4-ethoxy-2,3-difluoro-4'-propyl-1,1'-biphenyl

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-04-06 to 2011-05-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

2006

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: vapour pressure balance

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0.001 Pa

Key result

Test no.:

#2

Temp.:

25 °C

Vapour pressure:

0.001 Pa

Key result

Test no.:

#3

Temp.:

50 °C

Vapour pressure:

0.14 Pa

Thermal Stability

The DSC-measurement in a closed glass crucible showed an endothermic effect in the temperature range of 45 – 65 °C and no exothermal effect until the maximum test temperature of 350 °C.

 

Vapour Pressure Balance (Effusion Method)

The vapour pressure was measured in the temperature range of 17 °C to 92 °C. Above 27 °C a vapour pressure could be measured. The measured vapour pressures at the corresponding temperatures are listed in the following table:

 

Temperature / °C	Vapour pressure / hPa
*1) 31.6	4.2 x 10^-5
*1) 35.9	1.2 x 10^-4
*1) 39.8	2.9 x 10^-4
*1) 42.8	4.3 x 10^-4
*1) 47.7	7.8 x 10^-4
*2) 52.6	8.7 x 10^-4
*2) 58.7	1.8 x 10^-3
*2) 66.3	3.9 x 10^-3
*2) 73.9	8.7 x 10^-3
*2) 79.8	1.6 x 10^-2
*2) 85.1	2.7 x 10^-2
*2) 92.1	5.4 x 10^-2

*1) due to the results of the DSC measurement, it is supposed that the test item exists in its solid form

*2) due to the results of the DSC measurement, it Is supposed that the test item exists in its liquid form

 

The vapour pressure data showed an unusual behaviour with a two-staged curve shape. For the vapour pressure the regression to determine the coefficient of the Antoine equation A, B, C was done for the two stages of the curve separately. First for the curve shape in the temperature range 32 - 48 °C where due to the results of the DSC measurement, it is supposed that the test item exists in its solid form*1), and second for the curve shape in the temperature range 53 - 92 °C where it is supposed that the test item exists in its liquid form*2).

The values for 20, 25 and 50 °C are calculated, using the Antoine constants A, B and C.

In the temperature range 32 - 48 °C following constants were determined: A=21.09875, B=-7740.32, C=273.15. Vapour pressures of 4.95*10^-6 hPa at 20 °C, 1.37*10^-5 hPa at 25 °C and 1.4*10^-3 hPa at 50 °C were determined.

In the temperature range 53 - 92 °C following constants were determined: A=13.36243, B=-5350.62, C=273.15. Vapour pressures of 1.29*10^-5 hPa at 20 °C, 2.61*10^-5 hPa at 25 °C and 6.38*10^-4 hPa at 50 °C were determined.

Conclusions:

The vapour pressures for the solid form of the test item were determined to be 5.0*10^-4 Pa (20 °C), 1.4*10^-3 Pa (25 °C) and 1.4*10^-1 Pa (50 °C). 

Executive summary:

A study was performed according to OECD TG 104 and Commission Regulation (EC) No. 440/2008, method A.4 in order to determine the vapour pressure of the test item by using the effusion method (vapour pressure balance). The vapour pressure was measured at various temperatures between 17 and 92 °C. The vapour pressure data showed an unusual behaviour with a two-staged curve shape. Based on the DSC measurements the different curve shapes were supposed to be due to the respective state of the test item. One curve shape was observed in the temperature range 32 - 48 °C for the test item in its solid form. In the temperature range 53 - 92 °C the second curve shape for the test item in its liquid form was determined. The vapour pressures of the test item at 20, 25 and 50 °C were extrapolated by using the Antoine constants. As final results the calculated extrapolated values of the vapour pressure in the lower temperature range (32 – 48 °C, solid form of the test item) were: 5.0*10^-4 Pa (20 °C), 1.4*10^-3 Pa (25 °C) and 1.4*10^-1 Pa (50 °C). 

Description of key information

The vapour pressures for the solid form of the test item were determined to be 5.0*10^-4 Pa (20 °C), 1.4*10^-3 Pa (25 °C) and 1.4*10^-1 Pa (50 °C). 

Key value for chemical safety assessment

Vapour pressure:

0.001 Pa

at the temperature of:

20 °C

Additional information

A study was performed according to OECD TG 104 and Commission Regulation (EC) No. 440/2008, method A.4 in order to determine the vapour pressure of the test item by using the effusion method (vapour pressure balance). The vapour pressure was measured at various temperatures between 17 and 92 °C. The vapour pressure data showed an unusual behaviour with a two-staged curve shape. Based on the DSC measurements the different curve shapes were supposed to be due to the respective state of the test item. One curve shape was observed in the temperature range 32 - 48 °C for the test item in its solid form. In the temperature range 53 - 92 °C the second curve shape for the test item in its liquid form was determined. The vapour pressures of the test item at 20, 25 and 50 °C were extrapolated by using the Antoine constants. As final results the calculated extrapolated values of the vapour pressure in the lower temperature range (32 – 48 °C, solid form of the test item) were: 5.0*10^-4 Pa (20 °C), 1.4*10^-3 Pa (25 °C) and 1.4*10^-1 Pa (50 °C).