Environmental Defense Fund v. United States Environmental Protection Agency

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued September 24, 2024 Decided December 20, 2024
No. 23-1166
ENVIRONMENTAL DEFENSE FUND,
PETITIONER
v.
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY AND
MICHAEL REGAN, ADMINISTRATOR OF THE UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY,
RESPONDENTS
AMERICAN CHEMISTRY COUNCIL,
INTERVENOR
Consolidated with 23-1204
On Petitions for Review of Final Action by the United States
Environmental Protection Agency
Samantha Liskow argued the cause for petitioner
Environmental Defense Fund.
David Y. Chung argued the cause for petitioners American
Chemistry Council and American Fuel & Petrochemical

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Manufacturers, and intervenor American Chemistry Council.
With him on the briefs were Warren Lehrenbaum, Lynn T.
Phan, Laura Gooding, Richard S. Moskowitz, and Tyler J.
Kubik.
Elbert Lin, Matthew Z. Leopold, and Erica N. Peterson
were on the brief for amici curiae Chamber of Commerce of
the United States of America and National Association of
Manufacturers in support of petitioners American Chemistry
Council and American Fuel & Petrochemical Manufacturers.
Phillip R. Dupré, Attorney, U.S. Department of Justice,
argued the cause for respondents. With him on the brief were
Todd Kim, Assistant Attorney General, and Donald Sadowsky,
Brandon Levine, and Stephanie Schwarz, Attorneys, U.S.
Environmental Protection Agency.
Before: WALKER and PAN, Circuit Judges, and EDWARDS,
Senior Circuit Judge.
Opinion for the Court filed by Senior Circuit Judge
EDWARDS.
EDWARDS, Senior Circuit Judge: The Environmental
Protection Agency (“EPA”) issued a final rule implementing
section 2613 of the Toxic Substances Control Act (“TSCA”),
15 U.S.C. § 2613, as amended by the Frank R. Lautenberg
Chemical Safety for the 21st Century Act (the “Lautenberg
Amendments”), Pub. L. No. 114–182, 130 Stat. 448 (2016)
(codified at 15 U.S.C. § 2601 et seq.). The rule concerns the
assertion and treatment of confidential business information
(“CBI”) claims for information reported to or otherwise
obtained by EPA under the TSCA. See Confidential Business
Information Claims Under the Toxic Substances Control Act,

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88 Fed. Reg. 37,155 (June 7, 2023) (“CBI Rule”). This case
involves two sets of challenges to the CBI Rule.
Petitioner Environmental Defense Fund (“EDF”), a non-
profit environmental organization, challenges three aspects of
the Rule as contrary to law and arbitrary and capricious. EDF
challenges EPA’s regulatory definition of health and safety
study as impermissibly narrow and argues for a definition that
encompasses the entirety of a study document or report. EDF
also challenges EPA’s decision not to require substantiation
and routine agency review of pre-commercialization CBI
claims after commercialization, as well as EPA’s use of
permissive, as opposed to mandatory, language in select
provisions of the rule.
Petitioners American Chemistry Council and American
Fuel and Petrochemical Manufacturers (collectively “ACC”)
are national trade associations that represent U.S. companies
engaged in the business of chemistry or petrochemical
manufacturing. They argue that the CBI Rule allows for the
unlawful disclosure of information protected by section
2613(a) of the TSCA. Specifically, the TSCA prohibits EPA
from publicly disclosing a specific chemical identity once a
reporting entity, such as a chemical manufacturer, has satisfied
the requirements for asserting and substantiating a CBI claim
for that chemical identity. 15 U.S.C. § 2613(a). ACC argues
that nothing in section 2613 authorizes EPA to disclose that
confidential chemical identity merely because a downstream
reporting entity, such as a chemical importer, has submitted
information to EPA that includes only non-confidential
information, such as a chemical substance’s accession number.
These downstream entities, according to the ACC, may lack
knowledge of a substance’s specific chemical identity and,
thus, cannot assert and substantiate a CBI claim in accordance
with the Rule’s requirements.

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We deny EDF’s petition for review and grant ACC’s
petition for review. First, we hold that EPA’s regulatory
definition of health and safety study properly excludes matters
that do not bear on the effects of a chemical substance on health
or the environment. EPA’s definition is consistent with the best
reading of the statute and neither arbitrary nor capricious.
Second, EPA is correct that the TSCA does not require a
reporting entity to reassert and substantiate a CBI claim for
information statutorily exempted from substantiation and
agency review at the time of submission. Specifically, section
2613(c)(2)(G) exempts CBI claims for specific chemical
identities asserted prior to the date on which the chemical
substances are first offered for commercial distribution. These
specific chemical identities remain exempt from substantiation
and review until a post-commercialization CBI claim for the
same chemical is received by the agency or some other
statutory trigger applies. EPA’s CBI Rule is consistent with this
statutory exemption and provides a reasoned explanation for
eliminating pre-Lautenberg regulations that could not be
squared with the new exemption. Third, we hold that EPA’s
use of permissive language in select provisions of the Rule is
consistent with the TSCA and reasonably explained. EPA has
discretion to reserve its final determination of a CBI claim until
the end of the 90-day statutory review period. This discretion
is reflected in EPA’s use of permissive language when
describing its CBI claim review process. The TSCA also
permits, but does not require, the public disclosure of all non-
confidential information. EPA’s Rule is consistent with the
TSCA and reasonable in its use of permissive language with
respect to information not subject to express disclosure
mandates.
Fourth and last, we hold that the Rule’s assertion and
substantiation requirements are unlawful as applied to entities

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reporting by accession numbers and without knowledge of the
underlying chemical identity. As it now stands, the Rule
impermissibly allows for the unlawful disclosure of protected
confidential information. Reporting entities that lack
knowledge of specific chemical identities are unable to assert
or substantiate CBI claims for such identities. Nor do such
entities reveal any confidential chemical information merely by
reporting an accession number. Yet, these entities are required
by the Rule to assert and substantiate CBI claims for already
protected specific chemical identities. Otherwise, they waive
confidentiality for the specific chemical identity, causing an
upstream entity that did properly assert and substantiate a CBI
claim to lose confidentiality protection. This regulatory scheme
cannot be squared with the commands of the statute, which
require EPA to protect from disclosure chemical identities for
which CBI claims have been properly asserted.
Accordingly, we vacate EPA’s rule to the extent it allows
for the unlawful disclosure of confidential information.
I. BACKGROUND
A. The Toxic Substances Control Act
In 1976, Congress enacted the TSCA to prevent
unreasonable risks of injury to health and the environment from
the manufacture, processing, distribution in commerce, use and
disposal of chemical substances and mixtures. See 15 U.S.C.
§§ 2601-2697. The statute, as amended in 2016, authorizes
EPA to require reporting, record-keeping, and testing, and to
impose restrictions relating to chemical substances and
mixtures. See id. §§ 2603(a), 2605, 2607(a)(1).

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1. The Chemical Substance Inventory
Section 2604 of the TSCA requires that any person who
intends to manufacture a new chemical substance must submit
to EPA a notice of such intent at least 90 days before beginning
manufacture. Id. § 2604(a)(1)(B). A new chemical substance is
defined as any chemical not already listed on the TSCA
Chemical Substance Inventory (“Inventory”), which is a
comprehensive list of each chemical substance manufactured
in or imported into the United States that does not qualify for
an exemption or exclusion under the TSCA. See id. §§
2602(11), 2607(b). As relevant here, the notice required under
section 2604 is a Premanufacture Notice pursuant to 40 C.F.R.
part 720. EPA must review the notice. 15 U.S.C. § 2604(a)(3).
If EPA allows manufacture of the substance, then EPA will add
the chemical substance to the Inventory as of the date such
manufacture commences in the United States. Id. § 2607(b)(1).
To implement the Inventory in a manner that protects
confidentiality while also assisting the public in ascertaining
which chemical substances are already in commerce in the
United States, EPA maintains two distinct sections of the
Inventory. The public portion of the Inventory includes: (1)
non-confidential chemical substances identified in part by their
specific chemical identities and (2) public identifiers, such as
accession numbers, for chemical substances whose identities
are claimed as confidential. See 40 C.F.R. § 720.25(b)(1). An
accession number is a random six-digit non-confidential
number by which the chemical substance can later be
referenced. The confidential portion of the Inventory, which is
not available to the public, includes the specific chemical
identities of chemical substances claimed as confidential. Id.

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2. Reporting Rules
To obtain the information needed to compile and update
the Inventory, section 2607(a) authorizes EPA to promulgate
reporting rules requiring manufacturers and processors of
chemical substances to maintain and submit records to EPA.
See 15 U.S.C. § 2607(a). In 2011, EPA promulgated the
Chemical Data Reporting Rule (“CDR”), formerly known as
the Inventory Update Reporting Rule, which enables EPA to
collect and publish information on the manufacturing,
processing, and use of chemical substances on the Inventory.
TSCA Inventory Update Reporting Modifications; Chemical
Data Reporting, 76 Fed. Reg. 50,816 (Aug. 16, 2011),
amended 76 Fed. Reg. 54,932 (Sept. 6, 2011). The CDR applies
to manufacturers, including importers, that meet certain annual
production volume thresholds. 40 C.F.R. § 711.8.
Manufacturers must report under the CDR every four years and
provide, among other things, exposure-related information
associated with reportable chemical substances. Id. §§ 711.20,
711.15.
3. Confidentiality Claims
Subject to applicable regulations, any entity submitting
information to EPA under the TSCA may claim as CBI
information that they report, including the specific chemical
identity of the chemical substance for which they are reporting.
Specific chemical identity refers to the particular molecular
identity of a chemical substance, which can encompass
information on chemical structure, composition,
manufacturing process, and raw materials.
Confidentiality claims are governed by TSCA section
2613. 15 U.S.C. § 2613. The Lautenberg Amendments
substantially revised section 2613 to require, inter alia, the

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assertion of confidentiality claims to protect any information
submitted under the TSCA from disclosure, the substantiation
of such claims, and the review of such claims by EPA. See id.
§ 2613(c)(1)(A), (c)(3), (g). Section 2613 requires EPA to
protect from disclosure information, such as specific chemical
identities, for which a valid CBI claim has been asserted. Id. §
2613(a). This general prohibition against disclosure is subject
to specific limited exceptions. Id. § 2613(d). EPA is also
required to approve, approve in part and deny in part, or deny
confidentiality claims within 90 days of their assertion. Id. §
2613(g)(1)(A).
The requirements of assertion, substantiation, and review
are subject to various statutory exemptions. Certain categories
of information, such as health and safety studies, are ineligible
for confidential treatment. Id. § 2613(b)(2). The TSCA defines
“health and safety study” as:
[A]ny study of any effect of a chemical substance or
mixture on health or the environment or on both, including
underlying information and epidemiological studies,
studies of occupational exposure to a chemical substance
or mixture, toxicological, clinical, and ecological studies
of a chemical substance or mixture, and any test performed
pursuant to this chapter.
Id. § 2602(8). This exemption for health and safety studies does
not apply to information that discloses certain processing
information or portions of a chemical mixture. Id. § 2613(b)(2).
Such information is eligible for CBI protection. In addition,
“[i]nformation that is protected from disclosure under this
section, and which is mixed with information that is not
protected from disclosure under this section, does not lose its
protection from disclosure notwithstanding that it is mixed with

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information that is not protected from disclosure.” Id. §
2613(b)(1).
Furthermore, section 2613 outlines categories of
information that “shall not” be subject to substantiation or
agency review:
(A) Specific information describing the processes used in
manufacture or processing of a chemical substance,
mixture, or article.
(B) Marketing and sales information.
(C) Information identifying a supplier or customer.
(D) In the case of a mixture, details of the full composition
of the mixture and the respective percentages of
constituents.
(E) Specific information regarding the use, function, or
application of a chemical substance or mixture in a
process, mixture, or article.
(F) Specific production or import volumes of the
manufacturer or processor.
(G) Prior to the date on which a chemical substance is first
offered for commercial distribution, the specific chemical
identity of the chemical substance, including the chemical
name, molecular formula, Chemical Abstracts Service
number, and other information that would identify the
specific chemical substance, if the specific chemical
identity was claimed as confidential at the time it was
submitted in a notice under section 2604 of this title.
Id. § 2613(c)(2), (g)(1)(C). These categories of information are
not exempt, however, from section 2613(f), which outlines
circumstances in which EPA may or must require entities to

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reassert and substantiate their CBI claims, thereby subjecting
the claims to agency review. Id. § 2613(f). Likewise, section
2613(e)(1)(A) articulates that “information described in
subsection (c)(2)” shall be protected from disclosure “until
such time as” the submitting entity withdraws the claim or EPA
becomes aware that the information does not qualify for
protection from disclosure. Id. § 2613(e)(1)(A).
B. The EPA Confidential Business Information Rule
Section 2613 authorizes EPA to promulgate rules on the
assertion and treatment of confidentiality claims. See id. §
2613(c)(1)(A), (c)(3). Pursuant to this authority, EPA adopted
the CBI Rule to implement section 2613 after the Lautenberg
Amendments. As noted above, several provisions of the Rule
are at issue in this case.
1. The Regulatory Definition of Health and Safety
Study
EPA adopted a regulatory definition of “health and safety
study” that excludes certain categories of information,
including: (1) the name, address, or other identifying
information of the submitting company, (2) the identification
of the laboratory that conducted the study in cases where the
laboratory is part of or closely affiliated with the submitting
company, and (3) information pertaining to test substance
product development, advertising, or marketing plans, or to
cost and other financial data. 40 C.F.R. § 703.3(1), (4). EPA
explained its approach, as follows:
While such ancillary information may be contained in a
study document submitted under TSCA, EPA does not
consider such information to be part of a “health and safety
study” as defined in TSCA section [2602](8). That

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definition . . . does not seek to provide an exclusive list of
what is or is not “included” in the health and safety study
but instead clarifies that all “underlying” information must
be considered part of the study. . . . A study report may
contain information beyond that which is the basis for the
study. Information such as the names of lab technicians
neither form the basis for the study nor are relevant to the
study results.
Confidential Business Information Claims Under the Toxic
Substances Control Act, 87 Fed. Reg. 29,078, 29,089 (proposed
May 12, 2022).
2. Exemption from Substantiation and Review
The CBI Rule exempts from substantiation and review
CBI claims for specific chemical identities submitted prior to
commercialization:
A confidentiality claim for specific identity of a chemical
substance, where the submission is made prior to the date
on which the chemical substance whose identity is claimed
as confidential is first offered for commercial distribution,
is exempt from the requirement to substantiate
confidentiality claims at the time of submission.
40 C.F.R. § 703.5(b)(5)(ii)(A); see also id. § 703.7(a)(2).
In its pre-Lautenberg regulations, EPA required entities to
reassert and substantiate their pre-commercialization CBI
claims after commercialization. See 40 C.F.R. §§ 720.85(b)(1),
720.90(b)(2) (2022). Under those regulations, the exemption
granted to the CBI claim expired at the time of
commercialization, requiring the submitting party to return to
its previously submitted claim, reassert and substantiate it, and

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subject it to agency review. Under EPA’s new CBI Rule, those
previously submitted claims remain exempt from
substantiation and review. However, the next time an entity
reports on the same chemical after the chemical has been
commercialized, EPA will require the entity to assert and
substantiate its CBI claim to maintain the chemical’s
confidentiality. See EPA Response to Comments at 27, 48. In
addition, “[s]uch earlier claims may be reviewed or re-
reviewed, but not automatically—instead, they could be
reviewed under either the mandatory or discretionary
provisions of section [2613](f).” Id. at 27.
In response to comments on the agency’s change in
position, EPA acknowledged that its pre-Lautenberg
regulations required reassertion and approval. The agency
explained, however, that the “final rule . . . is a simple
restatement of the substantiation exemption in TSCA section
[2613](c)(2)(G) for CBI claims . . . [and] [t]here is nothing in
TSCA to suggest that such claims and corresponding CBI
treatment automatically expire at the occurrence of a certain
event.” EPA Response to Comments at 48. “[R]ather, the
exemption is inapplicable to claims made after the chemical is
offered for distribution in commerce, and if the claim is
revisited in the future, consistent with section [2613](f), the
exemption also no longer applies.” Id. at 48. EPA also
explained that the old regulation could not be retained because
it could not be squared with new requirements in the
Lautenberg Amendments. See 88 Fed. Reg. at 37,162; EPA
Response to Comments at 27. In EPA’s view, the new language
in section 2613, set forth in the Lautenberg Amendments,
mandated its current approach.

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3. Deficient Confidentiality Claims
The CBI Rule established a process for identifying and
addressing “deficient confidentiality claims.” 40 C.F.R.
§ 703.5(e). Under this provision, when a deficient claim is
identified by EPA in a submission, the agency puts on hold its
substantive review of the CBI claim and gives the submitter 10
business days to correct the deficiency. Id. § 703.5(e)(2). If the
deficiency is not remedied during this window, “EPA will
proceed with review of the submission and may deny the CBI
claim(s).” Id. (emphasis added).
In response to comments on its use of permissive language,
EPA explained that “the language employed was intentional, to
allow the possibility that a CBI claim deficiency might be
overcome or that the claim might no longer need a
determination (such as if . . . the submitter made a persuasive
argument that it was exempt from substantiation
requirements).” EPA Response to Comments at 41.
4. Public Disclosure
The CBI Rule elaborated on circumstances in which non-
confidential information “may” – as opposed to “must” – be
disclosed. First, the Rule provides that if an entity does not
include a CBI claim with its submission of information under
the TSCA, then EPA will not recognize a confidentiality claim
and “may” make the information available to the public. 40
C.F.R. § 703.5. Second, the Rule provides that EPA will
construe an unsubstantiated claim as a waiver of the claim and
“may” make the information public without any further notice
to the submitter. Id. § 703.8(d).

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5. Knowledge Issue
The CBI Rule also requires any entity submitting
information under the TSCA – including entities reporting by
non-confidential accession numbers and without knowledge of
the underlying chemical identity – to assert CBI claims for the
underlying chemical identity to maintain the chemical
identity’s confidentiality. See id. § 703.5. In the CBI Rule’s
preamble, EPA acknowledged that, during the rulemaking
process, commenters raised a concern that, under the CBI Rule,
downstream customers or processors of a specific chemical
would report under TSCA by accession number and, ignorant
of specific chemical identity, could inadvertently or
intentionally waive the confidentiality claim and cause the
substance to lose confidential status. 88 Fed. Reg. at 37,158. In
response to this concern, EPA explained that it “has
consistently maintained and provided public notice of its
position that if any submitting entity chooses not to assert
and/or substantiate a confidentiality claim for a chemical
identity . . . , the chemical identity is no longer entitled to
confidential treatment and may be published on the public
portion of the TSCA Inventory.” Id. In explaining why the CBI
Rule does not deal with the problem that had been identified by
commenters, EPA said:
The Agency recognizes that this issue might arise in
specific contexts. However, this final rule addresses a wide
variety of situations where the knowledge issue is not
presented. EPA believes that the best way to address
commenters’ concerns is to include measures in specific
TSCA reporting rules that take into account the reporting
entity’s lack of knowledge, where such measures are
necessary. Addressing the issue in the context of specific
reporting rules will allow EPA to take into consideration

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the unique reporting context for the rule, such as the
attributes of specific reporters.
Id.
C. Procedural History
On May 12, 2022, EPA issued its proposed CBI Rule. See
87 Fed. Reg. at 29,078. Petitioners EDF and ACC submitted
comments. See EDF Comments on Proposed Rule, EPA-HQ-
OPPT-2021-0419-0050 (July 11, 2022) (“EDF Comments”);
ACC Comments on Proposed Rule, EPA-HQ-OPPT-2021-
0419-0044 (July 11, 2022) (“ACC Comments”). EPA issued
the final CBI Rule on June 7, 2023. On June 29, 2023, EDF
filed a petition for review with this court. On August 4, 2023,
ACC filed a petition for review with this court, which was then
consolidated with EDF’s challenge to the CBI Rule.
ACC was granted leave to intervene in opposition to EDF’s
petition for review and EDF was granted leave to intervene in
opposition to ACC’s petition for review. After ACC filed its
opening brief, EDF decided not to file a brief in opposition to
ACC’s petition. The Chamber of Commerce of the United
States and the National Association of Manufacturers were
granted leave to participate as amici curiae in support of ACC.

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II. ANALYSIS
A. Standard of Review
Under the Administrative Procedure Act (“APA”), we will
hold unlawful and set aside final agency action that is
“arbitrary, capricious, an abuse of discretion, or otherwise not
in accordance with law.” 5 U.S.C. § 706(2)(A). In determining
whether an agency’s interpretation of its governing statute is
contrary to law, we must exercise our “independent judgment”
and “apply[] all relevant interpretive tools” to reach “the best
reading of the statute.” Loper Bright Enters. v. Raimondo, 144
S. Ct. 2244, 2262, 2266 (2024).
If an action is not contrary to law, it must be “reasonable
and reasonably explained.” FCC v. Prometheus Radio Project,
592 U.S. 414, 423 (2021); see also Motor Vehicle Mfrs. Ass’n
of U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 51-
52 (1983); Midwest Ozone Grp. v. EPA, 61 F.4th 187, 192
(D.C. Cir. 2023).
B. The Meaning of “Health and Safety Study”
In the TSCA, Congress defined “health and safety study”
as “any study of any effect of a chemical substance or mixture
on health or the environment or on both” and excluded such
studies from the information that may be claimed as
confidential. 15 U.S.C. §§ 2602(8), 2613(b)(2). In the CBI
Rule, EPA reasonably determined that certain information is
not part of a health and safety study and therefore may be
claimed as CBI. In particular, EPA interpreted “health and
safety study” as the evaluation of a chemical’s health and
environmental effects, not an entire document containing this
evaluation. EDF argues that EPA’s regulatory definition of
“health and safety study” is contrary to Congress’s definition

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of that term. EDF reads “health and safety study” as the entirety
of the written report or document submitted to the EPA. We
hold that EPA’s construction of the term reflects the best
reading of the statute.
1. The Best Reading of “Health and Safety Study”
“As with all questions of statutory interpretation, we start
with the text.” Pharm. Mfg. Rsch. Servs., Inc. v. FDA, 957 F.3d
254, 260 (D.C. Cir. 2020). Congress’s word choice in section
2602(8) is instructive. Section 2602(8) defines “health and
safety study” with reference to the information being studied,
specifically “any effect of a chemical . . . on health or the
environment.” 15 U.S.C. § 2602(8). Section 2602(8) also
defines “health and safety study” as “including underlying
information,” i.e., the data on which a study is based; certain
tests regarding a chemical’s effects; and certain studies on, for
example, the epidemiological or ecological effects of a
chemical. Id. Taken together, these words used to define a
health and safety study suggest that the term refers only to the
evaluation of a chemical’s health and environmental effects,
not the entire document containing that evaluation. Information
that is not part of an evaluation of a chemical’s effects or that
does not form the basis of that evaluation is not part of a health
and safety study.
This interpretation of the text finds support in section
2613(b)(1), which makes clear that CBI “protected from
disclosure . . . does not lose its protection” when “mixed with
information . . . not protected from disclosure.” Id.
§ 2613(b)(1). The TSCA thus recognizes that a single
document can contain a mix of both information that is exempt
from the disclosure protection of section 2613(a) and
information that is covered by that protection. A study
document, for example, may contain protected information –

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like the company that manufactures a chemical – and
unprotected information, like an evaluation of that chemical’s
effects. The former does not lose its protection by appearing in
the same document as the latter.
A limited definition of health and safety study also gives
effect to the purpose of the statute. With section 2613,
Congress sought to strike “a balance between protecting trade
secrets . . . and broadening access to information.” S. Rep. No.
114-67, at 21 (2015). The best reading of health and safety
study allows the public to access data and analysis regarding a
chemical’s effects, while protecting other sensitive information
that happens to be in the study document. A definition of health
and safety study that is limited to the evaluation of a chemical’s
effects best strikes the balance sought by Congress.
2. EPA’s Regulatory Definition
EPA’s regulatory definition is consistent with the best
reading of TSCA’s definition of “health and safety study.”
None of the information EPA identified as excluded from a
“health and safety study” is part of an evaluation of a
chemical’s effects, nor does it constitute the information
underlying that evaluation. See 40 C.F.R. § 703.3. Specifically,
the name of the submitting company, the name of the testing
laboratory, and product information (e.g., financial or
marketing information) do not pertain to the methods used, the
results reported, or the reasoning provided by an evaluation of
a chemical’s effect, nor the data on which that evaluation is
based. Their exclusion from EPA’s regulatory definition of
“health and safety study” is thus consistent with the TSCA.
EPA also provided a reasoned basis for these exclusions.
In response to comments on the relevance and utility of the
excluded information, EPA explained that “[t]hese existing

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carveouts . . . permit[] companies to redact information that is
arguably valuable to them while also not impacting the ability
of the public to access and interpret the study document.” EPA
Response to Comments at 12. This explanation is entirely
consistent with the purpose of the Lautenberg Amendments,
which was to strike “a balance between protecting . . . sensitive
commercial and financial information and broadening access
to information” to better inform the decisions made about
chemicals by various levels of government, companies, and the
general public. S. Rep. No. 114-67, at 21 (2015). EPA’s
exclusions are thus consistent not only with the statutory text
but also with the statutory purpose. Having addressed the need
for a balanced approach, EPA need not respond to every
comment on the value of the withheld information to the
public. See U.S. Satellite Broad. Co. v. FCC, 740 F.2d 1177,
1188 (D.C. Cir. 1984) (“[A]n agency need not respond to every
comment so long as it responds in a reasoned manner to
significant comments received.”).
EPA’s approach is also consistent with its past practice.
The agency’s longstanding position is that certain, limited
categories of information in a health and safety study report,
beyond the information identified in section 2613(b)(2), might
be entitled to confidential treatment. Since at least the early
1980s, EPA has interpreted “health and safety study” to
exclude information, such as company name or address,
financial statistics, or product codes, deemed irrelevant to any
health or environmental effect of a chemical. See 40 C.F.R.
§ 716.16(c)(2) (1984). When Congress enacted the Lautenberg
Amendments, it did not substantively change the provision of
section 2613 dealing with health and safety studies, which
suggests that Congress did not intend to undermine EPA’s
longstanding approach. See NLRB v. Bell Aerospace Co., 416
U.S. 267, 275 (1974) (“[W]here Congress has re-enacted the
statute without pertinent change . . . congressional failure to

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revise or repeal the agency’s interpretation is persuasive
evidence that the interpretation is the one intended by
Congress.”).
Thus, EPA’s interpretation of health and safety study is
consistent with the best reading of the statute, reasonably
explained, and consistent with past practice.
3. EDF’s Arguments to the Contrary
Still, EDF argues that “health and safety study” refers to
the entirety of the written report or document submitted to
EPA. EDF primarily relies on the ordinary meaning of the word
“study.” According to Merriam-Webster, “study” can mean
either (1) “a careful examination or analysis of a phenomenon,
development, or question” or (2) “the published report of such
a study.” Study, MERRIAM-WEBSTER, https://perma.cc/P4KK-
F6YN (last visited Dec. 3, 2024). EDF primarily relies on the
latter, contending that Congress defined health and safety study
expansively without any exclusions for pieces of information
found within the study documents. Statutory definitions,
however, “often ‘giv[e] ordinary words a limited or artificial
meaning.’” Telematch, Inc. v. U.S. Dep’t of Agric., 45 F.4th
343, 350 (D.C. Cir. 2022) (bracket in the source text). Here, the
statutory definition’s emphasis on what is being examined or
analyzed serves to limit the meaning of “health and safety
study” to the evaluation of a chemical’s effects and the data on
which that evaluation is based. Accordingly, the CBI Rule
distinguished a “study” from a “study document,” and
explained that a “study document” often includes extra
information that is not part of a “health and safety study,” as
that term is used in the TSCA. See 88 Fed. Reg. at 37,157.
EDF’s reading is also difficult to reconcile with section
2613(b)(1)’s recognition that protected and non-protected

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information will often be mixed. EDF attempts to square the
circle by pointing to section 2613(b)(2), which provides that
certain health and safety study information is nevertheless
protected from disclosure if it qualifies as CBI,
notwithstanding section 2613(b)(2)’s rule that information
from such studies is generally not protected. In particular,
section 2613(b)(2) protects “any information, including
formulas . . . , that discloses processes used in the
manufacturing or processing of a chemical substance or
mixture or, in the case of a mixture, the portion of the mixture
comprised by any of the chemical substances in the mixture.”
According to EDF, section 2613(b)(1) merely serves to ensure
that, with respect to a health and safety study, the information
protected by section 2613(b)(2) remains protected even when
it is in an otherwise non-protected health and safety study. But
EDF’s reading would render (b)(1) superfluous, as (b)(2) alone
would be sufficient to indicate that formulas, for example, are
to be redacted, notwithstanding the fact that they appear with
non-protected parts of such a study. Section 2613(b)(1) must
be read to apply to some other protected information mixed
with a not protected health and safety study.
EDF also argues that EPA’s regulatory definition violates
TSCA by establishing additional “carveouts” to section
2613(b)(2) beyond the two narrow exceptions identified in that
provision. However, section 2613(b)(2)’s exceptions relate to
information that is part of a health and safety study because that
information (e.g., “formulas . . . of a chemical substance”)
pertains to the evaluation of a chemical’s effects. EPA’s
regulatory definition does not create exceptions for information
that is part of a health and safety study; rather, it clarifies that
certain information is not part of such a study because it does
not pertain to such an evaluation.

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Lastly, EDF argues that EPA’s regulatory exclusions will
make it more difficult for the public to understand a chemical’s
uses and exposures, as well as the strength and reliability of the
studies. While the excluded information may be relevant to a
chemical’s effects generally, it is not information from a
particular study’s evaluation of a chemical’s effects on health
or the environment, nor is it information underlying that
evaluation. Product information, for example, may provide
clues about a chemical’s potential real-world effects, but it does
not constitute information from a specific study’s evaluation of
the chemical’s effects on, for example, the mortality rates of
water fleas. Because the excluded information does not pertain
to a particular evaluation of a chemical’s effects or the
underlying information, EPA is correct that the information is
not part of a “health and safety study.” In other words, the mere
fact that a member of the public may find certain information
in a study document useful does not cause that information to
become part of an evaluation of a chemical’s effects.
C. Exemption for Pre-Commercialization CBI Claims
In general, the TSCA requires entities submitting
information under the TSCA to substantiate any claim for CBI.
EPA then reviews these claims. Section 2613(c)(2) carves out
classes of information that “shall not be subject to
substantiation requirements” and that, per section 2613(g)(1),
are exempt from routine agency review. EDF and EPA do not
dispute that pursuant to section 2613(c)(2)(G), CBI claims for
chemical identities made “prior to” commercialization are not
subject to substantiation and routine review. The parties
disagree, however, as to the duration of this exemption.
Under EPA’s interpretation, the pre-commercialization
CBI claim remains exempt from substantiation and routine
review unless and until a post-commercialization CBI claim for

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that same chemical is received or some other statutory trigger
applies. Under EDF’s interpretation, the submitter must
reassert and substantiate, and EPA must review, the CBI claim
for chemical identity when the chemical is later offered for
commercial distribution. EDF also argues that EPA acted
arbitrarily and capriciously in reversing longstanding
regulations requiring post-commercialization substantiation
and review of pre-commercialization claims. We reject both of
EDF’s arguments.
First, EPA’s interpretation is consistent with the best
reading of the statute. Section 2613(c)(2) contains the statutory
mandate that a CBI claim for information described in
subsections (A) through (G) “shall not be subject to
substantiation requirements.” This mandate does not contain
durational language limiting the exemption to a discrete period
of time. Instead, the use of “shall not” is unequivocal: These
categories of information are exempt from substantiation.
Congress does impose a durational limit on subsection (G),
which describes the category of information at issue. In
subsection (G), the phrase “prior to” is best read to modify the
category of information to be exempt from substantiation: A
CBI claim for a specific chemical identity submitted “[p]rior to
the date on which the chemical substance is first offered for
commercial distribution” is exempt from substantiation.
Appearing nowhere in the mandate itself, this language is
relevant only to defining the category of information to be
exempt from substantiation, not the duration of the exemption.
Although the mandate in section 2613(c)(2) does not
contain a durational limit, it is not unconditional. Section
2613(e)(1)(A) requires EPA to protect from disclosure the
information described in subsection (c)(2) “until such time as”
the submitter withdraws the claim or EPA learns that the

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information “does not qualify for protection from disclosure.”
15 U.S.C. § 2613(e)(1)(A). In addition, the categories of
information described in subsection (A) through (G) are
“[s]ubject to subsection (f),” which outlines specific
circumstances in which the EPA must or may require
reassertion and substantiation. Id. § 2613(f). For example, EPA
is required to ask submitting entities “to reassert and
substantiate” their CBI claims if necessary for the EPA resolve
a Freedom of Information Act request for the exempted
information. Id. § 2613(f)(2)(A). Noticeably absent from the
enumerated list of triggers is commencement of commercial
distribution. Section 2613(f) does not require the EPA to
demand entities to reassert or substantiate their CBI claims for
specific chemical identities solely because of
commercialization. Instead, after a chemical substance is in
commercial distribution, the next time an entity reports on that
substance’s specific chemical identity, the entity will be
required to substantiate a CBI claim and EPA will review that
claim pursuant to section 2613.
Second, EPA did not act arbitrarily or capriciously in
eliminating its pre-Lautenberg regulatory provisions. Those
prior regulations did require entities to reassert and substantiate
their pre-commercialization CBI claims after
commercialization. See 40 C.F.R. §§ 720.85(b)(1),
720.90(b)(2) (2022). However, “[a]gencies are free to change
their existing policies as long as they provide a reasoned
explanation for the change.” Encino Motorcars, LLC v.
Navarro, 579 U.S. 211, 221 (2016). EPA reasonably explained
that its change in position was in response to new language in
the Lautenberg Amendments exempting pre-
commercialization claims from substantiation and review. EPA
found that the prior regulations could not be squared with the
statutory exemption. See EPA Response to Comments at 48.

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D. EPA’s Duties Under the TSCA
At several points in the CBI Rule, EPA uses permissive
language to describe its duties as to deficient CBI claims and
non-confidential information. EDF challenges these provisions
as unlawful, arguing that EPA improperly treats as
discretionary its mandatory duties under the TSCA. EDF also
argues that EPA replaced previous mandatory provisions with
discretionary provisions without adequate explanation. Both
arguments fail. The provisions at issue are consistent with the
best reading of the statutory text, and EPA’s use of permissive
language was reasonably explained.
1. The CBI Rule’s Treatment of Deficient CBI Claims
Although the TSCA does not give EPA discretion to
approve a deficient CBI claim, it does allow EPA to reserve its
final determination of a CBI claim until the end of the 90-day
review period. See 15 U.S.C. § 2613(g)(1)(A). Consistent with
the statute, the CBI Rule articulates that if a deficiency is not
remedied during the correction period – which lasts for 10
days, during which review of the underlying CBI claim is
suspended – then EPA will proceed with review of the
submission and may deny the CBI claim. 40 C.F.R.
§ 703.5(e)(2) (emphasis added). This “may deny” language
refers to the possibility that after the 10-day correction window
and before the end of the 90-day review period, intervening
factors may arise that affect EPA’s confidentiality
determination. Contrary to EDF’s contention, this language
does not grant EPA discretion to approve a deficient CBI claim.
A situation might arise, for example, where EPA receives a
CBI claim that it initially determines to be improperly
substantiated. EPA will suspend the underlying review for 10
business days to allow for a correction. If the submitter has not

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made the correction by the end of the 10-day period, the claim
remains deficient, but the 90-day statutory period may not have
expired. During the time remaining in the 90-day review
period, EPA may determine that substantiation is adequate and,
accordingly, approve the claim. Or it might determine that an
exception to substantiation and review applies and, therefore,
take no action on the claim. See 15 U.S.C. § 2613(g), (c)(2).
Conversely, a deficient claim that is corrected during the 10-
day window may nevertheless be deemed deficient upon
further inspection prior to the conclusion of review. Requiring
EPA to deny the deficient claim after the 10-day correction
period would short-circuit this process and deny EPA the
benefit of its statutorily authorized 90-day review period. Of
course, if the end of the 10-day period coincides with the end
of the 90-day statutory review period and the claim remains
deficient, then EPA must deny the claim.
EPA also reasonably explained its intentional use of this
permissive language. See EPA Response to Comments at 41
(“[T]he language employed was intentional, to allow the
possibility that a CBI claim deficiency might be overcome or
that the claim might no longer need a determination (such as if
. . . the submitter made a persuasive argument that it was
exempt from substantiation requirements).”).
2. The CBI Rule’s Treatment of Non-Confidential
Information
The best reading of the TSCA is that it permits, but does
not require, the disclosure of all information that falls outside
of the section 2613(a) prohibition on disclosure. Importantly,
the TSCA does not contain a general requirement of disclosure
for all non-confidential information. Instead, where Congress
does require information to be disclosed, it states so expressly.
For example, section 2607(b)(7) requires EPA to disclose

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chemical identities not subject to valid CBI claims. See 15
U.S.C. § 2607(b)(7). In addition, section 2625(j) lists five
categories of information, such as risk evaluation studies, that
the Administrator “shall make available to the public”
consistent with the requirements of section 2613. See id. §
2625(j). Such provisions suggest that, in the absence of an
express mandate, EPA is not subject to a mandatory duty to
disclose. See also id. § 2613(d) (listing information that “shall
be disclosed” in specific circumstances). Thus, EPA is under
no obligation to generally disclose all non-confidential
information when not required to under one of the statute’s
express mandates.
EPA’s use of permissive language in two provisions of the
CBI Rule is consistent with the statute’s express disclosure
mandates. See 40 C.F.R. §§ 703.8(d) (“[I]n the case of any
unsubstantiated claim, EPA will construe this as a waiver of the
claim and may make the information public without any further
notice to the submitter.”), 703.5 (“If no [CBI] claim
accompanies the submission, EPA will not recognize a
confidentiality claim, and the information in or referred to in
that submission may be made available to the public.”)
(emphases added). The TSCA does not require any and all
information not accompanied by a CBI claim, or accompanied
by an unsubstantiated CBI claim, to become publicly available.
Rather, such information shall be made available to the public
when required by the specific disclosure mandates, or when
requested by the public. See EPA Response to Comments at 41
(explaining that the use of permissive language “is not intended
to suggest that disclosure is in doubt when the information is
requested”).
EPA’s use of discretionary language is neither arbitrary nor
capricious. In its pre-Lautenberg regulations, EPA did require
the automatic and immediate disclosure of information that

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failed to meet statutory requirements for confidentiality. See 40
C.F.R. §§ 716.55(c), 704.7(b) (2022) (repealed 2023). EPA,
however, reasonably explained its change in position in
response to comments: The use of “may” when discussing
public disclosure is intended “to provide EPA with discretion
and flexibility on the timing for proactively or unilaterally
disclosing data, particularly when there is little or no evident
demand for the information.” EPA Response to Comments at
41. The prior regulations also could not be retained because
they did not “fully implement the new requirements under
section [2613] and ha[d] a good deal of variation in their
requirements.” EPA Response to Comments at 46.
Having properly explained why it eliminated the pre-
Lautenberg regulations, as well as why it has decided to use
permissive language in its new regulations, EPA has met the
standard for reasoned decision-making. See Encino Motorcars,
579 U.S. at 221 (“Agencies are free to change their existing
policies as long as they provide a reasoned explanation for the
change.”).
E. The CBI Rule As Applied to Entities Reporting by
Accession Number and Without Knowledge
Under the CBI Rule, a company with no knowledge of the
specific chemical identity of a particular chemical substance –
such as a downstream customer that only knows the
substance’s generic chemical name and non-confidential
accession number – could waive CBI protection for the specific
chemical identity simply by submitting a report to EPA that
identifies the substance by its non-confidential referents. This
is the case even where the downstream customer does not
possess any confidential information and, thus, is not in a
position to assert, much less substantiate, a CBI claim. The CBI
Rule is unlawful to the extent it allows such waiver to occur.

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The existing regulatory regime requires downstream users
of a chemical substance, such as a chemical processor or
importer, to report information to the EPA. These entities,
unlike chemical manufacturers, do not always have knowledge
of a chemical substance’s specific chemical identity.
Accordingly, EPA allows these entities to identify the chemical
substance for which they are reporting by its non-confidential
generic name or accession number, as opposed to its
confidential chemical identity. See 40 C.F.R. part 711; see also
40 C.F.R. § 711.15. Yet, despite these entities’ lack of
knowledge on the matter, the CBI Rule requires these entities
to assert and substantiate CBI claims for specific chemical
identities when reporting to the EPA, even when their reports
contain only non-confidential chemical information.
Otherwise, EPA deems confidentiality for the specific
chemical identity waived, and EPA may make the chemical
identity publicly available. In other words, an entity’s lack of
knowledge is no defense to the CBI Rule’s assertion and
substantiation requirements. This regulatory scheme cannot be
squared with the commands of the statute.
Once an entity has satisfied the requirements for asserting
and substantiating a confidentiality claim for a specific
chemical identity, the TSCA prohibits EPA from disclosing
that chemical identity except in narrow circumstances
enumerated in the statute. See 15 U.S.C. § 2613(a), (d)-(e). The
submission of a report that refers to a chemical substance by
only its non-confidential accession number is not among those
circumstances. Indeed, it is not clear that an entity that reports
using a non-confidential accession number has submitted
confidential information that would trigger the statute’s CBI
claim requirements in the first place. Section 2613(c)(1)(A)
requires a person seeking to protect from disclosure “any
information that person submits” under the TSCA to assert a

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confidentiality claim. It is a stretch to say that an entity that is
allowed to report by an accession number is submitting
information on the underlying specific chemical identity. They
merely submit information as to the chemical substance, not its
specific molecular identity. Accordingly, such entities are not
required to assert CBI claims for specific chemical identities
when merely reporting on a chemical substance by reference to
its generic name or accession number.
A reporting entity’s failure to assert and substantiate a CBI
claim for a specific chemical identity due to its lack of
knowledge of that identity is also not a statutory ground for
disclosure. Indeed, it is not clear how a downstream customer
who lacks knowledge can verify that the specific chemical
identity is not readily discoverable through reverse
engineering, as required for CBI claim assertion. Id. §
2613(c)(1)(B)(iv). The CBI Rule, as applied to these entities,
allows for the inadvertent waiver of confidentiality to occur,
thereby jeopardizing the confidentiality protections established
by upstream entities. Moreover, as the parties acknowledged
during oral argument, a downstream company may have no
interest in protecting the confidentiality of another company’s
trade secrets – and indeed, may have an interest in those secrets
becoming public. The CBI Rule would allow downstream
entities without knowledge to inadvertently or intentionally
waive a competitor’s CBI claim.
EPA acknowledges the genuine concern posed by this
knowledge issue and yet declines to address it in the CBI Rule.
It argues that the issue would be best addressed in later rules
that contain specifically tailored reporting requirements. This
argument is unpersuasive because the CBI Rule, as it currently
stands, allows for unauthorized disclosures of confidential
information, making it contrary to law. EPA cannot wait to
address this unlawfulness at a later point in time.

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It is also of no avail for the EPA to argue that it has long
required all entities, regardless of their knowledge, to assert
and substantiate CBI claims when reporting only by accession
number. ACC disputes EPA’s characterization of the agency’s
past practice, but even if we accepted EPA’s characterization,
the fact that the practice is longstanding cannot render it lawful.
To conclude, the CBI Rule is unlawful to the extent it
allows a downstream entity reporting on a chemical substance
by accession number and without knowledge of the underlying
specific chemical identity to waive confidentiality for that
specific chemical identity. Because we address ACC’s petition
on statutory grounds, we decline to reach ACC’s alternative
arguments that the EPA’s approach to the knowledge issue is
arbitrary and capricious.
III. CONCLUSION
For the reasons set forth above, we grant ACC’s petition
for review and deny EDF’s petition for review. As indicated in
the foregoing opinion, the CBI Rule fails review in only one
respect: The Rule is unlawful insofar as it requires entities
reporting by non-confidential accession numbers and without
knowledge of the underlying chemical identity to assert CBI
claims for the underlying chemical identity in order to maintain
the chemical identity’s confidentiality. 40 C.F.R. § 703.5.
Neither the TSCA nor good reason justifies these terms of the
CBI Rule. We hereby vacate these requirements under the CBI
Rule.

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