EPA
EPA Document# EPA-740-D-20-013
April 2020
United States Office of Chemical Safety and
Environmental Protection Agency Pollution Prevention
Draft Scope of the Risk Evaluation for
l,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-
Hexam ethylcyclopenta [y] -2-Benzopyran (HHCB)
CASRN 1222-05-5
HX
CH
April 2020
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TABLE OF CONTENTS
ACKNOWLEDGEMENTS 5
ABBREVIATIONS AND ACRONYMS 6
EXECUTIVE SUMMARY 7
1 INTRODUCTION 10
2 SCOPE OF THE EVALUATION 10
2.1 Reasonably Available Information 10
2.1.1 Search of Gray Literature 11
2.1.2 Search of Literature from Publicly Available Databases (Peer-Reviewed Literature) 12
2.1.3 Search of TSCA Submissions 17
2.2 Conditions of Use 18
2.2.1 Categories and Subcategories of Conditions of Use Included in the Scope of the Risk
Evaluation 19
2.2.2 Activities Excluded from the Scope of the Risk Evaluation 20
2.2.3 Production Volume 21
2.2.4 Overview of Conditions of Use and Lifecycle Diagram 21
2.3 Exposures 23
2.3.1 Physical and Chemical Properties 23
2.3.2 Environmental Fate and Transport 23
2.3.3 Releases to the Environment 23
2.3.4 Environmental Exposures 24
2.3.5 Occupational Exposures 24
2.3.6 Consumer Exposures 25
2.3.7 General Population Exposures 25
2.4 Hazards (Effects) 26
2.4.1 Environmental Hazards 26
2.4.2 Human Health Hazards 26
2.5 Potentially Exposed or Susceptible Subpopulations 26
2.6 Conceptual Models 27
2.6.1 Conceptual Model for Industrial and Commercial Activities and Uses 27
2.6.2 Conceptual Model for Consumer Activities and Uses 29
2.6.3 Conceptual Model for Environmental Releases and Wastes: Potential Exposures and
Hazards 31
2.7 Analysis Plan 33
2.7.1 Physical and Chemical Properties and Environmental Fate 33
2.7.2 Exposure 33
2.7.2.1 Environmental Releases 34
2.7.2.2 Environmental Exposures 36
2.7.2.3 Occupational Exposures 37
2.7.2.4 Consumer Exposures 38
2.7.2.5 General Population 40
2.7.3 Hazards (Effects) 42
2.7.3.1 Environmental Hazards 42
2.7.3.2 Human Health Hazards 43
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2.7.4 Summary of Risk Approaches for Characterization 45
2.8 Peer Review 46
REFERENCES 47
APPENDICES 52
Appendix A LIST OF GRAY LITERATURE SOURCES 52
Appendix B PHYSICAL AND CHEMICAL PROPERTIES OF HHCB 54
Appendix C ENVIRONMENTAL FATE AND TRANSPORT PROPERTIES OF HHCB 55
Appendix D REGULATORY HISTORY 57
D. 1 Federal Laws and Regulations .57
D.2 State Laws and Regulations ....................58
D.3 International Laws and Regulations .....58
Appendix E PROCESS, RELEASE AND OCCUPATIONAL EXPOSURE INFORMATION.. 60
E.l Process Information. ...60
E. 1.1 Manufacture (Including Import) 60
E. 1.1.1 Manufacturing 60
E.l. 1.2 Import 60
E. 1.2 Processing and Distribution 60
E. 1.2.1 Incorporation into a Formulation, Mixture or Reaction Product 60
E. 1.2.2 Incorporation into an Article 61
E.l.2.3 Repackaging 61
E.l.2.4 Recycling 61
E.l.3 Uses 61
E.l.3.1 Air Care Products 61
E.l.3.2 Cleaning and Furnishing Care Products 61
E. 1.3.3 Laundry and Dishwashing Products 62
E.l.3.4 Plastic and Rubber Products Not Covered Elsewhere 62
E.l.3.5 Paper Products 62
E.l.3.6 Other Uses: laboratory Chemical 62
E.l.3.7 Disposal 62
E.2 Sources Containing Potentially Relevant Data or Information .....63
Appendix F SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR INDUSTRIAL
AND COMMERCIAL ACTIVITIES AND USES 64
Appendix G SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR CONSUMER
ACTIVITIES AND USES 73
Appendix H SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR
ENVIRONMENTAL RELEASES AND WASTES 76
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LIST OF TABLES
Table 2-1. Results of Title Screening of Submissions to EPA under Various Sections of TSCA 18
Table 2-2. Categories and Subcategories of Conditions of Use Included in the Scope of the Risk
Evaluation 19
Table 2-3. Categories and Sources of Environmental Release Data 34
LIST OF FIGURES
Figure 2-1. Gray Literature Tags by Discipline for HHCB 11
Figure 2-2. Peer-reviewed Literature - Physical-Chemical Properties Search Results for HHCB 13
Figure 2-3. Peer-reviewed Literature - Fate and Transport Search Results for HHCB 14
Figure 2-4. Peer-reviewed Literature - Engineering Search Results for HHCB 15
Figure 2-5. Peer-reviewed Literature - Exposure Search Results for HHCB 16
Figure 2-6. Peer-reviewed Literature - Hazard Search Results for HHCB 17
Figure 2-7. HHCB Life Cycle Diagram 22
Figure 2-8. HHCB Conceptual Model for Industrial and Commercial Activities and Uses: Worker and
ONU Exposures and Hazards 28
Figure 2-9. HHCB Conceptual Model for Consumer Activities and Uses: Consumer Exposures and
Hazards 30
Figure 2-10. HHCB Conceptual Model for Environmental Releases and Wastes: Environmental
Exposures and Hazards 32
LIST OF APPENDIX TABLES
TableApx A-l. Gray Literature Sources That Yielded Results for HHCB 52
TableApx B-l. Physical and Chemical Properties of HHCB 54
TableApx C-l. Environmental Fate and Transport Properties of HHCB 55
Table_Apx D-l. Federal Laws and Regulations 57
Table_Apx D-2. State Laws and Regulations 58
Table Apx D-3. Regulatory Actions by other Governments, Tribes, and International Agreements 58
Table Apx F-l. Worker and ONU Exposure Conceptual Model Supporting Table 64
Table Apx G-l. Consumer Exposure Conceptual Model Supporting Table 73
Table Apx H-l. General Population and Environmental Exposure Conceptual Model Supporting Table
76
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ACKNOWLEDGEMENTS
This report was developed by the United States Environmental Protection Agency (U.S. EPA), Office of
Chemical Safety and Pollution Prevention (OCSPP), Office of Pollution Prevention and Toxics (OPPT).
Acknowledgements
The OPPT Assessment Team gratefully acknowledges participation or input from Intra-agency
reviewers that included multiple offices within EPA, Inter-agency reviewers that included multiple
Federal agencies, and assistance from EPA contractors Abt Associates (Contract No. EP-W-16-009),
Battelle (Contract No. EP-W-16-017), ERG (Contract No. EP-W-12-006), GDIT (Contract No.
HHSN316201200013W), ICF (Contract No. 68HERC19D0003), SRC (Contract No.
68HERH19D0022), and Versar (Contract No. EP-W-17-006).
Docket
Supporting information can be found in public docket: J ^ \ 11 ' ^1'T~2018-0430.
Disclaimer
Reference herein to any specific commercial products, process or service by trade name, trademark,
manufacturer or otherwise does not constitute or imply its endorsement, recommendation or favoring by
the United States Government.
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ABBREVIATIONS AND ACRONYMS
ACGIH
American Conference of Governmental Industrial Hygienists
BP
Boiling point
CAA
Clean Air Act
CASRN
Chemical Abstracts Service Registry Number
CBI
Confidential Business Information
CDR
Chemical Data Reporting
CFR
Code of Federal Regulations
CPCat
EPA Chemical and Product Categories
CWA
Clean Water Act
EC
Engineering Controls
ESD
Emission Scenario Document
EPA
U.S. Environmental Protection Agency
EU
European Union
FR
Federal Register
FYI
For Your Information
HHCB
l,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-Hexamethylcyclopenta[y]-2-Benzopyran
HHE
Health Hazard Evaluation
IMIS
Integrated Information Management System
Koc
Organic carbon-water partition coefficient
Kow
Octanol-water partition coefficient
NIOSH
National Institute for Occupational Safety and Health
NWQMC
National Water Quality Monitoring Council
OECD
Organisation for Economic Co-operation and Development
ONU
Occupational Non-User
OPPT
Office of Pollution Prevention and Toxics
OSHA
Occupational Safety and Health Administration
P-Chem
Physical and chemical
PEL
Permissible exposure limit
PESS
Potentially exposed or susceptible subpopulations
POTW
Publicly owned treatment works
PPE
Personal Protective Equipment
RCRA
Resource Conservation and Recovery Act
SDS
Safety data sheet
SDWA
Safe Drinking Water Act
SMILES
Simplified Molecular-Input Line-Entry System
tl/2
Half-life
TBD
To be determined
TIAB
Title and Abstract
TRI
Toxics Release Inventory
TSCA
Toxic Substances Control Act
USGS
United States Geological Survey
VP
Vapor pressure
WWTP
Wastewater treatment plant
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EXECUTIVE SUMMARY
In December 2019, EPA designated 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[y]-2-
benzopyran (HHCB; CASRN 1222-05-5) as a high-priority substance for risk evaluation following the
prioritization process required by section 6(b) of the Toxic Substances Control Act (TSCA) and
implementing regulations (40 CFR Part 702) (Docket ID: EPA-HQ-QPPT-2018-0430^) (U.S. EPA,
2019a). The first step of the risk evaluation process is the development of the scope document and this
document fulfills the TSCA regulatory requirement to issue a draft scope document as described in 40
CFR 702.41(c)(7). The draft scope for HHCB includes the following information: the conditions of use,
potentially exposed or susceptible subpopulations (PESS), hazards, and exposures that EPA plans to
consider in this risk evaluation, along with a description of the reasonably available information,
conceptual model, analysis plan and science approaches, and plan for peer review for this chemical
substance. EPA is providing a 45-day comment period on the draft scope. Comments received on this
draft scope document will help inform development of the final scope document and the risk evaluation.
General Information. HHCB is a synthetic polycyclic musk fragrance with a total annual production
volume in the United States between > 1 million and 10 million pounds.
Reasonably Available Information. EPA leveraged the data and information sources already described
in the document supporting the High-Priority Substance designation for HHCB to inform the
development of this draft scope document. To further develop this draft scope document, EPA
conducted a comprehensive search to identify and screen multiple evidence streams (i.e., chemistry, fate,
release and engineering, exposure, hazard), and the search and screening results to date are provided in
Section 2.1. EPA is seeking public comment on this draft scope document and will consider additional
information identified following publication of this draft scope document, as appropriate, in developing
the final scope document. EPA is using the systematic review process described in the Application of
Systematic Review in TSCA Risk Evaluations document (U.S. EPA, 2018a) to guide the process of
searching for and screening reasonably available information, including information already in EPA's
possession, for use and inclusion in the risk evaluation. EPA is applying these systematic review
methods to collect reasonably available information regarding hazards, exposures, PESS, and conditions
of use that will help inform the risk evaluation for HHCB.
Conditions of Use. EPA plans to evaluate manufacturing, including importing; processing; distribution
in commerce; industrial, commercial and consumer uses; and disposal of HHCB in the risk evaluation.
HHCB is manufactured and imported into the United States. HHCB is processed in several ways:
incorporated into formulation, mixture, or reaction products; incorporated into articles; and repackaged.
HHCB is used as an odor agent that is used in several industrial sectors (e.g., miscellaneous
manufacturing; soap, cleaning compound, and toilet preparation manufacturing; plastics material and
resin manufacturing; and all other chemical product and preparation manufacturing). HHCB is used in
several commercial and consumer products, such as air care products, cleaning and furnishing care
products, laundry and dishwashing products, personal care products, plastic and rubber products, and as
aroma chemicals. The consumer uses also include uses in paper products. All personal care products
using HHCB are non-TSCA uses.
Conceptual Model. The conceptual models for HHCB are presented in Section 2.6. Conceptual models
are graphical depictions of the actual or predicted relationships of conditions of use, exposure pathways
(e.g., media), exposure routes (e.g., inhalation, dermal, oral), hazards, and receptors throughout the life
cycle of the chemical substance. EPA plans to focus the risk evaluation for HHCB on the following
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exposures, hazards, and receptors with the understanding that updates may be made in the final scope
document after consideration of public comments and completion of the systematic review data
collection phase.
• Exposures (Pathways and Routes), Receptors and PESS. EPA plans to analyze both human and
environmental exposures and releases to the environment resulting from the conditions of use of
HHCB that EPA plans to consider in the risk evaluation. Exposures for HHCB are discussed in
Section 2.3. EPA identified environmental monitoring data reporting the presence of HHCB in
soil, air, drinking water, and groundwater. Additional information gathered through systematic
review searches will also inform expected exposures.
In Section 2.6.3, EPA presents the conceptual models describing the identified exposures
(pathways and routes), receptors and hazards associated with the conditions of use of HHCB
within the scope of the risk evaluation.
Preliminarily, EPA plans to evaluate the following human and environmental exposure
pathways, routes, receptors and PESS in the scope of the risk evaluation. However, EPA plans to
consider comments received on this draft scope and other reasonably available information when
finalizing this scope document, and to adjust the exposure pathways, exposure routes and
hazards included in the scope document as needed.
Occupational exposure pathways associated with industrial and commercial conditions
of use: EPA plans to evaluate exposures to workers and/or occupational non-users
(ONUs) via the inhalation route and exposures to workers via the dermal route associated
with the manufacturing, processing, use or disposal of HHCB (Section 2.3.5).
Consumer and bystander exposure pathways associated with consumer conditions of use:
EPA plans to evaluate the inhalation and dermal exposure to HHCB for consumers and
bystanders, and dermal exposure to HHCB for consumers during the handling of
automotive care products and plastic and rubber products (Section 2.3.6; Section 2.3.7).
General population pathways: EPA plans to evaluate exposure to HHCB via drinking
water or groundwater, ambient air, fish ingestion for the general population.
Environmental exposure pathways: EPA plans to evaluate exposure to HHCB for aquatic
and terrestrial receptors.
- PESS: EPA plans to include children, women of reproductive age (e.g., pregnant
women), workers, ONUs, consumers, and bystanders as PESS in the risk evaluation
(Section 2.5).
• Hazards. Hazards for HHCB are discussed in Section 2.4. EPA completed preliminary reviews
of information from peer-reviewed assessments and databases to identify potential environmental
and human health hazards for HHCB as part of the prioritization process. Environmental hazard
effects were identified for aquatic and terrestrial organisms. Information collected through
systematic review methods and public comments may identify additional environmental hazards
that warrant inclusion in the environmental hazard assessment of the risk evaluation.
EPA plans to use systematic review methods to evaluate the epidemiological and toxicological
literature for HHCB. Relevant mechanistic evidence will also be considered, if reasonably
available, to inform the interpretation of findings related to potential human health effects and
the dose-repose assessment. EPA plans to evaluate the potential human health hazard for HHCB
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identified during prioritization. The broad health effect category identified during prioritization is
developmental toxicity.
Analysis Plan. The analysis plan for HHCB is presented in Section 2.7. The analysis plan outlines the
general science approaches that EPA plans to use for the various information streams (i.e., chemistry,
fate, release and engineering, exposure, hazard) supporting the risk evaluation. The analysis plan is
based on EPA's knowledge of HHCB to date which includes a partial, but ongoing, review of identified
information as described in Section 2.1. EPA plans to continue to consider new information submitted
by the public. Should additional data or approaches become reasonably available, EPA may update its
analysis plan in the final scope document.
EPA plans to seek public comments on the systematic review methods supporting the risk evaluation for
HHCB, including the methods for assessing the quality of data and information and the approach for
evidence synthesis and evidence integration supporting the exposure and hazard assessments. The
details will be provided in a supplemental document that EPA anticipates releasing for public comment
prior to the finalization of the scope document.
Peer Review. The draft risk evaluation for HHCB will be peer reviewed as described in Section 2.8. Peer
review will be conducted in accordance with relevant and applicable methods for chemical risk
evaluations, including using EPA's Peer Review Handbook and other methods consistent with section
26 of TSCA (See 40 CFR 702.45).
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1 INTRODUCTION
This document presents for comment the scope of the risk evaluation to be conducted for HHCB under
the Frank R. Lautenberg Chemical Safety for the 21st Century Act. The Frank R. Lautenberg Chemical
Safety for the 21st Century Act amended TSCA, the Nation's primary chemicals management law, on
June 22, 2016. The new law includes statutory requirements and deadlines for actions related to
conducting risk evaluations of existing chemicals.
Under TSCA § 6(b), EPA must designate chemical substances as high-priority substances for risk
evaluation or low-priority substances for which risk evaluations are not warranted at the time, and upon
designating a chemical substance as a high-priority substance, initiate a risk evaluation on the substance.
TSCA § 6(b)(4) directs EPA in conducting risk evaluations for existing chemicals, to "determine
whether a chemical substance presents an unreasonable risk of injury to health or the environment,
without consideration of costs or other non- risk factors, including an unreasonable risk to a potentially
exposed or susceptible subpopulation identified as relevant to the risk evaluation by the Administrator
under the conditions of use."
TSCA § 6(b)(4)(D) and implementing regulations require that EPA publish the scope of the risk
evaluation to be conducted, including the hazards, exposures, conditions of use and PESS that the
Administrator expects to consider, within 6 months after the initiation of a risk evaluation. In addition, a
draft scope is to be published pursuant to 40 CFR 702.41. In December 2019, EPA published a list of 20
chemical substances that have been designated high-priority substances for risk evaluations (Docket ID:
EPA-HQ-OPPT-2018-0430), as required by TSCA § 6(b)(2)(B), which initiated the risk evaluation
process for those chemical substances. HHCB is one of the chemicals designated as a high-priority
substance for risk evaluation.
2 SCOPE OF THE EVALUATION
2.1 Reasonably Available Information
EPA conducted a comprehensive search for reasonably available information1 to support the
development of this draft scope document for HHCB. EPA leveraged the data and information sources
already identified in the documents supporting the chemical substance's high-priority substance
designation. In addition, EPA searched for additional data and information on physical and chemical
properties, environmental fate, engineering, exposure, environmental and human health hazards that
could be obtained from the following general categories of sources:
1. Gray literature, which is defined as the broad category of data/information sources not found in
standard, peer-reviewed literature databases;
2. Databases containing publicly available, peer-reviewed literature; and
3. Data and information submitted under TSCA sections 4, 5, 8(e), and 8(d), as well as "for your
information" (FYI) submissions.
1 Reasonably available information means information that EPA possesses or can reasonably generate, obtain, and synthesize
for use in risk evaluations, considering the deadlines specified in TSCA section 6(b)(4)(G) for completing such evaluation.
Information that meets the terms of the preceding sentence is reasonably available information whether or not the information
is confidential business information, that is protected from public disclosure under TSCA section 14 (40 CFR 702.33).
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Following the comprehensive search, EPA performed a title and abstract screening to identify
information potentially relevant for the risk evaluation process. This step also classified the references
into useful categories or tags to facilitate the sorting of information through the systematic review
process. The search and screening process was conducted based on EPA's general expectations for the
planning, execution and assessment activities outlined in the Application of Systematic Review in TSCA
Risk Evaluations document (U.S. EPA, 2018a). EPA will publish supplemental documentation on the
systematic review methods supporting the HHCB risk evaluation to explain the literature and screening
process presented in this document in the form of literature inventory trees. Please note that EPA
focuses on the data collection phase (consisting of data search, data screening, and data extraction)
during the preparation of the TSCA scope document, whereas the data evaluation and integration stages
will occur during the development of the draft risk evaluation and thus are not part of the scoping
activities described in this document.
The subsequent sections summarize the data collection activities completed to date for the general
categories of sources and topic areas (or disciplines) using systematic review methods. EPA plans to
seek public comments on the systematic review methods supporting the risk evaluation for HHCB upon
publication of the supplemental documentation of those methods.
2.1.1 Search of Gray Literature
EPA surveyed the gray literature2 and identified 37 search results relevant to EPA's risk assessment
needs for HHCB. Appendix A lists the gray literature sources that yielded 37 discrete data or
information sources relevant to HHCB. EPA further categorized the data and information into the
various topic areas (or disciplines) supporting the risk evaluation (e.g., physical chemistry,
environmental fate, ecological hazard, human health hazard, exposure, engineering) and the breakdown
is shown in Figure 2-1. EPA is currently identifying additional reasonably available information (e.g.,
public comments), and the reported numbers in Figure 2-1 may change.
Gray Literature Tags by Discipline
Phvsical.Chcmieal
Human. Health. Hazard
12/37
23/37
Exposure
Environmental. I Iazard
25/37
Engineering
0 25 50 75 100
Percent Tagged (%)
Figure 2-1. Gray Literature Tags by Discipline for HHCB
The percentages across disciplines do not add up to 100%, as each source may provide data or information for various topic
areas (or disciplines).
2 Gray literature is defined as the broad category of data/information sources not found in standard, peer-reviewed literature
databases (e.g., PubMed and Web of Science). Gray literature includes data/information sources such as white papers,
conference proceedings, technical reports, reference books, dissertations, information on various stakeholder websites, and
other databases.
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2.1.2 Search of Literature from Publicly Available Databases (Peer-Reviewed Literature)
EPA is currently conducting a systematic review of the reasonably available literature. This includes
performing a comprehensive search of the reasonably available peer review literature on physical-
chemical properties, environmental fate and transport, engineering (environmental release and
occupational exposure), exposure (environmental, general population and consumer) and environmental
and human health hazards of HHCB. Eligibility criteria were applied in the form of PECO (population,
exposure, comparator, outcome) statements. Included references met the PECO criteria, whereas
excluded references did not meet the criteria (i.e., not relevant), and supplemental material was
considered as potentially relevant. EPA plans to analyze the reasonably available information identified
for each discipline during the development of the risk evaluation. The literature inventory trees depicting
the number of references that were captured and those that were included, excluded, or tagged as
supplemental material during the screening process for each discipline area are shown in
Figure 2-2 through Figure 2-6. "TIAB" in these figures refers to title and abstract screening. Note that in
some figures the sum of the numbers for the various sub-categories may be larger than the broader
category because some studies may be included under multiple sub-categories. In other cases, the sum of
the various sub-categories may be smaller than the main category because some studies may not be
depicted in the sub-categories if their relevance to the risk evaluation was unclear.
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Boiling Point
log KOW
Henry's Law Constant
Vapor Pressure
Vapor Density
Retrieved for Full-text
Review
Included for Data
Extraction and Data
Evaluation
Dielectric Constant
Refractive index
Total for T1AB:
P-Chem
Supplemental Information
Exclusion
Exclusion
Figure 2-2. Peer-reviewed Literature - Physical-Chemical Properties Search Results for HHCB.
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Bioconcentration
Biodegradation
Hydrolysis
Photolysis
Retrieved for Full-text
Review
Sorption
347
Volatilization
Total for T1AB:
Fate
Wastewater Treatment
253
Exclusion
Other
Figure 2-3. Peer-reviewed Literature - Fate and Transport Search Results for HHCB.
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Environmental Releases
Included
Figure 2-4. Peer-reviewed Literature - Engineering Search Results for HHCB.
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ambient air (17]
aquatic species {54]
biosolids/sludge (50)
consumer uses and/or products (15)
dietary (10)
drinking water (10)
Excluded (38)
PECO relevant (237)
-W epidemiological/biomonitoring study (22)
Unique HERO IDs (283)
~4 Included (245)
Unclear {•
ground water (19)
Supplemental (0)
indoor air (13)
sediment (47)
soil (14)
surface water (116)
terrestrial species (18]
Figure 2-5. Peer-reviewed Literature - Exposure Search Results for HHCB.
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Human
Human Health Model
Animal
Ecotoxicologicai Model
Plant
44
Retrieved for Full-text
Review
ADME/TK/PBPK
Case Report/Series
427
322
Conference Abstract
Total for T1AB:
Hazard
Exclusion
Field Study
Mechanistic
Mixture
No Original Data
Supplemental
Material
Susceptible Population
Figure 2-6. Peer-reviewed Literature - Hazard Search Results for HHCB.
2.1.3 Search of TSCA Submissions
Table 2-1 presents the results of screening the titles of data sources and reports submitted to EPA under
various sections of TSCA as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century
Act. EPA screened a total of one submission using inclusion/exclusion criteria specific to individual
disciplines (see
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Table 2-1 for the list of disciplines). The details about the criteria are not part of this document but will
be provided in a supplemental document that EPA anticipates releasing prior to the finalization of the
scope document. EPA identified one submission that met the inclusion criteria in these statements and
identified zero submissions with supplemental data. EPA excluded zero submissions. EPA plans to
conduct additional deduplication at later stages of the systematic review process (e.g., full text
screening), when more information regarding the reports is available.
Table 2-1. Results of Title Screening of Submissions to EPA under Various Sections of TSCA
Discipline
Included
Supplemental
Physicochemical Properties
0
0
Environmental Fate and Transport
0
0
Environmental and General Population
Exposure
0
0
Occupational Exposure/Release
Information
0
0
Environmental Hazard
0
0
Human Health Hazard
1
0
2.2 Conditions of Use
As described in the Proposed Designation o f 1,3,4,6,7,8-Hexahych
Hexamethvlcyclopentafvl-2-Benzovvran (HHCB; CASRN1222-01 a Hieh-Priority Substance for
Risk Evaluation (U.S. EPA, 2019a), EPA assembled information from the Chemical Data Reporting
(CDR) program to determine conditions of use3 or significant changes in conditions of use of the
chemical substance. EPA also consulted a variety of other sources to identify uses of HHCB, including
published literature, company websites, and government and commercial trade databases and
publications. To identify formulated products containing HHCB, EPA searched for safety data sheets
(SDS) using internet searches, EPA Chemical and Product Categories (CPCat) data, and other resources
in which SDSs could be found. SDSs were cross-checked with company websites to make sure that each
product SDS was current. In addition, EPA incorporated communications with companies, industry
groups, and public comments to supplement the condition of use information.
EPA identified and described the categories and subcategories of conditions of use that EPA plans to
include in the scope of the risk evaluation (Section 2.2.1; Table 2-2). The conditions of use included in
the scope are those reflected in the life cycle diagrams and conceptual models.
After gathering reasonably available information related to the manufacture, processing, distribution in
commerce, use, and disposal of HHCB, EPA identified those activities for HHCB the Agency
determined not to be conditions of use or will otherwise be excluded during scoping. These activities are
described in Section 2.2.2.
3 Conditions of use means the circumstances, as determined by the Administrator, under which a chemical substance is
intended, known, or reasonably foreseen to be manufactured, processed, distributed in commerce, used, or disposed of.
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2.2.1 Categories and Subcategories of Conditions of Use Included in the Scope of the Risk
Evaluation
Table 2-2 lists the conditions of use that are included in the scope of the risk evaluation.
Table 2-2. Categories and Subcategories of Conditions of Use Included in the Scope of the Risk
Evaluation
l.ile Cycle
Stage
Category
Subcategory
Reference
Manufacture
Domestic manufacture
Domestic manufacture
CDRU.S. EPA (2019d)
Import
Import
CDRU.S. EPA (2019d)
Processing
Processing -
incorporation into
formulation, mixture or
reaction product
Odor agent (in all other chemical
product and preparation
manufacturing; miscellaneous
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; other: fragrance
mixtures and fragrance raw
material)
CDRU.S. EPA (2019d)
Processing -
incorporation into
articles
Odor agent (in plastics material
and resin manufacturing)
CDRU.S. EPA (2019d)
Repackaging
Odor agent (in all other chemical
product and preparation
manufacturing)
CDRU.S. EPA (2019d)
Recycling
Recycling
CDRU.S. EPA (2019d)
Distribution
in commerce
Distribution in
commerce
Distribution in commerce
Commercial
Use
Air care products (e.g.
aroma chemicals)
Air fresheners for motor vehicles
CDRU.S. EPA (2019d)
Continuous action air fresheners
(e.g. scented candles and solid/gel
air fresheners)
CDRU.S. EPA (2019d);
EPA-HO-OPPT-2018-0430-
001.2 (Fragrance Creators
Association ,2019)
Instant action air fresheners
(aerosol and sprays)
CDRU.S. EPA (2019d);
EPA-HO-OPPT-2018-0430-
0012 (Fragrance Creators
Association ,2019)
Cleaning and furnishing
care products
Cleaning products, including all-
purpose liquid cleaner and
bathroom cleaners (liquid, aerosol,
foam, and spray cleaners)
CDRU.S. EPA (2019d)
Laundry and
dishwashing products
Laundry products, including liquid
laundry detergent and fabric
softener
CDRU.S. EPA (2019d);
EPA-HO-OPPT-2018-0430-
0013 (Earthjustice, 2019)
Plastic and rubber
products not covered
elsewhere
Plastic and rubber products
CDRU.S. EPA (2019d)
Other use
Laboratory chemicals
Sigma-Aldrich (2019)
19
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Air fresheners for motor vehicles
CDR U.S. EPA (2019d)
Air care products (e.g.
aroma chemicals)
Continuous action air fresheners
(e.g. scented candles)
CDR U.S. EPA (2019d);
EPA-HO-OPPT-2018-0430-
0012 (Fragrance Creators
Association ,2019)
Instant action air fresheners
(aerosol and sprays)
CDR U.S. EPA (2019d);
EPA-HO-OPPT-2018-0430-
0012 (Fragrance Creators
Association ,2019)
Consumer
use
Cleaning and furnishing
care products
Cleaning products, including all-
purpose liquid cleaner and
bathroom cleaners (liquid, aerosol,
foam, and spray cleaners)
CDR U.S. EPA (2019d)
Laundry and
dishwashing products
Laundry products, including liquid
laundry detergent and fabric
softener
CDR U.S. EPA (2019d);
EPA-HO-OPPT-2018-0430-
0013 (Earthjustice, 2019)
Paper products
Paper products
CDR U.S. EPA (2019d)
Plastic and rubber
products not covered
elsewhere
Plastic and rubber products
CDR U.S. EPA (2019d)
Disposal
Disposal
Disposal
• Life Cycle Stage Use Definitions (40 CFR § 711.3)
"Industrial use" means use at a site at which one or more chemicals or mixtures are manufactured (including
imported) or processed. In the Proposed Designation of 1.3,4,6,7,8-Hexahvdro-4,6,6,7,8,8-
HexamethylcychpentafyJ-2-Benzopyran (HHCB; CASRN1222-05-5) as a High-Priority Substance for Risk
Evaluation (U.S. EPA, 2019a), there is an industrial use reported for HHCB as surface active agent. After further
communication with the industry reporting the use, EPA has concluded that the correct classification of the use of
HHCB is "commercial use" and "consumer use" in cleaning and furnishing care products and in laundry and
dishwashing products (EPA-HQ-OPPT-2018-0430-0018).
"Commercial use" means the use of a chemical or a mixture containing a chemical (including as part of an article)
in a commercial enterprise providing saleable goods or services.
"Consumer use" means the use of a chemical or a mixture containing a chemical (including as part of an article,
such as furniture or clothing) when sold to or made available to consumers for their use.
Although EPA has identified both industrial and commercial uses here for purposes of distinguishing scenarios in this
document, the Agency interprets the authority over "any manner or method of commercial use" under TSCA section
6(a)(5) to reach both.
• These categories of conditions of use appear in the Life Cycle Diagram, reflect CDR codes, and broadly represent
conditions of use of HHCB in industrial and/or commercial settings.
• These subcategories reflect more specific uses of HHCB.
• The Agency has included information in this draft scope document sourced from the 2012 and 2016 Chemical Data
Reporting (CDR) Rule collections. In instances where particular CDR data elements included in this document were
claimed as confidential business information (CBI), the Agency reviewed the claims and secured their declassification.
2.2.2 Activities Excluded from the Scope of the Risk Evaluation
As explained in the final rule, Procedures for Chemical Risk Evaluation Under the Amended Toxic
Substances Control Act, TSCA section 6(b)(4)(D) requires EPA to identify the hazards, exposures,
conditions of use, and the PESS the Administrator expects to consider in a risk evaluation, suggesting
that EPA may exclude certain activities that it determines to be conditions of use on a case-by-case basis
20
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(82 FR 33726, 33729; July 20, 2017). TSCA section 3(4) also grants EPA the authority to determine
what constitutes a condition of use for a particular chemical substance. EPA does not plan to include in
this scope or in the risk evaluation the activities described below that the Agency has concluded do not
constitute conditions of use.
HHCB is used in personal care products. After reviewing the public comments received during
prioritization and additional outreach to the commenters and consultations with the U.S. Federal Food
and Drug Administration, EPA determined that HHCB use in personal care products, including soaps,
meets the definition of cosmetic in section 201 of the Federal Food, Drug, and Cosmetic Act, 21 U.S.C.
§ 321, and are therefore excluded from the definition of "chemical substance" in TSCA § 3(2)(B)(vi) 4
Activities and releases associated with such personal care products use are therefore not "conditions of
use" (defined as circumstances associated with "a chemical substance," TSCA § 3(4)) and will not be
evaluated during risk evaluation.
2.2.3 Production Volume
As reported to EPA during the 2016 CDR reporting period and described here as a range to protect
production volumes that were claimed as confidential business information (CBI), total production
volume of HHCB in 2015 was between 1 million and 10 million pounds (U.S. EPA, 2017a). EPA also
considered pre-2015 CDR production volume information, as detailed in the Proposed Designation of
ihydro-4,6,6,7,8,8-Hexcmethylcyclopen1afy1-2-Benzopyran (HHCB; CASRN1222-05-5}
as a Hish-Priority Substance for Risk Evaluation (U.S. EPA, 2019a), and will include future production
volume information as it becomes available to support the environmental release assessment.
2.2.4 Overview of Conditions of Use and Lifecycle Diagram
This section provides a brief overview of the industrial, commercial, and consumer use categories
included in the life cycle diagram (Figure 2-7. HHCB Life Cycle Diagram). The life cycle diagram
depicts the conditions of use that EPA plans to consider in the risk evaluation for the various life cycle
stages as presented in Section 2.2.1. Appendix E contains more detailed descriptions (e.g., process
descriptions, worker activities, process flow diagrams) for each manufacture, processing, distribution in
commerce, use and disposal category.
The information in the life cycle diagram is grouped according to the CDR processing codes and use
categories (including functional use codes for industrial uses and product categories for industrial,
commercial and consumer uses).5 The production volume of HHCB in 2015 is included in the lifecycle
diagram, as reported to EPA during the 2016 CDR reporting period.
4 Chemical substance means any organic or inorganic substance of a particular molecular identity, including any combination
of such substances occurring in whole or in part as a result of a chemical reaction or occurring in nature, and any element or
uncombined radical. Chemical substance does not include (1) any mixture; (2) any pesticide (as defined in the Federal
Insecticide, Fungicide, and Rodenticide Act) when manufactured, processed, or distributed in commerce for use as a
pesticide; (3) tobacco or any tobacco product; (4) any source material, special nuclear material, or byproduct material (as
such terms are defined in the Atomic Energy Act of 1954 and regulations issued under such Act); (5) any article the sale of
which is subject to the tax imposed by section 4181 of the Internal Revenue Code of 1954 (determined without regard to any
exemptions from such tax provided by section 4182 or 4221 or any other provision of such Code), and; (6) any food, food
additive, drug, cosmetic, or device (as such terms are defined in section 201 of the Federal Food, Drug, and Cosmetic Act)
when manufactured, processed, or distributed in commerce for use as a food, food additive, drug, cosmetic, or device.
5 The descriptions are primarily based on the corresponding industrial function category and/or commercial and consumer
product category descriptions and can be found in EPA's Instructions for Reporting 20.1.6 TSCA Chemical Data Reporting.
21
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MFG/IMPORT
Manufacture
(Including
Import)
(lM-lOMlbs)
l,3,4,6,7,8-HEXAHYDRO-4,6,6,7,8,8-HEXAMETHYLCYCLOPENTA [G]-2-BENZOPYRAN (HHCB) (CAS RN 1222-05-5)
PROCESSING INDUSTRL4L, COMMERCIAL, CONSUMER USES RELEASES and WASTE DISPOSAL
I
Incorporation into Formulation,
Mixture, or Reaction Product
Odor agent in: All other chemical
product and preparation
manufacturing; Miscellaneous
manufacturing; Soap, cleaning
compound, and toilet preparation
manufacturing; Other: fragrance
mixtures and fragrance raw materials
Incorporation into Article
Odor agent in plastics and resin
manufacturing
Repackaging
Odor agent in all other chemical
product and preparation
manufacturing
X
Air Care Products1,2
e.g. air fresheners for motor vehicles, continuous action air
fresheners, instant action air fresheners
Cleaning and Furnishing Care Products1,2
e.g., cleaning products (all-purpose cleaner and bathroom cleaners,
both liquid and spray)
Laundry and Dishwashing Products1,2
e.g.. laundry and dishwashing detergent and fabric softeners
Paper Products2
e.g., odor agent in packaging (excluding food packaging)
Plastic and Rubber Products1,2
e.g., odor agent in commercial plastic and rubber products
t
Other Use1,2
e.g., laboratory chemical
Recycling
Disposal
See Conceptual
Model for
Environmental
Releases and Wastes
~
~
~
Manufacture
(Including
Import)
Processing
Uses:
1. Industrial
and/or
Commercial
2. Consumer
Figure 2-7. IIHCB Life Cycle Diagram
Volume is not depicted in the life cycle diagram for processing and industrial, commercial, and consumer uses as specific CDR production volumes are
claimed CBI or withheld pursuant to TSCA section § 14. Non-TSCA uses are excluded.
22
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2.3 Exposures
For TSCA exposure assessments, EPA plans to analyze exposures and releases to the environment
resulting from the conditions of use within the scope of the risk evaluation for of HHCB. Release
pathways and routes will be described to characterize the relationship or connection between the
conditions of use of the chemical and the exposure to human receptors, including PESS, and
environmental receptors. EPA plans to consider, where relevant, the duration, intensity (concentration),
frequency, and number of exposures in characterizing exposures to HHCB.
2.3.1 Physical and Chemical Properties
Consideration of physical and chemical properties is essential for a thorough understanding or prediction
of environmental fate (i.e., transport and transformation) and the eventual environmental concentrations.
They can also inform the hazard assessment. EPA plans to use the physical and chemical properties
presented in Appendix B, which are the same as those described in the Proposed Designation of
I _ > '< ' ahydro-4,6,6,7,8,8-Hexcmethvlcvclomnta[y1-2-Bemowri • • • i H * »
as a Hieh-Priority Substance for Risk Evaluation (U.S. EPA, 2019a), to support the development of the
risk evaluation for HHCB. The values for the physical and chemical properties (Appendix B) may be
updated as EPA collects additional information through systematic review methods.
2.3.2 Environmental Fate and Transport
Understanding of environmental fate and transport processes assists in the determination
of the specific exposure pathways and routes and human and environmental receptors that need to be
assessed in the risk evaluation for HHCB. EPA plans to use the environmental fate characteristics
presented in Appendix C, which are the same as those described in the Proposed Designation o f
1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-Hexcmtethvlcvclopentafy1-2-Benzotfwc
as a High-Priority Substance for Risk Evaluation (U.S. EPA, 2019a), to support the development of the
risk evaluation for HHCB. The values for the environmental fate properties (Appendix C) may be
updated as EPA collects additional information through systematic review methods.
2.3.3 Releases to the Environment
Releases to the environment from conditions of use are a component of potential exposure and may be
derived from reported data that are obtained through direct measurement, calculations based on
empirical data and/or assumptions and models.
For all conditions of use, EPA plans to review gray literature data sources identified in Appendix A
during risk evaluation using systematic review evaluation strategies for environmental releases and
occupational exposure data sources. EPA includes TRI data in TSCA existing chemical assessments, but
HHCB is not a TRI-listed chemical and thus TRI data are not available for it. As systematic review
continues for HHCB, published literature will identify potential routes of release of HHCB to the
environment. EPA may also reference the Organisation for Economic Co-operation and Development
(OECD) Emission Scenario Document (ESD) on the Blending of Fragrance Oils into Commercial and
Consumer Products to evaluate releases from applicable conditions of use.
According to the ESD on The Blending of Fragrance Oils into Commercial and Consumer Products,
there may be releases of HHCB from industrial sites to wastewater treatment plants (WWTP), surface
water, air, incineration, and landfills (OECD, 2010). Additional releases may occur from the commercial
and consumer use of products containing HHCB. HHCB use in cleaning products may result in releases
to POTWs. The spraying of air fresheners, use of wax melts, scented candles, or solid air fresheners
23
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containing HHCB may release HHCB into indoor air. HHCB formulated into plastic or paper products,
may be either incinerated or sent to a landfill.
EPA plans to review these data in conducting the exposure assessment component of the risk evaluation
for HHCB.
2.3.4 Environmental Exposures
The manufacturing, processing, distribution, use and disposal of HHCB can result in releases to the
environment and exposure to aquatic and terrestrial receptors (biota). Environmental exposures to biota
are informed by releases into the environment, overall persistence, degradation, and bioaccumulation,
and partitioning across different media. Concentrations of chemical substances in biota provide evidence
of exposure. EPA plans to review reasonably available information on environmental exposures in biota
to inform the development of the environmental exposure assessment for HHCB.
2.3.5 Occupational Exposures
EPA plans to analyze worker activities where there is a potential for exposure under the conditions of
use described in Section 2.2.1. In addition, EPA plans to analyze exposure to (ONUs; i.e., workers, who
do not directly handle the chemical but perform work in an area where the chemical is present). EPA
also expects to consider the effect(s) that engineering controls (EC) and/or personal protective
equipment (PPE) have on occupational exposure levels as part of the draft risk evaluation.
Worker activities associated with the conditions of use within the scope of the risk evaluation for HHCB
that will be analyzed include, but are not limited to:
• Unloading and transferring HHCB to and from storage containers to process vessels;
• Handling, transporting and disposing of waste containing HHCB;
• Cleaning and maintaining equipment;
• Using HHCB in process equipment (e.g., applicators, process vessels);
• Applying formulations and products containing HHCB onto substrates (e.g., spray applying
cleaning and deodorizing products containing HHCB);
• Sampling chemicals, formulations or products containing HHCB for quality control;
• Repackaging chemicals, formulations or products containing HHCB; and
• Performing other work activities in or near areas where HHCB is used.
HHCB is a liquid with a vapor pressure of 5.45 x 10"4 mm Hg at 25°C. HHCB's vapor pressure and use
as a fragrance chemical indicates the potential for inhalation exposure of workers and ONUs to vapors
generated by the liquid at ambient room temperature conditions. Additionally, there is the potential for
inhalation exposure to mists generated from use in spraying/aerosol products (e.g., liquid spray
cleaners).
EPA generally does not evaluate occupational exposures through the oral route because oral exposure is
typically incidental in nature. Workers may inadvertently transfer chemicals from their hands to their
mouths, ingest inhaled particles that deposit in the upper respiratory tract or consume contaminated
food, the frequency and significance of this exposure route are dependent on several factors including
the p-chem properties of the substance during expected worker activities, workers' awareness of the
chemical hazards, the visibility of the chemicals on the hands while working, workplace practices, and
personal hygiene that is difficult to predict (Cherrie et al., 2006). However, EPA will consider oral
exposure on a case-by-case basis for certain COUs and worker activities where there is information and
24
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data on incidental ingestion of inhaled dust. EPA will consider ingestion of inhaled dust as an inhalation
exposure for HHCB.
Based on the conditions of use, EPA plans to evaluate dermal exposures for workers because workers
are expected to have skin contact with solids and liquids. ONUs do not directly handle HHCB; therefore,
skin contact with liquid HHCB is not expected for ONUs.
2.3.6 Consumer Exposures
EPA plans to be evaluating consumer uses of HHCB in air care products, cleaning and furnishing care
products, laundry and dishwashing products, paper products and plastic and rubber products, and other
products (e.g. laboratory chemicals).
Consumers using or disposing of these products, and bystanders may be exposed to HHCB in vapors
which may lead to inhalation exposure. In addition, consumers using or disposing of air care, cleaning
and furnishing products and bystanders may also be exposed to HHCB in mists which may lead to
inhalation exposure. Furthermore, consumers using or disposing of cleaning and furnishing products and
laundry and dishwashing products. Bystanders may be exposed to HHCB in powders and dusts which
may lead to inhalation exposure. Lastly, consumers using or disposing of cleaning and furnishing care
products, laundry and dishwashing products, and other products including laboratory chemicals may be
exposed to HHCB in liquids which may lead to dermal exposure.
The estimated exposure to HHCB on the skin from the use of a combination of all classes of consumer
products on a daily basis was calculated by a European Union (EU) assessment to result in a "worst case
situation" of 0.85 mg/kg body weight per day (EU. 2008). The inhalation exposure of consumers to
HHCB in household cleaning products and air fresheners was estimated as lower, in total 0.0085 mg/kg
body weight per day (EU. 2008). The 2008 EU assessment concluded there was no need for further
information and/or testing and no need for risk reduction measures beyond those already being applied
for consumers (ELI. 2008).
EPA does not expect consumers nor bystanders to receive significant oral exposures to HHCB. In
addition, EPA does not expect bystanders to receive a significant amount of dermal exposure to HHCB.
2.3.7 General Population Exposures
Monitoring data were identified in EPA's data search for HHCB and can be used in the exposure
assessment. Relevant and reliable monitoring studies provide information that can be used in an
exposure assessment. Monitoring studies that measure environmental concentrations or concentrations
of chemical substances in biota provide evidence of exposure.
EPA plans to review reasonably available environmental monitoring data for HHCB. The U.S.
Geological Survey (USGS) Monitoring Data - National Water Quality Monitoring Council (NWQMC)
has identified HHCB in sediment, soil, ground water, and surface water (USGS, 1991a-e). Research
suggests moderate-range (regional) atmospheric transport of HHCB may occur, although long-range
transport is unlikely (U.S. EPA. 2014). HHCB was identified in filtered and non-filtered drinking water.
Measured concentrations within aquatic organisms and birds were also reported ( 14).
Releases of HHCB from specific conditions of use, such as consumer and commercial uses, product
processing through fragrance compounding, and end-product formulation, disposal, or waste treatment
activities may result in general population exposures due to ingestion of contaminated drinking water
near industrial processing sites ( 014. EU, 2008). Human exposure through ingestion of
25
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water and food including fish, root crops, and mother's milk was noted in a 2014 assessment as the main
route of exposure to humans. Exposure via inhalation route to the general population was considered to
be negligible, according to the 2014 EPA assessment (U.S. EPA. 2014). Currently, EPA is considering
oral exposure in its assessment of HHCB for the general population. However, an EU assessment
concluded there was no need for further information and/or testing and no need for risk reduction
measures beyond those already applied for the general population exposed via the environment (EU.
2008).
2.4 Hazards (Effects)
2.4.1 Environmental Hazards
As described in the Proposed Designation o f 1,3,4,6,7,8-Hexahydi
Hexamethylcyclownlaf yl-2-Benzomran (.HHCB: CASRN1222-05-5) as a High-Priority Substance for
Risk Evaluation (U.S. EPA 2019a), EPA considered reasonably available information from peer-
reviewed assessments and databases to identify potential environmental hazards for HHCB. EPA
considers all the potential environmental hazards for HHCB identified during prioritization (U.S. EPA
2019a) to be relevant for the risk evaluation and thus they remain within the scope of the evaluation.
EPA is in the process of identifying additional reasonably available information through systematic
review methods and public comments, which may update the list of potential environmental hazards
associated with HHCB. If necessary, EPA plans to update the list of potential hazards in the final scope
document of HHCB. Based on information identified during prioritization, environmental hazard effects
were identified for aquatic and terrestrial organisms.
2.4.2 Human Health Hazards
As described in the Proposed Designation of 1,3,4,6,7,8-Hexahydi
Hexamethylcvclopentaf yJ-2-Benzopwan (HHCB; CASRN 1222-05-5) as a High-Priority Substance for
Risk Evaluation (U.S. EPA 2019a), EPA considered reasonably available information from peer-
reviewed assessments and databases to identify potential human health hazards for HHCB. The health
effect categories screened for during prioritization included acute toxicity, irritation/corrosion, dermal
sensitization, respiratory sensitization, genetic toxicity, repeated dose toxicity, reproductive toxicity,
developmental toxicity, immunotoxicity, neurotoxicity, carcinogenicity, epidemiological or
biomonitoring studies and ADME. EPA plans to evaluate all of the potential human health hazards for
HHCB identified during prioritization. The broad health effect category identified during prioritization
was developmental toxicity. EPA is in the process of identifying additional reasonably available
information through systematic review methods and public input, which may update the list of potential
human health hazards under the scope of the risk evaluation. If necessary, EPA plans to update the list of
potential hazards in the final scope document of the HHCB risk evaluation.
2.5 Potentially Exposed or Susceptible Subpopulations
TSCA § 6(b)(4) requires EPA to determine whether a chemical substance presents an unreasonable risk
to "a potentially exposed or susceptible subpopulation identified as relevant to the risk evaluation."
TSCA §3(12) states that "the term 'potentially exposed or susceptible subpopulation' means a group of
individuals within the general population identified by the Administrator who, due to either greater
susceptibility or greater exposure, may be at greater risk than the general population of adverse health
effects from exposure to a chemical substance or mixture, such as infants, children, pregnant women,
workers, or the elderly." General population is "the total of individuals inhabiting an area or making up a
whole group" and refers here to the U.S. general population ( 011a).
26
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During the prioritization process, EPA identified the following PESS based on CDR information and
studies reporting developmental and reproductive effects: children (including those who consume breast
milk), women of reproductive age (e.g., pregnant women), workers (including ONUs), and consumers
(U.S. EPA 2019d). In addition, preliminary information indicates that HHCB may bioaccumulate in fish
(Appendix C); thus, populations with elevated fish ingestion are considered potentially exposed or
susceptible. EPA plans to evaluate these PESS in the risk evaluation.
In developing exposure scenarios, EPA plans to analyze reasonably available information to ascertain
whether some human receptor groups may be exposed via exposure pathways that may be distinct to a
particular subpopulation or life stage (e.g., children's crawling, mouthing or hand-to-mouth behaviors)
and whether some human receptor groups may have higher exposure via identified pathways of
exposure due to unique characteristics (e.g., activities, duration or location of exposure) when compared
with the general population ( 006a). Likewise, EPA plans to evaluate available human health
hazard information to ascertain whether some human receptor groups may have greater susceptibility
than the general population to the chemical's hazard(s).
2.6 Conceptual Models
In this section, EPA presents the conceptual models describing the identified exposures (pathways and
routes), receptors and hazards associated with the conditions of use of HHCB. Pathways and routes of
exposure associated with workers and ONUs are described in Section 2.6.1, and pathways and routes of
exposure associated with consumers are described in Section 2.6.2. Pathways and routes of exposure
associated with environmental releases and wastes are discussed and depicted the conceptual model
shown in Section 2.6.3.
2.6.1 Conceptual Model for Industrial and Commercial Activities and Uses
Figure 2-8. HHCB Conceptual Model for Industrial and Commercial Activities and Uses: Worker and
ONU Exposures and Hazards illustrates the conceptual model for the pathways of exposure from
industrial and commercial activities and uses of HHCB that EPA plans to include in the risk evaluation.
There are exposures to workers and/or ONUs via inhalation routes and/or exposures to workers via
dermal routes for all conditions of use identified in this scoping document. The conceptual model
includes potential inhalation exposures to HHCB through vapor, mists, and dusts, and dermal exposures
through contact with solid and liquid HHCB. In addition to the pathways illustrated in the figure, EPA
plans to evaluate activities resulting in exposures associated with distribution in commerce (e.g. loading,
unloading) throughout the various lifecycle stages and conditions of use (e.g. manufacturing, processing,
industrial use, commercial use, disposal) rather than a single distribution scenario.
For each condition of use identified in Section 2.2, an initial determination was made as to whether each
combination of exposure pathway, route, and receptor will be analyzed in the risk evaluation. The results
of that analysis along with the supporting rationale are presented in Appendix F.
27
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INDUSTRIAL AND COMMERCIAL PATHWAY EXPOSURE ROUTE RECEPTORS HAZARDS
ACTIVITIES /USES
Processing:
• Formulation into products:
¦ Incorporation into articles:
• Repackaging:
Liquid/Solid Contact
Dennal
Hazards potentially
associated with acute
and'or chronic
exposures
Workers,
Occupational
Non-Users
Fugitive
Air
Vap orMistDust
Use of Air Care Products
Inhalation
Use of Cleaning and Furnishing Care Products
Use of Laundry and Dishwashing Products
Use of Plastic and Rubber Products
Other Use
Workers.
Occupational
Non-Users
Waste Handling;
Treatment and
Disposal*
Vapor. Liquid'Solid.
Dust Contact
¦XDermaL Inhalation
Aqueous Wastes, Hazai'dous and Other So I id Wastes*
(See Conceptual Model for Env ironmental Releases and
* Includes wastes from industrial, commercial and consumer uses.
Wastes)
Figure 2-8. HHCB Conceptual Model for Industrial and Commercial Activities and Uses: Worker and ONU Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human receptors from industrial and commercial activities and uses of HHCB.
a Receptors include PESS (see Section 2.5).
b When data and information are available to support the analysis, EPA also considers the effect that EC and/or PPE have on occupational exposure level
28
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2.6.2 Conceptual Model for Consumer Activities and Uses
The conceptual model in Figure 2-9 presents the exposure pathways, exposure routes and hazards to
human receptors from consumer activities and uses of HHCB that EPA plans to include in the risk
evaluation. Inhalation is expected to be the primary route of exposure for consumers and plans to
evaluate inhalation exposures to HHCB vapors, mists, and dusts for consumers and bystanders. EPA
plans to evaluate dermal exposures via mists and direct contact to HHCB during the consumer uses of
the product types listed in Figure 2-9. Consumer oral exposures via mists and powders or dust
containing HHCB during use is expected to be negligible. As a result, oral ingestion of HHCB will not
be evaluated for consumers. In addition, since bystanders are not expected to have significant direct
dermal or oral contact to HHCB, these pathways will not be evaluated for bystanders. The supporting
rationale for consumer pathways that are in scope for HHCB are included in 2.8Appendix G.
29
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CONSUMER ACTIVITIES 8 EMOSTra: RECEPTORS HAZAKDS
Paper Products
Liquid Contact y
Dermal
Plastic and Rubber
Products
Air Care Products
^ Vapor Mist
Cleaning and
Furnishing Care
Products
Laundry and
Dishwashing Products
Other (e.g., laboratory
chemicals)
Wastewater, Liquid Wastes and Solid
Wastes (See Em'tmrnnemalReleases
Conceptual Mode's)
Consumer Handling of
Disposal and Waste
Hazards Potentially 1
Associated with
Acute and/or
Chronic Exposures J
Figure 2-9. HHCB Conceptual Model for Consumer Activities and Uses: Consumer Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human receptors from consumer activities and uses of HI-ICB.
a Receptors include PESS (see Section 2.5).
30
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2.6.3 Conceptual Model for Environmental Releases and Wastes: Potential Exposures
and Hazards
The conceptual model in Figure 2-10 presents the potential exposure pathways, exposure routes and
hazards to human and environmental receptors from releases and waste streams associated with
industrial, commercial and consumer uses of HHCB.
EPA plans to evaluate exposures to receptors (e.g., general population, aquatic, terrestrial species) that
may occur from industrial and/or commercial and consumer releases to air, drinking water, ground
water, and land, including biosolids and soil. Some aquatic species may be exposed to HHCB by
consuming sediments and swimming in water bodies in which HHCB is found. Some terrestrial species
may be exposed to HHCB via air and soil found in their natural habitats. Furthermore, the general
population may receive oral exposure to HHCB via fish ingestion and drinking water. They may also
receive dermal exposure to HHCB through recreational actives such as swimming in surface water
bodies. In addition, they may receive inhalation exposures to HHCB through vapor emissions from soil
or recycled wastes. The supporting rationale for general population and environmental pathways
considered for HHCB are included in 2.8Appendix H.
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RELEASES AND WASTES FROM INDUSTRIAL /
COMMERCIAL / CONSUMER USES
EXPOSURE PATHWAYS
EXPOSURE ROUTES
RECEPTORS
Industrial Pre
Treatment or
Industrial WWT
water. Sediment
indirect discharge
t
Aquatic
Kisli Ingestion
Species
wastewater or
POTW
Liquid wastes
Underground
Injection
Dnnkin
Water
Biosolids
Hazardous and
Municipal Waste
Landfill
Land
Disposal
Cicncral
Population
U round
Water
Solid Wastes
iquid Wastes
Hazardous and
Municipal Waste
Incinerators
.::l .i l ' i
ugitive Emissions
Off-site Waste
Transfer
I'crrcstrial
Species
Recycling, Other
Treatment
Emissions to Air
Hazards Potentially
Associated with
Acute and/or Chronic
Exposures
Figure 2-10. HHCB Conceptual Model for Environmental Releases and Wastes: Environmental Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human receptors from releases and wastes from industrial, commercial, and
consumer uses of HHCB that EPA plans to consider in the risk evaluation.
" Industrial wastewater or liquid wastes may be treated on-site and then released to surface water (direct discharge), or pre-treated and released to POTW (indirect
discharge). For consumer uses, such wastes may be released directly to POTW. Drinking water will undergo further treatment in drinking water treatment plant.
Groundwater may also be a source of drinking water.
b Receptors include PESS (see Section 2.5).
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2.7 Analysis Plan
The analysis plan is based on EPA's knowledge of HHCB to date which includes a partial, but not
complete review of reasonably available information as described in Section 2.1. EPA encourages
submission of additional data, such as full study reports or workplace monitoring from industry sources,
that may be relevant for EPA's evaluation of conditions of use, exposures, hazards and PESS during risk
evaluation. Further, EPA may consider any relevant CBI in a manner that protects the confidentiality of
the information from public disclosure. EPA plans to continue to consider new information submitted by
the public. Should additional data or approaches become reasonably available, EPA may update its
analysis plan in the final scope document.
2.7.1 Physical and Chemical Properties and Environmental Fate
EPA plans to analyze the p-chem properties and environmental fate and transport of HHCB as follows:
1) Review reasonably available measured or estimated p-chem and environmental fate
endpoint data collected using systematic review procedures and, where available,
environmental assessments conducted by other regulatory agencies.
EPA plans to review data and information collected through the systematic review methods and
public comments about the p-chem properties (Appendix B) and fate endpoints (Appendix C)
previously summarized in the Proposed Designation o f 1,3,4,6,7,8-Hexahych
Hexamethylcvclowntaf yJ-2-Benzopwan (HHCB; CASi 2-05-5) as a Hieh-Priority
Substance for Risk Evaluation (U.S. EPA 2019a). All sources cited in EPA's analysis will be
evaluated according to the procedures described in the systematic review documentation that
EPA plans to publish prior to finalizing the scope document. Where the systematic review
process fails to identify experimentally measured chemical property values of sufficiently high
quality, these values will be estimated using chemical parameter estimation models as
appropriate. Model-estimated fate properties will be reviewed for applicability and quality.
2) Using measured data and/or modeling, determine the influence of p-chem properties and
environmental fate endpoints (e.g., persistence, bioaccumulation, partitioning, transport)
on exposure pathways and routes of exposure to human and environmental receptors.
Measured data and, where necessary, model predictions of p-chem properties and environmental
fate endpoints will be used to characterize the persistence and movement of HHCB within and
across environmental media. The fate endpoints of interest include volatilization, sorption to
organic matter in soil and sediments, water solubility, aqueous and atmospheric photolysis rates,
aerobic and anaerobic biodegradation rates, and potential bioconcentration and bioaccumulation.
These endpoints will be used in exposure calculations.
3) Conduct a weight-of-evidence evaluation of p-chem and environmental fate data, including
qualitative and quantitative sources of information.
During risk evaluation, EPA plans to evaluate and integrate the p-chem and environmental fate
evidence identified in the literature inventory using the methods described in the systematic
review documentation that EPA plans to publish prior to finalizing the scope document.
2.7.2 Exposure
EPA plans to analyze exposure levels to HHCB via indoor air, ambient air, surface water, groundwater,
sediment, and soil for aquatic and terrestrial biota associated with exposure to HHCB. EPA has not yet
determined the exposure levels in these media or how they may be used in the risk evaluation. Exposure
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scenarios are sources (uses), exposure pathways, and exposed receptors. Draft release/exposure
scenarios corresponding to various conditions of use for HHCB are presented in Appendix F. EPA plans
to analyze scenario-specific exposures.
Based on their physical-chemical properties, expected sources, and transport and transformation within
the outdoor and indoor environment, chemical substances are more likely to be present in some media
and less likely to be present in others. Exposure level(s) can be characterized through a combination of
reasonably available monitoring data and modeling approaches.
2.7.2.1 Environmental Releases
EPA plans to analyze releases to environmental media as follows:
1) Review reasonably available published literature and other reasonably available
information on processes and activities associated with the conditions of use to analyze the
types of releases and wastes generated.
EPA has reviewed some key data sources containing information on processes and activities
resulting in releases, and the information found is described in Appendix E. EPA plans to
continue to review data sources identified in Appendix E during risk evaluation using the
evaluation strategy in the systematic review documentation that EPA plans to publish prior to
finalizing the scope document. Potential sources of environmental release data are summarized
in Table 2-3.
Table 2-3. Categories and Sources of Environmental Release Data
U.S. EPA Generic Scenarios
OECD Emission Scenario Documents
EU Risk Assessment Reports
2) Review reasonably available chemical-specific release data, including measured or
estimated release data (e.g., data from risk assessments by other environmental agencies).
EPA has reviewed key release data sources as summarized in Section 2.3.3. EPA plans to
continue to review relevant data sources during risk evaluation. EPA plans to match identified
data to applicable conditions of use and identify data gaps where no data are found for specific
conditions of use. EPA plans to attempt to address data gaps identified as described in steps 3
and 4 below by considering potential surrogate data and models.
Additionally, for conditions of use where no measured data on releases are available, EPA may
use a variety of methods including release estimation approaches and assumptions in the
Chemical Screening Tool for Occupational Exposures and Releases (Chem.STEER) (U.S. EPA.
2013V
3) Review reasonably available measured or estimated release data for surrogate chemicals
that have similar uses and physical properties.
Data for similar fragrance chemicals that are used in the same applications may be used as
surrogate for HHCB. EPA plans to review literature sources identified and if surrogate data are
found, EPA plans to match these data to applicable conditions of use for potentially filling data
gaps.
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4) Review reasonably available data that may be used in developing, adapting or applying
exposure models to the particular risk evaluation.
This item will be performed after completion of steps 2 and 3 above. EPA plans to consider
relevant data to determine whether the data can be used to develop, adapt or apply models for
specific conditions of use (and corresponding release scenarios). EPA plans to further consider
relevant regulatory requirements in estimating releases during risk evaluation.
5) Review and determine applicability of OECD Emission Scenario Documents (ESDs) and
EPA Generic Scenarios to estimation of environmental releases.
EPA has identified potentially relevant OECD Emission Scenario Documents (ESDs) and EPA
Generic Scenarios (GS) that correspond to some conditions of use; for example, the 2010 ESD
on The Blending of Fragrance Oils into Commercial and Consumer Products may be useful as
well as the ESD on Plastic Additives and the complementing document on Plastic Additives
During the Use of End Products (OECD, 2010) (OECD, 2009a) (OECD, 2019). EPA plans to
need to critically review these generic scenarios and ESDs to determine their applicability to the
conditions of use assessed.
EPA Generic Scenarios are available at the following: https://www.epa.gov/tsca-screening-
OECD Emission Scenario Documents are available at the following:
http://www.oecd.org/chemicalsafetv/risk-assessment/emissionscenariodocuments.htm
EPA plans to perform additional targeted research to understand those conditions of use, which
may inform identification of release scenarios. EPA may also need to perform targeted research
for applicable models and associated parameters that EPA may use to estimate releases for
certain conditions of use.
6) Map or group each condition of use to a release assessment scenario(s).
EPA has identified release scenarios and mapped (i.e., grouped) them to relevant conditions of
use as shown in Appendix F. EPA was not able to identify release scenarios corresponding to
some conditions of use (e.g. automotive care products, and recycling). EPA plans to perform
targeted research to understand those uses, which may inform identification of release scenarios.
EPA may further refine the mapping of release scenarios based on factors (e.g., process
equipment and handling, magnitude of production volume used, and release sources and usage
rates of HHCB and polymer products and formulations containing HHCB, or professional
judgment) corresponding to conditions of use as additional information is identified during risk
evaluation.
7) Evaluate the weight of the scientific evidence of environmental release data.
During risk evaluation, EPA plans to evaluate and integrate the exposure evidence identified in
the literature inventory using the methods described in the systematic review documentation that
EPA plans to publish prior to finalizing the scope document. The data integration strategy will be
designed to be fit-for-purpose in which EPA plans to use systematic review methods to assemble the
relevant data, evaluate the data for quality and relevance, including strengths and limitations,
followed by synthesis and integration of the evidence.
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2.7.2.2 Environmental Exposures
EPA plans to analyze the following in developing its environmental exposure assessment of HHCB:
1) Review reasonably available environmental and biological monitoring data for all media
relevant to environmental exposure.
For HHCB, environmental media which EPA plans to evaluate are sediment, biosolids, soil,
ambient air and surface water. The environmental exposure pathways which have been identified
in the literature include aquatic and terrestrial.
2) Review reasonably available information on releases to determine how modeled estimates
of concentrations near industrial point sources compare with available monitoring data.
Reasonably available environmental exposure models that meet the TSCA section 26(h) and (i)
Science Standards and that estimate surface water, sediment, and soil concentrations will be
analyzed and considered alongside available surface water, sediment, and soil monitoring data to
characterize environmental exposures. Modeling approaches to estimate surface water
concentrations, sediment concentrations and soil concentrations generally consider the following
inputs: direct release into surface water, sediment, or soil, indirect release into surface water,
sediment, or soil (i.e., air deposition), fate and transport (partitioning within media) and
characteristics of the environment (e.g., river flow, volume of lake, meteorological data).
3) Review reasonably available biomonitoring data for vegetation, invertebrates, fish, non-fish
vertebrates (i.e., amphibians, reptiles, mammals). Consider whether these data could be
used to compare with comparable species or taxa-specific toxicological benchmarks.
Predatory bird species that consume fish with elevated levels of HHCB will be analyzed. If
species-specific biomonitoring data matches toxicity studies, direct comparisons can be made.
EPA plans to also consider refining data for other species by using body weight of the birds, fish
ingestion rate of birds, and typical fish species consumed.
4) Determine applicability of existing additional contextualizing information for any
monitored data or modeled estimates during risk evaluation.
There have been changes to use patterns of HHCB over the last few years. Monitoring data or
modeled estimates will be reviewed to determine how representative they are of applicable use
patterns.
Any studies which relate levels of HHCB in the environment or biota with specific sources or
groups of sources will be evaluated.
5) Group each condition(s) of use to the environmental assessment scenario(s).
EPA plans to refine and finalize exposure scenarios for environmental receptors by considering
combinations of sources (use descriptors), exposure pathways including routes, and populations
exposed. For HHCB, the following are noteworthy considerations in constructing exposure
scenarios for environmental receptors:
Estimates of surface water concentrations, sediment concentrations and soil
concentrations near industrial point sources based on available monitoring data;
Modeling inputs related to release into the media of interest, fate and transport, and
characteristics of the environment;
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Reasonably available biomonitoring data which could be used to compare with species or
taxa-specific toxicological benchmarks;
Applicability of existing additional contextualizing information for any monitored data or
modeled estimates during risk evaluation (review and characterize the spatial and
temporal variability, to the extent that data are available, and characterize exposed
aquatic and terrestrial populations); and
Weight of the scientific evidence of environmental occurrence data and modeled
estimates.
6) Evaluate the weight of the scientific evidence of environmental occurrence data and
modeled estimates.
During risk evaluation, EPA plans to evaluate and integrate the exposure evidence identified in
the literature inventory using systematic review methods.
2.7.2.3 Occupational Exposures
EPA plans to analyze both worker and ONU exposures as follows:
1) Review reasonably available exposure monitoring data for specific condition(s) of use.
EPA plans to review exposure monitoring data found in published literature (including both
personal exposure monitoring data (direct exposures) and area monitoring data (indirect
exposures)). EPA has reviewed reasonably available monitoring data collected by the
Occupational Safety and Health Administration (OSHA) and National Institute for Occupational
Safety and Health (NIOSH) and neither collected data for HHCB exposures. The most recent
submissions to CDR for HHCB will be used to identify manufacturing and processing
information for HHCB where occupational exposure may occur. CDR may also identify
potential uses of HHCB that would indicate occupational exposure. Additionally, systematic
review will identify published reports containing worker exposure monitoring data that will
inform the occupational exposure assessment of HHCB. EPA plans to continue to review data
sources identified in Appendix A for HHCB using systematic review evaluation strategies for
environmental releases and occupational exposure data sources.
2) Review reasonably available exposure data for surrogate chemicals that have uses,
volatility and chemical and physical properties similar to HHCB.
EPA plans to review literature sources identified and if surrogate data are found, these data will
be matched to applicable conditions of use for potentially filling data gaps. For several
conditions of use (e.g., air care products, cleaners, laundry products, and soaps), EPA may
consider other similar fragrances that share the same conditions of use as possible surrogates for
HHCB.
3) For conditions of use where data are limited or not available, review existing exposure
models that may be applicable in estimating exposure levels.
EPA has identified Emission Scenario Documents (ESDs) from the OECD. For example, the
ESP on The Blending of Fragrance Oils into Commercial and Consumer Products may be used
to estimate occupational exposures as well as the ESP on Plastic Additives and the
complementing document on Plastic Additives During the Use of End Products (OECD, 2010)
(OECD, 2009a) (OECD, 2019). EPA plans to need to critically review all generic scenarios and
ESDs to determine their applicability to the conditions of use assessed. EPA may conduct
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industry outreach efforts or perform supplemental, targeted research to understand those
conditions of use, which may inform identification of exposure scenarios. EPA plans to consider
inhalation exposure to vapor and mist models in the Chemical Screening Tool for Exposure and
Environmental Releases (ChemSTEER) Tool that are routinely used for assessing new
chemicals. EPA may also need to perform targeted research to identify applicable models that
EPA could use to estimate exposures for certain conditions of use (U.S. EPA, 2013).
4) Review reasonably available data that may be used in developing, adapting or applying
exposure models to a particular risk evaluation scenario.
This step will be performed after steps 2 and 3 are completed. Based on information developed
from steps 2 and 3, EPA plans to evaluate relevant data to determine whether the data can be
used to develop, adapt, or apply models for specific conditions of use (and corresponding
exposure scenarios).
5) Consider and incorporate applicable EC and/or PPE into exposure scenarios.
EPA plans to review potentially relevant data sources on EC and PPE as identified in Appendix
E to determine their applicability and incorporation into exposure scenarios during risk
evaluation.
6) Map or group each condition of use to occupational exposure assessment scenario(s).
EPA has identified occupational exposure scenarios and mapped them to relevant conditions of
use as shown in Appendix F. EPA may further refine the mapping/grouping of occupational
exposure scenarios based on factors (e.g., process equipment and handling, magnitude of
production volume used, and exposure/release sources) corresponding to conditions of use as
additional information is identified during risk evaluation.
7) Evaluate the weight of the scientific evidence of occupational exposure data, which may
include qualitative and quantitative sources of information.
During risk evaluation, EPA plans to evaluate and integrate the exposure evidence identified in
the literature inventory using the methods described in the systematic review documentation that
EPA plans to publish prior to finalizing the scope document. EPA plans to rely on the weight of
the scientific evidence when evaluating and integrating occupational data. The data integration
strategy will be designed to be fit-for-purpose in which EPA plans to use systematic review
methods to assemble the relevant data, evaluate the data for quality and relevance, including
strengths and limitations, followed by synthesis and integration of the evidence.
2.7.2.4 Consumer Exposures
EPA plans to analyze both consumers using a consumer product and bystanders associated with the
consumer using the product as follows:
1) Group each condition of use to consumer exposure assessment scenario(s).
Refine and finalize exposure scenarios for consumers by considering combinations of sources
(ongoing consumer uses), exposure pathways including routes, and exposed populations.
For HHCB, the following are noteworthy considerations in constructing consumer exposure
scenarios:
Conditions of use and type of consumer product
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Duration, frequency and magnitude of exposure
Weight fraction of chemical in products
Amount of chemical used
2) Evaluate the relative potential of indoor exposure pathways based on reasonably available
data.
Indoor exposure pathways expected to be relatively higher include vapors, mists, and dust
inhalation, and liquid dermal contact as a result of indoor use of HHCB consumer products.
Indoor exposure pathways expected to be relatively lower include liquid and mist oral ingestion,
and dermal contact with HCCB via dust. The data sources associated with these respective
pathways have not been comprehensively evaluated, so quantitative comparisons across
exposure pathways or in relation to toxicity thresholds are not yet available.
3) Review existing indoor exposure models that may be applicable in estimating indoor air,
indoor dust concentrations, or indoor dust surface loadings.
Indoor exposure models that estimate emissions from consumer products are available. These
models generally consider p-chem properties (e.g., vapor pressure, molecular weight), product
specific properties (e.g., weight fraction of the chemical in the product), use patterns (e.g.,
duration and frequency of use), user environment (e.g., room of use, ventilation rates), and
receptor characteristics (e.g., exposure factors, activity patterns). The OPPT's Consumer
Exposure Model (CEM) and other similar models can be used to estimate indoor air exposures
from consumer products.
4) Review reasonably available empirical data that may be used in developing, adapting or
applying exposure models to a particular risk evaluation scenario. For example, existing
models developed for a chemical assessment may be applicable to another chemical
assessment if model parameter data are available.
To the extent other organizations have already modeled a HHCB consumer exposure scenario
that is relevant to the OPPT's assessment, EPA plans to evaluate those modeled estimates. In
addition, if other chemicals similar to HHCB have been modeled for similar uses, those modeled
estimates will also be evaluated. The underlying parameters and assumptions of the models will
also be evaluated.
5) Review reasonably available consumer product-specific sources to determine how those
exposure estimates compare with each other and with indoor monitoring data reporting
HHCB in specific media (e.g., dust or indoor air).
The availability of HHCB concentration for various ongoing uses will be evaluated. This data
provides the source term for any subsequent indoor modeling. Source attribution between overall
indoor air and dust levels and various indoor sources will be analyzed.
6) Review reasonably available population- or subpopulation-specific exposure factors and
activity patterns to determine if PESS need to be further refined.
During risk evaluation, EPA plans to evaluate and integrate the exposure evidence identified in
the literature inventory using systematic review methods.
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7) Evaluate the weight of the scientific evidence of consumer exposure estimates based on
different approaches.
EPA plans to rely on the weight of the scientific evidence when evaluating and integrating data
related to consumer exposure. The weight of the scientific evidence may include qualitative and
quantitative sources of information. The data integration strategy will be designed to be fit-for-
purpose in which EPA plans to use systematic review methods to assemble the relevant data,
evaluate the data for quality and relevance, including strengths and limitations, followed by
synthesis and integration of the evidence.
2.7.2.5 General Population
EPA plans to analyze general population exposures as follows:
1) Refine and finalize exposure scenarios for general population by considering sources and
uses, exposure pathways including routes, and exposed populations.
For HHCB, the following are noteworthy considerations in constructing exposure scenarios for
the general population: routes of exposure, releases to air, water or land resulting from industrial,
commercial, and other conditions of use, in addition to:
Reviewing reasonably available environmental and biological monitoring data for media
to which general population exposures are expected;
For exposure pathways where data are not reasonably available, reviewing existing
exposure models that may be applicable in estimating exposure levels;
Considering and incorporating applicable media-specific regulations into exposure
scenarios or modeling;
Reviewing reasonably available data that may be used in developing, adapting or
applying exposure models to the particular risk evaluation; for example, existing models
developed for a chemical assessment may be applicable to another chemical assessment if
model parameter data are reasonably available;
Reviewing reasonably available information on releases to determine how modeled
estimates of concentrations near industrial point sources compare with reasonably
available monitoring data;
Reviewing reasonably available population- or subpopulation-specific exposure factors
and activity patterns to determine if PES S need be further defined;
Evaluating the weight of the scientific evidence of general population exposure data; and
Mapping or grouping each condition of use to general population exposure assessment
scenario(s).
EPA plans to evaluate a variety of data types to determine which types are most appropriate
when quantifying exposure scenarios. Environmental monitoring data, biomonitoring data,
modeled estimates, experimental data, epidemiological data, and survey-based data can all be
used to quantify exposure scenarios. In an effort to associate exposure estimates with sources of
exposure and/or conditions of use, EPA plans to consider source apportionment across exposure
scenarios during risk evaluation. EPA anticipates that there will be a wide range in the relative
exposure potential of the exposure scenarios identified in Appendix G. Source apportionment
characterizes the relative contribution of any of the following: a use/source toward a total media
concentration, a media concentration toward a total exposure route, or an exposure route toward
a total external or internal dose. This consideration may be qualitative, semi-quantitative, or
quantitative, and is dependent upon reasonably available data and approaches. For example, EPA
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may consider the co-location of TSCA industrial facilities with reasonably available monitoring
data or modeled estimates. EPA may compare modeled estimates for discrete outdoor and indoor
sources/uses that apply to unique receptor groups.
After refining and finalizing exposure scenarios, EPA plans to quantify concentrations and/or
doses for these scenarios. The number of scenarios will depend on how combinations of uses,
exposure pathways, and receptors are characterized. The number of scenarios is also dependent
upon the reasonably available data and approaches to quantify scenarios. When quantifying
exposure scenarios, EPA plans to use a tiered approach. First-tier analysis is based on data that is
readily available without a significant number of additional inputs or assumptions, and may be
qualitative, semi-quantitative, or quantitative. The results of first tier analyses inform whether
scenarios require more refined analysis. Refined analyses will be iterative and require careful
consideration of variability and uncertainty. Should data become reasonably available that
summarily alters the overall conclusion of a scenario through iterative tiering, EPA can refine its
analysis during risk evaluation.
2) Review reasonably available environmental and biological monitoring data for exposure
pathways and media to which general population exposures are expected.
General population exposure pathways expected to be relatively higher include ingestion of
water and food including fish, root crops, and mother's milk. General population exposure
pathways expected to be relatively lower include dermal contact to HHCB via liquids and mists,
and inhalation of HHCB via vapors, mists and dusts. The data sources associated with these
respective pathways have not been comprehensively evaluated, so quantitative comparisons
across exposure pathways or in relation to toxicity thresholds are not yet available.
3) For exposure pathways where empirical data is not available, review existing exposure
models that may be applicable in estimating exposure levels.
For HHCB, media where exposure models will be considered for general population exposure
include models that estimate ambient air concentrations, surface water concentrations, sediment
concentrations, soil concentrations, and uptake from aquatic and terrestrial environments into
edible aquatic and terrestrial organisms.
4) Review reasonably available exposure modeled estimates. For example, existing models
developed for a previous HHCB chemical assessment may be applicable to the EPA
assessment. In addition, another chemical's assessment may also be applicable if model
parameter data are reasonably available.
To the extent other organizations have already modeled HHCB general population exposure
scenario that is relevant to the OPPT's assessment, EPA plans to evaluate those modeled
estimates. In addition, if modeled estimates for other chemicals with similar physical chemical
properties and similar uses are available, those modeled estimates will also be evaluated. The
underlying parameters and assumptions of the models will also be evaluated.
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5) Review reasonably available information on releases to determine how modeled estimates
of concentrations near industrial point sources compare with reasonably available
monitoring data.
The expected releases from industrial facilities are changing over time. Any modeled
concentrations based on recent release estimates will be carefully compared with reasonably
available monitoring data to determine representativeness.
6) Review reasonably available information about population- or subpopulation-specific
exposure factors and activity patterns to determine if PESS need to be further defined (e.g.,
early life and/or puberty as a potential critical window of exposure).
For HHCB, exposure scenarios that involve PESS will consider age-specific behaviors, activity
patterns, and exposure factors unique to those subpopulations. For example, children will have
different intake rates for dust, soil, and diet than adults.
7) Evaluate the weight of the scientific evidence of general population exposure estimates
based on different approaches.
During risk evaluation, EPA plans to evaluate and integrate the exposure evidence identified in
the literature inventory using systematic review protocols.
2.7.3 Hazards (Effects)
2.7.3.1 Environmental Hazards
EPA plans to conduct an environmental hazard assessment of HHCB as follows:
1) Review reasonably available environmental hazard data, including data from alternative
test methods (e.g., computational toxicology and bioinformatics; high-throughput screening
methods; data on categories and read-across; in vitro studies).
EPA plans to analyze the hazards of HHCB to aquatic and terrestrial organisms, including plants,
invertebrates (e.g., insects, arachnids, mollusks, crustaceans), and vertebrates (e.g., mammals,
birds, amphibians, fish, reptiles) across exposure durations and conditions if potential
environmental hazards are identified through systematic review results and public comments.
Additional types of environmental hazard information will also be considered (e.g., analogue and
read-across data) when characterizing the potential hazards of TPP to aquatic and/or terrestrial
organisms.
Environmental hazard data will be evaluated using the environmental toxicity data quality
criteria outlined in the systematic review documentation that EPA plans to publish prior to
finalizing the scope document. The study evaluation results will be documented in the risk
evaluation phase and data from suitable studies will be extracted and integrated in the risk
evaluation process.
Hazard endpoints (e.g., mortality, growth, immobility, reproduction) will be evaluated, while
considering data availability, relevance, and quality.
2) Derive hazard thresholds for aquatic and/or terrestrial organisms.
Depending on the robustness of the evaluated data for a particular organism or taxa (e.g., aquatic
invertebrates), environmental hazard values (e.g., ECx, LCx, NOEC, LOEC, etc.) may be derived
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and used to further understand the hazard characteristics of HHCB to aquatic and/or terrestrial
species. Identified environmental hazard thresholds may be used to derive concentrations of
concern (COC), based on endpoints that may affect populations of organisms or taxa analyzed.
3) Evaluate the weight of scientific evidence of environmental hazard data.
During risk evaluation, EPA plans to evaluate and integrate the environmental hazard evidence
identified in the literature inventory using the methods described in the systematic review
documentation that EPA plans to publish prior to finalizing the scope document.
4) Consider the route(s) of exposure, based on reasonably available monitoring and modeling
data, and other available approaches to integrate exposure and hazard assessments.
EPA plans to consider the aquatic (e.g., water and sediment exposures) and terrestrial pathways
in the HHCB conceptual model. These organisms may be exposed to HHCB via several
environmental pathways (i.e., surface water, sediment, air, soil, diet).
5) Conduct an environmental risk characterization of HHCB.
EPA plans to conduct a risk characterization of HHCB to identify whether there are risks to the
aquatic and/or terrestrial environments from the measured and/or predicted concentrations of
HHCB found in environmental media (e.g., water, sediment, soil). Risk quotients (RQs) may be
derived by the application of hazard and exposure benchmarks to characterize environmental risk
(U.S. EPA. 1998; Barnthouse et al., 1982).
6) Consider a Persistent, Bioaccumulative, and Toxic (PBT) Assessment of HHCB.
EPA plans to consider assessing the persistence, bioaccumulation, and toxic (PBT) potential of
HHCB after reviewing relevant physical-chemical properties and exposure pathways. EPA plans
to assess the reasonably available studies collected from the systematic review process relating to
bioaccumulation and bioconcentration (e.g., BAF/BCF) of HHCB. In addition, EPA plans to
integrate traditional environmental hazard endpoint values (e.g., LCso, LOEC) and exposure
concentrations (e.g., surface water concentrations, tissue concentrations) for HHCB with the fate
parameters (e.g., BAF/BCF/BMF/TMF).
2.7.3.2 Human Health Hazards
EPA plans to analyze human health hazards as follows:
1) Review reasonably available human health hazard data, including data from alternative
test methods (e.g., computational toxicology and bioinformatics; high-throughput screening
methods; data on categories and read-across; in vitro studies; systems biology).
Human health studies will be evaluated using the systematic review evaluation strategies.
Mechanistic data may include analyses of alternative test data such as novel in vitro test methods
and high throughput screening. The association between acute and chronic exposure scenarios to
the agent and each health outcome will also be integrated. Study results will be extracted and
presented in evidence tables or another appropriate format by organ/system.
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2) In evaluating reasonably available data, determine whether particular human receptor
groups may have greater susceptibility to the chemical's hazard(s) than the general
population.
Reasonably available human health hazard data will be evaluated to ascertain whether some
human receptor groups may have greater susceptibility than the general population to HHCB
hazard(s). Susceptibility of particular human receptor groups to HHCB will be determined by
evaluating information on factors that influence susceptibility.
EPA has reviewed some sources containing hazard information associated with potentially
susceptible populations and lifestages such as pregnant women and infants. Pregnancy (i.e.,
gestation) and childhood are potential susceptible lifestages for HHCB exposure. EPA plans to
review the current state of the literature in order to potentially quantify these differences for risk
evaluation purposes.
3) Conduct hazard identification (the qualitative process of identifying non-cancer and cancer
endpoints) and dose-response assessment (the quantitative relationship between hazard
and exposure) for identified human health hazard endpoints.
Human health hazards from acute and chronic exposures will be identified by evaluating the
human and animal data that meet systematic review data quality criteria. Hazards identified by
studies meeting data quality criteria will be grouped by routes of exposure relevant to humans
(e.g., oral, dermal, inhalation) and by cancer and noncancer endpoints.
Dose-response assessment will be performed in accordance with EPA guidance (U.S. EPA.
2012a. 201 la. 1994). Dose-response analyses may be used if the data meet data quality criteria
and if additional information on the identified hazard endpoints are not available or would not
alter the analysis.
The cancer mode of action (MOA) determines how cancer risks can be quantitatively evaluated.
If cancer hazard is determined to be applicable to HHCB, EPA plans to evaluate information on
genotoxicity and the mode of action for all cancer endpoints to determine the appropriate
approach for quantitative cancer assessment in accordance with the U.S. EPA Guidelines for
Carcinogen Risk Assessment ( 35).
4) Derive points of departure (PODs) where appropriate; conduct benchmark dose modeling
depending on the reasonably available data. Adjust the PODs as appropriate to conform
(e.g., adjust for duration of exposure) to the specific exposure scenarios evaluated.
Hazard data will be evaluated to determine the type of dose-response modeling that is applicable.
Where modeling is feasible, a set of dose-response models that are consistent with a variety of
potentially underlying biological processes will be applied to empirically model the dose-
response relationships in the range of the observed data consistent with EPA's Benchmark Dose
Technical Guidance Document. Where dose-response modeling is not feasible, NOAELs or
LOAELs will be identified. Non-quantitative data will also be evaluated for contribution to
weight of the scientific evidence or for evaluation of qualitative endpoints that are not
appropriate for dose-response assessment.
EPA plans to evaluate whether the available PBPK and empirical kinetic models are adequate for
route-to-route and interspecies extrapolation of the POD, or for extrapolation of the POD to
44
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standard exposure durations (e.g., lifetime continuous exposure). If application of the PBPK
model is not possible, oral PODs may be adjusted by BW3 4 scaling in accordance with U.S. EPA.
(201 la), and inhalation PODs may be adjusted by exposure duration and chemical properties in
accordance with U.S. EPA. (1994).
5) Evaluate the weight of the scientific evidence of human health hazard data.
During risk evaluation, EPA plans to evaluate and integrate the human health hazard evidence
identified in the literature inventory under acute and chronic exposure conditions using
systematic review methods.
6) Consider the route(s) of exposure (oral, inhalation, dermal), available route-to-route
extrapolation approaches, reasonably available biomonitoring data and available
approaches to correlate internal and external exposures to integrate exposure and hazard
assessment.
At this stage of review, EPA believes there will be sufficient data to conduct a dose-response
analysis and/or benchmark dose modeling for the oral route of exposure. EPA plans to also
evaluate any potential human health hazards following dermal and inhalation exposure to
HHCB, which could be important for the worker, consumer, and general population risk
analysis. Reasonably available data will be assessed to determine whether a point of departure
can be identified for the dermal and inhalation routes. This may include using route-to-route
extrapolation methods where appropriate and depending on the nature of reasonably available
data.
If sufficient toxicity studies are not identified in the literature search to assess risks from dermal
and inhalation exposures, then a route-to-route extrapolation from oral toxicity studies would be
needed to assess systemic risks from dermal or inhalation exposures. Without an adequate PBPK
model, the approaches described in the EPA guidance document Risk Assessment Guidance for
Superfund Volume I: Human Health Evaluation Manual (Part E, Supplemental Guidance for
Dermal Risk Assessment) (U.S. EPA. 2.004) could be applied to extrapolate from oral to dermal
exposure. These approaches may be able to further inform the relative importance of dermal
exposures compared with other routes of exposure. Similar methodology may also be used for
assessing inhalation exposures
2.7.4 Summary of Risk Approaches for Characterization
Risk characterization is an integral component of the risk assessment process for both environmental and
human health risks. EPA plans to derive the risk characterization in accordance with EPA's Risk
Characterization Handbook (U.S. EPA. 2000). As defined in EPA's Risk Characterization Policy, "the
risk characterization integrates information from the preceding components of the risk evaluation and
synthesizes an overall conclusion about risk that is complete, informative and useful for decision
makers." Risk characterization is considered to be a conscious and deliberate process to bring all
important considerations about risk, not only the likelihood of the risk but also the strengths and
limitations of the assessment, and a description of how others have assessed the risk into an integrated
picture.
The level of information contained in each risk characterization varies according to the type of
assessment for which the characterization is written. Regardless of the level of complexity or
45
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information, the risk characterization for TSCA risk evaluations will be prepared in a manner that is
transparent, clear, consistent, and reasonable ( MM)) and consistent with the requirements of
the Procedures for Chemical Risk Evaluation Under the Amended Toxic Substances Control Act (82 FR
6). For instance, in the risk characterization summary, EPA plans to further carry out the
obligations under TSCA section 26; for example, by identifying and assessing uncertainty and
variability in each step of the risk evaluation, discussing considerations of data quality such as the
reliability, relevance and whether the methods utilized were reasonable and consistent, explaining any
assumptions used, and discussing information generated from independent peer review.
EPA plans to also be guided by EPA's Information Quality Guidelines ( .002) as it provides
guidance for presenting risk information. Consistent with those guidelines, EPA plans to identify in the
risk characterization the following: (1) Each population addressed by an estimate of applicable risk
effects; (2) The expected risk or central estimate of risk for the PESS affected; (3) Each appropriate
upper-bound or lower-bound estimate of risk; (4) Each significant uncertainty identified in the process
of the assessment of risk effects and the studies that would assist in resolving the uncertainty; and (5)
Peer reviewed studies known to the Agency that support, are directly relevant to, or fail to support any
estimate of risk effects and the methodology used to reconcile inconsistencies in the scientific
information.
2.8 Peer Review
Peer review will be conducted in accordance with EPA's regulatory procedures for chemical risk
evaluations, including using EPA's Peer Review Handbook and other methods consistent with section
26 of TSCA (See 40 CFR 702.45). As explained in the preamble to the Risk Evaluation Rule, the
purpose of peer review is for the independent review of the science underlying the risk assessment (see
82 Fed. Reg. 33726, 33744 [July 12, 2017]). Peer review will therefore address aspects of the underlying
science as outlined in the charge to the peer review panel such as hazard assessment, assessment of
dose-response, exposure assessment, and risk characterization. The draft risk evaluation for HHCB will
be peer reviewed.
46
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France. HERO ID: 6307807
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oclanguage=en. HERO ID: 6306751
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117. (93-E67). Givaudan Roure Corporate Safety and Environmental Affairs. HERO ID: 5349148
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ctNumber=W520608&brand=ALDRICH&PageToGoToURL=https%3A%2F%2Fwww.sigmaaldrich.co
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Simonich, SL;Begley, WM;Debaere, G;Echhoff, WS. (2000). Trace analysis of fragrance materials in
water and treated wastewater. Environ Sci Technol 34: 959-965. HERO ID: 5349155
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reference concentrations and application of inhalation dosimetry. Report number EPA/600/8-90/066F.
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U.S. EPA. (2002). Guidelines for ensuring and maximizing the quality, objectivity, utility, and integrity
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APPENDICES
Appendix A LIST OF GRAY LITERATURE SOURCES
Table Apx A-l provides a list of gray literature sources that yielded results for HHCB.
Table Apx A-l. Gray Literature Sources That Yielded Results for HHCB
Source/
Agency
Source Name
Source Type
Source Category
Aus.
Assm.
NICNAS Assessments (human health, Tier
I, II or III)
International
Resources
Assessment or
Related Document
ECHA
European Union Risk Assessment Report
(EU, 2008)
International
Resources
Assessment or
Related Document
ECHA
ECHA Documents (ECHA, 2019)
International
Resources
Assessment or
Related Document
EPA
Office of Water: STORET and WQX
US EPA
Resources
Database
EPA
TSCA Assessments
US EPA
Resources
Assessment or
Related Document
EPA
TSCA Data Needs Assessments or
Problem Formulation
US EPA
Resources
Assessment or
Related Document
EPA
Other EPA: Misc sources
US EPA
Resources
General Search
EPA
EPA: AP-42
US EPA
Resources
Regulatory
Document or List
EPA
TRI: Envirofacts Toxics Release Inventory
2017 Updated Dataset
US EPA
Resources
Database
EPA
Chemical Data Reporting (2012 and 2016
non-CBI CDR database)
US EPA
Resources
Database
EPA
Chemical Data Reporting (2012 and 2016
CBI CDR database)
US EPA
Resources
Database
EPA
EPA: Generic Scenario
US EPA
Resources
Assessment or
Related Document
EPA
EPA Discharge Monitoring Report Data
US EPA
Resources
Database
EPA
Office of Air: National Emissions
Inventory (NEI) - National Emissions
Inventory (NEI) Data (2014, 2011, 2008)
US EPA
Resources
Database
52
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EPA
Office of Air: CFRs and Dockets
US EPA
Resources
Regulatory
Document or List
KOECT
Kirk-Othmer Encyclopedia of Chemical
Technology Journal Article
Other Resource
Encyclopedia
NLM
National Library of Medicine's PubChem
Other US Agency
Resources
Database
OECD
OECD Emission Scenario Documents
International
Resources
Assessment or
Related Document
OECD
OECD: General Site
International
Resources
General Search
OSHA
U.S. OSHA Chemical Exposure Health
Data (CEHD) program data [ERG]
Other US Agency
Resources
Database
RIVM
RIVM Reports: Risk Assessments
International
Resources
Assessment or
Related Document
53
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Appendix B PHYSICAL AND CHEMICAL PROPERTIES OF HHCB
This appendix provides p-chem information and data found in preliminary data gathering for HHCB.
Table Apx B-l summarizes the p-chem property values preliminarily selected for use in the risk
evaluation from among the range of reported values collected as of March 2020. This table differs from
that presented in the Proposed Designation of 1,3,4,6,7.8-Hexahyc z
Hexamethvlcvclownfafy]-2-Benzovw<10"4 mm Hg at
25°C
NLM, 2018
High
Vapor density
Not available
Water solubility
1.75 mg/L at 25°C
NLM, 2018
High
Log Octanol/water partition
coefficient (Log Kow)
5.9
U.S. EPA, 2019
High
Henry's Law constant
1.06xl0"4 atm-m3/mole
at 25°C
U.S. EPA, 2012
Flash point
Not available
Auto flammability
Not available
Viscosity
12,914 cP
NLM, 2018
High
Refractive index
1.5342
O'Neil, 2013
High
Dielectric constant
Not available
a
Measured unless otherwise noted.
NA = Not applicable
54
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Appendix C ENVIRONMENTAL FATE AND TRANSPORT
PROPERTIES OF HHCB
Table Apx C-l provides the environmental fate characteristics that EPA identified and considered in
developing the scope for HHCB.
Table Apx C-l. Environmental Fate and Transport Properties of HHCB
Properly or
K ml point
Value
Reference
Direct
Photodegradati on
Direct photolysis is not expected to be an important fate
process because HHCB does not contain chromophores
that absorb at wavelengths >290 nm
NLM, 2018
Direct photolysis by sunlight and gas-phase reaction with
hydroxyl (-OH) radicals are considered to be the major
degradation routes for HHCB in the atmosphere
OECD, 2009b
Indirect
Photodegradati on
Half-life (ti/2) = 5 days (based on -OH reaction rate
constant of 2.6 x 10"11 cmVmolecules-second at an -OH
concentration of 1.5 x 106 -OH/cm"3)
OECD, 2009b
Hydrolysis
Stable; HHCB is not expected to undergo hydrolysis in the
environment due to its chemical structure, which lacks
functional groups known to undergo hydrolysis under
environmental conditions
NLM, 2018; OECD,
2009b
Biodegradation
0%/28 days CO2 evolution test (OECD test guideline 301
B) (aerobic water)
NLM, 2018; EU, 2008
18%/200 days activated sludge; byproducts identified were
galaxolide lactone and galaxolide hydroxy acid
NLM, 2018 citing
Balk and Ford, 1999a
Removal in
Wastewater
Treatment
92% total removal (0.8% by biodegradation, 91% by
sludge and 0.1% by volatilization to air; estimated)11
U.S. EPA, 2012c
91.5% removal activated sludge plant
EU, 2008 citing
Simonich, 2000
Bioconcentration
Factor
1,584 (whole fish, wet weight) bluegill sunfish (Lepomis
macrochirus) OECD Test guideline 305E
NLM, 2018 citing
Balk and Ford, 1999a
624 (fresh weight), 33,200 (lipid) zebrafish (Brachydanio
rerio), OECD Test guideline 305E
EU, 2008 citing Butte
andEwald, 1999
Bioaccumulation
Factor
52,370 (crucian carp), 66,030 (common carp), 39,400
(silver carp)
Hu, 2011
55
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Soil Organic
Carbon:Water
Partition
Coefficient (Log
Koc)
4.87
EU, 2008 citing
MacGillivray, 1966
3.6-3.9
EU, 2008 citing
Muller, 2002
3.8
EU, 2008 citing
Artola-Garciana, 2002
a Measured unless otherwise noted
b EPI Suite™physical property inputs: Log K0w = 5.90, boiling point = 325 °C, melting point = -5 °C, vapor pressure =
0.000545 mm Hg, water solubility = 1.75 mg/L, biodegradation half-life (in hours) in the primary clarifier of a sewage
treatment plant (STP; BioP) = 10,000, biodegradation half-life (in hours) in the aeration vessel of an STP (BioA) = 10,000
and biodegradation half-life (in hours) in the final settling tank of an STP (BioS) = 10,000, Simplified Molecular-Input Line-
Entry System (SMILES): 0(CC(c(clcc(c2C(C3C)(C)C)C3(C)C)c2)C)Cl
56
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Appendix D REGULATORY HISTORY
HHCB is subject to federal and state laws and regulations in the United States (TableApx D-l and
TableApx D-2). Regulatory actions by other governments, tribes and international agreements
applicable to HHCB are listed in Table Apx D-3.
D.l Federal Laws and Regulations
Table Apx D-l. Federal Laws and Regulations
Stalules/
Regulations
Description of Aiilhorilv/Uegulalion
Description of
Regulation
EPA Regulations
TSCA Section 6(b)
EPA is directed to identify high-priority
chemical substances for risk evaluation; and
conduct risk evaluations on at least 20 high
priority substances no later than three and one-
half years after the date of enactment of the
Frank R. Lautenberg Chemical Safety for the
21st Century Act.
HHCB is one of the 20
chemicals EPA designated
as a High-Priority
Substance for risk
evaluation under TSCA (84
. December 30,
2019). Designation of
HHCB as high-priority
substance constitutes the
initiation of the risk
evaluation on the chemical.
TSCA Section 8(a)
The TSCA section 8(a) CDR Rule requires
manufacturers (including importers) to give EPA
basic exposure-related information on the types,
quantities and uses of chemical substances
produced domestically and imported into the
United States.
HHCB manufacturing
(including importing),
processing and use
information is reported
under the CDR rule (76
FR 50816. August 16.
2011) (U.S. EPA,
2011b).
TSCA Section 8(b)
EPA must compile, keep current and publish a
list (the TSCA Inventory) of each chemical
substance manufactured (including imported) or
processed in the United States.
HHCB was on the initial
TSCA Inventory and
therefore was not subject
to EPA's new chemicals
review process under
TSCA section 5 (60 FR
16309, March 29, 1995)
(U.S. EPA, 1995).
TSCA Section 8(e)
Manufacturers (including importers), processors,
and distributors must immediately notify EPA if
they obtain information that supports the
One risk report was
received for HHCB
(May 1997) (U.S. EPA,
57
-------
Stalules/
Regulations
Description of Authority/Regulation
Description of
Regulation
conclusion that a chemical substance or mixture
presents a substantial risk of injury to health or
the environment.
ChemView. Accessed
(March 22, 2019)) (U.S.
EPA, 2017a)
Federal Insecticide,
Fungicide, and
Rodenticide Act
(FIFRA) - Sections 3
and 6
FIFRA governs the sale, distribution and use of
pesticides. Section 3 of FIFRA generally requires
that pesticide products be registered by EPA
prior to distribution or sale. Pesticides may only
be registered if, among other things, they do not
cause "unreasonable adverse effects on the
environment." Section 6 of FIFRA provides EPA
with the authority to cancel pesticide
registrations if either (1) the pesticide, labeling,
or other material does not comply with FIFRA;
or (2) when used in accordance with widespread
and commonly recognized practice, the pesticide
generally causes unreasonable adverse effects on
the environment.
HHCB is an approved
nonfood use inert
ingredient and as a
component of a
fragrance. (InertFinder.
Accessed (March 22,
2019)) (U.S. EPA,
2019e).
D.2 State Laws and Regulations
Table Apx D-2. State Laws and Regulations
State Actions
Description of Action
Chemicals of High
Concern to Children
Minnesota includes HHCB in the list of chemicals of high concern (Toxic
Free Kids Act Minn. Stat. 116.9401 to 116.9407) (MDH, 2019).
Other
California lists HHCB as a designated priority chemical for
biomonitoring (California SB 1379).
The Oregon Department of Environmental Quality lists HHCB as a
priority persistent pollutant (Oregon SB 737).
D.3 International Laws and Regulations
Table Apx D-3. Regulatory Actions by other Governments, Tribes, and International Agreements
( on ill rv/ Orga n i/at ion
Requirements and Restrictions
European Union
HHCB is registered for use in the EU. Chemicals Agency (ECHA)
database. (ECHA, 2018, Accessed April 2, 2019).
58
-------
Australia
HHCB was assessed under Human Health Tier II of the Inventory Multi-
Tiered Assessment and Prioritisation (IMAP). Use reported include
washing and cleaning products; air care products; anti-odour agents; floor
and surface treatment products; scented clothes and papers; car care
products; photochemicals; leather tanning and textile dyes; coatings and
paint thinners; polishes and wax blends; and adsorbents. (NICNAS, 2019,
accessed April 4, 2019/
Japan
HHCB is regulated in Japan under the following legislation:
Act on the Evaluation of Chemical Substances and Regulation of Their
Manufacture, etc. (Chemical Substances Control Law; CSCL)
(NITE, 2019, accessed April 4, 2019).
59
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Appendix E PROCESS, RELEASE AND OCCUPATIONAL
EXPOSURE INFORMATION
This appendix provides information and data found in preliminary data gathering for HHCB.
E.l Process Information
Process-related information potentially relevant to the risk evaluation may include process diagrams,
descriptions and equipment. Such information may inform potential release sources and worker
exposure activities.
E.l.l Manufacture (Including Import)
E.l.1.1 Manufacturing
HHCB is manufactured by a three-step reaction (Wiley-VCH, 2002; Zviely, 2002). First, a cycloaddition
reaction of .alpha.-methyl styrene and 2-methyl-2-butene (i.e., amylene) is performed under acidic
conditions to obtain 1,1,2,3,3-pentamethylindane (1). Second, the pentamethylindane (1) is
hydroxyalkylated with propylene oxide in a Friedel-Crafts reaction using aluminum chloride as a
catalyst. Third, the ring closure of the resulting 1,1,2,3,3- pentamethyl-5-(-hydroxyisopropyl)indane (2)
to l,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta-g-benzopyran (HHCB; Galaxolide) is
accomplished with paraformaldehyde and a lower aliphatic alcohol via the acetal or with
paraformaldehyde and a carboxylic acid anhydride via the acylate (U.S. EPA, 2014).
E.l.1.2 Import
EPA has not identified specific activities related to the import of HHCB at this time. However, EPA
anticipates that HHCB is shipped in bulk containers and may be repackaged into smaller containers for
resale, such as drums or bottles. The type and size of container will vary depending on customer requirement.
In some cases, QC samples may be taken at import and repackaging sites for analyses. Some import facilities
may only serve as storage and distribution locations, and repackaging/sampling may not occur at all import
facilities.
HHCB may be imported neat or as a component in a formulation. In the 2016 CDR, all eight companies
reporting the import of HHCB also reported the maximum concentration of the formulation as over 90
percent HHCB (U.S. EPA, 2019d).
HHCB is imported into the U.S. for processing and distribution. Releases are not expected to result from
import activities, but may occur at import sites if HHCB is also diluted and compounded onsite after import,
as further discussed below in the processing and distribution section.
E.1.2 Processing and Distribution
E. 1.2.1 Incorporation into a Formulation, Mixture or Reaction Product
Incorporation into a formulation, mixture or reaction product refers to the process of mixing or blending
of several raw materials to obtain a single product or preparation. HHCB is incorporated into
formulations as an odor agent during the manufacture of chemical products, soaps, cleaning compounds,
and fragrance mixtures (U.S. EPA, 2019d). HHCB-specific formulation processes were not identified;
however, at least one Emission Scenario Document (ESD) published by the OECD has been identified
that provide general process descriptions for these types of products.
60
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E. 1.2.2 Incorporation into an Article
Incorporation into an article typically refers to a process in which a chemical becomes an integral
component of an article (as defined at 40 CFR 704.3) for distribution in commerce. Exact process
operations involved in the incorporation of HHCB-containing formulations or reaction products are
dependent on the article. HHCB and HHCB formulations or reaction products are incorporated into
articles during the manufacturing of plastic material and resins. The ESD on Plastic Additives and the
complementing document on Plastic Additives During the Use of End Products will be referenced to
provide general process descriptions for the identified articles (OECD, 2009a) (OECD, 2019).
E. 1.2.3 Repackaging
EPA has not identified specific information for the repackaging of HHCB. EPA expects repackaging
sites receive the chemical in bulk containers and transfer the chemical from the bulk container into
another smaller container in preparation for distribution in commerce.
E. 1.2.4 Recycling
EPA did not identify HHCB-specific information for recycling.
E.1.3 Uses
Musks are considered important compounds to the fragrance industry because of their unique odor
properties, ability to improve the fixation of fragrance compounds, and ability to bind fragrances to
fabrics. The function of HHCB in fragrance formulations is as both a fragrance and a fragrance
enhancer.
HHCB is used as a fragrance ingredient in cleaning because it is alkali-stable and does not discolor in
light. HHCB and other musks provide a unique, dominant scent in products. Because HHCB binds
fragrances to fabric and skin, the scent is balanced and longer lasting. HHCB is often used in laundry
detergent fragrances because it is one of the few chemicals that can leave a small residual fragrance on
cloth after washing and can cover up odors from the detergent itself as well as from dirt in the wash
solution. Synthetic musks, including HHCB, also may be used to mask chemical odors and can be found
in products labeled "unscented," but do not seem to be added to products labeled "fragrance free" (U.S.
EPA, 2012c).
E.l.3.1 Air Care Products
2012 and 2016 CDR information indicated the use of HHCB in air care products (U.S. EPA, 2019d).
Product SDS data and public comments identified HHCB in continuous action air fresheners such as
candles, fragrance oils, scented bathroom clips, and air freshener plug-ins (Fragrance Creators
Association, 2019) (U.S. EPA 2019f). HHCB is also found in motor vehicle air fresheners and instant
action air fresheners such as aerosol sprays, pet deodorizer sprays, and car deodorizer sprays (U.S. EPA
2019f).
Commercial uses of these items may include the use of air care products for professional cleaning, odor
reduction near professional drivers, and deodorizing during car detailing.
E.l.3.2 Cleaning and Furnishing Care Products
2012 and 2016 CDR information indicated the use of HHCB in cleaning and furnishing care products
(U.S. EPA, 2019d). Specifically, product SDS data indicated HHCB is present in both liquid and spray
bathroom cleaners and multi-surface cleaners (U.S. EPA 2019f). Workers who use industrial or bulk
cleaners everyday may have occupational exposure to HHCB. Staff in commercial kitchens or
bathrooms, hotels, and any professional cleaning business may be included in the affected workers.
61
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E.l.3.3 Laundry and Dishwashing Products
Laundry detergent and fabric softeners were identified as containing HHCB based on product SDS
information and public comments (Earthjustice, 2019)(U.S. EPA 2019f). These products may present
occupational exposure in commercial laundromats and businesses that provide linen services, such as
hotels or resorts.
E.l.3.4 Plastic and Rubber Products Not Covered Elsewhere
EPA identified disposable floor mats and odor eliminating discs containing HHCB (U.S. EPA 2019f).
EPA also received a CBI claim regarding other plastic and rubber products containing HHCB.
E.1.3.5 Paper Products
EPA did not identify specific paper products containing HHCB at this time.
E.l.3.6 Other Uses: laboratory Chemical
A Safety Data Sheet for HHCB (<= 100% percent purity) indicates the recommended use as a laboratory
chemical. However, specific laboratory use activities are unknown (Sigma-Aldrich, 2019).
E.l.3.7 Disposal
Each of the conditions of use of HHCB may generate waste streams of the chemical that are collected
and transported to third-party sites for disposal, treatment, or recycling. Disposal of products and articles
containing HHCB will also be considered (e.g., paper products, plastics, etc.). Industrial sites that treat
or dispose onsite wastes that they themselves generate will be assessed for each condition of use.
Similarly, point source discharges of HHCB to surface water will be assessed for each condition of use
(point source discharges are exempt as solid wastes under RCRA). Wastes of HHCB that are generated
during a condition of use and sent to a third-party site for treatment, disposal, or recycling may include
the following:
• Wastewater: HHCB may be contained in wastewater discharged to POTW or other, non-public
treatment works for treatment. Industrial wastewater containing HHCB discharged to a POTW
may be subject to EPA or authorized NPDES state pretreatment programs. The assessment of
wastewater discharges to POTWs and non-public treatment works of HHCB will be evaluated
for each condition of use.
• Solid Wastes: Because of its properties, HHCB also partitions to solid phases in the wastewater
treatment process (sludge), and with further treatment can become concentrated in biosolids.
This organic carbon-rich material is disposed of by landfill or incineration or may be utilized for
land application to enhance physical soil properties as well as plant yield.
• Solid wastes are defined under RCRA as any material that is discarded by being: abandoned;
inherently waste-like; a discarded military munition; or recycled in certain ways (certain
instances of the generation and legitimate reclamation of secondary materials are exempted as
solid wastes under RCRA). Solid wastes may subsequently meet RCRA's definition of
hazardous waste by either being listed as a waste at 40 CFR §§ 261.30 to 261.35 or by meeting
waste-like characteristics as defined at 40 CFR §§ 261.20 to 261.24. Solid wastes that are
hazardous wastes are regulated under the more stringent requirements of Subtitle C of RCRA,
whereas non-hazardous solid wastes are regulated under the less stringent requirements of
Subtitle D of RCRA.
62
-------
HHCB is a not a listed or characterized as a hazardous waste under RCRA; therefore, HHCB is
not subject to RCRA subtitle C regulation. Discarded, unused pure and commercial grades of
HHCB are collected and disposed of by municipal waste landfills and incinerators.
E.2 Sources Containing Potentially Relevant Data or Information
There are currently no exposure limits for HHCB established by OSHA, NIOSH, or American
Conference of Governmental Industrial Hygienists (ACGIH). Because of this, there have been no
industrial health studies conducted by any of these organizations for possible worker exposure to
HHCB.
63
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Appendix F SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR INDUSTRIAL
AND COMMERCIAL ACTIVITIES AND USES
Table Apx F-l. Worker and ONU Exposure Conceptual Model Supporting Table
l.ili- (\ik-
(:ik-»iisinv
Siiiiiiriii
I!\|)iisiiiv
Ri'i'i'pliir /
Plans id
k;ilinn;ik-
Shim-
P;ilh\\;i\
Khmu-
Piipuhiliiin
l!\ ;i In ilk-
Liquid
Contact
Dermal
Workers
Yes
HHCB is manufactured as a liquid; therefore, EPA
plans to evaluate dermal exposures for workers
Solid
Contact
Dennal
Workers
No
111ICB is manufactured as a liquid; therefore,
exposures to solids for workers are not expected
Domestic
Manufacture/
Domestic
Manufacture/
Manufacture of
HHCB
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation exposure
Import
Import
Mist
Inhalation/
Dennal
Workers.
ONU
No
Mist generation is not expected during
Manufacturing
Dust
Inhalation/
Dennal
Workers.
ONU
No
111 ICB is manufactured as a liquid; therefore,
exposures to dust for workers are not expected
Manufacture
Liquid/Solid
Contact
Dennal
ONU
No
Dennal exposure by ()NU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
The potential for dermal exposure to workers
exists during import, but exposure will only occur
in the event the imported material is repackaged
Solid
Contact
Dermal
Workers
Yes
HHCB could be imported as a solid; therefore,
dermal exposures for workers are expected
Import
Import
Repackaging
of Import
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
Containers
Mist
Inhalation/
Dennal
Workers.
ONU
No
Mist generation is not expected during import or
repackaging
Dust
Inhalation/
Workers.
Yes
111 ICB could be imported as a solid; therefore.
I )ermal
ONU
exposures to dust for workers are expected
Liquid/Solid
Contact
Dennal
ONU
No
Dennal exposure by ()Nl J is not expected for this
condition of use as they are not expected to
directly handle the chemical
64
-------
l.ili- ( \ik-
Slum-
(:ik-»IIMIIV
Si'iii;irin
I!\|)iisiiiv
Khmu-
Ri'i'i'pliir /
Piipuhiliiin
Plans id
l!\ ;i In ilk-
k;ilinn;ik-
Liquid
Contact
Dermal
Workers
Yes
The potential for dcmial exposure to workers
exists during import, but exposure will only occur
in the event the imported material is repackaged
Solid
Contact
Dermal
Workers
Yes
HHCB could be imported as a solid; therefore,
dermal exposures for workers are expected
Repackaging
Odor agent (in
all other
chemical
product and
preparation
manufacturing)
Repackaging
into large and
small
containers
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation exposure
Mist
Inhalation/
Dermal
Workers.
ONU
No
Mist generation is not expected during import or
repackaging
Dust
Inhalation/
Dermal
Workers,
ONU
Yes
HHCB could be imported as a solid; therefore,
exposures to dust for workers are expected
Liquid/Solid
Contact
I )ermal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical.
Odor agent (in
all other
Liquid
Contact
Dermal
Workers
Yes
The potential for dermal exposure to workers
exists during formulation
Processing
chemical
product and
preparation
Solid
Contact
Dermal
Workers
Yes
HHCB may be incorporated into a solid or
powder; therefore, exposures to solids for workers
are expected
Incorporation
into
formulation,
manufacturing;
miscellaneous
manufacturing;
soap, cleaning
Formulation of
soap, cleaning
compound, and
toilet
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
mixture or
reaction
product
compound, and
toilet
preparation
manufacturing;
other:
fragrance
mixtures and
fragrance raw
material)
preparation
manufacturing
and fragrance
mixtures
Mist
Inhalation/
I )ermal
Workers.
ONU
No
Mist generation not expected during formulation
Dust
Inhalation/
Dermal
Workers,
ONU
Yes
HHCB may be incorporated into a solid or
powder; therefore, exposures to dust for workers
are expected
Liquid/Solid
Contact
Dermal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Incorporation
into Article
Odor agent (in
plastics
Plastics
Liquid
Contact
Dermal
Workers
Yes
The potential for dermal exposure to workers
exists during incorporation into articles
material and
resin
manufacturing)
resin
manufacturing
Solid
Contact
Dermal
Workers
Yes
HHCB may be incorporated into a solid or
powder; therefore, exposures to solids for workers
are expected
65
-------
l.ili- ( \ik-
Slum-
(:ili-»or\
Ri'k'iisi- /
l''\|>IIMIIV
Sii'ii;irin
I!\|)iisiiiv
Khmu-
Ki'ivpliir /
Piipuhiliiin
Plans id
l!\ ;i In ilk-
Kuliimuk-
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmllg) at
room temperature, EPA plans to evaluate
inhalation pathway
Mist
Inhalation/
Dermal
Workers.
ONU
No
Mist generation not expected during incorporation
into articles
Dust
Inhalation/
Dermal
Workers,
ONU
Yes
HHCB may be incorporated into a solid or
powder; therefore, exposures to dust for workers
are expected
Liquid/Solid
Contact
I )ermal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
HHCB is expected to be recycled as a liquid;
therefore, dermal exposures for workers are
expected
Solid
Contact
Dermal
Workers
No
IIIICU is expected to be recycled as a liquid;
therefore, exposures to solids for workers are not
expected
Recycling
Recycling
Recycling of
HHCB
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
Mist
Inhalation/
Dermal
Workers.
ONU
No
Mist generation is not expected during recycling
Dust
Inhalation/
Dermal
Workers.
ONU
No
1IIICU is expected to be recycled as a liquid;
therefore, exposures to dust for w orkers are not
expected
Liquid/Solid
Contact
1 )ermal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
The potential for dermal exposure to workers
exists during aerosol air freshener use
Industrial /
Air Care
Tnstant Action
Aerosol
application of
scented air
freshener
Solid
Contact
1 )ermal
Workers
No
IIIICU is used as a liquid in aerosols; therefore,
exposures to solids for workers are not expected
commercial
Products
Air Fresheners
Vapor
Inhalation
Workers.
ONU
No
Due to the low volatility (VP = 0.000545 mml Ig)
of III ICU. inhalation exposures from aerosol
applications are expected to be dominated by the
aerosol mist, such that exposures to vapors
evaporating from the mist droplets does not
66
-------
Life C \ ik-
(:ik-»or\
Ri'k'iisi- /
l''\|>IIMIIV
Siill;ili(i
I!\|)iisiiiv
Khmu-
Ri'i'i'pliir /
Piipuhiliiin
Plans l(i
l!\ ;illl;ik-
K;iliim;ik-
contribute significantly to IIIICU inhalation
exposures for this use
Mist
Inhalation/
Dermal
Workers,
ONU
Yes
Mist generation is expected during aerosol
application
Dust
Inhalation/
Dermal
Workers.
ONU
No
IIIICU is used as a liquid in aerosols: therefore,
exposures to dusts are not expected
Liquid/Solid
Contact
1 )ermal
ONU
No
Dennal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
I )ennal
Workers
Yes
Motor \ ehicle air fresheners are expected to have
liquid residue on a solid, paper substrate
Solid
Contact
Dermal
Workers
No
Although motor vehicle air fresheners are solids,
the substrate is a single, continuous solid with
liquid fragrance and therefore, exposures to solids
for workers are not expected
Air fresheners
for motor
Use of solid air
freshener
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmllg) at
room temperature, EPA plans to evaluate
inhalation pathway
vehicles
Mist
Inhalation/
1 )ermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
Solid dust exposure is not expected as the product
is one single, continuous piece. No powders are
expected.
Liquid/Solid
Contact
Dennal
ONU
No
Dennal exposure by ONI J is not expected for this
condition of use as they are not expected to
direcllv handle the chemical
Continuous
Action Air
Fresheners
Aroma
chemicals
Use of
solid/gel room
air freshener
and fragrance
oils
Liquid
Contact
Dermal
Workers
Yes
IIIICLS continuous action air fresheners are
typically a solid substrate with a liquid fragrance
or a thick gel fragrance mixture; therefore, liquid
dermal exposures for workers are expected
Solid
Contact
Dennal
Workers
No
Although some continuous air fresheners are
solids, the substrate is a single, continuous solid
with liquid/gel fragrance and therefore, exposures
to solids for workers are not expected
67
-------
l.ili- ( \ik-
(:ik-»IIMIIV
Si'iii;irin
I!\|)iisiiiv
Khmu-
Ki'ivpliir /
Piipuhiliiin
Plans id
l!\ ;i In ilk-
Kaliimak-
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 miiillg) at
room temperature, EPA plans to evaluate
inhalation pathway
Misl
Inhalation/
Dermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
Dermal
Workers.
ONU
No
IIIICB continuous action air fresheners do not
contain dusts; therefore, exposures to dust for
workers are not expected
Liquid/Solid
Contact
1 )ermal
ONU
No
Dermal exposure by ONU is not expected for this
condition ol" use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
No
Candles are solids, therefore, exposures to liquids
lor workers is not expected
Solid
Contact
Dermal
Workers
Yes
Candles are solids, therefore, exposures to solids
for workers is expected
Use of scented
candles
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
Misl
Inhalation/
1 )ermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
III ICB continuous action air fresheners do not
contain dusts: therefore, exposures to dust for
workers are not expected
Liquid/Solid
Contact
1 Jermal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directh handle the chemical
Cleaning and
Furnishing
Care Products
Cleaning
products,
including all-
purpose liquid
cleaner and
Spray
application of
Liquid
Contact
Dermal
Workers
Yes
HHCB is used as a liquid in sprays; therefore,
dermal exposures for workers are expected
cleaners and
deodorizers
(such as multi-
surface
cleaners and
Solid
Contact
1 Jermal
Workers
No
III ICB is used as a liquid in sprays: therefore,
exposures to solids for workers are not expected
bathroom
cleaners
(liquid,
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
68
-------
Life C \ ik-
(:ik-»or\
Ri'k'iisi- /
l''\|>IIMIIV
Siill;ili(i
I!\|)iisiiiv
Khmu-
Ki'ivpliir /
Piipuhiliiin
Plans l(i
l!\ alliak-
Kaliimak-
aerosol. foam,
spray, and
powder
cleaners)
bathroom
cleaners)
Mist
Inhalation/
1 )ermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
111ICM is used as a liquid in sprays: therefore,
exposures to dusts are not expected
Liquid/Solid
Contact
Dermal
ONU
No
Dermal exposure by ()NI J is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
HHCB is used as a liquid; therefore, dermal
exposures for workers are expected
Solid
Contact
1 )ennal
Workers
No
III ICM is used as a liquid: therefore, exposures to
solids for workers are not expected
Application of
liquid cleaners
(such as floor
cleaners and
hard-surface
cleaners)
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmllg) at
room temperature, EPA plans to evaluate
inhalation pathway
Mist
Inhalation/
1 )ermal
Workers.
ONLJ
No
Mist generation is not expected during this use
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
III ICM is used as a liquid: therefore, exposures to
dust for workers are not expected
Liquid/Solid
Contact
1 )ennal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
1 )ermal
Workers
Yes
The potential for dermal exposure to workers
exists during aerosol cleaner use
Solid
Contact
1 )ermal
Workers
No
111 ICM is used as a liquid in aerosols: therefore,
exposures to solids for workers are not expected
Application of
aerosol
cleaning
product
Vapor
Inhalation
Workers.
ONU
No
Due to the low volatility (VP = 0.000545 mml Ig)
of 111 ICM, inhalation exposures from aerosol
applications are expected to be dominated by the
aerosol mist, such that exposures to vapors
evaporating from the mist droplets does not
contribute significantly to 111 ICM inhalation
exposures for this use
Mist
Inhalation/
Dermal
Workers,
ONU
Yes
Mist generation is expected during aerosol
application
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
III ICM is used as a liquid in aerosols: therefore,
exposures to dusts are not expected
69
-------
Life C \ ik-
(:ik-»or\
Ri'k'iisi- /
l''\|>IIMIIV
Siill;ili(i
I!\|)iisiiiv
l';illi\\;i\
Khmu-
Ri'i'i'pliir /
Piipuhiliiin
I'kms l(i
l!\ ;illl;ik-
K;iliim;ik-
Liquid/Solid
Contact
Dermal
ONIJ
No
Dermal exposure by ()Nl J is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
No
III Id J cleaning powders are solids: therefore,
dermal exposures lor workers are not expected
Application of
powder
cleaners and
deodorizers
(such as hard
surface
cleaners and
carpet and
Solid
Contact
Dermal
Workers
Yes
HHCB cleaning powders are solids; therefore,
exposures to solids for workers are expected
Vapor
Inhalation
Workers.
ONIJ
No
LPA plans to evaluate inhalation pathway through
dust exposure
Mist
Inhalation/
1 )ermal
Workers.
ONIJ
No
Mist generation is not expected during this use
room
deodorizers)
Dust
Inhalation/
1 )ermal
Workers.
ONIJ
Yes
Solid dust exposure is expected as the products are
powders
Liquid/Solid
Contact
1 )ermal
ONIJ
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
HHCB is used as a liquid; therefore, exposures to
solids for workers are not expected
Solid
Contact
1 )ermal
Workers
No
IIIICU is used as a liquid; therefore, exposures to
solids for workers are not expected
Application of
liquid laundry
detergent,
fabric softener
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
Laundry and
Laundry
products,
including
liquid laundry
detergent and
fabric softener
Mist
Inhalation/
1 )ermal
Workers.
ONIJ
No
Mist generation is not expected during this use
Dishwashing
Products
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
IIIICU is used as a liquid; therefore, exposures to
dust lor workers are not expected
Liquid/Solid
Contact
Dermal
ONU
No
Dermal exposure by ()NI J is not expected for this
condition of use as they are not expected to
directly handle the chemical
Application of
solid laundry
detergent
Liquid
Contact
Dermal
Workers
No
III ICU washing powders are solids; therefore,
dermal exposures lor workers are not expected
Solid
Contact
Dermal
Workers
Yes
HHCB washing powders are solids; therefore,
exposures to solids for workers are expected
70
-------
Life C \ ik-
(:ik-»or\
Ri'k'iisi- /
l''\|>IIMIIV
Siill;ili(i
I!\|)iisiiiv
Khmu-
Ri'i'i'pliir /
Piipuhiliiin
Plans l(i
l!\ alliak-
Kaliimak-
Vapor
Inhalation
Workers.
ONU
No
LPA plans to evaluate inhalation pathway through
dust exposure
Mist
Inhalation/
Dermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
I )ermal
Workers.
ONU
Yes
Solid dust exposure is expected as the products are
pow ders
Liquid/Solid
Contact
1 )ermal
ONU
No
Dermal exposure by ONU is not expected lor this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
1 )ermal
Workers
No
IIIICU plastic and rubber packagings are solids;
therefore, dermal exposures lor workers are not
expected
Solid
Contact
Dermal
Workers
Yes
IJlICli plastic and rubber packagings are solids;
therefore, exposures to solids for workers are
expected
Plastic and
Plastic and
Interaction
with plastic
and rubber
packaging
Vapor
Inhalation
Workers.
ONU
No
LPA plans to evaluate inhalation pathway through
dust exposure
Rubber
Products
rubber
products
Mist
Inhalation/
Dermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
1 )ermal
Workers.
ONU
No
No dust exposure is expected as the IIIICU in the
product will be entrained in the packaging and not
handled in a way that will result in dust generation
(e.g., it will not be cut or sawed)
Liquid/Solid
Contact
Dermal
No
Dermal exposure by ()Nl J is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
IIIICU is used as a liquid; therefore, exposures to
solids for workers are not expected
Laboratory
Chemicals
Worker
Solid
Contact
1 )ermal
Workers
No
IIIICU is used as a liquid; therefore, exposures to
solids for workers are not expected
Other Uses
handling
HHCB
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
Mist
Inhalation/
1 )ermal
Workers.
ONU
No
Mist generation is not expected during this use
71
-------
Life C \ ik-
Slum-
(:ili-»or\
Ri-k-iisi- /
Siill;ili(i
I!\|)iisiiiv
Khmu-
Ri'i'i'pliir /
Piipuhiliiin
I'kms l(i
l!\ ;illl;ik-
K;iliim;ik-
Dust
Inhalation/
I )ermal
Workers.
ONU
No
IIIICU is used as a liquid; therefore, exposures to
dust for workers are not expected
Liquid/Solid
Contact
] )ennal
ONIJ
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid
Contact
Dermal
Workers
Yes
The potential for dermal exposure to workers
exists during this use as both liquid and solid
formulations may be disposed
Solid
Contact
Dermal
Workers
Yes
The potential for dermal exposure to workers
exists during this use as both liquid and solid
formulations may be disposed
Waste
Handling,
Treatment
and Disposal
Disposal of
HHCB wastes
Worker
Vapor
Inhalation
Workers,
ONU
Yes
Due to its volatility (VP = 0.000545 mmHg) at
room temperature, EPA plans to evaluate
inhalation pathway
Disposal
handling of
wastes
Mist
Inhalation/
Dermal
Workers.
ONU
No
Mist generation is not expected during this use
Dust
Inhalation/
Dermal
Workers
Yes
HHCB solid waste may create solid dust during
disposal
Dust
Inhalation/
I )ermal
ONU
No
Dermal exposure by ()Nl J is not expected for this
condition of use as they are not expected to
directly handle the chemical
Liquid/Solid
Contact
Dermal
ONU
No
Dermal exposure by ONU is not expected for this
condition of use as they are not expected to
directly handle the chemical
72
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Appendix G SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR CONSUMER
ACTIVITIES AND USES
Table Apx G-l. Consumer Exposure Conceptual Model Supporting Table
life
( \cle
Sl;i»e
( ;i(eiion
Siihmleiion
Uck'iiso from Source
l'l\|)OMIIV
Pillliwin
Koulc
Kcccplor
I'lilllS lo
Kiilioiiiilo
Consumer
Use
Paper
Products
Paper
Products
Direct contact through
application or use of
products using HHCB-
based products
Liquid (HHCB
fragrance oil)
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a liquid, and is in scope
Long-term
emission/mass-transfer
Vapor
Inhalation
Consumers
and
Bystanders
Yes
Due to its volatility (VP = 0.000545
mmHg) at room temperature, inhalation
pathway is in scope
Consumer
Use
Plastic and
Rubber
Products
Plastic and
Rubber
Products
Direct contact through
application or use of
products using HHCB-
based products
Liquid (HHCB
fragrance oil)
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a liquid, and is in scope
Long-term
emission/mass-transfer
Vapor
Inhalation
Consumers
and
Bystanders
Yes
Due to its volatility (VP = 0.000545
mmHg) at room temperature, inhalation
pathway is in scope
Consumer
Use
Air Care
Products
Air Care
Products
Direct contact through
application or use of
products using HHCB-
based products/
Long-term
emission/mass-transfer
Vapor/Mist
Inhalation
Consumers
and
Bystanders
Yes
Vapor, and mist generation is expected
during aerosol application. Due to its
volatility (VP = 0.000545 mmHg) at room
temperature, inhalation of vapor and mist
pathway is in scope
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a spray, and is in scope
73
-------
l.ilV
Cu-le
Sl;i»e
( iileiion
Siihciilciinn
Koloiisc from Source
l'l\|)OMIIV
PillllWil.t
Rouk'
Km'plor
Phins (o
l.\;ilu;ik'
Kiilioiiiilo
Consumer
Use
Cleaning
and
Furnishing
Care
Products
Cleaning and
Furnishing
Care Products
Direct contact through
application or use of
products using HHCB-
based products
Liquid
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a liquid, and is in scope
Direct contact through
application or use of
products using HHCB-
based products/
Long-term
emission/mass-transfer,
Direct Transfer to Dust
Vapor/Mist
Inhalation
Consumers
and
Bystanders
Yes
Vapor, and mist generation is expected
during aerosol application. Due to its
volatility (VP = 0.000545 mmHg) at room
temperature, inhalation of vapor and mist
pathway is in scope
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a spray, and is in scope
Dust
Inhalation
Consumers
and
Bystanders
Yes
Solid dust exposure pathway is expected as
during use of powdered soaps containing
HHCB, and is in scope
Consumer
Use
Laundry and
Dishwashing
Products
Laundry and
Dishwashing
Products
Direct contact through
application or use of
products using HHCB-
based products
Liquid
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a liquid, and is in scope
Direct contact through
application or use of
products using HHCB-
based products/
Long-term
emission/mass-transfer,
Direct Transfer to Dust
Vapor/Mist
Inhalation
Consumers
and
Bystanders
Yes
Vapor, and mist generation is expected
during aerosol application. Due to its
volatility (VP = 0.000545 mmHg) at room
temperature, inhalation of vapor and mist
pathway is in scope
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a spray, and is in scope
74
-------
l.ilV
Cu-le
Sl;i»e
( iileiion
Siihciilciinn
Koloiisc from Source
l'l\|)OMIIV
PillllWil.t
Roulc
Km'plor
Phins lo
Kiilioiiiilo
Dust
Inhalation
Consumers
and
Bystanders
Yes
Solid dust exposure pathway is expected as
during use of powdered soaps containing
HHCB, and is in scope
Consumer
Use
Other
Laboratory
Chemicals
Direct contact through
application or use of
products using HHCB-
based products
Liquid
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a liquid, and is in scope
Direct contact through
application or use of
products using HHCB-
based products/
Long-term
emission/mass-transfer
Vapor/Mist
Inhalation
Consumers
and
Bystanders
Yes
Vapor, and mist generation is expected
during aerosol application. Due to its
volatility (VP = 0.000545 mmHg) at room
temperature, inhalation of vapor and mist
pathway is in scope
Dermal
Consumers
Yes
Dermal exposure to consumers exists
during use as a spray, and is in scope
75
-------
Appendix H SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR
ENVIRONMENTAL RELEASES AND WASTES
Table A
ox H-l. Genera
Population and Environmental Exposure Conceptual Model Supporting Table
I .i IV
( >clo
Csilciion
Release
r.\|)(isuiv
P;illiw ;i> /
Medi.i
r.\|)(isui\'
Koii les
Reeeplor /
Population
Phins (o
R;iliun;ile
Near facility
ambient air
concentrations
Inhalation
General
Population
Yes
Emissions to Air
Emissions to Air
Indirect
deposition to
nearby bodies
of water and
soil catchments
Oral
Dermal
General
Population
Yes
TBD
Aquatic and
Terrestrial
Receptors
Yes
HHCB deposition to nearby
bodies of water and soil are
expected exposure pathways, not
covered under other EPA
regulations, and, therefore in
scope.
All
Wastewater or
Liquid Wastes
Industrial pre-
treatment and
wastewater
treatment, or POTW
Direct release
into surface
water and
indirect
partitioning to
sediment
TBD
Aquatic and
Terrestrial
Receptors
Yes
Release of HHCB into surface
water and indirect partitioning to
sediment exposure pathways to
aquatic and terrestrial receptors
will be analyzed
Oral
Dermal
General
Population
Yes
Release of HHCB into surface
water and indirect partitioning to
sediment and bioaccumulation
exposure pathways to the general
population will be analyzed.
Drinking Water
via Surface or
Ground Water
Oral
Dermal and
Inhalation
(e.g.
showering)
General
Population
Yes
Release of HHCB into surface
water and indirect partitioning to
drinking water is an expected
exposure pathway.
Biosolids:
application to
soil and/or
migration to
groundwater
and/or surface
water
Oral (e.g.
ingestion of
soil)
Inhalation
General
Population
Yes
TBD
Terrestrial
receptors
EPA will analyze the pathway
from biosolids to the general
population and terrestrial species.
Yes
76
-------
1 -i IV
( > cle
( iilcjion
Ki'k'iisi*
I'1\|)osiiiv
Pillliw ;¦> /
Modiii
K\|)umiiv
Koii Ics
Km'plor /
Populiilion
I'lilllS lo
I.MllllillC
Kiilioiiiilc
Disposal
Solid and Liquid
Wastes
Municipal landfill
and other land
disposal
Leachate to
soil, ground
water and/or
mitigation to
surface water
Oral
Dermal
General
Population
Yes
EPA will analyze the pathway
from municipal landfills and
other land disposal to the general
population, aquatic and terrestrial
receptors.
TBD
Aquatic and
Terrestrial
Receptors
77
------- |