United States Office of Chemical Safety and
m m Environmental Protection Agency Pollution Prevention
Proposed Designation of
Dicyclohexyl Phthalate
(CASRN 84-61-7)
as a 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 Summary and Additional Information on Conditions of Use 7
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 11
Approach 11
Results and Discussion 11
7. Hazard potential 11
Approach 11
Potential Human Health and Environmental Hazard Tables 12
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 17
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. Dicyclohexyl Phthalate (84-61-7) Categories and Subcategories of Conditions of Use
(2016 CDR Reporting Cycle) 5
Table 3. Dicyclohexyl Phthalate (84-61-7) Categories and Subcategories of Conditions of Use
(2012 CDR Reporting Cycle) 6
Table 4. Physical and Chemical Properties of Dicyclohexyl Phthalate 8
Table 5. Environmental Fate Characteristics of Dicyclohexyl Phthalate 9
Table 6. Potential Human Health Hazards Identified for Dicyclohexyl Phthalate 12
Table 7. Potential Environmental Hazards Identified for Dicyclohexyl 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 Definition
ACGIH American Conference of Governmental Industrial Hygienists
BAF Bioaccumulation Factor
BOD Biochemical Oxygen Demand
CAA Clean Air Act
CASRN Chemical Abstracts Service Registry Number
CBI Confidential Business Information
CDR Chemical Data Reporting
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
CWA Clean Water Act
EPCRA Emergency Planning and Community Right-to-Know Act
GC Gas Chromatography
IUR Inventory Update Reporting
K Thousand
M Million
MITI Ministry of International Trade and Industry, Japan
MP Melting Point
N/A Not Applicable
NHANES National Health and Nutrition Examination Survey
NIOSH National Institute for Occupational Safety and Health
OSHA Occupational Safety and Health Administration
•OH Hydroxyl Radical
PEL Permissible Exposure Limit
PPE Personal Protective Equipment
PVC Polyvinyl Chloride
REL Recommended Exposure Limit
SMILES Simplified Molecular-Input Line-Entry System
TBD To be determined
iv
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Term Definition
TLV Threshold Limit Value
TRI Toxics Release Inventory
TSCA Toxic Substances Control Act
VP Vapor Pressure
WS Water Solubility
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).
Dicyclohexyl phthalate 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 dicyclohexyl
phthalate is a suitable candidate for the proposed designation as a high-priority chemical
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
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 to 1-act-tsca
1
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information on dicyclohexyl phthalate, including relevant information received from the public
and other information as appropriate.
EPA will take comment on this proposed designation for 90 days before finalizing its designation
of dicyclohexyl phthalate. The docket number for providing comments on dicyclohexyl phthalate
is EPA-HQ-OPPT-2018-0504 and is available at www .regulations, gov
The information, analysis, and basis 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 dicyclohexyl phthalate
reported under the Inventory Update Reporting (IUR) rule and Chemical Data Reporting (CDR)
rule3.
Results and Discussion
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.
Table 1.1986-2015 National Aggregate Production Volume Data (Production Volume in
Pounds) i
Chemical ID
1986
1990
1994
1998
2002
2006
2011
2012
2013
2014
2015
Dicyclohexyl
Phthalate
(84-61-7)
>lMto
10M
>lMto
10M
>lMto
10M
>500K to
1M
>500K
to 1M
<500K
500K to
1M
500K to
1M
500K to
1M
500K to
1M
500K to
1M
Note: K = thousand; M = million
Reference: U.S. EPA (20.1.3) and U.S. EPA (20.1.7)
Production volume of dicyclohexyl phthalate in 2015, as reported to EPA during the 2016 CDR
reporting period, was between 500,000 and 1 million pounds. Production volume of for
dicyclohexyl phthalate for reporting years 1986 to 1994 was 1 million to 10 million pounds. The
production volume decreased for the following reporting years, in which 500 thousand to 1
million pounds of dicyclohexyl phthalate was manufactured or imported, except for 2006 when
less than 500,000 pounds was reported (Table 1).
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).
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 EPA 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 dicyclohexyl phthalate 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 pounds per site, except if
certain TSCA actions apply (in which case the reporting requirement is greater than 2,500
pounds 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. Based on the publicly
available4 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).
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. Dicyclohexyl phthalate
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 and solid waste based on the
conditions of use.
4 Some specific chemical uses may be claimed by CDR submitters as confidential business information (CBI) under
section 14 of TSCA. In these cases, EPA indicated that the information is CBI.
4
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Table 2. Dicyclohexyl Phthalate (84-61-7) Categories and Subcategories of Conditions of
Use5 (2016 CE
•R Reporting Cycle)
Life-Cycle
Stage
Category
Subcategory
Reference
Manufacturing
Domestic
Manufacturing/Import
CBI6
U.S. EPA
(2019b)
Manufacturing
Domestic Manufacturing
Domestic Manufacturing
U.S. EPA
(2019b)
Processing
Processing as a reactant
Processing aids not otherwise listed
in miscellaneous manufacturing
U.S. EPA
Processing as a reactant
Process regulator in:
- Paint and coating manufacturing
- Plastic material and resin
manufacturing
- Plastics product manufacturing
- Rubber product manufacturing
U.S. EPA
(20.1.9b)
Processing - incorporation
into formulation, mixture or
reaction product
Filler in rubber product
manufacturing
U.S. EPA
(20.1.9b)
Processing - incorporation
into formulation, mixture or
reaction product
Adhesive and sealant chemical in
adhesive manufacturing
U.S. EPA
Processing - incorporation
into formulation, mixture or
reaction product
Processing aids not otherwise listed
in services
U.S. EPA
(20.1.9b)
Processing - incorporation
into formulation, mixture or
reaction product
Plasticizer in:
- Plastics product manufacturing
- Printing ink manufacturing
U.S. EPA
(20.1.9b)
Processing - incorporation
into article
Plasticizer in plastics product
manufacturing
U.S. EPA
(20.1.9b)
Distribution in
( ommerce
Distribution in commerce
Commercial
Uses
Plastic and rubber products
not covered elsewhere
Plastic and rubber products not
covered elsewhere
U.S. EPA
Consumer
Uses
Plastic and rubber products
not covered elsewhere
Plastic and rubber products not
covered elsewhere
U.S. EPA
(20.1.9b)
5 Certain other uses that are excluded from TSCA are not captured in this table.
6 At this time, "CBI" indicates that a data element has been claimed CBI by the information submitter; it does not
reflect the result of an EPA substantiation review.
5
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Life-Cycle
Stage
Category
Subcategory
Reference
Disposal
Disposal
a CDR includes information on the manufacturing, processing, and use of chemical substances. 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.
Table 3. Dicyclohexyl Phthalate (84-61-7) Categories and Subcategories of Conditions of
Use 7 (2012 CDR Reporting Cycle)
Life-Cycle
Stage
Category
Subcategory
Reference
Manufacturing
Domestic Manufacturing/Import
CBI8
U.S. EPA
(2019b)
Manufacturing
Domestic Manufacturing
Domestic Manufacturing
U.S. EPA
(2019b)
Processing
Processing as a reactant
Process regulators in:
- Plastics material and resin
manufacturing
- Plastics product
manufacturing
U.S. EPA
12019b)
Processing
Processing - incorporating into
formulation, mixture or reaction
product
Process regulator in:
- Adhesive manufacturing
U.S. EPA
£2019b)
Processing
Processing - incorporating into
formulation, mixture or reaction
product
Adhesives and sealant chemical
in adhesive manufacturing
U.S. EPA
£2019b)
Processing
Processing - incorporating into
formulation, mixture or reaction
product
Paint additives and coating
additives not described by other
categories in print ink
manufacturing
U.S. EPA
(2019b)
Distribution in
( omnvi'ix'
Dislnliulion in commerce
Commercial
Uses
Building/construction materials not
covered elsewhere
Building/construction materials
not covered elsewhere
U.S. EPA
(2019b)
Commercial
I scs
Adhesives and sealants
Adhesives and sealants
U.S. EPA
Disposal
Disposal
7 Certain other uses that are excluded from TSCA are not captured in this table.
8 At this time, "CBI" indicates that a data element has been claimed CBI by the information submitter; it does not
reflect the result of an EPA substantiation review.
6
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Life-Cycle
Stage
Category
Subcategory
Reference
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
Other than two sites that reported unspecified consumer or commercial use of dicyclohexyl
phthalate in 2012 and 2016, consumer and commercial uses were not similar between those two
years. The 2012 CDR data show one site that used dicyclohexyl phthalate for commercial
adhesives and sealants, and one site that used this chemical for commercial building or
construction materials. The 2016 CDR data show a single site that used dicyclohexyl phthalate
for consumer and commercial plastic and rubber products. CDR data do not show any use of
dicyclohexyl phthalate in children's products. Consumer uses were also identified in additional
databases, which are included in the Exposure Potential section (Section 8).
Use of dicyclohexyl phthalate in industrial adhesive and printing ink manufacturing is consistent
between 2012 CDR and 2016 CDR data. Both the 2012 and 2016 CDR data show use of this
chemical at a single site each for industrial manufacture (processing as a reactant) of plastic
products and plastic material and resin. The 2016 CDR data, however, showed additional
industrial uses in paint and coating, rubber, and miscellaneous manufacturing, as well as services
(one site each).
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.
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 or other susceptible subpopulations may
be potentially 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 dicyclohexyl
phthalate.
Children
EPA used data reported to the 2012 and 2016 CDR to identify uses in products and articles
intended for children over time for dicyclohexyl phthalate. The 2012 and 2016 CDR did not
report any use of dicyclohexyl phthalate in children's products. EPA also identified potential
developmental hazards that would impact any stage of children's development.
7
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Women of reproductive age (e.g., pregnant women per TSCA statute)
EPA identified studies that observed developmental and reproductive effects following exposure
to dicyclohexyl phthalate (Section 7, Table 6). Thus, women of reproductive age were identified
as a potentially exposed or susceptible subpopulation with respect to dicyclohexyl phthalate.
Workers
Please refer to the Exposure Potential section (Section 8) for a 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 a summary of potential consumer
exposures, which EPA indicates that consumers are potentially exposed or susceptible
subpopulations based on greater exposure.
5. Persistence and bioaccumulation
Approach
EPA reviewed reasonably available information, such as physical and chemical properties and
environmental fate characteristics, to understand dicyclohexyl phthalate'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 dicyclohexyl phthalate, respectively.
Table 4. Physical and Chemical Properties of Dicyclohexyl Phthalate
Property or
Endpoint
Value3
Reference
Molecular Formula
C20H26O4
Haynes(2014)
Molecular Weight
330.418 g/mole
Haynes(2014)
Physical State
Solid
Haynes(2014)
Physical Form
Granular solid, crystalline solid; prisms
from alcohol
Havnes (2014): HSDB (2015)
Purity
>99% reported in studies
ECHA (2019)
Melting Point
66 °C
U.S. EPA (2012); HSDB (2015) citina
CRC (2014)
Boiling Point
322.3 °C (differential scanning
calorimetry method ASTM E537-07)b
ECHA (2019)
224 °C at 4 mm Hg
U.S. EPA (2012)
225 °C at 4 mm Hg
Haynes(2014)
222-228 °C at 3.75 mm Hg
IPCS (2005)
8
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Property or
Endpoint
Value3
Reference
Density
1.383 g/cm3 at 20 °C
HSDB (2015) citing Havnes (2014)
Vapor Pressure
8.69 x 10"7 mm Hg at 25 °C
U.S. EPA (2012); ECHA (2019) citing
Werner (1952)
Vapor Density
TBD
TBD
Water Solubility
4 mg/L at 24 °Cb
U.S. EPA (2012) citina Yalkowskv
and Dannenfleser (1992)
1.02 mg/L at 20 °C and pH 7 (OECD 105)
EO1M20M
Log Kow
4.82 at 25 °C (OECD 117, HPLC method)
ECHA (20.1.9)
Henry's Law
Constant
9.4 x 10"8 atm-m3/mole (calculated from
measured vapor pressure and water
solubility)
U.S. EPA (20.1.2)
Flash Point
TBD
TBD
Auto Flammability
TBD
TBD
Viscosity
TBD
TBD
Refractive Index
1.431 at 20 °C
HSDB (20.1.5) citina Havnes (2014)
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 Dicyclohexyl Phthalate
Property or Endpoint
Value3
Reference
Direct
Photodegradation
Contains chromophores that absorb at wavelengths
>290 nm and, therefore, may be susceptible to direct
photolysis by sunlight
HSDB (20.1.5) citina
Lyman et al. (1990)
Indirect
Photodegradation
ti/2 = 0.441 day (based on a 12-hour day with 1.5 x 106
•OH/cm3 and -OH rate constant of 2.43 x 10"11
cm3/molecule-second; estimated)b
) .1.2)
Hydrolysis
Not expected to undergo hydrolysis due to the lack of
functional groups that hydrolyze under environmental
conditions
HSDB (20.1.5) citina
Lyman et al. (1990)
Biodegradation
(Aerobic)
Water: 68.5%/4 weeks based on BOD and 91%/4
weeks based on GC (Japanese MITI test at an initial
test substance concentration of 100 ppm with sludge at
concentrations of 30 ppm)
NITE (2019)
Sediment: ti/2 = 11.1 days calculated in 6 river sediment
samples from Taiwan under aerobic conditions
HSDB (20.1.5) citina
Yuan et al. (2002)
9
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Property or Endpoint
Value3
Reference
Biodegradation
(Anaerobic)
Sediment: tin = 26.4 days calculated in 6 river sediment
samples from Taiwan under anaerobic conditions
HSDB (2015) citina
Yuan et al. (2002)
Wastewater Treatment
100% total removal (89% by biodegradation, 11% by
sludge adsorption, and 0% by volatilization to air;
estimated)b
U.S. EPA (2012)
Bioconcentration
Factor
1.2-3.2 and 0.5-6.9 (Cyprinus caprio); test substance
concentrations of 0.4 and 0.04 mg/L, respectively
? > M t,'018)
Bioaccumulation Factor
137 (log BAF = 2.1; estimated)b
U.S. EPA (2012)
Soil Organic
Carbon:Water Partition
Coefficient (Log Koc)
4.2 (estimated)13
U.S. EPA (2012)
Notes:
aMeasured unless otherwise noted;
bEPI Suite™physical property inputs: MP = 66 °C, VP = 8.69 x 10~7 mm Hg, WS = 4 mg/L, BioP = 4, BioA = 1 and
BioS = 1, SMILES: 0=C(0C(CCCCl)Cl)c(c(ccc2)C(=0)0C(CCCC3)C3)c2
•OH = hydroxyl radical; MITI = Ministry of International Trade and Industry; BOD = biochemical oxygen demand;
BAF = bioaccumulation factor; K0c = organic carbon-water partition coefficient
Results and Discussion
Dicyclohexyl phthalate is a granular solid with a melting point of 66 °C. Based on its vapor
pressure (8.69 x 10"7 mm Hg) and estimated Henry's Law Constant (9.4 x 10"8 atm-m3/mole),
dicyclohexyl phthalate is not expected to volatilize from water or soil. It is expected to be
immobile in soil (estimated log Koc 4.2).
It is readily biodegradable based on measured data reporting 68.5 and 91 percent degradation
over 28 days by biochemical oxygen demand (BOD) and gas chromatography (GC) using the
Japanese Ministry of International Trade and Industry (MITI) test. Aerobic and anaerobic
degradation half-lives of 11.1 and 26.4 days were recorded in sediment. Based on these studies,
dicyclohexyl phthalate is not expected to persist in the environment.
Dicyclohexyl phthalate in the air will be in the particulate form, which will be removed by wet
and dry precipitation. Small amounts will be in the vapor phase, which may directly and
indirectly photodegrade (half-life 5.3 hours). Bioconcentration factors of 0.5-6.9 and an
estimated bioaccumulation factor of 137 indicate that dicyclohexyl phthalate has a low potential
to bioaccumulate.
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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)
(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
Dicyclohexyl phthalate is not currently subject to the federal regulations named in the previous
paragraph.
7. Hazard potential
Approach
EPA considered reasonably available information from peer-reviewed assessments and databases
to identify potential human health and environmental hazards for dicyclohexyl phthalate (Tables
6 and 7, respectively).
Because there are very few publicly available assessments for dibutyl phthalate 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,
2018). It uses a comprehensive chemical-specific literature search of the open literature that is
conducted according to the Standard Operating Procedures (SOPs)9. 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 dicyclohexyl phthalate, if available,
to fill in potential data gaps when there were no reported observed effects for specific taxa
9 The ECOTOX Standard Operating Procedures (SOPs) can be found at:
>a.gov/ecotox/help.cfm?helptabs=tab4
11
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exposed to dicyclohexyl phthalate. There were no environmental hazard information identified
for dicyclohexyl phthalate (Table 7).
Potential Human Health and Environmental Hazard Tables
EPA identified human health hazards based on a review of the reasonable available information
on dicyclohexyl phthalate (Table 6). EPA is particularly interested in information from the public
on environmental hazards.
Table 6. Potential Human Health Hazards Idenl
tified for Dicyclohexyl Phthalate
Human Health
Hazards
Tested for
Specific Effect
Effect
Observed
Reference
Acute Toxicity
X
CPSC (2010). NICNAS (2016)
Repeated Dose Toxicity
X
X
CPSC (2010). NICNAS (2016)
Genetic Toxicity
X
X
CPSC (2010). NICNAS (2016)
Reproductive Toxicity
X
X
CPSC (2010). CPSC (2014). ECHA (2019).
Developmental
Toxicity
X
X
CPSC (2010). CPSC (2014). ECHA (2019).
NICNAS (2016)
Toxicokinetic
X
X
CPSC (2010). NICNAS (2016)
Irritation/Corrosion
X
X
CPSC (2010). NICNAS (2016)
Dermal Sensitization
X
CPSC (2010). NICNAS (2016)
Respiratory
Sensitization
X
CPSC (2010)
Carcinogenicity
CPSC (2010). NICNAS (2016)
Immunotoxicity
CPSC (2010)
Neurotoxicity
CPSC (2010)
Epidemiological
Studies or
Biomonitoring Studies
X
X
CPSC (2010)
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 Dicyclohexyl Phthalate
Media
Study Duration
Taxa Groups
High-Priority Chemical
Candidate
Dicyclohexyl Phthalate
(CASRN 84-61-7)
Isomers of
Dicyclohexyl Phthalate
(CASRN 84-61-7)
NONE
Reference
Number of
Studies
Observed
Effects
Number of
Studies
Observed
Effects
Aquatic
Acute exposure
Vegetation
-
-
Invertebrate
-
-
Fish
-
-
Non-fish vertebrate
(i.e., amphibians,
reptiles, mammals)
Chronic exposure
Vegetation
-
-
Invertebrate
-
-
Fish
-
-
Non-fish vertebrate
(i.e., amphibians,
reptiles, mammals)
Terrestrial
Acute exposure
Vegetation
-
-
Invertebrate
-
-
Vertebrate
-
-
Chronic exposure
Vegetation
-
-
Invertebrate
-
-
Vertebrate
-
-
The dash indicates that no studies relevant for environmental hazard were identified during the initial review and thus the "Observed Effects" column is left blank. 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 identify potential environmental,
worker/occupational, consumer, and general population exposures for dicyclohexyl phthalate.
Release potential for environmental and human health exposure
Dicyclohexyl phthalate 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
dicyclohexyl phthalate.
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
dicyclohexyl phthalate to inform occupational and consumer exposure potential. The results of
this review are detailed in the following tables.
General population exposure
EPA identified human biomonitoring data to inform dicyclohexyl phthalate's exposure potential
to the general population (Table 9).
Results and Discussion
Release potential for environmental and human health exposure
When chemical substances are used as a reactant, the industrial releases that are a relatively low
percentage of the production volume. Lower percentage releases occur when a high percentage
of the chemical reacts without excess loss during its use as an intermediate. The actual
percentages, quantities, and media of releases of the reported chemical associated with this
processing or use are not known.
When chemical substances are incorporated into formulations, mixtures, or reaction products, the
industrial releases that are 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.
When chemical substances have commercial or consumer use as adhesive and sealants, they can
have variable release percentages. If the chemical is used as a solvent, it may evaporate to the air
during the drying or curing of the adhesive or sealant. Other additives may be entrained in the
dried or cured adhesive or sealant but may be released to the environment due to abrasion of the
adhesive or sealant. The actual percentage and quantity of release of the reported chemical
associated with this category are not known but could be high.
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
14
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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.
Dicyclohexyl phthalate does not have an Occupational Safety and Health Administration
(OSHA) Permissible Exposure Limit (PEL) (OS 39), a National Institute for Occupational
Safety and Health (NIOSH) Recommended Exposure Limit (REL) (NIOSH 2010). or the
Threshold Limit Value (TLV) set by American Conference of Governmental Industrial
Hygienists (ACGIH).
Dicyclohexyl phthalate has a vapor pressure of 8.69 x 10"7 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. Some handling activities
of dicyclohexyl phthalate may generate dust, particularly when handled as a dry powder.
Workers may be exposed to aerosolized particles.
Dicyclohexyl phthalate is indicated as being used in adhesives and sealants, and paint additives
and coating additives. Products used as adhesive and sealants and paints additives may be
applied via spray or roll application methods. These methods may generate mists to which
workers may be exposed.
Consumer exposure
CDR reporting does not report any use of dicyclohexyl phthalate in consumer products.
However, the National Institutes of Health Household Products Database and the EPA's
Chemical and Products Database (CPDat) list uses of dicyclohexyl phthalate in consumer
products, such as adhesives, paints, and printing ink (Table 8). Available assessments reviewed
also indicate that dicyclohexyl phthalate is found in several additional consumer products, due to
its use as a plasticizer, heat sealer for cellulose, and in paper finishes, (CPSC 2010. CPSC 2014).
Table 8. Exposure Information for Consumers
Chemical
Identity
Consumer Product Database
Consumer Uses (List)
Dicyclohexyl
Phthalate
(84-61-7)
Adhesive, arts crafts products, building material, filler, filler building material, flooring,
hardener, insulation, paint, paper, photographic, plastic hardener, printing, printing ink,
wall building material
Reference: U.S. EPA (20.1.9a)
General population exposure
EPA anticipates releases of dicyclohexyl phthalate into the environment based on the conditions
of use for dicyclohexyl phthalate, particularly activities associated with the chemical's
manufacturing and use in a number of products as a plasticizer and as a heat sealer (CPSC 2010).
Based on fate properties, such as vapor pressure and water solubility, EPA anticipates possible
presence of dicyclohexyl phthalate in water and soil. A review of the available literature suggests
15
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that human biomonitoring data are available; however, no environmental concentration data or
ecological biomonitoring data were identified (Table 9).
Releases of dicyclohexyl phthalate from certain conditions of use, such as manufacturing,
disposal, or waste treatment activities, may result in general population exposures mainly via
dermal contact and inhalation from air releases (CPSC 2010). Dicyclohexyl phthalate is used in
polyvinyl chloride (PVC) and other plastics, adhesives, printing inks, paper, etc, (CPSC 2010.
TERA 2015). In the United States, the 2001 2002 National Health and Nutrition Examination
Survey (NHANES) measured metabolites of dicyclohexyl phthalate in urine at concentrations
ranging from below the level of detection (50th percentile) up to 0.400 [j,g/L creatinine (90th
percentile) (CPSC 2010).
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
no
yes
no
MDI (2002)
EPA Ambient Monitoring Technology
Information Center - Air Toxics Data
no
no
no
U.S. EPA (1990)
EPA Discharge Monitoring Report Data
no
no
no
U.S. EPA (2007)
EPA Unregulated Contaminant Monitoring
Rule
no
no
no
U.S. EPA (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
U.S. EPA (2006)
The National Health and Nutrition
Examination Survey
no
no
no
CDC (2013)
USGS Monitoring Data -National Water
Quality Monitoring Council
no
no
no
USGS (1991a)
USGS Monitoring Data -National Water
Quality Monitoring Council, Air
no
no
no
US
USGS Monitoring Data -National Water
Quality Monitoring Council, Ground Water
no
no
no
USGS Monitoring Data -National Water
Quality Monitoring Council, Sediment
no
no
no
USGS (199Id)
16
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USGS Monitoring Data -National Water
Quality Monitoring Council, Soil
no
no
no
USGS (199lei
USGS Monitoring Data -National Water
Quality Monitoring Council, Surface Water
no
no
no
USGS (.1.99.111
USGS Monitoring Data -National Water
Quality Monitoring Council, Tissue
no
no
no
US >le)
aConcen.= concentration
bBiomon.= biomonitoring
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.
10. Proposed designation and Rationale
Proposed designation: High-priority substance
Rationale: EPA identified and analyzed reasonably available information for exposure and
hazard and is proposing to find that dicyclohexyl phthalate 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 dicyclohexyl phthalate 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
dicyclohexyl phthalate may result in presence of the chemical in surface water, and groundwater,
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 human health hazards (e.g., repeated
dose toxicity, genetic toxicity, reproductive toxicity, developmental toxicity, toxicokinetic, and
irritation/corrosion). EPA has not identified environmental hazard concerns for aquatic or
terrestrial organisms due to exposures to dicyclohexyl phthalate.
17
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