Sodium 2-[methyl(1-oxododecyl)amino]ethanesulphonate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Principles of method if other than guideline:

The test is conducted in accordance with the procedure described in EU Regulation (EC) 440/2008, Annex Part A test A.4.

This method involves placing a quantity of sample in the sample chamber of the glassware and a suitable manometer liquid in the U-tube. The contents of the static glassware are connected to a vacuum system linked with pressure monitors to enable the reading of any pressure/ vacuum on the contents of the stati glassware. The system is evacuated until optimum vacuum is observed. This process is to ensure that there are no residual gasses within the system other than that of the test material.

The glassware is then isolated from the vacuum system. This is immediately followed by isolation of the sample chamber of the glassware so that any gas evolved from the sample will cause a displacement of the manometer liquid. When this is observed the levels of the liquid in the manometer is balanced by introducing a positive pressure using an inert gas (typically nitrogen) or negative pressure (using vacuum). The total pressure on the sample after the levels of the liquid in the manometer is balanced is then registered on the display unit coupled with the pressure transducers.

The glassware is then positioned in the constant temperature bath set to a desired starting temperature. As the static apparatus and its contents approaches temperature equilibrium in the bath, the levels of the manometer liquid are balanced using the posi tive or negative pressure depending on the direction of displacement. This procedure is repeated until the system achieves temperature and pressure equilibrium (i.e. no significant change in temperature or pressure is observed). The temperature and pressure displayed on the pressure monitors are then recorded. The temperature is subsequently set to a higher temperature (usually 5-25°C higher) and the procedure is repeated until enough data points are obtained.

GLP compliance:

yes (incl. QA statement)

Type of method:

static method

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

4.21 Pa

Test no.:

#2

Temp.:

20 °C

Vapour pressure:

2.91 Pa

Key result

Test no.:

#3

Temp.:

20 °C

Vapour pressure:

3.6 Pa

Remarks on result:

other: mean of 2 runs

Key result

Remarks on result:

other: A reading at 50°C was attempted but due to a fault that occurred in the manometer a measurement was not possible

An initial test run using 7.1 g of sample was started but aborted after testing at 30°C as bubbles were observed in the manometer liquid.

Run 2: 6.4g of sample was transferred to a round bottomed flask and degassed for approximately 41 hours. Vacuum at the start of analysis was 0.009 mbar.

Run 3: 7.3g of sample was transferred to a round bottomed flask and degassed over a total period of 91 hours. The starting vacuum was 0.009 mbar.

A reading at 50°C was attempted but due to a fault that occurred in the manometer a measurement was not possible.

Conclusions:

Experimental vapour pressure of SMLT was determined to be 3.6 Pa at 20°C (mean of 2 runs)

Executive summary:

Experimental vapour pressure of SMLT was determined to be 3.6 Pa at 20°C (mean of 2 runs)

Description of key information

Key Study

Experimental vapour pressure of SMLT was determined to be 3.6 Pa at 20°C (mean of 2 runs)

Supporting Study

The US EPA EPI Suite QSAR model software package (MPBPWIN v.143) was used to predict the vapour pressure of SMLT

The following SMILES string for SMLT was used as input to the model:

O=C(N(CCS(=O)([O-])=O)C)CCCCCCCCCCC.[Na+]

The vapour pressure of the substance was calculated to be 1.9E-13 Pa

Key value for chemical safety assessment

Vapour pressure:

3.6 Pa

at the temperature of:

20 °C