[Federal Register Volume 91, Number 71 (Tuesday, April 14, 2026)]
[Notices]
[Pages 19134-19136]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-07167]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-OPPT-2018-0430; EPA-HQ-OPPT-2018-0459; FRL-13309-01-OCSPP]
1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-Hexamethylcyclopenta [g]-2-
Benzopyran (HHCB) and Phthalic Anhydride Draft Risk Evaluations Under
the Toxic Substances Control Act (TSCA); Notice of Availability and
Request for Comment
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: The Environmental Protection Agency (EPA or Agency) is
announcing the availability of and seeking public comment on draft risk
evaluations under the Toxic Substances Control Act (TSCA) for
1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran
(HHCB) and phthalic anhydride. The purpose of risk evaluations under
TSCA is to determine whether a chemical substance presents an
unreasonable risk of injury to health or the environment under the
conditions of use (COUs), including unreasonable risk to potentially
exposed or susceptible subpopulations identified as relevant to the
risk evaluation by EPA, and without consideration of costs or non-risk
factors. EPA is seeking comment on the draft risk evaluations for HHCB
and phthalic anhydride.
DATES: Comments must be received on or before June 15, 2026.
ADDRESSES:
To submit comments on the HHCB draft risk evaluation, submit your
comments, identified by docket identification (ID) number EPA-HQ-OPPT-
2018-0430, online at https://www.regulations.gov by.
To submit comments on the phthalic anhydride draft risk evaluation,
submit your comments, identified by docket ID number EPA-HQ-OPPT-2018-
0459, online at https://www.regulations.gov.
Follow the online instructions for submitting comments. Do not
electronically submit any information you consider to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Members of the public should also be aware that
personal information included in any written comments may be posted on
the internet at https://www.regulations.gov. Additional information on
commenting or visiting the docket, along with more information about
dockets generally, is available at https://www.epa.gov/dockets.
FOR FURTHER INFORMATION CONTACT:
For technical information on HHCB: Jeffery Putt, Existing Chemical
Risk Management Division (7404M), Office of Pollution Prevention and
Toxics, Environmental Protection Agency, 1200 Pennsylvania Ave. NW,
Washington, DC 20460-0001; telephone number: (202) 564-3703; email
address: [email protected].
For technical information on phthalic anhydride: Wyn Zenni,
Existing Chemical Risk Management Division (7404M), Office of Pollution
Prevention and Toxics, Environmental Protection Agency, 1200
Pennsylvania Ave. NW, Washington, DC 20460-0001; telephone number:
(202) 564-6294; email address: [email protected].
For general information: The TSCA-Hotline, Goodwill of the Finger
Lakes, 422 South Clinton Ave., Rochester, NY 14620; telephone number:
(202) 554-1404; email address: [email protected].
SUPPLEMENTARY INFORMATION:
I. Executive Summary
A. Does this action apply to me?
This action is directed to the public in general and may be of
particular interest to those involved in the manufacture (defined under
TSCA section 3(9) to include import), processing, distribution, use,
and disposal of HHCB and/or phthalic anhydride, related industry trade
organizations, non-governmental organizations with an interest in human
and environmental health, State and local governments, Tribal Nations,
and/or those interested in the assessment of risks involving chemical
substances and mixtures regulated under TSCA. As such, the Agency has
not attempted to describe all the specific entities that this action
might apply to. If you need help determining applicability, consult the
relevant technical contact listed under FOR FURTHER INFORMATION
CONTACT.
B. What is the Agency's authority for taking this action?
The Agency is conducting these risk evaluations under TSCA section
6, (15 U.S.C. 2605) which requires that EPA conduct risk evaluations on
chemical substances and identifies the minimum components EPA must
include in the risk evaluations. Each risk evaluation must be conducted
consistent with the best available science, be based on the weight of
the scientific evidence, and consider reasonably available information,
and not consider costs or non-risk factors (15 U.S.C. 2625(h), (i), and
(k)). See also the implementing procedural regulations at 40 CFR part
702.
C. What action is the Agency taking?
EPA is announcing the availability of and seeking public comment on
draft risk evaluations under TSCA for HHCB and phthalic anhydride. The
purpose of risk evaluations under TSCA is to determine whether a
chemical substance presents an unreasonable risk of injury to human
health or the environment under the conditions of use, including
unreasonable risk to potentially exposed or susceptible subpopulations
identified as relevant to the risk evaluation by EPA, and without
consideration of costs or non-risk factors. EPA has used the best
available science to prepare these draft risk evaluations and, based on
the weight of scientific evidence, to preliminarily determine that HHCB
does not pose unreasonable risk to human health or the environment and
to preliminarily determine that phthalic anhydride does pose
unreasonable risk to human health driven primarily by certain COUs
analyzed in the draft risk evaluations.
D. What should I consider as I submit my comments to EPA?
1. Submitting CBI. Do not submit CBI or other sensitive information
to EPA through https://www.regulations.gov or email. To include
information in your comment that you consider to be CBI or otherwise
protected, please contact the person listed under FOR FURTHER
INFORMATION CONTACT to obtain special instructions before submitting
that information.
2. Tips for preparing comments. When preparing and submitting your
comments, see the commenting tips at https://www.epa.gov/dockets/commenting-epa-dockets.
II. Draft Risk Evaluation for HHCB
A. What is HHCB?
HHCB is primarily used as a synthetic musk compound found widely in
fragrances. HHCB is utilized in household products such as detergents,
cleaners, and air fresheners. HHCB is also a key ingredient in non-TSCA
uses including perfumes, cosmetics, and personal care products due to
its long-lasting scent properties. Workers may be exposed to HHCB
through dust, mist, or vapor when making or using these products.
Consumers may be exposed to HHCB through dust, mist, or vapor during
intended product use (e.g., cleaning a counter, placing an air
freshener in a bathroom or small room, or doing laundry). Environmental
releases occur primarily when fragrance
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products are disposed of down the drain, leading to HHCB entering
wastewater and, after treatment, being discharged in effluent from
Publicly Owned Treatment Works (POTWs). HHCB may also enter wastewater
through transfers of manufacturing wastes to POTWs.
B. The Risk Evaluation of HHCB
In December 2019, EPA announced its designation of HHCB (Docket ID:
EPA-HQ-OPPT-2018-0430) as a high-priority substance for risk evaluation
under TSCA (84 FR 71924 (FRL-10003-15)). In April 2020, EPA published
and sought public comment on the draft scope of the HHCB risk
evaluation (85 FR 19941 (FRL-10007-11-OCSPP)), and, after considering
public comments, issued the final scope on September 4, 2020 (85 FR
55281 (FRL-10013-90-OCSPP)).
C. Request for Comment
EPA seeks feedback on the assessment of risk presented in the draft
risk evaluation for HHCB, a copy of which is available in the docket,
and encourages all potentially interested parties, including
individuals, governmental and non-governmental organizations, non-
profit organizations, academic institutions, research institutions, and
private sector entities to comment on the draft risk evaluation. To the
extent possible, the Agency asks commenters to please cite any public
data related to or that support comments provided, and to the extent
permissible, describe any supporting data that is not publicly
available.
EPA welcomes specific input on each section of the draft risk
evaluation, and is particularly interested in:
Selection and characterization of the bioaccumulation
value, implementation of additional modeling refinements, and resulting
conclusions;
Use of screening-level exposure approaches for
occupational and consumer assessments;
Human health hazard conclusions (no acute toxicity and no
dermal toxicity at human-relevant doses), and characterization of
uncertainties associated with the lack of cancer bioassays, including
the application of elements of the Rethinking Carcinogenicity
Assessment for Agrochemicals Project.
D. Next Steps
After consideration of comments received from the public on the
draft risk evaluation and input from the Scientific Advisory Committee
on Chemicals (SACC) peer review, EPA will issue a final risk evaluation
for HHCB. Under TSCA section 6, EPA must use the final risk evaluation
as a basis to determine, based on the weight of scientific evidence,
whether or not the chemical presents an unreasonable risk to human
health or the environment under the chemical's COUs. This includes
risks to subpopulations who may be at greater risks than the general
population, such as children and workers. TSCA prohibits EPA from
considering non-risk factors (e.g., costs/benefits) during risk
evaluation.
For more information about the TSCA risk evaluation process for
existing chemicals, go to https://www.epa.gov/assessing-and-managing-chemicals-under-tsca.
III. Draft Risk Evaluation for Phthalic Anhydride
A. What is phthalic anhydride?
Phthalic anhydride is a white flaky solid primarily used as a
chemical intermediate in the manufacture of various products such as
plasticizers and resins. Phthalic anhydride is also found as an
ingredient in oil-based consumer products such as paints and coatings
and as a hardener in adhesives and sealants. Workers may be exposed to
phthalic anhydride through dermal contact or inhalation of dusts or
mist generated from spray applications when making or using these
products. Consumers may be exposed to phthalic anhydride through dermal
contact or through mist generated from spray applications during
intended product use (e.g., applying spray paint). Phthalic anhydride
released to the environment is expected to hydrolyze to ortho (o-)-
phthalic acid upon contact with water or atmospheric moisture. O-
phthalic acid enters wastewater and, after treatment, is discharged in
effluent from POTWs. Phthalic anhydride may also enter wastewater
through transfers of manufacturing wastes to POTWs, but will quickly
hydrolyze to o-phthalic acid. O-phthalic acid is also released through
stack and fugitive emissions, which can subsequently undergo air-to-
soil deposition. However, o-phthalic acid is not expected to sorb to
soils.
B. The Risk Evaluation of Phthalic Anhydride
In December 2019, EPA announced its designation of phthalic
anhydride (Docket ID: EPA-HQ-OPPT-2018-0459) as a high priority
substance for risk evaluation under TSCA (84 FR 71924 (FRL-10003-15)).
In April 2020, EPA published and sought public comment on the draft
scope of the phthalic anhydride risk evaluation (85 FR 22733 (FRL-
10008-05-OCSPP)), and, after considering public comments, issued the
final scope on September 4, 2020 (85 FR 55281 (FRL-10013-90-OCSPP)).
C. Request for Comment
EPA seeks feedback on the assessment of risk presented in the draft
risk evaluation for phthalic anhydride, a copy of which is available in
the docket, and encourages all potentially interested parties,
including individuals, governmental and non-governmental organizations,
non-profit organizations, academic institutions, research institutions,
and private sector entities to comment on the draft risk evaluation. To
the extent possible, the Agency asks commenters to please cite any
public data related to or that support comments provided, and to the
extent permissible, describe any supporting data that is not publicly
available.
EPA welcomes specific input on each section of the draft risk
evaluation, particularly input on the following:
Workplace exposure information including air monitoring
data including task-based exposure durations, air monitoring methods
(including uncertainties in existing methods such as OSHA 90),
engineering controls, personal protective equipment practices and
usage;
EPA's approach to estimate dermal exposures from spray
products for consumers and workers;
EPA's approach to estimate dermal exposure from contact
with solids for occupational exposure scenarios using the study by
Lansink (1996), including additional studies or information that may
inform dermal loading for contact with solids;
EPA's approach to determine dermal loadings for products
using the U.S. EPA (1992b) study wipe experiment, which incorporates
wiping off the excess product with a saturated cloth after application
as advised in the products' use instructions (e.g., Adhesives and
sealants);
Product-specific phthalic anhydride concentration ranges
and use patterns, including updated publicly available Safety Data
Sheets related to the use of phthalic anhydride in products considered
under COUs in this assessment (e.g., paint and coating products);
EPAs approach to assess inhalation exposures for acute
exposure durations of phthalic anhydride from consumer COUs using an 8-
hour time weighted average (TWA);
EPAs approach to assess inhalation exposures for acute
exposure durations of phthalic anhydride using an 8-hour TWA rather
than a short-term inhalation
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value (STEV) based on assumed task durations;
EPA's derivation of a STEV and occupational exposure
values (OEV) and the scientific robustness of deriving OEVs and STEVs
based on the dataset and the endpoints (i.e., respiratory
sensitization);
Newly available or recently published hazard/toxicology
studies relevant to phthalic anhydride;
The selection of environmental hazard thresholds based on
a relatively small hazard datasets;
The strengths and uncertainties of the methodology and
data used to derive acute and chronic concentration of concern for
aquatic thresholds and the strength of the data to support the
quantitative aquatic assessment;
The following weight of evidence conclusions from the
human health hazard assessment: (1) phthalic anhydride and o-phthalic
acid have low systemic toxicity via the oral exposure route; (2)
phthalic anhydride is a skin sensitizer; and (3) phthalic anhydride is
a respiratory sensitizer;
The underlying modeling and science used to inform the
inhalation toxicokinetics of phthalic anhydride (See Appendix F in the
Draft Human Health Hazard Assessment).
D. Next Steps
After consideration of comments received from the public on the
draft risk evaluation and input from the SACC peer review, EPA will
issue a final risk evaluation for phthalic anhydride. Under TSCA
section 6, EPA must determine in the final risk evaluation, based on
the weight of scientific evidence, whether or not the chemical presents
an unreasonable risk to human health or the environment under the
chemical's conditions of use. This includes consideration of risks to
potentially exposed susceptible subpopulations who may be at greater
risks than the general population, such as children and workers. TSCA
prohibits EPA from considering non-risk factors (e.g., costs/benefits)
during risk evaluation.
For more information about the TSCA risk evaluation process for
existing chemicals, go to https://www.epa.gov/assessing-and-managing-chemicals-under-tsca.
(Authority: 15 U.S.C. 2601 et seq.)
Dated: April 10, 2026.
Douglas M. Troutman,
Assistant Administrator, Office of Chemical Safety and Pollution
Prevention.
[FR Doc. 2026-07167 Filed 4-13-26; 8:45 am]
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