4'-methoxyacetophenone

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-03-31 to 2017-04-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: Knudsen cell

Key result

Temp.:

20 °C

Vapour pressure:

0.42 Pa

Remarks on result:

other: calculated

Temp.:

25 °C

Vapour pressure:

0.71 Pa

Remarks on result:

other: calculated

Temp.:

50 °C

Vapour pressure:

7.9 Pa

Remarks on result:

other: calculated

Thermal stability

In the range of 30 -50 °C of DSC run PN13147, an endothermic effect (melting) was observed. No further thermal effects were observed up to the maximum test temperature of 300 °C.

Table 1: Results of the DSC-measurement

No.	Sample weight / mg	Start / °C	Energy / J/g
PN13147	7.61	30 (endothermic)	110

Vapour pressure

Table 2: Measured vapour pressures of the test item

Test no	Temp. [°C]	Vapour pressure [Pa]
1	20.3	0.482
2	25.3	0.669
3	30.4	1.17
4	35.5	2.01
5	40.6	3.47
6	45.6	4.81
7	50.7	9.19

Conclusions:

The vapour pressure of the test item was assessed according to OECD Guideline 104 and EU Method A.4 and calculated by interpolation and extrapolation of the measured vapour pressure curve. The vapour pressure of the test item was calculated to be 0.42 Pa at 20 °C, 0.71 Pa at 25 °C and 7.9 Pa at 50 °C.

Executive summary:

The vapour pressure of the test item was determined according to OECD Guideline 104 and EU Method A.4 in compliance with the GLP principles. Before the vapour pressure was measured, the thermal stability of the test item was assessed via Difference Scanning Calometry (DSC) in a closed glass crucible under nitrogen from room temperature up to a temperature of 300 °C with a heating rate of 3 K/min. In the range of 30 -50 °C, an endothermic effect (melting) was observed. No further thermal effects were noted up to the maximum test temperature of 300 °C. For the main test, the test item was brought into the Knudsen cell before the test and was attached to a magnetic suspension balance. After that, the system was closed and the apparatus was evacuated (approximately 10^-6 Pa). A total of 7 segments were prepared for the entire measurement (temperature range: 20 to 51 °C). The series of segments commenced at the lowest desired measuring temperature. While measuring of each single segment, the decrease of weight of the Knudsen cell was measured by the magnetic suspension balance. Taking into account the geometry of the Knudsen cell orifice, physical data of the test item and the evaporation rate, the vapour pressure was calculated by interpolation and extrapolation of the measured vapour pressure curve. In result, the vapour pressure of the test item was calculated to be 0.42 Pa at 20 °C, 0.71 Pa at 25 °C and 7.9 Pa at 50 °C.

Description of key information

The vapour pressure of the test substance was determined to be 0.42 Pa at 20 °C.

Key value for chemical safety assessment

Vapour pressure:

0.42 Pa

at the temperature of:

20 °C

Additional information

Discussion

The vapour pressure of the test item was determined according to OECD Guideline 104 and EU Method A.4 in compliance with the GLP principles (Symrise AG, 2017). Before the vapour pressure was measured, the thermal stability of the test item was assessed via Difference Scanning Calometry (DSC) in a closed glass crucible under nitrogen from room temperature up to a temperature of 300 °C with a heating rate of 3 K/min. In the range of 30 -50 °C, an endothermic effect (melting) was observed. No further thermal effects were noted up to the maximum test temperature of 300 °C. For the main test, the test item was brought into the Knudsen cell before the test and was attached to a magnetic suspension balance. After that, the system was closed and the apparatus was evacuated (approximately 10^-6Pa). A total of 7 segments were prepared for the entire measurement (temperature range: 20 to 51 °C). The series of segments commenced at the lowest desired measuring temperature. While measuring of each single segment, the decrease of weight of the Knudsen cell was measured by the magnetic suspension balance. Taking into account the geometry of the Knudsen cell orifice, physical data of the test item and the evaporation rate, the vapour pressure was calculated by interpolation and extrapolation of the measured vapour pressure curve. In result, the vapour pressure of the test item was determined to be 0.42 Pa at 20 °C, 0.71 Pa at 25 °C and 7.9 Pa at 50 °C (calculated).