Notice2026-16263
o-Dichlorobenzene and p-Dichlorobenzene; Draft Risk Evaluations Under the Toxic Substances Control Act (TSCA); Notice of Availability and Request for Comment
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Published
August 10, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA or Agency) is announcing the availability of and seeking public comment on the draft risk evaluations under the Toxic Substances Control Act (TSCA) for o- dichlorobenzene (CASRN 95-50-1) and p-dichlorobenzene (CASRN 106-46-7). 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 public comment on the draft risk evaluations for o-dichlorobenzene and p- dichlorobenzene.
Full Text
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<title>Federal Register, Volume 91 Issue 152 (Monday, August 10, 2026)</title>
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[Federal Register Volume 91, Number 152 (Monday, August 10, 2026)]
[Notices]
[Pages 51488-51491]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-16263]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-OPPT-2018-0444; EPA-HQ-OPPT-2018-0446; FRL-13481-01-OCSPP]
o-Dichlorobenzene and p-Dichlorobenzene; 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 the draft
risk evaluations under the Toxic Substances Control Act (TSCA) for o-
dichlorobenzene (CASRN 95-50-1) and p-dichlorobenzene (CASRN 106-46-7).
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 public
comment on the draft risk evaluations for o-dichlorobenzene and p-
dichlorobenzene.
DATES: Comments must be received on or before October 9, 2026.
ADDRESSES: Submit your comments on the o-dichlorobenzene draft risk
evaluation, identified by docket identification (ID) number EPA-HQ-
OPPT-2018-0444, online at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Submit your
comments on the p-dichlorobenzene draft risk evaluation, identified by
docket ID number EPA-HQ-OPPT-2018-0446, online at <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Follow the online instructions for submitting comments. Do not
submit electronically any information you consider to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Additional instructions on commenting and
visiting the docket, along with more information about dockets
generally, are available at <a href="https://www.epa.gov/dockets">https://www.epa.gov/dockets</a>.
FOR FURTHER INFORMATION CONTACT:
For technical information on o-dichlorobenzene: Peter Deck,
Existing Chemical Risk Management Division, Office of Pollution
Prevention and Toxics, Environmental Protection Agency, 1200
Pennsylvania Ave. NW, Washington, DC 20460-0001; telephone number:
(202) 564-3703; email address: <a href="/cdn-cgi/l/email-protection#e58aa1a6a7cbb1b6a6a4a5809584cb828a93"><span class="__cf_email__" data-cfemail="305f7473721e64637371705540511e575f46">[email protected]</span></a>.
For technical information on p-dichlorobenzene: Ingrid Feustel,
Existing Chemical Risk Management Division, Office of Pollution
Prevention and Toxics, Environmental Protection Agency, 1200
Pennsylvania Ave. NW, Washington, DC 20460-0001; telephone number:
(202) 564-3199; email address: <a href="/cdn-cgi/l/email-protection#cdbd898e8fe3999e8e8c8da8bdace3aaa2bb"><span class="__cf_email__" data-cfemail="a8d8ecebea86fcfbebe9e8cdd8c986cfc7de">[email protected]</span></a>.
For general information: The TSCA Assistance Information Service
Hotline, Goodwill Vision Enterprises, 422 South Clinton Ave.,
Rochester, NY 14620; telephone number: (800) 471-7127 or (202) 554-
1404; email address: <a href="/cdn-cgi/l/email-protection#0551564644284d6a71696c6b60456075642b626a73"><span class="__cf_email__" data-cfemail="095d5a4a482441667d6560676c496c7968276e667f">[email protected]</span></a>.
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 o-dichlorobenzene and p-dichlorobenzene, 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.
[[Page 51489]]
B. What is the Agency's authority for taking this action?
The Agency is conducting this risk evaluation 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, consider reasonably available information, and
not consider costs or non-risk factors (15 U.S.C. 2605(b)(4), 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 o-dichlorobenzene and p-
dichlorobenzene, including related technical support documents. EPA
used the best available science to prepare these draft risk evaluations
and preliminarily determined, based on the weight of scientific
evidence, that o-dichlorobenzene and p-dichlorobenzene present
unreasonable risk to human health driven primarily by certain COUs
analyzed in the draft risk evaluations.
D. What should I consider as I prepare my comments?
1. Submitting CBI
Do not submit CBI to EPA through <a href="https://www.regulations.gov">https://www.regulations.gov</a> or
email. If you wish to include CBI in your comment, please follow the
applicable instructions at <a href="https://www.epa.gov/dockets/commenting-epa-dockets#rules">https://www.epa.gov/dockets/commenting-epa-dockets#rules</a> and clearly mark the information that you claim to be
CBI. Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR parts 2 and 703, as applicable.
2. Tips for preparing your comments.
When preparing and submitting your comments, see the commenting
tips at <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
II. Background
A. What is o-Dichlorobenzene?
o-Dichlorobenzene is a clear to pale yellow liquid with a pleasant,
aromatic odor. It exists in a liquid phase at ambient temperatures. o-
Dichlorobenzene is processed as a reactant and incorporated into
formulation, mixture, or reaction products. Industrial and commercial
uses range from use as a solvent in dyes and pigments to use in
lubricant and degreaser products and in inks and paint strippers.
Consumer uses include lubricant and degreaser products, air care
products, and other uses such as ceramics glazing and cleaning
products. It has low to moderate solubility in aqueous systems and is a
moderately volatile organic compound. Exposure to o-dichlorobenzene can
occur via inhalation of vapors during use and via the dermal route
through contact with solids or accidental splashing from liquid
products. When released to water or soil, o-dichlorobenzene volatilizes
to the surrounding atmosphere. Air is expected to be the primary
pathway of exposure to o-dichlorobenzene in the environment.
B. What is p-Dichlorobenzene?
p-Dichlorobenzene is a colorless to white crystalline solid that
has a strong, pungent odor and which is poorly soluble in water but
miscible in most organic solvents. At ambient temperature, it undergoes
sublimation, passing directly from a solid to a vapor state. Industrial
and commercial uses of p-dichlorobenzene range from the manufacture of
thermoplastic and use in solvents (which become part of product
formulation or mixtures) to use in air care products as continuous-
action air fresheners. Consumer uses include in air care products,
lubricants and greases, and building and construction products. The
volatilization of p-dichlorobenzene from these products has been
identified as a potential mechanism of exposure. Thus, exposure to p-
dichlorobenzene can occur via inhalation of vapors during use and via
the dermal route through contact with solids or accidental splashing
from liquid products. When released to water or soil, p-dichlorobenzene
volatilizes to the surrounding atmosphere. Air is expected to be the
primary pathway of exposure to p-dichlorobenzene in the environment.
C. Summary of Activities for the Risk Evaluations of o-and p-
Dichlorobenzene
In December 2019, EPA announced its designation of o-
dichlorobenzene (Docket ID: EPA-HQ-OPPT-2018-0444) and p-
dichlorobenzene (Docket ID: EPA-HQ-OPPT-2018-0446) as high priority
substances for risk evaluation under TSCA (84 FR 71924, December 30,
2019) (FRL-10003-15). In April 2020, EPA published and sought public
comment on the draft scopes of the o-dichlorobenzene and p-
dichlorobenzene risk evaluations (85 FR 19941, April 9, 2020) (FRL-
10007-11-OCSPP), and, after considering public comments, issued the
final scopes in September 2020 (85 FR 55281, September 4, 2020) (FRL-
10013-90-OCSPP). In April 2026, EPA released the draft hazard
assessments for both o-dichlorobenzene and p-dichlorobenzene for public
comment and external peer review by the Science Advisory Committee on
Chemicals (SACC) (91 FR 19131, April 14, 2026) (FRL-13266-01-OCSPP). As
part of the SACC deliberations, the Agency held a virtual public
meeting to discuss the draft hazard assessments for both o-
dichlorobenzene and p-dichlorobenzene in June 2026. For more
information about this meeting, go to the SACC website at <a href="https://www.epa.gov/tsca-peer-review/science-advisory-committee-chemicals-meetings">https://www.epa.gov/tsca-peer-review/science-advisory-committee-chemicals-meetings</a>. These documents, other supporting documents, and public
comments are in docket ID number EPA-HQ-OPPT-2026-1189 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. The draft risk evaluations for o-dichlorobenzene
and p-dichlorobenzene are being released with this notice and are
available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> in Docket ID numbers EPA-HQ-
OPPT-2018-0444 and EPA-HQ-OPPT-2018-0446, respectively.
EPA is now opening a 60-day public comment period on the draft risk
evaluations for both o-dichlorobenzene and p-dichlorobenzene. External
peer review is not needed on the draft risk evaluations and chemistry,
fate, release, and exposure assessments because in addition to the peer
review of the draft hazard assessments, as noted above, the
methodologies used in the development of the draft risk evaluations
have been previously peer reviewed by the SACC in published risk
evaluations for 1,1-dichloroethane (90 FR 26581, June 23, 2025) (FRL-
11809-04), 1,3-butadiene (91 FR 264, January 5, 2026) (FRL-12241-05-
OCSPP), and phthalates (91 FR 373, January 6, 2026) (FRL-13111-01-
OCSPP), as well as the Draft TSCA Screening Level Approach for
Assessing Ambient Air and Water Exposures to Fenceline Communities (87
FR 3294, January 21, 2022) (FRL-9392-01-OCSPP).
III. Request for Comment
EPA seeks feedback on the assessment of risk presented in the draft
risk evaluations for o-dichlorobenzene and p-dichlorobenzene, copies of
which are available in their respective dockets, 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
[[Page 51490]]
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 exposure
assessments, draft hazard assessments, and draft risk evaluations with
particular interest in the assessment of human exposures resulting from
industrial, commercial, and consumer use of o-dichlorobenzene and p-
dichlorobenzene; exposure controls and personal protective equipment
used to mitigate o-dichlorobenzene and p-dichlorobenzene exposures in
industrial settings; time-weighted average occupational inhalation
exposures using monitoring information from multiple shift lengths;
characterization of risks associated with the manufacture, use, and
disposal of o-dichlorobenzene and p-dichlorobenzene; and determination
of unreasonable risks associated with these substances.
Although EPA seeks public comment on all aspects of the draft risk
evaluation packages, the Agency particularly seeks comments on the
following for o-dichlorobenzene:
<bullet> Process descriptions, worker activities, concentrations
(in air, product, or process) and current prevalence of the following
o-dichlorobenzene activities:
1. Domestic manufacture;
2. Processing as a reactant;
3. Use in ink, toner, and colorant products;
4. Use as a cleaning product in the dry cleaning or furnishing care
industry including evidence of use in the U.S. as a spot cleaner or
alternative applications; and,
5. Consumer and commercial/occupational use as a cleaner for septic
and cesspool tanks.
<bullet> Consumer use septic tank cleaner products containing o-
dichlorobenzene including product availability, ingredients and
composition, and use instructions.
<bullet> Whether and how exposure controls and personal protective
equipment (PPE) are used during the manufacture, processing, and use of
o-dichlorobenzene for each of the COUs depicted in Table ES-1 of the
Draft Risk Evaluation for o-Dichlorobenzene. Although EPA has test
order data, additional information on when and where exposure controls
and PPE are used (including for protection against inhalation and
dermal exposures) would be informative.
<bullet> The application (i.e., mapping) of the Industrial Use of
Solvents OES to the three COUs:
1. Processing--Recycling;
2. Industrial Use--Solvents (which become part of product
formulation or mixture)--Printing ink manufacturing, paint and coating
manufacturing, synthetic dye and pigment manufacturing; and
3. Industrial Use--Non-incorporative activities--Processing aids,
not otherwise listed.
<bullet> The approach for derivation and utility of 15-min exposure
values, including extrapolation of the hour occupational exposure value
to a 15-min time-weighted average and extrapolation of the original
animal data down to a 30-min duration to calculate a short-term
exposure value based on principles of (ten Berge et al., 1986).
<bullet> The modeling approach used to determine inhalation
exposure to o-dichlorobenzene from the use of paints and coatings OES,
based on the Automotive Refinishing Spray Coating Mist Inhalation
Model, which estimates worker inhalation exposure based on the
concentration of the chemical of interest in the nonvolatile portion of
the sprayed product and the concentration of over sprayed mist/
particles (OECD, 2011).
<bullet> The confidence ratings applied to hazard and exposure
values in this risk evaluation. For example, EPA applied a Robust
confidence rating for both hazard values, including for the liver point
of departure when extrapolated to dermal exposure based on oral and
inhalation data.
The Agency particularly seeks comments on the following for p-
dichlorobenzene:
<bullet> Process descriptions, worker activities, concentrations,
and current prevalence of COUs of p-dichlorobenzene, including typical
schedules (shifts per year and hours per shift) for workers at sites
using p-dichlorobenzene.
<bullet> The representativeness of monitoring data compared to the
distribution of other sites at which the same OESs occur.
<bullet> Reasonableness of the assumption of negligible exposures
from products with very low, residual concentrations of p-
dichlorobenzene (i.e., Use of Lubricants and Greases and Use of Fuels
and Related Products OESs).
<bullet> Whether dermal exposure to workers is foreseeable in any
cases where a heated stream of neat, liquid p-dichlorobenzene is
present.
<bullet> Reasonableness of the assumptions used to estimate dermal
exposure, including for occupational non-users (ONUs).
<bullet> Representativeness of high-end exposure estimates for
intermediate dermal occupational exposures.
<bullet> Applicability of the Generic Model for Central Tendency
and High-End Inhalation Exposure to Total and Respirable Particulates
Not Otherwise Regulated to p-dichlorobenzene, which is a solid at room
temperature and also sublimates.
<bullet> Use of p-dichlorobenzene in abrasive grinding wheels, in
particular with respect to exposure for both workers and ONUs.
<bullet> Prevalence of the use of p-dichlorobenzene in
laboratories.
<bullet> Whether and how exposure controls and PPE are used during
the manufacture, processing, and use of p-dichlorobenzene for each of
the COUs, especially the use of gloves (e.g., prevalence of use and
glove material) during commercial use of p-dichlorobenzene in air care
products, and
1. Although EPA has test order data, additional information on when
and where exposure controls and PPE are used would be informative.
<bullet> Whether it is appropriate to normalize a 1-hour time
weighted average (TWA) concentration to a 24-hour TWA for a commercial
exposure scenario, when the hazard value is based on a 24-hour
exposure.
<bullet> The use of Indoor Environmental Concentrations in
Buildings with Conditioned and Unconditioned Zones (IECCU) to model
exposure to continuous action air fresheners for consumer and
commercial COUs, including model assumptions.
IV. Next Steps
EPA will consider comments received on the draft risk evaluations
as well as input from the SACC peer review of the draft hazard
assessments and then announce the availability of the final risk
evaluations for o-dichlorobenzene and p-dichlorobenzene. 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 a
chemical presents an unreasonable risk to health or the environment,
without consideration of costs or other non-risk factors, including
unreasonable risks to potentially exposed or susceptible subpopulations
identified as relevant to the risk evaluation by EPA, under the
chemical's COUs.
If EPA determines in its final risk evaluation that a chemical
presents an unreasonable risk to health or the environment, the
chemical will move to risk management action under TSCA section 6(a)
for the relevant COUs. Like the prioritization and risk evaluation
processes, there will be an opportunity
[[Page 51491]]
for public comment on any proposed risk management actions.
For more information about the TSCA risk evaluation process for
existing chemicals, go to <a href="https://www.epa.gov/assessing-and-managing-chemicals-under-tsca">https://www.epa.gov/assessing-and-managing-chemicals-under-tsca</a>.
(Authority: 15 U.S.C. 2601 et seq.)
Douglas M. Troutman,
Assistant Administrator, Office of Chemical Safety and Pollution
Prevention.
[FR Doc. 2026-16263 Filed 8-7-26; 8:45 am]
BILLING CODE 6560-50-P
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