m,m'-[carbonylbis[imino(3-methoxy-p-phenylene)azo]]bis(benzenesulphonic) acid, compound with 2,2'-iminodiethanol (1:2)

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: vapour pressure balance

Temp.:

20 °C

Vapour pressure:

< 0 Pa

Temp.:

25 °C

Vapour pressure:

< 0 Pa

Temp.:

50 °C

Vapour pressure:

< 0 Pa

Temp. [°C]	Vapour pressure [hPa], 1st measurement	Vapour pressure [hPa], 2nd measurement
70	5.2 x 10E-5	2.6 x 10E-6
80	1.2 x 10E-5	1.4 x 10E-6
90	3.5 x 10E-6	1.5 x 10E-6
100	2.6 x 10E-6	2.2 x 10E-6
110	3.4 x 10E-6	2.2 x 10E-6
120	2.6 x 10E-6	1.3 x 10E-6

The recommended range of the vapour pressure for this method is 10E-5 to 10E-2 hPa and for the temperature between approximately 0 and 120 °C.

The data points measured at 70 °C and 80 °C in the first measurement series showed a typical deviation caused by volatile impurities at the beginning of a measurement. All other measured vapour pressures were below the detection limit (1x10E-5 hPa).

Since the test did not yield vapour pressures sufficiently high to extrapolate to 20, 25 and 50 °C these values were estimated. According to the Antoine equation, the vapour pressure can be calculated

Conclusions:

A maximum vapour pressure of 8.9E-8 Pa was determined for Baycript gelb GGN at 25 °C.

Executive summary:

The vapour pressure of Bayscript gelb GGN was determined according to EC A.4 'vapour pressure: Effusion method', which is in most parts equivalent to OECD 104 'Vapur pressure' by effusion method. The method is based on the estimation of the mass of test item flowing out per unit of time of a Knudsen cell in the form of vapour, through a micro-orifice under ultra-vacuum conditions. The test item is filled into the test cell and placed in a furnace in the vacuum chamber from which the sample evaporates. The temperature of the cell with the test item is controlled by a surrounding heater. The vapour forms a molecular jet of defined geometry limited by an orifice. The mass of effused vapour is obtained by determining the loss of mass of the cell.

The vapour pressure was measured in the temperature range of 70 °C to 120 °C. In a first measurement series the measured vapour pressures showed an unusual behaviour which was most likely caused by volatile impurities. For this reason the measurement was repeated. In the second measurement series the test item was degassed at 50 °C for 8 hours. After the measurement it was determined that approx. 1 % (w/w) of the test item evaporated. Since the test did not yield vapour pressures sufficiently high to extrapolate to 20, 25 and 50 °C these values were estimated according to the Antoine equation.

A maximum vapour pressure of 8.9E-8 Pa was determined for Baycript gelb GGN at 25 °C.

Description of key information

The vapour pressure of Bayscript gelb GGN was determined according to EC A.4 'vapour pressure: Effusion method', which is in most parts equivalent to OECD 104 'Vapur pressure' by effusion method. The method is based on the estimation of the mass of test item flowing out per unit of time of a Knudsen cell in the form of vapour, through a micro-orifice under ultra-vacuum conditions.

A maximum vapour pressure of 8.9E-8 Pa was determined for Baycript gelb GGN at 25 °C.

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

25 °C