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EPA Document# EPA-740-D-25-017
May 2025
Office of Chemical Safety and
Pollution Prevention
United States
v/crM Environmental Protection Agency
Draft Risk Evaluation for Dibutyl Phthalate
(DBP)
CASRN 84-74-2
May 2025
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28 TABLE OF CONTENTS
29 ACKNOWLEDGEMENTS 9
30 EXECUTIVE SUMMARY 10
31 1 INTRODUCTION 16
32 1.1 Scope of the Risk Evaluation 16
33 1.1.1 Life Cycle and Production Volume 18
34 1.2 Conditions of Use Included in the Risk Evaluation 20
35 1.2.1.1 Conceptual Models 24
36 1.2.2 Populations and Durations of Exposure Assessed 29
37 1.2.2.1 Potentially Exposed and Susceptible Subpopulations 29
38 1.3 Organization of the Risk Evaluation 30
39 2 CHEMISTRY AND FATE AND TRANSPORT OF DBP 32
40 2.1 Summary of Physical and Chemical Properties 32
41 2.2 Summary of Environmental Fate and Transport 33
42 3 RELEASES AND CONCENTRATIONS OF DBP IN THE ENVIRONMENT 36
43 3.1 Approach and Methodology 36
44 3.1.1 Manufacturing, Processing, Industrial and Commercial 36
45 3.1.1.1 Crosswalk of Conditions of Use to Occupational Exposure Scenarios 36
46 3.1.1.2 Description of DBP Use for Each OES 41
47 3.1.2 Estimating the Number of Release Days per Year for Facilities in Each OES 42
48 3.1.3 Daily Release Estimation 43
49 3.1.4 Consumer Down-the-Drain and Landfills 43
50 3.2 Summary of Environmental Releases 44
51 3.2.1 Manufacturing, Processing, Industrial and Commercial 44
52 3.2.2 Weight of Scientific Evidence Conclusions for Environmental Releases from Industrial
53 and Commercial Sources 51
54 3.2.3 Strengths, Limitations, Assumptions, and Key Sources of Uncertainty for the
55 Environmental Release Assessment 62
56 3.3 Summary of Concentrations of DBP in the Environment 64
57 3.3.1 Weight of Scientific Evidence Conclusions 67
58 3.3.1.1 Surface Water 67
59 3.3.1.2 Ambient Air and Air to Soil Deposition 71
60 4 HUMAN HEALTH RISK ASSESSMENT 73
61 4.1 Summary of Human Exposures 74
62 4.1.1 Occupational Exposures 74
63 4.1.1.1 Approach and Methodology 74
64 4.1.1.2 Number of Workers and ONUs 78
65 4.1.1.3 Summary of Inhalation Exposure Assessment 79
66 4.1.1.4 Summary of Dermal Exposure Assessment 83
67 4.1.1.5 Weight of Scientific Evidence Conclusions for Occupational Exposure 86
68 4.1.1.5.1 Strengths, Limitations, Assumptions, and Key Sources of Uncertainty for the
69 Occupational Exposure Assessment 97
70 4.1.2 Consumer Exposures 98
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4.1.2.1 Summary of Consumer and Indoor Dust Exposure Scenarios and Modeling Approach
and Methodology 98
4.1.2.2 Modeling Dose Results by COU for Consumer and Indoor Dust 105
4.1.2.3 Indoor Dust Assessment 105
4.1.2.4 Weight of Scientific Evidence Conclusions for Consumer Exposure 106
4.1.2.5 Strength, Limitations, Assumptions, and Key Sources of Uncertainty for the
Consumer Exposure Assessment 106
4.1.3 General Population Exposures 114
4.1.3.1 General Population Screening Level Exposure Assessment Results 117
4.1.3.2 Daily Intake Estimates for the U.S. Population Using NHANES Urinary
Biomonitoring Data 124
4.1.3.3 Overall Confidence in General Population Screening Level Exposure Assessment 125
4.1.4 Human Milk Exposures 126
4.1.5 Aggregate and Sentinel Exposure 127
4.2 Summary of Human Health Hazard 127
4.2.1 Background 127
4.2.2 Non-Cancer Human Health Hazards of DBP 127
4.2.3 Cancer Human Health Hazards of DBP 129
4.3 Human Health Risk Characterization 132
4.3.1 Risk Assessment Approach 132
4.3.1.1 Estimation of Non-Cancer Risks 133
4.3.1.2 Estimation of Non-Cancer Aggregate Risks 134
4.3.2 Risk Estimates for Workers 134
4.3.2.1 Overall Confidence in Worker Risk Estimates for Individual DBP OES 154
4.3.2.2 Effect of Duration of Exposure on Dermal Risk Estimates 154
4.3.2.3 Consideration of Personal Protective Equipment (PPE) 155
4.3.2.3.1 Respiratory Protection 155
4.3.2.3.2 Glove Protection 156
4.3.2.4 Occupational Risk Estimates and Effect of PPE 157
4.3.3 Risk Estimates for Consumers 166
4.3.3.1 Overall Confidence in Consumer Risks 174
4.3.4 Risk Estimates for General Population 184
4.3.4.1 Overall Confidence in General Population Risk 184
4.3.5 Risk Estimates for Potentially Exposed or Susceptible Subpopulations 184
4.4 Cumulative Risk Considerations 186
4.4.1 Hazard Rel ative Potency 187
4.4.1.1 Relative Potency Factor Approach Overview 188
4.4.1.2 Relative Potency Factors 189
4.4.2 Cumulative Phthalate Exposure: Non-Attributable Cumulative Exposure to DEHP, DBP,
BBP, DIBP, and DINP Using NHANES Urinary Biomonitoring and Reverse Dosimetry 190
4.4.2.1 Weight of Scientific Evidence: Non-Attributable Cumulative Exposure to Phthalates 192
4.4.3 Estimation of Risk Based on Relative Potency 199
4.4.4 Risk Estimates for Workers Based on Relative Potency 201
4.4.4.1 Overall Confidence in Cumulative Worker Risk Estimates 202
4.4.5 Risk Estimates for Consumers Based on Relative Potency 209
4.4.5.1 Overall Confidence in Cumulative Consumer Risks 211
4.4.6 Cumulative Risk Estimates for the General Population 216
4.5 Comparison of Single Chemical and Cumulative Risk Assessments 216
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119 5 ENVIRONMENTAL RISK ASSESSMENT 218
120 5.1 Summary of Environmental Exposures 218
121 5.2 Summary of Environmental Hazards 221
122 5.3 Environmental Risk Characterization 224
123 5.3.1 Risk Assessment Approach 224
124 5.3.2 Risk Estimates for Aquatic and Terrestrial Species 225
125 5.3.3 Environmental Risk Characterization Summary 230
126 5.3.4 Overall Confidence and Remaining Uncertainties in Environmental Risk
127 Characterization 236
128 6 UNREASONABLE RISK DETERMINATION 239
129 6.1 Human Health 242
130 6.1.1 Populations and Exposures EPA Assessed for Human Health 243
131 6.1.2 Summary of Human Health Effects 243
132 6.1.3 Basis for Unreasonable Risk to Human Health 244
133 6.1.4 Workers 245
134 6.1.5 Consumers 247
135 6.1.6 General Population 250
136 6.2 Environment 251
137 6.2.1 Populations and Exposures EPA Assessed for the Environment 252
138 6.2.2 Summary of Environmental Effects 252
139 6.2.3 Basis for Unreasonable Risk to the Environment 252
140 6.3 Additional Information Regarding the Basis for the Risk Determination 254
141 REFERENCES 270
142 APPENDICES 285
143 Appendix A KEY ABBREVIATIONS AND ACRONYMS 285
144 Appendix B REGULATORY AND ASSESSMENT HISTORY 288
145 B.l Federal Laws and Regulations 288
146 B.2 State Laws and Regulations 293
147 B.3 International Laws and Regulations 294
148 B.4 Assessment History 297
149 Appendix C LIST OF TECHNICAL SUPPORT DOCUMENTS 299
150 Appendix D UPDATES TO THE DBP CONDITIONS OF USE TABLE 302
151 Appendix E CONDITIONS OF USE DESCRIPTIONS 314
152 E. 1 Manufacturing - Domestic Manufacturing 314
153 E.2 Manufacturing - Importing 314
154 E.3 Processing - Processing as a Reactant - Intermediate in Plastic Manufacturing 315
155 E.4 Processing - Incorporation into Formulation, Mixture, or Reaction Product - Solvents
156 (Which Become Part of Product Formulation or Mixture) in Chemical and Preparation
157 Manufacturing; in Soap, Cleaning Compound, and Toilet Preparation Manufacturing;
158 Adhesive Manufacturing; and in Printing Ink Manufacturing 315
159 E.5 Processing - Incorporation into Formulation, Mixture, or Reaction Product - Pre-Catalyst
160 Manufacturing 315
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E.6 Processing - Incorporation into Formulation, Mixture, or Reaction Product - Plasticizer in
Paint and Coating Manufacturing; Plastic Material and Resin Manufacturing; Rubber
Manufacturing; Soap, Cleaning Compound, and Toilet Preparation Manufacturing; Texiles,
Apparel, and Leather Manufacturing; in Printing Ink Manufacturing; Basic Organic
Chemical Manufacturing; and Adhesive and Sealant Manufacturing 316
E.7 Processing - Incorporation into Article - Plasticizer in Adhesive and Sealant Manufacturing;
Building and Construction Materials Manufacturing; Furniture and Related Product
Manufacturing; Ceramic Powders; Plastics Product Manufacturing; and Rubber Product
Manufacturing 317
E.8 Processing - Repackaging - Laboratory Chemicals in Wholesale and Retail Trade;
Plasticizers in Wholesale and Retail Trade; and Plastics Material and Resin Manufacturing ..318
E.9 Processing - Recycling 318
E.10 Distribution in Commerce 318
E. 11 Industrial Use - Non-Incorporative Activities - Solvent, Including in Maleic Anhydride
Manufacturing Technology 318
E.12 Industrial Use - Construction, Paint, Electrical, and Metal Products - Adhesives and
Sealants 319
E.13 Industrial Use - Construction, Paint, Electrical, and Metal Products - Paints and Coatings.... 319
E. 14 Industrial Use - Other Uses - Automotive Articles 319
E. 15 Industrial Use - Other Uses - Lubricants and Lubricant Additives 320
E. 16 Industrial Use - Other Uses - Propellants 320
E.17 Commercial Use - Automotive, Fuel, Agriculture, Outdoor Use Products - Automotive Care
Products 320
E.18 Commercial Use - Construction, Paint, Electrical, and Metal Products - Adhesives and
Sealants 321
E.19 Commercial Use - Construction, Paint, Electrical, and Metal Products - Paints and Coatings 321
E.20 Commercial Use - Furnishing, Cleaning, Treatment Care Products - Cleaning and
Furnishing Care Products 322
E.21 Commercial Use - Furnishing, Cleaning, Treatment/Care Products - Floor Coverings;
Construction and Building Materials Covering Large Surface Areas Including Stone, Plaster,
Cement, Glass, and Ceramic Articles; Fabrics, Textiles, and Apparel 322
E.22 Commercial Use - Furnishing, Cleaning, Treatment Care Products - Furniture and
Furnishings 323
E.23 Commercial Use - Packaging, Paper, Plastic, and Hobby Products - Ink, Toner, and Colorant
Products 323
E.24 Commercial Use - Packaging, Paper, Plastic, and Hobby Products - Packaging (Excluding
Food Packaging), Including Rubber Articles; Plastic Articles (Hard); Plastic Articles (Soft);
Other Articles with Routine Direct Contact During Normal Use, Including Ruber Articles;
Plastic Articles (Hard) 323
E.25 Commercial Use - Packaging, Paper, Plastic, and Hobby Products - Toys, Playground, and
Sporting Equipment 324
E.26 Commercial Use - Other Uses - Automotive Articles 324
E.27 Commercial Use - Other Uses - Laboratory Chemicals 324
E.28 Commercial Use - Other Uses - Chemiluminescent Light Sticks 325
E.29 Commercial Use - Other Uses - Inspection Penetrant Kit 325
E.30 Commercial Use - Other Uses - Lubricants and Lubricant Additives 325
E.31 Consumer Use - Automotive, Fuel, Agriculture, Outdoor Use Products - Automotive Care
Products 325
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E.32 Consumer Use - Construction, Paint, Electrical, and Metal Products - Adhesives and
Sealants 326
E.33 Consumer Use - Construction, Paint, Electrical, and Metal Products - Paints and Coatings... 326
E.34 Consumer Use - Furnishing, Cleaning, Treatment Care Products - Fabric, Textile, and
Leather Products 326
E.35 Consumer Use - Furnishing, Cleaning, Treatment/Care Products - Floor Coverings;
Construction and Building Materials Covering Large Surface Areas Including Stone, Plaster,
Cement, Glass, and Ceramic Articles; Fabrics, Textiles, and Apparel 327
E.36 Consumer Use - Furnishing, Cleaning, Treatment/Care Products - Cleaning and Furnishing
Care Products 327
E.37 Consumer Use - Packaging, Paper, Plastic, Hobby Products - Ink, Toner, and Colorant
Products 327
E.38 Consumer Use - Packaging, Paper, Plastic, Hobby Products - Packaging (Excluding Food
Packaging), Including Rubber Articles; Plastic Articles (Hard); Plastic Articles (Soft); Other
Articles with Routine Direct Contact During Normal Use, Including Rubber Articles; Plastic
Articles (Hard) 328
E.39 Consumer Use - Packaging, Paper, Plastic, Hobby Products - Toys, Playground, and
Sporting Equipment 328
E.40 Consumer Use - Other Use - Automotive Articles 328
E.41 Consumer Use - Other Uses - Chemiluminescent Light Sticks 329
E.42 Consumer Use - Other Uses - Lubricants and Lubricant Additives 329
E.43 Consumer Use - Other - Novelty Articles 329
E.44 Disposal 329
Appendix F DRAFT OCCUPATIONAL EXPOSURE VALUE DERIVATION 331
F. 1 Draft Occupational Exposure Value Calculations 331
LIST OF TABLES
Table 1-1. Categories and Subcategories of Use and Corresponding Exposure Scenario in the Risk
Evaluation for DBP 21
Table 2-1. Physical and Chemical Properties of DBP 32
Table 2-2. Summary of Environmental Fate Information for DBPa 34
Table 3-1. Crosswalk of Conditions of Use to Assessed Occupational Exposure Scenarios 36
Table 3-2. Crosswalk of Assessed Occupational Exposure Scenarios to Conditions of Use 39
Table 3-3. Description of the Function of DBP for Each OES 42
Table 3-4. Summary of EPA's Annual and Daily Release Estimates for Each OES 45
Table 3-5. Summary of Overall Confidence in Environmental Release Estimates by OES 52
Table 3-6. Summary of High-End DBP Concentrations in Various Environmental Media from
Environmental Releases 66
Table 3-7. Summary of Weight of Scientific Evidence Associated with Each OES 69
Table 4-1. Summary of Exposure Monitoring and Modeling Data for Occupational Exposure Scenarios
76
Table 4-2. Summary of Total Number of Workers and ONUs Potentially Exposed to DBP for Each OES
78
Table 4-3. Summary of Average Adult Worker Inhalation Exposure Results for Each OESa 81
Table 4-4. Summary of Average Adult Worker Dermal Exposure Results for Each OES 84
Table 4-5. Summary of Assumptions, Uncertainty, and Overall Confidence in Exposure Estimates by
OES 87
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Table 4-6. Summary of Consumer COUs, Exposure Scenarios, and Exposure Routes 100
Table 4-7. Weight of Scientific Evidence Summary Per Consumer COU 110
Table 4-8. Exposure Scenarios Assessed in General Population Screening Level Analysis 116
Table 4-9. Summary of the Highest Doses in the General Population through Surface and Drinking
Water Exposure 120
Table 4-10. Fish Ingestion for Adults in Tribal Populations Summary 122
Table 4-11. General Population Ambient Air Inhalation Exposure Summary 123
Table 4-12. Daily Intake Values and MOEs for DBP Based on Urinary Biomonitoring from the 2017 to
2018 NHANES Cycle 125
Table 4-13. Non-Cancer HECs and HEDs Used to Estimate Risks for Acute, Intermediate, and Chronic
Exposure Scenarios 131
Table 4-14. Exposure Scenarios, Populations of Interest, and Hazard Values 132
Table 4-15. Assigned Protection Factors for Respirators in OSHA Standard 29 CFR 1910.134 156
Table 4-16. Assigned Protection Factors for Different Dermal Protection Strategies 157
Table 4-17. Occupational Risk Estimation for Acute Exposure for Female of Reproductive Age
(Benchmark MOE = 30) 158
Table 4-18. Occupational Risk Table for DBP 160
Table 4-19. Consumer Risk Summary Table 175
Table 4-20. Draft Relative Potency Factors Based on Decreased Fetal Testicular Testosterone 189
Table 4-21. Cumulative Phthalate Daily Intake (|ig/kg-day) Estimates for Women of Reproductive Age,
Male Children, and Male Teenagers from the 2017-2018 NHANES Cycle 193
Table 4-22. Cumulative Phthalate Daily Intake (|ig/kg-day) Estimates for Women of Reproductive Age
(16-49 years old) by Race and Socioeconomic Status from the 2017-2018 NHANES
Cycle 195
Table 4-23. Risk Summary Table for Female Workers of Reproductive Age Using the RPF Analysis 203
Table 4-24. Consumer Cumulative Risk Summary Table 212
Table 5-1. DBP Concentrations Used in Environmental Risk Characterization 220
Table 5-2. Exposure Pathway to Receptors and Corresponding Risk Assessment for the DBP
Environmental Risk Characterization 225
Table 5-3. Environmental Risk Quotients (RQs) for Aquatic Organisms Associated with Surface Water
Releases of DBP 227
Table 5-4. Environmental Risk Quotients (RQs) for Benthic Organisms Associated with Sediment
Releases of DBP 228
Table 5-5. Environmental Risk Quotients (RQs) for Terrestrial Organisms Associated with Air
Deposition to Soil Releases of DBP 229
Table 5-6. Environmental Risk Summary Table for DBP 231
Table 5-7. DBP Evidence Table Summarizing Overall Confidence Derived for Environmental Risk
Characterization 238
Table 6-1. Supporting Basis for the Unreasonable Risk Determination for Human Health (Occupational
COUs) 255
Table 6-2. Supporting Basis for the Unreasonable Risk Determination for Human Health (Consumer
COUs) 261
LIST OF FIGURES
Figure 1-1. TSCA Existing Chemical Risk Evaluation Process 16
Figure 1-2. Draft Risk Evaluation Document Summary Map 18
Figure 1-3. DBP Life Cycle Diagram 19
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Figure 1-4. DBP Conceptual Model for Industrial and Commercial Activities and Uses: Potential
Exposure and Hazards 25
Figure 1-5. DBP Conceptual Model for Consumer Activities and Uses: Potential Exposures and Hazards
26
Figure 1-6. DBP Conceptual Model for Environmental Releases and Wastes: General Population
Hazards 27
Figure 1-7. DBP Conceptual Model for Environmental Releases and Wastes: Ecological Exposures and
Hazards 28
Figure 3-1. Overview of EPA's Approach to Estimate Daily Releases for Each OES 43
Figure 4-1. Approaches Used for Each Component of the Occupational Assessment for Each OES 75
Figure 4-2. Potential Human Exposure Pathways to DBP for the General Population 115
LIST OF APPENDIX TABLES
Table_Apx B-l. Federal Laws and Regulations 288
Table_Apx B-2. State Laws and Regulations 293
Table_Apx B-3. International Laws and Regulations 294
TableApx B-4. Assessment History of DBP 297
TableApx D-l. Changes to Categories and Subcategories of Conditions of Use Based on CDR and
Stakeholder Engagement 302
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ACKNOWLEDGEMENTS
The Assessment Team gratefully acknowledges participation, input, and review comments from U.S.
Environmental Protection Agency (EPA or the Agency) Office of Pollution Prevention and Toxics
(OPPT) and Office of Chemical Safety and Pollution Prevention (OCSPP) senior managers and science
advisors. The Agency is also grateful for assistance from EPA contractors in the preparation of this draft
risk evaluation: ERG Inc. (Contract No. 68HERC23D0006, 68HERD20A0002, and GS-00F-079CA);
General Dynamics Information Technology, Inc. (Contract No. HHSN316201200013W); ICF Inc., LLC
(Contract No. 68HERC19D000, 68HERD22A0001, and 68HERC23D0007); SpecPro Professional
Services, LLC (Contract No. 68HERC20D0021); and SRC Inc. (Contract No. 68HERH19D0022).
Docket
Supporting information can be found in the public docket, Docket ID (EPA-HQ-OPPT-2018-0503).
Disclaimer
Reference herein to any specific commercial products, process, or service by trade name, trademark,
manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring
by the United States Government.
Authors: Mark Myer (Assessment Lead and Environmental Hazard Assessment Co-Lead), Maiko
Arashiro and Olivia Wrightwood (General Population Exposure Assessment Co-Leads), Laura Krnavek
(Consumer and Indoor Dust Exposure Assessment Lead), Yashfin Mahid (Engineering Assessment
Lead), Ryan Sullivan and Juan Bezares Cruz (Physical and Chemical, and Fate Assessment Co-Leads),
Ashley Peppriell (Human Health Hazard Assessment Lead), Rachel McAnallen and Carolyn Mottley
(Risk Determination Co-Leads), Jennifer Brennan (past Assessment Lead and past Environmental
Hazard Assessment Lead), Collin Beachum (Branch Supervisor), Ana Corado (Branch Supervisor),
Todd Coleman, Grant Goedjen, Emily Griffin, Bryan Groza, Christelene Horton, Edward Lo, Anthony
Luz, Andrew Middleton, Catherine Ngo, Brianne Raccor, Michael Stracka, Nicholas Suek, Dyllan
Taylor, and Kevin Vuilleumier.
Contributors: Yousuf Ahmad, Andrea Amati, Amy Benson, Marcy Card, Nicholas Castaneda, Maggie
Clark, Jone Corrales, Cory Strope, Daniel DePasquale, Lauren Gates, Christina Guthrie, Myles Hodge,
Brandall Ingle-Carlson, Keith Jacobs, June Kang, Grace Kaupas, Yadi Lopez, Kiet Ly, Nerija Orentas,
Andrew Sayer, Shawn Shifflett, Alex Smith, Kelley Stanfield, Cory Strope, Joseph Valdez, Leora
Vegosen, Jason P. Wight, and Susanna Wegner.
Technical Support: Mark Gibson and Hillary Hollinger.
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EXECUTIVE SUMMARY
Background
EPA has evaluated the health and environmental risks of the chemical dibutyl phthalate (DBP) under the
Toxic Substances Control Act (TSCA). In this draft risk evaluation, EPA is preliminarily determining
that DBP presents an unreasonable risk of injury to human health based on identified risk to workers
from 20 conditions of use (COUs) and risk to consumers from 4 COUs, and that DBP presents an
unreasonable risk to the environment from 1 COU. After considering the risks posed under the COUs,
EPA did not identify a risk of injury to human health or the environment from the other 19 COUs that
would drive the unreasonable risk determination for DBP.
After this draft risk evaluation is informed by public comment and independent, expert peer review,
EPA will issue a final risk evaluation that includes its determination as to whether DBP presents
unreasonable risk to human health or the environment based on identified risk of injury from COUs.
DBP is primarily used as a plasticizer in polyvinyl chloride (PVC) in consumer, commercial, and
industrial applications—although it is also used in adhesives, sealants, paints, coatings, rubbers, and
n on-PVC plastics, as well as for other applications. Workers may be exposed to DBP when making
these products or otherwise using DBP in the workplace (Section 4.1.1). When it is manufactured or
used to make products, DBP can be released into water (Section 3.3.1.1) where because of its properties
most will end up in the sediment at the bottom of lakes and rivers. If released into the air (Section
3.3.1.2), DBP will attach to dust particles and be deposited on land or into water. Indoors, DBP has the
potential over time to be released from products and adhere to dust particles (Section 4.1.2). If it does,
people could inhale or ingest dust that contains DBP.
Laboratory animal studies have been conducted to study DBP to determine whether it causes a range of
non-cancer and cancer health effects on people. After reviewing the available studies, the Agency
concludes that there is robust evidence that DBP causes developmental toxicity (a non-cancer human
health hazard; Section 4.2.2). The most sensitive adverse developmental effects include effects on the
developing male reproductive system consistent with a disruption of androgen action—known as
phthalate syndrome—which results from decreased fetal testicular testosterone.
EPA is including DBP for cumulative risk assessment (CRA; Section 4.4) along with five other
phthalate chemicals that also cause effects on laboratory animals consistent with phthalate syndrome
( 2023d). Notably, assessments by Health Canada, U.S. Consumer Product Safety
Commission (U.S. CPSC), European Chemicals Agency (ECHA), and the Australian National Industrial
Chemicals Notification and Assessment Scheme (NICNAS) have reached similar conclusions regarding
the developmental effects of DBP. They have also conducted CRAs of phthalates based on these
chemicals' shared ability to cause phthalate syndrome. Furthermore, independent, expert peer reviewers
endorsed EPA's proposal to conduct a CRA of phthalates under TSCA during the May 2023 meeting of
the Science Advisory Committee on Chemicals (SACC) because humans are co-exposed to multiple
toxicologically similar phthalates that cause effects on the developing male reproductive system
consistent with a disruption of androgen action and phthalate syndrome. In this draft risk evaluation, the
Agency has evaluated cumulative exposure to phthalates using human biomonitoring data. Note that
these cumulative phthalate exposures cannot be attributed to specific COUs or other sources. This non-
attributable cumulative exposure and risk, representing the national population, was taken into
consideration by EPA in its draft risk evaluation for DBP. By taking into account cumulative risk as
other authoritative bodies have done, EPA is confident that it is not underestimating the risk of DBP
(Section 4.4).
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In December 2019, EPA designated DBP as a high-priority substance for TSCA risk evaluation and in
August 2020 released the Final Scope of the Risk Evaluation for Dibutyl Phthalate (1,2-
benzenedicarboxylic acid, 1,2-dibutyl ester); CASRN84-74-2 (U.S. EPA. 2020c). This draft risk
evaluation assesses human health risk to workers, including occupational non-users (ONUs); consumers,
including bystanders; and the general population exposed to environmental releases. It also assesses risk
to the environment. Manufacturers report DBP production volumes through the Chemical Data
Reporting (CDR) rule under the associated CAS Registry Number (CASRN) 84-74-2. The production
volume for DBP between 2016 and 2019 was between 1 to 10 million pounds (lb) based on the 2020
CDR data ( 1020b). EPA describes production volumes as a range to protect confidential
business information. The Agency has evaluated DBP across its TSCA COUs, ranging from
manufacture to disposal.
Past assessments of DBP from other government agencies that addressed a broad range of uses, which
may have included TSCA and non-TSCA uses, have concluded that DBP can pose risk to human health
based on its concentration in products and the environment. Notably, both the U.S. CPSC's and Health
Canada's risk assessments included consideration of exposure from children's products as well as from
other sources such as personal care products, diet, consumer products, and the environment. However,
these past assessments did not specifically consider exposure to workers. In the United States, Canada,
and the European Union, the weight fraction of DBP that can be incorporated into children's toys and
child care products is limited by regulation (see Appendix B for an overview of existing national and
international regulations on DBP). Limits on worker exposure to DBP exist in the United States,
Canada, the European Union, Australia, and elsewhere. Additional international regulatory restrictions
and labeling requirements for the use of DBP exist.
In this draft risk evaluation, EPA evaluated risks resulting from exposure to DBP from facilities that
manufacture, process, distribute, use or dispose of DBP under industrial and/or commercial COUs
subject to TSCA as well as consumer COUs relating to the products resulting from such manufacture
and processing. Human or environmental exposure to DBP through uses that are not subject to TSCA
(e.g., use in cosmetics, medical devices, food additives) were not specifically evaluated by the Agency
in reaching its preliminary determination. This is because these uses are excluded from TSCA's
definition of a chemical substance. Thus, conclusions from this evaluation cannot be extrapolated to
form conclusions about uses of DBP that are not subject to TSCA and that EPA did not evaluate.
Determining Unreasonable Risk to Human Health
EPA's TSCA existing chemical risk evaluations must determine whether a chemical substance does or
does not present unreasonable risk to human health or the environment from its COUs. The
unreasonable risk must be informed by the best available science. The Agency, in determining whether
DBP presents unreasonable risk to human health, considers risk-related factors as described in its 2024
risk evaluation framework rule. Risk-related factors include but are not limited to the type of health
effect under consideration; the reversibility of the health effect being evaluated; exposure-related
considerations (e.g., duration, magnitude, frequency of exposure); population exposed (including any
potentially exposed or susceptible subpopulations); and EPA's confidence in the information used to
inform the hazard and exposure values. If an estimate of risk for a specific scenario exceeds the standard
risk benchmarks, then the formal determination of whether those risks significantly contribute to the
unreasonable risk of DBP under TSCA must be both case-by-case and context-driven.
EPA evaluated the risks to people from being exposed to DBP at work, indoors, and outdoors. Risks
were characterized for occupational and consumer exposures to DBP alone as well as in combination
with the measured cumulative phthalate exposure that is experienced by the U.S. population and that
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cannot be attributed to a specific use. In its human health evaluation, the Agency used a combination of
screening level and more refined approaches to assess how people might be exposed to DBP through
breathing or ingesting dust or other particulates, as well as through skin contact. EPA has also authored
a draft cumulative risk technical support document including DBP and five other phthalate chemicals
that all cause the same health effect—phthalate syndrome ( 2024k). The CRA takes into
consideration differences in the ability of each phthalate to cause effects on the developing male
reproductive system. Use of this "relative potency" across all the phthalates EPA is reviewing that cause
phthalate syndrome provides a more robust risk assessment of DBP as well as a common basis for
adding risk across the six phthalates included in the cumulative assessment.
In determining whether DBP presents an unreasonable risk of injury to human health, EPA considered
the following potentially exposed and susceptible subpopulations (PESS) in its assessment: females of
reproductive age; pregnant women; infants; children and adolescents; people who frequently use
consumer products and/or articles containing high concentrations of DBP; people exposed to DBP in the
workplace; people in proximity to releasing facilities, including fenceline communities; and Tribes and
subsistence fishers whose diets include large amounts of fish. These subpopulations are PESS because
some have greater exposure to DBP per body weight (e.g., infants, children, adolescents) while others
may experience exposure from multiple sources or higher exposures than others.
EPA weighed the scientific evidence in order to determine confidence levels in underlying data sets and
risk estimates for human health (see Section 4.3). For the general population, the Agency has robust
confidence the risk estimates calculated were conservative and appropriate for a screening level analysis.
For workers, EPA has moderate to robust confidence in the risk estimates calculated for inhalation and
dermal exposure scenarios and has robust confidence that dermal exposure scenarios represent a
conservative upper bound on exposure. For consumers, the Agency has moderate to robust confidence in
the risk estimates calculated for inhalation, ingestion, and dermal exposure scenarios and has robust
confidence that dermal exposure scenarios represent a conservative upper bound on exposure.
Determining Unreasonable Risk to The Environment
In determining whether DBP presents an unreasonable risk of injury to the environment, EPA
considered the following groups of organisms in its assessment: aquatic vertebrates, aquatic
invertebrates, benthic invertebrates, aquatic plants and algae, terrestrial mammals, soil invertebrates, and
terrestrial plants. The Agency weighed the scientific evidence in order to determine confidence levels in
underlying data sets and risk estimates for the environment (see Section 5.3.4). EPA has slight to robust
confidence in its environmental data and risk estimates depending on the source of environmental
release information for each COU (see Section 5.3.4).
EPA has preliminarily determined that DBP presents unreasonable risk of injury to the environment
based on one COU, Disposal, due to chronic exposure to aquatic vertebrates. These findings are based
on wastewater release from treatment plants and is inclusive of wastewater treatment removal of DBP.
EPA has robust confidence in the exposure data underlying environmental releases to water for the
Disposal COU, as they are based on reported data at plant outfalls from the Discharge Monitoring
Report (DMR) database (see Section 3.2). Furthermore, EPA has robust confidence in the hazard data
underlying environmental toxicity estimates from DBP exposure in aquatic vertebrates as they are based
on high quality toxicity studies (see Section 5.2). EPA has robust overall confidence in the
environmental risk characterization for the Disposal COU, and EPA is preliminarily determining that the
Disposal COU may contribute significantly to unreasonable risk to the environment for DBP due to
chronic exposures to aquatic vertebrates from wastewater discharge.
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Summary, Considerations, and Next Steps
EPA has preliminarily determined that the following 24 COUs may significantly contribute to
unreasonable risk to human health:
• Manufacturing - domestic manufacturing (dermal and inhalation)
• Manufacturing - importing (dermal and inhalation)
• Processing - processing as a reactant - intermediate in plastic manufacturing (dermal and
inhalation)
• Processing - incorporation into formulation, mixture, or reaction product - solvents (which
become part of product formulation or mixture) in chemical product and preparation
manufacturing; soap, cleaning compound, and toilet preparation manufacturing; adhesive
manufacturing; and printing ink manufacturing (dermal and inhalation)
• Processing - incorporation into formulation, mixture, or reaction product - pre-catalyst
manufacturing (dermal and inhalation)
• Processing - incorporation into formulation, mixture, or reaction product - plasticizer in paint
and coating manufacturing; plastic material and resin manufacturing; rubber manufacturing;
soap, cleaning compound, and toilet preparation manufacturing; textiles, apparel, and leather
manufacturing; printing ink manufacturing; basic organic chemical manufacturing; and adhesive
and sealant manufacturing (dermal)
• Processing - incorporation into article - plasticizer in adhesive and sealant manufacturing;
building and construction materials manufacturing; furniture and related product manufacturing;
ceramic powders; plastics product manufacturing; and rubber product manufacturing (dermal)
• Processing - repackaging - laboratory chemicals in wholesale and retail trade; plasticizers in
wholesale and retail trade; and plastics material and resin manufacturing (dermal and inhalation)
• Industrial use - non-incorporative activities - solvent, including in maleic anhydride
manufacturing technology (dermal and inhalation)
• Industrial use - construction, paint, electrical, and metal products - adhesives and sealants
(dermal)
• Industrial use - construction, paint, electrical, and metal products - paints and coatings (dermal
and inhalation)
• Industrial use - other uses - lubricants and lubricant additives (dermal)
• Commercial use - automotive, fuel, agriculture, outdoor use products - automotive care products
(dermal)
• Commercial use - construction, paint, electrical, and metal products - adhesives and sealants
(dermal)
• Commercial use - construction, paint, electrical, and metal products - paints and coatings
(dermal and inhalation)
• Commercial use - furnishing, cleaning, treatment care products - cleaning and furnishing care
products (dermal)
• Commercial use - packaging, paper, plastic, toys, hobby products - ink, toner, and colorant
products (dermal and inhalation)
• Commercial use - other uses - laboratory chemicals (dermal)
• Commercial use - other uses - inspection penetrant kit (dermal and inhalation)
• Commercial use - other uses - lubricants and lubricant additives (dermal)
• Consumer use - automotive, fuel, outdoor use products - automotive care products (dermal)
• Consumer use - construction, paint, electrical and metal products - adhesives and sealants
(dermal)
• Consumer use - construction, paint, electrical and metal products - paints and coatings (dermal)
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• Consumer use - furnishing, cleaning, treatment/care products - cleaning and furnishing care
products (dermal)
EPA has preliminarily determined that one COU may significantly contribute to unreasonable risk to the
environment:
• Disposal (aquatic vertebrates)
EPA did not preliminarily identify an unreasonable risk of injury to human health and the environment
from the following 19 COUs:
• Processing - recycling
• Distribution in commerce
• Industrial use - other uses - automotive articles
• Industrial use - other uses - propellants
• Commercial use - furnishing, cleaning, treatment care products - floor coverings; construction
and building materials covering large surface areas including stone, plaster, cement, glass and
ceramic articles; fabrics, textiles, and apparel
• Commercial use - furnishing, cleaning, treatment care products - furniture and furnishings
• Commercial use - packaging, paper, plastic, toys, hobby products - packaging (excluding food
packaging), including rubber articles; plastic articles (hard); plastic articles (soft); other articles
with routine direct contact during normal use, including rubber articles; plastic articles (hard)
• Commercial use - packaging, paper, plastic, toys, hobby products - toys, playground, and
sporting equipment
• Commercial use - other uses - automotive articles
• Commercial use - other uses - chemiluminescent light sticks
• Consumer use - furnishing, cleaning, treatment/care products - fabric, textile, and leather
products
• Consumer use - furnishing, cleaning, treatment/care products - floor coverings; construction and
building materials covering large surface areas including stone, plaster, cement, glass and
ceramic articles; fabrics, textiles, and apparel
• Consumer use - packaging, paper, plastic, hobby products - ink, toner, and colorant products
• Consumer use - packaging, paper, plastic, hobby products - packaging (excluding food
packaging), including rubber articles; plastic articles (hard); plastic articles (soft); other articles
with routine direct contact during normal use, including rubber articles; plastic articles (hard)
• Consumer use - packaging, paper, plastic, hobby products - toys, playground, and sporting
equipment
• Consumer use - other uses - automotive articles
• Consumer use - other uses - chemiluminescent light sticks
• Consumer use - other uses - lubricants and lubricant additives
• Consumer use - other uses - novelty articles
This draft risk evaluation has been released for public comment and will undergo independent, expert
scientific peer review. EPA seeks public comment on all aspects of this draft risk evaluation. In
particular, the Agency seeks comment on whether and how exposure controls and personal protective
equipment (PPE; e.g., respirators, gloves) are used for each of the COUs. EPA also seeks information
that could be used to replace upper-bound or screening level assumptions, particularly for COUs that
may significantly contribute to unreasonable risk for DBP. EPA will issue a final DBP risk evaluation
after considering input from the public and peer reviewers. If in the final risk evaluation the Agency
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596 determines that DBP presents unreasonable risk to human health or the environment, EPA will initiate
597 regulatory action to the extent necessary so that DBP no longer presents such risk.
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1 INTRODUCTION
EPA has evaluated dibutyl phthalate (DBP) pursuant to section 6(b) of the Toxic Substances Control Act
(TSCA). DBP is primarily used as a plasticizer in polyvinyl chloride (PVC) in consumer, commercial,
and industrial applications—although it is also used in adhesives, sealants, paints, coatings, rubbers, and
non-PVC plastics, as well as for other applications. Section 1.1 summarizes the scope of this draft DBP
risk evaluation and provides information on production volume, a life cycle diagram (LCD), TSCA
conditions of use (COUs), and conceptual models used for DBP. Section 1.3 presents the organization of
this draft risk evaluation.
Figure 1-1 describes the major inputs, phases, and outputs/components of the TSCA risk evaluation
process, from scoping to releasing the final risk evaluation.
Inputs
• Existing Laws, Regulations,
and Assessments
• Use Document
Public Comments
Public Comments on
Draft Scope Document
* Analysis Plan
* Testing Results
* Data Evaluation Process
Data Integration
* Public Comments on
Draft RE
• Peer Review Comments
on Draft RE
Phase
Outputs
Figure 1-1. TSCA Existing Chemical Risk Evaluation Process
1.1 Scope of the Risk Evaluation
EPA evaluated risk to human and environmental populations for DBP. Specifically for human
populations, the Agency evaluated risk to workers including occupational non-users (ONUs) via
inhalation routes; risk to workers including ONUs via dermal routes; risk to consumers via inhalation,
dermal, and oral routes; and risk to bystanders via the inhalation route. Additionally, EPA incorporated
the following potentially exposed and susceptible populations (PESS) into its assessment—females of
reproductive age, pregnant women, infants, children and adolescents, people who frequently use
consumer products and/or articles containing high-concentrations of DBP, people exposed to DBP in the
workplace, and tribes whose diets include large amounts of fish. As described further in Section 4.1.3,
EPA assessed risks to the general population, which considered risk from exposure to DBP via oral
ingestion of surface water, drinking water, fish, and soil from air to soil deposition. For environmental
populations, the Agency evaluated risk to aquatic species via water and sediment as well as risk to
terrestrial species via soil and, qualitatively, through trophic transfer.
Consistent with EPA's Draft Proposed Approach for Cumulative Risk Assessment (CRA) of High-
Prior ity Phthalates and a Manufacturer-Requested Phthalate under the Toxic Substances Control Act
( 3d), EPA has also authored a draft cumulative risk technical support document (TSD) of
DBP and five other toxicologically similar phthalates {i.e., diethylhexyl phthalate [DEHP], dicyclohexyl
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phthalate [DCHP], diisobutyl phthalate [DIBP], butyl benzyl phthalate [BBP], and diisononyl phthalate
[DINP]) that are also being evaluated under TSCA based on a common toxicological endpoint {i.e.,
phthalate syndrome, which results from decreased fetal testicular testosterone) ( 2025x). This
TSD is also referred to as the "revised draft CRA TSD" in this draft risk evaluation. The cumulative
analysis takes into consideration differences in phthalate potency to cause effects on the developing
male reproductive system. Use of relative potency across the phthalates provides a more robust risk
assessment of DBP and a common basis for adding risk across the cumulative chemicals. Numerous
other regulatory agencies—Health Canada, U.S. Consumer Product Safety Commission (U.S. CPSC),
European Chemicals Agency (ECHA), and the Australian National Industrial Chemicals Notification
and Assessment Scheme (NICNAS)—have assessed phthalates for cumulative risk. Further, EPA's
proposal to conduct a cumulative risk assessment (CRA) of phthalates under TSCA was endorsed by the
Science Advisory Committee on Chemicals (SACC) as the best available science because humans are
co-exposed to multiple toxicologically similar phthalates that cause effects on the developing male
reproductive system consistent with a disruption of androgen action and phthalate syndrome. As
described further in Section 4.4, cumulative risk considerations focus on acute duration exposures to the
most susceptible subpopulations: female workers and consumers of reproductive age (16-49 years) as
well as male infants and male children (3-15 years) exposed to consumer products and articles.
The draft DBP risk evaluation comprises a series of technical support documents. Each technical support
document contains sub-assessments that inform adjacent, "downstream" TSDs. A basic diagram
showing the layout and relationship of these assessments is provided below in Figure 1-2. High-level
summaries of each relevant TSD are presented throughout this draft risk evaluation. Detailed
information for each TSD can be found in the corresponding documents, which are listed with citations
along with supplemental files in Appendix C.
These TSDs leveraged the data and information sources already identified in the Final Scope of the Risk
Evaluation for Dibutyl Phthalate (1,2-benzenedicarboxylic acid, 1,2-dibutyl ester); CASRN 84-74-2
(also called the "final scope for DBP" or "final scope document") ( 20c). OPPT conducted
a comprehensive search for "reasonably available information" to identify relevant DBP data for use in
the risk evaluation. The approach used to identify specific relevant risk assessment information was
discipline-specific and is detailed in the Draft Systematic Review Protocol for Dibutyl Phthalate (DBP)
( 2025w\ or as otherwise noted in the relevant TSDs.
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Non-cancer Human Health
Hazard Assessment
Meta-Analysis and BMD
Modeling of Fetal Testicular
Testosterone for
for DEHR DBP, BBR DIBR DCHP
Cancer Human Health
Hazard Assessment
for DEHR DBP. DIBR DCHP. BBP
Physical Chemistry, Fate
and Transport Assessment
Technical Support Document for
the Cumulative Risk Analysis of
DEHP, DBP, BBP, DIBR DCHP, and
DINP under TSCA
Exposure Assessments
Consumer and Indoor
Exposure Assessment
Environmental Release
and Occupational
Ex posu re Assess m e nt
Environmental Media,
General Population, and
Environmental
Ex posu re Assess m e nt
Draft Risk Evaluation
Conditions of Use
Human Health
Risk Characterization
Environmental Risk
Characterization
Unreasonable
Risk Determination
Environmental
Hazard Assessment
Chemical-specific systematic review protocol and data extraction files
Figure 1-2. Draft Risk Evaluation Document Summary Map
1.1.1 Life Cycle and Production Volume
The LCD shown in Figure 1-3 depicts the COUs that are within the scope of the risk evaluation, during
various life cycle stages, including manufacturing, processing, distribution, use (industrial, commercial,
consumer), and disposal. The information in the LCD is grouped according to the Chemical Data
Reporting (CDR) processing codes and use categories (including functional use codes for industrial uses
and product categories for industrial and commercial uses). The CDR Rule under TSCA section 8(a)
(see 40 CFR Part 711) requires certain U.S. manufacturers (including importers) to provide EPA with
information on the chemicals they manufacture or import into the United States. EPA collects CDR data
approximately every four years.
EPA included descriptions of the industrial, commercial, and consumer use categories identified from
the 2020 CDR in the LCD (Figure 1-3) (U.S. EPA. 2020b). The descriptions provide a brief overview of
the use category; the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl
Phthalate (U.S. EPA. 2025q) contains more detailed descriptions (e.g., process descriptions, worker
activities, process flow diagrams, equipment illustrations) for each manufacturing, processing, use, and
disposal category.
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MFG,IMPORT
Manufacture
(Including
Import)
680
681
682
683
PROCESSING
^
Processing as Reactant
Intermediate in plastic manufacturing
Incorporation into formulation, mixture, or reaction product
Solvents in: Chemical product and preparation manufacturing;
Soap, cleaning compounds, and toilet preparation manufacturing;
Adhesive manufacturing; Printing ink manufacturing
Pre-catalvst manufacturing
Piasticizer in: Paint and coating manufacturing; Plastics material
and resin manufacturing; Rubber manufacturing; Soap, cleaning
compound, and toilet preparation manufacturing; Textiles,
apparel, and leather manufacturing; Printing ink manufacturing;
Basic organic chemical manufacturing; Adhesive and sealant
manufactures
Incorporation into Article
Plasticizers in: Adhesive and sealant manufacturing; Building and
construction materials manufacturing; Furniture and related
product manufacturing; Ceramic powders; Plastics product
manufacturing; and Rubber product manufacturing
Repackaging
JL
Recycling
INDUSTRIAL, COMMERCIAL, CONSUMER USES
K> K>
-*>
Adheshes and sealants12
Automotive care products1'2
Cleaning and furnishings care products1
Floor coverings12
Furniture and furnishings 1
Inks, toner, and colorant products12
Paints and coatings 12
Packaging (excluding food packaging) ^
Solvent in maleic anhydride manufacturing1
Miscellaneous uses
e.g. Automotive articles1'2; Propellants12; Laboratory
chemical1. Chemiluminescent light sticks1-2; Inspection
penetrant kit1, Lubricants and lubricant additives1-2; Toys,
playground, and sporting equipment1-2. Fabric, Textile, and
leather products2, Novelty articles2
RELEASES AND
WASTE DISPOSAL
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The production volume for DBP between 2016 and 2019 was between 1 to 10 million pounds (lb) based
on the latest 2020 CDR data (U.S. EPA. 2020b). EPA described production volumes as a range to
protect production volume data claimed as confidential business information (CBI). For the 2016 and
2020 CDR cycle, collected data included the company name, volume of each chemical
manufactured/imported, the number of workers at each site, and information on whether the chemical
was used in the commercial, industrial, and/or consumer sector(s).
In the 2020 CDR, one site, Dystar LP in Reidsville, North Carolina, reported a production volume of
5 1,852 lb for domestic manufacturing of DBP for the 2019 CDR reporting year ( 2020b).
They had previously reported between 0 and 25,021 lb DBP manufactured between 2016 to 2018.
Polymer Additives, Inc. in Bridgeport, NJ reported manufacture of DBP but claimed their PV as CBI.
An additional three sites (4 sites total) reported their site activities as CBI; EPA assumed that these sites
may manufacture DBP. This resulted in a total of five potential DBP manufacturing sites, two sites with
known manufacturing activities and three sites with CBI activities.
EPA calculated the production volume for the four sites with CBI production volumes using a uniform
distribution set within the national PV range for DBP. EPA calculated the bounds of the range by taking
the national aggregate PV range reported in CDR (1-10 million lb) and subtracting out the PVs that
belonged to sites with known volumes (both manufacturing and import). Then, for each bound of the PV
range, EPA divided the value by the number of sites with CBI PVs for DBP. Based on the known PVs
from importers and manufacturers, the total calculated PV associated with the four sites with CBI PVs is
109,546 to 5,252,403 lb/year. Based on this (and after converting lb to kg), EPA set a uniform
distribution for the PV for the four sites with CBI PVs with lower bound of 49,689 kg/year, and an
upper-bound of 2,382,450 kg/year. For more information regarding DBP's PV for CDR reporters, refer
to Section 3.1 of the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl
Phthalate (DBP) ( 025q).
1.2 Conditions of Use Included in the Risk Evaluation
The final scope for DBP (U.S. EPA. 2020c) identified and described the life cycle stages, categories,
and subcategories that comprise TSCA COUs that EPA planned to consider in the risk evaluation. All
COUs for DBP included in this draft risk evaluation are reflected in the LCD (Figure 1-3) and
conceptual models (Section 1.2.1.1). Table 1-1 below presents all COUs for DBP.
In this draft risk evaluation, EPA made updates to the COUs listed in the final scope document (U.S.
E 20c). These updates reflect EPA's improved understanding of the COUs based on further
outreach, public comments, and updated industry code names under the CDR for 2020. Updates include
(1) additions and clarification of COUs based on new reporting in CDR for 2020 or information received
from stakeholders; (2) consolidation of redundant COUs from the processing life stage based on
inconsistencies found in CDR reporting for DBP processing and uses, and communications with
stakeholders about the use of DBP in industry; and (3) correction of typos or edits for consistency.
Appendix C provides a complete list of updates to the COUs between the final scope document and the
draft risk evaluation and an explanation of these updates. EPA may further refine the COU descriptions
for DBP that are included in the draft risk evaluation when the final risk evaluation for DBP is
published, based upon further outreach, peer-review comments, and public comments. Table 1-1
presents the revised COUs that were included and evaluated in this draft risk evaluation for DBP.
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728 Table 1-1. Categories and Subcategories of Use and Corresponding Exposure Scenario in the Risk
729 Evaluation for DBP
Life-Cycle
Stage"
Category''
Subcategory'
Reference(s)
Manufacturing
Domestic
manufacturing
Domestic manufacturing
(1 2020a. 2019b)
Importing
Importing
(1 2019b)
Processing
Processing as a
reactant
Intermediate in plastic
manufacturing
fW.R. Grace. 2024)
Incorporation into
formulation, mixture,
or reaction product
Solvents (which become part of
product formulation or mixture) in
chemical product and preparation
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; adhesive
manufacturing; and printing ink
manufacturing
fNLM. 2024: U.S. EPA. 2019b:
Kosaric, 1 : sli and Ash, 2009)
Pre-catalyst manufacturing
fW.R. Grace. 2024)
Plasticizer in paint and coating
manufacturing; plastic material and
resin manufacturing; rubber
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing; printing
ink manufacturing; basic organic
chemical manufacturing; and
adhesive and sealant manufacturing
fNLM. 2024: U.S. EPA. 2020a.
2019b)
Incorporation into
article
Plasticizer in adhesive and sealant
manufacturing; building and
construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics product
manufacturing; and rubber product
manufacturing
fNLM. 2024: NASA. 2020: U.S.
EPA. 2020a: AIA. 2019: U.S. EPA.
2019b: SpecialCliem, 2018)
Repackaging
Laboratory chemicals in wholesale
and retail trade; plasticizers in
wholesale and retail trade; and
plastics material and resin
manufacturing
fl 2020a. 2019b)
Recycling
Recycling
fl \. 2019b)
Distribution in
Commerce
Distribution in
commerce
Industrial Use
Non-incorporative
activities
Solvent, including in maleic
anhydride manufacturing
technology
(Huntsman. 2024: U.S. EPA. 2020a.
2019b)
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Life-Cycle
Stage"
Category''
Subcategory'
Reference(s)
Industrial Use
Construction, Paint,
Electrical, and Metal
Products
Adhesives and sealants
("NASA. 2020: MEM A. 2019:
Sendesi et ah. 2017: Whelton et ah.
2< : "d Motor Company, 2015a)
Paints and coatings
(Carboline. 2021: NASA. 2020)
Other uses
Automotive articles
("MEMA. 2019)
Lubricants and lubricant additives
("MEMA. 2019)
Propellants
(Liana et ah. 2021: U.S. EPA.
2020a: AIA. 2019)
Commercial
Use
Automotive, fuel,
agriculture, outdoor
use products
Automotive care products
(I \. 2020a)
Construction, paint,
electrical, and metal
products
Adhesives and sealants
(I \. 2020a: MEMA. 2019:
U.S. EPA. 2019b: Sendesi et ah.
2017: Whelton et ah. )
Paints and coatings
fNLM. 2024: U.S. EPA. 2020a.
2019b: GoodGmde. 2011:
Streitberser et ah, 2011)
Furnishing, cleaning,
treatment care
products
Cleaning and furnishing care
products
fNLM. 2024: U.S. EPA. 2019b:
GoodGuide, < )
Floor coverings; construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
articles; fabrics, textiles, and
apparel
fl 2020a. 2019b: Sendesi et
ah. 2017: Whelton et ah. 2017)
Furniture and furnishings
fl \. 2019b)
Packaging, paper,
plastic, toys, hobby
products
Ink, toner, and colorant products
fNLM. 2024: U.S. EPA. 2019b)
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
fNLM. 2024: U.S. EPA. 2020a.
2019b)
Toys, playground, and sporting
equipment
fl 2019a. f>
Other uses
Automotive articles
(MEMA. 2019)
Chemilumine scent light sticks
fl \. 2020d)
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Life-Cycle
Stage"
Category''
Subcategory'
Reference(s)
Commercial
Use
Other uses
Laboratory chemicals
("NASA. 2020: U.S. EPA. 2020d.
2019b)
Inspection penetrant kit
a \. 2020d: AIA. 2019)
Lubricants and lubricant additives
("NASA. 2020: U.S. EPA. 2020d:
MEMA. 2019)
Consumer Use
Automotive, fuel,
agriculture, outdoor
use products
Automotive care products
(I \. 2020a)
Construction, paint,
electrical, and metal
products
Adhesives and sealants
(MEMA. 2019: U.S. EPA. 2019b)
Paints and coatings
("NLM. 2024: U.S. EPA. 2020a.
2019b: GoodGuide, 2011:
Streitberser et ah, 2011)
Furnishing, cleaning,
treatment care
products
Fabric, textile, and leather products
fWSDE. 2023: U.S. EPA. 2020e.
2019b)
Floor coverings; construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
articles; fabrics, textiles, and
apparel
(I 2020a. 2019b)
Cleaning and furnishing care
products
("NLM. 2024: U.S. EPA. 2019b:
GoodGuide. 2011)
Packaging, paper,
plastic, toys, hobby
products
Ink, toner, and colorant products
(I 2019b)
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
("NLM. 2024: U.S. EPA. 2019b)
Toys, playground and sporting
equipment
(I 2019a. f)
Other Uses
Automotive articles
(MEMA. 2019)
Chemilumine scent light sticks
(I 2020d)
Lubricants and lubricant additives
(MEMA. 2019)
Novelty articles
(Sine et ah, 2023: Stabile, 2013)
Disposal
Disposal
Disposal
(I \. 2019b)
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Life-Cycle
Stage"
Category''
Subcategory'
Reference(s)
"Life Cycle Stage Use Definitions (40 CFR 711.3)
- "Industrial use" means use at a site at which one or more chemicals or mixtures are manufactured (including
imported) or processed.
- "Commercial use" means the use of a chemical or a mixture containing a chemical (including as part of an article) in
a commercial enterprise providing saleable goods or services.
- "Consumer use" means the use of a chemical or a mixture containing a chemical (including as part of an article, such
as furniture or clothing) when sold to or made available to consumers for their use.
- Although EPA has identified both industrial and commercial uses here for purposes of distinguishing scenarios in
this document, the Agency interprets the authority over "any manner or method of commercial use" under TSCA
Section 6(a)(5) to reach both.
h These categories of conditions of use appear in the Life Cycle Diagram, reflect CDR codes, and broadly represent
COUs of DBP in industrial and/or commercial settings.
c These subcategories represent more specific activities within the life cycle stage and category of the CPUs of DBP.
730 1.2.1.1 Conceptual Models
731 The conceptual model in Figure 1-4 presents the exposure pathways, exposure routes, and hazards to
732 human populations from industrial and commercial activities and uses of DBP. There is potential for
733 exposures to workers and/or ONUs via inhalation and via dermal contact. The conceptual model also
734 includes potential ONU dermal exposure to DBP from mists and dusts deposited on surfaces. EPA
735 evaluated activities resulting in exposures associated with distribution in commerce (e.g., loading,
736 unloading) throughout the various life cycle stages and COUs (e.g., manufacturing, processing,
737 industrial use, commercial use, and disposal).
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Industrial and Commercial Exposure Pathway Exposure Route Receptors Hazards
Activities/Uses*
739 Figure 1-4. DBP Conceptual Model for Industrial and Commercial Activities and Uses: Potential Exposure and Hazards
740 a Some products are used in both commercial and consumer applications. See Table 1-1 for categories and subcategories of conditions of use.
741 b Fugitive air emissions are emissions that are not routed through a stack and include fugitive equipment leaks from valves, pump seals, flanges,
742 compressors, sampling connections and open-ended lines; evaporative losses from surface impoundment and spills; and releases from building ventilation
743 systems.
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CONSUMER ACTIVITIES/
USES
EXPOSURE
PATHWAYS
EXPOSURE
ROUTES
POPULATIONS
EXPOSED
HAZARDS
Automotive, fuel, agriculture, outdoor
use products
Construction, paint, electrical, and
metal products
Furnishing, cleaning, treatment care
products
Packaging, paper, plastic, hobby
products
Other Uses
744
745
746
Consumer Handling of Disposal and
Waste
Wastewater, Liquid Wastes and Solid
-~ Wastes (See Environmental Releases
Conceptual Models)
Figure 1-5. DBP Conceptual Model for Consumer Activities and Uses: Potential Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes, and hazards to human populations from consumer activities and uses of DBP.
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RELEASES AND WASTES FROM INDUSTRIAL /
COMMERCIAL / CONSUMER USES
EXPOSURE PATHWAYS
EXPOSURE ROUTES
RECEPTORS
HAZARDS
Hazards Potentially
Associated with Lifetime
Cancer and or Non-Cancer
Chronic Exposures
Recycling, Other
Treatment
Emissions to Air
Kev:
Black Text and Solid Line
Pathways that were assessed
Gray Text and Dashed Line
Pathways that were not assessed
747
748
749
750
Figure 1-6. DBP Conceptual Model for Environmental Releases and Wastes: General Population Hazards
The conceptual model presents the exposure pathways, exposure routes, and hazards to human populations from releases and wastes from industrial,
commercial, and/or consumer uses of DBP.
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RELEASES A_\D WASTES FROM INDUSTRIAL /
COMMERCIAL / CONSUMER USES
EXPOSURE PATHWAYS
RECEPTORS
HAZARDS
751
752
753
754
Hazards Potentially
Associated with
Acute and. or Chronic
Exposures
Fugitive and Stack
Emissions
I
Kev:
Black Text and Solid Line
Pathways that were assessed
Gray Text and Dashed Line
Pathways that were not assessed
Figure 1-7. DBP Conceptual Model for Environmental Releases and Wastes: Ecological Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes, and hazards to ecological populations from releases and wastes from industrial,
commercial, and/or consumer uses of DBP.
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1.2.2 Populations and Durations of Exposure Assessed
Based on the conceptual models presented in Section 1.2.1.1, EPA evaluated risk to environmental and
human populations. Environmental risks were evaluated for acute and chronic exposure scenarios for
aquatic and terrestrial species, as appropriate. Human health risks were evaluated for acute,
intermediate, and chronic exposure scenarios, as applicable based on reasonably available exposure and
hazard data, as well as the relevant populations for each. Human populations assessed include the
following:
• Workers, including average adults and females of reproductive age;
• ONUs, including average adult workers (individuals of both sexes age 16+ years, including
pregnant workers)
• Consumers, including infants (<1 year), toddlers (1-2 years), children (3-5 and 6-10 years),
young teens (11-15 years), teenagers (16-20 years), and adults (21+ years);
• Bystanders, including infants (<1 year), toddlers (1-2 years), and children (3-5 and 6-10 years);
young teens (11-15 years), teenagers (16-20 years), and adults (21+ years); and
• General population, including infants (<1 year), toddlers (1-5 years), children (6-10 years),
youth (11-15 and 16-20 years), and adults (21+ years).
Note that the age groups for consumers, bystanders, and general population are different because each
life stage used unique exposure factors (e.g., mouthing, drinking water ingestion, fish consumption
rates). These exposure factors are provided in EPA's Exposure Factors Handbook: 2011 Edition (U.S.
W -01 I In-
consistent with its Draft Proposed Approach for Cumulative Risk Assessment (CRA) of High-Priority
Phthalates and a Manufacturer-Requested Phthalate under the Toxic Substances Control Act (U.S.
E 23d), EPA is focusing its relative potency factor (RPF) analysis and phthalate CRA on
populations most relevant to the common hazard endpoint (i.e., reduced fetal testicular testosterone)—
specifically females of reproductive age and male infants and male children. This approach emphasizes
a common health effect for sensitive subpopulations; however, additional health endpoints are identified
for broader populations and described in the individual non-cancer human health hazard assessments for
DBP (• ; r \ :024f). DC HP (\ " \ \ \ 2024g), DEHP (I * H \ _024h), BBP (l v \ -024e),
DIBP ( } 1> \ :024il and DINP 0 > {P \ . '.;4n). Additionally, EPA is focusing its RPF and
CRA on acute duration exposures. This is because—as described further in the Revised Draft Technical
Support Document for the CRA of DEHP, DBP, BBP, DIBP, DCHP, and DINP under TSCA (
2025x)—there is evidence that effects on the developing male reproductive system consistent with a
disruption of androgen action can result from a single exposure during the critical window of
development.
1.2.2.1 Potentially Exposed and Susceptible Subpopulations
TSCA section 6(b)(4)(A) requires that risk evaluations "determine whether a chemical substance
presents an unreasonable risk of injury to health or the environment, without consideration of costs or
other non-risk factors, including an unreasonable risk to a potentially exposed or susceptible
subpopulation identified as relevant to the risk evaluation by the Administrator, under the conditions of
use." TSCA section 3(12) states that "the term 'potentially exposed or susceptible subpopulation'
[PESS] means a group of individuals within the general population identified by the Administrator who,
due to either greater susceptibility or greater exposure, may be at greater risk than the general population
of adverse health effects from exposure to a chemical substance or mixture, such as infants, children,
pregnant women, workers, or the elderly."
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This draft risk evaluation considers PESS throughout the human health risk assessment (Section 4),
including throughout the exposure assessment, hazard identification, and dose-response analysis
supporting this assessment. EPA incorporated the following PESS into its assessment: females of
reproductive age, pregnant women, infants, children and adolescents, people who frequently use
consumer products and/or articles containing high concentrations of DBP, people exposed to DBP in the
workplace, and tribes whose diets include large amounts of fish. These subpopulations are PESS
because some have greater exposure to DBP per body weight (e.g., infants, children, adolescents) or due
to age-specific behaviors (e.g., mouthing of toys, wires, and erasers by infants and children assessed in
the consumer exposure scenarios), while some experience aggregate or sentinel exposures. EPA also
evaluated non-attributable exposures and cumulative risk to phthalates (i.e., DEHP, DBP, BBP, DIBP,
and DINP) using biomonitoring data from National Health and Nutrition Examination Survey
(NHANES). This non-attributable cumulative risk from exposure to DEHP, DBP, BBP, DIBP, and
DINP was taken into consideration as part of EPA's cumulative risk calculations for DBP, presented
below in Section 4.4 and around exposures to DBP from both occupational and consumer
COUs/occupational exposure scenarios (OESs).
Section 4.3.5 summarizes how PESS were incorporated into the draft risk evaluation through
consideration of potentially increased exposures and/or potentially increased biological susceptibility
and summarizes additional sources of uncertainty related to consideration of PESS.
1.3 Organization of the Risk Evaluation
This draft risk evaluation for DBP includes five additional major sections, and several appendices, as
described below:
• Section 2 summarizes basic physical and chemical characteristics as well as the fate and
transport of DBP.
• Section 3 includes an overview of releases and concentrations of DBP in the environment.
• Section 4 presents the human health risk assessment, including the exposure, hazard, and risk
characterization based on the COUs. It includes a discussion of PESS based on both greater
exposure and/or susceptibility as well as a description of aggregate and sentinel exposures.
Section 4 also discusses assumptions and uncertainties and how they potentially impact the
strength of the evidence of draft risk evaluation. Finally, Section 4 presents cumulative risk
estimates from exposure to BBP, DEHP, DBP, DIBP, DCHP, and DINP (Section 4.4), as well as
a comparison of the individual BBP risk assessment and the draft CRA (Section 4.5)
• Section 5 provides a discussion and analysis of the environmental risk assessment, including the
environmental exposure, hazard, and risk characterization based on the COUs for DBP. It also
discusses assumptions and uncertainties and how they potentially impact the strength of the
evidence of draft risk evaluation.
• Section 6 presents EPA's proposed determination of whether DBP presents an unreasonable risk
to human health or the environment under the assessed COUs.
• Appendix A provides a list of key abbreviations and acronyms used throughout this draft risk
evaluation.
• Appendix B provides a brief summary of the federal, state, and international regulatory history of
DBP.
• Appendix C incudes a list and citations for all TSDs and supplemental files included in the draft
risk evaluation for DBP.
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845 • Appendix D provides a summary of updates made to COUs for DBP from the final scope
846 document to this draft risk evaluation.
847 • Appendix E provides descriptions of the DBP COUs evaluated by EPA.
848 • Appendix F provides the draft occupational exposure value for DBP that was derived by EPA.
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849
850
851
852
853
854
855
856
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2 CHEMISTRY AND FATE AND TRANSPORT OF DBP
Physical and chemical properties determine the behavior and characteristics of a chemical that inform its
condition of use, environmental fate and transport, potential toxicity, exposure pathways, routes, and
hazards. Environmental fate and transport includes environmental partitioning, accumulation,
degradation, and transformation processes. Environmental transport is the movement of the chemical
within and between environmental media, such as air, water, soil, and sediment. Thus, understanding the
environmental fate of DBP informs the specific exposure pathways, and potential human and
environmental exposed populations that EPA considered in this draft risk evaluation.
Sections 2.1 and 2.2 summarize the physical and chemical properties, and environmental fate and
transport of DBP, respectively. See the Draft Chemistry, Fate, and Transport Assessment for Dibutyl
Phthalate (DBP) (U.S. EPA. 2024i).
2.1 Summary of Physical and Chemical Properties
EPA gathered and evaluated physical and chemical property data and information according to the
process described in the Draft Systematic Review Protocol for Dibutyl Phthalate (DBP) (U.S. EPA.
2025w). EPA considered both measured and estimated physical and chemical property data/information
as described in the Draft Physical Chemistry, Fate, and Transport Assessment for Dibutyl Phthalate
(DBP) ( H). The selected values are summarized in Table 2-1, as applicable. Information
on the full, extracted dataset is available in the Draft Data Quality Evaluation and Data Extraction
Information for Physical and Chemical Properties for Dibutyl Phthalate (DBP) ( E5k).
Table 2-1. Physical and Chemical Properties of DI
tP
Property
Selected Value(s)
Reference(s)
Overall Data Quality
Rating
Molecular formula
C16H22O4
-
-
Molecular weight
278.35 g/mol
-
-
Physical form
Oily liquid
O'Neil C
High
Melting point
-35 °C
Rumble (2018)
High
Boiling point
340 °C
O'Neil C
High
Density
1.0465 g/cm3
Rumble (2018)
High
Vapor pressure
2.01E-05 mm Hg
:oi9c)
High
Vapor density
9.58
NLM (2<
High
Water solubility
11.2 mg/L
Howard 5)
High
Organic carbon:water
(Log Koc)
3.69 (average of 7 values
ranging between 3.14-
3.94)
Xiamg et al. (2019);
Russell and Mcduffie
5)
High
Octanol:water partition
coefficient (log Kow)
4.5
NLM (2<
High
Octanol:air partition
coefficient (log Koa)
8.63 (EPI Suite™)
1 * n \,jo 1 )
High
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872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
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892
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Property
Selected Value(s)
Reference(s)
Overall Data Quality
Rating
Air:water partition
coefficient (log Kaw)
-4.131 (EPI Suite™)
i * n \,;o i )
High
Henry's Law constant
1.81E-06 atmm3/mol at
25 °C
NLM (2'
High
Flash point
157 °C
NLM (2'
High
Autoflammability
402 °C
NLM (2'
High
Viscosity
20.3 cP
NLM (2'
High
2.2 Summary of Environmental Fate and Transport
Reasonably available environmental fate data—including biotic and abiotic biodegradation rates,
removal during wastewater treatment, volatilization from water sources, and organic carbon:water
partition coefficient (log Koc)—are parameters used in the current risk evaluation. In assessing the
environmental fate and transport of DBP, EPA considered the full range of results from the available
highest quality data sources obtained during systematic review. Information on the full extracted dataset
is available in the Draft Data Quality Evaluation and Data Extraction Information for Environmental
Fate and Transport for Dibutyl Phthalate (DBP) ( 3251). Other fate estimates were based on
modeling results from EPI Suite™ (U.S. EPA. 2012b). a predictive tool for physical and chemical
properties and environmental fate estimation. Information regarding the model inputs is available in the
Draft Physical Chemistry and Fate and Transport Assessment for Dibutyl Phthalate (DBP) (U.S. EPA.
20241).
EPA evaluated the reasonably available information to characterize the environmental fate and transport
of DBP, the key points of the fate assessment for DBP ( ) are summarized below and
listed in Table 2-2.
Given the consistent results from numerous high-quality studies, there is robust evidence of the
following:
• DBP not expected to undergo significant direct photolysis but will undergo indirect
photodegradation by reacting with hydroxyl radicals in the atmosphere with a half-life of 1.13 to
1.15 days.
• DBP will partition to organic carbon and particulate matter in air.
• DBP will not hydrolyze under standard environmental conditions, but its hydrolysis rate
increases with increased pH and temperature in deep-landfill environments.
• DBP will biodegrade in aerobic surface water, soil, and wastewater treatment processes.
• DBP will not biodegrade under anoxic conditions and may have high persistence in anaerobic
soils and sediment.
• DBP will be removed with wastewater treatment and will sorb significantly to sludge, with a
small fraction being present in wastewater treatment plant (WWTP) effluent.
• DBP has low bioaccumulation potential.
• DBP may be persistent in surface water and sediment proximal to continuous points of release.
• DBP is expected to transform to monobutyl phthalate (MBP), butanol, and phthalic acid in the
environment.
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905 As a result of limited studies identified, there is moderate confidence that DBP
906 • Will be removed in conventional drinking water treatment systems both in the treatment process
907 and via reduction by chlorination and chlorination byproducts in post-treatment storage and
908 drinking water conveyance with a removal efficiency of 3 1 to 64.5 percent (Kong et al.. 2017;
909 Shan et al. 20161
910 Findings that were found to have a robust weight of evidence supporting them had one or more high-
911 quality studies that were largely in agreement with each other. Findings that were said to have a
912 moderate weight of evidence were based on a mix of high- and medium-quality studies that were largely
913 in agreement but varied in sample size and consistency of findings.
914
915 Table 2-2. Summary of Environmental Fate Information for DBPa
Parameter
Value
Reference(s)
Overall Data
Quality Rating
Aerobic primary
biodegradation in
water
68.3-100% in 7-28 days
NITE (2019): SRC (1983):
Tabak et al. (1981)
High
Aerobic
biodegradation in
sediment
ti/2 = 2.9 days in natural river
sediment collected from the
Zhonggang, Keya, Erren, Gaoping,
Donggang, and Danshui Rivers,
Taiwan
Yuan et al. (2002)
High
Anaerobic
biodegradation in
sediment
ti/2 = 14.4 days in natural river
sediment collected from the
Zhonggang, Keya, Erren, Gaoping,
Donggang, and Danshui Rivers in
Taiwan
Yuan et al. (2002)
High
Aerobic
biodegradation in soil
88.1-97.2% after 200 days in
Chalmers slit loam, Plainfield sand,
and Fincastle silt loam soils
In man et al. (1984)
High
Hydrolysis
ti/2 = approximately 22 years at pH 7
and 25 °C; KH = 1.0 ± 0.05E-02M1
sec"1 at pH 10-12 and 30 °C
ATSDR (1999); Wolfe et al.
(1980)
High
Photolysis
Direct: Expected to be susceptible to
direct photolysis by sunlight;
contains chromophores that absorb at
wavelengths >290 nm
Indirect: ti/2 =1.13 days (-OH rate
constant of 9.47E-12 OH/cm3) and
1.15 days (-OH rate constant of
9.28E-12 OH/cm3); (estimated based
on a 12-hour day with 1.5E06
•OH/cm3)
Lei et al. (2018); Peterson and
Staples (2003)
High
Environmental
degradation half-lives
1.15 days (air)
10 days (water)
20 days (soil)
Lei et al. (2018); SRC (1983)
High
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Parameter
Value
Reference(s)
Overall Data
Quality Rating
(selected values for
modeling)
90 days (sediment)
Wastewater treatment
plant (WWTP)
removal
65-98%
U.S. EPA (1982)
High
Aquatic
bioconcentration
factor (BCF)
2.9 ±0.1 and 30.6 ± 3.4 in brown
shrimp (Penaeus aztecus) at 100 and
500 ppb, respectively; 11.7 in
sheepshead minnow (Cyprinodon
variegate) at 100 ppb; 21.1 ± 9.3 and
41.6 ± 5.1 in American oyster
(Crassostrea virginica) at 100 and
500 ppb, respectively
Wofford et al. (1981)
High
Aquatic
bioaccumulation
factor (BAF)
100, 316, 251 and 1,259 L/kg dry
weight (dw) in bluegill, bass,
skygager, and crucian carp,
respectively.
Lee et al. (2019)
High
Aquatic Trophic
Magnification Factor
(TMF)
0.70 (Experimental; 18 marine
species)
Mackintosh et al. (2004)
High
Plant Concentration
Factor (PCF)
0.26-4.78 (Fruit and vegetables)
Sun et al. (2015)
High
Terr. Biota-sediment
accumulation factor
(BSAF)
0.242-0.460 (Eisenia fetida)
Ji and Dene ( ; Hu et al.
(2005)
High
a Additional information on value selection can be found in the Draft Physical Chemistry, Fate, and Transport
Assessment for Dibutyl Phthalate (DBP) (U.S. EPA, 2024j).
916
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3 RELEASES AND CONCENTRATIONS OF DBP IN THE
ENVIRONMENT
EPA estimated environmental releases and concentrations of DBP. Section 3.1 describes the approach
and methodology for estimating releases; Section 3.2 presents estimates of environmental releases; and
Section 3.3 presents the approach and methodology for estimating environmental concentrations as well
as a summary of concentrations of DBP in the environment.
3.1 Approach and Methodology
This section provides an overview of the approach and methodology for assessing releases to the
environment from industrial, commercial, and consumer uses. Specifically, Sections 3.1.1 through 3.1.3
describe the approach and methodology for estimating releases to the environment from industrial and
commercial uses.
3.1.1 Manufacturing, Processing, Industrial and Commercial
This subsection describes the grouping of manufacturing, processing, industrial and commercial COUs
into OESs as well as the use of DBP within each OES. Specifically, Section 3.1.1.1 provides a crosswalk
of COUs to OESs and 3.1.1.2 provides descriptions for the use of DBP within each OES.
3.1.1.1 Crosswalk of Conditions of Use to Occupational Exposure Scenarios
EPA categorized the COUs listed in Table 1-1 into OESs. Table 3-1 provides a crosswalk between the
COUs and OESs whereas Table 3-2 provides the reverse: a crosswalk of OESs to COUs. Each OES is
developed based on a set of occupational activities and conditions such that similar occupational
exposures and environmental releases are expected from the use(s) covered under that OES. For each
OES, EPA provided occupational exposure and environmental release results, which are expected to be
representative of the entire population of workers and sites for the given OES in the United States. In
some cases, EPA defined only a single OES for multiple COUs, while in other cases the Agency
developed multiple OESs for a single COU. EPA made this determination by considering variability in
release and use conditions and whether the variability required discrete scenarios or could be captured as
a distribution of exposures. The Draft Environmental Release and Occupational Exposure Assessment
for DibutylPhthalate (DBP) ( 2025q) provides further information on specific OESs.
Table 3-1. Crosswalk of Conditions of Use to Assessed Occupational Ex
COU
OES'
Life Cycle Stage"
Category''
Subcategory'
Manufacturing
Domestic manufacturing
Domestic manufacturing
Manufacturing
Importing
Importing
Import and repackaging
Processing
Repackaging
Laboratory chemicals in wholesale
and retail trade; plasticizers in
wholesale and retail trade; and
plastics material and resin
manufacturing
Import and repackaging
Processing as a reactant
Intermediate in plastic
manufacturing
Incorporation into
formulations, mixtures, or
reaction product
oosure Scenarios
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cou
OESrf
Life Cycle Stage"
Category''
Subcategory'
Solvents (which become part of
product formulation or mixture) in
chemical product and preparation
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; adhesive
manufacturing; and printing ink
manufacturing
Incorporation into
formulations, mixtures, or
reaction product
Processing
Incorporation into
formulation, mixture, or
reaction product
Plasticizer in paint and coating
manufacturing; plastic material and
resin manufacturing; rubber
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing; printing
ink manufacturing; basic organic
chemical manufacturing; and
adhesive and sealant manufacturing
Incorporation into
formulations, mixtures, or
reaction product;
PVC plastics compounding;
Non-PVC material
manufacturing
Pre-catalyst manufacturing
Incorporation into
formulations, mixtures, or
reaction product
Incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and
construction materials
manufacturing; furniture and related
product manufacturing; ceramic
powders; plastics product
manufacturing; and rubber product
manufacturing
PVC plastics converting;
Non-PVC material
manufacturing;
Recycling
Recycling
Recycling
Distribution in
Commerce
Distribution in
commerce
Distribution in commerce
Non-incorporative
activities
Solvent, including in maleic
anhydride manufacturing
technology
Industrial process solvent use
Construction, paint,
electrical, and metal
products
Adhesives and sealants
Application of adhesives and
sealants
Industrial Use
Paints and coatings
Application of paints and
coatings
Automotive articles
Fabrication or use of final
product or articles
Other uses
Lubricants and lubricant additives
Use of lubricants and
functional fluids
Propellants
Fabrication or use of final
product or articles
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cou
OESrf
Life Cycle Stage"
Category''
Subcategory'
Commercial Use
Automotive, fuel,
agriculture, outdoor use
products
Automotive care products
Use of lubricants and
functional fluids
Construction, paint,
electrical, and metal
products
Adhesives and sealants
Application of adhesives and
sealants
Paints and coatings
Application of paints and
coatings
Furnishing, cleaning,
treatment care products
Cleaning and furnishing care
products
Use of lubricants and
functional fluids
Floor coverings; construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
articles; fabrics, textiles, and
apparel;
Furniture and furnishings
Fabrication or use of final
product or articles
Packaging, paper,
plastic, toys, hobby
products
Ink, toner, and colorant products
Application of paints and
coatings
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
Fabrication or use of final
product or articles
Toys, playground, and sporting
equipment
Fabrication or use of final
product or articles
Other uses
Laboratory chemicals
Use of laboratory chemicals
Automotive articles
Fabrication or use of final
product or articles
Chemilumine scent light sticks
Fabrication or use of final
product or articles
Inspection penetrant kit
Use of penetrants and
inspection fluids
Lubricants and lubricant additives
Use of lubricants and
functional fluids
Disposal
Disposal
Disposal
Waste handling, treatment,
and disposal
"Life Cycle Stage Use Definitions (40 CFR 711.3)
- "Industrial use" means use at a site at which one or more chemicals or mixtures are manufactured (including
imported) or processed.
- "Commercial use" means the use of a chemical or a mixture containing a chemical (including as part of an article)
in a commercial enterprise providing saleable goods or services.
- "Consumer use" means the use of a chemical or a mixture containing a chemical (including as part of an article,
such as furniture or clothing) when sold to or made available to consumers for their use.
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COU
OESrf
Life Cycle Stage"
Category''
Subcategory'
- Although EPA has identified both industrial and commercial uses here for purposes of distinguishing scenarios
in this document, the Agency interprets the authority over "any manner or method of commercial use" under
TSCA section 6(a)(5) to reach both.
h These categories of COU appear in the life cycle diagram, reflect CDR codes, and broadly represent COUs of DBP in
industrial and/or commercial settings.
c These subcategories represent more specific activities within the life cycle stage and category of the COU of DBP.
d An OES is based on a set of facts, assumptions, and inferences that describe how releases and exposures take place within
an occupational COU. The occurrence of releases/exposures may be similar across multiple conditions of use (multiple
COUs mapped to single OES), or there may be several ways in which releases/exposures take place for a given condition
of use (single COU mapped to multiple OESs).
946
947
948 Table 3-2. Crosswalk of Assessed Occupational Exposure Scenarios to Conditions of Use
OES"
COU
Life Cycle Stage''
Category'
Subcategory''
Manufacturing
Manufacturing
Domestic
manufacturing
Domestic manufacturing
Import and
Manufacturing
Importing
Importing
repackaging
Processing
Repackaging
Laboratory chemicals in wholesale and retail
trade; plasticizers in wholesale and retail trade;
and plastics material and resin manufacturing
Processing
Processing as a
reactant
Intermediate in plastic manufacturing
Processing
Incorporation into
formulation,
Solvents (which become part of product
formulation or mixture) in chemical product
Incorporation
into formulations,
mixtures, or
reaction product
mixture, or reaction
product
and preparation manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; adhesive manufacturing; and
printing ink manufacturing
Processing
Incorporation into
formulation,
mixture, or reaction
product
Plasticizer in paint and coating manufacturing;
soap, cleaning compound, and toilet
preparation manufacturing; textiles, apparel,
and leather manufacturing; printing ink
manufacturing; basic organic chemical
manufacturing; and adhesive and sealant
manufacturing
Processing
Incorporation into
formulation,
mixture, or reaction
product
Pre-catalyst manufacturing
PVC plastics
compounding
Processing
Incorporation into
formulation,
mixture, or reaction
product
Plasticizer in plastic material and resin
manufacturing
PVC plastics
converting
Processing
Incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and construction
materials manufacturing; furniture and related
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OES"
COU
Life Cycle Stage''
Category'
Subcategory''
product manufacturing; ceramic powders;
plastics product manufacturing
Processing
Incorporation into
formulation,
mixture, or reaction
Plasticizer in plastic material and resin
manufacturing; rubber manufacturing
Non-PVC
materials
manufacturing
product
Processing
Incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and construction
materials manufacturing; furniture and related
product manufacturing; ceramic powders;
plastics product manufacturing; and rubber
product manufacturing
Commercial Use
Construction, paint,
Application of adhesives and sealants
Application of
adhesives and
sealants
electrical, and metal
products
Industrial Use
Construction, paint,
electrical, and metal
products
Application of adhesives and sealants
Commercial Use
Packaging, paper,
plastic, toys, hobby
products
Ink, toner, and colorant products
Application of
paints and
Commercial Use
Construction, paint,
electrical, and metal
Paints and coatings
coatings
products
Industrial Use
Construction, paint,
electrical, and metal
products
Paints and coatings
Industrial process
solvent use
Industrial Use
Non- incorporative
activities
Solvent, including in maleic anhydride
manufacturing technology
Use of laboratory
chemicals (solid)
Commercial Use
Other uses
Laboratory chemicals
Use of laboratory
chemicals
Commercial Use
Other uses
Laboratory chemicals
(liquid)
Commercial Use
Other uses
Lubricants and lubricant additives
Industrial Use
Other uses
Lubricants and lubricant additives
Use of lubricants
and functional
fluids
Commercial Use
Automotive, fuel,
agriculture, outdoor
use products
Automotive care products
Commercial Use
Furnishing, cleaning,
treatment care
products
Cleaning and furnishing care products
Use of penetrants
and inspection
fluids
Commercial Use
Other uses
Inspection penetrant kit
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OES"
COU
Life Cycle Stage''
Category'
Subcategory''
Commercial Use
Furnishing, cleaning,
treatment care
products
Floor coverings; construction and building
materials covering large surface areas
including stone, plaster, cement, glass and
ceramic articles; fabrics, textiles, and apparel
Commercial Use
Furnishing, cleaning,
treatment care
products
Furniture and furnishings
Commercial Use
Other uses
Automotive articles
Fabrication or use
Commercial Use
Other uses
Chemilumine scent light sticks
of final product
Industrial Use
Other uses
Automotive articles
or articles
Industrial Use
Other uses
Propellants
Commercial Use
Packaging, paper,
plastic, toys, hobby
products
Packaging (excluding food packaging),
including rubber articles; plastic articles (hard);
plastic articles (soft); other articles with routine
direct contact during normal use, including
rubber articles; plastic articles (hard)
Commercial Use
Packaging, paper,
plastic, toys, hobby
products
Toys, playground, and sporting equipment
Recycling
Processing
Recycling
Recycling
Waste handling,
treatment, and
Disposal
Disposal
Disposal
disposal
a An OES is based on a set of facts, assumptions, and inferences that describe how releases and exposures take place
within an occupational condition of use. The occurrence of releases/exposures may be similar across multiple conditions
of use (multiple COUs mapped to single OES), or there may be several ways in which releases/exposures take place for a
given condition of use (single COU mapped to multiple OESs).
b Life Cycle Stage Use Definitions (40 CFR 711.3)
- "Industrial use" means use at a site at which one or more chemicals or mixtures are manufactured (including
imported) or processed.
- "Commercial use" means the use of a chemical or a mixture containing a chemical (including as part of an article)
in a commercial enterprise providing saleable goods or services.
- "Consumer use" means the use of a chemical or a mixture containing a chemical (including as part of an article,
such as furniture or clothing) when sold to or made available to consumers for their use.
- Although EPA has identified both industrial and commercial uses here for purposes of distinguishing scenarios
in this document, the Agency interprets the authority over "any manner or method of commercial use" under
TSCA Section 6(a)(5) to reach both.
c These categories of conditions of use appear in the Life Cycle Diagram, reflect CDR codes, and broadly represent
conditions of use of DPB in industrial and/or commercial settings.
d These subcategories represent more specific activities within the life cycle stage and category of the conditions of use of
DBP.
949
950 3.1.1.2 Description of DBP Use for Each OES
951 After EPA characterized the OESs for the occupational exposure assessment of DBP, the occupational
952 uses of DBP for all OESs were summarized. Brief summaries of the uses of DBP for all OESs are
953 presented in Table 3-3.
954
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956
957
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Table 3-3. Description of the Function of DBP for Each PES
OES
Role/Function of DBP
Manufacturing
DBP is typically produced through the esteriflcation of the
carboxyl groups phthalic anhydride with n-butyl alcohol in the
presence of sulfuric acid as a catalyst.
Import and repackaging
DBP is imported domestically for use and/or may be repackaged
before shipment to formulation sites.
Incorporation into formulation, mixture, or
reaction product
DBP is used primarily as a plasticizer in the formulation of paints
and coatings. DBP is also incorporated into other products such as
adhesives, sealants, inks, toners, and colorant products.
PVC plastics compounding
DBP is used in PVC plastics to increase flexibility.
PVC plastics converting
DBP is used in PVC plastics to increase flexibility.
Non-PVC materials compounding and
converting
DBP is used in non-PVC polymers, such as resins, and as an
intermediate in rubber product manufacturing.
Application of adhesives and sealants
DBP is used as an additive in adhesives and sealants for industrial
and commercial use.
Application of paints and coatings
DBP is used in paint and coating products for industrial and
commercial use.
Industrial process solvent use
DBP is used as a solvent for industrial use, primarily for the
formulation of maleic anhydride.
Use of laboratory chemicals
DBP is a laboratory chemical used for laboratory analyses in
liquid and solid forms.
Use of lubricants and functional fluids
DBP is used as a functional fluid for processes in printing and
related support activities and is also used as a lubricant such as
textile fiber lubricant in industrial processes.
Use of penetrants and inspection fluids
DBP is used in inspection penetrant kits for commercial use.
Fabrication of final product from articles
DBP is found in a wide array of different final articles not found
in other OES including building and construction materials,
flooring materials, furniture, and furnishings.
Recycling
Some PVC plastics that contain DBP may be recycled either in-
house or at PVC recycling facilities to manufacture new PVC
material.
Waste handling, treatment, and disposal
Upon fabrication or use of DBP-containing products, residual
chemicals are disposed and released to air, wastewater, or
disposal facilities.
Distribution in commerce
Distribution in commerce consists of the transportation associated
with the moving of DBP-containing products and/or articles
between sites manufacturing, processing, and use COUs, or the
transportation of DBP containing wastes to recycling sites or for
final disposal.
3.1.2 Estimating the Number of Release Days per Year for Facilities in Each OES
The number of release days associated with the releases is included in the release tables for different
OES in section 3 of the Draft Environmental Release and Occupational Exposure Assessment for
DibutylPhthalate (DBP) (U.S. EPA. 2025q). Unless EPA identified conflicting information, EPA
assumed that the number of release days per year for a given release source equals the number of
operating days at the facility. EPA used information from National Emissions Inventory (NEI), generic
scenarios (GSs), emission scenario documents (ESDs), and other literature sources obtained through
systematic review to assess the number of operating days for releases. When monte carlo modeling was
performed to estimate releases, a discrete value or a range of input for the number of release days was
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965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
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input to the monte carlo simulation. The model generated the 50th and 95th percentiles of operating days
which was associated with the central tendency and high-end estimates of releases respectively. The
number of release days used in the assessment is expected to be reasonable since EPA used information
directly reported by facilities or information from sources which through EPA's systematic review
process.
3.1.3 Daily Release Estimation
For each OES, EPA estimated releases to each media of release using Toxics Release Inventory (TRI)
data (2017-2022), Discharge Monitoring Report (DMR) data (2017-2022), and NEI data (2017-2020)
or modeling as shown in Figure 3-1. Where available, EPA used NEI, GSs, or ESDs to estimate number
of release days, which EPA used to convert between annual release estimates and daily release
estimates. EPA used 2020 CDR, TRI, DMR, NEI, and Monte Carlo modeling data to estimate the
number of sites using DBP within an OES. The Draft Environmental Release and Occupational
Exposure Assessment for Dibutyl Phthalate (DBP) (U.S. EPA. 2025q) describes EPA's approach and
methodology for estimating daily releases and provides detailed facility level results for each OES.
For each OES, EPA estimated DBP releases per facility to each release media applicable to that OES.
For DBP, EPA assessed releases to water, air, or land (i.e., disposal to land).
Figure 3-1. Overview of EPA's Approach to Estimate Daily Releases for Each OES
TRI = Toxics Release Inventory; DMR = Discharge Monitoring Report; NEI = National Emissions Inventory;
CDR = Chemical Data Reporting; ESD = Emission Scenario Document; GS = Generic Scenario
3.1.4 Consumer Down-the-Drain and Landfills
EPA evaluated down-the-drain releases of DBP for consumer COUs qualitatively. Although EPA
acknowledges that there may be DBP releases to the environment via the cleaning and disposal of
adhesives, sealants, paints, coatings, cleaners, waxes, and polishes, the Agency did not quantitatively
assess down-the-drain and disposal scenarios of consumer products due to limited information from
monitoring data or modeling tools. EPA instead conducted a qualitative screening level assessment
using physical and chemical properties. See the Draft Consumer and Indoor Dust Exposure Assessment
for Dibutyl Phthalate (DBP) (U.S. EPA. 2025c) for further details.
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995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
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Adhesives, sealants, paints, coatings, cleaners, waxes, and polishes can be disposed down-the-drain
while users wash their hands, brushes, sponges, and other product applying tools. In addition, these
products can be disposed of when users no longer have use for them or have reached the product shelf
life and taken to landfills. All other solid products and articles listed in Table 4-5 of the Draft Consumer
and Indoor Dust Exposure Assessment for Dibutyl Phthalate (DBP) ( 2025c) can be removed
and disposed in landfills, or other waste handling locations that properly manage the disposal of
products like adhesives, sealants, paints, lacquers, and coatings. Section 3.2 in th e Draft Environmental
Media and General Population and Environmental Exposure for Dibutyl Phthalate (DBP) (U.S. EPA.
2025p) summarizes DBP monitoring data identified for landfills. Briefly, no studies were identified
which reported the concentration of DBP in landfills or in the surrounding areas in the U.S., but DBP
was identified in sludge in wastewater plants in China, Canada, and the U.S. DBP is expected to have a
high affinity to particulate (log Koc = 3.14-3.94) and organic media (log Kow = 4.5), which would limit
leaching to groundwater. Because of its high hydrophobicity and high affinity for soil sorption, it is
unlikely that DBP will migrate from landfills via groundwater infiltration.
3.2 Summary of Environmental Releases
3.2.1 Manufacturing, Processing, Industrial and Commercial
EPA combined its estimates for annual releases, release days, number of facilities, and hours of release
per day to estimate a range of daily releases for each OES. Table 3-4 presents a summary of these ranges
across facilities. See the Draft Environmental Release and Occupational Exposure Assessment for
Dibutyl Phthalate (DBP) (U.S. EPA. 2025q) for additional detail on deriving the overall confidence
score for each OES. EPA was not able to estimate site-specific releases for the final use of products or
articles OES. Disposal sites handling post-consumer, end-use DBP were not quantifiable due to the wide
and dispersed use of DBP in PVC and other products. Pre-consumer waste handling, treatment, and
disposal are assumed to be captured in upstream OES.
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1019 Table 3-4. Summary of EPA's Annual and Daily Release Estimates for Each PES
OES
Tvpc of Discharge," Air
Emission/' or Transfer
for Disposal'
Estimated Annual
Release
(kg/site-vear)''
Estimated Daily Release
(kg/site-dav)''
Number of
Facilities'
Source(s)
Central
Tendency4'
High-End
Central
Tendency4'
High-End
Manufacturing
Stack air
0.24
0.24
7.8E-04
7.8E-04
1-Dystar LP,
Reidsville, NC
CDR, peer-reviewed literature
(GS/ESD)
Fugitive air
9.9E-04
1.7E-03
3.3E-06
5.5E-06
Wastewater, incineration,
or landfill
558
585
1.9
2.0
Stack air
3.0
5.7
1.0E-02
1.9E-02
4
Environmental release modeling
Fugitive air
7.8E-04
1.6E-03
2.6E-06
5.4E-06
Wastewater, incineration,
or landfill
6,942
1.3E04
23
43
Import and
repackaging
Stack air
0
0
0
0
4
NEI
Stack air
0
227
0
0.87
10
TRI
Fugitive air
35
113
9.5E-02
0.31
4
NEI
Fugitive air
0
227
0
0.87
10
TRI
Wastewater
227
227
0.87
0.87
5
TRI/DMR
Land
5,994
3.7E04
16
103
2
TRI
Incorporation into
mixture,
formulation, or
reaction product
Stack air
0
8.4
0
3.4E-02
32
NEI
Stack air
0
311
0
1.2
18
TRI
Fugitive air
4.6
51
1.1E-02
0.18
32
NEI
Fugitive air
0
238
0
0.95
18
TRI
Wastewater
227
227
0.91
0.91
11
TRI/DMR
Land
510
1.0E04
2.0
40
3
TRI
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OES
Tvpc of Discharge," Air
Emission/' or Transfer
for Disposal'
Estimated Annual
Release
(kg/site-vear)''
Estimated Daily Release
(kg/site-dav)''
Number of
Facilities'
Source(s)
Central
Tendency4'
High-End
Central
Tendency4'
High-End
PVC plastic
compounding
Stack air
N/A
N/A
N/A
N/A
1
NEI (one site provided fugitive
air emissions but stated that stack
air releases were not applicable)
Stack air
10
13
4.2E-02
8.0E-02
1
TRI
Fugitive air
6.7
6.7
1.9E-02
1.9E-02
1
NEI
Fugitive air
1.4
1.4
5.5E-03
5.5E-03
1
TRI
Wastewater
0.28
43
1.1E-03
0.12
14
DMR
Land
2.7
566
9.5E-03
2.0
3
Surrogate data - Non-PVC
material manufacturing
PVC plastics
converting
Stack air
53
58
0.21
0.23
7
NEI
Stack air
0
0
0
0
1
TRI
Fugitive air
3.5E-02
1.8
6.8E-05
6.6E-03
7
NEI
Fugitive air
0.45
0.45
1.8E-03
1.8E-03
1
TRI
Wastewater
0.28
43
1.1E-03
0.12
14
Surrogate data - PVC plastics
compounding.
Land
2.7
566
9.5E-03
2.0
3
Surrogate data - Non-PVC
material manufacturing
Non-PVC
material
manufacturing
(compounding
and converting)
Stack air
9.0E-02
177
7.8E-05
0.61
49
NEI
Stack air
4.3
34
1.7E-02
0.26
4
TRI
Fugitive air
1.4
117
5.2E-03
0.44
49
NEI
Fugitive air
0.24
59
9.5E-04
0.45
4
TRI
Wastewater
4.5E-03
4.5E-03
1.8E-05
1.8E-05
1
TRI
Land
2.7
566
9.5E-03
2.0
3
TRI
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OES
Tvpc of Discharge," Air
Emission/' or Transfer
for Disposal'
Estimated Annual
Release
(kg/site-vear)''
Estimated Daily Release
(kg/site-dav)''
Number of
Facilities'
Source(s)
Central
Tendency4'
High-End
Central
Tendency4'
High-End
Application of
adhesives and
sealants''
Stack air
4.4E-06
99
1.7E-08
0.39
164
NEI
Stack air
0
0
0
0
1
TRI
Fugitive air
1.2
97
4.9E-03
0.39
164
NEI
Fugitive air
0
0
0
0
1
TRI
Incineration or landfill
291
1,357
1.4
7.1
94-973
generic sites
Modeled environmental release
Wastewater, incineration,
or landfill
209
860
0.97
4.5
Application of
paints and
coatings (no
spray control)''
Stack air
4.4E-06
99
1.7E-08
0.39
164
NEI
Stack air
0
0
0
0
1
TRI
Fugitive air
1.2
97
4.9E-03
0.39
164
NEI
Fugitive air
0
0
0
0
1
TRI
Wastewater
0
0
0
0
219-2,624
generic sites
Modeled environmental release
Incineration or landfill
92
368
0.36
1.4
Wastewater, incineration or
landfill
72
206
0.28
0.80
Unknown (air, wastewater,
incineration, or landfill)
1,957
8,655
7.6
34
Application of
paints and
coatings (spray
control) h
Stack air
4.4E-06
99
1.7E-08
0.39
164
NEI
Stack air
0
0
0
0
1
TRI
Fugitive air
1.2
97
4.9E-03
0.39
164
NEI
Fugitive air
0
0
0
0
1
TRI
Wastewater
0
0
0
0
219-2,660
generic sites
Modeled environmental release
Incineration or landfill
1,858
8,170
7.2
32
Wastewater, incineration or
landfill
72
206
0.28
0.80
Unknown (air, wastewater,
incineration, or landfill)
0
0
0
0
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OES
Tvpc of Discharge," Air
Emission/' or Transfer
for Disposal'
Estimated Annual
Release
(kg/site-vear)''
Estimated Daily Release
(kg/site-dav)''
Number of
Facilities'
Source(s)
Central
Tendency4'
High-End
Central
Tendency4'
High-End
Industrial process
solvent use
Stack air
96
192
0.38
0.77
2
NEI
Stack air
74
122
0.66
1.1
1
TRI
Fugitive air
181
182
0.72
0.73
2
NEI
Fugitive air
180
180
0.72
1.6
1
TRI
Wastewater
No data identified for this OES; EPA assumed no releases
to water for this use
N/A
N/A
Land
510
1.0E04
2.0
40
3
Surrogate data - Incorporation
into formulation, mixture, or
reaction product.
Use of laboratory
chemicals (liquid)
Fugitive air
1.4
2.7
3.8E-03
7.5E-03
2
NEI
Stack air
N/A
N/A
N/A
N/A
2
NEI
Wastewater, incineration,
or landfill
17
80
4.8E-02
0.22
5,587-36,873
generic sites
Modeled environmental release
Use of laboratory
chemicals (solid)
Fugitive air
1.4
2.7
3.8E-03
7.5E-03
2
NEI
Stack air
N/A
N/A
N/A
N/A
2
NEI
Wastewater, incineration,
or landfill
4.3
19
1.2E-02
5.2E-02
31,477-36,873
generic sites
Modeled environmental release
Unknown (air, wastewater,
incineration, or landfill)
1.5E-02
0.11
4.0E-05
2.9E-04
Incineration or landfill
1.9E-02
0.13
5.3E-05
3.5E-04
Use of lubricants
and functional
fluids
Landfill
6.4
35
3.0
13
3,337-39,808
generic sites
Modeled environmental release
Wastewater
15
74
6.8
26
Recycling
0.22
1.7
0.11
0.62
Fuel blending
(incineration)
5.0
37
2.3
14
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OES
Type of Discharge," Air
Emission,6 or Transfer
Estimated Annual
Release
(kg/site-year)d
Estimated Daily Release
(kg/site-day)e
Number of
Facilities^
Source(s)
for Disposal"
Central
Tendency®
High-End
Central
Tendency®
High-End
Use of penetrants
Fugitive air
1.6E-05
3.0E-05
6.4E-08
1.2E-07
and inspection
fluids (non-
Wastewater, incineration,
or landfill
6.7
8.7
2.7E-02
3.5E-02
14,538-20,770
generic sites
aerosol)
Modeled environmental release
Use of penetrants
Fugitive air
0.99
1.3
4.0E-03
5.2E-03
14,541-20,767
generic sites
and inspection
fluids (aerosol)
Wastewater, incineration,
or landfill
5.7
7.4
2.3E-02
3.0E-02
Fabrication and
final use of
No data was available to estimate releases for this OES and there were no suitable surrogate release data or models. This release is
products or
articles
described qualitatively.
Stack air
9.0E-02
177
7.8E-05
0.61
49
Stack air
4.3
34
1.7E-02
0.26
4
Surrogate data - Non-PVC
material manufacturing
Fugitive air
1.4
117
5.2E-03
0.44
49
Recycling
Fugitive air
0.24
59
9.5E-04
0.45
4
Wastewater
0.28
43
1.1E-03
0.12
14
Surrogate data - PVC plastics
compounding
Land
2.7
566
9.5E-03
2.0
3
Surrogate data - Non-PVC
material manufacturing
Stack air
0
105
0
0.37
147
NEI
Waste handling,
treatment, and
disposal
Stack air
0
190
0
1.5
20
TRI
Fugitive air
6.4E-05
19
2.0E-07
5.8E-02
147
NEI
Fugitive air
0
2.8
0
2.2E-02
20
TRI
Wastewater
1.1
78
3.9E-03
0.27
70
TRI/DMR
Land
4,762
7.1E04
17
247
12
TRI
11 Direct discharge to surface water; indirect discharge to non-POTW; indirect discharge to POTW
b Emissions via fugitive air; stack air; or treatment via incineration
c Transfer to surface impoundment, land application, or landfills
d For modeled results, the presented central tendency and high-end are the 50th and 95th percentile values of the modeled distribution. For programmatic data,
the presented central tendency is calculated from the median reported release amounts and high-end from the reported maximum release amounts. The specific
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OES
Tvpc of Discharge," Air
Emission/' or Transfer
for Disposal'
Estimated Annual
Release
(kg/site-vear)''
Estimated Daily Release
(kg/site-dav)''
Central
Tendency4'
High-End
Central
Tendency4'
High-End
Number of
Facilities'
Source(s)
central tendency and high-end values presented depends on the number of sites with programmatic data. For databases with six or more reporting facilities,
EPA estimated central tendency and high-end releases using the 50th and 95th percentile values, respectively. For three to five facilities, EPA estimated the
central tendency and high-end releases using the 50th percentile and maximum values, respectively. For two sites, EPA presented the midpoint and the
maximum value. Finally, EPA presented sites with only one data point as-is from the programmatic database.
'' Where available, EPA used peer-reviewed literature (e.g., GSs or ESDs to provide a basis to estimate the number of release days of dibutyl phthalate within a
COU).
' Where available, EPA used the 2020 CDR (US. EPA. 2020b). NEI (US. EPA. 2023a). DMR (US. EPA. 2024a). and TRI databases (US. EPA. 20240).
2020 U.S. County Business Practices (US. Census Bureau. 2022). and Monte Carlo models to estimate the number of sites that use DBP for each condition of
use. Some modeled OES calculated the number of facilities/sites, presented as 50th and 95th percentiles. Other modeled OES set the number of facilities
deterministically, presented as one value.
g The central tendency values for NEI air were calculated using the median of the reported releases at each site.
h Data for the Application of adhesives and sealants OES and Application of paints and coatings OES were assessed together as the release estimate details
provided by the database sources were insufficient to characterize between the two OESs. Data presented are expected to be representative for both OESs.
1020
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1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
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3.2.2 Weight of Scientific Evidence Conclusions for Environmental Releases from
Industrial and Commercial Sources
For each OES, EPA considered the assessment approach, the quality of the data and models, and the
uncertainties in the assessment results to determine a level of confidence for the environmental release
estimates. Table 3-5 provides EPA's weight of scientific evidence rating for each OES.
EPA integrated numerous evidence streams across systematic review sources to develop environmental
release estimates for DBP. The Agency made a judgment on the weight of scientific evidence supporting
the release estimates based on the strengths, limitations, and uncertainties associated with the release
estimates. EPA described this judgment using the following confidence descriptors: robust, moderate,
slight, or indeterminate.
In determining the strength of the overall weight of scientific evidence, EPA considered factors that
increase or decrease the strength of the evidence supporting the release estimate (whether measured or
estimated), including quality of the data/information, relevance of the data to the release scenario
(including considerations of temporal and spatial relevance), and the use of surrogate data when
appropriate. In general, higher rated studies (as determined through data evaluation) increase the weight
of scientific evidence when compared to lower rated studies, and EPA gave preference to chemical- and
scenario-specific data over surrogate data (e.g., data from a similar chemical or scenario). For example,
a conclusion of moderate weight of scientific evidence 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 weight of scientific evidence is
appropriate where there is limited information that does not sufficiently cover all sites within the COU,
and the assumptions and uncertainties are not fully known or documented. See EPA's Draft Systematic
Review Protocol Supporting TSCA Risk Evaluations for Chemical Substances, Version 1.0: A Generic
TSCA Systematic Review Protocol with Chemical-Specific Methodologies (also called the "Draft
Systematic Review Protocol") (U.S. EPA. 2021a) for additional information on weight of scientific
evidence conclusions.
Table 3-5 summarizes EPA's overall weight of scientific evidence conclusions for its release estimates
for each OES. NEI obtained a high data quality rating and TRI and DMR obtained a medium quality
rating from EPA's systematic review process. In general, modeled data had data quality ratings of
medium. As a result, for releases that used GSs/ESDs, the weight of scientific conclusion was moderate
when used in tandem with Monte Carlo modeling.
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1055 Table 3-5. Summary of Overall Confidence in Environmental Release Estimates by PES
OES
Weight of Scientific Evidence Conclusion in Release Estimates
Manufacturing
EPA found limited chemical specific data for the Manufacturing OES and assessed environmental releases using models and model
parameters derived from CDR. the 2023 Methodoloav for Estimating Environmental Releases from Sampling Wastes ("U.S. EPA.
2023f). and sources identified through svstematic review (including surrogate—DINP and DIDP—industr\-supplied data). EPA used
EPA/OPPT models combined with Monte Carlo modeling to estimate releases to the environment, with media of release assessed
using appropriate default input parameters from EPA/OPPT models and industry-supplied data. EPA believes a strength of the Monte
Carlo modeling approach is that variation in model input values allow for estimation of a range of potential release values that are
more likely to capture actual releases than a discrete value. Additionally, Monte Carlo modeling uses a large number of data points
(simulation runs) and considers the full distributions of input parameters. EPA used facility-specific DBP manufacturing volumes for
all facilities that reported this information to CDR. For facilities that did not report DBP manufacturing volumes to CDR, operating
parameters were derived using data from a current U.S. manufacturing site for DIDP and DINP that is assumed to operate using
similar operating parameters as DBP manufacturing. This information was used to provide more accurate estimates than the generic
values provided by the EPA/OPPT models. These strengths increase the weight of evidence.
The primary limitation of EPA's approach is the uncertainty in the representativeness of release estimates toward the true distribution
of potential releases. In addition, 1 DBP manufacturing site and 2 manufacturing and/or import sites claimed their DBP production
volume as CBI for the purpose of CDR reporting; therefore, DBP throughput estimates for these sites are based on the national
aggregate PV and reported import volumes from other sites. Additional limitations include uncertainties in the representativeness of
the surrogate industry-provided operating parameters from DIDP and DINP and the generic EPA/OPPT models used to calculate
environmental releases for DBP manufacturing sites. These limitations decrease the weight of evidence.
As discussed above, the strength of the analysis includes using Monte Carlo modeling, which can use a range as an input, increases
confidence in the analysis. However, several uncertainties discussed above, such as using surrogate parameters, reduced the
confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate,
considering the strengths and limitations of the reasonably available data.
Import and
repackaging
Air releases are assessed using reported releases from 2017-2022 TRI (U.S. EPA, 2024o). and 2017 and 2020 NEI (U.S. EPA, 2023a.
2019e). 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. The air releases assessment is based on 10 reporting sites in NEI and 4
reporting sites in TRI. Based on the NAICS and SIC codes used to map data from the reporting databases (CDR, DMR, etc.), there
may be 14 additional repackaging sites that we do not have reported releases for this media in this assessment.
Land releases are assessed using reported releases from 2017-2022 TRI. The primary limitation is that the land releases assessment is
based on 2 reporting sites (2 sites only reported air releases), and EPA did not have additional sources to estimate land releases from
this OES. Based on the NAICS and SIC codes used to map data from the reporting databases (CDR, DMR, NEI, etc.), there may be
26 additional repackaging sites that do not have reported releases for this media in this assessment.
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OES
Weight of Scientific Evidence Conclusion in Release Estimates
Water releases are assessed using reported releases from 2017-2022 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 1 reporting site under DMR and 4 reporting sites in TRI (2 sites only reported air releases), and EPA did not have
additional sources to estimate water releases from this OES. Based on the NAICS and SIC codes used to map data from the reporting
databases (CDR, NEI, etc.), there may be 23 additional repackaging sites that do not have reported releases for this media in this
assessment.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering the strengths
and limitations of reasonably available data.
Incorporation into
formulations,
mixtures, or
reaction products
Air releases are assessed using reported releases from 2017-2022 TRI ("U.S. EPA. 2024o). and 2017 and 2020 NEI ("U.S. EPA. 2023a.
2019e). The primarv strength of TRI data is that TRI compiles the data reported directlv bv facilities that manufacture, process, and/or
use DBP. 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. The air releases assessment is based on 32 reporting sites under NEI and
18 reporting sites in TRI (2 sites reported under both TRI and NEI). Based on the NAICS and SIC codes used to map data from the
reporting databases (CDR, DMR, etc.), there may be 2 additional incorporation into formulation, mixture, or reaction product sites
that do not have reported releases for this media in this assessment. The relatively large number of reporting sites is a strength for
these release estimates as they add variability to the assessment and as a result are more likely to be representative of the industry as a
whole.
Land releases are assessed using reported releases from 2017-2022 TRI. The primary limitation is that the land releases assessment is
based on three reporting sites, and EPA did not have additional sources to estimate land releases from this OES. Based on the NAICS
and SIC codes used to map data from the reporting databases (CDR, DMR, NEI, etc.), there may be 47 additional incorporation into
formulation, mixture, or reaction product sites that do not have reported releases for this media in this assessment.
Water releases are assessed using reported releases from 2017-2022 TRI. Factors that decrease the overall confidence for this OES
include the uncertainty in the accuracy of reported releases, the limitations in representativeness to all sites because TRI may not
capture all relevant sites, and EPA did not have additional sources to estimate water releases from this OES. The water releases
assessment is based on 11 reporting sites in TRI. Based on the NAICS and SIC codes used to map data from the reporting databases
(CDR, NEI, etc.), there may be 39 additional incorporation into formulation, mixture, or reaction product sites that do not have
reported releases for this media in this assessment.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
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OES
Weight of Scientific Evidence Conclusion in Release Estimates
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering the strengths
and limitations of reasonably available data.
PVC plastics
compounding
Air releases are assessed using reported releases from 2017-2022 TRI (U.S. EPA, 2024o). and 2017 and 2020 NEI (U.S. EPA, 2023a.
2019e). The primarv strength of TRI data is that TRI compiles the data reported directlv bv facilities that manufacture, process, and/or
use DBP. 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. The air releases assessment is based on 1 reporting site under NEI and 1
reporting site in TRI. Based on the NAICS and SIC codes used to map data from the reporting databases (CDR, DMR, etc.), there
may be 15 additional PVC plastics compounding sites that do not have reported releases for this media in this assessment.
TRI reporters identified for this OES reported 0 releases for land; however, it is uncertain if that is representative for PVC
compounding sites as a whole. Because of this, EPA assessed land releases using surrogate data from sites that were identified under
the OES for non-PVC materials manufacturing. Releases were estimated using reported releases from 2017-2022 TRI. The primary
limitation is that the land releases assessment is based on 3 reporting sites, and EPA did not have additional sources to estimate land
releases from this OES.
Water releases are assessed using reported releases from to DMR (U.S. EPA, 2024a). The primarv strength of DMR data is that it mav
capture additional sources that are not included in TRI due to reporting thresholds. A factor that decreases the overall confidence for
this OES include the uncertainty in the accuracy of reported releases. The water releases assessment is based on 14 reporting sites.
Based on the NAICS and SIC codes used to map data from the reporting databases (CDR, NEI, etc.), there may be 3 PVC plastics
compounding sites that do not have reported releases for this media in this assessment.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering the strengths
and limitations of reasonably available data.
PVC plastics
converting
Air releases are assessed using reported releases from 2017-2022 TRI (U.S. EPA, 2024o). and 2017 and 2020 NEI (U.S. EPA, 2023a.
2019e). The primarv strength of TRI data is that TRI compiles the data reported directlv bv facilities that manufacture, process, and/or
use DBP. 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. The air releases assessment is based on 7 reporting sites under NEI and 1
reporting site in TRI. Based on the NAICS and SIC codes used to map data from the reporting databases (CDR, DMR, etc.), there
may be 2 additional PVC plastics converting sites that do not have reported releases for this media in this assessment.
EPA did not identify land release data from TRI reporters for this OES. These releases were assessed using surrogate data from sites
that were identified under the OES for non-PVC materials manufacturing due to expected similarities in the processes that occur at the
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OES
Weight of Scientific Evidence Conclusion in Release Estimates
sites. Releases were estimated using reported releases from 2017-2022 TRI. The primary limitation is that the land releases
assessment is based on 3 reporting sites, and EPA did not have additional sources to estimate land releases from this OES.
EPA did not identify water release data from TRI and DMR reporters for this OES. These releases are assessed using surrogate data
from sites that were identified under the OES for PVC plastics compounding due to expected similarities in the processes that occur at
the sites. Water releases are assessed using reported releases from to DMR (U.S. EPA, 2024a). The primarv strength of DMR data is
that it may capture additional sources that are not included in TRI due to reporting thresholds. A factor that decreases the overall
confidence for this OES include the uncertainty in the accuracy of reported releases. The water releases assessment is based on 14
reporting sites.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering the strengths
and limitations of reasonably available data.
Non-PVC material
manufacturing
Air releases are assessed using reported releases from 2017-2022 TRI ("U.S. EPA. 2024o). and 2017 and 2020 NEI ("U.S. EPA. 2023a.
2019e). 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. The air releases assessment is based on 49 reporting sites under NEI and
4 reporting sites in TRI (one site reported under both TRI and NEI). The relatively large number of reporting sites is a strength for
these release estimates as they add variability to the assessment and as a result are more likely to be representative of the industry as a
whole.
Land releases are assessed using reported releases from 2017-2022 TRI. The primary limitation is that the land releases assessment is
based on 3 reporting sites, and EPA did not have additional sources to estimate land releases from this OES. Based on the NAICS and
SIC codes used to map data from the reporting databases (CDR, DMR, NEI, etc.), there may be 49 additional non PVC-material
manufacturing sites that do not have reported releases for this media in this assessment.
Water releases are assessed using reported releases from 2017-2022 TRI. The primary strength of TRI data is that TRI compiles the
best readily available release data for all reporting facilities. Factors that decrease the overall confidence for this OES include the
uncertainty in the accuracy of reported releases, the limitations in representativeness to all sites because TRI may not capture all
relevant sites, and EPA did not have additional sources to estimate water releases from this OES. The water releases assessment is
based on 1 reporting site in TRI. Based on the NAICS and SIC codes used to map data from the reporting databases (CDR, NEI, etc.),
there may be 51 additional sites that do not have reported releases for this media in this assessment.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
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OES
Weight of Scientific Evidence Conclusion in Release Estimates
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering the strengths
and limitations of reasonably available data.
Application of
adhesives and
sealants
Air releases are assessed usine reported releases from 2017 and 2020 NEI (U.S. EPA, 2023a. 2019e). NEI captures additional sources
that are not included in TRI due to reporting thresholds. Another factor that increases the strength of the data is that air release data
was provided by 166 reporting sites, which adds variability to the assessment. Factors that decrease the overall confidence for this
OES include the uncertainty in the accuracy of reported releases, the fact that the type of end-use product is uncertain between
adhesives/sealants and paint/coatings, and the limitations in representativeness to all sites because NEI may not capture all relevant
sites.
EPA was unable to identify chemical and site-specific releases to land and water and assessed these releases using the ESD on the Use
of Adhesives (OECD. 2015). EPA used EPA/O PPT models combined with Monte Carlo modeling to estimate releases to the
environment and media of release using appropriate default input parameters from the ESD and EPA/OPPT models. The Agency
believes a strength of the Monte Carlo modeling approach is that variation in model input values allow for estimation of a range of
potential release values that are more likely to capture actual releases than a discrete value. Monte Carlo modeling also considers a
large number of data points (simulation runs) and the full distributions of input parameters. Additionally, EPA used DBP-specific data
on concentration and application methods for different DBP-containing adhesives and sealant products in the analysis. These data
provide more accurate estimates than the generic values provided by the ESD. These strengths increase the weight of evidence.
The primary limitation of EPA's approach to land and water releases is the uncertainty in the representativeness of estimated release
values toward the true distribution of potential releases at all sites in this OES. Specifically, the generic default values in the ESD may
not represent releases from real-world sites that incorporate DBP into adhesives and sealants. Based on the number of formulated
products identified, the overall production volume of DBP for this OES was estimated by assuming that the portion of DBP with
uncertain end-use will be split between adhesives/sealants and paint/coating products. EPA lacks data on DBP-specific facility use
volume and number of use sites; therefore, the Agency based facility throughput estimates and number of sites on industry-specific
default facility throughputs from the ESD, DBP product concentrations, and the overall production volume range from CDR data
which has a reporting threshold of 25,000 lb. These limitations decrease the weight of evidence.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering the strengths
and limitations of reasonably available data.
Application of
paints and
coatings
Air releases are assessed using reported releases from 2017 and 2020 NEI (U.S. EPA. 2023a. 2019eV NEI captures additional sources
that are not included in TRI due to reporting thresholds. Another factor that increases the strength of the data is that air release data
was provided by 166 reporting sites, which adds variability to the assessment. Factors that decrease the overall confidence for this
OES include the uncertainty in the accuracy of reported releases, the fact that the type of end-use product is uncertain between
adhesives/sealants and paint/coatings, and the limitations in representativeness to all sites because NEI may not capture all relevant
sites.
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OES
Weight of Scientific Evidence Conclusion in Release Estimates
EPA was unable to identify chemical and site-specific releases to land and water and assessed these releases using the ESD on the
Application of Radiation Curable Coatings, Inks and Adhesives and the GS on Coating Application via Spray Painting in the
Automotive Refinishina Industry (OECD. 2011a. M. EPA used EPA/OPPT models combined with Monte Carlo modeling to estimate
releases to the environment. EPA assessed media of release using appropriate default input parameters from the ESD, GS, and
EPA/OPPT models and a default assumption that all paints and coatings are applied via spray application. EPA believes a strength of
the Monte Carlo modeling approach is that variation in model input values allow for estimation of a range of potential release values
that are more likely to capture actual releases than a discrete value. Monte Carlo modeling also considers a large number of data
points (simulation runs) and the full distributions of input parameters. Additionally, EPA used DBP-specific data on concentration for
different DBP-containing paints and coatings in the analysis. These data provide more accurate estimates than the generic values
provided by the GS and ESD. These strengths increase the weight of evidence.
The primary limitation of EPA's approach to land and water releases is the uncertainty in the representativeness of estimated release
values toward the true distribution of potential releases at all sites in this OES. Specifically, the generic default values in the GS and
ESD may not represent releases from real-world sites that incorporate DBP into paints and coatings. Additionally, EPA assumes spray
applications of the coatings, which may not be representative of other coating application methods. In addition, the Agency lacks data
on DBP-specific facility use volume and number of use sites; therefore, EPA based throughput estimates on values from ESD, GS,
and CDR data which has a reporting threshold of 25,000 lb and an annual DBP production volume range. Finally, EPA estimated the
overall production volume of DBP for this OES by assuming that the portion of DBP with uncertain end-use will be split between
adhesives/sealants and paint/coating products. These limitations decrease the weight of evidence.
As discussed above, the strength of the analysis includes using industry reported release data to NEI and using Monte Carlo modeling
that can use range as an input. However, several uncertainties discussed above, such as the unavailability of reported releases for land
and water, slightly reduced the confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this
assessment is moderate to robust, considering of the strengths and limitations of reasonably available data.
Industrial process
solvent use
Air releases are assessed using reported releases from 2017-2022 TRI ("U.S. EPA. 2024o). and 2017 and 2020 NEI ("U.S. EPA. 2023a.
2019e). 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. The air releases assessment is based on 2 reporting sites under NEI and 1
reporting site in TRI (site reported under both TRI and NEI). Based on the NAICS and SIC codes used to map data from the reporting
databases (CDR, DMR, etc.), there may be 1 additional industrial process solvent use site that is not accounted for in this assessment.
EPA was unable to identify land release data from TRI reporters for this OES. These releases were assessed using surrogate data from
sites that were identified under the OES for incorporation into formulation, mixtures, or reaction products due to expected similarities
in the processes that occur at the sites. Land releases were estimated using reported releases from 2017-2022 TRI. The primary
limitation is that the land releases assessment is based on 3 reporting sites, and EPA did not have additional sources to estimate land
releases from this OES.
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EPA was unable to identify water release data from TRI and DMR reporters for this OES; however, based on the specifics of DBP's
use in the process, the Agency does not expect water releases for this OES. This is based on process information provided by
Huntsman Corporation, which was rated hinh in svstematic review (Huntsman, 2015).
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources or using surrogate reported releases, slightly reduced
the confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to
robust, considering of the strengths and limitations of reasonably available data.
Use of laboratory
chemicals
Air releases are assessed usine reported releases from 2017 and 2020 NEI (U.S. EPA, 2023a. 2019e). NEI captures additional sources
that are not included in TRI due to reporting thresholds. NEI data was collected from 2 reporting sites. 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 NEI may not capture all relevant sites.
EPA were unable to identify chemical and site-specific releases to land and water and assessed these releases using the Draft GS on
the Use of laboratory chemicals (U.S. EPA. 2023h). EPA used EPA/OPPT models combined with Monte Carlo modeling to estimate
releases to the environment, and media of release using appropriate default input parameters from the GS and EPA/OPPT models for
solid and liquid DBP materials. EPA believes a strength of the Monte Carlo modeling approach is that variation in model input values
allow for estimation of a range of potential release values that are more likely to capture actual releases than a discrete value. Monte
Carlo modeling also considers a large number of data points (simulation runs) and the full distributions of input parameters. EPA used
SDSs from identified laboratory DBP products to inform product concentration and material states. These strengths increase the
weight of evidence.
EPA believes the primary limitation of the land and water release assessments to be the uncertainty in the representativeness of values
toward the true distribution of potential releases. In addition, the Agency lacks data on DBP-specific laboratory chemical throughput
and number of laboratories; therefore, EPA based the number of laboratories and throughput estimates on stock solution throughputs
from the Draft GS on the Use of Laboratory Chemicals and on CDR Reporting Thresholds. Additionally, because no entries in CDR
indicate a laboratory use and there were no other sources to estimate the volume of DBP used in this OES, EPA developed a high-end
bounding estimate based on the CDR reporting threshold of 25,000 lb or 5% of total product volume for a given use, which by
definition is expected to over-estimate the average release case. These limitations decrease the weight of evidence.
As discussed above, the strength of the analysis includes using industry reported release data to NEI and using Monte Carlo modeling
that can use range as an input. However, several uncertainties discussed above, such as the unavailability of reported releases for land
and water, slightly reduced the confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this
assessment is moderate to robust, considering of the strengths and limitations of reasonably available data.
Use of lubricants
and functional
fluids
EPA found limited chemical-specific data for the Use of lubricants and functional fluids OES and assessed releases to the
environment using the ESD on the Lubricant and Lubricant Additives. EPA used EPA/OPPT models combined with Monte Carlo
modeling to estimate releases to the environment and media of release using appropriate default input parameters from the ESD and
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EPA/OPPT models. The Agency believes the strength of the Monte Carlo modeling approach is that variation in model input values
and a range of potential release values are more likely to capture actual releases than discrete values. Monte Carlo modeling also
considers a large number of data points (simulation runs) and the full distributions of input parameters. EPA did not identify a
lubricant or functional fluid product that contained DBP but identified 1 DINP-containing functional fluid for use in Monte Carlo
analysis for the risk evaluation for that chemical. Therefore, EPA used products containing DINP as surrogate for concentration and
use data in the analysis. This data provides more accurate estimates than the generic values provided by the ESD.
The primary limitation of EPA's approach is the uncertainty in the representativeness of estimated release values toward the true
distribution of potential releases at all sites in this OES. Specifically, the generic default values in the ESD may not represent releases
from real-world sites using DBP-containing lubricants and functional fluids. In addition, EPA lacks information on the specific
facility use rate of DBP-containing products and number of use sites; therefore, EPA estimated the number of sites and throughputs
based on CDR, which has a reporting threshold of 25,000 lb (i.e., not all potential sites represented), and an annual DBP production
volume range that spans an order of magnitude. The respective share of DBP use for each OES presented in the EU Risk Assessment
Report may differ from actual conditions adding some uncertainty to estimated releases. Furthermore, EPA lacks chemical-specific
information on concentrations of DBP in lubricants and functional fluids and primarily relied on surrogate data. Actual concentrations
may differ adding some uncertainty to estimated releases.
As discussed above, the strength of the analysis includes using Monte Carlo modeling, which can use a range as an input, increases
confidence in the analysis. However, several uncertainties discussed above, such as the lack of availability of reported releases,
reduced the confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this assessment is
moderate, considering the strengths and limitations of the reasonably available data.
Use of penetrants
and inspection
fluids
EPA found limited chemical specific data for the Use of penetrants and inspection fluids OES and assessed releases to the
environment usine the ESD on the Use of Metalworkine Fluids (OECD, 201 lc). EPA used EPA/OPPT models combined with Monte
Carlo modeling to estimate releases to the environment, media of release using appropriate default input parameters from the ESD,
and EPA/OPPT models. The Agency believes the strength of the Monte Carlo modeling approach is that variation in model input
values and a range of potential release values are more likely to capture actual releases than discrete values. Monte Carlo modeling
also consider a large number of data points (simulation runs) and the full distributions of input parameters. EPA assessed an aerosol
and non-aerosol application method based on surrogate DINP-specific penetrant data that also provided DINP concentration. The
safety and product data sheets that EPA used to obtain these values provide more accurate estimates than the generic values provided
by the ESD.
The primary limitation of EPA's approach is the uncertainty in the representativeness of estimated release values toward the true
distribution of potential releases at all sites in this OES. Specifically, the generic default values in the ESD and the surrogate material
parameters may not be representative of releases from real-world sites that use DBP-containing inspection fluids and penetrants.
Additionally, because no entries in CDR indicate this OES use case and there were no other sources to estimate the volume of DBP
used in this OES, EPA developed a high-end bounding estimate based on CDR reporting threshold, which by definition is expected to
overestimate the average release case.
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Weight of Scientific Evidence Conclusion in Release Estimates
As discussed above, the strength of the analysis includes using Monte Carlo modeling, which can use a range as an input, increases
confidence in the analysis. However, several uncertainties discussed above, such as the lack of availability of reported releases,
reduced the confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this assessment is
moderate, considering the strengths and limitations of the reasonably available data.
Fabrication or use
of final product or
articles
No data were available to estimate releases for this OES and there were no suitable surrogate release data or models. This release is
described qualitatively.
Recycling
EPA found limited chemical specific data for the Recycling OES. EPA assessed releases to the environment from recycling activities
usine the Revised Draft GS for the Use of Additives in Plastic Compounding (U.S. EPA, 202le) as surrogate for the recvcline
process. EPA/OPPT models were combined with Monte Carlo modeling to estimate releases to the environment. EPA believes the
strength of the Monte Carlo modeling approach is that variation in model input values and a range of potential release values are more
likely to capture actual releases than discrete values. Monte Carlo modeling also considers a large number of data points (simulation
runs) and the full distributions of input parameters. EPA referenced the Quantification and evaluation of plastic waste in the United
States (Milbrandt et aL 2022). to estimate the rate of PVC recvclina in the United States. EPA estimated the DBP PVC market share
(based on the surrogate market shares from DINP and DIDP) to define an approximate recycling volume of PVC containing DBP.
These strengths increase the weight of evidence.
The primary limitation of EPA's approach is the uncertainty in the representativeness of estimated release values toward the true
distribution of potential releases at all sites in this OES. Specifically, the generic default values and release points in the GS represent
all types of plastic compounding sites and may not represent sites that recycle PVC products containing DBP. In addition, EPA lacks
DBP-specific PVC recycling rates and facility production volume data; therefore, EPA based throughput estimates on PVC plastics
compounding data and U.S. PVC recycling rates, which are not specific to DBP and may not accurately reflect current U.S. recycling
volume. DBP may also be present in non-PVC plastics that are recycled; however, EPA was unable to identify information on these
recycling practices. These limitations decrease the weight of evidence.
As discussed above, the strength of the analysis includes using Monte Carlo modeling, which can use a range as an input, increases
confidence in the analysis. However, several uncertainties discussed above, such as the lack of availability of reported releases,
reduced the confidence of the analysis. Therefore, EPA concluded that the weight of scientific evidence for this assessment is
moderate, considering the strengths and limitations of the reasonably available data.
Waste handling,
treatment, and
disposal
General Waste Handling, Treatment, and Disposal
Air releases for non-POTW sites are assessed using reported releases from 2017-2022 TRI, and 2017 and 2020 NEI. 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 147 sites under NEI and 20 sites in TRI (with 9 sites reporting under
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both NEI and TRI). Based on other reporting databases (CDR, DMR, etc), there are 12 additional non-POTW sites that do not have
reported releases for this media in this assessment.
Land releases for non-POTW are assessed using reported releases from 2017-2022 TRI. The primary limitation is that the land
releases assessment is based on 12 reporting sites, and EPA did not have additional sources to estimate land releases from this OES.
Based on the reporting databases (CDR, DMR, NEI, etc.), there are 214 additional waste handling, treatment, and disposal sites that
do not have reported releases for this media in this assessment.
Water releases for non-POTW sites are assessed using reported releases from 2017 to 2022 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 13 reporting sites under DMR and one reporting site in TRI, and EPA did
not have additional sources to estimate water releases from this OES. Based on other reporting databases (CDR, NEI, etc), there are
156 additional sites that do not have reported releases for this media in this assessment.
As discussed above, the strength of the analysis includes using industry reported release data to various EPA databases. However,
several uncertainties discussed above, such as not capturing all release sources, slightly reduced the confidence of the analysis.
Therefore, EPA concluded that the weight of scientific evidence for this assessment is moderate to robust, considering 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 2017-2022 DMR, which has a high overall
data quality determination from the systematic review process. A strength of using DMR data and the Pollutant Loading Tool used to
pull the DMR data 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. A total of 57 POTW/remediation sites reported
releases of DBP to DMR. Based on this information, for POTW releases, EPA has concluded that the weight of scientific evidence for
this assessment is moderate to robust, considering the strengths and limitations of reasonably available data.
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3.2.3 Strengths, Limitations, Assumptions, and Key Sources of Uncertainty for the
Environmental Release Assessment
Strengths
EPA compiled release information using reported releases from the 2017 through 2022 TRI (
21 ), 2017 through 2022 DMR ( >24a), and 2017 through 2020 NEI ( 3a,
2019e). NEI obtained a high data quality rating and TRI and DMR obtained a medium quality rating
from EPA's systematic review process. Furthermore, TRI-reporting facilities are required to submit their
"best available data" to EPA for TRI reporting purposes. Some facilities are required to measure or
monitor emission or other waste management quantities due to regulations unrelated to the TRI Program
(e.g., permitting requirements), or due to company policies. These existing, reasonably available data are
often used by facilities for TRI reporting purposes, as they represent the best available data (e.g., stack
releases can be directly measured by stack testing using EPA reference methods providing a directly
measured emission rate which can then be used to calculate annual emissions). DMR-reporting facilities
are required to monitor, measure, and report effluent at regular intervals, thus generating many site-
specific water release datapoints. Though NEI does not require stack testing or continuous emissions
monitoring and reporting agencies may use different emission estimation methods, reasonable estimates
may be obtained through mass-balance calculations, the use of emission factors, and engineering
calculations.
Limitations
Facilities are only 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 lb for manufacturers and processors and 10,000 lb for users). For
NEI, the Air Emissions Reporting Requirements (AERR) only requires Criteria Air Pollutants (CAP)
data reporting, Hazardous Air Pollutants (HAP) data reporting is voluntary. As a result, EPA augments
SLT-provided HAP data with other information to better estimate point, nonpoint, and mobile source
HAP emissions. For point sources, HAP augmentation is performed on each emissions source using the
WebFIRE database or data from TRI. DMR data are submitted by NPDES permit holders to states or
directly to the EPA according to the monitoring requirements of the facility's permit. States are only
required to load major discharger data into DMR and may or may not load minor discharger data. The
definition of major vs. minor discharger is set by each state and could be based on discharge volume or
facility size. Due to these limitations across programs, some sites may release DBP but are not included
in TRI, NEI, or DMR. It is uncertain, the extent to which, sites not captured in these databases release
DBP into the environment or whether releases from sites not in the databases are to water, air, or
landfill.
Manufacturers and importers of DBP submit CDR data to EPA if they meet reporting threshold
requirements. Sites are only required to report production data to CDR if their yearly production volume
exceeds 25,000 lb. Sites can claim their production volume as CBI, further limiting the production
volume information in CDR. As a result, some sites that produce or use DBP may not be included in the
CDR dataset and the total production volume for a given OES may be underestimated. The extent to
which sites that are not captured in the CDR release DBP into the environment is unknown. The media
of release for these sites is also unknown.
Assumptions and Uncertainties
There is some uncertainty in the DMR data pulled using the ECHO Pollutant Loading Tool Advanced
Search option. For facilities that reported having zero pollutant loads to DMR, the EZ Search Load
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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. 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.
When monitoring or direct measurement data are not reasonably available or are known to be non-
representative for TRI reporting purposes, the TRI regulations require that facilities determine release
and other waste management quantities of TRI-listed chemicals by making reasonable estimates.
There is additional uncertainty in daily release estimates for air emissions. Facilities reporting to TRI
report annual air emissions while NEI reports annual air emissions and the estimated number of release
days. To assess daily air emissions for TRI, EPA used relevant data from relevant ESDs or GSs to
estimate the expected number of release days.
CDR information on the downstream processing and use of DBP at facilities is also limited; therefore,
there is some uncertainty as to the production volume attributed to a given OES. For OES with limited
CDR data, EPA developed potential production volume ranges given reported CDR data, known
reporting thresholds, and the national aggregate production volume of 1,000,000 to 10,000,000 lb for
DBP in 2019. To handle an OES without programmatic data, EPA used the potential production volume
ranges as uniform distributions in Monte Carlo modeling when assessing releases for each OES. Due to
the wide range of potential production volumes attributable to certain OES, the overall releases may be
over or underestimated. DBP releases at each site may vary from day to day, such that on any given day
the actual daily release rate may be higher or lower than the estimated average daily release rate.
The EPA has further identified the following additional uncertainties that contribute to the overall
uncertainty in the environmental release assessment:
• Use of Census Bureau for Number of Facilities: In some cases, EPA estimated the maximum
number of facilities for a given OES using data from the U.S. Census. In such cases, the Agency
determined the maximum number of sites for use in Monte Carlo modeling from industry data
from the U.S. Census Bureau, County and Business Patterns dataset ( 2023).
• Uncertainties Associated with Facility Throughputs: EPA estimated facility throughputs of
DBP or DBP-containing products using various methods, including using generic industry data
presented in the relevant GS or ESD or by calculation based on estimated number of facilities
and overall production volume of DBP from CDR for the given OES. In either case, the values
used for facility throughputs may encompass a wide range of possible values. Due to these
uncertainties, the facility throughputs may be under or overestimated.
• Uncertainties Associated with Number of Release Days Estimate: For most OESs, EPA
estimated the number of release days using programmatic data where available, or from GSs,
ESDs, or SpERC factsheets when no programmatic data were found. In such cases, EPA used
applicable sources to estimate a range of release days over the course of an operating year. Due
to uncertainty in DBP-specific facility operations, release days may be under or overestimated.
• Uncertainties Associated with DBP-Containing Product Concentrations: In most cases, the
number of identified products for a given OES were limited. In such cases, EPA estimated a
range of possible DBP concentrations for products in the OES. However, the extent to which
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these products represent all DBP-containing products within the OES is uncertain. For OESs
with little-to-no reasonably available product data, EPA estimated DBP concentrations from GSs
or ESDs. Due to these uncertainties, the average product concentrations may be under or
overestimated.
3.3 Summary of Concentrations of DBP in the Environment
Based on the environmental release assessment summarized in Section 3.2 and presented in EPA's Draft
Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP) (
2025q). DBP is expected to be released to the environment via air, water, biosolids, and disposal to
landfills. Environmental media concentrations were quantified in ambient air, soil from ambient air
deposition, surface water, and sediment. Additional analysis of surface water used as drinking water was
conducted for the Human Health Risk Assessment (Section 4). Given limited available information on
DBP in soil and groundwater from releases to biosolids and landfills, along with the availability of high-
quality physical and chemical and fate data (Section 2), concentrations of DBP in soil and groundwater
from releases to biosolids and landfills were not quantified (discussed further below. Air releases of
DBP from fugitive and stack emissions with deposition to soil were estimated using the Integrated
Indoor/Outdoor Air Calculator (IIOAC) Model, as described in Section 8.1.3 of the Draft Environmental
Media, General Population, and Environmental Exposure Assessment for Dibutyl Phthalate (DBP)
( MM-
EPA relied on its fate assessment to determine which environmental pathways to consider for its
screening level analysis of environmental exposure and general population exposure. Details on the
environmental partitioning and media assessment can be found in Draft Chemistry, Fate, and Transport
Assessment for Dibutyl Phthalate (DBP) ( 24i). Briefly, based on DBP's fate parameters
and behavior (e.g., Henry's Law constant, log Koc, water solubility, fugacity modeling), EPA
anticipates DBP to be predominantly in water and soil, though DBP may also exist in air and sediments.
Therefore, EPA quantitatively assessed concentrations of DBP in surface water, sediment, ambient air,
and soil from air to soil deposition. Soil concentrations of DBP from land application of biosolids were
not quantitatively assessed due to limited available information as well as the expectation that DBP is to
have limited persistence potential and mobility in soils receiving biosolids. Thus, they present limited
exposure potential. In contrast, EPA has greater confidence in quantifying DBP concentrations in soil
resulting from air to soil deposition since it is direct deposition into soil rather than mobility from air to
soil (as with biosolids). Therefore, EPA quantified air to soil deposition with a screening level approach
for the purpose of the environmental exposure assessment.
Further detail on the screening level assessment of each environmental pathway can be found in the
Draft Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
Phthalate (DBP) ( :025p). EPA began its environmental and general population exposure
assessment with a screening level approach using the highest modeled environmental media
concentrations for the environmental pathways expected to be of greatest concern. The highest
environmental media concentrations were estimated using the release estimates for an OES associated
with a COU that, paired with conservative assumptions of environmental conditions, resulted in the
greatest modeled concentration of DBP in a given environmental medium type. Therefore, EPA did not
estimate environmental concentrations of DBP resulting from all OESs presented in Table 3-1. Details
on the use of screening level analyses in exposure assessment can be found in EPA's Guidelines for
Human Exposure Assessment ( ).
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For the water pathway, different hydrological flow rates were used for the different screening level
exposure scenarios. The 30Q51 flows (lowest 30-day average flow that occurs in a 5-year period) are
used to estimate acute, incidental human exposure through swimming or recreational contact. The
harmonic mean2 flows provide a more conservative estimate as compared to annual average flows and
are therefore preferred for assessing potential chronic human exposure via drinking water. The harmonic
mean is also used for estimating human exposure through fish ingestion because it takes time for
chemical concentrations to accumulate in fish. Lastly, for aquatic or ecological exposure, a 7Q103 flow
(lowest 7-day average flow that occurs in a 10-year period) is used to estimate exceedances of
concentrations of concern for aquatic life (U.S. EPA. 2007b).
For the screening level assessment, the OES(s) resulting in the highest environmental concentration of
DBP to be used for subsequent exposure screening varied by environmental media, as shown in Table
3-6. Releases to surface water were sorted by comparing daily release estimates with receiving water
body flow rates to determine the order of release concentrations prior to modeling. Manufacturing
yielded the highest water concentration using a 7Q10 flow, a 30Q5 flow, and harmonic mean flow. The
combined release estimates from the Waste handling, treatment, and disposal (stack; corresponding to
the Disposal COU) and Application of paints, coatings, adhesives, and sealants (fugitive; corresponding
to the Industrial/commercial use; Construction, paint, electrical, and metal products; and Adhesives and
sealants/paints and coatings COUs) OESs yielded the highest ambient air concentration. The summary
table also indicates whether the high-end estimate was used for environmental or general population
exposure assessment as well as which flow statistics were selected to screen for risks to human or
environmental health. For the screening level analysis, if the high-end environmental media
concentrations did not result in potential environmental or human health risk, no further OESs were
assessed, and no further refinements were pursued. For the surface water and ambient air pathways, only
the OESs resulting in the highest estimated water column or ambient air concentrations were carried
forward to the human health risk assessment {i.e., Manufacturing for water; Waste handling, treatment,
and disposal [stack]; Application of paints, coatings, adhesives, and sealants; and Application of paints,
coatings, adhesives, and sealants [fugitive] for ambient air). For aquatic ecological exposure, the OES
resulting in the highest estimated water column or sediment concentrations (Manufacturing) was used as
the starting point to determine the reference concentration for the screening assessment; see Sections 5.1
and 5.3.1 for details of how the ecological screening assessment was performed.
1 30Q5 is defined as 30 consecutive days of lowest flow over a 5-year period. These flows are used to determine acute human
exposures via drinking water (U.S. EPA. 2007b').
2 Harmonic mean is defined as the inverse mean of reciprocal daily arithmetic mean flow values. These flows represent a
long-term average and are used to generate estimates of chronic human exposures via drinking water and fish ingestion.
3 7Q10 is defined as 7 consecutive days of lowest flow over a 10-year period. These flows are used to calculate estimates of
chronic surface water concentrations to compare with the COCs for aquatic life.
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1229 Table 3-6. Summary of High-End DBP Concentrations in Various Environmental Media from
1230 Environmental Releases
OES"
Release
Media
Environmental Media
DBP
Concentration
Environmental or
General Population
Manufacturing
Water
Total water column
(7Q10) \ P50 flow c
1,160 ng/L
(286-day average)
Environmental
P75 flow
67.80 jig/L
(286-day average)
P90 flow
4.00 ng/L
(286-day average)
Manufacturing
Sediment
Benthic sediment
(7Q10), P50 flow
27 mg/kg
(7-day average)
Environmental
P75 flow
1.57 mg/kg
(7-day average)
P90 flow
0.093 mg/kg
(7-day average)
Fugitive: application
of paints, coatings,
adhesives, and sealants
stack: waste handling,
treatment, and disposal
Air deposition
to soil
Annual deposition rate
to soil
0.00178 mg/kg/yr
(3 65-day release)
Environmental and
General Population
Manufacturing
Water
Total water column
(30Q5) d, P50 flow c
885 |ig/L
General Population
P75 flow
46.6 jig/L
P90 flow
3.0 |ig/L
Waste handling,
treatment, and disposal
Water
Surface water (30Q5) d
14.5 ng/L
General Population
Surface water
(harmonic mean)c
14.5 ng/L
Waste handling,
treatment, and disposal
(stack)
Ambient air
Daily-averaged total
(fugitive and stack,
100 m)
17.26 (ig/m3
General Population
Application of paints,
coatings, adhesives,
and sealants
Application of paints,
coatings, adhesives,
and sealants (fugitive)
Annual-averaged total
(fugitive and stack,
100 m)
11.82 (ig/m3
General Population
"Table 3-1 provides the crosswalk of OES to COUs.
h 7Q10 is the 7 consecutive days of lowest flow over a 10-year period.
c The P50, P75, and P90 flows refer to the 50th, 75th, and 90th percentiles of the distribution of water body flow
rates in generic release scenarios; see Appendix B of the Draft Environmental Media, General Population, and
Environmental Exposure Assessment for Dibutyl Phthalate (DBF) (U.S. EPA, 2025p).
d30Q5 is defined as 30 consecutive days of lowest flow over a 5-year period.
'' Harmonic mean is defined as the inverse mean of reciprocal daily arithmetic mean flow values. These flows
represent a long-term average.
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3.3.1 Weight of Scientific Evidence Conclusions
Detailed discussion of the strengths, limitations, and sources of uncertainty for presented environmental
media concentrations leading to a weight of scientific evidence conclusion can be found in the Draft
Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
Phthalate (I)BP) (U.S. EPA. 2025p). However, the weight of scientific evidence conclusion is
summarized below for the modeled concentrations for surface water and ambient air.
For the screening level assessment, EPA used the release estimates presented in Table 3-4 to model DBP
concentrations in different environmental media. The Agency assessed additional variables when
considering the weight of scientific evidence for its estimation of environmental media concentrations.
Some additional considerations include the use of an additional model (Point Source Calculator of the
Variable Volume Water Model [VVWM-PSC], IIOAC, etc.) using the release as an input, the
applicability of the release data to the environmental media being considered, likelihood of an
occurrence of a release to the specific environmental compartment, and available monitoring data.
3.3.1.1 Surface Water
For the screening level human health assessment, EPA utilized releases associated with the
Manufacturing OES as it resulted in the highest surface water concentrations. EPA determined the
surface water concentration associated with this OES represented a conservative high-end exposure
scenario (approximately 20x higher than concentrations indicated by monitoring data) and was
appropriate to use in its screening level assessment to assess all other OESs and their associated COUs.
EPA utilized daily release information as an input to the Variable Volume Water Model with Point
Source Calculator Tool (VVWM-PSC) Model to estimate surface water concentrations for use in
general population and environmental exposure assessments. As mentioned in Section 3.2, the Agency
estimated a range for daily releases for each OES when possible. EPA was not able to estimate site-
specific releases for the Final use of products or articles OES. Disposal sites handling post-consumer,
end-use DBP were not quantifiable due to the wide and dispersed use of DBP in PVC and other
products. Pre-consumer waste handling, treatment, and disposal are assumed to be captured in upstream
OES. Several OESs had releases estimated using programmatic data. EPA compiled programmatic
release information using reported releases from TRI, DMR, and NEI. NEI obtained a high-quality
rating whereas TRI and DMR obtained a medium-quality rating from EPA's systematic review process,
as discussed in Table 3-5. One limitation was that the extent to which sites not captured in these
databases release DBP into the environment is uncertain. Additionally, not all OESs are represented in
these databases.
For OESs that did not have reported release data, releases were estimated using GSs/ESDs. For releases
that use GSs/ESDs, EPA concluded the weight of scientific conclusion was moderate. Five OESs
(Manufacturing, Application of adhesives and sealants, Application of paints and coatings, Use of
laboratory chemicals, and Use of penetrants and inspection fluids) had modeled releases from generic
scenarios for multimedia discharges to combinations of multiple of the following: water, wastewater
(POTW), incineration, landfill, and air. For these generic scenario OESs, there was insufficient
information to determine the fraction of the release going to each of the reported media types, including
to surface water. For these OESs, surface water, pore water, and sediment concentrations of DBP were
estimated using VVWM-PSC, assuming a conservative scenario in which all of the multimedia releases
were to surface water. Based on comparison with reported scenarios for DBP wastewater release, EPA
has less confidence in the unlikely combination of high-end releases of DBP to the lowest-flow generic
condition (P50) water bodies. Where EPA had sufficient data to produce estimates of releases to surface
water from generic scenarios (such as with the Use of lubricants and functional fluids OES), EPA
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estimated release concentrations, but these estimates had greater uncertainty in the modeled exposure
results relative to those releases for which EPA obtained programmatic release data.
Table 3-7 below identifies the data available for use in modeling surface water concentrations for each
OES and EPA's confidence in the estimated surface water concentrations used for exposure assessment.
For the screening level general population assessment, the Agency identified the OES (Manufacturing)
that resulted in the highest surface water concentrations to assess exposure (Table 3-6). EPA prioritized
use of programmatic data with actual release data from reporting facilities where overall confidence in
the estimates would be higher. For estimating surface water concentrations from releases, the Agency
prioritized the use of TRI annual release reports over DMR monitoring data, reviewing DMR period
data as supporting information for the releases reported to TRI. Releases from facilities reporting via
TRI Form A, which represents undefined releases to unspecified media types, less than 500 lb per year,
were not directly modeled. Because of this, and for the purpose of the tiered approach taken for the
general population analysis, environmental concentrations from potential releases to surface water from
facilities reporting via TRI Form A were expected to be lower than the high-end concentrations applied
for screening.
For facilities reporting releases to TRI and DMR, relevant flow data from the associated receiving water
body were collected by querying multiple EPA databases and permit IDs under the National Pollutant
Discharge Elimination System (NPDES). The flow data include self-reported hydrologic reach codes on
NPDES permits and the best available flow estimates from EPA and U.S. Geological Survey (USGS)
databases. Other model inputs were derived from reasonably available literature collected and evaluated
through EPA's systematic review process for TSCA risk evaluations. All monitoring and experimental
data included in this analysis were from articles rated medium or high quality from this process.
The weight of scientific evidence conclusions regarding confidence in the release estimates from
facilities and the associated receiving water body and hydrologic flow information described in the
preceding paragraphs, for the estimated surface water concentrations associated with each OES and
water release data type are presented in Table 3-7. EPA proceeded with the use of TRI data for modeling
surface water concentrations as a screening step for exposure pathways requiring screening level
refinement beyond the first tier employing release estimates from the Manufacturing OES. EPA
identified the Waste handling, treatment, and disposal OES as appropriate as it resulted in a high-end
surface water concentration based on reporting data for actual facilities. Additionally, release
concentrations were estimated at the point of release in the receiving water body, as a conservative
assumption to evaluate the upper-end of potential exposure concentrations for a given release. Overall,
EPA has robust confidence that the high-end estimated surface water concentration modeled using the
Manufacturing OES is appropriate to use in its high-end, screening level assessment to assess all OESs
and their associated COUs—including those with releases that were unable to be quantified—if no risk
is found beyond the benchmark. Releases from all other OESs and their associated COUs (including
OESs and COUs with releases that could not be quantified and those with releases modeled from generic
scenarios) are expected to result in lower environmental concentrations in surface water. Where risks in
subsequent analyses are found in excess of the appropriate benchmark, further analysis of other OES is
conducted. General population and environmental risk estimates from surface water can be found in
Sections 4.3.4 and 5.3.2, respectively.
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1322 Table 3-7. Summary of Weight of Scientific Evidence Associated with Each PES
OES"
Water Release
Data Type(s)
WOSE Surface Water Concentrations
Manufacturing b
Generic
Scenario
(multimedia)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Because EPA was unable to determine the
fraction of multimedia releases to surface water, the Agency estimated a
conservative scenario assuming that all multimedia releases went to
surface water. EPA has slight confidence in the precision of the high-end
of these estimates and resulting determinations of risk, due to
compounding conservative assumptions creating an unlikely release
scenario. However, the Agency has moderate to robust confidence in
these estimates representing a theoretical upper-bound of potential
release concentrations, which can effectively be applied in a screening
exercise to screen for risk.
Import and
repackaging
TRI, DMR
All reported releases to TRI within this OES were via Form A. Due to
EPA's high confidence that such releases to surface water, if present,
would not exceed the high-end releases applied for screening, no
quantitative estimate of surface water release concentrations was
conducted for this OES for TRI releases. One facility reporting to DMR
listed DBP monitoring but reported no discharge in the last decade.
Incorporation into
formulation, mixture,
or reaction product
TRI
All reported releases to TRI within this OES were via Form A. Due to
EPA's high confidence that such releases to surface water, if present,
would not exceed the high-end releases applied for screening, no
quantitative estimate of surface water release concentrations was
conducted for this OES.
PVC plastics
compounding
TRI, DMR
EPA conducted modeling using the PSC tool to estimate surface water
and sediment concentrations of DBP. PSC inputs include physical and
chemical properties of DBP which received a high confidence rating and
a reported DBP release from TRI which received a moderate to robust
rating. Based on this information, EPA concluded that the weight of
scientific evidence for this assessment is moderate to robust.
Non-PVC material
compounding
TRI, DMR
EPA conducted modeling using the SC tool to estimate surface water and
sediment concentrations of DBP. PSC inputs include physical and
chemical properties of DBP, which received a high confidence rating and
a reported DBP release from TRI, which received a moderate to robust
rating. Based on this information, EPA concluded that the weight of
scientific evidence for this assessment is moderate to robust.
Incorporation into
adhesives and
sealants
Generic
Scenario
(multimedia)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Because the Agency was unable to determine the
fraction of multimedia releases to surface water, EPA estimated a
conservative scenario assuming that all multimedia releases went to
surface water. EPA has slight confidence in the precision of the high-end
of these estimates and resulting determinations of risk, due to
compounding conservative assumptions creating an unlikely release
scenario. However, EPA has moderate to robust confidence in these
estimates representing a theoretical upper-bound of potential release
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OES"
Water Release
Data Type(s)
WOSE Surface Water Concentrations
concentrations, which can effectively be applied in a screening exercise
to screen out risk.
PVC plastics
converting (surrogate
release data from
PVC plastics
compounding)
TRI
EPA conducted modeling using the PSC tool to estimate surface water
and sediment concentrations of DBP. PSC inputs include physical and
chemical properties of DBP, which received a high confidence rating and
reported DBP releases from TRI, which received a moderate to robust
rating. Based on this information, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
Non-PVC material
converting
TRI
EPA conducted modeling using the PSC tool to estimate surface water
and sediment concentrations of DBP. PSC inputs include physical and
chemical properties of DBP, which received a high confidence rating and
reported DBP releases from TRI, which received a moderate to robust
rating. Based on this information, EPA concluded that the weight of
scientific evidence for this assessment is moderate to robust.
Recycling (surrogate
release data from
PVC plastics
compounding)
DMR
EPA conducted modeling using the PSC tool to estimate surface water
and sediment concentrations of DBP. PSC inputs include physical and
chemical properties of DBP, which received a high confidence rating and
reported DBP releases from TRI, which received a moderate to robust
rating. Based on this information, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
Industrial process
solvent use
No water
releases
EPA was unable to identify water release data from TRI and DMR
reporters for this OES; however, based on the specifics of DBP's use in
the process, EPA does not expect water releases for this OES.
Application of
adhesives and
sealants
Generic
Scenario
(multimedia)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Because the Agency was unable to determine the
fraction of multimedia releases to surface water, EPA estimated a
conservative scenario assuming that all multimedia releases went to
surface water. EPA has slight confidence in the precision of the high-end
of these estimates and resulting determinations of risk, due to
compounding conservative assumptions creating an unlikely release
scenario. However, EPA has moderate to robust confidence in these
estimates representing a theoretical upper bound of potential release
concentrations, which can effectively be applied in a screening exercise
to screen out risk.
Application of paints
and coatings
Generic
Scenario
(multimedia)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Because EPA was unable to determine the
fraction of multimedia releases to surface water, EPA estimated a
conservative scenario assuming that all multimedia releases went to
surface water. EPA has slight confidence in the precision of the high-end
of these estimates and resulting determinations of risk, due to
compounding conservative assumptions creating an unlikely release
scenario. However, EPA has moderate to robust confidence in these
estimates representing a theoretical upper bound of potential release
concentrations, which can effectively be applied in a screening exercise
to screen out risk.
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OES"
Water Release
Data Type(s)
WOSE Surface Water Concentrations
Use of laboratory
chemicals
Generic
Scenario
(multimedia)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Because the Agency was unable to model
releases to just surface water, EPA concluded that there was insufficient
precision in release data to calculate a surface water concentration based
on the release data.
Use of lubricants and
functional fluids
Generic
Scenario
(water-specific)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Sufficient release data were available to model a
surface water-specific release, and the resulting range of estimated
concentrations were below the high-end releases applied for general
population screening.
Use of penetrants and
inspection fluids
Generic
Scenario
(water-specific)
No facilities reported releases for this OES, so EPA modeled releases
using generic scenarios. Sufficient release data were available to model a
surface water-specific release, and the resulting range of estimated
concentrations were below the high-end releases applied for general
population screening.
Waste handling,
treatment, and
disposal
TRI, DMR
EPA conducted modeling using the PSC tool to estimate surface water
and sediment concentrations of DBP. PSC inputs include physical and
chemical properties of DBP, which received a high confidence rating and
reported DBP releases from TRI, which received a moderate to robust
rating. Based on this information, EPA concluded that the weight of
scientific evidence for this assessment is moderate to robust.
DMR = Discharge Monitoring Report; OES = occupational exposure scenario; PSC = point source calculator (tool); TRI =
Toxics Release Inventory
" Table 3-1 provides a crosswalk of industrial and commercial COUs to OES.
b The Manufacturing OES is highlighted as this scenario was used for screening level assessments.
3.3.1.2 Ambient Air and Air to Soil Deposition
EPA used the IIOAC Model, previously peer-reviewed methodology for fenceline communities (
22b), and integrated recommendations from that and other peer reviews to evaluate exposures
and deposition rates via the ambient air pathway for this assessment. The IIOAC Model was developed
based on a series of pre-run scenarios within American Meteorological Society/EPA Regulatory Model
(AERMOD; the Agency's regulatory model), which gives EPA greater confidence in the IIOAC Model
results. However, since results from IIOAC are based on the pre-run AERMOD scenarios, IIOAC
modeling is limited to the parameters (e.g., stack parameters, meteorological data, and other factors)
used as inputs to those pre-run AERMOD scenarios; thus limiting the flexibility of the IIOAC results for
highly site-specific or date specific modeling needs (e.g., if refined analyses are needed). The screening
level analyses presented in this assessment, IIOAC provides reliable and reproduceable results which
can be used to characterize upper-bound exposures and derive screening level risk estimates, giving
EPA moderate confidence in the results and findings.
The Agency considered three different datasets for DBP releases for this assessment. Those datasets
include EPA estimated releases based on production volumes of DBP from facilities that manufacture,
process, repackage, or dispose of DBP ( 025q); releases reported to TRI by industry (2017-
2022 reporting years); and releases reported to NEI (1 c. « i1 \ J025q) (2017 and 2020 reporting years).
This gives the Agency moderate confidence that release data utilized is representative and high-end
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releases are not missed. EPA uses the maximum daily releases of DBP across all OES/COUs as direct
inputs to the IIOAC Model, giving the Agency high confidence that the releases used are health
protective for a screening level analysis. However, the use of estimated or reported annual release data
and number of operating days to calculate daily average releases assumes operations are continuous and
releases are the same for each day of operation. This can underestimate short-term or daily exposure and
deposition rates because results may miss actual peak releases (and associated exposures) if higher and
lower releases occur on different days. The uncertainties associated with the release data are detailed in
the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate Qj.S.
25q).
The maximum daily fugitive release value used in this assessment was reported to the 2017 NEI dataset
and is associated with the Application of paints, coatings adhesives, and sealants OES. The maximum
daily stack release value used in this assessment was reported to the TRI dataset and is associated with
the Waste handling, treatment, and disposal OES. Both maximum daily release values represent the
maximum daily release reported across all facilities and COUs and are used as direct inputs to the
IIOAC Model to estimate concentrations and deposition rates. Additionally, these releases were reported
by two different facilities in two different locations. Therefore, these two releases do not align either
spatially or temporally. For this screening level ambient air assessment, EPA modeled these two releases
assuming they occurred from the same location, at the same time, during the same reporting year, and
under the same OES to determine a "total exposure" to DBP from both release types. These assumptions
provide a conservative estimate of total exposure, ensure possible exposure from either release type are
not missed, and retain health protective estimates of exposure and associated risk estimates. The lack of
spatial or temporal alignment gives the Agency low confidence in the exposure scenario modeled
(cannot occur at same time under assumptions modeled) and overestimates ambient concentrations and
deposition rates at the evaluated distances. Due to the conservative assumptions made along with the use
of the highest release estimates, EPA has robust confidence the modeled ambient air concentrations and
deposition rates are highly conservative estimates appropriate for a screening level analysis for all OESs
and associated COUs. Based on the risk findings described in Section 4.1.3.1—even with the
conservative assumptions and exposure scenario modeled—results indicate the total exposure or
deposition rate under this scenario still does not indicate an exposure or risk concern. Therefore, EPA
has robust confidence that exposure to and deposition rates of DBP via the ambient air pathway do not
pose an exposure or risk concern and no further, refined analysis is pursued. If new information becomes
available and after EPA's consideration of such information and results, under the same scenario and
assumptions, indicate an exposure or risk concern, then the Agency would have low confidence in the
results and refine the analysis to be more representative of a real exposure scenario (e.g., only determine
exposures and derive risk estimates based on a single facility reporting both release types).
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1378 4 HUMAN HEALTH RISK ASSESSMENT
DBP - Human Health Risk Assessment (Section 4):
Key Points
EPA evaluated all reasonably available information to support human health risk characterization of DBP
for workers, ONUs, consumers, bystanders, and the general population. Exposures to workers, ONUs,
consumers, bystanders, and the general population are described in Section 4.1. Human health hazards are
described in Section 4.2. Human health risk characterization is described in Section 4.3. The following
bullets summarize the key points.
Exposure Key Points
• EPA assessed inhalation and dermal exposures for workers and ONUs, as appropriate, for each OES
(Section 4.1.1). Both dermal and inhalation were primary routes of exposure, depending on the OES.
• EPA assessed inhalation, dermal, and oral exposures for consumers and bystanders, as appropriate,
for each TSCA COU (Section 4.1.2) in scenarios that represent a range of use patterns and
behaviors. The primary route of exposure was dermal for most products, followed by inhalation.
• EPA assessed inhalation, oral, and dermal exposures for the general population via ambient air,
surface water, drinking water, and fish ingestion for Tribal populations (Sections 4.1.3 and 4.3.4).
• EPA assessed non-attributable cumulative exposure to DEHP, DBP, BBP, DIBP, and DINP for the
U.S. civilian population using NHANES urinary biomonitoring data and reverse dosimetry (Section
4.4.2).
Hazard Key Points
• EPA identified adverse effects on the developing male reproductive system consistent with a
disruption of androgen action, leading to phthalate syndrome, as the most sensitive and robust non-
cancer hazard associated with oral exposure to DBP in experimental animal models (Section 4.2).
• A non-cancer POD of 2.1 mg/kg-day (derived from a BMDL5 = 9 mg/kg-day) was selected to
characterize non-cancer risks for acute, intermediate, and chronic durations of exposure. A total
uncertainty factor of 30 was selected for use as the benchmark margin of exposure.
• Under the Guidelines for Carcinogen Risk Assessment (U.S. EPA. 2005). EPA has preliminarily
determined that there is Suggestive Evidence of Carcinogenic Potential of DBP in rats based on
pancreatic cancer. Consistent with the guidelines, the Agency did not quantitatively evaluate DBP
for cancer risk.
• EPA derived draft relative potency factors (RPFs) based on a common hazard endpoint (i.e., reduced
fetal testicular testosterone). Draft RPFs were derived via meta-analysis and benchmark dose (BMD)
modeling.
Risk Assessment Key Points
• Dermal exposures drive acute non-cancer risks to workers in occupational settings (Section 4.3.2).
• Dermal exposures drive acute non-cancer risks to consumers (Section 4.3.3).
• For the general population, exposures to DBP through biosolids, landfills, surface water, drinking
water, fish ingestion, and ambient air were not determined to be pathways of concern.(Sections 4.1.3
and 4.3.4).
• EPA considered PESS throughout the exposure assessment, hazard identification, and dose-response
analysis supporting this draft risk evaluation (Section 4.3.4.1).
• EPA considered cumulative risk to workers and consumers through exposure to DBP from
individual COUs in combination with cumulative non-attributable national exposure to DEHP, DBP,
BBP, DIBP, and DINP as estimated from NHANES biomonitoring data (Sections 4.4.4 and 4.4.5).
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4.1 Summary of Human Exposures
4.1.1 Occupational Exposures
The following subsections briefly describe EPA's approach to assessing occupational exposures and
provide exposure assessment results for each OES. As stated in the final scope for DBP (U.S. EPA.
2020c). the Agency evaluated exposures to workers and occupational non-users (ONUs) via the
inhalation route, and exposures to workers via the dermal route associated with the manufacturing,
processing, use, and disposal of DBP. Also, EPA assessed dermal exposure to workers and ONUs from
mist and dust deposited on surfaces. The Draft Environmental Release and Occupational Exposure
Assessment for Dibutyl Phthalate (DBP) (U.S. EPA. 2025q) provides additional details on the
development of approaches and the exposure assessment results.
4.1.1.1 Approach and Methodology
As described in the final scope document ( ), EPA distinguished exposure levels among
potentially exposed employees for workers and ONUs. In general, the primary difference between
workers and ONUs is that workers may handle DBP and have direct contact with the DBP, while ONUs
work in the general vicinity of DBP but do not handle DBP. Where possible, for each condition of use
(COU), EPA identified job types and categories for workers and ONUs.
As discussed in Section 3.1.1.1, EPA established OESs to assess the exposure scenarios within each
COU; Table 3-1 provides a crosswalk between COUs and OESs. For occupational inhalation exposures,
EPA primarily used chemical-specific inhalation exposure monitoring data for the OESs. In the absence
of inhalation monitoring data, the Agency used inhalation exposure models to estimate central tendency
and high-end exposures. For cases where occupational dermal exposure to liquid DBP was assessed,
EPA used a flux-limited dermal absorption value derived from a study conducted by Doan et al. (2010)
to estimate high-end and central tendency dermal exposures. For occupational dermal exposure to solid
DBP, EPA used a flux-limited dermal absorption model to estimate high-end and central tendency
dermal exposures for workers in each OES. For occupational dermal exposure assessment, EPA
assumed a standard 8-hour workday and the chemical is contacted at least once per day. Because DBP
has low volatility and relatively low absorption, it is possible that the chemical remains on the surface of
the skin after dermal contact until the skin is washed. Therefore, in absence of exposure duration data,
EPA has assumed that absorption of DBP from occupational dermal contact with materials containing
DBP may extend up to 8 hours per day ( [.). However, dermal exposure may be eliminated
if a worker uses proper personal protective equipment (PPE; e.g., respirators, gloves) or washes their
hands after contact with DBP or DBP-containing material. Therefore, the assumption of an 8-hour
exposure duration for DBP may lead to overestimation of dermal exposure. For average adult workers,
the surface area of contact was assumed equal to the area of one hand (i.e., 535 cm2) or two hands (i.e.,
1,070 cm2) for central tendency or high-end exposures, respectively ( 201 la). The dermal
methods are described in the Draft Environmental Release and Occupational Exposure Assessment for
Dibutyl Phthalate (DBP) (U.S. EPA. 2025q).
EPA evaluated the quality of data sources using the data quality review evaluation metrics and rating
criteria described in the Draft Systematic Review Protocol ( 21a). The Agency assigned an
overall quality level of high, medium, or low to the relevant data. In addition, EPA established an
overall confidence level for the data when integrated into the occupational exposure assessment. The
Agency considered the assessment approach, quality of the data and models, and uncertainties in
assessment results to assign an overall weight of scientific evidence rating of robust, moderate, or slight.
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Figure 4-1. Approaches Used for Each Component of the Occupational Assessment for Each OES
PBZ = personal breathing zone; PNOR = particulates not otherwise regulated
For the inhalation and dermal exposure routes, EPA provided occupational exposure results that are
representative of central tendency and high-end exposure conditions. The central tendency is expected to
represent occupational exposures in the center of the exposure distribution for a given COU. For risk
evaluation, EPA used the 50th percentile (median), mean (arithmetic or geometric), mode, or midpoint
value of a distribution to represent the central tendency scenario. The Agency preferred to provide the
50th percentile of the distribution. However, if the full distribution was unknown, EPA used either the
mean, mode, or midpoint of the distribution to represent the central tendency, depending on the statistics
available for the distribution. The high-end exposure is expected to represent occupational exposures
that occur at probabilities above the 90th percentile but below the highest exposure for any individual
(U.S. EPA, 1992). For this draft risk evaluation, EPA provided high-end results at the 95th percentile. If
the 95th percentile was not reasonably available, the Agency used a different percentile greater than or
equal to the 90th percentile but less than or equal to the 99th percentile, depending on the statistics
available for the distribution. If the full distribution is not known and the preferred statistics are not
reasonably available, EPA estimated a maximum or bounding estimate in lieu of the high-end. Table 4-1
provides a summary of the approach used to assess worker and QNU exposures and the Agency's
weight of scientific evidence rating for the given exposure assessments.
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Table 4-1. Summary of Exposure Monitoring and Modeling Data for Occupational Exposure Scenarios
OES
Inhalation Exposure
Dermal Exposure
DBP Monitoring
Surrogate Monitoring
Modeling
Empirical
Modeling
Worker
# Data
Points /
# Data
Sources
ONU
#
Data
Point
Data
Quality
Ratings
Worker
# Data
Points /
# Data
Sou rces
ONU
#
Data
Point
Data
Quality
Ratings
Worker
ONU
Worker
Data
Quality
Rating
Worker
Manufacturing
3 data
sources"
X
N/A
M
X
N/A
X
N/A
N/A
X
X
M
X
Import and repackaging
X
N/A
X
N/A
N/A
3 data
sources"
X
N/A
M
X
X
M
X
Incorporation into
formulations, mixtures, or
reaction products
X
N/A
X
N/A
N/A
3 data
sources"
X
N/A
M
X
X
M
X
PVC plastics
compounding
X
N/A
X
N/A
N/A
4 data
points6
X
N/A
M
X
M
PVC plastics converting
4 data
points6
X
N/A
M
X
N/A
X
N/A
N/A
X
X
N/A
Non-PVC materials
manufacturing
(compounding and
converting)
X
N/A
X
N/A
N/A
4 data
points6
X
N/A
M
X
M
Application of paints and
coatings
14 data
points
X
N/A
M/H
X
N/A
X
N/A
N/A
X
X
M
X
Application of adhesives
and sealants
19 data
points'7
X
N/A
M
X
N/A
X
N/A
N/A
X
X
M
X
Use of laboratory
chemicals
X
N/A
X
N/A
N/A
19 data
points'7
X
N/A
M
X
M
Use of industrial process
solvents
X
N/A
X
N/A
N/A
3 data
source"
X
N/A
M
X
X
M
X
Use of lubricants and
functional fluids
X
N/A
X
N/A
N/A
19 data
points'7
X
N/A
M
X
X
M
X
Use of penetrants and
inspection fluids
X
N/A
X
N/A
N/A
X
N/A
X
N/A
N/A
X
M
X
Fabrication of final
product from articles
3 data
points
X
N/A
M
X
N/A
X
N/A
N/A
X
X
N/A
Recycling
X
N/A
X
N/A
N/A
X
N/A
X
N/A
N/A
X
X
N/A
Waste handling, treatment,
and disposal
X
N/A
X
N/A
N/A
X
N/A
X
N/A
N/A
X
X
N/A
Page 76 of 333
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OES
Inhalation Exposure
Dermal Exposure
DBP Monitoring
Surrogate Monitoring
Modeling
Empirical
Modeling
Worker
# Data
Points /
# Data
Sources
ONU
#
Data
Point
Data
Quality
Ratings
Worker
# Data
Points /
# Data
Sources
ONU
#
Data
Point
Data
Quality
Ratings
Worker
ONU
Worker
Data
Quality
Rating
Worker
ONU = occupational non-user
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.
Surrogate monitoring data means monitoring data from another similar OES was used.
M: Medium and H: High from EPA's systematic review process (U.S. EPA. 2021a')
Data quality ratings for reported data are based on EPA systematic review and include ratings Low (L), Medium (M), and High (H)
x No data available
^ Data available
" For the Manufacturing, Import and repackaging, Incorporation into formulations, mixtures, or reaction products, and Use of industrial process solvents OESs, the same
inhalation monitoring data were used. The monitoring data were obtained from three risk evaluations, each study presented a single exposure concentration during
manufacturing of DBP. However, these exposure values were estimated from multiple data points measured during DBP manufacturing. For more information, see
Section 3.1.4.2 of the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP) flJ.S. EPA, 2025a,).
h For PVC plastics compounding, PVC plastics converting, and Non-PVC materials manufacturing OESs, the same inhalation monitoring data from PVC plastics
converting were used.
c For Application of adhesives and sealants, Use of laboratory chemicals, and Use of lubricants and functional fluids OESs, the same monitoring data from application of
adhesives and sealants were used.
1445
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1446 4.1.1.2 Number of Workers and ONUs
1447 Table 4-2 summarizes the number of facilities and total number of exposed workers for all OESs. For
1448 scenarios in which the results are expressed as a range, the low end of the range is based on the 50th
1449 percentile estimate of the number of sites and the upper end of the range is based on the 95th percentile
1450 estimate of the number of sites. For some OESs, the estimated number of facilities is based on the
1451 number of reporting sites to the 2020 CDR(1, ^ \ :020b), NEI (\ v \ . '23a). DMR (I
1452 EPA. 2024a\ and TRI databases (\ ^ \ 3024o).
1453
1454 Table 4-2. Summary of Total Number of Workers and ONUs Potentially Exposed to DBP for Each
1455 OES
OES"
Total Exposed
Workers
Total Exposed
ONUs6
Number of
Facilities
Notes
Manufacturing
195
90
5
Number of workers and ONU estimates based on the
Bureau of Labor Statistics (BLS) and U.S. Census
Bureau data (U.S. BLS. 2023; U.S. Census Bureau.
2015). Number of facilities estimated based on
identified sites from CDR.
Import and
Repackaging
560
252
28
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS. 2023;
U.S. Census Bureau, 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
Incorporation
into
formulations,
mixtures, or
reaction
products
1,700
750
50
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau, 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
PVC plastics
compounding
459
204
17
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS. 2023;
U.S. Census Bureau, 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
PVC plastics
converting
180
50
10
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau, 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
Non-PVC
material
manufacturing
1,196
312
52
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
Application of
adhesives and
sealants
5,264-44,408
1,692-14,274
94-793
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS. 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated using modeled data.
Page 78 of 333
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OES"
Total Exposed
Workers
Total Exposed
ONUs6
Number of
Facilities
Notes
Application of
paints and
coatings
2,628-31,488
1,314-15,744
219-2,624
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated using modeled data.
Industrial
process solvent
use
117
54
3
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
Use of
laboratory
chemicals
36,873
331,857
36,873
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated using data from BLS.
Use of
lubricants and
functional
fluids
293,656-
3,503,104
73,414-
875,776
3,337-
39,808
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated using modeled data.
Use of
penetrants and
inspection
fluids
188,994-
270,010
87,228-
124,620
14,538-
20,770
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau. 2015). Number of facilities
estimated using modeled data.
Fabrication or
use of final
products or
articles
N/A
Number of sites data was unavailable for this OES.
Based on the BLS and U.S. Census Bureau data
(U.S. BLS. 2023; U.S. Census Bureau. 2015).
Recycling
754
406
58
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS, 2023;
U.S. Census Bureau, 2015). Number of facilities
estimated based on identified recycling sites.
Waste
handling,
treatment, and
disposal
2,951
1,589
227
Number of workers and ONU estimates based on the
BLS and U.S. Census Bureau data (U.S. BLS. 2023;
U.S. Census Bureau, 2015). Number of facilities
estimated based on identified sites from CDR, TRI,
NEI, and DMR.
a An OES is based on a set of facts, assumptions, and inferences that describe how releases and exposures take place within
an occupational COU. The occurrence of releases/exposures may be similar across multiple COUs (multiple COUs mapped
to single OES), or there may be several ways in which releases/exposures take place for a given COU (single COU mapped
to multiple OESs).
h ONUs do not directly handle DBP, but may be exposed to dust, vapors, or mists that enter their personal breathing zone
while working in locations near where DBP is handled by workers.
1456
1457 4.1.1.3 Summary of Inhalation Exposure Assessment
1458 Table 4-3 presents a summary of inhalation exposure results based on reasonably available monitoring
1459 data and exposure modeling for each OES. This tables provides a summary of the 8-hour time weighted
1460 average (8-hour TWA) inhalation exposure estimates, as well as the acute dose (AD), the intermediate
1461 average daily dose (IADD), and the chronic average daily dose (ADD). The Draft Environmental
1462 Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP) ( 2025q)
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1463 provides exposure results for females of reproductive age and ONUs—including additional details
1464 regarding AD, IADD, and ADD calculations along with EPA's approach and methodology for
1465 estimating inhalation exposures.
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1466 Table 4-3. Summary of Average Adult Worker Inhalation Exposure Results for Each PES"
OES
All Routes -
8-Hour TWA
(mg/m3)
AD
(mg/kg/day)
IADD
(mg/kg/day)
ADD
(mg/kg/day)
Method Used
CT
HE
CT
HE
CT
HE
CT
HE
Data Type(s)
Monitoring Data
Source(s)
Rating(s)h
Manufacturing
0.50
1.0
6.3E-02
0.13
4.6E-02
9.2E-02
4.3E-02
8.6E-02
Monitoring data
(ECB. 2008: ECJRC.
2004; SRC. 2 )
All three sources
received a rating
of medium
Import and
repackaging
0.50
1.0
6.3E-02
0.13
4.6E-02
9.2E-02
4.3E-02
8.6E-02
Surrogate
monitoring data
(ECB. 2008: ECJRC.
2004: SRC. 2 )
All three sources
received a rating
of medium
Incorporation into
formulations,
mixtures, or
reaction products
0.50
1.0
6.3E-02
0.13
4.6E-02
9.2E-02
4.3E-02
8.6E-02
Surrogate
monitoring data
(ECB. 2008: ECJRC.
2004: SRC. 2 )
All three sources
received a rating
of medium
PVC plastics
compounding
0.34
2.9
4.3E-02
0.36
3.1E-02
0.26
2.9E-02
0.25
Surrogate
monitoring data,
PNOR Modelc
for dust
(ECJRC. 2004)
Source received
a rating of
medium
PVC plastics
converting
0.34
2.9
4.3E-02
0.36
3.1E-02
0.26
2.9E-02
0.25
Monitoring data,
PNOR Model for
dust
(ECJRC. 2004)
Source received
a rating of
medium
Non-PVC
materials
manufacturing
(compounding
and converting)
0.29
1.7
3.6E-02
0.21
2.6E-02
0.15
2.4E-02
0.14
Surrogate
monitoring data,
PNOR Model for
dust
(ECJRC. 2004)
Source received
a rating of
medium
Application of
adhesives and
sealants
5.0E-02
0.10
6.3E-03
1.3E-02
4.6E-03
9.2E-03
4.0E-03
8.6E-03
Monitoring data
CNIOSH. 1977)
Source received
a rating of
medium
Application of
paints and
coatings
0.83
5.2
0.10
0.66
7.6E-02
0.48
7.1E-02
0.45
Monitoring data
(OSHA. 2019: Rohm
&Haas. 1990)
OSHA CEHD
received a rating
of high; the
Rohm & Haas
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OES
All Routes -
8-Hour TWA
(mg/m3)
AD
(mg/kg/day)
IADD
(mg/kg/day)
ADD
(mg/kg/day)
Method Used
CT
HE
CT
HE
CT
HE
CT
HE
Data Type(s)
Monitoring Data
Source(s)
Rating(s)h
source received a
rating of low
Use of industrial
process solvents
0.50
1.0
6.3E-02
0.13
4.6E-02
9.2E-02
4.3E-02
8.6E-02
Surrogate
monitoring data
(ECB. 2008: ECJRC.
All three sources
received a rating
of medium
2004; SRC. 2 )
Use of laboratory
chemicals (solid)
3.8E-02
0.54
4.8E-03
6.8E-02
3.5E-03
5.0E-02
3.3E-03
4.6E-02
PNOR Model for
dust
No monitoring data
source
N/A
Use of laboratory
chemicals (liquid)
5.0E-02
0.10
6.3E-03
1.3E-02
4.6E-03
9.2E-03
4.3E-03
8.6E-03
Surrogate
monitoring data
(NIOSH. 1977)
Source received
a rating of
medium
Use of lubricants
and functional
fluids
5.0E-02
0.10
6.3E-03
1.3E-02
4.2E-04
1.7E-03
3.4E-05
1.4E-04
Surrogate
monitoring data
(NIOSH. 1977)
Source received
a rating of
medium
Use of penetrants
and inspection
fluids
1.5
5.6
0.19
0.70
0.14
0.51
0.13
0.48
Near-field/far-
field approach
No monitoring data
source
N/A
Fabrication or use
of final products
from articles
0.10
0.84
1.3E-02
0.11
9.2E-03
7.7E-02
8.6E-03
7.2E-02
Monitoring data
(ECJRC. 2004;
Rudel et ah, 2001)
Both sources
received a rating
of medium
Recycling
0.11
1.6
1.4E-02
0.20
9.9E-03
0.14
9.2E-03
0.13
PNOR Model for
dust
No monitoring data
source
N/A
Waste handling,
treatment, and
disposal
0.11
1.6
1.4E-02
0.20
9.9E-03
0.14
9.2E-03
0.13
PNOR Model for
dust
No monitoring data
source
N/A
a AD = acute dose; ADD = chronic average daily dose; CT = central tendency; HE = high-end; IADD = intermediate average daily dose; OES = occupational
exposure scenario; TWA = time-weighted average
h The ratings included in this table reflect the rating of the data source as determined by the systematic review process. The rating of the data source per the
systematic review process is not reflective of the confidence in the risk estimates for the OES.
c Generic Model for Central Tendency and High-End Inhalation Exposure to Total and Rcsoirablc Particulates Not Otherwise Regulated ("PNOR Model") (U S.
EPA. 2021d)
1467
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1468 4.1.1.4 Summary of Dermal Exposure Assessment
1469 Table 4-4 presents a summary of dermal exposure results, which are based on reasonably available
1470 empirical dermal absorption data and dermal absorption modeling. Flux-based dermal approaches were
1471 considered more appropriate because DBP has relatively low absorption and low volatility. This table
1472 provides a summary of the acute potential dose rate (APDR) for occupational dermal exposure
1473 estimates, as well as the AD, the IADD, and the chronic ADD. The Draft Environmental Release and
1474 Occupational Exposure Assessment for Dibutyl Phthalate ( )25q) provides exposure results
1475 for females of reproductive age and ONUs. The Draft Environmental Release and Occupational
1476 Exposure Assessment for Dibutyl Phthalate also provides additional details regarding AD, IADD, and
1477 ADD calculations along with EPA's approach and methodology for estimating dermal exposures.
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1478 Table 4-4. Summary of Average Adult Worker Dermal Exposure Results for Each PES
Dermal Estimates (Average Adult Worker)
OES
Exposure Type
APDR"h (mg/day)
AD" (mg/kg/day)
IADD" (mg/kg/day)
ADD" (mg/kg/day)
Liquid'
Solid'
c Td
nEd
CTd
nEd
CTrf
HErf
CT"
HErf
Manufacturing
X
100
201
1.3
2.5
0.92
1.8
0.86
1.7
Import and repackaging
X
100
201
1.3
2.5
0.92
1.8
0.86
1.7
Incorporation into
formulation, mixture, or
reaction product
X
100
201
1.3
2.5
0.92
1.8
0.86
1.7
PVC plastics
compounding
X
X
102
204
1.3
2.5
0.93
1.9
0.87
1.7
PVC plastics converting
X
1.4
2.7
1.7E-02
3.4E-02
1.2E-02
2.5E-02
1.2E-02
2.3E-02
Non-PVC material
manufacturing
X
102
204
1.3
2.5
0.93
1.9
0.87
1.7
Application of adhesives
and sealants
X
100
201
1.3
2.5
0.92
1.8
0.80
1.7
Application of paints and
coatings
X
100
201
1.3
2.5
0.92
1.8
0.86
1.7
Use of laboratory
chemicals (liquid)
X
75
201
0.94
2.5
0.69
1.8
0.64
1.7
Use of laboratory
chemicals (solid)
X
1.4
2.7
1.7E-02
3.4E-02
1.2E-02
2.5E-02
1.2E-02
2.3E-02
Industrial process solvent
use
X
100
201
1.3
2.5
0.92
1.8
0.86
1.7
Use of lubricants and
functional fluids
X
56
169
0.70
2.1
4.7E-02
0.28
3.8E-03
2.3E-02
Use of penetrants and
inspection fluids
X
100
201
1.3
2.5
0.92
1.8
0.85
1.7
Fabrication or use of
final products and
articles
X
1.4
2.7
1.7E-02
3.4E-02
1.2E-02
2.5E-02
1.2E-02
2.3E-02
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Dermal Estimates (Average Adult Worker)
OES
Exposure Type
APDR"h (mg/day)
AD" (mg/kg/day)
IADD" (mg/kg/day)
ADD" (mg/kg/day)
Liquid'
Solid'
CTd
HErf
CTrf
HEd
CT d
he"
CTd
HE'
Recycling
X
1.4
2.7
1.7E-02
3.4E-02
1.2E-02
2.5E-02
1.2E-02
2.3E-02
Waste handling,
treatment, and disposal
X
1.4
2.7
1.7E-02
3.4E-02
1.2E-02
2.5E-02
1.2E-02
2.3E-02
a AD = acute dose; ADD = average daily dose; APDR = acute potential dose rate; IADD = intermediate average daily dose
b APDR values are reported for either liquid or solid exposure types as indicated by the "Exposure Type" column
c EPA used dermal absorption data for 7% oil-in-water DBP formulations to estimate occupational dermal exposures for liauid CDoan et aL 2010). The studv
received a rating of medium from EPA's systematic review process. EPA used an aqueous absorption model to estimate occupational dermal exposures for solid
(IIS. EPA. 2023c. 2004b!
d For average adult workers, central tendency means the surface area of contact was assumed equal to the area of one hand (i.e., 535 cm2) and high-end means
the surface area of contact was assumed eaual to the area of two hands (i.e.. 1.070 cm2) CU.S. EPA. ).
1479
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1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
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PUBLIC RELEASE DRAFT
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4.1.1.5 Weight of Scientific Evidence Conclusions for Occupational Exposure
Judgment on the weight of scientific evidence is based on the strengths, limitations, and uncertainties
associated with the exposure estimates. EPA considers factors that increase or decrease the strength of
the evidence supporting the exposure estimate—including quality of the data/information, applicability
of the exposure data to the COU (including considerations of temporal and 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, in accordance with the Draft
Systematic Review Protocol ( 2021a). For example, a conclusion of moderate is appropriate
where exposure data is generated from a generic model with high data quality and some chemical-
specific or industry-specific inputs, such that the exposure estimate is a reasonable representation of
potential sites within the OES. A conclusion of slight is appropriate where there is limited information
that does not sufficiently cover all potential exposures within the COU, and the assumptions and
uncertainties are not fully known or documented. See the Draft Systematic Review Protocol (
2021a) for additional information on weight of scientific evidence conclusions. Table 4-5 provides a
summary of EPA's overall confidence in its occupational exposure estimates for each of the OESs
assessed.
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Manufacturing
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 full-shift TWA inhalation exposure estimates for the Manufacturing OES. The primary strength
of this approach is the use of directly applicable monitoring data, which is preferrable to other assessment approaches, such as
modeling or the use of occupational exposure limits (OELs). EPA used personal breathing zone (PBZ) air concentration data pulled
from 3 sources to assess inhalation exposures CECB, 1*008; ECJRC. 2004; SRC. 2001). All 3 data sources received a rating of
medium from EPA's systematic review process. These data were DBP-specific, though it is uncertain whether the measured
concentrations accurately represent the entire industry.
The primary limitations of these data include the uncertainty of the representativeness of these data toward the true distribution of
inhalation concentrations for this scenario. Additionally, the dataset is only built on limited data points (3 data source) with a
significant spread of measurements. The SRC source cites an ACC study that provides a datapoint as a worst-case scenario, the
ECJRC, 2008 source only provides a single datapoint with uncertain statistics and the ECJRC, 2004 source provided a dataset with
an uncertain range and number of samples. EPA also assumed 8 exposure hours per day and 250 exposure days per year based on
continuous DBP exposure each working day for a typical worker schedule; it is uncertain whether this captures actual worker
schedules and exposures.
Although the use of monitoring data specific to this OES increases the strength of the analysis, the few uncertainties discussed in the
paragraph above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the
weight of scientific evidence for this assessment is moderate to robust.
Import and
repackaging
EPA used surrogate monitoring data from DBP manufacturing facilities to estimate worker inhalation exposures, due to no relevant
OES-specific data availability for import and repackaging inhalation exposures. The primary strength of this approach is the use of
monitoring data, which is preferrable to other assessment approaches, such as modeling or the use of OELs. EPA used PBZ air
concentration data pulled from 3 sources to assess inhalation exposures (ECB. 2008; ECJRC. 2004; SRC. 2001). All 3 data sources
received a rating of medium from EPA's systematic review process. These data were DBP-specific, though it is uncertain whether
the measured concentrations accurately represent the entire industry.
The primary limitations of these data include uncertainty in the representativeness of these data for this OES and true distribution of
inhalation concentrations in this scenario. Additionally, the dataset is only built on limited data points (3 data sources) with a
significant spread of measurements. The SRC source cites an ACC study that provides a datapoint as a worst-case scenario, the
ECJRC, 2008 source only provides a single datapoint with uncertain statistics and the ECJRC, 2004 source provided a dataset with
an uncertain range and number of samples. EPA also assumed 8 exposure hours per day and 250 exposure days per year based on
continuous DBP exposure each working day for a typical worker schedule; it is uncertain whether this captures actual worker
schedules and exposures.
Although the use of surrogate monitoring data increases the strength of the analysis, the few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
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Incorporation into
formulations,
mixtures, or
reaction products
EPA used surrogate monitoring data from DBP manufacturing facilities to estimate worker inhalation exposures, due to no data
availability for Incorporation into formulations, mixtures, or reaction products (adhesives, coatings, and other) inhalation exposures.
The primary strength of this approach is the use of monitoring data, which is preferrable to other assessment approaches, such as
modeling or the use of OELs. EPA used PBZ air concentration data pulled from 3 sources to assess inhalation exposures (ECB.
2008; ECJRC, 2004; SRC, 2001). All 3 data sources received a ratine of medium from EPA's svstematic review process. These data
were DBP-specific, though it is uncertain whether the measured concentrations accurately represent the entire industry.
The primary limitations of these data include uncertainty in the representativeness of these data for this OES and the true distribution
of inhalation concentrations in this scenario. Additionally, the dataset is only built on limited data points (3 data sources) with a
significant spread of measurements. The SRC source cites an ACC study that provides a datapoint as a worst-case scenario, the
ECJRC, 2008 source only provides a single datapoint with uncertain statistics and the ECJRC, 2004 source provided a dataset with
an uncertain range and number of samples. EPA also assumed 8 exposure hours per day and 250 exposure days per year based on
continuous DBP exposure each working day for a typical worker schedule; it is uncertain whether this captures actual worker
schedules and exposures.
Although the use of surrogate monitoring data increases the strength of the analysis, the few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
PVC plastics
compounding
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for PVC plastics compounding. EPA
used surrogate monitoring data from a PVC converting facility to estimate worker inhalation exposures due to no relevant OES-
specific data. The primary strength of this approach is the use of monitoring data, which is preferrable to other assessment
approaches, such as modeling or the use of OELs. EPA used PBZ air concentration data pulled from 1 source to assess inhalation
exposures to vapor. This source provided worker exposures from 2 different studies (ECJRC. 2004) and received a rating of medium
from EPA's systematic review process.
EPA also expects compounding activities to generate dust from solid PVC plastic products; therefore, the Agency incorporated the
PNOR Model ("U.S. EPA. 202 Id) into the assessment to estimate worker inhalation exposures to solid particulate. A strength of the
model is that the respirable PNOR range was refined using OSHA CEHD datasets, which EPA tailored to the Plastics and Rubber
Manufacturing NAICS code (NAICS 326). and the resulting dataset contains 237 discrete sample data points (OSHA, 2019). EPA
estimated the highest expected concentration of DBP based on the Generic Scenario for the Use of Additives in Plastic Compounding
(U.S. EPA, 2 ).
The primary limitations of these data include uncertainty in the representativeness of the vapor monitoring data and the PNOR Model
in capturing the true distribution of inhalation concentrations for this OES. Additionally, the vapor monitoring dataset consisted of
just 4 datapoints for workers, none of the datapoints indicate the worker tasks, and 2 of the data points are for an unspecified sector
of the "polymer industry." Furthermore, the OSHA CEHD dataset used in the PNOR Model is not specific to DBP. Finally, EPA
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assumed 8 exposure hours per day and 250 exposure days per year based on continuous DBP exposure during each working day for a
typical worker schedule. It is uncertain whether this assumption captures actual worker schedules and exposures.
Although the use of surrogate monitoring data increases the strength of the analysis, the few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
PVC plastics
converting
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for PVC plastics converting. EPA used
PBZ air concentration data pulled from 1 source to assess inhalation exposures to vapor. The primary strength of this approach is the
use of directly applicable monitoring data, which is preferrable to other assessment approaches such as modeling or the use of OELs.
This source provided worker exposures from 2 different studies (ECJRC. 2004) and received a rating of medium from EPA's
systematic review process.
EPA also expects converting activities to generate dust from solid PVC plastic products; therefore, the Agency incorporated the
PNOR Model (U.S. EPA, 202 Id) into the assessment to estimate worker inhalation exposures to solid particulate. A strength of the
model is that the respirable PNOR range was refined using OSHA CEHD datasets, which EPA tailored to the Plastics and Rubber
Manufacturing NAICS code (NAICS 326) and the resulting dataset contains 237 discrete sample data points (OSHA. 2019). EPA
estimated the highest expected concentration of DBP based on the Generic Scenario for the Use of Additives in Plastic Compounding
(U.S. EPA. 2 ).
The primary limitations of these data include uncertainty in the representativeness of the vapor monitoring data and the PNOR Model
in capturing the true distribution of inhalation concentrations for this OES. Additionally, the vapor monitoring dataset consisted of
just four datapoints for workers, none of the datapoints indicate the worker tasks, and 2 of the data points are for an unspecified
sector of the "polymer industry." Further, the OSHA CEHD dataset used in the PNOR Model is not specific to DBP. Finally, EPA
assumed 8 exposure hours per day and 250 exposure days per year based on continuous DBP exposure during each working day for a
typical worker schedule. It is uncertain whether this assumption captures actual worker schedules and exposures.
Although the use of monitoring data specific to this OES increases the strength of the analysis, the few uncertainties discussed in the
paragraph above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the
weight of scientific evidence for this assessment is moderate to robust.
Non-PVC materials
compounding and
converting
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for non-PVC materials compounding and
converting. The Agency used surrogate monitoring data from a PVC converting facility to estimate worker inhalation exposures due
to no relevant OES-specific data. The primary strength of this approach is the use of monitoring data, which is preferrable to other
assessment approaches such as modeling or the use of OELs. EPA used PBZ air concentration data pulled from 1 source to assess
inhalation exposures to vapor. This source provided worker exposures from 2 different studies (ECJRC, 2004) and received a ratine
of medium from EPA's systematic review process.
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EPA also expects compounding activities to generate dust from solid PVC plastic products; therefore, the Agency incorporated the
PNOR Model ("U.S. EPA. 202 Id) into the assessment to estimate worker inhalation exposures to solid particulate. A strength of the
model is that the respirable PNOR range was refined using OSHA CEHD datasets, which EPA tailored to the Plastics and Rubber
Manufacturing NAICS code (NAICS 326) and the resulting dataset contains 237 discrete sample data points (OSHA, 2019). EPA
estimated the highest expected concentration of DBP based on the Emission Scenario Document on Additives in Rubber Industry
COECD. 2004a).
The primary limitations of these data include uncertainty in the representativeness of the vapor monitoring data and the PNOR Model
in capturing the true distribution of inhalation concentrations for this OES. Additionally, the vapor monitoring dataset consisted of
just 4 datapoints for workers, none of the datapoints indicate the worker tasks, and 2 of the data points are for an unspecified sector
of the "polymer industry." Further, the OSHA CEHD dataset used in the PNOR Model is not specific to DBP. Finally, EPA assumed
8 exposure hours per day and 250 exposure days per year based on continuous DBP exposure during each working day for atypical
worker schedule. It is uncertain whether this assumption captures actual worker schedules and exposures.
Although the use of surrogate monitoring data increases the strength of the analysis, the few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
Application of
adhesives and
sealants
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for the application of adhesives and
sealants. The Agency used monitoring data from a NIOSH HHE that documented exposures at a single furniture assembly site to
estimate worker inhalation exposures to vapor. The primary strength of this approach is the use of directly applicable monitoring
data, which is preferrable to other assessment approaches such as modeling or the use of OELs. EPA used PBZ air concentration data
from this source to assess inhalation exposures fNIOSH. 1977). The source received a rating of medium from EPA's svstematic
review process.
The primary limitations of these data include uncertainty in the representativeness of the vapor monitoring data in capturing the true
distribution of inhalation concentrations for this OES. Only 1 use site type, furniture manufacturing, is represented by the data and
this may not represent the entire adhesive and sealant industry. Additionally, 100% of the vapor monitoring datapoints were below
the LOD and therefore the actual exposure concentration is unknown with the LOD used as an upper limit of exposure. Finally, EPA
assumed 8 exposure hours per day and 232-250 exposure days per year based on continuous DBP exposure during each working day
for a typical worker schedule with the exposure days representing the 5 0-95th percentile of the exposure day distribution. It is
uncertain whether this assumption captures actual worker schedules and exposures.
Although the use of monitoring data specific to this OES increases the strength of the analysis, the few uncertainties discussed in the
paragraph above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the
weight of scientific evidence for this assessment is moderate to robust and provides an upper-bound estimate of exposures.
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Application of
paints and coatings
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for the application of paints and coatings.
EPA identified 2 full-shift PBZ monitoring samples in OSHA's CEHD and a monitoring dataset from an industry sponsored study
found through EPA's literature search. The primary strength of this approach is the use of directly applicable monitoring data, which
is preferrable to other assessment approaches such as modeling or the use of OELs. EPA used PBZ air concentration data from the 2
sources, which represent 3 different use facilities, to assess inhalation exposures (OSHA. 2019; Rohm & Haas. 1990). The OSHA
CEHD source received a rating of high and the Rohm & Haas source received a rating of low from EPA's systematic review process.
The primary limitations of these data include uncertainty in the representativeness of the monitoring data in capturing the true
distribution of inhalation concentrations for this OES. Three different use sites are represented by the data but these may not
represent the overall DBP-containing paint and coating industry. Finally, EPA assumed 8 exposure hours per day and 250 exposure
days per year based on continuous DBP exposure during each working day for a typical worker schedule. It is uncertain whether this
assumption captures actual worker schedules and exposures.
Although the use of monitoring data specific to this OES increases the strength of the analysis, the few uncertainties discussed in the
paragraph above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the
weight of scientific evidence for this assessment is moderate to robust.
Use of industrial
process solvents
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for the Use of industrial process solvents.
Due to no relevant OES-specific data, EPA used surrogate monitoring data from DBP manufacturing facilities to estimate worker
inhalation exposures. The primary strength of this approach is the use of monitoring data, which is preferrable to other assessment
approaches such as modeling or the use of OELs. EPA used PBZ air concentration data pulled from 3 sources to assess inhalation
exposures (E )8; ECJRC, 2004; SRC, 2001). All 3 data sources received a ratine of medium from EPA's systematic review
process. These data were DBP-specific, though it is uncertain whether the measured concentrations accurately represent the entire
industry.
The primary limitations of these data include uncertainty in the representativeness of these data for this OES and the true distribution
of inhalation concentrations in this scenario. Additionally, the dataset is only built on limited data points (3 data sources) with a
significant spread of measurements. The SRC source sites an ACC conversation that provides a datapoint as a worst-case scenario,
the ECJRC, 2008 source only provides a single datapoint with uncertain statistics and the ECJRC, 2004 source provided a dataset
with an uncertain range and number of samples. EPA also assumed 8 exposure hours per day and 250 exposure days per year based
on continuous DBP exposure each working day for a typical worker schedule; it is uncertain whether this captures actual worker
schedules and exposures. DBP exposure each working day for atypical worker schedule; it is uncertain whether this captures actual
worker schedules and exposures.
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Although the use of surrogate monitoring data increases the strength of the analysis, the few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate.
Use of laboratory
chemicals
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for the Use of laboratory chemicals. Due
to no relevant OES-specific data, the Agency used surrogate monitoring data from a NIOSH HHE for Application of adhesives and
sealants OES to estimate worker vapor inhalation exposures as well as the PNOR Model (U.S. EPA. 202Id) to characterize worker
particulate inhalation exposures. The primary strength of this approach is the use of monitoring data, which are preferrable to other
assessment approaches such as modeling or the use of OELs. EPA used PBZ air concentration data from the NIOSH HHE to assess
inhalation exposures (NIOSH. 1977). The source received a rating of medium from EPA's systematic review process.
EPA also used the PNOR Model (U.S. EPA, 202Id) to estimate worker inhalation exposure to solid particulate. The model data is
based on OSHA CEHD data (OSHA, 2019). EPA used a subset of the respirable particulate data from the generic model identified
with the Professional, Scientific, and Technical Services NAICS code (NAICS code 54) to assess this OES, which the Agency
expects to be the most representative subset of the particulate data for use of laboratory chemicals in the absence of DBP-specific
data. EPA estimated the highest expected concentration of DBP in identified DBP-containing products applicable to this OES.
The primary limitation of this approach is uncertainty in the representativeness of the vapor monitoring data and the PNOR Model in
capturing the true distribution of inhalation concentrations for this OES. Additionally, the vapor monitoring data come from 1 source
where the identified samples were below the LOD and therefore the actual exposure concentration is unknown with the LOD used as
an upper limit of exposure. Further, the OSHA CEHD dataset used in the PNOR Model is not specific to DBP. EPA also assumed 8
exposure hours per day and 250 exposure days per year based on continuous DBP exposure each working day for a typical worker
schedule; it is uncertain whether this captures actual worker schedules and exposures.
Although the use of surrogate monitoring data increases the strength of the analysis, teh few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate and provides an upper-bound estimate of exposures.
Use of lubricants
and functional
fluids
EPA considered the assessment approach, the quality of the data, and the uncertainties in the assessment results to determine a
weight of scientific evidence conclusion for the 8-hour TWA inhalation exposure estimates for the Use of lubricants and functional
fluids. Due to no relevant OES-specific data, the Agency used surrogate monitoring data from the OES for application of adhesives
containing DBP to estimate worker vapor inhalation exposures. The primary strength of this approach is the use of monitoring data,
which are preferrable to other assessment approaches, such as modeling or the use of OELs. EPA used PBZ air concentration data
from this source to assess inhalation exposures (NIOSH, 1977). The source received a ratine of medium from EPA's svstematic
review process.
The primary limitation of this approach is uncertainty in the representativeness of the vapor monitoring data in capturing the true
distribution of inhalation concentrations for this OES. Additionally, the vapor monitoring data come from 1 source and 100% of the
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data were below the LOD. EPA also assumed 8 exposure hours per day and 2 to 4 exposure days per year based on a typical
equipment maintenance schedule; it is uncertain whether this captures actual worker schedules and exposures.
Although the use of surrogate monitoring data increases the strength of the analysis, teh few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA concluded that the weight of
scientific evidence for this assessment is moderate and provides an upper-bound estimate of exposures
Use of penetrants
and inspection
fluids
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 developed a Penetrant and Inspection Fluid
Near-Field/Far-Field Inhalation Exposure Model which uses a near-field/far-field approach and the inputs to the model were derived
from references that received ratings of medium-to-high for data quality in the systematic review process. EPA combined this model
with Monte Carlo modeling to estimate occupational exposures in the near-field (worker) and far-field (ONU) inhalation exposures.
A strength of the Monte Carlo modeling approach is that variation in model input values and a range of potential exposure values is
more likely than a discrete value to capture actual exposure at sites, the high number of data points (simulation runs), and the full
distributions of input parameters. EPA identified and used a DINP-containing penetrant/inspection fluid product as surrogate to
estimate concentrations, application methods, and use rate.
The primary limitation is the uncertainty in the representativeness of values toward the true distribution of potential inhalation
exposures. EPA lacks facility and DBP-specific product use rates, concentrations, and application methods, therefore, estimates are
made based on surrogate DINP-containing product. The Agency only found 1 product to represent this use scenario; however, and its
representativeness of all DBP-containing penetrants and inspection fluids is not known. Also, EPA based exposure days and
operating davs as specified in the ESD on the Use of Metalworkina Fluids (OE( ). which mav not be representative of all
facilities and workers that use these products.
Although the use of Monte Carlo modeling increases the strength of the analysis, teh few uncertainties discussed in the paragraph
above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA has concluded that the weight of
scientific evidence for this assessment is moderate.
Fabrication or Use
of Final Product
and Articles
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 full-shift TWA inhalation exposure estimates for the fabrication or use of final products or
articles OES. EPA used monitoring data from a facility melting, shaping, and gluing plastics and a facility welding plastic roofing
components (ECJRC, 2004; Rudel et al., 2001)to assess worker inhalation exposures to vapor. Both sources received a ratine of
medium from EPA's svstematic review process. EPA also utilized the PNOR Model (U S. EPA. 202id) to estimate worker
inhalation exposure to solid particulate. The primary strength of this approach is the use of monitoring data, which is preferrable to
other assessment approaches such as modeling or the use of OELs. For the vapor exposure, EPA used workplace DBP air
concentration data found from 2 sources to assess inhalation exposures to vapor. This data was DBP-specific and from facilities
manipulating finished DBP-containing articles.
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The respirable particulate concentrations used bv the generic model is based on OSHA CEHD data (OSHA, 2019). EPA used a
subset of the respirable particulate data from the generic model identified with the Furniture and Related Product Manufacturing
NAICS code (NAICS code 337) to assess this OES, which EPA expects to be the most representative subset of the particulate data
for this OES. EPA estimated the highest expected concentration of DBP in particulates during product fabrication using plasticizer
additive concentration information from the Use of Additives in Plastic Converting Generic Scenario (U.S. EPA, 2004a). These
strengths increase the weight of evidence.
The primary limitation is the uncertainty in the representativeness of values toward the true distribution of potential inhalation
exposures. Specifically, EPA lacks facility-specific particulate concentrations in air, and the representativeness of the data set used in
the model towards sites that actually handle DBP is uncertain. Further, the model lacks metadata on worker activities. EPA assumed
8 exposure hours per day based on continuous DBP particulate exposure while handling DBP-containing products on site each
working day for a typical worker schedule; it is uncertain whether this captures actual worker schedules and exposures. The Agency
set the number of exposure days for both central-tendency and high-end exposure estimates at 250 days per year based on EPA
default assumptions. Vapor exposures are not expected to significantly contribute to overall inhalation exposure compared to
particulate exposures. These limitations decrease the weight of evidence.
Although the use of monitoring data specific to this OES increases the strength of the analysis, the few uncertainties discussed in the
paragraph above reduce confidence of the analysis. Therefore, based on these strengths and limitations, EPA has concluded that the
weight of scientific evidence for this assessment is moderate and provides an upper-bound estimate of exposures.
Recycling
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 full-shift TWA inhalation exposure estimates for the recycling OES. EPA utilized the PNOR
Model (U.S. EPA, 202Id) to estimate worker inhalation exposure to solid particulate. The respirable particulate concentrations used
bv the generic model are based on OSHA CEHD data (OSHA, 2019). EPA used a subset of the respirable particulate data from the
generic model identified with the Administrative and Support and Waste Management and Remediation Services NAICS code
(NAICS code 56) to assess this OES, which EPA expects to be the most representative subset of the particulate data for this OES.
EPA estimated the highest expected concentration of DBP in plastic using plasticizer additive concentration information from the
Use of Additives in Plastic Converting Generic Scenario (U.S. EPA. 2004a). These strengths increase the weight of evidence.
The primary limitation is the uncertainty in the representativeness of values toward the true distribution of potential inhalation
exposures. Specifically, EPA lacks facility-specific particulate concentrations in air, and the representativeness of the data set used in
the model towards sites that actually handle DBP is uncertain. Further, the model lacks metadata on worker activities. The Agency
set the number of exposure days for both central-tendency and high-end exposure estimates at 250 days per year based on EPA
default assumptions. Also, it was assumed that each worker is potentially exposed for 8 hours per workday; however, it is uncertain
whether this captures actual worker schedules and exposures. These limitations decrease the weight of evidence.
Although the use of PNOR Model which is based on OSHA CEHD monitoring data increases the strength of the analysis, the few
uncertainties discussed in the paragraph above reduces confidence of the analysis. Therefore, based on these strengths and
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limitations, EPA has concluded that the weight of scientific evidence for this assessment is moderate and provides an upper-bound
estimate of exposures.
Waste handling,
treatment, and
disposal
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 full-shift TWA inhalation exposure estimates for the waste handling, treatment, and disposal
OES. EPA utilized the PNOR Model (U.S. EPA, 202Id) to estimate worker inhalation exposure to solid particulate. The respirable
particulate concentrations used bv the generic model are based on OSHA CEHD data (OSHA, 2019). EPA used a subset of the
respirable particulate data from the generic model identified with the Administrative and Support and Waste Management and
Remediation Services NAICS code (NAICS code 56) to assess this OES, which EPA expects to be the most representative subset of
the particulate data for this OES. EPA estimated the highest expected concentration of DBP in plastic using plasticizer additive
concentration information from the Generic Scenario for the Use of Additives in Plastic Compounding (U.S. EPA. 202 le). These
strengths increase the weight of evidence.
The primary limitation is the uncertainty in the representativeness of values toward the true distribution of potential inhalation
exposures. Specifically, EPA lacks facility-specific particulate concentrations in air, and the representativeness of the data set used in
the model towards sites that actually handle DBP is uncertain. Furthermore, the model lacks metadata on worker activities. The
Agency set the number of exposure days for both central-tendency and high-end exposure estimates at 250 days per year based on
EPA default assumptions. Also, it was assumed that each worker is potentially exposed for 8 hours per workday; however, it is
uncertain whether this captures actual worker schedules and exposures. These limitations decrease the weight of evidence.
Although the use of PNOR Model, which is based on OSHA CEHD monitoring data, increases the strength of the analysis, few
uncertainties discussed in the paragraph above reduce confidence of the analysis. Therefore, based on these strengths and limitations,
EPA has concluded that the weight of scientific evidence for this assessment is moderate and provides an upper-bound estimate of
exposures.
Dermal - Liquids
EPA used dermal absorption data for 7% oil-in-water DBP formulations to estimate occupational dermal exposures for liquid (Doan
et aL 2010). The tests were performed on guinea pigs, which have more permeable skin than humans (OECD. 2004b). meaning the
dermal absorption value is likely protective for human skin. However, it is acknowledged that variations in chemical concentration
and co-formulant components affect the rate of dermal absorption. Additionally, it is unclear how representative the data from Doan
et al. (2010) are for neat DBP. Because EPA assumed absorptive flux of DBP measured from guinea pis experiments serves as an
upper bound of potential absorptive flux of chemical into and through the skin for dermal contact with all liquid products. EPA is
confident that the dermal absorption data using guinea pigs provides an upper bound of dermal absorption of DBP.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the chemical is contacted at least once
per day. Because DBP has low volatility and relatively low absorption, it is possible that the chemical remains on the surface of the
skin after dermal contact until the skin is washed. Therefore, in absence of exposure duration data, EPA has assumed that absorption
of DBP from occupational dermal contact with materials containing DBP mav extend up to 8 hours per dav (U.S. EPA. 1991).
However, if a worker uses proper PPE or washes their hands after contact with DBP or DBP-containing materials dermal exposure
may be eliminated. Therefore, the assumption of an 8-hour exposure duration for DBP may lead to overestimation of dermal
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exposure. For average adult workers, the surface area of contact was assumed equal to the area of 1 hand (i.e., 535 cm2), or 2 hands
(i.e., 1.070 cm2), for central tendencv exposures, or hieh-end exposures, respectively (U.S. EPA, 201 la). Other parameters such as
frequency and duration of use, and surface area in contact, are well understood and representative. Despite moderate confidence in
the estimated values themselves, EPA has robust confidence that the dermal liquid exposure estimates are upper bound of potential
exposure scenarios.
Dermal - Solids
It is expected that dermal exposure to solid matrices would result in far less absorption, but there are no studies that report dermal
absorption of DBP from a solid matrix. For cases of dermal absorption of DBP from a solid matrix, EPA assumed that DBP will first
migrate from the solid matrix to a thin layer of moisture on the skin surface. Therefore, absorption of DBP from solid matrices is
considered limited bv aaueous solubilitv and is estimated usine an aaueous absorption model (U.S. EPA, 2023c. 2004b).
Nevertheless, it is assumed that absorption of the aqueous material serves as a reasonable upper bound for contact with solid
materials. Also, EPA acknowledges that variations in chemical concentration and co-formulant components affect the rate of dermal
absorption. For OES with lower concentrations of DBP in the solid, it is possible that the estimated amount absorbed using the
modeled flux value would exceed the amount of DBP available in the dermal load. In these cases, EPA capped the amount absorbed
to the maximum amount of DBP in the solid (i.e., the product of the dermal load and the weight fraction of DBP). For occupational
dermal exposure assessment, EPA assumed a standard 8-hour workday and the chemical is contacted at least once per day. Because
DBP has low volatility and relatively low absorption, it is possible that the chemical remains on the surface of the skin after dermal
contact until the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP from
occupational dermal contact with materials containing DBP mav extend up to 8 hours per dav (U.S. EPA. 1991). However, if a
worker uses proper PPE or washes their hands after contact with DBP or DBP-containing materials dermal exposure may be
eliminated. Therefore, the assumption of an 8-hour exposure duration for DBP may lead to overestimation of dermal exposure. EPA
also assumed an area of contact for average adult workers ranging from 535 cm2 (central tendency) to 1,070 cm2 (high-end) (U.S.
EPA, 201 la). The occupational dermal exposure assessment is limited in that it does not consider the uniaueness of each material
potentially contacted; however, the dermal exposure estimates are expected to be representative of materials potentially encountered
in occupational settings.
Therefore, the dermal absorption estimates assume that dermal absorption of DBP from solid objects would be limited by the
aqueous solubility of DBP. EPA has moderate confidence in the aspects of the exposure estimate for solid articles because of the
high uncertainty in the assumption of partitioning from solid to liquid, and because subsequent dermal absorption is not well
characterized. Additionally, there are uncertainties associated to the flux-limited approach which likely results in overestimations due
to the assumption about excess DBP in contact with skin for the entire work duration. Other parameters such as frequency and
duration of use, and surface area in contact have unknown uncertainties due to lack of information about use patterns. Despite
moderate confidence in the estimated values themselves, EPA has robust confidence that the exposure estimates are upper bound of
potential exposure scenarios.
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4.1.1.5.1 Strengths, Limitations, Assumptions, and Key Sources of Uncertainty for
the Occupational Exposure Assessment
EPA assigned overall confidence descriptions of high, medium, or low to the exposure assessments
based on the strength of the underlying scientific evidence. When the assessment is supported by robust
evidence, EPA's overall confidence in the exposure assessment is high; when supported by moderate
evidence, EPA's overall confidence is medium; when supported by slight evidence, EPA's overall
confidence is low.
Strengths
The exposure scenarios and exposure factors underlying the inhalation and dermal assessment are
supported by moderate to robust evidence. Occupational inhalation exposure estimates were informed
by moderate or robust sources of directly applicable and surrogate monitoring data or modeling was
used to estimate the inhalation exposure estimates. Exposure factors for occupational inhalation
exposure include duration of exposure, body weight, and breathing rate, which were informed by
moderate to robust data sources.
Limitations
The principal limitation of the exposure assessments is uncertainty in the representativeness of the data
and models used as there is limited direct exposure monitoring data for DBP in the literature from
systematic review. A limitation of the modeling methodologies is that most of the model input data from
GSs/ESDs, such as air speed or loss factors, are generic for the OESs and not specific to the use of DBP
within the OESs. Additionally, the selected generic models and data may not be representative of all
chemical- or site-specific work practices and engineering controls. Limitations associated with dermal
exposure assessment are described in Table 4-5.
Assumptions
When determining the appropriate model for assessing exposures to DBP, the Agency considered the
physical form of DBP during different OESs. DBP may be present in various physical forms such as a
powder, mist, paste, or in solution during the various OESs. EPA assessed each respective OES
assuming the physical form of DBP based on available product data, CDR data, and information from
applicable GSs/ESDs. Because the physical form of DBP can influence exposures substantially, EPA
assumed DBP is present in the physical form that is most prevalent and/or most protective for the given
OES when assessing the exposures.
EPA calculated chronic ADD values assuming workers and ONUs are exposed at the same level for
their entire working lifetime, which may result in an overestimate. Individuals may change jobs during
the course of their career such that they are no longer exposed to DBP and the actual ADD values
become lower than the estimates presented. EPA collected tenure data to estimate central tendency and
high-end working years of exposure that is assumed to inherently take into account workers changing
jobs. Assumptions associated with dermal exposure assessment are described in Table 4-5.
Uncertainties
EPA addressed variability in inhalation models by identifying key model parameters and applying
statistical distributions that mathematically define the parameter's variability. The Agency defined
statistical distributions for parameters using documented statistical variations where available. Where
the statistical variation was unknown, EPA made assumptions to estimate the parameter distribution
using available literature data, such as GSs and ESDs. However, there is uncertainty as to the
representativeness of the parameter distributions because these data are often not specific to sites that
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use DBP. In general, the effects of these uncertainties on the exposure estimates are unknown as the
uncertainties may result in either overestimation or underestimation of exposures, depending on the
actual distributions of each of the model input parameters. Uncertainties associated with dermal
exposure assessment are described in Table 4-5.
4.1.2 Consumer Exposures
The following subsections briefly describe EPA's approach to assessing consumer exposures and
provide exposure assessment results for each COU. The Draft Consumer and Indoor Dust Exposure
Assessment for Dibutyl Phthalate (DBP) ( 25c) provides additional details on the
development of approaches and the exposure assessment results. The consumer exposure assessment
evaluated exposures from individual COUs whereas the indoor dust assessment uses a subset of
consumer articles with large surface area and presence in indoor environments to garner COU specific
contributions to the total exposures from dust.
4.1.2.1 Summary of Consumer and Indoor Dust Exposure Scenarios and Modeling
Approach and Methodology
The major steps in performing a consumer exposure assessment are summarized below:
• identification and mapping of product and article examples following the consumer COU table
(Table 4-6), product, and article identification;
• compilation of products' and articles' manufacturing use instructions to determine patterns of
use;
• selection of exposure routes and exposed populations according to product/article use
descriptions;
• identification of data gaps and further search to fill gaps with studies, chemical surrogates or
product and article proxies, or professional judgement;
• selection of appropriate modeling tools based on available information and chemical properties;
• gathering of input parameters per exposure scenario; and
• parameterization of selected modeling tools.
Consumer products or articles containing DBP were matched with the identified consumer COUs. Table
4-6 summarizes the consumer exposure scenarios by COU for each product example(s), the exposure
routes, which scenarios are also used in the indoor dust assessment, and whether the analysis was
conducted qualitatively or quantitatively, see Sections 2.2.1 and 2.2.2 in ( 2025c) for detailed
descriptions, explanations, and rationale. The indoor dust assessment uses consumer product and article
information for selected items with the goal of recreating the indoor environment. The subset of
consumer products and articles that are used in the indoor dust assessment are selected for their potential
to have large surface area for dust collection, roughly larger than 1 m2
When a quantitative analysis of reasonably available information was conducted, exposure from the
consumer COUs was estimated by modeling. Exposure via inhalation and ingestion routes were modeled
using EPA's CEM, Version 3.2 (U.S. EPA. 2023c). Dermal exposures for both liquid products and solid
articles were calculated outside of CEM, see Draft Consumer Exposure Analysis for Dibutyl Phthalate
(DBP) ( Z025d) for calculations and inputs. CEM dermal modeling uses a dermal model
approach that assumes infinite DBP migration from product to skin without considering saturation
which result in overestimations of dose and subsequent risk, see Section 2.3 in U.S. EPA (2025c) for a
detailed explanation. Dermal exposures were estimated using a computational framework implemented
within a spreadsheet environment using a flux-limited, dermal absorption approach for liquid and solid
products ( !25d). For each exposure route, EPA used the 10th percentile, average, and 95th
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percentile value of an input parameter (e.g., weight fraction, surface area) where possible to characterize
low, medium, and high exposure scenarios for a given COU. If only a range was reported, EPA used the
minimum and maximum of the range as the low and high values, respectively. The average of the
reported low and high values from the reported range was used for the medium exposure scenario. See
Draft Consumer and Indoor Dust Exposure Assessment for Dibutyl Phthalate (DBP) ( 325 c)
for details about the consumer modeling approaches, sources of data, model parameterization, and
assumptions. High-, medium-, and low-intensity use exposure scenarios serve as a two-pronged
approach. First, it provides a sensitivity analysis with insight on the impact of the main modeling input
parameters (e.g., skin contact area, duration of contact, and frequency of contact) in the doses and risk
estimates. And second, the high-intensity use exposure scenarios are used first to screen for potential
risks at the upper bound of possible exposures and then, if needed, to refine.
Exposure via the inhalation route occurs from inhalation of DBP gas-phase emissions or when DBP
partitions to suspended particulate from direct use or application of products. However, DBP's low
volatility is expected to result in negligible gas-phase inhalation exposures. Sorption to suspended and
settled dust is likely to occur based on monitoring data (see indoor dust monitoring data in Section
4.1.2.1) and its affinity for organic matter that is typically present in household dust). Thus, inhalation
and ingestion of suspended and settled dust is considered in this draft assessment. Exposure via the
dermal route can occur from direct contact with products and articles. Exposure via ingestion depends
on the product or article use patterns. Exposure can occur via direct mouthing (i.e., directly putting
product in mouth) in which the person can ingest settled dust with DBP or directly ingesting DBP from
migration to saliva. Additionally, ingestion of suspended dust can occur when DBP migrates from article
to dust or partitions from gas-phase to suspended dust.
EPA made some adjustments to match CEM's lifestages to those listed in the U.S. Centers for Disease
Control and Prevention (CDC) guidelines ( 2_i) and EPA's ,4 Framework for Assessing Health
Risks of Exposures to Children ( 006). CEM lifestages are re-labeled from this point forward
as follows:
• Adult (21+ years) —~ Adult
• Youth 2 (16-20 years) —~ Teenager
• Youth 1 (11-15 years) —~ Young teen
• Child 2 (6-10 years) —~ Middle childhood
• Child 1 (3-5 years) —~ Preschooler
• Infant 2(1-2 years) —~ Toddler
• Infant 1 (<1 year) —~ Infant
EPA assessed acute, intermediate, and chronic exposures to DBP from consumer COUs. For the acute
dose rate calculations, an averaging time of 1 day is used representing the maximum time-integrated
dose over a 24-hour period during the exposure event. The chronic dose rate is calculated iteratively at a
30-second interval during the first 24 hours and every subsequent hour for 60 days and averaged over 1
year. Intermediate dose is the exposure to continuous or intermittent (depending on product) use during
a 30-day period, which is roughly 1 month. See Sections 2.2.1 and 2.2.2 and Appendix A in (
2025c) for details about acute, chronic, and intermediate dose calculations. Professional judgment and
product use descriptions were used to estimate events per day and per month/year for the calculation of
the intermediate/chronic dose.
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1635 Table 4-6. Summary of Consumer CPUs, Exposure Scenarios, and Exposure Routes
Consumer
Condition of Use
Category
Consumer Condition of Use
Subcategory
Produet/Artiele
Exposure Seenario and Route"
Evaluated Routes
Inhalation6
Dermal
Ingestion
Suspended
Dust
Settled
Dust
W)
=
xl
3
O
s
Automotive, fuel,
agriculture, outdoor
use products
Automotive care products
See automotive adhesives
Use of product in DIY small-scale auto
repair and hobby activities. Direct contact
during use; inhalation of emissions during
use
%/
%/
X
X
X
Construction, paint,
electrical, and metal
products
Adhesives and sealants
Adhesive for small
repairs
Direct contact during use
X
%/
X
X
X
Construction, paint,
electrical, and metal
products
Adhesives and sealants
Automotive adhesives
Use of product in DIY small-scale auto
repair and hobby activities. Direct contact
during use; inhalation of emissions during
use
%/
%/
X
X
X
Construction, paint,
electrical, and metal
products
Adhesives and sealants
Construction adhesives
Direct contact during use
X
%/
X
X
X
Construction, paint,
electrical, and metal
products
Paints and coatings
Metal coatings
Use of product in DIY home repair and
hobby activities. Direct contact during use;
inhalation of emissions during use
%/
%/
X
X
X
Construction, paint,
electrical, and metal
products
Paints and coatings
Sealing and refinishing
sprays (indoor use)
Application of product in house via spray.
Direct contact during use; inhalation of
emissions during use
%/
l/
X
X
X
Construction, paint,
electrical, and metal
products
Paints and coatings
Sealing and refinishing
sprays (outdoor use)
Application of product outdoors via spray.
Direct contact during use; inhalation of
emissions during use
%/
l/
X
X
X
Furnishing, cleaning,
treatment care
products
Fabric, textile, and leather
products
Synthetic leather clothing
Direct contact during use
X
%/
X
X
X
Furnishing, cleaning,
treatment care
products
Fabric, textile, and leather
products
Synthetic leather
furniture
Direct contact during use; inhalation of
emissions / ingestion of airborne
particulate; ingestion by mouthing
•%/ c
%/
•%/ c
•%/ c
%¦>'*
Furnishing, cleaning,
treatment/care
products
Cleaning and furnishing care
products
Spray cleaner
Application of product in house via spray.
Direct contact during use; inhalation of
emissions during use
%/
l/
X
X
X
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Consumer
Condition of Use
Category
Consumer Condition of Use
Subcategory
Product/Article
Exposure Scenario and Route"
Evaluated Routes
Inhalation6
Dermal
Ingestion
Suspended
Dust
Settled
Dust
©X
=
3
O
s
Furnishing, cleaning,
treatment/care
products
Cleaning and furnishing care
products
Waxes and polishes
Application of product in house via spray.
Direct contact during use; inhalation of
emissions during use
%/
l/
X
X
X
Furnishing, cleaning,
treatment/care
products
Floor coverings; construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
articles; fabrics, textiles, and
apparel
Vinyl flooring
Direct contact, inhalation of emissions /
ingestion of dust adsorbed chemical
%/ c
%/
%>' c
•%/ c
X
Furnishing, cleaning,
treatment/care
products
Floor coverings; construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
articles; fabrics, textiles, and
apparel
Wallpaper
Direct contact during installation (teenagers
and adults) and while in place; inhalation
of emissions / ingestion of dust adsorbed
chemical
•%/ c
%/
%>' c
•%/ c
X
Other uses
Novelty articles
Adult toys
Direct contact during use; ingestion by
mouthing
X
%/
X
X
Other uses
Automotive articles
Synthetic leather seats,
see synthetic leather
furniture
Direct contact during use; inhalation of
emissions / ingestion of airborne
particulate; ingestion by mouthing
l/ c
%/
%/ c
l/ c
X
Other uses
Automotive articles
Car mats
Direct contact during use; inhalation of
emissions / ingestion of airborne
particulate; ingestion by mouthing
•%/ c
%/
%>' c
•%/ c
X
Other uses
Chemiluminescent light sticks
Small articles with semi
routine contact; glow
sticks
Direct contact during use
X
%/
X
X
X
Other uses
Lubricants and lubricant additives
No consumer products
identified. See adhesives
for small repairs
Current products were not identified.
Foreseeable uses were matched with the
adhesives for small repairs because similar
use patterns are expected.
X
%/
X
X
X
Packaging, paper,
plastic, hobby
products
Ink, toner, and colorant products
No consumer products
identified. See adhesives
for small repairs
Current products were not identified.
Foreseeable uses were matched with the
X
%/
X
X
X
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Consumer
Condition of Use
Category
Consumer Condition of Use
Subcategory
Produet/Artiele
Exposure Scenario and Route"
Evaluated Routes
Inhalation6
Dermal
Ingestion
Suspended
Dust
Settled
Dust
©X
=
3
O
s
adhesives for small repairs because similar
use patterns are expected.
Packaging, paper,
plastic, hobby
products
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
Footwear
Direct contact during use
X
%/
X
X
X
Packaging, paper,
plastic, hobby
products
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
Shower curtains
Direct contact during use; inhalation of
emissions / ingestion of dust adsorbed
chemical while hanging in place
%/ c
%/
%/ c
%/ c
X
Packaging, paper,
plastic, hobby
products
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
Small articles with semi
routine contact;
miscellaneous items
including a pen, pencil
case, hobby cutting
board, costume jewelry,
tape, garden hose,
disposable gloves, and
plastic bags/pouches
Direct contact during use
X
%/
X
X
X
Packaging, paper,
plastic, hobby
products
Toys, playground, and sporting
equipment
Children's toys (legacy),
produced before cpsia
statutory and regulatory
limitations, 0.1%.
Collection of toys. Direct contact during
use; inhalation of emissions / ingestion of
airborne PM; ingestion by mouthing
•%/ c
%/
•%/ c
•%/ c
%¦>'*
Packaging, paper,
plastic, hobby
products
Toys, playground, and sporting
equipment
Children's toys (new),
produced after cpsia
statutory and regulatory
limitations, 0.1%.
Collection of toys. Direct contact during
use; inhalation of emissions / ingestion of
airborne particulate; ingestion by mouthing
l/ c
%/
l/ c
l/ c
%¦>'*
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Evaluated Routes
Ingestion
Consumer
Condition of Use
Category
Consumer Condition of Use
Subcategory
Product/Article
Exposure Scenario and Route"
Inhalation*
Dermal
Suspended
Dust
Settled
Dust
Mouthing
Packaging, paper,
plastic, hobby
products
Toys, playground, and sporting
equipment
Small Articles with Semi
Routine contact;
miscellaneous items
including a football,
balance ball, and pet toy
Direct contact during use
X
X
X
X
Packaging, paper,
plastic, hobby
products
Toys, playground, and sporting
equipment
Tire crumb and artificial
turf
Direct contact during use (particle
ingestion via hand-to-mouth)
d
Disposal
Disposal
Down the drain products
and articles
Down the drain and releases to
enviromnental media
X
X
X
X
X
Disposal
Disposal
Residential end-of-life
disposal, product
demolition for disposal
Product and article end-of-life disposal and
product demolition for disposal
X
X
X
X
X
DIY-do-it-yourself
CPSIA - Consumer Product Safety Improvement Act of 2008 (CPSIA section 108(a), 15 U.S.C. § 2057c(a);16 CFR. 1307.3(a)), Congress permanently prohibited the
sale of children's toys or childcare articles containing concentrations of more than 0.1 percent DBP.
" See Sections 2.2.1 and 2.2.2 in (U.S. EPA. 2025c) for details about exposure scenarios oer COU and product example and exposure routes assessed auantitativelv and
qualitatively.
h Inhalation scenarios considered suspended dust and gas-phase emissions.
c Scenario used in Indoor Dust Exposure Assessment in Section 4 in (U.S. EPA. 2025c). These indoor dust articles scenarios consider the surface area from multiple
articles such as toys, while furniture and flooring already have large surface areas. For these articles dust can deposit and contribute to significantly larger concentration
of dust than single small articles
d The tire crumb and artificial turf ingestion route assessment considers all 3 types of ingestions, settled dust, suspended dust, and mouthing altogether, but results cannot
be provided separately lias it was done for all other articles and products.
Quantitative consideration
* Qualitative Consideration
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Inhalation and Ingestion Exposure Routes Modeling Approaches
Key parameters for articles modeled in CEM 3.2 2 ( 3c) are summarized in detail in
Section 2 in Draft Consumer and Indoor Dust Exposure Assessment for Dibutyl Phthalate (DBP) (U.S.
E 25c). Calculations, sources, input parameters, and results are also available in Draft Consumer
Exposure Analysis for Dibutyl Phthalate (DBP) ( 25d). Generally, and when possible,
model parameters were determined based on specific articles identified in this assessment and CEM
defaults were only used where specific information was not available. A list of some of the most
important in developing representative scenarios for the selected modeling tools and approaches input
parameters for exposure from articles and products is included below:
• weight fraction (articles and products);
• density (articles and products);
• duration of use (products);
• frequency of use for chronic, acute, and intermediate (products);
• product mass used (products);
• article surface area (articles);
• chemical migration rate to saliva (articles);
• area mouthed (articles); and
• use environment volume (articles and products).
Of these, the chemical migration rate from articles to saliva and area mouthed are most important to
mouthing exposure scenarios. According to a sensitivity analysis conducted for CEM input parameters,
duration, frequency, and amount used are key determinants of estimated exposure concentrations.
For each scenario, high-, medium-, and low-intensity use exposure scenarios were developed in which
values for duration of use, frequency of use, and surface area were determined based on reasonably
available information or professional judgment. Each input parameter listed above was parameterized
according to the article-specific data found via systematic review. If article-specific data were not
available, CEM default parameters were used, or if CEM default parameters were not applicable, an
assumption based on article use descriptions by manufacturers was used, always leaning on the health
protective values. For example, for all scenarios, the near-field modeling option was selected to account
for a small personal breathing zone around the user during product use in which concentrations are
higher, rather than employing a single well-mixed room. This represents a conservative modeling
assumption in the absence of article-specific emission data. A near-field volume of 1 m3 was selected.
See Section 2.1 for weight fraction selection and Section 2.2.3 for parameterization details in the Draft
Consumer and Indoor Dust Exposure Assessment for Dibutyl Phthalate (DBP) ( 2025c).
Dermal Exposure Routes Modeling Approaches
Dermal modeling was conducted outside of CEM. The use of CEM for dermal absorption, which relies
on total concentration rather than aqueous saturation concentration, would greatly overestimate exposure
to DBP in liquid and solid products and articles. See U.S. EPA (2025c) for details. The dermal dose of
DBP associated with use of both liquid products and solid articles was calculated in a spreadsheet, see
Draft Consumer Exposure Analysis for Dibutyl Phthalate (DBP) ( 2025d). EPA used a dermal
exposure modeling approach with a range of conservative and plausible input parameters for contact
surface area as well as duration and frequency of contact. The flux-limited, screening dermal absorption
approaches for liquid and solid products and articles assume an excess of DBP in contact with the skin
independent of concentration in the article/product. Dermal flux values for liquid products was from
Doan et al. ( ), and solid products flux values were calculated and applied in the corresponding
scenario. The flux-limited screening approach provides an upper bound of dermal absorption of DBP
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and likely results in some overestimations, see Section 4.1.2.4 for a discussion on limitations, strengths,
and confidence. For each product or article, high-, medium-, and low-intensity use exposure scenarios
were developed. Values for duration of dermal contact and area of exposed skin were determined based
on the reasonably expected use for each item. Key parameters for the dermal model are shown in
Section 2.3 in (U.S. EPA. 2025c).
4.1.2.2 Modeling Dose Results by COU for Consumer and Indoor Dust
This section summarizes the dose estimates from inhalation, ingestion, and dermal exposure to DBP in
consumer products and articles. Detailed tables of the dose results for acute, intermediate, and chronic
exposures are available in the Draft Consumer Risk Calculator for DibutylPhthalate (DBP) (U.S. EPA.
2025e). Modeling dose results for acute, intermediate, and chronic exposures as well as data patterns are
described in Section 3 in the Draft Consumer and Indoor Exposure Assessment for Dibutyl Phthalate
(DBP) (U.S. EPA. 2025c). The remainder of this section provides a brief summary of the main dose
results patterns for visualizations.
For young teens, teenagers, and young adults (11-20 years) and adults (21+ years), dermal contact was a
strong driver of exposure to DBP across all routes, with the dose received being generally higher than or
similar to the dose received from exposure via inhalation or ingestion. The largest acute dose estimated
was for dermal exposure to adhesives, sealers, coatings, and waxes for young teens to adults. The largest
chronic dose estimated was for dermal and inhalation exposure to metal coatings for young teens to
adults, followed by dermal exposure to adhesives, footwear, and waxes. It is noteworthy that the dermal
analysis used a flux-limited approach, which has larger uncertainties than inhalation dose results—see
Section 4.1.2.4 for a detailed discussion of uncertainties within approaches, inputs, and overall estimate
confidence.
Among the younger lifestages, infant to 10 years, the pattern was less clear as these ages were not
designated as product users and therefore not modeled for dermal contact with any of the liquid products
assessed that resulted in larger dermal doses for the older lifestages. Key differences in exposures among
lifestages include designation as a product user or bystander; behavioral differences such as hand to
mouth contact times and time spent on the floor; and dermal contact expected from touching specific
articles that may not be appropriate for some lifestages.
4.1.2.3 Indoor Dust Assessment
Products and articles that contain DBP are ubiquitous in modern indoor environments and DBP can
partition, migrate, or evaporate (to a lesser extent based on physical and chemical properties) into indoor
air and concentrate in household dust. See Sections 4.1 and 4.2 of the Draft Consumer and Indoor
Exposure Assessment for Dibutyl Phthalate (DBP) (U. 2025c) for a summary of indoor dust
monitoring data that EPA used to establish the presence of DBP in indoor dust in the residential
environment. Exposure to DBP through dust ingestion, dust inhalation, and dermal absorption is a
particular concern for young children between the ages of 6 months and 2 years. This is because
crawling on the ground and pulling up on ledges increases hand-to-dust contact as does placing their
hands and objects in their mouths. Specifically, exposure to DBP via ingestion of dust was assessed for
all articles expected to contribute significantly to dust concentrations due to high surface area (exceeding
~1 m2) for either a single article or collection of similar articles, as appropriate. In a screening
assessment, EPA considered the aggregation of chronic dust ingestion doses, see Section 4.3 in in the
Draft Consumer and Indoor Exposure Assessment for Dibutyl Phthalate (DBP) ( 15c). The
highest dose was for preschoolers aged 3 to 5 years.
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Articles included in the indoor assessment included the following:
• synthetic leather furniture,
• vinyl flooring,
• in-place wallpaper,
• car mats,
• shower curtains,
• children's toys, both legacy and new, and
• tire crumb.
4.1.2.4 Weight of Scientific Evidence Conclusions for Consumer Exposure
Key sources of uncertainty for evaluating exposure to DBP in consumer goods and strategies to address
those uncertainties are described in detail in Section 5.1 of the Draft Consumer and Indoor Dust
Exposure Assessment for DibutylPhthalate (DBP) (U.S. EPA. 2025c). Generally, designation of robust
confidence suggests that the supporting scientific evidence weighed against the uncertainties is adequate
to characterize exposure assessments. The supporting weight of scientific evidence outweighs the
uncertainties to the point where it is unlikely that the uncertainties could have a significant effect on the
exposure estimate. The designation of moderate confidence suggests that the supporting scientific
evidence weighed against the uncertainties is reasonably adequate to characterize exposure assessments.
The designation of slight confidence is assigned when the weight of scientific evidence may not be
adequate to characterize the scenario, when the assessor is making the best scientific assessment
possible in the absence of complete information, and when there are additional uncertainties that may
need to be considered. The DBP consumer exposure overall confidence to use the results for risk
characterization ranges from moderate to robust, depending on COU scenario. The basis for the
moderate to robust confidence in the overall exposure estimates is a balance between using parameters
that will represent various populations' use patterns and leaning on conservative assumptions that are
deemed not excessive or unreasonable and are well characterized.
4.1.2.5 Strength, Limitations, Assumptions, and Key Sources of Uncertainty for the
Consumer Exposure Assessment
The exposure assessment of chemicals from consumer products and articles has inherent challenges due
to many sources of uncertainty in the analysis, including variations in product formulation, patterns of
consumer use, frequency, duration, and application methods. Variability in environmental conditions
may also alter physical and/or chemical behavior of the product or article. Table 4-7 summarizes the
overall confidence per COU and discusses the rationale used to assign the overall certainty. The
subsections preceding Table 4-7 describe sources of uncertainty for several parameters used in consumer
exposure modeling that apply across COUs and provide an in depth understanding of sources of
uncertainty and limitations and strengths within the analysis. The confidence to use the results for risk
characterization ranges from moderate to robust.
Product Formulation and Composition
Variability in the formulation of consumer products, including changes in ingredients, concentrations,
and chemical forms, can introduce uncertainty in exposure assessments. In addition, data were
sometimes limited for weight fractions of DBP in consumer goods. EPA obtained DBP weight fractions
in various products and articles from material safety data sheets, databases, and existing literature. A
significant number of DBP concentration in consumer goods data values were published across several
studies published by the Danish EPA (Danish EPA. 2020). EPA used the Danish EPA information under
the assumption that the weight fractions reported are representative of DBP content that could be present
in items sold in the United States. Where possible, EPA obtained multiple values for weight fractions for
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similar products or articles. The lowest value was used in the low exposure scenario, the highest value in
the high exposure scenario, and the average of all values in the medium exposure scenario. EPA
decreased uncertainty in exposure and subsequent risk estimates in the high-, medium-, and low-
intensity use scenarios by capturing the weight fraction variability and obtaining a better
characterization of the varying composition of products and articles within one COU. Overall weight
fraction confidence is moderate for products/articles with multiple sources but insufficient description
on how the concentrations were obtained, robust for products/articles with more than one source, and
slight for articles with only one source with unconfirmed content or little understanding on how the
information was produced.
Product Use Patterns
Consumer use patterns such as frequency of use, duration of use, method of application, and skin contact
area are expected to differ. Where possible, high, medium, and low default values from CEM 3.2's
prepopulated scenarios were selected for mass of product used, duration of use, and frequency of use. In
instances where no prepopulated scenario was appropriate for a specific product, low, medium, and high
values for each of these parameters were estimated based on the manufacturers' product descriptions.
EPA decreased uncertainty by selecting use pattern inputs that represent product and article use
descriptions and furthermore capture the range of possible use patterns in the high to low intensity use
scenarios. Exposure and risk estimates are considered representative of product use patterns and well
characterized. The overall confidence for most use patterns is rated robust.
Article Use Patterns
For articles inhalation and ingestion exposures, the high-, medium-, and low-intensity use scenarios
default values from CEM 3.2's prepopulated scenarios were selected for indoor use environment/room
volume, interzone ventilation, and surface layer thickness. For articles' dermal exposures use patterns
such as duration and frequency of use and skin contact area are expected to have a range of low to high
use intensities. For articles that do not use duration of use as an input in CEM, professional judgment
was used to select the duration of use/article contact duration for the low, medium, and high exposure
scenario levels for most articles except carpet tiles and vinyl flooring. Carpet tiles and vinyl flooring
contact duration values were taken from EPA's Standard Operating Procedures for Residential
Pesticide Exposure Assessment for the high exposure level (2 hours; time spent on floor surfaces) (U.S.
E ). ConsExpo (U.S. EPA. 2012c) for the medium exposure level (1 hour; time a child spends
crawling on treated floor), and professional judgment for the low exposure level (0.5 hour). There are
more uncertainties in the assumptions and professional judgment for contact duration inputs for articles;
thus, EPA has moderate confidence in those inputs.
Article Surface Area
The surface area of an article directly affects the potential for DBP emissions to the environment. For
each article modeled for inhalation exposure, low, medium, and high estimates for surface area were
calculated in Section 2 in U.S. EPA (2025c). This approach relied on manufacturer-provided dimensions
where possible, or values from EPA's Exposure Factors Handbook for floor and wall coverings. For
small items that might be expected to be present in a home in significant quantities, such as children's
toys, aggregate values were calculated for the cumulative surface area for each type of article in the
indoor environment. Overall confidence in surface area is robust for articles like furniture, wall
coverings, flooring, toys, and shower curtains because there is a good understanding of the presence and
dimensions of these articles in indoor environments.
Human Behavior
CEM 3.2 has three different activity patterns: stay-at-home; part-time out-of-the home (daycare, school,
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or work); and full-time out-of-the-home. The activity patterns were developed based on the
Consolidated Human Activity Database (CHAD). For all products and articles modeled, the stay-at-
home activity pattern was chosen as it is the most protective assumption.
Mouthing durations are a source of uncertainty in human behavior. The data used in this assessment are
based on a study in which parents observed children (n = 236) ages 1 month to 5 years of age for 15
minutes each session and 20 sessions in total (Smith and Norris. 2003). There was considerable
variability in the data due to behavioral differences among children of the same lifestage. For instance,
while children aged 6 to 9 months had the highest average mouthing duration for toys at 39 minutes per
day, the minimum duration was 0 minutes and the maximum was 227 minutes per day. The observers
noted that the items mouthed were made of plastic roughly 50 percent of the mouthing time, but this was
not limited to soft plastic items likely to contain significant plasticizer content. In another study, 169
children aged 3 months to 3 years were monitored by trained observers for 12 sessions at 12 minutes
each (Greene. 2002). They reported mean mouthing durations ranging from 0.8 to 1.3 minutes per day
for soft plastic toys and 3.8 to 4.4 minutes per day for other soft plastic objects (except pacifiers). Thus,
it is likely that the mouthing durations used in this assessment provide a health protective estimate for
mouthing of soft plastic items likely to contain DBP. EPA assigned a moderate confidence associated
with the duration of activity for mouthing because the magnitude of the overestimation is not well
characterized. All other human behavior parameters are well understood or the ranges used capture use
patterns representative of various lifestages, which results in a robust confidence in use patterns.
Inhalation and Ingestion Modeling Tool
Confidence in the model used considers whether the model has been peer reviewed, as well as whether it
is being applied in a manner appropriate to its design and objective. The model used, CEM 3.2, has been
peer reviewed (ERG. 2016). is publicly available, and has been applied in the manner intended by
estimating exposures associated with uses of household products and/or articles. This also considers the
default values data source(s) such as building and room volumes, interzonal ventilation rates, and air
exchange rates. Overall confidence in the proper use of CEM for consumer exposure modeling is robust.
Dermal Modeling of DBP Exposure for Liquids
Experimental dermal data was identified via the systematic review process to characterize consumer
dermal exposures to liquids or mixtures and formulations containing DBP. Section 2.3.1 in U.S. EPA
(2025c) provides a description of the selected study and rationale to use (Doan et al. 2010) whereas
Section 2.3.2 summarizes the approach and dermal absorption values used. The confidence in the dermal
exposure to liquid products model used in this assessment is moderate.
EPA selected Doan et al. Q ) as a representative study for dermal absorption to liquids. Doan et al.
(2010) is a study in guinea pigs and uses a formulation consisting of 7 percent oil-in-water, which is
preferred over studies that use neat chemicals. In addition, Doan et al. (2010) conducted both in vivo and
in vitro experiments in female, hairless guinea pigs to compare absorption measurements using the same
dose of DBP, which increases confidence in the data used. Although there is uncertainty regarding the
magnitude of the difference between dermal absorption through guinea pigs' skin vs. human skin for
DBP, based on DBP physical and chemical properties (size, solubility), EPA is confident that the dermal
absorption data using guinea pigs for (Doan et al.. 2010) provides an upper-bound estimate of dermal
absorption of DBP.
Another source of uncertainty regarding the dermal absorption of DBP from products or formulations
stems from the varying concentrations and co-formulants that exist in products or formulations
containing DBP. Dermal contact with products or formulations that have lower concentrations of DBP
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may exhibit lower rates of flux since there is less material available for absorption. Conversely, co-
formulants or materials within the products or formulations may lead to enhanced dermal absorption—
even at lower concentrations—but EPA is unclear of the magnitude of the enhanced dermal absorption.
Therefore, it is uncertain whether the products or formulations containing DBP would result in
decreased or increased dermal absorption.
In summary, for the purposes of this draft risk evaluation, EPA assumes that the absorptive flux of DBP
measured from in vitro guinea pig experiments serves as an upper bound of potential absorptive flux of
chemical into and through the skin for dermal contact with all liquid products or formulations.
Dermal Modeling of DBP Exposure for Solids
Because experimental dermal data were not identified via the systematic review process to estimate
dermal exposures to solid products or articles containing DBP, a modeling approach was used to
estimate exposures (see Section 2.3.3 in U.S. EPA (2025c)). EPA notes that there is uncertainty with
respect to the modeling of dermal absorption of DBP from solid matrices or articles. Similarly, since
there were no available data related to the dermal absorption of DBP from solid matrices or articles,
EPA has assumed that dermal absorption of DBP from solid objects would be limited by aqueous
solubility of DBP. During direct dermal contact, DBP can migrate to the aqueous phase available in the
skin surface or be weakly bound to the polymer. The fraction of DBP associated with polymer chains is
less likely to contribute to dermal exposure as compared to the aqueous fraction of DBP because the
chemical is strongly hydrophobic. To determine the maximum steady-state aqueous flux of DBP, EPA
utilized CEM ( 1023c) to first estimate the steady-state aqueous permeability coefficient of
DBP. The estimation of the steady-state aqueous permeability coefficient within CEM (
2023c) is based on a quantitative structure-activity relationship (QSAR) model presented by ten Berge
(2009). which considers chemicals with log(Kow) ranging from -3.70 to 5.49 and molecular weights
ranging from 18 to 584.6. The molecular weight and log(Kow) of DBP falls within the range suggested
by ten Berge (2009). Therefore, there is low to medium uncertainty regarding the accuracy of the QSAR
model used to predict the steady-state aqueous permeability coefficient for DBP. There are some
uncertainties on the assumption of migration from solid to aqueous media to skin, which assumes the
aqueous dermal exposure model assumes that DBP absorbs as a saturated aqueous solution {i.e.,
concentration of absorption is equal to water solubility), which would be the maximum concentration of
absorption of DBP expected from a solid material. EPA has moderate confidence in the dermal exposure
to solid products or articles modeling approach
Ingestion via Mouthing
The chemical migration rate of DBP was estimated based on data compiled in a review published by the
Danish EPA in 2016 (Dani ), see Section 2.2.3.1 in U.S. EPA (2025c). For chemical
migration rates to saliva, existing data were highly variable both within and between studies; for
example, the mild mouthing intensity range from 0.04 to 5.8 |ig/cm2-h with an average of 0.17 |ig/cm2-h
and a standard deviation of 1.4 |ig/cm2-h. As such, based on available data for chemical migration rates
of DBP to saliva, the range of values used in this assessment (0.17, 24.3, and 48.5 |ig/cm2-h for the mild,
medium, and harsh intensity respectively) are considered likely to capture the true value of the
parameter depending on article expected uses. For example, EPA assumes children mouthing practices
can be mild, medium, or harsh for children's toys. Although adults' mouthing practices for adult toys are
not expected to be harsh. Harsh mouthing of adult toys can likely result in the breakage or destruction of
the article and adults tend to control the harshness of their mouthing better than infants and toddlers.
EPA calculated a high-intensity use of adult toys using harsh mouthing approaches as part of the
screening approach and recognized that this highly conservative result is very unlikely behavior. The
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Agency did not identify use pattern information regarding adult toys and most inputs are based on
professional judgment assumptions.
A major limitation of all existing data is that DBP weight fractions for products tested in mouthing
studies skew heavily towards relatively high weight fractions (30-60%) whereas measurements for
weight fractions less than 15 percent are rarely represented in the dataset. Thus, it is unclear whether the
migration rate values are applicable to consumer goods with low (<15%) weight fractions of DBP,
where rates might be lower than represented by typical or worst-case values determined by existing data
sets.
EPA has a moderate confidence in mouthing estimates due to uncertainties about professional judgment
inputs regarding mouthing durations for adult toys and synthetic leather furniture for children. In
general, the chemical migration rate input parameter has a moderate confidence due to the large
variability in the empirical data used in this assessment and unknown correlation between chemical
migration rate and DBP concentration in articles.
Table 4-7. Weight of Scientific Evidence Summary Per Consumer CPU
Consumer COU Category
and Subcategory
Weight of Scientific Evidence
Overall
Confidence
Construction, paint,
electrical, and metal
products; Adhesives and
sealants
Three different scenarios were assessed under this COU for three product types
with differing use patterns: Adhesives for small repairs, automotive adhesives,
and construction adhesives. Adhesives for small repairs and construction
adhesives were assessed for dermal exposures only, due to the small product
amount and surface area used in each application, inhalation and ingestion
would have low exposure potential for these two scenarios. Automotive
adhesives were assessed for dermal and inhalation exposures. The overall
confidence in this COU's inhalation exposure estimate is robust because the
CEM default parameters represent actual use patterns and location of use. See
Section 2.1.2 in U.S. EPA (2025c) for number of products, product examples,
and weight fraction data.
For dermal exposure EPA used a dermal flux-limited approach, which was
estimated based on DBP dermal absorption in guinea pigs. The flux-limited
approach likely results in overestimations due to the assumption about excess
DBP in contact with skin. An overall moderate confidence in dermal
assessment of adhesives was assigned. Uncertainties about the difference
between human and guinea pig skin absorption increase uncertainty and due to
increased permeability of guinea pig skin as compared to human skin dermal
absorption estimates likely overestimate exposures. Other parameters such as
frequency and duration of use, and surface area in contact, are well understood
and representative, resulting in a moderate overall confidence.
Inhalation-
Robust
Dermal -
Moderate
Construction, paint,
electrical, and metal
products; Paints and
coatings
Three different scenarios were assessed under this COU for 3 product types
with differing use patterns: metal coatings, indoor sealing and refinishing
sprays, and outdoor sealing and refinishing sprays. All 3 scenarios were
assessed for dermal and inhalation exposures. The overall confidence in this
COU inhalation exposure estimate is robust because the CEM default
parameters represent actual use patterns and location of use. See Section 2.1.2
in U.S. EPA (2025c) for number of products, product examples, and weisht
fraction data.
For dermal exposure EPA used a dermal flux-limited approach, which was
estimated based on DBP dermal absorption in guinea pigs. The flux-limited
approach likely results in overestimations due to the assumption about excess
DBP in contact with skin. An overall moderate confidence in dermal
Inhalation-
Robust
Dermal -
Moderate
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Consumer COU Category
and Subcategory
Weight of Scientific Evidence
Overall
Confidence
assessment of adhesives was assigned. Uncertainties about the difference
between human and guinea pigs skin absorption increase uncertainty and due to
increased permeability of guinea pig skin as compared to human skin dermal
absorption estimates likely overestimate exposures. Other parameters such as
frequency and duration of use, and surface area in contact, are well understood
and representative, resulting in an overall confidence of moderate.
Furnishing, cleaning,
treatment care products;
Fabric, textile, and leather
products
Two different scenarios were assessed under this COU for articles with
differing use patterns: synthetic leather clothing and synthetic leather furniture.
Indoor synthetic furniture articles were assessed for all exposure routes as part
of the indoor exposure assessment (i.e., inhalation, ingestion (suspended and
settled dust, and mouthing), and dermal), while synthetic clothing was only
assessed for dermal contact since the articles were too small to result in
significant inhalation and ingestion exposures. The overall confidence in the
synthetic leather furniture and clothing COU inhalation exposure estimate is
robust because the CEM default parameters are representative of typical use
patterns and location of use. The stay-at-home activity use input parameter is
considered a conservative input that although representative of actual uses for
some populations is also believed to result in an upper-bound exposure. See
Section 2.1.1 in U.S. EPA (2025c) for article examples and weisht fraction
data.
The indoor furniture ingestion via mouthing exposure estimate overall
confidence is moderate due to uncertainties in the parameters used for chemical
migration to saliva, such as large variability in empirical migration rate data for
harsh, medium, and mild mouthing approaches. Additionally, there are
uncertainties from the unknown correlation between chemical concentration in
articles and chemical migration rates, and no reasonably available data were
available to compare and confirm selected rate parameters to better understand
uncertainties.
The dermal absorption estimate assumes that dermal absorption of DBP from
solid objects would be limited by the aqueous solubility of DBP. EPA has
moderate confidence in the aspects of the exposure estimate for solid articles
because of the high uncertainty in the assumption of partitioning from solid to
liquid, and because subsequent dermal absorption is not well characterized.
Additionally, there are uncertainties associated to the flux-limited approach
which likely results in overestimations due to the assumption about excess
DBP in contact with skin. Other parameters such as frequency and duration of
use, and surface area in contact have unknown uncertainties due to lack of
information about use patterns, resulting in an overall confidence of moderate.
Inhalation -
Robust
Ingestion -
Moderate
Dermal -
Moderate
Furnishing, cleaning,
treatment/care products;
Floor coverings;
construction and building
materials covering large
surface areas including
stone, plaster, cement,
glass, and ceramic articles;
fabrics, textiles, and apparel
Two different scenarios were assessed under this COU for articles with
differing use patterns: vinyl flooring and wallpaper. Both scenarios were part of
the indoor assessment and evaluated for all exposure routes except mouthing.
The scenarios capture the variability from varying manufacturing formulations
in the high-, medium-, and low-intensity use estimates and the weight fraction
ranges reported. The overall confidence in the vinyl flooring and wallpaper
COU inhalation exposure estimate is moderate because the CEM input
parameters are representative, but there are uncertainties in the surface area
used and location of use. The stay-at-home activity use input parameter is
considered a conservative input that although representative of actual uses for
some populations is also believed to result in an upper-bound exposure. See
Section 2.1.1 in U.S. EPA (2025c) for article examples and weisht fraction
data.
Inhalation -
Moderate
Ingestion -
Moderate
Dermal -
Moderate
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Consumer COU Category
and Subcategory
Weight of Scientific Evidence
Overall
Confidence
The dermal absorption estimate assumes that dermal absorption of DBP from
solid objects would be limited by the aqueous solubility of DBP. EPA has
moderate confidence in the aspects of the exposure estimate for solid articles
because of the high uncertainty in the assumption of partitioning from solid to
liquid, and because subsequent dermal absorption is not well characterized.
Additionally, there are uncertainties associated to the flux-limited approach
which likely results in overestimations due to the assumption about excess
DBP in contact with skin. Other parameters such as frequency and duration of
use, and surface area in contact, have unknown uncertainties due to lack of
information about use patterns, resulting in an overall confidence of moderate.
Other uses; Novelty articles
One scenario, adult toys, was assessed for this COU. The scenario was assessed
for dermal contact and ingestion via mouthing exposures. Inhalation exposures
were determined to be minimal due to small surface area to release DBP.
The adult toys ingestion exposure estimate overall confidence is moderate due
to uncertainties in the parameters used for chemical migration to saliva such as
large variability in empirical migration rate data for harsh, medium, and mild
mouthing approaches. Additionally, there are uncertainties from the unknown
correlation between chemical concentration in articles and chemical migration
rates, and no data were reasonably available to compare and confirm selected
rate parameters to better understand uncertainties. In addition, there are
unknown uncertainties in the use duration input parameters which were
assumed based on professional judgment. EPA calculated a high-intensity use
of adult toys using harsh mouthing approaches as part of the screening
approach, however recognizing that this highly conservative use pattern is very
unlikely behavior, it is not to be used to estimate risk. EPA did not identify use
pattern information regarding adult toys.
The dermal absorption estimate assumes that dermal absorption of DBP from
solid objects would be limited by the aqueous solubility of DBP. EPA has
moderate confidence in the aspects of the exposure estimate for solid articles
because of the high uncertainty in the assumption of partitioning from solid to
liquid, and because subsequent dermal absorption is not well characterized.
Additionally, there are uncertainties associated to the flux-limited approach
which likely results in overestimations due to the assumption about excess
DBP in contact with skin. Other parameters such as frequency and duration of
use, and surface area in contact have unknown uncertainties due to lack of
information about use patterns, resulting in an overall confidence of moderate.
Ingestion -
Moderate
Dermal -
Moderate
Other uses; Automotive
articles
Two different scenarios were assessed under this COU for articles with
differing use patterns: car mats and synthetic leather seats. Both scenarios were
part of the indoor assessment and evaluated for all exposure routes except
mouthing. The overall confidence in the inhalation exposure estimate for the
car mats and synthetic leather seats COU is robust because the CEM input
parameters are representative. The stay-at-home activity use input parameter is
considered a conservative input that although representative of actual uses for
some populations is also believed to result in an upper-bound exposure. See
Section 2.1.1 in U.S. EPA (2025c) for article examples and weisht fraction
data.
The dermal absorption estimate assumes that dermal absorption of DBP from
solid objects would be limited by the aqueous solubility of DBP. EPA has
moderate confidence in the aspects of the exposure estimate for solid articles
because of the high uncertainty in the assumption of partitioning from solid to
liquid, and because subsequent dermal absorption is not well characterized.
Additionally, there are uncertainties associated to the flux-limited approach
Inhalation
and Dust
Ingestion -
Robust
Dermal -
Moderate
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Consumer COU Category
and Subcategory
Weight of Scientific Evidence
Overall
Confidence
which likely results in overestimations due to the assumption about excess
DBP in contact with skin. Other parameters such as frequency and duration of
use, and surface area in contact have unknown uncertainties due to lack of
information about use patterns, resulting in an overall confidence of moderate.
Other uses;
Chemiluminescent light
sticks
One scenario was assessed for this COU, chemiluminescent light sticks. The
scenario was assessed for dermal exposures. Inhalation and ingestion exposures
were determined to be minimal due to small surface area to release DBP.
The dermal absorption estimate assumes that dermal absorption of DBP from
solid objects would be limited by the aqueous solubility of DBP. EPA has
moderate confidence in the aspects of the exposure estimate for solid articles
because of the high uncertainty in the assumption of partitioning from solid to
liquid, and because subsequent dermal absorption is not well characterized.
Additionally, there are uncertainties associated to the flux-limited approach
which likely results in overestimations due to the assumption about excess
DBP in contact with skin. Other parameters such as frequency and duration of
use, and surface area in contact, have unknown uncertainties due to lack of
information about use patterns, resulting in an overall confidence of moderate.
Dermal -
Moderate
Packaging, paper, plastic,
hobby products; Packaging
(excluding food
packaging), including
rubber articles; plastic
articles (hard); plastic
articles (soft); other articles
with routine direct contact
during normal use,
including rubber articles;
plastic articles (hard)
Three different scenarios were assessed under this COU for 3 article types with
differing use patterns: footwear, shower curtains, and small articles with semi
routine contact (e.g., miscellaneous items including a pen, pencil case, hobby
cutting board, costume jewelry, tape, garden hose, disposable gloves, and
plastic bags/pouches). Footwear and small articles with semi routine contact
scenarios were assessed for dermal exposures only. Shower curtains were
assessed for dermal and also part of the indoor assessment and evaluated for all
exposure routes except mouthing. The overall confidence in this COU
inhalation exposure estimate is robust because the CEM input parameters are
representative. The stay-at-home activity use input parameter is considered a
conservative input that although representative of actual uses for some
populations is also believed to result in an upper-bound exposure. See Section
2.1.1 in U.S. EPA (2025c) for article examples and weisht fraction data.
The dermal absorption estimate assumes that dermal absorption of DBP from
solid objects would be limited by the aqueous solubility of DBP. EPA has
moderate confidence in the aspects of the exposure estimate for solid articles
because of the high uncertainty in the assumption of partitioning from solid to
liquid, and because subsequent dermal absorption is not well characterized.
Additionally, there are uncertainties associated to the flux-limited approach
which likely results in overestimations due to the assumption about excess
DBP in contact with skin. Other parameters such as frequency and duration of
use, and surface area in contact, have unknown uncertainties due to lack of
information about use patterns, resulting in an overall confidence of moderate.
Inhalation
and Dust
Ingestion -
Robust
Dermal -
Moderate
Packaging, paper, plastic,
hobby products; Toys,
playground, and sporting
equipment
Packaging, paper, plastic,
hobby products; Toys,
playground, and sporting
equipment
Four different scenarios were assessed under this COU for various articles with
differing use patterns: legacy children's toys, and new children's toys, tire
crumb and artificial turf, and a variety of PVC articles with potential for routine
contact. Toys scenarios were included in the indoor assessment for all exposure
routes (inhalation, dust ingestion, mouthing, and dermal) with varying use
patterns and inputs. Tire crumb was also part of the indoor assessment for all
exposure routes except mouthing, while articles of routine contact were only
assessed for dermal exposures since they are too small to result in impactful
inhalation or ingestion exposures. The high-, medium-, and low-intensity
scenarios capture variability and provide a range of representative use patterns.
The overall confidence in this COU inhalation exposure estimate is robust
because a good understanding of the CEM model parameter inputs and
representativeness of actual use patterns and location of use. The stay-at-home
CEM
Inhalation -
Robust
Ingestion,
Tire crumb
Inhalation,
and Dermal
- Moderate
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Consumer COU Category
and Subcategory
Weight of Scientific Evidence
Overall
Confidence
activity use input parameter is considered a conservative input that although
representative of actual uses for some populations is also believed to result in
an uDDer-bound exposure. See Section 2.1.1 in U.S. EPA (2025c) for article
examples and weight fraction data. Tire crumb inhalation confidence is
moderate due to higher uncertainty in using surrogate chemical air
concentrations, while all other parameters are well understood and
representative of use patterns by the various age groups. The overall confidence
in this COU's mouthing and dermal exposure assessment is moderate.
The mouthing parameters used like duration and surface area for infants to
children are very well understood, while older groups have less specific
information because mouthing behavior is not expected. The chemical
migration value is DBP specific, and the only sources of uncertainty are related
to a large variability in empirical migration rate data for harsh, medium, and
mild mouthing approaches. Additionally, there are uncertainties from the
unknown correlation between chemical concentration in articles and chemical
migration rates, and no data were reasonably available to compare and confirm
selected rate parameters to better understand uncertainties.
Dermal absorption estimates are based on the assumption that dermal
absorption of DBP from solid objects will be limited by aqueous solubility of
DBP. EPA has moderate confidence for solid objects because the high
uncertainty in the assumption of partitioning from solid to liquid and
subsequent dermal absorption is not well characterized. Additionally, there are
uncertainties associated to the flux-limited approach which likely results in
overestimations due to the assumption about excess DBP in contact with skin.
Other parameters like frequency and duration of use, and surface area in
contact have unknown uncertainties due to lack of information about use
patterns, making the overall confidence of moderate.
4.1.3 General Population Exposures
General population exposures occur when DBP is released into the environment and the environmental
media is then a pathway for exposure. As described in the Draft Environmental Release and
Occupational Exposure Assessment for Dibutyl Phthalate (DBP) ( 2Q25q). releases of DBP
are expected in air, water, and disposal to landfills. Figure 4-2 provides a graphic representation of
where and in which media DBP is estimated to be found due to environmental releases and the
corresponding route of exposure for the general population.
EPA began its DBP exposure assessment using a screening level approach that relies on conservative
assumptions. Conservative assumptions, including default input parameters for modeling environmental
media concentrations, help characterize exposure resulting from the high-end of the expected
distribution. Several of the OESs presented in Table 1-1 report facility location data and releases in the
Toxics Release Inventory (TRI) and Discharge Monitoring Report (DMR) databases. When facility
location- or scenario-specific information were unavailable, EPA used generic EPA models and default
input parameter values as described in the Draft Environmental Release and Occupational Exposure
Assessment for Dibutyl Phthalate (DBP) (U.S. EPA, 2025aY Details on the use of screening level analyses
in exposure assessment can be found in EPA's Guidelines for Human Exposure Assessment (U.S. EPA,
2019d).
EPA considered a subset of the general population living near facilities releasing DBP to the ambient air
(which includes fenceline communities) as part of the ambient air exposure assessment. EPA utilized a
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pre-screening methodology described in EPA's Draft TSCA Screening Level Approach for Assessing
Ambient Air and Water Exposures to fence line Communities (Version 1.0) (U.S. EPA. 2022b) for the
ambient air exposure risk assessment. For other exposure pathways, EPA's screening method assessing
high-end exposure scenarios used release data that reflect exposures expected to occur in proximity to
releasing facilities, which would include fenceline populations.
EPA evaluated the reasonably available information for releases of DBP from facilities that use,
manufacture, or process DBP under industrial and/or commercial COUs subject to TSCA regulations
detailed in the Draft Environmental Release and Occupational Exposure Assessment for Di butyl
Phthalate (DBP) (U.S. EPA. 2025q). As described in Section 3.3, using the release data, EPA modeled
predicted concentrations of DBP in surface water, sediment, drinking water, and ambient air in the
United States. Table 3-6 summarizes the high-end DBP concentrations in environmental media from
environmental releases. The reasoning for assessing different pathways qualitatively or quantitatively is
discussed briefly in Section 3.3 and additional detail can be found in the Draft Environmental Media,
General Population, and Environmental Exposure Assessment for Di butyl Phthalate (DBP) (U.S. EPA.
2025p).
I Air I
^ t
Bathing
Landfills
(Industrial or
Muncipal)
Ambient Air
Inhalation
Drinking
Water
Drinking
Water
Wastewater
Facility
Dermal
Water
Treatment
Inhalation
Aquatic and
Terrestrial
Animal
Inqestion
Oral
——j Soil and
5011 I Dust
Oral,
Inhalation
Water
Recreation
Oral Dermal
Surface Water
Groundwater pump
Groundwater
I Sediment I
Figure 4-2. Potential Human Exposure Pathways to DBP for the General Population
Potential routes of exposure are shown in italics under each potential pathway of exposure.
High-end estimates of DBP concentration in the various environmental media presented in the Draft
Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
Phthalate (DBP) (U.S. EPA. 2025p) were used for screening level purposes in the general population
exposure assessment. EPA's Guidelines for Human Exposure Assessment (U.S. EPA. 2019d) defines
high-end exposure estimates as a "plausible estimate of individual exposure for those individuals at the
upper end of an exposure distribution, the intent of which is to convey an estimate of exposure in the
upper range of the distribution while avoiding estimates that are beyond the true distribution." If risk is
not found for these individuals with high-end exposure, no risk is anticipated for central tendency
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exposures, which is defined as "an estimate of individuals in the middle of the distribution." Therefore,
if there is no risk for an individual identified as having the potential for the highest exposure associated
with a COU for a given pathway of exposure, that pathway was determined not to be a pathway of
concern and not pursued further. If any pathways were identified as a pathway of concern for the general
population, further exposure assessments for that pathway would be conducted to include higher tiers of
modeling when available, refinement of exposure estimates, and exposure estimates for additional
subpopulations and OES/COUs.
Identifying individuals at the upper end of an exposure distribution included consideration of high-end
exposure scenarios defined as those associated with the industrial and commercial releases from a COU
and OES that resulted in the highest environmental media concentrations. As described in Section 3.3,
EPA focused on estimating high-end concentrations of DBP from the largest estimated releases for the
purpose of its screening level assessment for environmental and general population exposures. This
means that EPA considered the environmental concentration of DBP in a given environmental media
resulting from the OES that had the highest release compared to any other OES for the same releasing
media. Release estimates from OES resulting in lower environmental media concentrations were not
considered for this screening level assessment. Additionally, individuals with the greatest intake rate of
DBP per body weight were considered to be those at the upper end of the exposure.
Table 4-8 summarizes the high-end exposure scenarios that were considered in the screening level
analysis, including the lifestage assessed as the most potentially exposed population based on intake rate
and body weight. Table 4-8 also indicates which pathways were evaluated quantitatively or
qualitatively. Exposure was assessed quantitatively only when environmental media concentrations were
quantified for the appropriate exposure scenario. For example, exposure from soil or groundwater
resulting from DBP release to the environment via biosolids or landfills was not quantitatively assessed
because DBP concentrations to the environment from biosolids and landfills were not quantified. Due to
the high confidence in the biodegradation rates and physical and chemical data, there is robust
confidence that DBP will not be mobile and will have low persistence potential in receiving soils.
Similarly, there is robust confidence that DBP is unlikely to be present in landfill leachates. However,
exposure was still assessed qualitatively for exposures potentially resulting from biosolids and landfills.
Further details on the screening level approach and exposure scenarios evaluated by EPA for the general
population are provided in the Draft Environmental Media, General Population, and Environmental
Exposure Assessment for Dibutyl Phthalate (DBP) (U.S. EPA. 2025p). OESs resulting in the highest
modeled environmental media concentrations were selected for the purpose of screening level analyses.
Table 4-8. Exposure Scenarios Assessed in General Population Screening Level Analysis
OES
Exposure
Pathway
Exposure
Route
Exposure Scenario
Lifestage
Analysis
(Quantitative
or Qualitative)
All
Biosolids
A1
scenarios assessed qualitatively
Qualitative
All
Landfills
All scenarios assessed qualitatively
Qualitative
Manufacturing
Surface
water
Dermal
Dermal exposure to
DBP in surface water
during swimming
All
Quantitative
Waste handling,
treatment, and disposal
Oral
Incidental ingestion of
DBP in surface water
during swimming
All
Quantitative
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OES
Exposure
Pathway
Exposure
Route
Exposure Scenario
Lifestage
Analysis
(Quantitative
or Qualitative)
Manufacturing
Waste handling,
treatment, and disposal
Drinking
water
Oral
Ingestion of drinking
water
All
Quantitative
Manufacturing
Fish
ingestion
Oral
Ingestion of fish for
general population
Adults and
young toddlers
(1-2 years old)
Quantitative
Ingestion of fish for
subsistence fishers
Adults (16 to
<70 years old)
Quantitative
Ingestion of fish for
Tribal populations
Adults (16 to
<70 years old)
Quantitative
Waste handling,
treatment, disposal
(stack)
Ambient air
Inhalation
Inhalation of DBP in
ambient air from
industrial releases
All
Quantitative
Application of paints,
coatings, adhesives,
and sealants (fugitive)
Oral
Ingestion of DBP in
soil from air to soil
deposition resulting
from industrial
releases
Infant and
Children (6
month to 12
years)
Quantitative
EPA also considered biomonitoring data, specifically urinary biomonitoring data from CDC's
NHANES, to estimate exposure using reverse dosimetry (see Section 10.2 of the Draft Environmental
Media, General Population, and Environmental Exposure Assessment for Dibutyl Phthalate (DBP)
(Is S 1 P \ 2025pV). Reverse dosimetry is a powerful tool for estimating exposure, but reverse
dosimetry modeling does not distinguish between routes or pathways of exposure and does not allow for
source apportionment (i.e., exposure from TSCA COUs cannot be isolated from uses that are not subject
to TSCA). Instead, reverse dosimetry provides an estimate of the total dose (or aggregate exposure)
responsible for the measured biomarker. Therefore, intake doses estimated using reverse dosimetry are
not directly comparable to the exposure estimates from the various environmental media presented in
this document. However, the total intake dose estimated from reverse dosimetry can help contextualize
the exposure estimates from exposure pathways outlined in Table 4-8 as being potentially under- or
overestimated.
4.1.3.1 General Population Screening Level Exposure Assessment Results
Land Pathway
EPA evaluated general population exposures via the land pathway (i.e., application of biosolids,
landfills) qualitatively. Due to hydrophobicity (log Kow = 4.5) and affinity for sorption to soil and
organic constituents in soil (log Koc = 3.14-3.94), DBP is unlikely to migrate to groundwater via runoff
after land application of biosolids. Additionally, the half-life of less than 1 day to 19 days in aerobic
soils (U.S. EPA. 2024D indicates that DBP will have low persistence potential in the aerobic
environments associated with freshly applied biosolids. Because the physical and chemical properties of
DBP indicate that it is unlikely to migrate from land applied biosolids to groundwater via runoff, EPA
did not model groundwater concentrations resulting from land application of biosolids.
Although there are limited measured data on DBP in landfill leachates, DBP may leach from landfill
material but is expected to have limited mobility beyond the landfill. DBP in leachate is unlikely to
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infiltrate groundwater due to the high affinity to organic matter and sediment. Interpretation of the high-
quality physical and chemical property data also suggest that DBP is unlikely to be present in landfill
leachate. Therefore, EPA concludes that further assessment of DBP in landfill leachate is not needed.
Surface Water Pathway - Incidental Ingestion and Dermal Contact from Swimming
As described in Section 3.3, EPA conducted modeling of reported releases, when available, to surface
water at the point of release {i.e., in the immediate water body receiving the effluent) to assess the
expected resulting environmental media concentrations from TSCA COUs. When reported releases were
unavailable for an OES, EPA estimated releases to surface water using generic scenarios as explained in
Section 3.2. EPA conducted modeling with VVWM-PSC to estimate concentrations of DBP within
surface water and to estimate settled sediment in the benthic region of streams. Releases associated with
the Manufacturing OES resulted in the highest total water column concentrations among reported
releases, with water concentrations of 885 |ig/L using 30Q5 flow (Table 4-9). Because of relevance to
the exposure route, acute incidental surface water exposures and acute drinking water exposures were
derived from the 30Q5 flow concentrations, and chronic drinking water exposures were derived from the
harmonic mean (HM) flow concentrations. COUs mapped to the Manufacturing OES are shown in
Table 3-1. As described in Section 3.3.1.1, Manufacturing OES was chosen as an appropriate OES for a
screening level assessment based on it resulting in a conservatively high surface water concentration
based on high volumes of releases associated with low flow metrics (P50). Additionally, the generic
release scenario for the Manufacturing OES estimates a combined release to wastewater, incineration, or
landfill. Because the proportion of the release from Manufacturing OES to just surface water could not
be determined from reasonably available information, for screening purposes, EPA assumed that all of
the release would be to wastewater to represent an upper bound of surface water concentrations.
These water column concentrations from the Manufacturing OES were used to estimate the (1) acute
dose rate (ADR) and average daily dose (ADD) from dermal exposure, and (2) incidental ingestion of
DBP while swimming for adults (21+ years), youths (11-15 years), and children (6-10 years). Detailed
results for all exposures can be found in Draft Environmental Media, General Population, and
Environmental Exposure Assessment for Dibutyl Phthalate (DBP) ( >25p). In this section,
exposure scenarios leading to the highest modeled dose are shown in Table 4-9.
For the purpose of a screening level assessment, EPA used a MOE approach using high-end exposure
estimates to determine if exposure pathways were pathways of concern for potential non-cancer risks.
MOEs for general population exposure through dermal exposure and incidental ingestion during
swimming ranged from 203 to 403 (compared to a benchmark of 30) for surface water concentrations
estimated using releases from Manufacturing OES (P50). Because all estimated MOEs exceeded the
benchmark, no additional scenarios were assessed. Thus, based on a screening level assessment, risks for
non-cancer health effects are not expected for the incidental ingestion or incidental dermal contact to
surface water during swimming.
Surface Water Pathway - Drinking Water
Similar to the assessment of incidental ingestion and dermal contact from swimming described above,
for screening level purposes, EPA assessed the OES resulting in the highest modeled surface water
concentrations in the drinking water exposure analysis. Manufacturing OES resulted in the highest total
water column concentrations among reported releases, with water concentrations of 885 |ig/L using
30Q5 flow (Table 4-9). Because of relevance to the exposure route, acute drinking water exposures were
derived from the 30Q5 flow concentrations whereas chronic drinking water exposures were derived
from the harmonic mean flow concentrations. As described above and in Section 3.3, surface water
concentrations modeled using releases associated with the Manufacturing OES represent an upper-
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bound based on many conservative assumptions—including all of the estimated total release going to
surface water, high releases paired with low flow assumptions (P50), and no treatment of wastewater
before release to the environment.
ADR and ADD values from drinking water exposure to DBP were calculated for various age groups but
the most exposed lifestage, infants (birth to <1 year), is shown below. Detailed results for all exposures
can be found in Draft Environmental Media, General Population, and Environmental Exposure
Assessment for Dibutyl Phthalate (DBP) ( 25p). Exposure scenarios leading to the highest
modeled dose are shown in Table 4-9; note that acute doses are presented here as they are greater than
chronic doses.
MOE for general population exposure through drinking water were 17 for the drinking water scenario
based on surface water concentrations estimated from releases associated with Manufacturing OES
paired with a low flow (P50) for the lifestage with the highest exposure (compared to a benchmark of
30) (Table 4-9). While there is moderate to robust confidence in the use of Manufacturing releases as an
upper-bounding condition to screen for risk (see Section 3.3), there is only slight confidence in the
precision of the estimated concentrations. This is particularly true in the case of the lowest flow (P50)
condition as EPA does not expect large releasers to discharge to a body of water consistent with the low
flow rate. Therefore, there is greater confidence that the medium (P75) and high flow (P90) scenarios
are representative of real-world practices. Because of this, EPA assessed additional scenarios including
drinking water exposures from the Manufacturing OES paired with a medium (P75) and high (P90) flow
as refinements to the most conservative scenario {i.e., Manufacturing releases to P50 flow). For the
refined scenarios the MOEs for the highest exposed lifestage were 319 and 4,958 for medium (P75) and
high flow (P90), respectively.
EPA also assessed the Waste handling, treatment, and disposal OES, which had the highest reported
release to surface water based on DMR. The Agency has higher confidence in the surface water
concentrations estimated from this release due to direct reporting of the release amounts and receiving
water bodies from the facilities within the OES. For the drinking water scenario for Waste handling,
treatment, and disposal OES, the MOE for the lifestage with the highest exposure (infants) was 1,026.
Based on the screening level assessment, EPA estimates low potential exposure to DBP via drinking
water—even under high-end release scenarios and without considering expected treatment removal
efficiencies from drinking water treatment. These exposure estimates also assume that the drinking
water intake location is very close (within a few km) to the point of discharge and do not incorporate
any dilution beyond the point of discharge. Actual concentrations in raw and finished water are likely to
be lower than these conservative estimates as applying dilution factors will decrease the exposure for all
scenarios, while additional distances downstream would allow further partitioning and degradation.
Based on screening level analysis, risks for non-cancer health effects are not expected for the drinking
water pathway; therefore, the drinking water pathway is not considered to be a pathway of concern to
DBP for the general population.
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Table 4-9. Summary of the Highest Doses in the General Population through Surface and
Drinking Water Exposure
OES"
Water Column
Concentration
Incidental Dermal
Surface Water''
Incidental Ingestion
Surface Water1
Drinking Water''
30Q5 Cone.
(jig/L)
ADR
(mg/kg-
day)
Acute MOE
(Benchmark
MOE = 30)
ADR
(mg/kg-day)
Acute MOE
(Benchmark
MOE = 30)
ADR
(mg/kg-
day)
Acute MOE
(Benchmark
MOE = 30)
Manufacturing
(P50)
885.0
1.04E-02
203
4.74E-03
443
1.25E-01
17
Manufacturing
(P75)
46.6
Not
assessed®
Not assessed®
Not assessed®
Not assessed®
6.58E-03
319
Manufacturing
(P90)
3.0
Not
assessed®
Not assessed®
Not assessed®
Not assessed®
4.24E-04
4,958
Waste handling,
treatment, and
disposal
14.5
Not
assessed®
Not assessed®
Not assessed®
Not assessed®
2.05E-03
1,026
ADR = acute dose rate, MOE = margin of exposure; OES = occupational exposure scenario
" Table 3-1 provides a crosswalk of industrial and commercial COUs to OES.
b Most exposed age group: Adults (21+ years)
c Most exposed age group: Youth (11-15 years)
d Most exposed age group: Infant (birth to <1 year)
e These scenarios were not assessed because the MOE exceeded the benchmark of 30 in the prior scenario used for
screening
Fish Ingestion
The key parameters to estimate human exposure to DBP via fish ingestion are the surface water
concentration, bioaccumulation factor (BAF), and fish ingestion rate. Surface water concentrations for
DBP associated with a particular COU were modeled using VVWM-PSC as described in Section
3.3.1.1. The harmonic mean flow and resulting estimated concentrations in surface water and fish tissue
were applied to calculate exposure via fish ingestion because the harmonic mean flow is considered
representative of long-term DBP concentrations that would enter fish tissue over time. The details on the
BAF, which considers the animal's uptake of a chemical from both diet and the water column, can be
found in the Draft Environmental Media, General Population, and Environmental Exposure Assessment
for Dibutyl Phthalate (DBP) ( :5p).
EPA evaluated exposure and potential risk to DBP through fish ingestion for populations and age groups
that had the highest fish ingestion rate per kg of body weight—including for adults and young toddlers
in the general population, adult subsistence fishers, and adult Tribal populations. Children were not
considered for reasons explained in Sections 7.2 and 7.3 of the Draft Environmental Media, General
Population, and Environmental Exposure Assessment for Dibutyl Phthalate (DBP) ( )
Only the fish ingestion rate changes across the different populations; the surface water concentration and
BAF remain the same. ADR and ADD values from fish ingestion exposure to DBP were calculated for
various populations and age groups and can be found in Section 7 of the Draft Environmental Media,
General Population, and Environmental Exposure Assessment for Dibutyl Phthalate (DBP) (
2Q25p). but Table 4-10 shows only results for the Tribal populations as they represent the highest
exposure because of their elevated fish ingestion rates compared to both the general population and
subsistence fisher population. Exposure to Tribal populations were estimated based on current mean
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( ) and current 95th percentile (Polissar et ai. 2016) fish ingestion rate. Current
ingestion rate refers to the present-day consumption levels that are suppressed by contamination,
degradation, or loss of access. Heritage rates existed prior to non-indigenous settlement on Tribal
fishers' resources and changes to culture and lifeways. Therefore, current ingestion rates are considered
more representative of contemporary rates of fish consumption and are presented below. Heritage rates
are discussed in further detail in Draft Environmental Media, General Population, and Environmental
Exposure Assessment for Dibutyl Phthalate (DBP) (U.S. EPA. 2025p).
EPA used the solubility limit for DBP in water (11.2 mg/L; see Table 2-1) as the initial tier of the
screening level analysis, and screening level risk estimates were below the benchmark MOE for all
populations ( 25p). The next highest-tier refinement used the Manufacturing OES (high-end
releases) that resulted in the highest modeled DBP concentrations in surface water. As discussed in
Section 3.3, surface water concentrations for the Manufacturing OES were estimated for various flows
{i.e., P50, P75, and P90). EPA expects larger releases to occur to water bodies with higher flow rates
consistent with the P75 and P90 rather than lower flow rates represented by the P50. As such, DBP
exposure via fish ingestion for the Manufacturing OES based on the P50 flow rates was not evaluated.
Table 4-10 presents only risk estimates for Tribal populations as the most highly exposed populations.
Risk estimates using the Manufacturing OES (high-end releases, P75 flow rate) were above the
benchmark MOE for all populations except Tribal populations at the current 95th percentile ingestion
rate (MOE =19 and 25). Risk estimates using the P90 flow rate were above the benchmark MOE for all
populations.
While risk estimates for the Manufacturing OES at the P75 flow rate were below the benchmark MOE
for Tribal populations at the current 95th percentile ingestion rate, EPA has only slight confidence in the
results. That is because the Manufacturing OES had modeled releases from generic scenarios
discharging to multiple environmental media and there is insufficient information to determine the
fraction of release going to each of the media types (Section 3.3.1.1). EPA instead relied on reported
releases from TRI and DMR to evaluate the fish ingestion pathway. The Waste handling, treatment, and
disposal OES had the highest reported release to surface water based on DMR. No risk estimates were
below the benchmark MOE for this OES. EPA has moderate-to-robust confidence in these risk
estimates. Overall, the exposure to DBP via fish ingestion is not expected to be a pathway of concern.
Based on screening level analysis, risks for non-cancer health effects are not expected for Tribal
populations via the fish ingestion pathway; therefore, the fish ingestion pathway is not considered to be
a pathway of concern to DBP for Tribal populations, subsistence fishers, and the general population.
Further discussion on the resulting risk estimates from higher-tier refinements and conclusions is
provided in Section 4.3.4.
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Table 4-10. Fish Ingestion for Adults in Tribal Populations Summary
Calculation Method'
Current Mean Ingestion Rate''
(Benchmark MOE = 30)
Current Tribal Ingestion Rate'', 95th
Percentile''
ADR/ADD
(m g/kg-day)
Chronic and Acute
MOE"
ADR/ADD
(mg/kg-day)
Chronic and Acute
MOE"
Water solubility limit
(11.2 mg/L)
12.4 (tilapia)
9.50 (common carp)
0.2 (tilapia)
0.2 (common carp)
50.1 (tilapia)
38.3 (common carp)
0.0 (tilapia)
0.1 (common carp)
Manufacturing (HE,
P75, 0.02 mg/L)
2.70E-02 (tilapia)
2.07E-02 (common
carp)
78 (tilapia)
102 (common carp)
1.09E-01 (tilapia)
8.35E-05 (common
carp)
19 (tilapia)
25 (common carp)
Manufacturing (HE,
P90, 0.002 mg/L)
1.88E-03 (tilapia)
1.44E-03 (common
carp)
1,116 (tilapia)
1,457 (common
carp)
7.60E-03 (tilapia)
5.82E-03 (common
carp)
276 (tilapia)
361 (common carp)
Waste handling,
treatment, disposal -
POTW (4.60E-05
mg/L)
1.61E-02 (tilapia)
1.23E-02 (common
carp)
131 (tilapia)
171 (common carp)
6.48E-02 (tilapia)
4.96E-02 (common
carp)
32 (tilapia)
42 (common carp)
ADR = acute dose rate; ADD = average daily dose; CT = central tendency; HE = high-end, 95th percentile; MOE =
margin of exposure
" The acute and chronic MOEs are identical because the exposure estimates and the POD do not change between acute
and chronic.
b Current ingestion rate (mean at 2.7 g/kg-day and 95th percentile at 10.9 g/kg-day used in this assessment) refers to the
present-day consumption levels that are suppressed by contamination, degradation, or loss of access.
c Screening level assessment started with the water solubility limit and using the OES with highest surface water
concentrations (Plastic compounding).
Ambient Air Pathway
As part of the ambient air exposure assessment, EPA considered exposures to the general population in
proximity to releasing facilities, including fenceline communities, by utilizing a previously peer-
reviewed, pre-screening methodology described in EPA's Draft TSCA Screening Level Approach for
Assessing Ambient Air and Water Exposures to Fenceline Communities (Version 1.0) (
2022b). EPA used the IIOAC model to estimate ambient air concentrations and deposition rates using
pre-run results from a suite of dispersion scenarios in a variety of meteorological and land-use settings
within American Meteorological Society/EPA Regulatory Model (AERMOD). The maximum fugitive
release value used in this assessment was reported to the 2017 NEI dataset and is associated with the
Application of paints, coatings, adhesives, and sealants OES. The maximum stack release value used in
this assessment was reported to the TRI dataset and is associated with the Waste handling, treatment,
and disposal OES. Both maximum release values represent the maximum release reported across all
facilities and COUs and are used as direct inputs to the IIOAC model to estimate concentrations and
deposition rates. EPA used the maximum 95th percentile modeled concentrations and deposition rates
across a series of exposure scenarios considering particle size and urban/rural topography to characterize
exposures and derive risk estimates. Calculations for general population exposure to ambient air via
inhalation and ingestion from air to soil deposition for lifestages expected to be highly exposed based on
exposure factors can be found in Draft Ambient Air IIOAC Exposure Results and Risk Calculations
DibutylPhthalate (DBF) (U.S. EPA. 2025a). Inhalation exposure to DBP from ambient air is expected
to be much higher than exposure to DBP via soil ingestion resulting from air to soil deposition and is,
therefore, presented below for the screening level analysis.
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For a screening level assessment, EPA utilized the highest ambient air concentrations modeled from
release data from actual release facilities using conservative assumptions. The highest 95th percentile
modeled daily average concentration used to derive acute risk estimates for fugitive releases was 16.73
|ig/m3 and for stack releases was 0.53 |ig/m3. These concentrations occurred at 100 m from the releasing
facility and together result in a total exposure from facility releases of 17.26 |ig/m3. They are attributable
to two separate OESs: fugitive releases from Application of paints, coatings adhesives, and sealants
(corresponding to the Industrial/commercial use; Construction, paint, electrical, and metal products; and
Adhesives and sealants/paints and coatings COUs) and stack releases from Waste handling, treatment,
and disposal (corresponding to the Disposal COU). The highest 95th percentile modeled annual average
concentration used to derive chronic risk estimates for fugitive releases was 11.46 |ig/m3 and 0.37 |ig/m3
for stack releases. These concentrations occurred at 100 m from the releasing facility, together result in a
total exposure from facility releases of 11.82 |ig/m3 and are attributable to two separate OESs (fugitive
releases from Application of paints, coatings adhesives, and sealants and stack releases from Waste
handling, treatment, and disposal). Table 3-1 shows COUs mapped to each OES
Table 4-11 summarizes the total exposures and the associated MOE calculated using the inhalation
human equivalent concentration (HEC). The HEC is derived in the Draft Non-cancer Raman Health
Hazard Assessment for Dibutyl Phthalate (DBP) (U.S. EPA. 2024f) and based on an 80 kg adult. Using
the highest modeled 95th percentile air concentration, MOEs for general population exposure through
inhalation of ambient air are 695 for acute and 1,015 for chronic (compared to a benchmark of 30) for an
adult. Because the HEC was derived for adults, MOEs for other lifestages were not calculated. However,
considering similar or smaller inhalation rates for younger lifestages and greatest body weight difference
of a factor of 16.7 between an adult (80 kg) and newborn (4.8 kg) based on EPA's Exposure Factors
Handbook: 2011 Edition (U.S. EPA. 201 lb). MOEs for all lifestages will still exceed the benchmark
based on the estimates for adults.
Because these derived risk estimates based on the conservative screening analysis are well above
relative benchmarks for non-cancer health effects, EPA concludes inhalation of DBP via the ambient air
pathway is not a pathway of concern for the general population. Additionally, because exposure via soil
ingestion resulting from air to soil deposition is less than exposure from inhalation via ambient air, the
Agency concludes that soil ingestion resulting from air to soil deposition is not a pathway of concern for
the general population.
Table 4-11. General Population Ambient Air Inhalation Exposure Summary
OESfl
Acute (Daily Average)b
Chronic (Annual Average)b
Air Concentration
(jig/m3)
MOE
Air Concentration
(jig/m3)
MOE
Application of paints, coatings, adhesives, and
sealants (fugitive)
17.26
695
11.82
1,015
Waste handling, treatment, and disposal (stack)
11 Table 3-1 provides a crosswalk of industrial and commercial COUs to OES.
h EPA assumes the general population is continuously exposed (i.e., 24 hours per day, 365 days per year) to outdoor
ambient air concentrations. Therefore, daily average modeled ambient air concentrations are equivalent to acute
exposure concentrations, and annual average modeled ambient air concentrations are equivalent to chronic exposure
concentrations.
c Air concentrations are reported for the high-end (95th percentile) modeled value at 100 m from the emitting facility
and stack plus fugitive releases combined.
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4.1.3.2 Daily Intake Estimates for the U.S. Population Using NHANES Urinary
Biomonitoring Data
EPA used a screening level approach to calculate sentinel exposures to the general population from
TSCA releases. EPA also analyzed urinary biomonitoring data from the CDC's NHANES dataset to
provide context for aggregate exposures in the U.S. non-institutionalized, civilian population. The
NHANES dataset reports urinary concentrations for 15 phthalate metabolites specific to individual
phthalate diesters. EPA analyzed data for two metabolites of DBP; mono-3-hydroxybutyl phthalate
(MHBP) (measured in the 2015-2018 NHANES cycles) and mono-n-butyl phthalate (MnBP) (measured
in the 1999-2018 NHANES cycles). Urinary metabolite levels reported in the most recent NHANES
survey {i.e., 2017-2018) were used to calculate daily intake for various demographic groups reported
within NHANES (Table 4-12). Median daily intake estimates across demographic groups ranged from
0.21 to 0.56 |ig/kg-day, while 95th percentile daily intake estimates ranged from 0.59 to 2.02 |ig/kg-day.
The highest daily intake value estimated was for male toddlers (3 to <6 years old) and was 2.02 |ig/kg-
day at the 95th exposure percentile. Detailed results of the NHANES analysis can be found in Section
11.1 of Draft Environmental Media, General Population, and Environmental Exposure Assessment for
DibutylPhthalate (DBP) (U.S. EPA. 2025p).
Using 50th and 95th percentile daily intake values calculated from reverse dosimetry, EPA calculated
MOEs ranging from 4,100 to 10,000 at the 50th percentile and 1,000 to 3,600 at the 95th percentile
across demographic groups using the acute/intermediate/chronic POD {i.e., an HED of 2,100 |ig/kg-day)
based on reduced fetal testicular testosterone (Table 4-13). The lowest calculated MOE of 1,000 was for
male toddlers (3 to <6 years old), based on the 95th percentile exposure estimate. All calculated MOEs
at the 50th and 95th percentiles were above the benchmark of 30, indicating that aggregate exposure to
DBP alone does not pose a risk to the non-institutionalized, U.S. civilian population.
General population exposure estimates calculated from exposure to ambient air, surface water, fish
ingestion, and soil from TSCA releases are not directly analogous to daily intake values estimated via
reverse dosimetry from NHANES. While NHANES may be used to provide context for aggregate
exposures in the U.S. population, NHANES is not expected to capture exposures from specific TSCA
COUs that may result in high-dose exposure scenarios {e.g., occupational exposures to workers)—as
compared to EPA's general population exposure assessment which evaluates sentinel exposures for
specific exposure scenarios corresponding to TSCA releases. However, as a screening level analysis,
media-specific general population exposure estimates calculated were compared to daily intake values
calculated using reverse dosimetry of NHANES biomonitoring data. Comparison of the values showed
that many of the exposure estimates resulting from incidental dermal contact or ingestion of surface
water (assuming no wastewater treatment) (Table 4-9) and ingestion of fish for adults in Tribal
populations (assuming heritage ingestion rate; see the Draft Environmental Media, General Population,
and Environmental Exposure Assessment for Dibutyl Phthalate (DBP) ( 025pV) exceeded the
total daily intake values estimated using NHANES (Table 4-12).
Exposure estimates for the general population via ambient air, surface water, and drinking water
resulting from TSCA releases quantified in this document are likely overestimates. This is because
exposure estimates from individual pathways exceed the total intake values calculated from NHANES
measured even at the 95th percentile of the U.S. population for all ages. Further, this is consistent with
the U.S. CPSC's conclusion that DBP exposure comes primarily from diet for women, infants, toddlers,
and children and that the outdoor environment is not a major source of exposure to DBP (CPSC. 2014).
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2312 Table 4-12. Daily Intake Values and MOEs for DBP Based on Urinary Biomonitoring from the
2313 2017 to 2018 NHANES Cycle
Demographic
50th percentile
Daily Intake (95%
CI) (jig/kg-day)
95th percentile
Daily Intake (95%
CI) (jig/kg-day)
50th Percentile
MOE
(Benchmark = 30)
95th Percentile
MOE
(Benchmark = 30)
All
0.33 (0.3-0.36)
1.16 (0.96-1.35)
6,400
1,800
Females
0.31 (0.27-0.35)
1.02 (0.93-1.11)
6,800
2,100
Males
0.34 (0.31-0.37)
1.33 (0.93-1.72)
6,200
1,600
White non-Hispanic
0.33 (0.29-0.38)
0.97 (0.7-1.24)
6,400
2,200
Black non-Hispanic
0.32 (0.28-0.37)
1.18 (0.84-1.52)
6,600
1,800
Mexican-American
0.29 (0.24-0.33)
0.91 (0.68-1.13)
7,200
2,300
Other
0.38 (0.31-0.44)
1.8 (-0.29-3.88)
5,500
1,200
Above poverty level
0.38 (0.33-0.43)
1.26 (0.91-1.62)
5,500
1,700
Below poverty level
0.31 (0.27-0.34)
1.04 (0.84-1.24)
6,800
2,000
Toddlers (3 to <6 years old)
0.55 (0.5-0.6)
1.54(1.07-2)
3,800
1,400
Children (6 to <11 years old)
0.36(0.31-0.41)
1.37 (0.88-1.86)
5,800
1,500
Adolescents (12 to <16 years
old)
0.28 (0.21-0.34)
0.62 (0.37-0.88)
7,500
3,400
Adults (16+ years old)
0.21 (0.17-0.25)
0.61 (0.39-0.84)
10,000
3,400
Male toddlers (3 to <6 years old)
0.56 (0.49-0.63)
2.02(1.31-2.74)
3,800
1,000
Male children (6 to <11 years
old)
0.38 (0.32-0.44)
1.41 (-0.01 to 2.83)
5,500
1,500
Male adolescents (12 to <16
years old)
0.33 (0.26-0.4)
0.62 (-1.03 to 2.27)
6,400
3,400
Male adults (16+ years old)
0.21 (0.15-0.28)
0.59 (0.35-0.83)
10,000
3,600
Female toddlers (3 to <6 years
old)
0.51 (0.44-0.57)
1.44(1.04-1.84)
4,100
1,500
Female children (6 to <11 years
old)
0.34 (0.28-0.41)
0.95 (0.62-1.29)
6,200
2,200
Female adolescents (12 to <16
years old)
0.26 (0.17-0.34)
0.61 (0.29-0.94)
8,100
3,400
Women of reproductive age
(16-49 years old)
0.21 (0.16-0.26)
0.61fl
10,000
3,400
Female adults (16+ years old)
0.21 (0.16-0.26)
0.61fl
10,000
3,400
a 95% confidence intervals (CI) could not be calculated due to small sample size or a standard error of zero.
2314 4.1.3.3 Overall Confidence in General Population Screening Level Exposure
2315 Assessment
2316 The weight of scientific evidence supporting the general population exposure estimate is decided based
2317 on the strengths, limitations, and uncertainties associated with the exposure estimates. These are
2318 discussed in detail for ambient air, surface water, drinking water, and fish ingestion in the Draft
2319 Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
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Phthalate (DBP) ( 025p). EPA summarized its weight of scientific evidence using
confidence descriptors: robust, moderate, slight, or indeterminate. The Agency used general
considerations {i.e., relevance, data quality, representativeness, consistency, variability, uncertainties) as
well as chemical-specific considerations for its weight of scientific evidence conclusions.
EPA determined robust confidence in its qualitative assessment of biosolids and landfills. For its
quantitative assessment for surface water, drinking water, ambient air, and fish ingestion, the Agency
modeled exposure due to various general population exposure scenarios resulting from different
pathways of exposure. Exposure estimates utilized high-end inputs for the purpose of risk screening.
When available, monitoring data was compared to modeled estimates to evaluate overlap, magnitude,
and trends. EPA has robust confidence that modeled releases used are appropriately conservative for a
screening level analysis. Therefore, the Agency has robust confidence that no exposure scenarios will
lead to greater doses than presented in this evaluation. Despite slight and moderate confidence in the
estimated values themselves, confidence in exposure estimates capturing high-end exposure scenarios
was robust given that many of the modeled values exceeded those of monitored values and exceeded
total daily intake values calculated from NHANES biomonitoring data. This adds to confidence that
exposure estimates captured high-end exposure scenarios.
4.1.4 Human Milk Exposures
Infants are potentially more susceptible than older children, teens, and adults for various reasons—
including their higher exposure per body weight, immature metabolic systems, and the potential for
chemical toxicants to disrupt sensitive developmental processes. Reasonably available information from
studies of experimental animal models also indicates that DBP is a developmental and reproductive
toxicant ( 24f). EPA considered exposure and hazard information, as well as
pharmacokinetic models, to determine the most scientifically supportable appropriate approach to
evaluate infant exposure to DBP from human milk ingestion (U.S. EPA. 2025p).
EPA identified 13 biomonitoring studies, one of which is from the United States, from reasonably
available information that investigated if DBP or its metabolites were present in human milk. None of
the studies characterized if any of the study participants may be occupationally exposed to DBP.
Nonetheless, DBP or its metabolites were consistently detected in human milk. However, it is important
to note that biomonitoring data do not distinguish between exposure routes or pathways and do not allow
for source apportionment. In other words, biomonitoring data reflect total infant exposure through
human milk ingestion and the contribution of specific TSCA COUs to overall exposure cannot be
determined.
Furthermore, no human health studies have evaluated only lactational exposure from quantified levels of
DBP in milk. While EPA explored the potential to model milk concentrations and concluded that there
is insufficient information {e.g., sensitive and specific half-life data) available to support modeling of the
milk pathway, the Agency also concluded that modeling is not needed to adequately evaluate risks
associated with exposure through milk. This is because the POD used in this assessment is based on
male reproductive effects resulting from maternal exposures throughout sensitive phases of development
in multigenerational studies. EPA therefore has confidence that the risk estimates calculated based on
maternal exposures are protective of a nursing infant's greater susceptibility during this unique lifestage
whether due to sensitivity or greater exposure per body weight. Further discussion of the human milk
pathway is provided in the Draft Environmental Media, General Population, and Environmental
Exposure for Dibutyl Phthalate (DBP) ( :025p).
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4.1.5 Aggregate and Sentinel Exposure
TSCA section 6(b)(4)(I')(ii) (15 USC 2605(bX4)(F)(ii)) requires EPA, in conducting a risk evaluation,
to describe whether aggregate and sentinel exposures under the COUs were considered and the basis for
their consideration.
EPA defines aggregate exposure as "the combined exposures to an individual from a chemical substance
across multiple routes and across multiple pathways (40 CFR § 702.33)." For the draft DBP risk
evaluation, the Agency considered aggregate risk across all routes of exposure for each individual
consumer and occupational COU evaluated for acute, intermediate, and chronic exposure durations.
EPA did not consider aggregate exposure for the general population. As described in Section 4.1.3, a
risk screening approach was used for the general population exposure assessment.
EPA did not consider aggregate exposure scenarios across COUs because the Agency did not find any
evidence to support such an aggregate analysis based on the reasonably available information, such as
statistics of populations using certain products represented across COUs, or workers performing tasks
across COUs. However, EPA considered combined exposure across all routes of exposure for each
individual occupational and consumer COU to calculate aggregate risks (Sections 4.3.2 and 4.3.3).
EPA defines sentinel exposure as "the exposure to a chemical substance that represents the plausible
upper-bound of exposure relative to all other exposures within a broad category of similar or related
exposures (40 CFR 702.33)." In terms of this draft risk evaluation, the Agency considered sentinel
exposures by considering risks to populations who may have upper-bound exposures; for example,
workers and ONUs who perform activities with higher exposure potential or consumers who have higher
exposure potential or certain physical factors like body weight or skin surface area exposed. EPA
characterized high-end exposures in evaluating exposure using both monitoring data and modeling
approaches. Where statistical data are available, the Agency typically uses the 95th percentile value of
the available dataset to characterize high-end exposure for a given condition of use. For general
population and consumer exposures, EPA occasionally characterized sentinel exposure through a "high-
intensity use" category based on elevated consumption rates, breathing rates, or user-specific factors.
4.2 Summary of Human Health Hazard
4.2.1 Background
This section briefly summarizes the non-cancer and cancer human health hazards of DBP (Sections 4.2.2
and 4.2.3, respectively). Additional information on the non-cancer and cancer human health hazards of
DBP are provided in the Draft Non-cancer Human Health Hazard Assessment for Dibutyl Phthalate
(DBP) ( E024f) and the Draft Cancer Human Health Hazard Assessment for Di(2-ethylhexyl)
Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl Phthalate
(1)1 BP), andDicyclohexyl Phthalate (DCHP) ( 025b).
4.2.2 Non-Cancer Human Health Hazards of DBP
The majority of toxicokinetic data for DBP is derived from oral exposure studies. Although reasonably
available data on other routes of exposure are sparse, there is some indication that DBP can be expected
to be readily absorbed through the lung ( 2024f). Following oral exposure, DBP is hydrolyzed
in the gastrointestinal tract to MBP, which is then absorbed, systemically distributed, and can undergo
further metabolism (e.g., oxidation, glucuronidation) in the liver. Metabolites of DBP—not the parent
phthalate—are associated with the adverse effects of DBP. Most (67-97%) of the administered dose of
MBP is excreted in urine within 24 hours while a small proportion is also eliminated in the feces. DBP
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and its metabolites can cross the placenta to the developing fetus. As stated in the Draft Non-Cancer
Human Health Hazard Assessment for Dibutyl Phthalate (DBP) ( If), the Agency
assumed an oral absorption of 100 percent and an inhalation absorption of 100 percent. EPA is
proposing to use DBP dermal absorption data from an study by Doan et al. (2 ) to estimate the dermal
flux of DBP, as described previously in the Summary of Occupational Exposures (Sections 4.1.1) and
Summary of Consumer Exposures (Section 4.1.2).
EPA identified effects on the developing male reproductive system as the most sensitive and robust non-
cancer hazard associated with oral exposure to DBP in experimental animal models. Effects on the
developing male reproductive system were also identified as the most sensitive and robust non-cancer
effect following oral exposure to DBP by existing assessments of DBP, including those by the U.S.
Consumer Product Safety Commission (CPSC. 2014). Health Canada (Health Canada. 2020). European
Chemicals Bureau (ECJRC. 2004). European Chemicals Agency (ECI \ \ JO I j, h, JO 10), The
European Food Safety Authority (EFSA. 2005). the Australian National Industrial Chemicals
Notification and Assessment Scheme (NICNA.S. 2013). the National Toxicology Program Center for the
Evaluation of Risks to Human Reproduction (NTP. 2003). the California Office of Environmental
Health Hazard Assessment (OEHHA. 2007). and in other assessments (NASEM. 2017). EPA also
considered epidemiologic evidence qualitatively as part of hazard identification and characterization.
However, the Agency did not use epidemiology studies quantitatively for dose-response assessment—
primarily due to uncertainty associated with exposure characterization that is further discussed in the
Draft Non-cancer Human Health Hazard Assessment for Dibutyl Phthalate (DBP) ( 2024f).
Use of epidemiologic evidence qualitatively is consistent with phthalates assessment by Health Canada
(Health Canada. 2020) and the U.S. CPSC (2014).
EPA identified 37 oral exposure studies (35 of rats, 2 of mice) that investigated the developmental and
reproductive effects of DBP following gestational and/or perinatal exposure to DBP, including multi-
generational studies of reproduction (Wine et al.. 1997; NTP. 1995). However, there are limited data that
evaluate the effects of DBP following inhalation or dermal exposures. Data that evaluate chronic
exposures via any route are limited to one study (NTP. 2021). Across available studies, the most
sensitive developmental effects identified by EPA include effects on the developing male reproductive
system consistent with a disruption of androgen action and development of phthalate syndrome. The
Agency has previously concluded in the Draft Proposed Approach for Cumulative Risk Assessment of
High-Priority Phthalates and a Manufacturer-Requested Phthalate under the Toxic Substances Control
Act ( 2023d) that oral exposure to DBP can induce effects on the developing male
reproductive system consistent with a disruption of androgen action and described a mode of action
(MOA) for phthalate syndrome.
EPA is proposing a point of departure (POD) of 9 mg/kg-day (derived from a BMDLs; human
equivalent dose [HED] of 2.1 mg/kg-day) based on phthalate syndrome-related effects on the developing
male reproductive system {i.e., decreased fetal testicular testosterone) to estimate non-cancer risks from
oral exposure to DBP for acute, intermediate, and chronic durations of exposure in this draft risk
evaluation of DBP. The proposed POD was derived from EPA's updated meta-analysis originally
conducted by the National Academies of Sciences, Engineering, and Medicine (NASEM. 2017) and
subsequent benchmark dose (BMD) modeling of decreased fetal testicular testosterone (ex vivo testicular
testosterone production or testicular testosterone content) in eight studies of rats exposed to DBP during
gestation (Gray et al.. 2021; Furr et al.. 2014; Johnson et al.. 2011; Struve et al.. 2009; Howdeshell et al..
2008; Martino-Andrade et al.. 2008; Johnson et al.. 2007; Kuhl et al.. 2007). The 95 percent lower
confidence limit of the BMD associated with a five percent response (i.e., BMDLs) is 9 mg/kg-day
(HED 2.1 mg/kg-day) and is within the range of candidate PODs (i.e., 1-10 mg/kg-day) identified from
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other studies based on antiandrogenic effects on the developing male reproductive system (Furr et at..
2014; Moody et al.. 2013; Boekelheide et at.. 2009; Lee et at.. 2004). These studies support the selection
of the BMDLs of 9 mg/kg-day for the acute, intermediate, and chronic duration POD. The sole chronic
study identified by EPA does not offer a more sensitive candidate chronic POD {i.e., the 2-year NTP
(2021) study of rats supports a LOAEL of 510 mg/kg-day (HED =130 mg/kg-day).
EPA performed 3/4-body weight scaling to yield the HED and is applying the animal-to-human
uncertainty factor {i.e., interspecies uncertainty factor; UFa) of 3x and the within human variability
uncertainty factor {i.e., intraspecies uncertainty factor; UFh) of 10x. Thus, a total UF of 30x is applied
for use as the benchmark MOE. Overall, based on the strengths, limitations, and uncertainties discussed
in the Draft Non-cancer Human Health Hazard Assessment for Dibutyl Phthalate (DBP) (
2024f), EPA has robust overall confidence in the proposed POD based on effects on the developing
male reproductive system. This POD will be used to characterize risk from exposure to DBP for acute,
intermediate, and chronic exposure scenarios. The applicability and relevance of this POD for all
exposure durations (acute, intermediate, and chronic) is described in the Draft Non-cancer Human
Health Hazard Assessment for Dibutyl Phthalate (DBP) ( 024f). Risk estimates based on the
selected POD are relevant for females of reproductive age and males at any lifestage. Decreased fetal
testicular testosterone is the most sensitive endpoint. Additionally, there is (1) epidemiological evidence
that DBP exposure can adversely affect the developing male reproductive system consistent with
phthalate syndrome in males of any age, and (2) that DBP exposure at higher concentrations can cause
other health effects in females as well (see the Draft Non-cancer Human Health Hazard Assessment for
Dibutyl Phthalate (DBP) (U.S. EPA. 2024f)). Therefore, EPA considers the proposed POD to be
relevant across sex, lifestage, and durations of exposure.
No data are available for the dermal or inhalation routes that are suitable for deriving route-specific
PODs. Therefore, EPA is using the proposed acute/intermediate/chronic oral POD to evaluate risks from
dermal exposure to DBP. Differences between oral and dermal absorption are accounted for in dermal
exposure estimates in the draft risk evaluation for DBP. For the inhalation route, EPA is extrapolating
the oral HED to an inhalation human equivalent concentration (HEC) per EPA's Methods for Derivation
of Inhalation Reference Concentrations and Application of Inhalation Dosimetry ( )
using the updated human body weight and breathing rate relevant to continuous exposure of an
individual at rest provided in EPA's Exposure /•actors Handbook: 20/1I'ldition ( v H \ The
oral HED and inhalation HEC values selected by EPA to estimate non-cancer risk from
acute/intermediate/chronic exposure to DBP in the draft risk evaluation of DBP are summarized in Table
4-13.
4.2.3 Cancer Human Health Hazards of DBP
As discussed in the Draft Cancer Human Health Hazard Assessment for Di(2-ethylhexyl) Phthalate
(DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl Phthalate (DIBP), and
DicyclohexylPhthalate (DCHP) ( 2025b). available in vivo and in vitro genotoxicity assays of
DBP and in vivo carcinogenicity studies of DBP in rats and mice indicate that DBP is not a direct acting
genotoxicant or mutagen. However, there is some limited evidence that DBP might be weakly genotoxic
in some in vitro assays.
DBP has been evaluated for carcinogenicity in two recent chronic oral exposure studies (1 in rats, 1 in
mice) conducted by NTP (2021). Across available carcinogenicity studies, DBP showed no carcinogenic
activity in male or female B6C3F1 mice exposed to up to 1,306 to 1,393 mg/kg-day DBP through the
diet for 2 years, or in female SD rats exposed to up to 600 mg/kg-day DBP through the diet for 2 years
(NTP. 2021). In male SD rats, treatment with 510 mg/kg-day DBP caused a significant trend in
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increased incidence of pancreatic acinar cell adenomas in male SD rats fed diets containing DBP for 2
years (NTP. 2021). Overall, EPA considers there to be some limited evidence to support the conclusion
that chronic oral exposure to DBP causes pancreatic tumors in rats^ As discussed further in the Draft
Cancer Human Health Hazard Assessment for DEHP, DBP, BBP, DIBP, and DCHP (
2025b). read-across to other toxicologically similar phthalates such as DEHP and BBP that also induce
pancreatic acinar cell tumors in rats provides additional evidence to support the conclusion that
phthalates, including DBP, can cause pancreatic acinar cell adenomas in rats, supporting EPA's
conclusion.
Under the Guidelines for Carcinogen Risk Assessment ( 2005). EPA reviewed the weight of
scientific evidence for the carcinogenicity of DBP and has preliminarily determined that there is
Suggestive Evidence of Carcinogenic Potential of DBP in rodents. According to the Guidelines for
Carcinogen Risk Assessment (U.S. EPA. 2005). a descriptor of Suggestive Evidence of Carcinogenic
Potential is appropriate "when the weight of evidence is suggestive of carcinogenicity; a concern for
potential carcinogenic effects in humans is raised, but the data are judged not sufficient for a stronger
conclusion. This descriptor covers a spectrum of evidence associated with varying levels of concern for
carcinogenicity, ranging from a positive cancer result in the only study on an agent to a single positive
cancer result in an extensive database that includes negative studies in other species." EPA's
determination is based on evidence of pancreatic acinar cell adenomas in one study of male SD rats
(NTP. 2021). Pancreatic tumors were not observed in female SD rats or B6C3F1 mice of either sex in
NTP bioassays (NTP. 2021). According to the Guidelines for Carcinogen Risk Assessment (U.S. EPA.
2005). when there is Suggestive Evidence, "the Agency generally would not attempt a dose-response
assessment, as the nature of the data generally would not support one." Consistently, EPA is not
conducting a dose-response assessment for DBP or evaluating DBP for carcinogenic risk to humans.
Further information can be found in the Draft Cancer Human Health Hazard Assessment for Di(2-
ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl
Phthalate (DIBP), andDicyclohexylPhthalate (DCHP) (I v «« \ ,025b).
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2536 Table 4-13. Non-Cancer HECs and HEDs Used to Estimate Risks for Acute, Intermediate, and Chronic Exposure Scenarios
Target Organ
System
Species
Duration
POD
(mg/kg-
day)
Effect
HED a
(mg/kg-
day)
HEC
(mg/m3)
IPPm|
Benchmark
MOE
Reference (TSCA Study Quality Rating)b
Developing
male
reproductive
system
Rat
5-14 days
throughout
gestation
BMDL5 = 9
| fetal
testicular
testosterone
2.1
12 [1.0]
UFa= 3
ufh=io
Total UF=30
(Grav et ah, 2021) (High)
(FiffMiJMi) (High)
(Johnson et aL. 2011) (Medium)
(Strove et aL, 2009) (Medium)
(Howdesliell et aL. 2008) (Hish)
(Martino-Andrade et aL. 2008) (Medium)
(Johnson et aL, 2007) (Medium)
(Kuhl et aL, 2007) (Low)
BMDL5 = benchmark dose (lower confidence limit) associated with a 5% response level; HEC = human equivalent concentration; HED = human equivalent dose;
MOE = margin of exposure; POD = point of departure; UF = uncertainty factor
a EPA used allometric bodv weight scaling to the 3/4-t>ower to derive the HED. Consistent with EPA Guidance CU.S. EPA. 201 lc). the interspecies uncertainty
factor (UFa), was reduced from 10 to 3 to account for the remaining uncertainty associated with interspecies differences in toxicodynamics. EPA used a default
intraspecies (UFh) of 10 to account for variation in sensitivity within human populations.
b The BMDLs was derived through meta-regression and BMD modeling of fetal testicular testosterone data from eight studies of DBP with rats CGrav et aL 2021;
Furr et al., 2014; Johnson et al., 2011; Struve et aL, 2009; Howdesliell et aL, 2008; Martino-Andrade et aL, 2008; Johnson et aL, 2007; Kuhl et aL, 2007).
2537
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2538
4.3 Human Health Risk Characterization
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4.3.1 Risk Assessment Approach
The exposure scenarios, populations of interest, and toxicological endpoints used for evaluating risks
from acute, short-term/intermediate, and chronic/lifetime exposures are summarized below in Table
4-14.
Table 4-14. Exposure Scenarios, Populations of Interest, and Hazard Values
Workers
Male and female adolescents and adults (16+ years old) and females of reproductive age
directly working with DBP under light activity (breathing rate of 1.25 m3/h) (for further
details see (IIS. EPA. 2025a))
Exposure Durations
• Acute - 8 hours for a single workday
• Intermediate - 8 hours per workday for 22 days per 30-day period
• Chronic - 8 hours per workday for 250 days per year for 31 or 40 working years
Exposure Routes
• Inhalation and dermal
Occupational Non-Users
Male and female adolescents and adults (16+ years old) indirectly exposed to DBP within
the same work area as workers (breathing rate of 1.25 m3/h) (for further details see CU.S.
EPA. 2025 a))
Exposure Durations
• Acute, Intermediate, and Chronic - same as workers
Exposure Routes
Population of Interest
and Exposure
• Inhalation, dermal (for COUs where mist and dust deposited on surfaces)
Consumers
Scenario
Male and female infants (<1 year), toddlers (1-2 years), children (3-5 years and 6-10
years), young teens (11-15 years), teenagers (16-20 years) and adults (21+years) exposed
to DBP through product or articles use (for further details see (U.S. EPA, 2025c))
Exposure Durations
• Acute - 1 day exposure
• Intermediate - 30 days per year
• Chronic - 365 days per year
Exposure Routes
• Inhalation, dermal, and oral
Bystanders
Male and female infants (<1 year), toddlers (1-2 years), and children (3-5 years and 6-10
\ ears) incidentally exposed to DBP through product use (for further details see (U.S. EPA.
2025c))
Exposure Durations
• Acute - 1 day exposure
• Intermediate - 30 days per year
• Chronic - 365 days per year
Exposure Routes
• Inhalation
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Population of Interest
and Exposure
Scenario
General Population
Male and female infants, children, youth, and adults exposed to DBP through drinking
water, surface water, soil from air to soil deposition, and fish ingestion (for further details
see (U.S. EPA. 2025 p))
Exposure Durations
• Acute - Exposed to DBP continuously for a 24-hour period
• Chronic - Exposed to DBP continuously up to 33 years
Exposure Routes - Inhalation, dermal, and oral (depending on exposure scenario)
Cumulative Exposure Based on NHANES Biomonitoring
Children aged 3-5, 6-11 years, and 11 to <16 years; male and female adults 16+years; and
females of reproductive age (16-49 years of age) exposed to DEHP, DBP, BBP, DIBP, and
DINP through all exposure pathways and routes as measured through urinary biomonitoring
(i.e., NHANES) (for further details see (U.S. EPA, 2025x))
Exposure Durations
• Durations not easily characterized in urinary biomonitoring studies
• Likely between acute and intermediate as phthalates have elimination half-lives on the
order of several hours and are quickly excreted from the body in urine. Spot urine
samples, as collected through NHANES, are representative of relatively recent
exposures.
Exposure Routes
NHANES urinary biomonitoring data provides an estimate of aggregate exposure (i.e.,
exposure through oral, inhalation, and dermal routes)
Health Effects,
Concentration and
Time Duration
Non-Cancer Acute/Intermediate/Chronic Value
Sensitive health effect: Developmental toxicity (i.e., reduced fetal testicular testosterone
content)
HEC Daily, continuous (assumes breathing rate of 0.6125 m3/h and 24 hours/day for
continuous exposure CU.S. EPA. 201 la)) = 12 ma/m3 (1.0 ppm)
HED Daily = 2.1 mg/kg-day; dermal and oral
Total UF (benchmark MOE) = 30 (UFA = 3; UFH = 10)
Hazard Relative Potency
Relative potency factors for DBP, DEHP, BBP, DIBP, DCHP, and DINP were derived
based on reduced fetal testicular testosterone. DBP was selected as the index chemical (for
further details see (U.S. EPA, 2025x)).
RPFdbp = 1 (index chemical)
RPFdehp= 0.84
RPFbbp = 0.52
RPFdibp = 053
RPFdchp =1.66
RPFdinp = 0.21
Index chemical (DBP) POD = HED daily = 2.1 mg/kg-day
Total UF (benchmark MOE) = 30 (UFA = 3; UFH = 10)
2545 4.3.1.1 Estimation of Non-Cancer Risks
2546 EPA used a margin of exposure (MOE) approach to identify potential non-cancer risks for individual
2547 exposure routes {i.e., oral, dermal, inhalation). The MOE is the ratio of the non-cancer POD divided by a
2548 human exposure dose. Acute, short-term, and chronic MOEs for non-cancer inhalation and dermal risks
2549 were calculated using Equation 4-1.
2550
2551 Equation 4-1. Margin of Exposure Calculation
2552
Non — cancer Hazard Value (POD)
2553 MOE = -
Human Exposure
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Where:
MOE
Non-cancer Hazard Value (POD)
Human Exposure
Margin of exposure for acute, short-term, or chronic
risk comparison (unitless)
HEC (mg/m3) or HED (mg/kg-day)
Exposure estimate (mg/m3 or mg/kg-day)
MOE risk estimates may be interpreted in relation to benchmark MOEs. Benchmark MOEs are typically
the total UF for each non-cancer POD. The MOE estimate is interpreted as a human health risk of
concern if the MOE estimate is less than the benchmark MOE {i.e., the total UF). On the other hand, if
the MOE estimate is equal to or exceeds the benchmark MOE, the risk is not considered to be of concern
and mitigation is not needed. Typically, the larger the MOE, the more unlikely it is that a non-cancer
adverse effect occurs relative to the benchmark. When determining whether a chemical substance
presents unreasonable risk to human health or the environment, calculated risk estimates are not "bright-
line" indicators of unreasonable risk, and EPA has the discretion to consider other risk-related factors in
addition to risks identified in the risk characterization.
4.3.1.2 Estimation of Non-Cancer Aggregate Risks
As described in Section 4.1.5, EPA considered aggregate risk across all routes of exposure for each
individual consumer and occupational COU evaluated for acute, intermediate, and chronic exposure
durations. To identify potential non-cancer risks for aggregate exposure scenarios for workers (Section
4.3.2) and consumers (Section 4.3.3), EPA used the total MOE approach ( Dl). For this
approach, MOEs for each exposure route of interest in the aggregate scenario must first be calculated.
The total MOE for the aggregate scenario can then be calculated using Equation 4-2.
Equation 4-2. Total Margin of Exposure Calculation
1
Total MOE = jjj
MOE0rai MOEDermai MOEInhaiation
Where:
Total MOE
MOlUjrat
M
M()IUnha!allon
Margin of exposure for aggregate scenario (unitless)
Margin of exposure for oral route (unitless)
Margin of exposure for dermal route (unitless)
Margin of exposure for inhalation route (unitless)
Total MOE risk estimates may be interpreted in relation to benchmark MOEs, similarly as to described
in the preceding Section 4.3.1.1.
4.3.2 Risk Estimates for Workers
This section summarizes risk estimates for workers from inhalation and dermal exposures, as well as
aggregated exposures to DBP from individual DBP OESs and COUs across routes (
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Table 4-18). Risks are calculated for all exposed workers based on the DBP-derived PODs described in
Section 4.2.2. The occupational exposure values (OEVs) are discussed in Appendix F. This section
provides discussion and characterization of risk estimates for workers, including females of reproductive
age and ONUs, for the various OESs and COUs.
Manufacturing
For the manufacture of DBP, dermal exposure to liquids is expected to be the dominant route of
exposure. MOEs for high-end acute, intermediate, and chronic inhalation exposure ranged from 15 to 25
for average adult workers and females of reproductive age, while high-end dermal MOEs for the same
populations and exposure scenarios ranged from 0.8 to 1.3 (benchmark = 30). The central tendency
MOEs for the same populations and exposure scenarios ranged from 30 to 49 for inhalation exposure
and 1.7 to 2.7 for dermal exposure. Aggregation of inhalation and dermal exposures led to negligible
differences in risk when compared to risk estimates from dermal exposure alone. The MOEs presented
in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17 provides more information on
PPE that could be used to reduce the MOEs above the benchmark MOE. As noted previously, EPA is
interested in public comments that may inform the use of exposure controls and PPE for different COU.
The high-end and central tendency worker inhalation exposure results for this OES are based on data
from three different risk evaluations; each presented a single data point to characterize full-shift
exposure to workers during DBP manufacturing (ECB. 2008; ECJRC. 2004; SRC. 2001). To determine
central tendency and high-end values, EPA used the mid-point and maximum value, respectively, due to
limited data points. There is uncertainty about how well these data represent the true distribution of
actual inhalation concentrations for worker exposures in a specific facility, and the lack of ONU
exposure data, for which EPA used worker data as surrogate data; and that there are only three data
points used for the inhalation assessment.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
( ). However, if a worker uses proper PPE or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure l'aclors Handbook ( v «« \ 201 Li). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
the neat form of DBP is used. There is also uncertainty in the use of guinea pigs over human skin, as
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guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties about the
difference between human and guinea pigs skin absorption increase uncertainty.
Due to limited inhalation data points, both the central and high-end exposure estimates are expected to
be reflective of worker inhalation exposures for this OES. Also, since the dermal exposures are upper-
bound estimates, it can be conservatively assumed that the central tendency values of exposure estimates
are expected to be most reflective of worker dermal exposures. This applies to COUs covered under the
"Manufacturing" OES {i.e., Manufacturing COU: Domestic manufacturing).
Import and Repackaging
For the repackaging of DBP, dermal exposure from liquid contact is expected to be the dominant route
of exposure. MOEs for high-end acute, intermediate, and chronic inhalation exposure ranged from 15 to
25 for average adult workers and females of reproductive age, while high-end dermal MOEs for the
same populations and exposure scenarios ranged from 0.8 to 1.3 (benchmark = 30). The central tendency
MOEs for the same populations and exposure scenarios ranged from 30 to 49 for inhalation exposure
and 1.7 to 2.7 for dermal exposure. Aggregation of inhalation and dermal exposures led to negligible
differences in risk when compared to risk estimates from dermal exposure alone. The MOEs presented
in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17 provides more information on
PPE that could be used to reduce the MOEs above the benchmark MOE.
The high-end and central tendency worker inhalation exposure results for this OES are based on
surrogate data from three different risk evaluations; each presented a single data point to characterize
full-shift exposure to workers during DBP manufacturing (ECB. 2008; ECJRC. 2004; SRC. 2001). To
determine central tendency and high-end values, EPA used the mid-point and maximum value,
respectively, due to limited data points. There is uncertainty about how well these data represent the true
distribution of actual inhalation concentrations for worker exposures in a specific facility, and the lack of
ONU exposure data, for which EPA used worker data as surrogate data; and that there are only three
data points used for the inhalation assessment.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. Thus, in absence of exposure duration data, EPA has assumed that absorption of
DBP from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I j_). However, if a worker uses proper PPE or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( E01 la). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
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quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
the neat form of DBP is used. There is also uncertainty in the use of guinea pigs over human skin, as
guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties about the
difference between human and guinea pigs skin absorption increase uncertainty.
Due to limited inhalation data points, both the central and high-end exposure estimates are expected to
be reflective of worker inhalation exposures for this OES. Also, since the dermal exposures are upper-
bound estimates, it can be conservatively assumed that the central tendency values of exposure estimates
are expected to be most reflective of worker dermal exposures. This applies to COUs covered under the
Import and repackaging OES {i.e., Manufacture COU: Importing; processing COU: Repackaging COU
[Laboratory chemicals in wholesale and retail trade; plasticizers in wholesale and retail trade; and
plastics material and resin manufacturing]).
Incorporation into Formulations, Mixtures, or Reaction Products
For the incorporation of DBP into formulations, mixtures, or reaction products, dermal exposure from
liquid contact is expected to be the dominant route of exposure. MOEs for high-end acute, intermediate,
and chronic inhalation exposure ranged from 15 to 25 for average adult workers and females of
reproductive age, while high-end dermal MOEs for the same populations and exposure scenarios ranged
from 0.8 to 1.3 (benchmark = 30). The central tendency MOEs for the same populations and exposure
scenarios ranged from 30 to 49 for inhalation exposure and 1.7 to 2.7 for dermal exposure. Aggregation
of inhalation and dermal exposures led to negligible differences in risk when compared to risk estimates
from dermal exposure alone. The MOEs presented in this paragraph are with no use of PPE. Section
4.3.2.4 and Table 4-17 provides more information on PPE that could be used to reduce the MOEs above
the benchmark MOE.
The high-end and central tendency worker inhalation exposure results for this OES are based on
surrogate data from three different risk evaluations; each presented a single data point to characterize
full-shift exposure to workers during DBP manufacturing (ECB. 2008; ECJRC. 2004; SRC. 2001). To
determine central tendency and high-end values, EPA used the mid-point and maximum value,
respectively, due to limited data points. There is uncertainty about how well these data represent the true
distribution of actual inhalation concentrations for worker exposures in a specific facility, and the lack of
ONU exposure data, for which EPA used worker data as surrogate data; and that there are only three
data points used for the inhalation assessment.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. Thus, in absence of exposure duration data, EPA has assumed that absorption of
DBP from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I j_). However, if a worker uses proper PPE or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( E01 la). 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
male workers and 445 cm2 for female workers).
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High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP, and
the resultant dose based on exposure area. Although the Agency determined that all data were of
acceptable quality without notable deficiencies and integrated all the data into the final exposure
assessment, it's uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is
for OESs where a higher concentration of DBP is used. There is also uncertainty in the use of guinea
pigs over human skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore,
uncertainties about the difference between human and guinea pigs skin absorption increase uncertainty.
Due to limited inhalation data points, both the central and high-end exposure estimates are expected to
be reflective of worker inhalation exposures for this OES. Also, since the dermal exposures are upper-
bound estimates, it can be conservatively assumed that the central tendency values of exposure estimates
are expected to be most reflective of worker dermal exposures. This applies to the COUs covered under
the "Incorporation into formulations, mixtures, or reaction products" OES {i.e., Processing COU:
Processing as a reactant: [Intermediate in plastic manufacturing]; Incorporation into formulation,
mixture, or reaction product: [Solvents (which become part of product formulation or mixture) in
chemical product and preparation manufacturing; soap, cleaning compound, and toilet preparation
manufacturing; adhesive manufacturing; and printing ink manufacturing]; [Plasticizer in paint and
coating manufacturing; soap, cleaning compound, and toilet preparation manufacturing; textiles, apparel,
and leather manufacturing; printing ink manufacturing; basic organic chemical manufacturing; and
adhesive and sealant manufacturing]; and Pre-catalyst manufacturing).
PVC Plastics Compounding
For PVC plastics compounding, dermal contact with liquid DBP before it is incorporated into the
formulation is expected to be the dominant route of exposure. MOEs for high-end acute, intermediate,
and chronic inhalation exposure ranged from 5.3 to 8.6 for average adult workers and females of
reproductive age, while high-end dermal MOEs for the same populations and exposure scenarios ranged
from 0.8 to 1.3 (benchmark = 30). The central tendency MOEs for the same populations and exposure
scenarios ranged from 44 to 71 for inhalation exposure and 1.7 to 2.6 for dermal exposure. Aggregation
of inhalation and dermal exposures led to negligible differences in risk when compared to risk estimates
from dermal exposure alone. The MOEs presented in this paragraph are with no use of PPE. Section
4.3.2.4 and Table 4-17 provides more information on PPE that could be used to reduce the MOEs above
the benchmark MOE.
EPA did not identify chemical- or OES-specific inhalation monitoring data for DBP from systematic
review; however, EPA utilized surrogate vapor inhalation monitoring data from PVC plastics converting
to assess worker inhalation exposure to DBP vapors (ECJRC. 2004). To assess the high-end worker
exposure to DBP during the compounding process, EPA used the maximum available value (0.75
mg/m3). EPA assessed the average of the four available values as the central tendency (0.24 mg/m3).
EPA estimated worker inhalation exposures to dust using the Generic Model for Central Tendency and
High-End Inhalation Exposure to Total and Respirable Particulates Not Otherwise Regulated (PNOR
Model) for dust exposures ( 2Id). For inhalation exposure to PNOR, EPA determined the
50th and 95th percentiles of the surrogate dust monitoring data taken from facilities with NAICS codes
starting with 326 (Plastics and Rubber Manufacturing). EPA multiplied these dust concentrations by the
industry provided maximum potential DBP concentration in PVC material {i.e., 45%) to estimate DBP
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particulate concentrations in the air. Therefore, the differences in the central tendency and high-end dust
concentrations led to differences between the central tendency and high-end risk estimates.
There is uncertainty about how well the surrogate vapor monitoring data represent the true distribution
of vapor inhalation concentrations for actual worker exposures in a specific facility. Also, though the
PNOR {i.e., dust) concentration data provides a reliable range of dust concentrations that a worker may
experience in the compounding industry, the composition of workplace dust is uncertain. The exposure
and risk estimates assume that the concentration of DBP in workplace dust is the same as the
concentration of DBP in the PVC material. However, it is likely that workplace dust contains a variety
of constituents that do not contain any DBP in addition to particles from DBP-containing plastic
materials. The constituents that do not contain DBP would dilute the overall concentration of DBP in the
dust, and the concentration of DBP in workplace dust is likely less than the concentration of DBP in the
plastic material. Therefore, the estimated inhalation exposures to dust are likely overestimated.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults in the Exposure Factors Handbook ( ). For
central tendency estimates, the Agency 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 cm2for male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid DBP were determined using data from Doan
et al. (2010). The study estimated a dermal absorption rate from experiments on female hairless guinea
pigs using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP
absorption in skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux
of DBP and the resultant dose based on exposure area. Although the Agency determined that all data
were of acceptable quality without notable deficiencies and integrated all the data into the final exposure
assessment, it is uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is
for OESs where a higher concentration of DBP is used. There is also uncertainty in the use of guinea
pigs over human skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore,
uncertainties about the difference between human and guinea pigs skin absorption increase uncertainty.
For estimating high-end and central tendency occupational dermal exposures to solids, EPA assumed
that DBP will first migrate from the solid matrix to a thin layer of moisture on the skin surface.
Therefore, absorption of DBP from solid matrices is considered limited by aqueous solubility and is
estimated using an aqueous absorption model ( 023c. 2004b) as described in Appendix C in
the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP)
(I E025q). EPA assumes that absorption of the aqueous material serves as a reasonable upper
bound for contact with solid materials and used this to estimate the average absorptive flux of DBP and
the resultant dose based on worker exposure area.
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The PNOR Model uses conservative assumptions leading to upper-bound inhalation exposure estimates.
The dermal exposure estimates are also upper-bound estimates as discussed above. Therefore, the
central tendency values of exposure are expected to be most reflective of worker exposures within the
COUs covered under the PVC plastics compounding OES {i.e., Processing COUs: Incorporation into
formulation, mixture, or reaction product [Plasticizer in plastic material and resin manufacturing]).
PVC Plastics Converting
For PVC plastics converting, inhalation exposure is expected to be the dominant route of exposure.
MOEs for high-end acute, intermediate, and chronic inhalation exposure ranged from 5.3 to 8.6 for
average adult workers and females of reproductive age, while high-end dermal MOEs ranged from 62 to
98 (benchmark = 30). For central tendency, MOEs for the same population and exposure scenarios
ranged from 44 to 71 for inhalation exposure and 124 to 197 for dermal exposures. Aggregation of
inhalation and dermal exposures led to negligible differences in risk when compared to risk estimates
from inhalation exposure alone. The MOEs presented in this paragraph are with no use of PPE. Section
4.3.2.4 and Table 4-17 provides more information on PPE that could be used to reduce the MOEs above
the benchmark MOE.
EPA identified vapor inhalation monitoring data from a risk evaluation completed by the European
Commission's Joint Research Centre (ECJRC), which included four data points compiled from two
sources (ECJRC. 2004). To assess the high-end worker exposure to DBP during the converting process,
EPA used the maximum available value (0.75 mg/m3). EPA assessed the average of the four available
values as the central tendency (0.24 mg/m3). The Agency estimated worker inhalation exposures to dust
using the PNOR Model for dust exposures {x v < < \ _\V I < I). For inhalation exposure to PNOR, EPA
determined the 50th and 95th percentiles of the surrogate dust monitoring data taken from facilities with
NAICS codes starting with 326 (Plastics and Rubber Manufacturing). EPA multiplied these dust
concentrations by the industry provided maximum potential DBP concentration in PVC material {i.e.,
45%) to estimate DBP particulate concentrations in the air. Therefore, the differences in the central
tendency and high-end dust concentrations led to differences between the central tendency and high-end
risk estimates.
There is uncertainty about how well the surrogate vapor monitoring data represent the true distribution
of vapor inhalation concentrations for actual worker exposures in a specific facility. Also, although the
PNOR Model {i.e., dust) concentration data provides a reliable range of dust concentrations that a
worker may experience in the converting industry, the composition of workplace dust is uncertain. The
exposure and risk estimates assume that the concentration of DBP in workplace dust is the same as the
concentration of DBP in the PVC material. However, it is likely that workplace dust contains a variety
of constituents that do not contain any DBP in addition to particles from DBP-containing plastic
materials. The constituents that do not contain DBP would dilute the overall concentration of DBP in the
dust, and the concentration of DBP in workplace dust is likely less than the concentration of DBP in the
plastic material. Therefore, the estimated inhalation exposures to dust are likely overestimated.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. Thus, in absence of exposure duration data, EPA has assumed that absorption of
DBP from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I j_). However, if a worker uses proper PPE or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
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of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( £01 la). 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
male workers and 445 cm2 for female workers).
For estimating high-end and central tendency occupational dermal exposures to solids, EPA assumed
that DBP will first migrate from the solid matrix to a thin layer of moisture on the skin surface.
Therefore, absorption of DBP from solid matrices is considered limited by aqueous solubility and is
estimated using an aqueous absorption model ( 023c. 2004b) as described in Appendix C in
the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP)
( Z025q). EPA assumes that absorption of the aqueous material serves as a reasonable upper
bound for contact with solid materials and used this to estimate the average absorptive flux of DBP and
the resultant dose based on worker exposure area.
The PNOR Model uses conservative assumptions leading to upper-bound inhalation exposure estimates.
The dermal exposure estimates are also upper-bound estimates as discussed above. Therefore, the
central tendency values of exposure are expected to be most reflective of worker exposures within the
COUs covered under the "PVC plastics converting" OES {i.e., Processing COUs: Incorporation into
articles [Plasticizer in adhesive and sealant manufacturing; building and construction materials
manufacturing; furniture and related product manufacturing; ceramic powders; plastics product
manufacturing]).
Non-PVC Materials Manufacturing (Compounding and Converting)
For non-PVC materials manufacturing, dermal exposure from liquid contact to DBP is expected to be
the dominant route of exposure. In support of this, MOEs for high-end acute, intermediate, and chronic
inhalation exposure ranged from 9.0 to 15 for average adult workers and females of reproductive age,
while high-end dermal MOEs for the same populations and exposure scenarios ranged from 0.8 to 1.3
(benchmark = 30). The central tendency MOEs for the same populations and exposure scenarios ranged
from 53 to 86 for inhalation exposure and 1.7 to 2.6 for dermal exposure. Aggregation of inhalation and
dermal exposures led to negligible differences in risk when compared to risk estimates from dermal
exposure alone. The MOEs presented in this paragraph are with no use of PPE. Section 4.3.2.4 and
Table 4-17 provides more information on PPE that could be used to reduce the MOEs above the
benchmark MOE.
EPA did not identify chemical-specific or OES-specific inhalation monitoring data for DBP from
systematic review, however, EPA utilized surrogate vapor inhalation monitoring data from PVC plastics
converting to assess worker inhalation exposure to DBP vapors (ECJRC. 2004). To assess the high-end
worker exposure to DBP during the converting process, EPA used the maximum available value (0.75
mg/m3). EPA assessed the average of the four available values as the central tendency (0.24 mg/m3).
EPA estimated worker inhalation exposures using the PNOR Model for dust exposures (
202 Id). For inhalation exposure to PNOR, EPA determined the 50th and 95th percentiles of the
surrogate dust monitoring data taken from facilities with NAICS codes starting with 326 (Plastics and
Rubber Manufacturing). EPA multiplied these dust concentrations by the industry provided maximum
potential DBP concentration in non-PVC material (i.e., 20%) to estimate DBP particulate concentrations
in the air. Therefore, the differences in the central tendency and high-end dust concentrations led to
differences between the central tendency and high-end risk estimates.
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There is uncertainty about how well the surrogate vapor monitoring data represent the true distribution
of vapor inhalation concentrations for actual worker exposures in a specific facility Also, though the
PNOR {i.e., dust) concentration data provides a reliable range of dust concentrations that a worker may
experience in the converting industry, the composition of workplace dust is uncertain. The exposure and
risk estimates assume that the concentration of DBP in workplace dust is the same as the concentration
of DBP in the non-PVC material. However, it is likely that workplace dust contains a variety of
constituents that do not contain any DBP in addition to particles from DBP-containing non-PVC
materials. The constituents that do not contain DBP would dilute the overall concentration of DBP in the
dust, and the concentration of DBP in workplace dust is likely less than the concentration of DBP in the
non-PVC material. Therefore, the estimated inhalation exposures to dust are likely overestimated.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
( ). However, if a worker uses proper PPE or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure /''actors Handbook ( v «« \ 201 Li). For
central tendency estimates, the Agency 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 cm2for male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. EPA defined central tendency exposure as the average surface
area of the exposed worker population's hand, while the high-end value is based on the surface area of
two hands, therefore, the high-end value is twice that of the central tendency. Although EPA determined
that all data were of acceptable quality without notable deficiencies and integrated all the data into the
final exposure assessment, it's uncertain how representative the use of a 7 percent oil-in-water emulsion
formulation is for OESs where a higher concentration of DBP is used. There is also uncertainty in the
use of guinea pigs over human skin, as guinea pig tissue is known to be more permeable than human
tissue. Therefore, uncertainties about the difference between human and guinea pigs skin absorption
increase uncertainty. For estimating high-end and central tendency occupational dermal exposures to
solids, EPA assumed that DBP will first migrate from the solid matrix to a thin layer of moisture on the
skin surface. Therefore, absorption of DBP from solid matrices is considered limited by aqueous
solubility and is estimated using an aqueous absorption model ( 23c. 2004b) as described in
Appendix C in the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl
Phthalate (DBP) ( Q25q). EPA assumes that absorption of the aqueous material serves as a
reasonable upper bound for contact with solid materials and used this to estimate the average absorptive
flux of DBP and the resultant dose based on worker exposure area.
The PNOR Model uses conservative assumptions leading to upper-bound inhalation exposure estimates.
The dermal exposure estimates are also upper-bound estimates as discussed above. Therefore, the
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central tendency values of exposure are expected to be most reflective of worker exposures within the
COUs covered under the "Non-PVC materials manufacturing" OES {i.e., Processing COUs:
Incorporation into formulation, mixture, or reaction product [Plasticizer in plastic material and resin
manufacturing; rubber manufacturing]; and Incorporation into articles [Plasticizer in adhesive and
sealant manufacturing; building and construction materials manufacturing; furniture and related product
manufacturing; ceramic powders; plastics product manufacturing; and rubber product manufacturing]).
Application of Adhesives and Sealants
For application of adhesives and sealants containing DBP, dermal exposure to liquids is expected to be
the dominant route of exposure. MOEs for high-end acute, intermediate, and chronic inhalation exposure
ranged from 152 to 245 for average adult workers and females of reproductive age, while high-end
dermal MOEs for the same populations and exposure scenarios ranged from 0.8 to 1.3 (benchmark =
30). The central tendency MOEs for the same populations and exposure scenarios ranged from 304 to
529 for inhalation exposure and 1.7 to 2.9 for dermal exposure. Aggregation of inhalation and dermal
exposures led to negligible differences in risk when compared to risk estimates from dermal exposure
alone. The MOEs presented in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17
provides more information on PPE that could be used to reduce the MOEs above the benchmark MOE.
The high-end and central tendency worker inhalation exposure results for this OES are based on 19
monitoring samples in NIOSH's HHE database CNIQSH. 1977). Six of the samples were PBZ samples,
and the remaining 13 samples were area samples taken at various locations around an acrylic furniture
manufacturing site. The site uses 2-part adhesives where the part B component is 96.5 percent DBP.
Two of the area samples recorded values at the limit of detection, and the remaining 17 samples were
below the limit of detection. All samples were collected on AA cellulose membrane filters with 0.8|im
average pore size and a pump flow rate of 1 LPM. The detection limit was 0.01 mg/m3 by gas
chromatography. With all samples at or below the LOD, EPA assessed inhalation exposures as a range
from 0 to the LOD. EPA estimated the high-end exposure as equal to the LOD and the central tendency
as the midpoint {i.e., half the LOD). There is uncertainty about how well these data represent the true
distribution of actual inhalation concentrations in this scenario at a specific facility. In absence of ONU
exposure data, EPA used worker data as analogous data for ONU exposure.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
( ). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( 201 la). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
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skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
a higher concentration of DBP is used. There is also uncertainty in the use of guinea pigs over human
skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties
about the difference between human and guinea pigs skin absorption increase uncertainty.
As discussed above, inhalation exposure estimates are based on data which are below the LOD. EPA
estimated the high-end exposure as equal to the LOD and the central tendency as the midpoint {i.e., half
the LOD). Therefore, the inhalation exposure estimates are upper-bound estimates. Also, as discussed in
the paragraph above, the dermal exposure estimates are upper-bound estimates. So, the central tendency
values of exposure are expected to be most reflective of worker exposures within the COUs covered
under the "Application of adhesives and sealants" OES {i.e., Industrial Use COU: Construction, paint,
electrical, and metal products [Adhesives and sealants] and Commercial Use COU: Construction, paint,
electrical, and metal products [Adhesives and sealants]).
Application of Paints and Coatings
For the application of paints and coatings containing DBP, dermal and inhalation exposure routes are
both expected to significantly contribute to exposures at both the central-tendency and high-end, with
dermal exposures expected to be slightly dominant in its contribution. MOEs for high-end acute,
intermediate, and chronic inhalation exposure ranged from 2.9 to 4.7 for average adult workers and
females of reproductive age, while high-end dermal MOEs for the same populations and exposure
scenarios ranged from 0.8 to 1.3 (benchmark = 30). The central tendency MOEs for the same
populations and exposure scenarios ranged from 18 to 30 for inhalation exposure and 1.7 to 2.7 for
dermal exposure. Aggregation of inhalation and dermal exposures led to lower MOEs compared to
either individual route. The MOEs presented in this paragraph are with no use of PPE. Section 4.3.2.4
and Table 4-17 provides more information on PPE that could be used to reduce the MOEs above the
benchmark MOE.
To estimate inhalation exposures, EPA relied on monitoring data from OSHA's Chemical Exposure
Health Data database from two different inspections, one from 2011 of a fabric coating mill and one
from a janitorial services company (0 ). EPA additionally found 12 8-hour TWA monitoring
samples during systematic review completed by Rohm and Haas Co. which examined worker exposure
from painting interior rooms with roller and spray applicators (Rohm & Haas. 1990). With a total of 14
data points, EPA characterized the data by taking the 95th percentile and the 50th percentile of the
combined dataset to represent the high end and central tendency. There is uncertainty about how well
these data represent the true distribution of actual inhalation concentrations in this scenario at a specific
facility. In absence of ONU exposure data, EPA used worker data as analogous data for ONU exposure.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
( ). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
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cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( ). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
different formulations of DBP are used. There is also uncertainty in the use of guinea pigs over human
skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties
about the difference between human and guinea pigs skin absorption increase uncertainty.
Due to limited inhalation data points, both the central and high-end exposure estimates are expected to
be reflective of worker inhalation exposures for this OES. Also, since the dermal exposures are upper-
bound estimates, it can be conservatively assumed that the central tendency values of exposure estimates
are expected to be most reflective of worker dermal exposures. This applies to the COUs covered under
the "Application of paints and coatings" OES {i.e., Industrial Use COU: Construction, paint, electrical,
and metal products [Paints and coatings], Commercial Use COU: Construction, paint, electrical, and
metal products [Paints and coatings], and Commercial Use COU: Packaging, paper, plastic, toys, hobby
products [Ink, toner, and colorant products]).
Industrial Process Solvent Use
For the use of DBP as an industrial process solvent, dermal exposure from liquid contact is expected to
be the dominant route of exposure. MOEs for high-end acute, intermediate, and chronic inhalation
exposure ranged from 15 to 25 for average adult workers and females of reproductive age, while high-
end dermal MOEs for the same populations and exposure scenarios ranged from 0.8 to 1.3 (benchmark =
30). The central tendency MOEs for the same populations and exposure scenarios ranged from 30 to 49
for inhalation exposure and 1.7 to 2.7 for dermal exposure. Aggregation of inhalation and dermal
exposures led to negligible differences in risk when compared to risk estimates from dermal exposure
alone. The MOEs presented in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17
provides more information on PPE that could be used to reduce the MOEs above the benchmark MOE.
The high-end and central tendency worker inhalation exposure results for this OES are based on
analogous data from three different risk evaluations; each presented a single data point to characterize
full-shift exposure to workers during DBP manufacturing (ECB. 2008: ECJRC. 2004: SRC. 2001). To
determine central tendency and high-end values, EPA used the mid-point and maximum value,
respectively, due to limited data points. There is uncertainty about how well these data represent the true
distribution of actual inhalation concentrations in this scenario at a specific facility; the lack of ONU
exposure data, for which EPA used worker data as surrogate data; and that there are only three data
points used for the inhalation assessment.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
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the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( ). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP, and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
different formulations of DBP are used. There is also uncertainty in the use of guinea pigs over human
skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties
about the difference between human and guinea pigs skin absorption increase uncertainty.
Due to limited inhalation data points, both the central and high-end exposure estimates are expected to
be reflective of worker inhalation exposures for this OES. Also, since the dermal exposures are upper-
bound estimates, it can be conservatively assumed that the central tendency values of exposure estimates
are expected to be most reflective of worker dermal exposures. This applies to the COUs covered under
the "Industrial process solvent use" OES {i.e., Industrial Use (Non-incorporative activities [Solvent,
including in maleic anhydride manufacturing technology]).
Use of Laboratory Chemicals (solid)
The use of laboratory chemicals was assessed for solid and liquid products containing DBP. For solid
laboratory chemicals, inhalation exposure from dust generation is expected to be the dominant route of
exposure for solid lab chemicals. MOEs for high-end acute, intermediate, and chronic inhalation
exposure ranged from 28 to 45 for average adult workers and females of reproductive age, while high-
end dermal MOEs ranged from 62 to 98 (benchmark = 30). For central tendency, MOEs for the same
population and exposure scenarios ranged from 400 to 645 for inhalation exposure and 124 to 197 for
dermal exposures. For solid laboratory chemicals exposure, the aggregation of inhalation and dermal
exposures led to negligible differences in risk when compared to risk estimates from inhalation exposure
alone. The MOEs presented in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17
provides more information on PPE that could be used to reduce the MOEs above the benchmark MOE.
EPA estimated worker inhalation exposures to dust from solid lab chemicals using the PNOR Model for
dust exposures (U.S. EPA. 202Id). For inhalation exposure to PNOR, EPA determined the 50th and
95th percentiles of the surrogate dust monitoring data taken from facilities with NAICS codes starting
with 54 (Professional, Scientific, and Technical Services). EPA determined the 50th and 95th percentiles
of the surrogate dust monitoring data and multiplied these dust concentrations by the industry provided
maximum potential DBP concentration in lab chemicals {i.e., 20%) to estimate DBP particulate
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concentrations in the air. Therefore, the differences in the central tendency and high-end dust
concentrations led to differences between the central tendency and high-end risk estimates.
Although the PNOR Model {i.e., dust) concentration data provides a reliable range of dust
concentrations that a worker may experience in the laboratory setting, the composition of workplace
dust is uncertain. The exposure and risk estimates assume that the concentration of DBP in workplace
dust is the same as the concentration of DBP in the laboratory chemical. However, it is likely that
workplace dust contains a variety of constituents that do not contain any DBP in addition to particles
from DBP-containing laboratory chemical. The constituents that do not contain DBP would dilute the
overall concentration of DBP in the dust, and the concentration of DBP in workplace dust is likely less
than the concentration of DBP in the laboratory chemical. Therefore, the estimated inhalation exposures
to dust are likely overestimated.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( ). 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
male workers and 445 cm2 for female workers).
For estimating high-end and central tendency occupational dermal exposures to solids, EPA assumed
that DBP will first migrate from the solid matrix to a thin layer of moisture on the skin surface.
Therefore, absorption of DBP from solid matrices is considered limited by aqueous solubility and is
estimated using an aqueous absorption model ( 023c. 2004b) as described in Appendix C in
the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP)
(I E025q). EPA assumes that absorption of the aqueous material serves as a reasonable upper
bound for contact with solid materials and used this to estimate the average absorptive flux of DBP and
the resultant dose based on worker exposure area.
The PNOR Model uses conservative assumptions leading to upper-bound inhalation exposure estimates.
The dermal exposure estimates are also upper-bound estimates as discussed above. Therefore, the
central tendency values of exposure are expected to be most reflective of worker exposures within the
COUs covered under the "Use of laboratory chemicals" OES {i.e., Commercial Use COU: Other uses:
[Laboratory Chemicals]).
Use of Laboratory Chemicals (Liquid)
For the use of liquid laboratory chemicals, dermal exposures to liquids are expected to be the dominant
route of exposure. MOEs for high-end acute, intermediate, and chronic inhalation exposure ranged from
152 to 245 for average adult workers and females of reproductive age, while high-end dermal MOEs for
the same populations and exposure scenarios ranged from 0.8 to 1.3 (benchmark = 30). The central
tendency MOEs for the same populations and exposure scenarios ranged from 304 to 491 for inhalation
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exposure and 2.2 to 3.6 for dermal exposure. Aggregation of inhalation and dermal exposures led to
negligible differences in risk when compared to risk estimates from dermal exposure alone. The MOEs
presented in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17 provides more
information on PPE that could be used to reduce the MOEs above the benchmark MOE.
For liquid laboratory chemicals, no vapor inhalation exposure data was found from systematic review,
and EPA used data from the adhesives and sealants OES as a surrogate data source due to the expected
similarity in usage and concentrations. The adhesives and sealant data consists of 19 monitoring samples
in a NIOSH HHE (NIOSH. 1977). Six of the samples were PBZ samples, and the remaining 13 samples
were area samples taken at various locations around an acrylic furniture manufacturing site. With all
samples at or below the LOD, EPA assessed inhalation exposures as a range from zero to the LOD. EPA
estimated the high-end exposure as equal to the LOD and the central tendency as the midpoint {i.e., half
the LOD). There is uncertainty about how well these data represent the true distribution of actual
inhalation concentrations in this scenario at a specific facility. In absence of ONU exposure data, EPA
used worker data as analogous data for ONU exposure.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( 101 la). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
a higher concentration of DBP is used. There is also uncertainty in the use of guinea pigs over human
skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties
about the difference between human and guinea pigs skin absorption increase uncertainty.
As discussed above, inhalation exposure estimates is based on data which are below the LOD. EPA
estimated the high-end exposure as equal to the LOD and the central tendency as the midpoint {i.e., half
the LOD). Therefore, the inhalation exposure estimates are upper-bound estimates. Also, as discussed in
the paragraph above, the dermal exposure estimates are upper-bound estimates. So, the central tendency
values of exposure are expected to be most reflective of worker exposures within the COUs covered
under the "Use of laboratory chemicals" OES {i.e., Commercial use COU: Other uses: [Laboratory
Chemicals]).
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Use of Lubricants and Functional Fluids
For the use of lubricants and functional fluids containing DBP, dermal exposure from liquid contact is
expected to be the dominant route of exposure. MOEs for high-end acute, intermediate, and chronic
inhalation exposure ranged from 152 to 15,330 for average adult workers and females of reproductive
age, while high-end dermal MOEs for the same populations and exposure scenarios ranged from 1.0 to
99 (benchmark = 30). The central tendency MOEs for the same populations and exposure scenarios
ranged from 304 to 61,320 for inhalation exposure and 3.0 to 594 for dermal exposure. Aggregation of
inhalation and dermal exposures led to negligible differences in risk when compared to risk estimates
from dermal exposure alone. The MOEs presented in this paragraph are with no use of PPE. Section
4.3.2.4 and Table 4-17 provides more information on PPE that could be used to reduce the MOEs above
the benchmark MOE.
The high-end and central tendency worker inhalation exposure results for this OES are based on 19
analogous adhesive and sealant use monitoring samples in NIOSH's HHE database (NIQSt ). Six
of the samples were PBZ samples, and the remaining 13 samples were area samples taken at various
locations around an acrylic furniture manufacturing site. The site uses 2-part adhesives where the part B
component is 96.5 percent DBP. Two of the area samples recorded values at the limit of detection, and
the remaining 17 samples were below the limit of detection. All samples were collected on AA cellulose
membrane filters with 0.8|i average pore size and a pump flow rate of 1 LPM. The detection limit was
0.01 mg/m3 by gas chromatography. With all samples at or below the LOD, EPA assessed inhalation
exposures as a range from 0 to the LOD. EPA estimated the high-end exposure as equal to the LOD and
the central tendency as the midpoint {i.e., half the LOD). There is uncertainty about how well these data
represent the true distribution of inhalation concentrations in this scenario at a specific facility and in the
lack of ONU exposure data, for which EPA used worker data as surrogate data.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( 101 la). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
a higher concentration of DBP is used. There is also uncertainty in the use of guinea pigs over human
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skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties
about the difference between human and guinea pigs skin absorption increase uncertainty.
As discussed above, inhalation exposure estimates is based on data which are below the LOD. EPA
estimated the high-end exposure as equal to the LOD and the central tendency as the midpoint {i.e., half
the LOD). Therefore, the inhalation exposure estimates are upper-bound estimates. Also, as discussed in
the paragraph above, the dermal exposure estimates are upper-bound estimates. So, the central tendency
values of exposure are expected to be most reflective of worker exposures within the COUs covered
under the "Use of lubricants and functional fluids" OES {i.e., Commercial Use COU: Other Uses:
[Lubricants and lubricant additives]; Furnishing, cleaning, treatment care products: [Cleaning and
furnishing care products]; Automotive, fuel, agriculture, outdoor use products [Automotive care
products]; and the Industrial use COU: Other uses: [Lubricants and lubricant additives]).
Use of Penetrants and Inspection Fluids
For the use of penetrants and inspection fluids, dermal and inhalation exposure routes are both expected
to significantly contribute to exposures at both the central-tendency and high-end ranges, with dermal
exposures expected to be slightly dominant in its contribution. MOEs for high-end acute, intermediate,
and chronic inhalation exposure ranged from 2.7 to 4.4 for average adult workers and females of
reproductive age, while high-end dermal MOEs for the same populations and exposure scenarios ranged
from 0.8 to 1.3 (benchmark = 30). The central tendency MOEs for the same populations and exposure
scenarios ranged from 10 to 16 for inhalation exposure and 1.7 to 2.7 for dermal exposure. Aggregation
of inhalation and dermal exposures led to lower MOEs compared to either individual route. The MOEs
presented in this paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17 provides more
information on PPE that could be used to reduce the MOEs above the benchmark MOE.
EPA based the central tendency and high-end exposure estimates on a near-field/far-field approach
(A.IHA. 2009) for aerosol modeling, and the product concentration was based on the range provided by
the singular surrogate product which contained DINP {i.e., 10-20%) rather than DBP. As a result,
calculated central tendency and high-end risk values were similar. Reliance on a single surrogate
product for this OES adds uncertainty to the representativeness of the modeled inhalation exposures.
Further, although the surrogate product information indicates that the product is aerosol and brush
applied, EPA assessed only aerosol application due to limited data for this OES. The aerosolization of
DBP-containing fluids generates a mist of droplets in the near-field, resulting in inhalation and dermal
exposure to workers, although dermal exposure is the primary contributor to the presented aggregate risk
value. Aerosol application may overestimate inhalation exposures for brush application methods. Also,
there is uncertainty related to the concentration of DBP in penetrant or inspection fluid products since
the only available product data were for DINP. However, central tendency levels of exposure from the
near-field/far-field exposure modeling are expected to represent the 50th percentile of worker exposures
from the use of aerosols containing DBP. High-end levels of exposure are generally associated with
higher product concentrations and use rates. Although most worker exposures to DBP through aerosol
application of inspection fluids and penetrants are expected to be closer to the central tendency exposure
values for this COU, a confluence of a subset of variables {e.g., low ventilation, high concentration, high
use rate) would result in risk below the benchmark. While most workers are not expected to experience
these conditions, they may occur and expected for an acute 1-day exposure.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
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from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( 101 la). 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
male workers and 445 cm2 for female workers).
High-end and central tendency dermal exposures to liquid were determined using data from Doan et al.
(2010). The study estimated a dermal absorption rate from experiments on female hairless guinea pigs
using a formulation of 7 percent oil-in-water emulsion. Using the study's estimate for DBP absorption in
skin, 56.3 percent of the 1 mg/cm2 dose over 24 hours, EPA estimated the steady-state flux of DBP and
the resultant dose based on exposure area. Although EPA determined that all data were of acceptable
quality without notable deficiencies and integrated all the data into the final exposure assessment, it's
uncertain how representative the use of a 7 percent oil-in-water emulsion formulation is for OESs where
a higher concentration of DBP is used. There is also uncertainty in the use of guinea pigs over human
skin, as guinea pig tissue is known to be more permeable than human tissue. Therefore, uncertainties
about the difference between human and guinea pigs skin absorption increase uncertainty.
The central tendency values of exposure estimates are expected to be most reflective of worker
inhalation exposures to reasonably expected conditions and the high-end values of exposure estimates
are expected to be most reflective of workers exposed to potentially elevated {e.g., due to low
ventilation, high concentration, high use rate) inhalation exposures. Also, since the dermal exposure
estimates are upper-bound estimates, the central tendency values of exposure estimates are expected to
be most reflective of worker exposures for dermal exposures. These exposures are experienced by
workers within the COUs covered under the "Use of penetrants and inspection fluids" OES {i.e.,
Commercial Use COU: Other uses: [Inspection penetrant kit]).
Fabrication or Use of Final Product or Articles
For fabrication or use of final product or articles, inhalation exposure was assessed from both vapors
generated from materials that contain DBP and activities such as cutting, grinding, or drilling that may
generate dust. For this OES, dermal and inhalation exposure routes are both expected to equally
contribute to exposures at the central tendency prediction range, but inhalation exposures are expected to
be dominant at the high-end range. MOEs for high-end acute, intermediate, and chronic inhalation
exposure ranged from 18 to 29 for average adult workers and females of reproductive age, while high-
end dermal MOEs for the same populations and exposure scenarios ranged from 62 to 98 (benchmark =
30). For central tendency, MOEs for the same population and exposure scenarios ranged from 152 to
245 for inhalation exposure and 124 to 197 for dermal exposures. Aggregation of inhalation and dermal
exposures led to lower MOEs compared to either individual route. The MOEs presented in this
paragraph are with no use of PPE. Section 4.3.2.4 and Table 4-17 provides more information on PPE
that could be used to reduce the MOEs above the benchmark MOE.
EPA estimated worker inhalation exposures to vapor from one sample that was taken at a facility that
melted, shaped, and joined plastics, and two inhalation exposure data points from the machine and
manual welding of plastic roofing materials (ECJRC. 2004; Rudel et al.. 2001). With the three discrete
data points, EPA could not create a full distribution of monitoring results to estimate central tendency
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and high-end exposures. To assess the high-end worker exposure to DBP during the fabrication process,
EPA used the maximum available value (0.03 mg/m3) and used the median of the three available values
as the central tendency (0.01 mg/m3). EPA estimated worker inhalation exposures to solid particulate
using the PNOR Model for dust exposures ( ). For inhalation exposure to PNOR, EPA
determined the 50th and 95th percentiles of the surrogate dust monitoring data taken from facilities with
NAICS codes starting with 337 (Furniture and Related Product Manufacturing). EPA multiplied these
dust concentrations by the maximum DBP concentration in PVC {i.e., 45%) to estimate DBP particulate
concentrations in the air. Therefore, the differences in the central tendency and high-end dust
concentrations led to significant differences between the central tendency and high-end risk estimates.
There is uncertainty about how well the surrogate vapor monitoring data represent the true distribution
of vapor inhalation concentrations for actual worker exposures in a specific facility the lack of ONU
exposure data, for which EPA used worker data as surrogate data, and that there are only three data
points used for the inhalation assessment. Also, although the PNOR Model {i.e., dust) concentration data
provides a reliable range of dust concentrations that a worker may experience in the fabrication industry,
the composition of workplace dust is uncertain. The exposure and risk estimates assume that the
concentration of DBP in workplace dust is the same as the concentration of DBP in the material.
However, it is likely that workplace dust contains a variety of constituents that do not contain any DBP
in addition to particles from DBP-containing materials. The constituents that do not contain DBP would
dilute the overall concentration of DBP in the dust, and the concentration of DBP in workplace dust is
likely less than the concentration of DBP in the material. Therefore, the estimated inhalation exposures
to dust are likely overestimated.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [.). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( E01 la). 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
male workers and 445 cm2 for female workers).
For estimating high-end and central tendency occupational dermal exposures to solids, EPA assumed
that DBP will first migrate from the solid matrix to a thin layer of moisture on the skin surface.
Therefore, absorption of DBP from solid matrices is considered limited by aqueous solubility and is
estimated using an aqueous absorption model ( 023c. 2004b) as described in Appendix C in
the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP)
(I E025q). EPA assumes that absorption of the aqueous material serves as a reasonable upper
bound for contact with solid materials and used this to estimate the average absorptive flux of DBP and
the resultant dose based on worker exposure area.
The PNOR Model uses conservative assumptions leading to upper-bound inhalation exposure estimates.
The dermal exposure estimates are also upper-bound estimates as discussed above. Therefore, the
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central tendency values of exposure are expected to be most reflective of worker exposures within the
COUs covered under the "Fabrication or final use of products or articles" OES {i.e., Industrial Use
COU: Other uses: [Automotive articles; Propellants]; and Commercial Use COU: Furnishing, cleaning,
treatment care products: [Floor coverings; construction and building materials covering large surface
areas including stone, plaster, cement, glass and ceramic articles; fabrics, textiles, and apparel; Furniture
and furnishings]; Packaging, paper, plastic, toys, hobby products: [Packaging (excluding food
packaging), including rubber articles; plastic articles (hard); plastic articles (soft); other articles with
routine direct contact during normal use, including rubber articles; plastic articles (hard), Toys,
playground, and sporting equipment]; Other uses: [Automotive articles, Chemiluminescent light sticks].
Recycling and Waste Handling, Treatment and Disposal
The approaches for the recycling OES and the waste handling, treatment and disposal OES are identical
and therefore consolidated here. For both OESs, the inhalation exposure from dust generation is
expected to be the dominant route of exposure. MOEs for high-end acute, intermediate, and chronic
inhalation exposure ranged from 9.7 to 16 for average adult workers and females of reproductive age,
while high-end dermal MOEs for the same populations and exposure scenarios ranged from 62 to 98
(benchmark = 30) for both OESs. The central tendency MOEs for the same populations and exposure
scenarios ranged from 141 to 227 for inhalation exposure and 124 to 197 for dermal exposure for both
OESs. Aggregation of inhalation and dermal exposures led to slight differences in risk when compared
to risk estimates from inhalation exposure alone. The MOEs presented in this paragraph are with no use
of PPE. Section 4.3.2.4 and Table 4-17 provides more information on PPE that could be used to reduce
the MOEs above the benchmark MOE.
EPA estimated worker inhalation exposures using the PNOR Model for dust exposures (
202 Id). For inhalation exposure to PNOR, EPA determined the 50th and 95th percentiles of the
surrogate dust monitoring data taken from facilities with NAICS codes starting with 56 (Administrative
and Support and Waste Management and Remediation Services). EPA multiplied these dust
concentrations by the industry provided maximum DBP concentration in PVC {i.e., 45%) to estimate
DBP particulate concentrations in the air. PVC concentration was used for this estimate because it is
expected to be the predominant type of waste containing DBP that is recycled or disposed of. Therefore,
the differences in the central tendency and high-end dust concentrations led to significant differences
between the central tendency and high-end risk estimates.
Though the PNOR Model {i.e., dust) concentration data provides a reliable range of dust concentrations
that a worker may experience in the recycling and disposal industry, the composition of workplace dust
is uncertain. The exposure and risk estimates assume that the concentration of DBP in workplace dust is
the same as the concentration of DBP in PVC Plastics. However, it is likely that workplace dust contains
a variety of constituents that do not contain any DBP in addition to particles from DBP-containing PVC
plastics materials. The constituents that do not contain DBP would dilute the overall concentration of
DBP in the dust, and the concentration of DBP in workplace dust is likely less than the concentration of
DBP in the PVC plastics material. Therefore, the estimated inhalation exposures to dust are likely
overestimated.
For occupational dermal exposure assessment, EPA assumed a standard 8-hour workday and the
chemical is contacted at least once per day. Because DBP has low volatility and relatively low
absorption, it is possible that the chemical remains on the surface of the skin after dermal contact until
the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of DBP
from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I j_). However, if a worker uses proper PPE, or washes their hands after contact with DBP
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or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. Regarding surface area
of occupational dermal exposure, EPA assumed a high-end value of 1,070 cm2 for male workers and 890
cm2 for female workers. These high-end occupational dermal exposure surface area values are based on
the mean two-hand surface area for adults EPA's Exposure Factors Handbook ( 201 la). 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
male workers and 445 cm2 for female workers).
For estimating high-end and central tendency occupational dermal exposures to solids, EPA assumed
that DBP will first migrate from the solid matrix to a thin layer of moisture on the skin surface.
Therefore, absorption of DBP from solid matrices is considered limited by aqueous solubility and is
estimated using an aqueous absorption model ( 023c. 2004b) as described in Appendix C in
the Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP)
( Z025q). EPA assumes that absorption of the aqueous material serves as a reasonable upper
bound for contact with solid materials and used this to estimate the average absorptive flux of DBP and
the resultant dose based on worker exposure area.
The PNOR Model uses conservative assumptions leading to upper-bound inhalation exposure estimates.
The dermal exposure estimates are also upper-bound estimates as discussed above. Therefore, the
central tendency values of exposure are expected to be most reflective of worker exposures within the
COUs covered under the COUs covered under the "Recycling" and the "Disposal" OESs {i.e.,
Processing COU: "Recycling" and Disposal COU: "Disposal").
Distribution in Commerce
For purposes of assessment in this draft risk evaluation, distribution in commerce consists of the
transportation associated with the moving of DBP or DBP-containing products and/or articles between
sites manufacturing, processing, and use COUs, or the transportation of DBP containing wastes to
recycling sites or for final disposal. EPA expects all the DBP or DBP-containing products and/or articles
to be transported in closed system or otherwise to be transported in a form {e.g., articles containing
DBP) such that there is negligible potential for releases except during an incident. Therefore, no
occupational exposures are reasonably expected to occur, and no separate assessment was performed for
estimating releases and exposures from distribution in commerce.
4.3.2.1 Overall Confidence in Worker Risk Estimates for Individual DBP OES
As described in Section 4.1.1.5 and the Draft Environmental Release and Occupational Exposure
Assessment for Dibutyl Phthalate (U. 2025q). EPA has moderate to robust confidence in the
assessed inhalation exposures, and robust confidence in the non-cancer POD selected to characterize risk
from acute, intermediate, and chronic duration exposures to DBP (see Section 4.2). EPA also has
moderate to robust confidence that the dermal exposures estimated are upper bound of potential
exposures to workers. Overall, EPA has moderate to robust confidence in the risk estimates calculated
for worker and ONU inhalation and dermal exposure scenarios. Sources of uncertainty associated with
these occupational COUs are discussed above in Section 4.3.2.
4.3.2.2 Effect of Duration of Exposure on Dermal Risk Estimates
Because the dermal flux rate of DBP absorption is insufficient to deplete the loading dose applied to the
hands during an 8-hour work shift, and because DBP has low volatility and is not expected to evaporate
from the hands, it is possible that the chemical remains on the surface of the skin after dermal contact
until the skin is washed. So, in absence of exposure duration data, EPA has assumed that absorption of
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DBP from occupational dermal contact with materials containing DBP may extend up to 8 hours per day
(I [). However, if a worker uses proper PPE, or washes their hands after contact with DBP
or DBP-containing materials, dermal exposure may be eliminated. Therefore, the assumption of an 8-
hour exposure duration for DBP may lead to overestimation of dermal exposure. For example, for the
Manufacturing OES, if the average adult worker's hand is in contact with DBP for over 25 minutes and
female of reproductive age worker's hand is in contact with DBP for over 30 minutes the central
tendency MOEs are below the benchmark MOE of 30.
4.3.2.3 Consideration of Personal Protective Equipment (PPE)
Occupational Safety and Health Adminstration (OSHA) and National Institute for Occupational Safety
and Health (NIOSH) recommend employers utilize the hierarchy of controls4 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 PPE. The
hierarchy of controls prioritizes the most effective measures, which 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, followed by administrative controls or
changes in work practices to reduce exposure potential (e.g., source enclosure, local exhaust ventilation
systems). Administrative controls are policies and procedures instituted and overseen by the employer to
protect worker exposures. OSHA and NIOSH recommend the use of PPE (e.g., respirators, gloves) as
the last means of control, when the other control measures cannot reduce workplace exposure to an
acceptable level.
4.3.2.3.1 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,
providing respirators that are applicable and suitable for the purpose intended. Respirator selection
provisions are provided in section 1910.134(d) and require that appropriate respirators be selected based
on the respiratory hazard(s) to which the worker will be exposed, in addition to workplace and user
factors that affect respirator performance and reliability. Assigned protection factors (APFs) are
provided in Table 1 under section 1910.134(d)(3)(i)(A) (see below in Table 4-15) and refer to the level
of respiratory protection that a respirator or class of respirators is expected to provide to employees
when the employer implements a respiratory protection program according to the requirements of
OSHA's Respiratory Protection Standard.
Workers are required to use respirators that meet or exceed the required level of protection listed in
Table 4-15. Based on the APF, inhalation exposures may be reduced by a factor of 5 to 10,000, if
respirators are properly worn and fitted.
4 https://www.osha.gov/sites/defanlt/files/Hierarchv of Controls 02.01.23 form 508 2.pdf
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Table 4-15. 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)
4.3.2.3.2 Glove Protection
Gloves are selected in industrial settings based on characteristics (permeability, durability, required task
etc). Data on the frequency of glove use {i.e., the proper use of effective gloves) in industrial settings is
very limited. An initial literature review suggests that there is unlikely to be sufficient data to justify a
specific probability distribution for effective glove use for handling of DBP specifically, for a given
industry. Instead, EPA explored the impact of effective glove use by considering different percentages
of effectiveness {e.g., 25% vs. 50% effectiveness).
Gloves only offer barrier protection until the chemical breaks through the glove material. Using a
conceptual model, Cherrie et al. (2004) proposed a glove workplace protection factor, defined as 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 the protection factor varies with
time. The ECETOC TRA model v.3.2 represents the glove protection factor as a fixed, assigned value
equal to 5, 10, or 20 (Marquart et al..: ). Like the APR for respiratory protection, the inverse of the
protection factor is the fraction of the chemical that penetrates the glove. Table 4-16 presents APFs for
different dermal protection characteristics.
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Table 4-16. Assigned Protection Factors for Different Dermal Protection Strategies
Dermal Protection Characteristics
Setting
Protection
Factor, PF
a. No gloves used, or any glove/gauntlet without permeation data
and without employee training
Industrial and
Commercial
Uses
1
b. Gloves with available permeation data indicating that the
material of construction offers good protection for the substance
5
c. Chemically resistant gloves (i.e., as b above) with "basic"
employee training
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 Uses
Only
20
Source: (Marciiiart et ah, 2017)
4.3.2.4 Occupational Risk Estimates and Effect of PPE
Table 4-17 below presents the acute duration risk estimates for female workers of reproductive age and
the corresponding PPE that would result in a worker MOE above the benchmark MOE. For occupational
risk estimates, Female workers of reproductive age are the most sensitive exposed population with the
lowest worker MOEs. Furthermore, the acute exposure duration results in the lowest worker MOEs for
this population. This means that PPE that raises the MOE above the benchmark for a female worker of
reproductive age in the acute exposure duration will also raise the MOE above the benchmark for all
other workers and exposure durations. Risk estimates for other populations, durations, and health effects
for all the COUs/OES are included in the Draft Risk Calculator for Occupational Exposures for Dibutyl
Phthalate (DBF) flJ.S. Q25tJ. Additionally, the risk calculator contains MOE calculations and
PPE information for all the OES.
Table 4-17 includes three main sections according to the route of exposure: inhalation, dermal, and
aggregate exposure. For inhalation, typical respirator applied protection factor (APF) values of 10, 25,
50, 1000 and 10,000 were compared to the calculated MOE and the benchmark MOE to determine the
level of APF that could be used to bring MOEs above the benchmark MOE. For dermal exposures,
typical dermal Protection Factor (PF) values of 5, 10, and 20 were compared to the calculated MOE and
the benchmark MOE to determine the level of PF that could be used to bring MOEs above the
benchmark MOE. For aggregate exposures, the APF and/or PF that could be used to bring MOEs above
the benchmark are also shown. In cases, when it is not possible to raise MOE to above the benchmark
with the use of respiratory and/or dermal protection, PPE with maximum APF/PF and the corresponding
MOE values are shown in the table. The appropriateness of any protection factor that demonstrates
exposures resulting in a worker MOE above the benchmark MOE may require additional consideration.
The presented protection factors simply represent a value by which corresponding PPE may
theoretically increase the estimated worker MOE above the benchmark MOE. The practicality and
feasibility of implementing any PPE corresponding to a protection factor is part of a larger evaluation of
effective occupational control strategies. Such an evaluation should take into consideration the hierarchy
of hazard control options. The hierarchy of controls from most to least effective are elimination,
substitution, engineering controls, administrative controls, and personal protective equipment.
For inhalation, based on the risk characterization in Section 4.3.2, either the central tendency or both the
central tendency and high-end exposure estimates may be reflective of worker inhalation exposures
depending on the OES. Table 4-17 shows that using PPE for inhalation scenarios when the MOEs are
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3658 below the benchmark MOE, reduces the exposures to above the benchmark MOE. For dermal, based on
3659 the risk characterization in Section 4.3.2, the central tendency exposure estimates are expected to be
3660 most reflective of worker dermal exposures for all OESs because the dermal exposure estimates are
3661 upper-bounds. Table 4-17Table shows when dermal protection is used, the central tendency MOEs for
3662 all OESs are increased to above the benchmark for dermal exposures.
3663
3664 Table 4-17. Occupational Risk Estimation for Acute Exposure for Female of Reproductive Age
Benchmark MC
>E = 30
Occupational
Scenario
Expos.
Level
Inhalation
Dermal
Aggregate
Worker
MOE
No PPE
Worker
MOE with
PPE'
APF6c
Worker
MOE
No I'I'i:
Worker
MOE with
PPE'
PF6c
Worker
MOE
No I'I'I!
Worker
MOE with
ppi:'
Manufacturing
CT
3d
Ai
hench in ark
N/A
I.S
3<.
PF 20
1.7
0.9
\.n
0.9
\.n
0.9
\.n
o.s
33 (API lu.
PI 2(ii
IS (API 5<).
PI 2(ii
HE
15
152
APF
10
0.9
IS
PF 20
Import and
repackaging
CT
30
At
benchmark
N/A
I.S
3<.
PF 20
33 (API lu.
PI 2d i
IS (API'5ii.
PI 2(ii
HE
15
152
APF
10
0.9
IS
PF 20
Incorporation into
formulations,
mixtures, or
reaction product
CT
30
At
benchmark
N/A
I.S
3<.
PF 20
33 (API lu.
PI 2d i
IS ( API' 5(1.
PI 2(D
HE
15
152
APF
10
0.9
IS
PF 20
PVC plastics
compounding
CT
44
Above
benchmark
N/A
I.S
3<.
PF 20
33 (API Id.
PI 2(ii
IS (API'
1 .(Kid. PI' 2(ii
HE
5.3
53
APF
10
0.9
IS
PF 20
PVC plastics
converting
CT
44
5.3
Above
benchmark
N/A
135
Above
benchmark
N/A
33
Above
benchmark
HE
53
APF
10
67
Above
benchmark
N/A
4.9
\.n
O.S
I.S
0.9
\.n
0.7
\.n
0.9
45 ( API'251
Non-PVC
materials
manufacturing
CT
53
Above
Ivnclimark
N/A
I.S
3<.
PF 20
34 ( API' Id.
PI 2(ii
IS (API'
1 .(Kid. PI' 2(ii
HE
9.0
lAi
APF
10
0.9
IS
PF 20
Application of
adhesives and
sealants
CT
304
Above
benchmark
N/A
I.S
3<.
PF 20
33 i PI '2d i
IS ( API' Id.
PI 2(ii
HE
152
IS
2.9
Above
benchmark
N/A
0.9
IS
PF 20
Application of
paints and
coatings
CT
184
APF
10
I.S
3<.
PF 20
3d ( API' Id.
PI 2(ii
IS ( API'
1 .(Kid. PI' 2(ii
HE
73
APF
25
0.9
IS
PF 20
Industrial process
solvent use
CT
30
At
benchmark
N/A
I.S
3<.
PF 20
33 ( API' Id.
PI 2(ii
IS ( API' 5(1.
PI 2(ii
HE
15
152
APF
10
0.9
IS
PF 20
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Occupational
Scenario
Expos.
Level
Inhalation
Dermal
Aggregate
Worker
MOE
No PPE
Worker
MOE with
PPEC
APF6c
Worker
MOE
No PPE
Worker
MOE with
PPEC
ppic
Worker
MOE
No PPE
Worker
MOE with
PPE6c
Use of laboratory
chemicals (solid)
CT
400
Above
benchmark
N/A
135
Above
benchmark
N/A
101
Above
benchmark
HE
28
282
APF
10
67
Above
benchmark
N/A
20
54 (APF 10)
Use of laboratory
chemicals (liquid)
CT
304
Above
benchmark
N/A
2.4
49
PF 20
2.4
42 (PF 20)
HE
152
Above
benchmark
N/A
0.9
18
PF 20
0.9
18 (APF 10,
PF 20)
Use of lubricants
and functional
fluids
CT
304
Above
benchmark
N/A
3.3
33
PF 10
3.2
54 (PF 20)
HE
152
Above
benchmark
N/A
1.1
22
PF 20
1.1
22 (APF 25,
PF 20)
Use of penetrants
and inspection
fluids
CT
10
101
APF
10
1.8
36
PF 20
1.5
32 (APF 25,
PF 20)
HE
2.7
68
APF
25
0.9
18
PF 20
0.7
18 (APF
1,000, PF 20)
Fabrication or use
of final product or
articles
CT
152
Above
benchmark
N/A
135
Above
benchmark
N/A
71
Above
benchmark
HE
18
181
APF
10
67
Above
benchmark
N/A
14
49 (APF 10)
Recycling
CT
141
Above
benchmark
N/A
135
Above
benchmark
N/A
69
Above
benchmark
HE
9.7
97
APF
10
67
Above
benchmark
N/A
8.4
40 (APF 10)
Waste handling,
treatment, and
disposal
CT
141
Above
benchmark
N/A
135
Above
benchmark
N/A
69
Above
benchmark
HE
9.7
97
APF
10
67
Above
benchmark
N/A
8.4
40 (APF 10)
" Benchmark MOE = 30. Bold text in a gray shaded cell indicates an MOE is below the benchmark value of 30.
h CT = central tendency; HE = high-end; PPE = personal protective equipment, MOE = margin of exposure, PF =
protection factor, APF = assigned protection factor
c PPE with the least amount of APF/PF that could be used to reduce MOE values above the benchmark MOE are shown in
the table with corresponding MOE values. In cases, when it is not possible to raise MOE to above the benclunark with
PPE, PPE with maximum APF/PF and the corresponding MOE values are shown in the table.
d The Draft Risk Calculator for Occupational Exposures for Dibutvl Phthalate (DBP) (U.S. EPA. 2025t) contains MOE
calculations and PPE information for all the OES for all durations (acute, intermediate, and chronic).
3666
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3668 Table 4-18. Occupational Risk Table for DBP
cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Manufacturing
- Domestic
manufacturing
Domestic manufacturing
Manufacturing
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
1.6
2.2
2.3
HE
17
23
25
0.8
1.1
1.2
0.8
1.1
1.2
Female of
Reproductive Age
CT
30
41
44
1.8
2.5
2.7
1.7
2.3
2.5
HE
15
21
22
0.9
1.2
1.3
0.9
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
Manufacturing
- Importing
Importing
Import and
repackaging
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
1.6
2.2
2.3
HE
17
23
25
0.8
1.1
1.2
0.8
1.1
1.2
Processing -
Repackaging
Laboratory chemicals in
wholesale and retail trade;
plasticizers in wholesale and
retail trade; and plastics material
and resin manufacturing
Female of
Reproductive Age
CT
30
41
44
1.8
2.5
2.7
1.7
2.3
2.5
HE
15
21
22
0.9
1.2
1.3
0.9
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
Processing -
Processing as a
reactant
Intermediate in plastic
manufacturing
Incorporation
into
formulations,
mixtures, or
reaction
product
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
1.6
2.2
2.3
Processing -
Incorporation
into
formulation,
mixture, or
reaction product
Solvents (which become part of
product formulation or mixture)
in chemical product and
preparation manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
adhesive manufacturing; and
printing ink manufacturing
Plasticizer in paint and coating
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing;
printing ink manufacturing; basic
organic chemical manufacturing;
and adhesive and sealant
manufacturing
HE
17
23
25
0.8
1.1
1.2
0.8
1.1
1.2
Pre-catalyst manufacturing
Female of
Reproductive Age
CT
30
41
44
1.8
2.5
2.7
1.7
2.3
2.5
HE
15
21
22
0.9
1.2
1.3
0.9
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
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cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Processing -
Processing:
incorporation
into
formulation,
mixture, or
reaction product
Plasticizer in plastic material and
resin manufacturing
PVC plastics
compounding
Average Adult
Worker
CT
49
67
71
1.7
2.3
2.4
1.6
2.2
2.3
HE
5.9
8.0
8.6
0.8
1.1
1.2
0.7
1.0
1.1
Female of
Reproductive Age
CT
44
60
65
1.8
2.4
2.6
1.7
2.4
2.5
HE
5.3
7.2
7.8
0.9
1.2
1.3
0.8
1.0
1.1
ONU
CT
49
67
71
124
169
181
35
48
51
Processing -
Processing:
incorporation
into articles
Plasticizer in adhesive and
sealant manufacturing; building
and construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics
product manufacturing
PVC plastics
converting
Average Adult
Worker
CT
49
67
71
124
169
181
35
48
51
HE
5.9
8.0
8.6
62
85
90
5.4
7.3
7.8
Female of
Reproductive Age
CT
44
60
65
135
184
197
33
45
49
HE
5.3
7.2
7.8
67
92
98
4.9
6.7
7.2
ONU
CT
49
67
71
124
169
181
35
48
51
Processing -
Processing:
incorporation
into
formulation,
mixture, or
reaction product
Plasticizer in plastic material and
resin manufacturing; rubber
manufacturing
Non-PVC
materials
manufacturing
Average Adult
Worker
CT
59
80
86
1.7
2.3
2.4
1.6
2.2
2.3
HE
9.9
14
15
0.8
1.1
1.2
0.8
1.0
1.1
Female of
Reproductive Age
CT
53
73
78
1.8
2.4
2.6
1.7
2.4
2.5
Processing -
Incorporation
into articles
Plasticizer in adhesive and
sealant manufacturing; building
and construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics
product manufacturing; and
rubber product manufacturing
HE
9.0
12
13
0.9
1.2
1.3
0.8
1.1
1.2
ONU
CT
59
80
86
124
169
181
40
54
58
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cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acule
Inlcr.
Chronic
Acule
Inlcr.
Chronic
Acule
Inlcr.
Chronic
Commercial
Use -
Construction,
paint, electrical,
and metal
products
Adhesives and sealants
Application of
adhesives and
sealants
Average Adult
Worker
CT
336
458
529
1.7
2.3
2.(>
1.7
2.3
2.(>
HE
168
229
245
0.N
I.I
1.2
O.S
I.I
1.2
Female of
Reproductive Age
CT
304
415
479
I.S
2.5
2.<)
I.S
2.5
2.S
Industrial Use -
Construction,
paint, electrical,
and metal
products
Adhesives and sealants
HE
152
207
m
0.<)
1.2
1.3
0.<)
1.2
1.3
ONU
CT
336
458
529
1.7
2.3
2.6
1.7
2.3
2.(>
Commercial
Use -
Packaging,
paper, plastic,
toys, hobby
products
Ink, toner, and colorant products
Application of
paints and
coatings
Average Adult
Worker
CT
2(1
2S
30
1.7
2.3
2.4
1.5
2.1
2.3
HE
3.2
4.4
4.7
O.S
I.I
1.2
0.7
0.<)
1.0
Female of
Reproductive Age
CT
IS
25
27
I.S
2.5
2.7
1.7
2.3
2.4
HE
2M
4.0
4.2
0.9
1.2
1.3
0.7
0.<)
1.0
Commercial
Use -
Commercial use
- Construction,
paint, electrical,
and metal
products
Paints and coatings
ONU
CT
20
2S
30
2.2
3.1
3.3
2.0
2.S
2.<)
Industrial Use -
Non-
incorporative
activities
Solvent, including in maleic
anhydride manufacturing
technology
Industrial
process solvent
use
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
l.(t
2.2
2.3
hi;
17
23
25
O.S
I.I
1.2
O.S
I.I
1.2
Female of
Reproductive Age
CT
30
41
44
I.S
2.5
2.7
1.7
2.3
2.5
hi;
15
21
22
0.<)
1.2
1.3
0.<)
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
Commercial
Use - Other
uses
Laboratory chemicals
Use of
laboratory
chemicals
(solid)
Average Adult
Worker
CT
442
603
645
124
169
181
97
132
141
HE
31
42
45
62
85
90
21
2S
30
Female of
Reproductive Age
CT
400
546
584
135
184
197
101
138
147
HE
2S
38
41
67
92
98
20
27
29
ONU
CT
442
603
645
124
169
181
97
132
141
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cou
Inhalation Risk Estimates
Dermal Risk Estimates
Aggregate Risk Estimates
Life Cvele
OES
Worker
Exposure
(Benchmark MOE = 30)
(Benehmark MOE = 30)
(Benehmark MOE = 30)
Stage -
Category
Subcategory
Population
Level
Aeute
Inter.
Chronie
Aeule
Inler.
Chrome
Aeule
Inler.
Chronic
Commercial
Use - Other
uses
Use of
laboratory
chemicals
Average Adult
CT
336
458
491
2.2
3.1
3.3
2.2
3.0
3.3
Laboratory chemicals
Worker
HE
168
229
245
O.S
I.I
1.2
O.S
I.I
1.2
Female of
CT
304
415
444
2.4
3.3
3.(i
2.4
3.3
3.5
(liquid)
Reproductive Age
HE
152
207
222
0.<)
1.2
1.3
0.<)
1.2
1.3
ONU
CT
336
458
491
N/A
N/A
N/A
336
458
491
Commercial
Lubricants and lubricant
Average Adult
CT
336
5,040
61,320
3.0
45
546
3.0
44
541
Use - Other
additives
Worker
HE
168
1,260
15,330
1.0
7.5
91
1.0
7.4
90
uses
Female of
Reproductive Age
CT
304
4,563
55,514
3.3
49
594
3.2
48
588
Industrial Use -
Other uses
Lubricants and lubricant
additives
Use of
HE
152
1,141
13,878
1.1
S.I
99
I.I
S.I
98
Commercial
Use -
Automotive,
Automotive care products
lubricants and
functional
fluids
ONU
CT
336
5,040
61,320
N/A
N/A
N/A
336
5.040
61,320
fuel,
agriculture,
outdoor use
products
Use of
penetrants and
inspection
fluids
Average Adult
CT
11
15
16
1.7
2.3
2.5
1.5
2.0
2.1
Commercial
Worker
HE
3.0
4.1
4.4
O.S
I.I
1.2
0.7
0.<)
1.0
Use - Other
Inspection penetrant kit
Female of
CT
10
14
15
I.S
2.5
2.7
1.5
2.1
2.3
uses
Reproductive Age
hi;
2.7
3.7
4.0
0.<)
1.2
1.3
0.7
0.<)
1.0
ONU
CT
329
449
487
1.7
2.3
2.5
1.7
2.3
2.5
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cou
Inhalation Risk Estimates
Dermal Risk Estimates
Aggregate Risk Estimates
Life Cycle
Stage -
Category
Subcategory
OES
Worker
Population
Exposure
Level
(Benchmark MOE = 30)
(Benchmark MOE = 30)
(Benchmark MOE = 30)
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Floor coverings; construction and
CT
168
229
245
124
169
181
71
97
104
building materials covering large
surface areas including stone,
Commercial
Use -
plaster, cement, glass and
ceramic articles; fabrics, textiles,
Average Adult
Worker
Furnishing,
and apparel
cleaning,
Furniture and furnishings
treatment care
products
HF.
2(1
27
29
62
85
90
15
21
22
Female of
CT
152
207
111
135
184
197
71
97
104
Reproductive Age
hi;
IS
25
2(>
67
92
98
14
l«)
21
Fabrication or
ONU
CT
168
229
245
124
169
181
71
97
104
Commercial
Automotive articles
use of final
product or
articles
Use - Other
Chemiluminescent light sticks
uses
Propellants
Commercial
Use -
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other
Packaging,
paper, plastic,
toys, hobby
products
articles with routine direct
contact during normal use,
including rubber articles; plastic
articles (hard)
Toys, playground, and sporting
equipment
Average Adult
CT
156
212
227
124
169
181
69
94
101
Processing -
Recycling
Worker
HE
11
15
16
62
85
90
<).l
12
13
Recycling
Recycling
Female of
CT
141
192
206
135
184
197
69
94
101
Reproductive Age
HE
9.7
13
14
67
92
98
12
12
ONU
CT
156
212
227
124
169
181
69
94
101
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cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Disposal -
Disposal
Disposal
Waste
handling,
treatment, and
disposal
Average Adult
Worker
CT
156
212
227
124
169
181
69
94
101
HE
11
15
16
62
85
90
9.1
12
13
Female of
Reproductive Age
CT
141
192
206
135
184
197
69
94
101
HE
9.7
13
14
67
92
98
8.4
12
12
ONU
CT
156
212
227
124
169
181
69
94
101
" The Draft Risk Calculator for Occupational Exposures for Dibutvl Phthalate (DBP) (U.S. EPA, 2025t) contains MOE values with PPE for all the OES for all
populations (average adult workers, female of reproductive age, and ONUs) and all durations (acute, intermediate, and chronic).
Bold text in a gray shaded cell indicates an MOE below the benchmark value of 30.
3669
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PUBLIC RELEASE DRAFT
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4.3.3 Risk Estimates for Consumers
Table 4-19 summarizes the dermal, inhalation, ingestion, and aggregate MOEs used to characterize non-
cancer risk for acute, intermediate, and chronic exposure to DBP, and presents these values for all
lifestages for each COU. A screening level assessment for consumers considers high-intensity exposure
scenario risk estimates and relies on conservative assumptions to assess exposures that would be
expected to be on the high end of the expected exposure distribution. MOEs for high-intensity exposure
scenarios are shown for all consumer COUs, while MOEs for medium-intensity exposure scenarios are
shown only for COUs with high-intensity MOEs at, or under the benchmark of 30, see listed COUs
below. Further, Table 4-19 provides MOEs for the modeling indoor exposure assessment. The main
objective in reconstructing the indoor environment using consumer products and articles commonly
present in indoor spaces is to calculate exposure and risk estimates by COU, and by product and article,
from indoor dust ingestion and inhalation. EPA identified article-specific information by COU to
construct relevant and representative exposure scenarios. Exposure to DBP via ingestion of dust was
assessed for all articles expected to contribute significantly to dust concentrations due to high surface
area (> ~1 m2) for either a single article or collection of like articles as appropriate. Articles included in
the indoor environment assessment included: adult toys, children's toys (new and legacy), synthetic
leather furniture, car mats, shower curtains, vinyl flooring, and wallpaper used in place. COUs
associated with articles included in the indoor environment assessment are indicated with footnote c in
Table 4-19.
Of note, the risk summary below is based on the most sensitive non-cancer endpoint for all relevant
duration scenarios {i.e., developmental toxicity for acute, intermediate, and chronic durations). MOEs
for all high-, medium- and low-intensity exposure scenarios for all COUs are described in the Draft
Consumer Risk Calculator for Dibutyl Phthalate (DBP) ( )25e).
COUs with MOEs for High-Intensity Exposure Scenarios Above Benchmark
The screening level assessment for consumers considers high-intensity exposure scenario risk estimates,
MOEs, and relies on conservative assumptions to assess exposures that would be expected to be on the
high end of the expected exposure distribution. If MOEs are above the benchmark of 30 for the high-
intensity use scenario then any exposures with lower intensity use inputs would result in larger MOEs.
Consumer COUs that resulted in MOEs for high-intensity exposure scenarios above the benchmark of
30 for acute, chronic and intermediate exposures are summarized in Table 4-19 and in the following list:
• Furnishing, cleaning, treatment care products; floor coverings; construction and building
materials covering large surface areas including stone, plaster, cement, glass and ceramic
articles; fabrics, textiles, and apparel
• Furnishing, cleaning, treatment care products: fabric, textile, and leather products
• Other uses; automotive articles
• Other uses; chemiluminescent light sticks
• Other uses; novelty articles
• Packaging, paper, plastic, toys, hobby products; packaging (excluding food packaging),
including rubber articles; plastic articles (hard); plastic articles (soft); other articles with routine
direct contact during normal use, including rubber articles; plastic articles (hard)
Variability in MOEs for these high-intensity exposure scenarios results from use of different exposure
factors for each COU and product/article examples that led to different estimates of exposure to DBP.
As described in the Draft Consumer and Indoor Dust Exposure Assessment for Dibutyl phthalate (DBP)
(I 1025c) and Draft Non-Cancer Human Health Hazard Assessment for Dibutyl Phthalate
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(DBP) ( If), EPA has moderate to robust confidence in the exposure estimates and robust
confidence in the non-cancer hazard value used to estimate non-cancer risk for these COUs. EPA is
confident that the high-intensity use scenarios used in the screening approach represent an upper-bound
estimate and provide a health protective estimate for consumer exposures.
COUs with MOEs for Exposure Scenarios Below Benchmark
The screening level assessment for consumers considers high-intensity exposure scenario risk estimates,
MOEs, and relies on conservative assumptions to assess exposures that would be expected to be on the
high-end of the expected exposure distribution. If MOEs are below the benchmark of 30 for the high-
intensity use scenario, EPA reevaluates the approaches and inputs used and determines if refinement of
those is needed. In addition, the Agency considers the medium-intensity use scenario as either a possible
upper-bound estimate by reevaluating inputs and approaches or endeavors in the refinement of
approaches by using other modeling tools or other input parameters within the same modeling tools. See
Section 2 in Draft Consumer and Indoor Dust Exposure Assessment for Dibutyl Phthalate (DBP) fU.S.
25c) for details about the consumer modeling approaches, sources of data, model
parameterization, and assumptions. After reevaluating approaches and input parameters for each
consumer COU with MOEs below the benchmark EPA concludes that further refinement of input
parameters is not likely to result in different MOEs than those already presented in Table 4-19.
Consumer COUs that resulted in MOEs for high-intensity exposure scenarios below the benchmark of
30 for acute, chronic and intermediate exposures are summarized in Table 4-19 and in the following list:
• Construction, paint, electrical, and metal products: adhesives and sealants
• Construction, paint, electrical, and metal products: paints and coatings
• Furnishing, cleaning, treatment care products: cleaning and furnishing care products
• Packaging, paper, plastic, hobby products; toys, playground, and sporting equipment
The consumer COUs that resulted in MOEs below the benchmark of 30 are discussed in further detail in
the subsections below. Each subsection expands on each COU and the aspects driving the MOEs below
the benchmark.
Construction, Paint, Electrical, and Metal Products: Adhesives and Sealants
This section summarizes the risk estimates, MOEs, below the benchmark of 30 for the titled COU.
Products with similar DBP content and expected use patterns were grouped together for modeling as
described below. Some products were not assessed for inhalation exposure due to the small volume of
the product which is expected to be used, short durations of use and thus a shorter duration for emissions
to air to occur (e.g., adhesives with short working times (less than a few minutes) until solidification and
liquids poured directly into a reservoir that is capped after product addition), and/or products used in
outdoor conditions where air exchange rates are high and product application is not expected to generate
aerosols. Three different product scenarios were assessed under this COU for products with differing use
patterns including: adhesives for small repairs, automotive adhesives, and construction adhesives.
• One all-purpose adhesive used for small repairs was identified with DBP content. The reported
DBP content was less than 3 percent (W aim art. i ). Because small volumes of this adhesive
are expected to be used and the working time is short (<5 min), this product was evaluated for
dermal exposure only.
® Two adhesive products for home repair or construction bonding were identified with DBP
content. One anchoring adhesive used for anchoring metal rebar into cured concrete and masonry
was reported to have a DBP content of 0.1 to 5 percent (ITW Red Head. 2016). and one paste
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designed to watertight details in construction was reported to have a DBP content of 10 to 30
percent (Vaproshield. 2018). Both products are used outdoors in relatively small quantities and
not applied in a manner expected to generate significant aerosols. As such, these products were
modeled for dermal exposure only.
® One metal bonding adhesive used for small to moderately sized automotive repairs was
identified with DBP content of 1 to less than 3 percent (Ford Motor Company. 2015b). This
product was modeled for dermal and inhalation (because of possible large amount uses)
exposure. DBP weight fractions of 0.01, 0.015, and 0.03 w/w in low, medium, and high
inhalation exposure scenarios.
Of the three product scenarios assessed for this COU, only the acute doses (24-hour exposure; see
Sections 2.2.1 and 2.2.2 and Appendix A in ( ) for details about acute, intermediate, and
chronic dose calculations) for automotive and construction adhesives resulted in MOEs less than the
benchmark of 30. The automotive and construction adhesives COU resulted in MOEs less than 30 in the
dermal, acute, high- and medium-intensity use exposure scenarios. The MOEs for both automotive and
construction adhesives were 7, 8, and 7 respectively for young teen, teenager, and adult in the high-
intensity exposure route. For the medium-intensity exposure route the MOEs were 28, 31 and 29 for
young teen, teenagers, and adults. For construction adhesives and automotive adhesives, the duration of
skin contact used in the high-, medium-, and low-intensity use scenarios were 120, 60, and 30 minutes
respectively (Section 2.3.4 in U.S. EPA (2025c)). The contact area for the high-intensity use scenario
corresponded to inside of two hands including palms and fingers, for medium-intensity scenario contact
area was inside of one hand including palms and fingers, and low intensity scenario used 10 percent of
hands (some fingers) (Section 2.3.4 in U.S. EPA (2025c)).
For dermal exposure EPA used the liquid products dermal flux-limited approach, which was estimated
based on DBP in vitro dermal absorption in guinea pigs. An overall moderate confidence in dermal
assessment of adhesives was assigned. The difference between human and guinea pig skin absorption
increase uncertainty and due to increased permeability of guinea pig skin as compared to human skin
dermal absorption estimates likely overestimate exposures. Other parameters such as frequency and
duration of use, and surface area in contact, are well understood and representative, resulting in an
overall moderate confidence.
Construction, Paint, Electrical, and Metal Products: Paints and Coatings
This section summarizes the risk estimates, MOEs, below the benchmark of 30 for the titled COU.
Three different scenarios were assessed under this COU including: metal coatings, indoor sealing and
refinishing sprays, and outdoor sealing and refining sprays. All three scenarios were assessed for dermal
and inhalation exposures.
• Outdoor sealing and refinishing sprays: Four waterproofing coating products for roofs, decks,
and walkway applications were identified with DBP content. Identified product examples were
Hydrostop premium finish coat, Hydrostop premium foundation coat, Hydrostop traffic deck
coating, and Lanco seal (roof coating). The combined weight fractions used for the high-,
medium-, and low-intensity use inhalation exposure scenarios were 0.0005, 0.017, and 0.1 w/w
respectively. Though these products are for outdoor only use, inhalation exposure may be
significant due to relatively large volumes of product used and aerosol generation during spray
application. As such, these products were modeled for both inhalation and dermal exposures
during product application or do-it-yourself (DIY) activities for young teens, teenagers, and
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adults. Bystanders (infants to middle childhood) were assessed for inhalation exposures while
someone else, a DIYer, was using the product. Product application scenarios for inhalation and
dermal contact were modeled to occur outside. The duration of skin contact used in the high-,
medium-, and low-intensity use scenarios were 480, 240, and 120 minutes respectively, on the
account of needing two coats for proper product application and covering a large surface
(Section 2.3.4 in U.S. EPA (2025c)). The contact area for the high-, medium-, and low-intensity
use scenario corresponded to 10 percent of hands (Section 2.3.4 in U.S. EPA (2025c)). While for
other products in this COU it was assumed that users did not wash their hands until the task was
completed, these products are very sticky and likely require hand washing or at least wiping
hands. EPA assumes that the user can wipe their hands while some of the product remains,
therefore a surface area contact of 10 percent of the hands was selected. The dermal MOEs for
the acute, high exposure intensity scenario for outdoor sealing and refinishing spray products
were 9, 10, and 9 for young teens, teenagers, and adults. The MOE values for the medium-
intensity use exposure scenarios were 18, 19, and 18 for young teens, teenagers, and adults.
• Indoor sealing and refinishing sprays: Four waterproofing coating products for roofs, decks, and
walkway applications were identified with DBP content. Identified product examples were
Franklin side out gym floor finish, crystal floor finish, SWC nature one 100% Aery EN CED,
and SWC nature one renew. The combined weight fractions used for the high-, medium-, and
low-intensity use inhalation exposure scenarios were 0.01, 0.02, and 0.03 w/w respectively. The
products were assessed for inhalation and dermal exposures during product application or DIY
activities for young teens, teenagers, and adults. Bystanders (infants to middle childhood) were
assessed for inhalation exposures while someone else, a DIYer, was using the product. Product
application scenarios for inhalation and dermal contact were modeled to occur indoors (garage).
The duration of skin contact used in the high-, medium-, and low-intensity use scenarios were
270, 180, and 90 minutes respectively on the account of needing two coats for proper product
application on a semi large surface (smaller than for the outdoor products) (Section 2.3.4 in U.S.
EPA (2025c)). The contact area for the high-intensity use scenario corresponded 10 percent of
hands for the high-, medium-, and low-intensity use scenarios. These products are very sticky
and likely require hand washing or at least wiping hands. EPA assumes that the user can wipe
their hands while some of the product remains, therefore a surface area contact of 10 percent of
the hands was selected (Section 2.3.4 in U.S. EPA (2025c)). The MOEs for the high exposure
intensity scenario for indoor sealing and refinishing sprays were 16, 17 and 16 respectively for
young teen, teenage and adult. The medium-intensity MOEs were 23, 26, and 24 for the same
lifestage categories.
• Metal coatings: Two metal coating products were assessed for inhalation and dermal exposures
during product application or DIY activities for young teens, teenagers, and adults. Bystanders
(infants to middle childhood) were assessed for inhalation exposures while someone else, a
DIYer, was using the product. Product application scenarios for inhalation and dermal contact
were modeled to occur indoors (garage). One anti-fouling boat coating was identified with 2.5 to
10 percent DBP content, and one aluminum primer was identified with 1 to 2.5 percent DBP
content. The combined weight fractions were 0.01 w/w, 0.04 w/w, and 0.1 used for the low,
medium, and high-intensity use exposure scenarios. The durations of skin contact used in the
high-, medium-, and low-intensity use scenarios were 120, 60, and 30 minutes respectively
(Section 2.3.4 in U.S. EPA (2025c)). The contact area for the high-intensity use scenario
corresponded to the inside of two hands (including palms and fingers), and the medium-intensity
use scenario used the inside of one hand (Section 2.3.4 in U.S. EPA (2025c)). For the metal
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coatings COU, the MOEs for the acute, dermal, high-intensity scenario were 7, 8, and 7
respectively for young teen, teenage, and adult. For the dermal medium-intensity use exposure
scenario, the MOEs were 28, 31, and 29.
The MOEs for the chronic, high-intensity, inhalation scenario were 26 and 28 for the infant and toddler
lifestages (assessed as bystanders which is a non-user of the product that is in the vicinity). The duration
of use per event is the same as the duration of dermal contact for high-, medium-, and low-intensity used
exposure scenarios, 120, 60, and 30 minutes. For chronic exposures EPA assumed weekly uses during a
year which is 52 events in one year of exposure. The preschoolers and middle childhood children MOE
values were above 30. The differences between infants and toddlers with preschoolers and middle
childhood is the inhalation rates and body weights ratio. The same exposure concentration is inhaled at a
faster rate for the younger lifestages while in a smaller body weight resulting in higher doses and lower
MOEs.
For all three product scenarios assessed for this COU, the acute dermal pathway resulted in MOEs less
than the benchmark of 30 in both the high and medium-intensity use scenarios for young teens,
teenagers, and adults. For dermal exposure, EPA used the liquid products dermal flux-limited approach,
which was estimated based on DBP in vitro dermal absorption in guinea pigs. EPA determined an
overall moderate confidence in the dermal assessment for paints and coatings. The Agency assumes an
excess of DBP is in contact with the skin and that the absorptive flux of DBP measured from in vitro
guinea pig experiments serves as an upper-bound of potential absorptive flux of chemical into and
through the skin for dermal contact with all liquid products. Uncertainties about the difference between
human and guinea pig skin absorption increase uncertainty and due to increased permeability of guinea
pig skin as compared to human skin dermal absorption estimates likely overestimate exposures. Other
parameters such as frequency and duration of use, and surface area in contact, are well understood and
representative, resulting in a moderate overall confidence.
The overall confidence in this COU's inhalation exposure estimate is robust because the CEM default
parameters represent actual use patterns and location of use. Differences in MOEs between the high,
medium, and low-intensity inhalation exposure scenarios result from use of different exposure
parameters in CEM. Key parameters that differed between high- and medium-intensity scenarios include
weight fraction {i.e., 0.1 vs. 0.04 for metal coatings), product mass used {i.e., 1,427 vs. 713 g for metal
coatings), and inhalation rates used per lifestage. Inhalation rates for lifestages range from 0.74 to 0.46
m3/h for adults to infants respectively, with the largest difference between infants and the next lifestage.
Other CEM exposure factors were kept constant between high- and medium-intensity inhalation
scenarios {e.g., surface layer thickness, volume of use environment, interzone ventilation rate). In these
product inhalation scenarios DBP is released into the gas-phase. The product inhalation scenario tracks
chemical transport among the source, air, airborne and settled particles, and indoor sinks. The approach
accounts for (1) emissions, (2) mixing within the gas phase, (3) transfer to particulates by partitioning,
(4) removal due to ventilation, (5) removal due to cleaning of settled particulates and dust to which DBP
has partitioned, and (6i) sorption or desorption to/from interior surfaces. The emissions from the product
were modeled with a single exponential decay model. This means that chronic and acute exposure
duration scenarios use the same emissions/air concentration data based on the weight fraction but have
different averaging times for the air concentration used. The acute data uses concentrations for a 24-hour
period at the peak, while the chronic data was averaged over the entire 1-year period. Because air
concentrations for most of the year are significantly lower than the peak value, the air concentration
used in chronic dose calculations is lower than acute. The overall confidence in this COU's inhalation
and dust ingestion exposure estimates are robust because the CEM default parameters represent actual
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use patterns and location of use (see Section 2.2.3.2 in U.S. EPA (2025c)). and the estimated surface
area is well characterized and represents a wide range of plausible uses.
Aggregate risk estimates across all evaluated exposure routes {i.e., dermal and inhalation) to DBP for
metal coatings was also considered. The chronic high-intensity use aggregate exposure scenario MOE
for young teens to adults was below 30. The dermal and ingestion exposures contributed equally to the
aggregated MOE values. The MOE values were 49, 54, and 51 for young teens, teenagers, and adults
respectively for dermal exposure while the MOE values were 51, 62, and 75 for young teens, teenagers,
and adults respectively for inhalation exposure. The aggregated MOEs for young teens, teenagers, and
adults were 25, 29, and 30, respectively.
Furnishing, Cleaning, Treatment Care Products: Cleaning and Furnishing Care Products
This section summarizes the risk estimates, MOEs, below the benchmark of 30 for the titled COU. Two
different scenarios were assessed under this COU for two product types with differing use patterns:
Spray cleaner and waxes and polishes. Both scenarios were assessed for dermal and inhalation
exposures, but only the acute dermal high-intensity use scenario resulted in MOEs below the benchmark
of 30 for the assessed lifestages: young teens and adults for the spray cleaner, and young teens,
teenagers, and adults for the polishes and waxes. The acute dermal high-intensity use MOE values for
spray cleaner were 28 and 29 for young teens and adults respectively, and the medium-intensity use
scenario MOE values were 110 and 120 for young teens and adults respectively. The acute dermal high-
intensity use MOE values for polishes and waxes were 14, 15, and 14 for young teens, teenagers, and
adults respectively, and the dermal medium-intensity use scenario MOE values were 56, 62, and 58 for
young teens, teenagers, and adults respectively.
Two cleaning and furnishing care products with DBP content were identified from a 2012 study on U.S.
consumer products (Dodsom et al. 2012). Due to the different format and application, these items were
modeled separately. One spray cleaning product used for tub and tile cleaning was identified with
reported DBP content. One polish/wax used for floors and furniture was identified with reported DBP
content. EPA has a moderate confidence in using these products to generally represent this COU due to
the age of the study (10+ years), and that it was only one source.
Key parameters for the dermal model include duration of dermal contact, frequency of dermal contact,
total contact area, and dermal flux. An increase in any of these parameters results in an increase in
exposure. For liquid and paste products, it was assumed that contact with the product occurs at the
beginning of the period of use and the product is not washed off the skin until use is complete. As such,
the duration of dermal contact for these products is equal to the duration of use applied in CEM
modeling for products assessed for inhalation. The skin contact duration for spray cleaner for the highl-
and medium-intensity use scenarios were 30 and 15 minutes respectively, and for waxes and polishes 60
and 30 minutes (Section 2.3.4 in U.S. EPA (2025c)). EPA has a robust confidence in the input
parameters used for skin contact duration.
For contact area EPA used professional judgment based on product use descriptions from manufacturers.
For spray cleaners and polishes and waxes, EPA assumed that these items would be in contact with the
skin on the inside of two hands (palms, fingers) for the high-intensity use scenario, and the inside of one
hand for the medium-intensity use scenario. EPA has robust confidence in the input parameters used for
skin contact surface area.
EPA used a screening dermal flux-limited approach, which was estimated based on DBP in vitro dermal
absorption in guinea pigs. Though there is uncertainty regarding the magnitude of the difference
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between dermal absorption through guinea pigs' skin versus human skin for DBP, based on DBP
physical and chemical properties (size, solubility), EPA is confident that the in vitro dermal absorption
data using guinea pigs for (Doan et al. 2010) provides an upper-bound of dermal absorption of DBP.
Dermal contact with products or formulations that have low concentrations of DBP may exhibit lower
rates of flux since there is less material available for absorption. Conversely, co-formulants or materials
within the products or formulations may lead to enhanced dermal absorption, even at lower
concentrations. Therefore, it is uncertain whether the dermal exposure to products or formulations
containing DBP would result in decreased or increased dermal absorption.
Based on the available dermal absorption data for DBP, EPA has made assumptions that result in
exposure assessments that are the most conservative representing upper-bound estimates. Considering
the unknown uncertainties from the flux-limited approach and input parameters such as frequency and
duration of use, and area of skin in contact, are well understood and representative, the overall
confidence in dermal exposure estimates for liquid and paste products is moderate.
Packaging, Paper, Plastic, Hobby Products; Toys, Playground, and Sporting Equipment
This section summarizes the risk estimates, MOEs, below the benchmark of 30 for the titled COU. Four
different scenarios were assessed under this COU for various articles with differing use patterns: legacy
children's toys, new children's toys, tire crumb and artificial turf, and a variety of PVC articles with
potential for routine contact. Children's toy scenarios were included in the indoor assessment for all
exposure routes (inhalation, dust ingestion, mouthing, and dermal) with varying use patterns and inputs.
Tire crumb was also part of the indoor assessment for all exposure routes except mouthing. Articles of
routine contact were only assessed for dermal exposures since they are too small to result in impactful
inhalation or ingestion exposures. Aggregate risk estimates for DBP exposure across all evaluated
exposure routes for legacy children's toys were the only scenario within this COU with an MOE below
the benchmark of 30. The acute, high-intensity use aggregate exposure scenario MOE for legacy toys
was 23 for the infants. The high-intensity use scenario dermal, ingestion, and inhalation MOEs were
112, 51, and 69, respectively. The ingestion and inhalation MOEs are the primary contributors to the
aggregated MOE value of 23.
Children's toys were assessed for DBP exposure by inhalation, dust ingestion, dermal and mouthing
routes. Under the Consumer Product Safety Improvement Act (CPSIA) of 2008 (CPSIA section 108(a),
15 U.S.C. § 2057c(a); 16 CFR § 1307.3(a)), Congress permanently prohibited the sale of children's toys
or childcare articles containing concentrations of more than 0.1 percent DBP. However, it is possible
that some individuals may still have children's toys in the home that were produced before statutory and
regulatory limitations. A relatively recent survey, 2020, by the Danish EPA of PVC products purchased
from foreign online retailers found that DBP content in a toy bath duck of 1.7 percent exceeded the
current Danish regulatory limit of 0.1 percent DBP (Danish EPA. 2020). In the U.S. market, the High
Priority Chemicals Data System (HPCDS) database contained data for DBP measurements in 96
toy/game items with reporting dates from 2017 to 2024. While there is some uncertainty about the
materials these items are manufactured from, based on the limited descriptions in the database, EPA
determined that these items are likely composed primarily of plastic and rubber components. For
example, some of the descriptions provided for toys were dolls, puppets, action figures, board games,
toy vehicles, soft toys, toy soldiers, glow in the dark plastic bugs, waterproof pouches, pink plastic
recorder, and yellow bendy man. One item with DBP content over the statutory and regulatory limit of
0.1 percent was listed as a non-ride toy vehicle (WSDE. 2020).
EPA assessed exposure to DBP in children's toys under two scenarios. In the first exposure scenario,
new toys produced for the U.S. market are assumed to comply with statutory and regulatory limits and
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were therefore assessed with DBP weight fractions of 0.001 w/w in low, medium, and high exposure
scenarios. In the second scenario, legacy toys are assessed with weight fractions reported in the HPCDS
database, (WSDE. 2020). that are above the statutory and regulatory limit of 0.001 w/w. Based on the
reported data, the weight fractions of DBP used in low, medium, and high-intensity use exposure
scenarios were 0.005 w/w, 0.0075 w/w, and 0.01 w/w. One new toy in the HPCDS database tested 8 or
more years after the CPSIA had components with DBP content above (1 order of magnitude above) the
statutory and regulatory limit of 0.01 percent fWSDE. 2020).
Children's toys generally have a small surface area for an individual item, but consumers may have
many of the same type of item in a home. As phthalates are ubiquitous in PVC materials, it is reasonable
to assume that in a collection of toys all of the items may have DBP content. As such, surface area for
these items was estimated by assuming that a home has several of these items rather than one. The
surface area of new and legacy toys was varied for the low-, medium-, and high-intensity use exposure
scenarios based on EPA's professional judgment of the number and size of toys present in a bedroom.
The low intensity use scenario was based on 5 small toys measuring 15cmxl0cm><5 cm, the
medium-intensity use scenario was based on 20 medium toys measuring 20 cm x 15 cm x 8 cm, and the
high-intensity use scenario was based on 30 large toys measuring 30 cm x 25 cm x 15 cm. EPA used the
stay-at-home 20 hour exposure duration and bedroom for location of articles CEM inputs for inhalation
and dust ingestion exposure estimates. The overall confidence in this COU's inhalation and dust
ingestion exposure estimate is robust because of a good understanding of the CEM model parameter
inputs and representativeness of actual use patterns and location of use.
For mouthing exposure, key parameters include the rate of chemical migration from the article to saliva
(|ig/cm2/h), surface area mouthed (cm2), and duration of mouthing (min/day). The mouthing parameters
used, such as duration of use (39.2 min/day EPA Exposure Factors Handbook Table 4-23 (U.S. EPA.
201 la)) and surface area for infants (standardized value of 10 cm2 (Danish < < \ Niino et at..
2003; Niino et at.. 2001)) are very well understood. The chemical migration value is DBP specific,
empirically derived, and the main sources of uncertainty are related to a large variability in empirical
migration rate data for harsh, medium, and mild mouthing approaches. Additionally, there are
uncertainties from the unknown correlation between chemical concentration in articles and chemical
migration rates, and no data were reasonably available to compare and confirm selected rate parameters
to better understand uncertainties.
Infants skin contact duration for the high-intensity use scenario was 137 minutes and the skin contact
area was inside of two hands including palms and fingers (Section 2.3.4 in U.S. EPA (2025c)). Dermal
absorption estimates are based on the assumption that dermal absorption of DBP from solid objects will
be limited by aqueous solubility of DBP. EPA has moderate confidence for solid objects because the
high uncertainty in the assumption of partitioning from solid to liquid and subsequent dermal absorption
is not well characterized. Additionally, there are uncertainties associated to the flux-limited approach
which likely results in overestimations due to the assumption about excess DBP in contact with skin.
Other parameters like frequency and duration of use, and surface area in contact have unknown
uncertainties due to lack of information about use patterns, making the overall confidence of moderate.
Indoor Dust
Exposure to DBP via ingestion of dust was assessed for all articles expected to contribute significantly
to dust concentrations. The articles are included in the indoor assessment due to high surface area
(exceeding ~1 m2) for either a single article or collection of like articles as appropriate. Articles included
in the indoor assessment include in-place wallpaper, vinyl flooring, synthetic leather furniture, car mats,
shower curtains, tire crumb, and children's toys (legacy and new). In a screening assessment for indoor
Page 173 of 333
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dust ingestion, EPA considered the aggregation of chronic dust ingestion doses (Section 4.1.2.3).
However, the indoor assessment was further refined to only consider articles assumed to be present in
residential indoor environments because of the use of the stay-at-home CEM inputs would result in
greater exposures than other non-residential environment options. Articles considered in this indoor
assessment include synthetic leather furniture, vinyl flooring, in-place wallpaper, shower curtains, and
children's toys (new and legacy). Car mats and tire crumb were considered not to be continuously
available in residential indoor environments, as car mats are present in vehicles, and tire crumb is
present in gyms and outdoor recreational areas. The highest refined aggregated dose from indoor chronic
ingestion of settled dust was for preschoolers, aged 3 to 5 years and resulted in an MOE of 7,500. See
Draft Consumer Risk Calculator for Dibutyl Phthalate (DBP) ( 25e). All other doses were
lower and would have resulted in even larger MOEs.
4.3.3.1 Overall Confidence in Consumer Risks
As described in Section 4.1.2 and in more detail in the Draft Consumer and Indoor Exposure
Assessment for Dibutyl Phthalate (DBP) ( 25c). EPA has moderate and robust confidence
in the assessed inhalation, ingestion, and dermal consumer exposure scenarios, and robust confidence in
the non-cancer POD selected to characterize risk from acute, intermediate, and chronic duration
exposures to DBP (see Section 4.2 and ( E024DY The exposure doses used to estimate risk
relied on conservative inputs and parameters that are considered representative of a wide selection of use
patterns. Overall, EPA has moderate to robust confidence in the risk estimates calculated for consumers
inhalation, ingestion, and dermal exposure scenarios. Sources of uncertainty associated with the ten
consumer COUs with MOEs less than 30 are discussed above in Section 4.3.3.
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4075 Table 4-19. Consumer Risk Summary Table
Litestagc (years) IMOE
Lite Cycle Stage: COU:
Subcategory
Exposure
Route
Exposure
(Benchmark IMOE = 30)
Product or Article
Duration
Scenario
(H, M, L) a
Infant
(<1
Toddler
(1-2
Pre-
schooler
Middle
Childhood
Young
Teen
Teenagers
(16-20
Adults
(21+
Year)
Years)
(3-5 years)
(6-10 years)
(11-15 years)
years)
years)
Consumer Uses: Automotive, fuel,
agriculture, outdoor use products:
Uses were matched with automotive adhesives.
Automotive care products
H
-
-
-
-
7
s
7
Dermal
M
-
-
-
-
2X
31
2l)
L
-
-
-
-
140
150
140
Acute
Ingestion
-
-
-
-
-
-
-
-
Automotive
adhesives
Inhalation
H
160 b
170 b
210 b
300 b
370
440
540
H
-
-
-
-
7
s
7
Aggregate
M
-
-
-
-
2X
31
2l)
L
-
-
-
-
140
150
140
Dermal
H
-
-
-
-
210
230
220
Intermed.
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
4,800 b
5,100 b
6,200 b
9,000 b
1.1E04
1.3E04
1.6E04
Aggregate
H
-
-
-
-
210
230
210
Consumer Uses: Construction, paint,
electrical, and metal products:
Adhesives and sealants
Chronic
-
-
-
-
-
-
-
-
-
H
-
-
-
-
7
s
7
Dermal
M
-
-
-
-
28
31
Acute
L
-
-
-
-
140
150
140
Construction
adhesives
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Dermal
H
-
-
-
-
210
230
220
Intermed.
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Chronic
-
-
-
-
-
-
-
-
-
Dermal
H
-
-
-
-
70
77
72
Acute
Ingestion
-
-
-
-
-
-
-
-
Adhesives for small
repairs
Inhalation
-
-
-
-
-
-
-
-
Intermed.
-
-
-
-
-
-
-
-
-
Dermal
H
-
-
-
-
490
540
510
Chronic
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
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Lit'estage (years) MOE
Lite Cycle Stage: COU:
Subcategory
Exposure
Route
Exposure
(Benchmark MOE = 30)
Product or Article
Duration
Scenario
(H, M, L) a
Infant
(<1
Toddler
(1-2
Pre-
schooler
Middle
Childhood
Young
Teen
Teenagers
(16-20
Adults
(21+
Year)
Years)
(3-5 years)
(6-10 years)
fl 1-15 vears)
vears)
vears)
H
-
-
-
-
7
S
7
Dermal
M
-
-
-
-
2N
31
2*>
L
-
-
-
-
140
150
140
Acute
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
72 4
76 4
94 4
130 4
130
160
190
Aggregate
H
-
-
-
-
7
7
7
M
-
-
-
-
24
26
26
Metal coatings
L
-
-
-
-
89
100
100
Interned.
-
-
-
-
-
-
-
-
-
Dermal
H
-
49
54
51
Ingestion
-
-
-
-
-
-
-
Chronic
Inhalation
H
2(> "
28"
49 4
51
62
75
M
130 4
140''
170 4
250 4
290
340
420
Aggregate
H
-
-
-
-
25
2*>
30
M
-
-
-
-
120
130
140
Consumer Uses: Construction, paint,
electrical, and metal products: Paints
and coatings
H
-
-
-
-
k.
17
16
Dermal
M
-
-
-
-
23
26
24
L
-
-
-
-
47
51
48
Acute
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
100 4
no4
140 4
190 4
260
300
380
Indoor flooring
Aggregate
H
-
-
-
-
15
16
15
sealing and
M
-
-
-
-
22
24
23
refrnishing products
L
-
-
-
-
45
49
46
Dermal
H
-
-
-
-
470
510
480
Interned.
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
3,100 4
3,300 4
4,100 4
5,800 4
7,800
9,100
1.1E04
Aggregate
H
-
-
-
-
440
490
460
Chronic
-
-
-
-
-
-
-
-
-
H
-
-
-
-
')
10
')
Dermal
M
-
-
-
-
IS
1')
IS
Sealing and
refrnishing sprays
(outdoor use)
L
-
-
-
-
35
39
36
Acute
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
92 4
98 4
120 4
150 4
49
66
Aggregate
H
-
-
-
-
S
S
s
M
-
-
-
-
15
16
16
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Life Cycle Stage: COU:
Subcategory
Exposure
Route
Exposure
Lifestage (years) MOE
(Benchmark MOE = 30)
Product or Article
Duration
Scenario
(H, M, L) a
Infant
(<1
Toddler
(1-2
Pre-
schooler
Middle
Childhood
Young
Teen
Teenagers
(16-20
Adults
(21+
Year)
Years)
(3-5 years)
(6-10 years)
(11-15 years)
years)
years)
L
-
-
-
-
35
38
36
Consumer Uses: Construction, paint,
electrical, and metal products: Paints
and coatings
Sealing and
refmishing sprays
(outdoor use)
Dennal
H
-
-
-
-
260
290
270
Intenned.
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
2,800 b
2,900 b
3,600 b
4,500 b
1,500
2,000
2,200
Aggregate
H
-
-
-
-
220
250
240
Chronic
-
-
-
-
-
-
-
-
-
Dennal
H
-
-
-
-
-
_d
_d
Acute
M
-
-
-
-
-
76
72
Ingestion
-
-
-
-
-
-
-
-
Consumer Uses: Furnishing,
Synthetic leather
clothing
Inhalation
-
-
-
-
-
-
-
-
cleaning, treatment care products:
Intenned.
-
-
-
-
-
-
-
-
-
Fabric, textile, and leather products
Dennal
H
-
-
-
-
-
_d
_d
Chronic
M
-
-
-
-
-
540
510
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
H
_d
_d
_d
_d
_d
_d
_d
Dennal
M
_d
_d
41
54
69
76
72
L
_d
140
160
200
250
280
260
H
83
140
220
2.3E06
4.1E06
5.2E06
12E06
Ingestionc
M
280
380
670
2.3E07
4.1E07
5.2E07
1.2E08
Acute
L
1.1E05
7.6E04
1.4E05
3.4E07
6.1E07
7.7E07
1.7E08
H
5.7E04
6.0E04
7.4E04
1.1E05
1.5E05
1.8E05
2.2E05
Inhalation c
M
5.8E05
6.1E05
7.5E05
1.1E06
1.5E06
1.8E06
2.2E06
Consumer Uses: Furnishing,
cleaning, treatment care products:
Fabric, textile, and leather products
Synthetic leather
furniture
L
8.8E05
9.3E05
1.1E06
1.6E06
2.3E06
2.7E06
3.4E06
H
83
140
220
1E05
1.5E05
1.7E05
2.1E05
Aggregate
M
280
380
39
54
69
76
72
L
9.7E04
140
160
200
250
280
260
Intenned.
-
-
-
-
-
-
-
-
-
H
_d
_d
_d
_d
_d
_d
_d
Dennal
M
_d
_d
41
54
69
76
72
L
_d
140
160
200
250
280
260
Chronic
H
83
140
220
2.5E06
4.5E06
5.7E06
1.3E07
Ingestionc
M
280
380
670
2.5E07
4.5E07
5.7E07
1.3E08
L
1.1E05
7.6E04
1.4E05
3.7E07
6.7E07
8.4E07
1.9E08
Inhalation c
H
5.9E04
6.3E04
7.7E04
1.1E05
1.6E05
1.8E05
2.3E05
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Lite Cycle Stage: COU:
Subcategory
Consumer Uses: Furnishing,
cleaning, treatment care products:
Fabric, textile, and leather products
Product or Article
Synthetic leather
furniture
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lit'estage (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5 years)
Middle
Childhood
(6-10 years)
Young
Teen
(11-15 years)
Teenagers
(16-20
years)
Adults
(21+
vears)
M
6.0E05
6.4E05
7.9E05
1.1E06
1.6E06
1.9E06
2.3E06
L
9.2E05
9.7E05
1.2E06
1.7E06
2.4E06
2.8E06
3.5E06
Aggregate
H
83
140
220
1.1E05
1.5E05
1.8E05
2.2E05
M
280
380
39
54
69
76
72
L
120
140
160
200
250
280
260
Consumer uses: Furnishing, cleaning,
treatment care products: Floor
coverings; construction and building
materials covering large surface areas
including stone, plaster, cement,
glass and ceramic articles; fabrics,
textiles, and apparel
Vinyl flooring
Acute
Dermal
H
240
280
320
400
510
550
520
Ingestionc
H
2.4E04
1.9E04
1.7E04
4.8E04
8.6E04
1.1E05
2.4E05
Inhalation c
H
800
850
1,000
1,500
2,100
2,500
3,100
Aggregate
H
180
210
240
310
410
450
440
Intermed.
-
-
-
-
-
-
-
-
-
Chronic
Dermal
H
240
280
320
400
510
550
520
Ingestionc
H
7.9E04
6.4E04
5.7E04
1.6E05
2.9E05
3.6E05
8.1E05
Inhalation c
H
3,800
4,000
4,900
7,100
1.0E04
1.2E04
1.5E04
Aggregate
H
220
260
300
380
480
530
500
Wallpaper (in-
place)
Acute
Dermal
H
120
140
160
200
250
280
-
Ingestionc
H
1.0E05
8.3E04
7.3E04
2.1E05
3.7E05
4.7E05
1.0E06
Inhalation c
H
3,500
3,700
4,500
6,500
9.2E3
1.1E04
1.3E04
Aggregate
H
120
130
160
190
250
270
1.3E04
Chronic
Dermal
H
120
140
160
200
250
280
9.5E04
Ingestionc
H
3.4E05
2.8E05
2.5E05
7.0E05
1.3E06
1.6E06
3.5E06
Inhalation c
H
1.6E04
1.7E04
2.1E04
3.1E04
4.3E04
5.1E04
6.3E04
Aggregate
H
120
140
160
200
250
280
3.8E04
Wallpaper
(installation)
Acute
Dermal
H
-
-
-
-
130
140
130
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
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Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lit'estage (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5 years)
Middle
Childhood
(6-10 years)
Young
Teen
(11-15 years)
Teenagers
(16-20
years)
Adults
(21+
vears)
Consumer uses: Furnishing, cleaning,
treatment care products: Cleaning
and furnishing care products
Spray cleaner
Acute
Dermal
H
-
-
-
-
28
31
29
M
-
-
-
-
110
120
120
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
6.7E04
7.1E044
8.7E044
1.3E054
3.7E04
4.8E04
5.5E04
M
1.4E05 4
1.5E05 4
1.8E05 4
2.7E05 4
7.7E04
9.6E04
1.1E05
Aggregate
H
6.7E04
7.1E04
8.7E04
1.3E05
28
31
29
M
1.4E05
1.5E05
1.8E05
2.7E05
110
120
120
Chronic
Dermal
H
-
-
-
-
200
220
200
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
1.2E054
1.2E054
1.5E054
2.2E054
1.3E05
1.7E05
2.0E05
Aggregate
H
1.2E05
1.2E05
1.5E05
2.2E05
200
220
200
Waxes and polishes
Acute
Dermal
H
-
-
-
-
14
15
14
M
-
-
-
-
56
62
58
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
1.0E054
1.1E054
1.3E054
1.9E054
2.6E05
3.0E05
3.7E05
Aggregate
H
1.0E05
1.1E05
1.3E05
1.9E05
14
15
14
M
1.6E05
1.7E05
2.0E05
2.9E05
56
62
58
Chronic
Dermal
H
-
-
-
-
99
110
100
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
8,500 4
9,1004
1.1E044
1.6E044
2.0E04
2.4E04
2.9E04
Aggregate
H
8,500
9,100
1.1E04
1.6E04
98
110
100
Consumer uses: Packaging, paper,
plastic, toys, hobby products: Ink,
toner, and colorant products
No consumer products identified. Foreseeable uses were matched with adhesives for small repairs because similar use patterns are expected.
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Lit'estage (years) MOE
Lite Cycle Stage: COU:
Subcategory
Exposure
Route
Exposure
(Benchmark MOE = 30)
Product or Article
Duration
Scenario
(H, M, L) a
Infant
(<1
Toddler
(1-2
Pre-
schooler
Middle
Childhood
Young
Teen
Teenagers
(16-20
Adults
(21+
Year)
Years)
(3-5 years)
(6-10 years)
(11-15 years)
years)
vears)
Dermal
H
60
70
81
100
130
140
130
Acute
Ingestion
-
-
-
-
-
-
-
-
Footwear
Inhalation
-
-
-
-
-
-
-
-
components
Dermal
H
60
70
81
100
130
140
130
Chronic
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Dermal
H
340
400
460
570
720
780
730
Acute
Ingestionc
H
1.1E06
9.0E05
8.0E05
2.3E06
4.1E06
5.1E06
1.1E07
Consumer uses: Packaging, paper,
plastic, toys, hobby products;
Inhalation c
H
1.4E04
1.5E04
1.8E04
2.6E04
3.7E04
4.3E04
5.3E04
Shower curtains
Aggregate
H
330
380
450
550
700
770
720
Packaging (excluding food
Dermal
H
340
400
460
570
720
780
730
packaging), including rubber articles;
plastic articles (hard); plastic articles
(soft); other articles with routine
direct contact during normal use,
including rubber articles; plastic
Chronic
Ingestionc
H
3.7E06
3.0E06
2.6E06
7.5E06
1.3E07
1.7E07
3.8E07
Inhalation c
H
6.6E04
7.0E04
8.6E04
1.2E05
1.7E05
2.0E05
2.5E05
Aggregate
H
340
390
450
560
710
780
730
Small articles with
Dermal
H
120
140
160
200
250
280
260
articles (hard)
semi routine
Acute
Ingestion
-
-
-
-
-
-
-
-
contact;
miscellaneous items
Inhalation
-
-
-
-
-
-
-
-
including a pen,
pencil case, hobby
cutting board,
Dermal
H
120
140
160
200
250
280
260
Ingestion
-
-
-
-
-
-
-
-
costume jewelry,
tape, garden hose,
disposable gloves,
and plastic
bags/pouches
Chronic
Inhalation
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Life Cycle Stage: COU:
Subcategory
Exposure
Route
Exposure
Lifestage (years) MOE
(Benchmark MOE = 30)
Product or Article
Duration
Scenario
(H, M, L) a
Infant
(<1
Toddler
(1-2
Pre-
schooler
Middle
Childhood
Young
Teen
Teenagers
(16-20
Adults
(21+
Year)
Years)
(3-5 years)
(6-10 years)
(11-15 years)
years)
years)
Dermal
H
110
130
150
190
240
260
-
Acute
Ingestionc
H
52
200
380
8.5E04
1.5E05
1.9E05
4.3E05
Inhalation c
H
690
740
900
1,300
1,800
2,200
2,700
Children's toys
Aggregate
H
34
71
97
160
210
230
2,700
(New)
Dermal
H
110
130
150
190
240
260
-
Chronic
Ingestionc
H
52
200
390
2.8E05
5.1E05
6.4E05
1.4E06
Inhalation c
H
3,300
3,500
4,300
6,200
8,800
1.0E04
1.3E04
Aggregate
H
35
77
110
180
230
250
1.3E04
Dermal
H
110
130
150
190
240
260
-
Ingestionc
H
51
190
340
8,500
1.5E04
1.9E04
4.3E04
Acute
Inhalation c
H
69
74
90
130
180
220
270
Children's toys
(legacy)
Aggregate
H
23
38
49
76
100
120
270
Aggregate
M
64
91
120
180
230
250
1,400
Dermal
H
110
130
150
190
240
260
-
Consumer uses: Packaging, paper,
plastic, toys, hobby products: Toys,
playground, and sporting equipment
Chronic
Ingestionc
H
52
190
370
2.8E04
5.1E04
6.4E04
1.4E05
Inhalation c
H
330
350
430
620
880
1,000
1,300
Aggregate
H
32
64
86
140
190
210
1,300
Dermal
H
-
-
1.1E06
1.2E06
1.6E06
1.8E06
1.7E06
Acute
Ingestion
H
-
-
3.4E08
7.7E08
1.4E09
3.5E09
3.9E09
Inhalation
H
-
-
2.5E08
3.7E08
1.9E08
3.6E08
3.9E08
Tire crumb
Aggregate
H
-
-
1.1E06
1.2E06
1.5E06
1.8E06
1.7E06
Dermal
H
-
-
5.4E06
5.7E06
4.1E06
4.7E06
8.0E06
Chronic
Ingestion
H
-
-
1.6E09
3.6E09
3.6E09
9.1E09
1.8E10
Inhalation
H
-
-
1.2E09
1.7E09
5.0E08
9.5E08
1.8E09
Aggregate
H
-
-
5.3E06
5.7E06
4.1E06
4.6E06
8.0E06
Small articles with
Dermal
H
120
140
160
200
250
280
260
semi routine
Acute
Ingestion
-
-
-
-
-
-
-
-
contact;
miscellaneous items
including a football,
balance ball, and
Inhalation
-
-
-
-
-
-
-
-
Dermal
H
120
140
160
200
250
280
260
Chronic
Ingestion
-
-
-
-
-
-
-
-
pet toys
Inhalation
-
-
-
-
-
-
-
-
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Lit'estage (years) MOE
Lite Cycle Stage: COU:
Subcategory
Exposure
Route
Exposure
(Benchmark MOE = 30)
Product or Article
Duration
Scenario
(H, M, L) a
Infant
(<1
Toddler
(1-2
Pre-
schooler
Middle
Childhood
Young
Teen
Teenagers
(16-20
Adults
(21+
Year)
Years)
(3-5 years)
(6-10 years)
(11-15 years)
years)
vears)
Dermal
H
120
140
160
200
250
280
260
Small articles with
semi routine
contact; glow sticks
Acute
Ingestion
-
-
-
-
-
-
-
-
Consumer uses: Other v:
Inhalation
-
-
-
-
-
-
-
-
Chemiluminescent light sticks
Dermal
H
120
140
160
200
250
280
260
Chronic
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Dermal
H
-
-
-
-
1,800
2,000
1,800
Acute
Ingestionc
H
3.8E06
3.1E06
2.8E06
7.7E06
1.3E07
1.7E07
3.4E07
Inhalation c
H
6.1E04
6.5E04
7.9E04
1.1E05
1.6E05
1.9E05
2.4E05
Car mats
Aggregate
H
6.0E04
6.3E04
7.7E04
1.1E05
1,800
1,900
1,800
Dermal
H
-
-
-
-
1.3E04
1.4E04
1.3E04
Chronic
Ingestionc
H
1.3E07
1.1E07
9.5E06
2.6E07
4.5E07
5.7E07
1.2E08
Inhalation c
H
3.0E05
3.1E05
3.9E05
5.6E05
7.9E05
9.2E05
1.1E06
Aggregate
H
2.9E05
3.1E05
3.7E05
5.4E05
1.2E04
1.4E04
1.3E04
H
_d
_d
_d
_d
_d
_d
_d
Dermal
M
_d
_d
41
54
69
76
72
L
_d
140
160
200
250
280
260
H
83
140
220
2.3E06
4.1E06
5.2E06
1.2E07
Ingestionc
M
280
380
670
2.3E07
4.1E07
5.2E07
1.2E08
Consumer uses: Other uses:
Acute
L
1.1E05
7.6E04
1.4E05
3.4E07
6.1E07
7.7E07
1.7E08
Automotive articles
H
5.7E04
6.0E04
7.4E04
1.1E05
1.5E05
1.8E05
2.2E05
Inhalation c
M
5.8E05
6.1E05
7.5E05
1.1E06
1.5E06
1.8E06
2.2E06
L
8.8E05
9.3E05
1.1E06
1.6E06
2.3E06
2.7E06
3.4E06
Synthetic leather
H
83
140
220
1.0E05
1.5E05
1.7E05
2.1E05
seats (see synthetic
Aggregate
M
280
380
39
54
69
76
72
leather furniture)
L
9.7E04
140
160
200
250
280
260
H
_d
_d
_d
_d
_d
_d
_d
Chronic
Dermal
M
_d
_d
41
54
69
76
72
L
_d
140
160
200
250
280
260
H
83
140
220
2.5E06
4.5E06
5.7E06
1.3E07
Ingestionc
M
280
380
670
2.5E07
4.5E07
5.7E07
1.3E08
L
1.1E05
7.6E04
1.4E05
3.7E07
6.7E07
8.4E07
1.9E08
H
5.9E04
6.3E04
7.7E04
1.1E05
1.6E05
1.8E05
2.3E05
Chronic
Inhalation c
M
6.0E05
6.4E05
7.9E05
1.1E06
1.6E06
1.9E06
2.3E06
L
9.2E05
9.7E05
1.2E06
1.7E06
2.4E06
2.8E06
3.5E06
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Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lit'estage (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5 years)
Middle
Childhood
(6-10 years)
Young
Teen
(11-15 years)
Teenagers
(16-20
years)
Adults
(21+
vears)
Aggregate
H
83
140
220
1.1E05
1.5E05
1.8E05
2.2E05
M
280
380
39
54
69
76
72
L
120
140
160
200
250
280
260
Consumer uses: Other uses: Novelty
articles
Adult toys
Acute
Dermal
H
-
-
-
-
-
780
730
M
-
-
-
-
-
1,100
1,000
Ingestion
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
190
210
Inhalation
-
-
-
-
-
-
-
-
Aggregate
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
160
170
Chronic
Dermal
H
-
-
-
-
-
780
730
M
-
-
-
-
-
1,100
1,000
Ingestion
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
190
210
Inhalation
-
-
-
-
-
-
-
-
Aggregate
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
160
170
Consumer uses: Other uses:
Lubricants and lubricant additives
No consumer products identified. Foreseeable uses were matched with adhesives for small repairs because similar use patterns are expected.
"Exposure scenario intensities include high (H), medium (M), and low (L).
4 MOE for bystander scenario
c Exposure routes evaluated for indoor environments.
d Scenario was deemed to be unlikely due to high uncertainties.
Bold text in a gray shaded cell indicates an MOE below the benchmark value of 30.
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4.3.4 Risk Estimates for General Population
As described in the Draft Environmental Media and General Population Screening for Dibutyl
Phthalate (DBP) ( :025p) and Section 4.1.3, EPA employed a screening level approach for
general population exposures for DBP releases associated with TSCA COUs. Fenceline communities
were considered as part of the general population in proximity to releasing facilities as part of the
ambient air exposure assessment by utilizing pre-screening methodology described in EPA's Draft
TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline
Communities (Version 1.0) ( 322b). For other exposure pathways, the Agency's screening
method assessing high-end exposure scenarios used release data that reflect exposures expected to occur
in proximity to releasing facilities, which would include fenceline communities.
EPA evaluated surface water, drinking water, fish ingestion, and ambient air pathways quantitatively.
Land pathways {i.e., landfills and application of biosolids) were assessed qualitatively, and were
inclusive of down-the-drain disposal of consumer products and landfill disposal of consumer articles
(see Section 3.1.4 for details on the qualitative assessment of consumer disposal of DBP-containing
products and articles). For pathways assessed quantitatively, high-end estimates of DBP concentration in
the various environmental media were used for screening level purposes. EPA used an MOE approach
using high-end exposure estimates to determine whether an exposure pathway had potential non-cancer
risks. High-end exposure estimates were defined as those associated with the industrial and commercial
releases from a COU and OES that resulted in the highest environmental media concentrations.
Therefore, if there is no risk for an individual identified as having the potential for the highest exposure
associated with a COU for a given pathway of exposure, then that pathway was determined not to be a
pathway of concern and not pursued further. If any pathways were identified as a pathway of concern for
the general population, further exposure assessments for that pathway would be conducted to include
higher tiers of modeling when available and exposure estimates for additional subpopulations and
COUs. Based on the screening level approach described in Section 4.1.3 and the qualitative assessment
of landfill and biosolids pathways as described above, exposure to DBP through biosolids, landfills,
surface water, drinking water, fish ingestion, and ambient air were not determined to be pathways of
concern for any COU listed in Table 3-1.
4.3.4.1 Overall Confidence in General Population Risk
As described in Sections 3.3.1.1 and 4.1.3.3 and in more technical detail in th q Draft Environmental
Media and General Population and Environmental Exposure for Dibutyl Phthalate (DBP) (U.S. EPA.
2025p). EPA has robust confidence that modeled releases used for the screening level analysis are
appropriately conservative for a screening level analysis. Therefore, EPA has robust confidence that no
exposure scenarios will lead to greater doses than presented in this evaluation. Despite moderate
confidence in the estimated values themselves, confidence in exposure estimates capturing high-end
exposure scenarios was robust given the conservative assumptions used for the estimates. Along
with EPA's robust confidence in the non-cancer POD selected to characterize risk from acute,
intermediate, and chronic duration exposures to DBP (see Section 4.2 and ( 324f)), EPA has
robust confidence that the risk estimates calculated for the general population were conservative and
appropriate for a screening level analysis.
4.3.5 Risk Estimates for Potentially Exposed or Susceptible Subpopulations
EPA considered PESS throughout the exposure assessment and throughout the hazard identification and
dose-response analysis supporting the draft DBP risk evaluation.
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Some population group lifestages may be more susceptible to the health effects of DBP exposure. As
discussed in Section 4.2 and in Section 5.2 of EPA's Draft Non-cancer Human Health Hazard
Assessment for Dibutyl Phthalate (DBP) ( 24f), exposure to DBP leads to adverse effects
on the developing male reproductive system consistent with a disruption of androgen action and
phthalate syndrome in experimental animal models and therefore females of reproductive age, pregnant
women, infants, children and adolescents are considered to be susceptible subpopulations. These
susceptible lifestages were considered throughout the draft risk evaluation. For example, females of
reproductive age were evaluated for occupational exposures to DBP for each COU (Section 4.3.2) and
infants (<1 year), toddlers (1-2 years), and middle school children (6-10 years) were evaluated for
exposure to DBP through consumer products and articles (Section 4.3.3). The non-cancer POD for DBP
selected by EPA for use in risk characterization is based on the most sensitive developmental effect (i.e.,
reduced fetal testicular testosterone production) observed and is expected to be protective of susceptible
subpopulations. Additionally, EPA used a value of 10 for the UFh to account for human variability. The
Risk Assessment Forum, in A Review of the Reference Dose and Reference Concentration Processes,
discusses some of the evidence for choosing the default factor of 10 when data are lacking—including
toxicokinetic and toxicodynamic factors as well as greater susceptibility of children and elderly
populations (U.S. EPA. 2002b).
The available data suggest that some groups or lifestages have greater exposure to DBP. This includes
people exposed to DBP at work, those who frequently use consumer products and/or articles containing
high-concentrations of DBP, those who may have greater intake of DBP per body weight (e.g., infants,
children, and adolescents), and those exposed to DBP through certain age-specific behaviors (e.g.,
mouthing of toys, wires, and erasers by infants and children) leading to greater exposure. EPA
accounted for these populations with greater exposure in the draft DBP risk evaluation as follows:
• EPA evaluated a range of OESs for workers and ONUs, including high-end exposure scenarios
for females of reproductive age (a susceptible subpopulation) and average adult workers.
• EPA evaluated a range of consumer exposure scenarios, including high-intensity exposure
scenarios for infants and children (susceptible subpopulations). These populations had greater
intake per body weight and exposure due to age-specific behaviors (e.g., mouthing of toys by
infants and children).
• EPA evaluated a range of general population exposure scenarios, including high-end exposure
scenarios for infants and children (susceptible subpopulations). These populations had greater
intake per body weight.
• EPA evaluated exposure of children to DBP through use of legacy and new toys.
• EPA evaluated exposure to DBP through fish ingestion for subsistence fishers and Tribal
populations.
• EPA aggregated occupational inhalation and dermal exposures for each COU for females of
reproductive age (a susceptible subpopulation) and average adult workers.
• EPA aggregated consumer inhalation, dermal, and oral exposures for each COU for infants and
children (susceptible subpopulations).
• EPA evaluated cumulative exposure to DEHP, DBP, BBP, DIBP, and DINP for the U.S. civilian
population using NHANES urinary biomonitoring data and reverse dosimetry for females of
reproductive age (16-49 years) and male children (3-5, 6-11, and 12-15 years of age) (discussed
in Section 4.4).
• For females of reproductive age, black non-Hispanic women had slightly higher 95th percentile
cumulative exposures to DEHP, DBP, BBP, DIBP, and DINP compared to females of other races
(e.g., white non-Hispanic, Mexican America). The 95th percentile cumulative exposure estimate
for black non-Hispanic women served as the non-attributable national cumulative exposure
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estimate used by EPA to evaluate cumulative risk to workers and consumers (discussed in
Section 4.4).
4.4 Cumulative Risk Considerations
EPA developed & Revised Draft Technical Support Document for the Cumulative Risk Analysis of
DEHP, DBF, BBP, DIBP, DCHP, andDINP Under TSCA ( 25x) (revised draft CRA TSD)
for the CRA of six toxicologically similar phthalates being evaluated under Section 6 of TSCA: di(2-
ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), dicyclohexyl
phthalate (DCHP), diisobutyl phthalate (DIBP), and diisononyl phthalate (DINP). EPA previously
issued a Draft Proposed Approach for Cumulative Risk Assessment of High-Priority Phthalates and a
Manufacturer-Requested Phthalate under the Toxic Substances Control Act (draft 2023 approach),
which outlined an approach for this assessment ( 23d). EPA's proposal was subsequently
peer-reviewed by the Science Advisory Committee on Chemicals (SACC) in May 2023 (U.S. EPA.
2023e). In the 2023 draft approach, EPA identified a cumulative chemical group and PESS [15 U.S.C. §
2605(b)(4)], Based on toxicological similarity and induced effects on the developing male reproductive
system consistent with a disruption of androgen action and phthalate syndrome, EPA proposed a
cumulative chemical group of DEHP, BBP, DBP, DCHP, DIBP, and DINP, but not diisodecyl phthalate
(DIDP). This approach emphasizes a uniform measure of hazard for sensitive subpopulations, namely
females of reproductive age and/or male infants and children, however additional health endpoints are
known for broader populations and described in the individual non-cancer human health hazard
assessments for DEHP (• ^ \ :024h\ DBP (\ " \ \\ _024fl. DIBP (\ " \ \\ 20241), BBP
0 v 2024e\ DCHP (U.S. EPA. 2024gl and DINP 0 ! V \ . '.!4n), including hepatic, kidney,
and other developmental and reproductive toxicity.
EPA's approach for assessing cumulative risk is described in detail in the revised draft CRA TSD (U.S.
25x) and incorporates feedback from the SACC ( 023e) on EPA's 2023 draft
proposal ( ?23d). The Agency is focusing its CRA on acute duration exposures of females of
reproductive age, male infants, and male children to six toxicologically similar phthalates {i.e., DEHP,
DBP, BBP, DIBP, DCHP, DINP) that induce effects on the developing male reproductive system
consistent with a disruption of androgen action and phthalate syndrome. The Agency is further focusing
its CRA on acute duration exposures because there is evidence that effects on the developing male
reproductive system consistent with a disruption of androgen action can result from a single exposure
during the critical window of development (see Section 1.5 of ( 25x) for further details). To
evaluate cumulative risk, EPA is using a relative potency factor (RPF) approach. RPFs for DEHP, DBP,
BBP, DIBP, DCHP, and DINP were developed using a meta-analysis and benchmark dose (BMD)
modeling approach based on a uniform measure {i.e., reduced fetal testicular testosterone). EPA is also
using NHANES data to supplement, not substitute, evaluations for exposure scenarios for TSCA COUs
to provide non-attributable, total exposure for addition to the relevant scenarios presented in the
individual risk evaluations.
The analogy of a "risk cup" is used throughout Section 4.4 to describe cumulative exposure estimates.
The risk cup term is used to help conceptualize the contribution of various phthalate exposure routes and
pathways to overall cumulative risk estimates and serves primarily as a communication tool. The
term/concept describes exposure estimates where the full cup represents the total exposure that leads to
risk (cumulative MOE) and each chemical contributes a specific amount of exposure that adds a finite
amount of risk to the cup. A full risk cup indicates that the cumulative MOE has dropped below the
benchmark MOE {i.e., total UF), whereas cumulative MOEs above the benchmark indicate that only a
portion of the risk cup is full.
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The remainder of this human health CRA section is organized as follows:
• Section 4.4.1 - Describes the approach used by EPA to derive draft RPFs for DEHP, DBP, BBP,
DIBP, DCHP, and DINP based on reduced fetal testicular testosterone, which are used by EPA
as part of the current CRA and to assess exposures to individual phthalates by scaling to an index
chemical (RPF analysis). Section 2 of EPA's draft revised CRA TSD (U.S. EPA. 2025x)
provides more details.
• Section 4.4.2 - Briefly describes the approach used by EPA to calculate cumulative non-
attributable phthalate exposure for the U.S. population using NHANES urinary biomonitoring
and reverse dosimetry. Section 4 of EPA's draft revised CRA TSD (U.S. EPA. 2025x) provides
additional details.
• Section 4.4.3 - Describes how EPA combined exposures to DBP from individual consumer and
occupational COUs/OES with cumulative non-attributable phthalate exposures from NHANES
to estimate cumulative risk. An empirical example is also provided. Section 5 of EPA's draft
revised CRA TSD ( 25x) provides additional details.
• Sections 4.4.4 through 4.4.6 - Summarize risk estimates for workers, consumers, and the general
population based on relative potency assumptions.
For additional details regarding EPA's draft CRA, readers are directed to the following TSDs/reports:
• Revised Draft Technical Support Document for the Cumulative Risk Analysis of Di(2-ethylhexyl)
Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl
Phthalate (DIBP), Dicyclohexyl Phthalate (DCHP), and Diisononyl Phthalate (DINP) Under the
Toxic Substances Control Act (TSCA) (U.S. EPA. 2025x);
• Draft Meta-Analysis and Benchmark Dose Modeling of Fetal Testicular Testosterone for Di(2-
ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP),
Diisobutyl Phthalate (DIBP), and Dicyclohexyl Phthalate (DCHP) ( 024d);
• Draft Proposed Approach for Cumulative Risk Assessment of High-Priority Phthalates and a
Manufacturer-Requested Phthalate under the Toxic Substances Control Act (U.S. EPA. 2023d);
• Draft Proposed Principles of Cumulative Risk Assessment under the Toxic Substances Control
Act (U.S. EPA. 2023e): and
• Science Advisory Committee on Chemicals meeting minutes andfinal report, No. 2023-01 - A set
of scientific issues being considered by the Environmental Protection Agency regarding: Draft
Proposed Principles of Cumulative Risk Assessment (CRA) under the Toxic Substances Control
Act and a Draft Proposed Approach for CRA of High-Priority Phthalates and a Manufacturer-
Requested Phthalate ( ).
4.4.1 Hazard Relative Potency
This section briefly summarizes the RPF approach used by EPA to evaluate phthalates for cumulative
risk. Section 4.4.1.1 provides a brief overview and background for the RPF approach methodology,
while Section 4.4.1.2 provides a brief overview of the draft RPFs derived by EPA for DEHP, DBP,
BBP, DIBP, DCHP, and DINP based on decreased fetal testicular testosterone. Further details regarding
the draft relative potency analysis conducted by EPA are provided in the following two TSDs:
• Revised Draft Technical Support Document for the Cumulative Risk Analysis of Di(2-ethylhexyl)
Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl
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Phthalate (DIBP), Dicyclohexyl Phthalate (DCHP), and Diisononyl Phthalate (DINP) Under the
Toxic Substances Control Act (TSCA) (U.S. EPA. 2025x); and
• Draft Meta-Analysis and Benchmark Dose Modeling of Fetal Testicular Testosterone for Di(2-
ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP),
Diisobutyl Phthalate (DIBP), and Dicyclohexyl Phthalate (DCHP) ( 024d).
4.4.1.1 Relative Potency Factor Approach Overview
For the RPF approach, chemicals being evaluated require data that support toxicologic similarity (e.g.,
components of a mixture share a known or suspected common MO A or share a common apical
endpoint/effect) and have dose-response data for the effect of concern over similar exposure ranges
(I E023b. 2000. 1986). RPF values account for potency differences among chemicals in a
mixture and scale the dose of one chemical to an equitoxic dose of another chemical (i.e., the index
chemical). The chemical selected as the index chemical is often among the best characterized
toxicologically and considered to be representative of the type of toxicity elicited by other components
of the mixture. Implementing an RPF approach requires a quantitative dose-response assessment for the
index chemical and pertinent data that allow the potency of the mixture components to be meaningfully
compared to that of the index chemical. In the RPF approach, RPFs are calculated as the ratio of the
potency of the individual component to that of the index chemical using either (1) the response at a fixed
dose, or (2) the dose at a fixed response (Equation 4-3).
Equation 4-3. Calculating RPFs
ppr _ BMDR-ic
RPF' - Tmd^~
Where:
BMD = Benchmark dose (mg/kg/day)
R = Magnitude of response (i.e., benchmark response)
/ = ith chemical
IC = Index chemical
After scaling the chemical component doses to the potency of the index chemical, the scaled doses are
summed and expressed as index chemical equivalents for the mixture (Equation 4-4).
Equation 4-4. Calculating Index Chemical Equivalents
71
Index Chemical EquivalentsMIX = ^ d-i x RPFi
Where:
i=i
Index chemical equivalents = Dose of the mixture in index chemical equivalents
(mg/kg/day)
di = Dose of the ith chemical in the mixture (mg/kg/day)
RPFi = Relative potency factor of the ith chemical in the mixture
(unitless)
Non-cancer risk associated with exposure to an individual chemical or mixture can then be assessed by
calculating an MOE, which in this case is the ratio of the index chemical's non-cancer hazard value
(e.g., the BMDL) to an estimate of exposure expressed in terms of index chemical equivalents. The
MOE is then compared to the benchmark MOE (i.e., the total uncertainty factor associated with the
assessment) to characterize risk.
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4.4.1.2 Relative Potency Factors
Derivation of Draft RPFs
To derive RPFs for DEHP, DBP, BBP, DIBP, DCHP, and DINP, EPA utilized a meta-analysis and
BMD modeling approach similar to that used by NASEM (2017) to model decreased fetal testicular
testosterone. As described further in EPA's Draft Meta-Analysis and Benchmark Dose Modeling of
Fetal Testicular Testosterone for DEHP, DBP, BBP, DIBP, and DCHP ( 2024d), the Agency
evaluated benchmark responses (BMRs) of 5, 10, and 40 percent. For input into the CRA of phthalates,
EPA has derived draft RPFs using BMD40 estimates (Table 4-20). For further details regarding RPFs
derivation, see Section 2 of the draft CRA TSD ( 25x).
Selection of the Index Chemical
As described further in Section 2 of (draft CRA TSD) ( 2025x). EPA has preliminarily
selected DBP as the index chemical. DBP has a high-quality toxicological database of studies
demonstrating effects on the developing male reproductive system consistent with a disruption of
androgen action and phthalate syndrome. Furthermore, studies of DBP demonstrate toxicity
representative of all phthalates in the cumulative chemical group and DBP is well characterized for the
MOA associated with phthalate syndrome. Finally, compared to other phthalates, including well-studied
phthalates such as DEHP, DBP has the most dose-response data available in the low-end range of the
dose-response curve where the BMD5 and BMDL5 are derived, which provides a robust and
scientifically sound foundation of BMD and BMDL estimates on which the RPF approach is based.
Table 4-20. Draft Relative Potency Factors Based on Decreased
Fetal Testicular Testosterone
Phthalate
BMD40
(mg/kg-day)
RPF Based on BMD40
DBP (Index chemical)
149
1
DEHP
178
0.84
DIBP
279
0.53
BBP
284
0.52
DCHP
90
1.66
DINP
699
0.21
Index Chemical POD
As with any risk assessment that relies on BMD analysis, the POD is the lower confidence limit used to
mark the beginning of extrapolation to determine risk associated with human exposures. As described
further in the non-cancer human health hazards of DEHP (I v « « \ 2024h), DBP (I v « « \ 2024f),
BBP (1 c ! ^ \ - '24c). DIBP ( * n \ .0240. DCHP 0 * J r \ .'.!), and DINP (' ! V \
2024m) (see Appendices titled "Considerations for Benchmark Response (BMR) Selection for Reduced
Fetal Testicular Testosterone" in each hazard assessment), EPA has reached the conclusion that a BMR
of 5 percent is the most appropriate and health protective response level for evaluating decreased fetal
testicular testosterone. For the index chemical, DBP, the BMDL5 for the best fitting linear-quadratic
model is 9 mg/kg-day for reduced fetal testicular. Using allometric body weight scaling to the 3/4- power
( ), EPA extrapolated an HED of 2.1 mg/kg-day to use as the POD for the index
chemical in the CRA.
Selection of the Benchmark MOE
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Consistent with Agency guidance ( 22c. 2002b). EPA selected an intraspecies uncertainty
factor (UFh) of 10, which accounts for variation in susceptibility across the human population and the
possibility that the available data might not be representative of individuals who are most susceptible to
the effect. EPA used allometric body weight scaling to the 3/4-power to derive an HED of 2.1 mg/kg-day
DBP, which accounts for species differences in toxicokinetics. Consistent with EPA Guidance (U.S.
E ), the interspecies uncertainty factor (UF \), was reduced from 10 to 3 to account for
remaining uncertainty associated with interspecies differences in toxicodynamics. Overall, a total
uncertainty factor of 30 was selected for use as the benchmark margin of exposure for the CRA (based
on an interspecies uncertainty factor [UFa] of 3 and an intraspecies uncertainty factor [UFh] of 10).
Weight of Scientific Evidence
EPA has preliminary selected an HED of 2.1 mg/kg-day (BMDLs of 9 mg/kg-day) as the index chemical
(DBP) POD. This POD is based on a meta-analysis and BMD modeling of decreased fetal testicular
testosterone from eight studies of rats gestationally exposed to DBP. EPA has also derived draft RPFs of
1, 0.84, 0.53, 0.52, 1.66, and 0.21 for DBP (index chemical), DEHP, DffiP, BBP, DCHP, andDINP,
respectively, based on a common toxicological outcome {i.e., reduced fetal testicular testosterone). EPA
has robust overall confidence in the proposed POD for the index chemical {i.e., DBP) and the derived
draft RPFs.
Application of RPF provides a more robust basis for assessing the dose-response to the common hazard
endpoint across all assessed phthalates. For a subset of the phthalates with a more limited toxicological
data set, scaling by the RPF and application of the index chemical POD provides a more sensitive and
robust hazard assessment than the chemical-specific POD. Readers are directed to the revised draft CRA
TSD (I v i i \ ^'25x) for a discussion of the weight of evidence supporting EPA's preliminary
conclusions.
4.4.2 Cumulative Phthalate Exposure: Non-Attributable Cumulative Exposure to DEHP,
DBP, BBP, DIBP, and DINP Using NHANES Urinary Biomonitoring and Reverse
Dosimetry
This section briefly summarizes EPA's approach and results for estimating non-attributable cumulative
exposure to phthalates using NHANES urinary biomonitoring data and reverse dosimetry. Readers are
directed to Section 4 of EPA's revised draft CRA TSD (U.S. EPA. 2025x) for additional details.
NHANES is an ongoing exposure assessment of the U.S. population's exposure to environmental
chemicals using biomonitoring. The NHANES biomonitoring data set is a national, statistical
representation of the general, non-institutionalized, civilian U.S. population. CDC's NHANES data set
provides an estimate of average aggregate exposure to individual phthalates for the U.S. population.
However, exposures measured via NHANES cannot be attributed to specific sources, such as TSCA
COUs or other sources. Given the short half-lives of phthalates, neither can NHANES capture acute, low
frequency exposures. Instead, as concluded by the SACC review of the draft 2023 approach, NHANES
provides a "snapshot" or estimate of total, non-attributable phthalate exposure for the U.S. population
and relevant subpopulations ( I023g). These estimates of total non-attributable exposure can
supplement assessments of scenario-specific acute risk in individual risk evaluations.
Monoester metabolites of BBP, DBP, DEHP, DIBP, and DINP in human urine are regularly measured
as part of the NHANES biomonitoring program and are generally detectable in human urine at a high
frequency, including during the most recent NHANES survey period {i.e., 2017-2018). One urinary
metabolite {i.e., monocyclohexyl phthalate [MCHP]) of DCHP was included in NHANES from 1999
through 2010, but was excluded from NHANES after 2010 due to low detection levels and a low
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frequency of detection in human urine (detected in <10% of samples in 2009-2010 NHANES survey)
(CDC. 2013).Therefore. EPA did not use NHANES urinary biomonitoring data to estimate a daily
aggregate intake value for DCHP through reverse dosimetry.
EPA used urinary phthalate metabolite concentrations for DEHP, DBP, BBP, DIBP, and DINP
measured in the most recently available NHANES survey (2017-2018) to estimate the average daily
aggregate intake of each phthalate through reverse dosimetry for
1. Women of reproductive age (16-49 years);
2. Male children (4 to <6 years, used as a proxy for male infants and toddlers);
3. Male children (6-11 years); and
4. Male children (12 to <16 years).
Since NHANES does not include urinary biomonitoring for infants or toddlers, and other national data
sets are not available, EPA used biomonitoring data from male children 3 to less than 6 years of age as a
proxy for male infants (<1 year) and male toddlers (1-2 years). See Section 4 of ( 25x) for
further details regarding the reverse dosimetry approach. Aggregate daily intake estimates for these
populations are presented in Table 4-21.5 Aggregate daily intake values were also calculated for females
of reproductive age stratified by race and socioeconomic status (Table 4-22). A similar analysis by race
was not done for male children because the NHANES sample size is smaller for this population.
Aggregate daily intake values for each phthalate were then scaled by relative potency using the RPFs in
Table 4-20, expressed in terms of index chemical (DBP) equivalents, and summed to estimate
cumulative daily intake in terms of index chemical (DBP) equivalents using the approach outlined in
Sections 4.4.1 and 4.4.3.
Because EPA is focusing its CRA on acute exposure durations, EPA selected 95th percentile exposure
estimates from NHANES to serve as the non-attributable nationally representative exposure estimate for
use in its CRA. For females of reproductive age, EPA's analysis indicates that black, non-Hispanic
women have slightly higher 95th percentile cumulative phthalate exposure compared to other racial
groups; thus, 95th percentile cumulative exposure estimates for black non-Hispanic females of
reproductive age was selected for use in the CRA of DBP (Table 4-22).
The 95th percentile of national cumulative exposure serves as the estimate of non-attributable phthalate
exposure for its CRA of DBP as follows:
• Women of reproductive age (16-49 years, black non-Hispanic): 5.16 |ig/kg-day index chemical
(DBP) equivalents. This serves as the non-attributable contribution to worker and consumer
females of reproductive age in Section 4.4.4 and Section 4.4.5.
• Males (3-5 years): 10.8 |ig/kg-day index chemical (DBP) equivalents. This serves as the non-
attributable contribution to consumer male infants (<1 year), toddlers (1-2 years), and
preschoolers (3-5 years) in Section 4.4.5. Since NHANES does not include urinary
biomonitoring for infants (<1 year) or toddlers (1-2 years), and other national data sets are not
available, EPA used biomonitoring data from male children (3 to <6 years) as a proxy for male
infants and toddlers.
• Males (6-11 years): 7.35 |ig/kg-day index chemical (DBP) equivalents This serves as the non-
attributable contribution to consumer male children (6-10 years) in Section 4.4.5.
5 EPA defines aggregate exposure as the "combined exposures to an individual from a single chemical substance across
multiple routes and across multiple pathways" (40 CFR section 702.33").
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• Males (12-15 years): 4.36 |ig/kg-day index chemical (DBP) equivalents. This serves as the non-
attributable contribution to consumer male teenagers (11-15 years) in Section 4.4.5.
4.4.2.1 Weight of Scientific Evidence: Non-Attributable Cumulative Exposure to
Phthalates
Overall, EPA has robust confidence in the derived estimates of non-attributable cumulative exposure
from NHANES urinary biomonitoring using reverse dosimetry. EPA used urinary biomonitoring data
from the CDC's national NHANES dataset, which provides a statistical representation of the general,
non-institutionalized, civilian U.S. population. To estimate daily intake values from urinary
biomonitoring for each phthalate, EPA used reverse dosimetry. The reverse dosimetry approach used by
EPA has been used extensively in the literature and has been used by CPSC (2014) and Health Canada
(Health Canada. 2020) to estimate phthalate daily intake values from urinary biomonitoring data.
However, given the short half-lives of phthalates, NHANES biomonitoring data are not expected to
capture low frequency exposures and may be an underestimate of acute phthalate exposure.
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4443 Table 4-21. Cumulative Phthalate Daily Intake (jig/kg-day) Estimates for Women of Reproductive Age, Male Children, and Male
4444 Teenagers from the 2017-2018 NHANES Cycle
Population
Percentile
Phthalate
Aggregate
Daily Intake
(jig/kg-day)
RPF
Aggregate
Daily Intake
in DBP
Equivalents
(jig/kg-day)
%
Contribution
to Cumulative
Exposure
Cumulative Daily
Intake
(DBP Equivalents,
jig/kg-day)
Cumulative
MOE (POD =
2,100 jig/kg-
day)
% Contribution
to Risk Cup
(Benchmark
30)
DBP
0.21
1
0.210
22.1
DEHP
0.53
0.84
0.445
46.9
50
BBP
0.08
0.52
0.042
4.38
0.950
2,211
1.4%
Females
(16-49 years;
n = 1,620)
DIBP
0.2
0.53
0.106
11.2
DINP
0.7
0.21
0.147
15.5
DBP
0.61
1
0.610
17.2
DEHP
1.48
0.84
1.24
35.0
95
BBP
0.42
0.52
0.218
6.15
3.55
592
5.1%
DIBP
0.57
0.53
0.302
8.51
DINP
5.6
0.21
1.18
33.1
DBP
0.56
1
0.560
18.4
DEHP
2.11
0.84
1.77
58.2
50
BBP
0.22
0.52
0.114
3.76
3.04
690
4.3%
Males
(3-5 years;
n = 267)
DIBP
0.57
0.53
0.302
9.93
DINP
1.4
0.21
0.294
9.66
DBP
2.02
1
2.02
18.6
DEHP
6.44
0.84
5.41
49.9
95
BBP
2.46
0.52
1.28
11.8
10.8
194
15.5%
DIBP
2.12
0.53
1.12
10.4
DINP
4.8
0.21
1.01
9.30
Males
(6-11 years;
n = 553)
DBP
0.38
1
0.380
20.1
50
DEHP
1.24
0.84
1.04
55.1
1.89
1,111
2.7%
BBP
0.16
0.52
0.083
4.40
DIBP
0.33
0.53
0.175
9.26
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Population
Percentile
Phthalate
Aggregate
Daily Intake
(jig/kg-day)
RPF
Aggregate
Daily Intake
in DBP
Equivalents
(jig/kg-day)
%
Contribution
to Cumulative
Exposure
Cumulative Daily
Intake
(DBP Equivalents,
jig/kg-day)
Cumulative
MOE (POD =
2,100 jig/kg-
day)
% Contribution
to Risk Cup
(Benchmark =
30)"
DINP
1
0.21
0.210
11.1
DBP
1.41
1
1.41
19.2
DEHP
4.68
0.84
3.93
53.5
95
BBP
0.84
0.52
0.437
5.94
7.35
286
10.5%
DIBP
1.62
0.53
0.859
11.7
DINP
3.4
0.21
0.714
9.71
DBP
0.33
1
0.330
27.6
DEHP
0.66
0.84
0.554
46.4
50
BBP
0.14
0.52
0.073
6.09
1.19
1,758
1.7%
Males
(12-15 years;
n = 308)
DIBP
0.21
0.53
0.111
9.32
DINP
0.6
0.21
0.126
10.5
DBP
0.62
1
0.620
14.2
DEHP
2.51
0.84
2.11
48.3
95
BBP
0.64
0.52
0.333
7.63
4.36
482
6.2%
DIBP
0.59
0.53
0.313
7.17
DINP
4.7
0.21
0.987
22.6
a A cumulative exposure of 70 |_ig DBP equivalents/kg-day would result in a cumulative MOE of 30 (i.e., 2,100 |_ig DBP-equivalents/kg-day ^ 70 |_ig DBP
equivalents/kg-day = 30), which is equivalent to the benchmark of 30, indicating that the exposure is at the threshold for risk. Therefore, to estimate the percent
contribution to the risk cup, the cumulative exposure expressed in DBP equivalents is divided by 70 |_ig DBP equivalents/kg-day to estimate percent contribution
to the risk cup.
4445
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4446 Table 4-22. Cumulative Phthalate Daily Intake (jig/kg-day) Estimates for Women of Reproductive Age (16-49 years old) by Race and
4447 Socioeconomic Status from the 2017-2018 NHANES Cycle
Race/
Socioeconomic
Status (SES)
Percentile
Phthalate
Aggregate
Daily Intake
(jig/kg-day)
RPF
Aggregate
Daily Intake
in DBP
Equivalents
(jig/kg-day)
%
Contribution to
Cumulative
Exposure
Cumulative Daily
Intake
(DBP Equivalents,
jig/kg-day)
Cumulative
MOE (POD
= 2,100
jig/kg-day)
% Contribution
to Risk Cup
(Benchmark =
30)"
DBP
0.22
1
0.22
21.6
DEHP
0.59
0.84
0.50
48.6
50
BBP
0.10
0.52
0.05
5.1
1.02
2,058
1.5%
DIBP
0.20
0.53
0.11
10.4
Race: white non-
Hispanic
(n = 494)
DINP
0.70
0.21
0.15
14.4
DBP
0.58
1
0.58
17.6
DEHP
1.44
0.84
1.21
36.6
95
BBP
0.29
0.52
0.15
4.6
3.30
636
4.7%
DIBP
0.55
0.53
0.29
OO
00
DINP
5.10
0.21
1.07
32.4
DBP
0.10
1
0.10
15.0
DEHP
0.38
0.84
0.32
47.9
50
BBP
0.04
0.52
0.02
3.1
0.667
3,151
1.0%
DIBP
0.15
0.53
0.08
11.9
Race: black non-
Hispanic
(n = 371)
DINP
0.70
0.21
0.15
22.1
DBP
0.48
1
0.48
9.3
DEHP
4.28
0.84
3.60
69.7
95
BBP
0.30
0.52
0.16
3.0
5.16
407
7.4%
DIBP
0.40
0.53
0.21
4.1
DINP
3.40
0.21
0.71
13.8
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Race/
Socioeconomic
Status (SES)
Percentile
Phthalate
Aggregate
Daily Intake
(jig/kg-day)
RPF
Aggregate
Daily Intake
in DBP
Equivalents
(jig/kg-day)
%
Contribution to
Cumulative
Exposure
Cumulative Daily
Intake
(DBP Equivalents,
jig/kg-day)
Cumulative
MOE (POD
= 2,100
jig/kg-day)
% Contribution
to Risk Cup
(Benchmark =
30)"
Race: Mexican
American
(n = 259)
50
DBP
0.19
1
0.19
22.4
0.849
2,474
1.2%
DEHP
0.49
0.84
0.41
48.5
BBP
0.06
0.52
0.03
3.7
DIBP
0.17
0.53
0.09
10.6
DINP
0.60
0.21
0.13
14.8
95
DBP
0.42
1
0.42
11.6
3.61
582
5.2%
DEHP
1.24
0.84
1.04
28.9
BBP
0.39
0.52
0.20
5.6
DIBP
0.46
0.53
0.24
6.8
DINP
8.10
0.21
1.70
47.1
Race: Other
(n = 496)
50
DBP
0.26
1
0.26
25.3
1.03
2041
1.5%
DEHP
0.64
0.84
0.54
52.2
BBP
0.07
0.52
0.04
3.5
DIBP
0.15
0.46
0.07
6.7
DINP
0.60
0.21
0.13
12.2
95
DBP
0.84
1
0.84
20.7
4.06
517
5.8%
DEHP
1.37
0.84
1.15
28.3
BBP
0.41
0.52
0.21
5.2
DIBP
0.46
0.53
0.24
6.0
DINP
7.70
0.21
1.62
39.8
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Race/
Socioeconomic
Status (SES)
Percentile
Phthalate
Aggregate
Daily Intake
(jig/kg-day)
RPF
Aggregate
Daily Intake
in DBP
Equivalents
(jig/kg-day)
%
Contribution to
Cumulative
Exposure
Cumulative Daily
Intake
(DBP Equivalents,
jig/kg-day)
Cumulative
MOE (POD
= 2,100
jig/kg-day)
% Contribution
to Risk Cup
(Benchmark =
30)"
DBP
0.21
1
0.21
22.0
DEHP
0.53
0.84
0.45
46.6
50
BBP
0.09
0.52
0.05
4.9
0.955
2,199
1.4%
DIBP
0.20
0.53
0.11
11.1
SES: Below
poverty level
(n = 1,056)
DINP
0.70
0.21
0.15
15.4
DBP
0.82
1
0.82
18.2
DEHP
1.75
0.84
1.47
32.7
95
BBP
0.34
0.52
0.18
3.9
4.50
467
6.4%
DIBP
0.51
0.53
0.27
6.0
DINP
8.40
0.21
1.76
39.2
DBP
0.20
1.00
0.20
27.9
DEHP
0.31
0.84
0.26
36.3
50
BBP
0.06
0.52
0.03
4.3
0.718
2,924
1.0%
DIBP
0.15
0.53
0.08
11.1
SES: At or above
poverty level
(n = 354)
DINP
0.70
0.21
0.15
20.5
DBP
0.48
1.00
0.48
16.3
DEHP
1.07
0.84
0.90
30.5
95
BBP
0.45
0.52
0.23
7.9
2.94
713
4.2%
DIBP
0.65
0.53
0.34
11.7
DINP
4.70
0.21
0.99
33.5
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Race/
Socioeconomic
Status (SES)
Percentile
Phthalate
Aggregate
Daily Intake
(jig/kg-day)
RPF
Aggregate
Daily Intake
in DBP
Equivalents
(jig/kg-day)
%
Contribution to
Cumulative
Exposure
Cumulative Daily
Intake
(DBP Equivalents,
jig/kg-day)
Cumulative
MOE (POD
= 2,100
jig/kg-day)
% Contribution
to Risk Cup
(Benchmark =
30)"
DBP
0.26
1.00
0.26
23.2
DEHP
0.67
0.84
0.56
50.1
50
BBP
0.06
0.52
0.03
2.8
1.12
1,870
1.6%
DIBP
0.23
0.53
0.12
10.9
SES: Unknown
DINP
0.70
0.21
0.15
13.1
(n = 210)
DBP
0.60
1.00
0.60
25.5
2.35
893
3.4%
DEHP
0.86
0.84
0.72
30.7
95
BBP
0.21
0.52
0.11
4.6
DIBP
0.35
0.53
0.19
7.9
DINP
3.50
0.21
0.74
31.2
a A cumulative exposure of 70 |_ig DBP equivalents/kg-day would result in a cumulative MOE of 30 (i.e., 2,100 |_ig DBP-equivalents/kg-day ^ 70 |_ig DBP
equivalents/kg-day = 30), which is equivalent to the benchmark of 30, indicating that the exposure is at the threshold for risk. Therefore, to estimate the percent
contribution to the risk cup, the cumulative exposure expressed in DBP equivalents is divided by 70 |_ig DBP equivalents/kg-day to estimate percent contribution
to the risk cup.
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4.4.3 Estimation of Risk Based on Relative Potency
As described in the revised draft CRA TSD (U.S. EPA. 2025x1 EPA is focusing its exposure assessment
for the CRA for DBP on evaluation of exposures through individual TSCA consumer and occupational
DBP COUs as well as non-attributable cumulative exposure to DEHP, DBP, BBP, DIBP, and DINP
using NHANES urinary biomonitoring data and reverse dosimetry. Furthermore, EPA is considering
two options for characterizing cumulative risk. The Agency uses the first option to estimate cumulative
risk in which all phthalate exposures are scaled by relative potency using the RPFs presented in Table
4-20 to express phthalate exposure in terms of index chemical (DBP) equivalents. Exposures from
individual DBP consumer or worker COUs/OES were then combined to estimate cumulative risk.
Cumulative risk was estimated using the four-step process outlined below, along with one empirical
example of how EPA calculated cumulative risk for one occupational OES for DBP {i.e., PVC plastics
converting). In the second option, which is presented in Section 5.2 of revised draft CRA TSD (U.S.
E 25x), individual phthalate exposures for consumer and occupational COUs are not scaled by
relative potency factors but use the individual phthalate hazard values and are combined with non-
attributable cumulative exposures estimated using NHANES. Both options are compared in Section 5.4
of the revised draft CRA TSD and both options for calculating cumulative risk will be peer reviewed by
the SACC in 2025. Following peer review and public comment, EPA will select one option for
characterizing cumulative risk in the final DBP risk evaluation.
Step 1: Convert DBP Exposure Estimates from Each Individual Consumer and Occupational COU to
Index Chemical Equivalents (i. e., Occupational and Consumer Exposure from Sections 4.1.1 and
4.1.2, Respectively)
In this step, DBP acute duration exposure estimates from each consumer and occupational COU/OES
are scaled by relative potency and expressed in terms of index chemical (DBP) equivalents using
Equation 4-5. This step is repeated for all individual exposure estimates for each route of exposure being
assessed for each COU {i.e., inhalation and dermal exposures for occupational COUs; inhalation,
ingestion, and dermal exposure for consumer COUs).
Equation 4-5. Scaling DBP Exposures by Relative Potency
DBP Exposure {in DBP equivalents) = ADRoute xx RPFdbp
Where:
DBP exposure = Acute exposure for a given route of exposure from a single
occupational or consumer COU expressed in terms of |ig/kg index
chemical (DBP) equivalents
ADRoute i = Acute dose in |ig/kg from a given route of exposure from a single
occupational or consumer COU/OES
RPFdibp = The relative potency factor (unitless) for DBP (index chemical) is
1.0. (Table 4-20).
Example: 50th percentile inhalation, dermal, and aggregate DBP exposures for female workers of
reproductive age are 47.4, 15.6, and 63.0 |ig/kg for the PVC plastics converting OES (
2025q). Using Equation 4-5, inhalation, dermal, and aggregate DBP exposures for this OES can be
scaled by relative potency. Because the RPF for DBP (index chemical) is 1.0, the inhalation, dermal, and
aggregate DBP exposure estimates do not change.
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Step 2: Estimate Non-attributable Cumulative Exposure to DEHP, DBP, BBP, DIBP, and DINP
Using NHANES Urinary Biomonitoring Data and Reverse Dosimetry (see Section 4.4.2 for Further
Details)
Non-attributable exposure for a national population to DEHP, DBP, BBP, DIBP, and DINP was
estimated using Equation 4-6, where individual phthalate daily intake values estimated from NHANES
biomonitoring data and reverse dosimetry were scaled by relative potency, expressed in terms of index
chemical (DBP) equivalents, and summed to estimate non-attributable cumulative exposure in terms of
DBP equivalents. Equation 4-6 was used to calculate the cumulative exposure estimates provided in
Table 4-21 and Table 4-22.
Equation 4-6. Estimating Non-attributable Cumulative Exposure to DEHP, DBP, BBP, DIBP, and
DINP
Cumulative Exposure (Non — attributable)
= (DIdehp x RPFdehp) + (DIdbp x RPFdbp) + (DIbbp x RPFbbp)
+ (DIdibp x RPFdibp) + (DIdinp x RPFdinp)
Where:
Cumulative exposure (non-attributable) is expressed in index chemical (DBP) equivalents
(lig/kg-day).
DI is the daily intake value (|ig/kg-day) for each phthalate that was calculated using NHANES
urinary biomonitoring data and reverse dosimetry. DI values for each phthalate for each assessed
population are provided in Table 4-21 and Table 4-22.
RPF is the relative potency factor (unitless) for each phthalate from Table 4-20.
Example: The 95th percentile cumulative exposure estimate of 5.16 |ig/kg-day DBP equivalents for
black, non-Hispanic females of reproductive age (Table 4-22) is calculated using Equation 4-6 as
follows:
5.16 [ig/kgDBP equivalents
= (4.28 |ig/kg DEHP x 0.84) + (0.48 |ig/kg DBP x 1) + (0.30 |ig/kg BBP x 0.52)
+ (0.40 [ig/kg DIBP x 0.53) + (3.40 [ig/kgDINP x 0.21)
Step 3: Calculate MOEs for DBP Exposures and for Each Phthalate Exposure Included in the
Cumulative Scenario
Next, MOEs are calculated for each exposure of interest that is included in the cumulative scenario
using Equation 4-7. For example, this step involves calculating MOEs for inhalation and dermal DBP
exposures for each individual COU/OES in Step 1, and an MOE for non-attributable cumulative
phthalate exposure from Step 2 above.
Equation 4-7. Calculating MOEs for Exposures of Interest for Use in the RPF and Cumulative
Approaches
Index Chemical (DBP) POD
MOEi =
Exposure1 in DBP Equivalents
Where:
MOE\ (unitless) = The MOE calculated for each exposure of interest included
in the cumulative scenario
Index Chemical (DBP) POD = The POD selected for the index chemical, DBP; the index
chemical POD is 2,100 |ig/kg (Section4.4.1).
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Exposurei = The exposure estimate in DBP equivalents for the pathway
of interest {i.e., from Step 1 or 2 above).
Example: Using Equation 4-7, the MOEs for inhalation and dermal DBP exposure estimates for the PVC
plastics converting OES in DBP equivalents from Step 1 and the MOE for the non-attributable
cumulative exposure estimate in DBP equivalents from Step 2 are 44, 135, and 407, respectively.
2,100 [xg/kg
MOEcumuiative Non-attribUtable ~ 407 —
MOEcou_Inhaiation — 44 —
5.16 \ig/kg
2,100 [xg/kg
47.4 |ig/kg
2,100 [xg/kg
MOEcou_Dermai — 135 —
15.6 |ig/kg
Step 4: Calculate the Cumulative MOE
For the cumulative MOE approach, MOEs for each exposure of interest in the cumulative scenario are
first calculated (Step 3). The cumulative MOE for the cumulative scenario can then be calculated using
Equation 4-8, which shows the addition of MOEs for the inhalation and dermal exposures routes from
an individual DBP COU as well as the MOE for non-attributable cumulative exposure to phthalates
from NHANES urinary biomonitoring and reverse dosimetry. Additional MOEs can be added to the
equation as necessary {e.g., for the ingestion route for consumer scenarios).
Equation 4-8. Cumulative Margin of Exposure Calculation
1
Cumulative MOE = jjj
MOEcou-jnhdidtign MOEcou_Dermai MOilcujnujative-Non-attrt&uta&ie
Example: The cumulative MOE for the PVC plastics converting OES is 31 and is calculated by
summing the MOEs for each exposure of interest from Step 3 as follows:
1
Cumulative MOE = 31 = j —
44 + l35 + 407
4.4.4 Risk Estimates for Workers Based on Relative Potency
This section summarizes RPF analysis risk estimates for female workers of reproductive age from acute
duration exposures to DBP. In the RPF analysis, EPA focused its occupational risk assessment on this
population and exposure duration because as described in Section 4.4 and ( )25x\ this
population and exposure duration is considered most directly applicable to the common hazard outcome
that serves as the basis for the RPF analysis {i.e., reduced fetal testicular testosterone).
To evaluate cumulative risk to female workers of reproductive age, EPA combined inhalation and
dermal exposures to DBP from each individual occupational COU/OES with non-attributable
cumulative exposure to DEHP, DBP, BBP, DIBP, and DINP (estimated from NHANES urinary
biomonitoring using reverse dosimetry). As described in Section 4.4.3, for each individual phthalate
exposures were scaled by relative potency per chemical, expressed in terms of index chemical (DBP)
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equivalents, and summed to estimate cumulative exposure and cumulative risk for each COU. Because
DBP is the index chemical and the RPF is 1, scaling has no effect on individual DBP exposure
estimates. MOEs in Table 4-23 are shown both with (cumulative MOE) and without (MOEs for
individual DBP COU derived using the RPF analysis) the addition of non-attributable cumulative
exposure (estimated from NHANES using reverse dosimetry) so that MOEs scaled by relative potency
can be compared.
As discussed in Section 4.3.2, high-end aggregate MOEs ranged from 0.7 to 20 for all 16 OES evaluated
in the individual DBP risk assessment, while central tendency aggregate MOEs ranged from 1.7 to 3.2
for 11 of the 16 OESs evaluated in the individual DBP risk assessment. Addition of non-attributable
cumulative exposure would have no impact on risk conclusions for these OES. For the remaining five
OESs {i.e., PVC plastics converting; Use of laboratory chemicals [solids]; Fabrication or use of final
products or articles; Recycling; and Waste handling, treatment, and disposal), central tendency
aggregate MOEs ranged from 33 to 101 in the individual DBP risk assessment (Section 4.3.2). As can be
seen from Table 4-23, for the same five OESs {i.e., PVC plastics converting; Use of laboratory
chemicals [solids]; Fabrication or use of final products or articles; Recycling; and Waste handling,
treatment, and disposal), the addition of non-attributable cumulative exposure (from NHANES) resulted
in central tendency cumulative acute MOEs ranging from 31 to 81 (cumulative benchmark = 30).
Therefore, in no case did the addition of non-attributable cumulative exposure (from NHANES) result in
MOEs dropping below the benchmark of 30.
4.4.4.1 Overall Confidence in Cumulative Worker Risk Estimates
As described in Section 4.1.1.5 and the Draft Environmental Release and Occupational Exposure
Assessment for Dibutyl Phthalate (U, 2025q). EPA has moderate to robust confidence in the
assessed inhalation and dermal OESs (Table 4-5). The Agency has robust confidence in the RPFs and
index chemical POD used to calculate the RPF analysis and cumulative MOEs (Section 4.4.1.2). To
derive RPFs and the index chemical POD, the Agency integrated data from multiple studies evaluating
fetal testicular testosterone using a meta-analysis approach and conducted BMD modeling. Finally, the
Agency has robust confidence in the non-attributable cumulative exposure estimates for DEHP, DBP,
BBP, DIBP, and DINP derived from NHANES urinary biomonitoring data using reverse dosimetry
(Section 4.4.2.1). Overall, EPA has moderate to robust confidence in the cumulative risk estimates
calculated for worker exposure scenarios (Table 4-23).
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Table 4-23. Risk Summary Table for Female Workers of Reproductive Age Using the RPF Analysis
Acute MOEs for Female Workers of Reproductive Age
(Benchmark = 30)
Life Cycle Stage -
Category
Subcategory
OES
Exposure
Level
Inhalation
MOE (DBP
COU; Exposure
to DBP)
Dermal MOE
(DBP COU;
Exposure to
DBP)
Aggregate MOE
(DBP COU;
Exposure to
DBP)
Cumulative MOE
(Aggregate DBP
MOE + Cumulative
Non-Attributable)"
Manufacturing -
CT
30
1.8
1.7
1.7
Domestic
Manufacturing
Domestic Manufacturing
Manufacturing
HE
15
0.9
0.9
0.9
Manufacturing -
Importing
CT
30
1.8
1.7
1.7
Importing
HE
15
0.9
0.9
0.9
Processing -
Repackaging
Laboratory chemicals in wholesale
and retail trade; plasticizers in
wholesale and retail trade; and
plastics material and resin
manufacturing
Import and
repackaging
Processing -
Processing as a
reactant
Intermediate in plastic
manufacturing
CT
30
1.8
1.7
1.7
Processing -
Incorporation into
formulation,
mixture, or
reaction product
Solvents (which become part of
product formulation or mixture) in
chemical product and preparation
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; adhesive
manufacturing; and printing ink
manufacturing
Incorporation into
formulations,
mixtures, or
reaction products
Plasticizer in paint and coating
manufacturing; plastic material
and resin manufacturing; rubber
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing;
printing ink manufacturing; basic
organic chemical manufacturing;
and adhesive and sealant
manufacturing
HE
15
0.9
0.9
0.9
Pre-catalyst manufacturing
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Life Cycle Stage -
Category
Subcategory
OES
Exposure
Level
Acute MO.Es for Female Workers of Reproductive Age
(Benchmark = 30)
Inhalation
MOE (DBP
COL; Exposure
to DBP)
Dermal MOE
(DBP COIJ;
Exposure to
DBP)
Aggregate MOE
(DBP COIJ;
Exposure to
DBP)
Cumulative MOE
(Aggregate DBP
MOE + Cumulative
Non-Attributable)"
Processing -
Processing:
incorporation into
formulation,
mixture, or
reaction product
Plasticizer in paint and coating
manufacturing; plastic material
and resin manufacturing; rubber
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing;
printing ink manufacturing; basic
organic chemical manufacturing;
and adhesive and sealant
manufacturing
PVC plastics
compounding
CT
44
1.8
1.7
1.7
HE
5.3
0.9
0.8
0.8
Processing -
Processing:
incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and
construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics product
manufacturing; and rubber product
manufacturing
PVC plastics
converting
CT
44
135
33
31
HE
5.3
67
4.9
4.9
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Life Cycle Stage -
Category
Subcategory
OES
Exposure
Level
Acute MO.Es for Female Workers of Reproductive Age
(Benchmark = 30)
Inhalation
MOE (DBP
COL; Exposure
to DBP)
Dermal MOE
(DBP COIJ;
Exposure to
DBP)
Aggregate MOE
(DBP COIJ;
Exposure to
DBP)
Cumulative MOE
(Aggregate DBP
MOE + Cumulative
Non-Attributable)"
Processing -
Processing:
incorporation into
formulation,
mixture, or
reaction product
Plasticizer in paint and coating
manufacturing; plastic material
and resin manufacturing; rubber
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing;
printing ink manufacturing; basic
organic chemical manufacturing;
and adhesive and sealant
manufacturing
Non-PVC materials
manufacturing
(compounding and
converting)
CT
53
1.8
1.7
1.7
HE
9.0
0.9
0.8
0.8
Processing -
Incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and
construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics product
manufacturing; and rubber product
manufacturing
Commercial Use -
Construction,
paint, electrical,
and metal products
Adhesives and sealants
Application of
adhesives and
sealants
CT
304
1.8
1.8
1.8
HE
152
0.9
0.9
0.9
Industrial Use -
Construction,
paint, electrical,
and metal products
Adhesives and sealants
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Life Cycle Stage -
Category
Subcategory
OES
Exposure
Level
Acute MO.Es for Female Workers of Reproductive Age
(Benchmark = 30)
Inhalation
MOE (DBP
COL; Exposure
to DBP)
Dermal MOE
(DBP COU;
Exposure to
DBP)
Aggregate MOE
(DBP COU;
Exposure to
DBP)
Cumulative MOE
(Aggregate DBP
MOE + Cumulative
Non-Attributable)"
Commercial Use -
Packaging, paper,
plastic, toys, hobby
products
Ink, toner, and colorant products
Application of
paints and coatings
CT
18
1.8
1.7
1.7
HE
2.9
0.9
0.7
0.7
Commercial Use -
Commercial use -
Construction,
paint, electrical,
and metal products
Paints and coatings
Industrial Use -
Construction,
paint, electrical,
and metal products
Industrial Use -
Non-incorporative
activities
Solvent, including in maleic
anhydride manufacturing
technology
Use of Industrial
Process Solvents
CT
30
1.8
1.7
1.7
HE
15
0.9
0.9
0.9
Commercial Use -
Other uses
Laboratory chemicals
Use of laboratory
chemicals (Solid)
CT
400
135
101
81
HE
28
67
20
19
Commercial Use -
Other uses
Laboratory chemicals
Use of laboratory
chemicals (Liquid)
CT
304
2.4
2.4
2.4
HE
152
0.9
0.9
0.9
Commercial Use -
Other uses
Lubricants and lubricant additives
Use of lubricants
and functional
fluids
CT
304
3.3
3.2
3.2
HE
152
1.1
1.1
1.1
Chemiluminescent light sticks
Industrial Use -
Other uses
Lubricants and lubricant additives
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Acute MOEs for Female Workers of Reproductive Age
(Benchmark = 30)
Life Cycle Stage -
Category
Subcategory
OES
Exposure
Level
Inhalation
MOE (DBP
COU; Exposure
to DBP)
Dermal MOE
(DBP COU;
Exposure to
DBP)
Aggregate MOE
(DBP COU;
Exposure to
DBP)
Cumulative MOE
(Aggregate DBP
MOE + Cumulative
Non-Attributable)"
Commercial Use -
Inspection penetrant kit
Use of penetrants
and inspection
fluids
CT
10
1.8
1.5
1.5
Other uses
HE
2.7
0.9
0.7
0.7
Cleaning and furnishing care
CT
152
135
71
61
products
Commercial Use -
Furnishing,
cleaning, treatment
care products
Floor coverings; construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
articles; fabrics, textiles, and
apparel;
Furniture and furnishings
Commercial Use -
Automotive, fuel,
agriculture,
outdoor use
products
Automotive care products
Fabrication or use
of final products or
HE
18
67
14
14
Commercial Use -
Other Uses
Automotive articles
articles
Industrial Use -
Automotive articles
Other Uses
Propellants
Commercial Use -
Packaging, paper,
plastic, toys, hobby
products
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
Toys, playground, and sporting
equipment
Processing -
Recycling
Recycling
CT
141
135
69
59
Recycling
HE
9.7
67
8.4
8.3
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Life Cycle Stage -
Category
Subcategory
OES
Exposure
Level
Acute MOEs for Female Workers of Reproductive Age
(Benchmark = 30)
Inhalation
MOE (DBP
COU; Exposure
to DBP)
Dermal MOE
(DBP COU;
Exposure to
DBP)
Aggregate MOE
(DBP COU;
Exposure to
DBP)
Cumulative MOE
(Aggregate DBP
MOE + Cumulative
Non-Attributable)"
Disposal -
Disposal
Disposal
Waste handling,
treatment, and
disposal
CT
141
135
69
59
HE
9.7
67
8.4
8.3
" The acute cumulative MOE is derived by summing inhalation exposure from each individual DBP COU with dermal exposure from the same E
cumulative non-attributable exposure to DEHP, DBP, BBP, DIBP, and DINP. Non-attributable cumulative exposure was estimated from NHAN
biomonitoring data using reverse dosimetry. All exposure estimates were (1) scaled by relative potency, (2) expressed in index chemical equivak
equivalents), (3) summed to calculate cumulative exposure in index chemical equivalents, and then (4) compared to the index chemical POD (i.e
day) to calculate the cumulative MOE.
BP COU and the
ES urinary
ints (i.e., DBP
, HED of 2.1 mg/kg-
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4.4.5 Risk Estimates for Consumers Based on Relative Potency
This section summarizes cumulative risk estimates for consumers from acute duration exposures to
DBP. EPA focused its CRA on females of reproductive age and male infants and children. EPA focused
its consumer CRA on these populations for the acute exposure duration because, as described in Section
4.4 and ( 2025x), these populations and exposure duration are considered most directly
applicable to the common hazard outcome that serves as the basis for the cumulative assessment {i.e.,
reduced fetal testicular testosterone). For consumers, EPA did not specifically evaluate females of
reproductive age or male infants and children; however, consumer exposures of teenagers (16-20 years)
and adults (21+ years) were considered a proxy for females of reproductive age, while infants (<1 year),
toddlers (1-2 years), children (3-5 and 6-10 years), and young teens (11-15 years) were considered a
proxy for male infants and children.
To evaluate cumulative risk to consumers, EPA combined inhalation, dermal, and ingestion exposures to
DBP from each individual consumer COU and product/article exposure scenario with non-attributable
cumulative exposure to DEHP, DBP, BBP, DIBP, and DINP (estimated from NHANES urinary
biomonitoring using reverse dosimetry). As described in Section 4.4.3, for each individual phthalate
exposures were scaled by relative potency per chemical, expressed in terms of index chemical (DBP)
equivalents, and summed to estimate cumulative exposure and cumulative risk for each COU. Because
DBP is the index chemical and the RPF is 1, scaling has no effect on individual DBP exposure
estimates.
As described in Section 4.3.3, EPA evaluated a number of product or article example exposure scenarios
associated with five consumer COUs. Of the evaluated product or article examples, 14 (associated with
5 COUs) have high-intensity cumulative MOEs ranging 46 to 482 (cumulative benchmark = 30) (listed
below). Seven product or article examples (associated with 3 COUs) have high-intensity aggregate
MOEs less than 30 (listed below). For these seven product or article examples, the addition of non-
attributable cumulative exposure from NHANES has no effect on risk conclusions, and these seven
product or articles examples are not further discussed. Two product or article examples (associated with
2 COUs) have high-intensity cumulative MOEs ranging from 27 to 29 (benchmark = 30). Notably, one
of these product or article examples also had high-intensity MOEs less than 30 for several consumer age
groups in the individual DBP consumer risk characterization (Section 4.3.3; Table 4-19). However, for
this one product or article example, several new consumer age groups have cumulative MOEs below 30
that were above 30 in the individual DBP consumer risk characterization (Table 4-24). The newly
identified consumer age groups for this product or article example are discussed further below.
Product or Article Examples with Acute High-Intensity Cumulative Moes Ranging from 46 to 482
As can be seen from Table 4-24, cumulative MOEs for high-intensity scenarios ranged from 46 to 482
for all consumer age groups evaluated for 14 product or articles examples (associated with 5 COUs),
including the following:
• Construction, paint, electrical, and metal products: adhesives for small repairs (cumulative
MOEs: 61-65);
• Furnishing, cleaning, treatment/care products: vinyl flooring (cumulative MOEs: 94-221);
• Furnishing, cleaning, treatment/care products: wallpaper (in-place) (cumulative MOEs: 72-395);
• Furnishing, cleaning, treatment/care products: wallpaper (installation) (cumulative MOEs:
98-103);
• Other uses: car mats (cumulative MOEs: 194-379);
• Other uses: small articles with semi routine contact; glow sticks (cumulative MOEs: 74-166);
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• Other uses: novelty articles: adult toys (cumulative MOEs: 262-268);
• Furnishing, cleaning, treatment care products: synthetic leather clothing (cumulative MOEs: 61-
64);
• Furnishing, cleaning, treatment care products: synthetic leather furniture (cumulative MOEs: 58-
406);
• Packaging, paper, plastic, hobby products: footwear components (cumulative MOEs: 46-103);
• Packaging, paper, plastic, hobby products: shower curtains (cumulative MOEs: 122-286);
• Packaging, paper, plastic, hobby products: tire crumb (cumulative MOEs: 194-482);
• Packaging, paper, plastic, hobby products: small articles with semi routine contact;
miscellaneous items including a pen, pencil case, hobby cutting board, costume jewelry, tape,
garden hose, disposable gloves, and plastic bags/pouches (cumulative MOEs: 74-166); and
• Packaging, paper, plastic, hobby products: small articles with semi routine contact;
miscellaneous items including a football, balance ball, and pet toy (cumulative MOEs: 74-166).
Product or Article Examples with Acute High-Intensity Aggregate from the Individual DBP
Assessment and Cumulative Moes Less than 30
As can be seen from Table 4-19 and Table 4-24, aggregate and cumulative MOEs for high-intensity
scenarios were less than 30 for the same consumer age groups evaluated for seven product or article
examples (associated with 3 COUs), including:
• Construction, paint, electrical, and metal products: metal coatings;
• Construction, paint, electrical, and metal products: indoor flooring sealing and refinishing
products;
• Construction, paint, electrical, and metal products: sealing and refinishing sprays (outdoor use);
• Construction, paint, electrical, and metal products: automotive adhesives;
• Construction, paint, electrical, and metal products: construction adhesives;
• Furnishing, cleaning, treatment care products: waxes and polishes; and
• Packaging, paper, plastic, hobby products: children's toys (legacy).
Product or Article Examples with Acute Cumulative Moes Ranging from 27 to 29
As can be seen from Table 4-24, cumulative MOEs for high-intensity scenarios ranged from 27 to 29 for
two product or articles examples (associated with 2 COUs). One of these product or article examples
also had MOEs less than 30 in the individual DBP consumer risk assessment (Section 4.3.3); however,
at least one new consumer age group had a cumulative MOEs below 30 that was above 30 in the
individual DBP consumer risk characterization (Table 4-19). These include the following:
• Furnishing, cleaning, treatment/care products: spray cleaner. Acute high-intensity cumulative
MOEs ranged from 27 to 29 for young teens (11-15 years), teenagers (16-20 years), and adults
(21+ years), while medium-intensity cumulative MOEs ranged from 90 to 95 for these same age
groups (Table 4-24). All of these age groups, except teenagers (16-20 years) (high-intensity
aggregate MOE = 31), also had high-intensity MOEs below 30 in the individual DBP consumer
risk assessment (Table 4-19).
• Packaging, paper, plastic, hobby products: children's toys (new). The acute high-intensity
cumulative MOE was 29 for infants (<1 year), while the medium-intensity cumulative MOE was
55 for the age group (Table 4-24). Comparatively, the acute high-intensity aggregate MOE was
34 for infants (<1 year) in the individual DBP consumer risk assessment (Table 4-19). Acute
high-intensity cumulative MOEs ranged from 52 to 353 for other evaluated age groups.
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EPA characterizes consumer COUs and product or article examples as part of the individual DBP
assessment in Section 4.3.3, while these consumer COUs are characterized for cumulative risk above in
this section. One factor contributes to the lower cumulative MOEs compared to the MOEs in the
individual DBP consumer risk assessment—that is the addition of non-attributable cumulative phthalate
exposure from NHANES. Because DBP is the index chemical and the RPF is 1, scaling by relative
potency has no effect on DBP exposure estimates. Similarly, the same POD (HED of 2.1 mg/kg-day)
based on reduced fetal testicular testosterone is used to calculate MOEs in the individual DBP
assessment and in the cumulative risk assessment. EPA calculated non-attributable cumulative exposure
to DEHP, DBP, BBP, DIBP, and DINP using NHANES urinary biomonitoring data from the 2017 to
2018 survey (most recent data set available) and reverse dosimetry (see Section 4.4.2 and (
2025x) for further details), representing exposure to a national population.
Non-attributable cumulative exposure estimates were scaled by relative potency and expressed in index
chemical (DBP) equivalents. Non-attributable cumulative exposure was then combined with acute
inhalation, dermal, and ingestion DBP exposures for each individual product or article example
exposure scenario scaled by relative potency. For infants, toddlers, and preschoolers, EPA added a non-
attributable cumulative exposure of 10.8 |ig/kg index chemical (DBP) equivalents to calculate the
cumulative MOE, which contributes 15.5 percent to the risk cup with a benchmark MOE of 30. For
middle-aged children, EPA added a non-attributable cumulative exposure of 7.35 |ig/kg index chemical
(DBP) equivalents to calculate the cumulative MOE, which contributes 10.5 percent to the risk cup with
a benchmark MOE of 30. For young teens (11-15 years), EPA added a non-attributable cumulative
exposure of 4.36 |ig/kg index chemical (DBP) equivalents to calculate the cumulative MOE, which
contributes 6.2 percent to the risk cup with a benchmark MOE of 30. For teenagers (16-20 years) and
adults (21+ years), EPA added a non-attributable cumulative exposure of 5.15 |ig/kg index chemical
(DBP) equivalents to calculate the cumulative MOE, which contributes 7.4 percent to the risk cup with a
benchmark MOE of 30.
4.4.5.1 Overall Confidence in Cumulative Consumer Risks
As described in Section 4.1.2, and in more technical details in the Draft Consumer and Indoor Exposure
Assessment for Dibutyl Phthalate (DBP) (\ c< « ^ \ . /'25c). EPA has moderate or robust confidence in
the assessed inhalation, ingestion, and dermal consumer exposure scenarios. The Agency has robust
confidence in the RPFs and index chemical POD used to calculate the cumulative MOEs (Section
4.4.1.2). To derive RPFs and the index chemical POD, EPA integrated data from multiple studies
evaluating fetal testicular testosterone using a meta-analysis approach and conducted BMD modeling.
Finally, EPA has robust confidence in the non-attributable cumulative exposure estimates because they
were calculated from CDC's NHANES biomonitoring dataset, which provides a statistically
representative sampling of the U.S. civilian population (Section 4.4.2.1). Furthermore, the Agency used
a well-established reverse dosimetry approach to calculate phthalate daily intake values from urinary
biomonitoring data. Overall, EPA has moderate to robust confidence in the cumulative risk estimates
calculated for consumer exposure scenarios (Table 4-24).
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4748 Table 4-24. Consumer Cumulative Risk Summary Table
Life Cycle Stage: COU:
Subcategory
Product or Article
Exposure
Level
(H, M, L)«
Exposure Scenario
Lifestage (Years)
MOE (Based on All Exposures in Index Chemical Equivalents)
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Preschooler
(3-5 years)
Middle
Childhood
(6-10
years)
Young
Teen
(11-15
years)
Teenager
(16-20
years)
Adult
(21+
years)
Automotive, Fuel,
Agriculture, Outdoor Use
Products: Automotive care
products
Uses were matched with automotive adhesives.
Construction, Paint,
Electrical, and Metal
Products: Adhesives and
sealants
Automotive adhesives
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
88
90
100
146
1c
1c
1c
Construction adhesives
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
-
-
-
-
1c
8c
1c
Adhesives for small
repairs
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
-
-
-
-
61
65
61
Construction, Paint,
Electrical, and Metal
Products: Paints and coatings
Metal coatings
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
194
194
194
286
lc
8c
1c
Indoor flooring sealing
and refmishing products
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
68
70
80
116
14c
16c
15 c
Sealing and refmishing
sprays (outdoor use)
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
62
65
74
98
1c
8c
8c
Furnishing, Cleaning,
Treatment Care Products:
Fabric, textile, and leather
products
Synthetic leather
clothing
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
-
-
-
-
-
e
e
M
Cumulative (Aggregate COU +
Cumulative Non-attributable)
-
-
-
-
-
64
61
Synthetic leather
furniture
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
58
82
103
285
480
406
406
Furnishing, Cleaning,
Treatment/Care Products:
Floor coverings; construction
and building materials
covering large surlace areas
including stone, plaster,
cement, glass, and ceramic
articles; fabrics, textiles, and
apparel
Vinyl flooring
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
94
100
108
150
221
214
212
Wallpaper (in-place)
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
72
79
86
116
163
162
395
Wallpaper (installation)
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
100
103
98
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Life Cycle Stage: COU:
Subcategory
Product or Article
Exposure
Level
(H, M, L) a
Exposure Scenario
Lifestage (Years)
MOE (Based on All Exposures in Index Chemical Equivalents)
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Preschooler
(3-5 years)
Middle
Childhood
(6-10
years)
Young
Teen
(11-15
years)
Teenager
(16-20
years)
Adult
(21+
years)
Furnishing, Cleaning,
Treatment/Care Products:
Cleaning and furnishing care
products
Spray cleaner
H
Dermal (COU alone)
-
-
-
-
28
31
29
Inhalation (COU alone)
66,922 d
71,040 d
87,390 d
125,504 d
37,467
47,754
55,143
Aggregate (COU alone)
-
-
-
-
28
31
29
Cumulative (NHANES)
194
194
194
286
482
407
407
Cumulative (Aggregate COU +
Cumulative NHANES)
194
194
194
285
21c
29 4
21c
M
Dermal (COU alone)
-
-
-
-
113
123
115
Inhalation (COU alone)
141,507rf
150,215 d
184,788 d
265,379 d
77,062
95,900
113,066
Aggregate (COU alone)
-
-
-
-
113
123
115
Cumulative (NHANES)
194
194
194
286
482
407
407
Cumulative (Aggregate COU +
Cumulative NHANES)
194
194
194
285
91
95
90
Waxes and polishes
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
194
194
194
285
14c
15 c
14c
Packaging, paper, plastic,
toys hobby products: Ink,
toner, and colorant products
No consumer products identified. Foreseeable uses were matched with adhesives for small repairs because similar use patterns are expected.
Packaging, Paper, Plastic,
Hobby Products: Packaging
(excluding food packaging),
including rubber articles;
plastic articles (hard); plastic
articles (soft)
Footwear components
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
46
51
57
74
100
103
98
Shower curtains
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
122
129
135
189
286
266
261
Small articles with semi
routine contact;
miscellaneous items
including a pen, pencil
case, hobby cutting
board, costume jewelry,
tape, garden hose,
disposable gloves, and
plastic bags/pouches
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
74
81
88
118
166
165
159
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Lite Cycle Stage: COU:
Subcategory
Exposure
Lit'estage (Years)
MOE (Based on All Exposures in Index Chemical Equivalents)
(Benchmark MOE = 30)
Product or Article
Level
(H, M, L) a
Exposure Scenario
Infant
(<1
Year)
Toddler
(1-2
Years)
Preschooler
(3-5 years)
Middle
Childhood
(6-10
years)
Young
Teen
(11-15
years)
Teenager
(16-20
years)
Adult
(21+
vears)
Dermal (COU alone)
112
131
151
188
237
260
-
Ingestion (COU alone)
52
197
382
84,935
151,691
191,207
427,072
Inhalation (COU alone)
693
735
904
1,299
1,841
2,150
2,678
H
Aggregate (COU alone)
34
71
97
164
210
231
2,661
Cumulative (NHANES)
194
194
194
286
482
407
407
Children's toys (new)
Cumulative (Aggregate COU +
Cumulative NHANES)
29 4
52
65
104
146
148
353
Dermal (COU alone)
140
163
189
234
296
324
-
Ingestion (COU alone)
177
444
1,323
344,795
615,767
776,168
1,733,372
Packaging, Paper, Plastic,
Inhalation (COU alone)
2,821
2,994
3,683
5,290
7,499
8,758
10,908
Hobby Products: Toys,
Playground, and Sporting
Equipment
M
Aggregate (COU alone)
76
115
158
224
285
312
10,840
Cumulative (NHANES)
194
194
194
286
482
407
407
Cumulative (Aggregate COU +
Cumulative NHANES)
55
72
87
126
179
177
392
Children's toys (legacy)
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
21c
31
39
60
85
91
161
Tire crumb
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
-
-
194
286
482
407
407
Small articles with semi
routine contact;
miscellaneous items
including a football,
balance ball, and pet toy
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
74
81
88
118
166
165
159
Other Uses:
Chemiluminescent light
sticks
Small articles with semi
routine contact; glow
sticks
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
74
81
88
118
166
165
159
Other Uses: Automotive
products, other than fluids
Car mats
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
194
194
194
285
379
336
333
Synthetic leather seats
(see synthetic leather
furniture)
H
Cumulative (Aggregate COU +
Cumulative Non-attributable)
58
82
103
285
480
406
406
Other Uses: Novelty articles
Adult toys
H
Cumulative (Aggregate COU +
Cumulative NHANES)
-
-
-
-
-
268
262
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Life Cycle Stage: COU:
Subcategory
Product or Article
Exposure
Level
(H, M, L) a
Exposure Scenario
Lifestage (Years)
MOE (Based on All Exposures in Index Chemical Equivalents)
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Preschooler
(3-5 years)
Middle
Childhood
(6-10
years)
Young
Teen
(11-15
years)
Teenager
(16-20
years)
Adult
(21+
years)
Other uses: Lubricants and
lubricant additives
No consumer products identified. Foreseeable uses were matched with adhesives for small repairs because similar use patterns are expected.
"Exposure scenario intensities include high (H), medium (M), and low (L).
4 MOEs for this age group are <30 in the cumulative assessment, but not the individual DBP risk assessment.
c MOEs for this age group are <30 in both the cumulative and individual DBP risk assessment.
d MOE for bystander scenario.
* Scenario was deemed to be unlikely due to high uncertainties.
4749
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4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
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4.4.6 Cumulative Risk Estimates for the General Population
For DBP, EPA did not evaluate cumulative risk for the general population from environmental releases.
As discussed in Section 4.1.3, the Agency employed a screening level approach to assess risk from
exposure to DBP for the general population from environmental releases. However, as discussed in
Section 4.4.2, EPA did evaluate cumulative exposure and risk from exposure to phthalates DEHP, DBP,
BBP, DIBP, and DINP using NHANES urinary biomonitoring data. As noted previously, the NHANES
biomonitoring dataset is a national, statistical representation of the general, non-institutionalized,
civilian U.S. population and provides estimates of average aggregate exposure to individual phthalates.
As can be seen from Table 4-21, and as discussed in more detail in the Revised Draft Technical Support
Document for the Cumulative Risk Analysis of DEHP, DBP, BBP, DIBP, DCHP, and DINP Under
TSCA (U.S. EPA. 2025x1 95th percentile cumulative MOEs ranged from 194 to 592 (cumulative
benchmark = 30) for females of reproductive age and male children. These MOEs indicate both that the
risk cup is 6.2 to 15.5 percent full and that cumulative exposure to DEHP, DBP, DIBP, BBP, and DINP,
based on the most recent NHANES survey data (2017-2018), does not currently pose a risk to most
male children or pregnant women within the U.S. civilian population.
4.5 Comparison of Single Chemical and Cumulative Risk Assessments
In support of the developed CRA, EPA has relied substantially on existing CRA-related work by the
Agency's Risk Assessment Forum (RAF), EPA Office of Pesticide Programs (OPP), the Organisation
for Economic Co-operation and Development (OECD), the European Commission, and the World
Health Organization (WHO) and International Programme on Chemical Safety (IPCS):
• Guidelines for the Health Risk Assessment of Chemical Mixtures ( !6);
• Guidance for Identifying Pesticide Chemicals and Other Substances that Have a Common
Mechanism of Toxicity (U.S. EPA. 1999);
• Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures (
00);
• General Principles for Performing Aggregate Exposure and Risk Assessments ( [);
• Guidance on Cumulative Risk Assessment of Pesticide Chemicals that Have a Common
Mechanism of Toxicity ( ?02a);
• Framework for Cumulative Risk Assessment ( )03);
• Concepts, Methods and Data Sources for Cumulative Health Risk Assessment of Multiple
Chemicals, Exposures, and Effects: A Resource Document ( 07a);
• Pesticide Cumulative Risk Assessment: Framework for Screening Analysis Purpose (U.S. EPA.
2016b);
• Advances in Dose Addition For Chemical Mixtures: A White Paper ( $b).
• Phthalates and Cumulative Risk Assessment: The Tasks Ahead (NRC. 2008);
• State of the Art Report on Mixture Toxicity (Kortenkamp et ai. 2009);
• Risk Assessment of Combined Exposure to Multiple Chemicals: A WHO/IPCS Framework (Meek
et ai. 2011); and
• Considerations for Assessing the Risks of Combined Exposure to Multiple Chemicals (
2018).
EPA has evaluated risks for workers (Section 4.3.2), consumers (Section 4.3.3), and the general
population (Section 4.3.4) from exposure to DBP alone, as well as cumulative risks for workers (Section
4.4.4) and consumers (Section 4.4.5) that take into account differences in relative potency and
cumulative non-attributable exposure to DEHP, DBP, BBP, DIBP, and DINP from NHANES
biomonitoring and reverse dosimetry.
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There are several notable differences between the individual DBP assessment (Section 4.3) and the CRA
(Section 4.4). As part of the individual DBP assessment (Section 4.3), EPA considered all human health
hazards of DBP and selected a POD based on a BMDLs for reduced fetal testicular testosterone to
characterize risk from exposure to DBP. As part of its exposure assessment in the individual DBP
assessment, EPA considered acute, intermediate, and chronic exposures durations for a broad range of
populations—including female workers of reproductive age, average adult workers, ONUs, the general
population, and consumers of various lifestages (e.g., infants, toddlers, children, adults). Furthermore, in
the individual DBP assessment, EPA evaluated inhalation and dermal exposures to workers, as well as
consumer exposure to DBP via the inhalation, dermal, and ingestion exposure routes. In contrast, the
CRA is more focused in scope (Section 4.4). First, the CRA is based on a uniform measure of hazard
(i.e., reduced fetal testicular testosterone) that serves as the basis for deriving RPFs and the index
chemical (DBP) POD, which were derived via meta-analysis and BMD modeling (Section 4.4.1).
Second, the CRA is focused on acute duration exposures and the most sensitive populations (i.e.,
females of reproductive age, male infants, male children) (Section 4.4). Finally, for the CRA, DBP
exposures from individual consumer and worker COUs were combined with non-attributable cumulative
exposure to DEHP, DBP, BBP, DIBP, and DINP from NHANES.
Both the individual DBP assessment (Section 4.3) and the CRA (Section 4.4) led to the same
conclusions regarding risk estimates for workers (Section 4.4.4). For consumers, the individual DBP
assessment (Section 4.3) and the CRA (Section 4.4) led to similar conclusions regarding risk for 21 out
of 23 product or article examples evaluated (Section 4.4.5). As discussed in Section 4.4.5, high-
intensity, acute, cumulative MOEs were less than 30 for several age groups for two product or articles
example exposure scenarios, whereas high-intensity, acute, aggregate MOEs were equal to or greater
than 30 for these age groups in the individual DBP assessment. Overall, one factor influenced
differences in risk estimates between the individual DBP assessment (Section 4.3) and the CRA (Section
4.4); that is, addition of non-attributable cumulative exposure to DEHP, DBP, BBP, DIBP, and DINP
from NHANES. Overall, this non-attributable cumulative exposure contributes 6.2 to 15.5 percent to the
risk cup, depending on the population and age group.
EPA has robust confidence in its CRA and moderate to robust confidence in its individual assessment of
DBP for workers (Section 4.3.2.1), consumers (Section 4.3.3.1), and the general population (Section
4.3.4). RPFs used to scale for relative potency were calculated based on a common hazard endpoint (i.e.,
reduced fetal testicular testosterone) using data from multiple studies evaluating effects of phthalates on
fetal testicular testosterone using a meta-analysis and BMD modeling approach for each of the six
phthalates included in the cumulative chemical group ( E025x). This analysis provides a
robust basis for assessing the dose-response for the common hazard endpoint (i.e., reduced fetal
testicular testosterone) across the six toxicologically similar phthalates included in the CRA.
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4833 5 ENVIRONMENTAL RISK ASSESSMENT
DBP - Environmental Risk Assessment (Section 5):
Key Points
EPA considered all reasonably available information identified through the systematic review
process under TSCA to characterize environmental risk for DBP. The following bullets summarize
the key points.
• Aquatic species:
o RQs greater than 1 were identified with robust overall confidence from water releases
from the Waste handling, treatment, and disposal OES and the associated Disposal
COU for chronic exposure to DBP in aquatic vertebrates (RQ = 9.23) and aquatic
invertebrates (RQ = 1.18).
¦ This COU had robust overall confidence because the surface water release
estimate (and associated surface water concentrations of DBP) for its associated
OES was derived from data reported to DMR.
o RQs greater than 1 were identified for the PVC plastics compounding OES and
associated COUs for chronic exposure to DBP in aquatic vertebrates (RQ = 1.04). The
same RQ was also identified for the PVC plastics converting and recycling OES, which
used the PVC plastics compounding OES releases as a surrogate.
¦ These OESs and associated COUs had robust overall confidence because the
surface water release estimates (and associated surface water concentrations of
DBP) for its associated OES was derived from data reported to TRI. EPA does
not use RQ values as a bright4ine to determine the unreasonable risk.
o No RQs greater than 1 were identified for other OESs/COUs for aquatic species from
releases to water.
• Benthic (sediment-dwelling) species:
o No RQs greater than 1 were identified for chronic exposures to DBP in benthic
organisms from releases to sediment.
• Terrestrial species:
o No RQs greater than 1 were identified for exposures to DBP in terrestrial mammals
through trophic transfer.
o No RQs greater than 1 were identified for exposures to DBP soil invertebrates from
releases to soil.
o No RQs greater than 1 were identified for exposures to DBP in terrestrial plants from
releases to soil.
4834 5.1 Summary of Environmental Exposures
4835 EPA assessed environmental concentrations of dibutyl phthalate (DBP) in air, water, and land for use in
4836 environmental exposure (Table 5-1). The environmental exposures are described in the Draft Physical
4837 Chemistry and Fate and Transport Assessment for Dibutyl Phthalate (DBP) (U.S. EPA. 2024i) and the
4838 Draft Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
4839 Phthalate (DBP) (U.S. EPA. 2025p). DBP will preferentially sorb into sediments, soils, particulate
4840 matter in air, and in wastewater solids during wastewater treatment. High-quality studies of DBP
4841 biodegradation rates and physical and chemical properties indicate that DBP will have limited
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persistence and mobility in soils receiving biosolids. Surface water, pore water, and sediment
concentrations of DBP were modeled using VVWM-PSC. The Waste handling, treatment, and disposal
OES (refer to Table 3-2 for a crosswalk of COUs to each OES) resulted in the highest surface water
concentrations of DBP from reported releases, up to 14.40 |ig/L in both chronic (>60 days) and acute
(1-7 day) scenarios. Sediment concentrations from this OES ranged from 0.178 mg DBP/kg dry
sediment (mg/kg) in chronic scenarios to 0.334 mg/kg sediment in acute scenarios. These DMR-reported
releases are based on releases to surface water at the external outfall of a POTW; therefore, no additional
wastewater treatment removal efficiency was applied.
For the Use of lubricants and functional fluids OES, reported releases were not obtained by EPA and a
generic release to water was modeled. Based on comparison with reported scenarios for DBP
wastewater release, the Agency does not expect high releases of DBP to the lowest-flow generic
condition (P50 7Q10) water bodies. For this reason, EPA had higher confidence in the use of the P90
7Q10 flow rate for this scenario, and this rate was used in the environmental assessment for the Use of
lubricants and functional fluids OES and corresponding COUs. The use of the P90 flow rate resulted in
modeled surface water concentrations that ranged from 0.03 |ig/L in chronic (>60-day) scenarios to 2.42
|ig/L in acute (1 to 7-day) scenarios. Sediment concentrations from this OES at the P90 flow rate ranged
from 0.00065 mg/kg in chronic scenarios to 0.006 mg/kg in acute scenarios. Because all water and
sediment concentrations were below concentrations of concern for this OES and associated COUs, the
P90 flow was used without consideration of wastewater treatment removal efficiency.
Five OESs (Manufacturing, Application of adhesives and sealants, Application of paints and coatings,
Use of laboratory chemicals, and Use of penetrants and inspection fluids) had modeled releases from
generic scenarios for multimedia discharges to combinations of multiple of the following parameters:
water, wastewater (POTW), incineration, landfill, and air. For these OESs, there was insufficient
information to determine the fraction of the release going to each of the reported media types, including
to surface water. For these OESs, surface water, pore water, and sediment concentrations of DBP were
estimated using VVWM-PSC and assuming a conservative scenario in which all of the multimedia
releases were to surface water. Based on comparison with reported scenarios for DBP wastewater
release, EPA does not expect high releases of DBP to the lowest-flow generic condition (P50 7Q10)
water bodies. For this reason, the Agency had higher confidence in the use of the P90 7Q10 flow rate for
this scenario and this rate was used in the environmental assessment. The use of the P90 flow rate
resulted in modeled surface water concentrations for the highest OES (Manufacturing) that were up to
4.00 |ig/L in both chronic (>60-day) and acute (1 to 7-day) scenarios without wastewater treatment.
Because these generic scenarios did not include wastewater treatment and some water concentrations
were above concentrations of concern, as an additional refinement wastewater treatment removal
efficiency was applied. Concentrations ranged between 0.080 |ig/L and 1.40 |ig/L with wastewater
treatment based on estimated wastewater treatment removal efficiency of 65 to 98 percent (U.S. EPA.
1982) (Table 2-2). Sediment concentrations from these OESs at the P90 flow rate ranged from 0.0499
mg/kg in chronic scenarios to 0.093 mg/kg in acute scenarios.
There are uncertainties in the relevance of limited monitoring data for biosolids and landfill leachate to
the COUs considered. However, based on high-quality physical and chemical property data, EPA
determined that DBP will have low persistence potential and mobility in soils. Therefore, groundwater
concentrations resulting from releases to the landfill or to agricultural lands via biosolids applications
were not quantified but were discussed qualitatively. Air releases of DBP from fugitive and stack
emissions with deposition to soil were estimated using IIOAC, as described in Section 8.1.3 of the Draft
Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
Phthalate (DBP) ( 025p). The highest annual deposition rate to soil, 1.78 |ig/kg/year
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(0.00178 mg/kg/year), was based on a combination of fugitive emissions from the Application of paints,
coatings, adhesives, and sealants OES and stack emissions from the Waste handling, treatment, and
disposal OES and was located 100 m from the point of release. These releases were combined to form a
single highest-emissions scenario for the screening analysis (see Section 4.1.3). Based on the half-life of
DBP in soil, equilibrium soil concentrations from air releases are expected to be lower than this
deposition rate (see Section 5.3.2).
Limited measured data were reasonably available from the scientific literature on DBP concentrations in
soils, biosolids, soils receiving biosolids, and landfills. No monitoring data of DBP in these
environments were reasonably available. Limited reasonably available information was available related
to the uptake and bioavailability of DBP in soils. DBP is expected to have minimal air to soil deposition.
Based on estimated water solubility (11.2 mg/L) and hydrophobicity (log Kow = 4.5; log Koc = 3.14—
3.94), DBP is expected to have low bioavailability in soil. Based on the reasonably available evidence,
trophic transfer of DBP in aquatic or terrestrial organisms is not expected and DBP has low
bioaccumulation and biomagnification potential.
Table 5-1. DBP Concentrations Used in Environmental Risk Characterization
OES"
Release
Media
Environmental Media
DBP Concentration
Data Source
Acute
(1-7 days)
Chronic
(>60 days)
Waste handling,
treatment, and
disposal
Water
Total water column (7Q10) b
14.40 jig/L
14.40 jig/L
DMR
(reported
release)
Sediment
Benthic sediment (7Q10)
0.334 mg/kg
0.178 mg/kg
PVC plastics
compounding
Water
Total water column (7Q10)
1.63 jig/L
1.63 jig/L
Sediment
Benthic sediment (7Q10)
0.038 mg/kg
0.022 mg/kg
Use of
lubricants and
functional fluids
Water
Total water column (7Q10), P50
flow c
703 jig/L
7.38 jig/L
Generic
release
(wastewater)
P75 flow
41 Mg/L
0.57 jig/L
P90 flow
2.42 jig/L
0.03 jig/L
Sediment
Benthic sediment (7Q10), P50 flow
1.71 mg/kg
0.188 mg/kg
P75 flow
0.146 mg/kg
0.015 mg/kg
P90 flow
0.006 mg/kg
0.00065 mg/kg
Manufacturing
Water
Total water column (7Q10), P50
flow c
1,160 jig/L
1,160 jig/L
Generic
release
(multimedia)
P75 flow
67.80 jig/L
67.80 jig/L
P90 flow, no wastewater treatment
4.00 ng/L
4.00 jig/L
P90 flow, 65% wastewater
treatment efficiency
1.40 jig/L
1.40 jig/L
P90 flow, 98% wastewater
treatment efficiency
0.080 (ig/L
0.080 (ig/L
Sediment
Benthic sediment (7Q10), P50 flow
27.0 mg/kg
14.5 mg/kg
P75 flow
1.57 mg/kg
0.839 mg/kg
P90 flow
0.093 mg/kg
0.0499 mg/kg
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OES"
Release
Media
Environmental Media
DBP Concentration
Data Source
Acute
(1-7 days)
Chronic
(>60 days)
Application of
paints and
coatings (no
spray control)
Water
Total water column (7Q10), P50
flow c
920 |_ig/L
920 |_ig/L
Generic
release
(multimedia)
P75 flow
53.6 (ig/L
53.6 (ig/L
P90 flow, no wastewater treatment
3.17 (ig/L
3.17 (ig/L
P90 flow, 65% wastewater
treatment efficiency
1.11 (ig/L
1.11 (ig/L
P90 flow, 98% wastewater
treatment efficiency
0.063 (ig/L
0.063 (ig/L
Sediment
Benthic sediment (7Q10), P50 flow
21.3 mg/kg
11.4 mg/kg
P75 flow
1.24 mg/kg
0.664 mg/kg
P90 flow
0.073 mg/kg
0.039 mg/kg
Fugitive:
application of
paints, coatings,
adhesives, and
sealants; stack:
waste handling,
treatment, and
disposal
Air
deposition
to soil
Annual deposition rate to soil
1.78 (ig/kg/yr (0.00178
mg/kg/yr)
NEI/TRI
(Reported
release)
"Table 3-1 provides the crosswalk of OES to COUs.
b 7Q10 is the 7 consecutive days of lowest flow over a 10-year period.
c The P50, P75, and P90 flows refer to the 50th, 75th, and 90th percentiles of the distribution of water body flow rates in
generic release scenarios; see Appendix B of the Draft Environmental Media, General Population, and Environmental
Exposure Assessment for Dibutyl Phthalate (DBP) (U.S. EPA, 2025p).
5.2 Summary of Environmental Hazards
EPA evaluated the reasonably available information for environmental hazard endpoints associated with
DBP exposure to ecological receptors in aquatic and terrestrial ecosystems. The Agency reviewed a total
of 98 references for DBP environmental hazard. Nine references included toxicity information for more
than one taxonomic group; therefore, the number of studies considered by taxonomic group sums to
more than 98. These references included acute and chronic exposures via water, soil, sediment, and
food. EPA reviewed 68 studies for toxicity to aquatic organisms. Of these aquatic studies, 55 met the
criteria for consideration for development of hazard thresholds. EPA reviewed 35 studies for toxicity to
terrestrial wildlife organisms, including plants. Of these terrestrial studies, 30 met the criteria for
consideration for development of hazard thresholds. In addition to the 30 high or medium quality
terrestrial wildlife studies, EPA considered 13 terrestrial vertebrate studies for toxicity to DBP in human
health using animal model rodent species that contained ecologically relevant reproductive endpoints.
Studies that were excluded from consideration either (1) received a data quality determination of low or
uninformative, (2) demonstrated no acute or chronic effects up to the highest dose tested, (3) did not
demonstrate any apical health effects, or (4) did not demonstrate any health effects up to the limit of
DBP solubility in water as determined by EPA at 1 1.2 mg/L (U.S. EPA. 20241). Overall confidence in
the hazard values for each taxonomic group and duration is provided in this section; for more
information on the weight of scientific evidence, including the strengths and limitations of the data that
led to these overall confidence conclusions, see Section 2.4 of the Draft Environmental Hazard
Assessment for Dibutyl Phthalate (DBP) (1 c< < i1 \ J024c).
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Acute Aquatic Vertebrates, Aquatic Invertebrates, and Benthic Invertebrates
EPA has robust confidence that DBP has acute effects on aquatic vertebrates, aquatic invertebrates, and
benthic invertebrates in the environment. This robust confidence is supported by a species sensitivity
distribution (SSD) incorporating 9 empirical studies with mortality endpoints, supplemented by 53
estimated acute toxicity values from Web-ICE version 4.0. EPA estimated the HCos to obtain a
concentration that would protect 95 percent of aquatic species from acute effects. Based on the HCos
derived from the SSD, the acute concentration of concern (COC) for acute effects on aquatic vertebrates
and invertebrates is 347.6 |ig/L DBP.
Chronic Aquatic Vertebrates
EPA has robust confidence that DBP has chronic effects on aquatic vertebrates in the environment. This
robust confidence is supported by eleven studies in which effects on mortality, growth, reproduction,
and development were observed in five fish species and two amphibian species. The COC was derived
from a multigenerational study in Japanese medaka (Oryzias latipes) (EAG Laboratories. 2018). In this
study, the growth of the F1 and F2 generations of fish was significantly affected by exposure to DBP.
There was a significant inhibition of body weight in F1 generation males at the lowest concentration
studied after exposure of the F0 generation through spawning, plus 112 days of exposure in the F1
generation, with an unbounded lowest-observed-effect concentration (LOEC) value of 15.6 |ig/L DBP.
After applying an assessment factor (AF) of 10 (I v H \ < l I, 2012a). the chronic COC for
aquatic vertebrates is 1.56 |ig/L DBP.
Chronic Aquatic Invertebrates
EPA has robust confidence that DBP has chronic effects on aquatic invertebrates in the environment.
This robust confidence is supported by 8 studies in which effects on mortality, growth, reproduction, and
development were observed in 10 species. The COC was derived from a 14-day study in the marine
amphipod crustacean Monocorophium acheruscicum (Taeatz et ai. 1983). In this study, a 14-day
chronic value (ChV) of 122.3 |ig/L DBP was observed for reduction in population abundance.
Populations were reduced by 91 percent at the LOEC, which was 340 |ig/L DBP. Higher doses resulted
in a complete loss of amphipods in the aquaria. This study was rated medium quality. Based on the
presence of a clear dose-response relationship and a population-level fitness endpoint, the 14-day ChV
for reduction in population abundance in the marine amphipod crustacean was selected to derive the
chronic COC for aquatic invertebrates. After applying an AF of 10 (1 c. « ^ \ JO I * v, :01 I, JO I Ja), the
chronic COC for aquatic invertebrates is 12.23 |ig/L DBP.
Chronic Benthic Invertebrates
EPA has robust confidence that DBP has chronic effects on benthic invertebrates in the environment.
This robust confidence is supported by five studies in which effects on mortality, growth, and
development were observed in six species. The COC was derived from a 10-day study in the midge
(Chironomus tentans) (Lake Superior Research Institute. 1997). In this study, a 10-day ChV at 1,143.3
mg DBP/kg dry sediment in medium total organic carbon (TOC) sediments (4.80% TOC) was observed
for population loss. This study was rated high quality. This ChV was the middle of three for the midge;
the experiment was repeated with low, medium, and high TOC sediments and toxicity decreased with
the increase in TOC, as expected for a relatively hydrophobic compound like DBP based on equilibrium
partitioning theory. The chosen endpoint for deriving the COC, medium-TOC, was selected because it is
the closest to the assumed TOC level (4%) used in Point Source Calculator to estimate DBP exposure in
benthic organisms. Population was reduced by 76.7 percent at the LOEC, which was 3,090 mg DBP/kg
dry sediment. Higher doses resulted in a similar degree of population loss in the medium-TOC
treatment; however, all population losses were significantly different from controls (p < 0.05, one-way
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4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
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ANOVA with Dunnett's test). This endpoint was considered acceptable to derive a COC because of
population-level relevance and a demonstrated dose-response relationship. After applying an AF of 10 to
the ChV at 1,143.3 mg/kg ( 16c. 2014. 2012a). the chronic COC for benthic invertebrates is
114.3 mg DBP/kg dry sediment.
Aquatic Plants and Algae
EPA has moderate confidence that DBP has adverse effects on aquatic plants and algae in the
environment. This moderate confidence is supported by seven high/medium quality studies, of which
three identified hazard values below the DBP limit of water solubility, for one species of green algae
(Selenastrum capricornutum). The COC was derived from a 96-hour study in green algae (Adachi et ai.
2006). In this study, a 96-hour ChV of 3 16 |ig/L DBP was observed for reduced population abundance.
This study was rated medium quality. There was significant reduction in the algal population at the
LOEC, which was 1,000 |ig/L DBP, relative to an increase in the algal population at the NOEC of 100
|ig/L DBP and in controls. The population reduction was increased with a higher dose of DBP.
Therefore, this endpoint was considered acceptable to derive a COC because of population-level
relevance and a demonstrated dose-response relationship. After applying an AF of 10 (
2014. 2012a). the COC for aquatic plants and algae is 3 1.6 |ig/L DBP.
Terrestrial Vertebrates
EPA has moderate confidence that DBP has adverse effects on terrestrial vertebrates in the environment.
This moderate confidence is supported by thirteen studies in which effects on reproduction were
observed in rats (Rattus norvegicus) and mice (Mus musculus). Two additional studies examined DBP
exposure to eggs in the chicken (Gallus gallus) and the Japanese quail (Coturnix japonica), but no
adverse effects were observed at any dose. The hazard value (HV) was derived from a three-generation
reproduction study (NT 5) in the Sprague-Dawley rat. In this study, a 17-week LOAEL was
observed for significant reduction in number of live pups per litter at 80 mg/kg-bw/day DBP intake in
dams. This study was rated high quality. The above referenced study also found a LOAEL for reduced
bodyweight in F2 pups at the same dose (80 mg/kg-bw/day). The lowest bounded NOAEL/LOAEL pair
for which a ChV could be calculated was significantly reduced bodyweight in F1 pups at a ChV of 115.4
mg/kg-bw/day, but this effect was not as sensitive as reduced number of live pups per litter. Other
effects of DBP exposure included significantly decreased (1) female body weight in dams, (2) male sex
ratio (percentage of male pups), (3) mating index and pregnancy index in the F1 generation, and (4)
reduced male pup weight gain. Based on reduction in live pups per litter, the results found in NTP
(1995) indicated that the HV for toxicity in terrestrial vertebrates is 80 mg/kg-bw/day DBP.
Soil Invertebrates
EPA has robust confidence that DBP has adverse effects on soil invertebrates in the environment. This
robust confidence is supported by two studies in which effects on mortality and reproduction were
observed in two species. The HV was derived from a 21-day study in the springtail (Folsomiafimetaria)
(Jensen et ai. 2001). with an EC 10 of 14 mg DBP/kg dry soil for reduced reproduction. This study was
rated high quality. Reproduction was reduced by approximately 60 percent at the lowest concentration
tested, which was 100 mg DBP/kg dry soil, with reproduction completely eliminated at higher doses.
Based on an EC10 for reduced reproduction in the springtail, the HV for soil invertebrates is 14 mg
DBP/kg dry soil.
Terrestrial Plants
EPA has moderate confidence that DBP has adverse effects on terrestrial plants in the environment. This
moderate confidence is supported by 12 studies, of which 6 contained acceptable endpoints below the
limit of water solubility for DBP that identified effects on growth in 10 species. The HV was derived
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from a 40-day exposure in bread wheat (Triticum aestivum) (Gao et ai. 2019). The lowest-observed-
adverse-effect-level (LOAEL) in this study for reduction in leaf and root biomass in bread wheat
seedlings was 10 mg/kg dry soil. There was a clear dose-response observed, with biomass reduction
increasing as the dose of DBP increased. At the highest dose (40 mg/kg), root and leaf biomass were
reduced by 29.93 and 32.10 percent, respectively. Because the most sensitive endpoint in this study was
an unbounded LOAEL, the actual threshold dose might have been lower than the lowest dose studied.
However, no information was available in the study to adjust the value to account for this uncertainty.
The HV for terrestrial plants for DBP derived from this study is 10 mg/kg dry soil.
5.3 Environmental Risk Characterization
5.3.1 Risk Assessment Approach
The environmental risk characterization of DBP was conducted to evaluate whether the potential
releases and resultant exposures of DBP in water, air, or soil will exceed the DBP concentrations
observed to result in hazardous effects to aquatic or terrestrial organisms. In evaluating the DBP
exposure concentrations, monitored and modeled DBP concentrations in surface water were used
quantitatively. Concentrations of DBP in soil (biosolids, landfills, air deposition) and air is limited or is
not expected to be bioavailable and were used qualitatively. In evaluating the environmental hazard of
DBP, a weight of evidence approach (U.S. EPA. 2021a) was used to select hazard threshold
concentrations for the derivation of risk quotients for aquatic organisms. The weight of evidence
approach was also used to select hazard threshold concentrations for a description of risk for terrestrial
organisms.
Environmental risk was characterized by calculating risk quotients or RQs ( ; Barnthouse
etai. 1982). The RQ is defined in Equation 5-1 below.
Equation 5-1. Calculating the Risk Quotient
Predicted Environmental Concentration
^ Hazard Threshold
For aquatic organisms, the "effect level" is a derived COC based on a hazard effects concentration. The
COC used to calculate RQs for aquatic organisms was derived from hazard values resulting from acute
and chronic exposures to DBP. The benchmark value for RQs in environmental risk characterization is
1. An RQ equal to 1 indicates that the exposures are the same as the concentration that causes effects. If
the RQ exceeds 1, the exposure is greater than the effect concentration. If the RQ is less than 1, the
exposure is less than the effect concentration.
In addition to modeled environmental concentrations from releases of DBP (Section 3.3), environmental
monitoring and biomonitoring data were reviewed to assess wildlife exposure to DBP (
2025p). EPA qualitatively assessed the potential for trophic transfer of DBP through food webs to
wildlife using the available environmental monitoring information and physical and chemical properties.
DBP is not expected to be persistent in the environment as it is expected to degrade rapidly under most
environmental conditions (although there is delayed biodegradation in low-oxygen media); and DBP's
bioavailability is expected to be limited ( 2024i). DBP is expected to have low
bioaccumulation potential, biomagnification potential, and low potential for uptake based on estimated
log BCF (bioconcentration factor) of 2.02 to 2.35 and a log BAF (bioaccumulation factor) of 2.20 to
2.37.
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5.3.2 Risk Estimates for Aquatic and Terrestrial Species
EPA expects the main environmental exposure pathways for DBP to be releases to surface water and
subsequent deposition to sediment, and limited dispersal from fugitive and stack air release deposition to
soil. The Agency calculated an RQ for aquatic and benthic organisms based on modeled environmental
surface water and sediment DBP concentrations and for terrestrial organisms based on modeled soil
concentrations via air deposition near facilities releasing DBP. A summary of relevant exposure
pathways to receptors and resulting qualitative risk estimates is presented in Table 5-2. EPA used a
screening approach, followed by refinement if appropriate, to characterize environmental risk; an RQ for
the highest reference environmental concentration was first calculated for each receptor group, and if the
RQ did not exceed the benchmark value of 1 then no further RQs were calculated. If the RQ exceeded
the benchmark, then refinements were applied to the screening environmental concentration if
appropriate. The risk characterization proceeded to the next-highest releasing COU/OES until the
resulting RQs were less than 1 or all COU/OESs were characterized. Wastewater treatment removal was
applied as a refinement to the approach for generic scenario COU/OES where such treatment was not
already reflected in estimated surface water releases if RQs greater than 1 were identified without
treatment. For non-POTW TRI Form R or DMR-reported COU/OES, reported surface water releases are
based on releases offsite (TRI Form R) or monitoring at the outfall to surface water (DMR) and already
reflect any applicable pretreatment and wastewater treatment, and no additional wastewater treatment
removal was applied (see Section 2.3.3.1 of the Draft Environmental Release and Occupational
Exposure Assessment for DibutylPhthalate (DBP) ( 2025q).
Table 5-2. Exposure Pathway to Receptors and Corresponding Risk Assessment for the DBP
Environmental Risk C
laracterization
Exposure Pathway
Receptor
Risk Assessment
Surface water
Acute exposure to aquatic and benthic
organisms (aquatic and benthic vertebrates
and invertebrates)
No RQ >1 identified
Chronic exposure to aquatic vertebrates
RQ 9.23 for Waste handling,
treatment, and disposal; 1.04
for PVC plastics compounding
Chronic exposure to aquatic invertebrates
RQ 1.18 for Waste handling,
treatment, and disposal
Chronic exposure to benthic invertebrates
No RQ >1 identified
Aquatic plants and algae
No RQ >1 identified
Sediment
Benthic organisms
No RQ >1 identified
Air deposition to soil
Soil invertebrates; terrestrial plants
No RQ >1 identified
Trophic transfer
Aquatic and terrestrial organisms
Qualitative; No RQ calculated
Biosolids
Terrestrial mammal
Qualitative; No RQ calculated
Landfills
Terrestrial mammal
Qualitative; No RQ calculated
Surface Water
COCs were derived for several aquatic receptors in surface water for DBP, including acute and chronic
exposures to aquatic vertebrates, aquatic invertebrates, and benthic invertebrates, and aquatic plants and
algae.
Acute Exposure to Aquatic and Benthic Organisms: The COC for acute exposure to aquatic organisms,
including aquatic and benthic vertebrates and invertebrates, was derived from an SSD containing
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empirical and modeled hazard data for more than 50 organisms ( 024c) and is 347.6 |ig/L
DBP. This acute COC for mortality is based on 96 hours of exposure. The reference value for water
concentration, based on the high-end release in the Waste handling, treatment, and disposal OES, is
14.40 |ig/L over a 4-day averaging time, and the resulting RQ is 0.04. Risk quotients did not exceed 1
for acute exposures to aquatic and benthic organisms for this OES and all others with lower estimated
water concentrations.
Chronic Exposure to Aquatic Vertebrates: The COC for chronic exposure to aquatic vertebrates was
derived from a 112-day exposure in a multigenerational study in Japanese medaka (Oryzias latipes)
( iboratories. 2018) and is 1.56 |ig/L DBP. EPA calculated RQs exceeding 1 for chronic exposure
to aquatic vertebrates at the high end of estimated releases for the Waste handling, treatment, and
disposal, Application of paints and coatings, and PVC plastics compounding OESs, with RQ of 9.23 and
1.04, respectively. RQs also exceeded 1 for the PVC plastics converting OES and Recycling OES,
which used the PVC plastics compounding OES releases as a surrogate.
Chronic Exposure to Aquatic Invertebrates: The COC for chronic exposure to aquatic invertebrates was
derived from a 14-day study in the marine amphipod crustacean Monocorophium acheruscicum (Taeatz
et ai. 1983) and is 12.23 |ig/L DBP. EPA calculated RQs exceeding 1 for chronic exposure to aquatic
invertebrates at the high end of estimated releases for the Waste handling, treatment, and disposal OES,
with an RQ of 1.18.
Aquatic Plants and Algae: The COC for exposure to aquatic plants and algae was derived from a 96-
hour study in green algae (Se/enastrum capricornutum) (Adachi et ai. 2006) and is 31.6 |ig/L DBP. The
reference value for water concentration, based on the high-end release in the Waste handling, treatment,
and disposal OES, is 14.40 |ig/L over a 4-day averaging time, and the resulting RQ is 0.46. Risk
quotients did not exceed 1 for exposures to aquatic plants and algae for this OES and all others with
lower estimated water concentrations.
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5130 Table 5-3. Environmental Risk Quotients (RQs) for Aquatic Organisms Associated with Surface
5131 Water Releases of DBP
OES
DBP
Concentration
(Hg/L)
Receptor
Exposure
Duration
Hazard Value
(Hg/L)
Risk
Quotient
Overall
Confidence
Waste handling,
treatment, and
disposal"; high-end
14.40 (4-day
average)
SSD'': Acute
aquatic and
benthic organisms
4 days
347.6
0.04
Robust
Waste handling,
treatment, and
disposal; High-end
14.40 (286-day
average)
9.23
Robust
Manufacturing17 d;
high-end
1.40 (286-day
average), 65%
wastewater
treatment
efficiency
Japanese medaka
(Oryzias latipes),
Chronic aquatic
vertebrates
112 days
0.90
Moderate
Application of paints
and coatings'7high
end
1.11 (286-day
average), 65%
wastewater
treatment
efficiency
1.56
0.71
Moderate
PVC plastics
compounding; PVC
plastics compounding^
g; high-end
1.63 (246-day
average)
1.04
Robust
Waste handling,
treatment, and
disposal; high-end
14.40 (21-day
average)
Marine amphipod
(Monocorophium
ache rusci cum),
chronic aquatic
invertebrates
14 days
12.23
1.18
Robust
Waste handling,
treatment, and
disposal; high-end
14.40 (4-day
average)
Green algae
(Selenastrum
capricornutum),
aquatic plants and
algae
4 days
31.6
0.46
Robust
" The associated COU fortius OES is "Disposal."
h Species sensitivity distribution; see Section 5.2.
c These OES had multimedia releases; the RQs presented here assume all multimedia releases are to surface water; see
Section 5.1.
d The associated COU for this OES is Manufacturing; domestic manufacturing.
e The associated COUs for this OES are Industrial uses; construction, paint, electrical, and metal products; paints and
coatings; Commercial uses; construction, paint, electrical, and metal products; paints and coatings; and Commercial uses;
packaging, paper, plastic, hobby products; Ink, toner and colorant products.
' The associated COU for this OES is Processing; incorporation into formulation, mixture, or reaction product; plasticizer in
paint and coating manufacturing; plastic material and resin manufacturing; rubber manufacturing; soap, cleaning compound,
and toilet preparation manufacturing; textiles, apparel, and leather manufacturing; printing ink manufacturing; basic organic
chemical manufacturing; and adhesive and sealant manufacturing.
g The PVC plastics compounding OES release was used as a surrogate for the PVC plastics converting and Recycling OESs.
The associated COUs for these OESs are Processing; incorporation into articles; plasticizer in adhesive and sealant
manufacturing; building and construction materials manufacturing; furniture and related product manufacturing; ceramic
powders; plastics product manufacturing; and rubber product manufacturing; and Recycling, respectively.
5132
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Sediment
DBP is expected to partition primarily to soil and sediment, regardless of the compartment of
environmental release ( ). DBP is not expected to undergo long-range transport and is
expected to be found predominantly in sediments near point sources, with a decreasing trend in sediment
concentrations downstream due to DBP's strong affinity and sorption potential for organic carbon in
sediment. EPA's reference sediment concentrations under low flow conditions of 0.334 mg DBP/kg
sediment ( )25p). corresponding to the Waste handling, treatment, and disposal OES, reflect
the physical and chemical properties of DBP and its predicted affinity for sediment ( 2024i).
but may be overestimated due to conservative parameters and use of the VVM-PSC three compartment
model. DBP is not expected to be persistent in the environment as it is expected to degrade rapidly under
most environmental conditions with delayed biodegradation in low-oxygen media ( I024j.).
EPA derived a COC for chronic exposure to benthic organisms from a 10-day study in the midge
{Chironomus tentans) (Lake Superior Research Institute. 1997) of 114.3 mg DBP/kg sediment. Because
the screening value for sediment concentration, based on the Waste handling, treatment, and disposal
OES, is 0.334 mg/kg and the associated RQ is 0.003, EPA did not identify RQs exceeding 1 for chronic
exposure to benthic organisms in sediment.
Table 5-4. Environmental Risk Quotients (RQs) for Benthic Organisms Associated with Sediment
Releases of DBP
OES
Sediment
Concentration
(mg/kg)
Organism
Exposure
Duration
Hazard
Value
(mg/kg)
RQ
Overall
Confidence
Waste handling,
treatment, and
disposal^ high-end
0.334 (7-day
average)
Midge
(iChironomus
tentans); benthic
organism
10 days
114.3 mg/kg
0.003
Robust
a The associated COU for this OES is Disposal.
Air Deposition to Soil
Modeling results indicate a rapid decline in DBP concentrations from air deposition to soil. The
Application of paints, coatings, adhesives and sealants and Waste handling, treatment, and disposal OES
resulted in the highest fugitive and stack releases of DBP, respectively, with annual average deposition
rates to soil at 100 m of 0.268 and 0.033 mg/m2, respectively, for a total annual deposition rate of 0.302
mg/m2 This annual deposition rate corresponds to an annual contribution to average soil concentration
of 1.78 |ig/kg/yr (0.00178 mg/kg/yr). Because the biodegradation half-life of DBP in aerobic soils is on
the order of days to weeks ( 24i) and the half-life in anaerobic soils is up to 65 days
(Shanker et at.. 1985; Inman et at.. 1984). use of this annual rate as the reference soil concentration
likely overestimates the equilibrium soil concentration in the environment. Because DBP has low
bioaccumulation potential and experiences biodilution across trophic levels ( 2024i;
Mackintosh et at.. 2004). the transfer of DBP through a food web is expected to dilute in each trophic
level and will be less than the amount deposited to soil. For soil invertebrates and terrestrial plants, the
hazard value is four orders of magnitude higher than the estimated soil concentration, with RQ values of
1,27/10 4 and 1,87/10 4, respectively. EPA did not identify RQs exceeding 1 for terrestrial animals and
plants.
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Table 5-5. Environmental Risk Quotients (RQs) for Terrestrial Organisms Associated with Air
Deposition to Soil Releases of DBP
Release
Soil
Concentration
Organism
Exposure
Duration
Hazard
Value
RQ
Overall
Confidence
Fugitive: Application
of paints, coatings,
adhesives and
sealants"
Stack: Waste
handling, treatment,
and disposal6
0.00178 mg/kg
(3 65-day release)
Springtail
(Folsomia
fimetaria); soil
invertebrate
21 days
14 mg/kg
1.27E-04
Robust
Bread wheat
(Triticum
aestivum);
terrestrial plant
40 days
10 mg/kg
1.78E-04
Robust
a The associated COU for this OES is Industrial/commercial use; construction, paint, electrical, and metal products;
adhesives and sealants/paints and coatings.
b The associated COU for this OES is Disposal.
Landfill (to Surface Water, Sediment)
Due to its high affinity for organic carbon and organic media (log Koc = 3.14-3.94; log Kow = 4.5),
DBP is expected to be present at low concentrations in landfill leachate. No studies have directly
evaluated the presence of DBP in landfill or waste leachate. DBP that may present in landfill leachates is
not expected to be mobile in receiving soils and sediments due to its high affinity for organic carbon. No
studies were identified which reported the concentration of DBP in landfills or in the surrounding areas.
There is limited information regarding DBP in dewatered biosolids, which may be sent to landfills for
disposal. DBP has been identified in U.S.-based and international surveys of wastewater sludge. A 2012
survey of North American wastewater plants (Canada and United States) identified DBP in sludge at
concentrations ranging from 1.7 to 1,260 ng/g dry weight (Ikonomou et ai. 2012). These concentrations
were well below hazard values for benthic organisms (114.3 mg/kg; 1 ng/g is equivalent to 0.001 mg/kg)
and below concentrations that might be expected to transfer up the food web via trophic transfer and
potentially affect terrestrial organisms. DBP is not likely to be persistent in groundwater/subsurface
environments unless anoxic conditions exist. As a result, the qualitative evidence indicates that DBP
migration from landfills to surface water and sediment is limited and not likely to lead to environmental
concentrations that exceed hazard values for aquatic and terrestrial organisms. For the same reasons,
DBP from down-the-drain disposal of consumer products or landfill disposal of consumer articles is not
likely lead to environmental concentrations that exceed hazard values for aquatic and terrestrial
organisms (see Section 3.1.4 for further details on the qualitative assessment of consumer disposal of
DBP-containing products and articles).
Biosolids
A 2012 survey of North American wastewater plants (Canada and United States) identified DBP in
wastewater sludge at concentrations ranging from 1.7 to 1,260 ng/g dry weight (Ikonomou et ai. 2012).
Post-aerobic treatment of activated sludges has been shown to reduce the concentration of DBP (100%
removal) and other phthalates (11-100% removal) (Tomei et ai. 2019). There are currently no U.S.-
based studies reporting DBP concentration in biosolids or in soil following land application. DBP
containing sludge and biosolids have not been reported for uses in surface land disposal or agricultural
application.
DBP is not expected to be persistent in topsoil if it is applied to land through biosolids applications.
Several academic studies have reported on degradation of DBP in aerobic soils. The half-life of DBP in
anaerobic soils range from less than 1 day to 19 days (Cheng et ai. 2018; Zhao et ai. 2016; Yuan et ai.
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2011: Xu et al. 2008; Wang et al. 1997; Russell et al. 1985; Shanker et al.. 1985V In mixed aerobic
and anaerobic conditions in which oxygen or terminal electron acceptors may not be readily replaced,
the degradation of DBP may be slower. Current research suggests that the half-life of DBP may be
extended to as long as 65 days under evolving aerobic conditions (Inman et al.. 1984). In strictly
anaerobic soil conditions, DBP appears to degrade under comparable rates to aerobic or evolutionary
conditions with half-lives reported from 19 to 36 days (Shanker et al.. 1985; Inman et al.. 1984). Based
on the solubility (11.2 mg/L) and hydrophobicity (log Koc = 3.14-3.94; log Kow = 4.5), DBP is not
expected to have potential for significant bioaccumulation, biomagnification, or bioconcentration in
exposed organisms.
High-end releases from industrial facilities are unlikely to be released directly to municipal wastewater
treatment plants without pretreatment or to be directly land applied following on-site treatment at the
industrial facility itself. The highest reported DBP concentrations within biosolids from reasonably
available literature (1.7-1,260 ng/g; 1 ng/g is equivalent to 0.001 mg/kg) and estimated DBP soil
concentrations following the application of biosolids to agricultural lands (up to 0.03 mg/kg; see Table
3-2 of the Draft Environmental Media, General Population, and Environmental Exposure for Dibutyl
Phthalate (DBP) (U.S. EPA. 2025p)) are several orders of magnitude below the hazard values for
benthic organisms (114.3 mg/kg), soil organisms (14 mg/kg), or terrestrial plants (10 mg/kg). These
comparisons support the qualitative assessment that potential DBP concentrations in biosolids are not
likely to lead to environmental concentrations that exceed hazard values for environmental organisms.
5.3.3 Environmental Risk Characterization Summary
Table 5-6 summarizes the environmental risk characterization for DBP. In summary, EPA's
environmental risk characterization indicates that environmental concentrations of DBP exceed hazard
values (i.e., RQ >1) for environmental organisms based on the following COUs:
• Processing; incorporation into formulation, mixture, or reaction product; plasticizer in plastic
material and resin manufacturing;
• Processing; incorporation into articles; plasticizer in adhesive and sealant manufacturing;
building and construction materials manufacturing; furniture and related product manufacturing;
ceramic powders; plastics product manufacturing; and rubber product manufacturing;
• Recycling; and
• Disposal.
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5239 Table 5-6. Environmental Risk Summary Table for DBP
Life Cycle Stage;
Category
Subcategory
OES
Organism
RQ (Benchmark = 1)
Overall
Confidence
Aquatic vertebrates,
RQ < 1 based on
Moderate
Manufacturing;
Domestic
manufacturing
Domestic manufacturing
Manufacturing
aquatic invertebrates,
benthic invertebrates,
aquatic plants and
algae
application of
wastewater treatment
efficiency (Table 2-2)
Terrestrial vertebrates,
soil invertebrates,
terrestrial plants
RQ < 1 based on
screening assessment"
Robust
Manufacturing;
Importing
Importing
Processing;
Repackaging
Laboratory chemicals in wholesale and
retail trade; plasticizers in wholesale
and retail trade; and plastics material
and resin manufacturing
Import and
repackaging
All
RQ < 1 based on
screening assessment"
Robust
Processing;
Processing as a
reactant
Intermediate in plastic manufacturing
Solvents (which become part of product
formulation or mixture) in chemical
Processing;
Incorporation into
formulation, mixture,
or reaction product
product and preparation manufacturing;
soap, cleaning compound, and toilet
preparation manufacturing; adhesive
manufacturing; and printing ink
manufacturing
Incorporation into
formulations,
mixtures, or reaction
product
All
RQ < 1 based on
screening assessment"
Robust
Plasticizer in paint and coating
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel, and
leather manufacturing; printing ink
manufacturing; basic organic chemical
manufacturing; and adhesive and
sealant manufacturing
Pre-catalyst manufacturing
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Life Cycle Stage;
Category
Subcategory
OES
Organism
RQ (Benchmark = 1)
Overall
Confidence
Processing:
Processing:
incorporation into
formulation, mixture,
or reaction product
Plasticizer in plastic material and resin
manufacturing
PVC plastics
compounding
Aquatic vertebrates,
chronic
1.04
Robust
All others
RQ < 1 based on
screening assessment"
Processing;
Processing:
incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and
construction materials manufacturing;
furniture and related product
manufacturing; ceramic powders;
plastics product manufacturing
PVC plastics
converting
Aquatic vertebrates,
chronic
1.04 (Surrogate from
I'YC plastics
com pounding OKS)
Robust
All others
RQ < 1 based on
screening assessment"
Processing;
Processing:
incorporation into
formulation, mixture,
or reaction product
Plasticizer in plastic material and resin
manufacturing; rubber manufacturing
Non-PVC materials
manufacturing
All
RQ < 1 based on
screening assessment"
Robust
Processing;
Incorporation into
articles
Plasticizer in adhesive and sealant
manufacturing; building and
construction materials manufacturing;
furniture and related product
manufacturing; ceramic powders;
plastics product manufacturing; and
rubber product manufacturing
Commercial Use;
Construction, paint,
electrical, and metal
products
Adhesives and sealants
Application of
adhesives and
sealants
All
RQ < 1 based on
screening assessment"
Robust
Industrial Use;
Construction, paint,
electrical, and metal
products
Adhesives and sealants
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Life Cycle Stage;
Category
Subcategory
OES
Organism
RQ (Benchmark = 1)
Overall
Confidence
Commercial Use;
Packaging, paper,
plastic, toys, hobby
products
Ink, toner, and colorant products
Aquatic vertebrates,
aquatic invertebrates,
benthic invertebrates,
aquatic plants and
algae
RQ < 1 based on
application of
wastewater treatment
efficiency (Table 2-2)
Moderate
Commercial Use;
Commercial use:
construction, paint,
electrical, and metal
products
Paints and coatings
Application of paints
and coatings
Terrestrial vertebrates,
soil invertebrates,
terrestrial plants
RQ < 1 based on
screening assessment"
Robust
Industrial Use;
Construction, paint,
electrical, and metal
products
Industrial Use;
Non-incorporative
activities
Solvent, including in maleic anhydride
manufacturing technology
Industrial process
solvent use
All
RQ less than 1 based on
screening assessment"
Robust
Commercial Use;
Other uses
Laboratory chemicals
Use of laboratory
chemicals (solid)
All
RQ less than 1 based on
screening assessment
Robust
Commercial Use;
Other uses
Laboratory chemicals
Use of laboratory
chemicals (liquid)
All
RQ less than 1 based on
screening assessment"
Robust
Commercial Use;
Other uses
Lubricants and lubricant additives
Industrial Use;
Other uses
Lubricants and lubricant additives
Commercial Use;
Automotive, fuel,
agriculture, outdoor
use products
Automotive care products
Use of lubricants
and functional fluids
All
RQ less than 1 based on
screening assessment"
Robust
Commercial Use;
Furnishing, cleaning,
treatment care
products
Cleaning and furnishing care products
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Life Cycle Stage;
Category
Subcategory
OES
Organism
RQ (Benchmark = 1)
Overall
Confidence
Commercial Use;
Other uses
Inspection penetrant kit
Use of penetrants
and inspection fluids
All
RQ < 1 based on
screening assessment"
Robust
Commercial Use;
Furnishing, cleaning,
treatment care
products
Floor coverings; construction and
building materials covering large
surface areas including stone, plaster,
cement, glass and ceramic articles;
fabrics, textiles, and apparel
Furniture and furnishings
Fabrication or use of
final product or
articles
All
Addressed qualitatively6
Robust
Commercial Use;
Other uses
Automotive articles
Chemiluminescent light sticks
Industrial Use;
Other uses
Automotive articles
Propellants
Commercial Use;
Packaging, paper,
plastic, toys, hobby
products
Packaging (excluding food packaging),
including rubber articles; plastic articles
(hard); plastic articles (soft); other
articles with routine direct contact
during normal use, including rubber
articles; plastic articles (hard)
Toys, playground, and sporting
equipment
Processing;
Recycling
Recycling
Recycling
Aquatic vertebrates,
chronic
1.04 (Surrogate from
PNC plastics
compounding OKS)
Robust
All others
RQ 1 based nil
sciveniiiij asscssnvnl
<).23
MS
Disposal; Disposal
Disposal
Waste handling,
treatment and
disposal
Aquatic vertebrates,
chronic
Aquatic invertebrates,
chronic
Robust
All others
RQ ^ 1 based uii
screening assessment"
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Life Cycle Stage;
Category
Subcategory
OES
Organism
RQ (Benchmark = 1)
Overall
Confidence
Distribution in
Commerce
Multiple
Multiple
All
Addressed qualitatively c
Robust
Consumer Use (All
Uses, Disposal)
Multiple
Multiple
All
Addressed qualitatively d
Robust
a See Section 5.3.1.
b See Section 3.2.1. EPA did not quantitatively assess environmental releases for this COU due to the lack of process-specific and DBP-specific data; however,
EPA expects releases from this COU to be small and dispersed in comparison to other upstream COU.
c See Section 4.3.2. EPA expects all DBP or DBP-containing products and/or articles to be transported in closed systems or otherwise to be transported in a
form (e.g., articles containing DBP) such that there is negligible potential for releases except during an incident. Therefore, no environmental exposures are
reasonably expected to occur, and no separate assessment was performed for estimating releases and exposures from distribution in commerce.
d see Section 3.1.4 for further details on the qualitative assessment of consumer disposal of DBP-containing products and articles; disposal is the only pathway
for environmental exposure to DBP from consumer COUs
Bold lc\l in a gra\ shaded cell indicates an RQ exceeding the benchmark value of 1.
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5.3.4 Overall Confidence and Remaining Uncertainties in Environmental Risk
Characterization
The overall confidence in the environmental risk characterization synthesizes confidence from
environmental exposures and environmental hazards. Exposure confidence is detailed in the Draft
Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
Phthalate (DBF) ( ,025p). Hazard confidence is detailed in the Draft Environmental Hazard
Assessment for Dibutyl Phthalate (DBP) ( 24c). Confidence determinations for each group
of environmental organisms characterized are provided in Table 5-7.
Environmental Exposure Confidence
EPA modeled environmental exposure due to various exposure scenarios resulting from different
pathways of exposure. Exposure estimates used high-end inputs for the purpose of a screening level
analysis as demonstrated within the land pathway for modeled concentrations of DBP in biosolids-
amended soils at relevant COUs and air to soil deposition of DBP. EPA has robust confidence in its
qualitative assessment and conclusions pertaining to exposures from biosolids and landfills.
For the water pathway, relevant flow data from the associated receiving water body were collected for
facilities reporting to TRI. Quantified release estimates to surface water were evaluated with PSC
modeling. For each COU with surface water releases, the highest estimated release to surface water was
modeled as a conservative reference concentration for a screening assessment. Releases were evaluated
for resulting environmental media concentrations at the point of release {i.e., in the immediate receiving
water body receiving the effluent). Wastewater treatment removal was applied as a refinement to the
approach for generic scenario COU/OES where such treatment was not already reflected in estimated
surface water releases if RQs greater than 1 were identified without treatment. For DMR-reported
COU/OES, reported surface water releases are based on monitoring at the outfall to surface water and
already reflect any applicable pretreatment and wastewater treatment, and no additional wastewater
treatment removal was applied (see Section 2.3.3.1 of the Draft Environmental Release and
Occupational Exposure Assessment for Dibutyl Phthalate (DBP) ( :5q).
Within the water pathway, monitoring data were compared to modeled estimates to evaluate overlap,
magnitude, and trends. Differences in magnitude between modeled and measured concentrations may be
due to measured concentrations not being geographically or temporally close to known releasers of
DBP. For reported releases, the high-end modeled concentrations in the surface water are the same order
of magnitude as the high-end monitored concentrations found in surface water. This confirms EPA's
expectation that a tiered screening approach beginning with high-end modeled reported releases is
appropriate. Reported release estimates were modeled from data reported to the TRI and DMR
databases. As such, EPA has moderate to robust confidence in the release data and the resulting modeled
surface water concentrations at the point of release in the receiving water body. Despite slight to
moderate confidence in the estimated absolute values themselves, confidence in exposure estimates
capturing high-end exposure scenarios was robust given the many conservative assumptions which
yielded modeled values exceeding those of monitored values. For those COUs in which surrogate water
release data were used, EPA has moderate confidence in the applicability of the release data and the
resulting modeled surface water concentrations. For those COUs in which generic scenario water release
data were used (including those with multimedia releases), EPA has slight confidence in the
applicability of the release data and the resulting modeled surface water concentrations. The Agency has
robust confidence that DBP has limited bioaccumulation and bioconcentration potential based on
physical, chemical, and fate properties, biotransformation, and empirical metrics of bioaccumulation
metrics. For further information on confidence in environmental exposure, see the Draft Environmental
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Media, General Population, and Environmental Exposure Assessment for Dibutyl Phthalate (DBP)
(I > S 1 V \ 2025p).
Aquatic Species Overall Confidence
The overall confidence in the risk characterization for the aquatic assessment is robust for COUs
characterized by reported releases and those COUs that use reported releases as a surrogate, and
moderate for those COUs that use generic releases. EPA has robust confidence that the release estimates
modeled from TRI and DMR databases captures high-end exposure scenarios given the many
conservative assumptions which yielded modeled values exceeding those of monitored values. EPA has
moderate confidence that the full range of release estimates for generic scenarios capture high-end
exposure scenarios because (1) these release estimates are based on generic industrial release scenarios
rather than reported release data, and (2) EPA is not as confident in generic modeled estimates of
receiving water body flows as it is less clear where generic releases occur relative to reported releases.
EPA has slight confidence in the application of individual estimates of surface water and sediment
concentrations from release estimates based on generic scenarios (including those with multimedia
releases) because they are based on generic industrial release scenarios rather than reported release data
and it is unclear whether individual estimates of media releases (to water, landfills, air, etc) are an
overestimate. Hazard confidence in the COCs for acute aquatic and benthic organisms, chronic aquatic
vertebrates, and chronic aquatic invertebrates was robust, while hazard confidence in the COCs for
chronic benthic invertebrates and aquatic plants and algae was moderate. For more information on the
confidence values for hazard, see Section 2.4 in the Draft Environmental Hazard Assessment for Dibutyl
Phthalate (DBP) ( EPA. 2024c).
Terrestrial Species Overall Confidence
The overall confidence in the risk characterization for terrestrial mammals, soil invertebrates, and
terrestrial plants is robust. EPA has robust confidence in its qualitative assessment and conclusions
pertaining to exposures from biosolids and landfills, and robust confidence in risk characterization
conclusions based on its estimates of DBP air deposition to soil. Hazard confidence in the HV for soil
invertebrates was robust, while hazard confidence in the HVs for terrestrial mammals and terrestrial
plants was moderate. For terrestrial mammals, the HV was based on human health animal model rodent
studies (Sprague-Dawley rat, Rattus norvegicus) because no reasonably available information was
identified for exposures of DBP to mammalian wildlife. This resulted in moderate confidence in the HV
due to extrapolation from laboratory rats to mammalian wildlife. For terrestrial plants, the HV was based
on cultivated agricultural strains, and this resulted in moderate confidence in the HV due to
extrapolation from agricultural plants to wild-type plants. For more information on the confidence
values for hazard, see Section 2.4 in the Draft Environmental Hazard Assessment for Dibutyl Phthalate
(DBP) ( 2024c). Overall, because terrestrial concentrations of DBP are expected to be low and
because DBP has low bioaccumulation and biomagnification potential in aquatic and terrestrial
organisms, and thus low potential for trophic transfer through food webs, EPA has robust confidence in
its screening level assessment that there is low potential for DBP exposures to terrestrial mammals and
plants. The Agency has assessed that despite having moderate confidence in terrestrial mammalian and
terrestrial plant hazard values, EPA has robust confidence that environmental DBP exposures to
terrestrial organisms will be far below those hazard values. Furthermore, EPA has robust confidence that
soil exposures to DBP as estimated by a conservative screening approach are far below hazard values for
soil invertebrates. EPA thus has robust confidence in its risk characterization for terrestrial organisms.
Trophic Transfer Overall Confidence
EPA did not conduct a quantitative analysis of DBP trophic transfer. Due to the physical and chemical
properties, environmental fate, and exposure parameters of the DBP, it is not expected to persist in
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surface water, groundwater, or air. DBP has a water solubility of 11.2 mg/L, a log Koc value of 3.69, an
estimated BCF value of 159.4 L/kg, monitored fish BAF values between 110 and 1,247 L/kg, monitored
aquatic invertebrate BAF values between 500 and 6,600 L/kg, and a terrestrial biota-sediment
accumulation factor (BSAF) between 0.35 and 11.8 kg/kg. DBP is expected to have low
bioaccumulation potential, no apparent biomagnification potential, and thus low potential for uptake
overall. For further information on the sources of these values, please see the Draft Chemistry, Fate, and
Transport Assessment for Dibutyl Phthalate (DBP) (U. 2024i). Given the reasonably available
data, EPA has robust confidence that that DBP is found in relatively low concentrations (or not at all) in
aquatic organism tissues, especially at higher trophic levels. Furthermore, DBP has low bioaccumulation
and biomagnification potential in aquatic and terrestrial organisms and therefore low potential for
trophic transfer through food webs. For these reasons, EPA does not expect risk from trophic transfer in
wildlife at environmentally relevant concentrations of DBP.
Table 5-7. DBP Evidence Table Summarizing Overall Confidence Derived for Environmental Risk
Characterization
Types of Evidence
Exposure
Hazard
Trophic
Transfer
Risk
Characterization
C onfidence
Aquatic
Acute aquatic assessment
+ + + VVWM-PSC,
TRI/DMR Releases fl
+ + VVWM-PSC,
Surrogate b
+ VVWM-PSC,
Generic c
+ + + AERMOD d
+ + +
+ + +
Robust for TRI/DMR
releases and
surrogates, Moderate
for generic releases
Chronic aquatic vertebrate assessment
+ + +
+ + +
Chronic aquatic invertebrate assessment
+ + +
+ + +
Chronic benthic assessment
+ +
+ + +
Aquatic plants and algae assessment
+ +
+ + +
Tcnvslnal
( limine mammalian assessment
\ A (Not quantified)
+ +
Robust
Soil invertebrate assessment
+ + + AERMOD
+ + +
+ + +
Robust
Terrestrial plant assessment
+ + + AERMOD
+ +
+ + +
Robust
a EPA conducted modeling VVWM-PSC tool to estimate concentrations of DBP within surface water and sediment.
b For some OESs with no identified releases from TRI/DMR, surrogates from other OESs were used. EPA has
moderate confidence in the use of these surrogates for environmental risk characterization.
c For some OESs, generic release scenarios (including those with multimedia releases) were used. EPA has slight
confidence in the use of these generic releases for environmental risk characterization.
d EPA used AERMOD to estimate ambient air concentrations and air deposition of DBP from EPA-estimated
releases.
+ + + Robust confidence suggests thorough understanding of the scientific evidence and uncertainties. The
supporting weight of scientific evidence outweighs the uncertainties to the point where it is unlikely that the
uncertainties could have a significant effect on the risk estimate.
+ + Moderate confidence suggests some understanding of the scientific evidence and uncertainties. The supporting
scientific evidence weighed against the uncertainties is reasonably adequate to characterize risk estimates.
+ Slight confidence is assigned when the weight of scientific evidence may not be adequate to characterize the
scenario, and when the assessor is making the best scientific assessment possible in the absence of complete
information. There are additional uncertainties that may need to be considered.
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6 UNREASONABLE RISK DETERMINATION
TSCA section 6(b)(4) requires EPA to conduct a risk evaluation to determine whether a chemical
substance presents an unreasonable risk of injury to health or the environment, without consideration of
costs or other nonrisk factors, including an unreasonable risk to a PESS identified by EPA as relevant to
this risk evaluation, under the COUs.
EPA is preliminarily determining that DBP presents unreasonable risk of injury to human health and the
environment based on (1) identified risk to workers from 20 COUs, (2) risk to consumers from 4 COUs,
and (3) on identified risk to the environment from 1 COU. The unreasonable risk results from risk
identified for 25 out of 44 total COUs of DBP. Of the 31 occupational COUs, 9 have risk due to dermal
exposure and 11 have risk due to dermal, inhalation, and aggregate exposure. Of the 13 consumer
COUs, 4 have risk due to dermal exposure. Of the 44 COUs, only 1 (Disposal) had environmental risk
due to chronic exposure to DBP based on releases to surface water. This preliminary unreasonable risk
determination is based on the information provided in previous sections of this draft risk evaluation, the
appendices, and technical support documents for this draft risk evaluation in accordance with TSCA
section 6(b). This preliminary unreasonable risk determination and the underlying evaluation are
consistent with the best available science (TSCA section 26(h)) and based on the weight of scientific
evidence (TSCA section 26(i)).
As noted in the Executive Summary, DBP is primarily used as a plasticizer in polyvinyl chloride (PVC)
in consumer, commercial, and industrial applications—although it is also used in adhesives, sealants,
paints, coatings, rubbers, and non-PVC plastics, as well as for other applications.
EPA notes that human or environmental exposure to DBP through non-TSCA uses (e.g., cosmetics, use
of shells and cartridges as identified in 26 U.S.C. § 4181, and food additives such as food contact
materials) were not specifically evaluated by the Agency because these uses are explicitly excluded from
TSCA's definition of chemical substance. Thus, it is not appropriate to extrapolate from this preliminary
risk determination to form conclusions about uses of DBP that are not subject to TSCA and that EPA did
not evaluate.
Additionally, where relevant, the Agency conducted analyses on aggregate exposures and cumulative
risk. Aggregate exposure analyses consider effects on populations that are exposed to DBP via multiple
routes (e.g., dermal contact, ingestion, and inhalation). Cumulative risk analyses consider human health
risks related to exposures to multiple chemicals. EPA included DBP in its draft cumulative risk analysis
TSD along with five other toxicologically similar phthalate chemicals (i.e., DEHP, DINP, DIBP, BBP,
and DCHP) that are also being evaluated under TSCA ( 2025x). Based on the revised draft
CRA TSD, the Agency has considered the draft cumulative risk (i.e., human health risks related to
exposures to multiple phthalates) and the NHANES biomonitoring data in this preliminary DBP
unreasonable risk determination and concluded that aggregate MOEs for at least one consumer group
dropped below the benchmark in the cumulative analysis for two product scenarios associated with two
different COUs: Consumer use - packaging, paper, plastic, hobby products - toys, playground, sporting
equipment and Consumer use - furnishing, cleaning, treatment/care products - cleaning and furnishing
care products. Additional discussion about EPA's preliminary unreasonable risk determination for
consumer uses is provided in Section 6.1.5 while information about the cumulative risk considerations
and analysis is provided in Section 4.4.
EPA has preliminarily determined that the following 24 COUs may significantly contribute to
unreasonable risk to human health:
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• Manufacturing - domestic manufacturing (dermal and inhalation)
• Manufacturing - importing (dermal and inhalation)
• Processing - processing as a reactant - intermediate in plastic manufacturing (dermal and
inhalation)
• Processing - incorporation into formulation, mixture, or reaction product - solvents (which
become part of product formulation or mixture) in chemical product and preparation
manufacturing; soap, cleaning compound, and toilet preparation manufacturing; adhesive
manufacturing; and printing ink manufacturing (dermal and inhalation)
• Processing - incorporation into formulation, mixture, or reaction product - pre-catalyst
manufacturing (dermal and inhalation)
• Processing - incorporation into formulation, mixture, or reaction product - plasticizer in paint
and coating manufacturing; plastic material and resin manufacturing; rubber manufacturing;
soap, cleaning compound, and toilet preparation manufacturing; textiles, apparel, and leather
manufacturing; printing ink manufacturing; basic organic chemical manufacturing; and adhesive
and sealant manufacturing (dermal)
Processing - incorporation into article - plasticizer in adhesive and sealant manufacturing;
building and construction materials manufacturing; furniture and related product manufacturing;
ceramic powders; plastics product manufacturing; and rubber product manufacturing (dermal)
Processing - repackaging - laboratory chemicals in wholesale and retail trade; plasticizers in
wholesale and retail trade; and plastics material and resin manufacturing (dermal and inhalation)
Industrial use - non-incorporative activities - solvent, including in maleic anhydride
manufacturing technology (dermal and inhalation)
Industrial use - construction, paint, electrical, and metal products - adhesives and sealants
(dermal)
Industrial use - construction, paint, electrical, and metal products - paints and coatings (dermal
and inhalation)
Industrial use - other uses - lubricants and lubricant additives (dermal)
Commercial use - automotive, fuel, agriculture, outdoor use products - automotive care products
(dermal)
Commercial use - construction, paint, electrical, and metal products - adhesives and sealants
(dermal)
Commercial use - construction, paint, electrical, and metal products - paints and coatings
(dermal and inhalation)
Commercial use - furnishing, cleaning, treatment care products - cleaning and furnishing care
products (dermal)
Commercial use - packaging, paper, plastic, toys, hobby products - ink, toner, and colorant
products (dermal and inhalation)
Commercial use - other uses - laboratory chemicals (dermal)
Commercial use - other uses - inspection penetrant kit (dermal and inhalation)
Commercial use - other uses - lubricants and lubricant additives (dermal)
Consumer use - automotive, fuel, outdoor use products - automotive care products (dermal)
Consumer use - construction, paint, electrical and metal products - adhesives and sealants
(dermal)
Consumer use - construction, paint, electrical and metal products - paints and coatings (dermal)
Consumer use - furnishing, cleaning, treatment/care products - cleaning and furnishing care
products (dermal)
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EPA has preliminarily determined that the following COU may significantly contribute to unreasonable
risk to the environment:
• Disposal (aquatic vertebrates)
EPA did not preliminarily identify an unreasonable risk of injury to human health or the environment
from the following 19 COUs:
• Processing - recycling
• Distribution in commerce
• Industrial use - other uses - automotive articles
• Industrial use - other uses - propellants
• Commercial use - furnishing, cleaning, treatment care products - floor coverings; construction
and building materials covering large surface areas including stone, plaster, cement, glass and
ceramic articles; fabrics, textiles, and apparel
• Commercial use - furnishing, cleaning, treatment care products - furniture and furnishings
• Commercial use - packaging, paper, plastic, toys, hobby products - packaging (excluding food
packaging), including rubber articles; plastic articles (hard); plastic articles (soft); other articles
with routine direct contact during normal use, including rubber articles; plastic articles (hard)
• Commercial use - packaging, paper, plastic, toys, hobby products - toys, playground, and
sporting equipment
• Commercial use - other uses - automotive articles
• Commercial use - other uses - chemiluminescent light sticks
• Consumer use - furnishing, cleaning, treatment/care products - fabric, textile, and leather
products
• Consumer use - furnishing, cleaning, treatment/care products - floor coverings; construction and
building materials covering large surface areas including stone, plaster, cement, glass and
ceramic articles; fabrics, textiles, and apparel
• Consumer use - packaging, paper, plastic, hobby products - ink, toner, and colorant products
• Consumer use - packaging, paper, plastic, hobby products - packaging (excluding food
packaging), including rubber articles; plastic articles (hard); plastic articles (soft); other articles
with routine direct contact during normal use, including rubber articles; plastic articles (hard)
• Consumer use - packaging, paper, plastic, hobby products - toys, playground, and sporting
equipment
• Consumer use - other uses - automotive articles
• Consumer use - other uses - chemiluminescent light sticks
• Consumer use - other uses - lubricants and lubricant additives
• Consumer use - other uses - novelty articles
For some COUs, the Agency has limited information to derive risk estimates (such as MOEs or RQs) to
support a determination of whether the COU contributes to unreasonable risk of injury to human health
or the environment. In such cases, EPA integrates reasonably available information (e.g., read-across
evidence, p-chem properties, available monitoring data) in a risk characterization using a weight of
evidence approach and professional judgment to support conclusions. The risk characterizations of
COUs without risk estimates are a best estimate of what EPA expects given the weight of scientific
evidence without overstating the science.
The unreasonable risk determination must be informed by science, and in making a finding of "presents
unreasonable risk," EPA considers risk-related factors beyond exceedance of benchmarks. Risk-related
factors include the type and severity of health effects under consideration, the reversibility of the health
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effects being evaluated, exposure-related considerations (e.g., duration, magnitude, frequency of
exposure), or population exposed—particularly populations with greater exposure or greater
susceptibility (PESS), and the confidence in the information used to inform the hazard and exposure
values. EPA also considers, where relevant, the Agency's analyses on aggregate exposures and
cumulative risk. For COUs evaluated quantitatively, as described in the risk characterization, EPA based
the risk determination on the risk estimate that best represented the COU. Additionally, in the risk
evaluation, the Agency describes the strength of the scientific evidence supporting the human health and
environmental assessments as robust, moderate, slight, or indeterminate.
Robust confidence suggests thorough understanding of the scientific evidence and uncertainties, and the
supporting weight of scientific evidence outweighs the uncertainties to the point where it is unlikely that
the uncertainties could have a significant effect on the risk estimates. Moderate confidence suggests
some understanding of the scientific evidence and uncertainties, and the supporting scientific evidence
weighed against the uncertainties is reasonably adequate to characterize risk. Slight confidence is
assigned when the weight of scientific evidence may not be adequate to characterize the risk, and when
the Agency is making the best scientific assessment possible in the absence of complete information.
This draft risk evaluation discusses important assumptions and key sources of uncertainty in the risk
characterization, and these are described in more detail in the respective weight of scientific evidence
conclusions sections for fate and transport (Section 2.2), environmental release (Sections 3.2.2 and
3.2.3), environmental concentrations (Section 3.3.1), environmental exposures and hazards (Section
5.3.4), and human health exposures and hazards (Sections 4.1.1.5, 4.1.2.4, and 4.1.3.3). It also includes
overall confidence and remaining uncertainties sections for human health (Sections 4.3.2.1, 4.3.3.1, and
4.3.4.1) and environmental (Section 5.3.4) risk characterizations. In general, EPA makes an
unreasonable risk determination based on risk estimates that have an overall confidence rating of
moderate or robust because those confidence ratings indicate the scientific evidence is adequate to
characterize risk estimates despite uncertainties or is such that it is unlikely the uncertainties could have
a significant effect on the risk estimates.
6.1 Human Health
Calculated non-cancer risk estimates (MOEs6) can provide a risk profile of DBP by presenting a range
of estimates for different health effects for different COUs. When characterizing the risk to human
health from occupational exposures during risk evaluation under TSCA, EPA conducts baseline
assessments of risk and makes its determination of unreasonable risk in a manner that takes in
consideration reasonably available information (e.g., test order information, site visits) regarding the use
of respiratory protection or other PPE.7 This allows EPA to make unreasonable risk determinations
based on the available information regarding workers. In addition, the risk estimates are based on
exposure scenarios with monitoring data that reflect existing requirements, such as those established by
OSHA (i.e., permissible exposure limit [PEL]) or through industry or sector best practices. In this draft
risk evaluation, some of the risk estimates calculated do not reflect use of PPE; however, Table 4-17
provides more information on PPE, including risk estimates calculated with PPE, that could be used to
reduce the exposures, so that the risk estimates are above the benchmark MOE. Because EPA does not
currently have information regarding use of PPE under the COUs, the preliminary risk determination is
based on the risk estimates that do not reflect use of PPE.
6 EPA derives non-cancer MOEs by dividing the non-cancer POD (HEC [mg/m3] or HED [mg/kg-day]) by the exposure
estimate (mg/m3 or mg/kg-day). Section 4.3.1 has additional information on the risk assessment approach for human health.
7 It should be noted that, in some cases, baseline conditions may reflect certain mitigation measures, such as engineering
controls, in instances where exposure estimates are based on monitoring data at facilities that have engineering controls in
place.
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To characterize risk from non-cancer endpoints, the estimated MOEs are compared to their respective
benchmark MOE. The benchmark MOE accounts for the total uncertainty in a POD. The benchmark
MOE is the total of several individual uncertainty factors relevant to a given POD with values usually of
1, 3, or 10. For DBP, two uncertainty factors were used to derive a benchmark MOE: (1) UFa of 3 for
the uncertainty in extrapolating animal data to humans {i.e., interspecies variability), and (2) UFh of 10
for the variation in sensitivity among the members of the human population {i.e., intrahuman/
intraspecies variability). Therefore, the benchmark MOE for DBP is 30; is based on effects on the
developing male reproductive system; and was used to characterize risk from exposure to DBP for acute,
intermediate, and chronic exposure scenarios. A lower benchmark MOE {e.g., 30) indicates greater
certainty in the data (because the total UF for the relevant POD is low). A higher benchmark MOE {e.g.,
100) would indicate more extrapolation uncertainty for specific hazard endpoints and scenarios.
Additional information regarding the non-cancer hazard identification and the benchmark MOE is
provided in Section 4.2.2 of this draft risk evaluation. An MOE that is less than the benchmark MOE is a
starting point for informing a determination of unreasonable risk of injury to human health, based on
non-cancer effects. It is important to emphasize that these calculated risk estimates alone are not "bright-
line" indicators of unreasonable risk.
6.1.1 Populations and Exposures EPA Assessed for Human Health
EPA has evaluated risk to workers (16+ years old), including ONUs and females of reproductive age
directly working with DBP; consumers and bystanders (adults and children), as well as the general
population (including fenceline communities) using reasonably available monitoring and modeling data
for inhalation, dermal, and ingestion exposures, as applicable. The Agency has evaluated risk from
inhalation, incidental ingestion of inhaled dust, and dermal exposure of DBP to workers, including
ONUs. EPA has also evaluated risk from inhalation, dermal, and ingestion exposures for consumers. For
the general population, EPA has evaluated risk from (1) ingestion exposures via drinking water,
incidental surface water ingestion during swimming, fish ingestion (including subsistence and Tribal
fishers), and soil ingestion by children; (2) dermal exposure to surface water during swimming; (3) acute
and chronic inhalation exposure; and (4) exposures measured through urinary biomonitoring {i.e.,
NHANES). EPA concluded it is not necessary to separately model risks to infants consuming the human
milk of exposed individuals because the POD used in the assessment is based on male reproductive
effects resulting from maternal exposures in multi-generational studies. EPA therefore has confidence
that the risk estimates calculated based on maternal exposures are protective of a nursing infant's greater
susceptibility during this unique lifestage whether due to sensitivity or greater exposure per body
weight. Descriptions of the data used for human health exposure are in Section 4.1. Uncertainties for
overall exposures are presented in the respective occupational, consumer, and general population
exposure sections of this draft risk evaluation and are considered in the preliminary unreasonable risk
determination.
6.1.2 Summary of Human Health Effects
EPA has preliminary determined that DBP presents unreasonable risk to human health because of non-
cancer phthalate syndrome-related effects on the developing male reproductive system {i.e., decreased
fetal testicular testosterone) in the following populations:
• workers from acute, intermediate, and chronic dermal and inhalation exposures; and
• consumers from dermal exposures.
With respect to health endpoints upon which EPA has based this unreasonable risk determination, the
Agency has robust confidence in the developmental toxicity POD. The POD is based on phthalate
syndrome-related effects on the developing male reproductive system {i.e., decreased fetal testicular
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testosterone) and was derived used BMD modeling. Risk estimates based on the POD are relevant for
females of reproductive age and males at any lifestage. Decreased fetal testicular testosterone is the most
sensitive endpoint for DBP. Additionally, there is epidemiological evidence that DBP exposure can
adversely affect the developing male reproductive system consistent with phthalate syndrome in males
of any age, and that DBP exposure at higher concentrations can cause other health effects in females as
well (see the Draft Non-cancer Human Health Hazard Assessment for Dibutyl Phthalate (DBP) (11 S
E 24D). Therefore, EPA considers the proposed decreased fetal testicular testosterone POD to be
relevant across sex, lifestage, and durations. The confidence in the POD and descriptions of the data
used to determine the human health effects from DBP are explained in Section 4.2.2. Additional
information about EPA's confidence in the human health hazard of DBP is provided in Section 4.2.2.
With respect to carcinogenicity, overall, EPA considers there to be some limited evidence to support the
conclusion that chronic oral exposure to DBP causes pancreatic tumors in rats. Under the Guidelines for
Carcinogen Risk Assessment (U.S. EPA. 2005). the Agency reviewed the weight of scientific evidence
for the carcinogenicity of DBP and has preliminarily determined that there is Suggestive Evidence of
Carcinogenic Potential of DBP in rodents. According to the Guidelines for Carcinogen Risk
Assessment, when there is Suggestive Evidence, "the Agency generally would not attempt a dose-
response assessment, as the nature of the data generally would not support one." Consistently, EPA is
not conducting a dose-response assessment for DBP or evaluating DBP for carcinogenic risk to humans.
The human health risk estimates for consumers and bystanders, and the general population are presented
and characterized in Section 4.3. Human health risk estimates for workers including ONUs are presented
in Table 4-18 and characterized in Section 4.3. Again, the benchmarks are not bright-lines, and EPA has
discretion to consider other risk-related factors when concluding whether a COU significantly
contributes to the unreasonable risk of the chemical substance.
6.1.3 Basis for Unreasonable Risk to Human Health
In developing the exposure and hazard assessments for DBP, EPA has analyzed reasonably available
information to ascertain whether some human populations may have greater exposure and/or
susceptibility than the general population to the hazard posed by DBP. For the DBP draft risk
evaluation, EPA has accounted for the following PESS: females of reproductive age; pregnant women;
infants; children and adolescents; people who frequently use consumer products and/or articles
containing high concentrations of DBP; people exposed to DBP in the workplace; people in proximity to
releasing facilities, including fenceline communities; and Tribes and subsistence fishers whose diets
include large amounts of fish. Section 4.3.5 summarizes how PESS were incorporated into the risk
evaluation through consideration of potentially increased exposures and/or potentially increased
biological susceptibility and summarizes additional sources of uncertainty related to consideration of
PESS.
Because EPA was able to calculate risk estimates for PESS groups in this assessment (e.g., female
workers of reproductive age, infants and children), the Agency did not always use risk estimates based
on high-end exposure levels as the basis of the unreasonable risk determination for DBP. Additionally,
EPA considered whether high-end risk estimates represented sentinel exposure levels accurately. As
explained in the human health risk characterization (Section 4.3), for most occupational COUs, central-
tendency risk estimates were used to preliminarily determine unreasonable risk. The assumptions of an
8-hour exposure duration for DBP may overestimate dermal exposure; however, even a 25-minute
exposure of a femal worker of reproductive age or 20-minute exposure to workers under the
Manufacturing OES could result in risk estimates below the benchmark MOE. Similarly, for consumer
COUs, high-intensity risk estimates were used to preliminarily determine unreasonable risk—except for
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the consumer use of synthetic leather articles, automotive articles, and novelty articles. The UFh of 10
for human variability that EPA has applied to MOEs accounts for increased susceptibility of
populations. The non-cancer POD for DBP selected by the Agency for use in risk characterization is
based on the most sensitive developmental effect {i.e., reduced fetal testicular testosterone production)
observed and is expected to be protective of susceptible subpopulations. More information on how EPA
characterized sentinel and aggregate risks is provided in Section 4.1.5, and more information on how the
Agency characterized PESS risks is provided in Section 4.3.5.
Additionally, EPA did not consider aggregate exposure scenarios across COUs because the Agency did
not find any evidence to support such an aggregate analysis, such as statistics of populations using
certain products represented across COUs or workers performing tasks across COUs. However, EPA
considered combined exposure across all routes of exposure for each individual occupational and
consumer COU to calculate aggregate risks (Sections 4.3.2 and 4.3.3). The Agency aggregated
exposures across routes for workers, including ONUs, as well as consumers for COUs with quantitative
risk estimates. EPA has identified at least one consumer COU where aggregating exposures across all
exposure routes indicated risk where there was no risk indicated when considering a single route. EPA
did not consider aggregate exposure for the general population. As described in Section 4.1.3, the
Agency employed a risk screening approach for the general population exposure assessment. More
information on how EPA characterized sentinel and aggregate risks is provided in Section 4.1.5.
In addition to the analysis done for DBP alone (referred to as "individual analysis"), EPA applied both
the methods and principles of CRA {Draft Proposed Approach for Cumulative Risk Assessment (CRA)
of High-Priority Phthalates and a Manufacturer-Requested Phthalate under the Toxic Substances
Control Act (U.S. EPA, 2023 c) as well as the Revised Draft Technical Support Document for the
Cumulative Risk Analysis of Di(2-ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl
Phthalate (BBP), Diisobutyl Phthalate (DIBP), Dicyclohexyl Phthalate (DCHP), and Diisononyl
Phthalate (DINP) Under the Toxic Substances Control Act (TSCA) (U.S. EPA. 2025xV) to derive non-
cancer risk estimates for occupational and consumer exposures. EPA's draft CRA includes cumulative
exposure to other toxicologically similar phthalates being evaluated under TSCA {i.e., DEHP, DCHP,
BBP, DIBP, and DINP) and uses an "Relative Potency Factor (RPF) analysis" to characterize risk. DBP
was used as the index chemical for the meta-analysis and BMD modeling approach to model decreased
fetal testicular testosterone. Because DBP is the index chemical and the RPF is 1, scaling by relative
potency has no effect on the DBP exposure estimates used to derive DBP cumulative risk estimates.
More information on how EPA characterized the risk from the cumulative exposure to the phthalates is
provided in Section 4.4.1.
The revised draft CRA TSD also includes the addition of a non-attributable cumulative exposure to
DEHP, DBP, BBP, DIBP, and DINP as estimated from NHANES urinary biomonitoring data using
reverse dosimetry. The NHANES exposure is non-attributable—meaning it cannot be attributed to
specific COUs or other sources that may result in high-dose exposure scenarios {e.g., occupational
exposures to workers)—but likely includes exposures attributable to both COUs assessed under TSCA
and other, non-TSCA sources {e.g., diet, food packaging, cosmetics).
6.1.4 Workers
Based on the occupational risk estimates and related risk factors, EPA is preliminarily determining that
DBP presents unreasonable risk due to
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• non-cancer risks from acute, intermediate, and chronic dermal and inhalation exposure to
workers, including ONUs, that contribute to the preliminary determination of unreasonable risk
due to certain COUs.
More information on occupational risk estimates is in Section 4.3.2, including the effect of PPE on the
occupational risk estimates (Section 4.3.2.4. and Table 4-17). The occupational risk estimates are not
impacted by the results from the cumulative risk assessment, even with the addition of non-attributable
cumulative exposure NHANES urinary biomonitoring data. EPA's confidence in the cumulative MOEs
for workers is moderate to robust (Section 4.4.4.1).
EPA is preliminarily determining that 20 COUs may significantly contribute to unreasonable risk of
injury to human health for workers, including ONUs.
High-end inhalation risk estimates were used to preliminarily determine unreasonable risk due to eight
COUs. High-end inhalation risk estimates were used for one occupational COU (Commercial use -
inspection penetrant kits) for the acute exposure duration because the high-end inhalation risk estimates
are expected to be most reflective of workers exposed to potentially elevated exposures (e.g., low
ventilation, high concentration, high use rate) for an acute duration; however, central tendency risk
estimates were used for intermediate and chronic inhalation exposure durations, as well as dermal
exposure risk estimates, (see in Section 4.3.2, "Use of penetrants and inspection fluids"). For seven
COUs—(1) Manufacturing - domestic manufacturing; (2) Manufacturing - importing; (3) Processing -
processing as a reactant - intermediate in plastic manufacturing; (4) Processing - incorporation into
formulation, mixture, or reaction product - solvents (which become part of product formulation or
mixture) in chemical product and preparation manufacturing; soap, cleaning compound, and toilet
preparation manufacturing; adhesive manufacturing; and printing ink manufacturing; (5) Processing -
incorporation into formulation, mixture, or reaction product - pre-catalyst manufacturing; (6) Processing
- repackaging; and (7) Industrial use - non-incorporative activities - solvent, including in maleic
anhydride manufacturing technology)—due to limited inhalation data points, both the central and high-
end exposure estimates are expected to be reflective of worker inhalation exposures. Also, since the
dermal exposures are upper-bound estimates, the central tendency values of exposure estimates are
expected to be more reflective of worker dermal exposures (see Section 4.3.2). For all other COUs, EPA
is using the central tendency risk estimates to preliminarily determine unreasonable risk due to
inhalation, dermal, and aggregate exposure due to the uncertainties involved in the inhalation exposure
estimates and the uncertainties present in the representativeness of the skin permeability data in the
dermal exposure estimate, which varies with each OES mapped to occupational COUs, as described in
Section 4.3.2. Overall, EPA has moderate to robust confidence in the risk estimates calculated for
worker and ONU inhalation and dermal exposure scenarios.
For cases where occupational dermal exposure to liquid DBP was assessed, EPA used a flux-limited
dermal absorption value derived from a study conducted by Doan et al. (2010) to estimate high-end and
central tendency dermal exposures. For occupational dermal exposure to solid DBP, EPA used a flux-
limited dermal absorption model to estimate high-end and central tendency dermal exposures for
workers in each OES. Both methods are described in the Draft Environmental Release and
Occupational Exposure Assessment for Dibutyl Phthalate (DBP) ( 2025q) (see also Section
4.1.1.1). Dermal exposure for ONUs was assessed for COUs where contact with DBP-containing mist or
dust on surfaces was expected. For the occupational dermal exposure assessment, EPA assumed a
standard 8-hour workday and the chemical is contacted at least once per day. Because DBP has low
volatility and relatively low absorption, it is possible that the chemical remains on the surface of the skin
after dermal contact until the skin is washed. So, in absence of exposure duration data, EPA has assumed
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that absorption of DBP from occupational dermal contact with materials containing DBP may extend up
to 8 hours per day ( ). However, if a worker uses proper PPE or washes their hands after
contact with DBP or DBP-containing materials, dermal exposure may be eliminated. Therefore, the
assumption of an 8-hour exposure duration for DBP may lead to overestimation of dermal exposure.
For average adult workers, the surface area of contact was assumed equal to the area of one hand {i.e.,
535 cm2), or two hands {i.e., 1,070 cm2), for central tendency exposures, or high-end exposures,
respectively ( .). Despite moderate confidence in the estimated values themselves, EPA
has robust confidence that the dermal liquid exposure estimates are upper bound of potential exposure
scenarios. Additionally, there are uncertainties associated to the flux-limited approach which likely
results in overestimations due to the assumption about excess DBP in contact with skin for the entire
work duration. EPA has considered the weight of scientific evidence for dermal risk estimates to be
sufficient for determining whether a COU significantly contributes to unreasonable risk. More
information on the Agency's confidence in these risk estimates and the uncertainties associated with
them can be found in Section 4.1.1.5.
For three COUs (Industrial use - construction, paint, electrical, and metal products - paints and
coatings; Commercial use - construction, paint, electrical, and metal products - paints and coatings; and
Commercial use - packaging, paper, plastic, hobby products - ink, toner and colorant products), EPA is
preliminary determining that these COUs significantly contribute to the unreasonable risk of injury to
human health due to acute, intermediate, and chronic dermal exposure (MOEs from 1.7-3.3 for each
population assessed). The MOEs were below the benchmark for acute, intermediate, and chronic
inhalation exposure; however, the intermediate and chronic duration risk estimates are at or only slightly
below the benchmark (25+ for each population assessed). Taking into consideration the dermal exposure
as well as the aggregate exposure assessment and risk estimates, the Agency believes that there is
enough evidence to support EPA's preliminary determination that these COUs also significantly
contribute to unreasonable risk of injury to human health due to intermediate and chronic inhalation
exposure, as well as acute inhalation exposure. However, EPA preliminarily finds that dermal exposure
is the driver of unreasonable risk presented by DBP.
EPA has assessed one (the following) occupational COU without deriving risk estimates:
• Distribution in commerce: EPA expects DBP to be transported in sealed containers from import
sites to downstream processing and use sites, or for final disposal. EPA also expects under
standard operating procedures, along with the expectation that DBP would be transported in a
closed system, that there is negligible potential for releases except during an incident. Therefore,
no occupational exposures are reasonably expected to occur and exposures and releases that
could occur during distribution in commerce would not result in unreasonable risk.
EPA's overall risk characterization confidence for workers is summarized in Section 4.3.2.1.
6.1.5 Consumers
Based on the consumer risk estimates and related risk factors, EPA is preliminarily determining that
DBP presents unreasonable risk due to non-cancer risk from
• acute dermal exposure for consumers.
EPA is preliminarily determining that four COUs may significantly contribute to unreasonable risk of
injury to human health for consumers.
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EPA reviewed the parameters for the exposure scenarios analyzed under each COU and preliminarily
determined risk based on the most representative intensity assessed. For eight COUs, the high-intensity
risk estimates were used in making a preliminary unreasonable risk determination—even after
considering the conservative assumptions used in the dermal assessment. However, for the following
five COUs, different intensity risk estimates were considered for the preliminary unreasonable risk
determination:
• High-intensity dermal and medium-intensity aggregate and ingestion risk estimates were used for
Consumer use - other uses - novelty articles;
• Low-intensity dermal for infants and toddlers and medium-intensity risk estimates for all other
exposure routes and lifestages were used for Consumer use - furnishing, cleaning, treatment/care
products - fabric, textile, and leather products;
• Low-intensity dermal for infants and toddlers and medium-intensity risk estimates for all other
exposure routes and lifestages were used for Consumer use - other uses - automotive articles;
• Medium-intensity inhalation risk estimates were used for infants and toddlers for Consumer use
- construction, paint, electrical, and metal products - paints and coatings; and
• Medium-intensity risk estimates were used for Consumer use - packaging, paper, plastic, toys,
hobby products - toys, playground, sporting equipment.
See Section 4.3.3 and the Draft Consumer and Indoor Dust Exposure Assessment for Dibutyl phthalate
(DBPj ( E025c) for additional information.
For dermal exposure, the CEM Model assumes infinite DBP migration from product to skin without
considering saturation which results in overestimations of dose and subsequent risk, see Section 2.3 in
U.S. EPA (2025c) for a detailed explanation. Because of this, CEM was not used to model consumer
dermal exposures, and instead dermal exposures were estimated using a flux-limited dermal absorption
approach for liquid and solid products ( 025d). For each exposure route, EPA used the 10th
percentile, average, and 95th percentile value of an input parameter (e.g., weight fraction, surface area)
where possible to characterize low-, medium-, and high-intensities for a given COU. If only a range was
reported, EPA used the minimum and maximum of the range as the low and high values, respectively.
The average of the reported low and high values from the reported range was used for the medium
exposure scenario. Section 4.1.2.1 includes a description of the uncertainties and methods used to
evaluate dermal exposure for consumers. See Draft Consumer and Indoor Dust Exposure Assessment for
Dibutyl Phthalate (DBP) (U.S. EPA. 2025c) for details about the consumer modeling approaches,
sources of data, model parameterization, and assumptions. The largest chronic dose estimated was for
dermal and inhalation exposure to metal coatings for young teens to adults, followed by dermal exposure
to adhesives, footwear, and waxes. It is noteworthy that the dermal screening analysis with the flux-
limited approach has larger uncertainties than inhalation dose results; see Section 4.1.2.4 for a detailed
discussion of uncertainties within approaches, inputs, and overall estimate confidence (Section 4.1.2.2).
One COU, Consumer use - construction, paint, electrical, and metal products - paints and coatings, was
assessed using three different exposure scenarios: (1) metal coatings, (2) indoor sealing and refinishing
sprays, and (3) outdoor sealing and refinishing spray. Metal coatings refer to consumer or DIY paint-
type products that can be sprayed in a home setting. The metal coatings exposure scenario was assessed
for bystanders for children under 10 years of age who could be exposed from consumers using those
products at home. Per the Draft Consumer and Indoor Dust Exposure Assessment for Dibutyl phthalate
(DBP) ( 5c), metal coating products are expected to be used in comparatively smaller
scale projects and were thus modeled at use durations of 120, 60, and 30 minutes. For metal coating
products, daily use was not considered likely, but the product could reasonably be used weekly for
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hobby projects or a variety of small projects. Therefore, this product was modeled at a use frequency of
52 times per year. The overall confidence in this COU inhalation exposure estimate is robust because the
CEM default parameters represent actual use patterns and location of use. The resulting chronic
inhalation MOEs for bystanders from the high-intensity scenario were below the benchmark of 30 for
infants and toddlers (children <2 years old; MOEs of 26 and 28, respectively). However, based on the
conservative assumptions used in the assessment, the frequency of use likely overestimates potential
exposure, and the medium-intensity is a more representative scenario of exposure for this COU.
Medium-intensity exposure risk estimates for the metal coatings scenario were 130 and 140 for infants
and toddlers, respectively. Therefore, EPA is preliminarily determining that this COU does not
contribute to unreasonable risk for infants and toddlers for bystander inhalation exposure. EPA is also
preliminarily determining that this COU significantly contributes to unreasonable risk for acute dermal
and aggregate exposure for young teens, teenagers and adults using these products based on the metal
coatings exposure scenario; see Table 6-2 for additional information.
For the COU Consumer use - packaging, paper, plastic, toys, hobby products - toys, playground,
sporting equipment, EPA used four exposure scenarios: (1) children's toys (new); (2) children's toys
(legacy); (3) small articles with semi routine contact - miscellaneous items including a football, balance
ball, and pet toy; and (4) tire crumb. The individual chemical analysis indicated risk only to infants who
use legacy toys and there was no risk indicated for infants who use newer toys {i.e., toys containing
<0.1% DBP) (MOE of 23 for high-intensity, acute aggregate exposure for legacy toys based on
individual chemical analysis, and MOE of 21 for high-intensity, acute aggregate exposure for legacy
toys based on cumulative assessment with non-attributable NHANES data). For new toys, after factoring
in the non-attributable NHANES data, the MOE is 29 for aggregate exposure for infants (children <1
year). This additional risk indicated by the draft cumulative analysis supports EPA's risk conclusion
about the overall COU because the individual chemical analysis also indicated acute aggregate risk for
infants based on the high-intensity exposure scenario for the use of legacy toys {i.e., toys containing
>0.1% DBP).
The legacy toys assessment provides a range of reasonable values that reflect possible exposures. The
high-intensity risk estimates likely represent an upper boundary for exposure and may, in some cases,
overestimate the highest possible dose expected. One such case is inhalation-ingestion of DBP in dust
and particulates. CEM assumes that 100 percent of the chemical that is on the dust or particulate matter
will be absorbed when the dust or particulate matter is inhaled or ingested. This is highly unlikely to be
the case as bioavailability is generally reduced in inhaled particles as compared to gas phase or aerosol
chemicals. The bioavailable fraction of DBP in dust and particulate matter would be difficult to quantify
due to the absence of quantitative data in literature. However, EPA recognizes that the assumption of
100 percent absorption through inhalation of DBP in dust/particulate matter and ingestion of DBP in
dust/particulate matter likely overestimate exposure by these routes.
The aggregation across routes for a high-intensity exposure scenario for infants resulted in an MOE
value of 23. The inhalation and ingestion of surface dust are the main contributors to the overall
aggregate MOE value. The inhalation scenarios are explained above. The surface dust ingestion scenario
model estimates the DBP concentration in settled dust on a toy's surface, assuming primarily that DBP
partitions directly from the toy to settled dust. The model assumes exposure to occur through dust intake
via incidental ingestion assuming a daily stay-at-home dust ingestion rate per lifestage. The model,
assuming instantaneous equilibrium is achieved for partitioning, represents an upper-bound scenario.
Overestimation of DBP concentration in the dust compartment happens when incidental ingestion after
inhalation and hand-to-mouth are both included in every ingestion estimate. The model estimates that
DBP enters the air phase and while suspended it can partition to dust particles generated by material
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wear and surfaces, which makes incidental ingestion after inhalation possible. Subsequently, the
suspended particulate settles, which makes hand-to-mouth ingestion possible. The overestimation
magnitude and effect cannot be quantified with any accuracy or certainty based on current literature. The
aggregated MOE overall confidence originates from compounding and intensifying the uncertainties
from each aggregated exposure route. The overestimation for all three high-intensity exposure routes
suggest that the high-intensity use aggregate scenario may not reflect or capture realistic exposures.
Given this information, the Agency is basing this preliminary risk determination on the medium-
intensity use of toys, as it is representative of the middle of the range of exposures; therefore, EPA is
preliminary determining that, for DBP, the COU Consumer use - packaging, paper, plastic, toys, hobby
products - toys, playground, sporting equipment does not significantly contribute to unreasonable risk.
More information on the cumulative risk considerations is provided in Section 4.4.
The DBP consumer exposure overall confidence to use the results for risk characterization ranges from
moderate to robust, depending on COU scenario (Section 4.1.2.4). EPA's overall confidence in the
acute, intermediate, and chronic consumer inhalation, ingestion, and dermal exposure risk estimates
ranges from moderate to robust. The Agency has moderate to robust confidence in the risk
estimates calculated for consumers inhalation, ingestion, and dermal exposure scenarios (Section
4.3.3.1), and has robust confidence that dermal exposure scenarios represent a conservative, upper-
bound on exposure. EPA's confidence in the cumulative consumer MOEs is moderate to robust (Section
4.4.5.1).
6.1.6 General Population
Based on the risk estimates, EPA did not identify risk to the general population from the following
exposure routes and pathways for DBP:
• exposure via the land pathway {i.e., application of biosolids and landfills);
• incidental ingestion and dermal contact from swimming;
• acute and chronic ingestion of drinking water;
• acute and chronic ingestion exposure from fish ingestion;
• acute and chronic inhalation exposure to ambient air in proximity to releasing facilities,
including fenceline communities; and
• soil ingestion exposure from air deposition to soil.
As stated in Section 4.3.4, EPA evaluated surface water, drinking water, fish ingestion, and ambient air
pathways quantitatively using a screening level approach for DBP releases associated with COUs (see
the Draft Environmental Media and General Population Screening for Dibutyl Phthalate (DBP) (US
25p) and Section 4.1.3 for additional details about the assessment and assessment process).
Land pathways {i.e., landfills and application of biosolids) were assessed qualitatively, and were
inclusive of down-the-drain releases of consumer products and landfill disposal of consumer articles
(see Section 3.1.4 for details on the qualitative assessment of consumer disposal of DBP-containing
products and articles). For pathways assessed quantitatively, high-end estimates of DBP concentration in
the various environmental media were used for screening level purposes. EPA used an MOE approach
using high-end exposure estimates to determine whether an exposure pathway had potential non-cancer
risks. High-end exposure estimates were defined as those associated with the industrial and commercial
releases from a COU and OES that resulted in the highest environmental media concentrations.
Therefore, if there is no risk for an individual identified as having the potential for the highest exposure
associated with a COU for a given pathway of exposure, then that pathway was determined not to be a
pathway of concern and not pursued further. Based on the screening level approach described in Section
4.1.3, and the qualitative assessment of landfill and biosolids pathways described in Section 3.1.4, EPA
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did not identify risk to the general population from exposure to DBP through biosolids, landfills, surface
water, drinking water, fish ingestion, and ambient air.
EPA has robust confidence that the risk estimates calculated for the general population were
conservative and appropriate for a screening level analysis. The Agency also has robust confidence that
modeled releases used are appropriately conservative for a screening level analysis. Therefore, the
Agency has robust confidence that no exposure scenarios will lead to greater doses than presented in this
evaluation. Despite slight and moderate confidence in the estimated values themselves, confidence in
exposure estimates capturing high-end exposure scenarios was robust given that many of the modeled
values exceeded those of monitored values and exceeded total daily intake values calculated from
NHANES biomonitoring data, adding to confidence that exposure estimates captured high-end exposure
scenarios (Section 4.1.3.3).
6.2 Environment
Based on the environmental risk assessment, EPA is preliminarily determining that DBP presents
unreasonable risk of injury to the environment from the Disposal COU due to chronic exposure for
aquatic vertebrates using a screening approach with refinements. For environmental pathways which
were quantitatively assessed, EPA compared the highest release estimates to environmental media for a
given pathway with the hazard values for aquatic and terrestrial plants. If the exposure for the COU with
the highest amount of environmental release {i.e., the COU with the highest environmental exposures,
the most conservative exposure estimates) did not exceed the hazard threshold for aquatic or terrestrial
plants, it was determined that exposures due to releases from other COUs would not lead to
environmental risk. If the analysis indicated risk, then the next-highest releasing exposure scenario was
evaluated until all COUs were characterized. Discussion of the screening approach and the refinements
made can be found in Section 5.3.
Using the screening approach with refinements, EPA was able to calculate RQs. Calculated RQs can
provide a risk profile by presenting a range of estimates for different environmental hazard effects for
different COUs. An RQ equal to 1 indicates that the exposures are the same as the concentration that
causes effects. An RQ less than 1, when the exposure is less than the effect concentration, generally
indicates that there is not a risk of injury to the environment that would support a determination of
unreasonable risk for the chemical substance. An RQ greater than 1, when the exposure is greater than
the effect concentration, generally indicates that there is risk of injury to the environment that would
support a determination of unreasonable risk for the chemical substance. Additionally, if a chronic RQ is
1 or greater, the Agency evaluates whether the chronic RQ is 1 or greater for 30 days or more based on
the exposure period of the hazard toxicity tests before making a determination of unreasonable risk.
Based on the quantitative screening approach with refinements, EPA is preliminarily determining that
one COU, Disposal, significantly contributes to unreasonable risk to the environment.
EPA has qualitatively evaluated COUs without RQs and is preliminarily determining they do not
contribute to unreasonable risk to the environment, including distribution in commerce. Risk to the
environment from consumer down-the-drain releases and end-of-life disposal was assessed qualitatively
for the 13 consumer COUs under the Disposal COU (see Section 3.1.4). Based on the qualitative
assessment, EPA is preliminarily determining that consumer down-the-drain releases and end-of-life
disposal do not contribute to unreasonable risk to the environment; however the Disposal COU, may,
because of the results of the quantitative environmental risk assessment. Results indicated chronic risk
for aquatic vertebrates due to high-end releases to surface water. More information about how COUs
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were assessed for risk to the environment are summarized in Table 5-2 and Table 5-6 of this draft risk
evaluation.
6.2.1 Populations and Exposures EPA Assessed for the Environment
For aquatic organisms, EPA has evaluated exposures via surface water and trophic transfer. For benthic
organisms, EPA has evaluated exposures via surface water and sediment. For aquatic plants and algae,
the Agency evaluated exposures via surface water. For soil invertebrates and terrestrial plants, EPA
evaluated exposures via air deposition to soil. For terrestrial organisms, the Agency has evaluated
exposures via trophic transfer. Additionally, EPA evaluated terrestrial mammal exposures from
biosolids and landfills.
For aquatic and terrestrial species, EPA expects the main environmental exposure pathways for DBP to
be releases to surface water and subsequent deposition to sediment, and limited dispersal from fugitive
and stack air release deposition to soil, respectively. Trophic transfer, biosolids, and landfills were all
qualitatively assessed and did not indicate risk for the environment.
EPA's confidence in the aquatic exposure assessment ranges from slight (for COUs that were assessed
using generic releases) to robust (for COUs with TRI/DMR releases). Additional information about the
Agency's confidence in the aquatic, terrestrial, and trophic transfer exposure assessments is provided in
Table 5-7 of this draft risk evaluation.
6.2.2 Summary of Environmental Effects
EPA is preliminarily determining that one COU, Disposal, may significantly contribute to unreasonable
risk to the environment because of chronic effects for mortality, growth, reproduction, and development
for aquatic vertebrates.
EPA has robust confidence that DBP has chronic effects on aquatic vertebrates in the environment.
More information about the Agency's confidence in the aquatic, terrestrial, and trophic transfer hazard
assessments is in Table 5-7 of this draft risk evaluation.
6.2.3 Basis for Unreasonable Risk to the Environment
Based on the risk evaluation for DBP—including the risk estimates, the environmental effects of DBP,
the exposures, physical and chemical properties of DBP, and consideration of uncertainties—EPA has
preliminarily identified unreasonable risk to the environment from DBP.
EPA quantitatively evaluated surface water, sediment and air deposition to soil exposure pathways (with
the exception of eight COUs as explained below), and qualitatively evaluated trophic transfer, biosolids
and landfills exposure pathways. Consistent with the Agency's determination of unreasonable risk to
human health, the RQ is not treated as a bright-line and other risk-based factors may be considered (e.g.,
confidence in the hazard and exposure characterization, duration, magnitude, uncertainty) for purposes
of making an unreasonable risk determination.
Four COUs evaluated quantitatively resulted in RQs greater than 1. Three COUs have RQs of 1.04.
Although EPA has robust confidence in the risk characterization, the Agency does not use the RQ of 1
as a bright-line and considering the assumptions in the modeling of water concentrations, EPA is
preliminarily determining that these three COUs do not contribute to unreasonable risk to the
environment for DBP (see Table 5-6). One COU, Disposal, has RQs of 9.23 and 1.18 for chronic
exposure to aquatic vertebrates and invertebrates, respectively. The RQs are based on wastewater release
from treatment plants and are inclusive of wastewater treatment removal of DBP. As stated in Section
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5.3.4, for reported releases, the high-end modeled concentrations in the surface water are the same order
of magnitude as the high-end monitored concentrations found in surface water. However, per the Draft
Environmental Media, General Population, and Environmental Exposure for Dibutyl Phthalate (DBP),
the modeled surface water concentration value for the Disposal COU is higher than the highest reported
monitored concentration value found in data obtained through the Water Quality Portal (WQP), which
houses publicly available water quality data from the USGS, EPA, and state, federal, Tribal, and local
agencies. (The highest monitored concentration was 8.2 |ig/L, whereas the modeled concentration for
the Disposal COU is 14.40 |ig/L) ( ?25p). Given the conservative nature of the
environmental risk assessment and that the Agency does not use a bright-line approach for determining
unreasonable risk, EPA is preliminarily determining that the Disposal COU does not significantly
contribute to unreasonable risk of injury to the environment from chronic exposure for aquatic
invertebrates. However, EPA is still preliminarily determining that the Disposal COU significantly
contributes to unreasonable risk to the environment because of chronic exposures to aquatic vertebrates
from wastewater discharge to surface water.
One COU evaluated with the Manufacturing OES (Manufacturing - domestic manufacturing) and three
COUs evaluated with the Application of paints and coatings OES (Industrial use - construction, paint,
electrical, and metal products - paints and coatings; Commercial use - construction, paint, electrical,
and metal products - paints and coatings; and Commercial use - packaging, paper, plastic, hobby
products - ink, toner and colorant products) indicated chronic risk for aquatic vertebrates due to surface
water exposure. However, EPA has slight confidence in the risk characterization for these COUs
because they are based on generic industrial release scenarios rather than reported release data and it is
unclear whether individual estimates of media releases (to water, landfills, air, etc.) are an overestimate
(Section 5.3.4). Therefore, EPA is preliminarily determining, that for DBP, these four COUs do not
contribute to unreasonable risk to the environment.
For all environmental pathways, eight COUs do not appear to contribute to unreasonable risk to the
environment for DBP based on a qualitative assessment of the Fabrication or use of final products or
articles OES, indicating that environmental releases are expected to be minimal and dispersed. In
addition, EPA evaluated activities resulting in exposures associated with distribution in commerce
throughout the various life cycle stages and COUs (e.g., manufacturing, processing, industrial use,
commercial use, transportation) rather than a single distribution scenario. EPA expects that
environmental releases from distribution in commerce will be similar or less than the exposure estimates
from the COUs evaluated that did not exceed hazard to ecological receptors. EPA further expects all the
DBP or DBP-containing products and/or articles to be transported in closed system or otherwise to be
transported in a form (e.g., articles containing DBP) such that there is negligible potential for releases
except during an incident. Therefore, no separate assessment was performed for estimating releases and
exposures from distribution in commerce (see Table 5-6).
EPA evaluated down-the-drain releases of DBP for consumer COUs qualitatively. Although EPA
acknowledges that there may be DBP releases to the environment via the cleaning and disposal of
adhesives, sealants, paints, coatings, cleaner, waxes, and polishes, the Agency did not quantitatively
assess down-the-drain and disposal scenarios of consumer products due to limited information from
monitoring data or modeling tools. However, the consideration of the physical and chemical properties
of DBP allows the Agency to conduct a qualitative assessment. No studies were identified which
reported the concentration of DBP in landfills or in the surrounding areas in the United States, but DBP
was identified in sludge in wastewater plants in China, Canada, and the United States. DBP is expected
to have a high affinity to particulate and organic media which would limit leaching to groundwater.
Because of its high hydrophobicity and high affinity for soil sorption, it is unlikely that DBP will
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migrate from landfills via groundwater infiltration. Therefore, DBP from down-the-drain releases from
consumer products or landfill disposal of consumer articles is not likely to pose risk to aquatic and
terrestrial organisms (see Table 5-6).
EPA qualitatively assessed the potential for trophic transfer of DBP through food webs to wildlife. DBP
is not expected to be persistent in the environment as it is expected to degrade rapidly under most
environmental conditions (although there is delayed biodegradation in low-oxygen media); and DBP's
bioavailability is expected to be limited (see Section 5.3.1). With respect to trophic transfer,
concentrations of DBP in soil (biosolids, landfills, air deposition) and air is limited or is not expected to
be bioavailable and were also assessed qualitatively.
There are uncertainties in the relevance of limited monitoring data for biosolids and landfill leachate to
the COUs considered. However, based on high-quality physical and chemical property data, EPA
determined that DBP will have low persistence potential and mobility in soils. Therefore, groundwater
concentrations resulting from releases to the landfill or to agricultural lands via biosolids applications
were not quantified but were discussed qualitatively. For ambient air/emissions to soil, where the highest
stack emissions were combined with the highest fugitive emissions for screening, EPA did not aggregate
other COUs or environmental exposure pathways. This consideration is further detailed in the Draft
Environmental Media, General Population, and Environmental Exposure Assessment for Dibutyl
Phthalate (DBP) ( 025p). Due to its physical and chemical properties, environmental fate,
and exposure parameters, DBP is not expected to persist in surface water, groundwater, or air.
EPA's overall environmental risk characterization confidence levels range from moderate (for generic
releases) to robust (for TRI/DMR releases and surrogates) for its qualitative and quantitative aquatic and
terrestrial assessments for all pathways, with the exception of four COUs (Manufacturing - domestic
manufacturing; Industrial use - construction, paint, electrical and metal products - paints and coatings;
Commercial use - construction, paint, electrical and metal products - paints and coatings; and
Commercial use - packaging, paper, plastic, hobby products - ink, toner and colorant products) that
have moderate confidence for the surface water pathway. EPA's confidence in the environmental risk
assessment is summarized in Table 5-7 of this draft risk evaluation.
6.3 Additional Information Regarding the Basis for the Risk
Determination
Table 6-1 and Table 6-2 summarize the basis for this preliminary unreasonable risk determination of
injury to human health presented in this DBP risk evaluation. In these tables, bold text indicates that an
MOE is below the benchmark value. These tables identify the duration of exposure (e.g., acute,
intermediate, chronic duration) and the exposure route to the population or receptor. As explained in
Section 6.2, for this preliminary unreasonable risk determination, EPA has considered the effects of
DBP to human health, including PESS, as well as a range of risk estimates as appropriate, risk-related
factors, and the confidence in the analysis. See Sections 4.3 and 5.3 for a summary of risk estimates.
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6091 Table 6-1. Supporting Basis for the Unreasonable Risk Determination for Human Health (Occupational CPUs)
cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Manufacturing
- Domestic
manufacturing
Domestic manufacturing
Manufacturing
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
1.6
2.2
2.3
HE
17
23
25
0.8
1.1
1.2
0.8
1.1
1.2
Female of
Reproductive Age
CT
30
41
44
1.8
2.5
2.7
1.7
2.3
2.5
HE
15
21
22
0.9
1.2
1.3
0.9
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
Manufacturing
- Importing
Importing
Import and
repackaging
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
1.6
2.2
2.3
HE
17
23
25
0.8
1.1
1.2
0.8
1.1
1.2
Processing -
Repackaging
Laboratory chemicals in
wholesale and retail trade;
plasticizers in wholesale and
retail trade; and plastics material
and resin manufacturing
Female of
Reproductive Age
CT
30
41
44
1.8
2.5
2.7
1.7
2.3
2.5
HE
15
21
22
0.9
1.2
1.3
0.9
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
Processing -
Processing as a
reactant
Intermediate in plastic
manufacturing
Incorporation
into
formulations,
mixtures, or
reaction
product
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
1.6
2.2
2.3
Processing -
Incorporation
into
formulation,
mixture, or
reaction product
Solvents (which become part of
product formulation or mixture)
in chemical product and
preparation manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
adhesive manufacturing; and
printing ink manufacturing
Plasticizer in paint and coating
manufacturing; soap, cleaning
compound, and toilet preparation
manufacturing; textiles, apparel,
and leather manufacturing;
printing ink manufacturing; basic
organic chemical manufacturing;
and adhesive and sealant
manufacturing
HE
17
23
25
0.8
1.1
1.2
0.8
1.1
1.2
Pre-catalyst manufacturing
Female of
Reproductive Age
CT
30
41
44
1.8
2.5
2.7
1.7
2.3
2.5
HE
15
21
22
0.9
1.2
1.3
0.9
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
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cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Processing -
Processing:
incorporation
into
formulation,
mixture, or
reaction product
Plasticizer in plastic material and
resin manufacturing
PVC plastics
compounding
Average Adult
Worker
CT
49
67
71
1.7
2.3
2.4
1.6
2.2
2.3
HE
5.9
8.0
8.6
0.8
1.1
1.2
0.7
1.0
1.1
Female of
Reproductive Age
CT
44
60
65
1.8
2.4
2.6
1.7
2.4
2.5
HE
5.3
7.2
7.8
0.9
1.2
1.3
0.8
1.0
1.1
ONU
CT
49
67
71
124
169
181
35
48
51
Processing -
Processing:
incorporation
into articles
Plasticizer in adhesive and
sealant manufacturing; building
and construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics
product manufacturing
PVC plastics
converting
Average Adult
Worker
CT
49
67
71
124
169
181
35
48
51
HE
5.9
8.0
8.6
62
85
90
5.4
7.3
7.8
Female of
Reproductive Age
CT
44
60
65
135
184
197
33
45
49
HE
5.3
7.2
7.8
67
92
98
4.9
6.7
7.2
ONU
CT
49
67
71
124
169
181
35
48
51
Processing -
Processing:
incorporation
into
formulation,
mixture, or
reaction product
Plasticizer in plastic material and
resin manufacturing; rubber
manufacturing
Non-PVC
materials
manufacturing
Average Adult
Worker
CT
59
80
86
1.7
2.3
2.4
1.6
2.2
2.3
HE
9.9
14
15
0.8
1.1
1.2
0.8
1.0
1.1
Female of
Reproductive Age
CT
53
73
78
1.8
2.4
2.6
1.7
2.4
2.5
Processing -
Incorporation
into articles
Plasticizer in adhesive and
sealant manufacturing; building
and construction materials
manufacturing; furniture and
related product manufacturing;
ceramic powders; plastics
product manufacturing; and
rubber product manufacturing
HE
9.0
12
13
0.9
1.2
1.3
0.8
1.1
1.2
ONU
CT
59
80
86
124
169
181
40
54
58
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cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acule
Inlcr.
Chronic
Acule
Inlcr.
Chronic
Acule
Inlcr.
Chronic
Commercial
Use -
Construction,
paint, electrical,
and metal
products
Adhesives and sealants
Application of
adhesives and
sealants
Average Adult
Worker
CT
336
458
529
1.7
2.3
2.(>
1.7
2.3
2.(>
HE
168
229
245
0.N
I.I
1.2
O.S
I.I
1.2
Female of
Reproductive Age
CT
304
415
479
I.S
2.5
2.<)
I.S
2.5
2.S
Industrial Use -
Construction,
paint, electrical,
and metal
products
Adhesives and sealants
HE
152
207
m
0.<)
1.2
1.3
0.<)
1.2
1.3
ONU
CT
336
458
529
1.7
2.3
2.6
1.7
2.3
2.(>
Commercial
Use -
Packaging,
paper, plastic,
toys, hobby
products
Ink, toner, and colorant products
Application of
paints and
coatings
Average Adult
Worker
CT
2(1
2S
30
1.7
2.3
2.4
1.5
2.1
2.3
HE
3.2
4.4
4.7
O.S
I.I
1.2
0.7
0.<)
1.0
Female of
Reproductive Age
CT
IS
25
27
I.S
2.5
2.7
1.7
2.3
2.4
HE
2M
4.0
4.2
0.9
1.2
1.3
0.7
0.<)
1.0
Commercial
Use -
Commercial use
- Construction,
paint, electrical,
and metal
products
Paints and coatings
ONU
CT
20
2S
30
2.2
3.1
3.3
2.0
2.S
2.<)
Industrial Use -
Non-
incorporative
activities
Solvent, including in maleic
anhydride manufacturing
technology
Industrial
process solvent
use
Average Adult
Worker
CT
34
46
49
1.7
2.3
2.4
l.(t
2.2
2.3
hi;
17
23
25
O.S
I.I
1.2
O.S
I.I
1.2
Female of
Reproductive Age
CT
30
41
44
I.S
2.5
2.7
1.7
2.3
2.5
hi;
15
21
22
0.<)
1.2
1.3
0.<)
1.2
1.3
ONU
CT
34
46
49
N/A
N/A
N/A
34
46
49
Commercial
Use - Other
uses
Laboratory chemicals
Use of
laboratory
chemicals
(solid)
Average Adult
Worker
CT
442
603
645
124
169
181
97
132
141
HE
31
42
45
62
85
90
21
2S
30
Female of
Reproductive Age
CT
400
546
584
135
184
197
101
138
147
HE
2S
38
41
67
92
98
20
27
29
ONU
CT
442
603
645
124
169
181
97
132
141
Page 257 of 333
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May 2025
cou
Inhalation Risk Estimates
Dermal Risk Estimates
Aggregate Risk Estimates
Life Cvele
OES
Worker
Exposure
(Benchmark MOE = 30)
(Benehmark MOE = 30)
(Benehmark MOE = 30)
Stage -
Category
Subcategory
Population
Level
Aeute
Inter.
Chronie
Aeule
Inler.
Chrome
Aeule
Inler.
Chronic
Commercial
Use - Other
uses
Use of
laboratory
chemicals
Average Adult
CT
336
458
491
2.2
3.1
3.3
2.2
3.0
3.3
Laboratory chemicals
Worker
HE
168
229
245
O.S
I.I
1.2
O.S
I.I
1.2
Female of
CT
304
415
444
2.4
3.3
3.(i
2.4
3.3
3.5
(liquid)
Reproductive Age
HE
152
207
222
0.<)
1.2
1.3
0.<)
1.2
1.3
ONU
CT
336
458
491
N/A
N/A
N/A
336
458
491
Commercial
Lubricants and lubricant
Average Adult
CT
336
5,040
61,320
3.0
45
546
3.0
44
541
Use - Other
additives
Worker
HE
168
1,260
15,330
1.0
7.5
91
1.0
7.4
90
uses
Female of
Reproductive Age
CT
304
4,563
55,514
3.3
49
594
3.2
48
588
Industrial Use -
Other uses
Lubricants and lubricant
additives
Use of
HE
152
1,141
13,878
1.1
S.I
99
I.I
S.I
98
Commercial
Use -
Automotive,
Automotive care products
lubricants and
functional
fluids
ONU
CT
336
5,040
61,320
N/A
N/A
N/A
336
5.040
61,320
fuel,
agriculture,
outdoor use
products
Use of
penetrants and
inspection
fluids
Average Adult
CT
11
15
16
1.7
2.3
2.5
1.5
2.0
2.1
Commercial
Worker
HE
3.0
4.1
4.4
O.S
I.I
1.2
0.7
0.<)
1.0
Use - Other
Inspection penetrant kit
Female of
CT
10
14
15
I.S
2.5
2.7
1.5
2.1
2.3
uses
Reproductive Age
hi;
2.7
3.7
4.0
0.<)
1.2
1.3
0.7
0.<)
1.0
ONU
CT
329
449
487
1.7
2.3
2.5
1.7
2.3
2.5
Page 258 of 333
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May 2025
cou
Inhalation Risk Estimates
Dermal Risk Estimates
Aggregate Risk Estimates
Life Cycle
Stage -
Category
Subcategory
OES
Worker
Population
Exposure
Level
(Benchmark MOE = 30)
(Benchmark MOE = 30)
(Benchmark MOE = 30)
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Floor coverings; construction and
CT
168
229
245
124
169
181
71
97
104
building materials covering large
surface areas including stone,
Commercial
Use -
plaster, cement, glass and
ceramic articles; fabrics, textiles,
Average Adult
Worker
Furnishing,
and apparel
cleaning,
Furniture and furnishings
treatment care
products
HF.
2(1
27
29
62
85
90
15
21
22
Female of
CT
152
207
111
135
184
197
71
97
104
Reproductive Age
hi;
IS
25
2(>
67
92
98
14
l«)
21
Fabrication or
ONU
CT
168
229
245
124
169
181
71
97
104
Commercial
Automotive articles
use of final
product or
articles
Use - Other
Chemiluminescent light sticks
uses
Propellants
Commercial
Use -
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other
Packaging,
paper, plastic,
toys, hobby
products
articles with routine direct
contact during normal use,
including rubber articles; plastic
articles (hard)
Toys, playground, and sporting
equipment
Average Adult
CT
156
212
227
124
169
181
69
94
101
Processing -
Recycling
Worker
HE
11
15
16
62
85
90
<).l
12
13
Recycling
Recycling
Female of
CT
141
192
206
135
184
197
69
94
101
Reproductive Age
HE
9.7
13
14
67
92
98
12
12
ONU
CT
156
212
227
124
169
181
69
94
101
Page 259 of 333
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May 2025
cou
OES
Worker
Population
Exposure
Level
Inhalation Risk Estimates
(Benchmark MOE = 30)
Dermal Risk Estimates
(Benchmark MOE = 30)
Aggregate Risk Estimates
(Benchmark MOE = 30)
Life Cycle
Stage -
Category
Subcategory
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Acute
Inter.
Chronic
Disposal -
Disposal
Disposal
Waste
handling,
treatment, and
disposal
Average Adult
Worker
CT
156
212
227
124
169
181
69
94
101
HE
11
15
16
62
85
90
9.1
12
13
Female of
Reproductive Age
CT
141
192
206
135
184
197
69
94
101
HE
9.7
13
14
67
92
98
8.4
12
12
ONU
CT
156
212
227
124
169
181
69
94
101
" The Draft Risk Calculator for Occupational Exposures for Dibutvl Phthalate (DBP) (U.S. EPA, 2025t) contains MOE values with PPE for all the OES for all
populations (average adult workers, female of reproductive age, and ONUs) and all durations (acute, intermediate, and chronic).
Bold text in a gray shaded cell indicates an MOE below the benchmark value of 30.
6092
Page 260 of 333
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PUBLIC RELEASE DRAFT
May 2025
6093 Table 6-2. Supporting Basis for the Unreasonable Risk Determination for Human Health (Consumer CPUs)
Life Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lifestage (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
years)
Consumer Uses: Automotive, fuel,
agriculture, outdoor use products:
Automotive care products
Uses matched with automotive adhesives
Consumer Uses: Construction,
paint, electrical, and metal
products: Adhesives and sealants
Automotive
adhesives
Acute
Dermal
H
-
-
-
-
7
S
7
M
-
-
-
-
2S
31
V)
L
-
-
-
-
140
150
140
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
160 4
170 4
210 4
300 4
370
440
540
Aggregate
H
-
-
-
-
7
S
7
M
-
-
-
-
2S
31
2<)
L
-
-
-
-
140
150
140
Intermed.
Dermal
H
-
-
-
-
210
230
220
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
4,800 b
5,100 b
6,200 b
9,000 4
1.1E04
1.3E04
1.6E04
Aggregate
H
-
-
-
-
210
230
210
Chronic
-
-
-
-
-
-
-
-
-
Construction
adhesives
Acute
Dermal
H
-
-
-
-
7
S
7
M
-
-
-
-
2S
31
V)
L
-
-
-
-
140
150
140
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Intermed.
Dermal
H
-
-
-
-
210
230
220
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Chronic
-
-
-
-
-
-
-
-
-
Adhesives for small
repairs
Acute
Dermal
H
-
-
-
-
70
77
72
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Intermed.
-
-
-
-
-
-
-
-
-
Chronic
Dermal
H
-
-
-
-
490
540
510
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Page 261 of 333
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PUBLIC RELEASE DRAFT
May 2025
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lifestagc (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Tochller
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
vcars)
Consumer Uses: Construction,
paint, electrical, and metal
products: Paints and coatings
Metal coatings
Acute
Dermal
H
-
-
-
-
7
8
7
M
-
-
-
-
28
31
2<)
L
-
-
-
-
140
150
140
Ingestion
-
-
-
-
-
-
-
Inhalation
H
72 4
76 b
94 b
130 b
130
160
190
Aggregate
H
-
-
-
-
7
7
7
M
-
-
-
-
24
26
26
L
-
-
-
-
89
100
100
Intermed.
-
-
-
-
-
-
-
-
-
Chronic
Dermal
H
-
-
-
-
49
54
51
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
26 "
28*
34 b
49 b
51
62
75
M
130 4
140 4
170 4
250 4
290
340
420
Aggregate
H
-
-
-
-
25
2')
30
M
-
-
-
-
120
130
140
Indoor flooring
sealing and
refinishing products
Acute
Dermal
H
-
-
-
-
l(t
17
16
M
-
-
-
-
23
26
24
L
-
-
-
-
47
51
48
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
100 b
no6
140 b
190 b
260
300
380
Aggregate
H
-
-
-
-
15
16
15
M
-
-
-
-
22
24
23
L
-
-
-
-
45
49
46
Intermed.
Dermal
H
-
-
-
-
470
510
480
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
3,100 b
3,300 b
4,100 b
5,800 b
7,800
9,100
1.1E04
Aggregate
H
-
-
-
~
440
490
460
Chronic
-
-
-
-
-
~
-
-
-
Sealing and
refinishing sprays
(outdoor use)
Acute
Dermal
H
-
-
-
-
9
10
9
M
-
-
-
~
IS
19
IS
L
-
-
-
~
35
39
36
Ingestion
-
-
-
-
-
-
-
-
Page 262 of 333
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PUBLIC RELEASE DRAFT
May 2025
Life Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) *
Lifestage (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
Teen
(11-15
years)
Teenagers
(16-20
years)
Adults
(21+
years)
Consumer Uses: Construction,
paint, electrical, and metal
products: Paints and coatings
Sealing and
refinishing sprays
(outdoor use)
Acute
Inhalation
H
92 4
98 4
120 4
150 4
49
66
73
Aggregate
H
-
-
-
-
8
8
8
M
-
-
-
-
15
16
16
L
-
-
-
-
35
38
36
Intermed.
Dermal
H
-
-
-
-
260
290
270
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
2,800 b
2,900 b
3,600 b
4,500 4
1,500
2,000
2,200
Aggregate
H
-
-
-
-
220
250
240
Chronic
-
-
-
-
-
-
-
-
-
Consumer Uses: Furnishing,
cleaning, treatment care products:
Fabric, textile, and leather products
Synthetic leather
clothing
Acute
Dermal
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
16
72
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Intermed.
-
-
-
-
-
-
-
-
-
Chronic
Dermal
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
540
510
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Consumer Uses: Furnishing,
cleaning, treatment care products:
Fabric, textile, and leather products
Synthetic leather
furniture
Acute
Dermal
H
_d
_d
_d
_d
_d
_d
_d
M
_d
_d
41
54
69
16
72
L
_d
140
160
200
250
280
260
Ingestion c
H
83
140
220
2.3E06
4.1E06
5.2E06
12E06
M
280
380
670
2.3E07
4.1E07
5.2E07
1.2E08
L
1.1E05
7.6E04
1.4E05
3.4E07
6.1E07
7.7E07
1.7E08
Inhalation c
H
5.7E04
6.0E04
7.4E04
1.1E05
1.5E05
1.8E05
2.2E05
M
5.8E05
6.1E05
7.5E05
1.1E06
1.5E06
1.8E06
2.2E06
L
8.8E05
9.3E05
1.1E06
1.6E06
2.3E06
2.7E06
3.4E06
Aggregate
H
83
140
220
1E05
1.5E05
1.7E05
2.1E05
M
280
380
39
54
69
76
72
L
9.7E04
140
160
200
250
280
260
Intermed.
-
-
-
-
-
-
-
-
-
Chronic
Dermal
H
_d
_d
_d
_d
_d
_d
_d
M
_d
_d
41
54
69
16
72
Page 263 of 333
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PUBLIC RELEASE DRAFT
May 2025
Exposure
Scenario
(H, M, L) a
Lifestagc (years) MOE
(Benchmark MOE = 30)
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
years)
Dermal
L
_d
140
160
200
250
280
260
H
83
140
220
2.5E06
4.5E06
5.7E06
1.3E07
Ingestion c
M
280
380
670
2.5E07
4.5E07
5.7E07
1.3E08
Consumer Uses: Furnishing,
cleaning, treatment care products:
Fabric, textile, and leather products
L
1.1E05
7.6004
1.4E05
3.7E07
6.7E07
8.4E07
1.9E08
Synthetic leather
Chronic
H
5.9E04
6.3E04
7.7E04
1.1E05
1.6E05
1.8E05
2.3E05
furniture
Inhalation c
M
6.0E05
6.4E05
7.9E05
1.1E06
1.6E06
1.9E06
2.3E06
L
9.2E05
9.7E05
1.2E06
1.7E06
2.4E06
2.8E06
3.5E06
H
83
140
220
1.1E05
1.5E05
1.8E05
2.2E05
Aggregate
M
280
380
39
54
69
76
72
L
120
140
160
200
250
280
260
Dermal
H
240
280
320
400
510
550
520
Acute
Ingestion c
H
2.4E04
1.9E04
1.7E04
4.8E04
8.6E04
1.1E05
2.4E05
Inhalation c
H
800
850
1,000
1,500
2,100
2,500
3,100
Vinyl flooring
Aggregate
H
180
210
240
310
410
450
440
Intermed.
-
-
-
-
-
-
-
-
-
Dermal
H
240
280
320
400
510
550
520
Chronic
Ingestion c
H
7.9E04
6.4E04
5.7E04
1.6E05
2.9E05
3.6E05
8.1E05
Consumer uses: Furnishing,
cleaning, treatment care products:
Floor coverings; construction and
Inhalation c
H
3,800
4,000
4,900
7,100
1.0E04
1.2E04
1.5E04
Aggregate
H
220
260
300
380
480
530
500
Dermal
H
120
140
160
200
250
280
-
building materials covering large
surface areas including stone,
plaster, cement, glass and ceramic
Acute
Ingestion c
H
1.0E05
8.3E04
7.3E04
2.1E05
3.7E05
4.7E05
1.0E06
Inhalation c
H
3,500
3,700
4,500
6,500
9.2E03
1.1E04
1.3E04
articles; fabrics, textiles, and
apparel
Wallpaper (in-place)
Aggregate
H
120
130
160
190
250
270
1.3E04
Dermal
H
120
140
160
200
250
280
9.5E04
Chronic
Ingestion c
H
3.4E05
2.8E05
2.5E05
7.0E05
1.3E06
1.6E06
3.5E06
Inhalation c
H
1.6E04
1.7E04
2.1E04
3.1E04
4.3E04
5.1E04
6.3E04
Aggregate
H
120
140
160
200
250
280
3.8E04
Wallpaper
(installation)
Dermal
H
-
-
-
-
130
140
130
Acute
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Page 264 of 333
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May 2025
Exposure
Scenario
(H, M, L) a
Lifestagc (years) MOE
(Benchmark MOE = 30)
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
Teen
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
years)
Dermal
H
-
-
-
-
28
31
29
M
-
-
-
-
110
120
120
Ingestion
-
-
-
-
-
-
-
-
Acute
Inhalation
H
6.7E04
7.1E044
8.7E044
1.3E054
3.7E04
4.8E04
5.5E04
M
1.4E05 4
1.5E05 4
1.8E05 4
2.7E05 4
7.7E04
9.6E04
1.1E05
Spray cleaner
Aggregate
H
6.7E04
7.1E04
8.7E04
1.3E05
28
31
29
M
1.4E05
1.5E05
1.8E05
2.7E05
110
120
120
Dermal
H
-
-
-
-
200
220
200
Consumer uses: Furnishing,
cleaning, treatment care products:
Cleaning and furnishing care
Chronic
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
1.2E054
1.2E054
1.5E054
2.2E054
1.3E05
1.7E05
2.0E05
Aggregate
H
1.2E05
1.2E05
1.5E05
2.2E05
200
220
200
products
Dermal
H
-
-
-
-
14
15
14
M
-
-
-
-
56
62
58
Ingestion
-
-
-
-
-
-
-
-
Acute
Inhalation
H
1.0E054
1.1E054
1.3E054
1.9E054
2.6E05
3.0E05
3.7E05
Waxes and polishes
Aggregate
H
1.0E05
1.1E05
1.3E05
1.9E05
14
15
14
M
1.6E05
1.7E05
2.0E05
2.9E05
56
62
58
Dermal
H
-
-
-
-
99
110
100
Chronic
Ingestion
-
-
-
-
-
-
-
-
Inhalation
H
8,5004
9,1004
1.1E044
1.6E044
2.0E04
2.4E04
2.9E04
Aggregate
H
8,500
9,100
1.1E04
1.6E04
98
110
100
Consumer uses: Packaging, paper,
plastic, toys, hobby products: Ink,
toner, and colorant products
No consumer products identified. Foreseeable uses were matched with adhesives for small repairs because similar use patterns are expected.
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PUBLIC RELEASE DRAFT
May 2025
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lifestagc (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
years)
Consumer uses: Packaging, paper,
plastic, toys, hobby products;
Packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other articles
with routine direct contact during
normal use, including rubber
articles; plastic articles (hard)
Footwear
components
Acute
Dermal
H
60
70
81
100
130
140
130
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Chronic
Dermal
H
60
70
81
100
130
140
130
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Shower curtains
Acute
Dermal
H
340
400
460
570
720
780
730
Ingestion c
H
1.1E06
9.0E05
8.0E05
2.3E06
4.1E06
5.1E06
1.1E07
Inhalation c
H
1.4E04
1.5E04
1.8E04
2.6E04
3.7E04
4.3E04
5.3E04
Aggregate
H
330
380
450
550
700
770
720
Chronic
Dermal
H
340
400
460
570
720
780
730
Ingestion c
H
3.7E06
3.0E06
2.6E06
7.5E06
1.3E07
1.7E07
3.8E07
Inhalation c
H
6.6E04
7.0E04
8.6E04
1.2E05
1.7E05
2.0E05
2.5E05
Aggregate
H
340
390
450
560
710
780
730
Small articles with
semi routine contact;
miscellaneous items
including a pen,
pencil case, hobby
cutting board,
costume jewelry,
tape, garden hose,
disposable gloves,
and plastic
bags/pouches
Acute
Dermal
H
120
140
160
200
250
280
260
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Chronic
Dermal
H
120
140
160
200
250
280
260
Ingestion
—
—
—
—
—
—
—
—
Inhalation
Page 266 of 333
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PUBLIC RELEASE DRAFT
May 2025
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lifestagc (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
years)
Consumer uses: Packaging, paper,
plastic, toys, hobby products:
Toys, playground, and sporting
equipment
Children's toys
(New)
Acute
Dermal
H
110
130
150
190
240
260
-
Ingestion c
H
52
200
380
8.5E04
1.5E05
1.9E05
4.3E05
Inhalation c
H
690
740
900
1,300
1,800
2,200
2,700
Aggregate
H
34
71
97
160
210
230
2,700
Chronic
Dermal
H
110
130
150
190
240
260
-
Ingestion c
H
52
200
390
2.8E05
5.1E05
6.4E05
1.4E06
Inhalation c
H
3,300
3,500
4,300
6,200
8,800
1.0E04
1.3E04
Aggregate
H
35
77
110
180
230
250
1.3E04
Children's toys
(Legacy)
Acute
Dermal
H
110
130
150
190
240
260
-
Ingestion c
H
51
190
340
8,500
1.5E04
1.9E04
4.3E04
Inhalation c
H
69
74
90
130
180
220
270
Aggregate
H
23
38
49
76
100
120
270
Aggregate
M
64
91
120
180
230
250
1,400
Chronic
Dermal
H
110
130
150
190
240
260
-
Ingestion c
H
52
190
370
2.8E04
5.1E04
6.4E04
1.4E05
Inhalation c
H
330
350
430
620
880
1,000
1,300
Aggregate
H
32
64
86
140
190
210
1,300
Tire crumb
Acute
Dermal
H
-
-
1.1E06
1.2E06
1.6E06
1.8E06
1.7E06
Ingestion
H
-
-
3.4E08
7.7E08
1.4E09
3.5E09
3.9E09
Inhalation
H
-
-
2.5E08
3.7E08
1.9E08
3.6E08
3.9E08
Aggregate
H
-
-
1.1E06
1.2E06
1.5E06
1.8E06
1.7E06
Chronic
Dermal
H
-
-
5.4E06
5.7E06
4.1E06
4.7E06
8.0E06
Ingestion
H
-
-
1.6E09
3.6E09
3.6E09
9.1E09
1.8E10
Inhalation
H
-
-
1.2E09
1.7E09
5.0E08
9.5E08
1.8E09
Aggregate
H
-
-
5.3E06
5.7E06
4.1E06
4.6E06
8.0E06
Small articles with
semi routine contact;
miscellaneous items
including a football,
balance ball, and pet
toys
Acute
Dermal
H
120
140
160
200
250
280
260
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Chronic
Dermal
H
120
140
160
200
250
280
260
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Page 267 of 333
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PUBLIC RELEASE DRAFT
May 2025
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lifestagc (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T ccnagcrs
(16-20
years)
Adults
(21+
years)
Consumer uses: Other:
Chemiluminescent light sticks
Small articles with
semi routine contact;
glow sticks
Acute
Dermal
H
120
140
160
200
250
280
260
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Chronic
Dermal
H
120
140
160
200
250
280
260
Ingestion
-
-
-
-
-
-
-
-
Inhalation
-
-
-
-
-
-
-
-
Consumer uses: Other uses:
Automotive articles
Car mats
Acute
Dermal
H
-
-
-
-
1,800
2,000
1,800
Ingestion c
H
3.8E06
3.1E06
2.8E06
7.7E06
1.3E07
1.7E07
3.4E07
Inhalation c
H
6.1E04
6.5E04
7.9E04
1.1E05
1.6E05
1.9E05
2.4E05
Aggregate
H
6.0E04
6.3E04
7.7E04
1.1E05
1,800
1,900
1,800
Chronic
Dermal
H
-
-
-
-
1.3E04
1.4E04
1.3E04
Ingestion c
H
1.3E07
1.1E07
9.5E06
2.6E07
4.5E07
5.7E07
1.2E08
Inhalation c
H
3.0E05
3.1E05
3.9E05
5.6E05
7.9E05
9.2E05
1.1E06
Aggregate
H
2.9E05
3.1E05
3.7E05
5.4E05
1.2E04
1.4E04
1.3E04
Synthetic leather
seats (see synthetic
leather furniture)
Acute
Dermal
H
_d
_d
_d
_d
_d
_d
_d
M
_d
_d
41
54
69
76
72
L
_d
140
160
200
250
280
260
Ingestion c
H
83
140
220
2.3E06
4.1E06
5.2E06
1.2E07
M
280
380
670
2.3E07
4.1E07
5.2E07
1.2E08
L
1.1E05
7.6E04
1.4E05
3.4E07
6.1E07
7.7E07
1.7E08
Inhalation c
H
5.7E04
6.0E04
7.4E04
1.1E05
1.5E05
1.8E05
2.2E05
M
5.8E05
6.1E05
7.5E05
1.1E06
1.5E06
1.8E06
2.2E06
L
8.8E05
9.3E05
1.1E06
1.6E06
2.3E06
2.7E06
3.4E06
Aggregate
H
83
140
220
1.0E05
1.5E05
1.7E05
2.1E05
M
280
380
39
54
69
76
72
L
9.7E04
140
160
200
250
280
260
Chronic
Dermal
H
_d
_d
_d
_d
_d
_d
_d
M
_d
_d
41
54
69
76
72
L
_d
140
160
200
250
280
260
Ingestion c
H
83
140
220
2.5E06
4.5E06
5.7E06
1.3E07
M
280
380
670
2.5E07
4.5E07
5.7E07
1.3E08
L
1.1E05
7.6E04
1.4E05
3.7E07
6.7E07
8.4E07
1.9E08
Page 268 of 333
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PUBLIC RELEASE DRAFT
May 2025
Lite Cycle Stage: COU:
Subcategory
Product or Article
Duration
Exposure
Route
Exposure
Scenario
(H, M, L) a
Lifestage (years) MOE
(Benchmark MOE = 30)
Infant
(<1
Year)
Toddler
(1-2
Years)
Pre-
schooler
(3-5
years)
Middle
Childhood
(6-10
years)
Young
T een
(11-15
years)
T eenagers
(16-20
years)
Adults
(21+
years)
Consumer uses: Other uses:
Automotive articles
Synthetic leather
seats (see synthetic
leather furniture)
Chronic
Inhalation c
H
5.9E04
6.3E04
7.7E04
1.1E05
1.6E05
1.8E05
2.3E05
M
6.0E05
6.4E05
7.9E05
1.1E06
1.6E06
1.9E06
2.3E06
L
9.2E05
9.7E05
1.2E06
1.7E06
2.4E06
2.8E06
3.5E06
Aggregate
H
83
140
220
1.1E05
1.5E05
1.8E05
2.2E05
M
280
380
39
54
69
76
72
L
120
140
160
200
250
280
260
Consumer uses: Other uses:
Novelty articles
Adult toys
Acute
Dermal
H
-
-
-
-
-
780
730
M
-
-
-
-
-
1,100
1,000
Ingestion
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
190
210
Inhalation
-
-
-
-
-
-
-
-
Aggregate
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
160
170
Chronic
Dermal
H
-
-
-
-
-
780
730
M
-
-
-
-
-
1,100
1,000
Ingestion
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
190
210
Inhalation
-
-
-
-
-
-
-
-
Aggregate
H
-
-
-
-
-
_d
_d
M
-
-
-
-
-
160
170
Consumer uses: Other uses:
Lubricants and lubricant additives
No consumer products identified. Foreseeable uses were matched with adhesives for small repairs because similar use patterns are expected.
"Exposure scenario intensities include high (H), medium (M), and low (L).
4 MOE for bystander scenario
c Exposure routes evaluated for indoor environments.
d Scenario was deemed to be unlikely due to high uncertainties.
Bold text in a gray shaded cell indicates an MOE below the benchmark value of 30.
6094
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6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
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REFERENCES
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0022
ACC. (2023). ACC High Phthalates Panel response to the US EPA information request dated September
5, 2023 relevant to the DINP and DIDP risk evaluations. Washington, DC.
Adachi. A; Asa. K; Okano. T. (2006). Efficiency of rice bran for removal of di-n-butyl phthalate and its
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AIHA. (2009). Mathematical models for estimating occupational exposure to chemicals. In CB Keil; CE
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ams.aiha.org/amsssa/ecssashop.show product detail?p mode=detail&p product semo=889
Armada. D; Llompart. M; Celeiro. M; Garcia-C astro. P; Ratola. N: Dagnac. T; de Boer. J. (2022).
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AT SDR. (1999). Toxicological profile for di-n-butyl phthalate (update): Draft for public comment
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ATSDR. (2001). Toxicological Profile For Di-n-Butyl Phthalate [ATSDR Tox Profile],
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Chen ii. Y; Wan. Q; Yuan. L; Yu. X. (2018). Pegradation of dibutyl phthalate in two contrasting
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6150
6151
6152
6153
6154
6155
6156
6157
6158
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6161
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6189
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CP SC. (2010). Toxicity review of di-n-butyl phthalate. In Toxicity review for di-n-butyl phthalate
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CP SC. (2014). Chronic Hazard Advisory Panel on phthalates and phthalate alternatives (with
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Danish EPA. (2016). Survey No. 117: Determination of migration rates for certain phthalates.
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Doan. K; Bronaugh. RL; Yourick. II. (2010). In vivo and in vitro skin absorption of lipophilic
compounds, dibutyl phthalate, farnesol and geraniol in the hairless guinea pig. Food Chem
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Dodson. RE: Nishioka. M; Standkn 1 < l^novicb 1 iv. JG: Rudel. RA. (2012). Endocrine
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935-943. http://dx.doi.cnv l _ - 3/ehn llOlO'v
)oratories. (2018). Dibutyl phthalate: Medaka extended one generation reproduction test (final
report). (83260). Washington, DC: U.S. Environmental Protection Agency.
EC/HC. (1994). Canadian environmental protection act priority substances list assessment report:
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(2002b). A review of the reference dose and reference concentration processes [EPA Report],
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evaluation manual, (part E: Supplemental guidance for dermal risk assessment).
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multiple chemicals, exposures, and effects: A resource document [EPA Report], (EPA/600/R-
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Program], Washington, DC.
(2011a). Exposure factors handbook: 2011 edition [EPA Report], (EPA/600/R-090/052F).
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Washington, DC. http://cfpub.epa.gov/ncea/cfM/recordisplay.cfm?deid=236252
(201 lc). Recommended use of body weight 3/4 as the default method in derivation of the oral
reference dose. (EPA100R110001). Washington, DC.
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U.S. EPA. (2012a). Benchmark dose technical guidance [EPA Report], (EPA 100R12001). Washington,
DC: U.S. Environmental Protection Agency, Risk Assessment Forum.
https://www.epa.gov/risk/benchmark-dose-technical-guidance
U.S. EPA. (2012b). Estimation Programs Interface Suite™ for Microsoft® Windows, v 4.1 1 [Computer
Program], Washington, DC. Retrieved from https://www.epa.gov/tsca-screening-tools/epi-
suitetm-estimation-program-interface
U.S. EPA. (2012c). Standard operating procedures for residential pesticide exposure assessment.
Washington, DC: U.S. Environmental Protection Agency, Office of Pesticide Programs.
https://www.epa.gov/sites/default/files/2015-08/documents/usepa-opp-
hj dential sops oct2012.pdf
U.S. EPA. (2014). Framework for human health risk assessment to inform decision making. Final [EPA
Report], (EPA/100/R-14/001). Washington, DC: U.S. Environmental Protection, Risk
Assessment Forum, https://www.epa.gov/risk/framework-human-health-risk-assessment-inform-
decisi on-making
U.S. EPA. (2016a). Hydraulic fracturing for oil and gas: Impacts from the hydraulic fracturing water
cycle on drinking water resources in the United States [EPA Report], (EPA/600/R-16/236F).
Washington, DC. https://cfpub.epa.gov/ncea/hfstudy/recordisplay.cfm?deid=332990
U.S. EPA. (2016b). Pesticide cumulative risk assessment: Framework for screening analysis.
Washington, DC: Office of Pesticide Programs, https://www.epa.gov/pesticide-science-and-
assessing-pesticide-risks/pesticide-cumulative-risk-assessment-framework
U.S. EPA. (2016c). Weight of evidence in ecological assessment [EPA Report], (EPA/100/R-16/001).
Washington, DC: Office of the Science Advisor.
https://nepis.epa. gov/Exe/ZyPURL.cgi?Dockey=P 100SFXR.txt
U.S. EPA. (2017). Estimation Programs Interface Suite™ v.4.1 1. Washington, DC: U.S. Environmental
Protection Agency, Office of Pollution Prevention Toxics. Retrieved from
https://www.epa.gov/tsca-screening-tools/download-epi-suitetm-estimation-program-interface-
v411
U.S. EPA. (2018). ChemView. Retrieved from https://chemview.epa.gov/chemview
U.S. EPA. (2019a). 40 CFR 1307: Prohibition of children's toys and child care articles containing
specified phthalates. (Code of Federal Regulations Title 16 Part 1307).
(2019b). 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. (2019c). Chemistry Dashboard Information for Dibutyl Phthalate. 84-74-2.
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U.S. EPA. (2019d). Guidelines for human exposure assessment [EPA Report], (EPA/100/B-19/001).
Washington, DC: Risk Assessment Forum. https://www.epa.gov/sites/production/files/2Q2Q-
01/documents/guidelinesfor human exposure assessment fiimaC If
U.S. EPA. (2019e). National Emissions Inventory (NE1) [database]: CASRNs 79-00-5, 75-34-3, 107-06-
2, 78-87-5, 84-61-7, 106-99-0, 106-93-4, 50-00-0, 85-44-9, 106-46-7, 85-68-7, 84-74-2, 117-81-
7, and 115-86-6 [Database], Washington, DC. Retrieved from https://www.epa.gov/air~
emissions-inventories/national-emissions-inventorv-nei
U.S. EPA. (2019f). Synthetic turf field recycled tire crumb rubber research under the Federal Research
Action Plan, Final report part 1: Tire crumb rubber characterization, volume 1. (EPA/600/R-
19/051.1). Washington, DC: U.S. Environmental Protection Agency, ATSDR, CDC.
https://www.epa.gov/sites/default/files/2019~
08/documents/synthetic turf field recycled tire crumb rubber research under the federal res
earch action plan final report part 1 volume 1 .pdf
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 dibutyl phthalate (1,2-benzenedicarboxylic
acid, 1,2-dibutyl ester); CASRN 84-74-2 [EPA Report], (EPA-740-R-20-016). Washington, DC:
Office of Chemical Safety and Pollution Prevention.
https://www.epa.gov/sites/default/files/2020-09/documents/casrn 84-74-
-,'»'butyl phthalate final scoi>' 0 |;df
U.S. EPA. (2020d). Letter regarding Department of Defense's (DoD) comments on DBP. Washington,
DC. https://www.regulations.gov/document/ Q-QPPT-2018-0503-0036
(2020e). Use report for dibutyl phthalate (DBP) - (1,2-Benzenedicarboxylic acid, 1,2- dibutyl
ester) (CAS RN 84-74-2). (EPA-HQ-OPPT-2018-0503-0023). Washington, DC: U.S.
Environmental Protection Agency. https://www.regulations.gov/document/EPA-HQ-OPPT-
2018-0503-0023
U.S. EPA. (202 la). 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.regulations.gov/document/EPA-HQ-OPPT-2'
0005
U.S. EPA. (202 lb). Final scope of the risk evaluation for di-isodecyl phthalate (D1DP) (1,2-
benzenedicarboxylic acid, 1,2-diisodecyl ester and 1,2-benzenedicarboxylic acid, di-C9-ll-
branched alkyl esters, ClO-rich); CASRN 26761-40-0 and 68515-49-1 [EPA Report], (EPA-740-
R-21-001). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.epa.gov/system/files/documents/2021-08/casn di-isodecvl-phthalate-
final-scope.pdf
U.S. EPA. (202 lc). Final scope of the risk evaluation for di-isononyl phthalate (DINP) (1,2-benzene-
dicarboxylic acid, 1,2-diisononyl ester, and 1,2-benzenedicarboxylic acid, di-C8-10-branched
alkyl esters, C9-rich); CASRNs 28553-12-0 and 68515-48-0 [EPA Report], (EPA-740-R-21-
002). Washington, DC: Office of Chemical Safety and Pollution Prevention.
https://www.epa.gov/system/files/documents/2021-Q8/casrn-2l di-isononyl-phthalate-
final-scope.pdf
U.S. EPA. (202 Id). Generic model for central tendency and high-end inhalation exposure to total and
respirable Particulates Not Otherwise Regulated (PNOR). Washington, DC: Office of Pollution
Prevention and Toxics, Chemical Engineering Branch.
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U.S. EPA. (202 le). Use of additives in plastic compounding - Generic scenario for estimating
occupational exposures and environmental releases (Revised draft) [EPA Report], Washington,
DC: Office of Pollution Prevention and Toxics, Risk Assessment Division.
U.S. EPA. (2022a). Access chemical data reporting data: 2020 CDR data (up-to-date as of April 2022)
[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. (2022b). Draft TSCA. screening level approach for assessing ambient air and water exposures
to fenceline communities (version 1.0) [EPA Report], (EPA-744-D-22-001). Washington, DC:
Office of Chemical Safety and Pollution Prevention, U.S. Environmental Protection Agency.
https://www.epa.eov/sYStem/files/documents/20 lraft~fenceline~report sacc.pdf
U.S. EPA. (2022c). ORD staff handbook for developing IRIS assessments. (EPA600R22268).
Washington, DC: U.S. Environmental Protection Agency, Office of Research and Development,
Center for Public Health and Environmental Assessment.
https://cfpub.epa.eov/ncea/iris drafts/recordi spl ay. cfm ?deid=356370
U.S. EPA. (2023a). 2020 National Emissions Inventory (NEI) Data (August 2023 version) (Version
August 2023). Washington, DC: US Environmental Protection Agency. Retrieved from
https://www.epa.gov/air~emissions~inventories/2020~national~emissions~inventorv~nei~data
U.S. EPA. (2023b). Advances in dose addition for chemical mixtures: A white paper. (EPA/100/R-
23/001). Washington, DC. https://assessments.epa. gov/risk/document/&deid=
(2023c). Consumer Exposure Model (CEM) Version 3.2 User's Guide. Washington, DC.
https://www.epa.gov/tsca~screening~tools/consumer~exposure~model~cem~versio jters-
guide
U.S. EPA. (2023d). Draft Proposed Approach for Cumulative Risk Assessment of High-Priority
Phthalates and a Manufacturer-Requested Phthalate under the Toxic Substances Control Act.
(EPA-740-P-23-002). Washington, DC: U.S. Environmental Protection Agency, Office of
Chemical Safety and Pollution Prevention. https://www.regulations.gov/document/EPA-HQ-
QPPT-2022-0918-0009
U.S. EPA. (2023e). Draft Proposed Principles of Cumulative Risk Assessment under the Toxic
Substances Control Act. (EPA-740-P-23-001). Washington, DC: U.S. Environmental Protection
Agency, Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA~HQ-0] 22-0918-0008
U.S. EPA. (2023f). Methodology for estimating environmental releases from sampling waste (revised
draft). Washington, DC: Office of Pollution Prevention and Toxics, Chemical Engineering
Branch.
U.S. EPA. (2023g). Science Advisory Committee on Chemicals meeting minutes and final report. No.
2023-01 - A set of scientific issues being considered by the Environmental Protection Agency
regarding: Draft Proposed Principles of Cumulative Risk Assessment (CRA) under the Toxic
Substances Control Act and a Draft Proposed Approach for CRA of High-Priority Phthalates and
a Manufacturer-Requested Phthalate. (EPA-HQ-OPPT-2022-0918). Washington, DC: U.S.
Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA~HQ-OPPT-2022-0918-0067
U.S. EPA. (2023h). 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. (2024a). Discharge Monitoring Report (DMR) data: Dibutyl phthalate (DBP), reporting years
2017-2022. Washington, DC.
(2024b). Discussion with Dibutyl Phthalate (DBP) Stakeholder. Available online
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U.S. EPA. (2024c). Draft Environmental Hazard Assessment for Dibutyl Phthalate (DBP). Washington,
DC: Office of Pollution Prevention and Toxics, https://www.epa.gov/assessing-and-managing-
chemicals-under-tsca/risk-evaluation-dibutyl-phthalate-12-
benzene#:~:text=EPA%20designated%20DBP%20as%20a.undergoing%20risk%20evaluations
%20under%20TSCA.
U.S. EPA.. (2024d). Draft meta-analysis and benchmark dose modeling of fetal testicular testosterone for
di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP),
diisobutyl phthalate (DIBP), and dicyclohexyl phthalate (DCHP). Washington, DC: Office of
Pollution Prevention and Toxics.
U.S. EPA. (2024e). Draft Non-Cancer Human Health Hazard Assessment for Butyl Benzyl Phthalate
(BBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2024f). Draft Non-Cancer Human Health Hazard Assessment for Dibutyl Phthalate (DBP).
Washington, DC: Office of Pollution Prevention and Toxics, https://www.epa.gov/assessing-and-
manaeine-chemicals-under-tsca/risk-evaluation-dibutyl-phthalate-12-
benzene#:~:text=EPA%20designated%20DBP%20as%20a.undergoing%20risk%20evaluations
%20under%20TSCA.
U.S. EPA. (2024g). Draft non-cancer human health hazard assessment for Dicyclohexyl phthalate
(DCHP). Washington, DC: Office of Pollution Prevention and Toxics.
(2024h). Draft Non-Cancer Human Health Hazard Assessment for Diethylhexyl Phthalate
(DEHP). Washington, DC: Office of Pollution Prevention and Toxics.
(2024i). Draft Non-Cancer Human Health Hazard Assessment for Diisobutyl Phthalate
(DIBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2024j). Draft Physical Chemistry, Fate, and Transport Assessment for Dibutyl Phthalate
(DBP). Washington, DC: Office of Pollution Prevention and Toxics.
https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-evaluation-dibutvl-
phthc
benzene#:~:text=EPA%20designated%20DBP%20as%20a.undergoing%20risk%20evaluations
%20under%20TSCA.
U.S. EPA. (2024k). Draft Technical Support Document for the Cumulative Risk Analysis of Di(2-
ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP),
Diisobutyl Phthalate (DIBP), Dicyclohexyl Phthalate (DCHP), and Diisononyl Phthalate (DINP)
Under the Toxic Substances Control Act (TSCA). (EPA-740-D-24-019). Washington, DC:
Office of Chemical Safety and Pollution Prevention.
https://www.reeiilations.eov/dociiment/EPA-HQ-0] 0503-0077
U.S. EPA. (20241). Environmental Exposure Assessment for Diisodecyl Phthalate (DIDP). Washington,
DC: Office of Pollution Prevention and Toxics, https://www.reeiilations.eov/document/
HO-OPPT-2 [73
U.S. EPA. (2024m). Environmental hazard assessment for diisononyl phthalate (DINP). Washington,
DC: Office of Pollution Prevention and Toxics. https://www.reeulations.eov/docket/EPA-HQ-
QPPT-2018-0436
U.S. EPA. (2024n). Non-cancer human health hazard assessment for diisononyl phthalate (DINP).
Washington, DC: Office of Pollution Prevention and Toxics.
https://www.reeiilations.eov/docket/EPA-HQ-OPPT-2018-0436
U.S. EPA. (2024o). Toxics Release Inventory (TRI) data: Dibutyl phthalate (DBP), reporting years
2017-2022. Washington, DC.
(2025a). Draft Ambient Air IIOAC Exposure Results and Risk Calculations for Dibutyl
Phthalate (DBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2025b). Draft cancer human health hazard assessment for Di(2-ethylhexyl) Phthalate
(DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl Phthalate (DIBP),
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and Dicyclohexyl Phthalate (DCHP). Washington, DC: Office of Pollution Prevention and
Toxics.
U.S. EPA. (2025c). Draft Consumer and Indoor Exposure Assessment for Dibutyl Phthalate (DBP).
Washington, DC: Office of Pollution Prevention and Toxics.
(2025d). Draft Consumer Exposure Analysis For Dibutyl Phthalate (DBP). Washington, DC:
Office of Pollution Prevention and Toxics.
(2025e). Draft Consumer Risk Calculator For Dibutyl Phthalate (DBP). Washington, DC:
Office of Pollution Prevention and Toxics.
(2025f). Draft Data Extraction Information for Environmental Hazard and Human Health
Hazard Animal Toxicology and Epidemiology for Dibutyl Phthalate (DBP). Washington, DC:
Office of Pollution Prevention and Toxics.
U.S. EPA. (2025g). Draft Data Extraction Information for General Population, Consumer, and
Environmental Exposure for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution
Prevention and Toxics.
U.S. EPA. (2025h). Draft Data Quality Evaluation and Data Extraction Information for Dermal
Absorption for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution Prevention and
Toxics.
U.S. EPA. (2025i). Draft Data Quality Evaluation and Data Extraction Information for Environmental
Fate and Transport for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution Prevention
and Toxics.
U.S. EPA. (2025j). Draft Data Quality Evaluation and Data Extraction Information for Environmental
Release and Occupational Exposure for Dibutyl Phthalate (DBP). Washington, DC: Office of
Pollution Prevention and Toxics.
U.S. EPA. (2025k). Draft Data Quality Evaluation and Data Extraction Information for Physical and
Chemical Properties for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution
Prevention and Toxics.
U.S. EPA. (20251). Draft Data Quality Evaluation Information for Environmental Hazard for Dibutyl
Phthalate (DBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2025m). Draft Data Quality Evaluation Information for General Population, Consumer, and
Environmental Exposure for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution
Prevention and Toxics.
U.S. EPA. (2025n). Draft Data Quality Evaluation Information for Human Health Hazard Animal
Toxicology for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution Prevention and
Toxics.
U.S. EPA. (2025o). Draft Data Quality Evaluation Information for Human Health Hazard Epidemiology
for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2025p). Draft Environmental Media and General Population and Environmental Exposure
for Dibutyl Phthalate (DBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2025q). Draft Environmental Release and Occupational Exposure Assessment for Dibutyl
Phthalate (DBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2025r). Draft Fish Ingestion Risk Calculator For Dibutyl Phthalate (DBP). Washington, DC:
Office of Pollution Prevention and Toxics.
(2025s). Draft Occupational and Consumer Cumulative Risk Calculator for Dibutyl Phthalate
(DBP). Washington, DC: Office of Pollution Prevention and Toxics.
(2025t). Draft Risk Calculator For Occupational Exposures For Dibutyl Phthalate (DBP).
Washington, DC: Office of Pollution Prevention and Toxics.
(2025u). Draft Summary of Human Health Hazard Animal Toxicology Studies for Dibutyl
Phthalate (DBP) - Literature Published from 2014 to 2019. Washington, DC: Office of Pollution
Prevention and Toxics.
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U.S. EPA. (2025v). Draft Surface Water Human Exposure Risk Calculator For Dibutyl Phthalate (DBP).
Washington, DC: Office of Pollution Prevention and Toxics.
(2025w). Draft systematic review protocol for Dibutyl phthalate (DBP). Washington, DC:
Office of Pollution Prevention and Toxics.
(2025x). Revised Draft Technical Support Document for the Cumulative Risk Analysis of
Di(2-ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP),
Diisobutyl Phthalate (DIBP), Dicyclohexyl Phthalate (DCHP), and Diisononyl Phthalate (DINP)
Under the Toxic Substances Control Act (TSCA). Washington, DC: Office of Pollution
Prevention and Toxics.
Vaproshield. (2018). Safety Data Sheet (SDS): VaproLiqui-flash. Vaproshield L.
W.R. Grace. (2024). Memorandum For The Record: Meeting with W. R. Grace & Co.-Conn. (Grace)
and EPA to Discuss Phthalates in Catalyst Systems Used in the Manufacture of Plastics.
Waim art. (2019). Devcon weld-it all purpose waterproof household cement. W aim art.
Warn i. P; Shi. H; Qian. Y. (1997). Biodegradation of phthalic acid ester in soil by indigenous and
introduced microorganisms. Chemosphere 35: 1747-1754. http://dx.doi.oi ^80045-
6535(97)00255-5
Whelton. \< v Uannahan. J: Boor. BE; Howarter \ tnittgMood. IP; Jafvert. CT. (2017). Cured-In-
Place-Pipe (CIPP): Inhalation and dermal exposure risks associated with sanitary sewer, storm
sewer, and drinking water pipe repairs. Available online at https://blogs.cdc.gov/niosh-science-
btog/ 9/26/cipp/
Wine. RN; Li. LH; Barnes. LH; Gulati. DK; Chapin. RE. (1997). Reproductive toxicity of di-n-
butylphthalate in a continuous breeding protocol in Sprague-Dawley rats. Environ Health
Perspect 105: 102-107. http://dx.doi.org/ Vehp.97105102
Woff ¥ilsey. CD: Neff. GS: Giam. CS: NefF. JM. (1981). Bioaccumulation and metabolism of
phthalate esters by oysters, brown shrimp, and sheepshead minnows. Ecotoxicol Environ Saf 5:
202-210. http://dx.doi.cny 10 tOt; 01 I M V'0035-x
Wolfe. NL: Steen. WC: Burns. LA. (1980). Phthalate ester hydrolysis: Linear free energy relationships.
Chemosphere 9: 403-408. http://dx.doi.org/10.1016/0045-6535(80)90023-5
WSDE. (2020). High Priority Chemicals Data System (HPCDS) [Database], Retrieved from
https://hpcds.theic2.org/Search
WSDE. (2023). PTDB Reporting: Product Testing Database [Database], Lacey, WA. Retrieved from
https://apps.ecology.wa.gov/ptdbreporting/Default.aspx
Xiam 1 W^.XD: Chen \U \t<. i U It VA It U i ,» faou. DM: Wong. MM. 1 i. OX.
(2019). Sorption Mechanism, Kinetics, and Isotherms of Di- n-butyl Phthalate to Different Soil
Particle-Size Fractions. J Agric Food Chem 67: 4734-4745.
http://dx.doi.org/10J02 l/acs.iafc.8b06357
Xu 1 j t \\ ang. O (2008). Occurrence and degradation characteristics of dibutyl phthalate (DBP)
and di-(2-ethylhexyl) phthalate (DEHP) in typical agricultural soils of China. Sci Total Environ
393: 333-340. http://dx.doi.org/10.1016/i.scitotenv.200S 01 001
Yuan. SY: Ltti \ \ t iiang 1H (201 1). Biodegradation of phthalate esters in polluted soil by using
organic amendment. J Environ Sci Health B 46: 419-425.
http://dx.doi.org 10 1080/03601234.201 I -
Yuan. SY: Liu. C: Liao. CS: Chan (2002). Occurrence and microbial degradation of phthalate
esters in Taiwan river sediments. Chemosphere 49: 1295-1299. http://dx.doij )045-
6535(02)00495-2
Zhao. H: Du. H: Fein 'x \t.tng. L. ei: Li t. H. ui: Cai «Mo. C. (2016). Biodegradation of di-n-
butylphthalate and phthalic acid by a novel Providencia sp 2D and its stimulation in a compost-
amended soil. Biol Fertil Soils 52: 65-76. http://dx.doi.otv 10 100 100 '< I 01 ^ 10 "4-8
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6831
6832
6833
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6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
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APPENDICES
Appendix A KEY ABBREVIATIONS AND ACRONYMS
ADD
Average daily dose
ADC
Average daily concentration
AERMOD
American Meteorological Society/EPA Regulatory Model
BBP
Butyl benzyl phthalate
BLS
Bureau of Labor Statistics
CAP
Criteria Air Pollutant
CASRN
Chemical Abstracts Service Registry Number
CBI
Confidential business information
CDC
Centers for Disease Control and Prevention (U.S.)
CDR
Chemical Data Reporting
CEHD
Chemical Exposure Health Data
CEM
Consumer Exposure Model
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act
CFR
Code of Federal Regulations
COC
Concentration of concern
CPSC
Consumer Product Safety Commission
CWA
Clean Water Act
DBP
Dibutyl phthalate
DCHP
Dicyclohexyl phthalate
DEHP
Diethylhexyl phthalate
DIBP
Diisobutyl phthalate
DIDP
Diisodecyl phthalate
DINP
Dicyclohexyl phthalate
DIY
Do-it-yourself
DMR
Discharge Monitoring Report
ECJRC
European Commission's Joint Research Centre
EPA
Environmental Protection Agency (or "the Agency")
EPCRA
Emergency Planning and Community Right-to-Know Act
ESD
Emission Scenario Document
EU
European Union
FDA
Food and Drug Administration
FFDCA
Federal Food, Drug, and Cosmetic Act
GS
Generic scenario
Koc
Soil organic carbon: water partitioning coefficient
Kow
Octanol: water partition coefficient
HAP
Hazardous Air Pollutant
HEC
Human equivalent concentration
HED
Human equivalent dose
HV
Hazard value
IADD
Intermediate average daily dose
IIOAC
Integrated Indoor/Outdoor Air Calculator (Model)
IR
Ingestion rate
LCD
Life cycle diagram
LOD
Limit of detection
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6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
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LOAEL
Lowest-observed-adverse-effect level
LOEC
Lowest-observed-effect concentration
Log Koc
Logarithmic organic carbon: water partition coefficient
Log Kow
Logarithmic octanol: water partition coefficient
MBP
Monobutyl phthalate
MOE
Margin of exposure
NAICS
North American Industry Classification System
NEI
National Emissions Inventory
NHANES
National Health and Nutrition Examination Survey
NHDPlus
National Hydrography Dataset Plus
NICNAS
National Industrial Chemicals Notification and Assessment Scheme
NOAEL
No-observed-adverse-effect level
NOEC
No-observed-effect-concentration
NPDES
National Pollutant Discharge Elimination System
NTP
National Toxicology Program
OCSPP
Office of Chemical Safety and Pollution Prevention
OECD
Organisation for Economic Co-operation and Development
OEL
Occupational exposure limit
OES
Occupational exposure scenario
OEV
Occupational exposure value
ONU
Occupational non-user
OPPT
Office of Pollution Prevention and Toxics
OSHA
Occupational Safety and Health Administration (U.S.)
P50
The 50th percentile or median flow rate of a distribution of hydrologic flows
P75
The 75th percentile flow rate of a distribution of hydrologic flows
P90
The 90th percentile flow rate of a distribution of hydrologic flows
PBZ
Personal breathing zone
PECO
Population, exposure, comparator, and outcome
PEL
Permissible exposure limit (OSHA)
PESS
Potentially exposed or susceptible subpopulations
PND
Postnatal day
PNOR
Particulates not otherwise regulated
POD
Point of departure
POTW
Publicly owned treatment works
PPAR.a
Peroxisome proliferator activated receptor alpha
PV
Production volume
PVC
Polyvinyl chloride
REL
Recommended Exposure Limit
RPF
Relative potency factor
SACC
Science Advisory Committee on Chemicals
SDS
Safety data sheet
SOC
Standard Occupational Classification
SpERC
Specific Emission Release Category
SSD
Species sensitivity distribution
SUSB
Statistics of U.S. Businesses (U.S. Census)
TOC
Total organic carbon
TRI
Toxic Release Inventory
TRV
Toxicity reference value
TSCA
Toxic Substances Control Act
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6916 TSD Technical support document
6917 TWA Time-weighted average
6918 UF Uncertainty factor
6919 U.S. United States
6920 VVWM-PSC Variable Volume Water Model with Point Source Calculator Tool
6921 WWTP Wastewater treatment plant
6922 7Q10 The lowest 7-day average flow that occurs (on average) once every 10 years
6923 30Q5 The lowest 30-day average flow that occurs (on average) once every 5 years
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6924 Appendix B REGULATORY AND ASSESSMENT HISTORY
6925 B.l Federal Laws and Regulations
6926
6927 Table Apx B-l. Federal Laws and Regulations
Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
EPA statutes/regulations
Toxic Substances
Control Act (TSCA) -
section 6(b)
EPA is directed to identify high-
priority chemical substances for risk
evaluation; and conduct risk
evaluations on at least 20 high priority
substances no later than three and one-
half years after the date of enactment
of the Frank R. Lautenberg Chemical
Safety for the 21st Century Act.
Dibutyl phthalate is one of the 20
chemicals EPA designated as a High-
Priority Substance for risk evaluation
under TSCA (84 FR 71924. December
30, 2019). Designation of dibutyl
phthalate as high-priority substance
constitutes the initiation of the risk
evaluation on the chemical.
Toxic Substances
Control Act (TSCA) -
section 8(a)
The TSCA section 8(a) CDR Rule
requires manufacturers (including
importers) to give EPA basic exposure-
related information on the types,
quantities and uses of chemical
substances produced domestically and
imported into the United States.
Dibutyl phthalate manufacturing
(including importing), processing and
use information is reported under the
CDR rule (85 FR 20122. Aoril 9.
2020).
Toxic Substances
Control Act (TSCA) -
section 8(b)
EPA must compile, keep current and
publish a list (the TSCA Inventory) of
each chemical substance manufactured
(including imported) or processed in
the United States.
Dibutyl phthalate was on the initial
TSCA Inventory and therefore was not
subject to EPA's new chemicals review
process under TSCA Section 5 (60 FR
16309. March 29. 1995V
Toxic Substances
Control Act (TSCA) -
section 8(e)
Manufacturers (including importers),
processors, and distributors must
immediately notify EPA if they obtain
information that supports the
conclusion that a chemical substance or
mixture presents a substantial risk of
injury to health or the environment.
Seven substantial risk reports received
for dibutyl phthalate (1996 -2010)
(U.S. EPA. 2018). Accessed April 8.
2019).
Toxic Substances
Control Act (TSCA) -
section 4
Provides EPA with authority to issue
rules and orders requiring
manufacturers (including importers)
and processors to test chemical
substances and mixtures.
In 1989, EPA entered an Enforceable
Consent Agreement under TSCA
Section 4 with six companies to
perform certain chemical fate and
environmental effects on certain Alkyl
Phthalates (54 FR 618. January 9.
1989).
Twelve chemical data submissions
from test rules received for dibutyl
phthalate: 1 acute aquatic plant toxicity,
8 acute aquatic toxicity, 2 chronic
aquatic toxicity, and 1 vapor pressure.
(U.S. EPA, 2018). Listings undated.
Accessed April 8, 2019.
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
Emergency Planning
and Community Right-
To-Know Act (EPCRA)
- section 313
Requires annual reporting from
facilities in specific industry sectors
that employ 10 or more full-time
equivalent employees and that
manufacture, process or otherwise use
a TRI-listed chemical in quantities
above threshold levels. A facility that
meets reporting requirements must
submit a reporting form for each
chemical for which it triggered
reporting, providing data across a
variety of categories, including
activities and uses of the chemical,
releases and other waste management
(e.g., quantities recycled, treated,
combusted) and pollution prevention
activities (under section 6607 of the
Pollution Prevention Act). These data
include on- and off-site data as well as
multimedia data (i.e., air, land and
water).
Dibutyl phthalate is a listed substance
subject to reporting requirements under
40 CFR 372.65 effective as of Januarv
01, 1987.
Clean Air Act (CAA) -
section 112(b)
Defines the original list of 189
Hazardous Air Pollutants (HAPs).
Under 112(c) of the CAA, EPA must
identify and list source categories that
emit HAP and then set emission
standards for those listed source
categories under CAA section 112(d).
CAA section 112(b)(3)(A) specifies
that any person may petition the
Administrator to modify the list of
HAP by adding or deleting a substance.
Since 1990, EPA has removed two
pollutants from the original list leaving
187 at present.
Dibutyl phthalate is listed as a HAP (42
).
Clean Air Act (CAA) -
section 112(d)
Directs EPA to establish, by rule,
NESHAPs for each category or
subcategory of listed major sources and
area sources of HAPs (listed pursuant
to section 112(c)). For major sources,
the standards must require the
maximum degree of emission reduction
that EPA determines is achievable by
each particular source category. This is
generally referred to as maximum
achievable control technology
(MACT). For area sources, the
standards must require generally
achievable control technology (GACT)
though may require MACT.
EPA has established NESHAPs for a
number of source categories that emit
dibutyl phthalate to air (see
littos://www.eDa.eov/stationarv-
sources-air-Dollution/national-
emission-standards-hazardous-air-
Dollutants-neshaD-9)
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
Clean Water Act (CWA)
- section 304(a)(1)
Requires EPA to develop and publish
ambient water quality criteria (AWQC)
reflecting the latest scientific
knowledge on the effects on human
health that may be expected from the
presence of pollutants in any body of
water.
In 2015, EPA published updated
AWQC for dibutyl phthalate, including
a recommendation of 20 (ig/L for
"Human Health for the consumption of
Water + Organism" and 30 (ig/L for
"Human Health for the consumption of
Organism Only" for states and
authorized tribes to consider when
adopting criteria into their water quality
standards. (Docket ID: EPA-HO-OW-
2014-0135-0242)
Clean Water Act
(CWA) - sections 301,
304, 306, 307, and 402
Clean Water Act section 307(a)
establishes a list of toxic pollutants or
combination of pollutants under the
CWA. The statute specifies a list of
families of toxic pollutants also listed
in the Code of Federal Regulations at
40 CFR Part 401.15. The "priority
pollutants" specified by those families
are listed in 40 CFR Part 423 Appendix
A. These are pollutants for which best
available technology effluent
limitations must be established on
either a national basis through rules
(sections 301(b), 304(b), 307(b), 306)
or on a case-by-case best professional
judgement basis in NPDES permits,
see section 402(a)(1)(B). EPA
identifies the best available technology
that is economically achievable for that
industry after considering statutorily
prescribed factors and sets regulatory
requirements based on the performance
of that technology.
Dibutyl phthalate is designated as a
toxic pollutant under section
307(a)(1) of the CWA and as such is
subject to effluent limitations. (40
CFR 401.15).
Under CWA section 304, dibutyl
phthalate is included in the list of total
toxic oraanics (TTO) (40 CFR
413.02(i)).
Clean Water Act
(CWA) - sections
311(b) (2) (A) and
501(a) of the Federal
Water Pollution Control
Act.
Requires EPA to develop, promulgate,
and revise as may be appropriate,
regulations designating as hazardous
substances, other than oil, which, when
discharged present an imminent and
substantial danger to the public health
or welfare, including, but not limited
to, fish, shellfish, wildlife, shorelines,
and beaches.
Dibutvl phthalate is a designated
hazardous substance in accordance with
Secti .1 ^ 1 U s»K 2)1 A) of the Federal
Water Pollution Control Act.
Resource Conservation
and Recovery Act
(RCRA) - section 3001
Directs EPA to develop and
promulgate criteria for identifying the
characteristics of hazardous waste, and
for listing hazardous waste, taking into
account toxicity, persistence, and
degradability in nature, potential for
accumulation in tissue and other
Dibutyl phthalate is included on the list
of hazardous wastes pursuant to RCRA
3001. RCRA Hazardous Waste Code:
U069 (40 CFR 261.33).
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
related factors such as flammability,
corrosiveness, and other hazardous
characteristics.
Comprehensive
Environmental
Response, Compensation
and Liability Act
(CERCLA) - sections
102(a) and 103
Authorizes EPA to promulgate
regulations designating as hazardous
substances those substances which,
when released into the environment,
may present substantial danger to the
public health or welfare or the
environment. EPA must also
promulgate regulations establishing the
quantity of any hazardous substance
the release of which must be reported
under section 103.
Section 103 requires persons in charge
of vessels or facilities to report to the
National Response Center if they have
knowledge of a release of a hazardous
substance above the reportable quantity
threshold.
Dibutyl phthalate is a hazardous
substance under CERCLA. Releases of
dibutyl phthalate in excess of 10 lb
must be reported (40 CFR 302.4).
Superfund Amendments
and Reauthorization Act
(SARA) -
Requires the Agency to revise the
hazardous ranking system and update
the National Priorities List of
hazardous waste sites, increases state
and citizen involvement in the
superfund program and provides new
enforcement authorities and settlement
tools.
Dibutyl phthalate is listed on SARA, an
amendment to CERCLA and the
CERCLA Priority List of Hazardous
Substances. This list includes
substances most commonly found at
facilities on the CERCLA National
Priorities List (NPL) that have been
deemed to pose the greatest threat to
public health.
Oilier federal sUilules ivijulalions
Federal Food, Drug, and
Cosmetic Act (FFDCA)
Provides the FDA with authority to
oversee the safety of food, drugs and
cosmetics.
Dibutyl phthalate is listed as an
optional substance to be used in:
adhesives to be used as components
of articles intended for use in
packaging, transporting, or holding
food (21 CFR 175.105); the base
sheet and coating of cellophane,
alone or in combination with other
phthalates where total phthalates do
not exceed 5 percent ( R
177.1200).
The FDA has reviewed phthalates in
cosmetic products but does not
restrict their use.
Consumer Product Safety
Improvement Act of
2008 (CPSIA)
Under section 108 of the Consumer
Product Safety Improvement Act of
2008, CPSC prohibits the manufacture
for sale, offer for sale, distribution in
The use of dibutyl phthalate at
concentrations greater than 0.1
percent is banned in toys and child
care articles (16 CFR part 1307).
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
commerce or importation of eight
phthalates in toys and childcare articles
at concentrations greater than 0.1
percent: di-ethylhexyl phthalate,
dibutyl phthalate, butyl benzyl
phthalate, di-isononyl phthalate, di-
isobutyl phthalate, di-n-pentyl
phthalate, di-n-hexyl phthalate and
dicyclohexyl phthalate.
Federal Hazardous
Materials Transportation
Act (HMTA)
Section 5103 of the Act directs the
Secretary of Transportation to:
• Designate material (including an
explosive, radioactive material,
infectious substance, flammable or
combustible liquid, solid or gas,
toxic, oxidizing or corrosive
material, and compressed gas) as
hazardous when the Secretary
determines that transporting the
material in commerce may pose an
unreasonable risk to health and
safety or property.
• Issue regulations for the safe
transportation, including security,
of hazardous material in intrastate,
interstate and foreign commerce.
Dibutyl phthalate is listed as a
hazardous material with regard to
transportation and is subject to
regulations prescribing requirements
applicable to the shipment and
transportation of listed hazardous
materials (70 FR 34381. June 14 2005).
("49 CFR Dart 172.101 Appendix A)
Occupational Safety and
Health Administration
(OSHA) Permissible
Exposure Limit (PEL)
Requires employers to provide their
workers with a place of employment
free from recognized hazards to safety
and health, such as exposure to toxic
chemicals, excessive noise levels,
mechanical dangers, heat or cold
stress or unsanitary conditions (29
U.S.C. § 651 et seq.). Under the Act,
OSHA can issue occupational safety
and health standards including such
provisions as Permissible Exposure
Limits (PELs), exposure monitoring,
engineering and administrative
control measures, and respiratory
protection.
Dibutvl phthalate is listed in OSHA
Tab . OSHA issued occupational
safety and health standards for dibutyl
phthalate that included a PEL of 5
mg/m3 as an 8-hour TWA.
6928
6929
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6930 B.2 State Laws and Regulations
6931
Table Apx B-2. State
^aws and Regulations
State Actions
Description of Action
State Air
Regulations
Allowable Ambient Levels: New Hampshire (E : Regulated Toxic
Air Pollutants); Rhode Island (Air Pollution Regulation No. 22)
State Drinking
Water Standards
and Guidelines
Florida (Fla. Admin. Code R Ch ); Michigan (Mich. Admin. Code
r.299.44 and v.: ). Minnesota (Minn R Chap. 4720).
State PELs
California (PEL of 5 DDm and no STEL) (Cal Code Regs. Title 8. ^ 1 ^);
Hawaii (PEL-TWA of 5 mg/m3 and PEL-STEL of 10 mg/m3) (Hawaii
Administrative Rules Section 12-60-50)
State Right-to-
Know Acts
Massachusetts (105 Code Mass. Regs. § 670.000 Appendix A); New Jersev
(8:59 N.J. Admin. Code § 9.1); Pennsylvania (P.L. 734. N ind 34 Pa.
Code § 323)
Chemicals of High
Concern to Children
Several states have adopted reporting laws for chemicals in children's
products containing dibutvl phthalate. including: Maine (38 MRS A. Chapter
16-D); Oregon (Toxic-Free Kids Act Senate Bill 478. 2015); Vermont (18
V.S.A § 1776); and Washington State (Wash. Admin. Code 173-334-130
Volatile Organic
Compound (VOC)
Regulations for
Consumer Products
California regulations may set VOC limits for consumer products and/or ban
the sale of certain consumer products as an ingredient and/or impurity.
California (Title 17. California Code of Regulations. Division 3. Chapter 1.
Subchapter ss 1. 2. 3 and 4). Under the Aerosol Coating Products
Regulation, a Maximum Incremental Reactivity value has been established
for dibutvl phthalate (Subchapter e 1. § 94700).
Other
California listed dibutyl phthalate on Proposition 65 in 2005 due to
developmental toxicity, female and male reproductive toxicity (Cal Code
Regs. Title 27. § 27001).
Dibutvl phthalate is listed as a Candidate Chemical under California's Safer
Consumer Products Program (Health and Safety Code § 25252 and 25253).
California issued a Health Hazard Alert for dibutvl phthalate (Hazard
Evaluation System and Information Service. 2016).
Dibutyl phthalate is on the Massachusetts Toxic Use Reduction Act (TURA)
list of 2019 (300 C ).
6933
6934
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693 5 B.3 International Laws and Regulations
6936
6937 Table Apx B-3. International Laws and Regulations
Country/
Organization
Requirements and Restrictions
Canada
Dibutvl phthalate is on the Domestic Substances List (Government of
Canada. Managing substances in the environment. Substances search
Database accessed April 10, 2019).
Other regulations include:
• Canada's National Pollutant Release Inventory (NPRI). Canada Gazette
Part II, Vol. 128, No. 9, May 04 1994, SOR/94-311
• Dibutvl ohthalate did not meet the criteria under subsection 73(1) of the
Canadian Environmental Protection A< ).
European Union
Dibutvl phthalate is registered for use in the EU. (European Chemicals
Agency (EC atabase. Accessed April 10. 2019.)
In 2008, dibutyl phthalate was listed on the Candidate list as a Substance
of Verv High Concern (SVHC) under regulation (EC) ' 306 -
REACH (Registration. Evaluation. Authorization and Restriction of
Chemicals due to its reproductive toxicity (category IB).
In 2012, dibutvl phthalate was added to Ann REACH
(Authorisation List) with a sunset date of December 21, 2015. After the
sunset date, only persons with approved authorization applications may
continue to use the chemical (European Chemicals Agency (ECHA)
database. The exempted category of use is: uses in the immediate
packaging of medicinal products covered under Regulation (EC) No
726/2004, Directive 2001/82/EC, and/or Directive 2001/83/EC. Accessed
April 10, 2019.
Applications for authorizations to use, including in propellants,
electronics manufacture and closed manufacturing processes:
Under Anne HL dibutvl phthalate:
1. shall not be used as substances or in mixtures, individually or in any
combination of the phthalates listed in column 1 of this entry, in a
concentration equal to or greater than 0,1 % by weight of the plasticized
material, in toys and childcare articles
2. shall not be placed on the market in toys or childcare articles,
individually or in any combination of the first three phthalates listed in
column 1 of this entry, in a concentration equal to or greater than 0,1 %
by weight of the plasticized material.
In addition, di-isobutyl phthalate shall not be placed on the market after 7
July 2020 in toys or childcare articles, individually or in any combination
with the first three phthalates listed in column 1 of this entry, in a
concentration equal to or greater than 0,1 % by weight of the plasticized
material.
3. Shall not be placed on the market after 7 July 2020 in articles,
individually or in any combination of the phthalates listed in column 1 of
this entry, in a concentration equal to or greater than 0,1 % by weight of
the plasticized material in the article.
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Country/
Organization
Requirements and Restrictions
4. Paragraph 3 shall not apply to:
(a) articles exclusively for industrial or agricultural use, or for use
exclusively in the open air, provided that no plasticized material comes
into contact with human mucous membranes or into prolonged contact
with human skin;
(b) aircraft, placed on the market before 7 January 2024, or articles,
whenever placed on the market, for use exclusively in the maintenance or
repair of those aircraft, where those articles are essential for the safety and
airworthiness of the aircraft;
(c) motor vehicles within the scope of Directive 2007/46/EC, placed on
the market before 7 January 2024, or articles, whenever placed on the
market, for use exclusively in the maintenance or repair of those vehicles,
where the vehicles cannot function as intended
without those articles;
(d) articles placed on the market before 7 July 2020;
(e) measuring devices for laboratory use, or parts thereof;
(f) materials and articles intended to come into contact with food within
the scope of Regulation (EC) No 1935/2004 or Commission Regulation
(EU)No 10/20111;
(g) medical devices within the scope of Directives 90/385/EEC,
93/42/EEC or 98/79/EC, or parts thereof;
(h) electrical and electronic equipment within the scope of Directive
2011/65/EU;
(i) the immediate packaging of medicinal products within the scope of
Regulation (EC) No 726/2004, Directive 2001/82/EC or Directive
2001/83/EC;
(j) toys and childcare articles covered by paragraphs 1 or 2.
5. For the purposes of paragraphs 1, 2, 3 and 4(a),
(a) 'plasticized material' means any of the following homogeneous
materials:
- polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinyl
acetate (PVA), polyurethanes,
- any other polymer (including, inter alia, polymer foams and rubber
material) except silicone rubber and natural latex coatings,
- surface coatings, non-slip coatings, finishes, decals, printed designs,
- adhesives, sealants, paints and inks.
European Commission Directive (ELJ) 2015/863 of 3 1 March 2015
amended Annex II to Directive 2011/65/EU, to restrict dibutyl phthalate
at 0.1% or greater so that:
- The restriction of dibutyl phthalate shall apply to medical devices,
including in vitro medical devices, and monitoring and control
instruments, including industrial monitoring and control instruments,
from 22 July 2021.
- The restriction of dibutyl phthalate shall not apply to cables or spare
parts for the repair, the reuse, the updating of functionalities or upgrading
of capacity of EEE placed on the market before 22 July 2019, and of
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Country/
Organization
Requirements and Restrictions
medical devices, including in vitro medical devices, and monitoring and
control instruments, including industrial monitoring and control
instruments, placed on the market before 22 July 2021.
- The restriction of dibutyl phthalate shall not apply to toys which are
already subject to the restriction of di-ethylhexyl phthalate, butyl benzyl
phthalate and dibutyl phthalate through entry 51 of Annex XVII to
Regulation (EC) No 1907/2006.
Dibutvl phthalate is subiect to the Restriction of Hazardous Substances
Directive (RoH ;63. which restricts the use of hazardous
substances at more than 0.1% by weight at the 'homogeneous material'
level in electrical and electronic equipment, beginning July 22, 2019.
(European Commission RoHS).
Australia
Dibutyl phthalate was assessed under Human Health and Environment
(Phthalate esters) Tier II of the Inventory Multi-Tiered Assessment and
Prioritisation (I ). Dibutyl phthalate has been listed and assessed as a
Priority Existing Chemical (PEC/36. November 2013).
NICNAS found no reports of the phthalate being manufactured as a raw
material in Australia. Dibutyl phthalate is imported into Australia mainly
as a component of finished products or mixtures and also as a raw
material for local formulation and processing. There are currently no
restrictions on the manufacture, import or use of dibutyl phthalate in
Australia.
Dibutyl phthalate is listed in the Safe Work Australia List of Designated
Hazardous Substances contained in the Hazardous Substances
Information System (HSIS) as a Reproductive Toxicant Category 2
(requiring it to be labelled with the risk phrase [R61]—May cause harm
to the unborn child); and Reproductive Toxicant Category 3 (requiring the
risk phrase [R62]—Possible risk of impaired fertility). Data accessed
April 10, 2019:
Japan
Dibutyl phthalate is regulated in Japan under the following legislation:
• Act on the Evaluation of Chemical Substances and Regulation of
Their Manufacture, etc, (Chemical Substances Control Law; CSCL)
• Act on Confirmation, etc. of Release Amounts of Specific Chemical
Substances in the Environment and Promotion of Improvements to
the Management Thereof
• Industrial Safety and Health Act (ISHA)
• Air Pollution Control Law
As referenced in the National Institute for National Institute for
Technology and Evaluation [NITE] Chemical Risk Information Platform
[ Accessed April 10, 2019
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Country/
Organization
Requirements and Restrictions
World Health
Organization (WHO)
Established a tolerable daily intake of 66 jag dibutyl phthalate/kg body
weight based on a LOAEL of 66 mg/kg body weight per day for
developmental and reproductive toxicity in rats from a continuous
breeding studv. incorporating an uncertainty factor of 1,000. (WHO
Environmental Health Criteria 189. 1997)
Australia, Austria,
Belgium, Canada,
Denmark, France,
Germany, Ireland,
Japan, Latvia, New
Zealand, Norway,
People's Republic of
China, Poland,
Romania, Singapore,
South Africa, South
Korea, Spain, Sweden,
Switzerland, United
Kingdom
Occupational exposure limits for dibutvl phthalate (GESTIS International
limit values for chemical agent1 > Occupational exposure limit < W 1 s)
database. Accessed February 14, 2025).
6938
B.4 Assessment History
Table Apx B-4. Assessment History of DBP
Authoring Organization
Publication(s)/Hyperlink(s) and Year
LIW publications
National Center lor Ln\ iionmental Assessment
Integrated Risk Information S\ stem (IRIS). chemical
assessment summary, dibutyl phthalate; CASRN 84-74-
2 ( k 1987)
Other I S -based organizations
National Academies of Sciences, Engineering, and
Medicine
Application of systematic review methods in an overall
strategy for evaluating low-dose toxicity from endocrine
active chemicals (NASEM, 2017)
U.S. Department of Health and Human Services,
Public Health Service, Agency for Toxic Substances
and Disease Registry (ATSDR)
Toxicoloaical Profile for Di-n-Butvl Phthalate (ATSDR.
2001)
U.S. Consumer Product Safety Commission (U.S.
CPSC)
Chronic Hazard Panel on Phthalates and Phthalate
Alternatives Final Report (with Appendices) CCPSC. 2014)
Toxicitv Review of DBP (CPSC, 2010)
National Toxicology Program (NTP), Center for the
Evaluation of Risks to Human Reproduction
(CERHR), National Institute of Health (NIH)
NTP-CERHR Monograph on the Potential Human
Reproductive and Developmental Effects of Di-n-Butyl
Phthalate (DBP) (NTP, 2003)
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Office of Environmental Health Hazard Assessment
(OEHHA), California Environmental Protection
\ucnc\
Proposition 65 Maximum Allowable Dose Level (MADL)
for Reproductive Toxicity for Di-(n-butyl)phthalate (DBP)
( )
Ink-riKilioiuil
European Union, European Chemicals Agency
(ECHA), European Chemicals Bureau (ECB)
European Union risk assessment report: Dibutyl phthalate.
Vol. 29. 1st prioritv list (ECJRC. 2003)
European Union Risk Assessment Report: Dibutyl
phthalate with addendum to the environmental section
(ECJRC. 2004)
Evaluation of new scientific evidence concerning the
restrictions contained in Annex XVII to Regulation (EC)
No 1907/2006 (REACH): Review of new available
information for dibutyl phthalate (DBP) CAS No 84-74-2
Einecs No 201-557-4 (ECHA. 2010)
Opinion on an Annex XV dossier proposing restrictions on
four Dhthalates (DEHP. BBP. DBP. DIBP) (ECHA. 2017b)
Annex to the Background document to the Opinion on the
Annex XV dossier proposing restrictions on four phthalates
(DEHP. BBP. DBP. DIBP) (ECHA. 2017a)
European Food Safety Authority (EFSA)
Opinion of the Scientific Panel on food additives,
flavourings, processing aids and materials in contact with
food (AFC) related to di-Butylphthalate (DBP) for use in
food contact materials (EFSA. 2005)
Update of the Risk Assessment of Di-butylphthalate
(DBP), Butyl-benzyl-phthalate (BBP), Bis(2-
ethylhexyl)phthalate (DEHP), Di-isononylphthalate
(DINP) and Di-isodecylphthalate (DIDP) for Use in Food
Contact Materials (EFSA. 2019)
Government of Canada, Environment Canada,
Health Canada
Canadian Environmental Protection Act: Priority
Substances List Assessment Report: Dibutyl Phthalate
(EC/HC. 1994)
Screening Assessment: Phthalate Substance Grouping
(Health Canada. 2020)
State of the Science Report - Part 1: Phthalates Substance
Grouping: Medium-Chain Phthalate Esters. Chemical
Abstracts Service Registry Numbers 84-61-7; 84-64-0; 84-
69-5; 523-31-9; 5334-09-8; 16883-83-3; 27215-22-1;
27987-25-3; 68515-40-2; 71888-89-6 (EC/HC. 2015)
National Industrial Chemicals Notification and
Assessment Scheme (NICNAS), Australian
Government
Priority Existing Chemical Assessment Report: Dibutyl
ohthalate (NICNAS. 2013)
Existing Chemical Hazard Assessment Report: Dibutyl
Phthalate (NICNAS. 2008)
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Appendix C LIST OF TECHNICAL SUPPORT DOCUMENTS
Appendix C incudes a list and citations for all supplemental documents included in the Draft Risk
Evaluation for DBP.
Associated Systematic Review Protocol and Data Quality Evaluation and Data Extraction
Documents - Provide additional detail and information on systematic review methodologies used as
well as the data quality evaluations and extractions criteria and results.
Draft Systematic Review Protocol for Dibutyl Phthalate (DBP) ( 325w) - In lieu of an
update to the Draft Systematic Review Protocol Supporting TSCA Risk Evaluations for Chemical
Substances, also referred to as the "2021 Draft Systematic Review Protocol" ( 2la), this
systematic review protocol for the Draft Risk Evaluation for DBP describes some clarifications and
different approaches that were implemented than those described in the 2021 Draft Systematic
Review Protocol in response to (1) SACC comments, (2) public comments, or (3) to reflect
chemical-specific risk evaluation needs. This supplemental file may also be referred to as the "DBP
Systematic Review Protocol."
Draft Data Quality Evaluation and Data Extraction Information for Physical and Chemical
Properties for Dibutyl Phthalate (DBP) (U.S. EPA. 2025k) - Provides a compilation of tables for the
data extraction and data quality evaluation information for DBP. Each table shows the data point,
set, or information element that was extracted and evaluated from a data source that has information
relevant for the evaluation of physical and chemical properties.
Draft Data Quality Evaluation and Data Extraction Information for Environmental Fate and
Transport for Dibutyl Phthalate (DBP) (U.S. EPA. 2025i) - Provides a compilation of tables for the
data extraction and data quality evaluation information for DBP. Each table shows the data point,
set, or information element that was extracted and evaluated from a data source that has information
relevant for the evaluation for environmental fate and transport.
Draft Data Quality Evaluation and Data Extraction Information for Environmental Release and
Occupational Exposure for Dibutyl Phthalate (DBP) (U.S. EPA. 2025i) - Provides a compilation of
tables for the data extraction and data quality evaluation information for DBP. Each table shows the
data point, set, or information element that was extracted and evaluated from a data source that has
information relevant for the evaluation of environmental release and occupational exposure.
Draft Data Quality Evaluation and Data Extraction Information for Dermal Absorption for Dibutyl
Phthalate (DBP) (U.S. EPA. 2025h) - Provides a compilation of tables for the data extraction and
data quality evaluation information for DBP. Each table shows the data point, set, or information
element that was extracted and evaluated from a data source that has information relevant for the
evaluation for dermal absorption.
Draft Data Quality Evaluation Information for General Population, Consumer, and Environmental
Exposure for Dibutyl Phthalate (DBP) ( 1025m) - Provides a compilation of tables for the
data quality evaluation information for DBP. Each table shows the data point, set, or information
element that was evaluated from a data source that has information relevant for the evaluation of
general population, consumer, and environmental exposure.
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6991
6992
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6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
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Draft Data Extraction Information for General Population, Consumer, and Environmental Exposure
for Dibutyl Phthalate (DBF) ( 2025e) - Provides a compilation of tables for the data
extraction for DBP. Each table shows the data point, set, or information element that was extracted
from a data source that has information relevant for the evaluation of general population, consumer,
and environmental exposure.
Draft Data Quality Evaluation Information for Human Health Hazard Epidemiology for Dibutyl
Phthalate (DBP) ( 025o) - Provides a compilation of tables for the data quality
evaluation information for DBP. Each table shows the data point, set, or information element that
was evaluated from a data source that has information relevant for the evaluation of epidemiological
information.
Draft Data Quality Evaluation Information for Human Health Hazard Animal Toxicology for
Dibutyl Phthalate (DBP) (U.S. EPA. 2025n) - Provides a compilation of tables for the data quality
evaluation information for DBP. Each table shows the data point, set, or information element that
was evaluated from a data source that has information relevant for the evaluation of human health
hazard animal toxicity information.
Draft Data Quality Evaluation Information for Environmental Hazardfor Dibutyl Phthalate (DBP)
( E0251) - Provides a compilation of tables for the data quality evaluation information for
DBP. Each table shows the data point, set, or information element that was evaluated from a data
source that has information relevant for the evaluation of environmental hazard toxicity information.
Draft Data Extraction Information for Environmental Hazard and Human Health Hazard Animal
Toxicology and Epidemiology for Dibutyl Phthalate (DBP) ( )25f) - Provides a
compilation of tables for the data extraction for DBP. Each table shows the data point, set, or
information element that was extracted from a data source that has information relevant for the
evaluation of environmental hazard and human health hazard animal toxicology and epidemiology
information.
Associated Technical Support Documents (TSDs) - Provide additional details and information on
exposure, hazard, and risk assessments.
Draft Fate & Physical Chemistry Assessment for Dibutyl Phthalate (DBP) ( ,024i).
Draft Environmental Release and Occupational Exposure Assessment for Dibutyl Phthalate (DBP)
( >025qY
Draft Consumer and Indoor Exposure Assessment for Dibutyl Phthalate (DBP) ( 15c).
Draft Environmental Media, General Population, and Environmental Exposure for Dibutyl
Phthalate (DBP) ( 025pY
Draft Environmental Hazard Assessment for Dibutyl Phthalate (DBP) ( 324m).
Draft Non-cancer Human Health Hazard Assessment for Dibutyl Phthalate (DBP) (
20249-
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Draft Cancer Human Health Hazard Assessment for Di(2-ethylhexyl) Phthalate (DEHP), Dibutyl
Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl Phthalate (DIBP), and Dicyclohexyl
Phthalate (DCHP) (I v «« \ -°25b).
Draft Consumer Exposure Analysis for Dibutyl Phthalate (DBP) ( 2025d).
Draft Consumer Risk Calculator for Dibutyl Phthalate (DBP) ( 25e).
Draft Risk Calculator for Occupational Exposures for Dibutyl Phthalate (DBP) ( 25t).
Draft Fish Ingestion Risk Calculator for Dibutyl Phthalate (DBP) ( 25r)
Draft Surface Water Human Exposure Risk Calculator for Dibutyl Phthalate (DBP) (U.S. EPA.
2025V)
Draft Occupational and Consumer Cumulative Risk Calculator for Dibutyl Phthalate (DBP) (U.S.
EPA. 2025s)
Draft Ambient Air IIOAC Exposure Results And Risk Calculations for Dibutyl Phthalate (DBP)
( 1025^)
Draft Meta-Analysis and Benchmark Dose Modeling of Fetal Testicular Testosterone for Di(2-
ethylhexyl) Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl
Phthalate (DIBP), and Dicyclohexyl Phthalate (DCHP) (I v «« \ _024d).
Revised Draft Technical Support Document for the Cumulative Risk Analysis of Di(2-ethylhexyl)
Phthalate (DEHP), Dibutyl Phthalate (DBP), Butyl Benzyl Phthalate (BBP), Diisobutyl Phthalate
(DIBP), Dicyclohexyl Phthalate (DCHP), and Diisononyl Phthalate (DINP) Under the Toxic
Substances Control Act (TSCA) (U.S. EPA. 2025x).
Draft Summary of Human Health Hazard Animal Toxicology Studies for Dibutyl Phthalate (DBP) -
Literature Publishedfrom 2014 to 2019 ( 2025u).
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Appendix D UPDATES TO THE DBP CONDITIONS OF USE TABLE
After the publication of the final scope document ( 020c). EPA received updated
submissions from the 2020 CDR cycle (1 ; S 1 T \ 2020a). In addition to new submissions received
under the 2020 CDR cycle, the use and processing codes changed for the 2020 CDR cycle. Therefore,
EPA amended the description of certain DBP COUs based on those new submissions and new use and
processing codes. Also, the Agency received information from stakeholders about uses of DBP. For
cases where COUs were consolidated under a category, if the category was not present in the scope, the
nomenclature was taken directly from the 2020 CDR cycle codes and categories. TableApx D-l
summarizes the changes to the COUs based on the new codes in the 2020 CDR and any other additional
information reasonably available to EPA since the publication of the final scope document.
Table Apx D-l. Changes to Categories and Subcategories of Conditions of Use Based on CDR and
Stakeholder Engagement
Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
Manufacturing -
Import
Import
Changed category and
subcategory by adding "ing"
Importing
Processing -
Processing as a
reactant
Intermediates in all
other basic organic
chemical
manufacturing
Removed based on stakeholder
feedback (U.S. EPA. 2024b)
N/A
Processing -
Processing as a
reactant
Plasticizers in
wholesale and retail
trade
Consolidated subcategory into
processing; incorporation into
article, plasticizer to avoid
duplication based on 2020 CDR
reporting codes.
N/A
N/A
N/A
Added "intermediate in plastic
manufacturing" subcategory due
to stakeholder feedback fW. R.
Grace, 2024).
Processing - processing as a
reactant - intermediate in plastic
manufacturing
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
Solvents (which
become part of
product formulation
or mixture) in all
other chemical
product and
preparation
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy
Consolidated "soap, cleaning
compound, and toilet preparation
manufacturing"; and "ink, toner,
and colorant manufacturing"
sectors under this COU.
Consolidated functional fluids
(closed systems) in printing and
related support activities with the
2020 CDR reports of DBP as a
solvent in printing ink
manufacturing under one COU.
The name was changed to "ink,
toner, and colorant
Processing - incorporation into
formulation, mixture, or reaction
product - solvents (which become
part of product formulation or
mixture) in chemical product and
preparation manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
adhesive manufacturing; and ink,
toner, and colorant manufacturing
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
manufacturing" sector to be
consistent with other phthalates.
Added "adhesive manufacturing"
and "chemical product and
preparation manufacturing"
sectors based on a 2020 CDR
report.
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
Intermediate in
asphalt paving,
roofing, and coating
materials
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated subcategory into
processing - incorporation into
article, plasticizer to avoid
duplication based on to the 2020
CDR codes and stakeholder
feedback (U.S. EPA. 2024b)
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in adhesive
and sealant manufacturing;
building and construction
materials manufacturing; furniture
and related product
manufacturing; ceramic powders;
plastics product manufacturing;
and rubber product manufacturing
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
N/A
Changed category by removing
"ing" and replacing with
incorporation, removed
"processing -"to avoid
redundancy.
New COU based on stakeholder
feedback fW.R. Grace. 2024).
Processing - incorporation into
formulation, mixture, or reaction
product - pre-catalyst
manufacturing
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
Plasticizer in paint
and coating
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
formulation, mixture or reaction
product - plasticizer in..." COU.
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
Adhesives and
sealant chemicals in
construction
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
formulation, mixture or reaction
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
product - plasticizer in..." COU,
with a name change to "adhesive
and sealant manufacturing"
sector.
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
Intermediates in
petrochemical
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Removed COU based on
feedback from stakeholder that it
is not a correct use for DBP
(U.S. EPA. 2024b)
N/A
Processing -
Processing -
Incorporating into
formulation, mixture or
reaction product
Plasticizers in plastic
material and resin
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
formulation, mixture or reaction
product - plasticizer in..." COU.
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
processing -
incorporating into
formulation, mixture or
reaction product
Plasticizers in plastic
product
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
formulation, mixture or reaction
product - plasticizer in..." COU,
specifically as "plastic material
and resin manufacturing."
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
processing -
incorporating into
formulation, mixture or
reaction product
Functional fluids
(closed systems) in
printing and related
support activities;
solvent in printing
ink manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated under solvent in
ink, toner, and colorant
manufacturing sector under the
"Processing - incorporation into
Processing - incorporation into
formulation, mixture, or reaction
product - solvents (which become
part of product formulation or
mixture) in chemical product and
preparation manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
adhesive manufacturing; and ink,
toner, and colorant manufacturing
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
formulation, mixture, or reaction
product; solvents..COU.
Processing -
processing -
incorporating into
formulation, mixture or
reaction product
Intermediate in
rubber product
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
formulation, mixture or reaction
product - plasticizer in..." COU,
with a name change to "rubber
manufacturing" sector.
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
processing -
incorporating into
formulation, mixture or
reaction product
Plasticizers in soap,
cleaning compound,
and toilet preparation
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
formulation, mixture or reaction
product - plasticizer in..." COU.
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
processing -
incorporating into
formulation, mixture or
reaction product
Solvents in soap,
cleaning compound,
and toilet preparation
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated under the
"Processing - incorporation into
formulation, mixture, or reaction
product; solvents..." COU as
"soap, cleaning compound, and
toilet preparation manufacturing"
sector.
Processing - incorporation into
formulation, mixture, or reaction
product - solvents (which become
part of product formulation or
mixture) in chemical product and
preparation manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
adhesive manufacturing; and ink,
toner, and colorant manufacturing
Processing -
incorporating into
formulation, mixture or
reaction product
Plasticizers in
textiles, apparel, and
leather
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
Processing - incorporation into
formulation, mixture, or reaction
product - plasticizer in paint and
coating manufacturing; plastic
material and resin manufacturing;
rubber manufacturing; soap,
cleaning compound, and toilet
preparation manufacturing;
textiles, apparel, and leather
manufacturing; printing ink
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
formulation, mixture or reaction
product - plasticizer in..." COU.
manufacturing; basic chemical
manufacturing; and adhesive and
sealant manufacturing
Processing -
processing -
incorporating into
articles
Plasticizers in
adhesive
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated "plastics product
manufacturing" and "rubber
product manufacturing" sectors
under this COU.
Added "building and
construction materials
manufacturing" and "furniture
and related product
manufacturing" sectors based on
2020 CDR cycle submissions.
Added "and sealant" to better
describe the adhesive
manufacturing sector based on
2020 CDR codes.
Added "ceramic powders" due to
public comment (NASA, 2020).
Processing - incorporation into
article - plasticizer in adhesive
and sealant manufacturing;
building and construction
materials manufacturing; furniture
and related product
manufacturing; ceramic powders;
plastics product manufacturing;
and rubber product manufacturing
Processing -
processing -
incorporating into
articles
Plasticizers in rubber
product
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
articles - plasticizer in..." COU.
Processing - incorporation into
article - plasticizer in adhesive
and sealant manufacturing;
building and construction
materials manufacturing; furniture
and related product
manufacturing; ceramic powders;
plastics product manufacturing;
and rubber product manufacturing
Processing; processing
- incorporating into
articles
Plasticizers in
plastics product
manufacturing
Changed category by removing
"ing" and replacing with
"incorporation," removed
"processing -"to avoid
redundancy.
Consolidated with other
plasticizer COUs under the
"Processing - incorporation into
articles; plasticizer in..." COU.
Processing - incorporation into
article - plasticizer in adhesive
and sealant manufacturing;
building and construction
materials manufacturing; furniture
and related product
manufacturing; ceramic powders;
plastics product manufacturing;
and rubber product manufacturing
Processing -
repackaging
Laboratory chemicals
in wholesale and
retail trade
Consolidated with "plasticizers
in wholesale and retail trade"
repackaging COU.
Processing - repackaging -
laboratory chemicals in wholesale
and retail trade; plasticizers in
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
Added plastics material and resin
manufacturing based on 2020
CDR data.
wholesale and retail trade; and
plastics material and resin
manufacturing
Industrial Uses; non-
incorporative use
Solvent in
Huntsman's maleic
anhydride
manufacturing
technology
Changed "uses" in life cycle
stage to "use."
Consolidated with the "solvent"
subcategory under this category
to avoid redundancy.
Changed subcategory to be more
general to incorporate a 2020
CDR report of "absorbent in
miscellaneous manufacturing."
Industrial use - non-incorporative
activities - solvent, including in
maleic anhydride manufacturing
technology
Industrial Uses; Non-
incorporative use
Solvent
Consolidated with the
subcategory for "solvent in
Huntsman's maleic anhydride
manufacturing technology"
Industrial use - non-incorporative
activities - solvent, including in
maleic anhydride manufacturing
technology
N/A
N/A
Changed "uses" in life cycle
stage to "use."
Added "Industrial use -
construction, paint, electrical,
and metal products - adhesives
and sealants" based on public
comment (NASA. 2020: MEMA.
20191
Industrial use - construction,
paint, electrical, and metal
products - adhesives and sealants
N/A
N/A
Changed "uses" in life cycle
stage to "use."
Added "Industrial use -
construction, paint, electrical,
and metal products - paints and
coatings" based on public
comment (NASA. 2020: MEMA.
20191
Industrial use - construction,
paint, electrical, and metal
products - paints and coatings
N/A
N/A
Changed "uses" in life cycle
stage to "use."
Added "Industrial Use - other
uses - automotive articles" based
on public comment (MEMA,
20191
Industrial use - other uses -
automotive articles
N/A
N/A
Changed "uses" in life cycle
stage to "use."
Added "Industrial Use - other
uses - lubricants" based on
public comment (MEMA, 2019).
Industrial use - other uses -
lubricants and lubricant additives
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
Commercial Uses -
Explosive materials
Explosive materials
Changes "uses" in life cycle
stage to "use."
Updated life cycle stage to
"industrial use" based on public
comment (AIA„ 2019) and
reasonable available information
(Liang et aL, 2021);
The name was changed to "other
uses" and the subcategory to
"propellants" to more accurately
reflect the use of DBP in
explosive materials regulated
under TSCA.
Industrial use - other uses -
propellants
N/A
N/A
Changed "uses" in life cycle
stage to "use."
Added "Commercial Use -
automotive, fuel, agriculture,
outdoor use products -
automotive care products" to be
consistent with 2020 CDR codes.
Commercial use - automotive,
fuel, agriculture, outdoor use
products - automotive care
products
Commercial Uses -
Adhesives and sealants
Adhesives and
sealants
Changed "uses" in life cycle
stage to "use."
Changed the name of the
category to "construction, paint,
electrical, and metal products" to
be consistent with 2020 CDR
codes.
Commercial use - construction,
paint, electrical, and metal
products - adhesives and sealants
Commercial Uses -
Paints and coatings
Paints and coatings
Changed "uses" in life cycle
stage to "use."
Changed the name of the
category to "construction, paint,
electrical, and metal products" to
be consistent with 2020 CDR
codes.
Commercial use - construction,
paint, electrical, and metal
products - paints and coatings
Commercial Uses -
Cleaning and
furnishing care
products
Cleaning and
furnishing care
products
Changed "uses" in life cycle
stage to "use."
Changed the name of the
category to "furnishing, cleaning,
treatment care products" to be
consistent with 2020 CDR codes.
Commercial use - furnishing,
cleaning, treatment care products
- cleaning and furnishing care
products
Commercial Uses -
Cleaning and
furnishing care
products
Floor coverings
Changed "uses" in life cycle
stage to "use."
Commercial use - furnishing,
cleaning, treatment care products
- construction and building
materials covering large surface
areas including stone, plaster,
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
Changed the name of the
category to "furnishing, cleaning,
treatment care products" to
be consistent with 2020 CDR
codes.
Changed the name of the
subcategory to "construction and
building materials covering large
surface areas including stone,
plaster, cement, glass and
ceramic articles - fabrics,
textiles, and apparel" to be
consistent with 2020 CDR codes.
cement, glass and ceramic
articles; fabrics, textiles, and
apparel
Commercial Uses -
Cleaning and
furnishing care
products
Furniture and
furnishings not
covered elsewhere
Changed "uses" in life cycle
stage to "use."
Changed the name of the
category to "furnishing, cleaning,
treatment care products" to
be consistent with 2020 CDR
codes. The new name does not
include "not covered elsewhere."
Commercial use - furnishing,
cleaning, treatment care products
- furniture and furnishings
Commercial Uses -
Ink, toner, and colorant
products
Ink, toner, and
colorant products
Changed "uses" in life cycle
stage to "use."
Changed the name of the
category to "packaging, paper,
plastic, toys, hobby products" to
be consistent with 2020 CDR
codes.
Commercial use - packaging,
paper, plastic, toys, hobby
products - ink, toner, and colorant
products
Commercial Uses -
rubber and plastic
products not covered
elsewhere
Rubber and plastic
products not covered
elsewhere
Changed "uses" in life cycle
stage to "use."
Changed the name of the
category to "packaging, paper,
plastic, toys, hobby products"
to be consistent with 2020 CDR
codes.
Changed the name of the
subcategory to "packaging
(excluding food packaging),
including rubber articles; plastic
articles (hard); plastic articles
(soft) - other articles with
routine direct contact during
normal use, including rubber
articles; plastic articles (hard)" to
be consistent with 2020 CDR
codes.
Commercial use - packaging,
paper, plastic, toys, hobby
products - packaging (excluding
food packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other
articles with routine direct contact
during normal use, including
rubber articles; plastic articles
(hard)
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
N/A
N/A
Added "Toys, playground, and
sporting equipment" subcategory
to the "Packaging, paper, plastic,
toys, hobby products" category
based on additional information
(U.S. EPA. 2019a. ft.
Commercial use - packaging,
paper, plastic, toys, hobby
products - toys, playground, and
sporting equipment
Commercial Uses -
Personal care products
Personal care
products
Removed COU since no personal
care products containing DBP
were identified.
N/A
Commercial Uses -
miscellaneous uses
Laboratory chemicals
chemiluminescent
light sticks inspection
penetrant kit
lubricants
Changed "uses" in life cycle
stage to "use."
Changed "miscellaneous" in the
name of the category to "other"
to be consistent with other
phthalate risk evaluations.
Split COU into different COUs
with different subcategories for
clarity.
Commercial use - other uses -
laboratory chemicals
Commercial use - other uses -
chemiluminescent light sticks
Commercial use - other uses -
inspection penetrant kit
Commercial use - other uses -
lubricants and lubricant additives
N/A
N/A
Added "Automotive care
products" subcategory and
"Automotive, fuel, agriculture,
outdoor use products" category
based on 2020 CDR cycle
submissions.
Consumer use - automotive, fuel,
agriculture, outdoor use products
- automotive care products
Consumer Uses -
Adhesives and sealants
Adhesives and
sealants
Changed "uses" in life cycle
stage to "use."
Changed name of category to
"construction, paint, electrical,
and metal products" to be
consistent with 2020 CDR codes.
Commercial use - construction,
paint, electrical, and metal
products - adhesives and sealants
Consumer Uses -
Paints and coatings
Paints and coatings
Changed "uses" in life cycle
stage to "use."
Changed name of category to
"construction, paint, electrical,
and metal products" to be
consistent with 2020 CDR codes.
Consumer use - construction,
paint, electrical, and metal
products - paints and coatings
Consumer Uses -
Cleaning and
furnishing care
products
Fabric, textile, and
leather products not
covered elsewhere
Changed "uses" in life cycle
stage to "use."
Change name of category to
"furnishing, cleaning, treatment
care products" to be consistent
with 2020 CDR codes. The new
name does not include "not
covered elsewhere."
Consumer use - furnishing,
cleaning, treatment care products
- fabric, textile, and leather
products
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
Consumer Uses -
Floor coverings
Floor coverings
Changed "uses" in life cycle
stage to "use."
Changed name of category and
subcategory to be consistent with
2020 CDR cycle codes.
Commercial use - furnishing,
cleaning, treatment care products
- floor coverings; construction
and building materials covering
large surface areas including
stone, plaster, cement, glass and
ceramic articles; fabrics, textiles,
and apparel
Consumer Uses -
Cleaning and
furnishing care
products
Cleaning and
furnishing care
products
Changed "uses" in life cycle
stage to "use."
Changed name of category to
"furnishing, cleaning, treatment
care products" to be consistent
with 2020 CDR codes.
Consumer use - furnishing,
cleaning, treatment care products
- cleaning and furnishing care
products
Consumer Uses - Arts,
crafts, and hobby
materials
Arts, crafts, and
hobby materials
Removed category and
subcategory because it was not
reported in CDR data in 2016, or
2020, and no relevant products
could be identified.
N/A
Consumer Uses -
Plastic and rubber
products not found
elsewhere
Plastic and rubber
products not found
elsewhere
Changed "uses" in life cycle
stage to "use."
Changed name of category to
"packaging, paper, plastic, toys,
hobby products" to be consistent
with other phthalate risk
evaluations.
Changed name of subcategory to
"packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other
articles with routine direct
contact during normal use,
including rubber articles; plastic
articles (hard)" to be consistent
with 2020 CDR codes.
Consumer use - packaging, paper,
plastic, toys, hobby products -
packaging (excluding food
packaging), including rubber
articles; plastic articles (hard);
plastic articles (soft); other
articles with routine direct contact
during normal use, including
rubber articles; plastic articles
(hard)
N/A
N/A
Changed "uses" in life cycle
stage to "use."
Change name of category to
"packaging, paper, plastic, toys,
hobby products" to be consistent
with 2020 CDR codes.
Consumer use - packaging, paper,
plastic, toys, hobby products -
toys, playgrounds, and sporting
equipment
Consumer Uses -
Miscellaneous Uses
Chemiluminescent
light sticks
Changed "uses" in life cycle
stage to "use."
Consumer use - other uses -
chemiluminescent light sticks
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7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
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Life Cycle Stage and
Category in the Final
Scope Document
Subcategory in the
Final Scope
Document
Occurred Change
Revised COU in the 2025 Draft
Risk Evaluation
Change name of category to
"other uses" to be consistent with
other phthalate risk evaluations.
N/A
N/A
Added "automotive articles"
based on stakeholder information
received since publication of the
final scope document (MEMA,
20191
Consumer use - other uses -
automotive articles
N/A
N/A
Added "lubricants and lubricant
additives" based on stakeholder
information received since
publication of the final scope
document (MEMA. 2019).
Consumer use - Other uses -
lubricants and lubricant additives
N/A
N/A
Added subcategory "novelty
articles" based on additional
information (Stabile, 2013).
Consumer use - other uses -
novelty articles
In addition, EPA is including further detail about edits to the following COUs, which are presented in
TableApx D-l:
• In the 2016 CDR cycle, one company reported the use of DBP in processing - processing as a
reactant - intermediates in all other basic organic chemical manufacturing ( b).
Upon outreach with the stakeholder, they clarified that the report of DBP as an intermediate in
all other basic organic chemical manufacturing was not a representative use for DBP (
2024b).
• In the 2020 CDR cycle, one company reported the use of DBP in processing - processing as a
reactant - plasticizers in wholesale and retail trade (U.S. EPA. 2020a). EPA has determined not
to include this activity as a separate COU and considers it captured under "processing,
incorporation into articles" and "processing, incorporation into formulation, mixture, or reaction
product." DBP is not used as a reactant in a chemical reaction, rather DBP is used as plasticizer.
The use as a plasticizer is better described as "processing - incorporation into formulation,
mixture or reaction product" and/or as "processing - incorporation into articles. Therefore, EPA
changed the functional use to plasticizer and consolidated this 2020 CDR submission under
"processing - incorporation into formulation, mixture, or reaction product plasticizer."
• "Processing -processing as a reactant - Intermediate in plastic manufacturing" and
"Processing - incorporation into formulation, mixture, or reaction product - Pre-catalyst
manufacturing" were added after a stakeholder informed the Agency that DBP is used in
polyolefin production as part of a catalyst and in reactions to make polyolefins fW.R. Grace.
2024).
• "Commercial Use - toys, playground, and sporting equipment' was added to the draft risk
evaluation based on the use of recycled rubber tire crumb to build synthetic turf playing fields
and playground contains DBP.
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7112 • "Consumer use - novelty articles" was added to the draft risk evaluation based on Agency
7113 research into the use of various phthalate in adult sex toys {i.e., novelty products).
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7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
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Appendix E CONDITIONS OF USE DESCRIPTIONS
The following descriptions are intended to include examples of uses so as not to exclude other activities
that may also be included in the COUs of the chemical substance. To better describe the COU, EPA
considered CDR submissions from the last two CDR cycles for DBP (CASRN 84-74-2) and the COU
descriptions reflect what EPA identified as the best fit for that submission. Examples of articles,
products, or activities are included in the following descriptions to help describe the COU but are not
exhaustive. EPA uses the terms "articles" and "products" or product mixtures in the following
descriptions and is generally referring to articles and products as defined by 40 CFR Part 751. There
may be instances where the terms are used interchangeably by a company or commenters, or by EPA in
reference to a code from the CDR reports which are referenced; for example, "plastic products
manufacturing," or "fabric, textile, and leather products." EPA will clarify as needed when these
references are included throughout the COU descriptions below.
E.l Manufacturing - Domestic Manufacturing
Domestic manufacturing means to manufacture or produce DBP within the Unites States. For purposes
of the DBP risk evaluation, this includes the extraction of DBP from a previously existing chemical
substance or complex combination of chemical substances and loading and repackaging (but not
transport) associated with the manufacturing or production of DBP.
DBP is typically manufactured through the catalytic esterification of the phthalic anhydride with n-butyl
alcohol in the presence of an acid as a catalyst. A typical manufacturing operation takes place in closed
systems either via batch or more automated continuous operations and will involve the purification of
dibutyl phthalate product streams via either vacuum distillation or by passing over activated charcoal as
a means of recovering unreacted alcohols ( 320c). This condition of use includes the typical
manufacturing process and any other similar manufacturing of DBP.
Examples of CDR Submissions
In the 2016 CDR cycle, one company reported domestic manufacture of DBP, and in 2020, two
companies reported domestic manufacture of DBP ( ;0b, 2019b).
E.2 Manufacturing - Importing
Import refers to the import of DBP into the customs territory of the United States. This condition of use
includes loading/unloading and repackaging (but not transport) associated with the import of DBP. In
general, chemicals may be imported into the United States in bulk via water, air, land, and intermodal
shipments. These shipments take the form of oceangoing chemical tankers, rail cars, tank trucks, and
intermodal tank containers ( >20c). Imported DBP is shipped in liquid form with
concentrations ranging from 1 to 100 percent DBP ( 2019b).
Examples of CDR Submissions
In the 2016 CDR cycle, 1 1 companies reported importation of DBP as a liquid ( )b). EPA
has identified two sites that imported DBP directly to their sites for on-site processing or use and nine
sites that imported DBP directly to other sites for processing or use ( 020c).
In the 2020 CDR cycle, seven companies reported importation of DBP as a liquid ( 020b).
Five companies reported that the imported chemical substance is never physically at the reporting site
(e.g., the chemical substance from a foreign country is directly imported to another location such as a
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7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
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warehouse, a processing or use site, or a customer's site). One company reported the importation for the
purposes of repackaging in various industries.
E.3 Processing - Processing as a Reactant - Intermediate in Plastic
Manufacturing
This COU refers to the use of a chemical as a reactant; that is, the use of DBP in a chemical reaction,
which occurs when a chemical substance is added to a product or product mixture after its manufacture
for distribution in commerce. In this case, DBP is used in a catalyst formulation for processing as a
reactant in the generation of poly olefins {i.e., polypropylene and polyethylene). EPA's understanding is
that very small amounts of DBP are used as a catalyst for the associated chemical reactions {i.e., 1 g
used for 40,000 g of polypropylene). As the reaction progresses, the catalyst degrades and a small
amount of DBP (1-3 parts per million) remains encapsulated in the final product fW.R. Grace. 2024).
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.4 Processing - Incorporation into Formulation, Mixture, or Reaction
Product - Solvents (Which Become Part of Product Formulation or
Mixture) in Chemical and Preparation Manufacturing; in Soap,
Cleaning Compound, and Toilet Preparation Manufacturing;
Adhesive Manufacturing; and in Printing Ink Manufacturing
This COU refers to the preparation of a product; that is, the incorporation of DBP into formulation,
mixture, or a reaction product which occurs when a chemical substance is added to a product or product
mixture after its manufacture, for distribution in commerce, in this case as a solvent in various industrial
sectors.
DBP can be used as a solvent in various sectors, including soap, cleaning compound, toilet preparation
manufacturing, all other chemical product and preparation manufacturing, adhesive manufacturing, and
printing ink manufacturing. In the soap, cleaning compound, and toilet preparation manufacturing
sector, DBP can be used as a cleaner or degreaser (U.S. EPA. 2019b).
Examples of CDR Submissions
In the 2016 CDR cycle, one company reported the use of DBP as a solvent for cleaning or degreasing in
soap, cleaning compound, and toilet preparation manufacturing. Additionally, one company reported the
use of DBP in functional fluids for printing ink manufacturing, and two companies reported the use of
DBP in the chemical product and preparation manufacturing sector (U.S. EPA. 2019b).
In the 2020 CDR cycle, one company reported the use of DBP as a solvent in adhesive manufacturing;
this company also reported the use of DBP as a solvent in printing ink manufacturing. Additionally, one
company reported the use of DBP in all other chemical product and preparation manufacturing (U.S.
E 20a).
E.5 Processing - Incorporation into Formulation, Mixture, or Reaction
Product - Pre-Catalyst Manufacturing
This COU refers to the preparation of a product; that is, the incorporation of DBP into formulation,
mixture, or a reaction product which occurs when a chemical substance is added to a product (or product
mixture) after its manufacture, for distribution in commerce.
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7222
7223
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May 2025
DBP is used in pre-catalyst manufacturing prior to its use as a catalyst component for polyolefin
manufacturing. As part of this process, DBP is included in the solids in the pre-catalyst at about 10
percent as a solid that is suspended in a solvent or an oil (W.R. Grace. 2024).
Examples of CDR Submissions
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.6 Processing - Incorporation into Formulation, Mixture, or Reaction
Product - Plasticizer in Paint and Coating Manufacturing; Plastic
Material and Resin Manufacturing; Rubber Manufacturing; Soap,
Cleaning Compound, and Toilet Preparation Manufacturing; Textiles,
Apparel, and Leather Manufacturing; in Printing Ink Manufacturing;
Basic Organic Chemical Manufacturing; and Adhesive and Sealant
Manufacturing
This COU refers to the preparation of a product; that is, the incorporation of DBP into formulation,
mixture, or a reaction product which occurs when a chemical substance is added to a product (or product
mixture), after its manufacture, for distribution in commerce—in this case, processing of DBP as a
plasticizer into several different products for use in multiple sectors.
In manufacturing of plastic material and resin through non-PVC and PVC compounding, DBP is
blended into polymers. Compounding involves the mixing of the polymer with the plasticizer and other
chemical such as, fillers and heat stabilizers. The plasticizer needs to be absorbed into the particle to
impart flexibility to the polymer. For PVC compounding, compounding occurs through mixing of
ingredients to produce a powder (dry blending) or a liquid (Plastisol blending). The most common
process for dry blending involves heating the ingredients in a high-intensity mixer and transfer to a cold
mixer. The Plastisol blending is done at ambient temperature using specific mixers that allow for the
breakdown of the PVC agglomerates and the absorption of the plasticizer into the resin particle.
Examples of CDR Submissions
In the 2016 CDR cycle, use of DBP as a plasticizer was reported for the following sectors: three
companies in paint and coating manufacturing; one company in plastics product manufacturing; one
company in textiles, apparel, and leather manufacturing; one company in soap, cleaning compound, and
toilet preparation manufacturing; one company in petrochemical manufacturing; one company in all
other basic organic chemical manufacturing; and one company in plastics material and resin
manufacturing ( 9b).
In the 2020 CDR cycle, one company reported the use of DBP as a plasticizer in plastics material and
resin manufacturing; one company reported the use of DBP as a plasticizer in textiles, apparel, and
leather manufacturing; and one company reported the use of DBP as a plasticizer in plastics product
manufacturing ( JA. 2020a).
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7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
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PUBLIC RELEASE DRAFT
May 2025
E.7 Processing - Incorporation into Article - Plasticizer in Adhesive and
Sealant Manufacturing; Building and Construction Materials
Manufacturing; Furniture and Related Product Manufacturing;
Ceramic Powders; Plastics Product Manufacturing; and Rubber
Product Manufacturing
This COU refers to the preparation of an article; that is, the incorporation of DBP into articles, meaning
DBP becomes a component of the article, after its manufacture, for distribution in commerce. In this
case, DBP is present in a raw material such as rubber or plastic that contains a mixture of plasticizers
and other additives, and this COU refers to the manufacturing of PVC and non-PVC articles, including
rubber, plastic, and miscellaneous articles using those raw materials. PVC articles are manufactured
after the formation of a raw material that can contain a mixture of plasticizer and other additives. The
raw material is converted by processes such as calendaring, extrusion, injection molding, and plastisol
spread coating (ACC. 2020). This COU encompasses the step that occurs immediately after PVC
compounding, where the compounded resin is sent to an extruder that shapes and sizes the plastic into an
article or pellet to be used in downstream processing at PVC or non-PVC conversion sites (U.S. EPA.
2X ). DBP also is an additive in inks, which are then incorporated into textiles and articles (
2020c). This COU also includes the incorporation of the rubber or plastic and other articles into finished
articles, such as electrical and electronic articles, machinery, mechanical appliances, fabric, textiles and
leather articles, or furniture and furnishings. This COU also includes activities identified by the U.S.
Department of Defense.
Plastisol technology or film calendaring technology is used in the production of plastic and rubber
products such as textiles, apparel, and leather; vinyl tape; flexible tubes; profiles; and hoses (ACC.
2023).
In toy manufacturing, toys could contain up to 0.1 percent of DBP ( t). (The CPSC has a
regulatory limit of no more than 0.1 percent for DBP concentration in toys.) Additionally, it is possible
that DBP could be incorporated into playground equipment manufacturing due to its use as a plasticizer
in PVC and non-PVC articles that may be components of playground equipment.
EPA expects that the use of DBP in textiles, apparel, and leather manufacturing is associated with PVC
applications for durable vinyl articles, such as raincoats, boots, and gloves.
DBP is also reported to be used as a plasticizer in tapecasting for ceramic powders (NASA. 2020).
Examples of CDR Submissions
In the 2016 CDR cycle, use of DBP as a plasticizer was reported for the following sectors: one company
in adhesive manufacturing; one company in rubber product manufacturing; and two companies in
plastics product manufacturing. Additionally, one company reported use of DBP as an intermediate in
asphalt paving, roofing, and coating materials manufacturing. EPA's understanding is that DBP, if used
as an intermediate for article manufacturing, likely is used as a plasticizer, which is why this CDR report
was included under this COU ( v << \ .^19b).
In the 2020 CDR cycle, use of DBP as a plasticizer was reported for the following sectors: one company
in plastics material and resin manufacturing; one company in furniture and related product
manufacturing and in construction; and one company in adhesives manufacturing and in plastics product
manufacturing ( 2020a).
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7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
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PUBLIC RELEASE DRAFT
May 2025
E.8 Processing - Repackaging - Laboratory Chemicals in Wholesale and
Retail Trade; Plasticizers in Wholesale and Retail Trade; and Plastics
Material and Resin Manufacturing
Repackaging refers to the preparation of DBP for distribution in commerce in a different form, state, or
quantity than originally received or stored by various industrial sectors, including wholesale and retail
trade, laboratory chemicals manufacturing, and plastic material and resin manufacturing. This includes
the transferring of a chemical substance from a bulk container into smaller containers. This COU would
not apply to the relabeling or redistribution of a chemical substance without removing the chemical
substance from the original container it was supplied in.
Examples of CDR Submissions
In the 2016 CDR cycle, two companies reported repackaging DBP as a plasticizer in wholesale and
retail trade and one company reported repackaging DBP as a laboratory chemical ( b).
In the 2020 CDR cycle, two companies reported repackaging DBP as a plasticizer in wholesale and
retail trade and plastic material and resin manufacturing ( 320a).
E.9 Processing - Recycling
This COU refers to the process of treating generated waste streams {i.e., which would otherwise be
disposed of as waste), containing DBP, that are collected, either on-site or at a third-party site, for
commercial purpose ( b). DBP is primarily recycled industrially in the form of DBP-
containing PVC waste streams. New PVC can be manufactured from recycled and virgin materials
(Lowe et ai. 2021).
Examples of CDR Submissions
In the 2016 CDR cycle, two companies reported recycling DBP ( .019b).
This use does not have CDR data reported for the 2020 cycle.
E.10 Distribution in Commerce
For purposes of assessment in this risk evaluation, distribution in commerce consists of the
transportation associated with the moving of DBP or DBP-containing products and/or articles between
sites manufacturing, processing, or recycling DBP or DBP-containing products and/or articles, or to
final use sites, or for final disposal of DBP or DBP-containing products and/or articles. More broadly
under TSCA, "distribution in commerce" and "distribute in commerce" are defined under TSCA section
3(5).
E.ll Industrial Use - Non-Incorporative Activities - Solvent, Including in
Maleic Anhydride Manufacturing Technology
This COU refers to the DBP as it is used as a solvent in various industrial sectors. Specifically, this
includes using DBP in the process of maleic anhydride manufacturing.
EPA understands that DBP is used in the manufacturing of maleic anhydride; however, DBP is not
incorporated into the maleic anhydride product (Huntsman. 2024).
Examples of CDR Submissions
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7340
7341
7342
7343
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7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
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May 2025
One company reported the use of DBP in non-incorporative activities in the 2016 CDR cycle (U.S. EPA.
2019b).
The use was reported again in the 2020 CDR cycle for "non-incorporative activities" under
miscellaneous manufacturing, as an absorbent (U.S. EPA. 2020a).
E.12 Industrial Use - Construction, Paint, Electrical, and Metal Products -
Adhesives and Sealants
This COU refers to DBP as it is used in various industrial sectors as a component of adhesive or sealant
mixtures, meaning the use of DBP after it has already been incorporated into an adhesive and/or sealant
product or mixture, as opposed to when it is used upstream, (e.g., when DBP is processed into the
adhesive and sealant formulation).
DBP is used in adhesives and sealant in the manufacture of automobiles (MEMA. 2019). DBP may be
found in adhesives, potting compounds, sealants, and putties used in the manufacture, operations and
maintenance of aerospace products (AIA. 2019). Specific application of DBP-containing adhesives in
aerospace includes adhesives critical to electrical/circuit boards, and as a processing aid for crosslinking
in cement for acrylic processing ( ). DBP is a component of adhesives and sealants used in the
testing test articles and human-rated spaceflight hardware ( 20). This COU also includes
activities identified by the U.S. Department of Defense.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.13 Industrial Use - Construction, Paint, Electrical, and Metal Products -
Paints and Coatings
This COU refers to the use of DBP in various industrial sectors as a component of industrial paints and
coatings. This includes the use of DBP after it has already been incorporated into a paint or coating
product or mixture, as opposed to when it is used upstream (e.g., when DBP is processed into the paint
or coating formulation).
DBP is used in coatings in the manufacture of automobiles (MEMA. 2019). DBP may be found in
conductive and interior coatings used in the manufacture, operations, and maintenance of aerospace
products ( U \ 1' ). This COU also includes activities identified by the U.S. Department of Defense.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.14 Industrial Use - Other Uses - Automotive Articles
This COU refers to the use of DBP in the automobile manufacturing sector as a component in various
automotive articles. This is a use of DBP after it has already been incorporated into a plastic article, as
opposed to when it is used upstream (e.g., when DBP is processed into an article).
DBP was identified in numerous components in the exterior and interior of the vehicle, the powertrain,
the chassis, and the electrical system. DBP was identified in 391 parts, including those used in
replacement parts. Some examples of parts are the passenger side seat buckle, the engine assembly, the
trim panel assembly on the body of the door, and the center floor full console on the passenger side
(MEMA. 2019). Based on DBP being found downstream in tire crumb applications for playgrounds and
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7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
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PUBLIC RELEASE DRAFT
May 2025
turf (Armada et al.. 202.. I v «« \ 2019D. users may be handling DBP in tires for automobiles in
industrial settings.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.15 Industrial Use - Other Uses - Lubricants and Lubricant Additives
This COU refers to the industrial use of DBP incorporated within lubricant products. DBP is used in
products for industrial applications including synthetic lubricants and anti-seize compounds in
automobile and aerospace applications (NASA. 202;'. v «« \ J020d; MEM A. 2019). For the
industrial use of these products, EPA expects them to be poured or applied by workers in factories and
other industrial settings. This COU also includes activities identified by the U.S. Department of Defense.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.16 Industrial Use - Other Uses - Propellants
This COU refers to the industrial use of DBP incorporated into propellants. This COU encompasses
incorporating DBP into a propellant, loading of that propellant into a cartridge, and TSCA use of said
cartridge, e.g., installing into aircraft ejection seats and use of aircraft ejection seats. DBP is included in
some aerospace applications as a component of the propellant in aircraft ejection seats (A I A. 2019).
DBP is also used by ammunition processors, although this COU does not include the use of ammunition
(I E020a). DBP is used as a deterring agent in propellants where it coats the propellant granules
and slows the combustion process so that the propellant burns slowly at first and increases gradually as
the combustion process progresses (Liang et al.. 2021).
This COU does not include use of dibutyl phthalate in propellants in articles, or components of articles
subject to Section 4181 of the Internal Revenue Code of 1954; for example, ammunition, since such use
is outside the scope of the definition of "chemical substance" TSCA section 3(2)(B)(v), is not being
considered as a "condition of use" and will not be evaluated during risk evaluation ( 2020c).
This COU also includes activities identified by the U.S. Department of Defense.
Examples of CDR Submissions
In the 2020 CDR cycle, one company reported the use of DBP at an ammunition plant (
2020a).
E.17 Commercial Use - Automotive, Fuel, Agriculture, Outdoor Use
Products - Automotive Care Products
This COU refers to the commercial use of DBP in automotive care products. This COU includes the use
of DBP-containing products for automotive upkeep in a commercial setting.
DBP is used in various automotive product applications. EPA notes that this reporting code in the 2020
CDR cycle is intended to describe exterior car washes and soaps, exterior car waxes, polishes, and
coatings, touch up paint, and interior car care products (U.S. EPA. 2022a).
Examples of CDR Submissions
In the 2020 CDR cycle, one company reported the use of DBP as a plasticizer in interior car care
products. Another company reported the use of DBP in exterior car waxes, polishes, and coatings (U.S.
E 20a).
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7429
7430
7431
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7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
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PUBLIC RELEASE DRAFT
May 2025
E.18 Commercial Use - Construction, Paint, Electrical, and Metal
Products - Adhesives and Sealants
This COU refers to the commercial use of DBP in adhesives and sealants. This includes the use of DBP-
containing adhesives and sealants in a commercial setting, such as a business or non-industrial job site,
such as an office, property owned by a client for which commercial services are being provided, or an
auto shop, as opposed to upstream use of DBP (e.g., when DBP-containing products are used in the
manufacturing of construction products) or use in an industrial setting. This COU also includes activities
identified by the U.S. Department of Defense.
Workers in a commercial setting generally apply adhesives and sealants that already have DBP
incorporated as a plasticizer. Adhesives and sealants (which could also be fillers and putties) are highly
malleable materials used to repair, smooth over or fill minor cracks in holds and buildings. EPA expects
that commercial applications of adhesives and sealants containing DBP would occur using non-
pressurized methods based on products identified in the marketplace for DBP and other similar
chemicals.
EPA identified several commercially available (denoted as being possibly industrial, commercial, or
consumer viable) adhesive products which contain DBP at various concentrations. These adhesive and
sealants can be applied using a caulk gun ( )20e).
DBP is an additive in polyester, vinyl ester, or epoxy resin for in-place repairs to pipes such as water
mains. Workers repair pipes in place by first inserting a resin-impregnated liner in the damaged pipe,
then forcing steam, hot water, or ultraviolet light across the liner to cure the resin ( 320c).
DBP is used in adhesives and sealants in the manufacture of automobiles (MEMA. 2019). EPA expects
that these types of products could also be used commercially in automobile repair applications.
Examples of CDR Submissions
In the 2016 CDR cycle, four companies reported the use of DBP in adhesives and sealants (U.S. EPA.
2019b).
In the 2020 CDR cycle, one company reported the use of DBP in hot-melt adhesives and one company
reported the use of DBP in fillers and putties (U.S. EPA. 2020a).
E.19 Commercial Use - Construction, Paint, Electrical, and Metal Products
- Paints and Coatings
This COU refers to the commercial use of DBP already incorporated as a plasticizer in paints and
coatings.
EPA expects that some of these products are likely to be used for industrial applications; however, this
COU only encompasses the products purchased by commercial operations and applied by professional
contractors in various commercial settings. EPA also expects that compared to the industrial
applications, these products would be used in smaller scale in commercial settings for similar purposes
(e.g., corrosion and water protection on structural components, residential construction). This COU
encompasses solvent and water-based paints.
Examples of CDR Submissions
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7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
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7489
7490
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May 2025
In the 2016 CDR cycle, three companies reported the use of DBP in paints and coatings (
2019b).
In the 2020 CDR cycle, one company reported the use of DBP in water-based paint and in solvent-based
paint (U.S. EPA. 2020a).
E.20 Commercial Use - Furnishing, Cleaning, Treatment Care Products -
Cleaning and Furnishing Care Products
This COU refers to the commercial use of DBP in cleaning and furnishing care products. The
commercial users of products under this category would be expected to apply cleaning and furnishing
care products that contain DBP either manually or with automated equipment ( 320c). EPA
expects that the type of products reported under this COU are likely to be both commercial and
consumer in nature; however, this COU encompasses only the commercial uses of the products. This
COU also includes activities identified by the U.S. Department of Defense.
DBP may be present in cleaning and furnishing care products, such as glass window cleaning
formulations, carpet and floor cleaners, spot removers, and shoe care products ( 020c). DBP
was also reported as present in polishes/waxes and in alternative tub/tile cleaner (Dodson et al. 2012).
Examples of CDR Submissions
In the 2016 CDR cycle, two companies reported the use of DBP in cleaning and furnishing care products
(I >019b).
E.21 Commercial Use - Furnishing, Cleaning, Treatment/Care Products -
Floor Coverings; Construction and Building Materials Covering
Large Surface Areas Including Stone, Plaster, Cement, Glass, and
Ceramic Articles; Fabrics, Textiles, and Apparel
This COU refers to the commercial installation of floor covering containing DBP covering large surface
areas including stone, plaster, cement, glass and ceramic articles; and fabrics, textiles, and apparel. DBP
is expected to be already incorporated into floor coverings, and this COU describes handling and
installing tiles, carpeting, etc.
DBP may be a constituent of various building/construction materials because of its use as a general-
purpose plasticizer in PVC applications. EPA expects that certain building/construction materials that
would be covered by this COU in commercial use would include items such as vinyl and PVC-backed
carpeting, and other construction/building materials covering large surface areas.
Examples of CDR Submissions
In the 2016 CDR cycle, one company reported the use of DBP in floor coverings ( )).
In the 2020 CDR cycle, one company reported the use of DBP as a plasticizer in construction and
building materials covering large surface areas including stone, plaster, cement, glass, and ceramic
articles; fabrics, textiles, and apparel ( 20a).
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7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
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7534
7535
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May 2025
E.22 Commercial Use - Furnishing, Cleaning, Treatment Care Products -
Furniture and Furnishings
This COU refers to the commercial use of DBP already incorporated into furniture and furnishings. This
COU includes use of DBP already incorporated into furniture upholstery or in plastic materials to make
furniture ( )20c).
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.23 Commercial Use - Packaging, Paper, Plastic, and Hobby Products -
Ink, Toner, and Colorant Products
This COU is refers to the commercial use of DBP in inks, toner, and colorants, that can be used in
packaging, paper, plastic, toys, hobby products and articles. This COU also includes activities identified
by the U.S. Department of Defense.
DBP is used in printing ink and pigments ( ,0e). EPA expects that the majority of ink,
toner, and colorant products containing DBP would be commercial in nature; however, it is possible that
these products are used by consumers for commercial purposes as many of the commercial products are
available for consumer purchasers through various online vendors. This COU encompasses only the
commercial uses of these products by workers and consumer DIYers. EPA would expect the commercial
uses of these products by consumer DIYers to be similar to typical applications in commercial printing
and drafting shops, albeit on a smaller scale.
Examples of CDR Submissions
In the 2016 CDR cycle, one company reported the use of DBP in ink, toner, and colorant products (
E ).
E.24 Commercial Use - Packaging, Paper, Plastic, and Hobby Products -
Packaging (Excluding Food Packaging), Including Rubber Articles;
Plastic Articles (Hard); Plastic Articles (Soft); Other Articles with
Routine Direct Contact During Normal Use, Including Rubber
Articles; Plastic Articles (Hard)
This COU refers to the commercial use of DBP in various plastic and rubber packaging and in soft and
hard plastic articles and rubber articles. EPA notes that the CDR use code for "packaging (excluding
food packaging), including rubber articles; plastic articles (hard); plastic articles (soft)" includes
examples such as phone covers, personal tablet covers, styrofoam packaging, and bubble wrap. In
addition, the CDR processing and use code for "other articles with routine direct contact during normal
use including rubber articles; plastic articles (hard)" in the 2020 CDR cycle includes examples such as
gloves, boots, clothing, rubber handles, gear lever, steering wheels, handles, pencils, and handheld
device casing. This COU also includes activities identified by the U.S. Department of Defense.
The articles provided as examples under this code are likely to be both commercial and consumer in
nature. This COU refers to the commercial use of these articles. Soft packaging containing DBP would
be used during packaging of articles in commercial settings. Hard articles containing DBP would be
used in commercial settings.
Examples of CDR Submissions
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7559
7560
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7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
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7579
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May 2025
In the 2016 CDR cycle, two companies reported the use of DBP in plastic and rubber products not
covered elsewhere, which is listed as both "packaging (excluding food packaging), including rubber
articles; plastic articles (hard); plastic articles (soft)" and as "other articles with routine direct contact
during normal use, including rubber articles; plastic articles (hard)" in the 2020 CDR cycle (
2019b).
E.25 Commercial Use - Packaging, Paper, Plastic, and Hobby Products -
Toys, Playground, and Sporting Equipment
This COU refers to the commercial use of DBP in toys, playground, and sporting equipment. The COU
includes the commercial installation, use, and maintenance of toys, playgrounds, and sporting equipment
that contain DBP (such as in daycare or school environments by workers such as teachers or providers).
This use refers to workers molding or otherwise fabricating articles already containing DBP into other
articles for commercial and consumer applications, as well as during installation of sporting or
playground equipment.
DBP can be used as a plasticizer to provide flexibility to toys. The Consumer Product Safety
Improvement Act (CPSIA) of 2008 placed a prohibition on DBP that limited manufacturers' use of DBP
in children's toys to 0.1 percent (U.S. EPA. 2019a). Toys containing DBP that were manufactured
and/or processed prior to the CPSIA restriction in 2008 may still be in use. DBP is reported to be found
downstream in tire crumb applications for playgrounds and turf, and this COU includes the commercial
use of playgrounds and turf that contains DBP (U.S. EPA. 2019D.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.26 Commercial Use - Other Uses - Automotive Articles
This COU refers to the commercial use of DBP in automotive articles, which already have DBP
incorporated into them. This COU refers to the use of DBP-containing automotive articles in a
commercial setting, such as an automotive parts business or a worker driving a vehicle, as opposed to
upstream use of DBP (e.g., when DBP-containing products are used in the manufacturing of the
automobile) or use in an industrial setting. This COU also includes activities identified by the U.S.
Department of Defense.
DBP was identified in numerous components in the exterior and interior of the vehicle, the powertrain,
the chassis, and the electrical system. DBP was identified in 391 parts, including those used in
replacement parts. Some examples of parts are the passenger side seat buckle, the engine assembly, the
trim panel assembly on the body of the door, and the center floor full console on the passenger side
(ME? ). DBP is reported to be found downstream in tire crumb applications for playgrounds and
turf ( \i iaada et at.. 202 J; 1 c< « i1 \ 2Q19D.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.27 Commercial Use - Other Uses - Laboratory Chemicals
This COU refers to the use of DBP as a laboratory chemical.
DBP can be used as a laboratory chemical such as a chemical standard or reference material during
analyses. Some laboratory chemical manufacturers identify use of DBP as a certified reference material
and research chemical.
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Commercial use of laboratory chemicals may involve handling DBP by hand-pouring or pipette and
either adding to the appropriate labware in its pure form to be diluted later or added to dilute other
chemicals already in the labware. EPA expects that laboratory DBP products are pure DBP in neat liquid
form. The Agency notes that the same applications and methods used for quality control can be applied
in industrial and commercial settings.
Examples of CDR Submissions
In the 2016 CDR cycle, one company reported the use of DBP in laboratory chemicals (
2019b).
E.28 Commercial Use - Other Uses - Chemiluminescent Light Sticks
This COU refers to the commercial use of DBP incorporated into chemiluminescent light sticks,
sometimes referred to colloquially as glow sticks. DBP is present in chemiluminescent light sticks as
part of some Department of Defense applications ( 020d). This COU also includes activities
identified by the U.S. Department of Defense.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.29 Commercial Use - Other Uses - Inspection Penetrant Kit
This COU refers to the commercial use of DBP incorporated in inspection penetrant kits. Inspection
fluids or penetrants are used to reveal surface defects on metal parts, including cracks, folds, or pitting.
Penetrant testing can be used to detect imperfections and flaws that are not detectable by the eye. DBP is
present in inspection penetrant kits as part of some government Agency applications ( ?20d).
This COU also includes activities identified by the U.S. Department of Defense.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.30 Commercial Use - Other Uses - Lubricants and Lubricant Additives
This COU refers to the commercial use of lubricants and lubricant additives that contain DBP for
commercial applications such as synthetic lubricants and anti-seize compounds in automobile and
aerospace applications (NASA. 2020; 20d; MEM A. 2019; Texacone. 2016). Lubricants
and lubricant additives may be poured or applied by workers in auto repair and other maintenance shops.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.31 Consumer Use - Automotive, Fuel, Agriculture, Outdoor Use Products
- Automotive Care Products
This COU refers to the consumer use of DBP in automotive care products. This COU includes the use of
DBP-containing products in a consumer DIY setting.
DBP is used in various automotive product applications. EPA notes that this reporting code in the 2020
CDR cycle is intended to describe exterior car washes and soaps, exterior car waxes, polishes, and
coatings, touch up paint, and interior car care ( 322a).
The consumer use was not reported to EPA in the 2016 or 2020 CDR cycles, but EPA expects the
commercial automotive care products reported in the CDR cycles are available to consumers for use in a
DIY setting.
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E.32 Consumer Use - Construction, Paint, Electrical, and Metal Products -
Adhesives and Sealants
This COU refers to the consumer use of DBP in adhesives and sealants, including fillers and putties.
EPA notes in the final scope that DBP is used as an adhesive and sealant ( 21c). The
Agency expects that the use of these types of products would occur in commercial applications;
however, EPA notes that this product are likely to be sourced by DIY consumers through various online
vendors. DBP-containing adhesives and sealants are used in automotive applications (MEMA.! ).
The Agency does expect the primary use of the automotive adhesives and sealants to be industrial and
commercial in nature but the possibility for consumer use is still possible. This COU includes consumer
DIYers who may perform exterior or interior car maintenance involving adhesives and sealants. Any
product containing DBP which is applied as an undercover coating, would most likely be applied by
spraying the coating on the underside of the vehicle.
Examples of CDR Submissions
In the 2016 CDR cycle, two companies reported the use of DBP in adhesives and sealants (
2019b).
In the 2020 CDR cycle, one company reported the use of DBP in fillers and putties ( '0a).
E.33 Consumer Use - Construction, Paint, Electrical, and Metal Products -
Paints and Coatings
This COU refers to the consumer use of DBP in paints and coatings. Consumers generally use paints and
coatings containing DBP in an indoor environment and DIYers handle the paints and coatings that have
DBP incorporated into the product. DBP is used in a variety of paint and coating products and is often
used as a surfactant in paints and coatings.
Examples of CDR Submissions
In the 2020 CDR cycle, one company reported the use of DBP in water-based paint and in solvent-based
paint (U.S. EPA. 2020a).
E.34 Consumer Use - Furnishing, Cleaning, Treatment Care Products -
Fabric, Textile, and Leather Products
This COU refers to the consumer use of DBP already incorporated as a plasticizer in fabric, textile, and
synthetic leather products and/or articles. This COU includes consumer wear and use of DBP-containing
textiles. EPA expects this COU to include consumer use of DBP in in apparel, including in cases where
DBP has been incorporated into the fabric as a plasticizer.
The Washington State Department of Ecology identified 1,326 reports of DBP use in children's
products, primarily in footwear between 2012 and 2019 fWSDE. 2023; 320c).
Examples of CDR Submissions
This use was not reported to EPA in the 2016 or 2020 CDR cycle.
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E.35 Consumer Use - Furnishing, Cleaning, Treatment/Care Products -
Floor Coverings; Construction and Building Materials Covering
Large Surface Areas Including Stone, Plaster, Cement, Glass, and
Ceramic Articles; Fabrics, Textiles, and Apparel
This COU refers to the consumer use of DBP in solid flooring and construction and building materials.
Consumers generally use flooring containing DBP in an indoor environment and DIYers handle the
construction materials (e.g., tiles, carpeting) that have DBP incorporated into the articles, which may
involve cutting and shaping the articles for installation.
Examples of CDR Submissions
In the 2016 CDR cycle, one company reported the use of DBP in floor coverings ( )).
In the 2020 CDR cycle, one company reported the use of DBP as a plasticizer in construction and
building materials covering large surface areas including stone, plaster, cement, glass, and ceramic
articles; fabrics, textiles, and apparel ( 20a).
E.36 Consumer Use - Furnishing, Cleaning, Treatment/Care Products -
Cleaning and Furnishing Care Products
This COU refers to the consumer use of cleaning and furnishing care products containing DBP. The
consumer users of products under this category would be expected to manually apply cleaning and
furnishing care products that contain DBP (U.S. EPA. 2020c).
DBP may be present in cleaning and furnishing care products, such as glass window cleaning
formulations, carpet and floor cleaners, spot removers, and shoe care products ( 020c). EPA
expects that the type of products reported under this COU are likely to be both commercial and
consumer in nature; however, this COU refers to the consumer use only.
This use was not reported in the 2016 or 2020 CDR cycles.
E.37 Consumer Use - Packaging, Paper, Plastic, Hobby Products - Ink,
Toner, and Colorant Products
This COU refers to the consumer use of DBP in inks, toner, and colorants, that can be used in
packaging, paper, plastic, toys, hobby products and articles.
DBP is used in ink, toner, and colorant products, including coloring agents, printing inks, digital inks,
and inks and toners used in the electronics industry ( 20c). EPA expects that the majority of
ink, toner, and colorant products containing DBP would be commercial in nature; however, it is possible
that these products are used by DIY consumers as many of the commercial products are available for
consumer purchasers through various online vendors. This COU refers to the consumer use of these
products. EPA would expect that if consumer DIYers were to use these products they would apply them
in the same fashion as industrial users, on a smaller scale in a non-commercial setting.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
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E.38 Consumer Use - Packaging, Paper, Plastic, Hobby Products -
Packaging (Excluding Food Packaging), Including Rubber Articles;
Plastic Articles (Hard); Plastic Articles (Soft); Other Articles with
Routine Direct Contact During Normal Use, Including Rubber
Articles; Plastic Articles (Hard)
This COU refers to the consumer use of DBP in various packaging, paper, plastic, and hobby products.
EPA notes that this use was reported as plastic and rubber products not covered elsewhere in the 2016
CDR reporting cycle and is intended to describe products such as phone covers, personal tablet covers,
styrofoam packaging, and bubble wrap. EPA also expects that the type of products reported under this
COU are likely to be both commercial and consumer in nature. This COU refers to the consumer use of
these products.
Examples of CDR Submissions
In the 2016 CDR cycle, two companies reported the use of DBP in plastic and rubber products not
covered elsewhere, which is listed as both "packaging (excluding food packaging), including rubber
articles; plastic articles (hard); plastic articles (soft)" and as "other articles with routine direct contact
during normal use, including rubber articles; plastic articles (hard)" in the 2020 CDR cycle (
2019b).
E.39 Consumer Use - Packaging, Paper, Plastic, Hobby Products - Toys,
Playground, and Sporting Equipment
This COU refers to the consumer use of DBP in toys, playground, and sporting equipment. The COU
includes the consumer use or storage of toys, playgrounds, and sporting equipment that contain DBP.
The use also refers to the DIY building of home sporting equipment.
DBP can be used as a plasticizer to provide flexibility to toys. The Consumer Product Safety
Improvement Act (CPSIA) of 2008 placed a prohibition on DBP that limited manufacturers' use of DBP
in children's toys to 0.1 percent ( ?a). Toys containing DBP that were manufactured
and/or processed prior to the CPSIA restriction in 2008 may still be in use. DBP is reported to be found
downstream in tire crumb applications for playgrounds and turf ( ).
The consumer use was not reported to EPA in the 2016 or 2020 CDR cycles, but EPA expects the
commercial toys, playground, and sporting equipment reported in the CDR cycles are available to
consumers for use.
E.40 Consumer Use - Other Use - Automotive Articles
This COU refers to the consumer use of DBP in automotive articles. This COU includes the use of DBP-
containing automotive articles in a consumer DIY setting or by consumers driving a vehicle.
DBP is used in various automotive applications. DBP is used in auto parts and equipment maintenance
(MEMA. 2019). DBP was identified in 391 auto parts. In total, in the IMDS data system, DBP is listed
in approximately 76,000 parts. These parts are found spread throughout the body/exterior, the interior,
the powertrain, the chassis, and the electrical system, and include fuel tank assemblies, hose assemblies,
wiring and computers, seat parts, and mats and carpeting (ME1S ). DBP is reported to be found
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downstream in tire crumb applications for playgrounds and turf (Armada et ai. 2022;
Consumers may be exposed to tires when handling tires for replacement on automobiles.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.41 Consumer Use - Other Uses - Chemiluminescent Light Sticks
This COU refers to the consumer use of DBP incorporated into chemiluminescent light sticks,
sometimes referred to colloquially as glow sticks. EPA was notified that DBP is present in
chemiluminescent light sticks as part of some governmental applications (U.S. EPA. 2020d).
Chemiluminescent light sticks are also available to consumers and are typically advertised as "glow
sticks;" the North Carolina poison control cites glow sticks containing DBP as a health hazard for
consumers (NC Poison Control. 2023).
The consumer use was not reported to EPA in the 2016 or 2020 CDR reporting cycles.
E.42 Consumer Use - Other Uses - Lubricants and Lubricant Additives
This COU refers to the consumer use of DBP incorporated within lubricant products. DBP is used in
products for consumer applications including synthetic lubricants and anti-seize compounds in
automotive applications (NASA. 2020; U.S. EPA. 2020d; MEM A. 2019). EPA expects that the type of
products for automotive applications reported under this COU are likely to be both commercial and
consumer in nature. This COU encompasses only the consumer use of these products. For the consumer
use of these products, EPA expects them to be poured or applied by consumers as part of DIY auto
repair activities.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.43 Consumer Use - Other - Novelty Articles
This COU refers to the consumer use of DBP in adult novelty articles.
This COU is describing adult sex toys that are available for consumer use in the United States. Although
the U.S. Food and Drug Administration (FDA) classifies certain sex toys (such as vibrators) as
obstetrical and gynecological therapeutic medical devices, many manufacturers label these products "for
novelty use only" and are not subject to the FDA regulations (Stabile. ). This same study indicated
tested concentrations of phthalates between 24 and 49 percent of the tested sex toys for creating a softer,
more flexible plastic (Stabile.! ), and EPA assumed that the concentration of DBP in these products
to be analogous to the overall content of the mix of phthalates tested and found in this study.
This use was not reported to EPA in the 2016 or 2020 CDR cycles.
E.44 Disposal
For purposes of the DBP risk evaluation, this COU refers to the DBP in a waste stream that is collected
from facilities and households and are unloaded at and treated or disposed at third-party sites. Each of
the COUs of DBP may generate waste streams of the chemical. This COU also encompasses DBP
contained in wastewater discharged by consumers or occupational users to POTW or other, non-POTW
for treatment, as well as other wastes. DBP is expected to be released to other environmental media,
such as introductions of biosolids to soil or migration to water sources and through waste disposal (e.g.,
disposal of formulations containing DBP, plastic and rubber products, textiles, and transport containers).
Disposal may also include destruction and removal by incineration (\ v « « \ 1 ^)- Additionally,
DBP has been identified in EPA's Hydraulic Fracturing for Oil and Gas: Impacts from the Hydraulic
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Fracturing Water Cycle on Drinking Water Resources in the United States, December 2016 document to
be a chemical reported to be detected in produced water, which is subsequently disposed (
2016a). Recycling of DBP and DBP-containing products is considered a different COU. Environmental
releases from industrial sites are assessed in each COU and are not considered as part of the Disposal
COU. Activities and releases associated with the use of DBP in propellants in articles, or components of
articles subject to Section 4181 of the Internal Revenue Code of 1954, which are outside the scope of the
definition of "chemical substance" TSCA section 3(2)(B)(v), are not considered as part of the Disposal
COU.
Activities and releases associated with the use of dibutyl phthalate in propellants in articles, or
components of articles subject to Section 4181 of the Internal Revenue Code of 1954, which are outside
the scope of the definition of "chemical substance" TSCA section 3(2)(B)(v), are not considered as part
of the disposal COU.
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Appendix F DRAFT OCCUPATIONAL EXPOSURE VALUE
DERIVATION
EPA has calculated a draft 8-hour existing chemical occupational exposure value to summarize the
occupational exposure scenario and sensitive health endpoints into a single value. This calculated draft
value may be used to support risk management efforts for DBP under TSCA section 6(a), 15 U.S.C. §
2605. EPA calculated the draft value rounded to 0.6 mg/m3 for inhalation exposures to DBP as an 8-
hour time-weighted average (TWA) and for consideration in workplace settings (see Appendix F. 1)
based on the acute, non-cancer human equivalent concentration (HEC) for developmental toxicity {i.e.,
decreased fetal testicular testosterone).
TSCA requires risk evaluations to be conducted without consideration of costs and other non-risk
factors, and thus this draft occupational exposure value represents a risk-only number. If risk
management for DBP follows the finalized risk evaluation, EPA may consider costs and other non-risk
factors, such as technological feasibility, the availability of alternatives, and the potential for critical or
essential uses. Any existing chemical exposure limit used for occupational safety risk management
purposes could differ from the draft occupational exposure value presented in this appendix based on
additional consideration of exposures and non-risk factors consistent with TSCA section 6(c).
This calculated draft value for DBP represents the exposure concentration below which exposed workers
and ONUs are not expected to exhibit any appreciable risk of adverse toxicological outcomes,
accounting for PESS. It is derived based on the most sensitive human health effect {i.e., decreased fetal
testicular testosterone) and exposure duration {i.e., acute) relative to benchmarks and a standard
occupational scenario assumption of an 8-hour workday.
EPA expects that at the draft occupational exposure value of 0.05 ppm (0.6 mg/m3), a worker or ONU
also would be protected against developmental toxicity from intermediate and chronic duration
occupational exposures if ambient exposures are kept below this draft occupational exposure value. The
Agency has not separately calculated a draft short-term {i.e., 15-minute) occupational exposure value
because EPA did not identify hazards for DBP associated with this very short duration.
NIOSH 5020 and OSHA 104 analytical methods can be used for detecting DBP in air.
The Occupational Safety and Health Administration (OSHA) set a permissible exposure limit (PEL) as
an 8-hour TWA for DBP of 5 mg/m3 (OSHA. 2020). EPA located several occupational exposure limits
for DBP (CASRN 84-74-2) in other countries (u \ 2022). Identified 8-hour TWA values ranged from
0.58 mg/m3 in Germany, New Zealand, and Poland to 10 mg/m3 in South Africa. Additionally, EPA
found that New Zealand and the United Kingdom have an established occupational exposure limit of
0.58 and 5 mg/m3 (8-hour TWA) in each country's code of regulation that is enforced by each country's
worker safety and health agency.
F.l Draft Occupational Exposure Value Calculations
This appendix presents the calculations used to estimate draft occupational exposure values using inputs
derived in this draft risk evaluation. Multiple values are presented below for hazard endpoints based on
different exposure durations. For DBP, the most sensitive occupational exposure value is based on non-
cancer developmental effects and the resulting 8-hour TWA is rounded to 0.6 mg/m3.
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Draft Acute Non-Cancer Occupational Exposure Value
The draft acute occupational exposure value (EVaCute) was calculated as the concentration at which the
acute MOE would equal the benchmark MOE for acute occupational exposures using EquationApx
F-l:
Equation Apx F-l.
HECacute ATHECacute IRresting
|7 Y — ^
Benchmark MOEacute ED I ^workers
24/i n£10rm3
1.0 ppm — 0.6125 w
—rr— * -77j— * 5— = 0-05 ppm
30 Oh m3
d hr
/mg\ EV ppm * MW 0.05 ppm * 278.mg
EVacute \m3 / MolarVolume 24 45 —^— ^ m3
mol
Draft Intermediate Non-Cancer Occupational Exposure Value
The draft intermediate occupational exposure value (EVintermediate) was calculated as the concentration at
which the intermediate MOE would equal the benchmark MOE for intermediate occupational exposures
using Equation Apx F-2:
Equation Apx F-2.
gy HECjntermefljate ^ AThec intermediate^ ^resting
intermediate Benchmark MOfjntermediate ED*EF IRworkers
24/i m3
1.0 ppm —*30d 0.6125-jjt mg
= "lo"*Th—"—W = 007 ppm = °'8 W
-t-*22 a 1.25 -Tr-
et hr
Draft Chronic Non-Cancer Exposure Value
The draft chronic occupational exposure value (EVchronic) was calculated as the concentration at which
the chronic MOE would equal the benchmark MOE for chronic occupational exposures using
EquationApx F-3:
Equation Apx F-3.
gy HECchronjc ^ AT^ec chronic ^ ^resting
chronic Benchmark MOEchronic ED*EF*WY IRworkers
24h 365d m3
l.Oppm *4°y . 0.6125- ^ _
* 8h 250d * m3
0.07 ppm = 0.8 -§
5n on /bua ri m3
JU —* *40 V 125——
d y hr
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Where:
ATh
'.ecate
A TnECintermediate
A TnECchronic
Benchmark MOEacute =
Benchmark MOEintermediate =
Benchmark MOEchronic =
EVacute
EVintermediate
E V chronic —
ED
EF
HEC
IR
Molar Volume =
MW
WY
Averaging time for the POD/HEC used for evaluating non-cancer
acute occupational risk based on study conditions and HEC
adjustments (24 h/day).
Averaging time for the POD/HEC used for evaluating non-cancer
intermediate occupational risk based on study conditions and/or
any HEC adjustments (24 h/day for 30 days).
Averaging time for the POD/HEC used for evaluating non-cancer
chronic occupational risk based on study conditions and/or HEC
adjustments (24 h/day for 365 days/year) and assuming the
same number of years as the high-end working years (WY, 40
years) for a worker.
Acute non-cancer benchmark margin of exposure, based on the
total uncertainty factor of 30
Intermediate non-cancer benchmark margin of exposure, based on
the total uncertainty factor of 30
Chronic non-cancer benchmark margin of exposure, based on the
total uncertainty factor of 30
Acute occupational exposure value
Intermediate occupational exposure value
Chronic occupational exposure value
Exposure duration (8 h/day)
Exposure frequency (1 day for acute, 22 days for intermediate, and
250 days/year for chronic and lifetime)
Human equivalent concentration for acute, intermediate, or chronic
non-cancer occupational exposure scenarios
Inhalation rate (default is 1.25 m3/h for workers and 0.6125 m3/h
assumed from "resting" animals from toxicity studies)
24.45 L/mol, the volume of a mole of gas at 1 atm and 25 °C
Molecular weight of DBP (278.35 g/mole)
Working years per lifetime at the 95th percentile (40 years).
Unit conversion:
1 ppm = 11.38 mg/m3 (see equation associated with the EVacute calculation)
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