Phosphoric acid, hexadecyl esters, potassium salts with cetyl alcohol and isostearyl isostearate

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

From September 05, 2017 to September 12, 2017

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

Suspected influence of trapped gases/impurities

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

EU Regulation (EC) 440/2008, Annex Part A test A4.

Deviations:

not specified

GLP compliance:

yes

Type of method:

static method

Key result

Test no.:

#1

Temp.:

ca. 20 °C

Vapour pressure:

ca. 277 Pa

Remarks on result:

other: Calculated extrapolated value

Full test results

Temp/°C	Temp/K		P/mbar	**P/Pa
		Run 1
20.0	293.15		3.4	340
		Run 2
*20	293.15		2.77	277
20.0	293.15		2.8	280
30.1	303.25		5.3	530
40.1	313.25		8.8	880
50.0	323.15		16.8	1680

* - Determined by extrapolation

** - Calculated

Comment

Run 1 – The test substance was degassed for 16 h under vacuum. The vacuum pressure at start of test was 0.0016 mbar. The test substance failed to stabilise after 8 h and was left overnight to stabilise after 24 h the reading was 3.4 mbar.

Run 2 – The test substance was degassed for 8 h under vacuum. The vacuum pressure at start of test was 0.0014 mbar. The test substance was left overnight to stabilise, after 16 h the reading at 20°C was 2.8 mbar.

Conclusions:

Under study conditions, the vapour pressure of the test substance was determined to be 277 Pa at 20°C.

Executive summary:

A study was conducted to determine the vapour pressure of the test substance using static method, according to EC Method A.4, in compliance with GLP. For Run 1, the test substance was degassed for 16 h under vacuum. The vacuum pressure at start of test was 0.16 mbar. The test substance failed to stabilise after 8 h and was left overnight to stabilise after 24 h the reading was 340 Pa. For Run 2, the test substance was degassed for 8 h under vacuum. The vacuum pressure at start of test was 0.14 Pa The test substance was left overnight to stabilise, after 16 h the reading at 20°C was 280 Pa. Under study conditions, the vapour pressure of the test substance was determined to be 277 Pa at 20°C (Chilworth, 2017).

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction from an well known and acknowledged tool. See below under 'Overall remarks, attachments' for applicability domain.

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs: Chapter R.6. QSARs and grouping of chemicals

Principles of method if other than guideline:

Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the vapour pressure values were estimated for the individual components followed by the determination of an overall weighted-average value using the mole fractions of all the individual components.

Key result

Test no.:

#1

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0.001 Pa

Remarks on result:

other: Weighted average vapour pressure estimation using MPBPWIN v.1.43

QSAR Prediction results

Chemical names	SMILES	Mole fraction Xi = (mi/Mi)/∑ (mi/Mi)	VP (Pa)	VP * xi (Pa)	Domain evaluation
Potassium hexadecyl hydrogen phosphate	CCCCCCCCCCCCCCCCOP(O)(=O)[O-].[K+]	0.0986535	2.38E-08	2.35E-09	ID - MW and MP, OD - BP and VP
Potassium dihexadecyl phosphate	CCCCCCCCCCCCCCCCOP(=O)(OCCCCCCCCCCCC)[O-].[K+]	0.079339646	2.74E-06	2.17E-07	ID - MW and MP, OD - BP and VP
hexadecan-1-ol	CCCCCCCCCCCCCCCCO	0.60494496	1.19E-03	7.20E-04	ID - MW, MP and VP, OD - BP
Isostearyl isostearate	CC(C)CCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCC(C)C	0.217061893	5.12E-09	1.11E-09	ID - MW and MP, OD - BP and VP
		1.0000000		0.00072

ID - In Domain, OD - Out Domain

BP - Boiling Point, MP - Melting Point, VP - Vapour pressure

VP
Experimental Database Structure Match: no data
SMILES : CCCCCCCCCCCCCCCCOP(=O)(O(K))O(K)
CHEM  :
MOL FOR: C16 H33 O4 P1 K2		MW (Training set)	MW (Validation)
MOL WT : 398.61	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
			BP cut off (deg C)
Boiling Point: 480.00 deg C (Adapted Stein and Brown Method)		OD	226.85
Melting Point:  75.00 deg C (Adapted Joback Method)
Melting Point: 166.61 deg C (Gold and Ogle Method)
Mean Melt Pt : 120.81 deg C (Joback; Gold,Ogle Methods)			MP cut off
Selected MP:  90.27 deg C (Weighted Value)		ID	350 deg C
Vapor Pressure Estimations (25 deg C):
(Using BP: 480.00 deg C (estimated))
(Using MP: 90.27 deg C (estimated))
VP: 5.99E-010 mm Hg (Antoine Method)
: 7.98E-008 Pa (Antoine Method)
VP: 2.06E-008 mm Hg (Modified Grain Method)
: 2.74E-006 Pa (Modified Grain Method)
VP: 4.2E-008 mm Hg (Mackay Method)
: 5.61E-006 Pa (Mackay Method)
Selected VP: 2.06E-008 mm Hg (Modified Grain Method)			VP cut off
: 2.74E-006 Pa (Modified Grain Method)		OD	0.0001333 Pa
Subcooled liquid VP: 8.76E-008 mm Hg (25 deg C, Mod-Grain method)
: 1.17E-005 Pa (25 deg C, Mod-Grain method)
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 1 | -CH3             |  21.98 |  21.98
Group | 15 | -CH2-            |  24.22 | 363.30
Group | 3 | -O- (nonring)    |  25.16 |  75.48
Group | 1 | O=P<             | 107.23 | 107.23
Group | 1 | Metal (Na,K,Li)  | 500.00 | 500.00
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1266.17
RESULT- corr | BOILING POINT in deg Kelvin | 889.32
Special-Limit| BOILING POINT in deg Kelvin | 753.16
| BOILING POINT in deg C      | 480.00
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 1 | -CH3             |  -5.10 |  -5.10
Group | 15 | -CH2-            |  11.27 | 169.05
Group | 3 | -O- (nonring)    |  22.23 |  66.69
Group | 1 | O=P<             |  50.00 |  50.00
Group | 1 | Metal (Na,K,Li)  | 350.00 | 350.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 753.14
Special-limit| MELTING POINT in deg Kelvin | 348.16
| MELTING POINT in deg C      |  75.00
-------------------------------------------------------
| MELTING POINT in deg C      |  75.00
-------------------------------------------------------
Experimental Database Structure Match: no data
SMILES : CCCCCCCCCCCCCCCCOP(=O)(O(K))OCCCCCCCCCCCCCCCC
CHEM  :
MOL FOR: C32 H66 O4 P1 K1		MW (Training set)	MW (Validation)
MOL WT : 584.95	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
			BP cut off (deg C)
Boiling Point: 480.00 deg C (Adapted Stein and Brown Method)		OD	226.85
Melting Point:  75.00 deg C (Adapted Joback Method)
Melting Point: 166.61 deg C (Gold and Ogle Method)
Mean Melt Pt : 120.81 deg C (Joback; Gold,Ogle Methods)			MP cut off
Selected MP:  90.27 deg C (Weighted Value)		ID	350 deg C
Vapor Pressure Estimations (25 deg C):
(Using BP: 480.00 deg C (estimated))
(Using MP: 90.27 deg C (estimated))
VP: 5.99E-010 mm Hg (Antoine Method)
: 7.98E-008 Pa (Antoine Method)
VP: 2.06E-008 mm Hg (Modified Grain Method)
: 2.74E-006 Pa (Modified Grain Method)
VP: 4.2E-008 mm Hg (Mackay Method)
: 5.61E-006 Pa (Mackay Method)
Selected VP: 2.06E-008 mm Hg (Modified Grain Method)			VP cut off
: 2.74E-006 Pa (Modified Grain Method)		OD	0.0001333 Pa
Subcooled liquid VP: 8.76E-008 mm Hg (25 deg C, Mod-Grain method)
: 1.17E-005 Pa (25 deg C, Mod-Grain method)
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 2 | -CH3             |  21.98 |  43.96
Group | 30 | -CH2-            |  24.22 | 726.60
Group | 3 | -O- (nonring)    |  25.16 |  75.48
Group | 1 | O=P<             | 107.23 | 107.23
Group | 1 | Metal (Na,K,Li)  | 500.00 | 500.00
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1651.45
RESULT- corr | BOILING POINT in deg Kelvin | 1073.91
Special-Limit| BOILING POINT in deg Kelvin | 753.16
| BOILING POINT in deg C      | 480.00
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 2 | -CH3             |  -5.10 | -10.20
Group | 30 | -CH2-            |  11.27 | 338.10
Group | 3 | -O- (nonring)    |  22.23 |  66.69
Group | 1 | O=P<             |  50.00 |  50.00
Group | 1 | Metal (Na,K,Li)  | 350.00 | 350.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 917.09
Special-limit| MELTING POINT in deg Kelvin | 348.16
| MELTING POINT in deg C      |  75.00
-------------------------------------------------------
Experimental Database Structure Match:
Name    : HEXADECANOL
CAS Num : 029354-98-1
Exp MP (deg C): 49-50
Exp BP (deg C): ---
Exp VP (mm Hg): ---
Experimental Database Structure Match:
Name    : 1-HEXADECANOL
CAS Num : 036653-82-4
Exp MP (deg C): 49.3
Exp BP (deg C): 334
Exp VP (mm Hg): 6.00E-06 (extrapolated)
(Pa  ): 8.00E-004
Exp VP (deg C): 25
Exp VP ref   : DAUBERT,TE & DANNER,RP (1995)
SMILES : CCCCCCCCCCCCCCCCO
CHEM  :
MOL FOR: C16 H34 O1		MW (Training set)	MW (Validation)
MOL WT : 242.45	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
			BP cut off (deg C)
Boiling Point: 330.79 deg C (Adapted Stein and Brown Method)		OD	226.85
Melting Point:  57.74 deg C (Adapted Joback Method)
Melting Point:  79.48 deg C (Gold and Ogle Method)
Mean Melt Pt :  68.61 deg C (Joback; Gold,Ogle Methods)			MP cut off
Selected MP:  68.61 deg C (Mean Value)		ID	350 deg C
Vapor Pressure Estimations (25 deg C):
(Using BP: 334.00 deg C (exp database))
(Using MP: 49.30 deg C (exp database))
VP: 4.48E-006 mm Hg (Antoine Method)
: 0.000598 Pa (Antoine Method)
VP: 8.93E-006 mm Hg (Modified Grain Method)
: 0.00119 Pa (Modified Grain Method)
VP: 0.000354 mm Hg (Mackay Method)
: 0.0472 Pa (Mackay Method)
Selected VP: 8.93E-006 mm Hg (Modified Grain Method)			VP cut off
: 0.00119 Pa (Modified Grain Method)		ID	0.0001333 Pa
Subcooled liquid VP: 1.04E-005 mm Hg (25 deg C, exp database VP )
: 0.00139 Pa (25 deg C, exp database VP )
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 1 | -CH3             |  21.98 |  21.98
Group | 15 | -CH2-            |  24.22 | 363.30
Group | 1 | -OH (primary)    |  88.46 |  88.46
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 671.92
RESULT- corr | BOILING POINT in deg Kelvin | 603.95
| BOILING POINT in deg C      | 330.79
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 1 | -CH3             |  -5.10 |  -5.10
Group | 15 | -CH2-            |  11.27 | 169.05
Group | 1 | -OH (primary)    |  44.45 |  44.45
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 330.90
| MELTING POINT in deg C      |  57.74
-------------------------------------------------------
Experimental Database Structure Match: no data
SMILES : CC(C)CCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCC(C)C
CHEM  :
MOL FOR: C36 H72 O2		MW (Training set)	MW (Validation)
MOL WT : 536.97	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
			BP cut off (deg C)
Boiling Point: 532.26 deg C (Adapted Stein and Brown Method)		OD	226.85
Melting Point: 234.65 deg C (Adapted Joback Method)
Melting Point: 197.13 deg C (Gold and Ogle Method)
Mean Melt Pt : 215.89 deg C (Joback; Gold,Ogle Methods)			MP cut off
Selected MP: 215.89 deg C (Mean Value)		ID	350 deg C
Vapor Pressure Estimations (25 deg C):
(Using BP: 532.26 deg C (estimated))
(Using MP: 215.89 deg C (estimated))
VP: 1.65E-013 mm Hg (Antoine Method)
: 2.2E-011 Pa (Antoine Method)
VP: 3.84E-011 mm Hg (Modified Grain Method)
: 5.12E-009 Pa (Modified Grain Method)
VP: 1.14E-010 mm Hg (Mackay Method)
: 1.52E-008 Pa (Mackay Method)
Selected VP: 3.84E-011 mm Hg (Modified Grain Method)			VP cut off
: 5.12E-009 Pa (Modified Grain Method)		OD	0.0001333 Pa
Subcooled liquid VP: 4.15E-009 mm Hg (25 deg C, Mod-Grain method)
: 5.53E-007 Pa (25 deg C, Mod-Grain method)
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 4 | -CH3             |  21.98 |  87.92
Group | 29 | -CH2-            |  24.22 | 702.38
Group | 2 | >CH-             |  11.86 |  23.72
Group | 1 | -COO- (ester)    |  78.85 |  78.85
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1091.05
RESULT- corr | BOILING POINT in deg Kelvin | 805.42
| BOILING POINT in deg C      | 532.26
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 4 | -CH3             |  -5.10 | -20.40
Group | 29 | -CH2-            |  11.27 | 326.83
Group | 2 | >CH-             |  12.64 |  25.28
Group | 1 | -COO- (ester)    |  53.60 |  53.60
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 507.81
| MELTING POINT in deg C      | 234.65
-------------------------------------------------------

Conclusions:

Using the Modified Grain method of the MPBPWIN v1.43 program (EPI Suite v4.11), the weighted average vapour pressure of the test substance was calculated to be 7.2E-4 Pa.

Executive summary:

The vapour pressure (VP) value for the test substance were estimated using the Modified Grain method of the MPBPWIN v1.43 program of EPI Suite v4.11. Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the vapour pressure values were estimated for the individual components followed by the determination of an overall weighted-average value using the mole fractions of all the individual components. SMILES codes were used as the input parameter for the vapour pressure estimation for the individual constituents. The estimated vapour pressure of the constituents were found to range from 5.12E-9 to 1.19E-3 leading to a weighted average value of 7.2E-4 (US EPA, 2018), indicating that the test substance has low volatility (ECHA R.7c, 2017). The estimates for the major constituents are considered to be reliable with restrictions, as they do not completely fall within of the applicability domain.

Reference 3

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction from an well known and acknowledged tool. See below under 'Overall remarks, attachments' for applicability domain.

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs: Chapter R.6. QSARs and grouping of chemicals

Deviations:

not applicable

Principles of method if other than guideline:

Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the vapour pressure values were estimated for the individual components followed by the determination of an overall weighted-average value using the mole fractions of all the individual components.

Key result

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0.002 Pa

QSAR TEST results

Chemical names	SMILES	Mole fraction Xi = (mi/Mi)/∑ (mi/Mi)	TEST VP (Nearest neighbour method in mmhg)	TEST VP (Nearest neighbour method in Pa)	TEST VP (Nearest neighbour method in Pa) * xi	MAE for chemicals with similarity coefficient ≥ 0.5; External and training dataset MAE are 0.82 and 0.72, respectively	Domain evaluation for MAE
Potassium hexadecyl hydrogen phosphate	CCCCCCCCCCCCCCCCOP(O)(=O)[O-].[K+]	0.0986535	2.65E-07	3.03E-03	2.99E-04	1.23 and 1.23	OD - External and training dataset
Potassium dihexadecyl phosphate	CCCCCCCCCCCCCCCCOP(=O)(OCCCCCCCCCCCC)[O-].[K+]	0.079339646	7.50E-10	1.95E-09	1.55E-10	0.98 and 1.13	OD - External and training dataset
hexadecan-1-ol	CCCCCCCCCCCCCCCCO	0.60494496	2.25E-05	3.03E-03	1.83E-03	0.77 and 0.78	ID - External dataset, OD - training dataset
Isostearyl isostearate	CC(C)CCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCC(C)C	0.217061893	1.45E-11	1.95E-09	4.24E-10	0.90 and 1.03	OD - External and training dataset
		1.0000000			0.0021

MAE (mean absolute error), OD - Out domain, ID - In domain

For detailed results, kindly refer the attached background material section.

Conclusions:

Using the Nearest neighbor method of the T.E.S.T. v4.2.1 program, the vapour pressure of the test substance was calculated to be 2.1E-3 Pa.

Executive summary:

The vapour pressure (VP) value for the test substance was estimated using the Nearest neighbor method method of the T.E.S.T. v4.2.1 program. SMILES code was used as the input parameter for the vapour pressure estimation for the test substance. Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the vapour pressure values were estimated for the individual components followed by the determination of an overall weighted-average value using the mole fractions of all the individual components. The estimated vapour pressure of the constituents were found to range from 4.24E-10 to 1.83E-3 leading to a weighted average value of 2.1E-3 (US EPA, 2018), indicating that the test substance has low volatility (ECHA R.7c, 2017). However, the confidence in the prediction is considered to be low, as the mean absolute error (MAE) values for similar chemicals (≥0.5) were determined to be higher (i.e., 0.77 to 1.23 and 0.78 to 1.23) in comparison to the MAE values for external and training data set (i.e. 0.82 and 0.72). The estimate for the test substance considered to be reliable with restrictions, as it does not completely fall within of the applicability domain.

Description of key information

The vapour pressure of the test substance was determined experimentally using static method, according to EU Method A.4 (Chilworth, 2017) as well using QSAR models EPI Suite and T.E.S.T (US EPA, 2018).

Key value for chemical safety assessment

Vapour pressure:

0.002 Pa

at the temperature of:

25 °C

Additional information

- Experimental VP: 277 Pa (using static method); the VP value is suspected to be influenced by trapped gases/impurities.

- Weighted average QSAR based VP: 0.00072 Pa at 25°C (using EPI Suite v.4.11) and 0.0021 Pa at 25°C (using T.E.S.T. v4.2.1). The estimates for the major constituents are considered to be reliable with restrictions, as they do not completely fall within of the applicability domain.

- VP values for the main constituents, phosphate esters (PSE), alcohol and isoalkyl esters: 0.00289 Pa at 20°C (using effusion method) for mono- and di- C16 PSE, K+ (ECHA REACH dossier on CAS 19035-79-1); 0.0014-0.0016 Pa at 25˚C for hexadecane-1-ol (OECD SIDS, 2006); 9.79E-12 at 20 °C (Estimated using SPARC v.4.6) for isostearyl isostearate (ECHA REACH dossier on CAS:41669-30-1) respectively.

 

Overall, based on the above information, the test substance can be considered to have low volatility potential. In absence of a reliable experimental value for the overall test substance, the relatively higher QSAR based VP value of 0.0021 Pa has been considered further for hazard/risk assessment as a conservative approach.