Reaction mass of hexadecyl dihydrogen phosphate and cetyl alcohol (mono- C16 PSE and C16-OH)

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From July 18, 2017 to August 24, 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

yes

Type of method:

static method

Key result

Test no.:

#2

Temp.:

ca. 20.4 °C

Vapour pressure:

< 1 Pa

Remarks on result:

other: Estimated based on individual components vapour pressure

Conclusions:

Under the study conditions, the vapour pressure could not be determined. Based on SDS the vapour pressure is expected to be <1 Pa at 20.4˚C.

Executive summary:

A study was conducted to determine the vapour pressure of the test substance using static method, according to EU Method A.4, in compliance with GLP. During the study pressure equilibration was not achieved over 7 h therefore experimental determination of the vapour pressure was terminated. Based on available information (SDS), the vapour pressure of the individual components was estimated as less than 1 Pa. However there was suspicion that some impurities may be causing the increase in vapour observed in the experimental determination. Under the study conditions, the estimated vapour pressure of the test substance based on the individual components is determined to be <1 Pa at 20.4˚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 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 (Pa)*xi	Domain evaulation
Hexadecyl Dihydrogen Phosphate	CCCCCCCCCCCCCCCCOP(O)(O)=O	0.605918	5.46E-08	3.31E-08	ID (Molecular weight and Melting point) OD(Boiling point, Vapour pressure)
dihexadecyl hydrogen phosphate	CCCCCCCCCCCCCCCCOP(O)(=O)OCCCCCCCCCCCCCCCC	0.027208	3.48E-08	9.47E-10	ID (Molecular weight and Melting point) OD(Boiling point, Vapour pressure)
hexadecan-1-ol	CCCCCCCCCCCCCCCCO	0.366874	1.19E-03	4.37E-04	ID (Molecular weight, Vapour pressure and Melting point) OD(Boiling point)
				4.37E-04

ID - In Domain, OD - Out Domain

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

Experimental Database Structure Match: no data
SMILES : CCCCCCCCCCCCCCCCOP(O)(O)=O
CHEM  :
MOL FOR: C16 H35 O4 P1		MW (Training set)	MW (Validation)
MOL WT : 322.43	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
			BP cut off (deg C)
Boiling Point: 454.33 deg C (Adapted Stein and Brown Method)		OD	226.85
Melting Point:  75.00 deg C (Adapted Joback Method)
Melting Point: 151.62 deg C (Gold and Ogle Method)
Mean Melt Pt : 113.31 deg C (Joback; Gold,Ogle Methods)			MP cut off
Selected MP:  87.77 deg C (Weighted Value)		ID	350 deg C
Vapor Pressure Estimations (25 deg C):
(Using BP: 454.33 deg C (estimated))
(Using MP: 87.77 deg C (estimated))
VP: 1.24E-011 mm Hg (Antoine Method)
: 1.65E-009 Pa (Antoine Method)
VP: 4.1E-010 mm Hg (Modified Grain Method)
: 5.46E-008 Pa (Modified Grain Method)
VP: 1.93E-007 mm Hg (Mackay Method)
: 2.58E-005 Pa (Mackay Method)
Selected VP: 4.1E-010 mm Hg (Modified Grain Method)			VP cut off
: 5.46E-008 Pa (Modified Grain Method)		OD	0.0001333 Pa
Subcooled liquid VP: 1.64E-009 mm Hg (25 deg C, Mod-Grain method)
: 2.19E-007 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 | 2 | -OH (alcohol)    | 106.27 | 212.54
Group | 1 | -O- (nonring)    |  25.16 |  25.16
Group | 1 | O=P<             | 107.23 | 107.23
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 928.39
RESULT- corr | BOILING POINT in deg Kelvin | 727.49
| BOILING POINT in deg C      | 454.33
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 1 | -CH3             |  -5.10 |  -5.10
Group | 15 | -CH2-            |  11.27 | 169.05
Group | 2 | -OH (alcohol)    |  44.45 |  88.90
Group | 1 | -O- (nonring)    |  22.23 |  22.23
Group | 1 | O=P<             |  50.00 |  50.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 447.58
Special-limit| MELTING POINT in deg Kelvin | 348.16
| MELTING POINT in deg C      |  75.00
-------------------------------------------------------
Experimental Database Structure Match:
Name    : Dicetylphosphate
CAS Num : 002197-63-9
Exp MP (deg C): 74-75
Exp BP (deg C): ---
Exp VP (mm Hg): ---
SMILES : CCCCCCCCCCCCCCCCOP(O)(=O)OCCCCCCCCCCCCCCCC
CHEM  :
MOL FOR: C32 H67 O4 P1		MW (Training set)	MW (Validation)
MOL WT : 546.86	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: 74.00 deg C (exp database))
VP: 3.64E-012 mm Hg (Antoine Method)
: 4.85E-010 Pa (Antoine Method)
VP: 2.61E-010 mm Hg (Modified Grain Method)
: 3.48E-008 Pa (Modified Grain Method)
VP: 6.09E-008 mm Hg (Mackay Method)
: 8.12E-006 Pa (Mackay Method)
Selected VP: 2.61E-010 mm Hg (Modified Grain Method)			VP cut off
: 3.48E-008 Pa (Modified Grain Method)		OD	0.0001333 Pa
Subcooled liquid VP: 7.58E-010 mm Hg (25 deg C, Mod-Grain method)
: 1.01E-007 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 | 1 | -OH (alcohol)    | 106.27 | 106.27
Group | 2 | -O- (nonring)    |  25.16 |  50.32
Group | 1 | O=P<             | 107.23 | 107.23
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1232.56
RESULT- corr | BOILING POINT in deg Kelvin | 873.22
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 | 1 | -OH (alcohol)    |  44.45 |  44.45
Group | 2 | -O- (nonring)    |  22.23 |  44.46
Group | 1 | O=P<             |  50.00 |  50.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 589.31
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
-------------------------------------------------------

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 4.37E-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 5.46E-8 to 1.19E-3 leading to a weighted average value of 4.37E-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.

Description of key information

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

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

25 °C

Additional information

- Experimental VP: vapour pressure could not be determined using static method; expected to be <1 Pa (based on SDS);

- Weighted average QSAR based VP = 4.37E-4 Pa at 25°C (using EPI Suite v.4.11). The estimates for the major constituents are considered to be reliable with restrictions, as they do not completely fall within of the applicability domain.

Overall, based on the above information, the test substance can be considered to have low volatility potential. In absence of a reliable experimental value, the weighted average QSAR based VP value of 4.37E-4 Pa has been considered further for hazard/risk assessment as a conservative approach.