA Testing
In 1976, the Congress became concerned that many
chemical substances expose humans and the environment to
“an unreasonable risk of injury to health or the environment.”
15 U.S.C. § 2601(a)(2). In order to “prevent unreasonable risks
of injury,” the Congress enacted the TSCA, Pub. L. No. 94-
469, 90 Stat. 2003 (1976) (codified at 15 U.S.C. §§ 2601–
2629). S. REP. NO. 94-698, at 1 (1976). Under the TSCA,
entities that manufacture and process such chemicals must
develop and maintain adequate data. 15 U.S.C. § 2601(b)
(1976). The statute requires the entities to test substances to
determine whether their manufacture, distribution, processing
or use “does or does not present an unreasonable risk of injury
to health or the environment.” Id. § 2603(a)(2) (1976). Before
promulgating its “testing” rule, however, the EPA is first
required to find that (1) the chemical “may present an
unreasonable risk of injury to health or the environment”; (2)
the EPA lacks sufficient data and experience to determine or

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predict the chemical’s effects; and (3) testing “is necessary to
develop such data.” Id. § 2603(a)(1)(A) (1976) (emphasis
added). Once the EPA determines that a chemical substance
poses an unreasonable risk, the TSCA authorizes it to regulate
the substance. See id. § 2605 (1976).3
By the 2010s, the Congress expressed “persistent
concerns” regarding the EPA’s slow pace in implementing the
TSCA, H.R. REP. NO. 114-176, at 12 (2015), and so—
recognizing shortcomings based on statutory structure, court
decisions and the EPA’s interpretation of those decisions—it
revised the statute via the 2016 Amendments. S. REP. NO . 114-
67, at 2 (2015); Frank R. Lautenberg Chemical Safety for the
21st Century Act, Pub. L. No. 114-182, 130 Stat. 448 (2016)
(codified at 15 U.S.C. §§ 2601–2629). The 2016 Amendments
require the EPA to designate chemicals as “high-priority” or
“low-priority.” 15 U.S.C. § 2605(b)(1). The EPA then
conducts a risk evaluation for each high-priority chemical to
determine whether it presents an “unreasonable risk of injury
to health or the environment.” Id. § 2605(b)(3)–(4). If it
concludes the chemical presents an unreasonable risk of injury,
it can then regulate the chemical through a rulemaking. Id.
§ 2605(a). The 2016 Amendments instruct the EPA to
complete high-priority risk evaluations within 3 years. Id.
§ 2605(b)(4)(G); H.R. REP. NO. 114-176, at 25. Significant to
this litigation, they also supplement the EPA’s existing test rule
authority—codified at Section 2603(a)(1)—with “[a]dditional
testing authority” under Section 2603(a)(2). That authority
allows the EPA to impose a testing requirement on targeted
entities via “rule, order, or consent agreement” and applies
whenever new information “is necessary” in order to perform
a risk evaluation. 15 U.S.C. § 2603(a)(2); H.R. REP. NO. 114-
3 The post-2016 TSCA retains each of these requirements. See
15 U.S.C. §§ 2601(b), 2603(a)(1), 2605(a).

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176, at 22–23. The EPA may choose whether to proceed under
Section 2603(a)(1) or (a)(2). See 15 U.S.C. § 2603(a)(2) (“In
addition to the authority provided under paragraph (1), the
Administrator may [develop information] by rule, order, or
consent agreement . . . .” (emphasis added)).
Before the EPA can compel targeted entities to test—“by
rule, order, or consent agreement”—under its Section
2603(a)(2) authority, it must take several steps. Id. First, it must
provide a Statement of Need that (1) identifies “the need for the
new information”; (2) describes how “reasonably available”
information informs the EPA’s decision; (3) “explain[s] the
basis for any decision that requires the use of vertebrate
animals”; and (4) if applicable, explains its rationale for
issuance of a test order instead of a rule or consent agreement.
Id. § 2603(a)(3). Next, the EPA must address how a screening
test or other available information supports additional testing.
Id. § 2603(a)(4). A rule, order or consent agreement must
identify the chemical substance to be tested and the protocols
and methodologies for developing the required information. Id.
§ 2603(b)(1). In determining protocols and methodologies, it
must consider the costs as well as the reasonably foreseeable
availability of facilities to perform the testing. Id. In addition
to explaining the basis for vertebrate testing in its Statement of
Need, the EPA must consider “existing information” such as
toxicity, computational toxicology, bioinformatics and high-
throughput screening methods. Id. § 2603(h)(1)(A).4 Finally,
4 “High-throughput screening” is a “[p]rocess that allows
automated testing of large numbers of chemical and/or biological
compounds for a specific biological target.” High-Throughput
Toxicology, EPA, https://perma.cc/V3TE-ZH2P. The EPA refers to
toxicity information, computational toxicology, bioinformatics and
high-throughput screening methods as New Approach
Methodologies (NAMs). Strategic Plan to Promote the Development
and Implementation of Alternative Test Methods Within the TSCA

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the EPA must conduct each risk evaluation consistent with the
“best available science” and its decision must be based on the
“weight of the scientific evidence.” Id. § 2625(h), (i); see also
40 C.F.R. § 702.33.
B. 1,1,2-Trichloroethane
This case involves the EPA’s risk evaluation of 1,1,2-
TCA, a colorless, sweet-smelling liquid used in chemical
production. See Final Scope of the Risk Evaluation for 1,1,2-
TCA, EPA Doc. # EPA-740-R-20-003, at 11 (Aug. 2020),
https://perma.cc/N78Z-QGX5 (Final Scope Doc.). The EPA
established a list of twenty high-priority substances, including
1,1,2-TCA. High-Priority Substance Designations Under the
TSCA, 84 Fed. Reg. 71924, 71934 (Dec. 30, 2019). This
designation triggered TSCA’s Section 2605(b)(3)–(4) risk
evaluation. See id. (“[A] final designation as a High-Priority
Substance initiates the risk evaluation for the chemical
substance.”).
Following 1,1,2-TCA’s high-priority designation, the EPA
issued a lengthy 1,1,2-TCA final scope document that outlined
hazards, exposures, conditions of use and potentially exposed
sub-populations. Final Scope Doc. Next, the EPA issued a test
order under its Section 2603(a)(2) authority. Order Under
Section 4(a)(2) of the Toxic Substances Control Act, EPA-HQ-
OPPT-2018-0421 (Jan. 14, 2021), https://perma.cc/LW7Z-
AZX5 (January 2021 Test Order). The test order required a
chronic toxicity exposure study of aquatic benthic midges and
occupational studies on inhalation and dermal exposure to
humans and included a Statement of Need. Id. at 2–8. The
Program, EPA Doc. # EPA-740-R1-8004, at 6 (June 22, 2018),
https://perma.cc/4NY3-93GG; see also List of Alternative Test
Methods and Strategies (or New Approach Methodologies [NAMs]),
EPA (Feb. 4, 2021), https://perma.cc/4GYA-66D8.

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targeted entities can use various options to respond, including
developing the information via testing (Option 1) or submitting
existing studies and other relevant information to the EPA
(Option 2). Id. at 13–16.
In March 2022, the EPA issued a second 1,1,2-TCA test
order that Vinyl Institute challenges here. Order Under Section
4(a)(2) of the Toxic Substances Control Act, EPA-HQ-OPPT-
2018-0421 (March 24, 2022), https://perma.cc/KQ57-LPFA
(March 2022 Test Order).5 The test order requires reproductive
testing of earthworms and birds for chronic toxicity. Id. at 6.
The avian reproduction test involves administering 1,1,2-TCA
continuously to the northern bobwhite quail’s diet. See
Ecological Effects Test Guidelines: OCSPP 850.2300 Avian
Reproduction Test, EPA-HQ-OPPT-2009-0154-0012 (Jan.
2012), https://perma.cc/5W8L-XEQJ. The EPA provided a
Statement of Need explaining how: it lacks data on 1,1,2-
TCA’s chronic toxicity to earthworms and birds; reasonably
available information does not close the data gap; a test order
allows the EPA to gather the needed information more quickly
than the rulemaking and consent agreement routes do; and no
new approach methodologies (NAMs) can replace the ordered
vertebrate testing for chronic toxicity. March 2022 Test Order
at 5–9. The test order acknowledged a previous acute toxicity
study regarding chicken embryos—the 1979 Elovaara study—
but explained that it failed to fill the chronic toxicity data gap.
Id. at 9. The EPA also cited data on potential vertebrate
exposure to 1,1,2-TCA from the U.S. Geological Survey’s
(USGS) National Water Quality Monitoring Council. Id. The
test order gave the seven targeted entities multiple response
options, including developing the information by testing
5 The EPA amended the March 2022 Test Order in April 2022
to correct an error and again in August 2022 to remove two targeted
entities.

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(Option 1) or submitting existing studies and other relevant
information “that [they] believe the EPA has not considered”
(Option 2). Id. at 11.
C. Procedural Posture
On June 2, 2022, Vinyl Institute responded to the March
2022 Test Order on behalf of the seven targeted entities by
selecting Option 1—developing information by conducting
both the avian and earthworm reproduction tests. But
previously, on May 23, Vinyl Institute had timely petitioned
the Court for review of the March 2022 Test Order. See 15
U.S.C. § 2618(a). Vinyl Institute challenges only the avian
reproduction test. In August 2022, Vinyl Institute moved to
supplement the administrative record pursuant to 15 U.S.C.
§ 2618(b) with a report prepared by scientific consultant
Stantec (Stantec Report). A motions panel referred the motion
to us.
We have jurisdiction of the petition for review under 15
U.S.C. § 2618(a)(1)(A) and of the Section 2618(b) motion
under 15 U.S.C. § 2618(b).
II. S ECTION 2603( A )(2) TEST ORDER REQUIREMENTS
A. Standard of Review
The 2016 Amendments instruct us to “hold unlawful and
set aside” a test order if it “is not supported by substantial
evidence in the record taken as a whole.” 15 U.S.C.
§ 2618(c)(1)(B)(i)(II). Our interpretation of this standard of
review presents an issue of first impression.
Under the pre-2016 TSCA, as noted supra, the EPA could
compel manufacturers to test via a rulemaking only, 15 U.S.C.
§ 2603 (1976), and judicial review of a TSCA rule weighed

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“substantial evidence in the rulemaking record . . . taken as a
whole.” 15 U.S.C. § 2618(c)(1)(B)(i) (1976) (emphasis added);
see also Env’t Def. Fund, Inc. v. EPA, 636 F.2d 1267, 1277
(D.C. Cir. 1980). Section 2618 defined “rulemaking record” as
the rule under review, any required findings and any oral
transcripts or written submissions made during the rule’s
promulgation. 15 U.S.C. § 2618(a)(3) (1976). In Chemical
Manufacturers Association v. EPA (CMA), we determined that
the TSCA’s “substantial evidence” review of a test rule is
“more searching” and “demanding” than the APA’s substantial
evidence review. 859 F.2d 977, 992 (D.C. Cir. 1988) (quotation
omitted). The Congress “contemplated that the TSCA standard
should be viewed as a distinct standard.” Id. at 991. And the
legislative history indicated Congressional intent to make the
TSCA substantial evidence standard stricter than its APA
counterpart. Id. at 991–92 (citing H.R. REP. No. 94-1679, at 96
(1976) (Conf. Rep.)).
The 2016 Amendments granted the EPA additional
authority regarding test orders, 15 U.S.C. § 2603(a)(2), and
again included a judicial review provision, 15 U.S.C.
§ 2618(c)(1)(B)(i)(II). A court will “hold unlawful and set
aside” a test order if it “finds that the order is not supported by
substantial evidence in the record taken as a whole.” 15 U.S.C.
§ 2618(c)(1)(B)(i)(II). The only difference between the review
of test orders and the review of Section 2603(a)(1) test rules
(now codified at 15 U.S.C. § 2618(c)(1)(B)(i)(I)) is the
omission of “rulemaking” from the former.6 Thus, as it did with
the test rule standard at issue in CMA, the Congress explicitly
rejected the application of the APA’s substantial evidence
standard and drafted an alternate standard for test order review.
6 The 2016 Amendments made one other minor adjustment to
the judicial review provision by deleting the statutory definition of
“rulemaking record” in 15 U.S.C. § 2618(a)(3) (1976).

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See CMA, 859 F.2d at 991–92; 15 U.S.C.
§ 2618(c)(1)(B)(i)(II). Test order review, then, is distinct from
APA review. See CMA, 859 F.2d at 991. In CMA, we described
the required review of the test rule being challenged there as
“fairly rigorous” and more “searching” than the APA standard.
Id. at 992. The same standard applies here. But CMA did not
address what documents constitute the record “taken as a
whole,” the issue we must now decide in the test order context.
The record of course includes the test order itself—
including the statutorily required Statement of Need. See 15
U.S.C. § 2603(a)(3). But the parties dispute whether the non-
public portion of the administrative record—provided to Vinyl
Institute only after it filed suit—is to be considered part of the
record. The non-public portion of the 1,1,2-TCA
administrative record contains several spreadsheets addressing
the applicability of NAMs to high-priority substances, studies
considered by the EPA, estimates of testing costs and burdens
and the 1979 Elovaara Study. There was—and is—no public
access to this portion of the record. The EPA argues that we
should consider facts and data in the entire administrative
record—both public and internal—because the “standard of
review is based on the record as a whole, not just the Test
Order.” EPA Br. 32; see Oral Arg. Tr. 21:16–23:24. Vinyl
Institute protests that the EPA’s use of the non-public portion
constitutes prohibited post hoc reasoning because the EPA
failed to provide all of the data on which it relied.
We agree with Vinyl Institute that “the record taken as a
whole” cannot lawfully include those non-public portions that
the EPA did not reveal until this litigation began. First, the
EPA’s reliance on an administrative record that keeps portions
thereof from the public is in tension with a bedrock principle
of administrative law: agency action is upheld only “upon the
validity of the grounds upon which the [agency] itself based its

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action.” SEC v. Chenery Corp. (Chenery I), 318 U.S. 80, 88
(1943); see also Kevin M. Stack, The Constitutional
Foundations of Chenery, 116 YALE L.J. 952, 992–98 (2007)
(Chenery I’s reason-giving requirement increases democratic
accountability and reduces arbitrariness). When the EPA
requires testing via rulemaking, the court reviews the
“rulemaking record”—information fully available to the
public—for substantial evidence. 15 U.S.C.
§ 2618(c)(1)(B)(i)(I). And when the EPA chooses the test order
alternative, as it did with the March 2022 Test Order, it cannot
rely on a non-public reason to satisfy its Section 2603 burden.
See Algonquin Gas Transmission Co. v. FERC, 948 F.2d 1305,
1316 (D.C. Cir. 1991) (declining to consider FERC’s record
evidence that “was nowhere considered in either of the
Commission’s orders below”). Section 2618(c)(1)(B)(i)(II)’s
review of the record “taken as a whole” does not permit the
EPA to rely on undisclosed supporting data. Cf. Motor Vehicle
Mfrs. Ass’n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 50
(1983) (“It is well-established that an agency’s action must be
upheld, if at all, on the basis articulated by the agency itself.”).
Second, the text offers no support for the EPA’s claim that
the statute’s “record taken as a whole” language allows us to
review the entire record—whether or not portions thereof have
been made public. EPA Br. 38. It is well established that we
may review agency action only on “the grounds upon which
the [agency] itself based its action.” Chenery I, 318 U.S. at 88.
The Congress could not have intended that the record “taken as
a whole” encompasses non-public information that the EPA
failed to disclose at the time of its final action. We do not
countenance an agency’s reliance on “a body of private law.”
Tax Analysts v. I.R.S., 117 F.3d 607, 619 (D.C. Cir. 1997).
The agency’s counterarguments lack merit. It claims Vinyl
Institute could have asked to see any undisclosed portion of the

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administrative record before initiating litigation. But that
option—if it existed—does not relieve the EPA of its statutory
burden to satisfy Section 2603’s requirements with substantial
evidence in the record “taken as a whole.” 15 U.S.C.
§ 2618(c)(1)(B)(i)(II).7 The EPA cannot rely on the non-public
administrative record to meet its evidentiary burden.
B. The EPA’s Section 2603 Burden
Having set forth the substantial evidence standard
applicable to TSCA test orders, we now review whether the
EPA provided substantial evidence to meet its Section 2603
burden regarding six discrete matters.
1. Need for New Information
As part of the required Statement of Need, the EPA “shall
identify the need for the new information.” 15 U.S.C.
§ 2603(a)(3). Need is determined by the scope of the EPA’s
risk evaluation of a given chemical as it is required to “integrate
7 Defining “the record” to include only the public portions
thereof does not limit the court’s review to the test order only. We
also consider other publicly available documents relied on by the
EPA. The EPA’s classification of 1,1,2-TCA as a high-priority
chemical substance is part of “the record.” See 84 Fed. Reg. at 71934.
After its initial risk evaluation, the EPA must publish a final scope
document addressing hazards, exposures, conditions of use and
potential exposed sub-populations that it intends to weigh in
evaluating high-priority substances. 15 U.S.C. § 2605(b)(4)(D). The
119-page final scope document for 1,1,2-TCA is also part of “the
record.” See Final Scope Doc. Indeed, the March 2022 Test Order
incorporates the final scope document by reference. March 2022 Test
Order at 6, 21. The January 2021 Test Order for 1,1,2-TCA is also
publicly available and cited in the March 2022 Test Order. Id. at 5,
21. The EPA can—and does—rely on all of these publicly available
documents as part of the record.

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and assess available information on hazards and exposures.”
Id. § 2605(b)(4)(F)(i). The Statement of Need also requires the
EPA to “describe how information reasonably available to the
Administrator was used to inform the decision to require new
information.” Id. § 2603(a)(3). We uphold its identification of
a need for, and description of, information only if it provides
substantial evidence therefor within the meaning of Section
2618(c)(1)(B)(i)(II).
Based on 1,1,2-TCA’s final scope document, the EPA
determined that it needed to assess environmental hazards and
risks to aquatic and terrestrial plants, invertebrates and
vertebrates. March 2022 Test Order at 7. The test order
explained how it evaluated data for 1,1,2-TCA and analogous
chemicals (analogues). Id. It used its Analog Identification
Methodology (AIM) software to identify seven analogues to
1,1,2-TCA. Id. It searched for hazard data pertaining to 1,1,2-
TCA and the analogues in its ECOTOX Knowledgebase and
from information submitted to it via the TSCA and other
programs. Id. The March 2022 Test Order noted the earlier
January 2021 Test Order that addressed aquatic data gaps. Id.
After assessing this information, the EPA identified 1,1,2-TCA
acute exposure data for soil invertebrates, mammals and birds
as well as chronic exposure data for mammals and vegetation.
Id. at 7–8. But it failed to identify chronic exposure data—for
1,1,2-TCA or the analogues—for soil invertebrates and birds.
Id. Monitoring data from USGS’ National Water Quality
Monitoring Council identified 1,1,2-TCA in media, including
ground water, sediment, soil and surface water, to which birds
can be exposed. Id. at 9. Accordingly, the EPA issued the
March 2022 Test Order to close the chronic toxicity data gap.
Id. at 7.
Nonetheless, it failed to provide substantial evidence of
how the reasonably available information informed the

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decision to require new avian testing. In Table 1, the EPA
acknowledged hazard data for acute bird exposure to 1,1,2-
TCA and 1,1,1-TCA (an analogue). Id. at 8 tbl.1. The test order
described the 1,1,2-TCA acute exposure data, captured in the
1979 Elovaara egg injection study. Id. at 9. The EPA
adequately explained that its acute toxicity finding in chick
embryos indicated the need for additional data on “potential
effect following chronic dietary exposure.” Id. Its reference to
this one study only, however, fails our “searching” substantial
evidence review. See CMA, 859 F.2d at 991. The EPA failed to
explain or even identify the 1,1,1-TCA bird acute exposure
study in the test order itself. March 2022 Test Order at 8. It also
noted the 1,1,2-TCA mammalian chronic exposure data in
Table 1 but failed to identify the study. Id. Nor did it explain
whether mammalian chronic exposure data can be extrapolated
to birds. Id. Yet in a declaration submitted only to us, an EPA
official explains that “toxicologists do not extrapolate
mammalian toxicity data to birds because there are significant
differences between the anatomy and physiology of birds and
mammals and uncertainty in comparisons increases with larger
taxonomic distances.” J.A. 114. The EPA should have
explained why it could not extrapolate mammalian chronic
exposure data to avian chronic exposure in its Statement of
Need description of reasonably available information.
Identifying close but ultimately inapplicable studies and
explaining, in the record, why it could not extrapolate other
potentially relevant findings could constitute substantial
evidence of “how information reasonably available to the
Administrator was used to inform the decision to require new
information.” 15 U.S.C. § 2603(a)(3).
Again, we find the EPA’s counterarguments unavailing.
Another provision of the TSCA requires the EPA to publish “a
list of the studies considered by the Administrator in carrying
out each such risk evaluation, along with the results of those

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studies.” Id. § 2625(j)(4). According to the EPA, the Congress
would have written a similar requirement into Section 2603 if
it had wanted the agency to include all studies it either
reviewed or rejected in the Statement of Need, but that
requirement would have contradicted the Congress’ intent to
expedite TSCA risk evaluations. See S. REP. NO . 114-67, at 10.
Although the EPA need not list every study in the test order’s
Statement of Need to satisfy our substantial evidence review, it
must provide substantial evidence of the need for new
information as well as an assessment of available information.
15 U.S.C. § 2603(a)(3).8
2. Basis for Vertebrate Testing
The Statement of Need also requires the EPA to “explain
the basis for any decision that requires the use of vertebrate
animals.” 15 U.S.C. § 2603(a)(3). Before requiring vertebrate
testing, the EPA must consider “reasonably available existing
information,” including new approach methodologies (NAMs)
of toxicity information, computational toxicology,
bioinformatics and high-throughput screening methods and
their prediction models. Id. § 2603(h)(1)(A). By requiring the
agency to consider NAMs, the Congress intended the EPA to
reduce its use of vertebrate animal testing. Id. § 2603(h)(1).
As explained in the March 2022 Test Order, the EPA
considered computational toxicology and bioinformatics in
determining a need for new information. March 2022 Test
Order at 8. In particular, it applied the AIM tool to identify
8 One of the non-public administrative record’s data
spreadsheets does identify 1,1,2-TCA studies the EPA considered.
J.A. 37–41 (referencing studies reflected in Table 1 of the March
2022 Test Order at 8); see also EPA Br. 32. But we cannot consider
these data spreadsheets because they were not publicly available
when the EPA issued its March 2022 Test Order.

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analogues. Id. It concluded, however, that “[r]easonably
available data, computational toxicology, or high-throughput
screening methods and predictions models are not available
and/or cannot be used to address” 1,1,2-TCA’s chronic toxicity
to birds. Id. And “[n]o approved or readily available [NAMs]
were identified that could be used.” Id.
Under our searching substantial evidence review, these
conclusory statements fail to explain the basis for vertebrate
testing or to demonstrate adequately the EPA’s consideration
of NAMs. The non-public administrative record reflects that
the EPA did consider several NAMs, including ChemACE,
ECOSAR and OncoLogic. J.A. 33 (Data Gap Spreadsheet).
And in its brief, the EPA succinctly explains why the NAMs it
considered were inapplicable. For example, ChemACE did not
identify any analogous chemicals to 1,1,2-TCA; ECOSAR
predicted hazards for aquatic species, not birds; and OncoLogic
addressed cancer in humans, not birds. EPA Br. 28. As part of
its Statement of Need, the EPA should (1) indicate that it
considered NAMs before requiring vertebrate testing and (2)
explain why vertebrate testing is needed. Although the non-
public administrative record and the EPA’s brief cover these
matters, they are not part of the record subject to our review for
substantial evidence. See supra Section II.A.
3. Tiered Screening and Testing
The TSCA imposes an additional requirement when the
EPA considers whether to conduct additional testing of a
specific chemical. If “information available to the
Administrator justifies more advanced testing . . . without first
conducting screening-level testing,” the EPA can proceed with
advanced testing. 15 U.S.C. § 2603(a)(4). Otherwise, the EPA
“shall employ a tiered screening and testing process.” Id. It

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does so by considering “results of screening-level tests or
assessments of available information.” Id. (emphasis added).
Vinyl Institute protests that the EPA did not conduct
screening tests. Vinyl Institute construes the disjunctive “or” to
require that the EPA use both screening-level tests and
assessments of available information. It relies on the
justification clause, through which the EPA can bypass the
tiered screening and testing process.9 See 15 U.S.C.
§ 2603(a)(4). According to Vinyl Institute, the Congress would
not have included the justification clause if the EPA could
choose between screening tests or assessing available
information to complete the tiered screening and testing
process. We disagree. Section 2603(a)(4) instructs the EPA to
first consider if available information justifies bypassing the
tiered screening and testing process altogether. If the EPA does
not find support for a bypass—a high standard—it “shall
employ a tiered screening or testing process.” Id. (emphasis
added).
The EPA claims that it conducted the tiered screening and
testing process by assessing available information. It searched
peer-reviewed literature databases for studies involving 1,1,2-
TCA. March 2022 Test Order at 6–7. It also searched “gray
literature” such as technical reports, reference books and
dissertations. Id. at 7. It evaluated public comments submitted
to the agency regarding 1,1,2-TCA. Id. Then, as discussed, it
identified analogues, searched for toxicity studies and
considered relevant NAMs. See supra Subsections II.B.1 and
2. It thus assessed available information before ordering the
9 The justification clause allows the EPA to bypass the tiered
screening and testing process if available information “justifies more
advanced testing . . . without first conducting screening-level
testing.” 15 U.S.C. § 2603(a)(4).

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seven targeted entities to conduct the avian chronic toxicity
testing.
Nonetheless, the record lacks substantial evidence that the
EPA adequately assessed available information. As discussed
supra, the EPA failed to identify and explain sufficiently the
relevant available studies or to address the (in)applicability of
any NAMs. See 15 U.S.C. § 2603(a)(3). The assessment of
available information in the Section 2603(a)(4) tiered
screening and testing process thus rises and falls with
Statement of Need requirements in Section 2603(a)(3).
4. Order versus Rule or Consent Agreement
The EPA may exercise its new “[a]dditional testing
authority” “by rule, order, or consent agreement.” 15 U.S.C.
§ 2603(a)(2). If it chooses the test order route, the Statement of
Need must address “why issuance of an order is warranted
instead of promulgating a rule or entering into a consent
agreement.” Id. § 2603(a)(3).
The EPA explained that the March 2022 Test Order will
allow it “to obtain the needed information more quickly than if
the EPA were to issue a . . . rulemaking or consent agreement.”
March 2022 Test Order at 8. Vinyl Institute believes “[t]his is
not an adequate explanation” but it points to no statutory
language barring the EPA from choosing the test order route
based on that route’s comparative speed. Vinyl Institute Br. 37;
see also ACC Amicus Br. 4–5. Indeed, the 2016 Amendments’
legislative history expressly discussed reducing barriers to
EPA’s testing authority. See H.R. REP. NO . 114-176, at 22–23;
S. REP. NO. 114-67, at 10. In 2022, an EPA official testified
before the Congress that many chemical risk evaluations have
fallen behind schedule and would not be completed by their
2023 deadlines. Testimony of Michal Ilana Freedhoff before
the Senate Committee on the Environment and Public Works,

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at 6–7 (June 22, 2022), https://perma.cc/H7WQ-MEHJ; see 15
U.S.C. § 2605(b)(4)(G) (requiring that risk evaluations be
completed within three years, subject to one six-month
extension); 84 Fed. Reg. at 71,925 (designating 1,1,2-TCA in
December 2019, with a June 2023 deadline). The EPA’s choice
to use the more expeditious test order method makes sense to
us—the agency is, after all, behind schedule.10 The EPA
provided a sufficient explanation for why it issued a test order
instead of a rulemaking or consent agreement.
5. Demonstration of Bird Exposure to 1,1,2-TCA
Vinyl Institute argues the EPA must provide some
demonstration of avian exposure to 1,1,2-TCA at potentially
toxic levels before issuing a test order. Granted, Section
2625(k) requires the agency to take hazard and exposure
information into consideration. But Section 2603 does not
instruct the EPA to address exposure in the test order. Vinyl
Institute’s argument reverses the TSCA’s allocation of
burdens. The development of chemical effects information
“should be the responsibility of those who manufacture and
those who process such chemical substances and mixtures.” 15
U.S.C. § 2601(b)(1). The TSCA imposes many burdens on the
EPA before it can issue a test order under Section 2603(a)(2)—
including issuing a Statement of Need, implementing a tiered
10 Amici PCRM and PETA argue that the Congress listed “rule,
order, or consent agreement” in that order to indicate a hierarchy.
PCRM/PETA Amicus Br. 9–10. Under their interpretation, the EPA
must first consider rulemaking, then test orders and finally consent
agreements. Id. The text does not support their reading. The
Congress’ use of the disjunctive “or” suggests that all three options—
rule, order or consent agreement—are equally available. See Encino
Motorcars, LLC v. Navarro, 584 U.S. 79, 87 (2018) (“or” is “almost
always disjunctive” unless statutory context overcomes its ordinary
meaning).

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screening and testing process and considering costs and
availability of facilities—but targeted entities have the ultimate
burden to test 1,1,2-TCA for avian chronic toxicity.
After instituting a TSCA risk evaluation but before issuing
a Section 2603(a)(2) test requirement, the EPA must
“determine[] that the information is necessary” “to perform a
risk evaluation.” Id. § 2603(a)(2)(A). The 1,1,2-TCA risk
evaluation requires an assessment of hazard and risk to plants,
invertebrates and vertebrates—including birds. March 2022
Test Order at 7. After considering the avian acute toxicity data
from the 1979 Elovaara study and the USGS’ monitoring data
demonstrating potential exposure to birds, the EPA reasonably
determined that it needed avian chronic toxicity data. Id. at 8–
9. Substantial evidence in the record indicates that avian
chronic toxicity information is necessary for the EPA to
complete its 1,1,2-TCA risk evaluation. It did not need to
demonstrate a certain level of exposure before issuing the test
order.11
6. Costs and Reasonable Availability
A test order must identify the chemical substance for
which testing is required, the protocols and methodologies for
11 The parties dispute how the exposure standard set forth in
CMA applies here. Under the original TSCA test rule provision, the
EPA had to find that a chemical “may present an unreasonable risk
of injury to health or the environment” before issuing a test rule. 15
U.S.C. § 2603(a)(1)(A) (1976); see also id. § 2603(a)(1)(A)(i)(I)
(2016). In CMA, we concluded that the EPA must have a “more-than-
theoretical basis for inferring the existence of exposure.” 859 F.2d at
988. Because the EPA issued the March 2022 Test Order under
Section 2603(a)(2)’s “[a]dditional testing authority,” however,
CMA’s interpretation of Section 2603(a)(1)’s unreasonable risk
requirement is inapplicable.

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testing and the period needed to complete the testing. 15 U.S.C.
§ 2603(b)(1). “In determining the protocols and methodologies
and period to be included,” the EPA’s “considerations shall
include the relative costs of the various test protocols and
methodologies . . . and the reasonably foreseeable availability
of the facilities and personnel needed to perform the testing.”
Id. According to the EPA, this provision imposes two distinct
requirements: it must identify the chemical substance,
protocols and time period in the test order but it must simply
consider costs and availability of facilities, presumably pre-test
order. It submits that it did consider costs, demonstrated by a
spreadsheet in its non-public administrative record that
estimated avian reproduction testing costs at $288,283. Vinyl
Institute insists that the EPA had to identify the relative costs
of, and the availability of facilities for, the avian reproduction
tests in the test order itself.
Again, we review the “the record taken as a whole” for
substantial evidence. 15 U.S.C. § 2618(c)(1)(B)(i)(II). The
EPA did not publish the cost estimate spreadsheet at the time it
issued the March 2022 Test Order and it is therefore not in the
record “taken as a whole.” See supra Section II.A. To satisfy
Section 2603(b)(1), the EPA must provide substantial evidence
that it considered the relative costs of the protocols and the
reasonably foreseeable availability of facilities and personnel
to conduct the testing. 15 U.S.C. §§ 2603(b)(1);
2618(c)(1)(B)(i)(II).12 The EPA did not provide substantial
evidence of these factors—again, in the record as the TSCA
defines it—that is, “taken as a whole.”
12 The EPA gave no consideration to the reasonably foreseeable
availability of facilities and personnel in either the record under
review or the non-public portion of the administrative record. See 15
U.S.C. § 2603(b)(1).

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III. S ECTION 2618( B) MOTION
Under TSCA Section 2618(b), a party can move for leave
to “make additional oral submissions or written presentations”
for the EPA’s consideration. A movant must show “to the
satisfaction of the court” that the additional information (1)
“would be material” and (2) “there were reasonable grounds
for the submissions and [for] failure to make such submissions
and presentations in the proceeding before the Administrator.”
15 U.S.C. § 2618(b) (emphasis added). Once the movant
makes these showings, the court “may order the Administrator
to provide additional opportunity” to the movant to submit the
information. Id. Although no court has yet reviewed a TSCA
Section 2618(b) motion, other regulatory statutes contain
similar materiality and reasonable grounds tests. See, e.g., 15
U.S.C. § 45(c) (Federal Trade Commission Act); 16 U.S.C.
§ 825l(b) (Federal Power Act); 29 U.S.C. § 160(e) (National
Labor Relations Act); 33 U.S.C. § 1369(c) (Clean Water Act).
The Supreme Court has endorsed the materiality and
reasonable grounds requirements because they ensure that such
motions are “used only for proper purposes, and not abused by
resort to [them] as a mere instrument of delay.” Southport
Petroleum Co. v. NLRB, 315 U.S. 100, 104 (1942). Vinyl
Institute seeks to admit the Stantec Report pursuant to Section
2618(b).
A. Extent of “Proceeding”
The movant must demonstrate “reasonable grounds” for
failing to submit the additional evidence “in the proceeding
before the Administrator.” 15 U.S.C. § 2618(b). The parties
disagree on the date the proceeding ended. Vinyl Institute
claims it ended upon issuance of the March 2022 Test Order.
The EPA argues the proceeding continued after issuance
because the EPA can consider submissions from targeted

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entities and may even extinguish a testing obligation. Looking
at the text’s plain meaning and the Congress’ intent, we find
that the “proceeding” continues after the EPA issues a Section
2603(a)(2) test order.
Before 2016, the EPA could compel testing only via a
rulemaking but a party could nonetheless move to supplement
under Section 2618(b), so long as the party could show
materiality and reasonable grounds for failing to submit during
the proceeding. 15 U.S.C. § 2618(b) (1976). “[P]roceeding”
referred to the rulemaking proceeding because at that time that
was the only procedural mechanism to compel testing. The
2016 Amendments amended Section 2618(b), extending its
application to “an action under this section to review . . . an
order under section 2603.” 15 U.S.C. § 2618(b) (emphases
added).
In general, “Proceeding” means “business conducted by a
court or other official body.” Proceeding, Black’s Law
Dictionary (11th ed. 2019). An “administrative proceeding”
means a “hearing, inquiry, investigation, or trial before an
administrative agency.” Administrative Proceeding, Black’s
Law Dictionary (11th ed. 2019). The March 2022 Test Order
does not mark the end of an inquiry, but the beginning. The
EPA’s investigation of 1,1,2-TCA’s toxicity requires targeted
entities to develop information to aid the EPA in its
investigation. The March 2022 Test Order is only part of the
EPA’s ongoing inquiry. The test order’s text supports the
ongoing nature of the inquiry because, at least under Option 2,
the EPA considers “whether the study and/or other relevant
information [submitted by targeted entities] satisfies” the test
order and may “extinguish those testing obligations from this
Order that are no longer necessary.” March 2022 Test Order at

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11.13 A submission under Option 2 can potentially end the
EPA’s investigation of a specific chemical. Thus, the
“proceeding” continues after the EPA issues the test order.
The Congress’ intent also supports our reading of
“proceeding.” The 2016 Amendments gave the EPA the
authority to issue test orders without notice to, or past
engagement with, a targeted entity. See S. REP. NO. 114-67, at
10; H.R. REP. NO . 114-176, at 22–23. The targeted entity
necessarily, then, has no opportunity to submit information to
the EPA before the test order issues because it has no notice of
the test order. Vinyl Institute’s interpretation of “proceeding”
would violate the canon against surplusage because every
Section 2618(b) movant following the test order issuance
would have “reasonable grounds” for failing to supplement.
See TRW Inc. v. Andrews, 534 U.S. 19, 31 (2001).
B. Reasonable Grounds for Delayed Submission
Vinyl Institute claims it had a reasonable ground for failing
to submit additional information pursuant to Option 2 because
it did not know what information the EPA had already
considered and the EPA improperly shifted the burden to prove
the test order’s necessity to it. We conclude that Option 2 gave
Vinyl Institute a fair opportunity to submit the Stantec Report.
Vinyl Institute’s failure to avail itself of Option 2 does not
constitute reasonable grounds for its delayed submission. It
need not know exactly what information the EPA considered
13 Under Option 2, the EPA has extinguished several test orders
after receiving sufficient studies. With regard to Phosphoric acid
Triphenyl Ester (TPP), the EPA reviewed a study submitted by the
target entity and “extinguish[ed] this testing requirement for the
TSCA Section 4(a)(2) order for TPP.” Memo Extinguishing OCSPP
850.4500 Testing Requirement, EPA-HQ-OPPT-2018-0458-0054
(Apr. 30, 2021), https://perma.cc/F7P5-F7SU.

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to avail itself of Option 2, which instructs it to “[u]se this option
to submit an existing study and/or other scientifically relevant
information that you believe the EPA has not considered.”
March 2022 Test Order at 3 (emphasis added). Option 2
encourages the targeted entity to submit responsive
information because it “may be in possession of studies
unknown or inaccessible to the Agency.” Test Orders Under
TSCA Section 4: Questions and Answers, EPA Doc. # EPA
705-G-2021-3737, at 3 (Jan. 2022), https://perma.cc/B8QQ-
WJTB. Vinyl Institute need not submit only information that
the EPA has not yet considered. The March 2022 Test Order
itself provides significant information to which Vinyl Institute
can respond under Option 2. Vinyl Institute had access to the
119-page final scope document on 1,1,2-TCA risk evaluation,
the EPA explanation of the “information reasonably available
to the Administrator” and the agency’s evaluation of the 1979
Elovaara study. See 15 U.S.C. § 2603(a)(3). Vinyl Institute
could have submitted a responsive report based on the
information it believed the EPA had not considered.14 March
2022 Test Order at 3. Although Option 2 provides only 30 days
to respond, the March 2022 Test Order explicitly allows for a
deadline extension if requested. Id. at 9–10. Vinyl Institute did
not request an extension.
In addition, Option 2 does not improperly shift burdens.
Although Section 2603(a) details duties the EPA must perform
before issuing a test order, the TSCA ultimately assigns “those
14 As discussed supra, the complete test order administrative
record is not available to targeted entities—at least until they institute
litigation. Vinyl Institute claims it must review the administrative
record before responding under Option 2. This raises another
surplusage issue because, according to Vinyl Institute, a targeted
entity without access to the non-public administrative record will
always have reasonable grounds for failing to respond under Option
2.

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who manufacture and those who process such chemical
substances” the burden to develop information regarding “the
effect of chemical substances and mixtures on health and the
environment.” 15 U.S.C. § 2601(b)(1); see CMA, 859 F.2d at
980. After the EPA satisfies its Section 2603(a)(2) duties and
issues the order, the burden then shifts to the target entity to
follow one of the test order options. Option 1 places the burden
of testing on Vinyl Institute and Option 2 places the burden of
submitting studies and other scientifically relevant information
on Vinyl Institute. March 2022 Test Order at 11. The EPA can
extinguish any further testing obligation if it receives sufficient
information under Option 2.15 Vinyl Institute could have
submitted the Stantec Report under Option 2. Its failure to do
so dooms its motion to supplement.
For the foregoing reasons, we grant Vinyl Institute’s
petition for review, vacate the March 2022 Test Order and
remand to the EPA for proceedings consistent with this
opinion. We deny Vinyl Institute’s motion to supplement.
So ordered.
15 See supra note 13.

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