EPA Document# EPA-740-R-20-001
August 2020
Office of Chemical Safety and
Pollution Prevention
Final Scope of the Risk Evaluation for
0-Dichlorobenzene
CASRN 95-50-1
August 2020
SEPA
United States
Environmental Protection Agency
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TABLE OF CONTENTS
ACKNOWLEDGEMENTS 7
ABBREVIATIONS AND ACRONYMS 8
EXECUTIVE SUMMARY 12
1 INTRODUCTION 15
2 SCOPE OF THE EVALUATION 15
2.1 Reasonably Available Information 15
2.1.1 Search of Gray Literature 16
2.1.2 Search of Literature from Publicly Availab le Databases (Peer-reviewed Literature) 17
2.1.3 Search of TSCA Submissions 26
2.2 Conditions of Use 27
2.2.1 Categories and Subcategories of Conditions of Use Included in the Scope of the Risk
Evaluation 28
2.2.2 Activities Excluded from the Scope of the Risk Evaluation 30
2.2.3 Production Volume 31
2.2.4 Overview of Conditions of Use and Lifecycle Diagram 32
2.3 Exposures 34
2.3.1 Physical and Chemical Properties 34
2.3.2 Environmental Fate and Transport 36
2.3.3 Releases to the Environment 36
2.3.4 Environmental Exposures 38
2.3.5 Occupational Exposures 38
2.3.6 Consumer Exposures 39
2.3.7 General Population Exposures 40
2.4 Hazards (Effects) 40
2.4.1 Environmental Hazards 40
2.4.2 Human Health Hazards 40
2.5 Potentially Exposed or Susceptible Subpopulations 41
2.6 C onceptual Mod el s 41
2.6.1 Conceptual Model for Industrial and Commercial Activities and Uses: Potential Exposures
and Hazards 42
2.6.2 Conceptual Model for Consumer Activities and Uses 44
2.6.3 Conceptual Model for Environmental Releases and Wastes: Potential Exposures and
Hazards (Regulatory Overlay) 46
2.6.3.1 Exposure Pathways and Risks Addressed by Other EPA Administered Statutes 48
2.6.3.2 Conceptual Model for Environmental Releases and Wastes: Potential Exposures and
Hazards 55
2.7 Analysis Plan 57
2.7.1 Physical and Chemical Properties and Environmental Fate 57
2.7.2 Exposure 58
2.7.2.1 Environmental Releases 58
2.7.2.2 Environmental Exposures 59
2.7.2.3 Occupational Exposures 61
2.7.2.4 Consumer Exposures 62
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2.7.2.5 General Population 63
2.7.3 Hazards (Effects) 65
2.7.3.1 Environmental Hazards 65
2.7.3.2 Human Health Hazards 66
2.7.4 Summary of Risk Approaches for Characterization 69
2.8 Peer Review 70
REFERENCES 71
APPENDICES 77
Appendix A ABBREVIATED METHODS FOR SEARCHING AND SCREENING 77
A. 1 Literature Search of Publicly Available Databases 77
A. 1.1 Search Term Genesis and Chemical Verification 77
A. 1.2 Publicly Available Database Searches 78
A. 1.2.1 Query Strings for the Publicly Available Database Searches on o-Dichlorobenzene 79
A.1.2.2 Data Prioritization for Environmental Hazard, Human Health Hazard, Fate and Physical
Chemistry 86
A. 1.2.3 Data Prioritization for Occupational Exposures and Environmental Releases and
General Population, Consumer and Environmental Exposures 87
A.2 Peer-Reviewed Screening Process 87
A.2.1 Inclusion/Exclusion Criteria 88
A.2.1.1 PECO for Environmental and Human Health Hazards 88
A.2.1.2 PECO for Consumer, Environmental, and General Population Exposures 90
A.2.1.3 RESO for Occupational Exposure and Environmental Releases 91
A.2.1.4 PESO for Fate and Transport 93
A.2.1.5 Generation of Hazard Heat Maps 96
A.3 Gray Literature Search and Screening Strategies 97
A.3.1 Screening of Gray Literature 97
A.3.2 Initial Screening of Sources using Decision Logic Tree 98
A.3.3 TSCA Submission Searching and Title Screening 99
A.3.4 Gray Literature Search Results for o-Dichlorobenzene 100
Appendix B PHYSICAL AND CHEMICAL PROPERTIES OF o-DICHLOROBENZENE.... 104
Appendix C ENVIRONMENTAL FATE AND TRANSPORT PROPERTIES OF o-
DICHLOROBENZENE 105
Appendix D REGULATORY HISTORY 107
D. 1 Federal Laws and Regulations 107
D.2 State Laws and Regulations 112
D.3 International Laws and Regulations 114
Appendix E PROCESS, RELEASE AND OCCUPATIONAL EXPOSURE INFORMATION 116
E. 1 Process Information 116
E.l.l Import 116
E. 1.2 Processing and Distribution 116
E. 1.2.1 Processing as a Reactant 116
E. 1.2.2 Incorporated into a Formulation, Mixture or Reaction Product 116
E.1.3 Uses 117
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E. 1.3.1 Solvents (Which Become Part of Product Formulation or Mixture) 117
E. 1.3.2 Functional Fluids (Closed System) 117
E. 1.3.3 Ink, Toner, and Colorant Products 118
E. 1.3.4 Coatings and Paints, Thinners, Paint Removers 118
E.1.3.5 Lubricants and Greases 118
E. 1.3.6 Fuels and Related Products 118
E. 1.3.7 Air Care Products 118
E.1.3.8 OtherUses 119
E.1.4 Disposal 119
E.2 Preliminary Occupational Exposure Data 119
Appendix F SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR INDUSTRIAL
AND COMMERCIAL ACTIVITIES 121
Appendix G SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR CONSUMER
ACTIVITIES AND USES 131
Appendix H SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR
ENVIRONMENTAL RELEASES AND WASTES 135
LIST OF TABLES
Table 2-1. Results of Title Screening of Submissions to EPA under Various Sections of TSCAa 27
Table 2-2. Categories and Subcategories of Conditions of Use Included in the Scope of the Risk
Evaluation 28
Table 2-3. Physical and Chemical properties of o-Dichlorobenzene 34
Table 2-4. Summary of o-Dichlorobenzene TRI Production-Related Waste Managed in 2018 37
Table 2-5. Summary of Releases of o-Dichlorobenzene to the Environment During 2018 38
Table 2-6. Categories and Sources of Environmental Release Data 58
Table 2-7. Potential Sources of Occupational Exposure Data 61
LIST OF FIGURES
Figure 2-1. Gray Literature Tags by Discipline for o-Dichlorobenzene 17
Figure 2-2. Peer-reviewed Inventory Tree Literature- Physical and Chemical Properties Search Results
for o-Dichlorobenzene 18
Figure 2-3. Peer-reviewed Literature Inventory Tree - Fate and Transport Search Results for o-
Dichlorobenzene 19
Figure 2-4. Peer-reviewed Literature Inventory Heat Map - Fate and Transport Search Results for o-
Dichlorobenzene 20
Figure 2-5. Peer-reviewed Literature Inventory Tree - Engineering Search Results for o-
Dichlorobenzene 21
Figure 2-6. Peer-reviewed Literature Inventory Heat Map - Engineering Search Results for o-
Dichlorobenzene 22
Figure 2-7. Peer-reviewed and Gray Literature Inventory Tree - Exposure Search Results for o-
Dichlorobenzene 23
Figure 2-8. Peer-reviewed and Gray Literature Inventory Heat Map -Exposure Search Results foro-
Dichlorobenzene 24
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Figure 2-9. Peer-reviewed Literature Inventory Tree - Human Health and Environmental Hazards Search
Results for o-Dichlorobenzene 25
Figure 2-10. Peer-reviewed Literature Inventory Heat Map - Human Health and Environmental Hazards
Search Results for o-Dichlorobenzene 26
Figure 2-11. o-Dichlorobenzene Life Cycle Diagram 33
Figure 2-12. Box and Whisker Plots of Reported Physical and Chemical Property Values 36
Figure 2-13. o-Dichlorobenzene Conceptual Model for Industrial and Commercial Activities and Uses:
Worker and Occupational Non-User Exposures and Hazards 43
Figure 2-14. o-Dichlorobenzene Conceptual Model for Consumer Activities and Uses: Consumer
Exposures and Hazards 45
Figure 2-15. o-Dichlorobenzene Conceptual Model for Environmental Releases and Wastes:
Environmental and General Population Exposures and Hazards (Regulatory Overlay).. 47
Figure 2-16. o-Dichlorobenzene Conceptual Model for Environmental Releases and Wastes:
Environmental and General Population Exposures and Hazards 56
LIST OF APPENDIX TABLES
Table_Apx A-l. Sources of Verification for Chemical Names and Structures 77
TableApx A-2. Summary of Data Sources, Search Dates and Number of Peer-Reviewed Literature
Search Results for o-Dichlorobenzene 79
Table Apx A-3. Hazards Title and Abstract and Full-text PECO Criteria for o-Dichlorobenzene 88
Table Apx A-4. Major Categories of Potentially Relevant Supplemental Material for o-Dichlorobenzene
89
Table Apx A-5. Generic Inclusion Criteria for the Data Sources Reporting Exposure Data on General
Population, Consumers and Environmental Receptors 90
Table Apx A-6. Pathways Identified as Supplemental for o-Dichlorobenzenea 91
Table Apx A-7. Inclusion Criteria for Data Sources Reporting Engineering and Occupational Exposure
Data 91
Table Apx A-8. Engineering, Environmental Release and Occupational DataNecessary to Develop the
Environmental Release and Occupational Exposure Assessments 92
Table Apx A-9. Inclusion Criteria for Data or Information Sources Reporting Environmental Fate and
Transport Data 94
Table Apx A-10. FateEndpoints and Associated Processes, Media and Exposure Pathways Considered
in the Development of the Environmental Fate Assessment 95
Table_Apx A-l 1. Decision Logic Tree Overview 99
Table Apx A-12. Gray Literature Sources that Yielded Results for o-Dichlorobenzene 100
Table_Apx B-l. Summary Statistics for Reviewed Physical Properties 104
Table Apx C-l. Environmental Fate and Transport Properties of o-Dichlorobenzene 105
Table_Apx D-l. Federal Laws and Regulations 107
Table_Apx D-2. State Laws and Regulations 112
Table Apx D-3. Regulatory Actions by other Governments, Tribes, and International Agreements.... 114
Table Apx E-l. Summary of NIOSHHHEs with Monitoring for o-Dichlorobenzene a 120
TableApx F-l. Worker and Occupational Non-User Exposure Conceptual Model Supporting Table 121
Table Apx G-l. Consumer Exposure Conceptual Model Supporting Table 131
Table Apx H-l. Environmental Exposure Conceptual Model Supporting Table 135
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LIST OF APPENDIX FIGURES
Figure Apx A-l. Decision Logic Tree Used to Screen Gray Literature Results
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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),
GDIT (Contract No. HHSN316201200013W), ERG (Contract No. EP-W-12-006), ICF (Contract No.
68HERC19D0003), SRC (Contract No. 68HERH19D0022), and Versar (Contract No. EP-W-17-006).
EPA also acknowledges the contributions of technical experts from EPA's Office of Research and
Development.
Docket
Supporting information can be found in public docket: EPA-HQ-QPPT-2018-0444.
Disclaimer
Reference herein to any specific commercial products, process or service by tradename, 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
ng
Microgram(s)
AAL
Allowable Ambient Levels
AC
Acute concentration
ACGIH
American Conference of Government Industrial Hygienists
ADME
Absorption, Distribution, Metabolism, and Excretion
Apx
Appendix
ATSDR
Agency for Toxic Substances and Disease Registry
AUC
Area Under the Curve
AWQC
Ambient Water Quality Criteria
BAF
Bioaccumulation Factor
BCF
Bioconcentration Factor
BW3/4
Body weight scaling to the 3/4 power
CAA
Clean Air Act
CARB
California Air Resources Board
CASRN
Chemical Abstracts Service Registry Number
CBI
Confidential Business Information
CCD
Chemical Control Division
CCL
C ont aminant C and id at e Li st
CDC
Centers for Disease Control
CDR
Chemical Data Reporting
CEHD
Chemical Exposure Health Data
CERCLA
Comprehensive Environmental Response, Compensation and Liability Act
CESSD
Chemistry, Economics and Sustainable Strategies Division
CFR
Code of Federal Regulations
ChemSTEER
Chemical Screening Tool for Exposure and Environmental Releases
COC
Concentration of Concern
CoRAP
Community Rolling Action Plan
COU
Conditions of Use
CPCat
Chemical and Product Categories
CPID
Consumer Product Information Database
CSCL
Chemical Substances Control Law
DHHS
Department of Health and Human Services
DMR
Discharge Monitoring Report
DNA
Deoxyribonucleic Acid
EC
Engineering controls
ECOTOX
ECOTOXicology knowledgebase
ED
Exposure duration
E-FAST
Exposure and Fate Assessment Screening Tool
E-FAST2
Exposure and Fate Assessment Screening Tool version 2
EPA
Environmental Protection Agency
EPCRA
Emergency Planning and Community Right-to-Know Act
EPI Suite™
Estimation Program Interface Suite™
EPS
Expanded Polystyrene
ERG
Eastern Research Group, Inc.
ESD
Emission Scenario Document
EU
European Union
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FDA Food and Drug Administration
FF Far field
g/L Gram(s) per Liter
HERO Health and Environmental Research Online
Hg Mercury
HHE Health Hazard Evaluation
HMTA Hazardous Materials Transportation Act
HPV High Production Volume
HQ Headquarters
HSDB Hazardous Substances Data Bank
HUC Hydrologic Unit Code
IA Indoor air
I ARC International Agency for Research on Cancer
IECCU Indoor Environmental Concentrations in Buildings with Conditioned and
Unconditioned Zones
IMIS Integrated Management Information System
K Thousand
kg Kilogram(s)
km Kilometer(s)
L Liter(s)
lb Pound
LC50 Lethal Concentration of 50% test organisms
LEV Local exhaust ventilation
LOAEL Lowest Observed Adverse Effect Level
LOEC Lowest Observed Effect Concentration
m Meter(s)
m3 Cubic Meter(s)
MACT Maximum Achievable Control Technology
MCL Maximum Contaminant Level
MCLG Maximum Contaminant Level Goal
mg Milligram(s)
mg/kg-bw Milligram(s) per kilogram body weight
mg/L Milligram(s) per Liter
mg/m3 Milligram(s) per cubic meter
mg/mL Milligram(s) per milliliter
mmHg Millimeter(s) of Mercury
MOA Mode of Action
MOE Margin of exposure
MRL Minimal Risk Level
n number
N/A Not Applicable
NHANES National Health and Nutrition Examination Survey
NICNAS National Industrial Chemicals Notification and Assessment Scheme
(Australia)
NIH National Institutes of Health
NIOSH National Institute for Occupational Safety and Health
NITE National Institute of Technology and Evaluation
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NOAEL
No Observed Adverse Effect Level
NOEC
No Observed Effect Concentration
NPDES
National Pollutant Discharge Elimination System
NPDWR
National Primary Drinking Water Regulations
NPL
National Priorities List
NPRI
National Pollutant Release Inventory
NR
Not Reported
NRC
National Research Council
NSPS
New Source Performance Standards
NTP
National Toxicology Program
NWIS
National Water Information System
OCSPP
Office of Chemical Safety and Pollution Prevention
OECD
Organisation for Economic Co-operation and Development
OEHHA
Office of Environmental Health Hazard Assessment (California)
OEL
Occupational Exposure Limit
OES
Occupational Exposure Scenario
OLEM
Office of Land and Emergency Management
ONU
Occupational Non-User
OPPT
Office of Pollution Prevention and Toxics
ORD
Office of Research and Development
OSHA
Occupational Safety and Health Administration
OST
Office of Science and Technology
OSWER
Office of Solid Waste and Emergency Response
OW
Office of Water
P
Persistence
PBPK
Physiologically Based Pharmacokinetic
PBT
Persistent, Bioaccumulative, Toxic
PECO
Population, Exposure, Comparator and Outcome
PEL
Permissible Exposure Limit
PESS
Potentially Exposed or Susceptible Subpopulations
POD
Point of Departure
POTW
Publicly Owned Treatment Works
ppb
Part(s) per billion
PPE
Personal Protective Equipment
ppm
Part(s) per million
PS
Point Source
PV
Production Volume
PWS
Public Water System
QA
Quality Assurance
QC
Quality Control
QSAR
Quantitative Structure Activity Relationship
RA
Risk Assessment
RAD
Risk Assessment Division
RCRA
Resource Conservation and Recovery Act
REACH
Registration, Evaluation, Authorisation and Restriction of Chemicals (European
Union)
REL
Recommended Exposure Limit
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RfC
Reference Concentration
RfD
Reference dose
RQ
Risk Quotient
SAB
Science Advisory Board
SACC
Science Advisory Committee on Chemicals
SAR
Structure-activity relationship
SARA
Superfund Amendments and Reauthorization Act
SD
Standard deviation
SDS
Safety Data Sheet
SDWA
Safe Drinking Water Act
SIC
Standard Industrial Classification
SIDS
Screening Information Dataset
STEL
Short-term Exposure Limit
STORET
STORage and RETrieval (water quality data warehouse)
SVOC
Semivolatile Organic Compounds
SWC
Surface Water Concentration
T
Toxic (used withPBT)
TIAB
Title and Abstract
TLV
Threshold Limit Value
TRI
Toxics Release Inventory
TSCA
Toxic Substances Control Act
TTO
Total Toxic Organics
TWA
Time-weighted average
U.S.
United States
U.S.C.
United States Code
UCMR
Unregulated Contaminant Monitoring Rule
UIC
Underground Injection Control
US EPA
United States Environmental Protection Agency
USGS
United States Geological Survey
VOC
Volatile Organic Compound
VP
Vapor Pressure
WQP
Water Quality Portal
WQX
Water Quality Exchange
WWT
Wastewater Treatment
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EXECUTIVE SUMMARY
In December 2019, EPA designated o-dichlorobenzene (CASRN 95-50-1) as a high-priority substance
for risk evaluation following the prioritization process as required by Section 6(b) of the Toxic
Substances Control Act (TSCA) and implementing regulations (40 CFR Part 702) (Docket ID: EPA-
HQ-QPPT-2019-0131). The first step of the risk evaluation process is the development of the draft scope
document. EPA published the Draft Scope of the Risk Evaluation for o-Dichlorobenzene CASRN 95-50-
1 (EPA Document No. EPA-740-D-20-001) (U.S. EPA. 2020c) and provided a 45-day comment period
on the draft scope per 40 CFR 702.41(c)(7). EPA has considered comments received (Docket ID: EPA-
HQ-QPPT-2018-0444) during the public comment period to inform the development of this final scope
document, and public comments received will continue to inform the development of the risk evaluation
for o-dichlorobenzene. This document fulfills the TSCA requirement to issue a final scope document per
TSCA Section 6(b)(4)(D) and as described in 40 CFR 702.41(c)(8). The scope foro-dichlorobenzene
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.
General Information. o-Dichlorobenzene is a colorless, volatile liquid that is poorly soluble in water but
miscible with most organic solvents. It has a total production volume in the United States between
100,000 and 500,000 pounds.
Reasonably Available Information. EPA leveraged the data and information sources already described
in the Proposed Designation of o-Dichlorobenzene (CASRN95-50-1) as a High-Priority Substance for
Risk Evaluation (U.S. EPA. 2019e) to inform the development of this scope document. Furthermore,
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 are
provided in Section 2.1. EPA used the systematic review process described in Appendix A to search for
and screen reasonably available information, including information already in EPA's possession, for
inclusion in the risk evaluation. This information includes the hazards, exposures, PESS, and conditions
of use that may help inform the risk evaluation foro-dichlorobenzene. EPA has focused on the data
collection phase (consisting of data search, data screening, and data extraction) during the preparation of
the scope document, whereas the data evaluation and integration stages will occur during the
development of the risk evaluation and thus are not part of the scoping activities described in this
document. EPA will consider additional information identified following publication of this scope
document, as appropriate, in developing the risk evaluation, including the Chemical Data Reporting
(CDR) information that the Agency will receive by the end of November 2020.
Conditions of Use. EPA plans to evaluate the importing, processing, distribution in commerce,
industrial, commercial and consumer uses, and disposal of o-dichlorobenzene in the risk evaluation, o-
Dichlorobenzene is imported into the United States. The chemical is processed as a reactant and
incorporated into formulation, mixture, or reaction products. The identified processing activities also
include recycling of o-dichlorobenzene. Several industrial and commercial uses were identified that
range from use as a solvent in dyes and pigments to use in lubricant and degreaser products and in inks
and paint strippers. Consumer uses were reported in lubricant and degreaser products, air care products,
and other uses such as ceramics glazing and cleaning products. EPA identified these conditions of use
from information reported to EPA through CDR and Toxics Release Inventory (TRI) reporting,
published literature, public comments, and consultation with stakeholders for both uses currently in
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production and uses whose production may have ceased. EPA revised the conditions of use in the final
scope of the risk evaluation based on additional information and public comments (Docket ID: EPA-
HQ-QPPT-2018-0444) on the draft scope document for o-dichlorobenzene. EPA is aware of information
reporting use of o-dichlorobenzene in pesticides; however, they are not conditions of use for the
chemical substance as defined in TSCA § 3(2) and (4). Section 2.2 provides details about the conditions
of use within the scope of the risk evaluation.
Conceptual Model The conceptual models for o-dichlorobenzene 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 considered reasonably available information as
well as public comments received on the draft scope document for o-dichlorobenzene in finalizing the
exposure pathways, exposure routes, and hazards EPA plans to evaluate in the risk evaluation. As a
result, EPA plans to focus the risk evaluation for o-dichlorobenzene on the following exposures, hazards
and receptors.
• Exposures (Pathways and Routes), Receptors and PESS. EPA plans to evaluate releases to the
environment as well as human and environmental exposures resulting from the conditions of use
of o-dichlorobenzene that EPA plans to consider in risk evaluation. Exposures for o-
dichlorobenzene are discussed in Section 2.3. Additional information gathered through
systematic review searches will also inform expected exposures.
EPA's plan for evaluating environmental exposure pathways in the scope of the risk evaluation
considers whether and how other EPA administered statutes and regulatory programs cover o-
dichlorobenzene in media pathways falling under the jurisdiction of those authorities. Section
2.6.3.1 discusses pathways under the jurisdiction of other EPA-administered laws. In Section
2.6.3.2, EPA presents the conceptual model describing the identified exposures (pathways and
routes), receptors and hazards associated with the conditions of use of o-dichlorobenzene within
the scope of the risk evaluation.
EPA considered reasonably available information and comments received on the draft scope for
o-dichlorobenzene in determining the human and environmental exposure pathways, routes,
receptors and PESS for inclusion in the final scope. EPA plans to evaluate the following human
and environmental exposure pathways, routes, receptors and PESS in the scope of the risk
evaluation:
- Occupational exposure: EPA plans to evaluate exposures to workers and occupational
non-users (ONUs) via the inhalation route and exposures to workers via the dermal route
associated with manufacturing, processing, industrial/commercial use, and disposal of o-
dichlorobenzene.
- Consumer and bystander exposure: EPA plans to evaluate the inhalation and dermal
exposure to o-dichlorobenzene when consumers are using lubricants and greases, fuels
and related products, air care and other products.
- General population exposure: EPA plans to evaluate general population exposure to o-
dichlorobenzene via inhalation of ambient air.
- PESS: EPA plans to include children, women of reproductive age (e.g., pregnant
women), workers and consumers as receptors and PESS in the risk evaluation.
- Environmental exposure: EPA plans to evaluate exposure to o-dichlorobenzene for
aquatic and terrestrial receptors.
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• Hazards. Hazards for o-dichlorobenzene are identified in Section 2.4. EPA completed
preliminary reviews (e.g., federal and international government chemical assessments) to
identify potential environmental and human health hazards for o-dichlorobenzene as part of the
prioritization (U.S. EPA. 2019e) and scoping process (U.S. EPA. 2020c). EPA also considered
reasonably available information collected through systematic review methods as outlined in
Appendix A and public comments received on the draft scope for o-dichlorobenzene in
determining the broad categories of environmental and human health hazard effects to be
evaluated in the risk evaluation. EPA will use systematic review methods to evaluate the
epidemiological and toxicological literature for o-dichlorobenzene.
EPA plans to evaluate all potential environmental and human health hazard effects identified for
o-dichlorobenzene in Sections 2.4.1 and 2.4.2, respectively. Identified through the data screening
phase of systematic review, the potential environmental hazard effects and related information
that EPA plans to consider forthe risk evaluation include: AD ME, PBPK, cancer,
developmental, endocrine, hematological and immune, mortality, musculoskeletal, nutritional
and metabolic, reproductive and respiratory for o-dichlorobenzene. Similarly, the potential
human health hazard effects and related information identified through prioritization and the data
screening phase of systematic review for o-dichlorobenzene that EPA plans to consider forthe
risk evaluation include: ADME, PBPK, cancer, cardiovascular, developmental, endocrine,
gastrointestinal, hematological and immune, hepatic, mortality, musculoskeletal, neurological,
nutritional and metabolic, ocular and sensory, renal, reproductive, respiratory and skin and
connective tissue.
Analysis Plan. The analysis plan for o-dichlorobenzene is presented in Section 2.7. The analysis plan
outlines the general science approaches that EPA plans to use for the various evidence streams (i.e.,
chemistry, fate, release and engineering, exposure, hazard) supporting the risk evaluation. The analysis
plan is based on EPA's knowledge of o-dichlorobenzene to date which includes review of identified
information as described in Section 2.1. Should additional data or approaches become reasonably
available, EPA may consider them forthe risk evaluation.
Peer Review. The draft risk evaluation for o-dichlorobenzene will be peer reviewed. Peer review will be
conducted in accordance with relevant and applicable methods for chemical risk evaluations, including
using EPA's Peer Review Handbook (U.S. EPA, 2015b) and other methods consistent with Section 26
of TSCA (see 40 CFR 702.45).
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1 INTRODUCTION
This document presents the scope of the risk evaluation to be conducted for o-dichlorobenzene 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 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), the Environmental Protection Agency (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 to conduct 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 nonrisk 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-HO-OPPT-2Q19-0131) (84 FR 71924, December 30, 2019), as required by TSCA § 6(b)(2)(B),
which initiated the risk evaluation process for those chemical substances. o-Dichlorobenzene is one of
the chemicals designated as a high priority substance for risk evaluation. On April 9, 2020, EPA
published the Draft Scope of the Risk Evaluation for o-Dichlorobenzene (EPA Document No. 740-D-20-
001) (85 FR 19941, April 9, 2020) (U.S. EPA, 2020c) for a 45-day public comment period. After
reviewing and considering the public comments received (Docket ID: EPA-HQ-QPPT-2018-0444) on
the draft scope document, EPA is now publishing this final scope document pursuant to 40 CFR
702.41(c)(8).
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 final scope document for o-dichlorobenzene. EPA leveraged the data and
information sources already collected 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. Databases containing publicly available, peer-reviewed literature;
2. Gray literature, which is defined as the broad category of data/information sources not found in
standard, peer-reviewed literature databases;
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 underTSCA Section 14 (40 CFR 702.33).
-------
3. Data and information submitted under TSCA Sections 4, 5, 8(e), and 8(d), as well as "for your
information" (FYI) submissions.
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.
Search terms were used to search each of the literature streams forgathering o-dichlorobenzene studies.
These terms and the methods used to develop them are listed in Appendix A. The studies resulting from
the search process were loaded into the EPA Health and Environmental Research Online (HERO)
database and then prioritized to screen first the literature likely relevant for each of the disciplines: fate,
physical/chemical properties, engineering, exposure and hazard. The tools and methods used to manage
the screening process are also outlined in Appendix A. The studies resulting from the search underwent
a title/abstract screening process, which tagged them by topic or category. Following this, a
determination was made to move studies forward into full-text screening. The criteria used in the
screening process for each discipline are found in the population, exposure, comparator, outcome
(PECO) statements listed in Appendix A. The screening process results are presented in the form of
literature inventory trees and evidence tables in Section 2.1.2. The screening process was conducted
based on EPA's planning, execution and assessment activities outlined in Appendix A.
EPA has focused on the data collection phase (consisting of data search, data screening, and data
extraction) during the preparation of the scope document, whereas the data evaluation and integration
stages will occur during the development of the 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.
2.1.1 Search of Gray Literature
EPA surveyed the gray literature2 and identified 108 search results relevant to EPA's risk evaluation
needs for o-dichlorobenzene. Appendix A.3.4 lists the gray literature sources that yielded 108 discrete
data or information sources relevant to o-dichlorobenzene. EPA further categorized the data and
information into the various topic areas (or disciplines) supporting the risk evaluation (e.g., physical and
chemical properties, environmental fate, ecological hazard, human health hazard, exposure,
engineering), and the breakdown is shown in Figure 2-1. EPA will consider additional reasonably
available information from gray literature if it becomes available during the risk evaluation phase.
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, technicalreports, reference books, dissertations, information on various stakeholderwebsites and
other databases.
16
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Gray Literature Tags by Discipline
0 25 50 75 100
Percent Tagged (%)
Figure 2-1. Gray Literature Tags by Discipline for o-Dichlorobenzene
The percentages across disciplines do not add up to 100%, as each source may provide data or
information for various topic areas (or disciplines).
2.1.2 Search of Literature from Publicly Available Databases (Peer-reviewed
Literature)
EPA has begun the systematic review process and has conducted searching and screening of the
reasonably available literature using the process outlined in Appendix A. This includes performing a
comprehensive search of the reasonably available peer review literature on physical and 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 o-dichlorobenzene. Eligibility criteria were applied in the form of PECO 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 (see Appendix A.2).
EPA plans to evaluate the reasonably available information identified for each discipline during the
development of the risk evaluation.
EPA created literature inventory trees to graphically illustrate the flow of data and information sources
following full-text screening (see Figure 2-2, Figure 2-3, Figure 2-5, Figure 2-7, Figure 2-9). For the
physical and chemical, fate, engineering and hazard literature, EPA used the Health Assessment
Workplace Collaborative (HAWC) tool to develop web-based literature inventory trees illustrating,
through interactive links, studies that were included or excluded. These literature inventory trees
enhance the transparency of the decisions resulting from the screening process described in Appendix A.
For each of the corresponding disciplines, the literature was tagged to be included for evaluation during
the risk evaluation process. Literature inventory trees for physical and chemical properties are provided
as static diagrams (Figure 2-2). For all other disciplines, static screen captures are provided in addition
to links to the interactive trees. The links show individual studies that were tagged as included,
excluded, or supplemental and excluded studies. Supplemental studies did not meet all inclusion criteria
but may be considered during the risk evaluation as supporting information (see Appendix A). These
studies can be accessed through the hyperlink provided in the associated caption. 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.
17
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In addition, EPA tabulated the number and characteristics of the data and information sources included
in the full-text screening process in the form of a literature heat map for the fate, engineering, exposure
and hazard information (see Figure 2-4, Figure 2-6, Figure 2-8 and Figure 2-10). For each of these four
disciplines, a static image of the literature inventory heat map is provided, and a link to the interactive
version presented in HAWC is included in the caption below each diagram.
Figure 2-2. Peer-reviewed Inventory Tree Literature- Physical and Chemical Properties Search
Results for o-Dichlorobenzene
Data in this static figure represent references obtained from the publicly available databases search (see
Appendix A. 1.2) that were included during full-text screening as of June 2, 2020. TT AB refers to "title
and abstract" screening.
18
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16)
Bioconcentration
18,
Biodegradation
Hydrolysis
Retrieved for Full-text
Review
Included for Data Extraction
and Evaluation
Excluded at Full-text
©
Photolysis
Sorption
e
Supplemental
Supplemental Material ¦
Full-text
Volatilization
0
Wastewater Treatment
0
Other
Figure 2-3. Peer-reviewed Literature Inventory Tree - Fate and Transport Search Results for o-
D ichlorobenzene
Click here view the interactive literature inventory tree. Data in this figure represent references obtained
from the publicly available databases search (see Appendix A. 1.2) that were included during full-text
screening as of June 2, 2020. Additional data may be added to this interactive version as they become
available.
19
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Media
Endpoint
Air
Soil,
Sediment
Wastewater,
Biosolids
Water
Other
Grand Total
Bioconcentration
3
6
1
13
16
Biodegradation
2
14
1
14
18
Hydrolysis
Photolysis
2
2
4
Sorption
2
34
1 3
26
35
Volatilization
2
4
1
3
6
Wastewater T reatment
2
7
5
7
Other
2
1
3
2
5
Grand Total
8
47
12
55
74
Figure 2-4. Peer-reviewed Literature Inventory Heat Map - Fate and Transport Search Results
for o-Dichlorobenzene
Click here to view the interactive version for additional study details. The column totals, row totals, and
grand totals indicate total numbers of unique references, as some references may be included in multiple
cells. The various shades of color visually represent the number of relevant references identified by
media or endpoint. The darker the color, the more references are available for a given media or endpoint.
Data in this figure represents references obtained from the publicly available databases search (see
Appendix A. 1.2) that were included during full-text screening as of June 2, 2020. Additional data may
be added to the interactive version as they become available.
20
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General Engineering
Assessment
Retrieved lor Full-text
Review
! 3015
TSCA Engineering o-DCB
(2020)
Excluded
©
Supplemental
Included during Full-text
Review
©
Environmental Release
Excluded during Full-text
Review
Occupational Exposure
Figure 2-5. Peer-reviewed Literature Inventory Tree - Engineering Search Results foro-
D ichlorobenzene
Click here for interactive literature inventory tree. Data in this figure represent references obtained from
the publicly available databases search (see Appendix A. 1.2) that were included during full-text
screening as of August 5, 2020. Additional data may be added to the interactive version as they become
available.
21
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Datajype z Evidence Tags
Description of release source
26
Release frequency
3
Environmental
Release or emission factors
29
Releases
Release quantity
26
Waste treatment methods and pollution control
20
Total
51
Chemical concentration
20
Life cycle description
15
General
Engineering
Assessment
No evidence tag
Number of sites
6
9
Process description
20
Production, import, or use volume
25
Throughput
5
Total
49
Area sampling data
28
Dermal exposure data
7
Engineering control
5
Exposure duration
14
Exposure frequency
8
Exposure route
26
Occupational
No evi dence tag
6
Exposures
Number of workers
12
Particle size characterization
Personal protective equipment
13
Personal sampling data
19
Physical form
16
Worker activity description
21
Total
53
Grand Total
93
Figure 2-6. Peer-reviewed Literature Inventory Heat Map - Engineering Search Results for o-
Dichlorobenzene
Click here to view the interactive version for additional study details. Data in this figure represent
references obtained from the publicly available databases search (see Appendix A. 1.2.) that were
included during full-text screening as of August 5, 2020. Additional data may be added to the interactive
version as they become available.
22
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"
Data Sources Obtained
From Peer-Reviewed
Literature Search
©
Monitoring Study
©
Modeling Study
,—- ©
Completed Assessment
©
Experimental Study
©
Epidemiological Study
©
©
Retriejf^d^ill-text
Excluded - TIAB
eluded- T
(38)
Supplemental ¦ TIAB
lnclude0~^ajll-text
©
Excluded • Full-text
©
Supplemental • Full-text
©
Data Sources Obtained
From Grey Literature Search
©
Survey
®
Monitoring Study
©
Modeling Study
©
Completed Assessment
©
Experimental Study
©
Epidemiological Study
©
©
Survey
Figure 2-7. Peer-reviewed and Gray Literature Inventory Tree - Exposure Search Results foro
Dichlorobenzene
Click here to view the interactive literature inventory tree. Data in this figure represent all references
obtained from the publicly available databases search (see Appendix A. 1.2), and gray literature
references search (see Appendix A.3) that were included during full-text screening as of July 31, 2020.
Additional data may be added to the interactive version as they become available.
23
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Data Type
Media (group)
Monitoring
Study
Modeling Study
Completed
Assessment
Experimental
Study
Epidemiological
Study
Database
Survey
Grand Ti
Ambient Air
26
2
10
3
3
4
2
31
Biosoiids/Sludge
2
1
1
2
Drinking Water
Groundwater
Land Disposal/ Landfill
Sediment
2
3
1
4
Soil
6
3
1
8
Surface Water
5
1
5
1
1
1
8
Wastewater
1
3
1
3
Aquatic Species
2
1
2
1
3
Terrestrial Species
2
1
1
1
2
Consumer
6
2
4
12
1
17
Dietary
5
1
5
1
1
1
1
7
Dust
1
1
1
1
1
Exposure Factors
5
1
3
2
1
2
2
7
Exposure Pathway
8
2
6
2
2
2
2
11
Human Biomonitoring 1
27
1
5
1
4
4
2
29
Indoor Air
43
6
11
11
1
1
1
53
Isomers
8
2
2
2
1
10
Use Information
4
1
8
1
2
1
9
No Evidence Type
Grand Total
76
7
21
14
6
9
4
96
Figure 2-8. Peer-reviewed and Gray Literature Inventory Heat Map -Exposure Search Results for
0-DichIorobenzene
Click here to view the interactive version for additional study details. The column totals, row totals, and
grand totals indicate total numbers of unique references, as some references may be included in multiple
cells. Hie various shades of color visually represent the number of relevant references identified by
exposure media or datatype. The darker the color, the more references are available for a given
exposure media or datatype. Data in this figure represent all references obtained from the publicly
available databases search (see Appendix A. 1.2), and gray literature references search (see Appendix
A 3) that were included during full-text screening as of July 31, 2020. Additional data may be added to
the interactive version as they become available.
24
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/-w"1
Included during Full text
Review
©
(75,
Animal
Plant
Human He*ltr> Model
0
> Heaitn
©
Environmental Model
3S35
©
Cxcludvd during full tOKl
Review
S*ipp*«men«*J Material -
FUll-UKt
Mechamvtic
®
•ChMNl
ADME/TK/PBPK
^-©
®
Case Study ot Case Series
®
No Original Oata
©
Conference Abstract
©
Non-English Record
Figure 2-9. Peer-reviewed Literature Inventory Tree - Human Health and Environmental
Hazards Search Results for o-Dichlorobenzene
Click here to view the interactive literature inventory tree. Data in this figure represent references
obtained from the publicly available databases search (see Appendix A. 1.2) that were included during
full-text screening as of June 10, 2020. Additional data may be added to the interactive version as they
become available.
25
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Evidence Type
Animal -
Animal -
Health Outcomes
Human
Human Health
Environmental
Plant
Grand Total
Model
Model
ADME
20
8
11
36
Cancer
3
6
1
10
Cardiovascular
4
4
Developmental
3
7
10
8
28
Endocrine
11
1
1
12
Gastrointestinal
4
4
Hematological and Immure
3
_ 26
2
30
Hepatic
I 30
2
31
Mortality
7
4
11
Musculoskeletal
4
1
5
Neurological
1
S
2
8
Nutritional and Metabolic
10
4
4
18
Ocu lar and Sensory
2
6
8
PBPK
1
1
2
Renal
16
16
Reproductive
3
2
7
1
12
Respiratory
2
13
4
18
Skin and Connective Tissue
1
1
No Tag
1
7
8
6
20
Grand Total
6
50
29
22
101
Figure 2-10. Peer-reviewed Literature Inventory Heat Map - Human Health and Environmental
Hazards Search Results for o-Dichlorobenzene
Click here to view the interactive version for additional study details. The numbers indicate the number
of studies with TIAB keywords related to a particular health outcome, not the number of studies that
observed an association with o-dichlorobenzene. Evidence types were manually extracted, and Health
Systems were determined via machine learning. Therefore, the studies examining multiple Health
Outcomes and Evidence types, connections between health outcome, and evidence type may not be
accurately represented. If a study evaluated multiple health outcomes or included multiple populations
or study designs, it is shown here multiple times. Data in this figure represents references obtained from
the publicly available databases search (see Appendix A. 1.2) that were included during full-text
screening as of June 10, 2020. Additional data may be added to the interactive version as they become
available.
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. EPA screened a total of 129 submissions using PECO or similar statements
that identify inclusion/exclusion criteria specific to individual disciplines (see Table 2-1 forthelist of
disciplines). The details about the criteria are presented in Appendix A.2.1. EPA identified 89
submissions that met the inclusion criteria in these statements and identified 28 submissions with
26
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supplemental data.3 EPA excluded 12 submissions because the reports were identified as one of the
following:
• Published report that would be identified via other peer or gray literature searches
• Summary of other reports
• Preliminary report of a final available submitted report
• Duplicate of another report
• Submission on a different chemical
• List of references with no original data
Table 2-1. Results of Title Screening of Submissions to EPA under Various Sections of TSCAa
Discipline
Included
Supplemental b
Physical and Chemical Properties
1
0
Environmental Fate and Transport
10
0
Environmental and General Population Exposure
46
1
Occupational Exposure/Release Information
12
0
Environmental Hazard
5
2
Human Health Hazard
30
25
a Individual submissions may be relevant to multiple disciplines.
b Included submissions may contain supplemental data for other disciplines, which will be identified at full-text review.
2.2 Conditions of Use
As described in the Proposed Designation of o-Dichlorobenzene (CASRN 95-50-1) as a High-Priority
Substance for Risk Evaluation (U.S. EPA. 2019e). EPA assembled information from the CDR and TRI
programs to determine conditions of use4 or significant changes in conditions of use of the chemical
substance. Once the 2020 CDR reporting period ends in November 2020, EPA will utilize the most
recent CDR information. EPA also consulted a variety of other sources to identify uses of o-
dichlorobenzene, including published literature, company websites, and government and commercial
trade databases and publications. To identify formulated products containing o-dichlorobenzene, EPA
searched for safety data sheets (SDS) using internet searches, EPA Chemical and Product Categories
(CPCat) (U.S. EPA, 2019c) 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
use information.
EPA identified and described the categories and subcategories of conditions of use that EPA plans to
consider in the risk evaluation (Section 2.2.1; Table 2-2). The conditions of use included in the scope of
the risk evaluation are those reflected in the life cycle diagrams and conceptual models.
3 EPA may further consider some supplemental or excluded references depending on the reasons for tagging as supplemental
or excluded.
4 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.
(TSCA § 3(4)).
27
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After gathering reasonably available information related to the manufacture, processing, distribution in
commerce, use, and disposal of o-dichlorobenzene, EPA identified those activities for o-
dichlorobenzene the Agency determined not to be conditions of use or will otherwise be excluded from
the scope of the risk evaluation. These excluded activities are described in Section 2.2.2.
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
Life-Cycle Stage a
Category b
Subcategory c
Reference
Manufacturing
Import
Import
U.S. EPA (2019a)
Processing
Processing as a
reactant
In all other chemical product and
preparation manufacturing
U.S. EPA (2019a)
Processing -
incorporation into
formulation,
mixture or
reaction product
Intermediates in All other basic
organic chemical manufacturing
U.S. EPA (2019a)
Solvents (which become part of
product formulation or mixture)
in Plastic material and resin
manufacturing; Petroleum
lubricating oil and grease
manufacturing; All other
chemical product and preparation
manufacturing
U.S. EPA (2019a); EPA-
HO-OPPT-2018-0444-
0013; EPA-HO-OPPT-
2018-0444-0026
Processing aid in Soap, cleaning
compound, and toilet preparation
manufacturing
EPA-HO-OPPT-2018-
0444-0017
Recycling
Recycling
U.S. EPA (2019a)
Distribution in
commerce
Distribution in
commerce
Distribution in commerce
Industrial use
Solvents (which
become part of
product
formulation or
mixture)
Printing ink manufacturing; Paint
and coating manufacturing;
Synthetic dye and pigment
manufacturing; All other basic
organic chemical manufacturing
U.S. EPA (2019a); EPA-
HO-OPPT-2018-0444-
0035
Functional fluids
(closed system)
All other basic organic chemical
manufacturing
EPA-HO-OPPT-2018-
0444-0035
Commercial use
Ink, toner, and
colorant products
Ink and toners
U.S. EPA (2019a); EPA-
HO-OPPT-2018-0444-
0004
28
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Paints and
coatings
Coatings and paints, thinners,
paint removers
U.S. EPA (2019a); EPA-
HO-OPPT-2018-0444-
0004
Lubricants and
greases
Lubricants and greases (e.g., oil
additives, degreasers, penetrant
for pneumatic tools)
EPA-HO-OPPT-2018-
0444-0004; EPA-HO-
OPPT-2018-0444-0013;
EP A-HO-OPPT-2019-
0131-0022; EPA-HO-
OPPT-2018-0444-0026;
Marvel Oil Company
(2017)
Fuels and related
products
Fuel additive for gasoline and
diesel
EPA-HO-OPPT-2018-
0444-0026; Marvel Oil
Company (2017)
Air care products
Continuous action air fresheners
(including toilet/urinal
d eod orizers/fresheners)
DeLima Associates (2014)
Other use
e.g., Laboratory chemicals;
Sheep-branding fluid; Cleaning
and furnishing care products
EP A-HO-OPPT-2018-
0444-0013; Heiniger
(2016)
Consumer use
Lubricants and
greases
Lubricants and greases (e.g., oil
additives, degreasers, penetrant
for pneumatic tools)
EP A-HO-OPPT-2018-
0444-0013; EPA-HO-
OPPT-2019-0131-0022;
EPA-HO-OPPT-2018-
0444-0026; Marvel Oil
Company (2017)
Fuels and related
products
Fuel additive for gasoline and
diesel
EPA-HO-OPPT-2018-
0444-0026; Marvel Oil
Company (2017)
Air care products
Continuous action air fresheners
(including toilet/urinal
d eod orizers/f resheners)
DeLima Associates (2014)
Other use
e.g., Thinners (Productsfor
cleaning brushes and tools used
with overglazes); Ceramics
glaze; Sheep-branding fluid;
Cleaning and furnishing care
products
EP A-HO-OPPT-2018-
0444-0013;
Duncan Enterprises
(2014), Duncan
Enterprises (2015),
Heiniger (2016)
Disposal
Disposal
Disposal
a- Life Cycle Stage Use Definitions (40 CFR §711.3)
- "Industrial use" meansuse at a site atwhich one or more chemicals or mixtures are manufactured (including
imported) or processed.
29
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- "Commercialuse" meanstheuse of a chemical or a mixture containing a chemical (including aspartof an
article) in a commercialenterprise providing saleable goods or services.
- "Consumeruse" meanstheuse of a chemical or a mixture containing a chemical (including aspartof anarticle,
such asfurniture or clothing) when sold to ormade available to consumers for their use.
- Although EPA has identified both industrial and commercial uses here forpurposes of distinguishing scenarios in
this document, the Agency interprets the authority over "any manner or method of commercialuse" underTSCA
Section 6(a)(5) to reach both.
b- These categories of conditions of use appear in the Life Cycle Diagram, reflect CDR codes, and broadly represent
conditions of use of o-dichlorobenzene in industrial and/or commercial settings.
c^ These subcategories reflect more specific conditions of use of o-dichlorobenzene.
In the final scope, EPA made the following changesto the conditions of use:
- EPA changed "processing - incorporation into formulation, mixture, or reaction product - pigments - in printing
ink manufacturing, paint and coatingmanufacturing, and synthetic dye and pigment manufacturing," to
"industrial use - solvents (which become part of product formulation ormixture) - printing ink manufacturing;
paint and coatingmanufacturing; and synthetic dye and pigment manufacturing" due to an am ended 2016 Form U
and communication with industry (EPA-HO-OPPT-2018-0444-00241
- EPA changed the subcategories of "commercialuse - otheruse -e.g., ... cleaning and furniture care products"
and "consumeruse - other use - e.g., ... cleaning and furniture care products" to "e.g., ...cleaning andfurnishing
care products" afterreview of the reporting categories under CDR.
- EPA added "processing- incorporation into formulation, mixture orreaction product - solvents (which become
part of product formulation ormixture) in petroleum lubricating oil and grease manufacturing" based on
consultation with industry (EPA-HO-OPPT-2018-0444-0026).
- EPA added "processing - incorporation into formulation,mixture orreaction product - solvents (which become
part of product formulation ormixture) in all other chemical product and preparation manufacturing" based on
consultation with industry (EPA-HO-OPPT-2018-0444-00261.
- EPA added "processing- incorporation into formulation, mixture orreaction product - processing aid in soap,
cleaning compound, and toilet preparation manufacturing" based on consultation with industry (EPA-HO-OPPT-
2018-0444-00171.
- EPA added "processing-recycling - recycling," to reflect the submittalby a company of an amended 2016 Form
U that reports o-dichlorobenzene is recycled.
- EPA added "industrial use - solvents (which become part ofproduct formulation or mixture)- all otherbasic
organic chemical manufacturing" based on a public comment (EPA-HO-OPPT-2018-0444-00351.
- EPA added "industrial use - functional fluids (closed system) - all otherbasic organic chemical manufacturing"
based on a public comment (EP A-H O-OPPT -2018-0444-00351.
- EPA added examplesto the subcategories of "commercialuse - lubricants and greases - lubricants and greases"
and "consumeruse - lubricants and greases - lubricants and greases" by adding"
-------
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. (82 FR 33736, 33729; July 20, 2017). TSCA Section 3(4) also grants
EPA discretion to determine the circumstances that are appropriately considered to be conditions of use
for a particular chemical substance5. As a result, EPA does not plan to include in this scope or in the risk
evaluation the activities described below that the Agency does not consider to be conditions of use or for
which EPA is exercising discretionary authority provided by TSCA Section 6(b)(4)(D).
TSCA Section 3(2) also excludes from the definition of "chemical substance" "any food, food additive,
drug, cosmetic, or device (as such terms are defined in Section 201 of the Federal Food, Drug, and
Cosmetic Act [21 U.S.C. 321]) when manufactured, processed, or distributed in commerce for use as a
food, food additive, drug, cosmetic, or device" as well as "any pesticide (as defined in the Federal
Insecticide, Fungicide, and Rodenticide Act [7 U.S.C. 136 et seq.]) when manufactured, processed, or
distributed in commerce for use as a pesticide." EPA has determined that the following uses of o-
dichlorobenzene are non-TSCA uses:
Public comments submitted to EPA in the docket during prioritization indicate the use of o-
dichlorobenzene in pesticides (EPA-HQ-QPPT-2018-0444-0013). The last pesticidal products
containing o-dichlorobenzene as the active ingredient were cancelled in 1992. It still appears in some
formulations; however, not as an active ingredient. EPA has determined that this use falls outside
TSCA's definition of "chemical substance." ii), the definition of "chemical substance" does not include
any pesticide (as defined in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. §
136 et seq. (1996)) when manufactured, processed, or distributed in commerce foruse as a pesticide.
Therefore, activities and releases associated with such pesticidal uses are not "conditions of
use" (defined in TSCA § 3(4) as circumstances associated with a "chemical substance") 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 o-dichlorobenzene in 2015 was between 100,000 and 500,000 pounds (U.S. EPA, 2020a).
EPA also uses pre-2015 CDR production volume information, as detailed in the Proposed Designation
of o-Dichlorobenzene (CASRN 95-50-1) as a High-Priority Substance for Risk Evaluation (U.S. EPA,
2019e) and will include more recent production volume information from the 2020 CDR reporting
period in the risk evaluation to support the exposure assessment.
5 Chemical substance means any organic or inorganic substance of a particular molecularidentity, 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 (TSCA
§ 3(2)).
31
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2.2.4 Overview of Conditions of Use and Lifecycle Diagram
Figure 2-11 provides the lifecycle diagram for o-dichlorobenzene. The life cycle diagram is a graphical
representation of the various life stages of the industrial, commercial and consumer use categories
included within the scope of the risk evaluation. 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). Appendix E contains
additional descriptions (e.g., process descriptions, worker activities, process flow diagrams) for each
manufacture, processing, distribution in commerce, use and disposal category.
32
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IMPORT
PROCESSING
INDUSTRIAL, COMMERCIAL, CONSUMER USES RELEASES and WASTE DISPOSAL
Processing as a Reactant
(e.g., in all other chemical product
and preparation manufacturing)
Incorporation into formulation,
mixture or reaction product
(e.g., intermediates in all other
basic organic chemical
manufacturing; Solvents (which
become part of product
formulation or mixture) in
plastic materialandresin
manufacturing; Petroleum
lubricating oil and grease
manufacturing; All other
chemical product and preparation
manufacturing; Processing aid in
soap, cleaning compound, and
toilet preparation manufacturing)
i
Recycling
i
Solvents (which become part of product
formulation or mixture)1
(e.g., Printing ink; Paints and coatings;
Synthetic dyes and pigments; All other
basic organic chemical manufacturing)
Functional Fluids (closed system)
(e.g., Coolant)
Ink, Toner, and Colorant Products
(e.g., ink and toners)
Paints and Coatings
(e.g., coating and paints; thinners; paint
removers)
Lubricants and greases
(e.g., lubricants and greases (e.g., oil
additives, degreasers, penetrant for
pneumatic tools))
Fuels and related products
(e.g., Fuel additive)
u
1,2
{e.g.
Air care products
continuous action air fresheners
(including toilet/urinal
deodorizers/fresheners))
Other Uses
(e.g., laboratory chemicals; sheep-branding
fluid; furnishing care products; thinners;
ceramics glaze)
See Conceptual Model for
Environmental Releases
and Wastes
Manufacture (Includinglmport)
Processing
Uses:
1. Industrialand/or
commercial
2. Consumer
Figure 2-11. o-Dichlorobenzene Life Cycle Diagram
33
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2.3 Exposures
For TSCA exposure assessments, EPA plans to analyze human and environmental exposures and
releases to the environment resulting from the conditions of use within the scope of the risk evaluation
of o-dichlorobenzene. In this section, the physical and chemical properties, environmental fate and
transport properties and releases to the environment are described in addition to potential human and
environmental exposures from TSCA conditions of use and from other possible or known sources.
Release pathways and routes will be described in Section 2.6 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 o-
dichlorobenzene.
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.
It can also inform the hazard assessment. Table 2-3 summarizes the physical and chemical property
values preliminarily selected for use in the risk evaluation from among the range of reported values
collected as of June 2020. This table differs from that presented in the Proposed Designation of o-
Dichlorobenzene (CASRN 95-50-1) as a High-Priority Substance for Risk Evaluation (U.S. EPA, 2019e)
and may be updated as EPA continues to evaluate and integrate additional information through
systematic review methods. Figure 2-12 summarizes the distribution of reported values for eight
physical and chemical properties routinely used in existing chemical risk evaluations. Appendix B
presents summary statistics for reported physical and chemical property values. All physical and
chemical property values that were extracted and evaluated as of June 2020 are presented in the
supplemental file Data Extraction and Data Evaluation Tables for Physical and Chemical Property
Studies (EPA-HO-QPPT-2018-0444Y
Table 2-3. Physical and Chemical properties of o-Dichlorobenzene
Property or Endpoint
Valuea
Reference
Data Quality
Rating
Molecular formula
C6H4Cl2
NA
NA
Molecular weight
147.00 g/mol
NA
NA
Physical state
Liquid
Rumble (2018)
High
Physical properties
Pale yellow with
pleasant, aromatic odor
RSC (2019)
High
Melting point
-17.03°C
O'Neil (2013)
High
Boiling point
180.2°C
Rumble (2018)
High
Density
1.3009 g/cm3 at 25°C
Baragi etal. (2005)
High
Vapor pressure
1.36 mm Hg at 25°C
NLM (2014)
High
Vapor density
5.05 (air =1)
NLM (2014)
High
Water solubility
156 mg/L at 25°C
NLM (2014)
High
Octanol/water partition
coefficient (log Kow)
3.43
NLM (2014)
High
34
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Property or Endpoint
Valuea
Reference
Data Quality
Rating
Henry's Law constant
0.00192 atnrmVmol at
25°C
U.S. EPA (2019b)
High
Flash point
66°C
O'Neil (2013)
Medium
Auto flammability
Not available
Viscosity
1.324 cP at 25°C
Barasi et al. (2005)
High
Refractive index
1.5499 at 25°C
Barasi et al. (2005)
High
Dielectric constant
10.36
Elsevier (2019)
High
a Measured unless otherwise noted.
NA =Not applicable
Figure 2-12 displays a summary of the data collected as of June 2020 for eight physical and chemical
values routinely used in TSC A existing chemical risk evaluations. The box and whisker plots for each
endpoint illustrate the mean (average, indicated by the blue diamond) and the 10th, 25th, 50th (median),
75th, and 90th percentiles. All individual data points are indicated by black squares, and the value
preliminarily selected for use in the risk evaluation is overlaid (indicated by the orange circle) to provide
context for where it lies within the distribution of the dataset. The number of unique primary data
sources is indicated below each box and whisker plot. If multiple sources presented equivalent values
and cited the same primary source, only one of those was included in the statistical calculations. As a
result, the number of sources listed in Figure 2-12 may differ from the total number of data sources
presented in Figure 2-2. Where no data could be identified through systematic review, text appears to
clearly demonstrate the gap for the endpoint.
35
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350-
300-
£ 250-
• 200-
150-
Boiling Point
-------
Under the Section 313 of the Emergency Planning and Community Right-to-Know Act (EPCRA), o-
dichlorobenzene is a TRI-reportable substance, underthe name 1,2-dichlorobenzene, effective January
01, 1987 (40 CFR 372.65). For TRI reporting6, facilities in covered sectors in the United States are
required to disclose releases and other waste management activity quantities of o-dichlorobenzene under
the C ASRN 95-50-1 if they manufacture (including import) or process more than 25,000 pounds or
otherwise use more than 10,000 pounds of the chemical in a given year by July 1 of the following year.
Table 2-4 provides production-related waste management data for o-dichlorobenzene reported by
facilities to the TRI program for reporting year 2018.7 As shown in the table, 17 facilities reported in
total over 55.3 million pounds of o-dichlorobenzene waste for 2018. Nearly all (97%) of the o-
dichlorobenzene managed as waste during 2018 was managed on site by recycling. Waste treatment
quantities (nearly 1.6 million pounds) accounted for 2.8% of the total. Contributions from quantities
burned for energy recovery or released to the environment were very small, amounting to only 0.5% and
0.1%, respectively, of the total quantity of o-dichlorobenzene managed as waste during 2018. Overall,
99.2% of the o-dichlorobenzene production-related waste was managed as such on site.
Table 2-4. Summary of o-Dichlorobenzene TRI Production-Related Waste Managed in 2018
Year
Number of
Facilities
(lbs)
Recycled
(lbs)
Recovered
for
Energy
(lbs)
Treated
(lbs)
Releaseda'b'c
(lbs)
Total
Production
Related
Waste
(lbs)
2018
17
53,448,206
272,008
1,560,880
62,159
55,343,252
Data source: 2018 TRI Data U.S. EPA (2019f>
a Terminology used in these columns may not match the more detailed data element names used in the TRI public data and analysis access points.
b Does notincludereleasesdue to one-time event notassociated with production such as remedial actions or earthquakes.
c Counts all releases including release quantities transferred and release quantities disposed ofby a receiving facility reporting to TRI.
Table 2-5 provides a summary of o-dichlorobenzene released to the environment during 2018 as
reported to TRI.2 Land disposal and releases to air accounted for nearly all releases to the environment,
with extremely minor contributions from discharges to water and other releases. Roughly 55% of total
releases were in the form of land disposal, with slightly more than half in Resource Conservation and
Recovery Act (RCRA) Subtitle C landfills, and slightly less than half in Class I underground injection
wells. o-Dichlorobenzene releases to air accounted for nearly all remaining environmental releases.
Roughly 60% of these air releases originated from point sources with fugitive air releases accounting for
the remainder. Overall, more than 99.9% of o-dichlorobenzene releases during 2018 occurred on site,
and only about three pounds of o-dichlorobenzene waste were sent off site for disposal.
6 For TRI reporting criteria see https://www.epa.gov/toxics-release-inventorv-tri-program/basics-tri-reporting
7 Reporting year2018 is the most recent TRI data available. Data presented in Table 2-4 were queried using TRI Explorer
and uses the 2018 National Analysis data set (released to the public in November 2019). This data set includes revisions for
the years 1988 to 2018 processed by EPA.
37
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Table 2-5. Summary of Releases of o-Dichlorobenzene to the Environment During 2018
Year
Number
of
Facilities
Air Releases
Water
Releases
Land Disposal
Other
Releases
a
(lbs)
Total
Releases b'c
(lbs)
Stack Air
Releases
(lbs)
Fugitive
Air
Releases
(lbs)
Class I
Under-
ground
Injection
(lbs)
RCRA
Subtitle C
Landfills
(lbs)
All other
Land
Disposal a
(lbs)
2018
17
16,672
11,380
7
15,700
18,400
0
0.101
62,159
28,052
34,100
Data source: 2018 TRI Data U.S. EPA (2019f>
a Terminology used in these columns may not match the more detailed data elem ait names used in the TRI public data and analysis access points.
b These release quantities do includereleases due to one-timeevents not associated with production such as remedial actions or earthquakes.
c Counts release quantities once at final disposition, accounting for transfers to other TRI reporting facilities th at ultimately dispose ofthe chemical waste.
While production-related waste managed shown in Table 2-4 excludes any quantities reported as
catastrophic or one-time releases (TRI Section 8 data), release quantities shown in Table 2-5 include
both production-related and non-production-related quantities. For o-dichlorobenzene the total release
quantities shown in each table are the same, but for other TRI chemicals total release quantities between
the two tables may differ slightly and may further reflect differences in TRI calculation methods for
reported release range estimates (U.S. EPA. 2019d).
EPA plans to review these data in conducting the exposure assessment component of the risk evaluation
for o-dichlorobenzene.
2.3.4 Environmental Exposures
The manufacturing, processing, distribution, use and disposal of o-dichlorobenzene 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 within the environment, and partitioning across different media. Concentrations of
chemical substances in biota provide evidence of exposure. EPA plans to review reasonably available
information on environmental exposure in biota to inform development of the environmental exposure
assessment for o-dichlorobenzene.
2.3.5 Occupational Exposures
EPA plans to evaluate worker activities where there is a potential for exposure under the various
conditions of use (manufacturing, processing, industrial/commercial uses, and disposal) described in
Section 2.2. In addition, EPA plans to evaluate exposure to occupational non-users (ONUs), i.e.,
workers who do not directly handle the chemical but perform work in an area where the chemical is
present. EPA also plans to consider the effect(s) that engineering controls (EC) and/or personal
protective equipment (PPE) have on occupational exposure levels as part of the risk evaluation.
Examples of worker activities associated with the conditions of use within the scope of the risk
evaluation for o-dichlorobenzene that EPA may analyze include, but are not limited to:
• Unloading and transferring o-dichlorobenzene to and from storage containers and process
vessels;
• Handling and disposing of waste containing o-dichlorobenzene;
• Cleaning and maintaining equipment;
• Sampling chemicals, formulations, or products containing o-dichlorobenzene for quality control;
38
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• Repackaging chemicals, formulations, or products containing o-dichlorobenzene;
• Performing other work activities in or near areas where o-dichlorobenzene is used.
o-Dichlorobenzene is a liquid with vapor pressure of 1.36 mmHg at room temperature. Based on the
chemical's volatility, EPA plans to analyze inhalation exposure to vapor for workers and ONUs. EPA
also plans to evaluate inhalation exposure to mists for workers and ONUs where products containing o-
dichlorobenzene may be spray-applied. EPA plans to evaluate dermal exposures for workers, who are
expected to have skin contact with o-dichlorobenzene. Occupational non-users do not directly handle o-
dichlorobenzene; therefore, skin contact with o-dichlorobenzene is not expected for occupational non-
users.
In addition, for certain COUs, o-dichlorobenzene may be present as a component of solid products. For
these COUs, EPA plans to consider inhalation exposure to dust/particulates (e.g., particulate generated
during handling of plastic resins, finishing operations associated with the manufacture and finishing of
plastics and plastic articles and incorporation of plastics and other article components into finished
products) for workers and ONUs.
EPA generally does not evaluate occupational exposures through the oral route. Workers and ONUs
may inadvertently ingest inhaled particles that deposit in the upper respiratory tract. In addition, workers
may transfer chemicals from their hands to their mouths. The frequency and significance of this
exposure route are dependent on several factors including the physical and chemical properties of the
substance during worker activities, the visibility of the chemicals on the hands while working,
workplace training and practices, and personal hygiene that is difficult to predict (Cherrie et aL 2006).
EPA will consider the relevance of this exposure route on a case-by-case basis, taking into consideration
the aforementioned factors and any reasonably available information, and may assess oral exposure for
workers for certain COUs and worker activities where warranted. For certain conditions of use of o-
dichlorobenzene, EPA plans to consider inhalation exposure to dust/particulates for workers and ONUs.
As inhalation exposure to dust/particulates may occur, EPA plans to consider potential exposure for
particulates that deposit in the upper respiratory tract from inhalation exposure and may be ingested via
the oral route.
The United States has several regulatory and non-regulatory exposure limits for o-dichlorobenzene: the
Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) (29 CFR
1910.1000) and the National Institute for Occupational Safety and Health (NIOSH) Recommended
Exposure Limit (REL) (NIOSH, 2018) are both equal to 50 parts per million (ppm) or 300 milligrams
(mg)/cubic meter (m3) as a ceiling limit. NIOSH has an Immediately Dangerous to Life or Health
(IDLH) value of 200 ppm (NIOSH, 2020, 2016). The American Conference of Governmental Industrial
Hygienists (ACGIH) sets the Threshold Limit Value (TLV) at 25 ppm for an 8-hour TWA (OSHA,
2009).
2.3.6 Consumer Exposures
According to reports of the 2016 CDR, lubricants and greases, air care products, fuels and related
products, as well as other uses, such as thinners, ceramics glaze, sheep-branding fluid, and cleaning and
furnishing care products, were identified as consumer products containing o-dichlorobenzene.
Consumers using or disposing of o-dichlorobenzene-based lubricants and greases, air care products,
fuels and related products and other products may be exposed to o-dichlorobenzene through direct solid
and liquid contact which may lead to dermal exposure, through vapor emissions, which may lead to
inhalation exposure, or through mist generation which may lead to inhalation and dermal exposure (see
39
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Appendix G). Bystanders present during the consumer use of lubricants and greases, air care products,
fuels and related products, and other products or disposal of o-dichlorobenzene may also be exposed to
vapor emissions and mist generation which may lead to inhalation and dermal exposure. Based on these
potential sources and pathways of exposure, EPA plans to analyze dermal and inhalation routes of
exposure to consumers that may result from the conditions of use of o-dichlorobenzene.
There were no reports to CDR of any use of o-dichlorobenzene in children's products.
2.3.7 General Population Exposures
Outdoor air levels have been measured and range from 0.01 to 0.1 ppb for o-dichlorobenzene (ATSDR,
2006). The primary route of exposure for the general population is inhalation. Average intake values for
the general population were estimated to be 1.8 |ig/day, on the basis of ambient outdoor samples from
seven large U.S. cities. Several groups within the general population have potentially higher exposures
(higher than background levels) to o-dichlorobenzene. These populations include individuals living near
sites where o-dichlorobenzene is produced or used in manufacturing and disposal sites. Individuals
living in proximity to hazardous waste sites may also be exposed to o-dichlorobenzene by contaminated
groundwater. If residential wells are the primary source of drinking water, this may pose a risk to human
health by consumption of contaminated water and by increased inhalation and dermal contact during
showering and bathing (ATSDR, 2006). Additionally, the National Fish Tissue Study states potential
exposure for the general population to this chemical in fish tissue from lakes and reservoirs of the
continental United States (U.S. EPA, 2009). The general population pathways in the scope of this
evaluation are described in Sections 2.6.3 and 2.7.2.5.
2.4 Hazards (Effects)
2.4.1 Environmental Hazards
EPA considered reasonably available information (e.g., federal and international government chemical
assessments) on o-dichlorobenzene as well as public comments received on the Proposed Designation of
o-Dichlorobenzene (CASRN 95-50-1) as a High-Priority Substance for Risk Evaluation (U.S. EPA,
2019e) and draft scope for o-dichlorobenzene (U.S. EPA, 2020c) to identify potential environmental
hazards. During prioritization, EPA identified environmental hazard effects for aquatic and terrestrial
organisms.
Since prioritization, EPA applied automated techniques during the data screening phase of systematic
review to identify the following potential environmental hazards and related information that may be
considered for the risk evaluation (as explained in Appendix A): AD ME, PBPK, cancer, cardiovascular,
developmental, endocrine, gastrointestinal, hematological and immune, hepatic, mortality, musculo-
skeletal, neurological, nutritional and metabolic ocular and sensory, renal, reproductive, respiratory, skin
and connective tissue (Figure 2-10). A summary of references identified during the screening step of
systematic review is included in the interactive literature inventory trees (Figure 2-9). As EPA continues
to evaluate reasonably available and relevant hazard information identified through systematic review,
EPA may update the list of potential hazard effects to be analyzed in the risk evaluation.
2.4.2 Human Health Hazards
EPA considered reasonably available information (e.g., federal and international government chemical
assessments) on o-dichlorobenzene as well as public comments received on the Proposed Designation of
o-Dichlorobenzene (CASRN 95-50-1) as a High-Priority Substance for Risk Evaluation (U.S. EPA.
2019e) and draft scope for o-dichlorobenzene (U.S. EPA, 2020c) to identify potential human health
hazards. During prioritization, EPA identified the following potential human health hazards and related
40
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information: ADME, PBPK, acute, repeat dose, genetic, reproductive, toxicokinetic, developmental,
irritation/corrosion, dermal sensitization, respiratory sensitization, cancer, immune and neurological
effects.
Since prioritization, EPA applied automated techniques during the data screening phase of systematic
review to identify the following potential environmental hazards and related information that may be
considered for the risk evaluation (as explained in Appendix A): ADME, PBPK, cancer, cardiovascular,
developmental, endocrine, gastrointestinal, hematological and immune, hepatic, mortality, musculo-
skeletal, neurological, nutritional and metabolic ocular and sensory, renal, reproductive, respiratory and
skin and connective tissue (Figure 2-10). A summary of references identified during the screening step
of systematic review is included in the interactive literature inventory trees (Figure 2-9). As EPA
continues to evaluate reasonably available and relevant hazard information identified through systematic
review, EPA may update the list of potential hazard effects to be analyzed in the 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 (U.S. EPA, 2011a).
EPA identified the following PESS based on CDR information, public comments received on the draft
scope for o-dichlorobenzene (Docket ID: EPA-QPPT-2018-0444) and studies reporting developmental
and reproductive effects: children, women of reproductive age (e.g., pregnant women), workers,
including ONUs and users, and consumers including users and bystanders (U.S. EPA, 2019a). EPA
plans to evaluate these PESS in the risk evaluation. Following further evaluation of the reasonably
available information, EPA may evaluate PESS in the general population as they relate to fence line
communities.
In developing exposure scenarios, EPA plans to analyze available data 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 (U.S. EPA. 2006b). 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). Based on these analyses, EPA may update the list of
PESS in the risk evaluation.
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 o-dichlorobenzene. 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, including those pathways that are under the
41
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jurisdiction of other EPA-administered laws, are discussed and depicted in the conceptual model shown
in Section 2.6.3.1. Pathways and routes of exposure associated with environmental releases and wastes,
excluding those pathways that are under the jurisdiction of other EPA-administered laws, are presented
in the conceptual model shown in Section 2.6.3.2.
2.6.1 Conceptual Model for Industrial and Commercial Activities and Uses:
Potential Exposures and Hazards
Figure 2-13 illustrates the conceptual model for the pathways of exposure from industrial and
commercial activities and uses of o-dichlorobenzene that EPA plans to include in the risk evaluation.
There is potential for exposures to workers and ONUs via inhalation routes and exposures to workers via
dermal routes. It is expected that inhalation exposure to vapors is the most likely exposure route. In
addition, workers at waste management facilities may be exposed via inhalation or dermal routes via
wastewater treatment, incineration or other disposal methods. 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,
and disposal) rather than a single distribution scenario. EPA anticipates inhalation and/or oral exposure
for workers and occupational non-users, and dermal exposure only for workers. In EPA's 1981 risk
assessment of dichlorobenzenes (U.S. EPA. 1981). inhalation exposures to vapor and mist were assessed
as the most likely exposure route; however, there is also potential dermal exposure for some conditions
of use, such as use in paints and coatings.
For each condition of use identified in Table 2-2, a determination was made as to whether or not EPA
plans to evaluate 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.
42
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INDUSTRIAL AND
COMMERCIAL ACTIVITIES / EXPOSURE PATHWAY EXPOSURE ROUTE RECEPTORS HAZARDS
USES
Figure 2-13. o-Dichlorobenzene Conceptual Model for Industrial and Commercial Activities and Uses: Worker and Occupational
Non-User 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 odichlorobenzene.
43
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2.6.2 Conceptual Model for Consumer Activities and Uses
The conceptual model in Figure 2-14 presents the exposure pathways, exposure routes and hazards to
human receptors from consumer activities and uses of o-dichlorobenzene. EPA expects inhalation to be
the primary route of exposure and plans to analyze inhalation exposures to o-dichlorobenzene vapor for
consumers and bystanders. There is potential for dermal exposures to o-dichlorobenzene via direct
contact with liquid or solid and via mists generated during consumer uses, and inhalation exposures to o-
dichlorobenzene via vapor and mists generated from use of consumer products. Bystanders are not
expected to have direct dermal contact to o-dichlorobenzene. In addition, oral exposures to o-
dichlorobenzene are expected to be negligible and, as a result, EPA does not plan to evaluate this route
of exposure for consumers or bystanders. The supporting rationale for consumer pathways considered
for o-dichlorobenzene are included in Appendix G.
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CONSUMER ACTIVITIES &
USES
EXPOSURE
PATHWAY
EXPOSURE
ROUTE
RECEPTORS
HAZARDS
Lubricants and Greases
Fuels and related
products
Air Care Products
Other Uses
(e.g., thinners, ceramics
glaze, sheep-branding
fluid, and cleaning and
furniture care products)
Consumer Handling of
Disposal and Waste
Liquid/Solid
Contact
Vapor/Mist
Hazards Potentially
Associated with Acute
and/or Chronic
Exposures
Wastewater, Liquid Wastes,
and Solid Wastes (see
Environmental Releases
Conceptual Models)
Figure 2-14. o-Dichlorobenzene 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
o-d ichl orob enzene.
45
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2.6.3 Conceptual Model for Environmental Releases and Wastes: Potential Exposures
and Hazards (Regulatory Overlay)
In this section, EPA presents the conceptual models describing the identified exposures (pathways and
routes from environmental releases and wastes), and hazards to general population and environmental
receptors associated with the conditions of use of o-dichlorobenzene within the scope of the risk
evaluation. This section also discusses those pathways that may be addressed pursuant to other EPA-
administered laws.
The conceptual model in Figure 2-15 presents the potential exposure pathways, exposure routes and
hazards to general population and environmental receptors from releases and waste streams associated
with industrial, commercial and consumer uses of o-dichlorobenzene. The conceptual model shows the
overlays, labeled and shaded to depict the regulatory programs under EPA-administered statutes and
associated pathways that EPA considered for the scope of the risk evaluation. The regulatory programs
that cover these environmental release and waste pathways are further described in Section 2.6.3.1.
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RELEASES AND WASTES FROM
INDUSTRIAL / COMMERCIAL /
CONSUMER USES
Emissions to Air
EXPOSURE PATHWAYS
CWA-AWQC
SDWA
EXPOSURE
ROITES
RECEPTORS
^-Fish Ingestion
" L Aquatic
Species
Hazardous and
Municipal Waste
Incinerators
\l . h Ground
F w Water M
Hazards Potentially
Associated with
Acute and'or Chronic
Exposures
Fugitive Emissions
Off-site Waste
Transfer
ir
r
Recycling. Other
Treatment
Inhalation
Terrestria
Species
Figure 2-15. o-Diehlorobenzene Conceptual Model for Environmental Releases and Wastes: Environmental and General Population
Exposures and Hazards (Regulatory Overlay)
The conceptual model presents the exposure pathways, exposure routes and hazards to human and environmental receptors from releases and wastes from
industrial, commercial, and consumer uses ofo-dichlorobenzene including the environmental statutes covering those pathways.
a) Industrial wastewater or liquid wastes may be treated on-site and then released to surface water (direct discharge), or pre-treated and released to
Publicly Owned Treatment Works (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. Ground water may also be a source of drinking water. Inhalation from drinking water
may occur via showering
b) Receptors include PESS (see Section 2.5).
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2.6.3.1 Exposure Pathways and Risks Addressed by Other EPA Administered
Statutes
In its TSCA Section 6(b) risk evaluations, EPA is coordinating action on certain exposure pathways and
risks falling under the jurisdiction of other EPA-administered statutes or regulatory programs. More
specifically, EPA is exercising its TSCA authorities to tailor the scope of its risk evaluations, rather than
focusing on environmental exposure pathways addressed under other EPA-administered statutes or
regulatory programs or risks that could be eliminated or reduced to a sufficient extent by actions taken
under other EPA-administered laws. EPA considers this approach to be a reasonable exercise of the
Agency's TSCA authorities, which include:
o TSCA Section 6(b)(4)(D): "The Administrator shall, not later than 6 months after the initiation
of a risk evaluation, publish the scope of the risk evaluation to be conducted, including the
hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations
the Administrator expects to consider.
o TSCA Section 9(b)(1): "The Administrator shall coordinate actions taken under this chapter with
actions taken under other Federal laws administered in whole or in part by the Administrator. If
the Administrator determines that a risk to health or the environment associated with a chemical
substance or mixture could be eliminated or reduced to a sufficient extent by actions taken under
the authorities contained in such other Federal laws, the Administrator shall use such authorities
to protect against such risk unless the Administrator determines, in the Administrator's
discretion, that it is in the public interest to protect against such risk by actions taken under this
chapter."
o TSCA Section 9(e): "... [I]f the Administrator obtains information related to exposures or
releases of a chemical substance or mixture that may be prevented or reduced under another
Federal law, including a law not administered by the Administrator, the Administrator shall
make such information available to the relevant Federal agency or office of the Environmental
Protection Agency."
o TSCA Section 2(c): "It is the intent of Congress that the Administrator shall carry out this
chapter in a reasonable and prudent manner, and that the Administrator shall consider the
environmental, economic, and social impact of any action the Administrator takes or proposes as
provided under this chapter."
o TSCA Section 18(d)(1): "Nothing in this chapter, nor any amendment made by theFrank R.
Lautenberg Chemical Safety for the 21st Century Act, nor any rule, standard of performance,
risk evaluation, or scientific assessment implemented pursuant to this chapter, shall affect the
right of a State or a political subdivision of a State to adopt or enforce any rule, standard of
performance, risk evaluation, scientific assessment, or any other protection for public health or
the environment that—(i) is adopted or authorized under the authority of any other Federal law
or adopted to satisfy or obtain authorization or approval under any other Federal law.
These TSCA authorities supporting tailored risk evaluations and intra-agency referrals are described in
more detail below:
TSCA Section 6(b)(4)(D)
TSCA Section 6(b)(4)(D) requires EPA, in developing the scope of a risk evaluation, to identify the
hazards, exposures, conditions of use, and PESS the Agency "expects to consider" in a risk evaluation.
This language suggests that EPA is not required to consider all conditions of use, hazards, or exposure
pathways in risk evaluations. As EPA explained in the Procedures for Chemical Risk Evaluation Under
the Amended Toxic Substances Control Act (82 FR 33726, July 20, 2017) ("Risk Evaluation Rule"),
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"EPA may, on a case-by-case basis, tailor the scope of the risk evaluation . .in order to focus its
analytical efforts on those exposures that are likely to present the greatest concern, and consequently
merit an unreasonable risk determination." 82 FR 33726, 33729 (July 20, 2017).
In the problem formulation documents for many of the first 10 chemicals undergoing risk evaluation,
EPA applied the same authority and rationale to certain exposure pathways, explaining that "EPA is
planning to exercise its discretion under TSCA 6(b)(4)(D) to focus its analytical efforts on exposures
that are likely to present the greatest concern and consequently merit a risk evaluation under TSCA, by
excluding, on a case-by-case basis, certain exposure pathways that fall under the jurisdiction of other
EPA-administered statutes." This is informed by the legislative history of the amended TSCA, which
supports the Agency's exercise of discretion to focus the risk evaluation on areas that raise the greatest
potential for risk. See June 7, 2016 Cong. Rec., S3519-S3520. Consistent with the approach articulated
in the problem formulation documents, and as described in more detail below, EPA is exercising its
authority under TSCA to tailor the scope of exposures evaluated in TSCA risk evaluations, rather than
focusing on environmental exposure pathways addressed under other EPA-administered, media-specific
statutes and regulatory programs.
TSCA Section 9(b)(1)
In addition to TSCA Section 6(b)(4)(D), the Agency also has discretionary authority under the first
sentence of TSCA Section 9(b)(1) to "coordinate actions taken under [TSCA] with actions taken under
other Federal laws administered in whole or in part by the Administrator." This broad, freestanding
authority provides for intra-agency coordination and cooperation on a range of "actions." In EPA's
view, the phrase "actions taken under [TSCA]" in the first sentence of Section 9(b)(1) is reasonably read
to encompass more than just risk management actions, and to include actions taken during risk
evaluation as well. More specifically, the authority to coordinate intra-agency actions exists regardless
of whether the Administrator has first made a definitive finding of risk, formally determined that such
risk could be eliminated or reduced to a sufficient extent by actions taken under authorities in other
EPA-administered Federal laws, and/or made any associated finding as to whether it is in the public
interest to protect against such risk by actions taken under TSCA. TSCA Section 9(b)(1) therefore
provides EPA authority to coordinate actions with other EPA offices without ever making a risk finding
or following an identification of risk. This includes coordination on tailoring the scope of TSCA risk
evaluations to focus on areas of greatest concern rather than exposure pathways addressed by other
EPA-administered statutes and regulatory programs, which does not involve a risk determination or
public interest finding under TSCA Section 9(b)(2).
In a narrower application of the broad authority provided by the first sentence of TSCA Section 9(b)(1),
the remaining provisions of Section 9(b)(1) provide EPA authority to identify risks and refer certain of
those risks for action by other EPA offices. Under the second sentence of Section 9(b)(1), "[i]f the
Administrator determines that a risk to health or the environment associated with a chemical substance
or mixture could be eliminated or reduced to a sufficient extent by actions taken under the authorities
contained in such other Federal laws, the Administrator shall use such authorities to protect against such
risk unless the Administrator determines, in the Administrator's discretion, that it is in the public interest
to protect against such risk by actions taken under [TSCA]." Coordination of intra-agency action on
risks under TSCA Section 9(b)(1) therefore entails both an identification of risk, and a referral of any
risk that could be eliminated or reduced to a sufficient extent under other EPA-administered laws to the
EPA office(s) responsible for implementing those laws (absent a finding that it is in the public interest to
protect against the risk by actions taken under TSCA).
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Risk may be identified by OPPT or another EPA office, and the form of the identification may vary. For
instance, OPPT may find that one or more conditions of use for a chemical substance present(s) a risk to
human or ecological receptors through specific exposure routes and/or pathways. This could involve a
quantitative or qualitative assessment of risk based on reasonably available information (which might
include, e.g., findings or statements by other EPA offices or other federal agencies). Alternatively, risk
could be identified by another EPA office. For example, another EPA office administering non-TSCA
authorities may have sufficient monitoring or modeling data to indicate that a particular condition of use
presents risk to certain human or ecological receptors, based on expected hazards and exposures. This
risk finding could be informed by information made available to the relevant office under TSCA Section
9(e), which supports cooperative actions through coordinated information-sharing.
Following an identification of risk, EPA would determine if that risk could be eliminated or reduced to a
sufficient extent by actions taken under authorities in other EPA-administered laws. If so, TSCA
requires EPA to "use such authorities to protect against such risk," unless EPA determines that it is in
the public interest to protect against that risk by actions taken under TSCA. In some instances, EPA may
find that a risk could be sufficiently reduced or eliminated by future action taken under non-TSCA
authority. This might include, e.g., action taken under the authority of the Safe Drinking Water Act
(SDWA) to address risk to the general population from a chemical substance in drinking water,
particularly if the Office of Water has taken preliminary steps such as listing the subject chemical
substance on the Contaminant Candidate List (CCL). This sort of risk finding and referral could occur
during the risk evaluation process, thereby enabling EPA to use more a relevant and appropriate
authority administered by another EPA office to protect against hazards or exposures to affected
receptors.
Legislative history on TSCA Section 9(b)(1) supports both broad coordination on current intra-agency
actions, and narrower coordination when risk is identified and referred to another EPA office for action.
A Conference Report from the time of TSCA's passage explained that Section 9 is intended "to assure
that overlapping or duplicative regulation is avoided while attempting to provide for the greatest
possible measure of protection to health and the environment." S. Rep. No. 94-1302 at 84. See also H.
Rep. No. 114-176 at 28 (stating that the 2016 TSCA amendments "reinforce TSCA's original purpose of
filling gaps in Federal law," and citing new language in Section 9(b)(2) intended "to focus the
Administrator's exercise of discretion regarding which statute to apply and to encourage decisions that
avoid confusion, complication, and duplication"). Exercising TSCA Section 9(b)(1) authority to
coordinate on tailoring TSCA risk evaluations is consistent with this expression of Congressional intent.
Legislative history also supports a reading of Section 9(b)(1) under which EPA coordinates intra-agency
action, including information-sharing under TSCA Section 9(e), and the appropriately positioned EPA
office is responsible for the identification of risk and actions to protect against such risks. See, e.g.,
Senate Report 114-67, 2016 Cong. Rec. S3522 (under TSCA Section 9, "if the Administrator finds that
disposal of a chemical substance may pose risks that could be prevented or reduced underthe Solid
Waste Disposal Act, the Administrator should ensure that the relevant office of the EPA receives that
information"); H. Rep. No. 114-176 at 28, 2016 Cong. Rec. S3522 (under Section 9, "if the
Administrator determines that a risk to health or the environment associated with disposal of a chemical
substance could be eliminated or reduced to a sufficient extent underthe Solid Waste Disposal Act, the
Administrator should use those authorities to protect against the risk"). Legislative history on Section
9(b)(1) therefore supports coordination with and referral of action to other EPA offices, especially when
statutes and associated regulatory programs administered by those offices could address exposure
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pathways or risks associated with conditions of use, hazards, and/or exposure pathways that may
otherwise be within the scope of TSC A risk evaluations.
TSCA Sections 2(c) and 18(d)
Finally, TSCA Section 2(c) supports coordinated action on exposure pathways and risks addressed by
other EPA-administered statutes and regulatory programs. Section 2(c) directs EPA to carry out TSCA
in a "reasonable and prudent manner" and to consider "the environmental, economic, and social impact"
of its actions under TSCA. Legislative history from around the time of TSCA's passage indicates that
Congress intended EPA to consider the context and take into account the impacts of each action under
TSCA. S. Rep. No. 94-698 at 14 ("the intent of Congress as stated in this subsection should guide each
action the Administrator takes under other sections of the bill").
Section 18(d)(1) specifies that state actions adopted or authorized under any Federal law are not
preempted by an order of no unreasonable risk issued pursuant to TSCA Section 6(i)(l) or a rule to
address unreasonable risk issued under TSCA Section 6(a). Thus, even if a risk evaluation were to
address exposures or risks that are otherwise addressed by other federal laws and, for example,
implemented by states, the state laws implementing those federal requirements would not be preempted.
In such a case, both the other federal and state laws, as well as any TSCA Section 6(i)(l) order or TSCA
Section 6(a) rule, would apply to the same issue area. See also TSCA Section 18(d)(l)(A)(iii). In
legislative history on amended TSCA pertaining to Section 18(d), Congress opined that "[t]his approach
is appropriate for the considerable body of law regulating chemical releases to the environment, such as
air and water quality, where the states have traditionally had a significant regulatory role and often have
a uniquely local concern." Sen. Rep. 114-67 at 26.
EPA's careful consideration of whether other EPA-administered authorities are available, and more
appropriate, for addressing certain exposures and risks is consistent with Congress' intent to maintain
existing federal requirements and the state actions adopted to locally and more specifically implement
those federal requirements, and to carry out TSCA in a reasonable and prudent manner. EPA believes it
is both reasonable and prudent to tailor TSCA risk evaluations, rather than attempt to evaluate and
regulate potential exposures and risks from those media under TSCA. This approach furthers
Congressional direction and EPA aims to efficiently use Agency resources, avoid duplicating efforts
taken pursuant to other Agency programs, and meet the statutory deadline for completing risk
evaluations.
EPA-administered statutes and regulatory programs that address specific exposure pathways and/or risks
are listed as follows:
Drinking Water Pathway
EPA has regular analytical processes to identify and evaluate unregulated drinking water contaminants
of potential regulatory concern for public water systems under the SDWA. In addition, the SDWA
requires EPA to review and revise "as appropriate" existing drinking water regulations every 6 years.
EPA has promulgated National Primary Drinking Water Regulations (NPDWRs) und er the SDWA for
o-dichlorobenzene. EPA has set an enforceable Maximum Contaminant Level (MCL) as close as
feasible to a health based, non-enforceable Maximum Contaminant Level Goal (MCLG). Public water
systems are required to monitor for the regulated chemical based on a standardized monitoring schedule
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to ensure compliance with the MCL. The MCL and MCLG for o-dichlorobenzene in water are both 0.6
mg/L.
The drinking water exposure pathway for o-dichlorobenzene is currently addressed in theNPDWR. As
such, EPA does not plan to evaluate exposures to the general population from drinking water exposure
in the risk evaluation. This regulatory coverage is represented by the dark blue shading in Figure 2-15.
EPA's Office of Water and Office of Pollution Prevention and Toxics will continue to work together
providing understanding and analysis of the SDWA regulatory analytical processes and to exchange
information related to toxicity and occurrence data on chemicals undergoing risk evaluation under
TSCA.
Ambient Water Pathway
EPA has developed Clean Water Act (CWA) Section 304(a) recommended human health criteria for 122
chemicals and aquatic life criteria for 47 chemicals. A subset of these chemicals is identified as "priority
pollutants" (103 human health and 27 aquatic life), including o-dichlorobenzene. The CWA requires that
states adopt numeric criteria for priority pollutants for which EPA has published recommended criteria
under Section 304(a), the discharge or presence of which in the affected waters could reasonably be
expected to interfere with designated uses adopted the state. For pollutants with recommended human
health criteria, EPA regulations require that state criteria contain sufficient parameters and constituents
to protect designated uses. Once states adopt criteria as water quality standards, the CWA requires that
National Pollutant Discharge Elimination System (NPDES) discharge permits include effluent limits as
stringent as necessary to meet standards CWA Section 301(b)(1)(C). This permit issuance process
accounts for risk in accordance with the applicable ambient water exposure pathway (human health or
aquatic life as applicable) for the designated water use.
EPA develops recommended water quality criteria under Section 304(a) of the CWA for pollutants in
surface water that are protective of aquatic life or human health designated uses. EPA has developed
recommended water quality criteria for protection of human health for o-dichlorobenzene which are
available for possible adoption into state water quality standards and are available for possible use by
NPDES permitting authorities in deriving effluent limits to meet state narrative criteria. See, e.g., 40
CFRpart 423, Appendix A; 40 CFR 131.11(b)(1); 40 CFR 122.44(d)(l)(vi). As such, EPA does not plan
to evaluate exposures to the general population from surface water in the risk evaluation under TSCA.
This regulatory coverage is represented by the light blue shading in Figure 2-15. EPA's OW and OPPT
will continue to work together to exchange information related to toxicity of chemicals undergoing risk
evaluation under TSCA. EPA may update its CWA Section 304(a) water quality criteria for o-
dichlorobenzene in the future under the CWA.
EPA has not developed CWA Section 304(a) recommended water quality criteria for the protection of
aquatic life for o-dichlorobenzene, so there are no national recommended criteria for this use available
for adoption into state water quality standards and available for use in NPDES permits. As such, EPA is
evaluating exposures to aquatic species from surface water in the risk evaluation under TSCA. The
Office of Water may issue CWA Section 304(a) aquatic life criteria for o-dichlorobenzene in the future.
On-site releases to land pathway
The Comprehensive Environmental Response, Compensation, and Liability Act — otherwise known as
CERCLA, provides broad authority under the statute (generally referred to as Superfund)to clean up
uncontrolled or abandoned hazardous-waste sites as well as accidents, spills, and other releases of
hazardous substances, pollutants and contaminants into the environment. The Comprehensive
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Environmental Response, Compensation, and Liability Act, otherwise known as CERCLA, provides
broad authority under the statute (generally referred to as Superfund) to clean up uncontrolled or
abandoned hazardous-waste sites as well as accidents, spills, and other releases of hazardous substances,
pollutants and contaminants into the environment. Through CERCLA, EPA was given authority to seek
out those parties potentially responsible for the release of hazardous substances and either have them
clean up the release or compensate the Federal government for undertaking the response action.
CERCLA Section 101(14) defines "hazardous substance" by referencing other environmental statutes,
including toxic pollutants listed under CWA Section 307(a); hazardous substances designated pursuant
to CWA Section 311(b)(2)(A); hazardous air pollutants listed under CAA Section 112; imminently
hazardous substances with respect to which EPA has taken action pursuant to TSC A Section 7; and
hazardous wastes having characteristics identified under or listed pursuant toRCRA Section 3001. See
40 CFR 302.4. CERCLA Section 102(a) also authorizes EPA to promulgate regulations designating as
hazardous substances those substances which, when released into the environment, may present
substantial danger to the public health or welfare or the environment. EPA must also promulgate
regulations establishing the quantity of any hazardous substance the release of which must be reported
under Section 103. Section 103 requires persons in charge of vessels or facilities to report to the
National Response Center if they have knowledge of a release of a hazardous substance above the
reportable quantity threshold.
o-Dichlorobenzene is a hazardous substance under CERCLA. Releases of o-dichlorobenzene in excess
of 100 lbs within a 24-hour period must be reported (40 CFR 302.4, 302.6). The scope of this EPA
TSC A risk evaluation does not include on-site releases to the environment of [chemical] at Superfund
sites and subsequent exposure of the general population or non-human species.
Disposal and Soil Pathways
o-Dichlorobenzene is included on the list of hazardous wastes pursuant toRCRA Section 3001 (40 CFR
§¦§¦ 261.33) as a listed waste on the U list (U070). The general standard in RCRA Section 3004(a) for the
technical criteria that govern the management (treatment, storage, and disposal) of hazardous waste are
those "necessary to protect human health and the environment," RCRA 3004(a). The regulatory criteria
for identifying "characteristic" hazardous wastes and for "listing" a waste as hazardous also relate solely
to the potential risks to human health or the environment (40 CFR §§ 261.11, 261.21-261.24). RCRA
statutory criteria for identifying hazardous wastes require EPA to "tak[e] into account toxicity,
persistence, and degradability in nature, potential for accumulation in tissue, and other related factors
such as flammability, corrosiveness, and other hazardous characteristics." Subtitle C controls cover not
only hazardous wastes that are landfilled, but also hazardous wastes that are incinerated (subject to joint
control under RCRA Subtitle C and the CAA hazardous waste combustion Maximum Achievable
Control Technology (MACT)) or injected into Underground Injection Control (UIC) Class I hazardous
waste wells (subject to joint control under Subtitle C and the SDWA)8.
EPA does not plan to evaluate on-site releases to land that go to underground injection or associated
exposures to the general population or terrestrial species in its risk evaluation. TRI reporting in 2018
indicated 15,700 pounds released to underground injection to Class I hazardous waste wells.
Environmental disposal of o-dichlorobenzene injected into Class I hazardous waste well types fall under
the jurisdiction of RCRA and SDWA and disposal of o-dichlorobenzene via underground injection is not
likely to result in environmental and general population exposures. See 40 CFR part 144.
8 This is not an exclusive list of Subtitle C authority, a sit also covers, for example, disposal to surface impoundments, waste
piles, and land treatment.
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EPA has identified releases to land that go to RCRA Subtitle C hazardous waste landfills. Based on
2018 reporting, the majority of TRI land disposal includes Subtitle C landfills (18,400 pounds) with a
much smaller amount transferred to "all other land disposal" both on-site and off-site (0 pounds in
2018). Design standards for Subtitle C landfills require double liner, double leachate collection and
removal systems, leak detection system, run on, runoff, and wind dispersal controls, and a construction
quality assurance program. They are also subject to closure and post-closure care requirements including
installing and maintaining a final cover, continuing operation of the leachate collection and removal
system until leachate is no longer detected, maintaining and monitoring the leak detection and
groundwater monitoring system. Bulk liquids may not be disposed in Subtitle C landfills. Subtitle C
landfill operators are required to implement an analysis and testing program to ensure adequate
knowledge of waste being managed, and to train personnel on routine and emergency operations at the
facility. Hazardous waste being disposed in Subtitle C landfills must also meet RCRA waste treatment
standards before disposal. See 40 CFRpart 264. As a result, EPA does not plan to evaluate on-site
releases to land from RCRA Subtitle C hazardous waste landfills or exposures of the general population
or terrestrial species from such releases in the TSCA evaluation. This regulatory coverage is represented
by the pink shading in Figure 2-15.
o-Dichlorobenzene is present in commercial and consumer products that may be disposed of in
Municipal Solid Waste (MSW) landfills. On-site releases RCRA Subtitle D municipal solid waste
landfills leading to exposures of the general population (including susceptible populations) or terrestrial
species from such releases are expected to be minimal based on current TRI releases (i.e., 0 lb in 2018)
for o-dichlorobenzene. While permitted and managed by the individual states, municipal solid waste
(MSW) landfills are required by federal regulations to implement some of the same requirements as
Subtitle C landfills. MSW landfills generally must have a liner system with leachate collection and
conduct groundwater monitoring and corrective action when releases are detected. MSW landfills are
also subject to closure and post-closure care requirements and must have financial assurance for funding
of any needed corrective actions. MSW landfills have also been designed to allow for the small amounts
of hazardous waste generated by households and very small quantity waste generators (less than 220 lb
per month). Bulk liquids, such as free solvent, may not be disposed of at MSW landfills. See 40 CFR
part 258. As a result, EPA does not plan to evaluate on-site releases to land from RCRA Subtitle D
municipal solid waste (MSW) landfills or exposures of the general population or terrestrial species from
such releases in the TSCA evaluation. This regulatory coverage is represented by the pink shading in
Figure 2-15.
On-site releases to land from industrial non-hazardous and construction/demolition waste landfills may
occur for o-dichlorobenzene. Industrial non-hazardous and construction/demolition waste landfills are
primarily regulated under authorized state regulatory programs. States must also implement limited
federal regulatory requirements for siting, groundwater monitoring, and corrective action, and a
prohibition on open dumping and disposal of bulk liquids. States may also establish additional
requirements such as for liners, post-closure and financial assurance, but are not required to do so. See
e.g., RCRA Section 3004(c), 4007; 40 CFRpart 257. As a result, EPA does not plan on evaluating on-
site releases to land from industrial non-hazardous waste and construction/demolition waste landfills or
associated exposures to the general population. This regulatory coverage is represented by the pink
shading in Figure 2-15.
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2.6.3.2 Conceptual Model for Environmental Releases and Wastes: Potential
Exposures and Hazards
As described in Section 2.6.3.1, some pathways in the conceptual models are covered under the
jurisdiction of other environmental statutes administered by EPA. The conceptual model depicted in
Figure 2-16. presents the exposure pathways, exposure routes and hazards to general population and
environmental receptors from releases and wastes from industrial, commercial, and consumer uses of o-
dichlorobenzene that EPA plans to evaluate.
The diagram shown in Figure 2-16 includes releases industrial, commercial and/or consumer uses to
water/sediment, biosolids and soil via direct and indirect discharges to water, that may lead to exposure
to aquatic and terrestrial receptors, and to the general population and terrestrial species from emissions
to air. The supporting basis for environmental pathways considered for o-dichlorobenzene are included
in Appendix H.
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RELE ASES AND WASTES FROM INDUSTRIAL EXPOSURE PATHWAYS EXPOSURE ROUTES RECEPTORS HAZARDS
COMMERCIAL / CONSUMER USES
Figure 2-16. o-Dichlorobenzene Conceptual Model for Environmental Releases and Wastes: Environmental and General Population
Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human and environmental receptors from releases and wastes from
industrial, commercial and consumer uses of o-dichlorobenzene that EPA plans to consider in risk evaluation.
a) 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.
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 o-dichlorobenzene resulting from the full-text
screening of reasonably available information as described in Section 2.1. EPA encourages submission
of additional existing data, such as full study reports or workplace monitoring from industry sources,
that may be relevant to EPA's evaluation of conditions of use, exposures, hazards and PESS during risk
evaluation. As discussed in the Application of Systematic Review in TSCA Risk Evaluations document
(U.S. EPA, 2018), targeted supplemental searches during the analysis phase may be necessary to
identify additional information (e.g., commercial mixtures) for the risk evaluation of o-dichlorobenzene.
For any additional data needs identified during the risk evaluation, EPA may use the Agency's TSCA
authorities under Sections 4, 8 or 11, as appropriate.
2.7.1 Physical and Chemical Properties and Environmental Fate
EPA plans to analyze the physical and chemical properties and environmental fate and transport of o-
dichlorobenzene as follows:
1) Review reasonably available measured or estimated physical and chemical and
environmental fateendpoint data collected using systematic review procedures and, where
reasonably available, environmental assessments conducted by other regulatory agencies.
EPA plans to evaluate data and information collected through the systematic review methods and
public comments about the physical and chemical properties (Appendix B) and fate endpoints
(Appendix C), some of which appeared in the Proposed Designation of o-Dichlorobenzene
(CASRN95-50-1) as a High-Priority Substance for Risk Evaluation (U.S. EPA, 2019e). All
sources cited in EPA's analysis will be evaluated according to the procedures and metrics
described in the Application of Systematic Review in TSCA Risk Evaluations (U.S. EPA, 2018).
Where the systematic review process does not identify experimentally measured chemical
property values of sufficiently high quality, testing will be requested under the TSCA Section 4
authority, or 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 physical and chemical
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 physical and chemical properties and
environmental fate endpoints will be used to characterize the persistence and movement of o-
dichlorobenzene within and across environmental media. The fate endpoints of interest include
volatilization, sorption to organic matter in 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 the scientific evidence evaluation of physical and chemical and
environmental fate data, including qualitative and quantitative sources of information
During risk evaluation, EPA plans to evaluate and integrate the environmental fate evidence
identified in the literature inventory using the Application of Systematic Review in TSCA Risk
Evaluations (U.S. EPA, 2018).
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2.7.2 Exposure
EPA plans to analyze exposure levels for indoor air, ambient air, surface water, sediment, groundwater,
aquatic biota, and terrestrial biota associated with exposure to o-dichlorobenzene. Based on its physical
and chemical properties, expected sources, and transport and transformation within the outdoor and
indoor environment, o-dichlorobenzene is more likely to be present in some of these media and less
likely to be present in others. EPA has not yet determined the exposure levels in these media. Exposure
level(s) can be characterized through a combination of reasonably available monitoring data and
estimated exposure levels from modeling approaches. Exposure scenarios are combinations of sources
(uses), exposure pathways, and exposed receptors. Draft exposure scenarios corresponding to various
conditions of use for o-dichlorobenzene are presented in Appendix F, Appendix G, and Appendix H.
EPA plans to analyze scenario-specific exposures.
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 sources containing information on processes and activities resulting in
releases, and the information found is described in Appendix E. EPA plans to review additional
data sources identified. Potential sources of environmental release data are summarized in Table
2-6 below:
Table 2-6. Categories and Sources of Environmental Release Data
U.S. EPA TRI Data
U.S. EPA Generic Scenarios
OECD Emission Scenario Documents
EURisk Assessment Reports
Discharge Monitoring Report (DMR) surface water discharge data for o-dichlorobenzene
from NPDES-permitted facilities
2) Review reasonably available chemical-specific release data, including measured or
estimated release data (e.gdata from risk assessments by other environmental agencies).
EPA has reviewed key release data sources including the Toxics Release Inventory (TRI), and
the data from this source is summarized in Section 2.3.3. EPA plans to continue to review
relevant data sources during risk evaluation. EPA will continue to consider additional reasonably
available information and will evaluate it during development of the risk evaluation. EPA plans
to match identified data to applicable conditions of use and identify data gaps where no data are
found for particular conditions of use. EPA plans to attempt to address data gaps identified as
described in #3 and #4 below by considering potential surrogate data and models.
Additionally, for conditions of use where no measured data on releases are reasonably available,
EPA may use a variety of methods including release estimation approaches and assumptions in
the Chemical Screening Tool for Exposures and Environmental Releases (ChemSTEER) (U.S.
EPA. 2015a).
3) Review reasonably available release data for surrogate chemicals that have similar uses
and physical properties.
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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.
4) Review reasonably available data that may be used in developing, adapting or applying
release models to the particular risk evaluation.
This item will be performed after completion of #2 and #3 above. 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 release scenarios). EPA has identified information from
various EPA statutes and sources (including, for example, regulatory limits, reporting thresholds
or disposal requirements) that may be relevant to consider for release estimation and
environmental exposures. 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 July 2009
ESP on Plastics Additives (OECD, 2009)and the September 2011 ESP on Chemical Industry
(OECD, 2011) may be useful. EPA plans to need to critically review these generic scenarios and
ESPsto determine their applicability to the conditions of use assessed.
EPA Generic Scenarios are available at the following: https://www.epa.gov/tsca-screening-
t ools/using-pred ictive-method s-assess-exposure-and -fat e-und er-t sca#fate.
OECP Emission Scenario Pocuments are available at the following:
http://www.oecd.org/chemicalsafety/risk-assessment/emissionscenariodocuments.htm
6) Map or group each condition of use to a release assessment scenario(s).
EPA has completed an initial mapping of release scenarios to relevant conditions of use as
shown in Appendix F. EPA plans to refine the mapping/grouping of release scenarios based on
factors (e.g., process equipment and handling, magnitude of production volume used, and
exposure/release sources) corresponding to conditions of use using reasonably available
information. EPA may perform supplemental targeted searches of peer-reviewed or gray
literature to better understand certain conditions of use to further develop release scenarios.
7) Evaluate the weight of the scientific evidence of environmental release data.
Puring risk evaluation, EPA plans to evaluate and integrate the environmental release evidence
identified in the literature inventory using the methods described in the Application of Systematic
Review in TSCA Risk Evaluations (U.S. EPA, 2018). EPA plans to integrate the data using
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.
2.7.2.2 Environmental Exposures
EPA plans to analyze the following in developing its environmental exposure assessment of o-
dichlorobenzene:
1) Review reasonably available environmental and biological monitoring data for all media
relevant to environmental exposure.
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For o-dichlorobenzene, environmental media which EPA plans to analyze are sediment, air and
water.
2) Review reasonably available information on releases to determine how modeled estimates
of concentrations near industrial point sources compare with reasonably available
monitoring data.
EPA plans to analyze and consider reasonably available environmental exposure models that
meet the scientific standards under TSC A Section 26(h). and that estimate surface water, and
sediment concentrations alongside reasonably available surface water, and sediment monitoring
data to characterize environmental exposures. Modeling approaches to estimate surface water
concentrations, sediment concentrations may generally include the following inputs: direct
release into surface water, or sediment, and indirect release into surface water, sediment, fate and
transport (partitioning within media) and characteristics of the environment (e.g., river flow,
volume of lake, meteorological data).
3) 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 o-dichlorobenzene over the last few years. EPA plans
to review and characterize monitoring data or modeled estimates to determine how representative
they are of ongoing use patterns.
Any studies which relate levels of o-dichlorobenzene in the environment or biota with specific
sources or groups of sources will be evaluated.
4) Group each condition(s) of use to environmental assessment scenario(s).
Refine and finalize exposure scenarios for environmental receptors by considering combinations
of sources (use descriptors), exposure pathways including routes, and populations exposed. For
o-dichlorobenzene, the following are noteworthy considerations in constructing exposure
scenarios for environmental receptors:
Estimates of surface water concentrations, and sediment concentrations near
industrial point sources based on reasonably available monitoring data.
Consider the following modeling inputs: release into the media of interest, fate and
transport and characteristics of the environment.
Reasonably available biomonitoring data. Monitoring data 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 reasonably available, and
characterize exposed aquatic and terrestrial populations.
Weight of the scientific evidence of environmental occurrence data and modeled
estimates.
5) 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 the methods described in Application of Systematic Review in
TSC A Risk Evaluations (U.S. EPA. 2018).
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2.7.2.3 Occupational Exposures
EPA plans to analyze both worker and occupational non-user exposures as follows:
1) Review reasonably available exposure monitoring data for specific condition(s) of use.
EPA plans to review exposure data including workplace monitoring data collected by
government agencies such as the OSHA and theNIOSH, and monitoring data found in published
literature. These workplace monitoring data include personal exposure monitoring data (direct
exposures) and area monitoring data (indirect exposures).
OSHA has established a permissible exposure limit (PEL) for o-dichlorobenzene. EPA plans to
consider the influence of such limits on occupational exposures in the occupational exposure
assessment. The following are some data sources identified thus far:
Table 2-7. Potential Sources of Occupational Exposure Data
2012 ATSDR Toxicological Profile
U.S. OSHA Chemical Exposure Health Data (CEHD) program data
U.S. NIOSH Health Hazard Evaluation (HHE) Program reports
2) Review reasonably available exposure data for surrogate chemicals that have uses,
volatility and chemical and physical properties similar to o-dichlorobenzene.
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.
3) For conditions of use where data are limited or not reasonably available, review existing
exposure models that may be applicable in estimating exposure levels.
EPA has identified potentially relevant OECD ESDs and EPA GS corresponding to some
conditions of use. For example, the April 2004 Spray Coatings in the Furniture Industry GS (U.S.
EPA. 2004b) and the September 2001 Manufacture and Use of Printing InkGS (U.S. EPA. 2001)
are some of the ESDs and GS's that EPA may use to estimate occupational exposures. EPA
plans to critically review these generic scenarios and ESDs to determine their applicability to the
conditions of use. EPA plans to perform supplemental targeted searches of peer-reviewed or gray
literature to understand those conditions of use, which may inform identification of exposure
scenarios. EPA may also need to perform targeted supplemental searches to identify applicable
models that EPA may use to estimate exposures for certain conditions of use.
4) Review reasonably available data that may be used in developing, adapting or applying exposure
models to a particular risk evaluation scenario.
Based on information developed from #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). EPA may utilize existing, peer-
reviewed exposure models developed by EPA, other government agencies, or reasonably
available in the scientific literature, or EPA may elect to develop additional models to assess
specific condition(s) of use. Inhalation exposure models may be simple box models or two-zone
(near-field/far-field) models. In two-zone models, the near-field exposure represents potential
inhalation exposures to workers, and the far-field exposure represents potential inhalation
exposures to ONUs.
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5) Consider and incorporate applicable EC and/or PPE into exposure scenarios.
EPA plans to review potentially relevant data sources on EC and PPE to determine their
applicability and incorporation into exposure scenarios during risk evaluation. OSHA
recommends employers utilize the hierarchy of controls to address hazardous exposures in the
workplace. The hierarchy of controls strategy outlines, in descending order of priority, the use of
elimination, substitution, ECs, administrative controls, and lastly PPE. EPA plans to assess
worker exposure pre- and post-implementation of EC, using reasonably available information on
control technologies and control effectiveness. For example, EPA may assess worker exposure in
industrial use scenarios before and after implementation of local exhaust ventilation.
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 (see Appendix F). As presented in the fourth column in Table Apx F-l, EPA has completed
an initial mapping of exposure scenarios to conditions of use. EPA plans to refine mapping or
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 reasonably available is reviewed during risk evaluation. EPA may perform
supplemental targeted searches of peer-reviewed or gray literature to better understand certain
conditions of use to further develop exposure scenarios.
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 Application of Systematic Review in
TSCA Risk Evaluations (U.S. EPA. 2018). EPA plans to rely on the weight of the scientific
evidence when evaluating and integrating occupational data. EPA plans to integrate the data
using 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 o-dichlorobenzene, the following are noteworthy considerations in constructing consumer
exposure scenarios:
Conditions of use
Duration, frequency and magnitude of exposure
Weight fraction of chemical in products
Amount of chemical used
2) Evaluate the potential of indoor exposure pathways based on reasonably available data.
Based on the physical and chemical properties of o-dichlorobenzene and the consumer uses
identified, inhalation of vapors and mists is expected to be an important indoor exposure
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pathway for consumers. EPA plans to review all reasonably available information in developing
the consumer exposure scenarios and evaluating the exposure pathways in indoor environments.
3) Review existing indoor exposure models that may be applicable in estimating indoor air
exposures.
Indoor exposure models that estimate emissions from use of 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 reasonably available.
To the extent other organizations have already modeled a o-dichlorobenzene 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 o-dichlorobenzene 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 o-
dichlorobenzene in specific media (e.g., indoor air).
The availability of o-dichlorobenzene concentration for various conditions of use will be
evaluated. This data provides the source term for any subsequent indoor modeling.
6) Review reasonably available population- or subpopulation-specific exposure factors and
activity patterns to determine if PESS need to be further refined.
For o-dichlorobenzene, EPA plans to evaluate exposure scenarios that involve PESS and plans to
consider age-specific behaviors, activity patterns and exposure factors unique to those
subpopulations. For some exposure scenarios related to consumer uses, EPA plans to consider
whether exposures for adults may different from those of children due to different activities (e.g.,
children may mouth certain products) or exposure factors (e.g., inhalation rates).
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. EPA plans to integrate the data using 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:
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1) Refine and finalize exposure scenarios for general population by considering sources
conditions of use, exposure pathways and routes.
For o-dichlorobenzene, the following are noteworthy considerations in constructing exposure
scenarios for the general population:
Review 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, review existing exposure
modeling approaches that may be applicable in estimating exposure levels.
Consider and incorporate applicable media-specific regulations into exposure scenarios
or modeling.
Review 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 and relevant.
Review reasonably available information on releases to determine how modeled
estimates of concentrations near industrial point sources compare with reasonably
available monitoring data.
Review reasonably available population- or subpopulation-specific exposure factors and
activity patterns to determine if PESS need be further defined.
Evaluate the weight of the scientific evidence of general population exposure data.
Map or group 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 inform exposure scenarios. EPA anticipates that there will be a range in the potential
exposures associated with the exposure scenarios identified in Section.2.6.
After refining and finalizing exposure scenarios, EPA plans to quantify concentrations and/or
doses. The number of scenarios will depend on the conditions of use, exposure pathways and
receptors. 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 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 include careful consideration of variability and uncertainty.
2) For exposure pathways where empirical data is not reasonably available, review existing
exposure models that may be applicable in estimating exposure levels.
For o-dichlorobenzene, media where exposure models will be considered for general population
exposure include models that estimate ambient air concentrations, surface water concentrations,
sediment concentrations, and uptake from aquatic and terrestrial environments into edible aquatic
and terrestrial organisms.
3) Review reasonably available exposure modeled estimates. For example, existing models
developed for a previous o-dichlorobenzene chemical assessment may be applicable to
EPA's assessment. In addition, another chemical's assessment may also be applicable if
model parameter data are reasonably available.
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To the extent other organizations have already modeled o-dichlorobenzene 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 or
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.
4) 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.
5) 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 o-dichlorobenzene, 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 and diet than adults.
6) Evaluate the weight of the scientific evidence of general population exposure estimates
based on different approaches.
During the risk evaluation, EPA plans to evaluate and integrate the exposure evidence identified
in the literature inventory using the methods described in the Application of Systematic Review in
TSCA Risk Evaluations (U.S. EPA. 2018).
2.7.3 Hazards (Effects)
2.7.3.1 Environmental Hazards
EPA plans to conduct an environmental hazard assessment of o-dichlorobenzene as follows:
1) Review reasonably available environmental hazard data, including data from alternative
test methods (e.gcomputational toxicology and bioinformatics; high-throughput screening
methods; data on categories and read-across; in vitro studies).
EPA plans to analyze the hazards of o-dichlorobenzene 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 o-dichlorobenzene
to aquatic and terrestrial organisms.
EPA plans to evaluate environmental hazard data using the evaluation strategies laid out in the
Application of Systematic Review in TSCA Risk Evaluations (U.S. EPA, 2018). The study
evaluation results will be documented in the risk evaluation phase and data from acceptable
studies will be extracted and integrated in the risk evaluation process.
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
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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.
2) Derive hazard thresholds for aquatic and 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)may be derived and
used to further understand the hazard characteristics of o-dichlorobenzene to aquatic and
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 the 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 Application of Systematic
Review in TSCA Risk Evaluations (U.S. EPA, 2018).
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 aquatic (e.g., water and sediment exposures) and terrestrial pathways in
the o-dichlorobenzene conceptual model. These organisms may be exposed to o-dichlorobenzene
via a number of environmental pathways (e.g., surface water, sediment, soil, diet).
5) Consider a persistent, bioaccumulative, and toxic (PBT) assessment of o-dichlorobenzene.
EPA plans to consider the persistence, bioaccumulation, and toxic (PBT) potential of o-
dichlorobenzene after reviewing relevant physical and 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 o-
dichlorobenzene. 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 o-dichlorobenzene with the fate parameters (e.g., BAF, BCF, BMF, IMF).
6) Conduct an environmental risk estimation and characterization of o-dichlorobenzene.
EPA plans to conduct a risk estimation and characterization of o-dichlorobenzene to identify if
there are risks to the aquatic and terrestrial environments from the measured and/or predicted
concentrations of o-dichlorobenzene in environmental media (e.g., water, sediment). 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). Analysis of risk for
characterization includes a confidence statement in risk estimation which qualitative judgment
describing the certainty of the risk estimate considering the strength the evidence scores for
hazard and exposure and the limitations, and relevance.
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).
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EPA plans to evaluate human health studies using the evaluation strategies laid out in the
Application of Systematic Review in TSCA Risk Evaluations (U.S. EPA, 2018)
and updates to the epidemiological data quality criteria released with the first ten risk
evaluations. The study evaluation results will be documented in the risk evaluation phase and
data from acceptable studies will be extracted and integrated in the risk evaluation process (U.S.
EPA. 2018).
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.
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 o-
dichlorobenzene hazard(s). Susceptibility of particular human receptor groups to o-
dichlorobenzene will be determined by evaluating information on factors that influence
susceptibility.
EPA has reviewed some sources containing hazard information associated with susceptible
populations and lifestages such as pregnant women and infants. Pregnancy (i.e., gestation) and
childhood are potential susceptible lifestages for o-dichlorobenzene exposure. EPA may quantify
these differences in the risk evaluation following further evaluation of the reasonably available
data and information.
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 the systematic review data quality criteria described in the
Application of Systematic Review in TSCA Risk Evaluations (U.S. EPA, 2018). 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 the cancer and noncancer endpoints identified in
Section 2.4.2.
Dose-response assessment will be performed in accordance with EPA guidance (U.S. EPA,
2012a, 2011a, 1994) developing points of departure (POD) for either margins of exposure
(MOEs), cancer slope factors (CSFs), oral slope factors (OSFs), and/or inhalation unit risks
(IURs). Dose-response analyses may be used if the data meet data quality criteria and if
additional information on the identified hazard endpoints are not reasonably available or would
not alter the analysis.
The cancer mode of action (MO A) analyses determine the relevancy of animal data to human
risk and how data can be quantitatively evaluated. If cancer hazard is determined to be applicable
to o-dichlorobenzene, EPA plans to evaluate information on genotoxicity and the MOA for all
cancer endpoints to determine the appropriate approach for quantitative cancer assessment in
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accordance with the U.S. EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005a). In
accordance with EPA's Supplemental Guidance for Assessing Susceptibility from Early-life
Exposures to Carcinogens (U.S. EPA, 2005b), EPA plans to determine whether age-dependent
adjustment factors (ADAFs) are appropriate for o-dichlorobenzene for specific conditions of use
based upon potential exposures to children.
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 (U.S. EPA, 2012a). 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 endpointsthat
are not appropriate for dose-response assessment.
EPA plans to evaluate whether the reasonably 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 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 (2011b), 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 the
methods described in the Application of Systematic Review in TSCA Risk Evaluations (U.S. EPA,
2018).
6) Consider the route(s) of exposure (e.goral, inhalation, dermal), reasonably available
route-to-route extrapolation approaches; biomonitoring data; and approaches to correlate
internal and external exposures to integrate exposure and hazard assessment.
At this stage of review, EPA believes there will be sufficient reasonably available 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 o-dichlorobenzene, which could be important for worker, consumer and
general population risk analysis. Reasonably available data will be assessed to determine
whether or not a point of departure can be identified for the dermal and inhalation routes.
If sufficient reasonably available toxicity studies are not identified through the systematic review
process to assess risks from inhalation or dermal exposure, then a route-to-route extrapolation
may be needed. The preferred approach is to use a PBPK model (U.S. EPA, 2006a). Without an
adequate PBPK model, considerations regarding the adequacy of data for route-to-route
extrapolation are described in Methods for Derivation of Inhalation Reference Concentrations
and Application of Inhalation Dosimetry (U.S. EPA, 1994). EPA may use these considerations
when determining whether to extrapolate from the oral to the inhalation route of exposure.
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Similar approaches for oral-to-dermal route extrapolation are described in 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, 2004a).
If there are acceptable inhalation data after completion of systematic review, EPA may also
consider extrapolating from the inhalation to the dermal route if first-pass metabolism through
the liver via the oral route is expected because in that case, use of data from the oral route is not
recommended (U.S. EPA. 1994). EPA may also consider inhalation-to-dermal route
extrapolation if an inhalation toxicity study with a sensitive hazard endpoint is used to evaluate
risks. Based on these considerations, EPA extrapolated from the inhalation to the dermal route
for several of the first ten risk evaluations under amended TSC A, including methylene chloride
(U.S. EPA, 2020d) and carbon tetrachloride (U.S. EPA, 2020b).
7) Conduct a human health risk estimation and characterization of o-dichlorobenzene.
Analysis of risk for characterization includes a confidence statement in risk estimation. This
confidence statement is based on qualitative judgment describing the certainty of the risk
estimate considering the strength of the evidence scores for hazard and exposure along with their
limitations and relevance. The lowest confidence evaluation for either hazard or exposure will
drive the overall confidence estimate.
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" (U.S. EPA, 2000). 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
information, the risk characterization for TSCA risk evaluations will be prepared in a manner that is
transparent, clear, consistent, and reasonable (U.S. EPA, 2000), and consistent with the requirements of
the Procedures for Chemical Risk Evaluation Under the Amended Toxic Substances Control Act (82 FR
33726, July 20, 2017). As discussed in 40 CFR 702.43, risk characterization has a number of
considerations. This is the step where EPA integrates the hazard and exposure assessments into risk
estimates forthe identified populations (including any PESS) and ecological characteristics and weighs
the scientific evidence for the identified hazards and exposures. The risk characterization does not
consider costs or other nonrisk factors, and takes into account, "where relevant, the likely duration,
intensity, frequency, and number of exposures under the condition(s) of use ...." The risk
characterization also summarizes the following considerations: (1) uncertainty and variability in each
step of the risk evaluation; (2) data quality, and any applicable assumptions used; (3) alternative
interpretations of data and analyses, where appropriate; and (4) any considerations for environmental
risk evaluations, if necessary (e.g., related to nature and magnitude of effects).
EPA plans to also be guided by EPA's Information Quality Guidelines (U.S. EPA, 2002) as it provides
guidance for presenting risk information. Consistent with those guidelines, in the risk characterization,
69
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EPA plans to also identify: (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 (U.S. EPA. 2015b) and other methods
consistent with Section 26 of TSCA (see 40 CFR 702.45). As explained in 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 o-
dichlorobenzene will be peer reviewed.
70
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production volume (HPV) chemicals: Chlorobenzenes category: Sponsored chemicals:
Monochlorobenzene (CASRN 108-90-7) (CA Index Name: Benzene, chloro-); 1,2-
Dichlorobenzene (CASRN 95-50-1) (CA Index Name: Benzene, 1,2-dichloro-); 1,3-
Dichlorobenzene (CASRN 541-73-1) (CA IndexName: Benzene, 1,3-dichloro-); 1,2,3-
Trichlorobenzene (CASRN 87-61-6) (CA IndexName: Benzene, 1,2,3-trichloro-). Washington,
DC: U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics.
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(EPA/100/R-12/001). Washington, DC: U.S. Environmental Protection Agency, Risk
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releases. Washington, DC: U.S. Environmental Protection Agency, https://www.epa.gov/tsca-
screening-tools/using-predictive-methods-assess-exposure-and-fate-under-tsca
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ed.). (EPA/100/B-15/001). Washington, DC: U.S. Environmental Protection Agency, Science
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risk evaluations. (740-P1-8001). Washington, DC: U.S. Environmental Protection Agency,
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Dichlorobenzene. 95-50-1. Available online at
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1 high-priority proposed designation 082319.pdf
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Public CDR database). Washington, DC: U.S. Environmental Protection Agency, Office of
Pollution Prevention and Toxics. ChemView: July 2020. https://chemview.epa.gov/chemview
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Dichlorobenzene CASRN 95-50-1 [EPA Report], (EPA-D-20-0001).
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dichlorobenzene draft scope.pdf
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(dichloromethane, dcm); CASRN: 75-09-2 (pp. 1-753). (EPA-740-R1-8010). Office of Chemical
Safety and Pollution Prevention, U.S. Environmental Protection Agency.
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https://www.epa.gov/sites/production/files/2020-
06/documents/l mecl risk evaluation final.pdf
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bfcb634a5235.pdf
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APPENDICES
Appendix A ABBREVIATED METHODS FOR SEARCHING AND
SCREENING
A. 1 Literature Search of Publicly Available Databases
A.1.1 Search Term Genesis and Chemical Verification
To develop the chemical terms for the subsequent literature search for o-dichlorobenzene, several online
sources were queried.
• California Department of Pesticide Regulation:
https://www.cdpr.ca.gov/docs/chemical/monster2.htm
• USEPA Chemistry Dashboard: https://comptox.epa.gov/dashboard
• University of Hertford shire PPDB: Pesticide Properties DataBase:
https://sitem.herts.ac.uk/aeru/ppdb/en/search.htm
• USEPA Reregistration Eligibility Decision (RED) documents:
https://archive.epa.gov/pesticides/reregistration/web/html/status.html
• Office of Pesticide Programs Pesticide Chemical Search:
https://ofmpub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:l
• Food and Agriculture Organization of the United Nations: http://www.fao.org/home/en/
• PAN Pesticides Database: http://www.pesticideinfo.org/Search Chemicals.isp
Prior to inclusion in the search term string, all forms of chemical names were subjected to verification
from several potential sources (e.g., USEPA Chemistry Dashboard, STN International-CAS; see
complete list of sources for chemical verification in TableApx A-l). From these sources, all chemical
names, synonyms, CAS number(s), tradenames, etc. were documented and used to generate terms for
database searches.
Table Apx A-l. Sources of Verification for Chemical Names and Structures
CHEMICAL SOURCE
CONTENTS
DOCUMENT
LOCATION
Chemistry Dashboard
(https://comptox.epa.gov/dashboard)
CAS Numbers, Synonyms, Structures,
Properties, Environmental Fate and
Transport.
Online
Dictionary of Chemical Names and
Synonyms
Wide assortment of chemical compounds
by chemical name and synonym, has CAS
index and some structure data
ECOTOX
Farm Chemicals Handbook-1992
Pesticide information, CAS numbers and
synonyms, some structure data
***Sometimes CAS number presented for
a compound is for the main constituent
only
ECOTOX
OPPT SMILES Verification Source
Structure Data
Electronic
verification
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CHEMICAL SOURCE
CONTENTS
DOCUMENT
LOCATION
RTECS (Registry of Toxic Effects of
chemical substance, 1983-84 ed.,2
vols)
Chemical names, synonyms and CAS
numbers
ECOTOX
Sigma - Aldrich website58784
http://www. sigma-ald rich. com
Organic and inorganic Compounds by
chemical name, has CAS index and some
structure and Physical Property data
Online
STN International (CAS) 1994
***Most complete source of chemical
name, synonym and structure information,
no physical properties
Online
The Pesticide Manual 10th edition,
1994
Pesticide Compounds by chemical name,
synonym, product code, has CAS index
and some structure and Physical Property
data
ECOTOX
TSCA (Toxic Substances Control Act
Chemical Substance Inventory, 1985
ed., 5 vols)
Chemical names, synonyms and CAS
numbers
ECOTOX
World Wide Web (misc. web sources)
A copy of the verification page is
saved to the Attachments tab of the
chemical entry. This includes
company MSDS sheets or Chemical
Labels.
Chemical names, synonyms and CAS
numbers
Online
California Department of Pesticide
Regulation
(http://www. cdDr.ca.gov/dDrdatabase.
Multiple databases containing chemicals,
pesticides, companies, products, etc.
Online
htm)
PAN Pesticide Database
(httD://www.Desticideinfo.org/Search
Chemicals.isD )
Pesticides searchable by name or CAS #.
Includes CAS #, Name, synonyms, targets,
toxicity data, related chemicals and
regulatory information.
Online
US EPA Office of Pesticide Programs
Pesticide Fate Database - No web
access available. An electronic copy
of the data file is located at the
Contractor site:
PFATE 37 Tables.mdb.
Multiple databases containing chemicals,
pesticides, companies, products, etc.
Online
A.1.2 Publicly Available Database Searches
The databases listed below were searched for literature containing the chemical search terms. Database
searching occurred during April and May of 2019 by an information specialist and the results were
stored in the Health and Environmental Research Online (HERO) database and assigned a HERO
reference identification number.9 The present literature search focused only on the chemical name
9EPA's HERO databaseprovidesaccesstothe scientific literature behindEPA science assessments. The database includes
more than 600,000 scientific references and data from the peer-reviewed literature used by EPA to develop its regulations.
78
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(including synonyms and trade names) with no additional limits. Full details of the search strategy for
each database are presented in Appendix A. 1.2.1 .
After initial deduplication in HERO10, these studies were imported into SWIFT Review software
(Howard et aL 2016) to identify those references most likely to be applicable to each discipline area
(i.e., consumer, environmental, and general population exposure, occupational exposure and
environmental releases, environmental hazards, human health hazards, and fate and physical chemistry).
A.l.2.1 Query Strings for the Publicly Available Database Searches on o-
Dichlorobenzene
TableApx A-2 presents a list of the data sources, the search dates and number of peer-reviewed
references resulting from the searches for o-dichlorobenzene. The sources are found as online databases
and the resulting references were gathered and uploaded into the EPA Health and Environmental
Research Online (HERO) database for literature screening.
Table Apx A-2. Summary of Data Sources, Search Dates and Number of Peer-Reviewed
Literature Search Results for o-Dichlorobenzene
Source
Date of Search
Number of References
Current Contents
05/06/2019
3682
ProQuest C SA
05/06/2019
3278
Dissertation Abstracts
05/06/2019
44
Science Direct
05/06/2019
1191
Agricola
05/06/2019
627
TOXNET
05/06/2019
2200
UNIFY
05/07/2019
366
PubMed
05/30/2019
1549
Totals:
12937
GENERAL
General search terms were compiled and used in the search strategies for each of the databases/sources
listed below. Based upon the online search manuals forthe respective databases/sources, it was
necessary to construct searches as noted for each of the sources. The search terms are listed below in full
for each source and noted if the general search terms or other search terms were used.
"1,2-Dichlorbenzene" OR "1,2-Dichlorbenzol" OR "1,2-Dichlorobenzene" OR "1,3-Dichlorbenzol" OR
"1,3-Dichlorobenzene" OR "1,3-diclorobenceno" OR "1,4-Chlorobenzene" OR "1,4-Dichlorbenzol" OR
"1,4-Dichlorobenzene" OR "1,4-Dichloro-Benzene" OR "12dichlorobenzene" OR "13Dichlorobenzene"
OR "2,4-Dichlorobenzene" OR "2,6-Dichlorobenzene" OR "Amisia-mottenschutz" OR "Caswell No.
301" OR "Caswell No. 632" OR "Chloroben" OR"Cloroben" OR "Di-chloricide" OR
"Dichlorobenzene" OR "Dichlorobenzene" OR "Dichlorobenzene (Mixed isomers)" OR
"Dichlorobenzene, p" OR "Dichlorobenzene, p-" OR "Dichlorobenzene, para" OR "Dichlorobenzene,
para-" OR "Dichlorocide" OR "Dilantin DB" OR "Dilatin DB" OR "Dilatin DBI" OR "Dowtherm E"
10 Deduplication in HERO involves first determining whether a matchingunique ID exists (e.g., PMID, WOSid, or DOI). If
one matches one that already exists in HERO, HERO will tag the existing reference instead of addingthe reference again.
Second, HERO checks if the samejournal, volume, issue and page number are already in HERO. Third, HEROmatcheson
the title, year, andfirst author.Title comparisons ignore punctuation and case.
79
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OR "Kaydox" OR "m-Dichlorbenzol" OR "m-Dichlorobenzene" OR "m-Dichlorobenzol" OR
"metadichlorobenzene" OR "meta-Dichlorobenzene" OR "Mottenschutzmittel Evau P" OR"Mott-Ex"
OR "m-Phenylene dichloride" OR "m-Phenylenedichloride" OR "NCI-C54944" OR "NCI-C54955" OR
"NSC 36935" OR "NSC 60644" OR "NSC 8754" OR "o/mDichlorobenzene" OR "o/m-
Dichlorobenzene" OR "o-Dichlor benzol"
"o-Dichlorbenzol" OR "o-Dichlorobenzene" OR "o-Dichlorobenzol" OR "Orthodichlorobenzene" OR
"ortho-Dichlorobenzene" OR "Orthodichlorobenzol" OR "Para crystals" OR "Paradichlorbenzol" OR
"Para-dichloro benzene" OR "Paradichlorobenzene" OR "para-Dichlorobenzene" OR
"Paradichlorobenzol" OR "Paradow" OR "Paramoth" OR "Paranuggets" OR "Parazene" OR "p-
Chlorophenyl chloride" OR "p-Dichlorbenzene" OR "p-Dichlorobenzene" OR "p-Dichloro-Benzene"
OR "p-Dichlorobenzol" OR "Persia-Perazol" OR "Rotamott" OR "Santochlor" OR "Special termite
fluid" OR "Termitkil" OR "UN 1591" OR "UNII-6PJ93I88XL" OR "UNII-75W0WNE5FP"
CURRENT CONTENTS CONNECT: (access.webofknowledge.com)
General Search Terms applied to the search strategy for Current Contents.
Date Searched: 05/06
Date Range of Search: 1970 to Present
N = 3,682
TS=("l,2-Dichlorbenzene" OR "1,2-Dichlorbenzol" OR "1,2-Dichlorobenzene" OR "1,3-Dichlorbenzol"
OR "1,3-Dichlorobenzene" OR "1,3-diclorobenceno" OR "1,4-Chlorobenzene" OR "1,4-Dichlorbenzol"
OR "1,4-Dichlorobenzene" OR "1,4-Dichloro-Benzene" OR "12dichlorobenzene" OR
"13Dichlorobenzene" OR "2,4-Dichlorobenzene" OR "2,6-Dichlorobenzene" OR "Amisia-
mottenschutz" OR "Caswell No. 301" OR "Caswell No. 632" OR "Chloroben" OR "Cloroben" OR "Di-
chloricide" OR "Dichlorobenzene" OR "Dichlorobenzene" OR "Dichlorobenzene (Mixed isomers)" OR
"Dichlorobenzene, p" OR "Dichlorobenzene, p-" OR "Dichlorobenzene, para" OR "Dichlorobenzene,
para-" OR "Dichlorocide" OR "Dilantin DB" OR "Dilatin DB" OR "Dilatin DBI" OR "Dowtherm E"
OR "Kaydox" OR "m-Dichlorbenzol" OR "m-Dichlorobenzene" OR "m-Dichlorobenzol" OR
"metadichlorobenzene" OR "meta-Dichlorobenzene" OR "Mottenschutzmittel Evau P" OR"Mott-Ex"
OR "m-Phenylene dichloride" OR "m-Phenylenedichloride" OR "NCI-C54944" OR "NCI-C54955" OR
"NSC 36935" OR "NSC 60644" OR "NSC 8754" OR "o/mDichlorobenzene" OR "o/m-
Dichlorobenzene" OR "o-Dichlor benzol")
N = 2,659
TS=("o-Dichlorbenzol" OR "o-Dichlorobenzene" OR "o-Dichlorobenzol" OR "Orthodichlorobenzene"
OR "ortho-Dichlorobenzene" OR "Orthodichlorobenzol" OR "Para crystals" OR "Paradichlorbenzol"
OR "Para-dichloro benzene" OR "Paradichlorobenzene" OR "para-Dichlorobenzene" OR
"Paradichlorobenzol" OR "Paradow" OR "Paramoth" OR "Paranuggets" OR "Parazene" OR "p-
Chlorophenyl chloride" OR "p-Dichlorbenzene" OR "p-Dichlorobenzene" OR "p-Dichloro-Benzene"
OR "p-Dichlorobenzol" OR "Persia-Perazol" OR "Rotamott" OR "Santochlor" OR "Special termite
fluid" OR "Termitkil" OR "UN 1591" OR "UNII-6PJ93I88XL" OR "UNII-75W0WNE5FP")
N= 1,023
PROQUEST Agricultural and Scientific Database: (www.csa.com)
General Search Terms applied to the search strategy forProQuest Agricultural and Scientific Database.
Date Searched: 05/06
Date Range of Search: 1900 to Present
80
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N = 3,278
ALL("l,2-Dichlorbenzene" OR "1,2-Dichlorbenzol" OR "1,2-Dichlorobenzene" OR "1,3-
Dichlorbenzol" OR "1,3-Dichlorobenzene" OR "1,3-diclorobenceno" OR "1,4-Chlorobenzene" OR "1,4-
Dichlorbenzol" OR "1,4-Dichlorobenzene" OR "1,4-Dichloro-Benzene" OR "12dichlorobenzene" OR
"13Dichlorobenzene" OR "2,4-Dichlorobenzene" OR "2,6-Dichlorobenzene" OR "Amisia-
mottenschutz" OR "Caswell No. 301" OR "Caswell No. 632" OR "Chloroben" OR "Cloroben" OR "Di-
chloricide" OR "Dichlorobenzene" OR "Dichlorobenzene" OR "Dichlorobenzene (Mixed isomers)" OR
"Dichlorobenzene, p" OR "Dichlorobenzene, p-" OR "Dichlorobenzene, para" OR "Dichlorobenzene,
para-" OR "Dichlorocide" OR "Dilantin DB" OR "Dilatin DB" OR "Dilatin DBI" OR "Dowtherm E"
OR "Kaydox" OR "m-Dichlorbenzol" OR "m-Dichlorobenzene" OR "m-Dichlorobenzol" OR
"metadichlorobenzene" OR "meta-Dichlorobenzene" OR "Mottenschutzmittel Evau P" OR "Mott-Ex"
OR "m-Phenylene dichloride" OR "m-Phenylenedichloride" OR "NCI-C54944" OR "NCI-C54955" OR
"NSC 36935" OR "NSC 60644" OR "NSC 8754" OR "o/mDichlorobenzene" OR "o/m-
Dichlorobenzene" OR"o-Dichlor benzol") AND STYPE("Scholarly Journals" OR Reports OR Thesis
OR "Government Documents") AND LA(ENG)
N = 2,498
ALL("o-Dichlorbenzol" OR "o-Dichlorobenzene" OR "o-Dichlorobenzol" OR "Orthodichlorobenzene"
OR "ortho-Dichlorobenzene" OR "Orthodichlorobenzol" OR "Para crystals" OR "Paradichlorbenzol"
OR "Para-dichloro benzene" OR "Paradichlorobenzene" OR "para-Dichlorobenzene" OR
"Paradichlorobenzol" OR "Paradow" OR "Paramoth" OR "Paranuggets" OR"Parazene" OR"p-
Chlorophenyl chloride" OR "p-Dichlorbenzene" OR "p-Dichlorobenzene" OR "p-Dichloro-Benzene"
OR "p-Dichlorobenzol" OR "Persia-Perazol" OR "Rotamott" OR "Santochlor" OR "Special termite
fluid" OR "Termitkil" OR "UN 1591" OR "UNII-6PJ93I88XL" OR "UNII-75W0WNE5FP") AND
STYPE("Scholarly Journals" OR Reports OR Thesis OR "Government Documents") AND LA(ENG)
N = 780
PROQUEST Dissertations and Theses: (search.proquest.com)
General Search Terms applied to the search strategy forProQuest Dissertations and Theses.
Date Searched: 05/06
Date Range of Search: 1900 to Present
N = 44
ALL("l,2-Dichlorbenzene" OR "1,2-Dichlorbenzol" OR "1,2-Dichlorobenzene" OR "1,3-
Dichlorbenzol" OR "1,3-Dichlorobenzene" OR "1,3-diclorobenceno" OR "1,4-Chlorobenzene" OR "1,4-
Dichlorbenzol" OR "1,4-Dichlorobenzene" OR "1,4-Dichloro-Benzene" OR "12dichlorobenzene" OR
"13Dichlorobenzene" OR "2,4-Dichlorobenzene" OR "2,6-Dichlorobenzene" OR "Amisia-
mottenschutz" OR "Caswell No. 301" OR "Caswell No. 632" OR "Chloroben" OR "Cloroben" OR "Di-
chloricide" OR "Dichlorobenzene" OR "Dichlorobenzene" OR "Dichlorobenzene (Mixed isomers)" OR
"Dichlorobenzene, p" OR "Dichlorobenzene, p-" OR "Dichlorobenzene, para" OR "Dichlorobenzene,
para-" OR "Dichlorocide" OR "Dilantin DB" OR "Dilatin DB" OR "Dilatin DBI" OR "Dowtherm E"
OR "Kaydox" OR "m-Dichlorbenzol" OR "m-Dichlorobenzene" OR "m-Dichlorobenzol" OR
"metadichlorobenzene" OR "meta-Dichlorobenzene" OR "Mottenschutzmittel Evau P" OR "Mott-Ex"
OR "m-Phenylene dichloride" OR "m-Phenylenedichloride" OR "NCI-C54944" OR "NCI-C54955" OR
"NSC 36935" OR "NSC 60644" OR "NSC 8754" OR "o/mDichlorobenzene" OR "o/m-
Dichlorobenzene" OR "o-Dichlor benzol") AND LA(ENG)
N = 28
81
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ALL("o-Dichlorbenzol" OR "o-Dichlorobenzene" OR "o-Dichlorobenzol" OR "Orthodichlorobenzene"
OR "ortho-Dichlorobenzene" OR "Orthodichlorobenzol" OR "Para crystals" OR "Paradichlorbenzol"
OR "Para-dichloro benzene" OR "Paradichlorobenzene" OR "para-Dichlorobenzene" OR
"Paradichlorobenzol" OR "Paradow" OR "Paramoth" OR "Paranuggets" OR"Parazene" OR"p-
Chlorophenyl chloride" OR "p-Dichlorbenzene" OR "p-Dichlorobenzene" OR "p-Dichloro-Benzene"
OR "p-Dichlorobenzol" OR "Persia-Perazol" OR "Rotamott" OR "Santochlor" OR "Special termite
fluid" OR "Termitkil" OR "UN 1591" OR "UNII-6PJ93I88XL" OR "UNII-75W0WNE5FP") AND
LA(ENG)
N= 16
SCIENCE DIRECT: (www.sciencedirect.com)
General Search Terms applied to the search strategy for Science Direct
Date Searched: 05/06
Date Range of Search: 1823 to Present
N= 1,191
Science Direct 01:
"1,2-Dichlorbenzene" OR "1,2-Dichlorbenzol" OR "1,2-Dichlorobenzene" OR "1,3-Dichlorbenzol" OR
"1,3-Dichlorobenzene" OR "1,3-diclorobenceno" OR "1,4-Chlorobenzene" OR "1,4-Dichlorbenzol" OR
" 1,4-Dichlorobenzene"
N = 563
Science Direct 02:
"1,4-Dichloro-Benzene" OR "12dichlorobenzene" OR "13Dichlorobenzene" OR "2,4-Dichlorobenzene"
OR "2,6-Dichlorobenzene" OR "Amisia-mottenschutz" OR "Caswell No. 301" OR "Caswell No. 632"
OR "Chloroben"
N = 22
Science Direct 03:
"Cloroben" OR "Di-chloricide" OR "Dichlorobenzene" OR "Dichlorobenzene" OR "Dichlorobenzene
(Mixed isomers)" OR "Dichlorobenzene, p" OR "Dichlorobenzene, p-" OR "Dichlorobenzene, para" OR
"Dichlorobenzene, para-"
N = 0
Science Direct 04:
"Dichlorocide" OR "Dilantin DB" OR "Dilatin DB" OR "Dilatin DBI" OR "Dowtherm E" OR "Kaydox"
OR "m-Dichlorbenzol" OR "m-Dichlorobenzene" OR "m-Dichlorobenzol"
N = 27
Science Direct 05:
"metadichlorobenzene" OR "meta-Dichlorobenzene" OR "Mottenschutzmittel Evau P" OR "Mott-Ex"
OR "m-Phenylene dichloride" OR "m-Phenylenedichloride" OR "NCI-C54944" OR "NCI-C54955" OR
"NSC 36935"
N= 12
Science Direct 06:
"NSC 60644" OR "NSC 8754" OR "o/mDichlorobenzene" OR "o/m-Dichlorobenzene" OR"o-Dichlor
benzol"
82
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N = 0
Science Direct 07:
"o-Dichlorbenzol" OR "o-Dichlorobenzene" OR "o-Dichlorobenzol" OR "Orthodichlorobenzene" OR
"ortho-Dichlorobenzene" OR "Orthodichlorobenzol" OR "Para crystals" OR "Paradichlorbenzol" OR
"Para-dichloro benzene"
N = 306
Science Direct 08:
"Paradichlorobenzene" OR "para-Dichlorobenzene" OR "Paradichlorobenzol" OR "Paradow" OR
"Paramoth" OR "Paranuggets" OR "Parazene" OR "p-Chlorophenyl chloride" OR "p-Dichlorbenzene"
N = 78
Science Direct 09:
"p-Dichlorobenzene" OR "p-Dichloro-Benzene" OR "p-Dichlorobenzol" OR "Persia-Perazol" OR
"Rotamott" OR "Santochlor" OR "Special termite fluid" OR "Termitkil" OR "UN 1591"
N = 183
Science Direct 10:
"UNII-6PJ93I88XL" OR "UNII-75W0WNE5FP"
N = 0
AGRICOLA: (www.nal.usda.gov)
General Search Terms applied to the search strategy for Agricola. The Agricola database contains a
significant amount of gray literature including proceedings, symposia, and progress reports from
government and educational institutions. Agricola is not used when conducting a search for the Office
of Water.
Date Searched: 05/06
Date Range of Search: 15th century to the Present
N = 627
Agricola 01:
1,2-Dichlorbenzene
1,2-Dichlorbenzol
1,2-Dichlorobenzene
1,3 -Dichlorbenzol
1,3 -Dichlorobenzene
1,3 -d iclorob enceno
1,4-Chlorobenzene
1,4-Dichlorbenzol
1,4-Dichlorobenzene
l,4-Dichloro-Benzene\
N = 178
Agricola 02:
12dichlorobenzene
13Dichlorobenzene
2,4-Dichlorobenzene
83
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2,6-Dichlorobenzene
Amisia-mottenschutz
Caswell No. 301
Caswell No. 632
Chloroben
Cloroben
Di-chloricide
N = 2
Agricola 03:
Dichlorobenzene
Dichlorobenzene
Dichlorobenzene (Mixed isomers)
Dichlorobenzene, p
Dichlorobenzene, p-
Dichlorobenzene, para
Dichlorobenzene, para-
Dichlorocide
Dilantin DB
Dilatin DB
N = 319
Agricola 04:
Dilatin DBI
DowthermE
Kaydox
m-Dichlorbenzol
m-Dichlorobenzene
m-D ichlorob enzol
metad ichlorob enzene
meta-Dichlorobenzene
Mottenschutzmittel Evau P
Mott-Ex
N = 8
Agricola 05:
m-Phenylene dichloride
m-Phenylenedichloride
NCI-C54944
NCI-C54955
NSC 36935
NSC 60644
NSC 8754
o/mDichlorobenzene
o/m-Dichlorobenzene
o-Dichlor benzol
N = 0
84
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Agricola 06:
o-Dichlorbenzol
o-Dichlorobenzene
o-Dichlorobenzol
Orthodichlorobenzene
ortho-D ichlorob enzene
Orthodichlorobenzol
Para crystals
Paradichlorbenzol
Para-dichloro benzene
Paradichlorobenzene
N = 74
Agricola 07:
para-Dichlorobenzene
Paradichlorobenzol
Paradow
Paramoth
Paranuggets
Parazene
p-Chlorophenyl chloride
p-Dichlorbenzene
p-Dichlorobenzene
p-Dichloro-B enzene
N = 46
Agricola 08:
p-Dichlorobenzol
Persia-Perazol
Rotamott
Santochlor
Special termite fluid
Termitkil
UN 1591
UNII-6PJ93I88XL
UNII-75W0WNE5FP
N = 0
TOXNET: (toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?TOXLINE)
General Search Terms applied to the search strategy for TOXNET.
Date Searched: 05/06
Date Range of Search: 1900 to Present
N = 2,200
TOXNET 01:
95-50-1 OR 106-46-7 OR541-73-1 OR25321-22-6
N = 2,200
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PubMed:
PubMed may be accessed through the EPA Desktop Library (https://www.ncbi.nlm.nih.gov/pubmed/)
Date Searched: 05/30/2019
Date Range of Search: 1900 to present
N = 1549
"1,2-Dichlorbenzene" OR "1,2-Dichlorbenzol" OR "1,2-Dichlorobenzene" OR "1,3-Dichlorbenzol" OR
"1,3-Dichlorobenzene" OR "1,3-diclorobenceno" OR "1,4-Chlorobenzene" OR "1,4-Dichlorbenzol" OR
"1,4-Dichlorobenzene" OR "1,4-Dichloro-Benzene" OR "12dichlorobenzene" OR "13Dichlorobenzene"
OR "2,4-Dichlorobenzene" OR "2,6-Dichlorobenzene" OR "Amisia-mottenschutz" OR "Caswell No.
301" OR "Caswell No. 632" OR "Chloroben" OR"Cloroben" OR "Di-chloricide" OR
"Dichlorobenzene" OR "Dichlorobenzene" OR "Dichlorobenzene (Mixed isomers)" OR
"Dichlorobenzene, p" OR "Dichlorobenzene, p-" OR "Dichlorobenzene, para" OR "Dichlorobenzene,
para-" OR "Dichlorocide" OR "Dilantin DB" OR "Dilatin DB" OR "Dilatin DBI" OR "Dowtherm E"
OR "Kaydox" OR "m-Dichlorbenzol" OR "m-Dichlorobenzene" OR "m-Dichlorobenzol" OR
"metadichlorobenzene" OR "meta-Dichlorobenzene" OR "Mottenschutzmittel Evau P" OR "Mott-Ex"
OR "m-Phenylene dichloride" OR "m-Phenylenedichloride" OR "NCI-C54944" OR "NCI-C54955" OR
"NSC 36935" OR "NSC 60644" OR "NSC 8754" OR "o/mDichlorobenzene" OR "o/m-
Dichlorobenzene" OR "o-Dichlor benzol"
N= 1120
"o-Dichlorbenzol" OR "o-Dichlorobenzene" OR "o-Dichlorobenzol" OR "Orthodichlorobenzene" OR
"ortho-Dichlorobenzene" OR "Orthodichlorobenzol" OR "Para crystals" OR "Paradichlorbenzol" OR
"Para-dichloro benzene" OR "Paradichlorobenzene" OR "para-Dichlorobenzene" OR
"Paradichlorobenzol" OR "Paradow" OR "Paramoth" OR "Paranuggets" OR"Parazene" OR"p-
Chlorophenyl chloride" OR "p-Dichlorbenzene" OR "p-Dichlorobenzene" OR "p-Dichloro-Benzene"
OR "p-Dichlorobenzol" OR "Persia-Perazol" OR "Rotamott" OR "Santochlor" OR "Special termite
fluid" OR "Termitkil" OR "UN 1591" OR "UNII-6PJ93I88XL" OR "UNII-75W0WNE5FP"
N = 429
ECOTOX UNIFY:
This is an internal EPA database that is not accessible to the public. Results from the ECOTOX Unify
search strategy.
Date Searched: 05/07
Date Range of Search: all years
N = 366
A.l.2.2 Data Prioritization for Environmental Hazard, Human Health Hazard, Fate
and Physical Chemistry
In brief, SWIFT Review has pre-set literature search strategies ("filters") developed by information
specialists that can be applied to identify studies that are more likely to be useful for identifying human
health and ecotoxicity content from those that likely do not (e.g., analytical methods). The filters
function like a typical search strategy where studies are tagged as belonging to a certain filter if the
terms in the filter literature search strategy appear in title, abstract, keyword or medical subject headings
(MeSH) fields content. The applied SWIFT Review filters focused on lines of evidence: human, animal
models for human health, ecological taxa (which includes ecotoxicological animal models, plants, and
other taxa), and in silico studies. The details of the search strategies that underlie the filters are available
online. Studies not retrieved using these filters were not considered further. Studies that included one or
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more of the search terms in the title, abstract, keyword, or MeSH fields were exported as a RIS file for
screening in Swift-ActiveScreener or DistillerSR11.
A.l.2.3 Data Prioritization for Occupational Exposures and Environmental Releases
and General Population, Consumer and Environmental Exposures
To prioritize references related to occupational exposure, environmental release, general population
exposure, consumer exposure, and environmental exposure, EPA used positive and negative seed studies
to build a classification model in SWIFT Review. The positive seeds were identified using relevant
literature pool for the first ten TSC A risk evaluations, while the negative seeds were identified from a
subset of literature for the current high-priority substances. The model was then applied to the
unclassified literature to generate a classification score for each reference. Scores above a certain
threshold value were then prioritized for further review in SWIFT-ActiveScreener.
A.2 Peer-Reviewed Screening Process
The studies identified from publicly available database searches and SWIFT-Review
filtering/prioritization were housed in HERO system and imported into SWIFT-ActiveScreener or
DistillerSR for title/abstract and full-text screening. Both title/abstract and full-text screening were
conducted by two independent reviewers. Screening is initiated with a pilot phase of screening (between
10 and 50) studies to identify areas where clarification in screening criteria might be needed or
chemical-specific supplemental material tags might be identified. Records that met PECO (or equivalent
criteria (A.2.1) during title and abstract screening were considered for full-text screening. At both the
title/abstract and full-text review levels, screening conflicts were resolved by topic-specific experts
and/or discussion among the primary screeners. For citations with no abstract, the articles are initially
screened based on all or some of the following: title relevance (titles that suggest a record is not relevant
can be excluded rather than marked as unclear), and page numbers (articles two pages in length or less
were assumed to be conference reports, editorials, or letters). During title/abstract or full-text level
screening in DistillerSR, studies that did not meet the PECO criteria, but which could provide
supporting information were categorized (or "tagged") as supplemental information.
It is important to emphasize that being tagged as supplemental material does not mean the study would
necessarily be excluded from consideration in an assessment. The initial screening level distinctions
between a study meeting the PECO criteria and a supplemental study are often made for practical
reasons and the tagging structures (as seen in the literature inventory trees and heat maps in Section 2.1
of this document) are designed to ensure the supplemental studies are categorized for easy retrieval if
needed while conducting the assessment. The impact on the assessment conclusions of individual studies
tagged as supporting material is often difficult to assess during the screening phase of the assessment.
These studies may emerge as being critically important to the assessment and need to be evaluated and
summarized at the individual study level (e.g., cancer MO A mechanistic or non-English-language
studies), or be helpful to provide context (e.g., summarize current levels of exposure, provide hazard
evidence from routes or durations of exposure not pertinent to the PECO), or not be cited at all in the
assessment (e.g., individual studies that contribute to a well-established scientific conclusion). Studies
maybe be tagged as supplemental material during either title and abstract or full-text screening. When
tagged as supplemental material during title and abstract screening, it may not be completely clear
whether the chemical of interest is reported in the study (i.e., abstracts may not describe all chemicals
11DistillerSR is a web-based systematic review software used to screen studies available at
https://www.evidencepartners.com/products/distillersr-svstematic-review-software.
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investigated). In these cases, studies are still tagged with the expectation that if full-text retrieval is
pursued, then additional screening would be needed to clarify if the study is pertinent.
A.2.1 Inclusion/Exclusion Criteria
A PECO statement is typically used to focus the research question(s), search terms, and
inclusion/exclusion criteria in a systematic review. PECO criteria were developed a priori to screening
and modified to fit the various discipline areas supporting theTSCA risk evaluations. Variations include
the RESO (receptor, exposure, scenario/setting, and outcome) used for the occupational exposure and
environmental releases discipline, and PESO (pathways/processes, exposures, setting/scenario, and
outcomes) used by the fate and transport discipline. All PECOs and PECO-equivalent criteria can be
found in the following sections.
A.2.1.1 PECO for Environmental and Human Health Hazards
The PECO used in this evidence map to identify literature pertinent to o-dichlorobenzene effects on
human health and environmental hazard is presented in TableApx A-3. In addition to the PECO
criteria, studies containing potentially relevant supplemental material were tracked and categorized
during the literature screening process as outlined in Table Apx A-4.
Table Apx A-3. Hazards Title and Abstract and Full-text PECO Criteria for o-Dichlorobenzene
PECO Element
Evidence
P
Human: Any population and life stage (occupationalor general population, including children
andothersensitive populations).
quatic and terrestrial species (live, whole organism) of any life stage (including preconception,
;tation,peripubertal, and adult stages). Include insects, spiders, amphibians, birds, crustaceans,
>ks, reptiles, worms and invertebrates. Bacteria andviruses arenot included. Inmost cases,
mimalmodels will get screened as "yes" or "unclear" at TIAB level. Although certain non-
q model systems are increa sing used to identify potentialhuman health hazards (e.g., Xenopus,
for simplicity animalmodelswill be further inventoried according to the categorization below:
Human health models: rat. mouse, rabbit, doe. hamster, guinea oie. cat. non -human orimate.
pig
Ecotoxicoloeical models: invertebrates (e.p.. insects, spiders, crustaceans.mollusks. and
worms) and vertebrates (e.g., mammals and all amphibians,birds, fish, and reptiles),
including wild mammals (e.g. Peromyscus sp.)
Plants: All aquatic and terrestrial species (live), including algal, moss, lichen and fungi species.
E
Relevant forms:
/>-Dichlorobenzene l,4-dichlorobenzene(CASRN 106-46-7) ando-dichlorobenzeneor 1,2-
dichlorobenzene(CASRN 95-50-1)
D-Dichlorobenzene fCASRN 106-46-7)has a numberof svnonvmsthat canbefound on the EPA
Chemistrv Dashboard, o-dichlorobenzene fCASRN 95-50-1) has a numberof svnonvmsthat can
be found on the EPA Chemistry Dashboard.
Forms that should be excluded: m-Dichlorobenzene or 1,3 -dichlorobenzene (CASRN 541 -
73-1)
No isomers were included for/>-dichlorobenzene (CASRN 106-46-7) and o-dichlorobenzene
(CASRN 95-50-1)
Human: Any exposure to />-dichlorobenzene (CASRN 106-46-7) and o-dichlorobenzene
(CASRN 95-50-1).
Animal: Any exposure to />-dichlorobenzene (CASRN 106-46-7) and o-dichlorobenzene
(CASRN 95-50-1), including via water, soil or sediment, injection (oral ortopical), diet,
dermal, and inhalation.
88
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PECO Element
Evidence
Plants: Exposure to />-dichlorobenzene (CASRN 106-46-7) and o-
-------
Category
Evidence
Conference abstracts
Records that do not contain sufficient documentation to support study
evaluation and data extraction.
Exposure studies
Exposure studies withbiomonitoring orbiomarker information (e.g.,
DCBs metabolites in blood or urine or DCB measured in whole body
human/animals) are considered AD ME. Environmental exposure studies
(e.g., DCB in dust) are EXCLUDED.
A.2.1.2 PECO for Consumer, Environmental, and General Population Exposures.
Table Apx A-5. Generic Inclusion Criteria for the Data Sources Reporting Exposure Data on
General Population, Consumers and Environmental Receptors
PECO Element
Evidence
Population
Human: General population; consumers; bystanders in the home; near-facility
populations (includes industrial and commercial facilities manufacturing,
processing, or using the chemical substance); children; susceptible populations
(life stages, preexisting conditions, genetic factors), pregnant women; lactating
women, women of child-bearing age. Many human population groups may be
exposed. No chemical-specific exclusions are suggested at this time.
Environmental: aquatic species, terrestrial species, terrestrial plants, aquatic
plants (field studies only)
Exposure
Expected Primary Exposure Sources, Pathways, Routes:
Pathways: indoor air/vapor/mist; indoor dust; particles; outdoor/ambient air;
surface water; biosolids; sediment; breastmilk; food items containing o-
dichlorobenzene including fish; consumer product uses in the home (including
consumer product containing chemical);
Routes of Exposure: Inhalation, Oral, Dermal
Comparator
(Scenario)
Human: Consider media-specific background exposure scenarios and
use/source specific exposure scenarios as well as which receptors are and are
not reasonably exposed across the projected exposure scenarios.
Environmental Consider media-specific background exposure scenarios and
use/source specific exposure scenarios as well as which receptors are and are
not reasonably exposed across the projected exposure scenarios.
Outcomes for
Exposure
Concentration or
Dose
Human: Acute, subchronic, and/or indoor air and water concentration estimates
(mg/m3 or mg/L). Both external potential dose and internal dose based on
biomonitoring and reverse dosimetry mg/kg/day will be considered.
Characteristics of consumer products or articles (weight fraction, emission rates,
etc) containing o-dichlorobenzene.
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PECO Element
Evidence
Environmental: A wide ranee of ecological receptors will be considered (ranee
depending on available ecotoxicity data) using surface water concentrations,
sediment concentrations.
Table Apx A-6. Pathways Ident
tified as Sup
plemental
'or o-Dichlorobenzene3
Chemical
Drinking
Water
Ambient Air
Air
Disposal
Land
Disposal
Underground
Disposal
Ground Water
0-Dichlo robenzene
X
--
--
X
X
X
a "Supplementalpathways"referto pathways addressed by other EPA administered statutes (see Section 2.6.3.1).
Studies tagged under these pathwayspro vide media information that is not prioritized in the screening process.
A.2.1.3 RESO for Occupational Exposure and Environmental Releases
EPA developed a generic RESO statement to guide the screening of engineering and occupational
exposure data or information sources for the TSCA risk evaluations. Data or information sources that
comply with the inclusion criteria specified in the RESO statement are eligible for inclusion, considered
for evaluation, and possibly included in the environmental release and occupational exposure
assessments. On the other hand, data or information sources that fail to meet the criteria in the RESO
statement are excluded from further consideration.
Assessors seek information on various chemical-specific engineering and occupational exposure data
needs as part of the process of developing the exposure assessment for each risk evaluation. EPA uses
the RESO statement (TableApx A-7) along with the information in TableApx A-8 when screening the
engineering and occupational exposure data and information.
Table Apx A-7. Inclusion Criteria for Data Sources Reporting Engineering and Occupational
Exposure Data
RESO Element
Evidence
Receptors
• Humans:
Workers, including occupational non-users
• Environment:
All environmental receptors (relevant release estimates input to Exposure)
Please refer to the conceptual models for more information about the
environmental and human receptors included in the TSCA risk evaluation.
Exposure
• Worker exposure to and relevant environmental releases of the chemical
substance from occupational scenarios:
Dermal and inhalation exposure routes (as indicated in the conceptual
model)
Oral route (as indicated in the conceptual model)
Please refer to the conceptual models for more information about the routes and
media/pathways included in the TSCA risk evaluation.
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Setting or
Scenario
• Any occupational setting or scenario resulting in worker exposure and relevant
environmental releases (includes all manufacturing, processing, use, disposal.
Outcomes
• Quantitative estimates* of worker exposures and of relevant environmental
releases from occupational settings
• General information and data related and relevant to the occupational
estimates*
* Metrics (e.g., mg/kg/day ormg/m3 for worker exposures, kg/site/day for releases) are determined by toxicologists for
worker exposures and by exposure assessors forreleases; also, the Engineering, Release and OccupationalExposureData
Needs (Table_Apx A-8) provides a list of related and relevant general information.
TableApx A-8. Engineering, Environmental Release and Occupational Data Necessary to
develop the Environmental Release and Occupational Exposure Assessments
Objective
Determined
during
Scoping
Type of Data a
General
Engineering
Assessment
(may apply to
Occupational
Exposures and
/ or
Environmental
Releases)
Description of the life cycle of the chemical(s) of interest, from manufacture to end-
of-life (e.g., each manufacturing, processing, or use step), and material flow
between the industrial and commercial life cycle stages.
The total annual U.S. volume (lb/yr or kg/yr) of the chemical(s) of interest
manufactured, imported, processed, and used; and the share of total annual
manufacturing and import volume that is processed or used in each life cycle step.
Description of processes, equipment, and unit operations during each industrial/
commercial life cycle step.
Material flows, use rates, and frequencies (lb/site-day or kg/site-day and days/yr;
lb/site-batch and batches/yr) of the chemical(s) of interest during each industrial/
commercial life cycle step. Note: if available, include weight fractions of the
chemicals (s) of interest and material flows of all associated primary chemicals
(especially water).
Number of sites that manufacture, process, or use the chemical(s) of interest for
each industrial/ commercial life cycle step and site locations.
Concentration of the chemical of interest
Occupational
Exposures
Description of worker activities with exposure potential during the manufacture,
processing, or use of the chemical(s) of interest in each industrial/commercial life
cycle stage.
Potential routes of exposure (e.g., inhalation, dermal).
Physical form of the chemical(s) of interest for each exposure route (e.g., liquid,
vapor, mist) and activity.
Breathing zone (personal sample) measurements of occupational exposures to the
chemical(s) of interest, measured as time-weighted averages (TWAs), short-term
exposures, or peak exposures in each occupational life cycle stage (or in a
workplace scenario similar to an occupational life cycle stage).
Area or stationary measurements of airborne concentrations of the chemical(s) of
interest in each occupational setting and life cycle stage (or in a workplace
scenario similar to the life cycle stage of interest).
For solids, bulk and dust particle size characterization data.
Dermal exposure data.
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Objective
Determined
during
Scoping
Type of Data a
Exposure duration (hr/day).
Exposure frequency (days/yr).
Number of workers who potentially handle or have exposure to the chemical(s) of
interest in each occupational life cycle stage.
PPE types employed by the industries within scope.
EC employed to reduce occupational exposures in each occupational life cycle stage
(or in a workplace scenario similar to the life cycle stage of interest), and
associated data or estimates of exposure reductions.
Environmental
Releases (to
relevant
environmental
media)
Description of sources of potential environmental releases, including cleaning of
residues from process equipment and transport containers, involved during the
manufacture, processing, or use of the chemical(s) of interest in each life cycle
stage.
Estimated mass (lb or kg) of the chemical(s) of interest released from industrial and
commercial sites to each environmental medium (water) and treatment and
disposal methods (POTW), including releases per site and aggregated over all
sites (annual release rates, daily release rates)
Release or emission factors.
Number of release days per year.
Waste treatment methods and pollution control devices employed by the industries
within scope and associated data on release/emission reductions.
a These are the tags included in the full-text screening form The screener makes a selection from these
specific tags, which describe more specific types of data or information.
In addition to the data types listed above, EPA may identify additional dataneeds for mathematical modeling.
These data needs will be determined on a case-by-case basis.
Abbreviations:
hr=Hour
kg=Kilogram(s)
lb=Pound(s)
yr=Y ear
PV=Particle volume
POTW=Publicly owned treatment works
PPE=Personal protection equipment
PSD=Particle size distribution
TWA=Time-weighted average
A.2.1.4 PESO for Fate and Transport
EPA developed a generic PESO statement to guide the screening of environmental fate data or
information sources for the TSCA risk evaluations. Data or information sources that comply with the
inclusion criteria in the PESO statement are eligible for inclusion, considered for evaluation, and
possibly included in the environmental fate assessment. On the other hand, data or information sources
that fail to meet the criteria in the PESO statement are excluded from further consideration.
Assessors seek information on various chemical-specific fate endpoints and associated fate processes,
environmental media and exposure pathways as part of the process of developing the environmental fate
assessment for each risk evaluation. EPA uses the PESO statement (Table Apx A-9) along with the
93
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information in TableApx A-10 when screening the fate data or information sources to ensure complete
coverage of the processes, pathways and data or information relevant to the environmental fate and
transport of the chemical substance undergoing risk evaluation.
Table Apx A-9. Inclusion Criteria for Data or Information Sources Reporting Environmental
7ate and Transport Data
PESO
Evidence
Element
Pathways and
Processes
Environmental fate, transport, partitioning and degradation behavior
across environmental media to inform exposure pathways of the
chemical substance of interest
Exposure pathways included in the conceptual models: air, surface water,
groundwater, wastewater, soil, sediment and biosolids.
Processes associated with the target exposure pathways
Bioconcentration and bioaccumulation
Destruction and removal by incineration
Please refer to the conceptual models for more information about the exposure
pathways included in each TSCA risk evaluation.
Exposure
Environmental exposure of environmental receptors (i.e., aquatic and
terrestrial organisms) to the chemical substance of interest, mixtures
including the chemical substance, and/or its degradation products and
metabolites
Environmental exposure of human receptors, including any PESS, to the
chemical substance of interest, mixtures including the chemical
substance, and/or its degradation products and metabolites
Please refer to the conceptual models for more information about the
Setting or Scenario
Any setting or scenario resulting in releases of the chemical substance of
interest into the natural or built environment (e.g., buildings including
homes or workplaces, or wastewater treatment facilities) that would expose
environmental (i.e., aquatic and terrestrial organisms) or human receptors
(i.e., general population, and PESS)
Outcomes
Fate properties which allow assessments of exposure pathways:
Abiotic and biotic degradation rates, mechanisms, pathways, and
products
Bioaccumulation magnitude and metabolism rates
Partitioning within and between environmental media (see Pathways
and Processes)
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TableApx A-10. Fate Endpoints and Associated Processes, Media and Exposure Pathways
Considered in the Development of the Environmental Fate Assessment
Fate Data Endpoint
Associated
Process(es)
Associated Media/Exposure Pathways
Surface
Water,
Wastewater,
Sediment
Soil,
Biosolids
Groundwater
Air
Required Environmental Fate Data
Abiotic reduction rates
or half-lives
Abiotic reduction,
Abiotic
dehalogenation
X
Aerobic biodegradation
rates or half-lives
Aerobic
biodegradation
X
X
Anaerobic
biodegradation rates or
half-lives
Anaerobic
biodegradation
X
X
X
Aqueous photolysis
(direct and indirect)
rates or half-lives
Aqueous
photolysis (direct
and indirect)
X
Atmospheric photolysis
(direct and indirect)
rates or half-lives
Atmospheric
photolysis (direct
and indirect)
X
Bioconcentration factor
(BCF),
Bioaccumulation factor
(BAF)
Bioconcentration,
Bioaccumulation
X
X
X
Biomagnification and
related information
Trophic
magnification
X
Desorption information
Sorption, Mobility
X
X
X
Destruction and
removal by incineration
Incineration
X
Hydrolysis rates or
half-lives
Hydrolysis
X
X
X
Koc and other sorption
information
Sorption, Mobility
X
X
X
Wastewater treatment
removal information
Wastewater
treatment
X
X
Supplemental (or Optional) Environmental Fate Data
Abiotic transformation
products
Hydrolysis,
Photolysis,
Incineration
X
X
95
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Fate Data Endpoint
Associated
Process(es)
Associated Media/Exposure Pathways
Surface
Water,
Wastewater,
Sediment
Soil,
Biosolids
Groundwater
Air
Required Environmental Fate Data
Aerobic
biotransformation
products
Aerobic
biodegradation
X
X
Anaerobic
biotransformation
products
Anaerobic
biodegradation
X
X
X
Atmospheric deposition
information
Atmospheric
deposition
X
Coagulation
information
Coagulation,
Mobility
X
X
Incineration removal
information
Incineration
X
A.2.1.5 Generation of Hazard Heat Maps
As stated in Appendix A. 1.2.2, SWIFT Review has pre-set literature search strategies ("filters")
developed by information specialists that can be applied to identify studies that are more likely to be
useful for identifying human health and ecotoxicity content. The filters function like a typical search
strategy where studies are tagged as belonging to a certain filter if the terms in the filter literature search
strategy appear in title, abstract, keyword or MeSH fields content.
Afterthe completion of full-text screening for hazard data, all references tagged as included (or "PECO-
relevant) were uploaded to the SWIFT Review tool for further filtering. The SWIFT Review filters
applied at this phase focused on types of health outcomes included: "ADME", "PBPK", "cancer",
"cardiovascular", "developmental", "endocrine", "gastrointestinal", "hematological and immune",
"hepatic", "mortality", "musculoskeletal", "neurological", "nutritional and metabolic", "ocular and
sensory", "renal", "reproductive", "respiratory", and "skin and connective tissue". The details of these
health outcome search strategies that underlie the filters are available online. Studies that included one
or more of the search terms in the title, abstract, keyword, or MeSH fields were exported and used to
populate the Hazard Heat Map (Figure 2-10) Studies that were not retrieved using these filters were
tagged as "No Tag". The evidence type listed in the heat map (e.g., human, animal-human health model,
animal- environmental model, and plant) was manually assigned to each reference by screeners during
the full-text screening.
The health outcome tags were originally designed for vertebrate systems, and as such, did not conform
well to plant evidence. Therefore, any plant studies tagged for: "cancer", "cardiovascular",
"gastrointestinal", "hematological and immune", "hepatic", "musculoskeletal", "neurological", "ocular
and sensory" and "renal and respiratory" were manually reviewed and re-tagged to more appropriate
health outcomes.
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A.3 Gray Literature Search and Screening Strategies
EPA conducted a gray literature search for available information to support the TSCA risk evaluations
for the next twenty TSCA risk evaluations. 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. Given the nature of how gray literature is searched and collected, results
may not come with a bibliographic citation or abstract and were therefore processed using a decision
tree logic described in A.3.1 for potential relevance prior to entering full text screening where a
discipline-specific PECO is applied.
Search terms were variable dependent on source and based on knowledge of a given source to provide
discipline-specific information. A summary of sources is provided in Appendix A.3.3. The criteria for
determining the potential relevance of documents identified from gray literature sources is described in
the following sections for each discipline.
A.3.1 Screening of Gray Literature
To reduce the overall burden of processing gray literature results, EPA developed a screening process to
determine the potential relevance of gray literature. This step was introduced prior to collecting the
resulting documents. Figure Apx A-l describes the decision logic used to screen gray literature results.
97
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I\>icntully Relevant
y Exclude from Gray Literature. \
I Check if caught ia Peer Review I
V Search J
FigureApx A-l. Decision Logic Tree Used to Screen Gray Literature Results
A.3.2 Initial Screening of Sources using Decision Logic Tree
The purpose of the inclusion/exclusion decision logic tree in Figure Apx A-l is to provide a broad,
general screening technique to determine whether each gray literature source should be included and
further screened or excluded with no additional screening necessary. The diamonds in the decision tree
require analysis by the screener, whereas the rectangular boxes are used to classify the type of source.
All the questions used in the decision process are provided in Table_Apx A-l 1.
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TableApx A-ll. Decision Logic Tree Overview
Step
Metric
Questions to Consider
1
Potential Relevance
Does the result have information (qualitative or
quantitative) related to TSCA risk evaluations?
* Apply Discipline relevancy metric
2.1.1
Is it a secondary data source (assessment, robust summary,
TSCA submission databases, etc.)?
2.1.2
Is the document from a peer reviewed/published journal?
2.2
Is there an established procedure for data collection,
communication, peer review, and/or reporting?
2.2.1
Complete / Available
Has the databeen provided by a US governmental/state
source?
2.2.2
Has the databeen provided by an international
governmental source?
2.3
Are these data publicly available/accessible?
2.3.1
Is the source TSCA CBI, proprietary, TSCA or NGO
stakeholder submission?
3
Duplicate
Does the result contain any duplicative information found in
other sources?
Results of the gray literature search and decision tree process are included in Appendix A.3.3.
A.3.3 TSCA Submission Searching and Title Screening
EPA screens information submitted under TSCA Sections 4, 5, 8(e), and 8(d), as well as for your
information (FYI) submissions. In the gray literature process defined in Appendix A.3.2, EPA considers
the databases that contain TSCA submissions to be secondary sources (Step 1.1) because the metadata in
the databases are secondary. These databases then advance to Step 2.3.1 and then to Process C. The
Process C steps are described here.
EPA first screens the titles using two screeners per title. EPA conducts this step primarily to reduce the
number of full studies to be obtained because some studies are available only on microfiche or in long-
term storage. Screening is done using the inclusion and exclusion criteria within the relevant PECOs,
PESOs or RESOs for each topic area (Appendix A.2.1). EPA excludes interim reports (e.g., interim
sacrifices for toxicity studies) and only final reports are further considered. If the title is not clear
regarding the document's contents, EPA obtains the full text and advances to the next steps.
After full texts are obtained, EPA reviewed some sources (prior to full-text screening) based on whether
they have several factors; primary data, an established procedure for peer review, data collection,
communication and/or reporting and are publicly available. Sources that have these factors will move on
to full text screening. Other sources will go straight to full text screening using PECO-type criteria
without going through this extra step.
EPA may decide to initiate a backwards search on sources that are deemed to have secondary data. In
situations where parameters such as procedures for peer review and data collection are unclear, EPA
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may reach out to the authors to retrieve information to gauge whether the source should be included or
excluded. Studies that are not publicly available (such as proprietary or CBI sources) may undergo
additional screening steps.
During the full-text screening step, two individuals screen each source according to the PECOs, PESOs
and RESOs (Appendix A.2.1).
Results of the TSCA submission search and decision tree process are included in Appendix A.3.4
A.3.4 Gray Literature Search Results for o-Dichlorobenzene
Table Apx A-12 provides a list of gray literature sources that yielded results for o-dichlorobenzene.
Table Apx A-12. Gray Literature Sources that Yielded Results for o-
)ichlorobenzene
Source
Agency
Source Name
Source Type
Source
Category
Source Website
ATSDR
ATSDR Tox Profile Updates
and Addendums
Other US
Agency
Resources
Assessment
or Related
Document
https://www.atsdr.cdc.gov/tox
p ro fi 1 e s/pro fi 1 e s ad den da. as p
ATSDR
ATSDR Toxicological
Profiles (original publication)
Other US
Agency
Resources
Assessment
or Related
Document
https://www.atsdr.cdc.gov/tox
profiles/index.asp
Australian
Government,
Department
of Health
NICNAS Assessments
(human health, Tier I, II or
HI)
International
Resources
Assessment
or Related
Document
https://www.in dustrialchemica
Is. go v. au/chemical -
inf ormati on/search-
assessments
CAL EPA
Technical Support
Documents for regulations:
Drinking Water Public Health
Goals
Other US
Agency
Resources
Assessment
or Related
Document
https ://o ehha. ca go v/ chemicals
CDC
CDC Biomonitoring Tables
Other US
Agency
Resources
Database
https://www.cdc.gov/exposure
report/index.html/
ECHA
ECHA Documents
International
Resources
Assessment
or Related
Document
https ://echa.europa eu/informat
ion-on-chemicals
Env Canada
Priority Substances List
Assessment Report; State of
Science Report, Environment
Canada Assessment
International
Resources
Assessment
or Related
Document
https://www.canada.ca/en/envi
ronment-climate-
change/services/canadian-
environmental-protection-act-
registry/substances-
list/priority-list, html
Env Canada
Guidelines, Risk
Management, Regulations
International
Resources
Assessment
or Related
Document
https://www.canada.ca/en.html
100
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Source
Agency
Source Name
Source Type
Source
Category
Source Website
Env Canada
Chemicals at a Glance (fact
sheets)
International
Resources
Assessment
or Related
Document
https ://www. Canada, ca/en/heal
th-canada/services/chemical-
substances/fact-
sheets/chemicals -glance .html
EPA
OPPT: TSCATS database
maintained at SRC (TSCA
submissions)
US EPA
Resources
Database
EPA
OPPT: Chemview(TSCA
submissions - chemical test
rule data and substantial risk
reports)
US EPA
Resources
Database
https ://ch em view, epa eov/che
mview
EPA
OPPT: CIS (CBI LAN)
(TSCA submissions)
US EPA
Resources
Database
EPA
Office of Water: STORET
and WQX
US EPA
Resources
Database
https: // www. waterquality data,
us/portal/
EPA
EPA Office of Water:
Ambient Water Quality
Criteria documents
US EPA
Resources
Assessment
or Related
Document
https://www.epa.gov/wqc
EPA
IRIS Summary
US EPA
Resources
Assessment
or Related
Document
https ://cfpub. epa gov/ncea/iris
drafts/atoz.cfm?list type=alp
ha
EPA
Office of Air: TRI
US EPA
Resources
Database
https://www.epa.gov/toxics-
release-inventory-tri-
pro.gr am/tri-data-and-tools
EPA
TSCA Hazard
Characterizations
US EPA
Resources
Assessment
or Related
Document
https ://ofmpub. epa gov/oppthp
v/hpv he characterization.get
report bv cas?doctvpe=2
EPA
EPA: AP-42
US EPA
Resources
Regulatory
Document or
List
https://www.epa.gov/air-
emissions-factors-and-
q uantification/ ap-42-
compilation-air-emissions-
factors
EPA
TRI: Envirofacts Toxics
Release Inventory 2017
Updated Dataset
US EPA
Resources
Database
https://www.epa.gov/enviro/tri
-customized-search
EPA
Other EPA: Misc sources
US EPA
Resources
General
Search
https://www.epa.gov/
EPA
Office of Air: CFRs and
Dockets
US EPA
Resources
Regulatory
Document or
List
https://www.epa.gov/stationar
y-sources-air-pollution
EPA
EPA: Generic Scenario
US EPA
Resources
Assessment
or Related
Document
https://www.epa.gov/tsca-
screening-tools/chemsteer-
chemical-screening-tool-
e\DOSures-and-en\ironmental-
releases#genericscenarios
101
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Source
Agency
Source Name
Source Type
Source
Category
Source Website
FDA
FDA Market Baskets
Other US
Agency
Resources
Assessment
or Related
Document
https://www.fda. gov/food/total
-diet-study/analytical-results-
total-diet-study
IARC
IARC Monograph
International
Resources
Assessment
or Related
Document
http://mono8raDhs.iarc.fr/ENG
/Monographs/PDFs/index.php
ILO
International Chemical Safety
Cards (ICSCs)
International
Resources
Database
https://www.ilo.Org/safework/i
nfo/publications/WCMS 1131
3 4/lans>—en/index. htm
Japan
Japanese Ministry of the
Environment Assessments -
Environmental Risk
Assessments (Class I
Designated Chemical
Substances Summary Table)
International
Resources
Regulatory
Document or
List
https://www.env.go.ip/en/che
mi/prtr/substances/
Japan
Japanese Ministry of the
Environment Assessments -
Environmental Risk
Assessments
International
Resources
Assessment
or Related
Document
http: //www. env. go. i p/en/ chemi
/chemicals/profile erac/index.
html
KOECT
Kirk-Othmer Encyclopedia of
Chemical Technology Journal
Article
Other
Resource
Encyclopedia
https:// onlinelibrary .wilev .com
/doi/book/10.1002/047123896
I
NIOSH
CDC NIOSH - Occupational
Health Guideline Documents
Other US
Agency
Resources
Assessment
or Related
Document
https://www.cdc.gov/niosh/top
ics/chemical.html/
NIOSH
CDC NIOSH - Pocket Guide
Other US
Agency
Resources
Database
https://www.cdc.gov/niosh/np
g/def ault.html
NIOSH
CDC NIOSH - Health Hazard
Evaluations (HHEs)
Other US
Agency
Resources
Assessment
or Related
Document
https ://www2a cdc. gov/hhe/se
arch, asp
NTP
Technical Reports
Other US
Agency
Resources
Assessment
or Related
Document
https://ntp.niehs.nih.gov/public
ations/rep orts/ind ex .html? type
=Technical+Report
OECD
OECD SIDS
International
Resources
Assessment
or Related
Document
https://hpvchemicals.oecd.org/
ui/Publications. aspx
OECD
OECD Emission Scenario
Documents
International
Resources
Assessment
or Related
Document
http://www.oecd.org/document
/46/0.2340.en 2649 201185 2
412462 1 1 1 1.00.html
OECD
OECD: General Site
International
Resources
General
Search
https://www.oecd.org/
OSHA
OSHA Chemical Exposure
Health Data
Other US
Agency
Resources
Database
https://www.osha gov/openrov
/healthsamples.html
102
-------
Source
Agency
Source Name
Source Type
Source
Category
Source Website
RIVM
Integrated Criteria
Documents
International
Resources
Assessment
or Related
Document
https://www.rivm.nl/en
RIVM
RIVM Reports: Risk
Assessments
International
Resources
Assessment
or Related
Document
https://www.rivm.nl/en
TERA
Toxicology Excellence for
Risk Assessment
Other
Resources
Assessment
or Related
Document
https://www.tera ora/
103
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Appendix B PHYSICAL AND CHEMICAL PROPERTIES OF o-
DICHLOROBENZENE
Table Apx B-l summarizes statistics for the physical and chemical property values identified through
systematic review as of June 2020. The "N" column indicates the number of unique primary sources of
data for that endpoint. That is, if multiple sources presented equivalent values and cited the same
primary source, only one of those was included in these statistics and included in the statistical
calculations. All physical and chemical property values that were extracted and evaluated as of June
2020 are presented in the supplemental file Data Extraction and Data Evaluation Tables for Physical
and Chemical Property Studies (EP A-HQ-QPPT-2018-0444).
Table Apx B-l. Summary Statistics for Reviewed Physical
Properties
Property or Endpoint
N
Unit
Mean
Standard
Deviation
Min
Max
Molecular formula
-
-
NA
NA
NA
NA
Molecular weight
-
g/mol
NA
NA
NA
NA
Physical state
4
-
NA
NA
NA
NA
Physical properties
2
-
NA
NA
NA
NA
Melting point
17
°C
-17.4
0.6
-18.5
-16.7
Boiling point
16
°C
180
0.90
178
181
Density
13
g/cm3
1.3031
0.0042
1.2934
1.3088
Vapor pressure
10
mm Hg
5.348
13.253
0.058
42.97
Vapor density
1
-
5.05
-
5.05
5.05
Water solubility
17
mg/L
133.9
30.9
92.3
200
Octanol/water partition
coefficient (log Kow)
11
-
3.40
0.086
3.28
3.57
Henry's Law constant
2
atnrmVmol
0.00171
0.000297
0.0015
0.00192
Flash point
0
°C
-
-
-
-
Auto flammability
0
°C
-
-
-
-
Viscosity
5
CP
1.609
0.666
1.272
2.8
Refractive index
8
-
1.5524
0.0088
1.5424
1.5729
Dielectric constant
1
-
10.36
-
10.36
10.36
NA = Not applicable
104
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Appendix C ENVIRONMENTAL FATE AND TRANSPORT
PROPERTIES OF 0-DICHLOROBENZENE
Table Apx C-l provides the environmental fate characteristics that EPA identified and considered in
developing the scope for o-dichlorobenzene. This information was presented in the Proposed
Designation of o-dichlorobenzene (CASRN95-50-1) as a High-Priority Substance for Risk Evaluation
(U.S. EPA, 2019e) and may be updated as EPA collects additional information through systematic
review methods.
Table Apx C-l. Environmental Fate and Transport Properties o
' o-Dichlorobenzene
Property or
Endpoint
Value3
Reference
Direct
Phot od egrad ation
Not expected; does not contain chromophores
that absorb at wavelengths >290 nm
NLM (2014) citing Lyman et al.
(1990); OECD (2001)
Indirect
Phot od egrad ation
ti/2 = 38 days (12-hour day; 5 x 105 OH/cm3)
from OH rate constant 4.2 x 10-13
cm3/molecule-second at 25 °Cb
NLM (2014) citing Atkinson
(1989); U.S. EPA (2012b)
ti/2 = 27 days (5 x 105 OH/cm3); -OH rate
constant 3 x 10"13 cm3/molecule-second
OECD (2001)
ti/2 = 53 days(l x 105 OH/cm3); -OH rate
constant 3 x 10"13 cm3/molecule-second
OECD (2001)
Hydrolysis
Stable; o-dichlorobenzene is not expected to
undergo
hydrolysis in the environment due to the
lack of hydrolysable functional groups
NLM (2014) citing Lyman et al.
(1990)
Biodegradation
0% of theoretical BOD/28 days (Japanese
MITT test) with activated sludge (aerobic
water)
NLM (2014) citing CITI (1992)
25%/300 days removed from an aerobic
soil column (closed system) (aerobic
soil)
OECD (2001)
100%/4 months in aerobic Rhine River
sediment column (closed system) after 60-
100-daylag period (aerobic sediment)
ATSDR (2006)
ti/2 = 37 days (first-order biodegradation rate
constant = 0.0188 days-1) in acclimated
anaerobic sediment slurry obtained from the
Tsurumi River, Japan (anaerobic sediment)
NLM (2014) citing Masunaga et al.
(1996)
6.3%/10 weeks in an alkaline soil sample
NLM (2014) citing Haider et al.
(1974)
ti/2 = 117 days in a heterogeneous aquifer at the
Columbus Air Force Base, Mississippi
NLM (2014) citing Stauffer TB
(1994)
105
-------
Property or
Endpoint
Value3
Reference
ti/2 = 12 days in pure culture laboratory batch
microcosms following a 13-day lag period
NLM (2014) citing Nielsen et al.
(1996)
Wastewater
Treatment
Elimination efficiencies from 15% to 53%
during infiltration and soil percolation of o-
dichlorobenzene containing wastewater from
a wastewater treatment plant
OECD (2001)
75% total removal (47% by biodegradation,
7% by sludge, 20% by volatilization to air;
estimated)13
U.S. EPA (2012b)
Bioconcentration
Factor
90-260 (carp) and 270-560 (rainbow trout)
NLM (2014) citing CITI (1992)
and Oliver and Niimi (1983)
6,212-19,700 (Se/enaslriim capricornutum,
algae)
NLM (2014) citing Casserly et al.
(1983); OECD (2001)
66 (whole-body BCF measured in bluegill
sunfish)
NLM (2014) citing Barrows et al.
(1980)
Bioaccumulation
Factor
240 (estimated)13
U.S. EPA (2012b)
Soil Organic
Carbon: Water
2.45 (in silt loam soil)
NLM (2014) citing Chiou et al.
(1979)
a Measured unless otherwise noted
bEPI Suite™ physical property inputs: Log Kow= 3.43, BP = 180 °C, MP = -16.7 °C, VP = 1.36 mm
Hg, WS = 156 mg/L, HLC = 0.00192 atm-m3/mole, BIOP = 40, BioA = 10 and BioS = 10 SMILES:
c(c(cccl)Cl)(cl)Cl
OH = hydroxyl radical; OECD = Organisation for Economic Cooperation and Development; TG = test
guideline; GC = gas chromatography; MITT = Ministry of International Trade and Industry; BCF =
bioaccumulation factor; BOD = biochemical oxygen demand
106
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Appendix D REGULATORY HISTORY
The chemical substance, o-dichlorobenzene, 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 o-dichlorobenzene are listed in Table Apx D-3.
D.l Federal Laws and Regulations
Table Apx D-l. Federal Laws and Regulations
Statutes/Regulations
Description of Authority/Regulation
Description of
Regulation
EPA Statutes/Regulations
Toxic Substances
Control Act (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.
o-Dichlorobenzene is one of
the 20 chemicals EPA
designated as a High-
Priority Substance for risk
evaluation under TSCA (84
FR 71924, December 30,
2019). Designation of o-
dichlorobenzene as high-
priority substance
constitutes the initiation of
the risk evaluation on the
chemical.
Toxic Substances
Control Act (TSCA) -
Section 8(a)
The TSCA Section 8(a) CDRRule 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.
o-D ichlorob enzene
manufacturing (including
importing), processing and
use information is reported
under the CDRrule (85 FR
20122, April 2, 2020).
Toxic Substances
Control Act (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.
o-D ichlorob enzene 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).
Toxic Substances
Control Act (TSCA) -
Section 4
Provides EPA with authority to issue rules,
enforceable consent agreements and orders
requiring manufacturers (including importers)
and processors to test chemical substances and
mixtures.
Four chemical data
submissions from test rules
were received for o-
d ichlorob enzene including
two water studies
(persistence and stability),
one mutagenicity/genetic
107
-------
Statutes/Regulations
Description of Authority/Regulation
Description of
Regulation
toxicity study (1983), and
one reproductive toxicity
studv (1989) (ChemView,
Accessed May 20, 2020)
Emergency Planning
and Community
Right-To-Know Act
(EPCRA) - Section
313
Requires annual reporting from facilities in
specific industry sectors that employ 10 or
more full-time equivalent employees and that
manufacture, process or otherwise use a TRI-
listed chemical in quantities above threshold
levels. A facility that meets reporting
requirements must submit a reporting form for
each chemical for which it triggered reporting,
providing data across a variety of categories,
including activities and uses of the chemical,
releases and other waste management (e.g.,
quantities recycled, treated, combusted) and
pollution prevention activities (under Section
6607 of the Pollution Prevention Act). These
data include on- and off-site data as well as
multimedia data(/.e., air, land and water).
o-Dichlorobenzene is a
listed substance subject to
reporting requirements
under 40 CFR 372.65
effective as of January 01,
1987.
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.
o-Dichlorobenzene was
registered as an
antimicrobial and
conventional chemical on
June 9, 1983. The last
products containing o-
dichlorobenzene as an active
ingredient were cancelled in
November 1992. No
registration actions have
been submitted in support of
o-dichlorobenzene, for
either antimicrobial or
conventional chemical uses.
No reregistration activities
have been conducted since
there are no active
registrations. Still appears in
some pesticidal formulations
based on SDSs. (Pesticide
Chemical Search, Accessed
May 20, 2020)
108
-------
Statutes/Regulations
Description of Authority/Regulation
Description of
Regulation
Clean Air Act (C A A) -
Section 111(b)
Requires EPA to establish new source
performance standards (NSPS) for any
category of new or modified stationary
sources that EPA determines causes, or
contributes significantly to, air pollution,
which may reasonably be anticipated to
endanger public health or welfare. The
standards are based on the degree of emission
limitation achievable through the application
of the best system of emission reduction
(BSER) which (taking into account the cost of
achieving reductions and environmental
impacts and energy requirements) EPA
determines has been adequately demonstrated.
o-Dichlorobenzene is
subject to the NSPS for
equipment leaks of volatile
organic compounds (VOCs)
in the synthetic organic
chemicals manufacturing
industry for which
construction, reconstruction
or modification began after
January 5, 1981 and on or
before November 7, 2006
(40 CFR Part 60, Subpart
VV).
Clean Air Act (C A A) -
Sections 211(a), (b),
(e), and (f)
Requires fuels and fuel additives that are
designated by EPA to be registered under 40
CFRPart 79, Registration of Fuels and Fuel
Additives.
While the composition of
registered fuels and fuel
additives is confidential, a
Safety Data Sheet for a fuel
additive identified p-
dichlorobenzene and o-
dichlorobenzene as
components. (List of
Registered Gasoline and
Diesel Additives, Accessed
June 4, 2020)
Clean Water Act
(CWA) Section
304(a)(1)
Requires EPA to develop and publish ambient
water quality criteria (AWQC) reflecting the
latest scientific knowledge on the effects on
human health that may be expected from the
presence of pollutants in any body of water.
In 2015 EPA published
updated AWQC foro-
dichlorobenzene, including a
recommendation of 1,000
(|ig/L) for "Human Health
for the consumption of
Water + Organism" and
3,000 (|ig/L) for "Human
Health for the consumption
of Organism Only" for
states and authorized tribes
to consider when adopting
criteria into their water
qualitv standards. (National
Recommended Water
Oualitv Criteria - Human
Health Criteria Table,
Accessed May 20, 2020)
109
-------
Statutes/Regulations
Description of Authority/Regulation
Description of
Regulation
Clean Water Act
(CWA) - Section
301(b), 304(b), 306,
207(a) and 307(b)
Clean Water Act Section 307(a) establishes a
list of toxic pollutants or combination of
pollutants under the CWA. The statute
specifies a list of families of toxic pollutants
also listed in the Code of Federal Regulations
at 40 CFRPart 401.15. The "priority
pollutants" specified by those families are
listed in 40 CFRPart 423 Appendix A. These
are pollutants for which best available
technology effluent limitations must be
established on either a national basis through
rules (Sections 301(b), 304(b), 307(b), 306) or
on a case-by-case best professional judgement
basis in NPDES permits, see Section
402(a)(1)(B). EPA identifies the best available
technology that is economically achievable for
that industry after considering statutorily
prescribed factors and sets regulatory
requirements based on the performance of that
technology.
o-Dichlorobenzene is
designated as a toxic
pollutant under Section
307(a)(1) of the CWA and
as such is subject to effluent
limitations (40 CFR401.15).
o-Dichlorobenzene is
designated as a priority
pollutant as well (40 CFR
Part 423 Appendix A Under
CWA Section 304, o-
dichlorobenzene is included
in the list of total toxic
organics (TTO) (40 CFR
413.02(DY
Clean Water Act
(CWA) - Section
311(b) (2)(A) and
501(a) of the Federal
Water Pollution
Control Act.
Requires EPA to develop, promulgate, and
revise as may be appropriate, regulations
designating as hazardous substances, other
than oil, which, when discharged present an
imminent and substantial danger to the public
health or welfare, including, but not limited to,
fish, shellfish, wildlife, shorelines, and
beaches.
o-Dichlorobenzene is a
designated hazardous
substance in accordance
with Section 311(b)(2)(A) of
the Federal Water Pollution
Control Act (43 FR 10474,
March 13, 1978).
Safe Drinking Water
Act (SDWA) - Section
1412
Requires EPA to publish a non-enforceable
maximum contaminant level goal (MCLG) for
a contaminant for which EPA makes the
determination that the contaminant: 1. may
have an adverse effect on the health of
persons; 2. is known to occur or there is a
substantial likelihood that the contaminant will
occur in public water systems with a
frequency and at levels of public health
concern; and 3. in the sole judgement of the
Administrator, regulation of the contaminant
presents a meaningful opportunity for health
risk reductions for persons served by public
water systems. When EPA publishes an
MCLG, EPA must also promulgate a National
o-Dichlorobenzene is
subject to NPDWRunder
the SDWA with a MCLG of
0.6 mg/L Public Health Goal
and an enforceable MCL of
0.6 mg/L (Section 1412) (52
FR 25690, January 30,
1991).
110
-------
Statutes/Regulations
Description of Authority/Regulation
Description of
Regulation
Primary Drinking Water Regulation
(NPDWR) which includes either an
enforceable maximum contaminant level
(MCL), or a required treatment technique.
Public water systems are required to comply
with NPDWRs.
Resource Conservation
and Recovery Act
(RCRA) - Section
3001
Directs EPA to develop and promulgate
criteria for identifying the characteristics of
hazardous waste, and for listing hazardous
waste, taking into account toxicity,
persistence, and degradability in nature,
potential for accumulation in tissue and other
related factors such as flammability,
corrosiveness, and other hazardous
characteristics.
o-Dichlorobenzene is
included on the list of
hazardous wastes pursuant
to RCRA 3001. RCRA
Hazardous Waste Code
U070 (40 CFR Section
261.33)
Comprehensive
Environmental
Response,
Compensation and
Liability Act
(CERCLA) - Sections
102(a) and 103
Authorizes EPA to promulgate regulations
designating as hazardous substances those
substances which, when released into the
environment, may present substantial danger
to the public health or welfare or the
environment.
EPA must also promulgate regulations
establishing the quantity of any hazardous
substance the release of which must be
reported under Section 103.
Section 103 requires persons in charge of
vessels or facilities to report to theNational
Response Center if they have knowledge of a
release of a hazardous substance above the
reportable quantity threshold.
o-Dichlorobenzene is a
hazardous substance under
CERCLA. Releases of o-
dichlorobenzene in excess of
100 pounds must be
reported (40 CFR 302.4).
Superfund
Amendments and
Reauthorization Act
(SARA)-
Requires the Agency to revise the hazardous
ranking system and update the National
Priorities List of hazardous waste sites,
increases state and citizen involvement in the
superfund program and provides new
enforcement authorities and settlement tools.
o-Dichlorobenzene is listed
on SARA, an amendment to
CERCLA and the CERCLA
Priority List of Hazardous
Substances. This list
includes substances most
commonly found at facilities
on the CERCLA National
Priorities List (NPL) that
have been deemed to pose
the greatest threat to public
health (Substance Priority
Ill
-------
Statutes/Regulations
Description of Authority/Regulation
Description of
Regulation
List, Accessed May 20,
2020).
Other Federal Statutes/Regulations
Occupational Safety
and Health Act
(OSHA)
Requires employers to provide their workers
with a place of employment free from
recognized hazards to safety and health, such
as exposure to toxic chemicals, excessive
noise levels, mechanical dangers, heat or cold
stress or unsanitary conditions (29 U.S.C
Section 651 et seq.).
Underthe Act, OSHA can issue occupational
safety and health standards including such
provisions as Permissible Exposure Limits
(PELs), exposure monitoring, engineering and
administrative control measures, and
respiratory protection.
OSHA issued occupational
safety and health standards
for o-dichlorobenzene that
included a PEL of (C)50
ppm (ceiling limit) (29 CFR
1910.1000V
Federal Hazardous
Materials
Transportation Act
(HMTA)
Section 5103 of the Act directs the Secretary
of Transportation to:
• Designate material (including an
explosive, radioactive material, infectious
substance, flammable or combustible
liquid, solid or gas, toxic, oxidizing or
corrosive material, and compressed gas)
as hazardous when the Secretary
determines that transporting the material
in commerce may pose an unreasonable
risk to health and safety or property.
• Issue regulations for the safe
transportation, including security, of
hazardous material in intrastate, interstate
and foreign commerce.
o-Dichlorobenzene is listed as
a hazardous material with
regard to transportation and is
subject to regulations
prescribing requirements
applicable to the shipment
and transportation of listed
hazardous materials (70 FR
34381, June 14 2005).
D.2 State Laws and Regulations
Table Apx D-2. State
^aws and Regulations
State Actions
Description of Action
State Air
Regulations
Allowable Ambient Levels
New Hampshire set a 24 hr AAL at 536 |_ig/m3 and Annual AAL at 357
usi/m3 (Env-A 1400: Regulated Toxic Air Pollutants). Rhode Island set a 1
112
-------
State Actions
Description of Action
hour AAL at 2000 ug/m3 and an Annual AAL at 300 ug/m3 (Air Pollution
Regulation No. 22).
State Drinking
Water Standards
and Guidelines
Arizona set an MCL of 0.6 mg/L and an MCLG of 0.6 mg/L for o-
dichlorobenzene (14 Ariz. Admin. Register 2978, August 1, 2008).
California set an MCL of 0.6 mg/L and a PHG of 0.6 mg/L in 1997 (Cal
Code Regs. Title 26, § 22-64444). Connecticut set an MCL of 0.6 mg/L for
o-dichlorobenzene (Conn. Agencies Regs. § 19-13-B102). Delaware set an
MCL of 0.6 mg/L for o-dichlorobenzene (Del. Admin. Code Title 16, §
4462). Florida set an MCL of 6000 mg/L for o-dichlorobenzene (Fla. Admin.
CodeR. Chap. 62-550). Maine set an MCL of 0.6 mg/L for o-
dichlorobenzene (10 144 Me. CodeR. Chap. 231). Massachusetts set an
MCL of 0.6 mg/L (310 Code Mass. Regs. § 22.00). Michigan set an MCL of
600 mg/L (Mich. Admin. Coder.299.44 and r.299.49, 2017). Minnesota set
an MCL of 600 mg/L(chronic) for o-dichlorobenzene (Minn R. Chap. 4720).
New Jersey set an MCL for 600 mg/L for o-dichlorobenzene (7:10 N.J
Admin. Code § 5.2). Pennsylvania set an MCL of .6 mg/L foro-
dichlorobenzene (25 Pa. Code § 109.202). Rhode Island set an MCL of 600
mg/L for o-dichlorobenzene (Rules and Regulations Pertaining to Public
Drinking Water R46-13-DWO).
State PELs
California PEL of 25 ppm, 150 mg/M and 50 ppm (Cal Code Regs. Title 8, §
5155)
Hawaii PEL: 50 ppm ceiling and 300 mg/M (Hawaii Administrative Rules
Section 12-60-50).
State Right-to-
Know Acts
o-Dichlorobenzene is listed on the Massachusetts Substance List
Massachusetts (105 Code Mass. Regs. § 670.000 Appendix A). New Jersey
lists o-dichlorobenzene on their Right-to-Know list (N.J.A.C. 7:1G).
Pennsylvania lists o-dichlorobenzene on their Right-to-Know list with an
Environmental Hazard notation (P.L. 734, No. 159 and 34 Pa. Code § 323).
Chemicals of High
Concern to Children
Several states have adopted reporting laws for chemicals in children's
products containing o-dichlorobenzene including Maine (38 MRSA Chapter
16-D).
Other
o-Dichlorobenzene is on the MA Toxic Use Reduction Act (TURA) list of
April 3. 2019 (301 CMR 41.00).
113
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D.3 International Laws and Regulations
Table Apx D-3. Regulatory Actions by other Governments, Tribes, and International Agreements
Country/
Organization
Requirements and Restrictions
Canada
o-Dichlorobenzene is on the Domestic Substances List (Government of
Canada. Managing substances in the environment. Substances Search.
Database accessed April 17, 2019). Other regulations include:
• Canada's National Pollutant Release Inventory (NPRI)
European Union
o-Dichlorobenzene was evaluated under the 2013 Community rolling action
plan (CoRAP) under regulation (European Commission [EC])
Nol907/2006 - REACH (Registration, Evaluation, Authorisation and
Restriction of Chemicals) (ECHA database. Accessed April 16, 2019).
Australia
o-Dichlorobenzene is subject to secondary notifications when importing or
manufacturing the chemical in Australia.
In 2001, o-dichlorobenzene was assessed. (o-Dichlorobenzene. Priority
Existing Chemical No. 14. Full Public Report (2001)).
Japan
o-Dichlorobenzene 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)
• Act on Confirmation, etc. of Release Amounts of Specific Chemical
Substances in the Environment and Promotion of Improvements to the
Management Thereof
• Industrial Safety and Health Act (ISHA)
• Japan Air Pollution Control Law
(National Institute of Technology and Evaluation rNITEl Chemical Risk
Information Platform TCHRIP1, Accessed April 11. 2019).
Australia, Austria,
Belgium, Canada-
Ontario, Canada-
Quebec, Denmark,
European Union,
Finland, France,
Germany, Ireland,
Italy, Japan, Latvia,
New Zealand,
People's Republic of
China, Poland,
Romania, Singapore,
South Korea, Spain,
Occupational exposure limits for o-dichlorobenzene (GESTIS International
limit values for chemical agents (Occupational exposure limits, OELs)
database. Accessed April 15, 2019.
114
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Country/
Organization
Requirements and Restrictions
Sweden, Switzerland,
The Netherlands,
Turkey, United
Kingdom
115
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Appendix E PROCESS, RELEASE AND OCCUPATIONAL
EXPOSURE INFORMATION
This appendix provides information and data found in preliminary data gathering for o-dichlorobenzene.
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 Import
In general, chemicals may be imported into the United States in bulk via water, air, land, and intermodal
shipments (Tomer and Kane, 2015). These shipments take the form of oceangoing chemical tankers,
railcars, tank trucks, and intermodal tank containers. o-Dichlorobenzene is a liquid at room temperature
and is shipped in bulk in aluminum tank trucks and steel or stainless-steel tank cars (Krishnamurti,
2001). Both imported and domestically manufactured commodity chemicals may be repackaged by
wholesalers for resale; for example, repackaging bulk packaging into 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.
E.1.2 Processing and Distribution
E.1.2.1 Processing as a Reactant
Processing as a reactant is the use of o-dichlorobenzene as a feedstock in the production of another
chemical via a chemical reaction in which o-dichlorobenzene is consumed to form the product. In the
2016 CDR, one company reported use of o-dichlorobenzene as an intermediate in the manufacture and
preparation of chemical products (U.S. EPA. 2019a). o-Dichlorobenzene is commonly reacted to form
the chemical 3,4-dichloroaniline, which is used in the production of several herbicides and forthe
production of 3,4,4'-trichlorocarbanilide (TCC), a bacteriostat used in deodorant soaps (Krishnamurti,
2001).
Exact operations for the use of o-dichlorobenzene as a reactant to produce other chemicals are not
known at this time. For using a chemical as a reactant, operations would typically involve unloading the
chemical from transport containers and feeding the chemical into a reaction vessel(s), where the
chemical would react either fully or to a lesser extent. Following completion of the reaction, the
produced substance may be purified further, thus removing unreacted o-dichlorobenzene (if any exists).
E.1.2.2 Incorporated 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. In the 2016 CDR, one company
reported the use of o-dichlorobenzene as a solvent in the manufacturing of plastic material and resin
(U.S. EPA. 2019a). The. Marvel Oil Company Inc. (EPA-HQ-QPPT-2018-0444-0026) provided a
description of their use of o-dichlorobenzene as a solvent in the manufacturing of petroleum lubricating
oil and grease; more specifically, their products, that contain o-dichlorobenzene, are used as an engine
oil additive or as a pneumatic tool lubricant. A commenter (EPA-HQ-OPPT-2018-0444-0013) indicated
possible use as a solvent in the manufacturing of all other chemical product and preparation, EPA plans
to further investigate the use of o-dichlorobenzene in all other chemical product and preparation during
the risk evaluation. Another company, Willert Home Products, is known to use o-dichlorobenzene as a
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processing aid in the manufacturing of soaps and cleaning compounds (EPA-HQ-QPPT-2018-0444-
0017), exact process and release information is not known at this time, however, EPA plans to further
analyze this use during the risk evaluation.
The exact processes used to formulate products containing o-dichlorobenzene are not known at this
time; however, several ESDs published by the OECD and Generic Scenarios published by EPA have
been identified that provide general process descriptions for these types of products.
As an example, in plastics and rubber manufacturing the formulation step usually involves the
compounding of the polymer resin with additives and other raw materials to form a masterbatch in either
open or closed blending processes (U.S. EPA, 2014a; OECD, 2009). After compounding, the resin is fed
to an extruder where is it converted into pellets, sheets, films or pipes (U.S. EPA, 2014b). EPA plans to
further investigate processing uses of o-dichlorobenzene during risk evaluation.
E.1.3 Uses
E.1.3.1 Solvents (Which Become Part of Product Formulation or Mixture)
At least one company has reported to EPA that o-dichlorobenzene is used to manufacture printing ink,
paints and coatings, and synthetic dyes and pigments (U.S. EPA, 2019a). EPA was not able to find
specific process related information regarding these uses, however, EPA believes that activities that
could reasonably be expected to occur could include; transfer of materials to processing vessels,
blending operations, packaging of products, container cleaning, use of final products, and waste
treatment and disposal. EPA plans to further analyze these conditions of use during the risk evaluation.
Another company has informed the EPA that it currently uses o-dichlorobenzene as a chemical
processing aid to manufacture organic chemicals at their U.S. manufacturing facility. They disclosed
that o-dichlorobenzene is used during the synthesis of another chemical substance and the o-
dichlorobenzene is removed, by distilation, from the manufacturing process before the other chemical
substance is synthesized. The company further states that o-dichlorobenzene is not an intermediate, i.e.,
is not consumed in whole or in part in the manufacture of another chemical substance, and the o-
dichlorobenzene does not become part of the finished product that is distributed in commerce (U.S.
EPA, 2019a); (EP A-HQ-QPPT-2018-0444-003 5). The identified function of the solvent is that is used as
a reaction media to form a compound that is used downstream to form a final product. According to the
2011 OECD ESD on the Chemical Industry; "For processing aids some specific applications will be
more important than others. Solvents used as a reaction medium, extraction solvent, cleaning agent, etc.,
are well known for environmental releases" (OECD, 2011). While the exact processes used by this
company are unknown at this time the ESD indicated several process steps that could reasonably be
expected to occur, these include, but are not limited to; loading materials to a reactor vessel, filtration of
the reaction product, cleaning of process equipment, recovery of the solvent via distilation, and disposal
of the used o-dichlorobenzene solvent (OECD, 2011).
E.1.3.2 Functional Fluids (Closed System)
One company has reported to EPA that they use a mixture of p-dichlorobenzene and o-dichlorobenzene
as a coolant in a closed system; the ratio of the two isomers is approximately 75% ortho and 25% para
(EPA-HQ-QPPT-2018-0444-003 5). This is consistent with the 2011 OECD Emissions Scenario
document on the Chemical industry which states; "heat transferring agents are a class of substances with
functions described like coolants, heating agents, and refrigerants". Furthermore, the ESD states that
"heat transferring agents are applied in closed systems and that under normal operating conditions no
releases to the environment are expected to occur" (OECD, 2011).
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E.1.3.3 Ink, Toner, and Colorant Products
The 2016 CDR reports use of o-dichlorobenzene in ink, toner, and colorant products at concentrations of
less than 30% by weight. Public comment from the Aerospace Industries Association (AIA) indicates o-
dichlorobenzene is a constituent in inks (U.S. EPA, 2019a);(EPA-HQ-OPPT-2Q 18-0444-0004). The
AIA comment specifically states that o-dichlorobenzene's use in inks includes its use as a precious
metal ink that can be brushed onto a substrate. At this time, it is unknown what the chemical's specific
function is in the ink; EPA plans to further investigate this use in the risk evaluation.
E.1.3.4 Coatings and Paints, Thinners, Paint Removers
The 2016 CDR reports use of o-dichlorobenzene in paints and coatings at concentrations of less than
30% by weight (U.S. EPA, 2019a). A public comment from the Aerospace Industries Association (AIA)
also indicates o-dichlorobenzene is used as a constituent in paint strippers, but does not provide
information on the specific function the chemical serves (EPA-HQ-QPPT-2018-0444-0004). EPA plans
to further investigate the specific coatings and paints, thinners, and paint removers use activities of o-
dichlorobenzene during the risk evaluation.
E.1.3.5 Lubricants and Greases
The AIA submitted public comments indicating that o-dichlorobenzene is a constituent in oils used in
the aerospace industry. These oils include automotive engine oils for vehicle or equipment engine
maintenance and oils used to maintain tools (EPA-HQ-QPPT-2018-0444-0004). The Motor and
Equipment Manufacturers Association (MEMA) and the Alliance of Automobile Manufacturers (the
Alliance) also submitted a public comment stating that various members of the Alliance identified using
o-dichlorobenzene in the production of various automobile parts and as a lubricant (EPA-HQ-OPPT-
2019-0131-0022). Another commenter (EPA-HQ-QPPT-2018-0444-0034) provided descriptions of their
use of o-dichlorobenzene as a component of common off the shelf lubricating oil, further informing
EPA's understanding of this condition of use.
E.1.3.6 Fuels and Related Products
The Consumer Product Information Database (CPID, 2020) identifies one fuel additive product that
contains this chemical. A fuel additive from Marvel Oil Company (2017) was found to contain 0.1 to 1
wt% o-dichlorobenzene, as per its safety datasheet (SDS) (Marvel Oil Company. 2017). Marvel
Mystery Oil is sold in small containers and can be added directly to the fuel tank or the crankcase of
engines for automobiles, trucks, agricultural and earth moving equipment, marine vehicles, recreational
vehicles, small powered landscaping equipment (such as chainsaws, lawn mowers, and snow blowers),
and gasoline-powered generators. Marvel Mystery Oil improves oil lubrication and sludge control,
improves fuel combustion, and aids engine cleaning (Marvel Oil Company, 2017).
E.1.3.7 Air Care Products
EPA identified various sources describing o-dichlorobenzene's use in air care products. GoodGuide's
(Good Guide. 2011) Pollution Scorecard identifies use of this chemical in non-personal, non-aerosol
deodorants and air fresheners. NLM (NLM, 2008)identifies use of o-dichlorobenzene as a garbage and
sewage deodorizer, and Kirk-Othmer (Krishnamurti, 2001) identifies use of o-dichlorobenzene in
garbage treatment in Japan.
An SDS for deodorizing moth balls produced by Willert Home Products, Inc. shows that the product
contains o-dichlorobenzene in concentrations between 0.1 - 1% by weight (Willert Home Products Inc..
2017). CPID and an SDS identify use of o-dichlorobenzene in a toilet bowl deodorizer also in
concentrations between 0.1 - 1% by weight (CPID, 2020; Home Depot, 2019). The toilet bowl
deodorizer is designed to be attached with a hanger to the interior of the toilet bowl, where it
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continuously deodorizes (Home Depot, 2019).
E.1.3.8 Other Uses
EPA has identified additional uses of o-dichlorobenzene in various other TSCA-covered conditions of
use, such as its use in laboratory chemicals (Harrell Industries, 2015). A commenter (EPA-HQ-OPPT-
2018-0444-0034) provided descriptions of their use of o-dichlorobenzene in analytical standards,
research, equipment calibration, and sample preparation applications and as a component of common off
the shelf fuel additive used in combustion research, including as a reference sample for analysis of
terrestrial and extraterrestrial material samples, which the commenter also indicated was a critical use,
further informing EPA's understanding of this condition of use. A sheep-branding fluid was found to
contain 10 - 30% o-dichlorobenzene, per its SDS (Heiniger, 2016). The Substances Prepared in Nordic
Countries (SPIN) database identifies use of o-dichlorobenzene in cleaning and washing agents in 2000
and the OECD identifies use of the chemical as a cleaning and washing agent (SPIN, 2019; OECD,
2001). Other uses of o-dichlorobenzene that were identified were its use in thinners used to clean
brushes and tools used with overglazes, and its use in some ceramics glazes (Johnson Matthev Inc.,
2017; Duncan Enterprises, 2015, 2014). EPA plans to further investigate these other use activities of o-
dichlorobenzene during the risk evaluation.
E.1.4 Disposal
Each of the conditions of use of o-dichlorobenzene may generate waste streams of the chemical that are
collected and transported to third-party sites for disposal, treatment, or recycling. Industrial sites that
treat or dispose onsite wastes that they themselves generate are assessed in each condition of use
assessment. Similarly, point source discharges of o-dichlorobenzene to surface water are assessed in
each condition of use assessment. Wastes of o-dichlorobenzene that are generated during a condition of
use and sent to a third-party site for treatment or disposal may include wastewater and solid wastes, o-
dichlorobenzene may be contained in wastewater discharged to POTW or other, non-public treatment
works for treatment. Industrial wastewater containing o-dichlorobenzene discharged to a POTW may be
subject to EPA or authorized NPDES state pretreatment programs. The assessment of wastewater
discharges toPOTWs and non-public treatment works of o-dichlorobenzene is included in each of the
condition of use assessments. 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). EPA plans to evaluate occupational exposures for disposal. Section 2.6.3.2
describes the identified exposures (pathways and routes from environmental releases to waste) and
hazards to general population and environmental receptors associated with the conditions of use of o-
dichlorobenzene within the scope of the risk evaluation.
For the 2018 reporting year of the TRI program, 17 facilities reported in total over 55.3 million pounds
of o-dichlorobenzene waste for 2018. Nearly all (97%) of the o-dichlorobenzene managed as waste
during 2018 was managed on site by recycling. Waste treatment quantities (nearly 1.6 million pounds)
accounted for 2.8% of the total. Contributions from quantities burned for energy recovery or released to
the environment were very small, amounting to only 0.5% and 0.1%, respectively, of the total quantity
of o-dichlorobenzene managed as waste. Overall, 99.2% of the o-dichlorobenzene production-related
waste was managed as such on site.
E.2 Preliminary Occupational Exposure Data
EPA presents below an example of occupational exposure-related information obtained from
preliminary data gathering. EPA plans to consider this information and data in combination with other
data and methods for use in the risk evaluation.
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Table Apx E-l summarizes NIOSH Health Hazard Evaluations identified during EPA's preliminary
data gathering. HHEs can be found at https://www.cdc.gov/niosh/hhe/. The OSHA CEHD did not
contain any monitoring data for o-dichlorobenzene between the years 2010 and 2019.
Table Apx E-l. Summary of NIOSH HHEs with Monitoring for o-Dichlorobenzene a
Y ear of
Publication
Report Number
Facility Description
1981
HETA 81-065-938
Vehicle maintenance facility (METRO Bus Maintenance Shop,
Washington, D.C.)
1980
HHE 77-99-726
Chemical manufacturer (DuPont Chambers Works, Deepwater,
New Jersey)
1976
74-107-279
Silicone manufacturer (General Electric Company, Silicone
Products Department, Waterford, New York)
a Table includes HHEs identified to date.
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Appendix F SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR INDUSTRIAL
AND COMMERCIAL ACTIVITIES
Table Apx F-l. Worker and Occupational Non-User Exposure Conceptual Model Supporting Table
Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Liquid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers
exists during import, but
exposure will only occur
in the event the imported
material is repackaged.
Solid
Contact
Dermal
Workers
No
The potential for
exposures to workers
does not exist during
import, as o-
dichlorobenzene exists as
a liquid at room
temperature.
Manufactiiriiig
Import
Import
Repackaging of
Import
Containers
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Mist
Inhalation
Workers,
ONU
No
Mist generation is not
expected during import or
repackaging.
Dust
Inhalation/Oral
Workers,
ONU
No
Dust generation is not
expected during import or
repackaging.
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
Processing
Asa Reactant
Reactants in All other
chemical product and
preparation
manufacturing
Reactants
Liquid
Contact
Dermal
Workers
Yes
The potential for
exposures to workers
exists during processing
of o-dichlorobenzene in
liquid form.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Solid
Contact
Dermal
Workers
No
The potential tor worker
exposures to sohds is not
expected during
processing as o-
dichlorobenzene is in
liquid form.
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene 's
vapor pressure (VP) (VP
= 1.36 miiiHg) at room
temperature.
Mist
Inhalation
Workers,
ONU
No
Mist generation is not
expected during
processing as a reactant.
Dust
Inhalation/Oral
Workers,
ONU
No
Dust generation is not
expected during
processing as a reactant.
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
Incorporated
into
formulation,
Intermediates in All
other basic organic
Intermediates
Liquid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers
exists during processing
(incorporation into
formulation, mixture, or
reaction product), as o-
dichlorobenzene is in
liquid form.
mixture, or
reaction
product
chemical
manufacturing
Solid
Contact
Dermal
Workers
No
The potential for worker
exposures to sohds is not
expected during
processing (incorporation
into formulation, mixture,
or reaction product), as o-
dichlorobenzene is in
liquid form.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Vapor
Inhalation
Workers,
ONU
Yes
t here is potential tor
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Mist
Inhalation
Workers,
ONU
No
Mist generation is not
expected during
processing (incorporation
into formulation, mixture,
or reaction product).
Dust
Inhalation/Oral
Workers,
ONU
No
Dust generation is not
expected during
processing (incorporation
into formulation, mixture,
or reaction product).
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
Solvents (which
become part of
product formulation
or mixture) in Plastic
material and resin
manufacturing;
Petroleum lubricating
oil and grease
manufacturing; All
other chemical
product and
preparation
manufacturing
Liquid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers
exists during processing
(incorporation into
formulation, mixture, or
reaction product), as o-
dichlorobenzene is in
liquid form.
Incorporated in
solvents in
product
formulation
Solid
Contact
Dermal
Workers
Yes
o-Dichlorobenzene may
be incorporated into a
solid or powder;
therefore, exposures to
solids for workers are
possible.
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Dust
Inhalation/Oral
Workers,
ONU
Yes
o-Dichlorobenzene may
be incorporated into a
solid or powder;
therefore, exposures to
solids for workers are
possible.
Mist
Inhalation
Workers,
ONU
No
Mist generation is not
expected during
processing.
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
Liquid/Solid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers
exists during processing,
as o-dichlorobenzene is
in liquid form; o-
dichlorobenzene may be
incorporated into a solid
or powder; therefore,
exposures to solids for
workers are possible.
Processing aid in
Soap, cleaning
compound, and toilet
preparation
manufacturing
Incorporated in
product
formulations
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 rnniHg) at room
temperature.
Mist
Inhalation
Workers,
ONU
No
Mist generation is not
expected during
processing.
Dust
Inhalation/Oral
Workers,
ONU
Yes
o-Dichlorobenzene may
be incorporated into a
solid or powder;
therefore, exposures to
solids for workers are
possible.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
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
Distribution in
commerce
Distribution
in commerce
Distribution in
commerce
Distribution of
bulk shipments
of o-
dichlorobenzene
and formulated
products
Liquid
Contact,
Vapor
Dermal,
Inhalation
Worker, ONU
Yes
EPA plans to analyze
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 as a single
distribution scenario.
Industrial Use
Solvents
(which
become part
of product
formulation
or mixture)
Printing ink
manufacturing; Paint
and coating
manufacturing;
Synthetic dye and
pigment
manufacturing; All
other basic organic
chemical
manufacturing
Use of industrial
products and
processing aids
containing o-
dichlorobenzene
Liquid/Solid
Contact
Dermal
Workers
Yes
These products are in
liquid/solid form;
therefore, exposures to
workers are possible.
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Mist/Dust
Inhalation/Oral
Workers,
ONU
Yes
Mist/dust generation is
possible during this use.
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
Functional
Fluids
(closed
system)
All other basic
organic chemical
manufacturing
Operations of
systems that
require the use of
Liquid/Solid
Contact
Dermal
Workers
Yes
These products are in
liquid/solid form;
therefore, exposures to
workers are possible.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
heat transter
fluids (coolant)
Vapor
Inhalation
Workers,
ONU
Yes
There is potential tor
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 lnmHg) at room
temperature.
Mist/Dust
Inhalation/Oral
Workers,
ONU
No
Mist/dust generation is
not expected during this
use.
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
Liquid/Solid
Contact
Dermal
Workers
Yes
Inks and toners are in
liquid/solid form;
therefore, exposures to
workers exists for o-
dichlorobenzene used in
inks and toners.
Ink, toner,
and colorant
products
Ink and toners
Used in inks and
toners
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Commercial
Uses
Mist/Dust
Inhalation/Oral
Workers,
ONU
Yes
Mist/dust generation is
possible during use of
inks and toners.
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
Paints and
coatings
Coatings and paints,
thinners, paint
removers
Used in paints
and coatings,
thinners, paint
removers
Liquid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers
exist during use of paints
and coatings, thinners,
paint removers.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Solid
Contact
Dermal
Workers
No
The potential tor worker
exposures to solid o-
dichlorobenzene is not
expected during use of
liquid paints and
coatings, thinners, paint
removers.
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Mist
Inhalation
Workers,
ONU
Yes
Hie potential of exposure
due to mist generation
exists during the
application of paints and
coalings, thinners, paint
removers.
Dust
Inhalation/Oral
Workers,
ONU
No
Dust generation is not
expected during the use
of paints and coalings,
thinners, paint removers.
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
Lubricants
and greases
Lubricants and
greases, degreasers
Use in lubricants
and greases,
degreasers
Liquid
Contact
Dermal
Workers
Yes
The potential for
exposures to workers
exists during use of o-
dichlorobenzene in
lubricants, greases, and
degreasers as o-
dichlorobenzene is in
liquid form.
Solid
Contact
Dermal
Workers
No
The potential for worker
exposures to sohd o-DCB
is not expected during
use in lubricants, greases,
or degreasers, as o-DCB
is in liquid form.
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Vapor
Inhalation
Workers,
ONU
Yes
There is potential lor
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Mist/Dust
Inhalation/Oral
Workers,
ONU
No
Mist generation is not
expected during its use as
in lubricants, greases, or
degreasers.
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
Liquid/Solid
Contact
Dermal
Workers
Yes
Fuel additives are
typically liquid form;
therefore, dermal
exposures to workers
exists for this use.
Fuels and
related
Fuel additive for
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
products
gasoline and diesel
Dust/Mist
Inhalation/Oral
Workers,
ONU
Yes
Dust/mist generation is
not expected for this use.
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
Air care
products
Continuous action air
fresheners (including
toilet/ urinal
deodorizers
/fresheners)
Used in air care
products
Liquid/Solid
Contact
Dermal
Workers
Yes
Air care products can be
in solid or liquid form;
therefore, exposures to
workers exists for o-
dichlorobenzene used in
air care products.
128
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Vapor
Inhalation
Workers,
ONU
Yes
There is potential tor
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Dust/Mist
Inhalation/Oral
Workers,
ONU
Yes
Dust/mist generation is
possible during use of air
care products.
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
Used as
laboratory
chemicals'
sheep-branding
fluids, and
furnishing care
products
Liquid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers is
expected during use of o-
dichlorobenzene as a
laboratory chemical,
sheep-branding fluid, or
in furnishing care
products as o-
dichlorobenzene is in
liquid form.
Other use
Laboratory chemicals;
sheep branding fluid,
furnishing care
products
Solid
Contact
Dermal
Workers
No
The potential for worker
exposures to solid o-
dichlorobenzene is not
expected during use as a
laboratory chemical,
sheep-branding fluid, or
in furnishing care
products as o-
dichlorobenzene is in
liquid form.
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
129
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Life Cycle
Stage
Category
Subcategory
Release /
Exposure
Scenario
Exposure
Pathway3
Exposure
Route
Receptor /
Population
Plans to
Evaluate
Rationale
Mist
Inhalation
Workers,
ONU
Yes
Mist generation is
possible during use of
furnishing care products
if the products are spray-
applied
Dust
Inhalation/Oral
Workers,
ONU
No
Dust generation is not
expected during its use as
a laboratory chemical,
sheep-branding fluid, or
in furnishing care
products.
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
Liquid/Solid
Contact
Dermal
Workers
Yes
Hie potential for
exposures to workers
exists during this use as
liquid/solid formulations
may be disposed
Emissions to air, in
wastewater, liquid
wastes, and solid
wastes
Worker handling
wastes
Vapor
Inhalation
Workers,
ONU
Yes
There is potential for
vapor generation based
on o-dichlorobenzene's
vapor pressure (VP) (VP
= 1.36 mmHg) at room
temperature.
Disposal
Disposal
Mist
Inhalation
Workers,
ONU
No
Mist generation is not
expected during disposal
of liquid wastes.
Dust
Inhalation/Oral
Workers,
ONU
Yes
Dust generation is
possible during disposal
of solid wastes.
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
a) Dermal exposure to mist and dust is included in liquid and solid contact,respectively.
130
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Appendix G
SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR CONSUMER
ACTIVITIES AND USES
Table Apx G-1. Consumer Exposure Conce
jtual Model Supporting
able
Life Cycle
Stage
Category
Subcategory
Release from
source
Exposure
Pathway
Route
Receptor
Plans to
Evaluate
Rationale
Consumer
Use
Lubricants and
greases
Lubricants and
greases, degreasers
Direct contact
through
application or
use of products
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
Long-term
emission/mass-
transferthrough
application or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichlorobenzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and
Dermal
Consumers
and
Bystanders
No
Hie product is not expected to be spray
applied; therefore, mist generation is not
expected.
Consumer
Use
Air care products
Continuous action
air fresheners
(including
toilet/urinal
deodorizers/
fresheners)
Direct contact
during
installation
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in installing the product. Bystanders
are not expected to come in direct contact
with the chemical.
Long-term
emission/mass-
transferthrough
installation or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichlorobenzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and
Dermal
Consumers
and
Bystanders
No
Hie product is not expected to be spray
applied; therefore, mist generation is not
expected.
Consumer
Use
Fuels and related
products
Fuel additive for
gasoline anddiesel
Direct contact
through
application or
use of products
Liquid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
131
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Life Cycle
Stage
Category
Subcategory
Release from
source
Exposure
Pathway
Route
Receptor
Plans to
Evaluate
Rationale
Long-term
emission/mass-
transferthrough
application or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichioro benzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and
Dermal
Consumers
and
Bystanders
No
Hie product is not expected to be spray
applied; therefore, mist generation is not
expected.
Consumer
Use
Other use
Thinners (Products
for cleaning brushes
and tools used with
overglazes)
Direct contact
through
application or
use of products
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
Long-term
emission/mass-
transferthrough
application or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichlorobenzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and
Dermal
Consumers
and
Bystanders
No
The product is not expected to be spray
applied; therefore, mist generation is not
expected.
Consumer
Use
Other use
Ceramics glaze
Direct contact
through
application or
use of products
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
Long-term
emission/mass-
transferthrough
application or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichlorobenzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and Oral
Consumers
and
Bystanders
No
The product is not expected to be spray
applied; therefore, mist generation is not
expected.
132
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Life Cycle
Stage
Category
Subcategory
Release from
source
Exposure
Pathway
Route
Receptor
Plans to
Evaluate
Rationale
Consumer
Use
Other use
Sheep-branding
fluid
Direct contact
through
application or
use of products
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
Long-term
emission/mass-
transferthrough
application or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichlorobenzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and
Dermal
Consumers
and
Bystanders
No
Hie product is not expected to be spray
applied; therefore, mist generation is not
expected.
Consumer
Use
Other use
Cleaning and
furnishing care
products
Direct contact
through
application or
use of products
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
Long-term
emission/mass-
transferthrough
application or
use of products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichlorobenzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through
application or
use of products
Mist
Inhalation
and
Dermal
Consumers
Yes
The potential for exposure due to mist
generation exists during the application of
cleaning and furnishing care products.
Direct contact
through
application or
use of products
Mist
Dermal
Bystanders
No
Exposure is expected to be primarily
restricted to consumers who are directly
involved in using the chemical. Bystanders
are not expected to come in direct contact
with the chemical.
Consumer
Handling of
Disposal and
Waste
Wastewater,
Liquid wastes
and solid wastes
Wastewater, Liquid
wastes and solid
wastes
Direct contact
through handling
or disposal of
products
Liquid/
Solid
Contact
Dermal
Consumers
Yes
Exposure is expected to be primarily
restricted to consumers who are directly
involved in handling or disposing the
chemical. Bystanders are not expected to
come in direct contact with the chemical.
133
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Life Cycle
Stage
Category
Subcategory
Release from
source
Exposure
Pathway
Route
Receptor
Plans to
Evaluate
Rationale
Long-term
emission/mass-
transferthrough
handling or
disposal of
products
Vapor
Inhalation
Consumers
and
Bystanders
Yes
o-Dichioro benzene is volatile at room
temperature; inhalation pathway should be
further analyzed.
Direct contact
through handling
or disposal of
products
Mist
Inhalation
and
Dermal
Consumers
and
Bystanders
No
Mist generation is not expected during
handling or disposal.
134
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Appendix H SUPPORTING INFORMATION - CONCEPTUAL MODEL FOR
ENVIRONMENTAL RELEASES AND WASTES
Table Apx H-l. Environmental Exposure Conceptual Model Supporting Table
Life Cycle
Stage
Category
Release
Exposure
Pathway /
Media
Exposure
Routes
Receptor /
Population
Plans to
Evaluate
Rationale
Near facility
ambient air
concentrations
Inhalation
General
Population
Yes
o-Dichlorobenzene air and deposition to
nearby bodies of water and soil are
Emissions to Air
Indirect
deposition to
Oral
Dermal
General
Population
Yes
expected exposure pathways.
Emissions to
nearby bodies of
water and soil
catchments
TBD
Aquatic and
Terrestrial
Receptors
Yes
Air
Hazardous and
Municipal Waste
Incinerator
Near facility
ambient air
concentrations/
Inhalation
General
Population
Stationary source releases of o-
dichlorobenzene to ambient air are under
the jurisdiction of the RCRA and CAA
All
Indirect
deposition to
nearby bodies of
water and soil
catchments
TBD
Aquatic and
Terrestrial
Species
No
Direct release
into surface
water and
TBD
Aquatic and
Terrestrial
Receptors
Yes
EPA has developed Ambient Water
Quality Criteria for protection ofhuman
health for o-dichlorobenzene.
Wastewater
or Liquid
Wastes
Industrial pre-
treatment and
wastewater
treatment, orPOTW
indirect
partitioning to
sediment
Oral
Dermal
General
Population
No
Drinking Water
via Surface or
Ground Water
Oral
Dermal and
Inhalation
(e.g.,
showering)
General
Population
No
The drinking water exposure pathway for
o-dichlorobenzene is currently addressed
in NPDWR
135
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Life Cycle
Stage
Category
Release
Exposure
Pathway /
Media
Exposure
Routes
Receptor /
Population
Plans to
Evaluate
Rationale
Biosolids:
application to
soil and/or
migration to
groundwater
and/or surface
water
Oral (e.g.,
ingestion of
soil)
Inhalation
General
Population
No
Unlikely to be a route to general
population.
TBD
Aquatic and
Terrestrial
receptors
Yes
Disposal
Solid and
Liquid
Wastes
Underground
injection
Migration to
groundwater,
potential
surf ace/drinking
water
Oral
Dermal
Inhalation
General
Population
No
o-Dichlorobenzene is released to Class I
Underground Injection Wells which are
covered by SDWA andRCRA.
Aquatic and
Terrestrial
Species
TBD
Hazardous,
Municipal landfill
and other land
disposal
Leachateto soil,
ground water
and/ormitigation
to surface water
Oral
Dermal
General
Population
No
o-Dichlorobenzene is included on the list
of hazardous wastes pursuant to RCRA
3001 (40 CFR §§261.33).
TBD
Aquatic and
Terrestrial
Receptors
136
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