[Federal Register Volume 88, Number 130 (Monday, July 10, 2023)]
[Notices]
[Pages 43562-43565]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-14445]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-OPPT-2022-0905; FRL-10798-02-OCSPP]
1,4-Dioxane; Draft Supplement to the TSCA Risk Evaluation;
Science Advisory Committee on Chemicals (SACC) Meeting; Notice of
Meeting 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 soliciting public comment on the
``2023 Draft Supplement to the 1,4-Dioxane Risk Evaluation'' prepared
under the Toxic Substances Control Act (TSCA) that is being submitted
to the Science Advisory Committee on Chemicals (SACC) for peer review.
The draft supplement is available for public review and comment and is
submitted to the SACC for peer review. The SACC will consider and
review the draft supplement at a 4-day virtual public meeting that was
previously announced in the Federal Register of March 23, 2023. The
virtual public meeting will be held on September 12-15, 2023, via a
webcast platform such as ``Zoomgov.com'' and audio teleconference.
DATES: The following is a chronological listing of the dates for the
specific activities that are described in more detail under
SUPPLEMENTARY INFORMATION.
September 1, 2023--Deadline for submitting a request for special
accommodations to allow EPA time to process the request before the
meeting.
September 8, 2023--Deadline for providing written comments on the
draft supplement.
September 8, 2023--Deadline for registering to be listed on the
meeting agenda to make oral comments during the virtual meeting.
September 15, 2023--Deadline for those not making oral comments to
register to receive the links to observe the meeting.
ADDRESSES:
To comment: Submit written comments, identified by docket
identification (ID) number EPA-HQ-OPPT-2022-0905, through the Federal
eRulemaking Portal 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)
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or other information whose disclosure is restricted by statute.
Copyrighted material will not be posted without explicit permission
from the copyright holder. 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.
To register for the meeting: For information on how to register and
access the virtual public meeting, please refer to the SACC website at
https://www.epa.gov/tsca-peer-review. EPA intends to announce
registration instructions on the SACC website by mid-August of 2023.
You may also subscribe to the following listserv for alerts regarding
this and other SACC-related activities at https://public.govdelivery.com/accounts/USAEPAOPPT/subscriber/new?topic_id=USAEPAOPPT_101.
To request special accommodations: For information on access or
services for individuals with disabilities, and to request
accommodation for a disability, please contact the Designated Federal
Official (DFO) listed under FOR FURTHER INFORMATION CONTACT.
FOR FURTHER INFORMATION CONTACT: The DFO, Dr. Alaa Kamel, Mission
Support Division (7602M), Office of Program Support, Office of Chemical
Safety and Pollution Prevention, Environmental Protection Agency;
telephone number: (202) 564-5336 or SACC main office number: (202) 564-
8450; email address: [email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. What action is the Agency taking?
EPA is announcing the availability of and soliciting public comment
on the ``2023 Draft Supplement to the 1,4-Dioxane Risk Evaluation.''
EPA is also announcing a 4-day virtual public meeting on September 12-
15, 2023, for the SACC to consider and review the draft supplement.
This September 2023 meeting was previously announced in the Federal
Register of March 23, 2023 (88 FR 17566 (FRL-10798-01-OCSPP)). EPA will
be soliciting comments from the SACC on the methodologies utilized in
the 2023 Draft Supplement to the 1,4-Dioxane Risk Evaluation that have
not been previously peer reviewed. EPA is also releasing for public
comment an updated risk determination for 1,4-dioxane (see docket ID
No. EPA-HQ-OPPT-2016-0723). EPA is not soliciting comments from the
SACC on the risk determination for 1,4-dioxane.
This document provides instructions for accessing the materials
provided to the SACC, submitting written comments, and registering to
provide oral comments and attend the virtual meeting.
B. What is the Agency's authority for taking this action?
The SACC was established by EPA in 2016 in accordance with the
Toxic Substances Control Act (TSCA), 15 U.S.C. 2625(o), to provide
independent advice and expert consultation, at the request of the
Administrator, with respect to the scientific and technical aspects of
issues relating to the implementation of TSCA. The SACC operates in
accordance with the Federal Advisory Committee Act (FACA), 5 U.S.C. 10,
and supports activities under the TSCA, 15 U.S.C. 2601 et seq., the
Pollution Prevention Act (PPA), 42 U.S.C. 13101 et seq., and other
applicable statutes.
C. Does this action apply to me?
This action is directed to the public in general. This action may,
however, be of interest to those involved in the manufacture,
processing, distribution, and disposal of chemical substances and
mixtures, and/or those interested in the assessment of risks involving
chemical substances and mixtures regulated under TSCA. Since other
entities may also be interested, the Agency has not attempted to
describe all the specific entities that may be affected by this action.
D. What should I consider as I submit my comments to EPA?
1. Submitting CBI
Contact the DFO listed under FOR FURTHER INFORMATION CONTACT for
instructions before submitted CBI or other sensitive information. Do
not submit this information to EPA electronically (e.g., through
https://www.regulations.gov or email). Clearly mark the part or all of
the information that you claim to be CBI. For confidential information
in a disk or CD-ROM that you mail to EPA, mark the outside of the disk
or CD-ROM as CBI and then identify electronically within the disk or
CD-ROM the specific information that is claimed as CBI. In addition to
one complete version of the comment that includes information claimed
as CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
2. Tips for Preparing Your Comments
When preparing and submitting your comments, see the commenting
tips at https://www.epa.gov/dockets/commenting-epa-dockets. See also
the instructions in Unit III.C.
II. Background
A. What is the purpose of the SACC?
The SACC provides independent scientific advice and recommendations
to the EPA on the scientific and technical aspects of risk assessments,
methodologies, and pollution prevention measures and approaches for
chemicals regulated under TSCA. The SACC is comprised of experts in
toxicology; environmental risk assessment; exposure assessment; and
related sciences (e.g., synthetic biology, pharmacology, biotechnology,
nanotechnology, biochemistry, biostatistics, physiologically based
pharmacokinetic modeling (PBPK), computational toxicology,
epidemiology, environmental fate, and environmental engineering and
sustainability). The SACC currently consists of 19 members. When
needed, the committee will be assisted by ad hoc reviewers with
specific expertise in the topics under consideration.
B. Why did EPA develop these documents?
TSCA requires EPA to conduct risk evaluations on prioritized
chemical substances and identifies the minimum components EPA must
include in all chemical substance risk evaluations. The purpose of
conducting risk evaluations is to determine whether a chemical
substance presents an unreasonable risk to human health or the
environment under the conditions of use. These evaluations include
assessing unreasonable risks to relevant potentially exposed or
susceptible subpopulations. As part of this process, EPA: (1)
integrates hazard and exposure assessments using the best available
science that is reasonably available to assure decisions are based on
the weight of the scientific evidence; and (2) conducts peer review for
risk evaluation approaches that have not been previously peer reviewed.
1,4-Dioxane was one of the first 10 chemical substances undergoing
the TSCA risk evaluation process after passage of the Frank R.
Lautenberg Chemical Safety for the 21st Century Act, which amended TSCA
in 2016. 1,4-Dioxane is primarily used as a solvent in a variety of
commercial and
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industrial applications such as the manufacture of other chemicals
(e.g., adhesives, sealants) or as a processing aid or laboratory
chemical. Although there are no direct consumer uses of 1,4-dioxane, it
is present as a byproduct in commercial and consumer products from
several manufacturing processes, including ethoxylation, sulfonation,
sulfation, and esterification.
In the 2019 Draft Risk Evaluation for 1,4-Dioxane (see https://www.regulations.gov/document/EPA-HQ-OPPT-2019-0238-0011), EPA reviewed
the exposures and hazards of 1,4-dioxane direct industrial and
commercial uses assessing risk from occupational exposures and surface
water exposures to environmental organisms. This assessment, which
included the physical and chemical properties, lifecycle information,
environmental fate and transport information, and hazard identification
and dose-response analysis was reviewed by the SACC. The Agency
considered the SACC feedback and is not seeking additional review at
this time as this information has not changed.
In November of 2020, EPA released for public comment a Draft
Supplement to the 2019 Draft Risk Evaluation (see https://www.regulations.gov/document/EPA-HQ-OPPT-2019-0238-0067). The November
2020 Draft Supplement assessed eight conditions of use (COUs) of 1,4-
dioxane as a byproduct in consumer products and general population
exposure from incidental contact with surface water. The Agency
determined that the additional analysis did not warrant SACC review.
The 2019 Draft Risk Evaluation and 2020 Draft Supplement were both
incorporated into the final Risk Evaluation for 1,4-Dioxane released in
December 2020 (see https://www.epa.gov/sites/default/files/2020-12/documents/1._risk_evaluation_for_14-dioxane_casrn_123-91-1.pdf). After
its release, EPA determined an additional supplement to the final Risk
Evaluation for 1,4-Dioxane was needed to consider critical exposure
pathways not previously assessed. Specifically, the 2023 Draft
Supplement includes evaluation of additional conditions of use in which
1,4-dioxane is present as a byproduct in industrial processes and
commercial products and evaluates risks from general population
exposures to 1,4-dioxane released to ambient surface water and
groundwater, ambient air, and land. To evaluate these additional
exposure pathways, the Agency used new methods and novel applications
of existing methods. These new methods described below have not been
the subject of public comment or peer review for applications in TSCA
risk evaluations.
In this 2023 Draft Supplement, EPA is relying on the physical and
chemical properties, lifecycle information, environmental fate and
transport information, and hazard identification and dose-response
analysis presented in the December 2020 final Risk Evaluation for 1,4-
Dioxane, thus, EPA is not seeking feedback on these topics. However,
EPA is seeking review of the methodologies listed below that have not
been previously peer reviewed and are utilized in this 2023 Draft
Supplement to the 1,4-Dioxane Risk Evaluation.
1. EPA Applied Monte Carlo Modeling in the Assessment of 1,4-Dioxane
Occupational Exposures and Environmental Releases
The Agency has utilized Monte Carlo approaches in TSCA risk
evaluations previously for specific conditions of use; however, the
application of Monte Carlo methods in the ``2023 Draft Supplement to
the 1,4-Dioxane Risk Evaluation'' was expanded to capture additional
exposure and release models for additional conditions of use. The
expanded application of these methods incorporates randomness and
variability to improve the representativeness of the resulting model
outputs. This was done to further improve exposure and release
estimates and is in response to previous SACC review comments received
on the first 10 chemical risk evaluations conducted under amended TSCA.
2. EPA Assessed Hydraulic Fracturing as a Condition of Use
This evaluation required consideration of new field operations data
that have not yet been considered in TSCA risk evaluations to estimate
occupational exposures and environmental releases from these
operations. EPA has developed a new generic exposure scenario for
hydraulic fracturing and applied it in the 2023 Draft Supplement along
with the Monte Carlo modeling to estimate a range of potential
releases.
3. EPA Assessed the Ambient Air Pathway To Determine Exposures and
Associated Risks to Fenceline Communities (a Subset of the General
Population)
The Agency assessed general population exposures via the inhalation
route through both single- and multi-year analyses. The single-year
analysis utilized the Fenceline 1.0 methodology described in the ``EPA
Toxic Substances Control Act (TSCA) Screening Level Approach for
Assessing Ambient Air and Water Exposures to Fenceline Communities,''
previously peer reviewed by the SACC (see, EPA (2022). Peer Review of
the EPA TSCA Screening Level approach for Assessing Ambient Air and
Water Exposures to Fenceline Communities March 15-17, 2022. https://www.regulations.gov/docket/EPA-HQ-OPPT-2021-0415/document.) EPA
quantitatively characterized exposures and risks to communities in
proximity to multiple facilities releasing 1,4-dioxane to air.
4. EPA Assessed General Population Exposures via Drinking Water Sourced
From Groundwater and Surface Water
Although the 2020 1,4-dioxane risk evaluation considered incidental
oral and dermal exposures to surface water, the 2020 analysis did not
consider drinking water exposures through sourcing of 1,4-dioxane
contained in surface water or groundwater.
a. Surface Water
1,4-Dioxane concentrations in surface water reported in
the 2023 draft supplemental risk evaluation were modeled based on known
facility and publicly owned treatment works releases directly to
surface water. This methodology is generally consistent with what was
previously done to aquatic exposures and presented in the draft
Fenceline 1.0 methodology previously reviewed by the SACC. However,
this analysis was modified to include consideration of multiple years
of release data, as recommended by SACC, and integrated NHDPlus flow
networks and flows to modernize approaches previously utilized in TSCA
risk evaluations. This assessment is the first time the modified
approach has been employed in a TSCA risk evaluation
1,4-Dioxane concentrations resulting from consumer and
commercial down-the-drain releases of 1,4-dioxane through publicly
owned treatment works to surface water were estimated. EPA used the
Stochastic Human Exposure and Dose Simulation Model (SHEDS) for high-
throughput (HT) (SHEDS-HT) model (see Environ. Sci. Technol. 2014, 48,
21, 12750-12759) predictions to estimate down-the-drain disposals
(Isaacs, 2014). SHEDS-HT was developed by EPA under the ExpoCast
program for evaluating chemicals based on the potential for
biologically relevant human exposure. This is the first TSCA risk
evaluation incorporating down-the-drain estimates based on SHEDS-HT
model predictions and is the first time the down-the-drain model has
been
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used for one of the first 10 chemical risk evaluations conducted under
amended TSCA.
1,4-Dioxane concentrations in surface water were modeled
based on multiple upstream sources, including releases from facilities
and publicly owned treatment works and down-the-drain releases. In
addition, EPA compared the modeled concentrations to drinking water
monitoring data for community water systems. This approach to
considering the contribution of multiple sources to drinking water
exposures is novel. EPA has not previously considered multiple sources
of releases when estimating exposure concentrations in surface water
for a chemical risk evaluation under TSCA.
b. Groundwater
1,4-Dioxane concentrations in groundwater were modeled for
two disposal pathways by applying the Delisting Risk Assessment
Software (DRAS) model in a novel way. DRAS is a multi-pathways model
developed by the EPA that calculates the potential human health risks
associated with disposing of a specific facility's given waste stream
in a landfill or surface impoundment. (See U.S. EPA. (2020). Hazardous
Waste Delisting Risk Assessment Software Version 4. Lenexa, KS: EPA
Region 6. https://www.epa.gov/hw/hazardous-waste-delisting-risk-assessment-software-dras.) DRAS was specifically designed to address
the Criteria for Listing Hazardous Waste. The 2023 Draft Supplement to
the 1,4-Dioxane Risk Evaluation presents a novel application of this
model and the first application in a TSCA chemical risk evaluation.
Specifically, EPA compared the modeled concentrations to monitoring
data from groundwater contaminations around the nation to consider if
they are within a reasonable range.
EPA is also seeking review of the overall synthesis of the results
of these novel methodologies and the integration of the results into
the 1,4-Dioxane Risk Evaluation. Feedback from this review will be
considered in the development of the final supplement to the 1,4-
dioxane risk evaluation. In addition, SACC reviewer feedback may help
refine EPA's methods for conducting release assessments and evaluating
general population exposures in risk evaluations of other chemicals
under TSCA.
III. Virtual Public Meeting of the SACC
A. What is the purpose of this public meeting?
The purpose of the 4-day virtual public meeting is the SACC peer
review of the methodologies that have not been previously peer reviewed
and are utilized in the 2023 Draft Supplement. Feedback from this
review will be considered in the development of the final Supplement to
the Risk Evaluation for 1,4-Dioxane. In addition, SACC reviewer
feedback may help refine EPA's methods for conducting release
assessments and evaluating general population exposures in risk
evaluations of other chemicals under TSCA.
EPA intends to provide a meeting agenda for each day of the
meeting, and as needed, may provide updated times for each day in the
meeting agenda that will be posted in the docket and on the SACC
website.
B. How can I access the documents submitted for review to the SACC?
The 2023 Draft Supplement and related documents, including
background documents, related supporting materials, and draft charge
questions provided to the SACC, are available in the docket. As
additional background materials become available and are provided to
the SACC, EPA will include those additional background documents (e.g.,
SACC members and consultants participating in this meeting and the
meeting agenda) in the docket. All of these documents will be available
through https://www.regulations.gov (docket ID No. EPA-HQ-OPPT-2022-
0905) and through links on the SACC website at https://www.epa.gov/tsca-peer-review.
After the public meeting, the SACC will prepare meeting minutes and
a final report document summarizing its recommendations to the EPA.
This document will also be available in the docket and the SACC
website.
C. How can I provide comments for the SACC's consideration?
To ensure proper receipt of comments it is imperative that you
identify docket ID No. EPA-HQ-OPPT-2022-0905 in the subject line on the
first page of your comments and follow the instructions in Unit I.D.
and in this unit.
1. Written Comments
The Agency encourages written comments for this meeting be
submitted by the deadlines set in the DATES section of this document
and following the instructions in this document.
2. Oral Comments
The Agency encourages each individual or group wishing to make
brief oral comments to the SACC during the peer review virtual public
meeting to follow the registration instructions that will be announced
on the SACC website by mid-August of 2023. Oral comments before the
SACC during the peer review virtual public meeting are limited to 5
minutes. In addition, each speaker should submit a written copy of
their oral comments and any supporting materials (e.g., presentation
slides) to the DFO prior to the meeting for distribution to the SACC by
the DFO.
D. How can I participate in the virtual public meeting?
The virtual public meeting will be held via a webcast platform such
as ``Zoomgov.com'' and audio teleconference. You must register online
to receive the webcast meeting link and audio teleconference
information. Please follow the registration instructions that will be
announced on the SACC website.
Authority: 15 U.S.C. 2625(o); 5 U.S.C 10.
Dated: July 3, 2023.
Michal Freedhoff,
Assistant Administrator, Office of Chemical Safety and Pollution
Prevention.
[FR Doc. 2023-14445 Filed 7-7-23; 8:45 am]
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