4-Ethoxy-2,3-difluoro-4'-methyl-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:

2018-10-13 to 2018-12-13

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7950 (Vapor Pressure)

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: Knudsen cell

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0.002 Pa

Key result

Test no.:

#2

Temp.:

25 °C

Vapour pressure:

0.003 Pa

Test no.:

#3

Temp.:

50 °C

Vapour pressure:

0.096 Pa

The vapour pressure was measured in the overall temperature range of 20 °C to 120 °C (first measurement 50 °C to 120 °C, second measurement 20 °C to 40 °C). The measured vapour pressures at the corresponding temperatures are listed below. After the measurement a mass loss of approx. 100 % (w/w) (first measurement) and approx.1 % (second measurement) was determined.

 

Measured vapour pressures and corresponding temperatures

 

Temperature / °C	Vapour pressure / hPa
50	7.6x10E-4
60	3.4 x 10E-3
80	3.0 x 10E-2
90	2.8 x 10E-5
100	n.e.
110	n.e
120	n.e
20*	1.2 x 10E-5
25*	3.6 x 10E-5
30*	7.2 x 10E-5
35*	1.5 x 10E-4
40*	3.5 x 10E-4
30*	7.4 x 10E-5

n.e.: not evaluable; *second measurement

 

The data points measured above 90 °C could not be evaluated. The data point at 90 °C showed a decreasing tendency. lt was assumed that the vapour pressure at these temperatures led to a significantly increased evaporation. This is in accordance to a nearly empty test cell after the test. In order to exclude an influence on the data points at lower temperatures the measurement was repeated.

 

Antoine parameters and extrapolated vapour pressures

 

T/°C	p/hPa	log (p/hPa) = A + B/(C+T[°C])
20	1.6 x 10E-5	A= 14.44975
25	3.3 x 10E-5	B= -5644.31
50	9.6 x 10E-5	C= 273.15

 

 

The following vapour pressure values for the test item were extrapolated from the experimental data

(vapour pressure: effusion method):

 

T/°C	p/hPa	p/Pa
20	1.6 x 10E-5	1.6x10*
25	3.3 x 10E-5	3.3 x 103
50	9.6 x 10E-5	9.6 x 102

 

Conclusions:

The vapour pressure of the test item was determined to be 1.6E-3 Pa at 20 °C, 3.3E-3 Pa at 25 °C and 9.6E-2 Pa at 50 °C, respectively.

Executive summary:

A study was conducted according to OECD TG 104 and Regulation (EC) No 440/2008 method A.4 to determine the vapour pressure of the test item using the effusion method: vapour pressure balance. The vapour pressure of the test item was determined at temperatures between 20 and 90 °C. Using the Antoine equation, the constants A and B were determined and the vapour pressure of the test item at 20, 25 and 50 °C was extrapolated from the experimental vapour pressure. The vapour pressure of the test item was determined to be 1.6E-3 Pa at 20 °C, 3.3E-3 Pa at 25 °C and 9.6E-2 Pa at 50 °C, respectively.

Description of key information

The vapour pressure of the test item was determined to be 1.6E-3 Pa at 20 °C, 3.3E-3 Pa at 25 °C and 9.6E-2 Pa at 50 °C, respectively.

Key value for chemical safety assessment

Vapour pressure:

0.003 Pa

at the temperature of:

25 °C

Additional information

A study was conducted according to OECD TG 104 and Regulation (EC) No 440/2008 method A.4 to determine the vapour pressure of the test item using the effusion method: vapour pressure balance. The vapour pressure of the test item was determined at temperatures between 20 and 90 °C. Using the Antoine equation, the constants A and B were determined and the vapour pressure of the test item at 20, 25 and 50 °C was extrapolated from the experimental vapour pressure. The vapour pressure of the test item was determined to be 1.6E-3 Pa at 20 °C, 3.3E-3 Pa at 25 °C and 9.6E-2 Pa at 50 °C, respectively.