Hexadecyltrimethylammonium methyl sulphate

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

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.

Specific details on test material used for the study:

Input data for the model: Representative SMILES of the individual constituents:
1. Hexadecyltrimethylammonium methyl sulphate: CCCCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)
2. C14: CCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)
3. C18: CCCCCCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)

See section 1.2 for composition details.

Key result

Test no.:

#1

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0.083 Pa

Remarks on result:

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

QSAR prediction full results

Chemical names	SMILES	Mole fraction Xi = (mi/Mi)/∑ (mi/Mi)	Exp Vp (Pa)	Exp Vp*xi	Domain evaluation
C16	CCCCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)	0.959806	8.30E-02	7.97E-02	ID (Molecular weight and VP cut off), MP and BP values entered are experimental
C14	CCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)	0.021522	8.30E-02	1.79E-03	ID (Molecular weight and VP cut off), MP and BP values entered are experimental
C18	CCCCCCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)	0.018672	8.30E-02	1.55E-03	ID (Molecular weight and VP cut off), MP and BP values entered are experimental
				8.30E-02

ID - In Domain, OD - Out Domain

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

VP-Exp
Experimental Database Structure Match: no data
SMILES : CCCCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)
CHEM  :	Domain evaluation
MOL FOR: C20 H45 N1 O4 S1		MW (Training set)	MW (Validation)
MOL WT : 395.65	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
Boiling Point: 600.40 deg C (Adapted Stein and Brown Method)
Melting Point: 349.84 deg C (Adapted Joback Method)
Melting Point: 236.91 deg C (Gold and Ogle Method)
Mean Melt Pt : 293.38 deg C (Joback; Gold,Ogle Methods)
Selected MP: 259.50 deg C (Weighted Value)
Vapor Pressure Estimations (25 deg C):
(Using BP: 304.00 deg C (user entered))
(Using MP: 68.00 deg C (user entered))
VP: 0.00047 mm Hg (Antoine Method)
: 0.0627 Pa (Antoine Method)
VP: 0.000622 mm Hg (Modified Grain Method)
: 0.083 Pa (Modified Grain Method)
VP: 0.00112 mm Hg (Mackay Method)
: 0.15 Pa (Mackay Method)
Selected VP: 0.000622 mm Hg (Modified Grain Method)		VP cut off
: 0.083 Pa (Modified Grain Method)	ID	0.0001333 Pa
Subcooled liquid VP: 0.00158 mm Hg (25 deg C, Mod-Grain method)
: 0.21 Pa (25 deg C, Mod-Grain method)
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 5 | -CH3             |  21.98 | 109.90
Group | 15 | -CH2-            |  24.22 | 363.30
Group | 2 | -O- (nonring)    |  25.16 |  50.32
Group | 1 | >S(=O)(=O)       | 171.58 | 171.58
Group | 1 | >N< (+5)         | 340.00 | 340.00
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1233.28
RESULT- corr | BOILING POINT in deg Kelvin | 873.56
| BOILING POINT in deg C      | 600.40
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 5 | -CH3             |  -5.10 | -25.50
Group | 15 | -CH2-            |  11.27 | 169.05
Group | 2 | -O- (nonring)    |  22.23 |  44.46
Group | 1 | >S(=O)(=O)       | 150.00 | 150.00
Group | 1 | >N< (+5)         | 340.00 | 340.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 800.51
RESULT-limit| MELTING POINT in deg Kelvin | 623.00
| MELTING POINT in deg C      | 349.84
-------------------------------------------------------
| MELTING POINT in deg C      | 349.84
-------------------------------------------------------
Experimental Database Structure Match: no data
SMILES : CCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)
CHEM  :	Domain evaluation
MOL FOR: C18 H41 N1 O4 S1		MW (Training set)	MW (Validation)
MOL WT : 367.59	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
Boiling Point: 577.20 deg C (Adapted Stein and Brown Method)
Melting Point: 349.84 deg C (Adapted Joback Method)
Melting Point: 223.36 deg C (Gold and Ogle Method)
Mean Melt Pt : 286.60 deg C (Joback; Gold,Ogle Methods)
Selected MP: 248.66 deg C (Weighted Value)
Vapor Pressure Estimations (25 deg C):
(Using BP: 304.00 deg C (user entered))
(Using MP: 68.00 deg C (user entered))
VP: 0.00047 mm Hg (Antoine Method)
: 0.0627 Pa (Antoine Method)
VP: 0.000622 mm Hg (Modified Grain Method)
: 0.083 Pa (Modified Grain Method)
VP: 0.00112 mm Hg (Mackay Method)
: 0.15 Pa (Mackay Method)
Selected VP: 0.000622 mm Hg (Modified Grain Method)		VP cut off
: 0.083 Pa (Modified Grain Method)	ID	0.0001333 Pa
Subcooled liquid VP: 0.00158 mm Hg (25 deg C, Mod-Grain method)
: 0.21 Pa (25 deg C, Mod-Grain method)
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 5 | -CH3             |  21.98 | 109.90
Group | 13 | -CH2-            |  24.22 | 314.86
Group | 2 | -O- (nonring)    |  25.16 |  50.32
Group | 1 | >S(=O)(=O)       | 171.58 | 171.58
Group | 1 | >N< (+5)         | 340.00 | 340.00
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1184.84
RESULT- corr | BOILING POINT in deg Kelvin | 850.36
| BOILING POINT in deg C      | 577.20
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 5 | -CH3             |  -5.10 | -25.50
Group | 13 | -CH2-            |  11.27 | 146.51
Group | 2 | -O- (nonring)    |  22.23 |  44.46
Group | 1 | >S(=O)(=O)       | 150.00 | 150.00
Group | 1 | >N< (+5)         | 340.00 | 340.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 777.97
RESULT-limit| MELTING POINT in deg Kelvin | 623.00
| MELTING POINT in deg C      | 349.84
-------------------------------------------------------
Experimental Database Structure Match: no data
SMILES : CCCCCCCCCCCCCCCCCCN(OS(=O)(=O)OC)(C)(C)(C)
CHEM  :	Domain evaluation
MOL FOR: C22 H49 N1 O4 S1		MW (Training set)	MW (Validation)
MOL WT : 423.70	ID	16.04	943.17
------------------------ SUMMARY MPBPWIN v1.43 --------------------
Boiling Point: 623.61 deg C (Adapted Stein and Brown Method)
Melting Point: 349.84 deg C (Adapted Joback Method)
Melting Point: 250.47 deg C (Gold and Ogle Method)
Mean Melt Pt : 300.15 deg C (Joback; Gold,Ogle Methods)
Selected MP: 270.34 deg C (Weighted Value)
Vapor Pressure Estimations (25 deg C):
(Using BP: 304.00 deg C (user entered))
(Using MP: 68.00 deg C (user entered))
VP: 0.00047 mm Hg (Antoine Method)
: 0.0627 Pa (Antoine Method)
VP: 0.000622 mm Hg (Modified Grain Method)
: 0.083 Pa (Modified Grain Method)
VP: 0.00112 mm Hg (Mackay Method)
: 0.15 Pa (Mackay Method)
Selected VP: 0.000622 mm Hg (Modified Grain Method)		VP cut off
: 0.083 Pa (Modified Grain Method)	ID	0.0001333 Pa
Subcooled liquid VP: 0.00158 mm Hg (25 deg C, Mod-Grain method)
: 0.21 Pa (25 deg C, Mod-Grain method)
-------+-----+--------------------+----------+---------
TYPE | NUM | BOIL DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 5 | -CH3             |  21.98 | 109.90
Group | 17 | -CH2-            |  24.22 | 411.74
Group | 2 | -O- (nonring)    |  25.16 |  50.32
Group | 1 | >S(=O)(=O)       | 171.58 | 171.58
Group | 1 | >N< (+5)         | 340.00 | 340.00
*  |    | Equation Constant |         | 198.18
=============+====================+==========+=========
RESULT-uncorr| BOILING POINT in deg Kelvin | 1281.72
RESULT- corr | BOILING POINT in deg Kelvin | 896.77
| BOILING POINT in deg C      | 623.61
-------------------------------------------------------
-------+-----+--------------------+----------+---------
TYPE | NUM | MELT DESCRIPTION | COEFF  | VALUE
-------+-----+--------------------+----------+---------
Group | 5 | -CH3             |  -5.10 | -25.50
Group | 17 | -CH2-            |  11.27 | 191.59
Group | 2 | -O- (nonring)    |  22.23 |  44.46
Group | 1 | >S(=O)(=O)       | 150.00 | 150.00
Group | 1 | >N< (+5)         | 340.00 | 340.00
*  |    | Equation Constant |         | 122.50
=============+====================+==========+=========
RESULT   | MELTING POINT in deg Kelvin | 823.05
RESULT-limit| MELTING POINT in deg Kelvin | 623.00
| MELTING POINT in deg C      | 349.84
-------------------------------------------------------

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 0.083 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 (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 weighted average vapour pressure value of the test substance was 0.083 Pa (US EPA, 2018). Based on calculated value, and the boiling point value of 304 °C, the test substance is considered having low volatility (ECHA R.7c, 2017). The estimates for the major constituents are considered to be reliable, as they fall within of the applicability domain.

Reference 2

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From July 13, 2017 to August 23, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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. 2 000 Pa

Remarks on result:

other: Author concluded that measured values are not representative of the material due to trapped gases/impurities

Key result

Test no.:

#2

Temp.:

ca. 20 °C

Vapour pressure:

ca. 1 140 Pa

Remarks on result:

other: Author concluded that measured values are not representative of the material due to trapped gases/impurities

Key result

Test no.:

#3

Temp.:

ca. 20 °C

Vapour pressure:

ca. 3 250 Pa

Remarks on result:

other: Author concluded that measured values are not representative of the material due to trapped gases/impurities

Full test results

Temp/°C	Temp/K		P/mbar	P/Pa
		Run 1
20*	293.15		20.31*	2031*
20.0	293.15		20	2000
30.0	303.15		31.5	3150
40.0	313.15		46.2	4620
50.0	323.15		67.3	6730
60.0	333.15		93.3	9330
		Run 2
20.0*	293.15		11.23*	1123*
20.0	293.15		11.4	1140
30.0	303.15		16.4	1640
40.0	313.15		25.2	2520
50.0	323.15		35.6	3560
20.0	293.15	Run3	32.5	3250

*determined by extrapolation

Run 1 – The sample was degassed for 15 hours under vacuum.

Run 2 – The sample was degassed for 24 hours under vacuum.

Run 3 – The sample was degassed for half an hour under vacuum.

Comment

The test material was found to take approx. 48 h to stabilise. It is suspected by the author that trapped solvent or gas is present and measured values are not representative of the material. A 3rd run was performed at 20°C only which was degassed for 0.5 hours under vacuum and provided a result of 3250 Pa. This supports the suspicion that trapped gases/ impurities are influencing the results. A less than value has therefore been reported.

Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint specific guidance Version 6.0 July 2017 states;

Impurities can have a large influence on vapour pressure. The influence depends on the amount of the impurity and the vapour pressure of that impurity. Small amounts of volatile impurities may increase the vapour pressure by several orders of magnitude. This has to be kept in mind when performing the measurements and for the interpretation of results. Therefore utmost care should be taken in the selection of the key study(ies), or weight-of-evidence approaches, that the data selected is representative of the substance being registered by the respective companies. (R7.1.5.5 Impurities; uncertainties)

Conclusions:

Under the study conditions, the vapor pressure of the test substance was determined to be <1140 Pa at 20°C.

Executive summary:

A study was conducted to determine the vapor pressure of the test substance (88.57% active), according to the EU method A.4, by static method, in compliance with GLP. Three runs were conducted during the study. The test substance samples took 48 h to stabilize and they were degassed under vacuum. It was also suspected by the author that trapped solvent or gas was present and measured values were not representative of the material. Run 1 (degassed, 15 h, under vacuum) and Run 2 (degassed, 24 h, under vacuum) did yield the results of 2031 and 1123 Pa respectively at 20°C, however, Run 3 (degassed, 0.5 h, under vacuum) yielded result of 3250 Pa. Based on these results of the study, the author concluded that trapped gases/impurities were influencing the results. Therefore, a less than value (<1140 Pa) has been reported for the study result. Under the study conditions, the vapor pressure of the test substance was determined to be <1140 Pa at 20°C (Chilworth, 2017).

Description of key information

Vapour pressure was determined using static method, according to the EU method A.4 (Chilworth, 2017) as well as using MPBPWIN v.1.43 QSAR program of EPI Suite v.4.11.

Key value for chemical safety assessment

Vapour pressure:

0.083 Pa

at the temperature of:

25 °C

Additional information

- Experimentally derived VP: <1140 Pa at 20°C (using static method). This value was considered not representative of the test substance as it was suspected to be influenced by trapped gas/impurities.

- Weighted average QSAR based VP: 0.083 Pa at 25°C (using MPBPWIN v.1.43 QSAR program of 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.

- VP of structurally similar substance, C12-14 ADMAES, which is part of the category: 0.0000029 Pa at 25°C (using effusion method)

Overall, based on the above information, the test substance can be considered to have low volatility. Further, the weighted average QSAR based VP value of 0.083 Pa has been considered further for hazard/risk assessment.