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Administrative data

Endpoint:
vapour pressure
Type of information:
experimental study
Adequacy of study:
key study
Study period:
March-April 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019
Report date:
2019

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method A.4 (Vapour Pressure)
Qualifier:
according to guideline
Guideline:
OECD Guideline 104 (Vapour Pressure Curve)
GLP compliance:
yes (incl. QA statement)
Type of method:
effusion method: isothermal thermogravimetry

Test material

Constituent 1
Chemical structure
Reference substance name:
2-[2,4-bis(tert-pentyl)phenoxy]-N-(3,5-dichloro-4-ethyl-2-hydroxyphenyl)butyramide
EC Number:
300-634-0
EC Name:
2-[2,4-bis(tert-pentyl)phenoxy]-N-(3,5-dichloro-4-ethyl-2-hydroxyphenyl)butyramide
Cas Number:
93951-12-3
Molecular formula:
C28H39Cl2NO3
IUPAC Name:
2-[2,4-bis(tert-pentyl)phenoxy]-N-(3,5-dichloro-4-ethyl-2-hydroxyphenyl)butyramide
Test material form:
solid
Details on test material:
Batch 44029
colour : White to off-white
retest date : 01/06/2019

Results and discussion

Vapour pressure
Key result
Test no.:
#1
Temp.:
20 °C
Vapour pressure:
0 Pa

Any other information on results incl. tables

The evaporation rate of the test item (VT) is calculated from the weight loss of the test item at defined temperatures in a constant stream of nitrogen over periods of time. Linear regression analysis of log VT versus 1/T (1000/T) is performed for the test item and for each reference item. The evaporation rates at 20 °C (VT, 20) are determined from these relationships. The relationship between the values of VT, 20 of the reference items and their known vapour pressures is estab-lished as a regression equation. The relationship between evapora-tion rate and vapour pressure, derived for 20 °C, includes the charac-teristics of the experimental setup, which are subsequently employed in the calculation of vapour pressure values at other temperatures.

VT= ΔmF∙t [g∙cm−2∙h−1]

where:

VT = evaporation rate [g∙cm−2∙h−1]

Δm = weight loss of the test item [g]

F = surface of the sample plate [cm2]

t = elapsed time for the weight loss [h]

Evaporation Rate Curve: log VT=a∙1000T+b

where:

a = slope

b = intercept

VT = evaporation rate [g∙cm−2∙h−1]

T = temperature [K]

The evaporation rates at VT 20 °C of the reference items are used to establish a regression of log PT ver-sus log VT, which characterizes the specific experimental setup. From this regression equation the va-pour pressure PT of the test item as a function of temperature is calculated based on the determined evaporation rate. logPT=C+D∙log VT

where:

PT = vapour pressure [Pa]

VT = evaporation rate [g∙cm−2∙h−1]

C, D = intercept and slope as constants specific for experi-mental set up determined from regression curve

Applicant's summary and conclusion

Conclusions:
The isothermal thermogravimetrical effusion method was applied for the deter-mination of the vapour pressure of the test item.
A value of the vapour pressure of the test item was determined using the data obtained between 160 °C and 190 °C. The vapour pressure of the test item was estimated to be 3.78 x 10-7 Pa at 20 °C.
Executive summary:

The evaluation of the vapour pressure was done with the reproducible weight loss values above > 1 μg/min in the temperature range between 160 °C and 200 °C.

The coefficient of correlation (R2) was 0.9981.

The coefficient of correlation (R2) was 0.9925.

The resulting equation was:

log PT=4.7740+1.1295∙log VT

Inserting the equation for log VT above, the following equation for the tempera-ture dependence of the vapour pressure of the test item is obtained:

log PT=C+D∙(a∙1000T +b)= C+(D∙b)+(D∙a∙1000 )/T

(where: a = -5.4828, b = 8.7997, C = 4.7740 and D = 1.1295)

With this equation, a following vapour pressure results were obtained:

3.78 x 10-7 Pa at 20 °C.