2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-3H-pyrazol-3-one

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well performed OECD study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Principles of method if other than guideline:

The method is based on the estimation of the mass of the test substance flowing out per unit of time
through a micro-orifice of a Knudsen cell in the form of vapour 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 is calculated by applying the Hertz-Knudsen relation with correction factors
that depend on parameters of the apparatus. It is calculated from the decrease of mass delta m during
an elapsed time period delta t.

GLP compliance:

no

Type of method:

effusion method: vapour pressure balance

Test material

Test material information

Constituent 1

Reference substance name:

2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-3H-pyrazol-3-one

EC Number:

224-330-1

Cas Number:

4314-14-1

Molecular formula:

C16H14N4O

IUPAC Name:

2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-3H-pyrazol-3-one

Details on test material:

purity: 99.2 %

Results and discussion

Vapour pressure

Vapour pressure 1

Temp.:

20 °C

Vapour pressure:

0 Pa

Vapour pressure 2

Temp.:

25 °C

Vapour pressure:

0 Pa

Vapour pressure 3

Temp.:

50 °C

Vapour pressure:

0 Pa

Any other information on results incl. tables

The vapour pressure was measured in the temperature range of 40 °C to 110 °C. The measured vapour pressures at the corresponding temperatures are listed in Table 1.

Table 1: Measured vapour pressures and corresponding temperatures

Temperature / °C Vapour pressure / hPa

40                     8.3 × 10-6

50                     1.4 × 10-5

60                     3.0 × 10-5

70                     3.4 × 10-5

80                     5.3 × 10-5

90                     1.4 × 10-4

100                     4.2 × 10-4

110                     1.3 × 10-3

Applicant's summary and conclusion

Conclusions:

The vapour pressure of the substance is
5.4 x 10(-7) Pa at 20°C, 1.3 x 10 (-6) Pa at 25°C , 7.2 x 10(-5) Pa at 50°C

Executive summary:

The vapour pressure of the substance was determined according to OECD guideline 104 respectively EU A.4 using the effusion method with a vapour pressure balance. The vapour pressure was measured in the temperature range of 40 °C to 110°C. The results were listed in a table and the required vapour pressure were evaluated from the graphic result.

The vapour pressure of the substance was found to be 5.4 x 10(-7) Pa at 20°C, 1.3 x 10 (-6) Pa at 25°C , 7.2 x 10(-5) Pa at 50°C