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[Federal Register Volume 89, Number 232 (Tuesday, December 3, 2024)]
[Notices]
[Pages 95782-95785]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-28287]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPPT-2024-0551; FRL-12418-01-OCSPP]

Benzyl Butyl Phthalate (BBP), Dibutyl Phthalate (DBP), Di(2-
ethylhexyl) Phthalate (DEHP), Diisobutyl Phthalate (DIBP), and 
Dicyclohexyl Phthalate (DCHP); Technical Support Documents; Science 
Advisory Committee on Chemicals (SACC) Peer Review; Request for 
Nominations of Ad Hoc Reviewers

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: The Environmental Protection Agency (EPA or Agency) is seeking 
public nominations of scientific and technical experts that EPA can 
consider for service as ad hoc reviewers assisting the Science Advisory 
Committee on Chemicals (SACC) with the peer review of the Agency's 
technical support documents for benzyl butyl phthalate (BBP), dibutyl 
phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl 
phthalate (DIBP), and dicyclohexyl phthalate (DCHP) and the cross-
phthalate technical support documents for human health benchmark dose 
(BMD) analysis, cancer analysis, and cumulative risk analysis. To 
facilitate nominations, this document provides information about the 
SACC, the intended topic for the planned peer review, the expertise 
sought for this peer review, instructions for submitting nominations to 
EPA, and the Agency's plan for selecting the ad hoc reviewers for this 
peer review. EPA is planning to convene a virtual public meeting of the 
SACC in the spring of 2025 to review the technical support documents.

DATES: Submit your nominations on or before January 2, 2025.

ADDRESSES: Submit your nominations to [email protected].

FOR FURTHER INFORMATION CONTACT: The Designated Federal Official (DFO) 
for the SACC is 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 call the SACC main office at (202) 564-8450; email address: 
[email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. What action is the Agency taking?

    The Agency is seeking public nominations of scientific and 
technical experts that EPA can consider for service as ad hoc reviewers 
assisting the SACC with the peer review of the Agency's technical 
support documents for the evaluation of the risks from BBP, DBP, DEHP, 
DIBP and DCHP to inform risk management decisions under TSCA. EPA is 
planning to hold a virtual public meeting in the spring of 2025 for the 
SACC to consider and review technical support documents. At that time, 
EPA will solicit comments from the SACC on the critical inputs and 
novel approaches for a variety of charge questions related to 
individual, draft chemical risk evaluations and the draft cumulative 
risk analysis.
    To facilitate nominations, this document provides information about 
the SACC, the intended topic for the planned peer review, the expertise 
sought for this peer review, instructions for submitting nominations to 
EPA, and the Agency's plan for selecting the ad hoc reviewers for this 
peer review.

B. What is the Agency's authority for taking this action?

    TSCA section 6(b) requires that EPA conduct risk evaluations on 
existing chemical substances and identifies the minimum components EPA 
must include in all chemical substance risk evaluations (15 U.S.C. 
2605(b)). The risk evaluation must not consider costs or other non-risk 
factors (15 U.S.C. 2605(b)(4)(F)(iii)). The specific risk evaluation 
process is addressed in 40 CFR part 702 and summarized on EPA's website 
at https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-evaluations-existing-chemicals-under-tsca.
    The SACC was established by EPA in 2016 in accordance with TSCA, 15 
U.S.C. 2625(o), to provide independent advice and expert consultation 
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 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 particular 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. 
Members of at-risk communities, non-

[[Page 95783]]

governmental organizations (NGOs) (particularly those with an interest 
in protecting health for at-risk communities), and Federal, State and 
local officials may also be interested. Since other entities may also 
be interested, the Agency has not attempted to describe all the 
specific entities to which this action may apply.

D. How can I stay informed about SACC activities?

    You may subscribe to the following listserv for alerts regarding 
this and other SACC-related activities: https://public.govdelivery.com/accounts/USAEPAOPPT/subscriber/new?topic_id=USAEPAOPPT_101.

II. Background

A. What is the purpose of the SACC?

    The SACC provides independent 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 (PBPK) modeling, computational toxicology, 
epidemiology, environmental fate, environmental engineering and 
sustainability). The SACC currently consists of 20 members. When 
needed, the committee will be assisted by ad hoc reviewers with 
specific expertise in the topics under consideration.

B. Why is EPA conducting these risk evaluations?

    TSCA requires EPA to conduct risk evaluations on high-priority 
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 (COUs). 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. 
For more information about the three stages of EPA's process for 
ensuring the safety of existing chemicals (i.e., prioritization, risk 
evaluation, and risk management), go to https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/how-epa-evaluates-safety-existing-chemicals.

C. Why did EPA develop these documents?

    EPA designated the following chemicals as High-Priority Substances 
for risk evaluation under TSCA in December 2019: BBP (Butyl Benzyl 
Phthalate, CASRN 85-68-7), DBP (Dibutyl Phthalate, CASRN 84-74-2), DEHP 
(Di(2-ethylhexyl) Phthalate, CASRN 117-81-7), DIBP (Diisobutyl 
Phthalate, CASRN 84-69-5), and DCHP (Dicyclohexyl Phthalate, CASRN 84-
61-7). For these chemicals, EPA published draft and final scope 
documents in April and August 2020, respectively and, is currently in 
the risk evaluation process. The scope documents outlined the hazards, 
exposures, conditions of use, and the potentially exposed or 
susceptible subpopulations the Agency expected to consider in its risk 
evaluations. Although there are some differences in conditions of use 
and exposures, these chemical substances are primarily used as 
plasticizers in polyvinyl chloride (PVC) products and in adhesives, 
sealants, paints, coatings, rubbers, and other applications. Because of 
the significant similarities in exposure and physical chemical 
properties of these phthalates, EPA is developing these risk 
evaluations and the cumulative risk assessment in parallel. DIDP and 
DINP were reviewed previously by the SACC (July 30-August 1, 2024); the 
draft risk evaluations for BBP, DBP, DEHP, DIBP and DCHP are 
incorporating many of the SACC recommendations from this previous peer 
review.
    EPA is soliciting comments from the SACC on a variety of charge 
questions related to the data, methods, models, approaches for these 
draft chemical risk evaluations, including the supporting draft 
cumulative risk assessment analysis. Many of the methods and analyses 
used in these evaluations are not novel and have been reviewed in the 
development of the tools used in various agency work products or in 
previous TSCA assessments. EPA is focusing peer review on the critical 
inputs and novel approaches.
    The draft risk evaluations for BBP, DBP, DEHP, DIBP and DCHP 
include analyses of physical chemical properties, fate and transport in 
the environment, exposure to workers, consumers and general population 
including potentially exposed susceptible subpopulations, releases to 
the environment, environmental hazard and risk characterization for 
terrestrial and aquatic species, and human health hazard and risk 
characterization for workers, consumers, and the general population. 
The draft cumulative risk assessment analysis was developed based on 
the Proposed Approach for Cumulative Risk Assessment under TSCA 
including recommendations from the May 2023 SACC review. Specifically, 
the cumulative risk assessment analysis technical support document 
calculates relative potency factors for phthalate syndrome for each of 
the six chemical substances based on a pooled dataset for assessing 
fetal testicular testosterone health endpoint and estimates cumulative 
non-attributable exposures from NHANES urinary biomonitoring data.

D. What is the topic of the planned SACC peer review?

    EPA anticipates soliciting peer review from the SACC on the 
following draft documents:
     Physical and chemical and environmental fate technical 
support documents for BBP, DBP, DEHP, DIBP and DCHP.
     Ecological hazard technical support documents for BBP, 
DBP, DEHP, DIBP and DCHP.
     Non-cancer human health hazard technical support documents 
for BBP, DBP, DEHP, DIBP and DCHP.
     Cancer technical support document (a single document that 
includes BBP, DBP, DEHP, DIBP and DCHP).
     Environmental Releases and Occupational Exposure technical 
support documents for BBP, DBP, DEHP, DIBP and DCHP.
     Environmental and General Population Exposures to 
Environmental Releases technical support documents for BBP, DBP, DEHP, 
DIBP and DCHP.
     Consumer and Indoor Air Exposure technical support 
documents for BBP, DBP, DEHP, DIBP and DCHP.
     Meta-analysis and benchmark dose technical support 
document developed for the draft cumulative risk assessment.
     Technical support document for the Cumulative Risk 
Analysis of Di(2-ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), 
Butyl Benzyl Phthalate (BBP), Diisobutyl Phthalate (DIBP), Dicyclohexyl 
Phthalate (DCHP), and Diisononyl Phthalate (DINP) under TSCA.
     Aspects of the risk evaluation for DCHP, including risk 
characterization and application of the cumulative risk analysis.

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    EPA expects to solicit feedback on the following scientific issues:
     Physical-chemical properties and environmental fate 
technical support documents. EPA expects to solicit feedback on the 
data and methods used to characterize physical-chemical properties and 
environmental fate of BBP, DBP, DEHP, DIBP and DCHP. Of particular 
importance are the n-octanol/water partition coefficients 
(Kow), organic carbon-water partition coefficients 
(Koc), n-octanol/air partition coefficients 
(Koa), bioaccumulation factors (BAF), and bioconcentration 
factors (BCF). For DCHP specifically, EPA expects to solicit specific 
feedback on the weight of the scientific evidence approach to describe 
the water solubility range for DCHP and the use of a single value as 
input to exposure models.
     Ecological hazard technical support documents. EPA expects 
to solicit feedback on the data and methods used to characterize 
ecological hazards of BBP, DBP, DEHP, DIBP and DCHP.
     Non-cancer human health hazard technical support 
documents. EPA expects to solicit feedback on multiple scientific areas 
including the selection of non-cancer points of departure used to 
characterize non-cancer risks from acute, intermediate, and chronic 
durations for BBP, DBP, DEHP, DIBP and DCHP. For DEHP there are 
additional hazards for which EPA will solicit input; specifically, 
female reproductive tract, inhalation, and glucose homeostasis/lipid 
metabolism.
     Cancer hazard technical support document. EPA has 
developed a single document evaluating cancer hazard potential for 
these phthalates. EPA expects to solicit feedback on the following: 
draft cancer classifications for DEHP, BBP, and DBP; tumor triad 
(liver, pancreatic, and testicular tumors) and PPAR[alpha] mode of 
action information relevant to DEHP; and the application of Rethinking 
Carcinogenicity Assessment for Agrochemicals Project (ReCAAP) weight of 
evidence framework for DCHP and DIBP.
     Meta-analysis and benchmark dose modeling technical 
support document and the cumulative risk assessment technical support 
documents. EPA expects to solicit input on the methods and data used to 
calculate background exposure levels from the NHANES data set, derive 
relative potency factors, index chemical selection, and methods and 
application of background exposures. The draft risk evaluation of DCHP 
will contain an example of the application of cumulative risk 
assessment analysis for an individual chemical. EPA anticipates 
requesting input on the integration of the cumulative approaches within 
the individual chemical risk characterization.
     Technical support documents for environmental and general 
population, consumer and indoor air, and occupational exposures. EPA 
expects to request feedback and guidance on the data and methods used 
in the draft exposure assessments. Included in this request for input 
will be issues related to dermal absorption, such as the interpretation 
of in vitro and in vivo studies and the use of flux-based calculations 
for occupational exposures. Of specific importance are the data and 
methods used to calculate dermal absorption and exposures in the 
occupational exposure and the consumer and indoor air exposure 
technical support documents.
    Given the large volume of material across the five HPS phthalates, 
EPA will be releasing chemical-specific technical support documents in 
batches ahead of the draft risk evaluations. The formal 60-day public 
comment period for each chemical risk evaluation will begin when the 
Agency publishes a notice of availability in the Federal Register and 
the chemical's full risk evaluation, including the risk 
characterization and risk determination, are posted to the chemical 
specific docket. Most immediately, the Agency anticipates that the DCHP 
risk evaluation, and its associated supporting documents, is expected 
to be released to the public at the end of December, and a notice of 
availability will begin the public comment period for the DCHP draft 
risk evaluation. Over the next several months, EPA expects to release 
all the technical support documents for BBP, DBP, DEHP, and DIBP into 
their respective chemical specific dockets as they are available, and 
their dockets will be open for submission of comments. Nonetheless, 
these TSDs will be formally available for a 60-day public comment 
period with the release of each chemical risk evaluation to follow.
    In the first quarter of 2025, OPPT will publish a notice of 
availability in the Federal Register for the draft charge questions and 
to begin an additional public comment period in this docket (EPA-HQ-
OPPT-2024-0551) specifically for the peer review by the SACC. At that 
time, all of the risk evaluation documents (e.g., technical support 
documents, supplemental files, etc.) relevant to peer review will also 
be made available in this docket for a targeted peer review. EPA 
anticipates requesting SACC peer review of the questions pertaining to 
critical inputs and novel approaches contained in these documents to 
constitute full peer review of the phthalate risk evaluations. The SACC 
peer review will be focused on the DCHP risk evaluation and associated 
supporting documents, and the technical support documents that describe 
the data and analyses of physical chemistry and fate, hazards, 
exposures, and releases for BBP, DBP, DEHP, and DIBP.
    In total, EPA anticipates six opportunities for public comment; 
five dockets and comment periods associated with each chemical (BBP, 
DBP, DEHP, DIBP and DCHP) and one docket focused on the SACC peer 
review.

III. Nominations for ad hoc Reviewers

A. Why is EPA seeking nominations for ad hoc reviewers?

    As part of a broader process for developing a pool of candidates 
for SACC peer reviews, EPA is asking the public and stakeholders for 
nominations of scientific and technical experts that EPA can consider 
as prospective candidates for service as ad hoc reviewers assisting the 
SACC with the peer reviews. Any interested person or organization may 
nominate qualified individuals for consideration as prospective 
candidates for this review by following the instructions provided in 
this document. Individuals may also self-nominate.
    Those who are selected from the pool of prospective candidates will 
be invited to attend the public meeting and to participate in the 
discussion of key issues and assumptions at the meeting. In addition, 
they will be asked to review and to help finalize the meeting minutes 
and final report.

B. What expertise is sought for this peer review?

    Individuals nominated for this SACC peer review should have 
expertise in one or more of the following areas: Physical and chemical 
properties of phthalates including water solubility, bioconcentration 
and bioaccumulation, analytical chemistry, modeling and field derived 
data; Ecological hazard identification including general ecological 
hazard identification and use of read-across and new alternative 
methods; Environmental releases including methods for modeling and 
considerations for use of monitoring data; General population exposure 
including use of screening methods and refinements; Occupational 
exposure including dermal exposure modeling with consideration of 
empirical absorption data; Consumer exposure and indoor air exposure 
including

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modeling data selection and interpretation and use of monitoring data; 
Human health toxicology including inhalation hazard, glucose 
metabolism, liver toxicity, phthalate syndrome, mode of action for 
cancer and non-cancer, benchmark dose modeling and dose response 
analysis; Cumulative and mixtures risk assessment for human health 
including index chemical selection and relative potency factor 
derivations; Biostatistics including analysis of NHANES biomonitoring 
data and derivation of occupational exposure limits; Epidemiology 
related to individual chemicals and phthalate mixtures for use in risk 
assessments.
    Nominees should be scientists who have sufficient professional 
qualifications, including training and experience, to be capable of 
providing expert comments on the scientific issues for this review.

C. How do I make a nomination?

    Submit your nomination as directed under ADDRESSES by the deadline 
indicated under DATES. Each nomination should include the following 
information: Contact information for the person making the nomination; 
name, affiliation, and contact information for the nominee; and the 
disciplinary and specific areas of expertise of the nominee.
    Do not submit confidential business information (CBI) or other 
sensitive information to EPA through email. If your nomination contains 
any information that you consider to be CBI or otherwise protected, 
please contact the DFO listed under FOR FURTHER INFORMATION CONTACT to 
obtain special instructions before submitting that information.

D. Will ad hoc reviewers be subjected to an ethics review?

    SACC members and ad hoc reviewers are subject to the provisions of 
the Standards of Ethical Conduct for Employees of the Executive Branch 
at 5 CFR part 2635, conflict of interest statutes in Title 18 of the 
United States Code and related regulations. In anticipation of this 
requirement, prospective candidates for service on the SACC will be 
asked to submit confidential financial information which shall fully 
disclose, among other financial interests, the candidate's employment, 
stocks, and bonds, and where applicable, sources of research support. 
EPA will evaluate the candidates' financial disclosure forms to assess 
whether there are financial conflicts of interest, appearance of a loss 
of impartiality, or any prior involvement with the development of the 
documents under consideration (including previous scientific peer 
review) before the candidate is considered further for service on the 
SACC. Selected candidates are required to complete an ethics training 
prior to conducting their reviews.

E. How will EPA select the ad hoc reviewers?

    The selection of scientists to serve as ad hoc reviewers for the 
SACC is based on the function of the Committee and the expertise needed 
to address the Agency's charge to the Committee. No interested 
scientists shall be ineligible to serve by reason of their membership 
on any other advisory committee to a federal department or agency or 
their employment by a federal department or agency, except EPA. Other 
factors considered during the selection process include availability of 
the prospective candidate to fully participate in the Committee's 
reviews, ability to be hired as an EPA Special Government Employee 
(SGE), absence of any conflicts of interest or appearance of loss of 
impartiality, independence with respect to the matters under review, 
and lack of bias. Although financial conflicts of interest, the 
appearance of loss of impartiality, lack of independence, and bias may 
result in non-selection, the absence of such concerns does not assure 
that a candidate will be selected to serve on the SACC.
    Numerous qualified candidates are often identified for SACC 
reviews. Therefore, selection decisions involve carefully weighing 
several factors including the candidates' areas of expertise and 
professional qualifications and achieving an overall balance of 
different scientific perspectives across reviewers. The Agency will 
consider all nominations of prospective candidates for service as ad 
hoc reviewers for the SACC that are received by the deadline listed 
under DATES. However, the final selection of ad hoc reviewers is a 
discretionary function of the Agency.
    EPA anticipates selecting approximately ten (10) ad hoc reviewers 
to assist the SACC in their review of the designated topic. EPA plans 
to make a list of candidates under consideration as prospective ad hoc 
reviewers for this review available for public comment by the winter of 
2025. The list will be available in the docket at https://www.regulations.gov (docket ID No. EPA-HQ-OPPT-2024-0551) and through 
the SACC website at https://www.epa.gov/tsca-peer-review.
    Authority: 15 U.S.C. 2625(o); 5 U.S.C. 10.

    Dated: November 26, 2024.
Michal Freedhoff,
Assistant Administrator, Office of Chemical Safety and Pollution 
Prevention.
[FR Doc. 2024-28287 Filed 12-2-24; 8:45 am]
BILLING CODE 6560-50-P
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