Screening-level Hazard Characterization Sponsored Chemical Phosphorus Acid, Triphenyl Ester, Reaction Products with Dipropylene Glycol (CASRN 116265-68-0)

U.S. Environmental Protection Agency
Hazard Characterization Document

December, 2012

SCREENING-LEVEL HAZARD CHARACTERIZATION

SPONSORED CHEMICAL

Phosphorus Acid, Triphenyl Ester, Reaction Products with Dipropylene

Glycol
(CASRN 116265-68-0)

The High Production Volume (HPV) Challenge Program1 was conceived as a voluntary initiative
aimed at developing and making publicly available screening-level health and environmental
effects information on chemicals manufactured in or imported into the United States in quantities
greater than one million pounds per year. In the Challenge Program, producers and importers of
HPV chemicals voluntarily sponsored chemicals; sponsorship entailed the identification and
initial assessment of the adequacy of existing toxicity data/information, conducting new testing if
adequate data did not exist, and making both new and existing data and information available to
the public. Each complete data submission contains data on 18 internationally agreed to "SIDS"

1 2

(Screening Information Data Setl ' ) endpoints that are screening-level indicators of potential
hazards (toxicity) for humans or the environment.

The Environmental Protection Agency's Office of Pollution Prevention and Toxics (OPPT) is
evaluating the data submitted in the HPV Challenge Program on approximately 1400 sponsored
chemicals by developing hazard characterizations (HCs). These HCs consist of an evaluation of
the quality and completeness of the data set provided in the Challenge Program submissions.

They are not intended to be definitive statements regarding the possibility of unreasonable risk of
injury to health or the environment.

2 3

The evaluation is performed according to established EPA guidance ' and is based primarily on
hazard data provided by sponsors; however, in preparing the hazard characterization, EPA
considered its own comments and public comments on the original submission as well as the
sponsor's responses to comments and revisions made to the submission. In order to determine
whether any new hazard information was developed since the time of the HPV submission, a
search of the following databases was made from one year prior to the date of the HPV
Challenge submission to the present: (ChemID to locate available data sources including
Medline/PubMed, Toxline, HSDB, IRIS, NTP, AT SDR, IARC, EXTOXNET, EPA SRS, etc.),
STN/CAS online databases (Registry file for locators, ChemAbs for toxicology data, RTECS,
Merck, etc.), Science Direct and ECHA4. OPPT's focus on these specific sources is based on
their being of high quality, highly relevant to hazard characterization, and publicly available.

1 U.S. EPA. High Production Volume (HPV) Challenge Program; http://www.epa.gov/chemrtk/index.htm.

2 U.S. EPA. HPV Challenge Program - Information Sources; http://www.epa.gov/chemrtk/pubs/general/guidocs.htm.

3 U.S. EPA. Risk Assessment Guidelines; http://cfpub.epa.gov/ncea/raf/rafguid.cfm.

4 European Chemicals Agency, http://echa.europa.eu.

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U.S. Environmental Protection Agency
Hazard Characterization Document

December, 2012

OPPT does not develop HCs for those HPV chemicals which have already been assessed
internationally through the HPV program of the Organization for Economic Cooperation and
Development (OECD) and for which Screening Initial Data Set (SIDS) Initial Assessment
Reports (SIAR) and SIDS Initial Assessment Profiles (SIAP) are available. These documents are
presented in an international forum that involves review and endorsement by governmental
authorities around the world. OPPT is an active participant in these meetings and accepts these
documents as reliable screening-level hazard assessments.

These hazard characterizations are technical documents intended to inform subsequent decisions
and actions by OPPT. Accordingly, the documents are not written with the goal of informing the
general public. However, they do provide a vehicle for public access to a concise assessment of
the raw technical data on HPV chemicals and provide information previously not readily
available to the public.

2

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U.S. Environmental Protection Agency
Hazard Characterization Document

Chemical Abstract Service Registry Number
(CASRN)

Chemical Abstract Index Name

Structural Formula

December, 2012

116265-68-0

Phosphorus acid, triphenyl ester, reaction
products with dipropylene glycol

See Appendix

Summary

Phosphorous acid, triphenyl ester, reaction products with dipropylene glycol is a liquid mixture
of aryl phosphites that have negligible vapor pressure and negligible water solubility. The
components of this mixture are expected to have low mobility in soil. Volatilization is expected
to be low for the components of this mixture. The rate of hydrolysis is not known; however,
phenyl phosphites have the potential to hydrolyze although hydrolysis may be a slow process
due to a lack of water solubility. The rate of atmospheric photooxidation is rapid; however, this
is not a relevant environmental degradation pathway since this substance is not expected to exist
in the vapor phase in the atmosphere. Based upon very limited data, phosphorous acid,
triphenyl ester, reaction products with dipropylene glycol is expected to have moderate
persistence (P2) and high bioaccumulation potential (B3).

No adequate data are available on acute oral, repeated-dose, reproductive, developmental and
genetic toxicity (gene mutations and chromosomal aberrations) endpoints with phosphorus acid,
triphenyl ester, reaction products with dipropylene glycol.

No adequate data are available for the fish, aquatic invertebrates, and aquatic plants endpoints.

Acute oral, repeated-dose, reproductive, developmental and genetic toxicity (gene mutations and
chromosomal aberrations) and the acute toxicity to fish and aquatic invertebrates and toxicity to
aquatic plants endpoints were identified as data gaps under the HPV Challenge Program.

The sponsor, Chemtura Corporation, submitted a Test Plan and Robust Summaries to EPA for
phosphorus acid, triphenyl ester, reaction products with dipropylene glycol (CASRN
116265-68-0; CA Index name: phosphorous acid, triphenyl ester, reaction products with
dipropylene glycol) on December 25* , 2005. EPA posted the submission on the ChemRTK
HPV Challenge website on January 25th, 2006

("http://www.epa. gov/oppt/chemrtk/pub s./suro.ro.ari es./phc " tc.htmY EPA comments on

the original submission were posted to the website on April 14th, 2006, and comments on the
revised submission were posted to the website on July 17th, 2008. Public comments were also
received and posted to the website. The sponsor submitted updated/revised documents on
November 10th, 2006, which were posted to the ChemRTK website on March 1st, 2007.

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Hazard Characterization Document

December, 2012

Substance Characterization

In the original submission the sponsor did not provide sufficient information on chemical
characterization for the sponsored chemical - Phosphorus acid, triphenyl ester, reaction products
with dipropylene glycol. The test plan did not indicate the test substance purity or information
on the commercial product(s). EPA requested that the sponsor provide more complete
compositional data for the test substance, including a range of molecular weights.

In its revised test plan, the sponsor provided additional information in IUCLID Data Set section
1.1.0; however, there is no clear statement of the range of structural composition of the
sponsored substance, its average molecular weight, number of repeating units, possible isomeric
complications, an approximate structural formula or variability of process formulations. The
name "poly(dipropylene glycol) phenyl phosphite" alone provides insufficient structural
information. The test plan states that the substance name "is intended to cover all the potential
products derived from the reaction". The test plan needs to indicate what these potential
products are in order to support an eventual hazard or risk characterization. Because the reaction
yields a complex product, the test plan should discuss the reaction, its possible and known
products including their structures and what subsequent treatment leads to the cited commercial
products, Weston DHOP, Weston THOP and Weston PTP. In particular, in the IUCLID section
1.1.0, Weston THOP is characterized as 30 - 60% tetraphenyl dipropyleneglycol "diphosphate"
(probably intended to be the diphosphite), a monomer that would be at the low end of the
spectrum of possible products and therefore, an important component of the sponsored
substance. However, it is impossible to determine from the submission whether this substance is
a significant component of the sponsored substance. In addition, the CAS number assigned by
the sponsor is for an oligomeric substance, not for a monomer.

Although the sponsor planned significant testing, EPA indicated that it would be difficult to
evaluate the utility and the results of the proposed testing because it is unclear whether potential
impurities such as trimeric or higher molecular-weight polyglycol substances, bridged
diphosphites, or partially reacted aryl alkyl phosphites are present in significant amounts. For
aquatic toxicity endpoints, the quantity of any higher molecular-weight components would help
determine the need for chronic vs. acute toxicity testing.

Supporting Chemicals

The sponsor indicated that the two proposed supporting chemicals are contained in commercial
products Weston DHOP and THOP (which includes CASRN 80584-86-7,
poly(dipropyleneglycol)triphosphite) and PTP (which includes CASRN 13474-96-9,
heptakis(dipropyleneglycol)triphosphite) that themselves are derived from the sponsored
substance and states that "Data from these potential products are relevant for the sponsored
substance..." The mere assertion of relevance is inadequate for the purposes of the HPV
Challenge Program. There is no structural comparison or other information presented to support
a relationship to the sponsored chemical. In addition, the data provided show vastly different
physicochemical properties (Table 2 in the revised test plan) for these two substances and it is
not clear which one (if either) would better represent the sponsored chemical.

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U.S. Environmental Protection Agency
Hazard Characterization Document

December, 2012

There is much confusion in the submission as to the identity of the supporting chemical having
CASRN 80584-86-7. The substance is incorrectly named in the test plan and throughout the
robust summaries as a phosphate rather than a phosphite. Only in the IUCLID section 1.1.0 the
substance is properly named, but in the same paragraph, the CASRNs associated with two other
names, are both incorrect.

1. Chemical Identity

1.1	Identification and Purity

Phosphorous acid, triphenyl ester, reaction products with dipropylene glycol is a liquid with
negligible vapor pressure and negligible water solubility.

1.2	Physical-Chemical Properties

The physical-chemical properties of phosphorous acid, triphenyl ester, reaction products with
dipropylene glycol are summarized in Table 1. The structure of the compound is provided in the
Appendix.

Table 1. Physical-Chemical Properties of Phosphorous acid, triphenyl ester, reaction
products with dipropylene glycol and Supporting Chemicals1'2

Property

Phosphorous acid,
triphenyl ester,
reaction products
with dipropylene
glycol

Heptakis(dipropylenegl
ycol) triphosphite
(supporting chemical)

Poly(dipropylene
glycol) phenyl
phosphite

(supporting chemical)

CASRN

116265-68-0

13474-96-9

80584-86-7

Molecular Weight

566 (typical)

1023 (typical)

823 (typical)

Physical State

Liquid

Liquid

Yellow liquid

Melting Point

No data3

No data3

No data3

Boiling Point

>300°C (estimated)4

>300°C (estimated)4

>300°C (estimated)4

Vapor Pressure

<1.0><10"10 mm Hg at
25°C (estimated)4

<1.0><10"10 mm Hg at
25°C (estimated)4

<1.0xl0"10 mm Hg at
25°C (estimated)4

Dissociation
Constant

Not applicable

Not applicable

Not applicable

Henry's Law
Constant

<1.0xl0"10 atm-
m3/mole at 25°C
(estimated)4

<1.0x10"10 atm-m3/mole
at 25°C (estimated)4

<1.0xl0"10 atm-m3/mole
at 25°C (estimated)4

Water Solubility

1.3 xlO"5 mg/L at 25°C
(estimated)4

185 mg/L at 25°C
(estimated)4

5.6xl0"9 mg/L at 25°C
(estimated)4

Log Kow

8.57 (estimated)4

-3.41 (estimated)4

10.51 (estimated)4

5

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U.S. Environmental Protection Agency
Hazard Characterization Document

December, 2012

1 Chcmtura Corporation. 2006. Revised Test Plan and Robust Summary for Phosphorous acid, triphenyl ester,
reaction products with dipropylene glycol. Available online at

http://www.epa. gov/oppt/chemrtk/pubs/summaries/phostries/c 16116tc.htm as of June 25, 2012.

Estimates based on SMILES notations for representative structures given in the Appendix. CASRN 116265-68-0:
c 1 (OP(Oc2ccccc2)OC(C)COCC(C)OP(Oc2ccccc2)Oc2ccccc2)ccccc 1; CASRN 13474-96-9: C(C)(COC(C)CO)OP
(0C(C)C0CC(C)0P(0C(C)C0CC(C)0P(0C(C)C0CC(C)0)0C(C)C0CC(C)0)0C(C)C0CC(C)0)0C(C)C0CC
(C)O; CASRN 80584-86-7; cl(OP(Oc2ccccc2)OC(C)COC(C)COP(Oc2ccccc2)OC(C)COCC(C)OP(Oc2ccccc2)
Oc2ccccc2)cccccl.

3The mixture will not have a well-defined melting point; since the substance is a liquid, it can be assumed to melt at
<25°C.

4U.S.EPA. 2012. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U.S. Environmental
Protection Agency, Washington, DC, USA. Available online at
http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of June 25, 2012.

2. General Information on Exposure

2.1	Production Volume and Use

CASRN 116265-68-0 had an aggregated production and/or import volume in the United States
between 500,000 pounds to 1 million pounds during calendar year 2005.

Non-confidential information in the IUR indicated that the industrial processing and uses of the
chemical include resin and synthetic rubber manufacturing as stabilizers. No commercial and
consumer uses were reported for the chemical.

2.2	Environmental Exposure and Fate

The components of phosphorous acid, triphenyl ester, reaction products with dipropylene glycol
are expected to possess low mobility in soil. No biodegradation studies were available for this
compound or the supporting substances. Volatilization is expected to be low for the components
of phosphorous acid, triphenyl ester, reaction products with dipropylene glycol. The rate of
hydrolysis is not known but phenyl phosphites have the potential to hydrolyze. However, the
low water solubility of this substance may attenuate this process. The rate of atmospheric
photooxidation is rapid; however, this is not a relevant environmental degradation pathway since
this substance is not expected to exist in the vapor phase in the atmosphere. An estimated
bioaccumulation factor (B AF) for a lower molecular weight representative aryl phosphite
suggests that components of this mixture may bioaccumulate. Phosphorous acid, triphenyl ester,
reaction products with dipropylene glycol is expected to have moderate persistence (P2) and high
bioaccumulation potential (B3).

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U.S. Environmental Protection Agency
Hazard Characterization Document

December, 2012

The environmental fate characteristics of phosphorous acid, triphenyl ester, reaction products
with dipropylene glycol are summarized in Table 2.

Table 2. Environmental Properties of of Phosphorous acid, triphenyl ester, reaction
products with dipropylene glycol and Supporting Chemicals1'2

Property

Phosphorous acid,
triphenyl ester, reaction
products with
dipropylene glycol

Heptakis(dipropylene
glycol) triphosphite
(supporting chemical)

Poly(dipropylene
glycol) phenyl
phosphite

(supporting chemical)

CASRN

116265-68-0

13474-96-9

80584-86-7

Photodegradati on
Half-life

1.0 hours (estimated)3

13.1 hours (estimated)3

0.6 hours (estimated)3

Hydrolysis Half-life

No data

Slowly hydrolyzes

No data

Biodegradation

No data

No data

No data

Bioaccumulation
Factor

BAF = 6,337 (estimated)3

BAF = 0.89

"3

(estimated)

BAF = 695

"3

(estimated)

Log Koc

9.7 (estimated)3

8.0 (estimated)3

13.1 (estimated)3

Fugacity

(Level III Model)3

Air (%)
Water (%)
Soil (%)
Sediment (%)

<0.1
1.3
31.6
67.1

<0.1
0.6
52.1
47.3

<0.1
0.7
40.8
58.4

Persistence4

P2 (moderate)

P2 (moderate)

P2 (moderate)

Bioaccumulation4

B3 (high)

B1 (low)

B1 (low)

1 Chcmtura Corporation. 2006. Revised Test Plan and Robust Summary for Phosphorous acid, triphenyl ester,
reaction products with dipropylene glycol. Available at

http://www.epa. gov/oppt/chemrtk/pubs/summaries/phostries/c 16116tc.htm as of June 25, 2012.

Estimates based on SMILES notations for representative structures given in the Appendix. CASRN 116265-68-0:
c 1 (OP(Oc2ccccc2)OC(C)COCC(C)OP(Oc2ccccc2)Oc2ccccc2)ccccc 1; CASRN 13474-96-9: C(C)(COC(C)CO)OP
(0C(C)C0CC(C)0P(0C(C)C0CC(C)0P(0C(C)C0CC(C)0)0C(C)C0CC(C)0)0C(C)C0CC(C)0)0C(C)C0CC
(C)O; CASRN 80584-86-7; cl(OP(Oc2ccccc2)OC(C)COC(C)COP(Oc2ccccc2)OC(C)COCC(C)OP(Oc2ccccc2)
Oc2ccccc2)cccccl

3U.S. EPA. 2012. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U.S. Environmental
Protection Agency, Washington, DC, USA. Available online at
http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of June 25, 2012.

4Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal
Register 64, Number 213 (November 4, 1999) pp. 60194-60204.

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Hazard Characterization Document

December, 2012

Conclusion: Phosphorous acid, triphenyl ester, reaction products with dipropylene glycol is a
liquid mixture of aryl phosphites that have negligible vapor pressure and negligible water
solubility. The components of this mixture are expected to have low mobility in soil.
Volatilization is expected to be low for the components of this mixture. The rate of hydrolysis is
not known; however, phenyl phosphites have the potential to hydrolyze although hydrolysis may
be a slow process due to a lack of water solubility. The rate of atmospheric photooxidation is
rapid; however, this is not a relevant environmental degradation pathway since this substance is
not expected to exist in the vapor phase in the atmosphere. Based upon very limited data,
phosphorous acid, triphenyl ester, reaction products with dipropylene glycol is expected to have
moderate persistence (P2) and high bioaccumulation potential (B3).

3. Human Health Hazard

Acute Oral Toxicity

No adequate data.

Data for the proposed supporting chemicals were submitted for this endpoint. However,
insufficient justification for the use of these data was provided. Further, an evaluation of the
MSDS for these substances shows that the sponsored substance is not present in these
commercial substances excepting for WESTON® PTP (Version 1.0, Revision Date 12/07/2010:
http://www.chemtura.eom/msd/external/e/result/result main fs.isp?C003=EN&P SSN=104104
&C002=NA-US-

SDS&C001=MSDS&P LANGU=E&C999=X&submit=Continue&P SYS=6&C013=&mvopt=
WESTON+PTP&CQ14=WESTON*PTP&submit=Submif). The MSDS for WESTON® PTP
identifies the sponsored substance (CASRN 116265-68-0) as a component. However, another
component [CASRN 13474-96-9; Heptakis (dipropyleneglycol)triphosphite] for this proposed
supporting chemical is identified in the test plan but is not noted in the MSDS for WESTON®
PTP, further adding to the confusion over the appropriateness of the use of data for the proposed
supporting chemicals.

Repeated-Dose, Reproductive and Developmental Toxicity

No data.

Genetic Toxicity — Gene Mutation and Chromosomal Aberrations

No data.

Conclusion: No adequate data are available on acute oral, repeated-dose, reproductive,
developmental and genetic toxicity (gene mutations and chromosomal Aberrations) with
phosphorus acid, triphenyl ester, reaction products with dipropylene glycol.

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U.S. Environmental Protection Agency	December, 2012

Hazard Characterization Document

4. Hazard to the Environment

Acute Toxicity to Fish and Aquatic Invertebrates and Toxicity to Aquatic Plants

No adequate data are available for the fish, aquatic invertebrates, and aquatic plants endpoints.

Conclusion: No adequate data are available for the fish, aquatic invertebrates, and aquatic
plants endpoints.

APPENDIX

Sponsored Chemical

Chemical Name

CASRN

Representative Structure1

Phosphorous acid,
triphenyl ester,
reaction products with
dipropylene glycol

116265-68-0

Representative structures for the sponsored chemical 'Phosphorous acid, triphenyl ester,
reaction products with dipropylene glycol'

0	CH,	CH, O"

1	I 3	I I

O O	O O

Molecular Weight =566.53
Exact Mass =566
Molecular Formula =C30H32O7P2

Molecular Composition =C 63.60% H 5.69% O 19.77% P 10.93%

0	CH,	CH, O v	CH, O'

1	I 3	I 3 I	I I
^-P^

0 o	o o	o o

CH,

Molecular Weight =822.77
Exact Mass =822

Molecular Formula =C42H49011P3

Molecular Composition =C 61.31% H 6.00% O 21.39% P 11.29%

0

1

O O

0	CH,	CH, O v	CH, O'

1	I 3	I I	I I
. Pv. A. ^ /O. ^Ps

O O	O O	O O

CH,

CH, CH,

Molecular Weight =1079.01

Exact Mass =1078

Molecular Formula =C54H66015P4

Molecular Composition =C 60.11% H 6.17% O 22.24% P 11.48%

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Supporting Chemicals

Chemical Name

CASRN

Representative Structure1

Bi s [ 13 -Hydroxy-7 - [2-
(2-hydroxypropoxy)-
1 -methyl ethoxy]-
1,5,9-trimethyl-
3,6,8,1 l-tetraoxa-7-
phosphatetradec-1 -
yi][2-(2-

hydroxypropoxy)-1 -
methyl ethyl jphosphine

13474-96-9

OH OH OH

h3c^| (^ch3 |^ch3
0 0 h3c 0

CH, H,C 0 CH, CH, o^xh, CH, 0

H0^0^cAo^0^cAo^0^cAo^0^OH
ch3 ch3 ch3 ch3

Representative structure of 'heptakis(dipropyleneglycol) triphosphite'

The CAS number 13474-96-9 is a close match for this description.

Supporting Chemicals

Chemical Name

CASRN

Representative Structure1

Oxybi spropylenebi s [(1
,5,9,13,17,21-
hexamethyl-
7,15,23,23-
tetraphenoxy-
3,6,8,11,14,16,19,22-
octaoxa-7,15,23 -
triphosphatricos-1 -
yl)(phenyl)phosphine]

80584-86-7

Ol jTji jTji

CH CH 0-^^ CH3

o'^o^^o'S-lrY o''"°

6 " 6

Representative structure for 'poly(dipropylene glycol) phenyl phosphite'
The CAS number '80584-86-7' does not match the description or structure'

Sponsor did not verify the identity of these structures. There is no clear statement of the range of structural
composition of the sponsored substance, its average molecular weight, or possible isomeric forms in the test plan or
summaries. Representative structures were developed using the limited information provided in the test plan. The
two supporting substances are not listed on the public TSCA inventory.

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