United States Office of Chemical Safety and
Environmental Protection Agency Pollution Prevention
Proposed Designation of
Di-isobutyl Phthalate (DIBP)
(CASRN 84-69-5)
as High-Priority Substance
for Risk Evaluation
August 22,2019
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Table of Contents
List of Tables iii
Acronyms and Abbreviations iv
1. Introduction 1
2. Production volume or significant changes in production volume 3
Approach 3
Results and Discussion 3
3. Conditions of use or significant changes in conditions of use 4
Approach 4
CDR Tables 4
CDR Summary and Additional Information on Conditions of Use 6
4. Potentially exposed or susceptible subpopulations 7
Approach 7
Results and Discussion 7
5. Persistence and bioaccumulation 8
Approach 8
Physical and Chemical Properties and Environmental Fate Tables 8
Results and Discussion 10
6. Storage near significant sources of drinking water 10
Approach 10
Results and Discussion 11
7. Hazard potential 11
Approach 11
Potential Human Health and Environmental Hazard Tables 11
8. Exposure potential 14
Approach 14
Results and Discussion 14
9. Other risk-based criteria that EPA determines to be relevant to the designation of the
chemical substance's priority 15
10. Proposed designation and Rationale 17
11. References 18
ii
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List of Tables
Table 1. 1986-2015 National Aggregate Production Volume Data (Production Volume in
Pounds) 3
Table 2. Di-isobutyl phthalate (84-69-5) Categories and Subcategories of Conditions of Use
(2016 CDR Reporting Cycle) 5
Table 3. Di-isobutyl phthalate (84-69-5) Categories and Subcategories of Conditions of Use
(2012 CDR Reporting Cycle) 6
Table 4. Physical and Chemical Properties of Di-isobutyl Phthalate 8
Table 5. Environmental Fate Characteristics of Di-isobutyl Phthalate 9
Table 6. Potential Human Health Hazards Identified for Di-isobutyl Phthalate 12
Table 7. Potential Environmental Hazards Identified for Di-isobutyl Phthalate 13
Table 8. Exposure Information for Consumers 15
Table 9. Exposure Information for the Environment and General Population 16
in
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Acronyms and Abbreviations
Term
Description
ACGIH
American Conference of Governmental Industrial Hygienists
AGD
Anogenital Distance
AGI
Anogenital Index
BAF
Bioaccumulation Factor
BCF
Bioconcentration Factor
CAA
Clean Air Act
CBI
Confidential Business Information
CDR
Chemical Data Reporting
CERCLA
Comprehensive Environmental Response, Compensation and Liability Act
CFR
U.S. Code of Federal Regulations
CHAP
Chronic Hazard Advisory Panel
CPDat
Chemical and Products Database
CPSC
U.S. Consumer Product Safety Commission
CWA
Clean Water Act
DIBP
Di-isobutyl Phthalate
EPCRA
Emergency Planning and Community Right-to-Know Act
IUR
Inventory Update Reporting
K
Thousand
M
Million
MIBP
Monoisobutyl Phthalate
NHANES
National Health and Nutrition Examination Survey
NICNAS
National Industrial Chemicals Notification and Assessment Scheme (Australia)
NIH
National Institutes of Health (NIH)
NIOSH
National Institute for Occupational Safety and Health
OECD
Organisation for Economic Co-operation and Development
OSHA
Occupational Safety and Health Administration
PEL
Permissible Exposure Limit
iv
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PPE
Personal Protective Equipment
REL
Recommended Exposure Limit
TBD
To be determined
TLV
Threshold Limit Value
TSCA
Toxic Substances Control Act
TRI
Toxics Release Inventory
WH
Withheld
V
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1. Introduction
In section 6(b)(1)(B) of the Toxic Substances Control Act (TSCA), as amended, and in the U.S.
Environmental Protection Agency's (EPA) implementing regulations (40 CFR 702.3)1, a high-
priority substance for risk evaluation is defined as a chemical substance that EPA determines,
without consideration of costs or other non-risk factors, may present an unreasonable risk of
injury to health or the environment because of a potential hazard and a potential route of
exposure under the conditions of use, including an unreasonable risk to potentially exposed or
susceptible subpopulations identified as relevant by EPA.
Before designating prioritization status, under EPA's regulations at 40 CFR 702.9 and pursuant
to TSCA section 6(b)(1)(A), EPA will generally use reasonably available information to screen
the candidate chemical substance under its conditions of use against the following criteria and
considerations:
• the hazard and exposure potential of the chemical substance;
• persistence and bioaccumulation;
• potentially exposed or susceptible subpopulations;
• storage near significant sources of drinking water;
• conditions of use or significant changes in the conditions of use of the chemical
substance;
• the chemical substance's production volume or significant changes in production volume;
and
• other risk-based criteria that EPA determines to be relevant to the designation of the
chemical substance's priority.
This document presents the review of the candidate chemical substance against the criteria and
considerations set forth in 40 CFR 702.9 for a may present risk finding. The information sources
used are relevant to the criteria and considerations and consistent with the scientific standards of
TSCA section 26(h), including, as appropriate, sources for hazard and exposure data listed in
Appendices A and B of the TSCA Work Plan Chemicals: Methods Document (February 2012)
(40 CFR 702.9(b)). EPA uses scientific information that is consistent with the best available
science. Final designation of the chemical substance as a high-priority chemical substance would
immediately initiate the risk evaluation process as described in the EPA's final rule, Procedures
for Chemical Risk Evaluation Under the Amended Toxic Substances Control Act (40 CFR 702).
Di-isobutyl phthalate (DIBP) is one of the 40 chemical substances initiated for prioritization as
referenced in the March 21, 2019 notice (84 FR 10491)2. EPA has determined that DIBP is a
suitable candidate for the proposed designation as a high-priority substance. The proposed
designation is based on the results of the review against the aforementioned criteria and
considerations as well as review of the reasonably available information on DIBP, including
relevant information received from the public and other information as appropriate.
1 For all 40 CFR 702 citations, please refer to:
https://www.govinfo.gov/content/pkg/CFR-2018-title40-vol33/xml/CFR-2018-title40-vol33-part702.xml and
https://www. regulations. gov/document?D=EPA~HQ~OPPT~2Q .1.6-0654-01.08
2 https://www.federalregister.gov/documents/2019/03/21/2019-05404/initiation-of-prioritization-under-the-toxic-
substances-co nt ro 1-act-tsca
1
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EPA will take comment on this proposed designation for 90 days before finalizing its designation
of DIBP. The docket number for providing comments on DIBP is EPA-HQ-OPPT-2018-0434
and is available at www.regulations.gov.
The information, analysis and basis used for the review of the chemical is organized as follows:
• Section 1 (Introduction): This section explains the requirements of the amended TSCA
and implementing regulations - including the criteria and considerations - pertinent to the
prioritization and designation of high-priority chemical substances.
• Section 2 (Production volume or significant changes in production volume): This section
presents information and analysis on national aggregate production volume of the
chemical substance.
• Section 3 (Conditions of use or significant changes in conditions of use): This section
presents information and analysis regarding the chemical substance's conditions of use
under TSCA.
• Section 4 (Potentially exposed or susceptible subpopulations): This section presents
information and analysis regarding potentially exposed or susceptible subpopulations,
including children, women of reproductive age, and workers, with respect to the chemical
substance.
• Section 5 (Persistence and bioaccumulation): This section presents information and
analysis regarding the physical and chemical properties of the chemical substance and the
chemical's fate characteristics.
• Section 6 (Storage near significant sources of drinking water): This section presents
information and analysis considered regarding the risk from the storage of the chemical
substance near significant sources of drinking water.
• Section 7 (Hazardpotential): This section presents the hazard information relevant to the
chemical substance.
• Section 8 (Exposurepotential): This section presents information and analysis regarding
the exposures to the chemical substance.
• Section 9 (Other risk-based criteria): This section presents the extent to which EPA
identified other risk-based criteria that are relevant to the designation of the chemical
substance's priority.
• Section 10 (Proposed designation): Based on the results of the review performed and the
information and analysis presented, this section describes the basis used by EPA to
support the proposed designation.
2
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2. Production volume or significant changes in production volume
Approach
EPA considered current volume or significant changes in volume of the chemical substance
using information reported by manufacturers (including importers). EPA assembled reported
information for years 1986 through 2015 on the production volume for DIBP reported under the
Inventory Update Reporting (IUR) rule and Chemical Data Reporting (CDR) rule3. The national
aggregate production volume, which is presented as a range to protect individual site production
volumes that are confidential business information (CBI), is presented in Table 1.
Results and Discussion
National aggregate production volume for DIBP generally declined from 1986 to 2011, after
which this information was withheld. From 1986 to 1998, aggregate production volume was
between 1 million and 10 million pounds. In 2002 and 2006, aggregate production volume was
between 500 thousand and 1 million pounds, and in reporting year 2011, 453,710 pounds of this
chemical was manufactured or produced (Table 1).
Table 1.1986-2015 National Aggregate Production Volume Data (Production Volume in
Pounds)
Chemical ID
1986
1990
1994
1998
2002
2006
2011
2012
2013
2014
2015
Di-isobutyl
>1M
>1M
>1M
>1M
>500K
>500K
453,710
WH
WH
WH
WH
Phthalate
to
to
to
to
to 1M
to 1M
(84-69-5)
10M
10M
10M
10M
K = thousand, M = million, WH = withheld4
Reference: U.S. EPA (2013) and U.S. EPA (
3 Over time, the requirements for reporting frequency, production volume thresholds, and chemical substances under
the Chemical Data Reporting (CDR) rule have changed. CDR was formerly known as the Inventory Update Rule
(IUR). The first IUR collection occurred in 1986 and continued every four years through 2006. As part of two
rulemakings in 2003 and 2005, EPA made a variety of changes to the IUR, including to change the reporting
frequency to every five years to address burdens associated with new reporting requirements. Additional changes to
reporting requirements were made in 2011, including to suspend and replace the 2011 submission period with a
2012 submission period, return to reporting every four years, and require the reporting of all years beginning with
2011 production volumes. The reporting of production volumes for all years was added because of the mounting
evidence that many chemical substances, even larger production volume chemical substances, often experience wide
fluctuations in production volume from year to year. In addition, also as part of the 2011 IUR Modifications final
rule (76 FR 50816, Aug 16, 2011), EPA changed the name of the regulation from IUR to CDR to better reflect the
distinction between this data collection (which includes exposure-related data) and the TSCA Inventory itself (which
only involves chemical identification information).
4 This information is withheld, because EPA is releasing the 2016 CDR data in stages. EPA released the initial 2016
CDR data in May 2017. The initial data included national production volume (released in ranges), other
manufacturing information, and processing and use information, except for information claimed by the submitter to
be confidential business information (CBI) or information that EPA is withholding to protect claims of CBI. EPA
anticipates releasing additional data after completion of an effort to obtain CBI substantiation required by the Frank
R. Lautenberg Chemical Safety for the 21st Century Act, which amended the Toxic Substances Control Act.
3
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3. Conditions of use or significant changes in conditions of use
Approach
EPA assembled information to determine conditions of use or significant changes in conditions
of use of the chemical substance. TSCA section 3(4) defines the term "conditions of use" to
mean the circumstances, as determined by the Administrator, under which a chemical substance
is intended, known, or reasonably foreseen to be manufactured, processed, distributed in
commerce, used, or disposed of.
A key source of reasonably available information that EPA considered for determining the
conditions of use for DIBP was submitted by manufacturers (including importers) under the
2012 and 2016 CDR reporting cycles. CDR requires manufacturers (including importers) to
report information on the chemical substances they produce domestically or import into the
United States greater than 25,000 lbs per site, except if certain TSCA actions apply (in which
case the reporting requirement is greater than 2,500 lbs per site). CDR includes information on
the manufacturing, processing, and use of chemical substances. Based on the known
manufacturing, processing and uses of this chemical substance, EPA assumes distribution in
commerce. CDR may not provide information on other life-cycle phases such as distribution or
chemical end-of-life after use in products (i.e., disposal). While EPA may be aware of additional
uses, CDR submitters are not required to provide information on chemical uses that are not
regulated under TSCA.
For chemical substances under review that are included on the Toxics Release Inventory (TRI)
chemical list, information disclosed by reporting facilities in Part II Section 3 ("Activities and
Uses of the Toxic Chemical at the Facility") of their TRI Form R reports was used to supplement
the CDR information on conditions of use. There is not a one-to-one correlation between
conditions of use reported under CDR and information reported in Part II Section 3 of the TRI
Form R because facilities are not required to disclose in their Form R submissions the specific
uses of TRI chemical substances they manufactured on-site or imported. DIBP is not included on
the TRI chemical list. For purposes of this proposed prioritization designation, EPA assumed
end-of-life pathways that include releases to air, wastewater, and solid and liquid waste based on
the conditions of use.
CDR Tables
Based on the publicly available5 manufacturing information, industrial processing and use
information, and consumer and commercial use information reported under CDR, EPA
developed a list of conditions of use for the 2016 and 2012 reporting cycles (Tables 2 and 3,
respectively).
5 Some specific chemical uses may be claimed by CDR submitters as confidential business information (CBI) under
section 14 of TSCA. In these cases, EPA has indicated that the information is CBI.
4
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Table 2. Di-isobutyl phthalate (84-69-5) Categories and Subcategories of Conditions of Use6
(2016 CDR Report
ting Cycle)
Life-Cycle Stage
Category
Subcategory
Reference
Manufacturing
Domestic manufacturing
Domestic manufacturing
t; -s HIM {20
19)
Manufacturing
Import
Import
10
19)
Processing
Incorporating into article
Plasticizers - construction;
plastics product
manufacturing; transportation
equipment manufacturing
U.S. EPA. (20
19)
Processing
Incorporating into
formulation, mixture, or
reaction product
Plasticizers - adhesive
manufacturing; plastics
product manufacturing
! ^ M \ v20tr0
Distribution in
Commuvc'1''
Distribution in
com mcicc
Commercial Uses
Adhesives and sealants
Adhesives and sealants
>01<- -
Commercial Uses
Plastic and rubber
products not covered
elsewhere
Plastic and rubber products not
covered elsewhere
! ^ n \ v20tr0
Consumer Uses
Adhesives and sealants
Adhesives and sealants
i r W \ v-Oi
Disposal:i
Disposal
11 CDR includes information on the manufacturing, processing, and use of chemicals. CDR may not provide
information on other life-cycle phases such as distribution or chemical end-of-life after use in products (i.e.,
disposal). The table row is highlighted in gray to indicate that no information is provided for this life-cycle stage.
b EPA is particularly interested in information from the public on distribution in commerce.
6 Certain other uses that are excluded from TSCA are not captured in this table.
5
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Table 3. Di-isobutyl phthalate (84-69-5) Categories and Subcategories of Conditions of Use7
(2012 CDR Report
ting Cycle)
Life-Cycle Stage
Category
Subcategory
Reference
Manufacturing
Domestic manufacturing
Domestic manufacturing
Processing
Incorporating into
formulation, mixture, or
reaction product
Solvents (which become part
of product formulation or
mixture) - plastics material
and resin manufacturing
Distribution in
Coninicive1''
Distribution in commuvc
Commuvial I scs
Disposal:i
Catalyst sol\cut
Disposal
Catalyst sol\cut
a CDR includes information on the manufacturing, processing, and use of chemicals. CDR may not provide
information on other life-cycle phases such as distribution or chemical end-of-life after use in products (i.e.,
disposal). The table row is highlighted in gray to indicate that no information is provided for this life-cycle stage.
b EPA is particularly interested in information from the public on distribution in commerce.
CDR Summary and Additional Information on Conditions of Use
There was an increase in reporting conditions of use for DIBP from the 2012 to 2016 CDR cycle.
In the 2016 CDR data, one site reported use of DIBP in consumer and commercial adhesives and
sealants, and another site reported use of this chemical in commercial plastic and rubber
products, neither of which was reported in 2012. In the 2012 CDR data, only one site reported a
commercial use of DIBP as a catalyst solvent. One site reported a single industrial use of DIBP
in the 2012 CDR cycle for plastic material and resin manufacturing. A single site reported the
same use in 2016, albeit for the functional category of plasticizers instead of solvents. Use of
DIBP for industrial adhesive and transportation equipment manufacturing and construction was
also reported in 2016. In the 2016 CDR data, two facilities reported that DIBP was not recycled
(e.g., remanufactured, reprocessed, or reused). In the 2012 CDR data, one facility reported that
DIBP was not recycled. Consumer uses were also identified in additional databases, which are
included in the Exposure Potential section (Section 8).
One public commenter (EPA-HQ-OPPT-2018-0434-0004) asserted that DIBP is present as an
additive and impurity in adhesives in amounts less than 0.1 percent. Another commenter (EPA-
HQ-OPPT-2018-0434-0005) mentioned that DIBP is often a by-product or intermediate in the
production of phthalate-containing plastics.
Should the Agency decide to make a final decision to designate this chemical substance as a
high-priority substance, further characterization of relevant TSCA conditions of use will be
undertaken as part of the process of developing the scope of the risk evaluation.
7 Certain other uses that are excluded from TSCA are not captured in this table.
6
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4. Potentially exposed or susceptible subpopulations
Approach
In this review, EPA considered reasonably available information to identify potentially exposed
or susceptible subpopulations, such as children, women of reproductive age, workers, consumers,
or the elderly. EPA analyzed processing and use information included on the CDR Form U.
These data provide an indication about whether children may be potentially exposed or other
susceptible subpopulations may be exposed. EPA also used human health hazard information to
identify potentially exposed or susceptible subpopulations.
Results and Discussion
At this stage, EPA identified children, women of reproductive age, consumers and workers as
subpopulations who may be potentially exposed or susceptible subpopulations for DIBP.
Children
EPA used data reported to the 2012 and 2016 CDR to identify uses in products and articles
intended for children over time for DIBP. The 2012 and 2016 CDR did not report any use of
DIBP in children's products. EPA also identified potential developmental hazards that would
impact any stage of children's development.
Women of reproductive age (e.g., pregnant women per TSCA statute)
EPA identified studies that observed developmental and reproductive effects following exposure
to DIBP (Section 7, Table 6). Thus, women of reproductive age were identified as a potentially
exposed or susceptible subpopulation.
Consideration of women of reproductive age as a potentially exposed or susceptible
subpopulation was also based on exposure because women of reproductive age are potential
workers in the manufacturing, processing, distribution in commerce, use, or disposal of the
chemical substance.
Workers
Please refer to the Exposure Potential section (Section 8) for summary of potential occupational
exposures, which EPA indicates that workers are potentially exposed or susceptible
subpopulations based on greater exposure.
Consumers
Please refer to the Exposure Potential section (Section 8) for summary of potential consumer
exposures, which EPA indicates that consumers are potentially exposed or susceptible
subpopulations based on greater exposure.
7
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5. Persistence and bioaccumulation
Approach
EPA reviewed reasonably available information, such as physical and chemical properties and
environmental fate characteristics, to understand DIBP's persistence and bioaccumulation.
Physical and Chemical Properties and Environmental Fate Tables
Tables 4 and 5 summarize the physical and chemical properties and the environmental fate
characteristics of DIBP, respectively.
Table 4. Physica
and Chemical Properties of Di-isobut
tyl Phthalate
Property or
Endpoint
Value3
Reference
Molecular
Formula
C16H22O4
CRC Handbook (Haynes, 2014)
Molecular
Weight
278.344 g/mole
CRC Handbook (Haynes, 2014)
Physical State
Liquid
CRC Handbook (Haynes, 2014)
Physical Form
Liquid
HSDB C citing Lewis (2007)
Purity
>99%; impurities include water
HSDB C citing CPSC (2011)
Melting Point
-64 °C
Phvsoroo (2
Boiling Point
296.5 °C
PhvsoroD (2012); HSDB C
citing CRC Handbook (Haynes,
2014)
Density
1.049 g/cm3
HSDB C citing Havnes (2010);
CRC Handbook (Haynes, 2014)
Vapor Pressure
4.76 x 10"5 at 25 °C
HSDB C citing Daubert and
Danner (1989)
Vapor Density
TBD
TBD
Water
Solubility
6.2 mg/L at 24 °Cb
PhvsProo (2012); HSDB (
citing Yalkowsky et al. (2010)
11.5 mg/Lat-25 °C
ECHA (2019)
Log Kow
4.11
HSDB (2013) citing Hansch et al.
(1995)
Henry's Law
Constant
2.8 x 10"6 atm-m3/mole (calculated
from measured vapor pressure and
water solubility)
EPI Suite (2
Flash Point
185 °C (open cup)
HSDB C citing NFPA (2010)
8
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Property or
Endpoint
Value3
Reference
Auto
Flammability
432 °C (autoignition temperature)
H.SDB C citing NFPA f201 (»
Viscosity
41 mPa • second at 20 °C
HSDBC citing Gerhartz r 1985")
Refractive
Index
1.49 at 25 °C
H.SDB C citing Lewis (2007)
Dielectric
Constant
TBD
TBD
Surface Tension
TBD
TBD
Notes:
aMeasured unless otherwise noted;
bSelected value
TBD = To be determined, if reasonably available. EPA is particularly interested in information from the public
on these properties or endpoints.
Table 5. Environmental Fate Characteristics of Di-isobutyl Pht
lalate
Property or Endpoint
Value3
Reference
Direct
Photodegradati on
May be susceptible due to potential
absorption
HSDB C
Indirect
Photodegradati on
ti/2 = 1.2 days (12-hour day at 1.5 x 106
OH/cm3) based on OH rate constant of
9.3 x 10"12 cm3/molecule-second at 25
°C; estimated)11
EPI Suite (2
Hydrolysis
ti/2 = 5,730 days (at pH = 8, based on a
rate constant of 0.0014 M"1 second"1)
Wolfe etal. (1980)
Biodegradation
(Aerobic)
98%/4 weeks (OECD 302C)
HSDB ('. citing Sedvkh
and Klopman (2007)
100%/6 days (die-away tests)
HSDB C citing Hattori
etal. (1975)
40%/28 days OECD 301B (C02
evolution)
ECHA (20 i 9)
Biodegradation
(Anaerobic)
0-30%/96 days (sewage sludge and
swamp water)
0-30%/56 days (marine sediment)
HSDB L •. ; i citing
Madsen et al. (1995)
Wastewater Treatment
99.5% total removal (92% by
biodegradation, 7.5% by sludge
adsorption, and 0% by volatilization to
air; estimated)11
EPI Suite (2
9
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Property or Endpoint
Value3
Reference
Bioconcentration
Factor
240 (log BCF = 2.4; estimated)13
EPI Suite (2012)
Bioaccumulation
Factor
26 (log BAF = 1.4; estimated)13
EPI Suite (2
Soil Organic
Carbon:Water Partition
Coefficient (Log Koc)
3.14
HSDB C citing Sabliic
etal. (1995)
Notes:
"Measured unless otherwise noted
bEPI Suite™ physical property inputs: Log Kow = 4.11, BP = 296.5 °C, MP = -64 °C, VP = 4.76 x 10 5 mm Hg, WS
= 6.2 mg/L, BioP = 4, BioA = 1, Bio S = 1 SMILES 0=C(0CC(C)C)c(c(cccl)C(=0)0CC(C)C)cl
Bioconcentration factor = BCF; Bioaccumulation factor = BAF
Results and Discussion
DIBP is a volatile liquid. Based on its vapor pressure (4.76 x 10"5 mm Hg) and calculated
Henry's Law constant (2.8 x 10"6 atm-m3/mole), DIBP is expected to volatilize from water and
moist soil surfaces, but not dry soils. It is expected to have low mobility in soil (log Koc 3.14).
DIBP is expected to biodegrade based on studies that demonstrated 98% degradation of DIBP in
4 weeks (OECD 302C) and 100% degradation in 6 days (die-away test). DIBP in the air will be
in the particulate and vapor phases and is expected to react with hydroxyl radicals at a rate that
corresponds to a half-life of 1.2 days. Additionally, respective estimated BCF and BAF values of
240 and 26, and a measured log Kow of 4.11 indicate that DIBP has low potential to
bioaccumulate.
6. Storage near significant sources of drinking water
Approach
To support the proposed designation, EPA screened each chemical substance under its conditions
of use with respect to the seven criteria in TSCA section 6(b)(1)(A) and 40 CFR 702.9. The
statute specifically requires the Agency to consider the chemical substance's storage near
significant sources of drinking water, which EPA interprets as direction to focus on the chemical
substance's potential human health hazard and exposure.
EPA reviewed reasonably available information, specifically looking to identify certain types of
existing regulations or protections for the proposed chemical substances. EPA considered the
chemical substance's potential human health hazards, including to potentially exposed or
susceptible subpopulations, by identifying existing National Primary Drinking Water
Regulations under the Safe Drinking Water Act (40 CFR Part 141) and regulations under the
Clean Water Act (CWA; 40 CFR 401.15). In addition, EPA considered the consolidated list of
chemical substances subject to reporting requirements under the Emergency Planning and
Community Right-to-Know Act (EPCRA; Section 302 Extremely Hazardous Substances and
Section 313 Toxic Chemicals), the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA; Hazardous Substances), and the Clean Air Act (CAA) Section 112(r)
10
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(Regulated Chemicals for Accidental Release Prevention). Regulation by one of these authorities
is an indication that the substance is a potential health or environmental hazard which, if released
near a significant source of drinking water, could present an unreasonable risk of injury to human
health or the environment.
Results and Discussion
As a phthalate ester, DIBP is designated as a toxic pollutant under 40 CFR 401.15, and as such,
is subject to effluent limitations. Specifically, DIBP is categorized as an "aromatic organic
chemical," as applicable to the process wastewater discharges resulting from the manufacture of
bulk organic chemicals (40 CFR 414.70). Additionally, several states have adopted water
pollution discharge programs which categorize DIBP as an "aromatic organic chemical," as
applicable to the process wastewater discharges resulting from the manufacture of bulk organic
chemicals, including Illinois (35 111. Adm. Code 307-2406) and Wisconsin (Wis. Adm. Code §
NR 235.60).
7. Hazard potential
Approach
EPA considered reasonably available information from peer-reviewed assessments and databases
to identify potential human health and environmental hazards for DIBP (Tables 6 and 7,
respectively).
Because there are very few publicly available assessments for DIBP with cited environmental
hazard data, EPA used the infrastructure of ECOTOXicology knowledgebase (ECOTOX) to
identify single chemical toxicity data for aquatic and terrestrial life (U.S. EPA, 2018a). It uses a
comprehensive chemical-specific literature search of the open literature that is conducted
according to the Standard Operating Procedures (SOPs)8. The environmental hazard information
was populated in ECOTOX and is available to the public. In comparison to the approach used to
survey human health hazard data, EPA also used a read-across approach to identify additional
environmental hazard data for isomers of DIBP, if available, to fill in potential data gaps when
there were no reported observed effects for specific taxa exposed to the DIBP (Table 7).
Potential Human Health and Environmental Hazard Tables
EPA identified human health and environmental hazards based on a review of the reasonable
available information on DIBP (Tables 6 and 7, respectively).
8 The ECOTOX Standard Operating Procedures (SOPs) can be found at:
https://cfpub.epa.gov/ecotox/help.cfm?helptabs=tab4
11
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Table 6. Potential Human Health Hazards Identified for Di-isobutyl Phthalate
Human Health
Hazards
Tested for
Specific Effect
Effect
Observed
Reference
Acute Toxicity
X
NICNAS (2.008a); NICNAS t
CPSC (2011); NICNAS (2008b)
Repeated Dose
Toxicity
X
X
cpscIjorKmcMAsJimi
Genetic Toxicity
X
NICNAS (2.008a); NICNAS O*l I
NICNAS (2008b)
Reproductive Toxicity
X
X
NICNAS (2008a); NICNAS C
CPSC (2011); CPSC (2014);
NICNAS (2.008b)
Developmental
Toxicity
X
X
NICNAS (2.008a); NICNAS C
CPSC (201 l);CPSv .J'Ml
NICNAS (2008b)
Toxicokinetic
X
NICNAS (2008a); CPSC (
CPSC (2014)
Irritation/Corrosion
X
NICNAS (2.008a); NICNAS C
CPSC (2011); NICNAS (2008b)
Dermal Sensitization
X
cpscT^Ti^cNAsTio^br^'
Respiratory
Sensitization
X
CPSC (2
Carcinogenicity
X
NICNAS (2008a); NICNAS C
CPSC (2011); NICNAS (2008b)
Immunotoxicity
Neurotoxicity
X
CPSC (2011); CPSC C
Epidemiological
Studies or
Biomonitoring Studies
X
CPSC (2014)
Note: The "X" in the "Effect Observed" column indicates when a hazard effect was reported by one or more of the
referenced studies. Blank rows indicate when information was not identified during EPA's review of reasonably
available information to support the proposed designation.
12
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Table 7. Potential Environmental Hazards Identified for Di-isobutyl Phthalate
High-Priority Chemical
Isomers of
Candidate
Di-isobutyl Phthalate (1,2-
Media
Study
Duration
Taxa Groups
Di-isobutyl Phthalate (1,2-
Benzene- dicarboxylic acid,
1,2- bis-(2methylpropyl)
ester) (DIBP)
(CASRN 84-69-5)
Benzene- dicarboxylic acid,
1,2- bis-(2methylpropyl)
ester) (DIBP)
(CASRN 84-69-5)
NONE
Reference
Number of
Observed
Number of
Observed
Studies
Effects
Studies
Effects
Aquatic
Acute
Vegetation
-
-
exposure
Invertebrate
1
X
-
Linden et al., 1979
Fish
1
X
-
Geiger et al., 1985
Non-fish vertebrate
—
—
(i.e., amphibians, reptiles,
mammals)
Chronic
Vegetation
-
-
exposure
Invertebrate
-
-
Fish
-
-
Non-fish vertebrate
—
—
(i.e., amphibians, reptiles,
mammals)
Terrestrial
Acute
Vegetation
-
-
exposure
Invertebrate
2
X
—
Boyd et al. (2016);
Lenoir et al. (2014)
Vertebrate
-
-
Chronic
Vegetation
-
-
exposure
Invertebrate
-
-
Vertebrate
2
X
—
Hardin et al. (1987);
Oishi and Hiraga (1980)
The dash indicates that no studies relevant for environmental hazard were identified during this initial screening and thus the "Observed Effects" column is left blank.
The X in the Observed Effects column indicates when a hazard effect was reported by one or more of the referenced studies. The N/A in the Observed Effects
column indicates when a hazard effect was not reported by one of the referenced studies' abstract (full reference review has not been conducted).
13
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8. Exposure potential
Approach
EPA considered reasonably available information to screen potential environmental,
worker/occupational, consumer, and general population exposures for DIBP.
Release potential for environmental and human health exposure
DIBP is not included on the TRI chemical list. EPA considered conditions of use reported in
CDR and the physical and chemical properties to inform the release potential of DIBP.
Worker/Occupational and consumer exposure
EPA's approach for assessing exposure potential was to review the physical and chemical
properties, conditions of use reported in CDR, and information from the National Institutes of
Health Consumer Product Database and the Chemical and Products Database (CPDat) for DIBP
to inform occupational and consumer exposure potential. The results of this review are detailed
in the following tables.
General population exposure
EPA identified environmental concentration data to inform DIBP's exposure potential to the
general population (Table 9).
Results and Discussion
Release potential for environmental and human health exposure
DIBP is not included on the TRI chemical list.
When chemical substances are incorporated into formulations, mixtures, or reaction products, the
industrial releases may be a relatively low percentage of the production volume. Lower
percentage releases occur when a high percentage of the volume is incorporated without
significant process losses during its incorporation into a formulation, mixture, or product. The
actual percentages, quantities, and media of releases of the reported chemical associated with this
processing or use are not known.
Worker/Occupational exposure
Worker exposures to this chemical may be affected by many factors, including but not limited to
volume produced, processed, distributed, used, and disposed of; physical form and
concentration; processes of manufacture, processing, and use; chemical properties such as vapor
pressure, solubility, and water partition coefficient; local temperature and humidity; and
exposure controls such as engineering controls, administrative controls, and the existence of a
personal protective equipment (PPE) program.
DIBP does not have an Occupational Safety and Health Administration (OSHA) Permissible
Exposure Limit (PEL) ( ), a National Institute for Occupational Safety and Health
(NIOSH) Recommended Exposure Limit (REL) (NIOSH 2018). or the Threshold Limit Value
(TLV) set by American Conference of Governmental Industrial Hygienists (ACGIH).
14
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DIBP has a vapor pressure of 4.76 x 10"5 mm Hg at 25 °C/77 °F. EPA assumes that inhalation
exposure is negligible when vapors are generated from liquids with vapor pressures below 0.001
mm Hg at ambient room temperature conditions.
DIBP is indicated as being used in adhesives and sealants. Products used as adhesive and
sealants may be applied via spray or roll application methods. These methods may generate mists
to which workers may be exposed.
Consumer exposure
CDR reporting and information from the National Institutes of Health Household Products
Database do not report any use of DIBP in consumer products. However, the EPA Chemical and
Products Database (C'PDat ) as well as available assessments indicate that DIBP has been used in
consumer products such as adhesives, building materials, cleaners, paints, lubricants and
building materials (CPSC ) (Table 8). Internal consumer exposure has been estimated to
account for 0.1 to 8 (J,g/kg bodyweight per day for infants and 0.05 to 2 (J,g/kg bodyweight per
day in adults (CPSC 2011).
Table 8. Exposure Information for Consumers
Chemical
Identity
Consumer Product Database
Consumer Uses (List)
Di-isobutyl
Phthalate
(84-69-5)
Adhesive, automotive, automotive care, building material, catalyst, cleaner, colorant,
filler, filler building material, flooring, footwear, fragrance, hardener, metal surface
treatment, paint, paint binding, paint hardener, paper, photographic, plastic, plastic
hardener, rubber, seal material, solvent, stain remover, toys, viscous liquid building
material, wall building material
Reference: CPDat
General population exposure
A review of the available literature suggests that environmental concentration data are available
(Table 9). Releases of DIBP from certain conditions of use, such as manufacturing, disposal, or
waste treatment activities, may result in general population exposures via drinking water
ingestion, dermal contact, and inhalation from air releases (CPSC ).
Available assessments reviewed indicate that diet has been reported the primary source of
exposure to DIBP with indoor air also contributing to total DIBP exposure (CPSC 2014). In the
United States, urinary DIBP levels have increased over the past four National Health and
Nutrition Examination Survey (NHANES) surveys (2001-2002; 2003-2004; 2005-2006; 2007-
2008) in all age groups, genders, and races, and in total (CPSC 2014).
9. Other risk-based criteria that EPA determines to be relevant to the designation of
the chemical substance's priority
EPA did not identify other risk-based criteria relevant to the designation of the chemical
substance's priority.
15
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Table 9. Exposure Information for the Environment and General Population
Database Name
Env.
Concen.
Data
Present?
Human
Biomon.
Data
Present?
Ecological
Biomon.
Data
Present?
Reference
California Air Resources Board
no
no
no
CARB (2005)
Comparative Toxicogenomics Database
yes
no
no
MDI (2002)
EPA Ambient Monitoring Technology
Information Center - Air Toxics Data
no
no
no
\(1990)
EPA Discharge Monitoring Report Data
no
no
no
\ (2007)
EPA Unregulated Contaminant Monitoring
Rule
no
no
no
\ (1996)
FDA Total Diet Study
no
no
no
FDA (1991)
Great Lakes Environmental Database
no
no
no
(2018b)
Information Platform for Chemical
Monitoring Data
no
no
no
EC (2018)
International Council for the Exploration of
the Sea
no
no
no
ICES (2018)
OECD Monitoring Database
no
no
no
OECD (2018)
Targeted National Sewage Sludge Survey
no
no
no
\ (2006)
The National Health and Nutrition
Examination Survey
no
no
no
CDC (2013)
USGS Monitoring Data -National Water
Quality Monitoring Council
no
no
no
rS(1991a)
USGS Monitoring Data -National Water
Quality Monitoring Council, Air
no
no
no
rS (1991b)
USGS Monitoring Data -National Water
Quality Monitoring Council, Ground Water
no
no
no
rS(1991c)
USGS Monitoring Data -National Water
Quality Monitoring Council, Sediment
no
no
no
S(199Id)
USGS Monitoring Data -National Water
Quality Monitoring Council, Soil
no
no
no
rS(1991e)
USGS Monitoring Data -National Water
Quality Monitoring Council, Surface Water
no
no
no
USGS (199If)
USGS Monitoring Data -National Water
Quality Monitoring Council, Tissue
no
no
no
USGS (1991s)
1 Conccn.= concentration
bBiomon.= biomonitoring
16
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10. Proposed designation and Rationale
Proposed designation: High-priority substance
Rationale: EPA identified and analyzed reasonably available information and concluded that
DIBP may present an unreasonable risk of injury to health and/or the environment, including
potentially exposed or susceptible subpopulations, (e.g., workers, consumers, women of
reproductive age, consumers, children). This is based on the potential hazard and potential
exposure of DIBP under the conditions of use described in this document to support the
prioritization designation. Specifically, EPA expects that the manufacturing, processing,
distribution, use and disposal of DIBP may result in presence of the chemical in surface water,
ingestion of the chemical in drinking water, inhalation of the chemical from air releases,
exposure to workers, exposure to consumers and exposure to the general population, including
exposure to children. In addition, EPA expects potential environmental (e.g., aquatic toxicity,
terrestrial toxicity), and human health hazards (e.g., repeated dose toxicity, reproductive toxicity,
developmental toxicity).
17
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11. References
*Note: All hyperlinked in-text citations are also listed below *
Boyd, WA; Smith, MV; Co, CA; Pirone, JR; Rice, JR; Shockley, KR; Freedman, JH. (2016).
Developmental effects of the ToxCast Phase I and Phase II Chemicals in Caenorhabditis elegans
and corresponding responses in Zebrafish, Rats, and Rabbits. Environ Health Perspect 124: 586-
593. https://www.ncbi.nlm.nih.eov/pmc/articles/PMC4858399/pdf/ehp.1409645.pdf
CARB (California Air Resources Board). (2005). California Air Resources Board (CARB):
Indoor air pollution in California [Database], Retrieved from
https://ww3.arb.ca.gov/research/apr/reports/13Q41.pdf
CDC (Centers for Diseases Control and Prevention). (2013). National Health and Nutrition
Examination Survey Data (NHANES) [Database], Atlanta, GA: CDC, National Center for
Health Statistics. Retrieved from https://www.cdc.gov/nchs/nhan.es/index.htm
CPSC (U.S. Consumer Product Safety Commission). (2011). Toxicity review of diisobutyl
phthalate (DiBP, CASRN 84-69-5). Bethesda, MD: U.S. Consumer Product Safety Commission.
https://web.archive.org/web/2019032006043 5/https://www. cpsc.gov/s3fs-
public/ToxicitvReviewOfl If
CPSC (U.S. Consumer Product Safety Commission). (2014). Chronic hazard advisory panel on
phthalates and phthalate alternatives. Bethesda, Maryland: U.S. Consumer Product Safety
Commission, Directorate for Health Sciences.
https://web.archive.Org/web/2Q17Q2Q216Q318/https://www. cpsc.gov/s3fs-public/CHAP-
REP O R T - With - App en di ce s. p df
CPSC (U.S. Consumer Product Safety Commission). (2015). Estimated phthalate exposure and
risk to pregnant women and women of reproductive age as assessed using four NHANES
biomonitoring data sets (2005/2006, 2007/2008, 2009/2010, 2011/2012). Rockville, Maryland:
U.S. Consumer Product Safety Commission, Directorate for Hazard Identification and
Reduction. https://web.arch.ive.Org/web/2 20312/h.ttps://www.cpsc.gov/s3fs-
public/NHANES-Biomonitoring-analvsis-for-Commission.pdf
Daubert, TE; Danner, RP. (1989). Physical and thermodynamic properties of pure chemicals:
Data compilation. Washington, DC: Taylor & Francis.
ECHA (European Chemicals Agency). (2019). Registration dossier: Diisobutyl phthalate
(CASRN 84-69-5). Helsinki, Finland. https://echa.eiiropa.eii/registration-dossierA/registered-
dossier/13519/7/1
EC (European Commission). (2018). Information Platform for Chemical Monitoring Data
(IPCHEM) [Database], Retrieved from
https://ipchem.irc.ec.europa.eu/RDSIdiscoverv/ipchem/index.html
18
-------
FDA (U.S. Food and Drug Administration). (1991). FDA Total Diet Study [Database], Retrieved
from http://www.fda.gov/Food/FoodScienceResearch/TotalDietStudv/ucml84293.htm
Geiger, DL; Northcott, CE; Call, DJ; Brooke, LT. (1985). Acute toxicities of organic chemicals
to fathead minnows (Pimephales promelas): Volume II. Superior, WI: University of Wisconsin-
Superior, Center for Lake Superior Environmental Studies.
Gerhartz, W. (1985). Ullmann's Encyclopedia of Industrial Chemistry (5th ed.). Deerfield Beach,
FL: VCH Publishers.
Hansch, C; Leo, A; Hoekman, D. (1995). Exploring QSAR: Hydrophobic, Electronic, and Steric
Constants. Washington, DC: American Chemical Society.
Hardin, BS, RL; Burg, JR; Booth, GM; Hazelden, KP; Mackenzie, KM; Piccirillo, VJ; Smith,
KN. (1987). Evaluation of 60 chemicals in a preliminary developmental toxicity test
Teratogenesis, Carcinogenesis, and Mutagenesis 7: 29-48.
http://onlinelibrary.wilev.com/doi. )2/tcm. 1770070106/ab stract
Hattori, Y; Kuge, Y; Nakagawa, S. (1975). Microbial decomposition of phthalate esters in
environmental water (pp. 951-954). Osaka Prefecture, Japan: Environmental Pollution Control
Center, Mizu Shori Gijutsu.
Haynes, WM. (2010). Physical constants of organic compounds. In CRC Handbook of
Chemistry and Physics. Boca Raton, FL: CRC Press. Taylor & Francis Group.
Haynes, WM. (2014). Diisobutyl phthalate. In CRC Handbook of Chemistry and Physics (95
ed.). Boca Raton, FL: CRC Press. Taylor & Francis Group.
HSDB (Hazardous Substances Data Bank). (2013). Diisobutyl phthalate: CASRN: 84-69-5.
Bethesda, MD: National Institutes of Health, Health & Human Services, U.S. National Library of
Medicine, http://toxnet.nlm.nih.eov/cgi-bin/sis/search2/r?dbs+hsdb:@term+@DOC]
ICES (International Council for the Exploration of the Sea). (2018). ICES-Dome [Database],
Retrieved from http://www.ices.dk/m.arine-data/data-portals/Pages/POME.aspx
Lenoir, AT, A; Devers, S; Christides, JP; Boulay, R; Cuvillier-Hot, V. (2014). Ant cuticular
response to phthalate pollution. Environmental Science and Pollution Research 21: 13446-13451
https://sff7e79fc3c3e7ccejimcontent.com/download/version/1529260858/modul 0669191/
Lewis, R, Sr. (2004). Data on diisobutyl phthalate. In Sax's Dangerous Properties of Industrial
Materials (11 ed.). Hoboken, NJ: Wiley Interscience. Wiley & Sons, Inc.
19
-------
Linden, EB, BE; Svanberg, O; Sundstrom, G. (1979). The acute toxicity of 78 chemicals and
pesticide formulations against two brackish water organisms, the bleak (Alburnus alburnus) and
the harpacticoid Nitocra spinipes. Chemosphere 8: 843-851
https://www.sciencedirect.com/science/article/pii/004565357990Q158
Madsen, T; Rasmussen, HB; Nilsson, L. (1995). Anaerobic biodegradation potentials in digested
sludge, a freshwater swamp and a marine sediment. Chemosphere 31: 4243-4258.
http://dx.doi.ors )Q45-6535f95)0Q30Q-W
MDI (MDI Biological Laboratory). (2002). Comparative Toxicogenomics Database (CTD)
[Database], Retrieved from http://ctdbase.ore
NFPA (National Fire Protection Association). (2010). Fire protection guide to hazardous
materials: 84-69-5. In Fire Protection Guide to Hazardous Materials (14th ed.). Quincy, MA.
NICNAS (National Industrial Chemicals Notification and Assessment Scheme). (2008a).
Existing chemical hazard assessment report: Diisobutyl pthalate. Sydney, Australia: Australian
Department of Health and Ageing, National Industrial Chemicals Notification and Assessment
Scheme, https://www.nicn.as.eov.au/ data/assets/word doc/0008/39545/DIBP-hazard-
assessment.docx
NICNAS (National Industrial Chemicals Notification and Assessment Scheme). (2008b).
Phthalates hazard compendium: A summary of physicochemical and human health hazard data
for 24 ortho-phthalate chemicals. Sydney, Australia: Australian Department of Health and
Ageing, National Industrial Chemicals Notification and Assessment Scheme.
https://www.nicnas.eov.aii/ data/assets/word doc/ 2/Phthalates-hazard-
com pen diuro. docx
NICNAS (National Industrial Chemicals Notification and Assessment Scheme). (2016). C4-6
side chain transitional phthalates: Human health tier II assessment. Sydney, Australia: Australian
Department of Health, National Industrial Chemicals Notification and Assessment Scheme.
https://www.nicnas.eov.au/chemical-inform.ation/imap-assessm.ents/imap-eroup-assessment-
report?assessment id=l 126#cas~A 84-74-2
NIOSH (National Institute for Occupational Safety and Health). (2018). NIOSH pocket guide to
chemical hazards: 1,1-dichloroethane. Atlanta, GA: United States Department of Health and
Human Services, Centers for Disease Control and Prevention, National Institute for Occupational
Safety and Health, http://www.cdc.eov/niosh/npe/nped0194.html
OECD (Organisation for Economic Co-operation and Development). (2018). OECD Monitoring
Database [Database],
20
-------
Oishi, SH, K. (1980). Testicular atrophy induced by phthalic acid esters: Effect on testosterone
and zinc concentrations Toxicology and Applied Pharmacology 53: 35-41.
http://www.sciencedirect.com/science/article/pii/0041008X809Q3786
OSHA (Occupational Safety & Health Administration). (2019). Permissible exposure limits:
OSHA annotated table Z-l. United States Department of Labor, Occupational Safety & Health
Administration, https://www.osha.eov/dsg/annotated-pels/tablez-l.html
Sabljic, A; Gusten, H; Verhaar, H; Hermens, J. (1995). QSAR modelling of soil sorption.
Improvements and systematics of log Koc vs. log Kow correlations. Chemosphere 32: 4489-
Sedykh, A; Klopman, G. (2007). Data analysis and alternative modelling of MITI-I aerobic
biodegradation. SAR and QSAR in Environmental Research 18: 693-709.
U.S. EPA (U.S. Environmental Protection Agency). (1990). EPA Ambient Monitoring
Technology Information Center (AMTIC): Air toxics data [Database], Retrieved from
https://www3. epa. gov/ttnamti 1 /toxdat.html
U.S. EPA (U.S. Environmental Protection Agency). (1996). EPA Unregulated Contaminant
Monitoring Rule (UCMR) [Database], Retrieved from https://www.epa.gov/dwucmr
U.S. EPA (U.S. Environmental Protection Agency). (2006). Targeted National Sewage Sludge
Survey (TNSSS) [Database], Retrieved from https://www.epa.gov/biosolids/sewage-sludge-
U.S. EPA (U.S. Environmental Protection Agency). (2007). EPA Discharge Monitoring Report
Data (EPA DMR) [Database], Retrieved from https://cfpub.epa.gov/dmr/
U.S. EPA (U.S. Environmental Protection Agency). (2012). PhysProp database. Estimation
Programs Interface Suite for Microsoft Windows, v 4.11: (CAS RN: 84-69-5) [Fact Sheet],
U.S. EPA (U.S. Environmental Protection Agency). (2012). TSCA Work Plan Chemicals:
Methods Document. Washington, DC. U.S. Environmental Protection Agency, Office of
Pollution Prevention and Toxics. February 2012. https://www.epa.gov/assessing-an.d-m.anagin.g-
chemicals-under-tsca/tsca-work-plan-methods-document
U.S. EPA (U.S. Environmental Protection Agency). (2013). 1986-2002 Inventory Update
Reporting rule data (Non-confidential Production Volume in Pounds. Washington, DC. U.S.
Environmental Protection Agency, Office of Pollution Prevention and Toxics. Retrieved: August
9, 2013.
4514.
Washington, DC
epa.gov/tsca-screening-
¦program-
interface
21
-------
U.S. EPA (U.S. Environmental Protection Agency). (2017). Chemical Data Reporting (2012 and
2016 Public CDR database). Washington, DC. U.S. Environmental Protection Agency, Office of
Pollution Prevention and Toxics. Retrieved from ChemView: June 2019.
U.S. EPA (U.S. Environmental Protection Agency). (2018a). ECOTOXKnowledgebase.
Washington, DC: U.S. Environmental Protection Agency, https://cfpub.epa.eov/ecotox/
U.S. EPA (U.S. Environmental Protection Agency). (2018b). Great Lakes Environmental
Database (GLENDA) [Database], Retrieved from https://www.epa.gov/great-lakes-
monitoring/great-lakes-fish-monitoring-surveillance-program-data
U.S. EPA (U.S. Environmental Protection Agency). (2019). Chemical Data Reporting (2012 and
2016 CBI CDR database). Washington, DC. U.S. Environmental Protection Agency, Office of
Pollution Prevention and Toxics. Retrieved: April 25, 2019.
U.S. EPA (U.S. Environmental Protection Agency). (2019). Chemical and Products Database
(CPDat). https://www.epa.eov/chemical-research/ch.em.ical-and-prodiicts-database-cpdat
USGS (U.S. Geological Survey). (1991a). USGS Monitoring Data: National Water Quality
Monitoring Council [Database], Retrieved from https://www.waterqiialitYdata.us/portal
USGS (U.S. Geological Survey). (1991b). USGS Monitoring Data: National Water Quality
Monitoring Council - Air [Database], Retrieved from
https://www.waterqualitvdata.us/portal/#sampleMedia=Air&mimeTvpe=csv
USGS (U.S. Geological Survey). (1991c). USGS Monitoring Data: National Water Quality
Monitoring Council - Groundwater [Database], Retrieved from
https://www.waterqualitvdata.us/portal/#siteTvpe=Aggregate%20groundwater%20use&sample
Media=Water&mimeTvpe=csv&dataProfile=activitvAll
USGS (U.S. Geological Survey). (1991d). USGS Monitoring Data: National Water Quality
Monitoring Council - Sediment [Database], Retrieved from
https://www.waterqualitvdata.us/portal/#sampleMedia=Sediment&mimeTvpe=csv
USGS (U.S. Geological Survey). (1991e). USGS Monitoring Data: National Water Quality
Monitoring Council - Soil [Database], Retrieved from
https://www.waterqualitvdata.us/portal/#sampleMedia=Soil&mimeTvpe=csv
USGS (U.S. Geological Survey). (1991f). USGS Monitoring Data: National Water Quality
Monitoring Council - Surface Water [Database], Retrieved from
https://www.waterqualitvdata.us/portal/#siteTvpe=Aggregate%20surface-water-
use&sampleMedia=Water&mimeType=csv
USGS (U.S. Geological Survey). (1991g). USGS Monitoring Data: National Water Quality
Monitoring Council - Tissue [Database], Retrieved from
https://www.waterqualitvdata.us/portal/#sampleMedia=Tissue&mimeTvpe=csv
22
-------
Wolfe, NL; Steen, WC; Burns, LA. (1980). Phthalate ester hydrolysis: Linear free energy
relationships. Chemosphere 9: 403-408.
Yalkowsky, SH; He, Y; Jain, P. (2010). Diisobutyl phthalate. In Handbook of Aqueous
Solubility Data (2nd ed.). Boca Raton, FL: CRC Press LLC.
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