Reaction mass of methyl 2-methylbenzene-1-sulfonate and methyl toluene-4-sulphonate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Principles of method if other than guideline:

Only three measuring points were taken. In OECD 104 it is mentioned to take 'approximately 5 to 10 measuring points in all' for the static method. However, the goodness of fit is considered to be sufficient (see 'Illustration').

GLP compliance:

no

Type of method:

static method

Temp.:

20 °C

Vapour pressure:

393 Pa

Temp.:

25 °C

Vapour pressure:

475 Pa

Temp.:

50 °C

Vapour pressure:

1 118 Pa

Temp.:

55 °C

Vapour pressure:

1 306 Pa

Results obtained in the measurement of the vapour pressures of the test substance

T [°C]	p [Pa]
70	2000
100	4400
130	8420

Conclusions:

The vapour pressure of the test substance was determined to be 393 Pa at 20 °C and 475 Pa at 25 °C.

Executive summary:

The vapour pressure of the test substance was determined by the static method according to OECD 104 and EC A.4. After filling in of the sample, the apparatus is submerged in an immersion thermostat. The sample is degassed several times by application of vacuum at a temperature which is low enough to ensure that the composition of the material is not altered.

During the measurement the voltage of the pressure transmitter is recorded. Due to the greater measurement accuracy of the applied experimental set-up at higher vapour pressures the measurements were performed at 70 °C, 100 °C und 130 °C.

The Antoine equation was fitted to the data in order to extrapolate the vapour pressure to the relevant temperatures of 20 °C, 25 °C, 50 °C and 55 °C.

The vapour pressure of the test substance was determined to be 393 Pa at 20 °C and 475 Pa at 25 °C.

Description of key information

The vapour pressure of the test substance was determined by the static method according to OECD 104 and EC A.4. After filling in of the sample, the apparatus is submerged in an immersion thermostat. During the measurement the voltage of the pressure transmitter is recorded. Due to the greater measurement accuracy of the applied experimental set-up at higher vapour pressures the measurements were performed at 70 °C, 100 °C und 130 °C.

The Antoine equation was fitted to the data in order to extrapolate the vapour pressure to the relevant temperatures of 20 °C, 25 °C, 50 °C and 55 °C.

The vapour pressure of the test substance was determined to be 393 Pa at 20 °C and 475 Pa at 25 °C.

Key value for chemical safety assessment

Vapour pressure:

393 Pa

at the temperature of:

20 °C