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i&ER^
United States
Environmental Protection Agency
July 2024
Office of Chemical Safety and
Pollution Prevention
Draft Risk Evaluation for
1,1-Dichloroethane
Supplemental File:
Supplemental Information on Environmental Release and Occupational
Exposure Assessment
CASRN: 75-34-3
ch3
CI
CI
July 2024
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TABLE OF CONTENTS
1 INTRODUCTION 11
1.1 Overview 11
1.2 Scope 11
2 COMPONENTS OF AN OCCUPATIONAL EXPOSURE AND RELEASE ASSESSMENT
15
2.1 Approach and Methodology for Process Descriptions 15
2.2 Approach and Methodology for Estimating Number of Facilities 15
2.3 Environmental Releases Approach and Methodology 16
2.3.1 Identifying Release Sources 17
2.3.2 Estimating Release Days per Year 17
2.3.3 Estimating Releases from Data Reported to EPA 19
2.3.3.1 Estimating Wastewater Discharges from TRI and DMR 20
2.3.3.2 Estimating Air Emissions from TRI and NEI 22
2.3.3.3 Estimating Land Disposals from TRI 23
2.3.4 Estimating Releases from Models 24
2.3.5 Estimating Releases Using Literature Data 24
2.3.6 Estimating Releases from Regulatory Limits 24
2.4 Occupational Exposure Approach and Methodology 25
2.4.1 Identifying Worker Activities 26
2.4.2 Estimating Number of Workers and Occupational Non-users 26
2.4.3 Estimating Inhalation Exposures 26
2.4.3.1 Inhalation Monitoring Data 26
2.4.3.2 Inhalation Exposure Modeling 28
2.4.3.3 Occupational Exposure Limits 28
2.4.4 Estimating Dermal Exposures 28
2.4.5 Estimating Acute, Subchronic and Chronic (Non-cancer and Cancer) Exposures 29
2.5 Evidence Integration for Environmental Releases and Occupational Exposures 29
2.6 Weight of Scientific Evidence Ratings for Environmental Release and Occupational Exposure
Estimates 30
3 SUMMARY OF OCCUPATIONAL EXPOSURE ESTIMATES 31
4 SUMMARY OF ENVIRONMENTAL RELEASE ESTIMATES 32
5 ENVIRONMENTAL RELEASE AND OCCUPATIONAL EXPOSURES ASSESSMENTS
BY OES 34
5.1.1 Process Description 34
5.1.2 Facility Estimates 35
5.1.3 Release Assessment 35
5.1.3.1 Environmental Release Points 35
5.1.3.2 Environmental Release Assessment Results 36
5.1.3.3 Weight of Scientific Evidence for Environmental Releases 36
5.1.4 Occupational Exposure Assessment 37
5.1.4.1 Worker Activities 37
5.1.4.2 Number of Workers and Occupational Non-users 37
5.1.4.3 Occupational Inhalation Exposure Results 38
5.1.4.4 Occupational Dermal Exposure Results 40
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5.1.4.5 Weight of Scientific Evidence for Occupational Exposures...
5.2 Distribution in Commerce
5.2.1 Process Description
5.2.2 Facility Estimates
5.2.3 Release Assessment
5.2.3.1 Environmental Release Points
5.2.3.2 Environmental Release Assessment
5.2.4 Occupational Exposure Assessment
5.2.4.1 Description of Exposure Sources and Methods of Mitigation
5.2.4.2 Estimates of Exposures
5.3 Processing as a Reactive Intermediate
5.3.1 Process Description
5.3.2 Facility Estimates
5.3.3 Release Assessment
5.3.3.1 Environmental Release Points
5.3.3.2 Environmental Release Assessment Results
5.3.3.3 Weight of Scientific Evidence for Environmental Releases ...
5.3.4 Occupational Exposure Assessment
5.3.4.1 Worker Activities
5.3.4.2 Number of Workers and Occupational Non-users
5.3.4.3 Occupational Inhalation Exposure Results
5.3.4.4 Occupational Dermal Exposure Results
5.3.4.5 Weight of Scientific Evidence for Occupational Exposures...
5.4 Processing—Repackaging
5.4.1 Process Description
5.4.2 Facility Estimates
5.4.3 Release Assessment
5.4.3.1 Environmental Release Points
5.4.3.2 Environmental Release Assessment Results
5.4.3.3 Weight of Scientific Evidence for Environmental Releases ...
5.4.4 Occupational Exposure Assessment
5.4.4.1 Worker Activities
5.4.4.2 Number of Workers and Occupational Non-users
5.4.4.3 Occupational Inhalation Exposure Results
5.4.4.4 Occupational Dermal Exposure Results
5.4.4.5 Weight of Scientific Evidence for Occupational Exposures...
5.5 Commercial Use as a Laboratory Chemical
5.5.1 Process Description
5.5.2 Facility Estimates
5.5.3 Release Assessment
5.5.3.1 Environmental Release Points
5.5.3.2 Environmental Release Assessment Results
5.5.3.3 Weight of Scientific Evidence for Environmental Releases ...
5.5.4 Occupational Exposure Assessment
5.5.4.1 Worker Activities
5.5.4.2 Number of Workers and Occupational Non-users
5.5.4.3 Occupational Inhalation Exposure Results
5.5.4.4 Occupational Dermal Exposure Results
5.5.4.5 Weight of Scientific Evidence for Occupational Exposures...
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5.6 Waste Handling, Treatment, and Disposal 65
5.6.1 Process Description 65
5.6.2 Facility Estimates 68
5.6.3 Release Assessment 68
5.6.3.1 Environmental Release Points 68
5.6.3.2 Environmental Release Assessment Results 68
5.6.3.3 Weight of Scientific Evidence for Environmental Releases 69
5.6.4 Occupational Exposure Assessment 70
5.6.4.1 Worker Activities 70
5.6.4.2 Number of Workers and Occupational Non-users 70
5.6.4.3 Occupational Inhalation Exposure Results 71
5.6.4.4 Occupational Dermal Exposure Results 72
5.6.4.5 Weight of Scientific Evidence for Occupational Exposures 73
5.7 Detailed Strengths, Limitations, Assumptions, and Key Sources of Uncertainties 74
5.7.1 Environmental Release Assessment 74
5.7.2 Occupational Exposure Assessment 76
5.7.2.1 Number of Workers 76
5.7.2.2 Analysis of Exposure Monitoring Data 76
5.8 Summary of Weight of Scientific Evidence for Environmental Releases and Occupational
Exposures 77
6 REFERENCES 81
Appendix A EXAMPLE OF ESTIMATING NUMBER OF WORKERS AND
OCCUPATIONAL NON-USERS 85
Appendix B EQUATIONS FOR CALCULATING ACUTE, SUBCHRONIC, AND
CHRONIC (NON-CANCER AND CANCER) INHALATION AND DERMAL
EXPOSURES 90
B.l Equations for Calculating Acute, Subchronic, and Chronic (Non-cancer, and Cancer)
Inhalation Exposures 90
B.2 Equations for Calculating Acute, Subchronic, and Chronic (Non-cancer, and Cancer)
Dermal Exposures 91
B.3 Acute, Subchronic, and Chronic (Non-cancer and Cancer) Equation Inputs 92
B.3.1 Exposure Duration (ED) 93
B.3.2 Breathing Rate Ratio 93
B.3.3 Exposure Frequency (EF) 93
B.3.4 Subchronic Exposure Frequency (EFsc) 94
B.3.5 Subchronic Duration (SCD) 94
B.3.6 Working Years (WY) 94
B.3.7 Lifetime Years (LT) 96
B.3.8 Body Weight (BW) 96
Appendix C SAMPLE CALCULATIONS FOR CALCULATING ACUTE AND CHRONIC
(NON-CANCER AND CANCER) INHALATION EXPOSURES 97
C.l Example High-End AC, ADC, LADC, and SADC Calculations 97
C.2 Example Central Tendency AC, ADC, LADC, and SADC Calculations 98
Appendix D DERMAL EXPOSURE ASSESSMENT METHOD 99
D. 1 Dermal Dose Equation 99
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D.2 Model Input Parameters
D.2.1 Surface Area
D.2.2 Dermal Load
D.2.3 Fractional Absorption
D.2.4 Weight Fraction of Chemical
D.2.5 Frequency of Events
Appendix E MODEL APPROACHES AND PARAMETERS
E.l EPA/OPPT Standard Models
E.2 Processing—Repackaging Model Approaches and Parameters
E.2.1 Model Equations
E.2.2 Model Input Parameters
E.2.3 Throughput Parameters
E.2.4 Number of Containers per Year
E.2.5 Release Days per Year
E.2.6 Operating Hours and Exposure Durations
E.2.7 Air Speed
E.2.8 Container Residue Loss Fraction
E.2.9 Diameters of Opening
E.2.10 Saturation Factor
E.2.11 Container Size
E.2.12Container Fill Rates
E.2.13 Ventilation Rate
E.2.14Mixing Factor
E,3 Commercial Use as a Laboratory Chemical Model Approach and Parameters
E.3.1 Model Equations
E.3.2 Model Input Parameters
E.3.3 Number of Sites
E.3.4 Throughput Parameters
E.3.5 Number of Containers Unloaded Annually per Site
E.3.6 Operating Days
E.3.7 Operating Hours
E.3.8 AirSpeed
E.3.9 Container Residue Loss Fraction
E.3.lOProduct Container Volume
E.3.11 Saturation Factor
E.3.12Container Fill Rates
E.3.13Equipment Cleaning Loss Fraction
E.3.14Diameters of Opening
E.3.15Product Data (Concentration and Density)
E.3.16 Ventilation Rate
E.3.17Mixing Factor
Appendix F CONSIDERATION OF ENGINEERING CONTROLS AND PERSONAL
PROTECTIVE EQUIPMENT
F. 1 Respiratory Protection
F.2 Glove Protection
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Appendix G PROCEDURES FOR MAPPING FACILITIES FROM STANDARD
ENGINEERING SOURCES TO OESs SCENARIOS AND COUs 131
(i.l Conditions of Use and Occupational Exposure Scenarios 131
G,2 Standard Sources Requiring Facility Mapping 133
G.3 OES Mapping Procedures 135
G.3.1 Chemical Data Reporting (CDR) 135
G.3.2 Toxics Release Inventory (TRI) 138
G.3.3 National Emissions Inventory (NEI) 140
G.3.4 Discharge Monitoring Report (DMR) 143
G.3.5 Occupational Safety and Health Administration (OSHA) Chemical and Exposure Data
(( III ID) 145
G.3.6 National Institute of Occupational Safety and Health (NIOSH) Health Hazard Evaluation
(I II III) 147
G.4 COU Mapping Procedures 148
G.5 Example Case Studies 149
G.5.1 CDR Mapping Examples 149
G.5.2 TRI Mapping Examples 152
G.5.3 NEI Mapping Examples 157
G.5.4 DMR Mapping Examples 165
G.5.5 OSHA CEHD Mapping Examples 166
G.5.6 NIOSH HHE Mapping Examples 168
G.5.7 COU Mapping Examples 168
G,6 TRI to CDR Use Mapping Crosswalk 171
Appendix H ESTIMATING DAILY WASTEWATER DISCHARGES FROM DISCHARGE
MONITORING REPORTS AND TOXICS RELEASE INVENTORY DATA 190
H.l Collecting and Mapping Wastewater Discharge Data to Conditions of Use and Occupational
Exposure Scenarios 190
H,2 Estimating the Number of Facility Operating Days per Year 191
H.3 Approach for Estimating Daily Discharges 192
H.3.1 Average Daily Wastewater Discharges 192
H.3.2 High-End Daily Direct Discharge for Facilities with DMR Data 192
H.3.3 High-End Daily Direct Consecutive Discharge for Facilities without DMRs 193
H.3.4 High-End Daily Indirect Discharges 193
H.3.5 1-Day Discharges 193
H.4 Trends in Wastewater Discharge Data: 5 Year Data Characterization 194
H.4.1 Decision Tree for DMR and TRI Wastewater Discharge Estimates 194
H.5 Example Facilities 196
Appendix I GUIDANCE FOR USING THE NATIONAL EMISSIONS INVENTORY AND
TOXIC RELEASE INVENTORY FOR ESTIMATING AIR RELEASES 218
I.l Background 218
1.2 Obtaining Air Emissions Data 218
I.2.1 Obtaining NEI Data 218
1.2.2 Obtaining TRI Data 218
1.3 Mapping NEI and TRI DATA to Occupational Exposure Scenarios 219
1.4 Estimating Air Releases Using NEI and TRI Data 219
1.4.1 Linking NEI and TRI Data 219
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1.4.2 Evaluation of Sub-annual Emissions 219
LIST OF TABLES
Table 1-1. Crosswalk of Subcategories of Use Listed in the Final Scope Document to Occupational
Exposure Scenarios Assessed in the Risk Evaluation 13
Table 3-1. Summary of EPA's Occupational Inhalation and Dermal Exposure Estimates 31
Table 4-1. Summary of EPA's Daily Release Estimates for Each OES and EPA's Overall Confidence
in These Estimates 32
Table 5-1. Summary of Environmental Releases During the Manufacture of 1,1-Dichloroethane 36
Table 5-2. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During
Manufacturing 38
Table 5-3. Inhalation Exposures to 1,1-Dichloroethane During Manufacturing 39
Table 5-4. Task-Length Inhalation Exposures to 1,1-Dichloroethane During Manufacturing 39
Table 5-5. Inhalation Exposures to 1,1-Dichloroethane During Manufacturing using Surrogate Data ... 40
Table 5-6. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Manufacturing 40
Table 5-7. Summary of Environmental Releases During the Processing of 1,1-Dichloroethane as a
Reactive Intermediate 48
Table 5-8. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During
Processing as a Reactive Intermediate 49
Table 5-9. Inhalation Exposures to 1,1-Dichloroethane During Processing as a Reactive Intermediate. 51
Table 5-10. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Processing as a Reactive
Intermediate 52
Table 5-11. Summary of Modeled Environmental Releases for the Repackaging of 1,1-
Dichloroethane 55
Table 5-12. Summary of Modeled Worker Inhalation Exposures for Processing—Repackaging of 1,1-
Dichloroethane for Laboratory Chemicals 57
Table 5-13. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Processing—
Repackaging 57
Table 5-14. Summary of Modeled Environmental Releases for the Commercial Use of 1,1-
Dichloroethane as a Laboratory Chemical 60
Table 5-15. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During the
Commercial Use as a Laboratory Chemical 62
Table 5-16. Inhalation Exposures to 1,1-Dichloroethane During Commercial Use of Laboratory
Chemicals 62
Table 5-17. Inhalation Exposures to 1,1-Dichloroethane During Commercial Use of Laboratory
Chemicals Using Surrogate Data 63
Table 5-18. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Commercial Use as a
Laboratory Chemical 64
Table 5-19. Summary of Environmental Releases During General Waste Handling, Treatment, and
Disposal 68
Table 5-20. Summary of Environmental Releases During Waste Handling, Treatment, and Disposal
(POTW) 69
Table 5-21. Summary of Environmental Releases During Waste Handling, Treatment, and Disposal
(Remediation) 69
Table 5-22. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During Waste
Handling, Disposal, and Treatment 71
Table 5-23. Inhalation Exposures of Workers to 1,1-Dichloroethane During General Waste Handling,
Treatment, and Disposal 72
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Table 5-24. Inhalation Exposures of Workers to 1,1-Dichloroethane During Waste Handling,
Treatment, and Disposal (POTW) 72
Table 5-25. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for General Waste Handling,
Treatment, and Disposal 73
Table 5-26. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Waste Handling,
Treatment, and Disposal (POTW) 73
Table 5-27. Summary of the Weight of Scientific Evidence Ratings for Environmental Releases 78
Table 5-28. Summary of the Weight of Scientific Evidence Ratings for Occupational Exposures 80
LIST OF FIGURES
Figure 1-1. Condition of Use to Occupational Exposure Mapping 12
Figure 5-1. Typical Release and Exposure Points During the Manufacture of 1,1-Dichloroethane
{OECD, 2011, 6306753} 35
Figure 5-2. Illustration of Distribution in Commerce and its Relation to Other Life Cycle Stages 42
Figure 5-3. Typical Release and Exposure Points During the Processing of 1,1-Dichloroethane as a
Reactive Intermediate 47
Figure 5-4. Typical Release and Exposure Points During the Repackaging of 1,1-Dichloroethane
{U.S. EPA, 2022, 11182966} 54
Figure 5-5. Typical Release and Exposure Points During the Laboratory Use of 1,1-Dichloroethane
{U.S. EPA, 2023, 10480466} 59
Figure 5-6. Typical Waste Disposal Process {U.S. EPA, 2017, 5080418} 66
Figure 5-7. Typical Industrial Incineration Process 67
LIST OF APPENDIX TABLES
TableApx A-l. SOCs with Worker and ONU Designations for All Conditions of Use Except Dry
Cleaning 86
Table Apx A-2. SOCs with Worker and ONU Designations for Dry Cleaning Facilities 86
TableApx A-3. Estimated Number of Potentially Exposed Workers and ONUs under NAICS
812320 88
Table Apx B-l. Parameter Values for Calculating Inhalation Exposure Estimates 92
Table Apx B-2. Overview of Average Worker Tenure from U.S. Census SIPP (Age Group 50+) 95
Table Apx B-3. Median Years of Tenure with Current Employer by Age Group 95
Table_Apx D-l. Summary of Model Input Values 99
Table Apx E-l. Models and Variables Applied for Release Sources in the Processing—Repackaging
OES 106
Table Apx E-2. Models and Variables Applied for Exposure Points in the Processing—Repackaging
OES 107
Table Apx E-3. Summary of Parameter Values and Distributions Used in the Processing—
Repackaging Models 109
Table Apx E-4. Models and Variables Applied for Release Sources in the Commercial Use as a
Laboratory Chemical OES 116
Table Apx E-5. Summary of Parameter Values and Distributions Used in the Commercial Use as a
Laboratory Chemical Model 118
Table Apx E-6. 1,1-Dichloroethane Concentrations and Densities for Commercial Use as a
Laboratory Chemical OES 124
Table Apx F-l. Assigned Protection Factors for Respirators in OSHA Standard 29 CFR 1910.134 ... 127
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TableApx F-2. Number and Percent of Establishments and Employees Using Respirators within 12
Months Prior to Survey 129
Table Apx F-3. Glove Protection Factors for Different Dermal Protection Strategies from ECETOC
I RA \ 3 130
TableApx G-l. Example Condition of Use Table with Mapped Occupational Exposure Scenarios ... 132
Table Apx G-2. EPA Programmatic Database Information that Aids OES/COU Mapping 134
Table Apx G-3. Step 1 for CDR Mapping Facilities 150
Table_Apx G-4. Step 2 for CDR Mapping Example Facilities 150
Table Apx G-5. Step 3 for CDR Mapping Example Facilities 151
Table_Apx G-6. Step 4 for CDR Mapping Example Facilities 151
Table Apx G-7. Step 1 for TRI Mapping Example Facilities 152
Table_Apx G-8. Step 2 for TRI Mapping Example Facilities 153
Table Apx G-9. Step 3 for TRI Mapping Example Facilities 156
Table Apx G-10. Step 4 for TRI Mapping Example Facilities 156
Table_Apx G-l 1. Step 5 for TRI Mapping Example Facilities 157
Table Apx G-12. Step la for NEI Mapping Example Facilities 158
Table Apx G-13. Step lb for NEI Mapping Example Facilities 161
Table_Apx G-14. Step 2 for NEI Mapping Example Facilities 162
Table_Apx G-15. Step 4 for NEI Mapping Example Facilities 163
Table_Apx G-16. Step 5 for NEI Mapping Example Facilities 164
Table_Apx G-17. Step 2 for DMR Mapping Example Facilities 165
Table_Apx G-18. Step 3 for DMR Mapping Example Facilities 165
Table Apx G-19. Step 2 for OSHA CEHD Mapping Example Facilities 166
Table Apx G-20. Step 3 for OSHA CEHD Mapping Example Facilities 167
Table Apx G-21. Step 1 for COU Mapping Example Facilities 169
Table_Apx G-22. Step 2 for COU Mapping Example Facilities 169
Table_Apx G-23. Step 3 for COU Mapping Example Facilities 170
Table_Apx G-24. Step 4 for COU Mapping Example Facilities 170
Table_Apx G-25. TRI-CDRUse Code Crosswalk 171
Table Apx H-l. List of Key Data Fields from TRI Basic Plus Data 199
Table_Apx H-2. Example Facilities' 2019 Annual Discharges 210
Table_Apx H-3. Westlake Vinyl Total Period Discharge Results 214
Table_Apx H-4. Westlake Vinyl 1-Day Discharges 216
TableApx H-5. Summary of Discharge Estimates for 2019 Example Facilities 217
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KEY ABBREVIATIONS AND ACRONYMS
CAA
Clean Air Act
CASRN
Chemical Abstracts Service Registry Number
CBI
Confidential Business Information
CDR
Chemical Data Reporting
CEHD
Chemical Exposure Health Data
CFR
Code of Federal Regulations
CWA
Clean Water Act
DMR
Discharge Monitoring Report
ECHO
Enforcement and Compliance History Online
EPA
Environmental Protection Agency
EPCRA
Emergency Planning and Community Right-to-Know Act
ESD
Emission Scenario Document
GS
Generic Scenario
HAP
Hazardous Air Pollutant
LOD
Limit of detection
NAICS
North American Industry Classification System
ND
Non-detect
NEI
National Emissions Inventory
NESHAP
National Emission Standards for Hazardous Air Pollutants
NIOSH
National Institute for Occupational Safety and Health
NPDES
National Pollutant Discharge Elimination System
NPDWR
National Primary Drinking Water Regulation
OECD
Organisation for Economic Co-operation and Development
OEL
Occupational exposure limit
OES
Occupational exposure scenario
ONU
Occupational non-user
OPPT
Office of Pollution Prevention and Toxics
OSHA
Occupational Safety and Health Administration
PBZ
Personal breathing zone
PEL
Permissible Exposure Limit
POTW
Publicly owned treatment works
PPE
Personal protective equipment
PV
Production volume
QC
Quality control
RCRA
Resource Conservation and Recovery Act
REL
Recommended Exposure Limit
SDS
Safety data sheet
SDWA
Safe Drinking Water Act
SpERC
Specific Environmental Release Categories
TLV
Threshold Limit Value
TRI
Toxics Release Inventory
TSCA
Toxic Substances Control Act
TWA
Time-weighted average
U.S.
United States
VOC
Volatile organic compound
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1 INTRODUCTION
1.1 Overview
This document provides details on the occupational exposure and environmental release assessment and
supplements the risk evaluation for 1,1-dichloroethane under the Frank R. Lautenberg Chemical Safety
for the 21st Century Act amended the Toxic Substances Control Act (TSCA). TSCA section 6(b)(4)
requires the United States Environmental Protection Agency (EPA) to establish a risk evaluation
process. In performing risk evaluations for existing chemicals, EPA is directed to "determine whether a
chemical substance presents an unreasonable risk of injury to health or the environment, without
consideration of costs or other non-risk factors, including an unreasonable risk to a potentially exposed
or susceptible subpopulation identified as relevant to the risk evaluation by the Administrator under the
conditions of use." In December of 2019, EPA published a list of 20 chemical substances that are the
subject of the Agency's initial chemical risk evaluations (81 FR 91927), as required by TSCA section
6(b)(2)(A). 1,1-Dichloroethane was one of these chemicals.
1,1-Dichloroethane, is a colorless oily liquid with characteristic (chloroform-like) odor that is used
primarily as a reactant and a laboratory chemical. All uses are subject to federal and state reporting
requirements. 1,1-Dichloroethane is a Toxics Release Inventory (TRI)-reportable substance effective
January 1, 1994. It is also on EPA's initial list of hazardous air pollutant (HAPs) under the Clean Air
Act (CAA), is a designated toxic pollutant under the Clean Water Act (CWA), and subject to National
Primary Drinking Water Regulations (NPDWR) under the Safe Drinking Water Act (SDWA).
1.2 Scope
EPA assessed environmental releases and occupational exposures for conditions of use (COUs) as
described in Table 3-1 of th q Draft Risk Evaluation for 1,1-Dichloroethane . To estimate environmental
releases and occupational exposures, EPA first developed occupational exposure scenarios (OESs)
related to the conditions of use of 1,1-dichloroethane. An OES is based on a set of facts, assumptions,
and inferences that describe how releases and exposures takes place within an occupational condition of
use. EPA developed the OESs to group processes or applications with similar sources of release and
occupational exposures that occur at industrial and commercial workplaces within the scope of the risk
evaluation. For each OES, occupational exposure and environmental release results are provided and are
expected to be representative of the entire population of workers and sites involved for the given OES in
the United States. EPA may define only a single OES for multiple COUs, while in other cases multiple
OESs may be developed for a single COU. EPA will make this determination by considering variability
in release and use conditions and whether the variability can be captured as a distribution of exposure or
instead requires discrete scenarios. Figure 1-1 depicts the ways that COUs may be mapped to OESs.
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cou
OES
COUs identified for the chemical during scoping are reviewed to
determine potential release and exposure scenarios (referred to as OES)
COU to OES mapping may come in many forms, as shown in this figure
One COU may map to one OES
Multiple COUs may be mapped to the same OES
Multiple COUs may be mapped to one OES when the COUs
have similar activities and exposure potentials, and exposures and
releases can be assessed for the COUs using a single approach
For example, the COUs for aerosol degreaser, interior car care
spot remover, and spray lubricant have been assessed together
under the OES for commercial aerosol products
COU liCOU 2|COU 3
OES
COU
OES l|OES 2lOES 3
One COU may be mapped to multiple OES
Mapping a COU to multiple OES allows for the assessment of
distinct scenarios that are expected to result in different releases and
exposures
For example, the COU for batch vapor degreasing has been assessed
as two separate OES: open-top and closed-loop degreasing
Figure 1-1. Condition of Use to Occupational Exposure Mapping
Table 1-1 shows mapping between the conditions of use in Table 3-1 of the Draft Risk Evaluation for
1, j-Dich/oroethane to the OESs assessed in this report. For 1,1-dichloroethane, EPA mapped OESs to
condition of uses using professional judgment based on available data and information. Several of the
condition of use categories and subcategories were grouped and assessed together in a single OES due to
similarities in the processes or lack of data to differentiate between them. This grouping minimized
repetitive assessments. In other cases, conditions of use subcategories were further delineated into
multiple OES based on expected differences in process equipment and associated releases/exposure
potentials between facilities.
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482 Table 1-1. Crosswalk of Subcategories of Use Listed in the Final Scope Document to Occupational
483 Exposure Scenarios Assessed in the Risk Evaluation
Conditions of Use
Occupational Exposure
Scenarios
Life Cycle Stage
Category"
Subcategory''
Manufacture
Domestic
Manufacturing
Domestic manufacturing
Manufacturing®
Processing
As a reactant
Intermediate in all other
basic organic chemical
manufacturing
Processing as a reactive
intermediate
As a reactant
Intermediate in all other
chemical product and
preparation manufacturing
Recycling
Recycling
Processing-
repackaging
Processing-repackaging
Processing-repackaging^
Distribution in
Commerce
Distribution in
commerce
Distribution in commerce
Distribution in commerce®
Commercial use
Other use
Laboratory chemical
Commercial use as a
laboratory chemical
Disposal^
Disposal
Disposal
General waste handling,
treatment, and disposal
Waste handling, treatment,
and disposal (POTW)
Waste handling, treatment,
and disposal (remediation)
a These categories of conditions of use reflect CDR codes and broadly represent conditions of use for 1,1-
dichloroethane in industrial and/or commercial settings.
b These subcategories reflect more specific uses of 1,1-dichloroethane.
c The manufacturing OES reflects intentional manufacturing of 1,1-dichloroethane. Manufacturing of 1,1-
dichloroethane as a byproduct or impurity will be assessed in the Risk Evaluation for 1,2-Dichloroethane.
'' New COU and associated OES where 1,1-dichloroethane is repackaged. This OES was not included in the final
scope document.
'' EPA considers the activities of loading and unloading of chemical product part of distribution in commerce.
These activities were assessed as part of the OES of: Manufacturing, processing as a reactive intermediate,
Processing-repackaging, and commercial use in laboratory chemicals. EPA's current approach for quantitively
assessing releases and exposures for the remaining aspects of distribution in commerce consists of searching
DOT and NRC data for incident reports pertaining to 1,1-dichloroethane distribution.
' Each of the conditions of use of 1,1-dichloroethane 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,
dispose, or directly discharge onsite wastes that they themselves generate are assessed in each condition of use
assessment. This section only assesses wastes of 1,1-dichloroethane that are generated during a condition of use
and sent to a third-party site for treatment, disposal, or recycling.
484
485 EPA's assessment of releases includes quantifying annual and daily releases of 1,1-dichloroethane to air,
486 water, and land. Releases to air include both fugitive and stack air emissions and emissions resulting
487 from on-site waste treatment equipment, such as incinerators. For purposes of this report, releases to
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water include both direct discharges to surface water and indirect discharges to publicly owned
treatment works (POTW) or non-POTW wastewater treatment (WWT). It should be noted that for
purposes of this risk evaluation, discharges to POTW and non-POTW WWT are not evaluated the same
as discharges to surface water. EPA considers removal efficiencies of POTWs and WWT plants and
environmental fate and transport properties when evaluating risks from indirect discharges. Releases to
land include any disposal of liquid or solids wastes containing 1,1-dichloroethane into landfills, land
treatment, surface impoundments, or other land applications. The purpose of this supplemental report is
only to quantify releases; therefore, downstream environmental fate and transport factors used to
estimate exposures to the general population and ecological species are not discussed. The details on
how these factors were considered when determining risk are described in the Draft Risk Evaluation for
1,1-Dichloroethane.
EPA's assessment of occupational exposures includes quantifying inhalation and dermal exposures to
1,1-dichloroethane. EPA categorizes occupational exposures into exposures to 'workers' and exposures
to 'ONUs'. Generally, EPA distinguishes workers as directly handling 1,1-dichloroethane as part of their
duties and have direct contact with the chemical, while ONUs are working in the general vicinity of
workers but do not handle 1,1-dichloroethane and do not have direct contact with 1,1-dichloroethane
being handled by the workers. EPA evaluated inhalation exposures to both workers and ONUs and
dermal exposures to workers.
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2 COMPONENTS OF AN OCCUPATIONAL EXPOSURE AND
RELEASE ASSESSMENT
The occupational exposure and environmental release assessment of each condition of use comprises the
following components:
• Process Description: A description of the OES, including the function of the chemical in the
OES; physical forms and weight fractions of the chemical throughout the process; the total
production volume associated with the OES; per site throughputs/use rates of the chemical;
operating schedules; and process vessels, equipment, and tools used during the condition of use.
• Estimates of Number of Facilities: An estimate of the number of sites that use 1,1-
dichloroethane for the given OES.
• Environmental Release Sources: A description of each of the potential sources of
environmental releases in the process and their expected media of release for the given OES.
• Environmental Release Assessment Results: Estimates of chemical released into each
environmental media (surface water, POTW, non-POTW WWT, fugitive air, stack air, and each
type of land disposal).
• Worker Activities: A description of the worker activities, including an assessment for potential
points of worker and occupational non-user (ONU) exposure.
• Number of Workers and ONUs: An estimate of the number of workers and occupational non-
users potentially exposed to the chemical for the given OES.
• Occupational Inhalation Exposure Results: Central tendency and high-end estimates of
inhalation exposure to workers and ONUs. See Section 2.4.3 for a discussion of EPA's statistical
analysis approach for assessing inhalation exposure.
• Occupational Dermal Exposure Results: Central tendency and high-end estimates of dermal
exposure to workers. See Section 2.4.4 for a discussion of EPA's approach for assessing dermal
exposure.
2.1 Approach and Methodology for Process Descriptions
EPA performed a literature search to find descriptions of processes involved in each OES. Where data
were available to do so, EPA included the following information in each process description:
• Total production volume associated with the OES;
• Name and location of sites the OES occurs;
• Facility operating schedules (e.g., year-round, 5 days/week, batch process, continuous process,
multiple shifts)
• Key process steps;
• Physical form and weight fraction of the chemical throughout the process steps;
• Information on receiving and shipping containers; and
• Ultimate destination of chemical leaving the facility.
Where 1,1-dichloroethane-specific process descriptions were unclear or not available, EPA referenced
generic process descriptions from literature, including relevant Emission Scenario Documents (ESD) or
Generic Scenarios (GS). Process descriptions for each OES can be found in Section 5.
2.2 Approach and Methodology for Estimating Number of Facilities
To estimate the number of facilities within each OES, EPA used a combination of bottom-up analyses of
EPA reporting programs and top-down analyses of U.S. economic data and industry-specific data.
Generally, EPA used the following steps to develop facility estimates:
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1. Identify or "map" each facility reporting for 1,1-dichloroethane in the 2016 and 2020 CDR (U.S.
; T \ -''20b, 20)9). 2015 to 2020 TRI ( ' < < \ ,:022d). 2015 to 2020 Discharge Monitoring
Report (DMR) (U.S. EPA. 2022b) and 2014 and 2017 National Emissions Inventory (NEI) (U.S.
22c) to an OES. The full details of the methodology for mapping facilities from EPA
reporting programs is described in Appendix G. In brief, mapping consists of using facility
reported industry sectors (typically reported as either North American Industry Classification
System (NAICS) or Standard Industrial Classification (SIC) codes), and chemical activity,
processing, and use information to assign the most likely OES to each facility.
2. Based on the reporting thresholds and requirements of each data set, evaluate whether the data in
the reporting programs is expected to cover most or all of the facilities within the OES. If so, no
further action was required, and EPA assessed the total number of facilities in the OES as equal
to the count of facilities mapped to the OES from each data set. If not, EPA proceeded to Step 3.
3. Supplement the available reporting data with U.S. economic and market data using the following
method:
a. Identify the NAICS codes for the industry sectors associated with the OES.
b. Estimate total number of facilities using the U.S. Census' Statistics of US Businesses
(SUSB) data on total establishments by 6-digit NAICS.
c. Use market penetration data to estimate the percentage of establishments likely to be
using 1,1-dichloroethane instead of other chemicals.
d. Combine the data generated in Steps 3.a through 3.c to produce an estimate of the
number of facilities using 1,1-dichloroethane in each 6-digit NAICS code and sum across
all applicable NAICS codes for the OES to arrive at a total estimate of the number of
facilities within the OES. Typically, EPA assumed this estimate encompasses the
facilities identified in Step 1; therefore, EPA assessed the total number of facilities for the
OES as the total generated from this analysis.
4. If market penetration data required for Step 3.c. are not available, use generic industry data from
GSs, ESDs, and other literature sources on typical throughputs/use rates, operating schedules,
and the 1,1-dichloroethane production volume used within the OES to estimate the number of
facilities. In cases where EPA identified a range of operating data in the literature for an OES,
EPA used stochastic modeling to provide a range of estimates for the number of facilities within
an OES. EPA provided the details of the approaches, equations, and input parameters used in
stochastic modeling in the relevant OES sections throughout this report.
2.3 Environmental Releases Approach and Methodology
Releases to the environment are a component of potential exposure and may be derived from reported
data that are obtained through direct measurement via monitoring, calculations based on empirical data,
and/or assumptions and models. For each OES, EPA attempted to provide annual releases, high-end and
central tendency daily releases, and the number of release days per year for each media of release (air,
water, and land).
EPA used the following hierarchy in selecting data and approaches for assessing environmental releases:
1. Monitoring and measured data:
a. Releases calculated from site-specific concentration in medium and flow rate data
b. Releases calculated from mass balances or emission factor methods using site-specific
measured data
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2. Modeling approaches:
a. Surrogate release data
b. Fundamental modeling approaches
c. Statistical regression modeling approaches
3. Release limits:
a. Company-specific limits
b. Regulatory limits (e.g., National Emission Standards for Hazardous Air Pollutants
[NESHAPs] or effluent limitations/requirements)
EPA's preference was to rely on facility-specific release data reported in TRI ( )22d). DMR
(I 1022b). and NEI (U.S. EPA. 2022c). where available. Where releases are expected for an
OES but TRI, DMR, and NEI data were not available or where EPA determined TRI, DMR, and/or NEI
data did not capture the entirety of environmental releases for an OES, releases were estimated using
data from literature, relevant ESDs or GSs, and/or existing EPA models. EPA's general approach to
estimating releases from these sources is described in Sections 2.3.1 through 2.3.6. Specific details
related to the use of release data or models for each OES can be found in Section 5.
The final release results may be described as a point estimate (i.e., a single descriptor or statistic, such as
central tendency or high-end) or a full distribution. EPA considered three general approaches for
estimating the final release result:
• Deterministic calculations: EPA used combinations of point estimates of each input parameter
to estimate a central tendency and high-end for each final release result. The Agency
documented the method and rationale for selecting parametric combinations to be representative
of central tendency and high-end in the relevant OES subsections in Section 5.
• Probabilistic (stochastic) calculations: EPA used Monte Carlo simulations using the full
distribution of each input parameter to calculate a full distribution of the final release results and
selecting the 50th and 95th percentiles of this resulting distribution as the central tendency and
high-end, respectively.
• Combination of deterministic and probabilistic calculations: EPA had full distributions for
some parameters but point estimates of the remaining parameters. For example, the Agency used
Monte Carlo modeling to estimate annual throughputs and emission factors, but only had point
estimates of release frequency and production volume. In this case, EPA documented the
approach and rationale for combining point estimates with distribution results for estimating
central tendency and high-end results in the relevant OES subsections in Section 5.
2.3.1 Identifying Release Sources
EPA performed a literature search to identify process operations that could potentially result in releases
of 1,1-dichloroethane to air, water, or land from each OES. For each OES, EPA identified the release
sources and the associated media of release. Where 1,1-dichloroethane-specific release sources were
unclear or not available, EPA referenced relevant ESD's or GS's. Descriptions of release sources for
each OES can be found in Section 5.
2.3.2 Estimating Release Days per Year
EPA typically assumed the number of release days per year from any release source will be equal to the
number of operating days at the facility unless information is available to indicate otherwise. To
estimate the number of operating days, EPA used the following hierarchy:
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1. Facility-specific data: EPA used facility-specific operating days per year data if available. If
facility-specific data was not available for one facility of interest but was available for other
facilities within the same OES, EPA estimated the operating days per year using one of the
following approaches:
a. If other facilities have known or estimated average daily use rates, EPA calculated the
days per year as: Days/year = Estimated Annual Use Rate for the facility (kg/year) /
average daily use rate from facilities with available data (kg/day).
b. If facilities with days per year data do not have known or estimate average daily use
rates, EPA used the average number of days per year from the facilities with such data
available.
2. Industry-specific data: EPA used industry-specific data available from GSs, ESDs, trade
publications, or other relevant literature.
3. Manufacture of large-production volume (PV) commodity chemicals: For the manufacture of
the large-PV commodity chemicals, EPA used a value of 350 days per year. This assumes the
plant runs seven days per week and 50 weeks per year (with two weeks down for turnaround)
and assumes that the plant is always producing the chemical.
4. Manufacture of lower-PV specialty chemicals: For the manufacture of lower-PV specialty
chemicals, it is unlikely the chemical is being manufactured continuously throughout the year.
Therefore, EPA used a value of 250 days per year. This assumes the plant manufactures the
chemical five days per week and 50 weeks per year (with two weeks down for turnaround).
5. Processing as reactant (intermediate use) in the manufacture of commodity chemicals:
Similar to #3, EPA assumed the manufacture of commodity chemicals occurs 350 days per year
such that the use of a chemicals as a reactant to manufacture a commodity chemical would also
occur 350 days per year.
6. Processing as reactant (intermediate use) in the manufacture of specialty chemicals: Similar
to #4, the manufacture of specialty chemicals is not likely to occur continuously throughout the
year. Therefore, EPA used a value of 250 days per year.
7. Other chemical plant OES (e.gprocessing into formulation and use of industrial
processing aids): For these OES, EPA assumed that the chemical of interest is not always in use
at the facility, even if the facility operates 24/7. Therefore, in general, EPA used a value of 300
days/year based on the "SpERC fact sheet—Formulation & (re)packing of substances and
mixtures—Industrial (Solvent-borne)" which uses a default of 300 days/year for the chemical
industry (ESIG. ). However, in instances where the OES uses a low volume of the chemical
of interest, EPA used 250 days per year as a lower estimate.
8. POTWs: Although EPA expects POTWs to operate continuously over 365 days per year, the
discharge frequency of the chemical of interest from a POTW will be dependent on the discharge
patterns of the chemical from the upstream facilities discharging to the POTW. However, there
can be multiple upstream facilities (possibly with different OES) discharging to the same POTW
and information to determine when the discharges from each facility occur on the same day or
separate days is typically not available. Therefore, EPA could not determine an exact number of
days per year the chemical of interest is discharged from the POTW and used a value of 365 days
per year. For more details on discharge frequencies for POTWs, refer to Section 2.3.3.1
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9. All other OES: Regardless of what the facility operating schedule is, other OES are unlikely to
use the chemical of interest every day. Therefore, EPA used a value of 250 days per year for
these OES.
2.3,3 Estimating Releases from Data Reported to EPA
Generally, EPA used the facility-specific release data reported in TRI, DMR, and NEI as annual releases
in each data set for each site and estimated the daily release by averaging the annual release over the
expected release days per year. EPA's approach to estimating release days per year is described in
Section 2.3.2.
Section 313 of the Emergency Planning and Community Right-to-Know Act (EPCRA) established the
TRI. TRI tracks the waste management of designated toxic chemicals from facilities within certain
industry sectors. Facilities are required to report to TRI if the facility has 10 or more full-time
employees; is included in an applicable NAICS code; and manufactures, processes, or uses the chemical
in quantities greater than a certain threshold (25,000 pounds [lb] for manufacturers and processors of
PCE and 10,000 lb for users of 1,1-dichloroethane). EPA makes the reported information publicly
available through TRI. Each facility subject to the rule must report either using a Form R or a Form A.
Facilities reporting using a Form R must report annually the volume of chemical released to the
environment {i.e., surface water, air, or land) and/or managed through recycling, energy recovery, and
treatment {e.g., incineration) from the facility. Facilities may submit a Form A if the volume of chemical
manufactured, processed, or otherwise used does not exceed 1,000,000 pounds per year (lb/year) and the
total annual reportable releases do not exceed 500 lb/year. Facilities reporting using a Form A are not
required to submit annual release and waste management volumes or use/sub-use information for the
chemical. Due to reporting limitations, some sites that manufacture, process, or use 1,1-dichloroethane
may not report to TRI and are therefore not included in EPA's assessment.
EPA included both TRI Form R and Form A submissions in the analysis of environmental releases. For
Form Rs, EPA assessed releases using the reported annual release volumes from each media. For Form
As, EPA attempted to estimate releases to each media using other approaches, where possible. Where no
was approaches were available to estimate releases from facilities reporting using Form A's, EPA
assessed releases using the 500 lb/year threshold for each release media; however, since this threshold is
for total site releases, the 500 lb/year is attributed one release media—not all (to avoid over counting the
releases and exceeding the total release threshold for Form A). For this draft risk evaluation, EPA used
TRI data from reporting years 2015 to 2020 to provide a basis for estimating releases (
2022d). Further details on EPA's approach to using TRI data for estimating releases are described in
Sections 2.3.3.1 through 2.3.3.3.
Under the Clean Water Act (CWA), EPA regulates the discharge of pollutants into receiving waters
through National Pollutant Discharge Elimination System (NPDES). A NPDES permit authorizes
discharging facilities to discharge pollutants to specified effluent limits. There are two types of effluent
limits: (1) technology-based and (2) water quality-based. While the technology-based effluent limits are
uniform across the country, the quality-based effluent limits vary and are more stringent in certain areas.
NPDES permits may also contain requirements for sewage sludge management.
NPDES permits apply pollutant discharge limits to each outfall at a facility. For risk evaluation
purposes, EPA was interested only on the outfalls to surface water bodies. NPDES permits also include
internal outfalls, but they aren't included in this analysis. This is because these outfalls are internal
monitoring points within the facility wastewater collection or treatment system, so they do not represent
discharges from the facility. NPDES permits require facilities to monitor their discharges and report the
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results to EPA and the state regulatory agency. Facilities report these results in DMRs. EPA makes these
reported data publicly available via EPA's Enforcement and Compliance History Online (ECHO)
system and EPA's Water Pollutant Loading Tool (Loading Tool). The Loading Tool is a web-based tool
that obtains DMR data through ECHO, presents data summaries and calculates pollutant loading (mass
of pollutant discharged). For this risk evaluation, EPA queried DMRs for all 1,1-dichloroethane point
source water discharges available for 2015 to 2020 ( E2b). Further details on EPA's
approach to using DMR data for estimating releases are described in Sections 2.3.3.1 and Appendix H.
The NEI was established to track emissions of Criteria Air Pollutants (CAPs) and CAP precursors and
assist with National Ambient Air Quality Standard (NAAQS) compliance under the Clean Air Act
(CAA). Air emissions data for the NEI are collected at the state, local, and tribal (SLT) level. SLT air
agencies then submit these data to EPA through the Emissions Inventory System (EIS). In addition to
CAP data, many SLT air agencies voluntarily submit data for pollutants on EPA's list of HAPs. EPA
uses the data collected from SLT air agencies, in conjunction with supplemental HAP data, to build the
NEI. EPA makes an updated NEI publicly available every 3 years. For this risk evaluation, EPA used
NEI data for reporting years 2014 and 2017 data to provide a basis for estimating releases (
2022c)
NEI emissions data is categorized into (1) point source data, (2) area or nonpoint source data, (3) onroad
mobile source data, and (4) nonroad mobile source data. EPA included all four data categories in the
assessment of environmental releases in this risk evaluation. Point sources are stationary sources of air
emissions from facilities with operating permits under Title V of the CAA, also called "major sources".
Major sources are defined as having actual or potential emissions at or above the major source
thresholds. While thresholds can vary for certain chemicals in NAAQS non-attainment areas, the default
threshold is 100 tons/year for non-HAPs, 10 tons per year for a single HAP, or 25 tons per year for any
combination of HAPs. Point source facilities include large energy and industrial sites and are reported at
the emission unit- and release point-level.
Area or nonpoint sources are stationary sources that do not qualify as major sources. The nonpoint data
are aggregated and reported at the county-level and include emissions from smaller facilities as well as
agricultural emissions, construction dust, and open burning. Industrial and commercial/institutional fuel
combustion, gasoline distribution, oil and gas production and extraction, publicly owned treatment
works, and solvent emissions may be reported in the point or nonpoint source categories depending upon
source size.
Onroad mobile sources include emissions from onroad vehicles that combust liquid fuels during
operation, including passenger cars, motorcycles, trucks, and buses. The nonroad mobiles sources data
include emissions from other mobile sources that are not typically operated on public roadways, such as
locomotives, aircraft, commercial marine vessels, recreational equipment, and landscaping equipment.
Onroad and nonroad mobile data is reported in the same format as nonpoint data; however, it is not
available for every chemical. For 1,1-dichloroethane, onroad and nonroad mobile data is available and
was used in the air release assessment. Further details on EPA's approach to using NEI data for
estimating releases are described in Section 2.3.3.2.
2.3.3.1 Estimating Wastewater Discharges from TRI and DMR
Where available, EPA used TRI and DMR data to estimate annual wastewater discharges, average daily
wastewater discharges, high-end daily wastewater discharges, and 1-day maximum wastewater
discharges. The estimates of high-end daily and 1-day maximums are based on data availability in DMR
as described in this section.
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Annual Wastewater Discharges
For TRI, annual discharges are reported directly by facilities. For DMR, annual discharges are
automatically calculated by the Loading Tool based on the sum of the discharges associated with each
monitoring period in DMR. Monitoring periods in DMR are set by each facility's NPDES permit and
can vary between facilities. Typical monitoring periods in DMR include monthly, bimonthly, quarterly,
biannual, and annual reporting. In instances where a facility reports a period's monitoring results as
below the limit of detection (LOD) (also referred to as a non-detect or ND) for a pollutant, the Loading
Tool applies a hybrid method to estimate the wastewater discharge for the period. The hybrid method
sets the values to half of the LOD if there was at least one detected value in the facility's DMRs in a
calendar year. If all values were less than the LOD in a calendar year, the annual load is set to zero.
Average Daily Wastewater Discharges
To estimate average daily discharges, EPA used the following steps:
1. Obtain total annual loads calculated from the Loading Tool and reported annual direct surface
water discharges and indirect discharges to POTW and non-POTW WWT in TRI.
2. For TRI reporters using a Form A, estimate annual releases using an alternative approach (see
Sections 2.3.4, 2.3.5, and 2.3.6) or at the threshold of 500 pounds per year.
3. Determine if any of the facilities receiving indirect discharges reported in TRI have reported
DMRs for the corresponding TRI reporting year, if so, exclude these indirect discharges from
further analysis. The associated surface water release (after any treatment at the receiving
facility) will be incorporated as part of the receiving facility's DMR.
4. Divide the annual discharges over the number of estimated operating days (estimated as
described in Section 2.3.2).
High-End Daily Wastewater Discharges
High-end daily wastewater discharges are an estimate of the high-end daily discharge rate that may take
place for a single monitoring period during the year for the facility as needed. As a first step, EPA only
analyzed high-end daily discharges for the facilities with DMRs accounting for the top 90% of non-
POTW annual discharges and the top 90% of POTW discharges. EPA analyzed high-end discharges
from the bottom 10% only in the case where unreasonable risk was found for facilities in the top 90%
with the smallest annual discharges. For 1,1-dichloroethane, facilities accounting for the top 95%
discharges were analyzed for high-end daily discharges.
EPA used the following steps to estimate high-end discharges for facilities with DMR data:
1. Identify the facilities that represent the top 90% of annual discharges for non-POTWs in the
DMRs and the top 90% of annual discharges for POTWs. Note: If EPA found unreasonable risks
for facilities in the top 90%, a second tier of facilities was evaluated. EPA continued to evaluate
additional tiers as needed.
2. Use the Loading Tool to obtain the reporting periods (e.g., monthly, bimonthly, quarterly,
biannually, annually) and required reporting statistics (e.g., average monthly concentration, max
daily concentration) for each external outfall at each facility identified in Step 1. When there is
one outfall reported in the Loading Tool, EPA assumed it is an external outfall. If multiple
outfalls are reported in the Loading Tool, EPA determined the external outfall by reviewing the
facility's permits.
3. For each external outfall at each facility, calculate the average daily load for each reporting
period by multiplying the period average concentration by the period average wastewater
flowrate.
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4. Sum the average daily loads from each external outfall for each period.
5. Select the period with the highest average daily load across all external outfalls as an estimate of
the high-end daily discharge assessed over the number of days in the period. The number of days
in the reporting period does not necessarily equate to the number of operating days in the
reporting period. For example, for a plant that operates 200 days/year, EPA used 200 rather than
365 days per year for average daily discharge. Therefore, discharges will not occur every day of
the reporting period, but only for a fraction estimated as: 200/365 = 68%. EPA multiplied the
number of days of the reporting period by this factor to maintain consistency between operating
days per year and operating days per reporting period.
EPA used the following steps to estimate high-end discharges for facilities without DMR data (e.g.,
facilities with TRI data but no DMR data):
1. Identify facilities that report under the NPDES program for the same chemical, same year, and
same OES as the TRI facility and report DMRs monthly. Note: if no monthly reporters exist,
reporters with less frequent reporting can be substituted provided the number of release days per
year are adjusted in subsequent steps. In such cases, the period data need to be normalized to
monthly averages by dividing the period load by the number of months in the period. EPA used
30.4167 days per month to normalize the period discharges (i.e., 365 days/12 months).
2. For each facility identified in #1, calculate the percentage of the total annual discharge that
occurred in the highest one-month period.
3. Calculate a generic factor for the OES as the average of the percentages calculated in #2.
4. Estimate the high-end daily discharge for each facility without DMRs by multiplying the annual
discharge by the generic factor from #3. For example, a facility reports 500 pounds (lb) released
per year and has a generic factor of 15% for the OES from #3. The estimated high-end chronic
daily discharge for the facility would be: 500 lb x 15% = 75 lb/month.
5. Use the value calculated in #4 as an estimate of the high-end daily discharge assessed over
30.4167 days per year (consistent with the normalization from step 1). For example, the high-end
daily discharge assessed over 30.4167 days per year for the facility with the estimated high-end
chronic daily discharge of 75 lb/month (from #4 above) is: 75 lb/month / 30.4167 days = 2.47
lb/day for 30.4167 days.
1-Day Maximum Wastewater Discharges
One-day maximum discharge rates estimate a discharge rate that may represent a 1-day maximum rate
for the facility as needed. Facilities required to report DMRs under the NPDES may sometimes be
required to report a daily maximum discharge concentration for the period. EPA used these values to
estimate 1-day maximum discharges by multiplying the maximum daily concentration by the
corresponding month's maximum daily wastewater flow rate. Where no such data existed for a facility
(i.e., facilities without DMRs or facilities with DMRs whose permits do not require reporting of 1-day
maximums), EPA did not have data to estimate a 1-day maximum discharge rate.
2,3,3.2 Estimating Air Emissions from TRI and NEI
Where available, EPA used TRI and NEI data to estimate annual and average daily fugitive and stack air
emissions. For air emissions, EPA attempted to estimate both release patterns (i.e., days per year of
release) and release durations (i.e., hours per day the release occurs).
Annual Emissions
Facility-level annual emissions are available for TRI reporters and major sources in NEI. EPA used the
reported annual emissions directly as reported in TRI and NEI for major sources. NEI also includes
annual emissions for area sources that are aggregated at the county-level. Area source data in NEI is not
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divided between sites or between stack and fugitive sources. Therefore, EPA only presented annual and
average daily emissions for each county-OES combination.
Average Daily Emissions
To estimate average daily emissions for TRI reporters and major sources in NEI, EPA used the
following steps:
1. Obtain total annual fugitive and stack emissions for each TRI reporter and major sources in NEI.
2. For TRI reporters using a Form A, estimate annual releases using an alternative approach (see
Sections 2.3.4, 2.3.5, and 2.3.6) or at the threshold of 500 pounds per year.
3. Divide the annual stack and fugitive emissions over the number of estimated operating days
(note: NEI data includes operating schedules for many facilities that can be used to estimate
facility-specific days per year).
4. Estimate a release duration using facility-specific data available in NEI, models, and/or literature
sources. If no data is available, list as "unknown".
To estimate average daily emissions from area sources, EPA followed a very similar approach as
described for TRI reporters and major sources in NEI; however, area source data in NEI is not divided
between sites or between stack and fugitive sources. Area data also does not include release duration
data as the emissions are aggregated at the county-level rather than facility level. Therefore, EPA only
presented average daily emissions for each county-OES combination by dividing the annual emissions
for the county by the estimated number of operating days.
2.3.3.3 Estimating Land Disposals from TRI
Where available, EPA used TRI data to estimate annual and average daily land disposal volumes. TRI
includes reporting of disposal volumes for a variety of land disposal methods, including underground
injection, RCRA Subtitle C landfills, land treatment, RCRA Subtitle C surface impoundments, other
surface impoundments, and other land disposal. EPA provided estimates for both a total aggregated land
disposal volume and disposal volumes for each disposal method reported in TRI.
Annual Land Disposal
Facility-level annual disposal volumes are available directly for TRI reporters. EPA used the reported
annual land disposal volumes directly as reported in TRI for each land disposal method. EPA combined
totals from all land disposal methods from each facility to estimate a total annual aggregate disposal
volume to land.
Average Daily Land Disposal
To estimate average daily disposal volumes, EPA used the following steps:
1. Obtain total annual disposal volumes for each land disposal method for each TRI reporter.
2. For TRI reporters using a Form A, estimate annual releases using an alternative approach (see
Sections 2.3.4, 2.3.5, and 2.3.6) or at the threshold of 500 pounds per year.
3. Divide the annual disposal volumes for each land disposal method over the number of estimated
operating days.
4. Combine totals from all land disposal methods from each facility to estimate a total aggregate
disposal volume to land.
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2.3.4 Estimating Releases from Models
Where releases were expected for an OES but TRI, DMR, and/or NEI data were not available or where
EPA determined they did not capture the entirety of environmental releases for an OES, EPA utilized
models to estimate environmental releases. Outputs from models may be the result of deterministic
calculations, stochastic calculations, or a combination of both deterministic and stochastic calculations.
For each OES with modeled releases, EPA followed these steps to estimate releases:
1. Identify release sources from process and associated release media.
2. Identify or develop model equations for estimating releases from each release source.
3. Identify model input parameter values from relevant literature sources.
4. If a range of input values is available for an input parameter, determine the associated
distribution of input values.
5. Calculate annual and daily release volumes for each release source using input values and model
equations.
6. Aggregate release volumes by release media and report total releases to each media from each
facility.
For release models that utilized stochastic calculations, EPA performed a Monte Carlo simulation using
the Palisade @Risk software1 with 100,000 iterations and the Latin Hypercube sampling method.
Detailed descriptions of the model approaches used for each OES, model equations, input parameter
values and associated distributions are provided in Section 5.
2.3.5 Estimating Releases Using Literature Data
Where available, EPA used data identified from literature sources to estimate releases. Literature data
may include directly measured release data or information useful for release modeling. Therefore,
EPA's approach to literature data differs depending on the type of literature data available. For example,
if facility-specific release data is available, EPA may use that data directly to estimate releases for that
facility. If facility-specific data is available for only a subset of the facilities within an OES, EPA may
also build a distribution of the available data and estimate releases from facilities within the OES using
central tendency and high-end values from the distribution. If facility-specific data is not available, but
industry- or chemical-specific emission factors are available, EPA may use those directly to calculate
releases for an OES or incorporate the emission factors into release models to develop a distribution of
potential releases for the OES. Detailed descriptions of how various literature data was incorporated into
release estimates for each OES are described in Section 5.
2.3.6 Estimating Releases from Regulatory Limits
If EPA did not have data or models to estimate environmental releases from an OES, EPA relied on
relevant regulatory limits, where available. Relevant regulatory limits may include Effluent Limitation
Guidelines (ELGs) and NESHAPs. ELGs are national regulatory standards set forth by EPA for
wastewater discharges to surface water and municipal sewage treatment plants. NESHAPs stationary
source standards for hazardous air pollutants. Both ELGs and NESHAPs are typically issued for specific
industries and may have chemical-specific or generic limits (e.g., limits on total organic carbon [TOC]
or volatile organic compounds [VOCs]). When utilizing regulatory limits, EPA gave preference to
chemical-specific limits and assumed facilities subject to the limit operate at the limit throughout the
year. EPA then assessed annual and daily releases at the regulatory limit.
1 @Risk; Palisade; htlps://www.patisade.coin/risk/.
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2.4 Occupational Exposure Approach and Methodology
For workplace exposures, EPA considered exposures to both workers who directly handle 1,1-
dichloroethane and ONUs who do not directly handle 1,1-dichloroethane but may be exposed to vapors,
particulates, or mists that enter their breathing zone while working in locations in close proximity to
where 1,1-dichloroethane is being used. EPA evaluated inhalation exposures to both workers and ONUs
and dermal exposures to workers.
EPA provided occupational inhalation and dermal exposure results representative of central tendency
conditions and high-end conditions. A central tendency is assumed to be representative of occupational
exposures in the center of the distribution for a given condition of use. For risk evaluation, EPA used the
50th percentile (median), mean (arithmetic or geometric), mode, or midpoint values of a distribution as
representative of the central tendency scenario. EPA's preference is to provide the 50th percentile of the
distribution. However, if the full distribution is not known, EPA may assume that the mean, mode, or
midpoint of the distribution represents the central tendency depending on the statistics available for the
distribution.
A high-end is assumed to be representative of occupational exposures that occur at probabilities above
the 90th percentile but below the exposure of the individual with the highest exposure (
1992a). For risk evaluation, EPA provided high-end results at the 95th percentile. If the 95th percentile
is not available, EPA used a different percentile greater than or equal to the 90th percentile but less than
or equal to the 99.9th percentile, depending on the statistics available for the distribution. If the full
distribution is not known and the preferred statistics are not available, EPA estimated a maximum or
bounding estimate in lieu of the high-end.
For each OES, EPA attempted to provide high-end and central tendency full-shift time-weighted
averages (TWAs) (typically as 8-hour TWAs) inhalation exposure concentrations and high-end and
central tendency acute potential dermal dose rates (APDR). EPA follows the following hierarchy in
selecting data and approaches for assessing occupational exposures:
1. Monitoring data:
a. Personal and directly applicable
b. Area and directly applicable
c. Personal and potentially applicable or similar
d. Area and potentially applicable or similar
2. Modeling approaches:
a. Surrogate monitoring data
b. Fundamental modeling approaches
c. Statistical regression modeling approaches
3. Occupational exposure limits:
a. Company-specific occupational exposure limits (OELs) (for site-specific exposure
assessments, e.g., there is only one manufacturer who provides to EPA their internal OEL
but does not provide monitoring data)
b. Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits
(PEL)
c. Voluntary limits (American Conference of Governmental Industrial Hygienists [ACGIH]
Threshold Limit Values [TLV], National Institute for Occupational Safety and Health
[NIOSH] Recommended Exposure Limits [REL], Occupational Alliance for Risk Science
(OARS) workplace environmental exposure level (WEEL) [formerly by AIHA])
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EPA used the estimated high-end and central tendency full-shift TWA inhalation exposure
concentrations and APDR to calculate exposure metrics required for risk evaluation. Exposure metrics
for inhalation exposures include acute concentrations (AC), subchronic average daily concentrations
(SCDC), average daily concentrations (ADC), and lifetime average daily concentrations (LADC).
Exposure metrics for dermal exposures include acute potential dose rate (APDR), acute retained dose
(ARD), chronic retained dose (CRD) non-cancer, and chronic retained dose (CRD) cancer. The
approach to estimating each exposure metric is described in Section 2.4.5.
2.4.1 Identifying Worker Activities
EPA performed a literature search to identify worker activities that could potentially result in
occupational exposures. Where worker activities were unclear or not available, EPA referenced relevant
ESD's or GS's. Worker activities for each condition of use can be found in Sections 5.1.4.1 through
5.6.4.1.
2.4.2 Estimating Number of Workers and Occupational Non-users
Where available, EPA used CDR data to provide a basis to estimate the number of workers and ONUs.
EPA supplemented the available CDR data with U.S. economic data using the following method:
1. Identify the North American Industry Classification System (NAICS) codes for the industry
sectors associated with these uses.
2. Estimate total employment by industry/occupation combination using the Bureau of Labor
Statistics' Occupational Employment Statistics (OES) data (BLS Data).
3. Refine the OES estimates where they are not sufficiently granular by using the U.S. Census'
Statistics of US Businesses (SUSB) (SUSB Data) data on total employment by 6-digit NAICS.
4. Use market penetration data to estimate the percentage of employees likely to be using 1,1-
dichloroethane instead of other chemicals.
5. Where market penetration data are not available, use the estimated workers/ONUs per site in the
6-digit NAICS code and multiply by the number of sites estimated from CDR, TRI, DMR and/or
NEI. In DMR data, sites report Standard Industrial Classification (SIC) codes rather than NAICS
codes; therefore, EPA mapped each reported SIC code to a NAICS code for use in this analysis.
6. Combine the data generated in Steps 1 through 5 to produce an estimate of the number of
employees using 1,1-dichloroethane in each industry/occupation combination and sum these to
arrive at a total estimate of the number of employees with exposure within the condition of use.
2.4.3 Estimating Inhalation Exposures
2.4.3.1 Inhalation Monitoring Data
EPA reviewed workplace inhalation monitoring data collected by government agencies such as OSHA
and NIOSH, monitoring data found in published literature {i.e., personal exposure monitoring data and
area monitoring data), and monitoring data submitted via public comments. Studies were evaluated
using the evaluation strategies laid out in the Application of Systematic Review in TSCA Risk
Evaluations (U.S. EPA. 2018a).
Exposures are calculated from the monitoring data sets provided in the sources depending on the size of
the data set. For data sets with six or more data points, central tendency and high-end exposures were
estimated using the 50th percentile and 95th percentile. For data sets with three to five data points,
central tendency exposure was calculated using the 50th percentile and the maximum was presented as
the high-end exposure estimate. For data sets with two data points, the midpoint was presented as a
midpoint value and the higher of the two values was presented as a higher value. Finally, data sets with
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only one data point presented the single exposure value. For data sets including exposure data that were
reported as below the limit of detection (LOD), EPA estimated the exposure concentrations for these
data, following EPA's Guidelines for Statistical Analysis of Occupational Exposure Data (
1994) which recommends using the ^j=- if the geometric standard deviation of the data is less than 3.0
and if the geometric standard deviation is 3.0 or greater.
A key source of monitoring data is samples collected by OSHA during facility inspections. OSHA
inspection data are compiled in an agency information system (OIS) for internal use. Air sampling data
records from inspections are entered into the OSHA Chemical Exposure Health Database (CEHD) that
can be accessed on the agency website (https://www.osha.eov/openeov/healthsamples.html). The
database includes personal breathing zone (PBZ) monitoring data, area monitoring data, bulk samples,
wipe samples, and serum samples. The collected samples are used for comparing to OSHA's
Permissible Exposure Limits (PEL). OSHA's CEHD website indicates that they do not: perform routine
inspections at every business that uses toxic/hazardous chemicals, completely characterize all exposures
for all employees every day, or always obtain a sample for an entire shift. Rather, OSHA performs
targeted inspections of certain industries based on National and regional emphasis programs, often
attempts to evaluate worst case chemical exposure scenarios, and develop "snapshots" of chemical
exposures and assess their significance (e.g., comparing measured concentrations to PELs).
EPA took the following approach to analyzing OSHA CEHD:
1. Download all data for 1,1-dichloroethane from all available years in the CEHD (generally 1984-
present).
2. Organize data by site (group data collected at the same site together).
3. Remove data in which all measurements taken at the site were recorded as "0" or below the limit
of detection as EPA could not be certain the chemical of interest was at the site at the time of the
inspection (Note: sites where bulk samples were collected that indicate 1,1-dichloroethane was
present were not removed from the data set).
4. Remove serum samples, bulk samples, wipe samples, and blanks. These data are not used in
EPA's assessment.
5. Assign each data point to an OES. Review NAICS codes, SIC codes, and as needed, company
information available online, to map each sample to an OES. In some instances, EPA was not
able to determine the OES from the information in the CEHD; in such cases, EPA did not use the
data in the assessment. EPA also removed data determined to be for non-TSCA uses or otherwise
out of scope.
6. Combine samples from the same worker. In some instances, OSHA inspectors will collect
multiple samples from the same worker on the same day (these are indicated by sample ID
numbers). In these cases, EPA combined results from each sample to construct an exposure
concentration based on the totality of exposures from each sample.
7. Occasionally, one or all the samples associated with a single sample number measured below the
limit of detection. Because the samples were often on different time scales (e.g., one hour vs four
hours), EPA did not include these data in the statistical analysis to estimate values below the
LOD as described previously in this section. Sample results from different time scales may vary
greatly as short activities my cause a large, short-term exposure that when averaged over a full-
shift are comparable to other full-shift data. Therefore, including data of different time scales in
the analysis may give the appearance of highly skewed data when in fact the full-shift data is not
skewed. Therefore, EPA performed the statistical analysis (as needed) using all the non-OSHA
CEHD data for each OES and applied the approach determined by the analysis to the non-detects
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in the OSHA CEHD data. Where all the exposure data for an OES came from CEHD, EPA used
only the 8-hr TWAs that did not include samples that measured below the LOD to perform the
statistical analysis.
8. Calculate 8-hr TWA results from combined samples. Where the total sample time was less than
eight hours, EPA calculated an 8-hr TWA by assuming exposures were zero for the remainder of
the shift.
It should be noted that the OSHA CEHD does not provide job titles or worker activities associated with
the samples; therefore, EPA assumed all data were collected on workers and not ONUs.
Specific details related to the use of monitoring data for each condition of use can be found in Section 5.
2.4.3.2 Inhalation Exposure Modeling
Where inhalation exposures are expected for an OES but monitoring data were not available or where
EPA determined monitoring data did not sufficiently capture the exposures for an OES, EPA attempted
to utilize models to estimate inhalation exposures. Outputs from models may be the result of
deterministic calculations, stochastic calculations, or a combination of both deterministic and stochastic
calculations. For each OES with modeled inhalation exposures, EPA followed these steps to estimate
exposures:
1. Identify worker activities/sources of exposures from process.
2. Identify or develop model equations for estimating exposures from each source.
3. Identify model input parameter values from relevant literature sources, including activity
durations associated with sources of exposures.
4. If a range of input values is available for an input parameter, determine the associated
distribution of input values.
5. Calculate exposure concentrations associated with each activity.
6. Calculate full-shift TWAs based on the exposure concentration and activity duration associated
with each exposure source.
7. Calculate exposure metrics (AC, SCDC, ADC, LADC) from full-shift TWAs.
For exposure models that utilize stochastic calculations, EPA performed a Monte Carlo simulation using
the Palisade @Risk software with 100,000 iterations and the Latin Hypercube sampling method.
Detailed descriptions of the model approaches used for each OES, model equations, input parameter
values and associated distributions are provided in Section 5.
2.4.3.3 Occupational Exposure Limits
If monitoring data or models were not available to estimate inhalation exposures from an OES, EPA
relied on relevant occupational exposure limits, where available. Relevant limits may include company-
specific limits, OSHA PELs, or voluntary limits, such as NIOSH RELs. When utilizing exposure limits,
EPA assumed facilities operate such that the workers are exposed at the limit every day of the work
year. If EPA used occupational exposure limits, an explanation of the use of this limit is included in
Section 5 for the relevant COU.
2.4.4 Estimating Dermal Exposures
Dermal exposure data was not reasonably available for the conditions of use in the assessment. Because
1,1-dichloroethane is a volatile liquid that readily evaporates from the skin, EPA estimated dermal
exposures using the Dermal Exposure to Volatile Liquids Model. This model determines an APDR
based on an assumed amount of liquid on skin during one contact event per day and the theoretical
steady-state fractional absorption for 1,1-dichloroethane. The exposure concentration is determined
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based on EPA's review of currently available products and formulations containing 1,1-dichloroethane.
The dose estimates assume one dermal exposure event (applied dose) per workday and approximately
0.3 percent of the applied dose is absorbed through the skin, for 1,1-dichloroethane in neat form.
Specific details of the dermal exposure assessment for each OES can be found in Section 5 and
equations for estimating dermal exposures can be found in Appendix E.
2.4,5 Estimating Acute, Subchronic and Chronic (Non-cancer and Cancer) Exposures
For each condition of use, the estimated exposures were used to calculate acute, subchronic, and chronic
(non-cancer and cancer) inhalation exposures and dermal doses. These calculations require additional
parameter inputs, such as years of exposure, exposure duration and frequency, and lifetime years.
For the final exposure result metrics, each of the input parameters (e.g., air concentrations, dermal doses,
working years, exposure frequency, lifetime years) may be a point estimate (i.e., a single descriptor or
statistic, such as central tendency or high-end) or a full distribution. EPA considered three general
approaches for estimating the final exposure result metrics:
• Deterministic calculations: EPA used combinations of point estimates of each parameter to
estimate a central tendency and high-end for each final exposure metric result. EPA documented
the method and rationale for selecting parametric combinations to be representative of central
tendency and high-end.
• Probabilistic (stochastic) calculations: EPA used Monte Carlo simulations using the full
distribution of each parameter to calculate a full distribution of the final exposure metric results
and selecting the 50th and 95th percentiles of this resulting distribution as the central tendency
and high-end, respectively.
• Combination of deterministic and probabilistic calculations: EPA had full distributions for some
parameters but point estimates of the remaining parameters. For example, EPA used Monte
Carlo modeling to estimate exposure concentrations, but only had point estimates of exposure
duration and frequency, and lifetime years. In this case, EPA documented the approach and
rationale for combining point estimates with distribution results for estimating central tendency
and high-end results.
Equations and sample calculations for these exposures can be found in Appendix B and Appendix C,
respectively.
2.5 Evidence Integration for Environmental Releases and Occupational
Exposures
Evidence integration for the environmental release and occupational exposure assessment includes
analysis, synthesis and integration of information and data to produce estimates of environmental
releases and occupational inhalation and dermal exposures. During evidence integration, EPA
considered the likely location, duration, intensity, frequency, and quantity of releases and exposures
while also considering factors that increase or decrease the strength of evidence when analyzing and
integrating the data. Key factors EPA considered when integrating evidence includes the following:
1. Data Quality: EPA only integrated data or information rated as high, medium, or low obtained
during the data evaluation phase. Data and information rated as uninformative are not used in
exposure evidence integration. In general, higher rankings are given preference over lower
ratings; however, lower ranked data may be used over higher ranked data when specific aspects
of the data are carefully examined and compared. For example, a lower ranked data set that
precisely matches the OES of interest may be used over a higher ranked study that does not as
closely match the OES of interest.
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2. Data Hierarchy: EPA used both measured and modeled data to obtain accurate and
representative estimates (e.g., central-tendency, high-end) of the environmental releases and
occupational exposures resulting directly from a specific source, medium, or product. If
available, measured release and exposure data are given preference over modeled data, with the
highest preference given to data that are both chemical-specific and directly representative of the
OES/exposure source.
EPA considered both data quality and data hierarchy when determining evidence integration strategies.
For example, EPA may have given preference to high quality modeled data directly applicable to the
OES being assessed over low quality measured data that is not specific to the OES. The final integration
of the environmental release and occupational exposure evidence combined decisions regarding the
strength of the available information, including information on plausibility and coherence across each
evidence stream.
2.6 Weight of Scientific Evidence Ratings for Environmental Release and
Occupational Exposure Estimates
For each OES, EPA considered the assessment approach, the quality of the data and models, and the
strengths, limitations, assumptions, and key sources of uncertainties in the assessment results to
determine a weight of scientific evidence rating. EPA considered factors that increase or decrease the
strength of the evidence supporting the release estimate—including quality of the data/information,
applicability of the release or exposure data to the OES (including considerations of temporal relevance,
locational relevance) and the representativeness of the estimate for the whole industry. The best
professional judgment is summarized using the descriptors of robust, moderate, slight, or indeterminant,
according to EPA's Application of Systematic Review in TSCA Risk Evaluations (U.S. EPA. 2021). For
example, a conclusion of moderate is appropriate where there is measured release data from a limited
number of sources such that there is a limited number of data points that may not cover most or all the
sites within the OES. A conclusion of slight is appropriate where there is limited information that does
not sufficiently cover all sites within the OES, and the assumptions and uncertainties are not fully
known or documented. See EPA's Application of Systematic Review in TSCA Risk Evaluations (U.S.
21) for additional information on weight of scientific evidence conclusions.
Weight of scientific evidence ratings for the environmental release and occupational exposure estimates
for each OES, including details on the basis EPA used to determine the rating, are provided in Section 5
for each OES. Weight of scientific evidence ratings for all OES are also summarized in tables in Section
5.8.
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1220 3 SUMMARY OF OCCUPATIONAL EXPOSURE ESTIMATES
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Table 3-1 summarizes the occupational inhalation exposure and dermal loading results for each OES. EPA's general approach for estimating
occupational exposures is explained in Section 2.4 and the specific basis for each estimate is discussed in the relevant subsection of Section 5.
Table 3-1. Summary of EPA's Occupational Inhalation and Dermal Exposure Estimates
Occupational Exposure
Scenario (OES)
Worker
Description
Exposure
Days (day/yr)
Worker Inhalation
Estimates (ppm)
ONU
Inhalation Estimates (ppm)
Worker Dermal Exposure
Estimates (mg/dav)
High-End
Central
Tendency
High-End
Central
Tcndcncv
High-End
Central Tendency
Manufacturing
Operator/process
technician
250
1.1
4.7E-03
2.0E-02
3.2E-03
6.7
2.3
Maintenance
technician
250
0.41
7.9E-02
Laboratory
technician
250
2.4E-02
1.1E-03
Processing as a Reactive
Intermediate
Operator/process
technician
250
1.1
4.7E-03
2.0E-02
3.2E-03
6.7
2.3
Maintenance
technician
250
0.41
7.9E-02
Laboratory
technician
250
2.4E-02
1.1E-03
Processing-Repackaging
-
250
13
3.5
3.5
6.7
2.3
Recycling
-
250
1.1
7.9E-02
2.0E-02
3.2E-03
6.7
2.3
Commercial Use as a Laboratory
Chemical
Laboratory
technician
250
2.4E-02
1.1E-03
1.1E-03
6.7
2.3
Distribution in Commerce
Not Estimated
General Waste Handling,
Treatment and Disposal
-
250
10
0.30
0.30
6.7
2.3
Waste Handling, Treatment and
Disposal (POTW)
-
250
0.68
0.25
0.25
6.7
2.3
Where EPA was not able to estimate ONU inhalation exposure from monitoring data or models, this was assumed equivalent to the central tendency experienced by
workers for the corresponding OES; dermal exposure for ONUs was not evaluated because they are not expected to be in direct contact with 1,1-dichloroethane.
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1226 4 SUMMARY OF ENVIRONMENTAL RELEASE ESTIMATES
1227 In Table 4-1, EPA provides a summary for each of the occupational exposure scenarios (OESs) by indicating the media of release and number
1228 of facilities. EPA provides high-end and central tendency daily and yearly release estimates.
1229
1230 Table 4-1. Summary of EPA's Daily Release Estimates for Each PES and EPA's Overall Confidence in These Estimates
Occupational Exposure
Scenario (OES)
Estimated Annual Release
(kg/site-yr)
Type of Discharge'',
Air Emission', or
T ransfer for
Disposal''
Estimated Daily Release
(kg/site-dav)''
Number of
Facilities
Source(s)
Central
Tendency
High-End"
Central
Tendency
High-End
Manufacturing
1.6
1,299
Surface water
4.7E-03
3.7
3
TRI/DMR
8.4
2,184
Fugitive air
2.4E-02
6.2
8
TRI
34
74
Fugitive air
9.5E-02
0.20
4
NEI
45
499
Stack air
0.13
1.4
9
TRI
33
Stack air
9.1E-02
1
NEI
1.4
2.1
Land
3.9E-03
6.0E-03
1
TRI
Processing as a reactive
intermediate
3.8E-03
7.5E-02
Surface water
1.1E-05
2.1E-04
60
TRI/DMR
2.3
155
Fugitive air
0.01
0.44
5
TRI
4.1
327
Fugitive air
1.2E-02
0.93
16
NEI
14
610
Stack air
0.04
1.7
4
TRI
3.8
526
Stack air
1.1E-02
1.5
23
NEI
0.45
Land
1.3E-02
1
TRI
Processing-repackaging
1.7E-02
0.40
Surface Water
5.0E-05
1.1E-03
3
DMR
11
19
Fugitive or stack air
0.24
0.46
2 generic
sites
Environmental
Release Modeling
275
320
Hazardous landfill or
incineration
6.0
9.4
Commercial use as a
laboratory chemical
1.1E-03
9.4E-03
Surface water
4.3E-06
3.7E-05
2
DMR
3.4
6.2
Fugitive air
9.5E-03
1.7E-02
2
NEI
2.0E-03
2.0E-03
Stack air
7.9E-06
7.9E-06
2
NEI
17
32
Fugitive or stack air
7.2E-02
0.14
43 to 138
generic sites
Environmental
Release Modeling
504
882
Hazardous landfill or
incineration
2.2
3.7
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Occupational Exposure
Estimated Annual Release
(kg/site-yr)
Type of Discharge'',
Air Emission', or
Estimated Daily Release
(kg/site-dav)''
Number of
Source(s)
Scenario (OES)
Central
Tendency
High-End"
T ransfer for
Disposal''
Central
Tendency
High-End
Facilities
9.3E-04
6.0E-03
Surface water
3.7E-06
2.4E-05
22
TRI/DMR
Waste Handling,
Treatment and Disposal
0.63
7.3
Fugitive air
2.5E-03
2.9E-02
7
TRI
34
202
Fugitive air
0.14
0.81
575
NEI
(non-POTW)
1.8E-02
0.82
Stack air
7.3E-05
3.3E-03
8
TRI
2.5
134
Stack air
1.0E-02
0.54
153
NEI
Waste Handling,
Treatment and Disposal
(POTW)
5.1E-03
8.9E-02
Surface water
1.4E-05
2.4E-04
126
DMR
Waste Handling,
Treatment and Disposal
(Remediation)
2.9E-04
8.5E-03
Surface water
8.0E-07
2.3E-05
42
DMR
Distribution in Commerce
N/A^
" "High-end" are defined as 95th percentile releases
h Direct discharge to surface water; indirect discharge to non-POTW; indirect discharge to POTW
c Emissions via fugitive air; stack air; or treatment via incineration
''Transfer to surface impoundment, land application, or landfills
e Where available, EPA used peer-reviewed literature (e.g., Generic Scenarios (GSs) or Emission Scenario Documents (ESDs) to provide a basis to estimate the number
of release days of 1,1-dichloroethane within a condition of use.
f EPA reviewed NRC data and DOT data for the 2015 to 2020 calendar vears for incident reports oertainine to distribution of 1.1-dichloroethane (NRC. 2009KDOT
Hazmat Incident Report Data}. EPA did not identify reported releases for 1,1-dichloroethane during distribution of the chemical.
1231
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5 ENVIRONMENTAL RELEASE AND OCCUPATIONAL
EXPOSURES ASSESSMENTS BY PES
The following sections contain process descriptions and the specific details (worker activities, analysis
for determining number of workers, exposure assessment approach and results, release sources, media of
release, and release assessment approach and results) for the assessment for each condition of use.
EPA assessed the conditions of use as stated in the Final Scope of the Risk Evaluation for 1,1-
Dichloroethane; CASRN 75-3-9 published by EPA in August 2020 ( 020c). with the addition
of the Processing—Repackaging OES.
5.1 Manufacturing
5.1.1 Process Description
CDR data indicated that the manufacture of 1,1-dichloroethane is an in-scope, occupational exposure
scenario that is performed in the United States ( 2020a. 2016). Various methods for
manufacture of 1,1-dichloroethane are discussed in the literature. 1,1-Dichloroethane may be produced
by chlorination of ethane or chloroethane, addition of hydrogen chloride to acetylene, or oxychlorination
with hydrogen chloride (Nj )20; Dreher et ai. 2014). Alternatively, 1,1-dichloroethane can be
produced commercially through the reaction of hydrogen chloride and vinyl chloride at 20 to 55 °C in
the presence of an aluminum, ferric, or zinc chloride catalyst. Other production methods include the
direct chlorination of ethane, the reaction of ethylene and chlorine in the presence of calcium chloride,
the reaction of phosphorus chloride and acetaldehyde, thermal chlorination, and photochlorination
(NCBI. 2020; \ I * Ok :01 ^).
1,1-Dichloroethane is also produced as a byproduct in the manufacture of 1,2-dichloroethane, which will
be evaluated in the risk evaluation for 1,2-dichloroethane ( 2020d). 1,1-Dichloroethane is
produced as reagent grade liquid, 99.7% pure with the following impurities: ethyl chloride 0.02%,
butylene oxide 0.08%, trichloroethylene 0.08%, ethylene dichloride 0.01%, unknown 0.14% (
2001). A portion of the volume of 1,1-dichloroethane produced is assumed to be repackaged and then
distributed for laboratory use, while the majority of the product is sent for processing as a reactant.
Figure 5-1 below highlights the typical process during the manufacture of 1,1-dichloroethane.
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Figure 5-1. Typical Release and Exposure Points During the Manufacture of 1,1-Dichloroethane
rOECD. 2011)
5.1.2 Facility Estimates
In the 2020 CDR, two companies, Geon Oxy Vinyl in Laporte, TX and Eagle US 2 LLC in Westlake,
LA reported manufacturing liquid 1,1-dichloroethane (U.S. EPA. 2020a). According to the Study Plan
for Inhalation and Dermal Monitoring submitted by the Vinyl Institute Consortium, eight additional
facilities reported manufacture of 1,1-dichloroethane, although some of these facilities only manufacture
1,1-dichloroethane as a byproduct or isolated intermediate {EPA-HQ-OPPT-2018-0426-0032}. EPA
identified all 10 sites in TRI, DMR, and NEI release data as well. In the 2020 CDR, the reported
aggregated production volume was 100,000,000 to <1,000,000,000 pounds; although the exact PV is
unknown due to CBI claims (U.S. EPA. 2020a). EPA did not identify data on facility operating
schedules; therefore, EPA assumes 350 days/yr of operation as discussed in Section 2.3.2.
5.1.3 Release Assessment
5.1.3.1 Environmental Release Points
Potential releases to air, wastewater, and land include equipment cleaning, transport container cleaning
and sampling waste. Additionally, releases may occur during leakage of pipes, flanges, and accessories
used for transport. Fugitive emissions may occur at loading racks and container filling from equipment
leaks and displaced vapor as containers are filled.
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5.1.3.2 Environmental Release Assessment Results
EPA used 2015 to 2020 DMR, 2015 to 2020 TRI, and 2017 NEI to estimate environmental releases
during the manufacture of 1,1-dichloroethane, as presented in Table 5-1. According to reported data,
1,1-dichloroethane is released through the following environmental media: surface water, fugitive air,
stack air, and land disposal.
Table 5-1. Summary of Environmental Releases During the Manufacture of 1,1-Dichloroethane
Environmental
Media
Estimated Yearly Release
Range across Sites (kg/yr)
Number
of
Release
Days
Daily Release
(kg/site-day)
Number
of
Facilities
Source(s)
Central
Tendency
High-End
Central
Tendency
High-End
Surface water
1.6
1,299
350
4.7E-03
3.7
3
TRI/DMR
Fugitive air
8.4
2,184
2.4E-02
6.2
8
TRI
Fugitive air
34
74
9.5E-02
0.20
4
NEI
Stack air
45
499
0.13
1.4
9
TRI
Stack air
33
9.1E-02
1
NEI
Land
1.4
2.1
3.9E-03
6.0E-03
1
TRI
5.1.3.3 Weight of Scientific Evidence for Environmental Releases
Water releases are assessed using reported releases from 2015 to 2020 TRI and DMR. The primary
strength of TRI data is that TRI compiles the best readily available release data for all reporting
facilities. The primary limitation is that the water release assessment is based on three reporting sites,
and EPA did not have additional sources to estimate water releases from this OES. Based on other
reporting databases (CDR, NEI, etc.), there are seven additional manufacturing sites that are not
accounted for in this assessment.
Air releases are assessed using reported releases from 2015 to 2020 TRI, and 2014 and 2017 NEI. A
strength of NEI data is that NEI captures additional sources that are not included in TRI due to reporting
thresholds. Factors that decrease the overall confidence for this OES include the uncertainty in the
accuracy of reported releases, and the limitations in representativeness to all sites because TRI and NEI
may not capture all relevant sites. Additionally, EPA made assumptions on the number of operating days
to estimate daily releases.
Land releases are assessed using reported releases from 2015 to 2020 TRI. The primary limitation is that
the land releases assessment is based on one reporting site, and EPA did not have additional sources to
estimate land releases from this OES. Based on other reporting databases (CDR, DMR, NEI, etc.), there
are nine additional manufacturing sites that are not accounted for in this assessment.
Based on this information, EPA has concluded that the weight of scientific evidence for this assessment
is moderate to robust and provides a plausible estimate of releases in consideration of the strengths and
limitations of reasonably available data.
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5,1.4 Occupational Exposure Assessment
5.1.4.1 Worker Activities
Workers are potentially exposed to 1,1-dichloroethane during its manufacture from the cleaning of
reaction equipment and storage containers. Additionally, workers are potentially exposed during the
handling and transport of the reaction mixture.
Workers may connect transfer lines or manually load 1,1-dichloroethane into transport containers.
Inhalation and dermal exposures are expected for both automated and manual loading and transfer
activities. Workers may experience inhalation and dermal exposure to 1,1-dichloroethane while during
the cleaning of reaction vessels and other equipment, as well as the rinsing of storage containers.
According to the final study report published by the Vinyl Institute Consortium (Stantec ChemRisk.
2023). workers in production areas wear the following standard PPE: fire-resistant clothing, coveralls,
hard hats, hearing protection, neoprene gloves, leather gloves, safety glasses, and steel toed boots. The
report also mentioned task-specific PPE, such as chemical suits worn during process opening, chemical
splash goggles, face shields, and full-face respirators.
ONUs include employees that work at the sites where 1,1-dichloroethane is manufactured, but they do
not directly handle the chemical and are therefore expected to have lower inhalation exposures and are
not expected to have dermal exposures through contact with liquids or solids. ONUs for this scenario
include supervisors, managers, and other employees that may be in the production area but do not
perform tasks that result in the same level of exposure as those workers that engage in tasks related to
the manufacture of 1,1-dichloroethane.
5.1.4.2 Number of Workers and Occupational Non-users
EPA used data from the Bureau of Labor Statistics (BLS) and the U.S. Census' Statistics of US
Businesses (SUSB) specific to the OES to estimate the number of workers and ONUs per site potentially
exposed to 1,1-dichloroethane during manufacturing ( x 2016; U.S. Census Bureau. 2015). This
approach involved the identification of relevant Standard Occupational Classification (SOC) codes
within the BLS data for the identified NAICS codes. Appendix A includes further details regarding
methodology for estimating the number of workers and ONUs per site. EPA assigned the following
NAICS codes for this OES:
• 325199: All Other Basic Organic Chemical Manufacturing
• 325180: Other Basic Inorganic Chemical Manufacturing
• 325110: Petrochemical Manufacturing
Table 5-2 summarizes the per site estimates for this OES based on the methodology described, including
the number of sites identified in Section 5.1.2.
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Table 5-2. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During
Manufacturing
Potential Number of Sites
NAICS Code
Exposed Workers per
Site3
Exposed Occupational
Non-users per Site11
10
325199: All Other Basic
Organic Chemical
Manufacturing
119
56
325180: Other Basic
Inorganic Chemical
Manufacturing
325110: Petrochemical
Manufacturing
" Number of workers and occupational non-users per site are calculated by dividing the exposed number of workers or
occupational non-users by the number of establishments.
5.1.4.3 Occupational Inhalation Exposure Results
Occupational inhalation data for 1,1-dichloroethane during manufacturing were provided via a Test
Order submission from the Vinyl Institute), which includes manufacturers and processors of 1,1-
dichloroethane (Stantec ChemRisk. 2023). EPA identified 57 worker and 5 ONU full-shift PBZ samples
from the test order data to estimate inhalation exposures during the manufacturing process. The data
included samples from the Westlake Chemical LCS Site in Westlake, LA, which manufactures 1,1-
dichloroethane as an isolated intermediate. The worker samples collected were from operators/process
technicians, maintenance technicians, and laboratory technicians at the site.
From this monitoring data, EPA calculated the 50th and 95th percentile 8-hr TWA concentrations to
represent a central tendency and high-end estimate of potential occupational inhalation exposures,
respectively, for this scenario. Using these 8-hr TWA exposure concentrations, EPA calculated the AC,
ADCsubchronic, ADC, and LADC as described in Appendix B. The results of these calculations are shown
in Table 5-3. In addition to the full-shift samples, the test order provided 36 task-length samples during
the manufacture of 1,1-dichloroethane as an isolated intermediate. The samples were taken during
routine tasks performed by operators/process technicians, maintenance technicians, and laboratory
technicians at the site. High-end and central tendency inhalation exposure estimates are presented in
Table 5-4.
For comparison, EPA also collected surrogate monitoring data from other chlorinated solvents: trans-
1,2-dichloroethylene and 1,2-dichloroethane. The trans-1,2-dichloroethylene data was provided via a
Vinyl Institute test order submission and contained 48 full-shift samples of workers during
manufacturing of the chemical.
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1373 Table 5-3. Inhalation Exposures to 1,1-Dichloroethane During Manufacturing
Worker
Description
8-hour TWA
Exposure
Concentrations
Acute Exposure
Concentrations (AC)
Subchronic Average
Daily Concentration
(A DCsuhchronic)
Average Daily
Concentration (ADC)
Lifetime Average
Daily Concentration
(LADC)
High-End
(ppm)
Central
Tendency
(ppm)
High-End
(ppm)
Central
Tendency
(ppm)
High-End
(ppm)
Central
Tendency
(ppm)
High-End
(ppm)
Central
Tendency
(ppm)
High-End
(ppm)
Central
Tendency
(ppm)
Operators/process
technician
1.1
4.7E-03
0.72
3.2E-03
0.53
2.3E-03
0.49
2.2E-03
0.25
8.7E-04
Maintenance
technician
0.41
7.9E-02
0.28
5.4E-02
0.21
4.0E-02
0.19
3.7E-02
9.9E-02
1.5E-02
Laboratory
technician
2.4E-02
1.1E-03
1.6E-02
7.7E-04
1.0E-02
5.6E-04
1.1E-02
5.3E-04
5.6E-03
2.1E-04
ONU
2.0E-02
3.2E-03
1.4E-02
2.2E-03
1.0E-02
1.6E-03
9.4E-03
1.5E-03
4.8E-03
5.9E-04
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Table 5-4. Task-
ength Inhalation Exposures to 1,1-Dichloroethane During Manufacturing
Exposure
Type
Worker Description
Number
of
Samples
Sample
Duration
(min)
Inhalation Estimates
(ppm)
High-
End
Central
Tendency
Task-Length
Exposure
Concentrations
Operators/process
technician
20
15 - 132
6.8
5.0E-03
Maintenance technician
7
15 - 121
8.6E-02
1.9E-02
Laboratory technician
9
33 - 176
7.2E-02
7.2E-03
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In addition, EPA compiled surrogate monitoring data from other volatile liquids assessed in previous
EPA Risk Evaluations. EPA identified a total of 397 full-shift worker samples from the following
volatile liquids: 1,4-dioxane, 1-bromopropane (1-BP), carbon tetrachloride, methylene chloride, n-
methylpyrrolidone (NMP), perchloroethy 1 ene (PCE), and trichloroethylene (TCE) (U.S. EPA. 2020e. £
g, h, L i, k). A summary of the inhalation exposure estimates for the manufacturing OES using 1,1-
dichloroethane test order and surrogate data is presented in Table 5-5. The surrogate monitoring data (no
vapor correction) identified from other volatile chemicals resulted in a high-end inhalation estimate of
2.7 ppm, which is slightly higher but within the same order of magnitude.
Table 5-5. Inhalation Exposures to 1,1-Dichloroethane During Manufacturing using Surrogate
Data
Exposure Type
Worker Inhalation Estimates
(ppm)
ONU Inhalation Estimates
(ppm)
High-End
Central
Tendency
High-End
Central
Tendency
8-hour TWA Exposure
Concentrations
2.7
0.12
0.16
8.0E-02
5.1.4.4 Occupational Dermal Exposure Results
EPA estimated dermal exposures for this OES using the Dermal Exposure to Volatile Liquid Model and
a fraction absorbed value of 0.3 percent. The maximum concentration evaluated for this dermal exposure
is 100% since 1,1-dichloroethane is expected to be manufactured as a neat liquid. Table 5-5 summarizes
the APDR, ARD, SCDD, CRD (non-cancer), and CRD (cancer) for 1,1-dichloroethane during
manufacturing. The high-ends are based on a higher loading rate of 1,1-dichloroethane (2.1 mg per cm2
per event) and two-hand contact, and the central tendencies are based on a lower loading rate of 1,1-
dichloroethane (1.4 mg per cm2 per event) and one-hand contact. OES-specific parameters for dermal
exposures are described in Appendix D.
Table 5-6. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Manufacturing
Modeled
Scenario
Exposure Concentration Type
High-End
Central
Tendency
Average Adult
Worker"
Acute Potential Dose Rate (APDR) (mg/day)
6.7
2.3
Acute Retained Dose (ARD) (mg/kg-day)
8.0E-02
3.0E-02
Subchronic Average Daily Dose (SCDD), non-cancer (mg/kg-
day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), cancer (mg/kg-day)
3.0E-02
1.0E-02
a Conditions where no gloves are used, or for any glove / gauntlet use without permeation data and without employee
training (PF =1).
5.1.4.5 Weight of Scientific Evidence for Occupational Exposures
EPA considered the assessment approach, the quality of the data, and uncertainties in assessment results
to determine a weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure
estimates. EPA used 1,1-dichloroethane test order inhalation data to assess inhalation exposures. The
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primary strength of these data is the use of personal and directly applicable data, and the number of
samples available for workers and ONUs. The primary limitation is that the data is from one site and
may not be representative of all manufacturing sites. Additionally, EPA assumed 250 exposure days per
year based on 1,1-dichloroethane exposure each working day for a typical worker schedule; it is
uncertain whether this captures actual worker schedules and exposures. Based on these strengths and
limitations, EPA has concluded that the weight of scientific evidence for the inhalation assessment is
moderate to robust and provides a plausible estimate of exposures in consideration of the strengths and
limitations of reasonably available data.
EPA estimated dermal exposures using modeling methodologies, which are supported by moderate
evidence. EPA used the EPA Dermal Exposure to Volatile Liquids to calculate the dermal retained dose.
This model modifies the EPA/OPPT 2-HandDermal Exposure to Liquids Model by incorporating a
"fraction absorbed (fabs)" parameter to account for the evaporation of volatile chemicals. These
modifications improve the modeling methodology; however, the modeling approach is still limited by
the low variability for different worker activities/exposure scenarios. Therefore, the weight of scientific
for the modeling methodologies is moderate.
The exposure scenarios and exposure factors underlying the dermal assessment are supported by
moderate to robust evidence. Dermal exposure scenarios were informed by moderate to robust process
information and GS/ESD. Exposure factors for occupational dermal exposure include amount of
material on the skin, surface area of skin exposed, and absorption of 1,1-dichloroethane through the
skin. These exposure factors were informed by literature sources, the ChemSTEER User Guide (H.S.
) for standard exposure parameters, and a European model, with ratings from moderate to
robust. Based on these strengths and limitations, EPA concluded that the weight of scientific evidence
for the dermal exposure assessment is moderate to robust for all OES.
5.2 Distribution in Commerce
5.2.1 Process Description
EPA expects that 1,1-dichloroethane and 1,1-dichloroethane-containing products are distributed
throughout commerce from manufacturing sites to processing repackaging sites. Repackaging sites are
expected to distribute 1,1-dichloroethane for laboratory use. Based on the information from the other
conditions of use, 1,1-dichloroethane may be transported in pure liquid form and in various liquid
formulations with a range of potential 1,1-dichloroethane concentrations.
Distribution of 1,1-dichloroethane in commerce may include loading and unloading activities that occur
during other life cycle stages (e.g., manufacturing, processing, repackaging, laboratory use, disposal),
transit activities that involve the movement of the chemical (e.g., via motor vehicles, railcars, water
vessels), and temporary storage and warehousing of the chemical during distribution (excluding
repackaging and other processing activities, which are included in other COUs). Therefore, EPA
assessed the distribution in commerce activities resulting in releases and exposures (e.g., loading,
unloading) throughout the various life cycle stages and COUs rather than a single distribution scenario.
Data for assessing releases and exposures occurring during transportation of 1,1-dichloroethane between
facilities, such as those from accidental spills, are generally not available.
Figure 5-2 shows an illustration of the distribution in commerce. The illustration shows red shading
indicating loading and unloading activities related to distribution in commerce included in the
assessment of the COUs within other life cycle stages. The red arrows indicate transport activities of
distribution in commerce, which include the transit via motor vehicles, railcars, water vessels, as
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examples, and any temporary storage or warehousing, relabeling, and redistribution. The transport
activities are what connect the life cycle stages (manufacture, processing, use, and disposal) together.
Figure 5-2. Illustration of Distribution in Commerce and its Relation to Other Life Cycle Stages
EPA did not identify data on the total volume of 1,1-dichloroethane distributed in commerce, nor
volumes typically transported by a transportation company over any timeframe. As discussed above,
since EPA is not separately assessing releases and exposures in a single distribution in commerce
scenario, EPA did not estimate 1,1-dichloroethane volumes or operating days for this condition of use.
5.2.2 Facility Estimates
Distribution in commerce involves transportation of 1,1-dichloroethane between facilities that manage
1,1-dichloroethane at the various life cycle stages. Other OESs address the facility information relevant
to handling 1,1-dichloroethane in each of these life cycle stages. EPA did not quantify the number of
transportation/warehousing companies or facilities, volume of 1,1-dichloroethane transported, or number
of transport vehicles. The amount of 1,1-dichloroethane distributed in commerce will scale with the
demand for 1,1-dichloroethane and 1,1-dichloroethane-containing products.
5.2.3 Release Assessment
5.2.3.1 Environmental Release Points
The main release source of 1,1-dichloroethane during distribution in commerce is accidental releases of
the compound during spill events. When a spill occurs, it must first be evaluated to determine a plan of
action for clean-up. Spill response cleanup times may vary depending on the severity, location, and
additional hazards associated with the spill which may require additional special measures to be taken.
Spill response actions may include the following:2
• Installing fences, warning signs, or other security or site control precautions where humans or
animals have access to the release;
• Drainage controls where needed to reduce migration of hazardous substances or pollutants off-
site or to prevent precipitation or run-off from other sources;
2 40 CFR 300.415 Hazardous Substance Response; https://www.govinfo.gov/content/pkg/CFR-2015-title40-vol28/xml/CFR-
2015-title40-vol28-part300.xinl#seqnum300.415
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• Stabilization of berms, dikes, or impoundments or drainage or closing of lagoons where needed
to maintain the integrity of the structures;
• Capping of contaminated soils or sludges—where needed to reduce migration of hazardous
substances or pollutants or contaminants into soil, ground, or surface water, or air;
• Using chemicals and other materials to retard the spread of the release or to mitigate its effects—
where the use of such chemicals will reduce the spread of the release;
• Excavation, consolidation, or removal of highly contaminated soils from drainage or other
areas—where such actions will reduce the spread of, or direct contact with, the contamination;
• Removal of drums, barrels, tanks, or other bulk containers that contain or may contain hazardous
substances or pollutants or contaminants—where it will reduce the likelihood of spillage;
leakage; exposure to humans, animals, or food chain; or fire or explosion;
• Containment, treatment, disposal, or incineration of hazardous materials—where needed to
reduce the likelihood of human, animal, or food chain exposure; or
• Provision of alternative water supply—where necessary immediately to reduce exposure to
contaminated household water and continuing until such time as local authorities can satisfy the
need for a permanent remedy.
Another strategy for spill cleanup, provided by the Department of Transportation (DOT), includes three
main steps:3
1. Sizing-up the spill;
2. Containment and Confinement; and
3. Disposal.
The first step, sizing-up the spill, involves an assessment of the spill by response personnel to identify
the hazardous substance and prevent the spill from spreading. This is a non-invasive attempt to gain an
understanding of the severity of the event. Generally, responders would look for the following
information:
• Identity of the materials;
• Amount of the release;
• Hazards associated with each material(s);
• Effects and risks on the public, property, and environment;
• Potential pathway of release—air, land, surface waters, or groundwater;
• Most appropriate measures for controlling the release to prevent/reduce the impact; and
• Safety measures to protect all response personnel.
To obtain this information, responders would use visual methods such as:
• Types and numbers of containers or cargo tanks;
• Placards, labels, and markings on containers or transportation vehicles;
• Vapors, clouds, run-offs, or suspicious substances;
• Biological indicators—dead vegetation, animals, insects, and fish; and
• Physical condition of containers.
In some cases, responders may need to utilize quantitative methods such as colorimetric tubes, pH paper,
and Splifyter classifier strips to detect the presence or release of hazardous chemicals.
3 Traffic Incident Management in Hazardous Materials Spills in Incident Clearance. Chapter 4.0 Hazard Materials Incident
Clearance Compliance Requirements, https://ops.fhwa.dot.gov/publications/fhwahop08058/40.htm
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Once the hazardous substance release has been identified, first responders may perform limited cleanup
activities by employing basic containment and confinement techniques. Spill containment involves
methods used to restrict any hazardous material to its original container. These methods may include
plugging, patching or overpacking the storage container. Spill confinement involves limiting the spread
of the hazardous substance release. Spill confinement techniques include mist knockdown/vapor
suppression, diversion of the spill, diking, booming, absorbing, fencing, and damming. For smaller
vehicular spills, one of the easiest control methods is the use of granular absorbents, oil absorbent pads,
or universal absorbent pads. These items are readily available and effective for smaller spills.
Once cleanup of the spill has occurred, professional licensed firms should be contracted to perform
disposal of the hazardous substance. First responders may improve the disposal process by mitigating
the spill following a standard operating procedure (SOP). The SOP should account for how to mitigate
the spill, package the waste for transport, and secure the waste until a licensed transportation and
disposal company can pick it up.
5.2.3.2 Environmental Release Assessment
When evaluating releases related to distribution in commerce of 1,1-dichloroethane, EPA considered
two sources including Toxic Release Inventory (TRI) data and National Response Center (NRC) data.
EPA examined data corresponding to the 2015 to 2020 calendar years for these data sources.
When evaluating the TRI data, EPA found that storage would not meet an activity threshold under
EPCRA section 313.4 Therefore, if a wholesale or warehouse facility reports to TRI, it is likely because
they are conducting a manufacturing, processing, or otherwise use activity, in which case we
appropriately map that facility to another OES (such as repackaging). If a wholesale or warehouse
facility stores, relabels, or redistributes a chemical product without opening the containers or performing
any processing activity, the facility likely is not required to report that chemical to TRI.
Since transit activities (transportation in tank trucks, railcars, etc) are not required to report to TRI,
wholesale and warehouse operations are not likely to submit Form Rs under TRI, and wholesale and
warehouse operations are less likely to have federally permitted releases subject to reporting (e.g.,
NPDES permits, Clean Air Act permits), NRC data of CERCLA-reportable accidental releases may be
the best option to quantify environmental releases during transport activities.
Section 103 of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) requires the person in charge of a vessel or an onshore or offshore facility immediately
notify the NRC when a CERCLA hazardous substance is released at or above the reportable quantity
(RQ) in any 24-hour period, unless the release is federally permitted.5 The NRC is an emergency call
center maintained and operated by the U.S. Coast Guard that fields initial reports for pollution and
railroad incidents. Information reported to the NRC is available on the NRC website.6
EPA downloaded NRC data for the 2015 to 2020 calendar years and reviewed it for reports pertaining to
distribution of 1,1-dichloroethane. Upon review, ERG found that none of the reported releases for 1,1-
dichloroethane appeared to occur during distribution of the chemical. It is important to note that the data
reported to NRC in the past does not correlate to possible spills in the future. Due to the lack of
correlation, EPA is unable to estimate the frequency or volume of any spills that may occur in the future
4 Question # 134; TRI Program GuideMe Questions and Answers; EPA.
5 CERCLA 103 - Release Notification; EPA.
6 U.S. Coast Guard National Response Center.
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or provide estimates representative of a "typical" spill, as each spill represents a unique scenario.
5.2.4 Occupational Exposure Assessment
5.2.4.1 Description of Exposure Sources and Methods of Mitigation
EPA gathered condition of use information from various literature sources that were evaluated through
the systematic review process. The systematic review process yielded one peer-reviewed research article
with information pertaining to the distribution of chemicals on Norwegian chemical tankers (Moen.
1991). Although the source did not contain any quantitative exposure data, it did state that workers may
be exposed when repairing leakages in the storage tanks.
In addition to repairing leakages in storage tanks, workers may also be exposed during the cleanup of
spills that may occur during transit activities, warehousing, or temporary storage. During spill cleanup
workers may be exposed through inhalation of vapors from the volatilization of 1,1-dichloroethane or
dermal contact with liquid or vapors of 1,1-dichloroethane. Typically, before spill cleanup occurs,
workers evaluate the spill and determine the appropriate PPE for the cleanup activities. EPA expects that
exposures may occur during cleanup activities listed in Section 5.2.3.1
5.2.4.2 Estimates of Exposures
From the examination of 2015 to 2020 NRC data, EPA did not identify any spill events occurred during
the distribution in commerce of 1,1-dichloroethane. ERG also examined DOT data using the Hazmat
Incident Report Search Tool.7 ERG found that during the 2015 to 2020 timeframe, only one spill
incident involving 1,1-dichloroethane had occurred. This incident occurred on a highway in Gardena,
CA (Report number E-2020050431).8 During the loading phase, 1,1-dichloroethane was incorrectly
packed into a fiberboard box. When the compound was being transported by Saia Motor Freight Line,
LLC, a rip/tear in the packaging caused a spill of 1,1-dichloroethane to occur. The incident caused a spill
of about 1 liquid cup of 1,1-dichloroethane and was cleaned up by Premium Environmental Services,
Inc. In addition to the Gardena, California spill event, EPA identified four additional spill events, all
occurring in or before 2005. These reports may be viewed in the DOT's Hazmat Incident Report Search
Tool.
EPA did not identify data to estimate the magnitude or frequency of worker exposures from spill
cleanup activities occurring from distribution in commerce of 1,1-dichloroethane. EPA expects the
magnitude of exposure to be dependent on the size and location of the spill and may have large
variability. For example, the Gardena, CA spill cited above may have resulted in relatively low
exposures due to the small volume of 1,1-dichloroethane spilled whereas a much larger spill (e.g., whole
drums or bulk containers spilling due to an accident during transit) may result in significantly higher
exposures to cleanup workers.
EPA expects that individual workers would be exposed to clean-up of spills of any one chemical during
distribution in commerce about once per year with a worst-case scenario involving the same worker
performing multiple spill cleanups of the same chemical in a year. However, similar to the magnitude of
exposures, the duration of spill cleanups is expected to be dependent on the specifics of each chemical
spill and could take minutes or days after the spill event to complete.
7 DOT Hazmat Incident Report Search Tool.
8 https://portal.phmsa.dot.gov/PDFGenerator/getPublicReport/OHMIR 5800-l?INCIDENTID=2078909.
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5.3 Processing as a Reactive Intermediate
As listed in Table 1-1, this OES includes the following conditions of use: intermediate in all other basic
organic chemical manufacturing, intermediate in all other chemical product and preparation
manufacturing, and recycling.
5.3.1 Process Description
CDR data indicated that processing 1,1-dichloroethane as a reactant or intermediate is an in-scope,
occupational exposure scenario that is performed in the United States ( 20a. 2016).
Processing as a reactant or intermediate is the use of 1,1-dichloroethane as a feedstock in the production
of another chemical via a chemical reaction in which 1,1-dichloroethane is consumed to form the
product. Nearly all of the manufactured 1,1-dichlorethane is used as an intermediate in the production of
other chemicals, primarily 1.1.1 -trichloroethane (Dreher et ai. 2014; RIVM. , I v «« \ 2000).
Other uses of 1,1-dichloroethane as an intermediate are negligible (Dreher et at.. 2014).
In the UK, liquid 1,1-dichloroethane is primarily shipped from manufacturing sites via pipelines,
although rail tankers and road tankers may also be used (OECD. 2009; >01). In the
production of 1,1,1-trichloroethane (tri-ethane), vinyl chloride is hydrochlorinated in the presence of a
catalyst to form 1,1-dichloroethane. After purification the 1,1-dichloroethane is then either thermally or
photochemically chlorinated to form tri-ethane (Axi; joratiom. 2016; Marshall and Pottenger.
2016; Dreher et ai. JO I i; 1 c< < i1 \ 2000). The concentration of 1.1-dichloroethane used in these
processes is unknown, although EPA assumes that it is used at a concentration of 99.7% from the
manufacturing process (U.S. EPA. 2001). Figure 5-3 below highlights the typical release and exposure
points during the processing of 1,1-dichloroethane as a reactant or intermediate.
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.©©©
........©©
©
Environmental Releases:
1. Releases to air from transferring volatile chemicals from transport containers.
2. Releases to air, water, incineration, or landfill from unloading solids from transport containers.
3. Releases to air, water, incineration, or land from cleaning of transport containers.
4. Releases to water, incineration, or land from cleaning of reaction vessels and other equipment.
5. Releases to air from reaction of volatile chemicals.
Transport
container
unloading
Reaction
Occupational Exposures:
A. Inhalation exposures to volatile liquids and dust and dermal exposure to solids and liquids from unloading transport
containers.
B. Inhalation exposures to volatile liquids and dermal exposures to solids and liquids from transport container cleaning.
C. Inhalation exposures to volatile liquids and dermal exposure to solids and liquids from reaction vessels and other
equipment cleaning.
Figure 5-3. Typical Release and Exposure Points During the Processing of 1,1-Dichloroethane as a
Reactive Intermediate
5.3.2 Facility Estimates
Using TRI, NEI, and DMR release data, EPA identified 90 facilities that potentially process 1,1-
dichloroethane as a reactive intermediate. Due to CBI claims on the annual PV of 1,1-dichloroethane,
EPA does not present annual or daily site throughputs; however, almost all manufactured 1,1-
dichloroethane is used for processing as a reactant (RIVM. 2007). EPA did not identify data on facility
operating schedules; therefore, EPA assumes 350 days/yr of operation as discussed in Section 2.3.2.
5.3.3 Release Assessment
5.3.3.1 Environmental Release Points
EPA expects releases to occur during container and equipment cleaning and sampling waste.
Environmental releases may also occur during the unloading of 1,1-dichloroethane from transport
containers into intermediate storage tanks and process vessels. Equipment leaks may occur while
connecting and disconnecting hoses and transfer lines. Specific release sources considered for estimating
releases are shown numbered as 1 through 5 in Figure 5-3. EPA expects the following types of releases:
1. Fugitive or stack air: Release points 1, 2, 3, and 5
2. Wastewater managed in onsite treatment or discharged to a POTW: Release points 1 and 2.
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3. Incineration or land: Release points 2, 3, and 4.
5.3.3.2 Environmental Release Assessment Results
EPA used 2015 to 2020 DMR, 2015 to 2020 TRI, and 2017 NEI to estimate environmental releases
during the processing of 1,1-dichloroethane as a reactive intermediate, as presented in Table 5-7.
According to reported data, 1,1-dichloroethane is released through the following environmental media:
surface water, fugitive air, stack air, and land disposal.
Table 5-7. Summary of Environmental Releases During the Processing of 1,1-Dichloroethane as a
Reactive Intermediate
Environmental
Media
Estimated Yearly
Release Range across
Sites (kg/yr)
Number
of
Release
Days
Daily Release
(kg/site-day)
Number of
Facilities
Source(s)
Central
Tendency
High-
End
Central
Tendency
High-
End
Surface water
3.8E-03
7.5E-02
350
1.1E-05
2.1E-04
60
TRI/DMR
Fugitive air
2.3
155
0.01
0.44
5
TRI
Fugitive air
4.1
327
1.2E-02
0.93
16
NEI
Stack air
14
610
0.04
1.7
4
TRI
Stack air
3.8
526
1.1E-02
1.5
23
NEI
Land
0.45
1.3E-02
1
TRI
5.3.3.3 Weight of Scientific Evidence for Environmental Releases
Water releases are assessed using reported releases from 2015 to 2020 TRI and DMR, which both have a
medium overall data quality determination from the systematic review process. The primary strength of
TRI data is that TRI compiles the best readily available release data for all reporting facilities. The water
release assessment is based on 60 reporting sites. Based on other reporting databases (CDR, NEI, etc.),
there are 30 additional sites that are not accounted for in this assessment.
Air releases are assessed using reported releases from 2015 to 2020 TRI, and 2014 and 2017 NEI. A
strength of NEI data is that NEI captures additional sources that are not included in TRI due to reporting
thresholds. Factors that decrease the overall confidence for this OES include the uncertainty in the
accuracy of reported releases, and the limitations in representativeness to all sites because TRI and NEI
may not capture all relevant sites.
Land releases are assessed using reported releases from 2015 to 2020 TRI. The primary limitation is that
the land release assessment is based on one reporting site, and EPA did not have additional sources to
estimate land releases from this OES. Based on other reporting databases (CDR, DMR, NEI, etc.), there
are 89 additional sites that are not accounted for in this assessment.
Based on this information, EPA has concluded that the weight of the scientific evidence for this
assessment is moderate to robust and provides a plausible estimate of releases in consideration of the
strengths and limitations of reasonably available data.
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5,3,4 Occupational Exposure Assessment
5.3.4.1 Worker Activities
During the processing of 1,1-dichloroethane as a reactive intermediate, workers are potentially exposed
to 1,1-dichloroethane when unloading transport containers, cleaning transport containers, and cleaning
reaction vessels or other equipment. These activities are all potential sources of worker exposure via
inhalation of vapor or dermal contact with liquids. EPA did not find information that indicates the extent
that engineering controls and worker PPE are used at facilities that processes 1,1-dichloroethane as a
reactive intermediate.
ONUs include employees (e.g., supervisors, managers) at the processing site that do not directly handle
1,1-dichloroethane. Therefore, the ONUs are expected to have lower inhalation exposures, lower vapor-
through-skin uptake, and no expected dermal exposure.
5.3.4.2 Number of Workers and Occupational Non-users
EPA used data from the Bureau of Labor Statistics (BLS) and the U.S. Census' Statistics of US
Businesses (SUSB) specific to the OES to estimate the number of workers and ONUs per site potentially
exposed to 1,1-dichloroethane during the processing as a reactive intermediate (V S HI S. 2*-m , I v
Census Bureau. ). This approach involved the identification of relevant Standard Occupational
Classification (SOC) codes within the BLS data for the identified NAICS codes. Appendix A includes
further details regarding methodology for estimating the number of workers and ONUs per site. EPA
assigned the following NAICS codes for this OES:
• 325199: All Other Basic Organic Chemical Manufacturing
• 325211: Plastics Material and Resin Manufacturing
• 325110: Petrochemical Manufacturing
• 325180: Other Basic Inorganic Chemical Manufacturing
Table 5-8 summarizes the per site estimates for this OES based on the methodology described, including
the potential number of sites identified in Section 5.3.2.
Table 5-8. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During
Processing as a Reactive Intermediate
Potential Number of Sites
NAICS Code
Estimated Average
Exposed Workers per
Site8
Estimated Average
Exposed Occupational
Non-users per Site"
90
325199: All Other Basic
Organic Chemical
Manufacturing
94
21
325211: Plastics Material
and Resin Manufacturing
325110: Petrochemical
Manufacturing
325180: Other Basic
Inorganic Chemical
Manufacturing
a Number of workers and occupational non-users per site are calculated by dividing the exposed number of workers
or occupational non-users by the number of establishments.
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5.3.4.3 Occupational Inhalation Exposure Results
EPA did not identify monitoring data for the processing as a reactive intermediate OES; however, EPA
assumed the exposures to be similar to manufacturing due to similar worker activities and the use of
primarily closed systems during processing. Therefore, EPA incorporated the manufacturing data into
the processing as a reactive intermediate exposure estimates. EPA has used this assessment approach in
previous risk evaluations, including th q Risk Evaluation for Perchloroethylene (PCE) (
20201).
As described in Section 5.1.4.3, EPA identified 57 worker and 5 ONU full-shift PBZ samples from the
Westlake Chemical LCS Site in Westlake, Louisiana, which manufactures 1,1-dichloroethane as an
isolated intermediate. The samples collected were from operators/process technicians, maintenance
technicians, and laboratory technicians at the site. From this monitoring data, EPA calculated the 50th
and 95th percentile 8-hr TWA concentrations to represent a central tendency and high-end estimate of
potential occupational inhalation exposures, respectively, for this scenario. Using these 8-hr TWA
exposure concentrations, EPA calculated the AC, ADCsubchronic, ADC, and LADC as described in
Appendix B. The results of these calculations are shown in Table 5-9.
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1734 Table 5-9. Inhalation Exposures to 1,1-Dichloroethane During Processing as a Reactive Intermediate
Worker
Description
8-hour TWA
Exposure
Concentrations
Acute Exposure
Concentrations (AC)
Subchronic Average
Daily Concentration
(A DCsuhchronic)
Average Daily
Concentration (ADC)
Lifetime Average
Daily Concentration
(LADC)
High-
End
(ppm)
Central
Tendency
(ppm)
High-
End
(ppm)
Central
Tendency
(ppm)
High-
End
(ppm)
Central
Tendency
(ppm)
High-
End
(ppm)
Central
Tendency
(ppm)
High-
End
(ppm)
Central
Tendency
(ppm)
Operators/process
technician
1.1
4.7E-03
0.72
3.2E-03
0.53
2.3E-03
0.49
2.2E-03
0.25
8.7E-04
Maintenance
technician
0.41
7.9E-02
0.28
5.4E-02
0.21
4.0E-02
0.19
3.7E-02
9.9E-02
1.5E-02
Laboratory
technician
2.4E-02
1.1E-03
1.6E-02
7.7E-04
1.0E-02
5.6E-04
1.1E-02
5.3E-04
5.6E-03
2.1E-04
ONU
2.0E-02
3.2E-03
1.4E-02
2.2E-03
1.0E-02
1.6E-03
9.4E-03
1.5E-03
4.8E-03
5.9E-04
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5.3.4.4 Occupational Dermal Exposure Results
EPA estimated dermal exposures for this OES using the Dermal Exposure to Volatile Liquid Model and
a fraction absorbed value of 0.3 percent. The maximum concentration evaluated for this dermal exposure
is 100% since 1,1-dichloroethane is expected to be received at the site in pure form. Table 5-10
summarizes the APDR, ARD, SCDD, CRD (non-cancer), and CRD (cancer) for 1,1-dichloroethane
during processing as a reactive intermediate. The high-ends are based on a higher loading rate of 1,1-
dichloroethane (2.1 mg per cm2 per event) and two-hand contact, and the central tendencies are based on
a lower loading rate of 1,1-dichloroethane (1.4 mg per cm2 per event) and one-hand contact. OES-
specific parameters for dermal exposures are summarized below in Table 5-10.
Table 5-10. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Processing as a
Reactive Intermediate
Modeled
Scenario
Exposure Concentration Type
High-End
Central
Tendency
Average
Adult
Worker"
Acute Potential Dose Rate (APDR) (mg/day)
6.7
2.3
Acute Retained Dose (ARD) (mg/kg-day)
8.0E-02
3.0E-02
Subchronic Average Daily Dose (SCDD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), cancer (mg/kg-day)
3.0E-02
1.0E-02
a Conditions where no gloves are used, or for any glove / gauntlet use without permeation data and without
employee training (PF =1).
5.3.4.5 Weight of Scientific Evidence for Occupational Exposures
EPA used inhalation data to assess inhalation exposures. The primary strength of this data is the use of
personal and potentially applicable data. The primary limitations of these data include the uncertainty of
the representativeness of these data toward the true distribution of inhalation concentrations in this
scenario since the data were surrogate from the manufacturing OES. EPA also assumed 250 exposure
days per year based on 1,1-dichloroethane exposure each working day for a typical worker schedule; it
is uncertain whether this captures actual worker schedules and exposures. Based on these strengths and
limitations, EPA has concluded that the weight of scientific evidence for this assessment is moderate and
provides a plausible estimate of exposures in consideration of the strengths and limitations of reasonably
available data.
EPA estimated dermal exposures using modeling methodologies, which are supported by moderate
evidence. EPA used the EPA Dermal Exposure to Volatile Liquids to calculate the dermal retained dose.
This model modifies the EPA/OPPT 2-HandDermal Exposure to Liquids Model by incorporating a
"fraction absorbed (fabs)" parameter to account for the evaporation of volatile chemicals. These
modifications improve the modeling methodology; however, the modeling approach is still limited by
the low variability for different worker activities/exposure scenarios. Therefore, the weight of scientific
for the modeling methodologies is moderate.
The exposure scenarios and exposure factors underlying the dermal assessment are supported by
moderate to robust evidence. Dermal exposure scenarios were informed by moderate to robust process
information and GS/ESD. Exposure factors for occupational dermal exposure include amount of
material on the skin, surface area of skin exposed, and absorption of 1,1-dichloroethane through the
skin. These exposure factors were informed by literature sources, the ChemSTEER User Guide (H.S.
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) for standard exposure parameters, and a European model, with ratings from moderate to
robust. Based on these strengths and limitations, EPA concluded that the weight of scientific evidence
for the dermal exposure assessment is moderate to robust for all OES.
5.4 Processing—Repackaging
5.4,1 Process Description
Repackaging was not included in the original scope document; however, 1,1-dichloroethane is expected
to be repackaged into smaller containers for laboratory use. Domestically manufactured commodity
chemicals may be shipped within the United States in liquid cargo barges, railcars, tank trucks, tank
containers, intermediate bulk containers (IBCs)/totes, and drums ( 2022a). Domestically
manufactured commodity chemicals may be repackaged by wholesalers for resale, for example,
repackaging bulk packaging into drums or bottles. There are no known 1,1-dichloroethane imports for
repackaging.
1,1-Dichloroethane may be received in its final formulation and transferred directly to smaller
containers, charged to a temporary storage tank, or transferred to a mixing tank and diluted or mixed
with other chemicals before repackaging ( 22a). 1,1-Dichloroethane is expected to be
shipped as a neat liquid with a purity of 99.7% (NCBI. 2020; ,001). EPA assumes that the
1,1-dichloroethane is repackaged at the same concentration as it arrives. Transport containers for
laboratory chemicals may range from 0.5 mL to 200 L, with an assumption of 3.79 L (1 gal) in the
absence of site-specific information. In some cases, QC samples may be taken at import and
repackaging sites for analyses. Figure 5-4 provides typical release and exposure points during the
repackaging of 1,1-dichloroethane.
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Environmental Releases:
1. Releases to air from unloading volatile chemicals from transport containers.
2. Releases to air, water, incineration, or landfill from unloading solids from transport containers.
3. Releases to water, incineration, or land from transport container residue (via container cleaning or direct disposal of
empty containers).
4. Releases to air from cleaning transport containers containing volatile chemicals
5. Releases to water, incineration or land from cleaning of storage/mixing vessels and other equipment.
6. Releases to air from cleaning equipment used to process volatile chemicals.
7. Releases to air from loading volatile chemicals into transport containers.
8. Releases to air, water, incineration, or landfill from loading solids into transport containers.
Occupational Exposures:
A. Inhalation exposures to volatile liquids and dust and dermal exposure to solids and liquids from unloading transport
containers.
B. Inhalation exposures to volatile liquids and dermal exposure to solids and liquids from transport container cleaning.
C. Inhalation exposures to volatile liquids and dermal exposure to solids and liquids from equipment cleaning.
D. Inhalation exposures to volatile liquids and dust and dermal exposure to solids and liquids from loading transport
containers.
Figure 5-4. Typical Release and Exposure Points During the Repackaging of 1,1-Dichloroethane
(U.S. EPA. 2022a).
5.4.2 Facility Estimates
For this OES, EPA identified three relevant facilities in DMR. However, the release estimates reported
by these facilities were below the limit of detection, and there were no releases reported to air and land
media. Due to the lack of companies reporting the import of 1,1-dichloroethane in CDR, EPA does not
present annual or daily site throughputs. EPA did not identify other data on current import volumes or
import sites from systematic review. Therefore, EPA assumed 1,1-dichloroethane may still be imported
at volumes below the CDR reporting threshold, and the environmental releases and occupational
exposures during the repackaging of 1,1-dichloroethane were modeled. As a conservative estimate, EPA
assumes two repackaging sites with an annual production volume of 50,000 lb. EPA additionally
assumes a shift length of 8 hours/day, 2,080 hours per year, which results in 260 days/yr of operation
according to the July 2022 Chemical Repackaging—Generic Scenario for Estimating Occupational
Exposures and Environmental Releases (U.S. EPA, 2022a).
5.4.3 Release Assessment
5.4.3.1 Environmental Release Points
EPA expects releases to occur during the emptying of drums, cleaning of emptied drums, and filling of
smaller containers. EPA estimated releases from import—repackaging using a Monte Carlo simulation
with 100,000 iterations and the Latin Hypercube sampling method using the models and approaches
described in Appendix E. Input parameters for the models were determined using data from literature
and the July 2022 Chemical Repackaging GS (U.S. EPA, 2022a). EPA used this method to estimate
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releases for individual release sources and summed the individual releases to each environmental media
to estimate total annual and daily facility releases. Specific release sources considered for estimating
releases are shown numbered as 1 through 8 in Figure 5-4. Because 1,1-dichloroethane is considered a
hazardous chemical, water releases are not expected for this OES (U.S. EPA. 2022a). EPA expects the
following types of releases:
1. Fugitive or Stack Air: Release points 1, 2, 4, 6, 7, and 8
2. Hazardous landfill/Incineration: Release points 2, 3, 5, and 8
5.4.3.2 Environmental Release Assessment Results
Appendix E includes the model equations and input parameters used in the Monte Carlo simulation for
this condition of use. EPA estimated 1,1-dichloroethane releases by simulating two sites importing and
processing 25,000 lb. per site. Table 5-11 summarizes the estimated release results for import—
repackaging based on the scenario applied. The high-ends are the 95th percentile of the respective
simulation output and the central tendencies are the 50th percentile.
Table 5-11. Summary of Modeled Environmental Releases for the Repackaging of 1,1-
Dichloroethane
Modeled
Scenario
Environmental Media
Annual Release
(kg/site-yr)
Number of Release
Days3
Daily Release
(kg/site-day)
Central
Tendency
High-End
Central
Tendency
High-End
Central
Tendency
High-End
Two sites;
25,000-lb
throughput
Fugitive or Stack Air
1.1E01
1.8E01
26
129
2.4E-01
4.4E-01
Hazardous landfill or
incineration
2.8E02
3.2E02
26
129
6.0
9.4
a EPA assumes that the number of operating days is equivalent to the number of drums imported per year (i.e., one
drum repackaged per day) but not to exceed 250 operating days per year. The number of release days presented in this
table is based on simulation outputs for the annual release divided by the daily release (grouped by high-end or central
tendency estimate), rounded to the closest integer. Annual totals may not add exactly due to rounding.
5.4.3.3 Weight of Scientific Evidence for Environmental Releases
All facility release data were below the limit of detection, therefore, EPA assessed releases to the using
the assumptions and values from the July 2022 Chemical Repackaging ( IS ( 023). which the
systematic review process rated medium for data quality. EPA used EPA/OPPT models combined with
Monte Carlo modeling to estimate releases to the environment, with media of release assessed using
assumptions from the ESD and EPA/OPPT models.
EPA believes a strength of the Monte Carlo modeling approach is that variation in model input values
and a range of potential releases values is more likely than a discrete value to capture actual releases at
sites. EPA lacks 1,1-dichloroethane facility production volume data and number of importing/
repackaging sites; therefore, throughput estimates are based on CDR reporting thresholds with an overall
release using a hypothetical scenario of two facilities.
Based on this information, EPA has concluded that the weight of scientific evidence for this assessment
is moderate to robust and provides a plausible estimate of releases in consideration of the strengths and
limitations of reasonably available data.
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5,4.4 Occupational Exposure Assessment
5.4.4.1 Worker Activities
During repackaging, workers are potentially exposed to 1,1-dichloroethane when transferring 1,1-
dichloroethane from the import drums into smaller containers. Workers may also be exposed via
inhalation of vapor or dermal contact with liquids when cleaning import drums following emptying.
EPA did not find information that indicates the extent that engineering controls and worker PPE are used
at facilities that repackage 1,1-dichloroethane from import drums into smaller containers.
ONUs include employees (e.g., supervisors, managers) at the import site, where repackaging occurs, that
do not directly handle 1,1-dichloroethane. Therefore, the ONUs are expected to have lower inhalation
exposures, lower vapor-through-skin uptake, and no expected dermal exposure.
5.4.4.2 Number of Workers and Occupational Non-users
As addressed in Section 5.4.2, EPA did not identify site-specific data for the number of facilities in the
Unites States repackaging 1,1-dichloroethane; therefore, EPA did not estimate the total number of
workers and ONUs exposed from this OES.
5.4.4.3 Occupational Inhalation Exposure Results
For this scenario, EPA applied the EPA Mass Balance Inhalation Model to exposure points described in
the July 2022 Chemical Repackaging GS ( )22a). particularly for the emptying of drums,
filling of containers, and cleaning of drums process described in the process description. The EPA Mass
Balance Inhalation Model estimates the concentration of the chemical in the breathing zone of the
worker based on a vapor generation rate (G). An 8-hour TWA is then estimated and averaged over eight
hours assuming no exposure occurs outside of those activities. Appendix E also describes the model
equations and other input parameters used in the Monte Carlo simulation for this OES. Worker
exposures were modeled for this OES; EPA did not have the approaches to separately model ONU
exposures.
EPA used the vapor generation rate and exposure duration parameters from the 1991 CEBManual (U.S.
) in addition to those used in the EPA Mass Balance Inhalation Model to determine a time-
weighted exposure for each exposure point. EPA estimated the time-weighted average inhalation
exposure for a full work-shift (EPA assumed an 8-hour work-shift) as an output of the Monte Carlo
simulation by summing the time-weighted inhalation exposures for each of the exposure points and
assuming 1,1-dichloroethane exposures were zero outside these activities.
Table 5-12 summarizes the estimated 8-hour TWA exposures, AC, ADC, LADC, and ADCsubchronic for
repackaging 1,1-dichloroethane. The high-end exposures presented in Table 5-12 are the 95th
percentiles of the respective simulation output, and the central tendency exposures are the 50th
percentiles. Equations for calculating AC, ADC, LADC, and ADCsubchronic are presented in Appendix B.
The estimated exposures assume that 1,1-dichloroethane is imported to the site in its pure form and
repackaged into smaller containers, with no engineering controls present. Actual exposures may differ
based on worker activities, 1,1-dichloroethane throughputs, and facility processes.
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Table 5-12. Summary of Modeled Worker Inhalation Exposures for Processing—Repackaging of
1,1-Dichloroethane for Laboratory Chemicals
Modeled Scenario
Exposure Concentration Type
Central
Tendency
(mg/mJ)
High-End
(mg/m3)
Data Quality
Rating of Air
Concentration
Data
2 sites,
22680 kg/yr
production volume
8-hr TWA Exposure Concentration
3.5
13
N/A: Modeled
data
AC based on 8-hr TWA
2.4
8.8
ADC based on 8-hr TWA
1.8
6.4
LADC based on 8-hr TWA
1.7E-01
3.1
ADCsubchronic based on 8-hr TWA
6.8E-02
1.6
5.4.4.4 Occupational Dermal Exposure Results
EPA estimated dermal exposures for this OES using the Dermal Exposure to Volatile Liquid Model and
a fraction absorbed value of 0.3 percent. The maximum concentration evaluated for this dermal exposure
is 100% since 1,1-dichloroethane is expected to be received at the site in pure form. Table 5-13
summarizes the APDR, ART), CRD (non-cancer), and CRD (cancer) for 1,1-dichloroethane during
processing—repackaging. The high-ends are based on a higher loading rate of 1,1-dichloroethane (2.1
mg per cm2 per event) and two-hand contact, and the central tendencies are based on a lower loading
rate of 1,1-dichloroethane (1.4 mg per cm2 per event) and one-hand contact. OES-specific parameters
for dermal exposures are described in Appendix D.
Table 5-13. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Processing—
Repackaging
Modeled
Scenario
Exposure Concentration Type
High-End
Central
Tendency
Average Adult
Worker"
Acute Potential Dose Rate (APDR) (mg/day)
6.7
2.3
Acute Retained Dose (ARD) (mg/kg-day)
8.0E-02
3.0E-02
Short-Term/Subchronic Retained Dose, Non-cancer
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), cancer (mg/kg-day)
3.0E-02
1.0E-02
a Conditions where no gloves are used, or for any glove / gauntlet use without permeation data and without
employee training (PF =1).
5.4.4.5 Weight of Scientific Evidence for Occupational Exposures
1,1-Dichloroethane monitoring data was not available for this scenario. Additionally, EPA did not
identify relevant monitoring data from other scenarios or chemicals assessed in previous EPA Risk
Evaluations. Therefore, EPA modeled inhalation exposures. EPA used assumptions and values from the
July 2022 Chemical Repackaging (IS ( |22a), which the systematic review process rated
high for data quality, to assess inhalation exposures (OECD. 2009).
EPA used EPA/OPPT models combined with Monte Carlo modeling to estimate inhalation exposures. A
strength of the Monte Carlo modeling approach is that variation in model input values and a range of
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potential exposure values is more likely than a discrete value to capture actual exposure at sites. The
primary limitation is the uncertainty in the representativeness of values toward the true distribution of
potential inhalation exposures. In addition, EPA lacks 1,1-dichloroethane facility production volume
data; and therefore, throughput estimates are based on CDR reporting thresholds. Also, EPA could not
estimate the number of exposure days per year associated with repackaging operations, so the exposure
days per year estimates are based on an assumed site throughput of imported containers. Based on these
strengths and limitations, EPA has concluded that the weight of scientific evidence for this assessment is
moderate and provides a plausible estimate of exposures.
EPA estimated dermal exposures using modeling methodologies, which are supported by moderate
evidence. EPA used the EPA Dermal Exposure to Volatile Liquids to calculate the dermal retained dose.
This model modifies the EPA/OPPT 2-HandDermal Exposure to Liquids Model by incorporating a
"fraction absorbed (fabs)" parameter to account for the evaporation of volatile chemicals. These
modifications improve the modeling methodology; however, the modeling approach is still limited by
the low variability for different worker activities/exposure scenarios. Therefore, the weight of scientific
for the modeling methodologies is moderate.
The exposure scenarios and exposure factors underlying the dermal assessment are supported by
moderate to robust evidence. Dermal exposure scenarios were informed by moderate to robust process
information and GS/ESD. Exposure factors for occupational dermal exposure include amount of
material on the skin, surface area of skin exposed, and absorption of 1,1-dichloroethane through the
skin. These exposure factors were informed by literature sources, the ChemSTEER User Guide (H.S.
) for standard exposure parameters, and a European model, with ratings from moderate to
robust. Based on this information, EPA has concluded that the weight of scientific evidence for this
assessment is moderate and provides a plausible estimate of exposures in consideration of the strengths
and limitations of reasonably available data.
5.5 Commercial Use as a Laboratory Chemical
5.5,1 Process Description
Laboratory use was included in the Final Scope of the Risk Evaluation for 1,1-Dichloroethane CASRN;
75-3-9 ( 3c) 1,1-Dichloroethane is used as a laboratory reference standard domestically for
instrument calibration and analytical method validation (Sigma-Aldrich. 2020). 1,1-Dichloroethane may
be received in transport containers ranging from 0.5 mL to 200 L (U.S. EPA. 2023). After receiving the
chemical, it is typically weighed or measured using a balance, then added to labware such as a beaker,
flask, test tube, or glass plate. If necessary, 1,1-dichloroethane may be diluted with water or mixed with
another laboratory chemical to form a solution. Analytical tests may be performed such as extraction,
distillation, chromatography, titration, filtration, or spectroscopy ( 2023).
1,1-Dichloroethane is used for analytical standards, research, and equipment calibration and sample
preparation applications. A critical use of 1,1-dichloroethane is a reference sample for analysis of
terrestrial and extraterrestrial material samples (EPA-HQ-QPPT-2018-0426-0026). Multiple safety data
sheets obtained by EPA described the concentration of 1,1-dichloroethane in gaseous and liquid
laboratory products. The concentrations of 1,1-dichloroethane in laboratory chemicals range from 0.01
to <=100 percent (Siema-Aldrich. 2020; Restek Corporation. 2019; Spex Certiprep. 2019; PerkinElmer
Inc. 2018; Phenova. 201S, \iu iv ^ v \ 1 U I , I , \ S» * * ^ > ierica. 2014).
Figure 5-5 below highlights typical release and exposure points during the use of laboratory chemicals.
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Environmental Releases:
1. Release to air from transferring volatile chemicals from transport containers.
2. Release to air, water, incineration, or landfill from transferring solid powders.
3. Release to water, incineration, or land from cleaning or disposal of transport containers.
4. Release to air from cleaning containers used for volatile chemicals.
5. Labware equipment cleaning residuals released to water, incineration, or landfill.
6. Release to air during labware equipment cleaning for volatile chemicals.
7. Release to air from laboratory analyses for volatile chemicals.
8. Release to water, incineration, or landfill from laboratory waste disposal.
Occupational Exposures:
A. Full-shift inhalation and dermal exposure from all activities.
B. Inhalation and dermal exposure from unloading chemicals from transport containers (if full-shift estimates are not
used).
C. Inhalation and dermal exposure during container cleaning throughout sample preparation and testing activities (if
full-shift estimates are not used).
D. Inhalation and dermal exposure during equipment cleaning (if full-shift estimates are not used).
E. Inhalation and dermal exposure during laboratory analyses (if full-shift estimates are not used).
F. Inhalation and dermal exposure during disposal of laboratory chemicals (non-quantifiable).
Figure 5-5. Typical Release and Exposure Points During the Laboratory Use of 1,1-
Dichloroethane (U.S. EPA, 2023)
5.5.2 Facility Estimates
EPA identified four relevant facilities in DMR and NEI. One of the facilities reported a release estimate
that was below the LOD in DMR. Due to the lack of data on the annual PV of 1,1-dichloroethane as a
laboratory chemical, EPA does not present annual or daily site throughputs. Almost all manufactured
1,1-dichloroethane is used for processing as a reactant, and only a small amount is used for laboratory
use (RTVMx-2007)- The environmental releases and occupational exposures during the laboratory use of
1,1-dichloroethane were modeled. As a conservative estimate, EPA assumes an annual 1,1-
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dichloroethane production volume of 50,000 lb and a distribution of 43 to 138 sites. EPA additionally
assumes between 174 and 260 (default) days of operation according to the Use of Laboratory Chemicals
GS ( 2023).
5.5.3 Release Assessment
5.5.3.1 Environmental Release Points
EPA expects releases to occur during the use of 1,1-dichloroethane as a laboratory chemical. EPA
estimated releases using a Monte Carlo simulation with 100,000 iterations and the Latin Hypercube
sampling method using the models and approaches described in Appendix E. Input parameters and
release points for the models were determined using data from literature and the Use of Laboratory
Chemicals—Generic Scenario for Estimating Occupational Exposures and Environmental Releases
(I 5). Specific release sources considered for estimating releases are shown numbered as 1
through 8 in Figure 5-5. Per the GS, EPA expects fugitive or stack air releases from unloading
containers, cleaning containers, cleaning laboratory equipment, and performing laboratory analyses.
Additionally, EPA expects releases to incineration or landfill.
5.5.3.2 Environmental Release Assessment Results
EPA estimated releases using a Monte Carlo simulation with 100,000 iterations and the Latin Hypercube
sampling method using the models and approaches described in Appendix E for this OES. Input
parameters for the models were determined using data from literature and the Use of Laboratory
Chemicals—Generic Scenario for Estimating Occupational Exposures and Environmental Releases
(I £023). EPA estimated 1,1-dichloroethane releases by simulating a scenario of an annual
production volume of 1,1-dichloroethane of 50,000 lb across all laboratories. Table 5-14 summarizes the
estimated release results for 1,1-dichloroethane use in laboratory chemicals based on the scenario
applied. The high-ends are the 95th percentile of the respective simulation output and the central
tendencies are the 50th percentile.
Table 5-14. Summary of Modeled Environmental Releases for the Commercial Use of 1,1-
Dichloroethane as a Laboratory Chemical
Modeled
Scenario
Environmental Media
Annual Release
(kg/site-yr)
Number of Release
Days3
Daily Release
(kg/site-day)
Central
Tendency
High-End
Central
Tendency
High-End
Central
Tendency
High-End
50,000 lb.
production
volume
Fugitive or Stack Air
1.7E01
3.0E01
235
258
7.4E-02
1.3E-01
Hazardous landfill or
incineration
5.0E02
8.8E02
235
258
2.2
3.7
a The number of release days presented in this table is based on simulation outputs for the annual release divided by the
daily release (grouped by high-end or central tendency estimate), rounded to the closest integer. Annual totals may not
add exactly due to rounding.
5.5.3.3 Weight of Scientific Evidence for Environmental Releases
EPA identified two facilities reporting water and air releases of 1,1-dichloroethane, However, EPA
determined this data is not sufficient to capture the entirety of environmental releases for this scenario.
Therefore, releases to the environment are assessed using the Draft GS on the Use of Laboratory
Chemicals, which has a high data quality rating from the systematic review process ( 13).
EPA used EPA/OPPT models combined with Monte Carlo modeling to estimate releases to the
environment, with media of release assessed using assumptions from the ESD and EPA/OPPT models.
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EPA assumed that the media of release for disposal of laboratory waste is to hazardous waste landfill or
incineration.
EPA believes a strength of the Monte Carlo modeling approach is that variation in model input values
and a range of potential releases values is more likely than a discrete value to capture actual releases at
sites. EPA believes the primary limitation to be the uncertainty in the representativeness of values
toward the true distribution of potential releases. In addition, EPA lacks 1,1-dichloroethane laboratory
chemical throughput data and number of laboratories; therefore, number of laboratories and throughput
estimates are based on stock solution throughputs from the Draft GS on the Use of Laboratory
Chemicals and on CDR reporting thresholds.
Based on this information, EPA has concluded that the weight of scientific evidence for this assessment
is moderate and provides a plausible estimate of releases in consideration of the strengths and limitations
of reasonably available data.
5,5,4 Occupational Exposure Assessment
5.5.4.1 Worker Activities
During the use of 1,1-dichloroethane as a laboratory chemical, workers are potentially exposed to 1,1-
dichloroethane during the following activities: transferring 1,1-dichloroethane from transport containers
to labware, laboratory sampling/analyses, and laboratory container/equipment cleaning. During these
activities workers may be exposed via inhalation of vapor or dermal contact with 1,1-dichloroethane.
According to the Vinyl Institute Test Order Report, workers in laboratory areas wear the following
standard PPE: fire-resistant clothing, lab coat, safety glasses, chemical splash goggles, nitrile gloves, and
steel toed boots. The report also listed the following task-specific PPE: half-face dust respirator (when
adding dry standards), half face respirator with organic vapor cartridges (when standards are weighed on
benchtop), chemical splash goggles, face shield, and nitrile gloves (Stantec ChemRisk. 2023).
ONUs include employees (e.g., supervisors, managers) present at the laboratory site that do not directly
handle 1,1-dichloroethane. Therefore, the ONUs are expected to have lower inhalation exposures, lower
vapor-through-skin uptake, and no expected dermal exposure.
5.5.4.2 Number of Workers and Occupational Non-users
EPA used data from the Bureau of Labor Statistics (BLS) and the U.S. Census' Statistics of US
Businesses (SUSB) specific to the OES to estimate the number of workers and ONUs per site potentially
exposed to 1,1-dichloroethane during its use as a laboratory chemical (I v v , I v t ensus
Bureau. 2015). This approach involved the identification of relevant Standard Occupational
Classification (SOC) codes within the BLS data for the identified NAICS codes. Appendix A includes
further details regarding methodology for estimating the number of workers and ONUs per site. EPA
assigned the following NAICS codes for this OES:
• 541380: Testing Laboratories
• 541713: Research and Development in Nanotechnology
• 541714: Research and Development in Biotechnology (except Nanobiotechnology)
• 541713: Research and Development in the Physical, Engineering, and Life Sciences (Except
Nanotechnology and Biotechnology)
Table 5-15 summarizes the per site estimates for this OES based on the methodology described,
including the potential number of sites identified in Section 5.5.2.
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Table 5-15. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During the
Commercial Use as a Laboratory Chemical
Potential Number of Sites
NAICS Code
Estimated Average
Exposed Workers per
Site0
Estimated Average
Exposed Occupational
Non-users per Site"
43-138
541380: Testing
Laboratories
2
16
541713- Research and
Development in
Nanotechnology
541714- Research and
Development in
Biotechnology (except
Nanobiotechnology)
541713- Research and
Development in the
Physical, Engineering, and
Life Sciences (Except
Nanotechnology and
Biotechnology)
a Number of workers and occupational non-users per site are calculated by dividing the exposed number of workers or
occupational non-users by the number of establishments.
5.5.4.3 Occupational Inhalation Exposure Results
Occupational inhalation data for 1,1-dichloroethane during the manufacturing process were provided via
a test order submission from the Vinyl Institute, which includes manufacturers and processors of 1,1-
dichloroethane. During the manufacturing process, EPA identified nine worker full-shift samples for
laboratory technicians. While there may be some difference between the activities between laboratory
technicians during the manufacturing process and the commercial laboratory use OES, EPA assumes the
laboratory exposures to be similar.
From this monitoring data, EPA calculated the 50th and 95th percentile 8-hr TWA concentrations to
represent a central tendency and high-end estimate of potential occupational inhalation exposures,
respectively, for this scenario. Using these 8-hr TWA exposure concentrations, EPA calculated the AC,
ADCsubchronic, ADC, and LADC as described in Appendix B. The results of these calculations are shown
in Table 5-16.
Table 5-16. Inhalation Exposures to 1,1-Dichloroethane During Commercial Use of Laboratory
Chemicals
Exposure Type
Worker Inhalation
Estimates (ppm)
ONU Inhalation
Estimates (ppm)
High-End
Central
Tendency
High-End
Central
Tendency
8-hour TWA Exposure Concentrations
2.4E-02
1.1E-03
1.1E-03
1.1E-03
Acute Exposure Concentrations (AC)
1.6E-02
7.7E-04
7.7E-04
7.7E-04
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Exposure Type
Worker Inhalation
Estimates (ppm)
ONU Inhalation
Estimates (ppm)
High-End
Central
Tendency
High-End
Central
Tendency
Subchronic Average Daily Concentration (ADCSUbchromc)
1.0E-02
5.7E-04
5.7E-04
5.7E-04
Average Daily Concentration (ADC)
1.1E-02
3.7E-04
5.3E-04
3.7E-04
Lifetime Average Daily Concentration (LADC)
5.6E-03
1.5E-04
2.7E-04
1.5E-04
For comparison, EPA referenced the 2022 Draft GS on the Use of Laboratory Chemicals (
2023). which listed surrogate data from 1,4-dioxane, methylene chloride, NMP, and PCE.
The GS presents the following two options:
1. Compare the molecular weight and vapor pressure for the chemical of interest to the available
surrogate data listed in Table 5-4 of the GS for 1,4-dioxane, methylene chloride, NMP, and PCE.
2. If the chemical of interest is not comparable in molecular weight and vapor pressure to the
chemicals in Table 5-4, EPA recommends assessing an exposure concentration of 0.87 ppm
(central tendency) to 8.18 ppm (high-end) for workers based on all available data in that table.
1,4-Dioxane and methylene chloride are the closest in molecular weight and vapor pressure to 1,1-
dichloroethane, although, they are not a direct match. Therefore, EPA used the highest values between
option one (1,4-dioxane and methylene chloride data) and option two to determine the exposure
estimates presented in Table 5-17 (U.S. EPA. 20201 h).
Table 5-17. Inhalation Exposures to 1,1-Dichloroethane During Commercial Use of Laboratory
Chemicals Using Surrogate Data
Exposure Type
Worker Inhalation Estimates
(ppm)
ONU Inhalation Estimates
(ppm)
High-End
Central
Tendency
High-End
Central
Tendency
8-hour TWA Exposure
Concentrations
15
0.90
0.90
The surrogate data resulted in high-end inhalation estimates of 15 ppm, which is several orders of
magnitude higher than the estimate of 2.4x 10~2 ppm.
5.5.4.4 Occupational Dermal Exposure Results
EPA estimated dermal exposures for this OES using the Dermal Exposure to Volatile Liquid Model and
a fraction absorbed value of 0.3 percent. The maximum concentration evaluated for this dermal exposure
is 100% since 1,1-dichloroethane is expected to be received at the site in pure form. Table 5-18
summarizes the APDR, ARD, SCDD, CRD (non-cancer), and CRD (cancer) for 1,1-dichloroethane
during commercial use as a laboratory chemical. The high-ends are based on a higher loading rate of
1,1-dichloroethane (2.1 mg per cm2 per event) and two-hand contact, and the central tendencies are
based on a lower loading rate of 1,1-dichloroethane (1.4 mg per cm2 per event) and one-hand contact.
OES-specific parameters for dermal exposures are described in Appendix D.
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Table 5-18. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Commercial Use as a
Laboratory Chemical
Modeled
Scenario
Exposure Concentration Type
High-End
Central
Tendency
Average
Adult
Worker"
Acute Potential Dose Rate (APDR) (mg/day)
6.7
2.3
Acute Retained Dose (ARD) (mg/kg-day)
8.0E-02
3.0E-02
Subchronic Average Daily Dose (SCDD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), cancer (mg/kg-day)
3.0E-02
1.0E-02
a Conditions where no gloves are used, or for any glove / gauntlet use without permeation data and without
employee training (PF =1).
5.5.4.5 Weight of Scientific Evidence for Occupational Exposures
EPA considered the assessment approach, the quality of the data, and uncertainties in assessment results
to determine a weight of scientific evidence conclusion for the 8-hr TWA inhalation exposure estimates.
EPA used inhalation data to assess inhalation exposures. The primary strength of these data is the use of
personal and potentially applicable data. The primary limitation is the number of samples available for
workers. Data was not available for ONUs. Additionally, there is uncertainty in the representativeness of
these data toward the true distribution of inhalation concentrations in this scenario since the laboratory
use occurred in a manufacturing setting. EPA assumed 250 exposure days per year based on 1,1-
dichloroethane exposure each working day for a typical worker schedule; it is uncertain whether this
captures actual worker schedules and exposures.
Based on these strengths and limitations, EPA has concluded that the weight of scientific evidence for
this assessment is moderate and provides a plausible estimate of exposures in consideration of the
strengths and limitations of reasonably available data.
EPA estimated dermal exposures using modeling methodologies, which are supported by moderate
evidence. EPA used the EPA Dermal Exposure to Volatile Liquids to calculate the dermal retained dose.
This model modifies the EPA/OPPT 2-Hand Dermal Exposure to Liquids Model by incorporating a
"fraction absorbed (fabs)" parameter to account for the evaporation of volatile chemicals. These
modifications improve the modeling methodology; however, the modeling approach is still limited by
the low variability for different worker activities/exposure scenarios. Therefore, the weight of scientific
for the modeling methodologies is moderate.
The exposure scenarios and exposure factors underlying the dermal assessment are supported by
moderate to robust evidence. Dermal exposure scenarios were informed by moderate to robust process
information and GS/ESD. Exposure factors for occupational dermal exposure include amount of
material on the skin, surface area of skin exposed, and absorption of 1,1-dichloroethane through the
skin. These exposure factors were informed by literature sources, the ChemSTEER User Guide (H.S.
) for standard exposure parameters, and a European model, with ratings from moderate to
robust. Based on these strengths and limitations, EPA concluded that the weight of scientific evidence
for the dermal exposure assessment is moderate to robust for all OES.
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5.6 Waste Handling, Treatment, and Disposal
5.6,1 Process Description
Each of the conditions of use of 1,1-dichloroethane may generate waste streams of the chemical that are
collected and transported to third-party sites for disposal or treatment, and these cases are assessed under
this condition of use. Industrial sites that treat or dispose onsite wastes that they themselves generate are
assessed within that relevant condition of use assessment. Similarly, point source discharges of 1,1-
dichloroethane to surface water are assessed within that relevant condition of use in Sections 5.1 through
5.6 (point source discharges are exempt as solid wastes under RCRA). Remediation is also included in
this condition of use, which involves the containment and mitigation of contaminations following
environmental incidents. Remediation sites that release 1,1-dichloroethane were identified based on
2015 to 2020 DMR data. Some of these sites were listed on the EPA RCRA Corrective Action (CA)
sites list. Wastes of 1,1-dichloroethane that are generated during a condition of use and sent to a third-
party site for treatment, disposal, or recycling may include the following:
• Wastewater: 1,1-Dichloroethane may be contained in wastewater discharged to POTW or other,
non-public treatment works for treatment. Industrial wastewater containing 1,1-dichloroethane
discharged to a POTW may be subject to EPA or authorized NPDES state pretreatment
programs. The assessment of wastewater discharges to POTWs and non-public treatment works
of 1,1-dichloroethane is included in each of the condition of use assessments in Sections 5.1
through 5.6.
• Solid Wastes: Solid wastes are defined under RCRA as any material that is discarded by being
abandoned, inherently waste-like, a discarded military munition, or recycled in certain ways
(certain instances of the generation and legitimate reclamation of secondary materials are
exempted as solid wastes under RCRA). Solid wastes may subsequently meet RCRA's definition
of hazardous waste by either being listed as a waste at 40 CFR 261.30 to 261.35 or by meeting
waste-like characteristics as defined at 40 CFR 261.20 to 261.24. Solid wastes that are hazardous
wastes are regulated under the more stringent requirements of Subtitle C of RCRA, whereas non-
hazardous solid wastes are regulated under the less stringent requirements of Subtitle D of
RCRA.
• 1,1-Dichloroethane is a U-listed hazardous waste under code U076 under RCRA: therefore,
discarded, unused pure and commercial grades of 1,1-dichloroethane are regulated as a
hazardous waste under RCRA (40 CFR 261.33(f)).
• Wastes Exempted as Solid Wastes under RCRA: Certain conditions of use of 1,1-dichloroethane
may generate wastes of 1,1-dichloroethane that are exempted as solid wastes under 40 CFR
261.4(a). For example, the generation and legitimate reclamation of hazardous secondary
materials of 1,1-dichloroethane may be exempt as a solid waste.
2020 TRI data lists off-site transfers of 1,1-dichloroethane to land disposal, wastewater treatment,
incineration, and recycling facilities. About 57% of off-site transfers were sent to wastewater treatment,
38% were recycled off-site, 4% were incinerated, and less than 1% is sent to land disposal (U.S. EPA.
2017b). Since almost all manufactured 1,1-dichloroethane is reacted in the production of other
chemicals, waste containing 1,1-dichloroethane will primarily be received from laboratory use sites
(RIVM. 2007Y
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Recycling
:«
Hazardous Waste Hazardous Waste V. |
Generation Transportation
Treatment
IIP*I-83®
r •—i ^ ^ Disp°«'
Figure 5-6. Typical Waste Disposal Process (U.S. EPA, 2017a)
Municipal Waste Incineration
Municipal waste combustors (MWCs) that recover energy are generally located at large facilities
comprising an enclosed tipping floor and a deep waste storage pit. Typical large MWCs may range in
capacity from 250 to over 1,000 tons per day. At facilities of this scale, waste materials are not generally
handled directly by workers. Trucks may dump the waste directly into the pit, or waste may be tipped to
the floor and later pushed into the pit by a worker operating a front-end loader. A large grapple from an
overhead crane is used to grab waste from the pit and drop it into a hopper, where hydraulic rams feed
the material continuously into the combustion unit at a controlled rate. The crane operator also uses the
grapple to mix the waste within the pit, in order to provide a fuel consistent in composition and heating
value, and to pick out hazardous or problematic waste.
Facilities burning refuse-derived fuel (RDF) conduct on-site sorting, shredding, and inspection of the
waste prior to incineration to recover recyclables and remove hazardous waste or other unwanted
materials. Sorting is usually an automated process that uses mechanical separation methods, such as
trommel screens, disk screens, and magnetic separators. Once processed, the waste material may be
transferred to a storage pit, or it may be conveyed directly to the hopper for combustion.
Tipping floor operations may generate dust. Air from the enclosed tipping floor, however, is
continuously drawn into the combustion unit via one or more forced air fans to serve as the primary
combustion air and minimize odors. Dust and lint present in the air is typically captured in filters or
other cleaning devices in order to prevent the clogging of steam coils, which are used to heat the
combustion air and help dry higher-moisture inputs ( Citto and Stu'ltz. 1992).
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Hazardous Waste Incineration
Commercial scale hazardous waste incinerators are generally two-chamber units, a rotary kiln followed
by an afterburner, that accept both solid and liquid waste. Liquid wastes are pumped through pipes and
are fed to the unit through nozzles that atomize the liquid for optimal combustion (Figure 5-7). Solids
may be fed to the kiln as loose solids gravity fed to a hopper, or in drums or containers using a conveyor
(ETC Hazardous Waste Resources Center. 2018); (Heritage. 2018).
Incoming hazardous waste is usually received by truck or rail, and an inspection is required for all waste
received. Receiving areas for liquid waste generally consist of a docking area, pumphouse, and some
kind of storage facilities. For solids, conveyor devices are typically used to transport incoming waste
(Kitto and Stultz. 1992); (ETC Hazardous Waste Resources Center. 2018)
Smaller scale units that burn municipal solid waste or hazardous waste (such as infectious and hazardous
waste incinerators at hospitals) may require more direct handling of the materials by facility personnel.
Units that are batch-loaded require the waste to be placed on the grate prior to operation and may
involve manually dumping waste from a container or shoveling waste from a container onto the grate.
Disposal Disposal
Figure 5-7. Typical Industrial Incineration Process
Municipal Waste Landfill
Municipal solid waste landfills are discrete areas of land or excavated sites that receive household
wastes and other types of non-hazardous wastes (e.g., industrial and commercial solid wastes).
Standards and requirements for municipal waste landfills include location restrictions, composite liner
requirements, leachate collection and removal system, operating practices, groundwater monitoring
requirements, closure-and post-closure care requirements, corrective action provisions, and financial
assurance. Non-hazardous solid wastes are regulated under RCRA Subtitle D, but states may impose
more stringent requirements.
Municipal solid wastes may be first unloaded at waste transfer stations for temporary storage, prior to
being transported to the landfill or other treatment or disposal facilities.
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Hazardous Waste Landfill
Hazardous waste landfills are excavated or engineered sites specifically designed for the final disposal
of non-liquid hazardous wastes. Design standards for these landfills require double liner, double leachate
collection and removal systems, leak detection system, run on, runoff and wind dispersal controls, and
construction quality assurance program ( 2018b). There are also requirements for closure and
post-closure, such as the addition of a final cover over the landfill and continued monitoring and
maintenance. These standards and requirements prevent potential contamination of groundwater and
nearby surface water resources. Hazardous waste landfills are regulated under Part 264/265, Subpart N.
5.6.2 Facility Estimates
Using release data, EPA identified 672 non-POTW (general) and 125 POTW facilities under this OES.
Additionally, EPA identified 42 remediation sites that release 1,1-dichloroethane based on DMR data.
Due to the lack of data on the annual PV of 1,1-dichloroethane for waste handling, treatment, and
disposal, EPA does not present annual or daily site throughputs. EPA did not identify data on facility
operating schedules; therefore, EPA assumes 250 days/yr of operation as discussed in Section 2.3.2.
5.6.3 Release Assessment
5.6.3.1 Environmental Release Points
Sources of potential environmental release include the unloading of solid or liquid waste containers.
Releases may occur while connecting and disconnecting of transfer lines and hoses, and during the
treatment of waste. EPA expects releases to air of volatile 1,1-dichloroethane during waste handling,
treatment, and disposal. Additionally, EPA expects releases of solid or liquid waste to land.
5.6.3.2 Environmental Release Assessment Results
EPA used 2015 to 2020 DMR, 2015 to 2020 TRI, and 2017 NEI to estimate environmental releases
during general waste handling, treatment, and disposal, as presented in Table 5-19. For non-POTW, 1,1-
dichloroethane is released through the following environmental media: surface water, fugitive air, and
stack air.
Table 5-19. Summary of Environmental Releases During General Waste Handling, Treatment,
and Disposal
Environmental
Media
Estimated Yearly Release
Range across Sites (kg/yr)
Number
of
Release
Days
Daily Release
(kg/site-day)
Number
of
Facilities
Source(s)
Central
Tendency
High-End
Central
Tendency
High-
End
Surface water
9.3E-04
6.0E-03
250
3.7E-06
2.4E-05
22
TRI/DMR
Fugitive air
0.63
7.3
2.5E-03
2.9E-02
7
TRI
Fugitive air
34
202
0.14
0.81
575
NEI
Stack air
1.8E-02
0.82
7.3E-05
3.3E-03
8
TRI
Stack air
2.5
134
1.0E-02
0.54
153
NEI
EPA used 2015 to 2020 DMR to estimate environmental releases during Waste handling, treatment, and
disposal (POTW), as presented in Table 5-20.
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Table 5-20. Summary of Environmental Releases During Waste Handling, Treatment, and
Disposal (POTW)
Environmental
Media
Estimated Yearly
Release Range across
Sites (kg/yr)
Number
of
Release
Days
Daily Release
(kg/site-day)
Number
of
Facilities
Source(s)
Central
Tendency
High-End
Central
Tendency
High-
End
Surface water
5.1E-03
8.9E-02
365
1.4E-05
2.4E-04
126
DMR
EPA used 2015 to 2020 DMR to estimate environmental releases during waste handling, treatment, and
disposal (remediation), as presented in Table 5-21. For remediation, 1,1-dichloroethane is released
through the surface water.
Table 5-21. Summary of Environmental Releases During Waste Handling, Treatment, and
Disposal (Remediation)
Environmental
Media
Estimated Yearly
Release Range across
Sites (kg/yr)
Number
of
Release
Days
Daily Release
(kg/site-day)
Number
of
Facilities
Source(s)
Central
Tendency
High-End
Central
Tendency
High-
End
Surface water
2.9E-04
8.5E-03
250
8.0E-07
2.3E-05
42
DMR
5.6.3.3 Weight of Scientific Evidence for Environmental Releases
General Waste Handling, Treatment, and Disposal
Water releases for non-POTW sites are assessed using reported releases from 2015 to 2020 TRI and
DMR. The primary strength of TRI data is that TRI compiles the best readily available release data for
all reporting facilities. For non-POTW sites, the primary limitation is that the water release assessment is
based on 22 reporting sites, and EPA did not have additional sources to estimate water releases from this
OES. Based on other reporting databases such as NEI, there are additional sites that are not accounted
for in this assessment.
Air releases for non-POTW sites are assessed using reported releases from 2015 to 2020 TRI, and 2014
and 2017 NEI. A strength of NEI data is that NEI captures additional sources that are not included in
TRI due to reporting thresholds. Factors that decrease the confidence for this OES include the
uncertainty in the accuracy of reported releases, and the limitations in representativeness to all sites
because TRI and NEI may not capture all relevant sites. The air release assessment is based on 650
reporting sites. Based on other reporting databases (CDR and DMR), there are 22 additional non-POTW
sites that are not accounted for in this assessment. Additionally, EPA made assumptions on the number
of operating days to estimate daily releases. EPA found that major sources of air emissions of 1,1-
dichloroethane in landfills come from sources other than 1,1-dichloroethane COUs of Manufacture,
Processing, and Commercial Use, specifically, the decomposition of 1,1,1-trichloroethane. However, it
is unclear how much 1,1,1-trichloroethane is disposed to landfills and how much 1,1-dichloroethane is
generated.
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Based on this information, EPA has concluded that the weight of scientific evidence for this assessment
is moderate to robust and provides a plausible estimate of releases in consideration of the strengths and
limitations of reasonably available data.
Waste Handling, Treatment, and Disposal (POTW and Remediation)
Water releases for POTW and remediation sites are assessed using reported releases from 2015 to 2020
DMR, which has a medium overall data quality determination from the systematic review process.
However, the Variability and Uncertainty data quality metric was determined to be low. A strength of
using DMR data and the Pollutant Loading Tool is that the tool calculates an annual pollutant load by
integrating monitoring period release reports provided to the EPA and extrapolating over the course of
the year. However, this approach assumes average quantities, concentrations, and hydrologic flows for a
given period are representative of other times of the year. Based on this information, for POTW releases,
EPA has concluded that the weight of the scientific evidence for this assessment is moderate to robust
and provides a plausible estimate of releases in consideration of the strengths and limitations of
reasonably available data.
5.6.4 Occupational Exposure Assessment
5.6.4.1 Worker Activities
Workers are potentially exposed to 1,1-dichloroethane during waste handling, treatment and disposal
during the unloading and cleaning of transport containers. Workers may experience inhalation of vapor
or dermal contact with liquids during the unloading process. EPA did not find information that indicates
the extent that engineering controls and worker PPE are used at facilities that handle, treat, and dispose
of waste containing 1,1-dichloroethane in the United States.
ONUs include employees that work at the sites where waste containing 1,1-dichlrooethane is treated, but
they do not directly handle the chemical and are therefore expected to have lower inhalation exposures
and are not expected to have dermal exposures through contact with liquids or solids. ONUs for this
scenario include supervisors, managers, and other employees that may be in the waste handling or
treatment area but do not perform tasks that result in the same level of exposure as those workers that
engage in tasks related to the handling or treatment of waste containing 1,1-dichlroethane.
5.6.4.2 Number of Workers and Occupational Non-users
EPA used data from the Bureau of Labor Statistics (BLS) and the U.S. Census' Statistics of US
Businesses (SUSB) specific to the OES to estimate the number of workers and ONUs per site potentially
exposed to 1,1-dichloroethane during waste handling, treatment, and disposal (1; S HI S. 2016; U.S.
Census Bureau. 2015). This approach involved the identification of relevant Standard Occupational
Classification (SOC) codes within the BLS data for the identified NAICS codes. Appendix Aincludes
further details regarding methodology for estimating the number of workers and ONUs per site. EPA
assigned the following NAICS codes for this OES:
• 562211: Hazardous Waste Treatment and Disposal
• 562213: Solid Waste Combustors and Incinerators
• 325211: Plastics Material and Resin Manufacturing
• 327310: Cement Manufacturing
• 327992: Ground Treated Mineral and Earth Manufacturing
• 221320: Sewage Treatment Facilities
Table 5-22 summarizes the per site estimates for this OES based on the methodology described,
including the potential number of sites identified in Section 5.6.2.
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Table 5-22. Estimated Number of Workers Potentially Exposed to 1,1-Dichloroethane During
Waste Handling, Disposal, and Treatment
Potential Number of Sites
NAICS Code
Estimated Average
Exposed Workers per
Site"
Estimated Average
Exposed Occupational
Non-users per Site"
562211: Hazardous Waste
Treatment and Disposal
562213: Solid Waste
Combustors and
Incinerators
672
325211: Plastics Material
and Resin Manufacturing
49
15
327310: Cement
Manufacturing
327992: Ground Treated
Mineral and Earth
Manufacturing
125
221320: Sewage Treatment
Facilities
24
12
a Number of workers and occupational non-users per site are calculated by dividing the exposed number of workers
or occupational non-users by the number of establishments.
5.6.4.3 Occupational Inhalation Exposure Results
No monitoring data were found for workers or ONUs during waste handling, treatment, and disposal of
1,1-dichloroethane. Therefore, EPA used surrogate data from 1,2-dichloroethane, as well as other
volatile liquids assessed in previous EPA Risk Evaluations to use as surrogate monitoring data for the
same OES ( 2024).
For general waste handling, treatment and disposal OES, EPA identified 22 full-shift worker samples
from methylene chloride. For the waste handling, treatment, and disposal (POTW) OES, EPA identified
three full-shift worker samples from 1,2-dichloroethane. In both cases, the OES are directly analogous;
therefore, EPA expects the process and associated exposure points to be the same or similar. EPA
applied a vapor correction factor when determining the exposure estimates for these OES. EPA did not
assess occupational exposures during remediation of 1,1-dichloroethane.
From this monitoring data, EPA calculated the 50th and 95th percentile 8-hr TWA concentrations to
represent a central tendency and high-end estimate of potential occupational inhalation exposures,
respectively, for this scenario. Using these 8-hr TWA exposure concentrations, EPA calculated the AC,
ADCsubchronic, ADC, and LADC as described in Appendix B. The results of these calculations are shown
in Table 5-23 and Table 5-24.
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2402 Table 5-23. Inhalation Exposures of Workers to 1,1-Dichloroethane During General Waste
2403 Handling, Treatment, and Disposal
Exposure Type
Worker Inhalation
Estimates (ppm)
ONU Inhalation Estimates
(ppm)
High-End
Central
Tendency
High-End
Central
Tendency
8-hour TWA Exposure Concentrations
10
0.30
0.30
0.30
Acute Exposure Concentrations (AC)
7.1
0.20
0.20
0.20
Subchronic Average Daily Concentration
(ADCsubchronic)
5.2
0.15
0.15
0.15
Average Daily Concentration (ADC)
4.9
0.14
0.14
0.14
Lifetime Average Daily Concentration
(LADC)
2.5
5.5E-02
7.1E-02
5.5E-02
2404
2405 Table 5-24. Inhalation Exposures of Workers to 1,1-Dichloroethane During Waste Handling,
2406 Treatment, and Disposal (POTW)
Exposure Type
Worker Inhalation
Estimates (ppm)
ONU Inhalation Estimates
(ppm)
High-End
Central
Tendency
High-End
Central
Tendency
8-hour TWA Exposure Concentrations
0.68
0.25
0.25
0.25
Acute Exposure Concentrations (AC)
0.46
0.17
0.17
0.17
Subchronic Average Daily Concentration
(ADCsubchronic)
0.34
0.13
0.13
0.13
Average Daily Concentration (ADC)
0.32
0.12
0.12
0.12
Lifetime Average Daily Concentration
(LADC)
0.16
4.7E-02
6.1E-02
4.7E-02
2407
2408 5.6.4.4 Occupational Dermal Exposure Results
2409 EPA estimated dermal exposures for this OES using the Dermal Exposure to Volatile Liquid Model and
2410 a fraction absorbed value of 0.3 percent. The maximum concentration evaluated for this dermal exposure
2411 is 100% since 1,1-dichloroethane is expected to be received at the site in pure form. Table 5-25 and
2412 Table 5-26 summarize the APDR, ARD, SCDD, CRD (non-cancer), and CRD (cancer) for 1,1-
2413 dichloroethane during waste handling, treatment, and disposal (general and POTW). The high-ends are
2414 based on a higher loading rate of 1,1-dichloroethane (2.1 mg per cm2 per event) and two-hand contact,
2415 and the central tendencies are based on a lower loading rate of 1,1-dichloroethane (1.4 mg per cm2 per
2416 event) and one-hand contact. OES-specific parameters for dermal exposures are described in Appendix
2417 D.
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Table 5-25. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for General Waste
Handling, Treatment, and Disposal
Modeled
Scenario
Exposure Concentration Type
High-End
Central
Tendency
Average Adult
Worker"
Acute Potential Dose Rate (APDR) (mg/day)
6.7
2.3
Acute Retained Dose (ARD) (mg/kg-day)
8.0E-02
3.0E-02
Subchronic Average Daily Dose (SCDD), non-cancer (mg/kg-
day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), cancer (mg/kg-day)
3.0E-02
1.0E-02
a Conditions where no gloves are used, or for any glove/gauntlet use without permeation data and without employee
training (PF =1).
Table 5-26. Summary of Dermal Exposure Doses to 1,1-Dichloroethane for Waste Handling,
Treatment, ant
Disposal (POTW)
Modeled
Scenario
Exposure Concentration Type
High-End
Central
Tendency
Average Adult
Worker"
Acute Potential Dose Rate (APDR) (mg/day)
6.7
2.3
Acute Retained Dose (ARD) (mg/kg-day)
8.0E-02
3.0E-02
Subchronic Average Daily Dose (SCDD), non-cancer (mg/kg-
day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), non-cancer (mg/kg-day)
6.0E-02
2.0E-02
Chronic Retained Dose (CRD), cancer (mg/kg-day)
3.0E-02
1.0E-02
" Conditions where no gloves are used, or for any glove / gauntlet use without permeation data and without employee
training (PF =1).
5.6.4.5 Weight of Scientific Evidence for Occupational Exposures
General Waste Handling, Treatment, and Disposal
1,1-dichloroethane monitoring data was not available for this scenario. Additionally, EPA did not
identify 1,1-dichloroethane monitoring data from other scenarios. Therefore, EPA used surrogate
inhalation data from methylene chloride to assess inhalation exposures. The primary limitations of these
data include the uncertainty of the representativeness of these data toward the true distribution of
inhalation concentrations in this scenario since the data were surrogate from methylene chloride, which
results in a moderate confidence rating. EPA also assumed 250 exposure days per year based on 1,1-
dichloroethane exposure each working day for a typical worker schedule; it is uncertain whether this
captures actual worker schedules and exposures.
Based on these strengths and limitations, EPA has concluded that the weight of scientific evidence for
this assessment is moderate and provides a plausible estimate of exposures in consideration of the
strengths and limitations of reasonably available data.
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Waste Handling, Treatment, and Disposal (POTW)
EPA used inhalation data to assess inhalation exposures. The primary limitations of these data include
the uncertainty of the representativeness of these data toward the true distribution of inhalation
concentrations in this scenario since the data were surrogate from 1,2-dichloroethane, which results in a
low confidence rating. In addition, the available surrogate data only provided three worker inhalation
monitoring data samples for wastewater treatment. EPA also assumed 250 exposure days per year based
on 1,1-dichloroethane exposure each working day for a typical worker schedule; it is uncertain whether
this captures actual worker schedules and exposures.
Based on these strengths and limitations, EPA has concluded that the weight of scientific evidence for
this assessment is moderate and provides a plausible estimate of exposures in consideration of the
strengths and limitations of reasonably available data.
5.7 Detailed Strengths, Limitations, Assumptions, and Key Sources of
Uncertainties
5.7,1 Environmental Release Assessment
EPA estimated air, water, and land releases of 1,1-dichloroethane using various methods and
information sources, including TRI, DMR, and NEI data, and GSs modeling with Monte Carlo. TRI and
DMR were determined to have overall data quality ratings of medium through EPA's systematic review
process, and NEI was determined to have a high-quality rating. EPA determined that the various GS had
overall data quality ratings of high or medium, depending on the GS.
Strengths
TRI, DMR, and NEI provided a comprehensive amount of release data for 1,1-dichloroethane. A
strength of using TRI is that it compiles the best readily available release data for all facilities that
reported to EPA. NEI data captures additional sources that are not included in TRI due to reporting
thresholds. Additionally, point sources in NEI report at the emission-unit level. A strength of using
DMR data and the Pollutant Loading Tool is that the tool calculates an annual pollutant load by
integrating monitoring period release reports provided to the EPA and extrapolating over the course of
the year. However, this approach assumes average quantities, concentrations, and hydrologic flows for a
given period are representative of other times of the year.
Although 1,1-dichloroethane monitoring data are preferred to modeled data, EPA strengthened modeled
estimates by using Monte Carlo modeling to allow for variation in environmental release calculation
input parameters according to the GS and other literature sources.
Limitations
When using TRI data to analyze chemical releases, it is important to acknowledge that TRI reporting
does not include all releases of the chemical and therefore, the number of sites for a given OES may be
underestimated. For each OES that had TRI, DMR, or NEI data, the analysis of releases for those OES
was limited to the facilities that reported releases to TRI, DMR, or NEI. Therefore, it is uncertain the
extent to which sites not captured in these databases have air, water, or land releases of 1,1-
dichloroethane.
EPA was unable to map certain facilities in DMR and NEI to an OES due to the lack of information
regarding the activity of 1,1-dichloroethane at the site. Therefore, some facilities are mapped to an
"Unknown" OES.
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Assumptions
To assess daily air and water discharges, EPA assumed that the number of facility operating days was
equal to the number of release days. EPA has developed generic estimates of operating days for a
particular OES, as described in Section 2.3.2. For the Commercial use of laboratory chemicals OES,
EPA assumed the number of operating days based on the Draft GS on Use of Laboratory Chemicals.
There is uncertainty that all sites for a given OES operate for the assumed duration; therefore, the
average daily releases may be higher if sites have fewer release days or lower if they have greater
release days. Furthermore, 1,1-dichloroethane concentrations in air emissions and wastewater release to
receiving waterbodies at each facility may vary from day-to-day such that on any given day the actual
daily releases may be higher or lower than the estimated average daily discharge. Thus, this approach
minimizes variations in emissions and discharges from day to day. EPA did not estimate daily land
releases due to the high level of uncertainty in the number of release days associated with land releases.
The Agency expects that sites may not send waste to landfills every day and are more likely to
accumulate waste for periodic shipments to landfills. However, sites that release to municipal landfills
may have more frequent release days based on the frequency of shipments.
Uncertainties
Uncertainties for using TRI, DMR, and NEI data include underestimation of the number of sites for a
given OES due to reporting thresholds in TRI, the accuracy of EPA's mapping of sites reporting to TRI,
DMR, and NEI to a specific OES, and quality of the data reported to TRI, DMR, and NEI.
Some uncertainties of using DMR data include the accuracy of EPA's mapping of sites reporting to
DMR to a specific OES, and quality of the data reported to DMR. Also, an uncertainty of using the
ECHO Pollutant Loading Tool Advanced Search option is that average measurements may be reported
as a quantity (kg/day) or a concentration (mg/L). Calculating annual loads from concentrations requires
adding wastewater flow to the equation, which increases the uncertainty of the calculated annual load. In
addition, for facilities that reported having zero pollutant loads to DMR, the EZ Search Load Module
uses a combination of setting non-detects equal to zero and as one-half the detection limit to calculate
the annual pollutant loadings. This method could cause overestimation or underestimation of annual and
daily pollutant loads.
Some uncertainties of using NEI data include the accuracy of EPA's mapping of sites reporting to NEI
to a specific OES. For point sources, there may be multiple OES at a single facility. Area/non-point
sources are aggregated on a county level. Additionally, there is uncertainty due to the voluntary
reporting of HAP data. As a result, EPA augments SLT-provided HAP data with other information to
better estimate point, nonpoint, and mobile source HAP emissions. NEI does not require stack testing or
continuous emissions monitoring, and reporting agencies may use a number of different emission
estimation methods with varying degrees of reliability. These methodologies include continuous
emissions monitoring, stack testing, site- and vendor-specific emission factors, SLT and/or other
emission factors, and engineering judgement.
One uncertainty for using various GS is the lack of specific 1,1-dichloroethane data. Because GS are
generic, assessed parameter values may not always be representative of applications specific to 1,1-
dichloroethane use in each OES. Another uncertainty is lack of consideration for release controls. The
GS assume that all activities occur without any release controls, and in an open-system environment
where vapor freely escape (U.S. EPA. 2023. 2022a). Actual releases may be less than estimated if
facilities utilize pollution control methods.
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In some cases, the number of facilities for a given OES was estimated using data from the U.S. Census.
In such cases, the average daily release calculated from sites reporting to TRI, NEI or DMR was applied
to the total number of sites reported in ( isus Bureau. 2015). It is uncertain how accurate this
average release is to actual releases at these sites; therefore, releases may be higher or lower than the
calculated amount.
5.7.2 Occupational Exposure Assessment
5.7.2.1 Number of Workers
There are several uncertainties surrounding the estimated number of workers potentially exposed to 1,1-
dichloroethane, as outlined below. Most are unlikely to result in a systematic underestimate or
overestimate but could result in an inaccurate estimate.
CDR data are used to estimate the number of workers associated with manufacturing. There are inherent
limitations to the use of CDR data as they are reported by manufacturers and importers of 1,1-
dichloroethane. Manufacturers and importers are only required to report if they manufactured or
imported 1,1-dichloroethane in excess of 25,000 lb at a single site during any calendar year; as such,
CDR may not capture all sites and workers associated with any given chemical.
There are also uncertainties with BLS data, which are used to estimate the number of workers for the
remaining conditions of use. First, BLS' OES employment data for each industry/occupation
combination are only available at the 3-, 4-, or 5-digit NAICS level, rather than the full 6-digit NAICS
level. This lack of granularity could result in an overestimate of the number of exposed workers if some
6-digit NAICS are included in the less granular BLS estimates but are not likely to use 1,1-
dichloroethane for the assessed applications. EPA addressed this issue by refining the OES estimates
using total employment data from the U.S. Census' SUSB. However, this approach assumes that the
distribution of occupation types (SOC codes) in each 6-digit NAICS is equal to the distribution of
occupation types at the parent 5-digit NAICS level. If the distribution of workers in occupations with
1,1-dichloroethane exposure differs from the overall distribution of workers in each NAICS, then this
approach will result in inaccuracy.
Second, EPA's judgments about which industries (represented by NAICS codes) and occupations
(represented by SOC codes) are associated with the uses assessed in this report are based on EPA's
understanding of how 1,1-dichloroethane is used in each industry. Designations of which industries and
occupations have potential exposures is nevertheless subjective, and some industries/occupations with
few exposures might erroneously be included, or some industries/occupations with exposures might
erroneously be excluded. This would result in inaccuracy but would be unlikely to systematically either
overestimate or underestimate the number of exposed workers.
5.7.2.2 Analysis of Exposure Monitoring Data
For several of the OES, 1,1-dichloroethane test order monitoring data was used to estimate inhalation
exposures. The primary strength of these data is the use of personal and directly applicable data, and the
number of samples available for workers and ONUs. The primary limitation is that EPA assumed 250
exposure days per year based on 1,1-dichloroethane exposure each working day for a typical worker
schedule; it is uncertain whether this captures actual worker schedules and exposures.
For the remaining OES, monitoring data from other volatile chemicals previously assessed in EPA Risk
Evaluations were used as surrogate. The principal limitation of the monitoring data is the uncertainty in
the representativeness of the data. Where few data are available, the assessed exposure levels are
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unlikely to be representative of worker exposure across the entire job category or industry. This may
particularly be the case when monitoring data were available for only one site. Differences in work
practices and engineering controls across sites can introduce variability and limit the representativeness
of monitoring data. Age of the monitoring data can also introduce uncertainty due to differences in
workplace practices and equipment used at the time the monitoring data were collected compared those
currently in use. Therefore, older data may overestimate or underestimate exposures, depending on these
differences. The effects of these uncertainties on the occupational exposure assessment are unknown, as
the uncertainties may result in either overestimation or underestimation of exposures depending on the
actual distribution of 1,1-dichloroethane air concentrations and the variability of work practices among
different sites.
This report uses existing worker exposure monitoring data to assess exposure to 1,1-dichloroethane
during several conditions of use. To analyze the exposure data, EPA categorized each data point as
either "worker" or "occupational non-user." The categorizations are based on descriptions of worker job
activity as provided in literature and EPA's judgment. In general, samples for employees that are
expected to have the highest exposure from direct handling of 1,1-dichloroethane are categorized as
"worker" and samples for employees that are expected to have the lower exposure and do not directly
handle 1,1-dichloroethane are categorized as "occupational non-user."
5.8 Summary of Weight of Scientific Evidence for Environmental Releases
and Occupational Exposures
Table 5-27 summarizes the weight of scientific evidence ratings for each media of release for each OES.
Table 5-28 summarizes the weight of scientific evidence ratings for the occupational exposures for each
OES. EPA's general approach for weight of scientific evidence ratings is explained in Section 2.6 and
the specific basis for each rating is discussed for each OES in the relevant subsection of Section 5.
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of the Weight of Scientific Evidence Ratings for Environmental Releases
OES
Release Media
Reported Data"
Data Quality
Ratings for
Reported Data
Modeling
Data Quality
Ratings for
Modeling''
Weight of Scientific
Evidence Conclusion
Manufacturing
Surface water
M
X
N/A
Moderate to Robust
Fugitive air
M
X
N/A
Fugitive air
H
X
N/A
Stack air
M
X
N/A
Stack air
H
X
N/A
Land
M
X
N/A
Processing as a
reactive intermediate
Surface water
M
X
N/A
Moderate to Robust
Fugitive air
M
X
N/A
Fugitive air
H
X
N/A
Stack air
M
X
N/A
Stack air
H
X
N/A
Land
M
X
N/A
Processing—
Repackaging—
repackaging
Fugitive or stack air
3c
N/A
M
Moderate to Robust
Hazardous landfill or
incineration
3c
N/A
M
Commercial use as a
laboratory chemical
Fugitive or stack air
3C
N/A
M
Moderate
Hazardous landfill or
incineration
3C
N/A
M
Surface water
M
3C
N/A
Moderate to Robust
Fugitive air
M
3C
N/A
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OES
Release Media
Reported Data"
Data Quality
Ratings for
Reported Data
Modeling
Data Quality
Ratings for
Modeling''
Weight of Scientific
Evidence Conclusion
General waste
handling, treatment,
and disposal
Fugitive air
H
X
N/A
Stack air
M
X
N/A
Stack air
H
X
N/A
Waste handling,
treatment, and
disposal (POTW)
POTW
M
X
N/A
Moderate to Robust
Waste handling,
treatment, and
disposal (remediation)
Surface water
M
X
N/A
Moderate to Robust
a Reported data includes data obtained from EPA databases (i.e., TRI, DMR, NEI) and facility release data from literature sources.
h Data quality ratings for models include ratings of underlying literature sources used to select model approaches and input values/distributions such as a
GS/ESD used in tandem with Monte Carlo modeling.
2607
2608
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Table 5-28. Summary of the Weight of Scientific Evidence Ratings for Occupational Exposures
Inhalation 1
l\|)osure
Dermal Exposure
OES
1,1-Dichloroethane Monitoring
Surrogate Monitoring
Modeling
Monitoring
Modelin
g
# Data
Points
# Data
Points
Data
# Data
Points
ON
U
# Data
Points
Data
Data
Worker
ONU
Quality
Ratings
Worker
Quality
Ratings
Worker
ONU
Worker
Quality
Rating
Worker
Manufacturing
57
~
5
H
~*
451
X
N/A
H
X
X
X
N/A
Processing as a reactive
•/
57
5
H
~*
46
X
N/A
M
X
X
X
N/A
intermediate
Processing—
X
N/A
X
N/A
N/A
X
N/A
X
N/A
N/A
V
X
X
N/A
Repackaging—
repackaging
Commercial use as a
9
X
N/A
H
~*
76
X
N/A
H
X
X
X
N/A
laboratory chemical
Recycling
V
57
5
H
X
N/A
X
N/A
N/A
X
X
X
N/A
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6 REFERENCES
Airgai 1 c. \1 H (2015). Safety data sheet: Toxic flammable gas mixture. SDS #014268. Airgas USA,
LLC. https://www.aireas.com/msds/014268.pdf
Airga (2017). Safety data sheet: Non-flammable gas mixture. SDS #021388. Version 1.
Date of issue/Date of revision 8/8/2017. Airgas USA, LLC.
https://www.aireas.com/msds/ S.pdf
Arnold t ! rtgei \< (2001). Evaporation of pure liquids from open surfaces. In JBHJ Linders (Ed.),
Modelling of Environmental Chemical Exposure and Risk (pp. 61-71). The Netherlands: Kluwer
Academic Publishers. http://dx.doi.org/10.10Q7/978-'' S.-0.I0 OSs i
AT SDR. (2015). Toxicological profile for 1,1-dichloroethane. Atlanta, GA: U.S. Department of Health
and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry.
https://clii4n.ore/download/contaminantfociis/dnapl/Chemistrv and Behavior/tox profile 1.1-
dce.pdf
Axiall Corporation. (2016). Product stewardship summary: Tri-ethane. Edition 2. Issue date: October
2016. Axiall Corporation. https://www.westlake.com/sites/default/files/Tri-
Eth an e%2 0 Sum m ary%2 OEd 1. p df
Baldwin. PE; Mavn (1998). A survey of wind speed in indoor workplaces. Ann Occup Hyg 42:
303-313. http://dx.doi.( 5/80003-4878(98)00031-3
Chem Service. (2015). Safety Data Sheet (SDS): 1,1-Dichlorethane solution. West Chester, PA: Chem
Service, Inc.
Cherrie. JW: Semple. S: Brouwer. D. (2004). Gloves and Dermal Exposure to Chemicals: Proposals for
Evaluating Workplace Effectiveness. Ann Occup Hyg 48: 607-615.
http://dx.doi.ore/10.1093/annhve/meh060
Drehtn >1 1 r^'utel. KK; Myers. ID; Lubl"' f ^ u^'ger. S: Potteneer. LH. (2014). Chloroethanes and
chloroethylenes. In B Elvers (Ed.), Ullmann's encyclopedia of industrial chemistry (6th ed., pp.
1-81). Hoboken, NJ: Wiley-VCH Verlag GmbH & Co.
http://dx.doi.ore/10.1002/14356007.oO->01 |;iib2
ESIG. (2012). SPERC fact sheet: Formulation & (re)packing of substances and mixtures - Industrial
(solvent-borne). Brussels, Belgium.
ETC Hazardous Waste Resources Center. (2018). High Temperature Incineration. Washington D C.:
Environmental Technology Council Hazardous Waste Resources Center, http://etc.ore/advanced-
technoloeies/hieh-temperature-incineration.aspx
Fehrenbacher. MC: Hummel. AA. (1996). Evaluation of the Mass Balance Model Used by the EPA for
Estimating Inhalation Exposure to New Chemical Substances. Am Ind Hyg Assoc J 57: 526-536.
Heritaee. (2018). Heritage website. Retrieved from https://www.heritaee-
enviro.com/services/incineration/
K ultz. SC. (1992). Steam: Its generation and use (40th ed.). Barberton, OH: Babcock &
Wilcox.
Marquart. H; Franken. R: Goei isman. W: Schinkel. J. (2017). Validation of the dermal
exposure model in ECETOC TRA. Ann Work Expo Health 61: 854-871.
http://dx.doi.ore/10.1093/annweh/wxx059
Marshall. KA; Potteneer. LH. (2016). Chlorocarbons and ch 1 orohydrocarbons. In Kirk-Othmer
Encyclopedia of Chemical Technology (4th ed.). New York, NY: John Wiley & Sons.
http://dx.doi.ore 10 1002/0 i i. $961 I": I IN:: IS050504 ,iOl wb3
Moen. BE. (1991). Work with chemicals on deck of Norwegian chemical tankers. Int. Arch Occup
Environ Health 62: 543-547. http://dx.doi.ore/10.1007/BF00381106
NCBI. (2020). Pub Chem Compound Summary for CID 6365: 1,1-Dichloroethane.
-------
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
PUBLIC RELEASE DRAFT
July 2024
NIQSH. (2003). Respirator Usage in Private Sector Firms. Washington D C.: United States Department
of Labor, Bureau of Labor Statistics and National Institute for Occupational Safety and Health.
https://www.cdc.gov/niosh/docs/respsurv/
NRC. (2009). Query/download NRC FOIA data [Database], Retrieved from
http://www.nrc.iisce.mil/foia.html
OECD. (2009). Emission scenario document on transport and storage of chemicals. Paris, France.
http://www.oecd. org/officialdocuments/publicdisplaydocumentpdf/?cote=env/im/mono(2009)26
& docl an guage=en
OECD. (201 1). Emission scenario document on the chemical industry. (JT03307750).
http://www.oecd.org/env/ehs/risk-assessment/48 Lpdf
PEI Associates. (1988). Releases during cleaning of equipment. Washington, DC: U.S. Environmental
Protection Agency, Office of Pesticides and Toxic Substances.
https://ofmpiib.epa.gov/apex/euideme ext/guideme/file/releases%20during%20cleaning%20of%
20equipment.pdf
PerkinElmer Inc. (2018). Safety data sheet: Blend-Volatile Organics Combination. Review date:
07/27/2018. PerkinElmer, Inc.
https://www.perkinelmer.com/Content/MSDSDatabase/MSDS N( N).pdf
Phenova. (2018). SDS - 601 Purgable Halocarbons Mix. Phenova.
Restek Corporation. (2019). Safety data sheet: 30633/8260B Calibration Mix #1. Revision number 13.
Revision date 04/12/19. Restek Corporation.
RIVM. (2007). Ecotoxi cological 1 y based environmental risk limits for several volatile aliphatic
hydrocarbons (pp. 217). (601782002/2007). Bilthoven, Netherlands: National Institute for Public
Health and the Environment (RIVM). https://www.rivm.nl/bibliotheek/rapporten/601782002.pdf
Sigma-Aldrich. (2020). 1,1 -Dichloroethane analytical standard. Sigma-Aldrich.
https://www.sigmaaldrich.com/cataloe/product/supelco/48512?lane=en&reeion=US
Spex Certiprep. (2019). SDS - Volatile Organics Mix. Spex Certiprep, L.
Stantec ChemRisk. (2023). Final study report: Inhalation monitoring of 1,1-dichloroethane (CASRN 75-
34-3). Washington, DC: Vinyl Institute Consortium.
IJ ;rica. (2014). Safety Data Sheet (SDS): 1,1-Dichlorethane (stabilized with nitromethane).
Portland, OR.
U.S. BLS. (2014). Employee Tenure News Release. Available online at
http://www.bls.gov/news.release/archives/tenure 0918^ m
U.S. BLS. (2016). May 2016 Occupational Employment and Wage Estimates: National Industry-
Specific Estimates. Available online at http://www.bls.gov/oes/tables.htm
U.S. Census Bureau. (2015). Statistics of U.S. Businesses (SUSB).
https://www.census.gov/data/tables/2015/econ/susb/2015-susb-annual.html
U.S. Census Bureau. (2019a). Survey of Income and Program Participation data. Available online at
https://www.census.gov/programs-survevs/sipp/data/datasets/20Q8-panel/wave-l.html (accessed
May 16, 2019).
U.S. Census Bureau. (2019b). Survey of Income and Program Participation: SIPP introduction and
history. Washington, DC. https://www.census.gov/programs-surveys/sipp/about/sipp-
introducti on -history .html
U.S. EPA. (1991). Chemical engineering branch manual for the preparation of engineering assessments.
Volume I. Ceb Engineering Manual. Washington, DC: Office of Pollution Prevention and
Toxics, US Environmental Protection Agency.
https://nepis.epa. gov/Exe/ZyPURL.cgi?Dockey=P 10000VS.txt
(1992a). Guidelines for exposure assessment. Federal Register 57(104):22888-22938 [EPA
Report], In Risk Assessment Forum. (EPA/600/Z-92/001). Washington, DC.
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm7dei' >3
Page 82 of 222
-------
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
PUBLIC RELEASE DRAFT
July 2024
(1992b). A laboratory method to determine the retention of liquids on the surface of hands
[EPA Report], (EPA/747/R-92/003). Washington, DC.
(1994). Guidelines for Statistical Analysis of Occupational Exposure Data: Final. United
States Environmental Protection Agency :: U.S. EPA.
(2000). Letter from vulcan chemicals to usepa submitting comments concerning 1,1-
dichloroethane and 1,1,2,2-tetrachloroethane as well as the proposed 14-day subacute oral testing
procotol. (EPA/OTS; Doc #40-90106032).
U.S. EPA. (2001). Sources, emission and exposure for trichloroethylene (TCE) and related chemicals
[EPA Report], In Govt Reports Announcements & Index (pp. 138). (EPA/600/R-00/099).
Washington, DC. https://cfpub.epa.gov/ncea/risk/recordisplay.ctM?deid=21006
U.S. EPA. (201 1). Exposure factors handbook: 201 1 edition [EPA Report], (EPA/600/R-090/052F).
Washington, DC: U.S. Environmental Protection Agency, Office of Research and Development,
National Center for Environmental Assessment.
https://nepis.epa. gov/Exe/ZyPURL.cgi?Dockev=P 100F2QS.txt
U.S. EPA. (2013). Updating CEB's method for screening-level estimates of dermal exposure. Chemical
Engineering Branch.
(2015). ChemSTEER user guide - Chemical screening tool for exposures and environmental
releases. Washington, D C. https://www.epa.gov/sites/production/files/2Q15-
05/docum ents/user gui de.pdf
U.S. EPA. (2016). Instructions for reporting 2016 TSCA chemical data reporting. (EPA/600/R-
09/052F). Washington, DC: U.S. Environmental Protection Agency, Office of Pollution
Prevention and Toxics, https://www.epa.gov/chemical-data-reporting/instructions-reporting-
2016-tsca-chemical-data-reporting
U.S. EPA. (2017a). Learn the Basics of Hazardous Waste. Available online at
https://www.epa.gov/hw/learn-basics-hazardous-waste
I v •! P \ (2017b). Toxics release inventory [Database], Washington, DC: U.S. Environmental
Protection Agency, Office of Pollution Prevention and Toxics. Retrieved from
https://www.epa.gov/toxics-release-inventorv-tri-program/tri-data-and-tools
U.S. EPA. (2018a). Application of systematic review in TSCA risk evaluations. (740-P1-8001).
Washington, DC: U.S. Environmental Protection Agency, Office of Chemical Safety and
Pollution Prevention, https://www.epa.gov/sites/production/files/2Q18-
06/documents/final application of sr in tsc if
U.S. EPA. (2018b). Hazardous Waste Management Facilities and Units. Available online at
https://www.epa.gov/hwpermitting/hazardous-waste-management-facilities-and-units
1 v M \ (2019). Chemical data reporting (2012 and 2016 public CDR database). Washington, DC:
U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics. Retrieved
from https://www.epa.gov/chemical-data-reporting
U.S. EPA. (2020a). 2020 CDR data [Database], Washington, DC: U.S. Environmental Protection
Agency, Office of Pollution Prevention and Toxics. Retrieved from
https://www.epa.gov/chemical-data-reporting/access-cdr-data
U.S. EPA. (2020b). 2020 CDR: Commercial and consumer use. Washington, DC.
U.S. EPA. (2020c). Final scope of the risk evaluation for 1,1-dichloroethane; CASRN 75-34-3. (EPA
740-R-20-004). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.epa.gov/sites/default/files/2020-Q9/documents/casrn 75-:
dichloroethane finalscope.pdf
U.S. EPA. (2020d). Final Scope of the Risk Evaluation for 1,2-Dichloroethane. (EPA-740-R-20-005).
Washington, DC: U.S. Environmental Protection Agency, Office of Chemical Safety and
Pollution Prevention, https://www.epa.gov/sites/default/files/2020-09/documents/casrn 107-06-
Moroethane final scope.pdf
Page 83 of 222
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2764
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2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
PUBLIC RELEASE DRAFT
July 2024
U.S. EPA. (2020e). Risk evaluation for 1 -bromopropane (n-Propyl bromide), CASRN: 106-94-5 [EPA
Report], (#740-Rl-8013). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA-HQ-0] 0235-0085
U.S. EPA. (2020f). Risk evaluation for 1,4-dioxane (CASRN: 123-91-1) [EPA Report], (EPA-740-R1-
8007). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA-HQ-Q] 0238-0092
U.S. EPA. (2020g). Risk evaluation for carbon tetrachloride (methane, tetrachloro-); CASRN: 56-23-5
[EPA Report], (EPA-740-R1-8014). Washington, DC: U.S. Environmental Protection Agency,
Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA-HQ-Q] 061
U.S. EPA. (2020h). Risk evaluation for methylene chloride (dichloromethane, DCM); CASRN: 75-09-2.
(EPA-740-R1-8010). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA-HQ-Q] 19-0437-0107
U.S. EPA. (2020i). Risk evaluation for n-M ethyl pyrrol i done (2-Pyrrolidinone, 1-Methyl-) (NMP);
CASRN: 872-50-4 [EPA Report], (EPA-740-R1-8009). Washington, DC: Office of Chemical
Safety and Pollution Prevention, https://www.reeulations.gov/document/EPA-HQ-QPPT-2019-
0236-0081
U.S. EPA. (2020j). Risk evaluation for perchloroethylene (Ethene, 1,1,2,2-Tetrachloro-); CASRN 127-
18-4 [EPA Report], (740-R1-8011). Washington, DC: Office of Chemical Safety and Pollution
Prevention, https://www.reeulations.gov/document/ '.Q-OPPT-2019-0502-0058
U.S. EPA. (2020k). Risk evaluation for trichloroethylene; CASRN: 79-01-6 [EPA Report],
(#740R18008). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA-HQ-QPPT-2019-0500-0113
U.S. EPA. (2021). Draft systematic review protocol supporting TSCA risk evaluations for chemical
substances, Version 1.0: A generic TSCA systematic review protocol with chemical-specific
methodologies. (EPA Document #EPA-D-20-031). Washington, DC: Office of Chemical Safety
and Pollution Prevention. https://www.reeiilations.eov/dociiment/EPA-HQ-QPPT-2'
0005
U.S. EPA. (2022a). Chemical repackaging - Generic scenario for estimating occupational exposures and
environmental releases (revised draft) [EPA Report], Washington, DC.
(2022b). Discharge Monitoring Report (DMR) data for 1,4-dioxane, 2013-2019. Washington,
DC. Retrieved from https://echo.epa.eov/trends/loadine-tool/water-pollution-search
(2022c). National emissions inventory (NEI). Available online at https://www.epa.eov/air-
emissions-inventories/national-emissions-inventorv (accessed August 31, 2022).
I v •! P \ (2022d). Toxics Release Inventory (TRI) data for 1,4-dioxane, 2013-2019. Washington, DC.
Retrieved from https://www.epa.eov/toxics-release-inventory-tri-proeram/tri-data-and-tools
(2023). Use of laboratory chemicals - Generic scenario for estimating occupational exposures
and environmental releases (Revised draft generic scenario) [EPA Report], Washington, DC:
U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Existing
Chemicals Risk Assessment Division.
U.S. EPA. (2024). Draft Risk Evaluation for 1,2-Dichloroethane. Washington, DC: Office of Pollution
Prevention and Toxics, Office of Chemical Safety and Pollution Prevention.
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Appendix A EXAMPLE OF ESTIMATING NUMBER OF WORKERS
AND OCCUPATIONAL NON-USERS
This appendix summarizes the methods that EPA/OPPT used to estimate the number of workers who are
potentially exposed to 1,1-dichloroethane in each of its conditions of use. The method consists of the
following steps:
1. Check relevant emission scenario documents (ESDs) and Generic Scenarios (GSs) for estimates
on the number of workers potentially exposed.
2. Identify the NAICS codes for the industry sectors associated with each condition of use.
3. Estimate total employment by industry/occupation combination using the Bureau of Labor
Statistics' Occupational Employment Statistics (OES) data (\] S HI S. 2016).
4. Refine the OES estimates where they are not sufficiently granular by using the U.S. Census'
(\] S Census Bureau. 2015) Statistics of U.S. Businesses (SUSB) data on total employment by
6-digit NAICS.
5. Estimate the percentage of employees likely to be using 1,1-dichloroethane instead of other
chemicals (i.e., the market penetration of 1,1-dichloroethane in the condition of use).
6. Estimate the number of sites and number of potentially exposed employees per site.
7. Estimate the number of potentially exposed employees within the condition of use.
Step 1: Identifying Affected NAICS Codes
As a first step, EPA/OPPT identified NAICS industry codes associated with each condition of use.
EPA/OPPT generally identified NAICS industry codes for a condition of use by the following:
• Querying the ]j._S C "ensus Bureau's NAICS Search tool using keywords associated with each
condition of use to identify NAICS codes with descriptions that match the condition of use.
• Referencing EPA/OPPT Generic Scenarios (GS's) and Organisation for Economic Co-operation
and Development (OECD) Emission Scenario Documents (ESDs) for a condition of use to
identify NAICS codes cited by the GS or ESD.
• Reviewing CDR data for the chemical, identifying the industrial sector codes reported for
downstream industrial uses, and matching those industrial sector codes to NAICS codes using
Table D-2 provided in the CDR reporting instructioi ( 2016).
Each condition of use section in the main body of this report identifies the NAICS codes EPA/OPPT
identified for the respective condition of use.
Step 2: Estimating Total Employment by Industry and Occupation
BLS's OES data provide employment data for workers in specific industries and occupations ( ,8^
2016). The industries are classified by NAICS codes (identified previously), and occupations are
classified by Standard Occupational Classification (SOC) codes.
Among the relevant NAICS codes (identified previously), EPA/OPPT reviewed the occupation
description and identified those occupations (SOC codes) where workers are potentially exposed to 1,1-
dichloroethane. Table Apx A-l shows the SOC codes EPA/OPPT classified as occupations potentially
exposed to 1,1-dichloroethane. These occupations are classified as workers (W) and occupational non-
users (O). All other SOC codes are assumed to represent occupations where exposure is unlikely.
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TableApx A-l. SOCs with Worker and ONU Designations for All Conditions of Use Except Dry
SOC
Occupation
Designation
11-9020
Construction Managers
O
17-2000
Engineers
O
17-3000
Drafters, Engineering Technicians, and Mapping Technicians
0
19-2031
Chemists
0
19-4000
Life, Physical, and Social Science Technicians
0
47-1000
Supervisors of Construction and Extraction Workers
0
47-2000
Construction Trades Workers
w
49-1000
Supervisors of Installation, Maintenance, and Repair Workers
0
49-2000
Electrical and Electronic Equipment Mechanics, Installers, and Repairers
w
49-3000
Vehicle and Mobile Equipment Mechanics, Installers, and Repairers
w
49-9010
Control and Valve Installers and Repairers
w
49-9020
Heating, Air Conditioning, and Refrigeration Mechanics and Installers
w
49-9040
Industrial Machinery Installation, Repair, and Maintenance Workers
w
49-9060
Precision Instrument and Equipment Repairers
w
49-9070
Maintenance and Repair Workers, General
w
49-9090
Miscellaneous Installation, Maintenance, and Repair Workers
w
51-1000
Supervisors of Production Workers
0
51-2000
Assemblers and Fabricators
w
51-4020
Forming Machine Setters, Operators, and Tenders, Metal and Plastic
w
51-6010
Laundry and Dry-Cleaning Workers
w
51-6020
Pressers, Textile, Garment, and Related Materials
w
51-6030
Sewing Machine Operators
0
51-6040
Shoe and Leather Workers
0
51-6050
Tailors, Dressmakers, and Sewers
0
51-6090
Miscellaneous Textile, Apparel, and Furnishings Workers
0
51-8020
Stationary Engineers and Boiler Operators
w
51-8090
Miscellaneous Plant and System Operators
w
51-9000
Other Production Occupations
w
W = worker designation; O = ONU designation
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For dry cleaning facilities, due to the unique nature of work expected at these facilities and that different
workers may be expected to share among activities with higher exposure potential (e.g., unloading the
dry-cleaning machine, pressing/finishing a dry-cleaned load), EPA/OPPT made different SOC code
worker and ONU assignments for this condition of use. Table Apx A-2 summarizes the SOC codes with
worker and ONU designations used for dry cleaning facilities.
2851 Table Apx A-2. SOCs with Worker and ONU Designations for Dry Cleaning Facilities
SOC
Occupation
Designation
41-2000
Retail Sales Workers
O
49-9040
Industrial Machinery Installation, Repair, and Maintenance Workers
W
49-9070
Maintenance and Repair Workers, General
w
49-9090
Miscellaneous Installation, Maintenance, and Repair Workers
w
51-6010
Laundry and Dry-Cleaning Workers
w
51-6020
Pressers, Textile, Garment, and Related Materials
w
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SOC
Occupation
Designation
51-6030
Sewing Machine Operators
O
51-6040
Shoe and Leather Workers
O
51-6050
Tailors, Dressmakers, and Sewers
0
51-6090
Miscellaneous Textile, Apparel, and Furnishings Workers
0
W = worker designation; O = ONU designation
After identifying relevant NAICS and SOC codes, EPA/OPPT used BLS data to determine total
employment by industry and by occupation based on the NAICS and SOC combinations. For example,
there are 110,640 employees associated with 4-digit NAICS 8123 (Drycleaning and Laundry Services)
and SOC 51-6010 (Laundry and Dry-Cleaning Workers).
Using a combination of NAICS and SOC codes to estimate total employment provides more accurate
estimates for the number of workers than using NAICS codes alone. Using only NAICS codes to
estimate number of workers typically result in an overestimate, because not all workers employed in that
industry sector will be exposed. However, in some cases, BLS only provide employment data at the 4-
digit or 5-digit NAICS level; therefore, further refinement of this approach may be needed (see next
step).
Step 3: Refining Employment Estimates to Account for lack of NA ICS Granularity
The third step in EPA/OPPT's methodology was to further refine the employment estimates by using
total employment data in the U.S. Census Bureau's SUSB (U.S. Census Bureau. 20.1.5). In some cases,
BLS OES's occupation-specific data are only available at the 4-digit or 5-digit NAICS level, whereas
the SUSB data are available at the 6-digit level (but are not occupation-specific). Identifying specific 6-
digit NAICS will ensure that only industries with potential 1,1-dichloroethane exposure are included. As
an example, OES data are available for the 4-digit NAICS 8123 Drycleaning and Laundry Services,
which includes the following 6-digit NAICS:
• NAICS 812310 Coin-Operated Laundries and Drycleaners;
• NAICS 812320 Drycleaning and Laundry Services (except Coin-Operated);
• NAICS 812331 Linen Supply; and
• NAICS 812332 Industrial Launderers.
In this example, only NAICS 812320 is of interest. The Census data allow EPA/OPPT to calculate
employment in the specific 6-digit NAICS of interest as a percentage of employment in the BLS 4-digit
NAICS.
The 6-digit NAICS 812320 comprises 46 percent of total employment under the 4-digit NAICS 8123.
This percentage can be multiplied by the occupation-specific employment estimates given in the BLS
OES data to further refine our estimates of the number of employees with potential exposure.
Table_Apx A-3 illustrates this granularity adjustment for NAICS 812320.
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TableApx A-3. Estimated Number of Potentially Exposed Workers and ONUs under NAICS
812320
NAICS
SOC
CODE
SOC Description
Occupation
Designation
Employment
by SOC at 4-
Digit NAICS
Level
% of Total
Employment
Estimated
Employment by
SOC at 6-Dijjit
NAICS Level
8123
41-2000
Retail Sales Workers
O
44,500
46.0%
20,459
8123
49-9040
Industrial Machinery
Installation, Repair, and
Maintenance Workers
w
1,790
46.0%
823
8123
49-9070
Maintenance and Repair
Workers, General
w
3,260
46.0%
1,499
8123
49-9090
Miscellaneous
Installation, Maintenance,
and Repair Workers
w
1,080
46.0%
497
8123
51-6010
Laundry and Dry-
Cleaning Workers
w
110,640
46.0%
50,867
8123
51-6020
Pressers, Textile,
Garment, and Related
Materials
w
40,250
46.0%
18,505
8123
51-6030
Sewing Machine
Operators
0
1,660
46.0%
763
8123
51-6040
Shoe and Leather
Workers
0
Not Reported for this NAICS Code
8123
51-6050
Tailors, Dressmakers, and
Sewers
0
2,890
46.0%
1,329
8123
51-6090
Miscellaneous Textile,
Apparel, and Furnishings
Workers
0
0
46.0%
0
Total Potentially Exposed Employees
206,070
94,740
Total Workers
72,190
Total Occupational Non-users
22,551
Note: numbers may not sum exactly due to rounding.
W = worker; O = occupational non-user
Source: US Census. 2015 ("U.S. Census Bureau. 2015): BLS. 2016 ("U.S. BLS. 2016).
Step 4: Estimating the Percentage of Workers Using 1,1-Dichloroethane Instead of Other Chemicals
In the final step, EPA/OPPT accounted for the market share by applying a factor to the number of
workers determined in Step 3. This accounts for the fact that 1,1-dichloroethane may be only one of
multiple chemicals used for the applications of interest. EPA/OPPT did not identify market penetration
data for any conditions of use. In the absence of market penetration data for a given condition of use,
EPA/OPPT assumed 1,1-dichloroethane may be used at up to all sites and by up to all workers
calculated in this method as a bounding estimate. This assumes a market penetration of 100%.
Step 5: Estimating the Number of Workers per Site
EPA/OPPT calculated the number of workers and occupational non-users in each industry/occupation
combination using the formula below (granularity adjustment is only applicable where SOC data are not
available at the 6-digit NAICS level):
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Number of Workers or ONUs in NAICS/SOC (Step 2) x Granularity Adjustment Percentage (Step 3) =
Number of Workers or ONUs in the Industry/Occupation Combination
EPA/OPPT then estimated the total number of establishments by obtaining the number of establishments
reported in the U.S. Census Bureau's SUSB ( ) data at the 6-digit NAICS level.
EPA/OPPT then summed the number of workers and occupational non-users over all occupations within
a NAICS code and divided these sums by the number of establishments in the NAICS code to calculate
the average number of workers and occupational non-users per site.
Step 6: Estimating the Number of Workers and Sites for a Condition of Use
EPA/OPPT estimated the number of workers and occupational non-users potentially exposed to 1,1-
dichloroethane and the number of sites that use 1,1-dichloroethane in a given condition of use through
the following steps:
6. A. Obtaining the total number of establishments by:
i. Obtaining the number of establishments from SUSB at the 6-digit NAICS level (Step 5)
for each NAICS code in the condition of use and summing these values; or
ii. Obtaining the number of establishments from the TRI, DMR, NEI, or literature for the
condition of use.
6.B. Estimating the number of establishments that use 1,1-dichloroethane by taking the total
number of establishments from Step 6. A and multiplying it by the market penetration factor
from Step 4.
6.C. Estimating the number of workers and occupational non-users potentially exposed to 1,1-
dichloroethane by taking the number of establishments calculated in Step 6.B and
multiplying it by the average number of workers and occupational non-users per site from
Step 5.
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EQUATIONS FOR CALCULATING ACUTE,
SUBCHRONIC, AND CHRONIC (NON-CANCER AND
CANCER) INHALATION AND DERMAL EXPOSURES
This report assesses 1,1-dichloroethane inhalation exposures to workers in occupational settings,
presented as 8-hr {i.e., full-shift) time weighted average (TWA). The full-shift TWA exposures are then
used to calculate acute exposure concentrations (AC), subchronic average daily concentrations (SADC),
average daily concentrations (ADC) for chronic, non-cancer risks, lifetime average daily concentrations
(LADC) for chronic, cancer risks.
This report also assesses 1,1-dichloroethane dermal exposures to workers in occupational settings,
presented as a dermal acute potential dose rate (APDR). The APDRs are then used to calculate acute
retained doses (AD), subchronic average daily doses (SCDD), average daily doses (ADD) for chronic
non-cancer risks, and lifetime average daily doses (LADD) for chronic cancer risks.
This appendix presents the equations and input parameter values used to estimate each exposure metric.
B.l Equations for Calculating Acute, Subchronic, and Chronic (Non-
cancer and Cancer) Inhalation Exposures
AC is used to estimate workplace inhalation exposures for acute risks {i.e., risks occurring as a result of
exposure for less than one day), per EquationApx B-l.
EquationApx B-l
Where:
AC =
C
ED =
BR
ATacute
SADC is used to estimate workplace exposures for subchronic risks and is estimated as follows:
Equation Apx B-2
Equation Apx B-3
Where:
SADC =
EFsc =
ATsc =
SCD =
Appendix B
C x ED x BR
AC = —
AT
ri1 acute
Acute exposure concentration
Contaminant concentration in air (TWA)
Exposure duration (hr/day)
Breathing rate ratio (unitless)
Acute averaging time (hr)
C x ED x EFSC x BR
SADC =
ATSC
hr
ATSC = SCD X 24-
day
Subchronic average daily concentration
Subchronic exposure frequency
Averaging time (hr) for subchronic exposure
Days for subchronic duration (day)
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ADC and LADC are used to estimate workplace exposures for non-cancer and cancer risks, respectively.
These exposures are estimated as follows:
EquationApx B-4
ADC or LADC =
C x ED x EF x WY x BR
AT or ATr
Equation Apx B-5
day hr
AT = WY x 365 — x 24
yr
day
Equation Apx B-6
ATr = LT x 365
day
yr
x 24-
hr
day
Where:
ADC = Average daily concentration used for chronic non-cancer risk calculations
LADC = Lifetime average daily concentration used for chronic cancer risk calculations
ED = Exposure duration (hr/day)
EF = Exposure frequency (day/yr)
WY = Working years per lifetime (yr)
AT = Averaging time (hr) for chronic, non-cancer risk
ATc = Averaging time (hr) for cancer risk
LT = Lifetime years (yr) for cancer risk
B.2 Equations for Calculating Acute, Subchronic, and Chronic (Non-
cancer and Cancer) Dermal Exposures
AD is used to estimate workplace dermal exposures for acute risks and are calculated using
EquationApx B-7.
Equation Apx B-7
Where:
AD =
APDR
BW
AD = Acute retained dose (mg/kg-day)
APDR = Acute potential dose rate (mg/day)
BW = Body weight (kg)
SCDDs is used to estimate workplace dermal exposures for subchronic risks, and is estimated using
EquationApx B-8.
Equation Apx B-8
SCDD =
APDR X EFSC
BW X SCD
Where:
SCDD = Subchronic average daily dose (mg/kg-day)
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ADD and LADD are used to estimate workplace dermal exposures for non-cancer and cancer risks and
are calculated using EquationApx B-9.
EquationApx B-9
APDR XEF XWY
ADD or LADD = -j
BW x 365 x (WY or LT)
yr v J
Where WY and LT are used in the denominator for ADD and LADD, respectively.
B,3 Acute, Subchronic, and Chronic (Non-cancer and Cancer) Equation
Inputs
The input parameter values in Table Apx B-l are used to calculate each of the above acute, subchronic,
and chronic exposure estimates. Where exposure is calculated using probabilistic modeling, the
calculations are integrated into the Monte Carlo simulation. Where multiple values are provided for ED,
it indicates that EPA may have used different values for different conditions of use. The EF and EFsc
used for each OES can differ and the values used are described in the appropriate sections of this report.
The maximum values used in the equations as well as a general summary for these differences are
described below in this section.
Table Apx B-l. Parameter Values for
Calculating Inhalation Exposure Estimates
Parameter Name
Symbol
Value
Unit
Exposure duration
ED
8
hr/day
Breathing rate ratio
BR
2.04
unitless
Exposure frequency
EF
125 to 350fl
days/yr
Exposure frequency,
subchronic
EFSC
22
days
Days for subchronic
duration
SCD
30
days
Working years
WY
31 (50th percentile)
40 (95th percentile)
years
Lifetime years, cancer
LT
78
years
Averaging time,
subchronic
ATSC
720
hr
Averaging time, non-
cancer
AT
271,560 (central tendency)6
350,400 (high-end)c
hr
Averaging rime, cancer
ATC
683,280
hr
Body weight
BW
80 (average adult worker)
72.4 (female of reproductive age)
kg
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Parameter Name
Symbol
Value
Unit
a Depending on OES
b Calculated using the 50th percentile value for working years (WY)
c Calculated using the 95th percentile value for working years (WY)
B.3.1 Exposure Duration (ED)
EPA generally uses an exposure duration of eight hours per day for averaging full-shift exposures.
B.3.2 Breathing Rate Ratio
EPA uses a breathing rate ratio, which is the ratio between the worker breathing rate and resting
breathing rate, to account for the amount of air a worker breathes during exposure. The typical worker
breathes about 10 m3 of air in 8 hours, or 1.25 m3/hr ( ) while the resting breathing rate is
0.6125 m3/hr ( ). The ratio of these two values is equivalent to 2.04.
B.3.3 Exposure Frequency (EF)
EPA generally uses a maximum exposure frequency of 250 days per year. However, for the
Processing—Repackaging OES, EPA used probabilistic modeling to estimate exposures and the
associated exposure frequencies, resulting in exposure frequencies below 250 days per year. The
estimation of the exposure frequency and associated distributions for each OES are described in the
relevant section of this report.
EF is expressed as the number of days per year a worker is exposed to the chemical being assessed. In
some cases, it may be reasonable to assume a worker is exposed to the chemical on each working day. In
other cases, it may be more appropriate to estimate a worker's exposure to the chemical occurs during a
subset of the worker's annual working days. The relationship between exposure frequency and annual
working days can be described mathematically as follows:
Equation Apx B-10
EF = fx AWD
Where:
EF
Exposure frequency, the number of days per year a worker is exposed to the
chemical (day/yr)
f
Fractional number of annual working days during which a worker is exposed to
the chemical (unitless)
AWD =
Annual working days, the number of days per year a worker works (day/yr)
BLS (U .S. BLS. 2016) provides data on the total number of hours worked and total number of
employees by each industry NAICS code. These data are available from the 3- to 6-digit NAICS level
(where 3-digit NAICS are less granular and 6-digit NAICS are the most granular). Dividing the total,
annual hours worked by the number of employees yields the average number of hours worked per
employee per year for each NAICS.
EPA has identified approximately 140 NAICS codes applicable to the multiple conditions of use for the
ten chemicals undergoing risk evaluation. For each NAICS code of interest, EPA looked up the average
hours worked per employee per year at the most granular NAICS level available (i.e., 4-digit, 5-digit, or
6-digit). EPA converted the working hours per employee to working days per year per employee
assuming employees work an average of eight hours per day. The average number of days per year
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worked, or AWD, ranges from 169 to 282 days per year, with a 50th percentile value of 250 days per
year. EPA repeated this analysis for all NAICS codes at the 4-digit level. The average AWD for all 4-
digit NAICS codes ranges from 111 to 282 days per year, with a 50th percentile value of 228 days per
year. 250 days per year is approximately the 75th percentile. In the absence of industry- and 1,1-
dichloroethane-specific data, EPA assumes the parameter/is equal to one for all conditions of use
except Processing—Repackaging. Repackaging used a discrete value of 0.962 for / The 0.962 value was
derived from the ratio of the number of operating days (260 days/yr) and the assumption that workers
are only potentially exposed up to 250 days/yr. Therefore, the default for/is 0.962 day of exposure/day
of operation for this OES.
B.3.4 Subchronic Exposure Frequency (EFsc)
For 1,1-dichloroethane, the SCD was set at 30 days. EPA estimated the maximum number of working
days within the SCD, using the following equation and assuming 5 working days/wk:
EquationApx B-ll
working days 30 total days
EFsc(max) = 5 x —total da s = days, rounded up to 22 days
7 0 awk"yS
B.3.5 Subchronic Duration (SCD)
EPA assessed a subchronic duration of 30 days based on the available health data.
B.3.6 Working Years (WY)
EPA has developed a triangular distribution for working years. EPA has defined the parameters of the
triangular distribution as follows:
• Minimum value: BLS CPS tenure data with current employer as a low-end estimate of the
number of lifetime working years: 10.4 years;
• Mode value: The 50th percentile tenure data with all employers from SIPP as a mode value for
the number of lifetime working years: 36 years; and
• Maximum value: The maximum average tenure data with all employers from SIPP as a high-end
estimate on the number of lifetime working years: 44 years.
This triangular distribution has a 50th percentile value of 31 years and a 95th percentile value of 40
years. EPA uses these values for central tendency and high-end ADC and LADC calculations,
respectively.
The BLS (U ,S. BLS. 2014) provides information on employee tenure with current employer obtained
from the Current Population Survey (CPS). CPS is a monthly sample survey of about 60,000 households
that provides information on the labor force status of the civilian non-institutional population age 16 and
over; CPS data are released every 2 years. The data are available by demographics and by generic
industry sectors but are not available by NAICS codes.
The U.S. Census' (U .S. Census Bureau. 2019a) Survey of Income and Program Participation (SIPP)
provides information on lifetime tenure with all employers. SIPP is a household survey that collects data
on income, labor force participation, social program participation and eligibility, and general
demographic characteristics through a continuous series of national panel surveys of between 14,000
and 52,000 households (U.S. Census Bureau. 2019a). EPA analyzed the 2008 SIPP Panel Wave 1, a
panel that began in 2008 and covers the interview months of September 2008 through December 2008
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(U.S. Census Bureau. 2019a. b). For this panel, lifetime tenure data are available by Census Industry
Codes, which can be cross-walked with NAICS codes.
SIPP data include fields for the industry in which each surveyed, employed individual works
(TJBIND1), worker age (TAGE), and years of work experience with all employers over the surveyed
individual's lifetime.9 Census household surveys use different industry codes than the NAICS codes
used in its firm surveys, so these were converted to NAICS using a published crosswalk. EPA calculated
the average tenure for the following age groups: (1) workers age 50 and older; (2) workers age 60 and
older; and (3) workers of all ages employed at time of survey. EPA used tenure data for age group "50
and older" to determine the high-end lifetime working years, because the sample size in this age group is
often substantially higher than the sample size for age group "60 and older". For some industries, the
number of workers surveyed, or the sample size, was too small to provide a reliable representation of the
worker tenure in that industry. Therefore, EPA excluded data where the sample size is less than five
from our analysis.
TableApx B-2 summarizes the average tenure for workers age 50 and older from SIPP data. Although
the tenure may differ for any given industry sector, there is no significant variability between the 50th
and 95th percentile values of average tenure across manufacturing and non-manufacturing sectors.
Table Apx B-2. Overview of Average Worker Tenure from U.S. Census SIPP (Age Group 50+)
Industry Sectors
Working Years
Average
50th
Percentile
95th
Percentile
Maximum
All industry sectors relevant to the 10 chemicals
undergoing risk evaluation
35.9
36
39
44
Manufacturing sectors (NAICS 31-33)
35.7
36
39
40
Non-manufacturing sectors (NAICS 42-81)
36.1
36
39
44
Source: ("U.S. Census Bureau. 2019a).
Note: Industries where sample size is less than five are excluded from this analysis.
BLS CPS data provides the median years of tenure that wage and salary workers had been with their
current employer. Table Apx B-3 presents CPS data for all demographics (men and women) by age
group from 2008 to 2012. To estimate the low-end value on number of working years, EPA uses the
most recent (2014) CPS data for workers aged 55 to 64 years, which indicates a median tenure of 10.4
years with their current employer. The use of this low-end value represents a scenario where workers are
only exposed to the chemical of interest for a portion of their lifetime working years, as they may
change jobs or move from one industry to another throughout their career.
Table Apx B-3. Median Years of Tenure with Current Employer by Age Group
Age
January 2008
January 2010
January 2012
January 2014
16 years and over
4.1
4.4
4.6
4.6
9 To calculate the number of years of work experience EPA took the difference between the year first worked
(TMAKMNYR) and the current data year {i.e., 2008). EPA then subtracted any intervening months when not working
(ETIMEOFF).
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Age
January 2008
January 2010
January 2012
January 2014
16 to 17 years
0.7
0.7
0.7
0.7
18 to 19 years
0.8
1.0
0.8
0.8
20 to 24 years
1.3
1.5
1.3
1.3
25 years and over
5.1
5.2
5.4
5.5
25 to 34 years
2.7
3.1
3.2
3.0
35 to 44 years
4.9
5.1
5.3
5.2
45 to 54 years
7.6
7.8
7.8
7.9
55 to 64 years
9.9
10.0
10.3
10.4
65 years and over
10.2
9.9
10.3
10.3
Source: BLS, 2014b.
3146 B.3.7 Lifetime Years (LT)
3147 EPA assumes a lifetime of 78 years for all worker demographics.
3148 B.3.8 Body Weight (BW)
3149 EPA assumes a body weight of 80 kg for average adult workers. EPA assumed a body weight of 72.4 kg
3150 for females of reproductive age, per Chapter 8 of the Exposure Factors Handbook ( ).
3151
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Appendix C SAMPLE CALCULATIONS FOR CALCULATING
ACUTE AND CHRONIC (NON-CANCER AND
CANCER) INHALATION EXPOSURES
Sample calculations for high-end and central tendency acute and chronic (non-cancer and cancer)
exposure concentrations for one condition of use, Manufacturing, are demonstrated below. The
explanation of the equations and parameters used is provided in Appendix A.
C.l Example High-End AC, ADC, LADC, and SADC Calculations
Calculate AChe:
CHE x ED x BR
AC„E =
AT,
acute
1.1 ppm x 8 hr/day x 2.04
AChe = 24 hFJd^ = 072 PPm
Calculate SADChe:
CHE x ED x EFSC x BR
SADC = — —
ATSC
1.1 ppm x 8-^x22^x2.04
SADCHE = — p- = 0.53 ppm
24-£Lx30^
day year
Calculate ADChe:
CHE x ED x EF XWY x BR
ADChe = — —
HE AT
1.1 ppm x 8x 350 x 40 years x 2.04
day year 7 „ _
ADChe = j r = 0.49 ppm
.„ „.rdays hr rr
40 years x 365—— x 24—
J yr day
Calculate LADChe:
CHE x ED x EF x WY x BR
LADChe = — —
HE ATC
1.1 ppm x 84^— x 350 x 40 years x 2.04
r _ ^ day year 7
LADChe = -T— = 0.25 ppm
78 years x 365—— x 24 hr/day
7 year ' 7
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C.2 Example Central Tendency AC, ADC, LADC, and SADC Calculations
Calculate ACct:
Cct x ED x BR
ACct = _
AT
ri1 acute
4.7 x 10-3 ppm x 8 hr/day x 2.04
ACcr = TAtoJtoy = 3"2 X 10
Calculate SADCct:
Cct x ED x EFSC x BR
SADCct = AT~
4.7 X 10"3 ppm x 8 x 22 X 2.04
SADCct = day year = 2 3 x 1Q_3
24-^1x30^
day year
Calculate ADCct:
Cct x ED x EF x WY x BR
ADCct = — —
AT
4.7 x 10~3 ppm x 8-t^— x 350^^1 x 31 years x 2.04
day year 7 ^
AD CCT = j r = 3.1 x 10 ppm
„,raays hr rr
31 years x 365—— x 24-j—
J yr day
Calculate LADCct:
Cct x ED x EF x WY x BR
LADCct = — —
ATC
4.7 x 10-3 ppm x 8-t— x 350 x 31 years x 2.04
, „ _ day year 7 „ ^ „ ,,
LADCct = 3 = 1-2 X 10 3 ppm
78 years x 365 a^S x 24 hr/day
7 year ' 7
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Appendix D DERMAL EXPOSURE ASSESSMENT METHOD
This appendix presents the modeling approach and equations to estimate occupational dermal exposures.
This method was developed through review of relevant literature and consideration of existing exposure
models, such as EPA/OPPT models and the ECETOC TRA.
D.l Dermal Dose Equation
EPA used the following equation to estimate the acute potential dose rate (APDR) from occupational
dermal exposures:
EquationApx D-l
APDR =S XQU x fabs x Yderm x FT
Where:
S
Qu
fabs
Yderm
FT
Surface area of skin in contact with the chemical formulation (cm2);
Dermal load {i.e., the quantity of the chemical formulation on the skin after the
dermal contact event, mg/cm2-event);
Fractional absorption of the chemical formulation into the stratum corneum,
accounting for evaporation of the chemical from the dermal load, Qu (unitless, 0 <
,/abs < 1);
Weight fraction of the chemical of interest in the liquid (unitless, 0 < Yderm < 1);
Frequency of events (integer number per day).
The inputs to the dermal dose equation are described in Appendix B.2.
D.2 Model Input Parameters
Table Apx D-l summarizes the model parameters and their values for estimating dermal exposures.
Additional explanations of EPA's selection of the inputs for each parameter are provided in the
subsections after this table.
Table Apx D-l. Summary of Model Input Values
Input Parameter
Symbol
Value
Unit
Rationale
Surface Area
S
535 (central tendency)
1,070 (high-end)
cm2
See Appendix D.2.1
Dermal Load
Qu
1.4 (central tendency)
2.1 (high-end)
mg/cm2-
event
See Appendix D.2.2
Fractional
Absorption
,/abs
0.003
unitless
See Appendix D.2.3
Weight Fraction
of Chemical
Yderm
1
unitless
See Appendix D.2.4
Frequency of
Events
FT
1
events/day
See Appendix D.2.5
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D.2.1 Surface Area
EPA used a high-end exposed skin surface area (S) for workers of 1,070 cm2 based on the mean two-
hand surface area for adult males ages 21 or older from Chapter 7 of EPA's Exposure Factors
Handbook (U.S. EPA.! ). For central tendency estimates, EPA assumed the exposure surface area
was equivalent to only a single hand (or one side of two hands) and used half the mean values for two-
hand surface areas {i.e., 535 cm2 for workers).
It should be noted that while the surface area of exposed skin is derived from data for hand surface area,
EPA did not assume that only the workers hands may be exposed to the chemical. Nor did EPA assume
that the entirety of the hands is exposed for all activities. Rather, EPA assumed that dermal exposures
occur to some portion of the hands plus some portion of other body parts {e.g., arms) such that the total
exposed surface area is approximately equal to the surface area of one or two hands for the central
tendency and high-end exposure scenario, respectively.
D.2.2 Dermal Load
The dermal load (Qu) is the quantity of chemical on the skin after the dermal contact event. This value
represents the quantity remaining after the bulk chemical formulation has fallen from the hand that
cannot be removed by wiping the skin {e.g., the film that remains on the skin). To estimate the dermal
load from each activity, EPA used data from references cited by EPA's September 2013 engineering
policy memorandum: Updating CEB 's Methodfor Screening-Level Assessments of Dermal Exposure
( 1013). This memorandum provides for the following dermal exposure scenarios:
• Routine and incidental contact with liquids {e.g., maintenance activities, manual cleaning of
equipment, filling drums, connecting transfer lines, sampling, and bench-scale liquid transfers);
• Routine immersion in liquids {e.g., handling of wet surfaces and spray painting);
• Routine contact with container surfaces {e.g., handling closed or empty bags of solid materials);
and
• Routine, direct handling of solids {e.g., filling/dumping containers of powders/flakes/granules,
weighing powder/scooping/mixing, handling wet or dried material in a filtration and drying
process).
For liquids, the memorandum uses values of 0.7 to 2.1 mg/cm2-event for routine or incidental contact
with liquids and 1.3 to 10.3 mg/cnr-event for routine immersion in liquids ( 1013). EPA used
the maximum from each range to estimate high-end dermal loads. The memorandum does not provide
recommended values for a central tendency dermal loading estimate. Therefore, EPA analyzed data
from EPA's technical report^ Laboratory Method to Determine the Retention of Liquids on the Surface
of the Hands ( b) that served as the basis for the liquid dermal loads provided in the 2013
memorandum. To estimate central tendency liquid dermal loading values, EPA used the 50th percentile
of the dermal loading results from the study for each type of activity {i.e., routine/incidental contact and
immersion). The 50th percentile was 1.7 mg/cm2-event for routine/incidental contact with liquids and
3.8 mg/cm2-event for routine immersion in liquids.
For 1,1-dichloroethane, EPA used high-end and central tendency dermal loading values of 1.4 and 2.1
mg/cm2-event, respectively, for each OES.
D.2.3 Fractional Absorption
EPA assumes a fractional absorption (/abs) of 0.003 for neat solutions. Since 1,1-dichloroethane is
expected to be received at all OES sites in pure form, EPA used a single fractional absorption of 0.003
across all OESs.
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D.2.4 Weight Fraction of Chemical
The weight fraction of 1,1-dichloroethane, Yderm, refers to the concentration of 1,1-dichloroethane in the
liquid formulation the worker's skin is exposed to. EPA generally assumes that this concentration will
be equal to the weight fraction of 1,1-dichloroethane in the chemical products being handled within the
OES. EPA assumes that 1,1-dichloroethane will be handled as a neat liquid with a weight fraction of 1
across all OES .
D.2.5 Frequency of Events
The frequency of events, FT, refers to the number of dermal exposure events per day. Depending on the
OES, workers may perform multiple activities throughout their shift that could potentially result in
dermal exposures. Equation Apx D-lEquation_Apx D-l shows a linear relationship between FT and
APDR; however, this fails to account for time between contact events. Since the chemical
simultaneously evaporates from and absorbs into the skin, dermal exposure is a function of both the
number of contact events per day and the time between contact events. Subsequent dermal exposure
events may only meaningfully increase the dermal dose if there is sufficient time between the contact
events to allow for significant evaporation/absorption of the previous exposure event. EPA did not
identify information on how many contact events may occur and the time between contact events.
Therefore, EPA assumes a single contact event per day for estimating dermal exposures for all OESs.
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Appendix E MODEL APPROACHES AND PARAMETERS
This appendix section presents the modeling approach and model equations used in estimating
environmental releases and occupational exposures for each of the applicable OESs. The models were
developed through review of the literature and consideration of existing EPA/OPPT models, ESDs,
and/or GSs. An individual model input parameter could either have a discrete value or a distribution of
values. EPA assigned statistical distributions based on reasonably available literature data. A Monte
Carlo simulation (a type of stochastic simulation) was conducted to capture variability in the model
input parameters. The simulation was conducted using the Latin hypercube sampling method in @Risk
Industrial Edition, Version 7.0.0. The Latin hypercube sampling method generates a sample of possible
values from a multi-dimensional distribution and is considered a stratified method, meaning the
generated samples are representative of the probability density function (variability) defined in the
model. EPA performed the model at 100,000 iterations to capture a broad range of possible input values,
including values with low probability of occurrence.
EPA used the 95th and 50th percentile Monte Carlo simulation model result values for assessment. The
95th percentile value represents the high-end release amount or exposure level, whereas the 50th
percentile value represents the typical release amount or exposure level. The following subsections
detail the model design equations and parameters for each of the OESs.
E.l EPA/OPPT Standard Models
This appendix section discusses the standard models used by EPA to estimate environmental releases of
chemicals and occupational inhalation exposures. All the models presented in this section are models
that were previously developed by EPA and are not the result of any new model development work for
this risk evaluation. Therefore, this appendix does not provide the details of the derivation of the model
equations which have been provided in other documents such as the ChemSTEER User Guide (U.S.
E ), Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Volume 1 (U.S. EPA. 1991). Evaporation ofpure liquids from open surfaces (Arnold and Engel. 2001).
Evaluation of the Mass Balance Model Used by the References Environmental Protection Agency for
Estimating Inhalation Exposure to New Chemical Substances (Fehrenbacher and Hummel. 1996). and
Releases During Cleaning of Equipment (PEI Associates. 1988) The models include loss fraction
models as well as models for estimating chemical vapor generation rates used in subsequent model
equations to estimate the volatile releases to air and occupational inhalation exposure concentrations.
The parameters in the equations of this appendix section are specific to calculating environmental
releases of 1,1-dichloroethane.
The EPA/OPPT Penetration Model estimates releases to air from evaporation of a chemical from an
open, exposed liquid surface. This model is appropriate for determining volatile releases from activities
that are performed indoors or when air velocities are expected to be less than or equal to 100 feet per
minute. The EPA/OPPT Penetration Model calculates the average vapor generation rate of the chemical
from the exposed liquid surface using the following equation:
EquationApx E-l
(8.24 X 10 ) * (MW^_dca) * Fcorrection J actor * VP * yj R®-t&air_speed * (0.25nDopening)
i_+ 1
29 + MW1:1_dca
Where:
Gactivity = Vapor generation rate for activity [g/s]
MWtcep = 1,1-dichloroethane molecular weight [g/mol]
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Fcorrectionjactor = Vapor pressure correction factor [unitless]
VP = 1,1-dichloroethane vapor pressure [torr]
Rateair speed = Air speed [cm/s]
Dopening = Diameter of opening [cm]
T = Temperature [K]
P = Pressure [torr]
The EPA/OPPT Mass Transfer Coefficient Model estimates releases to air from the evaporation of a
chemical from an open, exposed liquid surface. This model is appropriate for determining this type of
volatile release from activities that are performed outdoors or when air velocities are expected to be
greater than 100 feet per minute. The EPA/OPPT Mass Transfer Coefficient Model calculates the
average vapor generation rate of the chemical from the exposed liquid surface using the following
equation:
EquationApx E-2
}activity
(1.93 x 10 7) * {MW^_dca0JS) * FcorrectionJactor * VP * Rate°™speed * (Q.2SnD2openingY
¦ +
29 1 JIW,
Where:
uactivity
MWTcep
Fcorrection_f actor
VP
R(Xt6airspeed
Dopening
T
T0AD®^}„;„ (\[T — 5.87)2/s
opening ^
Vapor generation rate for activity [g/s]
1,1-dichloroethane molecular weight [g/mol]
Vapor pressure correction factor [unitless]
1,1-dichloroethane vapor pressure [torr]
Air speed [cm/s]
Diameter of opening [cm]
Temperature [K]
The EPA's Office of Air Quality Planning and Standards (OAQPS) AP-42 Loading Model estimates
releases to air from the displacement of air containing chemical vapor as a container/vessel is filled with
a liquid. This model assumes that the rate of evaporation is negligible compared to the vapor loss from
the displacement and is used as the default for estimating volatile air releases during both loading
activities and unloading activities. This model is used for unloading activities because it is assumed
while one vessel is being unloaded another is assumed to be loaded. The EPA/OAQPS AP-42 Loading
Model calculates the average vapor generation rate from loading or unloading using the following
equation:
Equation Apx E-3
CiYi ^
Fsaturation factor*MW-i,i-DCA*Vcontainer*378$-4 , *Fcorrection factor*VP* s~
r _ 3600hr
'-'activity ~
RATEfiii
Where:
u activity
Fsaturationj actor
MWTcep
^container
Fcorrection_f actor
Vapor generation rate for activity [g/s]
Saturation factor [unitless]
1,1-dichloroethane molecular weight [g/mol]
Volume of container [gal/container]
Vapor pressure correction factor [unitless]
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VP = 1,1-dichloroethane vapor pressure [torr]
RATEfm = Fill rate of container [containers/hr]
R = Universal gas constant [L*torr/mol-K]
T = Temperature [K]
For each of the vapor generation rate models, the vapor pressure correction factor (FcorreCtionj actor)
can be estimated using Raoult's Law and the mole fraction of 1,1-dichloroethane in the liquid of interest.
If calculating an environmental release, the vapor generation rate calculated from one of the above
models (EquationApx E-l, EquationApx E-2, and EquationApx E-3) is then used along with an
operating time to calculate the release amount:
Equation Apx E-4
s kg
RBlBCLSB^BCLVactipity Timeactivity * ^activity * 3600 * 0.001
Where:
Release_Yearactivity = 1,1-dichloroethane released for activity per site-year
[kg/site-yr]
Timeactivity = Operating time for activity [hr/site-yr]
Gactivity = Vapor generation rate for activity [g/s]
In addition to the vapor generation rate models, EPA uses various loss fraction models to calculate
environmental releases, including the following:
• EPA/OPPT Small Container Residual Model
• EPA/OPPT Drum Residual Model
• EPA/OPPT Multiple Process Vessel Residual Model
• EPA/OPPT Single Process Vessel Residual Model
The loss fraction models apply a given loss fraction to the overall throughput of 1,1-dichloroethane for
the given process. The loss fraction value or distribution of values differs for each model; however, the
models each follow the same general equation:
Equation Apx E-5
Release Yearactivity = PV
* Factivity Joss
Where:
Release_Yearactivity = 1,1-dichloroethane released for activity per site-year
[kg/site-yr]
PV = Production volume throughput of 1,1 -dichloroethane
[kg/site-yr]
Factivityjoss = Loss fraction for activity [unitless]
The EPA/OPPT Mass Balance Inhalation Model estimates a worker inhalation exposure to an estimated
concentration of chemical vapors within the worker's breathing zone using a one box model. The model
estimates the amount of chemical inhaled by a worker during an activity in which the chemical has
volatilized and the airborne concentration of the chemical vapor is estimated as a function of the source
vapor generation rate or the saturation level of the chemical in air. First, the applicable vapor generation
rate model (Equation Apx E-l, Equation Apx E-2, and Equation Apx E-3) is used to calculate the
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vapor generation rate for the given activity. With this vapor generation rate, the EPA/OPPTMass
Balance Inhalation Model calculates the volumetric concentration of
using the following equation:
EquationApx E-6
Cvactivity = Minimum-.
Where:
C u
° uactivity
Gactivity
MWTcep
Q
k
T
Fcorrection_f actor
VP
p
"170,000 * T *
r
uactivity
MWii-dca
* Q * k
1,000,000ppm * Fl
correction_f actor
* VP
Exposure activity volumetric concentration [ppm]
Exposure activity vapor generation rate [g/s]
1,1-dichloroethane molecular weight [g/mol]
Ventilation rate [ftVmin]
Mixing factor [unitless]
Temperature [K]
Vapor pressure correction factor [unitless]
1,1-dichloroethane vapor pressure [torr]
Pressure [torr]
Mass concentration can be estimated by multiplying the volumetric concentration by the molecular
weight of 1,1-dichloroethane and dividing by molar volume at standard temperature and pressure.
EPA uses the above equations in the 1,1-dichloroethane environmental release and occupational
exposure models, and EPA references the model equations by model name and/or equation number
within Appendix E.
E.2 Processing—Repackaging Model Approaches and Parameters
This appendix presents the modeling approach and equations used to estimate environmental releases
and occupational exposures for 1,1-dichloroethane during the Processing—repackaging OES. This
approach utilizes the ESD for Transport and Storage of Chemicals ("OECD. 2009) combined with Monte
Carlo simulation (a type of stochastic simulation).
Based on the ESD, EPA identified the following release sources from repackaging operations:
• Release source 1: Transfer Operation Losses to Air from Emptying Drum.
• Release source 2: Releases during Storage (not assessed).
• Release source 3: Transfer Operation Losses to Air from Filling Small Containers.
• Release source 4: Open Surface Losses to Air during Drum Cleaning.
• Release source 5: Drum Cleaning Releases to Landfill or Incineration.
Based on the ESD, EPA also identified the following inhalation exposure points:
• Exposure point A: Transfer Operation Exposures from Emptying Drum.
• Exposure point B: Transfer Operation Exposure from Filling Small Containers.
• Exposure point C: Exposures during Drum Cleaning.
Environmental releases and occupational exposures for 1,1-dichloroethane during repackaging are a
function of 1,1-dichloroethane's physical properties, container size, mass fractions, and other model
parameters. While physical properties are fixed, some model parameters are expected to vary. EPA used
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a Monte Carlo simulation to capture variability in the following model input parameters: ventilation rate,
mixing factor, air speed, saturation factor, loss factor, container sizes, working years, and drum fill rates.
EPA used the outputs from a Monte Carlo simulation with 100,000 iterations and the Latin Hypercube
sampling method in @Risk to calculate release amounts and exposure concentrations for this OES.
E.2.1 Model Equations
TableApx E-l provides the models and associated variables used to calculate environmental releases
for each release source within each iteration of the Monte Carlo simulation. EPA used these
environmental releases to develop a distribution of release outputs for the repackaging OES. The
variables used to calculate each of the following values include deterministic or variable input
parameters, known constants, physical properties, conversion factors, and other parameters. The values
for these variables are provided in Appendix E.2.2. The Monte Carlo simulation calculated the total 1,1-
dichloroethane release (by environmental media) across all release sources during each iteration of the
simulation. EPA then selected 50th percentile and 95th percentile values to estimate the central tendency
and high-end releases, respectively.
Table Apx E-l. Models and Variables Applied for Release Sources in the Processing—
Repackaging OES
Release Source
Model(s) Applied
Variables Used
Release source 1: Transfer
Operation Losses to Air from
Emptying Drum.
EPA/OAQPS AP-42 Loading Model
(EquationApx E-3)
Vapor Generation Rate: Fltl_DCA;
VP', F'saturation_unloading>
MWi i_dca> Vimport_cont> R> T,
RAT E^nid rum
Operating Time: RATEfiu_drum
Release source 2: Releases during
Storage (not assessed).
Not assessed; release is not expected to
lead to significant losses to the
environment unless there is an
accident.
Not applicable
Release source 3: Transfer
Operation Losses to Air from
Filling Small Containers.
EPA/OAQPS AP-42 Loading Model
(Equation Apx E-3)
Vapor Generation Rate: Fltl_DCA;
VP', Fsaturation_loading>
^^1,1 -DCA> Vfill_cont> R'> T>
RATEfui_smaiicont
Operating Time:
RATEfui_smaiicont
Release source 4: Open Surface
Losses to Air During Drum
Cleaning.
EPA/OPPT Penetration Model or
EPA/OPPTMass Transfer Coefficient
Model, based on air speed
(Equation Apx E-l, Equation Apx
E-2)
Vapor Generation Rate: ^-dca''
MW\,\_dca'> VP; RATEair speed;
Dopening_cont-cleaning> T', P
Operating Time: RATEfiu_drum
Release source 5: Drum Cleaning
Releases to Incineration or
Landfill.
EPA/OPPT Drum Residual Model
(EquationApx E-5)
PV, Fl0SSjr0nl
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Appendix E.2.6 provides equations and discussion for release source operating times used to calculate
releases to air as included in EquationApx E-4.
TableApx E-2 provides the models and associated variables used to calculate occupational exposures
for each exposure point within each iteration of the Monte Carlo simulation. EPA used these
occupational exposures to develop a distribution of exposure outputs for the repackaging OES. EPA
assumed that the same worker performed each exposure activity resulting in a total exposure duration of
up to 8 hours per day. The variables used to calculate each of the following exposure concentrations and
durations include deterministic or variable input parameters, known constants, physical properties,
conversion factors, and other parameters.
The values for these variables are provided in Appendix E.2.2 and Appendix E.2.3. The Monte Carlo
simulation calculated an 8-hr TWA exposure concentration for each iteration using the exposure
concentration and duration associated with each activity and assuming exposures outside the exposure
activities were zero. EPA then selected 50th percentile and 95th percentile values to estimate the central
tendency and high-end exposure concentrations, respectively.
Table Apx E-2. Models and Variables Applied for Exposure Points in the Processing—
Repackaging OES
Exposure Point
Modcl(s) Applied
Variables Used
Exposure point A: Transfer
Operation Exposures from
Emptying Drum
EPA/OPPTMass Balance
Inhalation Model with vapor
generation rate from EPA/OAQPS
AP-42 Loading Model
(EquationApx E-6)
Vapor Generation Rate: F11_DCA; VP;
Fsaturation unloading'' ^^1,1 -DCA>
^import_cont> T; RATEfmjirum; Q; k;
Vm
Exposure Duration: RATEfm arum
Exposure point B: Transfer
Operation Exposure from Filling
Small Containers
EPA/OPPT Mass Balance
Inhalation Model with vapor
generation rate from EPA/OAQPS
AP-42 Loading Model
(EquationApx E-6)
Vapor Generation Rate: F11_DCA; VP;
F'saturation_loading> ^^1,1 -DCA> ^small_cont>
R> T> RATEfiii_smaucont, Q, k, Vm
Exposure Duration. Vimp0rf C0nf, V^m conf,
RATEfu idrum
Exposure point C: Exposures
during Drum Cleaning
EPA/OPPT Mass Balance
Lnhalation Model with vapor
generation rate from EPA/OPPT
Penetration Model or EPA/OPPT
Mass Transfer Coefficient Model,
based on air speed
(EquationApx E-6)
Vapor Generation Rate: F11_DCA;
MW-l -l-dca' VP'> RATEair speed;
Dopening_cont-cleaning> T; P; Q; k; Vm
Exposure Duration: RATEfm arum
Appendix E.2.6 provides equations and discussion for exposure durations used for each exposure
activity. Note that the number of exposure days is set equal to the number of operating days per year up
to a maximum of 250 days per year. If the number of operating days is greater than 250 days per year,
EPA assumed that a single worker would not work more than 250 days per year such that the maximum
exposure days per year was still 250.
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3521 E.2.2 Model Input Parameters
3522 Table Apx E-3 summarizes the model parameters and their values for the Processing—repackaging
3523 Monte Carlo simulation. Additional explanations of EPA's selection of the distributions for each
3524 parameter are provided after this table.
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Table Apx E-3. Summary o
'Parameter Values and Dist
ributions Used in the Processing—Repackaging Models
Input
Parameter
Symbol
Unit
Deterministic
Values
Uncertainty Analysis Distribution
Parameters
Rationale / Basis
Value
Lower
Bound
Upper
Bound
Mode
Distribution
Type
Air Speed
RATEair speed
cm/s
10
1.3
202.2
-
Lognormal
See Section E.2.7
Container Loss
Fraction
Ftoss cont
kg/kg
0.025
0.017
0.03
0.025
Triangular
See Section E.2.8
Saturation Factor
Unloading
Fsaturation unloadi
ng
unitless
0.5
0.5
1.45
0.5
Triangular
See Section E.2.10
Saturation Factor
Loading
Fsaturation loading
unitless
0.5
0.5
1.45
0.5
Triangular
See Section E.2.10
Import Container
Volume
Vimport cont
gal/container
55
20
100
55
Triangular
See Section E.2.11
Small Container
Volume
Vprod cont
gal/container
5
5
20
5
Triangular
See Section E.2.11
Number of Sites
Ns
sites
2
-
-
-
-
"What-if" scenario input
Production
Volume Assessed
PVJb
lb/year
50,000
-
-
-
-
"What-if" scenario input
Production
Volume
PV
kg/year
22,680
-
-
-
-
PV input converted to
kilograms
Import
Concentration
FlJ-DCA import
kg/kg
1.0
-
-
-
-
Assumed pure 1,1-
dichloroethane repackaged
Temperature
T
Kelvin
298
-
-
-
-
Process parameter
Pressure
P
torr
760
-
-
-
-
Process parameter
Gas Constant
R
L*torr/(mol*
K)
62.36367
-
-
-
-
Universal constant
1,1-
dichloroethane
Vapor Pressure
VP
ton-
227
"
"
"
"
Physical property
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Input
Parameter
Symbol
Unit
Deterministic
Values
Uncertainty Analysis Distribution
Parameters
Rationale / Basis
Value
Lower
Bound
Upper
Bound
Mode
Distribution
Type
u-
dichloroethane
Density
Pl.l-DCA
kg/m3
1,168
Physical property
u-
dichloroethane
Molecular Weight
MWlJ-DCA
g/mol
98.95
—
—
—
—
Physical property
Fill Rate of Dram
RATEfUldrum
containers/hr
20
-
-
-
-
See Section E.2.12
Fill Rate of Small
Container
RA TEfUl small
containers/hr
60
-
-
-
-
See Section E.2.12
Diameter of
Opening for
Container
Cleaning
Dopening cont-
cleaning
cm
5.08
See Section E.2.9
Ventilation Rate
Q
ft3/min
3,000
500
10,000
3,000
Triangular
See Section E.2.13
Mixing Factor
k
unitless
0.5
0.1
1
0.5
Triangular
See Section E.2.14
3526
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E.2.3 Throughput Parameters
The facility production rate is calculated as an input value to be used in the model equations during each
iteration. The facility production rate is calculated using the following equation:
EquationApx E-7.
Where:
PV
Ns
PVsite
EPA assumed the number of release days in a single year is also equivalent to the number of import
containers unloaded for repackaging in a single year. This is a result of the production volume of 1,1-
dichloroethane selected only allows for the number of containers received in a single year to be between
26 to 129 containers per year. The equation to calculate the number of import containers is in Appendix
E.2.4.
E.2.4 Number of Containers per Year
EPA assumed that facilities unloaded one imported drum in a single day for repackaging. EPA assumes
1,1-dichloroethane is imported in its pure form at 100% concentration. Based on the two production
volumes and import container sizes shown in Table Apx E-3, this only allows for the number of
containers received in a single year to be between four to 40 containers per year. By assuming only one
imported drum is unloaded and repackaged in a single day, the number of containers unloaded per year
is equivalent to the number of release days per year. The number of import containers of 1,1-
dichloroethane used by a site per year is calculated using the following equation:
Equation Apx E-8
PV
NCont_yr ~ 7 m3 \
Ns * Pi,i-dca * ^0.00378541
gal) * ^import_cont
Production volume [kg/year]
1,1-dichloroethane density [kg/m3]
Import container volume [gal/container]
Number of sites [sites]
Annual number of import containers [container/site-year]
_ PV
PVsite ~ ~/v7
Production volume [kg/year]
Number of sites [sites]
Facility production rate [kg/site-year]
Where:
PV
Ptcep
Vimport_cont
Ns
Ncont_yr
E.2.5 Release Days per Year
EPA calculated the number of release days in a single year using the following equation:
Equation Apx E-9
/ 77-\
Pi,i-dca * ^0.00378541
gal) * ^^mP°rt-cont:
Where:
RD = Release days or Number of import containers [days/site-yr or
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containers/ site-yr]
Ptcep = 1,1-Dichloroethane density [kg/m3]
Vimport_cont = Import container volume [gal/container]
As described in Appendix E.2.4, EPA assumed that the number of import containers unloaded in a
single operating day was one. Therefore, the number of release days is equivalent to the number of
import containers, with a range of 26 to 129 release days.
E.2.6 Operating Hours and Exposure Durations
EPA estimated operating hours and exposure durations using calculations and parameters provided by
the ESD on Transport and Storage of Chemicals (OECD. 2009) and ChemSTEER User Guide (U.S.
E ). The operating time for release and exposure activities associated with unloading (release
source 1 and 4; exposure points A and C) are calculated using the following equation:
EquationApx E-10
1
TimeRP1/RP 4 —
K/il Efill drum
Where:
TimeRP1/RP4 = Operating time for release sources 1 and 4 [hrs/container]
RATEfiUdrum = Fill rate of drum [containers/hr]
For the emptying of drums, the ChemSTEER User Guide ( £015) indicates a drum fill rate of
20 drums per hour based on the Chemical Engineering Branch Manual for the Preparation of
Engineering Assessments, Volume 1 [CEB Manual] (U.S. EPA. 1991). EPA assumed that one drum is
imported and repackaged in a single operating day therefore equating the number of import containers
received in a single year to the number of release days per year. For the cleaning of drums, the
ChemSTEER User Guide ( ) uses the same drum fill rate as emptying drums to estimate
an exposure duration. EPA did not identify any other information on drum fill rates; therefore, EPA used
a single deterministic value for fill rate.
The operating hours for both release source 3 and exposure point B is calculated using the following
equation:
Equation Apx E-ll
Where:
TimeRP3
Vi
import_cont
Vfill_cont
RATE
TimeRP3 =
Vh
¦ import_cont
VfilLcont * RatefillSmallcont * ^
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source (operating hours rate for release source 3) and exposure point (exposure duration for exposure
point B).
E.2.7 Air Speed
Baldwin and Maynard measured indoor air speeds across a variety of occupational settings in the United
Kingdom (Baldwin and Mayn< )8), specifically, 55 work areas were surveyed. EPA analyzed the
air speed data from Baldwin and Maynard and categorized the air speed surveys into settings
representative of industrial facilities and representative of commercial facilities. EPA fit separate
distributions for these industrial and commercial settings and used the industrial distribution for this
OES.
EPA fit a lognormal distribution for the data set as consistent with the authors' observations that the air
speed measurements within a surveyed location were lognormally distributed and the population of the
mean air speeds among all surveys were lognormally distributed (Baldwin and Maynard. 1998). Since
lognormal distributions are bound by zero and positive infinity, EPA truncated the distribution at the
largest observed value among all of the survey mean air speeds.
EPA fit the air speed surveys representative of industrial facilities to a lognormal distribution with the
following parameter values: mean of 22.414 cm/s and standard deviation of 19.958 cm/s. In the model,
the lognormal distribution is truncated at a minimum allowed value of 1.3 cm/s and a maximum allowed
value of 202.2 cm/s (largest surveyed mean air speed observed in Baldwin and Maynard) to prevent the
model from sampling values that approach infinity or are otherwise unrealistically small or large
(Baldwin and Maynard. 1998).
Baldwin and Maynard only presented the mean air speed of each survey. The authors did not present the
individual measurements within each survey. Therefore, these distributions represent a distribution of
mean air speeds and not a distribution of spatially variable air speeds within a single workplace setting.
However, a mean air speed (averaged over a work area) is the required input for the model. EPA
converted the units to ft/min prior to use within the model equations.
E.2.8 Container Residue Loss Fraction
EPA previously contracted PEI Associates, Inc. (PEI) to conduct a study for providing estimates of
potential chemical releases during cleaning of process equipment and shipping containers (PEI
Associati 3). The study used both a literature review (analyzing cleaning practices and release
data) and a pilot-scale experiment to determine the amount of residual material left in vessels. The data
from literature and pilot-scale experiments addressed different conditions for the emptying of containers
and tanks, including various bulk liquid materials, different container constructions (e.g., lined steel
drums or plastic drums), and either a pump or pour/gravity-drain method for emptying. EPA reviewed
the pilot-scale data from PEI and determined a range and average percentage of residual material
remaining in vessels following emptying from drums by either pumping or pouring as well as tanks by
gravity-drain (PEI Associates. 1988).
EPA previously used the study results to generate default central tendency and high-end loss fraction
values for the residual models (e.g., EPA/OPPT Small Container Residual Model, EPA/OPPT Drum
Residual Model) provided in the ChemSTEER User Guide ( ). Previously, EPA adjusted
the default loss fraction values based on rounding the PEI study results or due to policy decisions. EPA
used a combination of the PEI study results and ChemSTEER User Guide default loss fraction values to
develop probability distributions for various container sizes.
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Specifically, EPA paired the data from the PEI study such that the residuals data for emptying drums by
pouring was aligned with the default central tendency and high-end values from the EPA/OPPTSmall
Container Residual Model, and the residuals data for emptying drums by pumping was aligned with the
default central tendency and high-end values from the EPA/OPPT Drum Residual Model. EPA applied
the EPA/OPPT Small Container Residual Model to containers with capacities less than 20 gallons, and
the EPA/OPPT Drum Residual Model to containers with capacities between 20 and 100 gallons Qj„S
I ).
For unloading drums via pouring, the PEI study experiments showed average container residuals in the
range of 0.03 percent to 0.79 percent with a total average of 0.32 percent (PEI Associates. 1988). The
EPA/OPPT Small Container Residual Model recommends a default central tendency loss fraction of 0.3
percent and a high-end loss fraction of 0.6 percent (I v < < \ _A. 2015). The
underlying distribution of the loss fraction parameter for small containers or drums is not known;
therefore, EPA assigned a triangular distribution defined by the estimated lower bound, upper bound,
and mode of the parameter values. EPA assigned the mode and upper bound values for the loss fraction
triangular distributions using the central tendency and high-end values from the respective ChemSTEER
User Guide model ( ). EPA assigned the lower bound values for the triangular
distributions using the minimum average percent residual measured in the PEI study for the respective
drum emptying technique (pouring or pumping) (PEI Associate l).
E.2.9 Diameters of Opening
The ChemSTEER User Guide indicates diameters for the openings for various vessels that may hold
liquids in order to calculate vapor generation rates during different activities ( ). In the
simulation developed for the processing—repackaging OES based on the ESD for Transport and
Storage of Chemicals (< 39), EPA used the default diameters of vessels from the ChemSTEER
User Guide for container cleaning.
For container cleaning activities, the ChemSTEER User Guide indicates a single default value of 5.08
cm ( 2015). Therefore, EPA could not develop a distribution of values for this parameter and
used the single value 5.08 cm from the ChemSTEER User Guide.
E.2.10 Saturation Factor
The Chemical Engineering Branch Manual for the Preparation of Engineering Assessments, Volume 1
[CEB Manual] indicates that during splash filling, the saturation concentration was reached or exceeded
by misting with a maximum saturation factor of 1.45 (II ). The CEB Manual indicates that
saturation concentration for bottom filling was expected to be about 0.5 ( ). The
underlying distribution of this parameter is not known; therefore, EPA assigned a triangular distribution
based on the lower bound, upper bound, and mode of the parameter. Because a mode was not provided
for this parameter, EPA assigned a mode value of 0.5 for bottom filling as bottom filling minimizes
volatilization ( ). This value also corresponds to the typical value provided in the
ChemSTEER User Guide for the EPA/OAQPS AP-42 Loading Model ( ).
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E.2.11 Container Size
The ChemSTEER User Guide (U.S. EPA. 2015) indicates a range of 20 to Fess than 100 gallons for the
volume capacity of drums modeled in container-related activities, and the ESD for Transport and
Storage of Chemicals (< 39) suggests nearly 80% of all steel drums in the United States have a
capacity of 55 gallons. The underlying distribution import drum sizes is not known; therefore, EPA
assigned a lower bound of 20 gallons, an upper bound of 100 gallons, and a mode of 55 gallons for the
import container volume distribution.
The ChemSTEER User Guide ( ) indicates a range of 5 to less than 20 gallons for the
volume capacity of small containers modeled in container-related activities with 5 gallons as the default
volume size. Therefore, EPA assigned a lower bound of 5 gallons, an upper bound of 20 gallons, and a
mode of 5 gallons for the small container volume distribution.
E.2.12 Container Fill Rates
The ChemSTEER User Guide (U.S. EPA. 2015) provides a typical fill rate of 20 containers per hour for
containers with 20 to 100 gallons of liquid and a typical fill rate of 60 containers per hour for containers
with less than 20 gallons of liquid.
E.2.13 Ventilation Rate
The CEB Manual ( ) indicates general ventilation rates in industry range from 500 to
10,000 ftVmin, with a typical value of 3,000 ftVmin. The underlying distribution of this parameter is not
known; therefore, EPA assigned a triangular distribution based on an estimated lower bound, upper
bound, and mode of the parameter. EPA assumed the lower and upper bound using the industry range of
500 to 10,000 ftVmin and the mode using the 3,000 ftVmin typical value ( ).
E.2.14 Mixing Factor
The CEB Manual ( ) indicates mixing factors may range from 0.1 to 1, with 1
representing ideal mixing. The CEB Manual references the 1988 ACGIH Ventilation Handbook, which
suggests the following factors and descriptions: 0.67 to 1 for best mixing; 0.5 to 0.67 for good mixing;
0.2 to 0.5 for fair mixing; and 0.1 to 0.2 for poor mixing (U.S. EPA. 1991). The underlying distribution
of this parameter is not known; therefore, EPA assigned a triangular distribution based on the defined
lower and upper bound and estimated mode of the parameter. The mode for this distribution was not
provided; therefore, EPA assigned a mode value of 0.5 based on the typical value provided in the
ChemSTEER User Guide for the EPA/OPPTMass Balance Inhalation Model ( ).
E.3 Commercial Use as a Laboratory Chemical Model Approach and
Parameters
This appendix presents the modeling approach and equations used to estimate environmental releases for
1,1-dichloroethane during the Commercial Use as a Laboratory Chemical OES. This approach utilized
the Use of Laboratory Chemicals—Generic Scenario for Estimating Occupational Exposures and
Environmental Releases (11 S 1 T \ 2023) combined with Monte Carlo simulations (a type of stochastic
simulation).
Based on the GS, EPA identified the following release sources from laboratory operations:
• Release source 1: Release during unloading of liquids
• Release source 2: Release during unloading of solids (not assessed)
• Release source 3: Release from cleaning transport container
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• Release source 4: Open surface losses to air during container cleaning
• Release source 5: Labware equipment cleaning
• Release source 6: Open surface losses during equipment cleaning
• Release source 7: Releases to air during laboratory analyses
• Release source 8: Release from disposal of laboratory waste
Environmental releases for 1,1-dichloroethane during use as a laboratory chemical are a function of 1,1-
dichloroethane's physical properties, container size, mass fractions, and other model parameters. While
some parameters are fixed, others are expected to vary. EPA used a Monte Carlo simulation to capture
variability in the following model input parameters: ventilation rate, mixing factor, air speed, saturation
factor, loss factor, container sizes, working years, and drum fill rates. EPA used the outputs from a
Monte Carlo simulation with 100,000 iterations and the Latin Hypercube sampling method in @Risk to
calculate release amounts and exposure concentrations for this OES.
E.3.1 Model Equations
TableApx E-4 provides the models and associated variables used to calculate environmental releases
for each release source within each iteration of the Monte Carlo simulation. EPA used these
environmental releases to develop a distribution of release outputs for the Commercial Use as a
Laboratory Chemical OES. The variables used to calculate each of the following values include
deterministic or variable input parameters. The values for these variables are provided in Appendix
E.3.2. The Monte Carlo simulation calculated the total 1,1-dichloroethane release (by environmental
media) across all release sources during each iteration of the simulation. EPA then selected 50th
percentile and 95th percentile values to estimate the central tendency and high-end releases,
respectively.
Table Apx E-4. Models and Variables Applied for Release Sources in the Commercial Use as a
Laboratory Chemical OES
Release Source
Model(s) Applied
Variables Used
Release source 1: Release during
unloading of liquid
EPA/OA QPS AP-42 Loading
Model
(EquationApx E-3)
Vapor Generation Rate: F11_DCA; VP;
Fsaturation unloading'' ^^1,1-DCA> Qcont>
T; RATEfm smallcont
Operating Time: RATEfillsmallcont;
Ncont unload yr ¦> O^days
Release source 2: Release during
unloading of solids
Not assessed; release is not
expected since 1,1-dichloroethane
is assumed to be managed as a
liquid
Not applicable
Release source 3: Release from
cleaning transport container
EPA/OPPT Small Container
Residual Model (Equation Apx
E-5)
Qchemsite day (recalc)? ^loss jsmallcont?
OP days
Release source 4: Open surface
losses to air during container
cleaning
EPA/OPPT Penetration Model or
EPA/OPPT Mass Transfer
Coefficient Model, based on air
speed (Equation Apx E-l and
EquationApx E-2)
Vapor Generation Rate: FTCEP; MW11_DCA;
VP, RATEair speed, Dconfainer, T, P
Operating Time: RATEfill smallcont;
Ncont unload yr ? O^days
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Release Source
Model(s) Applied
Variables Used
Release source 5: Labware
equipment cleaning
EPA/OPPTMultiple Process
Residual Model (Equation Apx
e-5;
Qchemsite day (recalc)? ^loss_equip? O^days
Release source 6: Open surface
losses during equipment
cleaning
EPA/OPPT Penetration Model or
EPA/OPPT Mass Transfer
Coefficient Model, based on air
speed (EquationApx E-l and
EquationApx E-2)
Vapor Generation Rate: FTCEP; MW11_DCA;
VP, RATEair speed, Dconfainer, T, P
Operating Time: OHequip
Release source 7: Releases to air
during laboratory analyses
EPA/OPPT Penetration Model or
EPA/OPPT Mass Transfer
Coefficient Model, based on air
speed (Equation Apx E-l and
Equation Apx E-2)
Vapor Generation Rate: F11_DCA;
MW1:1 -Dca> VP; RATEair speed;
Dcontainer lab analysis '• T; P
Operating Time: OHsamplinq
Release source 8: Release from
disposal
No model applicable; all
chemicals used in the laboratory
are expected to be disposed at the
end of each working day.
Remaining chemical not released
from the previous release sources
is released here
Not applicable
3770 E.3.2 Model Input Parameters
3771 Table Apx E-5 summarizes the model parameters and their values for the Commercial Use as a
3772 Laboratory Chemical Monte Carlo simulation. Additional explanations of EPA's selection of the
3773 distributions for each parameter are provided after this table.
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3774
3775 TableApx E-5. Summary of Parameter Values and Distributions Used in the Commercial Use as a Laboratory Chemical Model
Input Parameter
Symbol
Unit
Deterministic
Values
Uneertainty Analysis Distribution Parameters
Rationale / Basis
Value
Lower
Bound
Upper
Bound
Mode
Distribution
Tvpe
Air Speed
RATEair speed
cm/s
10
1.3
202.2
—
Lognormal
See SectionE.3.8
Loss Fraction for
Small Containers
Floss smallcont
kg/kg
0.003
0.0003
0.006
0.003
Triangular
See SectionE.3.9
Saturation Factor
Unloading
Fsaturation unloading
unitless
0.5
0.5
1.45
0.5
Triangular
See SectionE.3.11
Daily Throughput of
Stock Solutions
Qstock site day
mL/site-day
2,000
0.5
4,000
2,000
Triangular
See SectionE.3.4
Diameter of
Laboratory Analysis
Containers
Dcontainer lab analysis
cm
2.5
2.5
10
2.5
Triangular
See SectionE.3.14
Operating Days
TIMEoperating days
days/yr
260
173
261
260
Triangular
See SectionE.3.6
Production Volume
Assessed
PVlb
lb/yr
50,000
-
-
-
-
"What-if' scenario input
Production Volume
PV
kg/yr
22,680
-
-
-
-
PV input converted to
kilograms
Temperature
T
K
298
-
-
-
-
Process parameter
Pressure (torr)
Ptorr
torr
760
-
-
-
-
Process parameter
Pressure (atm)
Patm
Atm
1
-
-
-
-
Process parameter
Gas Constant
R
L*torr/mol-K
62.36367
-
-
-
-
Universal constant
1,1-dichloroethane
Vapor Pressure
VP
torr
227
-
-
-
-
Physical property
1,1-dichloroethane
Molecular Weight
MWi,i-dca
g/mol
98.95
-
-
-
-
Physical property
Molar Volume
Vmij-DCA
L/mol
24.45
-
-
-
-
Physical property
Fill Rate of Small
Container
RATEfill smallcont
containers/hr
60
-
-
-
-
See SectionE.3.12
Container Volume
Qcont
gal/container
1
-
-
-
-
See SectionE.3.10
Loss Fraction for
Equipment Cleaning
Floss equip
kg/kg
0.02
-
-
-
-
See SectionE.3.13
Hours per
Equipment Cleaning
OHequip clean
hrs
4
-
-
-
-
See SectionE.3.6
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Input Parameter
Symbol
Unit
Deterministic
Values
Lneertainty Analysis Distribution Parameters
Rationale / Basis
Value
Lower
Bound
Upper
Bound
Mode
Distribution
Type
Hours per Analysis
Sampling
OHsampling
hrs
1
-
-
-
-
See SectionE.3.6
Diameter of
Opening for
Container
Dcontainer
cm
5.08
See SectionE.3.14
Product density
Pproduct
kg/m3
-
Multiple distributions depending on
product data
Uniform
See SectionE.3.15
Product
Concentration
Fl,l-DCA_prod
kg/kg
-
Multiple distributions depending on
product data
Uniform
See SectionE.3.15
Ventilation Rate
Q
ft3/min
-
500
10,000
3,000
Triangular
See SectionE.3.16
Mixing Factor
k
unitless
-
0.1
1
0.5
Triangular
See SectionE.3.17
3776
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E.3.3 Number of Sites
The Use of Laboratory Chemicals—Generic Scenario for Estimating Occupational Exposures and
Environmental Releases (U.S. EPA. 2023) provides a method of determining the number of laboratory
sites based on the total annual production volume and annual throughput per site of the chemical of
interest. The total annual production volume is 50,000 lb/yr (see Section 5.5.3). The annual throughput
per site of 1,1-dichloroethane is determined according to Section E.3.4.
EquationApx E-12
Where:
Nsites
PV
Qchemsite yr
Nsites ~
PV
Qchem
site yr
Number of sites [site]
Annual production volume [kg/yr]
Annual Throughput of 1,1-dichloroethane [kg/site-yr]
E.3.4 Throughput Parameters
The Use of Laboratory Chemicals—Generic Scenario for Estimating Occupational Exposures and
Environmental Releases (U. 2023) provides daily throughput of 1,1-dichloroethane required for
laboratory stock solutions. According to the GS, laboratory liquid use rate ranges from 0.5 mL up to 4
liters per day. Laboratory stock solutions are used for multiple analyses and eventually need to be
replaced, The expiration or replacement times range from daily to 6 months ( 3). For this
scenario, EPA assumes stock solutions are prepared daily. Therefore, EPA assigned a triangular
distribution for the daily throughput of laboratory stock solutions with upper and lower bounds
corresponding to the high and low throughputs, 4,000 and 0.5 mL respectively, with a mode of 2,000
mL. The daily throughput of 1,1-dichloroethane is calculated using the following equation:
Equation Apx E-13
^ _ Qstock site day
Vchemsiteday ~ J mL
Pproduct * F1,1-DCAprod * 1000 ^^3" * 1000——
Where:
Qchemsite day = Daily Throughput of 1,1-dichloroethane [kg/site-day]
Qstock site day = Daily Throughput of Stock Solutions [kg/site-day]
Pproduct = Product density [kg/m3]
FTcEP_prod = Weight fraction of 1,1-dichloroethane in product [unitless]
The annual throughput of 1,1-dichloroethane is calculated using Equation Apx E-14 by multiplying the
daily throughput by the number of operating days. The number of operating days is determined
according to Section E.3.6.
Equation Apx E-14
Qchemsite yr ~ Qchemsite day * TIME0perating dayS
Where:
TIMEoperatingdays = Operating days [days/yr]
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The annual throughput of 1,1-dichloroethane cannot exceed the production volume limit of 50,000 lb/yr.
Therefore, in the event an iteration of the simulation does calculate an annual throughput greater than
the production volume limit, EPA set the number of sites equal to one, and the annual throughput equal
to the total annual production volume. The model then recalculated the number of operating days using
EquationApx E-15 below.
EquationApx E-15
PV
TIME0perating dayS (recalc) ~ "77 ~TT)
"sites Vchem site day
Where:
TIMEoperating days (recaic) = Recalculated number of operating days [days/yr]
E.3.5 Number of Containers Unloaded Annually per Site
EPA estimated the number of containers unloaded annually per site using the Use of Laboratory
Chemicals—Generic Scenario for Estimating Occupational Exposures and Environmental Releases
( ±023), as well as other parameters. The total number of containers unloaded annually per
site is calculated based on the annual throughput (See Section E.3.4), product concentration (See Section
E.3.15), and container volume (See Section E.3.10). The total number of containers unloaded annually
per site is calculated using Equation Apx E-16 below.
Equation Apx E-16
_ Qchem site yr
™cont unload yr ~ ~~7J
" 1,1—DC A prod vcont
Where:
NCont unload yr = Number of Containers Unloaded Annually per site [container/site-yr]
Qcont = Container volume [gal/container]
E.3.6 Operating Days
The Use of Laboratory Chemicals—Generic Scenario for Estimating Occupational Exposures and
Environmental Releases ( 1023). estimates the number of operating days from employment
data obtained through the U.S. Bureau of Labor Statistics (BLS) Occupational Employment Statistics.
The U.S. BLS assumes the operating duration per NAICS code or a 'year-round, full-time' hours figure,
to be 2,080 hours (U.S. EPA. 2023). Using this annual duration and an assumed daily shift lengths of 8-
,10-, and 12-hours/day, EPA calculated 260, 208, and 174 operating days/year, respectively.
E.3.7 Operating Hours
EPA estimated operating hours using the Use of Laboratory Chemicals—Generic Scenario for
Estimating Occupational Exposures and Environmental Releases (U.S. EPA. 2023). as well as other
parameters and equations. The operating hours for release sources 1 and 4 are calculated using the
number of product containers used at the site, the container fill rate, and operating days (see Section
E.3.6). The following equations provide the calculation.
Equation Apx E-17
„. NCOnt unload yr
TimeRP1/4 — datf
1 IM c 0perating days (recalc) * tiAl EfM smallcont
Where:
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T imeRP
RATEfis
RP1/4
1fill_smallcont
Operating times for release sources 1 and 4 [hrs/site-day]
Fill rate of small container [containers/hr]
For equipment cleaning, the Use of Laboratory Chemicals—Generic Scenario for Estimating
Occupational Exposures and Environmental Releases (U. 2023) uses the multiple vessel model
with a default release duration of 4 hours per day. Therefore, EPA assumes 4 hours per day as the
release for release source 6.
For laboratory analyses, the Use of Laboratory Chemicals—Generic Scenario for Estimating
Occupational Exposures and Environmental Releases ( 2023) provides a default release
estimate of 1 hour per day based on the default for sampling. EPA assumes 1 hour per day for release
source 7.
E.3.8 Air Speed
Baldwin and Maynard measured indoor air speeds across a variety of occupational settings in the United
Kingdom (Baldwin and Mavm M). Fifty-five work areas were surveyed across a variety of
workplaces. EPA analyzed the air speed data from Baldwin and Maynard and categorized the air speed
surveys into settings representative of industrial facilities and representative of commercial facilities.
EPA fit separate distributions for these industrial and commercial settings and used the industrial
distribution for this OES.
EPA fit a lognormal distribution for the data set as consistent with the authors' observations that the air
speed measurements within a surveyed location were lognormally distributed and the population of the
mean air speeds among all surveys were lognormally distributed (Baldwin and Maynard. 1998). Since
lognormal distributions are bound by zero and positive infinity, EPA truncated the distribution at the
largest observed value among all of the survey mean air speeds.
EPA fit the air speed surveys representative of industrial facilities to a lognormal distribution with the
following parameter values: mean of 22.414 cm/s and standard deviation of 19.958 cm/s. In the model,
the lognormal distribution is truncated at a minimum allowed value of 1.3 cm/s and a maximum allowed
value of 202.2 cm/s (largest surveyed mean air speed observed in Baldwin and Maynard) to prevent the
model from sampling values that approach infinity or are otherwise unrealistically small or large
(Baldwin and Mayn 98).
Baldwin and Maynard only presented the mean air speed of each survey. The authors did not present the
individual measurements within each survey. Therefore, these distributions represent a distribution of
mean air speeds and not a distribution of spatially variable air speeds within a single workplace setting.
However, a mean air speed (averaged over a work area) is the required input for the model. EPA
converted the units to ft/min prior to use within the model equations.
E.3.9 Container Residue Loss Fraction
EPA previously contracted PEI Associates, Inc (PEI) to conduct a study for providing estimates of
potential chemical releases during cleaning of process equipment and shipping containers (PEI
Associati |). The study used both a literature review of cleaning practices and release data as well
as a pilot-scale experiment to determine the amount of residual material left in vessels. The data from
literature and pilot-scale experiments addressed different conditions for the emptying of containers and
tanks, including various bulk liquid materials, different container constructions (e.g., lined steel drums
or plastic drums), and either a pump or pour/gravity-drain method for emptying. EPA reviewed the
pilot-scale data from PEI and determined a range and average percentage of residual material remaining
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in vessels following emptying from drums by either pumping or pouring as well as tanks by gravity-
drain (PEI Associates. 1988).
EPA previously used the study results to generate default central tendency and high-end loss fraction
values for the residual models (e.g., EPA/OPPT Small Container Residual Model, EPA/OPPT Drum
Residual Model) provided in the ChemSTEER User Guide ( ). Previously, EPA adjusted
the default loss fraction values based on rounding the PEI study results or due to policy decisions. EPA
used a combination of the PEI study results and ChemSTEER User Guide default loss fraction values to
develop probability distributions for various container sizes.
Specifically, EPA paired the data from the PEI study such that the residuals data for emptying drums by
pouring was aligned with the default central tendency and high-end values from the EPA/OPPT Small
Container Residual Model, and the residuals data for emptying drums by pumping was aligned with the
default central tendency and high-end values from the EPA/OPPT Drum Residual Model. EPA applied
the EPA/OPPT Small Container Residual Model to containers with capacities less than 20 gallons, and
the EPA/OPPT Drum Residual Model to containers with capacities between 20 and 100 gallons Qj„S
E ). For unloading drums by pouring, the PEI study experiments showed average container
residuals in the range of 0.03 percent to 0.79 percent with a total average of 0.32 percent (PEI
Associati 3). The EPA/OPPT Small Container Residual Model recommends a default central
tendency loss fraction of 0.3 percent and a high-end loss fraction of 0.6 percent ( ). For
unloading drums by pumping, the PEI study experiments showed average container residuals in the
range of 1.7 percent to 4.7 percent with a total average of 2.6 percent (PEI Associates. 1988). The
EPA/OPPT Drum Residual Model from the ChemSTEER User Guide recommends a default central
tendency loss fraction of 2.5 percent and a high-end loss fraction of 3.0 percent ( ). The
underlying distribution of the loss fraction parameter for small containers or drums is not known;
therefore, EPA assigned a triangular distribution defined by the estimated lower bound, upper bound,
and mode of the parameter values. EPA assigned the mode and upper bound values for the loss fraction
triangular distributions using the central tendency and high-end values from the respective ChemSTEER
User Guide model ( ). EPA assigned the lower bound values for the triangular
distributions using the minimum average percent residual measured in the PEI study for the respective
drum emptying technique (pouring or pumping) (PEI Associate |).
E.3.10 Product Container Volume
EPA did not identify container sizes for 1,1-dichloroethane use in laboratories from available literature.
Therefore, EPA assumes that 1,1-dichloroethane is transported in 1 L containers to small vials for use
per the Use of Laboratory Chemicals—Generic Scenario for Estimating Occupational Exposures and
Environmental Releases (11 S 1 T \ 2023).
E.3.11 Saturation Factor
The CEB Manual indicates that during splash filling, the saturation concentration was reached or
exceeded by misting with a maximum saturation factor of 1.45 ( ). The CEB Manual
indicates that saturation concentration for bottom filling was expected to be about 0.5 ( ).
The underlying distribution of this parameter is not known; therefore, EPA assigned a triangular
distribution based on the lower bound, upper bound, and mode of the parameter. Because a mode was
not provided for this parameter, EPA assigned a mode value of 0.5 for bottom filling as bottom filling
minimizes volatilization ( ). This value also corresponds to the typical value provided in
the ChemSTEER User Guide for the EPA/OAQPS AP-42 Loading Model (U.S. EPA. 2015).
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E.3.12 Container Fill Rates
The ChemSTEER User Guide (U.S. EPA. 2015) provides a typical fill rate of 60 containers per hour for
containers with less than 20 gallons of liquid.
E.3.13 Equipment Cleaning Loss Fraction
The Use of Laboratory Chemicals—Generic Scenario for Estimating Occupational Exposures and
Environmental Releases ( 1023) recommends using the EPA/OPPTMultiple Process Residual
Model to estimate the releases from equipment cleaning. The EPA/OPPT Multiple Process Residual
Model, as detailed in the ChemSTEER User Guide, (U.S. EPA. 2015) provides an overall loss fraction of
2 percent from equipment cleaning.
E.3.14 Diameters of Opening
The ChemSTEER User Guide indicates diameters for the openings for various vessels that may hold
liquids in order to calculate vapor generation rates during different activities ( ). In the
simulation developed for the Use in Laboratory Chemicals OES based on the Use of Laboratory
Chemicals—Generic Scenario for Estimating Occupational Exposures and Environmental Releases
(11 S 1 P \ 2023). EPA used default diameters of vessels from the ChemSTEER User Guide for
container and equipment cleaning, and laboratory analyses. For container and equipment cleaning, EPA
assessed a single value of 5.08 cm (U.S. EPA. 2015). For laboratory analyses, EPA applied the
EPA/OPPT Penetration Model and assumed two container sizes for sampling liquid product. For a
typical release estimate, the model assumes sampling occurs from a 2.5 cm diameter bottle opening; and
for a worst-case release estimate, the model assumes sampling occurs from a 10 cm diameter beaker
opening. The underlying distribution for laboratory container sizes is not known, therefore, EPA
assigned this parameter a triangular distribution with lower bound of 2.5 cm, upper bound or 10 cm, and
mode of 2.5 cm.
E.3.15 Product Data (Concentration and Density)
EPA compiled 1,1-dichloroethane concentration and product density information from laboratory
products containing 1,1-dichloroethane to develop distributions for concentration and density in the
simulation. SDSs for 1,1-dichloroethane laboratory products provided a single value for the 1,1-
dichloroethane concentration and product density in each product. Therefore, EPA used the values from
the SDSs as discrete input parameters. EPA did not have information on the prevalence or market share
of different laboratory products in commerce; therefore, EPA assumed a uniform distribution of
laboratory products. The model first selects a laboratory product for the iteration and then based on the
product selected, selects a concentration and density associated with that product. TableApx E-6
provides the 1,1-dichloroethane-containing laboratory products used in the model along with product-
specific concentration and density values used.
Table Apx E-6.1,1-Dichloroethane Concentrations and Densities for Commercial Use as a
Laboratory Chemical OES
Product
1,1 -Dichloroethane
Concentration
(Mass Fraction)
Concentration
Distribution
Density
(kg/m3)
Source
Reference(s)
1,1 -Dichloroethane
<1.00
Discrete (single
1,168
(MilliooreSiama.
48512
value)
(density listed as
2023)
1.17 g/cm3)
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Product
1,1 -Dichloroethane
Concentration
(Mass Fraction)
Concentration
Distribution
Density
(kg/m3)
Source
Reference(s)
1,1 -Dichloroethane
<1.00
Discrete (single
1,168
(Sigma-Aldrich,
36967
value)
(density listed as
2016)
1.17 g/cm3)
1,1 -Dichloroethane
(stabilized with
Nitromethane)
D0363
>0.95
Discrete (single
value)
1,168
(relative density
listed as 1.18
g/cm3)
(TCI America,
2014)
E.3.16 Ventilation Rate
The CEB Manual ( ) indicates general ventilation rates in industry range from 500 to
10,000 ft3/min, with a typical value of 3,000 ftVmin. The underlying distribution of this parameter is not
known; therefore, EPA assigned a triangular distribution based on an estimated lower bound, upper
bound, and mode of the parameter. EPA assumed the lower and upper bound using the industry range of
500 to 10,000 ftVmin and the mode using the 3,000 ftVmin typical value ( ).
E.3.17 Mixing Factor
The CEB Manual (U.S. EPA. 1991) indicates mixing factors may range from 0.1 to 1, with 1
representing ideal mixing. The CEB Manual references the 1988 ACGIH Ventilation Handbook, which
suggests the following factors and descriptions: 0.67 to 1 for best mixing; 0.5 to 0.67 for good mixing;
0.2 to 0.5 for fair mixing; and 0.1 to 0.2 for poor mixing ( ) The underlying distribution
of this parameter is not known; therefore, EPA assigned a triangular distribution based on the defined
lower and upper bound and estimated mode of the parameter. The mode for this distribution was not
provided; therefore, EPA assigned a mode value of 0.5 based on the typical value provided in the
ChemSTEER User Guide for the EPA/OPPTMass Balance Inhalation Model ( ).
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Appendix F CONSIDERATION OF ENGINEERING CONTROLS
AND PERSONAL PROTECTIVE EQUIPMENT
OSHA and NIOSH recommend 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, engineering controls, administrative controls, and lastly personal
protective equipment (PPE). The hierarchy of controls prioritizes the most effective measures first which
is to eliminate or substitute the harmful chemical (e.g., use a different process, substitute with a less
hazardous material), thereby preventing or reducing exposure potential. Following elimination and
substitution, the hierarchy recommends engineering controls to isolate employees from the hazard (e.g.,
source enclosure, local exhaust ventilation systems), followed by administrative controls (e.g., do not
open machine doors when running), or changes in work practices (e.g., maintenance plan to check
equipment to ensure no leaks) to reduce exposure potential. Administrative controls are policies and
procedures instituted and overseen by the employer to limit worker exposures. Under §1910.1000,
OSHA requires the use of engineering or administrative controls to bring exposures to the levels
permitted under the air contaminants standard. The respirators do not replace engineering controls and
they are implemented in addition to feasible engineering controls (29 CFR 1910.134(a)(1). The PPE
(e.g., respirators, gloves) could be used as the last means of control, when the other control measures
cannot reduce workplace exposure to an acceptable level.
The remainder of this section discusses respiratory protection and glove protection, including protection
factors for various respirators and dermal protection strategies. EPA's estimates of occupational
exposure presented in this document do not assume the use of engineering controls or PPE; however, the
effect of respiratory and dermal protection factors on EPA's occupational exposure estimates can be
explored in Risk Evaluation for 1,1-Dichloroethane, Supplemental Information Risk Calculator for
Occupational Exposures.
F,1 Respiratory Protection
OSHA's Respiratory Protection Standard (29 CFR 1910.134) requires employers in certain industries to
address workplace hazards by implementing engineering control measures and, if these are not feasible,
provide respirators that are applicable and suitable for the purpose intended. Engineering and
administrative controls must be implemented whenever employees are exposed above the PEL. If
engineering and administrative controls do not reduce exposures to below the PEL, respirators must be
worn. Respirator selection provisions are provided in part 1910.134(d) and require that appropriate
respirators are selected based on the respiratory hazard(s) to which the worker will be exposed and
workplace and user factors that affect respirator performance and reliability. Assigned protection factors
(APFs) are provided in Table 1 under part 1910.134(d)(3)(i)(A) (see below in TableApx F-l) and refer
to the level of respiratory protection that a respirator or class of respirators could provide to employees
when the employer implements a continuing, effective respiratory protection program. Implementation
of a full respiratory protection program requires employers to provide training, appropriate selection, fit
testing, cleaning, and change-out schedules in order to have confidence in the efficacy of the respiratory
protection.
If respirators are necessary in atmospheres that are not immediately dangerous to life or health, workers
must use NIOSH-certified air-purifying respirators or NIOSH-approved supplied-air respirators with the
appropriate APF. Respirators that meet these criteria may include air-purifying respirators with organic
vapor cartridges. Respirators must meet or exceed the required level of protection listed in Table Apx
F-l. Based on the APF, inhalation exposures may be reduced by a factor of 5 to 10,000 if respirators are
properly worn and fitted.
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For atmospheres that are immediately dangerous to life and health, workers must use a full facepiece
pressure demand self-contained breathing apparatus (SCBA) certified by NIOSH for a minimum service
life of 30 minutes or a combination full facepiece pressure demand supplied-air respirator (SAR) with
auxiliary self-contained air supply. Respirators that are provided only for escape from an atmosphere
that is immediately dangerous to life and health must be NIOSH-certified for escape from the
atmosphere in which they will be used.
Table Apx F-l. Assigned Protection Factors for Respirators in OSHA Standard 29 CFR 1910.134
Type of Respirator
Quarter
Mask
Half
Mask
Full
Facepiece
Helmet/
Hood
Loose-
Fitting
Facepiece
1. Air-Purifying Respirator
5
10
50
2. Power Air-Purifying Respirator (PAPR)
50
1,000
25/1,000
25
3. Supplied-Air Respirator (SAR) or Airline Respirator
• Demand mode
10
50
• Continuous flow mode
50
1,000
25/1,000
25
• Pressure-demand or other positive-pressure
mode
50
1,000
4. Self-Contained Breathing Apparatus (SCBA)
• Demand mode
10
50
50
• Pressure-demand or other positive-pressure
mode (e.g., open/closed circuit)
10,000
10,000
Source: 29 CFR 1910.134(d)(3)(i)(A)
The National Institute for Occupational Safety and Health (NIOSH) and the U.S. Department of Labor's
Bureau of Labor Statistics (BLS) conducted a voluntary survey of U.S. employers regarding the use of
respiratory protective devices between August 2001 and January 2002. The survey was sent to a sample
of 40,002 establishments designed to represent all private sector establishments. The survey had a 75.5%
response rate (NIOSH. 2003). A voluntary survey may not be representative of all private industry
respirator use patterns as some establishments with low or no respirator use may choose to not respond
to the survey. Therefore, results of the survey may potentially be biased towards higher respirator use.
NIOSH and BLS estimated about 619,400 establishments used respirators for voluntary or required
purposes (including emergency and non-emergency uses). About 281,800 establishments (45%) were
estimated to have had respirator use for required purposes in the 12 months prior to the survey. The
281,800 establishments estimated to have had respirator use for required purposes were estimated to be
approximately 4.5% of all private industry establishments in the U.S. at the time (NIOSH. 2003).
The survey found that the establishments that required respirator use had the following respirator
program characteristics (NIOSH. 2003):
• 59% provided training to workers on respirator use.
• 34%) had a written respiratory protection program.
• 47%) performed an assessment of the employees' medical fitness to wear respirators.
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• 24% included air sampling to determine respirator selection.
The survey report does not provide a result for respirator fit testing or identify if fit testing was included
in one of the other program characteristics.
Of the establishments that had respirator use for a required purpose within the 12 months prior to the
survey, NIOSH and BLS found (NIOSH. 2003V
• Non-powered air purifying respirators are most common, 94% overall and varying from 89% to
100%) across industry sectors.
• Powered air-purifying respirators represent a minority of respirator use, 15% overall and varying
from 7%> to 22% across industry sectors.
• Supplied air respirators represent a minority of respirator use, 17% overall and varying from 4%
to 37%) across industry sectors.
Of the establishments that used non-powered air-purifying respirators for a required purpose within the
12 months prior to the survey, NIOSH and BLS found (NIOSH. 2003):
• A high majority use dust masks, 76% overall and varying from 56% to 88% across industry
sectors.
• A varying fraction use half-mask respirators, 52% overall and varying from 26% to 66% across
industry sectors.
• A varying fraction use full-facepiece respirators, 23% overall and varying from 4% to 33%
across industry sectors.
Table Apx F-2 summarizes the number and percent of all private industry establishments and
employees that used respirators for a required purpose within the 12 months prior to the survey and
includes a breakdown by industry sector (NIOSH. 2003).
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4112
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TableApx F-2. Number and Percent of Establishments and Employees Using Respirators within
12 Months Prior to Survey
Industry
Establishments
Em
ployees
Number
Percent of All
Establishments
Number
Percent of
All
Employees
Total Private Industry
281,776
4.5
3,303,414
3.1
Agriculture, forestry, and fishing
13,186
9.4
101,778
5.8
Mining
3,493
11.7
53,984
9.9
Construction
64,172
9.6
590,987
8.9
Manufacturing
48,556
12.8
882,475
4.8
Transportation and public utilities
10,351
3.7
189,867
2.8
Wholesale Trade
31,238
5.2
182,922
2.6
Retail Trade
16,948
1.3
118,200
0.5
Finance, Insurance, and Real Estate
4,202
0.7
22,911
0.3
Services
89,629
4.0
1,160,289
3.2
F.2 Glove Protection
OSHA's hand protection standard (29 CFR 1910.138) requires employers select and require employees
to use appropriate hand protection when expected to be exposed to hazards such as those from skin
absorption of harmful substances; severe cuts or lacerations; severe abrasions; punctures; chemical
burns; thermal burns; and harmful temperature extremes. Dermal protection selection provisions are
provided in part 1910.138(b) and require that appropriate hand protection is selected based on the
performance characteristics of the hand protection relative to the task(s) to be performed, conditions
present, duration of use, and the hazards to which employees will be exposed.
Unlike respiratory protection, OSHA standards do not provide protection factors (PFs) associated with
various hand protection PPE, such as gloves, and data about the frequency of effective glove use—that
is, the proper use of effective gloves—is very limited in industrial settings. Initial literature review
suggests that there is unlikely to be sufficient data to justify a specific probability distribution for
effective glove use for a chemical or industry. Instead, the impact of effective glove use is explored by
considering different percentages of effectiveness.
Gloves only offer barrier protection until the chemical breaks through the glove material. Using a
conceptual model, Cherrie (Cherrie et ai. 2004) proposed a glove workplace protection factor: the ratio
of estimated uptake through the hands without gloves to the estimated uptake though the hands while
wearing gloves: this protection factor is driven by flux, and thus varies with time. The European Centre
for Ecotoxicology and Toxicology of Chemicals Targeted Risk Assessment (ECETOC TRA) model
represents the protection factor of gloves as a fixed, assigned protection factor equal to 5, 10, or 20
(Marquart et al. 2017) where, similar to the APF for respiratory protection, the inverse of the protection
factor is the fraction of the chemical that penetrates the glove. It should be noted that the described PFs
are not based on experimental values or field investigations of PPE effectiveness, but rather professional
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judgements used in the development of the ECETOC TRA model. EPA did not identify reasonably
available information on PPE usage to corroborate the PFs used in this model.
As indicated in TableApx F-3, use of protection factors above 1 is recommended only for glove
materials that have been tested for permeation against the 1,1-dichloroethane-containing liquids
associated with the condition of use. EPA has not found information that would indicate specific activity
training (e.g., procedure for glove removal and disposal) for tasks where dermal exposure can be
expected to occur in a majority of sites in industrial only OESs, so the PF of 20 would usually not be
expected to be achieved.
Table Apx F-3. Glove Protection Factors for Different Dermal Protection Strategies from
ECETOC TRA v3
Dermal Protection Characteristics
Affected User
Group
Indicated
Efficiency
(%)
Protection
Factor,
PF
a. Any glove / gauntlet without permeation data and
without employee training
Both industrial
and professional
users
0
1
b. Gloves with available permeation data indicating
that the material of construction offers good protection
for the substance
80
5
c. Chemically resistant gloves (i.e., as b above) with
"basic" employee training
90
10
d. Chemically resistant gloves in combination with
specific activity training (e.g., procedure for glove
removal and disposal) for tasks where dermal exposure
can be expected to occur
Industrial users
only
95
20
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Appendix G PROCEDURES FOR MAPPING FACILITIES FROM
STANDARD ENGINEERING SOURCES TO OESs
SCENARIOS AND COUs
G.l Conditions of Use and Occupational Exposure Scenarios
Condition of Use (COU)
TSCA section3(4) defines COUs as "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'. COUs included in the scope of EPA's risk evaluations
are typically tabulated in scope documents and risk evaluation documents as summaries of life cycle
stages, categories, and subcategories of use, as shown in Table Apx G-l. Therefore, a COU is defined
as a combination of life cycle stage, category, and subcategory. EPA identifies COUs for chemicals
during the scoping phase; this process is not discussed in this document.
Occupational Exposure Scenario (OES)
Thus far, EPA has not adopted a standardized definition for OES. The purpose of an OES is to group or
segment COUs for assessment of releases and exposures based on similarity of the operations and data
availability for each COU. For example, EPA may assess a group of multiple COUs together as one
OES due to similarities in release and exposure potential (e.g., the COUs for formulation of paints,
formulation of cleaning solutions, and formulation of other products may be assessed together as a
single OES). Alternatively, EPA may assess multiple OES for one COU because there are different
release and exposure potentials for a given COU (e.g., the COU for batch vapor degreasing may be
assessed as separate OES for open-top vapor degreasing and closed-loop vapor degreasing). OES
determinations are also largely driven by the availability of data and modeling approaches to assess
occupational releases and exposures. For example, even if there are similarities between multiple COUs,
if there is sufficient data to separately assess releases and exposures for each COU, EPA would not
group them into the same OES. This is depicted in Figure Apx G-l.
For chemicals undergoing risk evaluation, ERG/EPA maps each industrial and commercial COU to one
or more OES based on reasonably available data and information (e.g., CDR, use reports, process
information, public and stakeholder comments), assumptions, and inferences that describe how release
and exposure take place within a COU. ERG/EPA identify OES for COUs, not vice-versa (i.e., COUs
are not altered during OES mapping). The mapping of COUs to OES is separate from and occurs after
the identification of COUs. Both the identification of COUs and subsequent mapping of COUs to OES
occur early in the risk evaluation process and are not in scope of this document. This section is intended
to just provide background context on COUs and OES.
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4181 Table Apx G-l. Example Condition of Use Table with Mapped Occupational Exposure Scenarios
Condition of Use (COU)
Occupational Exposure
Scenario (OES)
Life Cycle
Stage
Category"
Subcategory
Manufacturing
Domestic
Manufacturing
Domestic
Manufacturing
Manufacturing
Import
Import
Repackaging
Processing
As a reactant
Intermediate in all
other basic organic
chemical
manufacturing
Processing as a Reactant
Processing—
Incorporation into
formulation, mixture, or
reaction product
Solvents (for cleaning
or degreasing)
Formulation
Adhesives and sealant
chemicals
Repackaging
Solvents (for cleaning
or degreasing)
Repackaging
Etc.
a Categories reflect CDR codes and broadly represent the industrial and/or commercial settings of the COU.
b The subcategories reflect more specific COUs.
4182
4183
OES
COUs identified for the chemical during scoping are critically
reviewed to determine potential release and exposure scenarios
(referred to as OES)
COU to OES mapping may come in many forms as shown in this
figure
One COU may map to one OES
Multiple COUs may be mapped to the same OES
Multiple COUs may be mapped to one OES when the COUs have
similar activities and exposure potentials, and exposures and
releases can be assessed for the COUs using a single approach
For example, the COUs for aerosol degreaser, interior car care spot
remover, and spray lubricant have been assessed together under the
OES for commercial aerosol products
COU liCOU 2
OES
OES llOES 210ES 3
One COU may be mapped to multiple OES
Mapping a COU to multiple OES allows for the assessment of
distinct scenarios that are not expected to result in similar releases
and exposures
For example, the COU for batch vapor degreasing has been assessed
as two separate OES: open-top and closed-loop degreasing
FigureApx G-l. Condition of Use to Occupational Exposure Scenario Mapping Options
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G.2 Standard Sources Requiring Facility Mapping
EPA utilizes release data from EPA programmatic databases and exposure data from standard sources to
complete occupational exposure and environmental release assessments, which are described below:
• Chemical Data Reporting (CDR). to which import and manufacturing sites producing the chemical at
or above a specified threshold must report. EPA uses CDR to identify COUs, OES, sites that import
or manufacture the chemical, and for information on physical form and concentration of the
chemical. In addition, EPA is currently developing the Tiered Data Reporting (TDR) rule, which
will establish reporting requirements, including changes to CDR, to collect information that better
meets data needs for the TSCA existing chemical program. The rule will have reporting
requirements tiered to specific stages of existing chemical assessments (e.g., prioritization, risk
evaluation) and harmonized to the Organization for Economic Co-operation and Development
(OECD) risk assessment framework, which will help to better inform uses of chemicals and improve
upon the OES mapping procedures in this document.
• Toxics Release Inventory (TRI). to which facilities handling a chemical covered by the TRI program
at or above a specified threshold must report. EPA uses TRI data to quantify air, water, and land
releases of the chemical undergoing risk evaluation.
• National Emissions Inventory (NEI). a compilation of air emissions of criteria pollutants, criteria
precursors and hazardous air pollutants from point and non-point source air emissions. EPA uses
NEI data to quantify air emissions of the chemical undergoing risk evaluation.
• Discharge Monitoring Report (DMRI a periodic report required of National Pollutant Discharge
Elimination System (NPDES) permitted facilities discharging to surface waters. EPA uses NEI data
to quantify surface water discharges of the chemical undergoing risk evaluation.
• Occupational Safety and Health Administration (OSHA): Chemical Exposure Health Data (CEHD).
a compilation of industrial hygiene samples taken when OSHA monitors worker exposures to
chemical hazards. EPA uses OSHA CEHD to quantify occupational inhalation exposures to the
chemical undergoing risk evaluation.
• National Institute of Occupational Safety and Health (NIOSH): Health Hazard Evaluations (HHEs).
a compilation of voluntary employee, union, or employer requested evaluations of health hazards
present at given workplace. EPA uses NIOSH HHE data to quantify occupational inhalation
exposures to the chemical undergoing risk evaluation.
To utilize the data from these sources, the facilities that report to each must first be mapped to an OES.
There may be other sources of data for specific facilities that require mapping the facilities to an OES;
however, this document covers the most common data sources. Additionally, EPA often uses data from
sources such as public and stakeholder comments, generic scenarios, and process data that are usually
not specific to an individual site; therefore, unlike the above sources, they do not involve the mapping of
specific sites to an OES. Therefore, they are not discussed further in this document.
Mapping procedures for the above sources are discussed in detail in the subsequent sections; however,
Table Apx G-2 includes a summary of the type of information reported by companies in each database
that helps to inform OES and COU mapping. This includes industrial classification codes such as those
associated with the North American Industry Classification System (NAICS) and Standard Industrial
Classification (SIC) system. Note that the U.S. government replaced SIC codes with NAICS codes in
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4230 1997; however, SIC codes are still used in DMR and are applicable for data from all listed sources for
4231 years prior to 1997. Additionally, some of the sources in Table Apx G-2 have specific reporting
4232 requirements that include flags for the type of processes that occur at the site.
4233
4234 Assessors should be sure that a facility that reports to multiple databases/sources is consistently mapped
4235 to the same OES, as applicable. This is not applicable if the facility reports separately for different
4236 areas/processes of their facility (e.g., a large chemical plant may report one block of unit operations
4237 separate from another such that they have different OES).
4238
4239 Table Apx G-2. EPA Programmatic Database Information that Aids OES/COU Mapping
Source
Reported Information
Useful for Mapping
OES/COU
Reporting Frequency
Notes
CDR
- Indication if the
chemical is imported or
domestically
manufactured
- Indication if the
chemical is imported but
never at the site, used on-
site, or exported
- Facilities must report to CDR
every four years
- New data sets take years to
become publicly available
- Latest reporting year with
available data: 2020
- While CDR also includes
information on downstream
processing and use, it does not
include site identities for these
operations; thus, it does not inform
reporting site OES/COU mapping.
- Claims of confidential business
information (CBI) can limit data
utility in risk evaluations.
TRI
- NAICS codes
- Flags for uses and
subuses of the chemical
- Release media
information
- Facilities must report to TRI
annually
- New data sets become
publicly available in October
for the previous year
- Latest reporting year with
available data: 2021
- Reporters must select from specific
uses (e.g., manufacture, import,
processing) and subuses (e.g.,
formulation additive, degreaser,
lubricant).
- Subuse information is only
available in data sets starting in
2018.
- Facilities may report with a Form
A under certain circumstances;a
Form A's do not require use/subuse
reporting.
NEI
- Source Classification
Codes (SCCs), which
classify different types of
activities that generate air
emissions
- Emissions Inventory
System (EIS) Sectors,
which classify industry
sectors
- NAICS codes
- Process description free-
text field (used for
additional information
about the process related
to the emission unit)
- Facilities must report to TRI
every three years
- New data sets take years to
become publicly available.
- Latest reporting year with
available date: 2020
- NEI contains specific SCC codes
and industry sectors from which
reporters select.
- Free-text fields are not mandatory
for the reporter to fill out.
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- Emission unit
description free-text field
DMR
- SIC codes
- National Pollutant
Discharge Elimination
System (NPDES) permit
numbers
- Facilities must report to DMR
at the frequency specified in
their NPDES permit, which is
typically monthly
- Data typically flows through
the State DMR reporting
platform to EPA's
Enforcement and Compliance
History Online (ECHO)
database continuously
- Sites that only report non-detection
of the chemical for the year are
generally excluded from mapping.
- NPDES permit numbers can
sometimes indicate the type of
general permit, which can inform
mapping (e.g., remediation general
permit).
OSHA
- NAICS or SIC codes
- OSHA conducts monitoring
as-needed for site
investigations
- Monitoring data is available
in CEHD when the
investigation and any
subsequent litigation cases are
closed
- Latest year in CEHD with
data: 2021
- CEHD includes data from 1984
and forward.
NIOSH
HHE
- Facility process
information
- Worker activities
- NIOSH conducts HHEs upon
request
- HHEs are published online
when NIOSH is completed
with the evaluation
- Latest year with a published
HHE: 2023
- NIOSH HHEs generally include
narrative descriptions of facility
processes and worker activities, with
specific information on how the
chemical being monitored for is
used.
a Facilities may report using a Form A if the annual reportable release amount of the chemical did not exceed 500
pounds for the reporting year, and the amounts manufactured, or processed, or otherwise used did not exceed 1
million pounds for that year.
4240
4241 G.3 PES Mapping Procedures
4242 This section contains procedures for mapping facilities to OES for each source discussed in Section G.2.
4243 G.3.1 Chemical Data Reporting (CDR)
4244 The only facilities required to report to CDR are those that manufacture or import specific chemicals at
4245 or above a specified threshold.10 Therefore, sites that report for the chemical of interest in CDR will
4246 generally be mapped to either the manufacturing or import/repackaging OES. These sites must also
4247 report the processing and uses of the chemical; however, these procedures are specific to mapping of the
4248 reporting site and not downstream processing or use sites.
4249
10 The 2020 CDR reporting instructions, including descriptions on the information required to be reported, can be found at:
https://www.epa.gov/chemical-data-reporting/instructions-reporting-2020-tsca-chemical-data-reporting.
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4261
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4264
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CDR, under TSCA, requires manufacturers (including importers) to provide EPA with information on
the production and use of chemicals in commerce. These facilities must report to CDR every four years.
For risk evaluations conducted under the amended TSCA, EPA has primarily used 2016 and 2020 CDR.
The procedures in this document are appliable to both 2016 and 2020 CDR data; however, there are
some data elements that are only applicable to 2020 CDR, which are called out in the procedures where
appliable. These procedures should be applicable to future CDR, depending on changes to reporting
requirements. When the TDR rule is implemented, these procedures will be updated accordingly.
Chemical data reported under CDR is classified using Industrial Function Category (IFC) codes and/or
commercial/consumer use product categories (PCs). CDR IFC codes describe the "intended physical or
chemical characteristics for which a chemical substance or mixture is consumed as a reactant;
incorporated into a formulation, mixture, reaction product, or article, repackaged; or used."
Alternatively, PCs describe the consumer and commercial products in which each reportable chemical is
used. EPA typically uses these CDR codes to identify the COUs for the chemical in the published scope
documents.
FigureApx G-2 depicts the steps that should be followed to map CDR reporting sites to OES. Each step
is explained in the text below the figure. Additionally, Section G.5.1 shows step-by-step examples for
using the mapping procedures to determine the OES for three example CDR reporting facilities.
Figure Apx G-2. OES Mapping Procedures for CDR
To map sites reporting to CDR, the following procedures should be used with the non-CBI CDR:
1. Review Manufacturing and Import Activity Information: The first step in the process is to review
the reported activity information to identify if the facility imports or manufactures the chemical.
a. If the facility reports domestic manufacturing, the manufacturing OES should be
assigned, even if the facility also reports importation or the facility may conduct other
operations with the chemical. This is because manufacturing of the chemical is expected
to be the primary operation, with any other processing or uses being ancillary operations.
b. If the chemical is being manufactured as a byproduct (this is a voluntary reporting
element starting in 2020 CDR), this may need to be considered separately from non-
byproduct manufacturing depending on assessment needs for the chemical.
c. If the facility does not manufacture the chemical and only imports the chemical, check if
additional processes occur at the site as described in the subsequent steps.
2. For Importation Sites. Review Fields for "Imported Never at Site". "Volume Exported", and
"Volume Used": The next step is to review these additional fields to determine if the reporting
facility conducts more than just importation activities.
a. If the facility imports the chemical, they must report if it is imported but never physically
at the reporting site. If the facility indicates the chemical is imported and never at site, the
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facility does not handle the chemical and the only applicable OES is importation. In such
cases, the assessor should proceed to Step 4. If the facility does not indicate the chemical
is imported and never at site, proceed to Step 2b.
b. If the facility reports a quantity for "volume exported" and this quantity is the same as
that imported, no additional OES occurs at the site beyond importation. In such cases, the
assessor should proceed to Step 4. If the exported quantity is not equal to volume
imported, assessors should check if any of the chemical is used at the reporting site per
Step 2c.
c. If the facility reports a quantity for "volume used", additional OES may be applicable to
the facility beyond manufacturing or importation. Proceed to Step 3 to identify and refine
additional OES.
3. Refine OES Assignments: If multiple OES were identified from the previous steps, a single
primary OES must be selected using additional facility information. OES determinations should
be made with the following considerations:
a. 6-digit NAICS code reported by the facility in CDR. Note that this is only a requirement
starting in 2020 CDR (e.g., for a facility that reported NAICS code was 325520,
Adhesive Manufacturing, the incorporation into a formulation, mixture, or reaction
product OES may be appropriate; for a facility reporting a NAICS code starting in
424690, Other Chemical and Allied Products Merchant Wholesalers, only the
repackaging OES is likely applicable).
b. Downstream processing and use information reported in CDR. The reporting site must
provide information on downstream processing and use of the chemical for all sites,
meaning it cannot be distinguished which processing and use information includes the
reporting site operations vs. downstream site operations. However, this information may
still help inform the operations at the reporting site and should be reviewed. Specifically,
for a given processing/use activity, if the submitter reports "Fewer than 10 sites" for the
"number of sites" field (which is the lowest number of sites that can be reported), there is
a likelihood that the facility's operations may be included in this processing/use activity.
In such cases, review the corresponding fields for "type of processing or use operation",
"industrial sector", and "function category" to help identify the OES. The greater number
of sites that are reported, the more likely that the associated processing and use
information includes information from downstream sites and the less reliable the
information is for mapping OES to the reporting site.
c. Internet research of the types of products made at the facility (e.g., if a facility's website
indicates the facility manufactures plastic products, the chemical may be used as a
processing aid or component in the plastic products, depending on the known uses of the
chemical within the plastics industry).
d. Information from other reporting databases as described in Step 3.
e. An evaluation of the OES that is most likely to result in a release (e.g., for facilities that
reported importation and may also conduct formulation per the reported NAICS code, the
formulation OES may be assigned, because, in most cases, importation would have a
lower likelihood of a release).
f. Grouped OES for similar uses (e.g., multiple facilities that may conduct formulation
operations based on the reported NAICS code may be assigned a grouped formulation
OES that covers all types of formulation [e.g., adhesives, paints, cleaning products]).
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4. Review Information from Other Databases: Other databases/sources (such as TRI, NEI, and
DMR) should be checked to see if the facility has reported to these. If so, the OES determined
from the mapping procedures for those databases (discussed in other sections of this document)
should also be used. It is important that the same facility is mapped consistently across multiple
databases/sources. The facility's TRI identification number (TRFID) and Facility Registry
Services identification number (FRS ID) can be used to identify sites that report to TRI, DMR,
and NEI. If the facility does not report to these databases, but additional OES are possible per
Step 2, the assessor should search available facility information on the internet.
Given the information available in CDR, ERG/EPA expects that, for most chemicals, 100% of the sites
reporting to CDR can feasibly be mapped to an OES.
G.3.2 Toxics Release Inventory (TRI)
TRI reporting is required for facilities that manufacture (including import), process, or otherwise use any
TRI-listed chemical in quantities greater than the established threshold in the calendar year AND have
10 or more full-time employee equivalents {i.e., a total of 20,000 hours or greater) and are included in a
covered NAICS code. Therefore, unlike CDR reporters that are primarily manufacturers and importers,
TRI reporters can be mapped to a variety of different OES.
FigureApx G-3 depicts the steps that should be followed to map TRI reporting sites to OES. Each step
is explained in the text below the figure. Additionally, Section G.5.2 shows step-by-step examples for
using the mapping procedures to determine the OES for three example TRI reporting facilities.
Figure Apx G-3. OES Mapping Procedures for TRI
To map sites reporting to TRI, the following procedures should be used:
1. Assign Chemical Data Reporting Codes using TRI-to-CDR Crosswalk: The first step in the TRI
mapping process is to map the uses and sub-uses reported by each facility to one or more 2016
CDR IFC codes. To do this, first compile all TRI uses/sub-uses for the reporting facility into a
single column, then map them to CDR IFC codes using the TRI-to-CDR Use Mapping crosswalk
(see Appendix B). This is a universal crosswalk that applies to all chemicals.
2. Develop Chemical-Specific Crosswalk to Link CDR Codes to OES: The next step is to develop a
separate CDR IFC code-to-OES crosswalk that links CDR IFC codes to OES for the chemical.
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To create this crosswalk, match the COU categories and subcategories from the COU table in the
published scope documents (like the example provided in Table 1-1) to the list of 2016 CDRIFC
codes in the CDR reporting instructions.11 The categories and subcategories of COUs typically
match the IFC code category. Recent examples of already completed CDR IFC code-to-OES
crosswalk can be found for the fenceline chemicals (1-bromopropane, methylene chloride, n-
Methylpyrrolidone, carbon tetrachloride, perchloroethylene, trichloroethylene, and 1,4-dioxane).
3. Assign PES: Each TRI facility is then mapped to one or more OES using the CDR IFC codes
assigned to each facility in Step 1 and the CDR IFC code-to-OES crosswalk developed in Step 2.
4. Refine OES Assignments: If a facility maps to more than one OES in Step 3, a single primary
OES must be selected using additional facility information. OES determinations should be made
with the following considerations:
a. 6-digit NAICS codes reported by the facility in TRI (e.g., for a facility that reported TRI
uses for both formulation and use as cleaner, EPA assigned the formulation OES if the
NAICS code was 325199, All Other Basic Organic Chemical Manufacturing; another
example is NAICS codes 562211, Hazardous Waste Treatment and Disposal, and
327310, Cement Manufacturing, almost always correspond to the disposal OES,
regardless of the reported TRI uses and sub-uses).
b. Internet research of the types of products made at the facility (e.g., if a facility's website
indicates the facility manufactures metal parts, the facility is likely to use chemicals for
degreasing or in a metalworking fluid) and information from sources cited in the COU
table and scoping document, such as public and stakeholder comments (i.e., EPA/ERG
will review sources cited in the COU table and scoping document to see if there is any
information specific to the reporting site that can be used to inform the mapping).
c. Information from other reporting databases as described in Step 5.
d. An evaluation of the OES that is most likely to result in a release (e.g., facilities that
reported both importation and formulation may be assigned a formulation OES, because,
in most cases, importation would have a lower likelihood of a release).
e. Grouped OES for similar uses/sub-uses (e.g., facilities that reported cleaner and degreaser
sub-uses may be assigned a grouped OES that covers both cleaning and degreasing
because the specific cleaning/degreasing operation cannot be determined from the TRI
data).
5. Review Information from Other Databases: Other databases/sources (including CDR, NEI, and
DMR) should be checked to see if the facility has reported to these. If so, the OES determined
from the mapping procedures for those databases (discussed in other sections of this document)
should also be used. It is important that the same facility is mapped consistently across multiple
databases/sources. The facility's TRFID and FRS ID can be used to identify sites that report to
TRI, DMR, and NEI.
6. Note that facilities that submit using a TRI Form A do not report TRI uses/sub-uses. To
determine the OES for these facilities, EPA will use information from Steps 4 and 5.
Given the information available in TRI, ERG/EPA expects that, for most chemicals, 100% of the sites
reporting to TRI can feasibly be mapped to an OES.
11 IFC codes and their definitions can be found in Table 4-11 of the CDR reporting instructions:
https://www.epa.gov/chemical-data-reporting/instructions-reporting-2016-tsca-chemical-data-reporting
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G.3.3 National Emissions Inventory (NEI)
The NEI is a compilation of air emissions of criteria pollutants, criteria precursors, and hazardous air
pollutants from point and non-point source air emissions. Air emissions data for the NEI are collected at
the state, local, and tribal (SLT) level. The Air Emissions Reporting Requirement rule requires SLT air
agencies to collect, compile, and submit criteria pollutant air emissions data to EPA. Many SLT air
agencies also voluntarily submit data for pollutants on EPA's list of hazardous air pollutants. Major
sources are required to report point source emissions data to their SLT air agency. Each SLT entity
must, in turn, report point source emissions data to EPA every one to three years, depending upon the
size of the source. Nonpoint estimates are typically developed by state personnel.
FigureApx G-4 depicts the steps that should be followed to map NEI reporting sites/records to OES.
Each step is explained in the text below the figure. Additionally, Section G.5.3 shows step-by-step
examples for using the mapping procedures to determine the OES for one point source example and one
nonpoint source example.
Figure Apx G-4. OES Mapping Procedures for NEI
To map sites reporting point source emissions and nonpoint emissions records for the chemical of
interest to NEI, the following procedures should be used:
1. Develop Crosswalks to Link NEI-Reported SCC and Sector Combinations to Chemical Data
Reporting Codes: The first step in mapping NEI data to potentially relevant OES is to develop a
crosswalk to map each unique combination of NEI-reported Source Classification Code (SCC)
(levels 1-4) and industry sectors to one or more CDR codes. This crosswalk is developed on a
chemical-by-chemical basis rather than an overall crosswalk for all chemicals because SCCs
correspond to emission sources rather than chemical uses such that the crosswalk to CDR codes
may differ from chemical to chemical. In some cases, it may not be possible to assign all SCC
sector combinations to CDR codes, in which case information from Step 5 can be used to help
make OES assignments. Separate crosswalks are needed for point and nonpoint source records,
as discussed below.
a. For the point source NEI data, the crosswalk should map each unique combination of
NEI-reported SCC and industry sectors to one or more CDR IFC codes.
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b. For nonpoint source NEI data, the crosswalk should link the SCC codes and sectors to
both CDRIFC codes and/or commercial/consumer use PCs. This is because the nonpoint
source data may include commercial operations, for which CDR PCs may be more
appropriate.
2. Use CDR Crosswalks to Assign CDR Codes: Next, the chemical-specific CDR crosswalk
developed in Step 1 should be used to assign CDR IFC codes to each point source NEI record
and CDR IFC codes and/or commercial/consumer use PCs to each nonpoint source NEI record.
3. Update CDR Crosswalks to Link CDR Codes to PES: The chemical-specific crosswalk
developed in Step 1 is then used to link the SCCs, sectors, and CDR codes in the crosswalk to an
OES. The OES will be assigned based on the chemical specific COU categories and
subcategories and the OES mapped to them as discussed in Section G.l.
4. Use CDR Crosswalks to Assign OES: The chemical-specific CDR crosswalks developed in
Steps 1-3 are then used to assign OES to each point source and nonpoint source NEI data record
{i.e., each combination of facility-SCC-sector). Note that the individual facilities in the point
source data set may have multiple emission sources, described by different SCC and sector
combinations within NEI, such that multiple OES map to these NEI records. In such cases, a
single, representative OES must be selected for each NEI record using the additional information
described in Step 5. Similarly, the sectors reported by nonpoint sources may map to multiple
CDR IFC or PC codes, such that multiple OES are applicable and must be refined to a single
OES for each NEI record.
5. Refine OES Assignments: The initial OES assignments may need to be confirmed and/or refined
to identify a single primary OES using the following information described below for point
source and nonpoint source records.
a. For point source records in NEI, use the following information to refine OES
assignments;
• Additional information available in NEI:
o Facility name.
o Primary NAICS code and description, populated from the EIS lookup
tables.
o Facility site description, which, when populated, is intended to describe
the type of industry the facility operates (similar to a NAICS description).
o Process description, which is a free-text field where reporters can provide
additional information about the process related to their emission unit.
o Emission unit description, which is a free-text field where reporters can
provide additional information about their emission units.
• Internet research of the types of products made at the facility {e.g., if a facility's
website indicates the facility manufactures metal parts, the facility is likely to use
chemicals for degreasing or in a metalworking fluid) and information from
sources cited in the COU table and scoping document, such as public and
stakeholder comments {i.e., EPA/ERG will review sources cited in the COU table
and scoping document to see if there is any information specific to the reporting
site that can be used to inform the mapping).
• Information from other reporting databases as described in Step b.
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• An evaluation of the OES that is most likely to result in a release (e.g., facilities
that map to both lubricant use and vapor degreasing may be assigned a vapor
degreasing OES, because, in most cases, vapor degreasing results in higher air
emissions).
• Grouped OES for similar uses/sub-uses (e.g., facilities that map to both general
cleaning and vapor degreasing may be assigned a grouped OES that covers both
cleaning and degreasing because the specific cleaning/degreasing operation
cannot be determined from the NEI data).
b. For nonpoint source records in NEI, use the following information to refine OES
assignments (there is no additional data reported to NEI by nonpoint sources that can help
refine the OES mapping):
• General knowledge about the use of the chemical in the reported sector, such as
from scope documents, public or stakeholder comments, process descriptions,
professional judgement, or already-identified sources from systematic review.
• Internet research of the uses of the chemical in the reported sector, if insufficient
information is not already available per the previous bullet.
• An evaluation of the OES that is most likely to result in a release (e.g., sectors
that map to both lubricant use and vapor degreasing may be assigned a vapor
degreasing OES, because, in most cases, vapor degreasing results in higher air
emissions).
• Grouped OES for similar uses/sub-uses (e.g., sectors that map to both general
cleaning and vapor degreasing may be assigned a grouped OES that covers both
cleaning and degreasing because the specific cleaning/degreasing operation
cannot be determined from the NEI data).
6. Review Information from Other Databases for Point Source Facilities: Other databases/sources
(including CDR, TRI, and DMR) should be checked to see if the point source facilities have
reported to these. If so, the OES determined from the mapping procedures for those databases
(discussed in other sections of this document) should also be used. It is important that the same
facility is mapped consistently across multiple databases/sources. The facility's TRFID and FRS
ID can be used to identify sites that report to TRI, DMR, and NEI.
7. Consider Options for NEI Records that Cannot be Mapped to an OES: Given the number of
records in NEI and the information available, it may not always be feasible to achieve mapping
of 100% of the sites reporting to NEI to an OES. For example, there may be NEI records for
restaurants or the commercial cooking sector, which do not map to an in-scope COU or OES.
Additionally, NEI records may include emissions from combustion byproducts for the chemical,
which does not correspond to a COU or OES. In such cases, multiple options may be appropriate
depending on assessment needs, such as:
a. Assigning the sites as having an unknown OES with 250 release days/year. This allows
for subsequent exposure modeling and the assessment of risk. For sites with identified
risk, the OES can then be mapped using the below resources.
b. Contacting the facility for clarification on the use of the chemical. ICR requirements also
apply when contacting 10 or more facilities. Note that information requests such as these
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may require an Information Collection Request (ICR) if 10 or more entities are
contacted.12
G.3.4 Discharge Monitoring Report (DMR)
Facilities must submit DMRs for chemicals when the following two conditions are met: (1) the facility
has an NPDES permit for direct discharges to surface water, and (2) the NPDES permit contains
monitoring requirements for the chemical of interest. Indirect discharges (e.g., those sent to an off-site
wastewater treatment plant or publicly owned treatment works) are not covered under the NPDES
program.
If a facility has discharge monitoring requirements for the chemical of interest, these requirements are
either technology-based or water-quality based. Typically, a facility has NPDES monitoring
requirements for a chemical because the facility somehow manufactures, processes, or uses the
chemical. However, it is possible for a facility to have monitoring requirements for a chemical they do
not handle if the facility falls within a guideline containing requirements for that chemical, as described
below.
• Technology-based guidelines: If the facility falls within a certain industrial sector, it may be
covered by a national effluent guideline. Effluent guidelines are industry-specific and contain
treatment technology-based guidelines for discharges of specified pollutants (chemicals)
commonly found within that industry.13 A common effluent guideline containing requirements
for chemicals that have or are currently undergoing risk evaluation is the Organic Chemicals,
Plastics & Synthetic Fibers (OCPSF) effluent guideline. Alternatively, if there is no applicable
effluent guideline for the facility, the permitting authority may establish technology-based
guidelines using best professional judgment. If a facility falls within an existing effluent
guideline, the permitting authority will generally include monitoring requirements in the
facility's NPDES permit that are consistent with the effluent guideline, even if the facility does
not handle all the chemicals for which there are monitoring requirements. Therefore, under this
reasoning, it is possible that a facility reporting for the chemical of interest in DMRs does not
actually handle the chemical.14
• Water quality-based guidelines: The receiving water for the facility's discharges is impaired such
that the permitting authority sets general water-quality based effluent limits and monitoring
requirements for chemicals that may further impair the water quality. It is possible that the
permitting authority uses these same general water-quality based requirements for all facilities
that discharge to the water body. Therefore, under this reasoning, it is possible that a facility
reporting for the chemical of interest in DMRs does not actually handle the chemical.5
Figure Apx G-5 depicts the steps that should be followed to map DMR reporting sites to OES. Each
step is explained in the text below the figure. Additionally, Section G.5.4 shows step-by-step examples
for using the mapping procedures to determine the OES for two example DMR reporting facilities.
12 More on Information Collection Requests can be found at: https://www.epa.gov/icr/icr-basics
13 A list of the industries for which EPA has promulgated effluent guidelines is available at:
https://www.epa.gOv/eg/industrial-effluent-guidelines#existing
14 Note that a facility may request to have monitoring requirements reduced or removed from the permit where historical
sampling demonstrates that these chemicals are consistently measured below the effluent limits. Thus, it is possible for a
facility to cease monitoring for the chemical of interest upon approval by the permitting authority.
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FigureApx G-5. OES Mapping Procedures for DMR
To map sites reporting to DMR, the following procedures should be used:
1. Review Information from Other Databases: Given the limited facility information reported in
DMRs, the first step for mapping facilities reporting to DMR should be to check other
databases/sources (including CDR, TRI, and NEI). If so, the OES determined from the mapping
procedures for those databases (discussed in other sections of this document) should be used. It is
important that the same facility is mapped consistently across multiple databases/sources. The
facility's TRFID and FRS ID can be used to identify sites that report to TRI, DMR, and NEI.
2. Assign OES: If the facility does not report to other databases, the following information should
be used to assign an OES.
a. 4-digit SIC codes reported by the facility in DMR (e.g., a facility that reported SIC code
2891, Adhesives and Sealants, likely formulates these products; a facility that reported
SIC code 4952, Sewerage Systems, likely treats wastewater). Note that SIC codes can be
crosswalked to NAICS codes, which are often more useful for mapping OES because
they are more descriptive than SIC codes.
b. Internet research of the types of products made at the facility (e.g., if a facility's website
indicates the facility manufactures metal parts, the facility is likely to use chemicals for
degreasing or in a metalworking fluid) and information from sources cited in the COU
table and scoping document, such as public and stakeholder comments (i.e., EPA/ERG
will review sources cited in the COU table and scoping document to see if there is any
information specific to the reporting site that can be used to inform the mapping).
3. Refine OES: If the specific OES still cannot be determined using the information in Step 2, the
following should be considered.
a. NPDES permit numbers reported in DMR. The permit number generally indicates if the
permit is an individual permit or a general permit.15 If the permit is a general permit, the
permit number can often indicate the type of general permit, which can provide
information on the operations at the facility.
• Individual NPDES permits are numbered in the format of the state abbreviation
followed by a seven-digit number (e.g., VA0123456). General permits are usually
numbered in the format of state abbreviation followed by one letter then a six-
digit number (e.g., VAGI 12345 or MAG912345).
• Since each state is slightly different in their general permit numbering, the general
permit number should be searched on the internet to determine the type of general
15 Information on individual and general NPDES permits can be found at: https://www.epa.gov/npdes/npdes-permit-basics
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permit. For the general permit number examples provided above, a permit number
beginning in "VAGI 1" signifies Virginia's general permit for concrete products
facilities and a permit number beginning with "MAG91" signifies Massachusetts'
general permit for groundwater remediation. Other common general permit types
include those for construction sites, mining operations, sites that only discharge
non-contact cooling water, and vehicle washes.
b. Searching for the permit online. If the specific NPDES permit for the facility can be
found online, it may contain some general process information for the facility that can
help inform the OES mapping. However, NPDES permits may be difficult to find online
and do not generally contain much information on process operations.
c. An evaluation of the OES that is most likely to result in a water release (e.g., for facilities
that report an SIC code for the production of metal products, both vapor degreasing and
metalworking fluid OES are applicable; in such cases, the metalworking fluid OES may
be assigned because it is more likely to result in water releases than vapor degreasing).
d. Grouped OES for similar uses (e.g., multiple facilities that may conduct formulation
operations based on the reported SIC code may be assigned a grouped formulation OES
that covers all types of formulation [e.g., adhesives, paints, cleaning products]).
4. Consider Options for DMR Sites that Cannot be Mapped to an OES: Given the limited
information available in DMR, it may not always be feasible to achieve mapping of 100% of the
sites reporting to DMR to an OES. In such cases, multiple options may be appropriate depending
on assessment needs, such as:
a. Assigning the sites as having an unknown OES with 250 release days/year. This allows
for subsequent exposure modeling and the assessment of risk. For sites with identified
risk, the OES can then be mapped using the below resources.
b. Contacting the state government for the NPDES permit, permit applications, past
inspection reports, and any available information on facility operations. Note that
information requests such as these may require an ICR if 10 or more entities are
contacted.
c. Contacting the facility for clarification on the use of the chemical. ICR requirements also
apply when contacting 10 or more facilities.
G.3.5 Occupational Safety and Health Administration (OSHA) Chemical and Exposure
Data (CEHD)
OSHA CEHD is a compilation of industrial hygiene samples (i.e., occupational exposure data) taken
when OSHA monitors worker exposures to chemical hazards. OSHA will conduct monitoring at
facilities that fall within targeted industries based on national and regional emphasis programs.16 OSHA
conducts monitoring to compare against occupational health standards. Therefore, unlike CDR, TRI,
NEI, and DMR, facilities are not required to report data to OSHA CEHD. Also, OSHA only visits
selected facilities, so the amount of OSHA data available for each OES is often limited.
Figure Apx G-6 depicts the steps that should be followed to map OSHA CEHD sites to OES. Each step
is explained in the text below the figure. Additionally, Section G.5.5 shows step-by-step examples for
using the mapping procedures to determine the OES for two example OSHA CEHD facilities.
16 More information on OSHA CEHD can be found at: https://www.osha.gov/opengov/health-sainples
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4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
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FigureApx G-6. OES Mapping Procedures for OSHA CEHD
Within the OSHA CEHD data, there may be sites for which all air sampling data are non-detect (below
the limit of detection) for the chemical. In these cases, if there is also no bulk sampling data indicating
the presence of the chemical, there is no evidence that the chemical is present at the site. OSHA may
have sampled for the chemical based on a suspicion or pre-determined sampling plan, and not because
the chemical was actually present at the site. Therefore, these sites do not need to be mapped to OES. To
map sites for which there is OSHA CEHD data that are not all non-detect for the chemical, the following
procedures should be used:
1. Review Information from Other Databases: Given the limited facility information reported in
OSHA CEHD, the first step for mapping facilities should be to check other databases/sources
(including CDR, TRI, NEI, and TRI). If so, the OES determined from the mapping procedures
for those databases (discussed in other sections of this document) should be used. It is important
that the same facility is mapped consistently across multiple databases/sources. Because facility
identifiers such as TRFID and FRS ID are not available in the CEHD, the name of the facility in
the CEHD will need to be compared to the facility names in other databases to identify if the
facility is present in multiple databases/sources.
2. Assign OES: If the facility does not report to other databases, the following information should
be used to assign an OES.
a. 4-digit SIC and 6-digit NAICS codes reported in the CEHD (e.g., a facility that reported
SIC code 2891, Adhesives and Sealants, likely formulates these products; a facility that
reported NAICS code 313320, Fabric Coating Mills, likely uses the chemical in fabric
coating).
b. Internet research of the types of products made at the facility (e.g., if a facility's website
indicates the facility manufactures metal parts, the facility is likely to use chemicals for
degreasing or in a metalworking fluid) and information from sources cited in the COU
table and scoping document, such as public and stakeholder comments (i.e., EPA/ERG
will review sources cited in the COU table and scoping document to see if there is any
information specific to the reporting site that can be used to inform the mapping).
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4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
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3. Refine PES: If the specific OES still cannot be determined using the information in Step 2, the
following should be considered.
a. An evaluation of the OES that is most likely to result in occupational exposures (e.g., for
facilities that report an SIC code for janitorial services, multiple OES may be applicable,
such as cleaning, painting (e.g., touch-ups), other maintenance activities; in such cases,
the cleaning OES may be assigned for volatile chemicals because it has the highest
exposure potential).
b. Grouped OES for similar uses (e.g., multiple facilities that may conduct formulation
operations based on the reported NAICS or SIC code may be assigned a grouped
formulation OES that covers all types of formulation [e.g., adhesives, paints, cleaning
products]).
4. Consider Options for OSHA CEHD Sites that Cannot be Mapped to an OES: Given the limited
information available in OSHA CEHD, it may not always be feasible to achieve mapping of
100% of the sites in the database to an OES. In such cases, multiple options may be appropriate
depending on assessment needs, such as:
a. Assigning the sites as having an unknown OES with 250 exposure days/year. This allows
for subsequent health modeling and the assessment of risk. For workers with identified
risk, the OES can then be mapped using the below resources.
b. Contacting OSHA for additional information on the facility from the OSHA
inspection/monitoring.
c. Contacting the facility for clarification on the use of the chemical. Note that information
requests such as these may require an ICR if 10 or more entities are contacted.
d. As discussed previously, sites for which all air monitoring data is non-detect for the
chemical and for which there is no bulk data indicating the presence of the chemical do
not need to be mapped to an OES. This is because the data do not provide evidence that
the chemical is present at the site.
G.3.6 National Institute of Occupational Safety and Health (NIOSH) Health Hazard
Evaluation (HHE)
NIOSH conducts HHEs at facilities to evaluate current workplace conditions and to make
recommendations to reduce or eliminate the identified hazards.17 NIOSH conducts HHEs at the request
of employers, unions, or employees in workplaces where employee health and wellbeing is affected by
the workplace. Therefore, unlike CDR, TRI, NEI, and DMR, facilities are not required to report data to
NIOSH under the HHE program. Also, NIOSH only visits selected facilities where an HHE was
requested, so the number of NIOSH HHEs available for each OES is often limited.
To map a facility that is the subject of a NIOSH HHE, the information in the HHE report should be
used. Specifically, the HHE report typically includes general process information for the facility,
information on how the chemical is used, worker activities, and the facility's SIC code. This information
should be sufficient to map the facility to a single representative OES. Additionally, given the extent of
information available about the subject facilities in NIOSH HHE reports, 100% of these facilities can be
mapped to an OES. Additionally, Section G.5.6 shows two examples of how to map NIOSH HHE
facilities to OES.
17 More information about NIOSH HHEs is available at: https://www.cdc.gov/niosh/hhe/about.html
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4730
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4733
4734
4735
4736
4737
4738
4739
4740
4741
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4743
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G.4 CPU Mapping Procedures
As discussed in Section G.l, there is not always a one-to-one mapping between COUs and OES.
FigureApx G-7 depicts the steps that should be followed to map sites from the standard sources
discussed in this document to COUs, using the OES mapping completed in Section G.3. Each step is
explained in the text below the figure. Additionally, Section G.5.7 shows step-by-step examples for
using the mapping procedures to determine the COU for three example facilities.
Figure Apx G-7. COU Mapping Procedures for Standard Sources Already Mapped to OES
To map facilities from standard sources (i.e., CDR, TRI, NEI, DMR, OSHA CEHD, NIOSH HHE) to
COUs, the following procedures should be used:
1. Map the Facility to an OES: To map a facility from a standard source to a COU, the facility
should first be mapped to an OES following the procedures for the specific source of data
(discussed in Section G.3).
2. Use the COU Table with Mapped OES to Assign COUs: At the point of the risk evaluation
process where EPA/ERG are mapping data from standard sources to OES and COU, EPA/ERG
have already mapped OES to each of the COUs from the scope document, as shown in Table
1-1. Crosswalk of Subcategories of Use Listed in the Final Scope Document to Occupational
Exposure Scenarios Assessed in the Risk Evaluation. This crosswalk between COUs and OES
should be used to identify the COU(s) for the facility using the OES mapped per Section G.3.
3. Refine the COU Assignment: In some instances, more than one COU may map to the facility. In
such cases, the following information should be used to try to narrow down the list of potentially
applicable COUs:
a. Information from the standard sources (e.g., if ERG/EPA assigned a grouped OES like
"Industrial Processing Aid" and the facility's NAICS code in TRI or NEI is related to
battery manufacturing, the COU can be identified as the "Processing Aid" category and
Process solvent used in battery manufacture" subcategory).
b. Internet research of the types of products made at the facility (e.g., if a facility's website
indicates the facility makes adhesives, the COU category of "Processing—Incorporation
into formulation, mixture or reaction product" and subcategory of "Adhesives and sealant
chemicals" can be assigned and the remaining subcategories [e.g., solvents for cleaning
or degreasing, solvents which become part of the product formulation or mixture] are not
applicable) and information from sources cited in the COU table and scoping document,
such as public and stakeholder comments (i.e., EPA/ERG will review sources cited in the
COU table and scoping document to see if there is any information specific to the
reporting site that can be used to inform the mapping).
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4760
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4. List all Potential CPUs: Where the above information does not narrow down the list of
potentially applicable COUs, EPA/ERG will list all the potential COUs and will not attempt to
select just one from the list where there is insufficient information to do so.
G.5 Example Case Studies
This section contains step-by-step examples of how to implement the OES and COU mapping
procedures listed in Sections G.3 and G.4 to determine OES for facilities that report to standard
engineering sources.
G.5.1 CDR Mapping Examples
This section includes examples of how to implement the OES mapping procedures for sites reporting to
CDR, as listed in Section G.3.1. Specifically, this section includes examples for three example sites that
reported to 2020 CDR for the round 2 chemical Di-isononyl phthalate (DINP). These example sites are
referred to as Facility A, Facility B, and Facility C.
To map Facilities A, B, and C to an OES, the following procedures are used with the non-CBI 2020
CDR database.
1. Review Manufacturing and Import Activity Information: The first step in the process is to review
the reported activity information to identify if the facility imports or manufactures the chemical.
Table Apx G-3 summarizes the information gathered from 2020 CDR for the three example
sites for this step.
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4778 Table Apx G-3. Step 1 for CDR Mapping Facilities
Facility
Name
Step la:
Reported Activity
Step lb:
Byproduct Information
Step lc:
Check Other
Activities?
OES Determination
Facility A
Domestically
Manufactured/Imported
Not known or reasonably
ascertainable
Not needed.
Per Step la, this site maps to the
Manufacturing OES.
Facility B
Imported
CBI
Yes
Cannot be determined in Step 1—
Proceed with Step 2.
Facility C
Imported
Not known or reasonably
ascertainable
Yes
Cannot be determined in Step 1—
Proceed with Step 2.
4779
4780 1. For Importation Sites. Review Fields for "Imported Never at Site". "Volume Exported", and "Volume Used": The next step is to
4781 review these additional fields to determine if the reporting facility conducts more than just importation activities. TableApx G-4
4782 summarizes the information gathered from 2020 CDR for the three example sites for this step.
4783
4784 Table Apx G-4. Step 2 for CDR Mapping Example Facilities
Facility
Name
Step 2a:
Imported Never
at Site
Step 2b:
Volume
Exported
Step 2c:
Volume
Used
OES Determination
Facility A
n/a: OES determined in Step 1
Facility B
CBI
CBI
CBI
Cannot be determined in Step 2: Proceed with Step 3.
Facility C
Yes
0
0
Since the facility only imports and does not use DINP, this site maps to
the ImDort/ReDackaging OES.
4785
4786 2. Refine PES Assignments: If multiple OES were identified from the previous steps, a single primary OES must be selected using
4787 additional facility information as discussed in Steps 3a to 3f. Table Apx G-5 summarizes the information gathered from 2020 CDR
4788 for the three example sites for this step.
4789
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Table Apx <
>5. Step 3 for CDR
Mapping Example Facilities
Facility
Name
Step 3a:
NAICS
Step3b:
Processing/Use
Information
Step 3c:
Internet Research
Step 3d-e: Other
Databases and
OES Grouping
OES Determination
Facility A
n/a: OES determined in Step 1
Facility B
325110,
Petrochemical
Manufacturing
CBI
Research indicates the facility is
a petrochemical plant and does
not indicate how DINP is used.
Check other
databases per Step
4.
Cannot be determined
in Step 2: Proceed with
Step 4.
Facility C
n/a: OES determined in Step 2
4791
4792
4793
4794
4795
4796
4797
3. Review Information from Other Databases: Lastly, other databases/sources (such as TRI, NEI, and DMR) should be checked to see if
the facility has reported to these. If the facility does not report to these databases, but additional OES are possible per Step 2, search
available facility information on the internet. Table Apx G-6 summarizes the information gathered from 2020 CDR for the three
example sites for this step.
Table Apx
G-6. Step 4 for CDR Mapping Example Facilities
Facility
Name
Step 4:
Other Databases
OES Determination
Facility A
n/a: OES determined in Step 1
Facility B
Using the FRS ID reported in CDR, this facility does not report to TRI, NEI, or
DMR. EPA searched the facility in EPA's ECHO database and found that the
facility does not have any listed NAICS codes, SIC codes, or permits, and appears
to be a warehouse from aerial imagery. Therefore, this facility is likely just an
importer.
Using the information from Step 4, this
site maps to the Import/Repackaging
OES.
Facility C
n/a: OES determined in Step 2
4798
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G.5.2 TRI Mapping Examples
This appendix includes examples of how to implement the OES mapping procedures for sites reporting to TRI, as listed in Section G.3.2.
Specifically, this appendix includes examples for three example sites that reported to TRI for the round 2 chemical 1,2-dichloroethane (1,2-
dichloroethane). These example sites are referred to as Facility D, Facility E, and Facility F.
To map Facilities D, E, and F to an OES, the following procedures are used with information from TRI.
1. Assign Chemical Data Reporting Codes using TRI-to-CDR Crosswalk: The first step in the TRI mapping process is to map the uses
and sub-uses reported by each facility to one or more 2016 CDRIFC codes. The uses and sub-uses reported to TRI by each example
site are compiled in TableApx G-7, along with the 2016 CDR IFC codes mapped using Appendix A.
Table Apx G-7. Step 1 for TRI Mapping Example Facilities
Facility
Name
TRI Form
Type
TRI Uses (Sub-uses)
2016 CDR IFC Codes
Facility D
R
Manufacture: produce, import, for onsite
use/processing, for sale/distribution, as a byproduct
Processing: as a reactant, as a formulation component
(P299 Other)
Otherwise Used: ancillary or other use (Z399 Other)
PK, U001, U003, U016, U013, U014, U018,
U019, U020, U023, U027, U028, orU999
Facility E
R
Otherwise Used: ancillary or other use (Z399 Other)
U001, U013, U014, U018, U020, orU023
Facility F
A
None—not reported in Form A submissions
2. Develop Chemical-Specific Crosswalk to Link CDR Codes to OES: The next step is to develop a separate CDR IFC code-to-OES
crosswalk that links CDR IFC codes to OES for the chemical. To create this crosswalk, match the COU and OES from the COU table
in the published scope documents to the list of 2016 CDR IFC codes in Appendix. The categories and subcategories of COUs typically
match the IFC code category. See Table Apx G-8 for the completed crosswalk for 1,2-dichloroethane.
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4818 Table Apx G-8. Step 2 for TRI Mapping Example Facilities
COU and OES from Published Scope Document
Mapping
Life Cycle
Stage
Category
Subcategory
Occupational
Exposure Scenario
2016 CDR
IFC Code
2016 CDR
IFC Code
Name
Rationale
Manufacturing
Domestic
Manufacturing
Domestic Manufacturing
Manufacturing
None
None
Per Section G.5.1,
there is no
corresponding CDR
code for this
COU/OES.
Repackaging
Repackaging
Repackaging
Repackaging
PK
Processing-
repackaging
Category matches
CDR code
Processing
Processing—As
a Reactant
Intermediate in Petrochemical
manufacturing
Plastic material and resin
manufacturing
All other basic organic
chemical manufacturing
Processing as a
reactant
U015;
U016;
U019;
U024
Processing as
a reactant
Category matches
CDR code
Processing
Processing—
Incorporation
into
formulation,
mixture, or
reaction product
Fuels and fuel additives: All
other petroleum and coal
products manufacturing
Incorporated into
formulation, mixture,
or reaction product
U012
Fuel and fuel
additives
Category matches
CDR code
Formulation of Adhesives and
Sealants
U002
Adhesives and
sealant
chemicals
Category matches
CDR code
Processing aids: specific to
petroleum production
U025
Processing
aids: specific
to petroleum
production
Category matches
CDR code
Distribution in
Commerce
Distribution in
Commerce
Distribution in Commerce
Distribution in
commerce
None
None
Per Section G.5.1,
there is no
corresponding CDR
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COU and OES from Published Scope Document
Mapping
code for this
COU/OES.
Industrial Use
Adhesives and
Sealants
Adhesives and Sealants
Adhesives and
sealants
U002
Adhesives and
sealant
chemicals
Category matches
CDR code
Functional
Fluids (Closed
Systems)
Engine Coolant Additive
Functional fluids
(closed systems)
U013
Functional
Fluids (closed
systems)
Category matches
CDR code
Lubricants and
Greases
Paste lubricants and greases
Lubricants and greases
U017
Lubricants
and Lubricant
additives
Category matches
CDR code
Oxidizing/Redu
cing Agents
Oxidation inhibitor in
controlled oxidative chemical
reactions
Oxidizing/reducing
agents
U019
Oxidizing/red
ucing agents
Category matches
CDR code
Cleaning and
Degreasing
Industrial and commercial
non-aerosol
cleaning/degreasing
Vapor Degreasing (TBD)
Solvents (for cleaning
and degreasing)
U029
Solvents (for
cleaning or
degreasing)
Category matches
CDR code
Commercial
Use
Cleaning and
Degreasing
Commercial aerosol products
(Aerosol degreasing, aerosol
lubricants, automotive care
products)
Plastic and
Rubber Products
Products such as: plastic and
rubber products
Plastics and rubber
products
None
None
Per Section G.5.1,
there is no
corresponding CDR
code for this
COU/OES.
Fuels and
Related
Products
Fuels and related products
Fuels and Related
Products
U012
Fuels and Fuel
Additives
Category matches
CDR code
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COU and OES from Published Scope Document
Mapping
Other use
Laboratory Chemical
Other use
None
Use-non-
incorporative
activities
This use does not
match any other CDR
codes and is non-
incorporative
Embalming agent
Waste
Handling,
Disposal,
Treatment, and
Recycling
Waste Handling,
Disposal,
Treatment, and
Recycling
Waste Handling, Disposal,
Treatment, and Recycling
Waste Handling,
Disposal, Treatment,
and Recycling
None
None
Per Section G.5.1,
there is no
corresponding CDR
code for this
COU/OES.
4819
4820 3. Assign PES: Each TRI facility is then mapped to one or more OES using the CDRIFC codes assigned to each facility in Step 1 and
4821 the CDR IFC code-to-OES crosswalk developed in Step 2. Table Apx G-9 includes the potential OES for each example facility per
4822 this step.
4823
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4824 Table Apx G-9. Step 3 for TRI Mapping Example Facilities
Facility
Name
TRI
Form
Type
2016 CDR IFC Codes
Crosswalked OES
OES Determination
Facility D
R
PK, U001, U003, U016,
U013, U014, U018, U019,
U020, U023, U027, U028, or
U999
Repackaging, Processing as a Reactant,
Functional Fluids (Closed Systems), or
Oxidizing/ Reducing Agents
Cannot be determined in Step 3:
proceed to Step 4.
Facility E
R
U001, U013, U014, U018,
U020, or U023
Functional Fluids (Closed Systems)
Since the facility maps to only one
OES, the OES is Functional Fluids
(Closed Systems).
Facility F
A
None; not reported in Form A submissions
Cannot be determined in Step 3:
proceed to Step 4.
4825
4826 4. Refine PES Assignments: If a facility maps to more than one OES in Step 3, a single primary OES must be selected using additional
4827 facility information per Steps 4a-e. Table Apx G-10 summarizes the information gathered for the three example sites for this step.
4828
4829 Table Apx G-10. Step 4 for TRI Mapping Example Facilities
Facility Name
Step 4a: NAICS
Code
Step 4b: Internet
Research
Step 4c: Other
Databases
Step 4d-e: Most
Likely OES or OES
Grouping
OES Determination
Facility D
486990, All Other
Pipeline
Transportation
The facility is a large
chemical
manufacturing plant.
Check databases
per Step 5.
Based on the type of
facility, the Processing
as a Reactant OES
seems the most likely
OES from Step 3.
Most likely
Processing as a
Reactant OES.
Check other
databases in Step 5 to
verify.
Facility E
n/a; OES determined in Step 3
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4832
4833
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Facility Name
Step 4a: NAICS
Code
Step 4b: Internet
Research
Step 4c: Other
Databases
Step 4d-e: Most
Likely OES or OES
Grouping
OES Determination
Facility F
325199, All Other
Basic Organic
Chemical
Manufacturing
The facility is a
chemical supplier
that does not appear
to produce
chemicals.
Check databases
per Step 5.
Based on the NAICS
code and type of
facility, the
Repackaging OES
seems the most likely.
Most likely
Repackaging OES.
Check other
databases in Step 5 to
verify.
5. Review Information from Other Databases: Other databases/sources (including CDR, NEI, and DMR) should be checked to see if the
facility has reported to these. If so, the OES determined from the mapping procedures for those databases (discussed in other sections
of this document) should also be used. It is important that the same facility is mapped consistently across multiple databases/sources.
The facility's TRFID and FRS ID can be used to identify sites that report to TRI, DMR, and NEI. Table Apx G-l 1 summarizes the
information gathered from other databases for the three example sites for this step.
Table Apx
G-ll. Step 5 for TRI Mapping Example Facilities
Facility
Name
Step 4:
Other Databases
OES Determination
Facility D
The facility did not report to 2016 or 2020 CDR. The facility reported to 2020
NEI, reporting emissions of 1,2-dichloroethane from storage tanks and process
equipment from chemical manufacturing processes and storage/transfer operations.
The facility reported DMRs for the past few years but reported no releases of 1,2-
dichloroethane to DMR.
The NEI information corroborates the
most likely OES determined in Step 4d.
Therefore, this site maps to the
Processing as a Reactant OES.
Facility E
n/a; OES determined in Step 3
Facility F
The facility did not report to 2016 or 2020 CDR, 2020 NEI, or the past few years
of DMR.
Since no additional information was
determined in Step 5, the site maps to the
Repackaging OES oer Steo 4d.
G.5.3 NEI Mapping Examples
This section includes examples of how to implement the OES mapping procedures for sites reporting to NEI, as listed in Section G.3.3.
Specifically, this section includes two examples for 1,2-dichloroethane from 2017 NEI: (1) Facility G, which is an industrial site that reported
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4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
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point source emissions under multiple NEI records, and (2) Example H, which is a county that reported non-point source emissions under
multiple NEI records.
To map Facility G (point source) and Example H (non-point source) NEI records to OES, the following procedures should be used:
1. Develop Crosswalks to Link NEI-Reported SCC and Sector Combinations to Chemical Data Reporting Codes: The first step in
mapping NEI data to potentially relevant OES is to develop a crosswalk to map each unique combination of NEI-reported Source
Classification Code (SCC) (levels 1-4) and industry sectors to one or more CDR codes. This crosswalk is developed on a chemical-by-
chemical basis rather than an overall crosswalk for all chemicals because SCCs correspond to emission sources rather than chemical
uses such that the crosswalk to CDR codes may differ from chemical to chemical. In some cases, it may not be possible to assign all
SCC sector combinations to CDR codes, in which case information from Step 5 can be used to help make OES assignments. Separate
crosswalks are needed for point and nonpoint source records, as shown in TableApx G-12 and TableApx G-13. Note that theses
tables only present the crosswalk for the SCC and sector codes relevant to Facility G (point source) and Example H (non-point source)
examples; there are many more SCC and sector codes reported for 1,2-dichloroethane in 2017 NEI.
Table Apx G-12. Step la for NEI Mapping Example Facilities
SCC Level One
SCC Level Two
SCC Level Three
SCC Level Four
Sector
Assigned CDR Code
Rationale
Chemical
Evaporation
Organic Solvent
Evaporation
Air Stripping
Tower
Solvent
Solvent—
Industrial
Surface
Coating &
Solvent Use
U029: Solvents (for
Cleaning and
Degreasing)
Based on
sector.
Chemical
Evaporation
Organic Solvent
Evaporation
Cold Solvent
Cleaning/Stripping
Other Not
Classified
Solvent—
Degreasing
U029: Solvents (for
Cleaning and
Degreasing)
Based on
sector.
Chemical
Evaporation
Organic Solvent
Evaporation
Dry Cleaning
Other Not
Classified
Solvent—
Dry
Cleaning
U029: Solvents (for
Cleaning and
Degreasing)
Based on
sector.
Chemical
Evaporation
Organic Solvent
Evaporation
Fugitive Emissions
General
Solvent—
Degreasing
U029: Solvents (for
Cleaning and
Degreasing)
Based on
sector.
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SCC Level One
SCC Level Two
SCC Level Three
SCC Level Four
Sector
Assigned CDR Code
Rationale
Chemical
Evaporation
Organic Solvent
Evaporation
Miscellaneous
Volatile Organic
Compound
Evaporation
Miscellaneous
Solvent—
Industrial
Surface
Coating &
Solvent Use
U029: Solvents (for
Cleaning and
Degreasing)
Based on
sector.
Chemical
Evaporation
Organic Solvent
Evaporation
Solvent Storage
General
Processes: Drum
Storage—Pure
Organic
Chemicals
Industrial
Processes—
Storage and
Transfer
n/a: no matching CDR
IFC, likely
Distribution in
Commerce
Matched
SCC and
Sector code.
Chemical
Evaporation
Organic Solvent
Evaporation
Solvent Storage
General
Processes: Spent
Solvent Storage
Industrial
Processes—
Storage and
Transfer
n/a: no matching CDR
IFC, likely
Distribution in
Commerce
Matched
SCC and
Sector code.
Chemical
Evaporation
Organic Solvent
Evaporation
Waste Solvent
Recovery
Operations
Other Not
Classified
Solvent—
Industrial
Surface
Coating &
Solvent Use
n/a: no matching CDR
IFC, likely Waste
Handling, Disposal
and Treatment
Matched to
SCC level 3
code.
Chemical
Evaporation
Organic Solvent
Evaporation
Waste Solvent
Recovery
Operations
Solvent Loading
Industrial
Processes—
Storage and
Transfer
n/a: no matching CDR
IFC, likely Waste
Handling, Disposal
and Treatment
Matched to
SCC level 3
code.
Industrial
Processes
Photo
Equip/Health
Care/Labs/Air
Condi t/ S wimPool s
Health Care—
Crematoriums
Cremation—
Animal
Industrial
Processes—
NEC
U999: Other
Does not fit
other CDR
code.
Industrial
Processes
Photo
Equip/Health
Health Care—
Crematoriums
Cremation—
Human
Industrial
Processes—
NEC
U999: Other
Does not fit
other CDR
code.
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SCC Level One
SCC Level Two
SCC Level Three
SCC Level Four
Sector
Assigned CDR Code
Rationale
Care/Labs/Air
Condi t/ S wimPool s
Industrial
Processes
Photo
Equip/Health
Care/Labs/Air
Condi t/ S wimPool s
Health Care—
Crematoriums
Crematory
Stack—Human
and Animal
Crematories
Industrial
Processes—
NEC
U999: Other
Does not fit
other CDR
code.
Industrial
Processes
Photo
Equip/Health
Care/Labs/Air
Condi t/ S wimPool s
Health Care
Miscellaneous
Fugitive
Emissions
Industrial
Processes—
NEC
U999: Other
Assume use
as a
laboratory
chemical in
the
healthcare
industry.
Industrial
Processes
Photo
Equip/Health
Care/Labs/Air
Condi t/ S wimPool s
Laboratories
Bench Scale
Reagents:
Research
Industrial
Processes—
NEC
U999: Other
SCC for
laboratories.
Industrial
Processes
Photo
Equip/Health
Care/Labs/Air
Condi t/ S wimPool s
Laboratories
Bench Scale
Reagents: Testing
Industrial
Processes—
NEC
U999: Other
SCC for
laboratories.
4857
4858
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4859 Table Apx G-13. Step lb for NEI Mapping Example Facilities
Sector
Assigned CDR Code
Rationale
Commercial Cooking
n/a; no matching CDR IFC
Unknown
Fuel Comb—Comm/Institutional—Biomass
U012: Fuels and fuel additives
Consistent with sector code
Fuel Comb—Comm/Institutional—Coal
U012: Fuels and fuel additives
Consistent with sector code
Fuel Comb—Industrial Boilers, ICEs—Biomass
U012: Fuels and fuel additives
Consistent with sector code
Fuel Comb—Industrial Boilers, ICEs—Coal
U012: Fuels and fuel additives
Consistent with sector code
Fuel Comb—Residential—Other
U012: Fuels and fuel additives
Consistent with sector code
Gas Stations
U012: Fuels and fuel additives
Consistent with sector code
Solvent—Consumer & Commercial Solvent Use
U029: Solvents (for cleaning or degreasing)
Consistent with sector code
Waste Disposal
n/a: no matching CDR IFC, likely Waste Handling,
Disposal and Treatment
Consistent with sector code
4860
4861 2. Use CDR Crosswalks to Assign CDR Codes: Next, the chemical-specific CDR crosswalk developed in Step 1 should be used to
4862 assign CDR IFC codes to each point source NEI record and CDR IFC codes and/or commercial/consumer use PCs to each nonpoint
4863 source NEI record. This is shown in Table Apx G-14 for Facility G (point source) and Example H (non-point source).
4864
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4868
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Table Apx G-14. Step 2 for NEI Mapping Example Facilities
Facility
Name
SCC Level
One
SCC Level Two
SCC Level
Three
SCC Level
Four
Sector
Assigned CDR IFC
Code
Facility G
Chemical
Evaporation
Organic Solvent
Evaporation
Air Stripping
Tower
Solvent
Solvent—Industrial
Surface Coating &
Solvent Use
U029: Solvents (for
Cleaning and
Degreasing)
Industrial
Processes
Photo Equip/Health
Care/Labs/Air
Condit/SwimPools
Laboratories
Bench Scale
Reagents:
Testing
Industrial Processes—
NEC
U999: Other
Example H
n/a: not applicable to nonpoint source
Commercial Cooking
n/a: no matching CDR
IFC
n/a: not applicable to nonpoint source
Fuel Comb—
Residential—Other
U012: Fuels and fuel
additives
n/a: not applicable to nonpoint source
Gas Stations
U012: Fuels and fuel
additives
3. Update CDR Crosswalks to Link CDR Codes to PES: The chemical-specific crosswalk developed in Step 1 is then used to link the
SCCs, sectors, and CDR codes in the crosswalk to an OES. The OES will be assigned based on the chemical specific COU categories
and subcategories and the OES mapped to them. The same crosswalk developed in TableApx G-8 (TRI Step 2) links CDR codes to
COUs and OES and is used in this example.
4. Use CDR Crosswalks to Assign OES: The chemical-specific CDR crosswalks developed in Steps 1-3 are then used to assign OES to
each point source and nonpoint source NEI data record {i.e., each combination of facility-SCC-sector). Note that the individual
facilities in the point source data set may have multiple emission sources, described by different SCC and sector combinations within
NEI, such that multiple OES map to each NEI record. In such cases, a single, representative OES must be selected for each NEI record
using the additional information described in Step 5. Similarly, the sectors reported by nonpoint sources may map to multiple CDR
IFC or PC codes, such that multiple OES are applicable and must be refined to a single OES. See Table Apx G-15 for completed Step
4 for the example facilities.
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4879 Table Apx G-15. Step 4 for NEI Mapping Example Facilities
Facility
Name
SCC Level
One
SCC Level Two
SCC Level
Three
SCC
Level
Four
Sector
Assigned
CDR IFC
Code
Mapped OES
OES
Determination
Facility G
Chemical
Evaporation
Organic Solvent
Evaporation
Air
Stripping
Tower
Solvent
Solvent—
Industrial
Surface
Coating &
Solvent Use
U029:
Solvents (for
Cleaning and
Degreasing)
Solvents (for
cleaning and
degreasing)
Since only one
OES maps to this
NEI record, the
OES is Solvents
(for cleaning and
decreasing)
Industrial
Processes
Photo
Equip/Health
Care/Labs/Air
Condit/SwimPools
Laboratories
Bench
Scale
Reagents:
Testing
Industrial
Processes—
NEC
U999: Other
Laboratory
Chemical
Embalming
Agent
Cannot be
determined in Step
4: Proceed with
Step 5.
n/a: not applicable to nonpoint source
Commercial
Cooking
n/a: no
matching
CDR IFC
None
Cannot be
determined in Step
4: Proceed with
Step 5.
Example H
n/a: not applicable to nonpoint source
Fuel Comb—
Residential—
Other
U012: Fuels
and fuel
additives
Incorporated
into
Formulation,
Mixture, or
Reaction
Product
Fuels and
Related
Products
Cannot be
determined in Step
4: Proceed with
Step 5.
n/a: not applicable to nonpoint source
Gas Stations
U012: Fuels
and fuel
additives
Incorporated
into
Formulation,
Mixture, or
Reaction
Product
Fuels and
Related
Products
Cannot be
determined in Step
4: Proceed with
Step 5.
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4881
4882
4883
4884
4885
4886
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4888
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5. Refine PES Assignments: The initial OES assignments may need to be confirmed and/or refined to identify a single primary OES
using the following information described in Steps 5a-b. See Table Apx G-16 for Facility G (point source) and Example H (non-point
source).
Table Apx G-16. Step 5 for NEI Mapping Example Facilities
Facility
Name
Sector
Step 5a: Additional Point Source
Information
Step 5b: Additional Non-
Point Source Information
OES Determination
Solvent—Industrial
Surface Coating &
Solvent Use
n/a: mapped to OES in Step 4
Facility G
Industrial Processes—
NEC
NAICS is 336415, Guided Missile and Space
Vehicle Propulsion Unit and Propulsion Unit
Parts Manufacturing. Emitting process is
analytical lab operations.
n/a
Information from Step 4 and
5a affirm the OES is
Laboratory Chemical.
Commercial Cooking
n/a
No knowledge is available on
the use of 1,2-dichloroethane
in commercial cooking
Cannot be determined in Step
5: Proceed to Step 7.
Example
H
Fuel Comb—
Re sidential—Other
n/a
1,2-dichloroethane may be
used in fuel additives.
Information from Step 4 and
5a affirm the OES is Fuels
and Related Products.
Gas Stations
n/a
1,2-dichloroethane may be
used in fuel additives.
Information from Step 4 and
5a affirm the OES is Fuels
and Related Products.
6. Review Information from Other Databases for Point Source Facilities: Other databases/sources (including CDR, TRI, and DMR)
should be checked to see if the point source facilities have reported to these. Facility G does not report to other databases. This step is
not applicable to non-point source Example H.
7. Consider Options for NEI Records that Cannot be Mapped to an OES: Given the number of records in NEI and the information
available, it may not always be feasible to achieve mapping of 100% of the sites reporting to NEI to an OES. This is the case for the
NEI record Example H—Commercial Cooking. In this case, the OES will be assessed, per Step 7a, as "unknown OES" with 250
release days/year. This allows for subsequent exposure modeling and the assessment of risk.
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4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
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4911
4912
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G.5.4 DMR Mapping Examples
This section includes examples of how to implement the OES mapping procedures for sites reporting to DMR, as listed in Section G.3.4.
Specifically, this appendix includes examples for two example sites that reported to DMR for 1,2-dichloroethane. These example sites are
referred to as Facility I and J.
To map Facilities I and J to an OES, the following procedures are used with information from DMR:
1. Review Information from Other Databases: Given the limited facility information reported in DMRs, the first step for mapping
facilities reporting to DMR should be to check other databases/sources (including CDR, TRI, and NEI). For these examples, neither
Facility I nor J reported to other databases.
2. Assign OES: If the facility does not report to other databases, the reported SIC code from DMR and internet research should be used
to map the facility to an OES, per Steps 2a and 2b. See TableApx G-17 for completed Step 2 for the example facilities.
Table Apx G-17.
Step 2 for DMR Map
ring Example Facilities
Facility Name
Step 2a: SIC Code
Step 2b: Internet Research
OES Determination
Facility I
4613, Refined
Petroleum Pipeline
Internet research indicates that the facility
is a fuel terminal.
Cannot be determined in Step 2: Proceed with Step 3.
Facility J
2821, Plastics
Materials and Resins
Internet research indicates the facility
makes poly vinyl chloride. 1,2-
dichloroethane is known to be used as a
reactant in this process.
This facilitv maps to the Processing as a Reactant OES.
based on the SIC code (which matches the subcategory
of use in the COU table, Table Apx G-8) and internet
research.
3. Refine OES: If the specific OES still cannot be determined using the information in Step 2, information in Steps 3a-d should be
considered. This includes searching for the facility NPDES permit and trying to determine which OES (or group of OES) is the most
likely. See Table Apx G-18 for completed Step 3 for the example facilities.
Table Apx G-18. Step 3 for DMR Map
ring Example Facilities
Facility Name
Step 3a: NPDES
Permit Number
Step 3b: Finding the
NPDES Permit
Step 3c-d: Most Likely
OES or Grouped OED
OES Determination
Facility I
VAG83MM A
search of VA NPDES
permits indicates that
permit numbers
The facility's NPDES
permit could not be found
online.
None of COUs or OES
for 1,2-dichloroethane in
Table Apx G-8 cover
remediation.
Since the facility's permit is for
remediation, the facility most likely does
not use 1,2-dichloroethane but the chemical
is present as a contaminant at the site. This
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4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
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Facility Name
Step 3a: NPDES
Permit Number
Step 3b: Finding the
NPDES Permit
Step 3c-d: Most Likely
OES or Grouped OED
OES Determination
starting in
"VAG0083" are
remediation general
permits.
does not correspond to an in-scope OES.
However, the OES should be designated as
"Remediation" for EPA to determine how/if
to present the release data.
Facility J
n/a: This facility was mapped to an OES in Step 2.
G.5.5 OSHA CEHD Mapping Examples
This section includes examples of how to implement the OES mapping procedures for sites in the OSHA CEHD data set, as listed in Section
G.3.5. Specifically, this section includes examples for two example sites in the OSHA CEHD data set for 1,4-dioxane. These example sites
are referred to as Facility K and L.
To map Facilities K and L to an OES, the following procedures are used with information from OSHA CEHD:
1. Review Information from Other Databases: Given the limited facility information reported in OSHA CEHD, the first step for mapping
facilities should be to check other databases/sources (including CDR, TRI, NEI, and TRI). For these examples, neither Facility K nor
L reported to other databases.
2. Assign OES: If the facility does not report to other databases, the reported SIC code from OSHA CEHD and internet research should
be used to map the facility to an OES, per Steps 2a and 2b. See TableApx G-19 for completed Step 2 for the example facilities.
Table Apx G-19. Step 2 for OSHA CE1
ID Mapping Example Facilities
Facility Name
Step 2a: SIC or
NAICS Code
Step 2b: Internet Research
OES Determination
Facility K
339112, Surgical and
Medical Instrument
Manufacturing
Internet research indicates that the facility
produces medical equipment for
cardiovascular procedures.
Based on the OES in Table Apx G-8, the most applicable
OES are likely Processing as a Reactant (for the production
of plastics used in equipment), Solvents (for Cleaning or
Degreasing), Plastics and Rubber Products, or Other Use.
The specific OES cannot be determined in Step 2: Proceed
with Step 3.
Facility L
5169, Chemicals and
Allied Products, Not
Internet research indicates the facility is a
waste management company.
This facilitv maps to the Waste Handling. Disposal.
Treatment, and Recvcline. based on information from
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Facility Name
Step 2a: SIC or
NAICS Code
Step 2b: Internet Research
OES Determination
Elsewhere Classified
internet research.
4929
4930 3. Refine PES: If the specific OES still cannot be determined using the information in Step 2, an evaluation of the OES that is most
4931 likely or a group of OES should be considered per Steps 3a and 3b. See Table Apx G-20 for completed Step 3 for the example
4932 facilities.
4933
4934 Table Apx G-20. Step 3 for OSHA CEHD Mapping Example Facilities
Facility Name
Step 3a: Mostly Likely OES
Step 3b: Grouped OED
OES Determination
Facility K
The scope document for 1,2-dichloroethane
indicates that the chemical is used to make
polyvinyl chloride that is then used in medical
devices. The use of 1,2-dichloroethane to produce
polyvinyl chloride falls under the Processing as a
Reactant OES (as an intermediate for plastics).
Not needed: the OES was
determined as Processing
as a Reactant in Step 3 a.
Per Step 3a, this facility maps to the
Processing as a Reactant OES. To further
support this determination, EPA may contact
OSHA for additional information on the visit
to this facility, per Step 4b.
Facility L
n/a: This facility was mapped to an OES in Step 2.
4935
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4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
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G.5.6 NIOSH HHE Mapping Examples
This section includes examples of how to implement the OES mapping procedures listed in Section
G.3.6 for two example NIOSH HHEs for 1,2-dichloroethane. To map facilities that are the subject of a
NIOSH HHE, the process information and other narrative descriptions in the NIOSH HHE should be
used.
1. The first example is for the following NIOSH HHE:
https://www.cdc.gov/niosh/hhe/reports/pdfs/80-186-1149.pdf. The following information is
found in the NIOSH HHE:
a. The facility produces plastic products, primarily plastic tubes for packaging.
b. 1,2-dichloroethane was used as a bonding agent for sealing packaging.
OES determination: Based on the OES for 1,2-dichloroethane (listed in TableApx G-8. Step 2
for TRI Mapping Example Facilities), the use of 1,2-dichloroethane for sealants falls under the
Adhesives and Sealants OES.
2. The second example is for the following NIOSH HHE:
https://www.cdc.gov/niosh/hhe/reports/pdfs/77-73-610.pdf. The following information is found
in the NIOSH HHE:
a. The facility is a chemical manufacturer.
b. The facility uses 1,2-dichloroethane as a solvent in a reaction to produce another
chemical.
OES determination: Based on the OES for 1,2-dichloroethane (listed in Table Apx G-8. Step 2
for TRI Mapping Example Facilities), the use of 1,2-dichloroethane as a reactant falls under the
Processing as a Reactant OES.
As discussed in Section G.3.6, NIOSH HHEs typically contain detailed process information and
description of how the chemical is used at the facility. Therefore, the mapping of NIOSH HHE facilities
to OES is straightforward.
G.5.7 COU Mapping Examples
This appendix includes examples of how to implement the COU mapping procedures for sites from
standard sources (i.e., CDR, TRI, NEI, DMR, OSHA CEHD, NIOSH HHE, as listed in Section G.4.
Specifically, this appendix uses the same example facilities (Facility D, Facility E, and Facility F) for
the TRI examples in Section G.5.2.
To map Facilities D, E, and F to an COUs, the following procedures should be used:
1. Map the Facility to an OES: To map a facility from a standard source to a COU, the facility
should first be mapped to an OES following the procedures for the specific source of data
(discussed in Section G.3). This mapping was completed in completed in Section G.5.2 and is
summarized in Table Apx G-21.
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4975
Table Apx G-2]
. Step 1 for COU Mapping Example Facilities
Facility Name
Step 1: OES Determination from Appendix A.2
Facility D
Processing as a Reactant
Facility E
Functional Fluids (Closed Systems)
Facility F
Repackaging
4976
4977
4978
4979
4980
4981
4982
4983
2. Use the CPU Table with Mapped PES to Assign CPUs: At the point of the risk evaluation
process where EPA/ERG are mapping data from standard sources to PES and CPU, EPA/ERG
have already mapped PES to each of the CPUs from the scope document. This crosswalk
between CPUs and PES, which is in TableApx G-8, for the example facilities should be used
to identify the CPU(s). See Table Apx G-22 for completed Step 2 for the example facilities.
Table Apx <
j-22. Step 2 for COU Mapping Example Facilities
Facility
Name
OES Determination
from Appendix A.2
Step 2: Mapped COUs
Facility D
Processing as a
Reactant
Using the CPU to PES crosswalk previously developed
(Table Apx G-8), the CPUs that map to this PES are:
Life Cycle
Stage
Category
Subcategory
Processing
Processing—
As a Reactant
Intermediate in
Petrochemical
manufacturing
Plastic material and resin
manufacturing
All other basic organic
chemical manufacturing
Facility E
Functional Fluids
(Closed Systems)
Using the CPU to PES crosswalk previously developed
(Table Apx G-8), only one CPU maps to this PES:
Life Cycle
Stage
Category
Subcategory
Industrial use
Functional
Fluids (Closed
Systems)
Engine Coolant Additive
Facility F
Repackaging
Using the CPU to PES crosswalk previously developed
(Table Apx G-8), only one CPU maps to this PES:
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4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
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Facility
Name
OES Determination
from Appendix A.2
Step 2: Mapped COUs
Life Cycle
Stage
Category
Subcategory
Repackaging
Repackaging
Repackaging
3. Refine the CPU Assignment: In some instances, more than one COU may map to the facility. In
such cases, the reported NAICS code and internet research should be used to try to narrow down
the list of potentially applicable COUs, per Steps 3a-b. See TableApx G-23 for completed Step
3 for the example facilities.
Table Apx G-2;
5. Step 3 for COU M
apping Example Facilities
Facility
Name
Step 3a: NAICS
Code
Step 3b: Internet
Research
COU Determination
Facility D
486990, All Other
Pipeline
Transportation
The facility is a
large chemical
manufacturing
plant.
The COU subcategory for "Plastic material
and resin manufacturing" can be
eliminated. However, the COU cannot be
narrowed down between the remaining two
subcategories of use. Proceed to Step 4.
Facility E
n/a: COU determined in Step 2
Facility F
n/a: COU determined in Step 2
4. List all Potential COUs: Where the above information does not narrow down the list of
potentially applicable COUs, EPA/ERG will list all the potential COUs and will not attempt to
select just one from the list where there is insufficient information to do so. Since a singular OES
was identified for Facility D and F, this step is not applicable to those facilities. For Facility F,
there are two possible COUs that are listed in Table Apx G-24. Since a COU consists of a life
cycle stage, category, and subcategory, all three should be presented in this step.
Table Ap
x G-24. Step 4 for COU Mapping Example Facilities
Facility
Name
Step 4: All Potential COUs
Facility
D
All potential COUs for this facility are as follows:
Life Cycle
Stage
Category
Subcategory
Processing
Processing—As a Reactant
Intermediate in Petrochemical
manufacturing
All other basic organic chemical
manufacturing
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5000 G.6 TRI to CDR Use Mapping Crosswalk
5001 TableApx G-25 presents the TRI-CDR Crosswalk used to map facilities to the OES for each chemical.
5002 "N/A" in the 2016 CDR code column indicates there is no corresponding CDR code that matches the
5003 TRI code. 2020 CDR introduced new codes for chemicals designated as high priority for risk evaluation;
5004 however, reporters may still use the same 2016 CDR codes listed in Table Apx G-25 for all other
5005 chemicals. For 2020 CDR reporting facilities using the new codes, the crosswalk between 2016 CDR
5006 codes and 2020 CDR codes in Table 4-15 of the 2020 CDR reporting instructions should be used with
5007 Table Apx G-25.
5008
Table Apx G-25. TI
'I-CDR
Jse Code Crosswalk
TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
3.1.a
Manufacture:
Produce
N/A
N/A
N/A
N/A
N/A
3.1.b
Manufacture:
Import
N/A
N/A
N/A
N/A
N/A
3.1.c
Manufacture:
For on-site
use/processin
g
N/A
N/A
N/A
N/A
N/A
3.1.d
Manufacture:
For
sale/distributi
on
N/A
N/A
N/A
N/A
N/A
3.1.e
Manufacture:
As a
byproduct
N/A
N/A
N/A
N/A
N/A
3.1.f
Manufacture:
As an
impurity
N/A
N/A
N/A
N/A
N/A
3.2.a
Processing:
As a reactant
N/A
N/A
PC
Processing as
a reactant
Chemical substance is used in
chemical reactions for the
manufacturing of another chemical
substance or product.
3.2.a
Processing:
As a reactant
P101
Feedstocks
N/A
N/A
N/A
3.2.a
Processing:
As a reactant
P102
Raw
Materials
N/A
N/A
N/A
3.2.a
Processing:
As a reactant
P103
Intermediate
s
U015
Intermediates
Chemical substances consumed in a
reaction to produce other chemical
substances for commercial advantage.
A residual of the intermediate
chemical substance which has no
separate function may remain in the
reaction product.
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
3.2.a
Processing:
As a reactant
P104
Initiators
U024
Process
regulators
Chemical substances used to change
the rate of a chemical reaction, start or
stop the reaction, or otherwise
influence the course of the reaction.
Process regulators may be consumed
or become part of the reaction product.
3.2.a
Processing:
As a reactant
P199
Other
U016
Ion exchange
agents
Chemical substances, usually in the
form of a solid matrix, are used to
selectively remove targeted ions from
a solution. Examples generally consist
of an inert hydrophobic matrix such as
styrene divinylbenzene or phenol-
formaldehyde, cross-linking polymer
such as divinylbenzene, and ionic
functional groups including sulfonic,
carboxylic or phosphonic acids. This
code also includes aluminosilicate
zeolites.
3.2.a
Processing:
As a reactant
P199
Other
U019
Oxidizing/
reducing agent
Chemical substances used to alter the
valence state of another substance by
donating or accepting electrons or by
the addition or removal of hydrogen to
a substance. Examples of oxidizing
agents include nitric acid,
perchlorates, hexavalent chromium
compounds, and peroxydisulfuric acid
salts. Examples of reducing agents
include hydrazine, sodium thiosulfate,
and coke produced from coal.
3.2.a
Processing:
As a reactant
P199
Other
U999
Other (specify)
Chemical substances used in a way
other than those described by other
codes.
3.2.b
Processing:
As a
formulation
component
N/A
N/A
PF
Processing-
incorporation
into
formulation,
mixture, or
reaction
product
Chemical substance is added to a
product (or product mixture) prior to
further distribution of the product.
3.2.b
Processing:
As a
formulation
component
P201
Additives
U007
Corrosion
inhibitors and
antiscaling
agents
Chemical substances used to prevent
or retard corrosion or the formation of
scale. Examples include
phenylenediamine, chromates,
nitrates, phosphates, and hydrazine.
3.2.b
Processing:
As a
P201
Additives
U009
Fillers
Chemical substances used to provide
bulk, increase strength, increase
hardness, or improve resistance to
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
formulation
component
impact. Fillers incorporated in a
matrix reduce production costs by
minimizing the amount of more
expensive substances used in the
production of articles. Examples
include calcium carbonate, barium
sulfate, silicates, clays, zinc oxide and
aluminum oxide.
3.2.b
Processing:
As a
formulation
component
P201
Additives
U010
Finishing
agents
Chemical substances used to impart
such functions as softening, static
proofing, wrinkle resistance, and
water repellence. Substances may be
applied to textiles, paper, and leather.
Examples include quaternary
ammonium compounds, ethoxylated
amines, and silicone compounds.
3.2.b
Processing:
As a
formulation
component
P201
Additives
U017
Lubricants and
lubricant
additives
Chemical substances used to reduce
friction, heat, or wear between moving
parts or adjacent solid surfaces, or that
enhance the lubricity of other
substances. Examples of lubricants
include mineral oils, silicate and
phosphate esters, silicone oil, greases,
and solid film lubricants such as
graphite and PTFE. Examples of
lubricant additives include
molybdenum disulphide and tungsten
disulphide.
3.2.b
Processing:
As a
formulation
component
P201
Additives
U034
Paint additives
and coating
additives not
described by
other codes
Chemical substances used in a paint or
coating formulation to enhance
properties such as water repellence,
increased gloss, improved fade
resistance, ease of application, foam
prevention, etc. Examples of paint
additives and coating additives include
polyols, amines, vinyl acetate ethylene
emulsions, and aliphatic
polyisocyanates.
3.2.b
Processing:
As a
formulation
component
P202
Dyes
U008
Dyes
Chemical substances used to impart
color to other materials or mixtures
(i.e., substrates) by penetrating the
surface of the substrate. Example
types include azo, anthraquinone,
amino azo, aniline, eosin, stilbene,
acid, basic or cationic, reactive,
dispersive, and natural dyes.
3.2.b
Processing:
As a
P202
Dyes
U021
Pigments
Chemical substances used to impart
color to other materials or mixtures
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
formulation
component
(i.e., substrates) by attaching
themselves to the surface of the
substrate through binding or adhesion.
This code includes fluorescent agents,
luminescent agents, whitening agents,
pearlizing agents, and opacifiers.
Examples include metallic oxides of
iron, titanium, zinc, cobalt, and
chromium; metal powder suspensions;
lead chromates; vegetable and animal
products; and synthetic organic
pigments.
3.2.b
Processing:
As a
formulation
component
P203
Reaction
Diluents
U030
Solvents
(which
become part of
product
formulation or
mixture)
Chemical substances used to dissolve
another substance (solute) to form a
uniformly dispersed mixture (solution)
at the molecular level. Examples
include diluents used to reduce the
concentration of an active material to
achieve a specified effect and low
gravity materials added to reduce cost.
3.2.b
Processing:
As a
formulation
component
P203
Reaction
Diluents
U032
Viscosity
adjustors
Chemical substances used to alter the
viscosity of another substance.
Examples include viscosity index (VI)
improvers, pour point depressants, and
thickeners.
3.2.b
Processing:
As a
formulation
component
P204
Initiators
U024
Process
regulators
Chemical substances used to change
the rate of a chemical reaction, start,
or stop the reaction, or otherwise
influence the course of the reaction.
Process regulators may be consumed
or become part of the reaction product.
3.2.b
Processing:
As a
formulation
component
P205
Solvents
U030
Solvents
(which
become part of
product
formulation or
mixture)
Chemical substances used to dissolve
another substance (solute) to form a
uniformly dispersed mixture (solution)
at the molecular level. Examples
include diluents used to reduce the
concentration of an active material to
achieve a specified effect and low
gravity materials added to reduce cost.
3.2.b
Processing:
As a
formulation
component
P206
Inhibitors
U024
Process
regulators
Chemical substances used to change
the rate of a chemical reaction, start,
or stop the reaction, or otherwise
influence the course of the reaction.
Process regulators may be consumed
or become part of the reaction product.
3.2.b
Processing:
As a
P207
Emulsifiers
U003
Adsorbents
and absorbents
Chemical substances used to retain
other substances by accumulation on
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
formulation
component
their surface or by assimilation.
Examples of adsorbents include silica
gel, activated alumina, and activated
carbon. Examples of absorbents
include straw oil, alkaline solutions,
and kerosene.
3.2.b
Processing:
As a
formulation
component
P208
Surfactants
U002
Adhesives and
sealant
chemicals
Chemical substances used to promote
bonding between other substances,
promote adhesion of surfaces, or
prevent seepage of moisture or air.
Examples include epoxides,
isocyanates, acrylamides, phenol,
urea, melamine, and formaldehyde.
3.2.b
Processing:
As a
formulation
component
P208
Surfactants
U023
Plating agents
and surface
treating agents
Chemical substances applied to metal,
plastic, or other surfaces to alter
physical or chemical properties of the
surface. Examples include metal
surface treating agents, strippers,
etchants, rust and tarnish removers,
and descaling agents.
3.2.b
Processing:
As a
formulation
component
P208
Surfactants
U031
Surface active
agents
Chemical substances used to modify
surface tension when dissolved in
water or water solutions or reduce
interfacial tension between two liquids
or between a liquid and a solid or
between liquid and air. Examples
include carboxylates, sulfonates,
phosphates, carboxylic acid, esters,
and quaternary ammonium salts.
3.2.b
Processing:
As a
formulation
component
P209
Lubricants
U017
Lubricants and
lubricant
additives
Chemical substances used to reduce
friction, heat, or wear between moving
parts or adjacent solid surfaces, or that
enhance the lubricity of other
substances. Examples of lubricants
include mineral oils, silicate and
phosphate esters, silicone oil, greases,
and solid film lubricants such as
graphite and PTFE. Examples of
lubricant additives include
molybdenum disulphide and tungsten
disulphide.
3.2.b
Processing:
As a
formulation
component
P210
Flame
Retardants
U011
Flame
retardants
Chemical substances used on the
surface of or incorporated into
combustible materials to reduce or
eliminate their tendency to ignite
when exposed to heat or a flame for a
short period of time. Examples include
inorganic salts, chlorinated, or
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
brominated organic compounds, and
organic phosphates/phosphonates.
3.2.b
Processing:
As a
formulation
component
P211
Rheological
Modifiers
U022
Plasticizers
Chemical substances used in plastics,
cement, concrete, wallboard, clay
bodies, or other materials to increase
their plasticity or fluidity. Examples
include phthalates, trimellitates,
adipates, maleates, and
lignosulphonates.
3.2.b
Processing:
As a
formulation
component
P211
Rheological
Modifiers
U032
Viscosity
adjustors
Chemical substances used to alter the
viscosity of another substance.
Examples include VI improvers, pour
point depressants, and thickeners.
3.2.b
Processing:
As a
formulation
component
P299
Other
U003
Adsorbents
and absorbents
Chemical substances used to retain
other substances by accumulation on
their surface or by assimilation.
Examples of adsorbents include silica
gel, activated alumina, and activated
carbon. Examples of absorbents
include straw oil, alkaline solutions,
and kerosene.
3.2.b
Processing:
As a
formulation
component
P299
Other
U016
Ion exchange
agents
Chemical substances, usually in the
form of a solid matrix, are used to
selectively remove targeted ions from
a solution. Examples generally consist
of an inert hydrophobic matrix such as
styrene divinylbenzene or phenol-
formaldehyde, cross-linking polymer
such as divinylbenzene, and ionic
functional groups including sulfonic,
carboxylic or phosphonic acids. This
code also includes aluminosilicate
zeolites.
3.2.b
Processing:
As a
formulation
component
P299
Other
U018
Odor agents
Chemical substances used to control
odors, remove odors, mask odors, or
impart odors. Examples include
benzenoids, terpenes and terpenoids,
musk chemicals, aliphatic aldehydes,
aliphatic cyanides, and mercaptans.
3.2.b
Processing:
As a
formulation
component
P299
Other
U019
Oxidizing/
reducing agent
Chemical substances used to alter the
valence state of another substance by
donating or accepting electrons or by
the addition or removal of hydrogen to
a substance. Examples of oxidizing
agents include nitric acid,
perchlorates, hexavalent chromium
compounds, and peroxydisulfuric acid
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
salts. Examples of reducing agents
include hydrazine, sodium thiosulfate,
and coke produced from coal.
3.2.b
Processing:
As a
formulation
component
P299
Other
U020
Photosensitive
chemicals
Chemical substances used for their
ability to alter their physical or
chemical structure through absorption
of light, resulting in the emission of
light, dissociation, discoloration, or
other chemical reactions. Examples
include sensitizers, fluorescents,
photovoltaic agents, ultraviolet
absorbers, and ultraviolet stabilizers.
3.2.b
Processing:
As a
formulation
component
P299
Other
U027
Propellants
and blowing
agents
Chemical substances used to dissolve
or suspend other substances and either
to expel those substances from a
container in the form of an aerosol or
to impart a cellular structure to
plastics, rubber, or 177hermos set
resins. Examples include compressed
gasses and liquids and substances
which release ammonia, carbon
dioxide, or nitrogen.
3.2.b
Processing:
As a
formulation
component
P299
Other
U028
Solid
separation
agents
Chemical substances used to promote
the separation of suspended solids
from a liquid. Examples include
flotation aids, flocculants, coagulants,
dewatering aids, and drainage aids.
3.2.b
Processing:
As a
formulation
component
P299
Other
U999
Other (specify)
Chemical substances used in a way
other than those described by other
codes.
3.2.c
Processing:
As an article
component
N/A
N/A
PA
Processing-
incorporation
into article
Chemical substance becomes an
integral component of an article
distributed for industrial, trade, or
consumer use.
3.2.c
Processing:
As an article
component
N/A
N/A
U008
Dyes
Chemical substances used to impart
color to other materials or mixtures
(i.e., substrates) by penetrating the
surface of the substrate. Example
types include azo, anthraquinone,
amino azo, aniline, eosin, stilbene,
acid, basic or cationic, reactive,
dispersive, and natural dyes.
3.2.c
Processing:
As an article
component
N/A
N/A
U009
Fillers
Chemical substances used to provide
bulk, increase strength, increase
hardness, or improve resistance to
impact. Fillers incorporated in a
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
matrix reduce production costs by
minimizing the amount of more
expensive substances used in the
production of articles. Examples
include calcium carbonate, barium
sulfate, silicates, clays, zinc oxide and
aluminum oxide.
3.2.c
Processing:
As an article
component
N/A
N/A
U021
Pigments
Chemical substances used to impart
color to other materials or mixtures
(i.e., substrates) by attaching
themselves to the surface of the
substrate through binding or adhesion.
This code includes fluorescent agents,
luminescent agents, whitening agents,
pearlizing agents, and opacifiers.
Examples include metallic oxides of
iron, titanium, zinc, cobalt, and
chromium; metal powder suspensions;
lead chromates; vegetable and animal
products; and synthetic organic
pigments.
3.2.c
Processing:
As an article
component
N/A
N/A
U034
Paint additives
and coating
additives not
described by
other codes
Chemical substances used in a paint or
coating formulation to enhance
properties such as water repellence,
increased gloss, improved fade
resistance, ease of application, foam
prevention, etc. Examples of paint
additives and coating additives include
polyols, amines, vinyl acetate ethylene
emulsions, and aliphatic
polyisocyanates.
3.2.c
Processing:
As an article
component
N/A
N/A
U999
Other (specify)
Chemical substances used in a way
other than those described by other
codes.
3.2.d
Processing:
Repackaging
N/A
N/A
PK
Processing-
repackaging
Preparation of a chemical substance
for distribution in commerce in a
different form, state, or quantity. This
includes transferring the chemical
substance from a bulk container into
smaller containers. This definition
does not apply to sites that only
relabel or redistribute the reportable
chemical substance without removing
the chemical substance from the
container in which it is received or
purchased.
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
3.2.e
Processing:
As an
impurity
N/A
N/A
N/A
N/A
N/A
3.2.f
Processing:
Recycling
N/A
N/A
N/A
N/A
N/A
3.3.a
Otherwise
Use: As a
chemical
processing
aid
N/A
N/A
U
Use-non
incorporative
Activities
Chemical substance is otherwise used
(e.g., as a chemical processing or
manufacturing aid).
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z101
Process
Solvents
U029
Solvents (for
cleaning or
degreasing)
Chemical substances used to dissolve
oils, greases, and similar materials
from textiles, glassware, metal
surfaces, and other articles. Examples
include trichloroethylene,
perchloroethylene, methylene
chloride, liquid carbon dioxide, and n-
propyl bromide.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z102
Catalysts
U020
Photosensitive
chemicals
Chemical substances used for their
ability to alter their physical or
chemical structure through absorption
of light, resulting in the emission of
light, dissociation, discoloration, or
other chemical reactions. Examples
include sensitizers, fluorescents,
photovoltaic agents, ultraviolet
absorbers, and ultraviolet stabilizers.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z102
Catalysts
U025
Processing
aids, specific
to petroleum
production
Chemical substances added to water-,
oil-, or synthetic drilling muds or other
petroleum production fluids to control
viscosity, foaming, corrosion,
alkalinity and pH, microbiological
growth, hydrate formation, etc., during
the production of oil, gas, and other
products from beneath the earth's
surface.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z102
Catalysts
U026
Processing
aids, not
otherwise
listed
Chemical substances used to improve
the processing characteristics or the
operation of process equipment or to
alter or buffer the pH of the substance
or mixture, when added to a process or
to a substance or mixture to be
processed. Processing agents do not
become a part of the reaction product
and are not intended to affect the
function of a substance or article
created. Examples include buffers,
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Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
dehumidifiers, dehydrating agents,
sequestering agents, and chelators.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z103
Inhibitors
U024
Process
regulators
Chemical substances used to change
the rate of a chemical reaction, start or
stop the reaction, or otherwise
influence the course of the reaction.
Process regulators may be consumed
or become part of the reaction product.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z103
Inhibitors
U025
Processing
aids, specific
to petroleum
production
Chemical substances added to water-,
oil-, or synthetic drilling muds or other
petroleum production fluids to control
viscosity, foaming, corrosion,
alkalinity and pH, microbiological
growth, hydrate formation, etc., during
the production of oil, gas, and other
products from beneath the earth's
surface.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z103
Inhibitors
U026
Processing
aids, not
otherwise
listed
Chemical substances used to improve
the processing characteristics or the
operation of process equipment or to
alter or buffer the pH of the substance
or mixture, when added to a process or
to a substance or mixture to be
processed. Processing agents do not
become a part of the reaction product
and are not intended to affect the
function of a substance or article
created. Examples include buffers,
dehumidifiers, dehydrating agents,
sequestering agents, and chelators.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z104
Initiators
U024
Process
regulators
Chemical substances used to change
the rate of a chemical reaction, start,
or stop the reaction, or otherwise
influence the course of the reaction.
Process regulators may be consumed
or become part of the reaction product.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z104
Initiators
U025
Processing
aids, specific
to petroleum
production
Chemical substances added to water-,
oil-, or synthetic drilling muds or other
petroleum production fluids to control
viscosity, foaming, corrosion,
alkalinity and pH, microbiological
growth, hydrate formation, etc., during
the production of oil, gas, and other
products from beneath the earth's
surface.
3.3.a
Otherwise
Use: As a
Z104
Initiators
U026
Processing
aids, not
Chemical substances used to improve
the processing characteristics or the
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
chemical
processing
aid
otherwise
listed
operation of process equipment or to
alter or buffer the pH of the substance
or mixture, when added to a process or
to a substance or mixture to be
processed. Processing agents do not
become a part of the reaction product
and are not intended to affect the
function of a substance or article
created. Examples include buffers,
dehumidifiers, dehydrating agents,
sequestering agents, and chelators.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z105
Reaction
Terminators
U024
Process
regulators
Chemical substances used to change
the rate of a chemical reaction, start,
or stop the reaction, or otherwise
influence the course of the reaction.
Process regulators may be consumed
or become part of the reaction product.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z105
Reaction
Terminators
U025
Processing
aids, specific
to petroleum
production
Chemical substances added to water-,
oil-, or synthetic drilling muds or other
petroleum production fluids to control
viscosity, foaming, corrosion,
alkalinity and pH, microbiological
growth, hydrate formation, etc., during
the production of oil, gas, and other
products from beneath the earth's
surface.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z105
Reaction
Terminators
U026
Processing
aids, not
otherwise
listed
Chemical substances used to improve
the processing characteristics or the
operation of process equipment or to
alter or buffer the pH of the substance
or mixture, when added to a process or
to a substance or mixture to be
processed. Processing agents do not
become a part of the reaction product
and are not intended to affect the
function of a substance or article
created. Examples include buffers,
dehumidifiers, dehydrating agents,
sequestering agents, and chelators.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z106
Solution
Buffers
U026
Processing
aids, not
otherwise
listed
Chemical substances used to improve
the processing characteristics or the
operation of process equipment or to
alter or buffer the pH of the substance
or mixture, when added to a process or
to a substance or mixture to be
processed. Processing agents do not
become a part of the reaction product
and are not intended to affect the
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
function of a substance or article
created. Examples include buffers,
dehumidifiers, dehydrating agents,
sequestering agents, and chelators.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z199
Other
U002
Adhesives and
sealant
chemicals
Chemical substances used to promote
bonding between other substances,
promote adhesion of surfaces, or
prevent seepage of moisture or air.
Examples include epoxides,
isocyanates, acrylamides, phenol,
urea, melamine, and formaldehyde.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z199
Other
U006
Bleaching
agents
Chemical substances used to lighten or
whiten a substrate through chemical
reaction, usually an oxidative process
which degrades the color system.
Examples generally fall into one of
two groups: chlorine containing
bleaching agents (e.g., chlorine,
hypochlorite, N-chloro compounds
and chlorine dioxide); and, peroxygen
bleaching agents (e.g., hydrogen
peroxide, potassium permanganate,
and sodium perborate).
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z199
Other
U018
Odor agents
Chemical substances used to control
odors, remove odors, mask odors, or
impart odors. Examples include
benzenoids, terpenes and terpenoids,
musk chemicals, aliphatic aldehydes,
aliphatic cyanides, and mercaptans.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z199
Other
U023
Plating agents
and surface
treating agents
Chemical substances applied to metal,
plastic, or other surfaces to alter
physical or chemical properties of the
surface. Examples include metal
surface treating agents, strippers,
etchants, rust and tarnish removers,
and descaling agents.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z199
Other
U025
Processing
aids, specific
to petroleum
production
Chemical substances added to water-,
oil-, or synthetic drilling muds or other
petroleum production fluids to control
viscosity, foaming, corrosion,
alkalinity and pH, microbiological
growth, hydrate formation, etc., during
the production of oil, gas, and other
products from beneath the earth's
surface.
3.3.a
Otherwise
Use: As a
Z199
Other
U026
Processing
aids, not
Chemical substances used to improve
the processing characteristics or the
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
chemical
processing
aid
otherwise
listed
operation of process equipment or to
alter or buffer the pH of the substance
or mixture, when added to a process or
to a substance or mixture to be
processed. Processing agents do not
become a part of the reaction product
and are not intended to affect the
function of a substance or article
created. Examples include buffers,
dehumidifiers, dehydrating agents,
sequestering agents, and chelators.
3.3.a
Otherwise
Use: As a
chemical
processing
aid
Z199
Other
U028
Solid
separation
agents
Chemical substances used to promote
the separation of suspended solids
from a liquid. Examples include
flotation aids, flocculants, coagulants,
dewatering aids, and drainage aids.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
N/A
N/A
U
Use-non
incorporative
Activities
Chemical substance is otherwise used
(e.g., as a chemical processing or
manufacturing aid).
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z201
Process
Lubricants
U017
Lubricants and
lubricant
additives
Chemical substances used to reduce
friction, heat, or wear between moving
parts or adjacent solid surfaces, or that
enhance the lubricity of other
substances. Examples of lubricants
include mineral oils, silicate and
phosphate esters, silicone oil, greases,
and solid film lubricants such as
graphite and PTFE. Examples of
lubricant additives include
molybdenum disulphide and tungsten
disulphide.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z202
Metalworkin
g Fluids
U007
Corrosion
inhibitors and
antiscaling
agents
Chemical substances used to prevent
or retard corrosion or the formation of
scale. Examples include
phenylenediamine, chromates,
nitrates, phosphates, and hydrazine.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z202
Metalworkin
g Fluids
U014
Functional
fluids (open
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in an open system.
Examples include antifreezes and
de-icing fluids such as ethylene and
propylene glycol, sodium formate,
potassium acetate, and sodium acetate.
This code also includes substances
incorporated into metal working
fluids.
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z203
Coolants
U013
Functional
fluids (closed
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in a closed system.
Examples include heat transfer agents
(e.g., coolants and refrigerants) such
as polyalkylene glycols, silicone oils,
liquified propane, and carbon dioxide;
hydraulic/transmission fluids such as
mineral oils, organophosphate esters,
silicone, and propylene glycol; and
dielectric fluids such as mineral
insulating oil and high flash point
kerosene. This code does not include
fluids used as lubricants.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z204
Refrigerants
U013
Functional
fluids (closed
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in a closed system.
Examples include heat transfer agents
(e.g., coolants and refrigerants) such
as polyalkylene glycols, silicone oils,
liquified propane, and carbon dioxide;
hydraulic/transmission fluids such as
mineral oils, organophosphate esters,
silicone, and propylene glycol; and
dielectric fluids such as mineral
insulating oil and high flash point
kerosene. This code does not include
fluids used as lubricants.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z205
Hydraulic
Fluids
U013
Functional
fluids (closed
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in a closed system.
Examples include heat transfer agents
(e.g., coolants and refrigerants) such
as polyalkylene glycols, silicone oils,
liquified propane, and carbon dioxide;
hydraulic/transmission fluids such as
mineral oils, organophosphate esters,
silicone, and propylene glycol; and
dielectric fluids such as mineral
insulating oil and high flash point
kerosene. This code does not include
fluids used as lubricants.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z299
Other
U013
Functional
fluids (closed
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in a closed system.
Examples include heat transfer agents
(e.g., coolants and refrigerants) such
as polyalkylene glycols, silicone oils,
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
liquified propane, and carbon dioxide;
hydraulic/transmission fluids such as
mineral oils, organophosphate esters,
silicone, and propylene glycol; and
dielectric fluids such as mineral
insulating oil and high flash point
kerosene. This code does not include
fluids used as lubricants.
3.3.b
Otherwise
Use: As a
manufacturin
gaid
Z299
Other
U023
Plating agents
and surface
treating agents
Chemical substances applied to metal,
plastic, or other surfaces to alter
physical or chemical properties of the
surface. Examples include metal
surface treating agents, strippers,
etchants, rust and tarnish removers,
and descaling agents.
3.3.c
Otherwise
Use:
Ancillary or
other use
N/A
N/A
U
Use-non
incorporative
Activities
Chemical substance is otherwise used
(e.g., as a chemical processing or
manufacturing aid).
3.3.c
Otherwise
Use:
Ancillary or
other use
Z301
Cleaner
U007
Corrosion
inhibitors and
antiscaling
agents
Chemical substances used to prevent
or retard corrosion or the formation of
scale. Examples include
phenylenediamine, chromates,
nitrates, phosphates, and hydrazine.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z301
Cleaner
U029
Solvents (for
cleaning or
degreasing)
Chemical substances used to dissolve
oils, greases, and similar materials
from textiles, glassware, metal
surfaces, and other articles. Examples
include trichloroethylene,
perchloroethylene, methylene
chloride, liquid carbon dioxide, and n-
propyl bromide.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z302
Degreaser
U003
Adsorbents
and
Absorbents
Chemical substances used to retain
other substances by accumulation on
their surface or by assimilation.
Examples of adsorbents include silica
gel, activated alumina, and activated
carbon. Examples of absorbents
include straw oil, alkaline solutions,
and kerosene.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z302
Degreaser
U029
Solvents (for
cleaning or
degreasing)
Chemical substances used to dissolve
oils, greases, and similar materials
from textiles, glassware, metal
surfaces, and other articles. Examples
include trichloroethylene,
perchloroethylene, methylene
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
chloride, liquid carbon dioxide, and n-
propyl bromide.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z303
Lubricant
U017
Lubricants and
lubricant
additives
Chemical substances used to reduce
friction, heat, or wear between moving
parts or adjacent solid surfaces, or that
enhance the lubricity of other
substances. Examples of lubricants
include mineral oils, silicate and
phosphate esters, silicone oil, greases,
and solid film lubricants such as
graphite and PTFE. Examples of
lubricant additives include
molybdenum disulphide and tungsten
disulphide.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z304
Fuel
U012
Fuels and fuel
additives
Chemical substances used to create
mechanical or thermal energy through
chemical reactions, or which are
added to a fuel for the purpose of
controlling the rate of reaction or
limiting the production of undesirable
combustion products, or which
provide other benefits such as
corrosion inhibition, lubrication, or
detergency. Examples of fuels include
coal, oil, gasoline, and various grades
of diesel fuel. Examples of fuel
additives include oxygenated
compound such as ethers and alcohols,
antioxidants such as
phenylenediamines and hindered
phenols, corrosion inhibitors such as
carboxylic acids, amines, and amine
salts, and blending agents such as
ethanol.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z305
Flame
Retardant
U011
Flame
retardants
Chemical substances used on the
surface of or incorporated into
combustible materials to reduce or
eliminate their tendency to ignite
when exposed to heat or a flame for a
short period of time. Examples include
inorganic salts, chlorinated, or
brominated organic compounds, and
organic phosphates/phosphonates.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z306
Waste
Treatment
U006
Bleaching
agents
Chemical substances used to lighten or
whiten a substrate through chemical
reaction, usually an oxidative process
which degrades the color system.
Examples generally fall into one of
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July 2024
TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
two groups: chlorine containing
bleaching agents (e.g., chlorine,
hypochlorites, N-chloro compounds
and chlorine dioxide); and peroxygen
bleaching agents (e.g., hydrogen
peroxide, potassium permanganate,
and sodium perborate).
3.3.c
Otherwise
Use:
Ancillary or
other use
Z306
Waste
Treatment
U018
Odor agents
Chemical substances used to control
odors, remove odors, mask odors, or
impart odors. Examples include
benzenoids, terpenes and terpenoids,
musk chemicals, aliphatic aldehydes,
aliphatic cyanides, and mercaptans.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z306
Waste
Treatment
U019
Oxidizing/redu
cing agent
Chemical substances used to alter the
valence state of another substance by
donating or accepting electrons or by
the addition or removal of hydrogen to
a substance. Examples of oxidizing
agents include nitric acid,
perchlorates, hexavalent chromium
compounds, and peroxydisulfuric acid
salts. Examples of reducing agents
include hydrazine, sodium thiosulfate,
and coke produced from coal.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z306
Waste
Treatment
U028
Solid
separation
agents
Chemical substances used to promote
the separation of suspended solids
from a liquid. Examples include
flotation aids, flocculants, coagulants,
dewatering aids, and drainage aids.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z307
Water
Treatment
U006
Bleaching
agents
Chemical substances used to lighten or
whiten a substrate through chemical
reaction, usually an oxidative process
which degrades the color system.
Examples generally fall into one of
two groups: chlorine containing
bleaching agents (e.g., chlorine,
hypochlorites, N-chloro compounds
and chlorine dioxide); and peroxygen
bleaching agents (e.g., hydrogen
peroxide, potassium permanganate,
and sodium perborate).
3.3.c
Otherwise
Use:
Ancillary or
other use
Z307
Water
Treatment
U018
Odor agents
Chemical substances used to control
odors, remove odors, mask odors, or
impart odors. Examples include
benzenoids, terpenes and terpenoids,
musk chemicals, aliphatic aldehydes,
aliphatic cyanides, and mercaptans.
Page 187 of 222
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
3.3.c
Otherwise
Use:
Ancillary or
other use
Z307
Water
Treatment
U019
Oxidizing/redu
cing agent
Chemical substances used to alter the
valence state of another substance by
donating or accepting electrons or by
the addition or removal of hydrogen to
a substance. Examples of oxidizing
agents include nitric acid,
perchlorates, hexavalent chromium
compounds, and peroxydisulfuric acid
salts. Examples of reducing agents
include hydrazine, sodium thiosulfate,
and coke produced from coal.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z307
Water
Treatment
U028
Solid
separation
agents
Chemical substances used to promote
the separation of suspended solids
from a liquid. Examples include
flotation aids, flocculants, coagulants,
dewatering aids, and drainage aids.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z308
Construction
Materials
N/A
N/A
N/A
3.3.c
Otherwise
Use:
Ancillary or
other use
Z399
Other
U001
Abrasives
Chemical substances used to wear
down or polish surfaces by rubbing
against the surface. Examples include
sandstones, pumice, silex, quartz,
silicates, aluminum oxides, and glass.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z399
Other
U013
Functional
fluids (closed
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in a closed system.
Examples include heat transfer agents
(e.g., coolants and refrigerants) such
as polyalkylene glycols, silicone oils,
liquified propane, and carbon dioxide;
hydraulic/transmission fluids such as
mineral oils, organophosphate esters,
silicone, and propylene glycol; and
dielectric fluids such as mineral
insulating oil and high flash point
kerosene. This code does not include
fluids used as lubricants.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z399
Other
U014
Functional
fluids (open
systems)
Liquid or gaseous chemical substances
used for one or more operational
properties in an open system.
Examples include antifreezes and de-
icing fluids such as ethylene and
propylene glycol, sodium formate,
potassium acetate, and sodium acetate.
This code also includes substances
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TRI
Section
TRI
Description
TRI
Sub-use
Code
TRI Sub-
use Code
Name
2016
CDR
Code
2016 CDR
Code Name
2016 CDR Functional Use
Definition
incorporated into metal working
fluids.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z399
Other
U018
Odor agents
Chemical substances used to control
odors, remove odors, mask odors, or
impart odors. Examples include
benzenoids, terpenes and terpenoids,
musk chemicals, aliphatic aldehydes,
aliphatic cyanides, and mercaptans.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z399
Other
U020
Photosensitive
chemicals
Chemical substances used for their
ability to alter their physical or
chemical structure through absorption
of light, resulting in the emission of
light, dissociation, discoloration, or
other chemical reactions. Examples
include sensitizers, fluorescents,
photovoltaic agents, ultraviolet
absorbers, and ultraviolet stabilizers.
3.3.c
Otherwise
Use:
Ancillary or
other use
Z399
Other
U023
Plating agents
and surface
treating agents
Chemical substances applied to metal,
plastic, or other surfaces to alter
physical or chemical properties of the
surface. Examples include metal
surface treating agents, strippers,
etchants, rust and tarnish removers,
and descaling agents.
5010
Page 189 of 222
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5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
PUBLIC RELEASE DRAFT
July 2024
Appendix H ESTIMATING DAILY WASTEWATER DISCHARGES
FROM DISCHARGE MONITORING REPORTS AND
TOXICS RELEASE INVENTORY DATA
This section provides steps and examples for estimating daily wastewater discharges from industrial and
commercial facilities manufacturing, processing, or using chemicals undergoing risk evaluation under
the Toxics Substances Control Act (TSCA). Wastewater discharges are reported either via Discharge
Monitoring Reports (DMRs) under the National Pollutant Discharge Elimination System (NPDES) or
the Toxics Release Inventory (TRI).
Estimation Methods are provided:
- Average Daily Wastewater Discharge Rate (kg/site-day);
- High-End Daily Wastewater Discharge Rate (kg/site-day);
- 1-Day Maximum Wastewater Discharge Rate (kg/site-day); and
- Trends over 5 years for a facility including the Minimum, Maximum and Median wastewater
discharge rate that has occurred for a facility within the past 5 years.
These estimates will be used in modeling to estimate surface water concentrations in receiving waters
for the assessment of risks to aquatic species and to the general population from drinking water.
H.l Collecting and Mapping Wastewater Discharge Data to Conditions of
Use and Occupational Exposure Scenarios
The first step in estimating daily releases is obtaining and mapping the relevant data to the Conditions of
Use (COUs) for the chemical that were identified in the Scoping Document. Some COUs may be broad
categories of use and additional steps may be taken in the Risk Evaluation to further define the COUs
into more specific Occupational Exposure Scenarios (OES). A methodology for how to do this mapping
step has been developed and the key steps are described below.
I. Query the Loading Tool and TRI for each of the past five years, starting with the most recent
calendar year for which TRI data are available. In general, when a facility reports under both the
NPDES program and TRI, EPA will perform comparisons of the data to determine if any
discrepancies exist and, if so, which data are more appropriate to use in the risk evaluation.
However, the two data sets are not updated concurrently. The Loading Tool automatically and
continuously checks ICIS-NPDES for newly submitted DMRs. The Loading Tool processes the
data weekly and calculates pollutant loading estimates; therefore, water discharge data (DMR
data) are available on a continual basis. Although the Loading Tool process data weekly, each
permitted discharging facility is only required to report their monitoring results for each pollutant
at a frequency specified in the permit (e.g., monthly, every two months, quarterly). TRI data is
only reported annually for the previous calendar year and is typically released in July (i.e., 2020
TRI data is released in July 2021). To ensure EPA is making an appropriate comparison between
the two data sets, EPA should only use data for years where data from both data sets are
available.
2. Remove the following DMR facility types from further analysis:
a. Facilities reporting zero discharges for the chemical of interest for each of the five years
queried as EPA cannot confirm if the pollutant is present at the facility.
3. Map each remaining facility to a condition of use (COU) and occupational exposure scenario
(OES). The OES will inform estimates of average operating days per year for the facility.
Page 190 of 222
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5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
PUBLIC RELEASE DRAFT
July 2024
H.2 Estimating the Number of Facility Operating Days per Year
The number of operating days per year (days/year) for each facility that reports wastewater discharges
may be available but will most likely be unknow. An approach has been developed for use in Risk
Evaluations for estimating the number of facility operating days before and is described below.
I. Facility-specific data: Use facility-specific data if available. If facility-specific data is not
available, estimate the days/year using one of the following approaches:
a. If facilities have known or estimated average daily use rates, calculate the days/year as:
Days/year = Estimated Annual Use Rate for the Site (kg/year) / average daily use rate
from sites with available data (kg/day).
b. If sites with days/year data do not have known or estimate average daily use rates, use the
average number of days/year from the sites with such data.
2. Industry-specific data: Industry-specific data may be available in the form of generic scenarios
(GSs), emission scenario documents (ESDs), trade publications, or other relevant literature. In
such cases, these estimates should take precedent over other approaches, unless facility-specific
data are available.
3. Manufacture of large-production volume (PV) commodity chemicals: For the manufacture of
the large-PV commodity chemicals, a value of 350 days/year should be used. This assumes the
plant runs 7 day/week and 50 week/year (with two weeks down for turnaround) and assumes that
the plant is always producing the chemical.
4. Manufacture of lower-PV specialty chemicals: For the manufacture of lower-PV specialty
chemicals, it is unlikely the chemical is being manufactured continuously throughout the year.
Therefore, a value of 250 days/year should be used. This assumes the plant manufactures the
chemical 5 days/week and 50 weeks/year (with 2 weeks down for turnaround).
5. Processing as reactant (intermediate use) in the manufacture of commodity chemicals:
Similar to #3, the manufacture of commodity chemicals is assumed to occur 350 days/year such
that the use of a chemicals as a reactant to manufacture a commodity chemical will also occur
350 days/year.
6. Processing as reactant (intermediate use) in the manufacture of specialty chemicals: Similar
to #4, the manufacture of specialty chemicals is not likely to occur continuously throughout the
year. Therefore, a value of 250 days/year can be used.
7. Other Chemical Plant PES (e.s.. processing into formulation and use of industrial
processing aids): For these OES, it is reasonable to assume that the chemical of interest is not
always in use at the facility, even if the facility operates 24/7. Therefore, in general, a value of
300 days/year can be used based on the "SpERC fact sheet—Formulation & (re)packing of
substances and mixtures—Industrial (Solvent-borne)" which uses a default of 300 days/year for
the chemical industry. However, in instances where the OES uses a low volume of the chemical
of interest, 250 days/year can be used as a lower estimate for the days/year.
8. POTWs: Although POTWs are expected to operate continuously over 365 days/year, the
discharge frequency of the chemical of interest from a POTW will be dependent on the discharge
patterns of the chemical from the upstream facilities discharging to the POTW. The upstream
discharge patterns will be addressed in a second-tier analysis. However, there can be multiple
upstream facilities (possibly with different OES) discharging to the same POTW and information
to determine when the discharges from each facility occur on the same day or separate days is
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typically not available. Therefore, an exact number of days/year the chemical of interest is
discharged from the POTW cannot be determined and a value of 365 days/year should be used.
9. All Other PES: Regardless of what the facility operating schedule is, other OES are unlikely to
use the chemical of interest every day. Therefore, a value of 250 days/year should be used for
these OES.
H.3 Approach for Estimating Daily Discharges
After the initial steps of selecting and mapping of the water discharge data and estimating the number of
facility operating days/yr have been completed, the next steps in the analysis are to make estimates of
daily wastewater discharges. This guidance presents approaches for making the following estimates:
• Average daily wastewater discharges: this approach averages out the yearly discharges into an
average daily discharge rate for the entire year for the facility.
• High-end daily wastewater discharges: this approach estimates a high-end daily discharge rate
that may take place for a period of time during the year for the facility.
• 1-Day maximum discharge rate: this approach estimates a discharge rate that may represent a 1-
day maximum rate for the facility.
H.3.1 Average Daily Wastewater Discharges
The following steps should be used to estimate the average daily wastewater discharge for each facility
for each year:
I. Obtain total annual loads calculated from the Loading Tool and reported annual surface water
discharges in TRI.
2. For facilities with both TRI and DMR data, compare the annual surface water discharges
reported to each to see if they agree. If not, select the data representing the highest annual
discharge.
3. Divide the annual discharge over the number of estimated operating days for the OES to which
the facility has been mapped. The number of operating days will differ for each OES and
chemical but typically ranges from 200 to 350 days/year (see Section 2.3.2 for approach to
estimating operating days/year).
This approach can be used for both direct discharges to surface water and indirect discharges to POTW
or non-POTW WWT. However, special care should be given to facilities reporting transfers to POTW or
non-POTW WWT plants in TRI as the subsequent discharge to surface water from these transfers may
already be accounted for in the receiving facilities DMRs.
H.3.2 High-End Daily Direct Discharge for Facilities with DMR Data
The following steps should be used to estimate the high-end daily direct discharge for each facility with
DMR data for each year:
1. Use the Loading Tool to obtain the reporting periods (e.g., monthly, bimonthly, quarterly,
biannually, annually) and required reporting statistics (e.g., average monthly concentration, max
daily concentration) for each external outfall at each facility. When there is one outfall reported
in the Loading Tool, assume it is an external outfall. If multiple outfalls are reported in the
Loading Tool, further investigation to determine the external outfall would be required, such as a
review of facility's permits.
2. For each external outfall at each facility, calculate the average daily load for each reporting
period by multiplying the period average concentration by the period average wastewater
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flowrate. If there is one outfall reported in the Loading Tool, we will assume it is an external
outfall. Further investigation is needed if multiple outfalls are reported in the Loading Tool to
determine the external outfall, such as a review of the facility's permit.
3. Sum the average daily loads from each external outfall for each period.
4. Select the period with the highest average daily load across all external outfalls as an estimate of
the high-end daily discharge assessed over the number of days in the period. The number of days
in the reporting period does not necessarily equate to the number of operating days in the
reporting period. For example, for a plant that operates 200 days/year, we use 200 rather than
365 days/year for average daily discharge. Therefore, discharges will not occur every day of the
reporting period, but only for a fraction: 200/365 = 68%. The number of days of the reporting
period should be multiplied by this factor to maintain consistency between operating days/year
and operating days/reporting period.
H.3.3 High-End Daily Direct Consecutive Discharge for Facilities without DMRs
Some facilities may report surface water discharges to TRI but are not required to monitor or report
those discharges under the NPDES. In such cases, EPA will only have the annual discharge value and
not discharge values from multiple periods throughout the year. To estimate the high-end daily direct
discharges for these facilities the following steps should be used:
1. Identify facilities that report under the NPDES program for the same chemical, same year, and
same OES as the TRI facility and report DMRs monthly. Note: if no monthly reporters exist,
reporters with less frequent reporting can be substituted provided the number of release days per
year are adjusted in subsequent steps.
2. For each facility identified in #1, calculate the percentage of the total annual discharge that
occurred in the highest one-month period.
3. Calculate a generic factor for the OES as the average of the percentages calculated in #2.
4. Estimate the high-end daily discharge for each facility without DMRs by multiplying the annual
discharge by the generic factor from #3. For example, a facility reports 500 pounds (lb) released
per year and has a generic factor of 15% for the OES from #3. The estimated high-end chronic
daily discharge for the facility would be: 500 lb x 15% = 75 lb/month.
5. Use the value calculated in #4 as an estimate of the high-end daily discharge assessed over 30
days per year. For example, the high-end daily discharge assessed over 30 days per year for the
facility with the estimated high-end chronic daily discharge of 75 lb/month (from #4 above) is:
75 lb/month / 30 days = 2.5 lb/day for 30 days.
This approach can also be applied to facilities that have less frequent reporting periods under the
NPDES program (e.g., facilities that report quarterly or biannually). Use the facility specific permit data
for less frequent reporting periods. Refer to Section H.5: Example Facilities for additional details.
H.3.4 High-End Daily Indirect Discharges
In general, EPA is unlikely to have detailed information to estimate high-end daily indirect discharges to
POTWs or non-POTW WWT and will only be able to calculate average daily discharges. However, in
some cases, EPA may have site-specific information that allows for the estimation of a range for the
release days per year (for example such information can be find in ECHO). In such instances, EPA can
calculate the high-end daily discharge as the annual discharge divided by the minimum number of
release days per year.
H.3.5 1-Day Discharges
Facilities required to report under the NPDES may sometimes be required to report a daily maximum
discharge concentration for the period. These values can be used to estimate 1-day discharges by
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multiplying the maximum daily concentration by the corresponding month's maximum daily wastewater
flow rate.
H.4 Trends in Wastewater Discharge Data: 5 Year Data Characterization
Wastewater discharge data may vary from year to year for a facility due to factors including the
economy. A trend of the releases from each facility can be used to characterize results and develop a
range of potential discharges from each site. A 5-year period will be used for this analysis. Prior to
calculating the five-year statistics, it is recommended that an evaluation be done of whether the 5-year
range includes any outlier years and remove them from the analysis to ensure no atypical years are being
included in the statistics. The interquartile rule for outliers can be used for this analysis.
The interquartile rule for outliers states that if the distance between a data point and the first or third
quartile is greater than 1.5 times the interquartile range (IQR), the data point is an outlier. The IQR is the
difference between the third quartile {i.e., 75th percentile) and first quartile {i.e., 25th percentile) of a
data set. Therefore, any values <25th percentile - 1.5IQR or values >75th percentile + 1.5IQR would be
considered outliers.
After any outliers are removed, the following five-year statistics should be determined for each facility:
I. Minimum, maximum, median, and most recent (if different than the maximum) annual
discharge.
2. Minimum, maximum, median, and most recent (if different than the maximum) average chronic
daily discharge.
3. Minimum, maximum, median, and most recent (if different than the maximum) high-end chronic
daily discharge; and
4. Minimum, maximum, median, and most recent (if different than the maximum) acute 1-day
discharge.
H.4.1 Decision Tree for DMR and TRI Wastewater Discharge Estimates
A Decision Tree for Wastewater Discharge Estimates Using TRI and/or DMR Data, provided as
Figure Apx H-l below, helps visualize the process for estimating daily discharges.
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RHTlME^ECRAFr
1^/2024
Obtain TRI Data
Obtain DMR Data
Remove Zero Reporters
and Remediation Sites
Map Each Facility to an
OES1
Estimate Operating
Days/Yr2
Estimate High-End Daily
Discharge
Estimate Average Daily
Discharge
Estimate One-Day
Maximum Discharge
identify Dischargers
in DMR
Determine Reporting
Period and Statistics for
Each Facility
Calculate Average Daily
Load for Each Period
and Sum Across Outfalls
Select Max as High-End
Daily Discharge over
Number of Days in the
Period
Identify Facilities with
Monthly DMRs in Same
OES
Calculate % of Annual
Discharge Occurring in
Highest One-Month
Period
Calculate Generic Factor
(GF) as Average %
Across Facilities
Assess High-End Daily
Discharge as Annual
Discharge from TRI
Multiplied by GF Over
30 Davs
Compare Annual TRI
and DMR Discharges for
Each Facility
Select Higher of Two
Values for Each Facility
Calculate One-Day
Maximums for Each
Period
Select Period with
Highest One-Day
Maximum Discharge
Average Annual
Discharge Over Number
of Operating Days
5213
5214
1 Method for mapping facilities to an OES described in a separate
methodology document.
2 Method for estimating operating days per year described in a
separate methodology document.
Provide Results to
Exposure Assessors
Does Facility
have Both DMR
and TRI Data?
One-Day Maximum
Cannot be Estimated
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H.5 Example Facilities
This section illustrates how to calculate both high-end and average daily discharges for situations where
a facility has both TRI and OMR data and where a facility only has TRI data. It also includes
calculations for 1-day daily discharges from DMR data. The examples provided are for two facilities
reporting for the pollutant 1,2-dichloroethane (1,2-dichloroethane):
1. Westlake Vinyls in Calvert City, KY: reports both DMR and TRI; and
2. Axiall LLC in Plaquemine, LA: reports to TRI only.
For purposes of this example, only a single year for each database is presented.
• Obtaining DMR Data
DMR data can be obtained through multiple methods; however, this method focuses on a single
approach for simplicity. To query the loading tool for all pollutant data, the user should go to the
following webpage: https://echo.epa.gov/trends/loading-tool/get-data/custom-search, select the reporting
year of interest and then enter a chemical CAS number as shown in Figure_Apx H-2.
Reporting Year j 2019
_>¦
Select reporting year
~ Search Criteria
Facility Location
Facility Characteristics
State
Facility Name
Select a State v
County
City
Facility 10 (NPDES, FRS, TRI, or CWNS)
ZIP Code (5-Oigit)
0 Only include facilities that link to TRI lD(s)
Major/Non-Major Designation (8) Any O Major O Non-Major
Permit Type
Select a Permit Type
EPA Region (View EPA Regional Map)
Select an EPA Region
Facility Type
Select a Facility Type
Facility Latitude
Facility Longitude
Radius (miles)
Facility Outfall/Monitoring Locations
Permit Feature ID {outfall/pipe number)
Monitoring Location Code
Receiving Watershed
Hydrologic Units
HUC Region
Treatment Technologies CWNS Data Dictionary
limit to facilities where technology is © Present
0 Facilities with an approved pretreatment program
B Fact lities with one or more CSO outfalls
0 Pesticide-producing establishments regulated under FiFR;
Q Abandoned, inactive, or uncontrolled hazardous es
0 Facilities subject to SPCC/FRP to prevent and rp\ >il spills
0 Facilities with intermittent discharges
Enter
CAS number
Figure Apx H-2. Loading Tool - Data Query
After clicking submit, the Loading Tool will present a list of data elements that can be selected or
deselected for the query. By default, all data elements will be selected and for this methodology, it is
suggested to leave that unchanged to ensure all relevant data fields are downloaded. The user should
then click "download", as shown in Figure_Apx H-3. This will provide an Excel spreadsheet with all the
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5236 facilities that are required to monitor for the pollutant for the selected year and their annual discharge
5237 calculated by the Loading Tool.
Data Elements
Discharge Identification Information
|j Select AU 1 Desert All
Basic Record Information - Required Fields
Period: Year or Monitoring Dtte
1 Outfall Number
NPDES Permit Number
) Monitoring Location Code
Facility K»me
O Perm rt Feature Latitude
Q Permit Feature Longitude
Parameter Code
Facility Information
Parameter Description
Q SIC Code
Q CAS Number
Q NAJCS Ccce
Q Toxic Weighting Factor (TWF)
Q FSSIO
Q Substance Registry System (SRS) ID
Q TRllD(i)
Q CWNSID(s)
Q Picility Type Indicator
Permit and OMR Data
Q Permit Ty pe
Q Limit Quantity I (Avg. kg/day)
Q Permit Effective Dste
O Limit Quantity 2 (Max, kg/day's
Q Permit Expiration Oste
~ Limit Concentration I (Minr mg/L)
Q StreetAddress
Q Limit Concentration 2 (Avg, mg/L)
Q City
Q Limit Concentration 3 [Max, mg^'L)
Q -tile
Q ZIP Code
Pollutant Loadings Data
~ County
Q EPA Region
Q Pollutant Load (kg/yrj
Q Congressional District
Q Max Allowable Load (kg/yr)
Q "aciiity Latitude
Q Wastewater Flow (MGal/day)
0 Facility Longitude
Q Average Daily Load (kg/day)
Q Major;"Non-Major Status
Q Average Concentration (mgA)
Q 12-Digit WBD HUC (FRS Derived))
Q Average Daily Flow (MGD)
0 WBO Subwatershed Name
Q Average Wastewater Temp (*F)
Q State Water Body Name (ICIS)
Q Average Wastewater pH
Q Reach Code
Q Load Over Limit (Option l) (kg/yr)
Q Listed for Impairment (ATTAINS)
Q Load Over Limit (Option 2) (kg/yr)
~ impairmentClass(ATTAINS)
d Includes Non-detects
Q Number of Combined Sewer Overflow (CSO; Outfalls
1 Estimation Factor
Q Total Facility Design Flow (MOD)
B Potential Outlier
Q Actual Average Facility Flow (MOD)
TRI Release Data
Q ChemicalName
Q TRI Direct Release
Q TRI Indirect Release
Download data
5242
5243
FigureApx H-3. Loading Tool - Download Facility Discharges from Query Results
• Obtaining TRI Data
TRI data is available in several formats with various levels of detail depending on the type of
information a user intends to use. For this analysis, the "Basic Plus Data Files" were used. This data can
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be obtained by going to the following website: https://www.epa.gov/toxics-release-inventory-tri-
program/tri-data-and-tools, selecting "Basic Plus Data Files", then "Go" as shown in Figure_Apx H-4.
TRI Data and Tools for Advanced/Customized Analysis
Basic Data Files
Basic Plus Data Files
Description: Data for a repomb&vear for the entire U.S. Each .zip file is made up of 10
.txt files that collectively contain alhigta elements from the TRI reporting form
(except Form R Schedule 1, which is avaifotej^separately). Recommended for users
familiar with TRI data.
Select "Basic Plus Data Files"
Contents: Facility-reported data
Output: Tab-delimited .txt files compressed into .zip files.
Select "Go" to bring up data
download page
Figure Apx H-4. Accessing Basic Plus Data Files"'
" Guides for accessing, downloading, and importing the Basic Plus Data files can be found on EPA's
website.
The subsequent webpage can then be used to select the reporting year of interest and download the data
files as shown in Figure_Apx H-5. This will provide a zip file containing multiple tab-delimited .txt
files, which can be imported into Excel Spreadsheets and contain all the 2019 TRI data for all chemicals,
including annual direct and indirect wastewater discharges. The files can then be filtered for the
chemical of interest and facilities with non-zero discharges.18 Table_Apx H-1 provides a list of key data
fields and which Basic Plus data file they can be obtained from.
18 Facilities using a Fonn A rather than a Fonn R to report to TRI do not report any release information: therefore, the
wastewater discharges for these facilities will be shown as "0" in the TRI data files. However, these may not be true zero
discharges. Discharges from these facilities may need to be estimated separately and is outside the scope of this document.
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5262 Table Apx H-l. List of Key Data Fields from TR1 Basic Plus Data
TRI Basic Plus
Data File
Field Name
US_la_[Year]
1 FORM TYPE
US_la_[Year]
2. REPORTING YEAR
US_la_[Year]
9. TRIFD
US la [Year]
10. FACILITY NAME
US_la_[Year]
O. FACILITY STREET
US I a [Year ]
12. FACILITY CITY
US_la_[Year]
13. FACILITY COUNTY
US_la_[Year]
14. FACILITY STATE
US_la_[Year]
15. FACILITY ZIP CODE
US la [Year]
41. PRIMARY NAICS CODE
The ten file types of Basic Plus data files are:
la: Facility, chemical, releases and other waste management summary information
lb: Chemical activities and uses
2a: On- and off-site disposal, energy recovery, recycling and treatment; non-production-
related waste quantities; production/activity ratio; source reduction activities
2b: Detailed on-site waste treatment methods and efficiency
3a: Transfers off site for disposal and further waste management
3b: Transfers to Publicly Owned Treatment Works (POTWs) Reporting Years 1987 thru
2011
3c: Transfers to Publicly Owned Treatment Works (POTWs) Reporting Years 2012 and Later
4: Facility information
5: Optional information on source reduction, recycling and pollution control
6: Additional miscellaneous and optional information
Select a Reporting Year
2019 v tJien clic
Download Data
Select Reporting Year
Figure Apx H-5. TRI - Downloading Basic Data Plus Files
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TRI Basic Plus
Data File
Field Name
US_la_[Year]
47. LATITUDE
US_la_[Year]
48. LONGITUDE
US_la_[Year]
74. FRS FACILITY ID
US_la_[Year]
76. CAS NUMBER
US_la_[Year]
77. CHEMICAL NAME
US_la_[Year]
81. UNIT OF MEASURE
US_la_[Year]
112. DISCHARGES TO STREAM A—STREAM NAME
US_la_[Year]
113. DISCHARGES TO STREAM A—RELEASE POUNDS
US_la_[Year]
114. DISCHARGES TO STREAM A—RELEASE RANGE CODE
US_la_[Year]
115. TOTAL DISCHARGES TO STREAM A
US_la_[Year]
116. DISCHARGES TO STREAM A—BASIS OF ESTIMATE
US_la_[Year]
117. DISCHARGES TO STREAM A—% FROM STORMWATER
US_la_[Year]
118. DISCHARGES TO STREAM B—STREAM NAME
US_la_[Year]
119. DISCHARGES TO STREAM B—RELEASE POUNDS
US_la_[Year]
120. DISCHARGES TO STREAM B—RELEASE RANGE CODE
US_la_[Year]
121. TOTAL DISCHARGES TO STREAM B
US_la_[Year]
122. DISCHARGES TO STREAM B—BASIS OF ESTIMATE
US_la_[Year]
123. DISCHARGES TO STREAM B—% FROM STORMWATER
US_la_[Year]
124. DISCHARGES TO STREAM C—STREAM NAME
US_la_[Year]
125. DISCHARGES TO STREAM C—RELEASE POUNDS
US_la_[Year]
126. DISCHARGES TO STREAM C—RELEASE RANGE CODE
US_la_[Year]
127. TOTAL DISCHARGES TO STREAM C
US_la_[Year]
128. DISCHARGES TO STREAM C—BASIS OF ESTIMATE
US_la_[Year]
129. DISCHARGES TO STREAM C—% FROM STORMWATER
US_la_[Year]
130. DISCHARGES TO STREAM D—STREAM NAME
US_la_[Year]
131. DISCHARGES TO STREAM D—RELEASE POUNDS
US_la_[Year]
132. DISCHARGES TO STREAM D—RELEASE RANGE CODE
US_la_[Year]
133. TOTAL DISCHARGES TO STREAM D
US_la_[Year]
134. DISCHARGES TO STREAM D—BASIS OF ESTIMATE
US_la_[Year]
135. DISCHARGES TO STREAM D—% FROM STORMWATER
US_la_[Year]
136. DISCHARGES TO STREAM E—STREAM NAME
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TRI Basic Plus
Data File
Field Name
US_la_[Year]
137. DISCHARGES TO STREAM E—RELEASE POUNDS
US_la_[Year]
138. DISCHARGES TO STREAM E—RELEASE RANGE CODE
US_la_[Year]
139. TOTAL DISCHARGES TO STREAM E
US_la_[Year]
140. DISCHARGES TO STREAM E—BASIS OF ESTIMATE
US_la_[Year]
141. DISCHARGES TO STREAM E—% FROM STORMWATER
US_la_[Year]
142. DISCHARGES TO STREAM F—STREAM NAME
US_la_[Year]
143. DISCHARGES TO STREAM F—RELEASE POUNDS
US_la_[Year]
144. DISCHARGES TO STREAM F—RELEASE RANGE CODE
US_la_[Year]
145 TOTAL DISCHARGES TO STREAM F
US_la_[Year]
146 DISCHARGES TO STREAM F—BASIS FOR ESTIMATE
US_la_[Year]
147. DISCHARGES TO STREAM F—% FROM STORMWATER
US_la_[Year]
148. DISCHARGES TO STREAM G—STREAM NAME
US_la_[Year]
149. DISCHARGES TO STREAM G—RELEASE POUNDS
US_la_[Year]
150. DISCHARGES TO STREAM G—RELEASE RANGE CODE
US_la_[Year]
151. TOTAL DISCHARGES TO STREAM G
US_la_[Year]
152. DISCHARGES TO STREAM G—BASIS FOR ESTIMATE
US_la_[Year]
153. DISCHARGES TO STREAM G—% FROM STORMWATER
US_la_[Year]
154. DISCHARGES TO STREAM H—STREAM NAME
US_la_[Year]
155. DISCHARGES TO STREAM H—RELEASE POUNDS
US_la_[Year]
156. DISCHARGES TO STREAM H—RELEASE RANGE CODE
US_la_[Year]
157. TOTAL DISCHARGES TO STREAM H
US_la_[Year]
158. DISCHARGES TO STREAM H—BASIS FOR ESTIMATE
US_la_[Year]
159. DISCHARGES TO STREAM H—% FROM STORMWATER
US_la_[Year]
160. DISCHARGES TO STREAM I—STREAM NAME
US_la_[Year]
161. DISCHARGES TO STREAM I—RELEASE POUNDS
US_la_[Year]
162. DISCHARGES TO STREAM I—RELEASE RANGE CODE
US_la_[Year]
163. TOTAL DISCHARGES TO STREAM I
US_la_[Year]
164. DISCHARGES TO STREAM I—BASIS FOR ESTIMATE
US_la_[Year]
165. DISCHARGES TO STREAM I—% FROM STORMWATER
US_la_[Year]
166. TOTAL NUMBER OF RECEIVING STREAMS
US_la_[Year]
167. TOTAL SURFACE WATER DISCHARGE
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TRI Basic Plus
Data File
Field Name
US_la_[Year]
217. OFF SITE—POTW RELEASES 81C
US_la_[Year]
218. OFF SITE—POTW RELEASES 81D
US_la_[Year]
219. OFF SITE—POTW RELEASES
US_la_[Year]
222. OFF-SITE—WASTEWATER TREATMENT RELEASE
(EXCLUDING POTWs)—METALS AND METAL COMPOUNDS ONLY
US_la_[Year]
224. OFF-SITE—WASTEWATER TREATMENT (EXCLUDING POTWS)
METALS AND METAL COMPOUNDS ONLY
US_la_[Year]
249. OFF-SITE—POTW TREATMENT
US_la_[Year]
253. OFF-SITE—WASTEWATER TREATMENT (EXCLUDING
POTWs)—NON-METALS ONLY
US_la_[Year]
259. TOTAL POTW TRANSFER
US_lb_[Year]
1. FORM TYPE
US_lb_[Year]
2. REPORTING YEAR
US_lb_[Year]
3. TRADE SECRET INDICATOR
US_lb_[Year]
4. SANITIZED INDICATOR
US_lb_[Year]
5. TITLE OF CERTIFYING OFFICIAL
US_lb_[Year]
6. NAME OF CERTIFYING OFFICIAL
US_lb_[Year]
7. CERTIFYING OFFICIAL'S SIGNATURE INDICATOR
US_lb_[Year]
8. DATE SIGNED
US_lb_[Year]
9. TRIFD
US_lb_[Year]
10. FACILITY NAME
US_lb_[Year]
11. FACILITY STREET
US_lb_[Year]
12. FACILITY CITY
US_lb_[Year]
13. FACILITY COUNTY
US_lb_[Year]
14. FACILITY STATE
US_lb_[Year]
15. FACILITY ZIP CODE
US_lb_[Year]
16. BIA CODE
US_lb_[Year]
17. TRIBE NAME
US_lb_[Year]
18. MAILING NAME
US_lb_[Year]
19. MAILING STREET
US_lb_[Year]
20. MAILING CITY
US_lb_[Year]
21. MAILING STATE
Page 202 of 222
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PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_lb_[Year]
22. MAILING PROVINCE
US_lb_[Year]
23. MAILING ZIP CODE
US_lb_[Year]
24. ENTIRE FACILITY IND
US_lb_[Year]
25. PARTIAL FACILITY IND
US_lb_[Year]
26. FEDERAL FACILITY IND
US_lb_[Year]
27. GOCO FACILITY IND
US_lb_[Year]
28. ASSIGNED FED FACILITY FLAG
US_lb_[Year]
29. ASSIGNED PARTIAL FACILITY FLAG
US_lb_[Year]
30. PUBLIC CONTACT NAME
US_lb_[Year]
31. PUBLIC CONTACT PHONE
US_lb_[Year]
32. PUBLIC CONTACT PHONE EXT
US_lb_[Year]
33. PUBLIC CONTACT EMAIL
US_lb_[Year]
34. PRIMARY SIC CODE
US_lb_[Year]
35. SIC CODE 2
US_lb_[Year]
36. SIC CODE 3
US_lb_[Year]
37. SIC CODE 4
US_lb_[Year]
38. SIC CODE 5
US_lb_[Year]
39. SIC CODE 6
US_lb_[Year]
40. NAICS ORIGIN
US_lb_[Year]
41. PRIMARY NAICS CODE
US_lb_[Year]
42. NAICS CODE 2
US_lb_[Year]
43. NAICS CODE 3
US_lb_[Year]
44. NAICS CODE 4
US_lb_[Year]
45. NAICS CODE 5
US_lb_[Year]
46. NAICS CODE 6
US_lb_[Year]
47. LATITUDE
US_lb_[Year]
48. LONGITUDE
US_lb_[Year]
49. D and B NR A
US_lb_[Year]
50. D and B NRB
US_lb_[Year]
51. RCRANR A
US_lb_[Year]
52. RCRA NR B
Page 203 of 222
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PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_lb_[Year]
53. RCRANRC
US_lb_[Year]
54. RCRA NR D
US_lb_[Year]
55. RCRA NR E
US_lb_[Year]
56. RCRA NR F
US_lb_[Year]
57. RCRA NR G
US_lb_[Year]
58. RCRA NR H
US_lb_[Year]
59. RCRA NR I
US_lb_[Year]
60. RCRA NR J
US_lb_[Year]
61. NPDES NR A
US_lb_[Year]
62. NPDESNRB
US_lb_[Year]
63 . NPDES NRC
US_lb_[Year]
64. NPDES NR D
US_lb_[Year]
65. NPDES NRE
US_lb_[Year]
66. NPDES NRF
US_lb_[Year]
67. NPDES NR G
US_lb_[Year]
68. NPDES NRH
US_lb_[Year]
69. NPDES NR I
US_lb_[Year]
70. NPDES NR J
US_lb_[Year]
71. PARENT COMPANY NAME
US_lb_[Year]
72. PARENT COMPANY D and B NR
US_lb_[Year]
73. STANDARDIZED PARENT COMPANY NAME
US_lb_[Year]
74. FRS FACILITY ID
US_lb_[Year]
75. DOCUMENT CONTROL NUMBER
US_lb_[Year]
76. CAS NUMBER
US_lb_[Year]
77. CHEMICAL NAME
US_lb_[Year]
78. MIXTURE NAME
US_lb_[Year]
79. ELEMENTAL METAL INCLUDED
US_lb_[Year]
80. CLASSIFICATION
US_lb_[Year]
81. UNIT OF MEASURE
US_lb_[Year]
82. METAL IND
US_lb_[Year]
83. REVISION CODE 1
Page 204 of 222
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PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_lb_[Year]
84. REVISION CODE 2
US_lb_[Year]
85. PRODUCE THE CHEMICAL
US_lb_[Year]
86. IMPORT THE CHEMICAL
US_lb_[Year]
87. ON-SITE USE OF THE CHEMICAL
US_lb_[Year]
88. SALE OR DISTRIBUTION OF THE CHEMICAL
US_lb_[Year]
89. AS A BYPRODUCT
US_lb_[Year]
90. AS A MANUFACTURED IMPURITY
US_lb_[Year]
91. USED AS A REACT ANT
US_lb_[Year]
92. P101 FEEDSTOCKS
US_lb_[Year]
93. PI02 RAW MATERIALS
US_lb_[Year]
94. PI03 INTERMEDIATES
US_lb_[Year]
95. PI04 INITIATORS
US_lb_[Year]
96. PI99 OTHER
US_lb_[Year]
97. ADDED AS A FORMULATION COMPONENT
US_lb_[Year]
98. P201 ADDITIVES
US_lb_[Year]
99. P202 DYES
US_lb_[Year]
100. P203 REACTION DILUENTS
US_lb_[Year]
101. P204 INITIATORS
US_lb_[Year]
102. P205 SOLVENTS
US_lb_[Year]
103. P206 INHIBITORS
US_lb_[Year]
104. P207 EMULSIFIERS
US_lb_[Year]
105. P208 SURFACTANTS
US_lb_[Year]
106. P209 LUBRICANTS
US_lb_[Year]
107. P210 FLAME RETARD ANTS
US_lb_[Year]
108. P211 RHEOLOGICAL MODIFIERS
US_lb_[Year]
109. P299 OTHER
US_lb_[Year]
110. USED AS AN ARTICLE COMPONENT
US_lb_[Year]
111. REPACKAGING
US_lb_[Year]
112. AS A PROCESS IMPURITY
US_lb_[Year]
113. PROCESSED / RECYCLING
US_lb_[Year]
114. USED AS A CHEMICAL PROCESSING AID
Page 205 of 222
-------
PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_lb_[Year]
115. Z101 PROCESS SOLVENTS
US_lb_[Year]
116. Z102 CATALYSTS
US_lb_[Year]
117. Z103 INHIBITORS
US_lb_[Year]
118. Z104 INITIATORS
US_lb_[Year]
119. Z105 REACTION TERMINATORS
US_lb_[Year]
120. Z106 SOLUTION BUFFERS
US_lb_[Year]
121. Z199 OTHER
US_lb_[Year]
122. USED AS A MANUFACTURING AID
US_lb_[Year]
123. Z201 PROCESS LUBRICANTS
US_lb_[Year]
124. Z202 METALWORKING FLUIDS
US_lb_[Year]
125. Z203 COOLANTS
US_lb_[Year]
126. Z204 REFRIGERANTS
US_lb_[Year]
127. Z205 HYDRAULIC FLUIDS
US_lb_[Year]
128. Z299 OTHER
US_lb_[Year]
129. ANCILLARY OR OTHER USE
US_lb_[Year]
130. Z301 CLEANER
US_lb_[Year]
131. Z302 DEGREASER
US_lb_[Year]
132. Z303 LUBRICANT
US_lb_[Year]
133. Z304 FUEL
US_lb_[Year]
134. Z305 FLAME RETARD ANT
US_lb_[Year]
135. Z306 WASTE TREATMENT
US_lb_[Year]
136. Z307 WATER TREATMENT
US_lb_[Year]
137. Z308 CONSTRUCTION MATERIALS
US_lb_[Year]
138. Z399 OTHER
US_3c_[Year]
1. FORM TYPE
US_3c_[Year]
2. TRIFID
US_3c_[Year]
3. DOCUMENT CONTROL NUMBER
US_3c_[Year]
4. CAS NUMBER
US_3c_[Year]
5. CHEMICAL NAME
US_3c_[Year]
7. MIXTURE NAME
US_3c_[Year]
6. ELEMENTAL METAL INCLUDED
Page 206 of 222
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PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_3c_[Year]
8. CLASSIFICATION
US_3c_[Year]
9. UNIT OF MEASURE
US_3c_[Year]
10. METAL INDICATOR
US_3c_[Year]
11. REVISION CODE 1
US_3c_[Year]
12. REVISION CODE 2
US_3c_[Year]
13. REPORTING YEAR
US_3c_[Year]
14. TRADE SECRET INDICATOR
US_3c_[Year]
15. FACILITY NAME
US_3c_[Year]
16. FACILITY STREET
US_3c_[Year]
17. FACILITY CITY
US_3c_[Year]
18. FACILITY COUNTY
US_3c_[Year]
19. FACILITY STATE
US_3c_[Year]
20. FACILITY ZIP CODE
US_3c_[Year]
21. ASSIGNED FED FACILITY FLAG
US_3c_[Year]
22. ASSIGNED PARTIAL FACILITY FLAG
US_3c_[Year]
23. BIA CODE
US_3c_[Year]
24. TRIBE NAME
US_3c_[Year]
25. ENTIRE FACILITY IND
US_3c_[Year]
26. PARTIAL FACILITY IND
US_3c_[Year]
27. FEDERAL FACILITY IND
US_3c_[Year]
28. GOCO FACILITY IND
US_3c_[Year]
29. PUBLIC CONTACT NAME
US_3c_[Year]
30. PUBLIC CONTACT PHONE
US_3c_[Year]
31. PUBLIC CONTACT PHONE EXT
US_3c_[Year]
32. PUBLIC CONTACT EMAIL
US_3c_[Year]
33. PRIMARY SIC CODE
US_3c_[Year]
34. SIC CODE 2
US_3c_[Year]
35. SIC CODE 3
US_3c_[Year]
36. SIC CODE 4
US_3c_[Year]
37. SIC CODE 5
US_3c_[Year]
38. SIC CODE 6
Page 207 of 222
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PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_3c_[Year]
39. NAICS ORIGIN
US_3c_[Year]
40. PRIMARY NAICS CODE
US_3c_[Year]
41. NAICS CODE 2
US_3c_[Year]
42. NAICS CODE 3
US_3c_[Year]
43. NAICS CODE 4
US_3c_[Year]
44. NAICS CODE 5
US_3c_[Year]
45. NAICS CODE 6
US_3c_[Year]
46. LATITUDE
US_3c_[Year]
47. LONGITUDE
US_3c_[Year]
48. DB NR. A
US_3c_[Year]
49. DBNRB
US_3c_[Year]
50. RCRA NR A
US_3c_[Year]
51. RCRA NR B
US_3c_[Year]
52. RCRA NR C
US_3c_[Year]
53. RCRA NR D
US_3c_[Year]
54. RCRA NR E
US_3c_[Year]
55. RCRA NR F
US_3c_[Year]
56. RCRA NR G
US_3c_[Year]
57. RCRA NR H
US_3c_[Year]
58. RCRA NR I
US_3c_[Year]
59. RCRA NR J
US_3c_[Year]
60. NPDES NR A
US_3c_[Year]
61. NPDES NRB
US_3c_[Year]
62. NPDES NR C
US_3c_[Year]
63 . NPDES NRD
US_3c_[Year]
64. NPDES NRE
US_3c_[Year]
65. NPDES NRF
US_3c_[Year]
66. NPDES NR G
US_3c_[Year]
67. NPDES NRH
US_3c_[Year]
68. NPDES NR I
US_3c_[Year]
69. NPDES NR J
Page 208 of 222
-------
PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_3c_[Year]
70. PARENT COMPANY NAME
US_3c_[Year]
11. PARENT COMPANY DB NR
US_3c_[Year]
72. STANDARDIZED PARENT COMPANY NAME
US_3c_[Year]
73. FRS FACILITY ID
US_3c_[Year]
74. POTW NAME
US_3c_[Year]
75. POTW ADDRESS
US_3c_[Year]
76. POTW CITY
US_3c_[Year]
77. POTW STATE
US_3c_[Year]
78. POTW COUNTY
US_3c_[Year]
79. POTW ZIP
US_3c_[Year]
80. POTW REGISTRY ID
US_3c_[Year]
81. QUANTITY TRANSFERRED
US_3c_[Year]
82. BASIS OF ESTIMATE
US_3c_[Year]
83. DISCHARGES TO WATER STREAMS
US_3c_[Year]
84. DISCHARGES TO WATER STREAMS—BASIS OF ESTIMATE
US_3c_[Year]
85. DISCHARGES TO OTHER ACTIVITIES
US_3c_[Year]
86. DISCHARGES TO OTHER ACTIVITIES—BASIS OF ESTIMATE
US_3c_[Year]
87. RELEASED TO AIR
US_3c_[Year]
88. RELEASED TO AIR—BASIS OF ESTIMATE
US_3c_[Year]
89. SLUDGE TO DISPOSAL
US_3c_[Year]
90. SLUDGE TO DISPOSAL—BASIS OF ESTIMATE
US_3c_[Year]
91. SLUDGE TO INCINERATION—METALS
US_3c_[Year]
92. SLUDGE TO INCINERATION—METALS—BASIS OF ESTIMATE
US_3c_[Year]
93. SLUDGE TO AGRICULTURAL APPLICATIONS
US_3c_[Year]
94. SLUDGE TO AGRICULTURAL APPLICATIONS—BASIS OF
ESTIMATE
US_3c_[Year]
95. OTHER OR UNKNOWN DISPOSAL
US_3c_[Year]
96. OTHER OR UNKNOWN DISPOSAL—BASIS OF ESTIMATE
US_3c_[Year]
97. OFF-SITE POTW RELEASES—8.1C
US_3c_[Year]
98. OFF-SITE POTW RELEASES—8. ID
US_3c_[Year]
99. OFF-SITE—POTW RELEASES
Page 209 of 222
-------
PUBLIC RELEASE DRAFT
July 2024
TRI Basic Plus
Data File
Field Name
US_3c_[Year]
100. OTHER OR UNKNOWN TREATMENT
US_3c_[Year]
101. OTHER OR UNKNOWN TREATMENT—BASIS OF ESTIMATE
US_3c_[Year]
102. SLUDGE TO INCINERATION—NONMETALS
US_3c_[Year]
103. SLUDGE TO INCINERATION—NONMETALS—BASIS OF
ESTIMATE
US_3c_[Year]
104. EXPERIMENTTAL AND ESTIMATED TREATMENT
US_3c_[Year]
105. EXPERIMENTTAL AND ESTIMATED TREATMENT—BASIS OF
ESTIMATE
US_3c_[Year]
106. TOTAL TREATED
5263
5264 • Mapping Facilities to an OES and Selecting the Number of Operating Days per Year
5265 Both facilities used in this example reported to the 2016 Chemical Data Reporting (CDR) as domestic
5266 manufacturers of 1,2-dichloroethane. Therefore, they are mapped to the manufacturing OES. Because
5267 1,2-dichloroethane is a commodity chemical, each facility is assumed to operate 350 days/year.
5268
5269 • Annual Facility Discharges
5270 Annual facility discharges can be obtained directly from the Loading Tool and TRI data file downloads
5271 for each facility. The 2019 annual discharges for the two facilities in this example are provided in
5272 TableApx H-2.
5273
5274 Table Apx H-2. Example Facilities' 2019 Annual Discharges
Facility
Annual Surface Water Discharge
from Loading Tool (kg)
Annual Reported Discharge from
TRI (kg)
Westlake Vinyls in
Calvert City, KY
209 kga
212 kg to surface water
0 kg to POTW and non-POTW WWT
Axiall LLC in
Plaquemine, LA
N/A: No DMR data for this facility
10 kg to surface water
0 kg to POTW and non-POTW WWT
aThe Loading Tool estimates this discharge a 495 lb (or 224 kg) as the sum of outfalls 001, 002, and 009.
However, the NPDES permit for this facility indicates that 002 and 009 are internal outfalls that discharge into
001. Therefore, discharges from 001 includes those from 002 and 009 and the total annual discharge shown in
the table is equal to the Loading Tool's estimate for outfall 001 only (461 lb or 209 kg). Review of NPDES
permits is generally outside the scope of this methodology document; however, permit information for
Westlake Vinvls can be found here: httDs://deD.eatewav.kv.eov/eSearch/Aeencvlnterest.
5275
5276 • Average Daily Discharges
5277 To calculate average daily discharges at each facility, the annual discharge is averaged over the number
5278 of operating as shown in the calculations below:
YR
5279 ADR = —
OD
Page 210 of 222
-------
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
PUBLIC RELEASE DRAFT
July 2024
Where:
ADR = Average daily discharge (kg/day)
YR = Annual discharge (kg/year)
OD = Operating days (days/year)
For Westlake Vinyls the annual discharge of 209 kg/year is averaged over 350 days/year (operating days
for manufacturers) to calculate the daily discharge using DMR as:
/ir>n 209 kg/yr „ , , , ,
ADR = — = — = 0.6 kq day
OD 350 days/yr
Similarly, for Westlake Vinyls the average daily discharge using TRI is calculated as the 212 kg/year
annual discharge over 350 days/year, as shown below:
/ir>n 212 kg/yr „ , , ,,
ADR = — = — = 0.6 kq day
OD 350 days/yr
For Axiall LLC, the average daily discharge is calculated as the annual discharge of 10 kg/year over 350
days/year:
YR 10 kg/yr
ADR = — = , , = 0.03 kg/day
OD 350 days/yr
• High-End Daily Discharges for Facilities with DMRs
To estimate high-end daily discharge for sites with DMRs, the reporting frequency and pollutant load for
each reporting period throughout the year must be determined. This information can be obtained from
the Loading Tool by going to the "Top Facility Discharges" table in the query results and clicking on the
desired facility name as shown in FigureApx H-6.19 This will open the details of the facility's DMR.
19 If the facility of interest is not listed in this table, the user can select "browse all facilities" to bring up a list of all facilities
monitoring for the chemical of interest.
Page 211 of 222
-------
PUBLIC RELEASE DRAFT
July 2024
Select facility of interest
A
Top Facility Discharges (2019)
NPDES ID
Facility 1 lame
City, Slate
Report
SIC
Code
HUC-12 Code
Avg Cone
(mg/L)
Max Cone
(mg/L)
Total
Pounds
(Ib/yr)
Total TWPE
(Ib-eq/yr)
Avg Flow
(MGD)
KYQ0^84^
WESTLAKE VINYLS
>UVERT
KY
DB
QJ
2812
060400060502
0.0191
0.2320
r
495
4.95
1.68
M10000868
DOW CHEMICAL-MIDLAND
MIDLAND, Ml
hb
0
2869
040802010604
0.0019
0.0167
r
415
4.15
5.52
TX0085570
FORMOSA PLASTICS
CORPORATION, TEXAS
POINT
COMFORT,
TX
00
Q
2821
121004010100
0.0008
0.0445
r
244
2.44
19.92
LA0002933
OCCIDENTAL CHEMICAL CORP
GEISMAR PLANT
GEISMAR, LA
as
u
2869
080702040101
0.0029
0.0351
i-
164
1.64
0.9016
TX0007412
OXY VINYLS LP - DEER PARK
PVC
DEER PARK,
TX
as
a j
2812
120401040703
0.0076
0.0320
i-
143
1.43
4.27
KY0003603
ARKEMAINC
CALVERT
CITY, KY
00
0
2819
060400060502
0.0083
0.0192
r
137
1.37
0.9300
LA0000761
EAGLE US 2 LLC-LAKE
CHARLES COMPLEX
LAKE
CHARLES, LA
as
0
2869
080802060301
0.1138
0.3830
r
78.97
0.7897
40.72
LA0000281
WESTLAKE VINYLS CO
GEISMAR. LA
00
id
2869
080702040103
0.0020
0.0097
i-
25.74
0.2574
0.8815
KY0023540
CENTRAL CITY STP
CENTRAL
CITY, KY
OB
0
4952
051100030505
0.0050
0.0050
r
25.01
0.2501
1.28
NJ0005100
CHEMOURSCHAMBERS
WORKS
DEEPWATER,
NJ
00
0
2869
020402060103
0.0017
0.0066
r
22.87
0.2287
3.67
l| Download All Data 1
Browse All Facilities
FigureApx H-6. Loading Tool—Accessing Facility-Specific Data
From the facility's DMR, the user can select the "View Permit Limits and Monitoring Requirements" to
determine the reporting frequency and the "View NPDES Monitoring Data Download" to obtain the
facility's DMRs for each pollutant at each outfall for each reporting period and the reporting period's
corresponding wastewater flowrate in an Excel Spreadsheet, as shown in Figure_Apx H-7 and
Figure Apx H-8.
Page 212 of 222
-------
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
PUBLIC RELEASE DRAFT
July 2024
WESTLAKE VINYLS, CALVERT CITY, 42029
NPDES ID: KYOO03484
FRSID: 110027373072
Other NPDES IDs associated with this FRS ID: None
TRI ID(s): 42029WSTLK2468I
Facility Type: NON-POTW
Permit Type: NPDES Individual Permit
Permit Effective Date: 10/01/2018
Permit Expiration Date: 09/30/2023
Major/Non-Major Indicator: Major
Permit Issuance: STATE OF KENTUCKY
Approved Pretreatment Program: N/A
Combined Sewer Overflow (CSO) Outfall: N/A
County: MARSHALL
Congressional District: Kentucky's 1st District
Latitude: 37.051111
Longitude: -88.334167
Facility Design Flow (Permit Application) (MGD): 4.65
Actual Average Facility Flow (Permit Application) (MGD): 3.83
Average Facility Flow in 2019 (MGD): 1.68
4-Digit SIC Code: 2812-ALKALIES AND CHLORINE
6-Digit NA1CS Code: -
Likely Point Source Category: 415 - Inorganic chemicals manufacturing
View Detailed Facility Report
S View Effluent Charts
View Permit Limits and Monitoring Requiremen
^^^Q_Vjew NPDE^onitorin^ata Download
~ View DMR and TRI Multi-Year Loading Report
Select Reporting Year: 2019
a
Top Pollutants | Vacility Loading Calculations©
View Permit Limits to Obtain
Reporting Frequency
Download DMRs
FigureApx H-7. Loading Tool—Accessing Monitoring Requirements and Reporting Period
Discharge Data
S*W. gateway, kv. gov/e Search/Agency Interest.
Page 213 of 222
-------
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
PUBLIC RELEASE DRAFT
July 2024
equation below.
PR = C x FR x 3.785-^- x 1 x 10~6 — xPD
gal mg
Where:
PR = Period discharge (kg/period)
C = Pollutant concentration (mg/L)
FR = Wastewater flowrate (gal/day)
PD = Number of days in the period (days/period)
The results from these calculations for Westlake Vinyl for 1,2-dichloroethane in 2019 are presented in
TableApx H-3.
Table Apx H-3. Westlake Vinyl Total Period Discharge Results
Reporting
Period End
Date
Monthly Average
Concentration
(mg/L)
Monthly Average
Wastewater Flow
(MGD)
Days per
Period
Period Discharge
(kg/period)
01/31/2019
0.014
3.3756
31
5.5
02/28/2019
0.004
3.6760
28
1.6
03/31/2019
0.232
3.6855
31
100
04/30/2019
0.015
3.5123
30
6.0
05/31/2019
0.007
3.3281
31
2.7
06/30/2019
0.122
3.2704
30
45
07/31/2019
0.060
3.0358
31
21
08/31/2019
0.013
3.0535
31
4.7
09/30/2019
0.027
3.1075
30
9.5
10/31/2019
0.012
2.5449
31
3.6
11/30/2019
0.012
3.1966
30
4.3
12/31/2019
0.010
3.6309
31
4.3
MGD = million gallons per day
As shown in Table Apx H-3, the period ending March 31, 2019, has the highest total discharge for
Westlake Vinyls. Using the highest period discharge, the high-end daily discharge can be calculated
using the following equation:
MPR 100 kg/period
HDR = —— = , , —— = 3.2 kg/day
PD 31 day /period
MPR 100 kg/period
HDR = —— = = 3.2 kg/day
PD 31 day /period
Page 214 of 222
-------
5343
5344
5345
5346
5347
5348
5349
5350
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Where:
HDR = High-end daily discharge (kg/day)
MPR = Maximum period discharge (kg/period)
PD = Number of days in the period (days/period)
• High-End Daily Discharges for Facilities without DMRs
To estimate the high-end daily discharge for TRI facilities without DMRs, a generic factor developed
using data from facilities mapped to the same OES with DMRs should be applied to the discharge from
facilities without DMRs. The first step is to identify facilities with DMRs for the same chemical, same
year, and same OES as the TRI facility and report DMRs monthly. For purposes of this example, only
the Westlake Vinyl's facility will be considered; however, in many instances data from multiple
facilities will be considered.
After identifying the relevant facility, the percentage of the total annual discharge that occurred in the
highest 1-month period should be calculated using the equation below and values from Westlake Vinyls:
MPR 100 kg/period
GF = —7777- = ^ , x 100 = 48%
YR 209 kg/yr
Where:
GF = Generic factor (year/period)
MPR = Maximum period discharge (kg/period)
YR = Annual discharge (kg/year)
If multiple facilities are included in the analysis, the GF used in the next steps should be the average of
the factors calculated for each facility. For this example, the factor of 48% will be used.
To calculate the high-end daily discharge from TRI sites without DMRs, the reported annual discharge
should be multiplied by the generic factor and divide by the number of days in a month (30 days) as
shown in the equation below using values for Axiall LLC:
GF X YR
HDR = ——— = 48% x 10 kg = 0.2 kg/day
30 days
Where:
HDR = High-end daily discharge (kg/day)
GF = generic factor (unitless)
YR = Annual discharge (kg/year)
This value is assessed over 30 days/period to approximate the high-end period of one month the results
are based on. Note, the GF calculated in this example is based on a facility with monthly reporting
periods which is the preferred method for estimating the GF and hence assesses over 30 days. In
situations where the GF is calculated using data from facilities with longer reporting periods, the number
of days should be adjusted accordingly.
• 1-Day Discharges
Data to estimate 1-day discharges can be obtained using a similar method as the high-end daily
discharges from DMR except concentration and flowrate values reported for the daily maximum for
each period should be used. The daily discharge is simply the daily maximum concentration multiplied
by the daily maximum flowrate (with proper unit conversions) as shown in the equation below.
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£ c Kq
5387 ODR = C x FR x 3.785—-xlxlO-6 —
gal mg
5388 Where:
5389 ODR = 1-day discharge (kg/day)
5390 C = Pollutant concentration (mg/L)
5391 FR = Wastewater flowrate (gal/day)
5392 The daily maximum for each period for Westlake Vinyls is provided in TableApx H-4.
5393
5394 Table Apx H-4. Westlake Vinyl 1-Day Discharges
Reporting Period
End Date
Daily Maximum
Concentration (mg/L)
Daily Maximum
Wastewater Flow (MGD)
Period Discharge
(kg/day)
01/31/2019
0.014
4.0153
0.2
02/28/2019
0.004
5.6582
0.1
03/31/2019
0.232
3.9410
3.5
04/30/2019
0.015
3.7962
0.2
05/31/2019
0.007
3.6638
0.1
06/30/2019
0.122
3.5840
1.7
07/31/2019
0.060
3.4168
0.8
08/31/2019
0.013
3.9349
0.2
09/30/2019
0.027
3.6647
0.4
10/31/2019
0.012
2.7171
0.1
11/30/2019
0.012
3.9522
0.2
12/31/2019
0.010
3.7360
0.1
MGD = million gallons per day
5395
5396 • Summary of Results
5397 The detailed results from each facility are provided in the accompanying spreadsheet; however, an
5398 overview of the results for each facility are provided in TableApx H-5.
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5399 Table Apx H-5. Summary of Discharge Estimates for 2019 Examp e Facilities
Facility
Annual Surface
Water Discharge
from Loading
Tool (kg)
Annual Reported
Discharge from TRI
(kg)
Average Daily
Discharge
(kg/day)
Release Days for
Average Daily
Discharge
(days/vr)
High-End
Daily
Discharge
(kg/day)
Release Days for
High-End Daily
Discharge
(davs/pcriod)
Maximum 1-day
Discharge (kg/dav)
Westlake
Vinyls in
Calvert City,
KY
209 kg
212 kg to surface
water
0 kg to POTW and
non-POTW WWT
0.6 (DMR)
0.6 (TRI)
350
3.2
31
3.5
Axiall LLC in
Plaquemine,
LA
N/A: No DMR
data for this
facility
10 kg to surface water
0 kg to POTW and
non-POTW WWT
0.03
350
0.2
30
N/A: data not
available to estimate
1-day discharge
5400
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Appendix I GUIDANCE FOR USING THE NATIONAL EMISSIONS
INVENTORY AND TOXIC RELEASE INVENTORY
FOR ESTIMATING AIR RELEASES
This section provides guidance for using EPA's National Emissions Inventory (NEI) and Toxics Release
Inventory (TRI) data to estimate air releases for certain chemicals undergoing risk evaluation under the
Toxic Substances Control Act (TSCA). These estimates will be used as inputs to air modeling for the
purposes of estimating ambient air concentrations.
1.1 Background
EPA's National Emissions Inventory (NEI) and Toxics Release Inventory (TRI) programs require
individual facilities, as well as state, local, and tribal (SLT) Air Agencies, to report information on
airborne chemical releases to the EPA. While the chemicals reported under each program differ, both
inventories include data for some of the chemicals undergoing TSCA risk evaluation. When available,
the NEI and TRI data include information on the sources, magnitude, and nature (e.g., stack vs. fugitive,
stack height, stack gas velocity/temperature) of airborne releases from industrial/commercial facilities
and other smaller emissions sources. Thus, these databases may provide useful information for
estimating air releases of TRI- and/or NEI-covered chemicals, for certain occupational exposure
scenarios (OES).
As the NEI and TRI programs operate under separate regulatory frameworks, the data reported under
these programs do not always overlap. For example, in 2017, approximately 745,000 lb of
perchloroethylene (PERC) air emissions were reported to TRI, whereas approximately 16.6 million lb of
PERC air emissions were reported to NEI. This document provides an approach for using NEI data, in
combination with TRI data, to estimate air emissions.
1.2 Obtaining Air Emissions Data
1.2.1 Obtaining NEI Data
The first step in using NEI data to estimate air releases is to obtain the NEI data in a workable format
that provides the requisite data for release estimation and modeling. The NEI data are available on
EPA's public website as downloadable zip files, divided into onroad, nonroad, nonpoint, and point
source data files.21 The zipped point source data files are extremely large and require specialized
database experience to query and manipulate. As an alternative, EPA's EIS Gateway allows registered
EPA users, registered SLT users, and approved contractors to query and download NEI data and
associated reporting code descriptions. As a result, this methodology uses the EIS Gateway to query
point source data. Following download, the point and nonpoint emissions data for the chemical of
interest will be imported into Microsoft (MS) Excel (or using an alternative tool, if the data exceeds
Excel's size threshold), to be filtered and manipulated. At this point, EPA will use the EIS lookup tables
to populate field descriptions for data fields reported as numerical codes (e.g., NAICS code).
1.2.2 Obtaining TRI Data
TRI data may be downloaded from EPA's public TRI Program, TRI Data and Tools website.22 Once the
csv file(s) has (have) been downloaded, the data are filtered by the chemical of interest using the CAS
number and/or chemical name. Relevant NEI data fields include reporting year, facility identifying
21 https://www.epa.gOv/air-emissions-iixventories/2017-natioiKil-emissions-iixventory-nei-data#datas
22 https://www.epa.gov/toxics-release-inventorv-tri-program/tri-data-and-tools
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information (e.g., name, address, FRS ID, and TRIFID), chemical information (chemical name, CAS),
primary NAICS codes, fugitive air releases, and stack air releases.
1.3 Mapping NEI and TRI DATA to Occupational Exposure Scenarios
Once TRI and NEI data is obtained, the next step is to map the data to OESs. For procedures for
mapping facilities from TRI and NEI to occupational exposure scenarios, refer to Appendix G.
1.4 Estimating Air Releases Using NEI and TRI Data
EPA will use the mapped NEI and TRI data to develop facility- and/or release-point-specific emissions
estimates for chemicals undergoing TSCA risk evaluation. The data summary will include pertinent
information for risk evaluation and emission modeling, such as facility location, annual releases, daily
releases, operating information, release type (i.e., stack vs. fugitive), and stack parameters.
1.4.1 Linking NEI and TRI Data
Although NEI and TRI have different reporting requirements, some major sources are expected to report
to both databases. The most reliable way to link the data sets is with a common identifier. NEI reports
EIS Facility Identifier and Facility Registry Identifier (FRSID), although the latter is not reliably
populated for all NEI records. TRI reports TRI Facility ID and FRSID. EPA will use its database of EIS
Alternate Facility Identifiers ("EISAltFacilityIdentifiers_20211221.accdb") to link TRIFID to an EIS
Facility Identifier. Linkages may be confirmed and/or refined using facility names and addresses, if
necessary.
Following linkage, EPA will review the linked NEI/TRI data to ensure that facilities with records in
both databases are assigned to a consistent OES. When discrepancies arise, EPA will resolve these
discrepancies using the data set with the greatest level of detail. In general, NEI provides more detailed
air emissions data than TRI. For example, NEI reports SCC levels 1 to 4, which provide insight into the
specific operations and/or process units associated with NEI-reported air emissions. For example,
"Chemical Evaporation Organic Solvent Evaporation Degreasing Entire Unit: Open-top Vapor
Degreasing" is a SCC description used in the NEI. This SCC description identifies the emission unit, not
only as a degreaser, but as a specific type of degreaser. NEI also includes free text fields where reporters
can include additional information about a particular facility and/or emission unit. TRI does not provide
this level of detail.
Following a review of OES assignments, the TRI and NEI data will be divided into separate tables by
OES code, which may be linked using the EIS Facility Identifier.
1.4.2 Evaluation of Sub-annual Emissions
As air emissions data in TRI and NEI are reported as annual values, sub-annual (e.g., daily) emissions
must be calculated from information on release duration, release days, and release pattern. While TRI
does not report information on release duration or pattern, this information may be estimated from
operating data reported to the NEI.23 Other sources of release duration and pattern information include
GSs and ESDs, literature sources, process information, and standard engineering methodology for
estimating number of release days. These sources are described in further detail below, in order of
preference.
23 Note that the NEI operating hours fields are not populated for all, or in the case of ethylene dibromide, most, NEI entries.
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5500
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Sources for Estimating Release Duration:
1. NEIdata: The NEI data set includes facility-specific air emissions estimates for major sources
and often includes data on the number of hours of operation per day for these facilities. The
number of operating hours from NEI can be used to inform release duration for the specific
facilities being assessed. Hours of operation for one facility in NEI are typically not used for a
different facility; however, engineers may consider conducting an analysis of operating hours for
multiple facilities in NEI that are a part of the same OES to develop a broader estimate of release
duration at the OES-level. EPA has previously used this approach to inform development of
GS/ESDs, but it is dependent on the amount of data and time available and should be discussed
on a chemical-specific basis.
2. Models: Models used to estimate air emissions and associated inhalation exposures (e.g., Tank
Truck and Rail car Loading and Unloading Release and Inhalation Exposure Model, Open-Top
Vapor Degreasing Near-Field/Far-Field Inhalation Exposure Model, Spot Cleaning Near-
Field/Far-Field Inhalation Exposure Model, models from GS/ESDs) sometimes include data on
release duration, which are usually either cited from literature or based on generic assumptions
about the activity being modeled. Release duration information from models may be presented
with non-modeled air emission data from NEI or TRI, if the model is applicable and expected to
represent the primary release source for the OES (e.g., release duration from the Tank Truck and
Rail car Loading and Unloading Release and Inhalation Exposure Model may be used with
estimates of air emissions for a facility in the Repackaging OES). For models that calculate
release duration as a distribution, such as from Monte Carlo simulations, the mean and range of
release durations from the model should be presented with the air emission estimate.
3. Literature: Literature sources from systematic review, including GS/ESDs, are another source of
information for release duration. Often, release duration information from literature sources may
be broad, such as a range of durations for a given operation. Alternatively, literature sources may
describe release duration qualitatively, such as "on and off throughout the day" or "over half the
day". Therefore, literature sources may inform release duration at the OES-level, as opposed to
at the facility-level. All details from literature sources on release duration, including qualitative
descriptions, should be presented with air emission estimates if they are available and there is no
other source of this data.
4. List as "unknown": Often, no information on release duration is available at either the facility or
OES-level from the above sources. In these cases, engineers should list that the release duration
is unknown.
Sources for Estimating Release Pattern
1. NEI data: The NEI data set includes facility-specific air emissions estimates for major sources
and often includes data on the number of days of operation per week and number of weeks of
operation per year for these facilities. NEI does not indicate if the number of days per week or
weeks per year of operation are consecutive or intermittent throughout the week/year; however,
these data are still useful and should be provided by engineers with air emission estimates to help
inform release patterns. Data on operational days per week and weeks per year for one facility in
NEI is typically not used for a different facility; however, engineers may consider conducting an
analysis of these data for multiple facilities in NEI that are a part of the same OES to develop a
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broader estimate of release pattern at the OES-level. EPA has previously used this approach to
inform development of GS/ESDs, but it is dependent on the amount of data and time available
and should be discussed on a chemical-specific basis.
2. Models: Models used to estimate air emissions (e.g., Tank Truck and Railcar Loading and
Unloading Release and Inhalation Exposure Model, Open-Top Vapor Degreasing Near-
Field/Far-Field Inhalation Exposure Model, Spot Cleaning Near-Field/Far-Field Inhalation
Exposure Model, models from GS/ESDs) sometimes, but rarely, include data on release pattern
from the underlying data sources. Release pattern information from models may be presented
with non-modeled air emission data (e.g., NEI, TRI) if the model is applicable and expected to
represent the primary release source for the OES (e.g., release pattern from the Tank Truck and
Railcar Loading and Unloading Release and Inhalation Exposure Model may be used with
estimates of air emissions for a facility in the Repackaging OES).
3. Literature: Literature sources from systematic review, including GS/ESDs, are another source of
information for release pattern. Often, literature sources provide general release pattern
information for a given operation. Therefore, literature sources may inform release pattern at the
OES-level, as opposed to at the facility-level. All details from literature sources on release
pattern, even if general and/or limited, should be presented with air emission estimates, if they
are available and there is no other source of this information.
4. List as "unknown " and provide operating days: Often, no information on release pattern is
available at either the facility or OES-level from the above sources. In these cases, engineers
should do the following:
a. List that the release pattern is unknown.
b. Provide the number of operating days for the facility based on project-level engineering
methodology, which is summarized below.
c. Provide any information based on process knowledge (e.g., commercial aerosol
degreasing using cans may occur on/off throughout a day and year).
Estimating Number of Operating Days for Point Sources
For major sources that report operating data to NEI, EPA will use these data to calculate operating hours
on a days per year basis. For major sources that do not report operating data in NEI (including facilities
that only report to TRI), EPA will estimate operating hours using the other data sources described above.
A hierarchical approach for estimating the number of facility operating days per year is described below.
1. Facility-specific data: Use facility-specific data, if available. NEI reports operating data as hours
per year, hours per day, days per week, and weeks per year.
a. If possible, calculate operating days per years as: Days/yr = hours per year ^ hours per
day.
b. If hours per year and/or hours per day are not reported, calculate days per year as:
Days/yr = Days per week x weeks per year
2. Facility-specific use rates: If information on facility-specific use rates is available, estimate
days/yr using one of the following approaches:
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PUBLIC RELEASE DRAFT
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a. If facilities have known or estimated average daily use rates, calculate the days/yr as:
Days/yr = Estimated Annual Use Rate for the Site (kg/yr) ^ average daily use rate from
sites with available data (kg/day).
b. If sites without days/yr data do not have known or estimated average daily use rates, use
the average number of days/yr from the sites with such data.
3. Industry-specific data: Industry-specific data may be available in the form of GSs, ESDs, trade
publications, or other relevant literature. In such cases, these estimates should take precedent
over other approaches, unless facility-specific data are available.
4. Manufacture of large-production volume (PV) commodity chemicals: For the manufacture of the
large-PV commodity chemicals, a value of 350 days/yr should be used. This assumes the plant
runs 7 day/week and 50 week/yr (with two weeks down for turnaround) and assumes that the
plant is always producing the chemical.
5. Manufacture oflower-PVspecialty chemicals: For the manufacture of lower-PV specialty
chemicals, it is unlikely the chemical is being manufactured continuously throughout the year.
Therefore, a value of 250 days/yr should be used. This assumes the plant manufactures the
chemical 5 days/week and 50 weeks/yr (with two weeks down for turnaround).
6. Processing as reactant (intermediate use) in the manufacture of commodity chemicals: As noted
above, the manufacture of commodity chemicals is assumed to occur 350 days/yr such that the
use of a chemical as a reactant to manufacture a commodity chemical will also occur 350
days/yr.
7. Processing as reactant (intermediate use) in the manufacture of specialty chemicals: As noted
above, the manufacture of specialty chemicals is not likely to occur continuously throughout the
year. Therefore, a value of 250 days/yr can be used.
8. Other chemical plant OES (e.g., processing into formulation and use of industrial processing
aids): For these OES, it is reasonable to assume that the chemical of interest is not always in use
at the facility, even if the facility operates 24/7. Therefore, a value of 300 days/yr can be used,
based on the European Solvent Industry Group's "SpERC fact sheet—Formulation &
(re)packing of substances and mixtures—Industrial (Solvent-borne)" default of 300 days/yr for
the chemical industry. However, in instances where the OES uses a low volume of the chemical
of interest, 250 days/yr can be used as a lower estimate for the days/yr.
9. All Other OESs: Regardless of facility operating schedule, other OES are unlikely to use the
chemical of interest every day. Therefore, a value of 250 days/yr should be used for these OESs.
Estimating Number of Operating Days for Area Sources
For area sources, EPA will also estimate operating days per year using information such as NEI
operating data for major source facilities within the same OES, general information about the OES, and
values from literature. Facility operating days per year will be used to calculate daily emissions from the
NEI and TRI annual emissions data, as:
Daily emissions (kg/day) = Annual emissions (kg/yr) ^ Operating days per year (days/yr)
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