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Administrative data

Endpoint:
vapour pressure
Type of information:
experimental study
Adequacy of study:
key study
Study period:
14 December 2017 - 08 February 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method A.4 (Vapour Pressure)
Version / remarks:
2016
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 104 (Vapour Pressure Curve)
Version / remarks:
2006
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 830.7950 (Vapor Pressure)
Version / remarks:
1996
Deviations:
no
GLP compliance:
yes
Type of method:
effusion method: isothermal thermogravimetry

Test material

Constituent 1
Chemical structure
Reference substance name:
Pregnenolone
EC Number:
205-647-4
EC Name:
Pregnenolone
Cas Number:
145-13-1
Molecular formula:
C21H32O2
IUPAC Name:
3-hydroxypregn-5-en-20-one
Test material form:
solid: particulate/powder
Details on test material:
- Physical appearance: white crystalline powder
- Storage conditions: at room temperature
Specific details on test material used for the study:
Melting temp.:189 - 195°C

Results and discussion

Vapour pressureopen allclose all
Key result
Temp.:
20 °C
Vapour pressure:
0 Pa
Key result
Temp.:
25 °C
Vapour pressure:
0 Pa

Any other information on results incl. tables

Table: Results of the isothermal TGA analysis (test item)

Temperature [°C]

Weight loss [µg/min]

νT

[g/cm2/h]

log νT

log PT

PT[Pa]

140

0.701966

8.38·10-5

-4.08

-0.08

0.83

 

0.809180

9.66·10-5

-4.02

0.00

0.99

150

1.41318

1.69·10-4

-3.77

0.31

2.0

 

1.42740

1.70·10-4

-3.77

0.31

2.1

160

3.17049

3.78·10-4

-3.42

0.76

5.7

 

3.17974

3.80·10-4

-3.42

0.76

5.7

170

7.05687

8.42·10-4

-3.07

1.20

16

 

7.13113

8.51·10-4

-3.07

1.21

16

Applicant's summary and conclusion

Conclusions:
The vapour pressure of the substance at 20°C was determined to be 2.2E-8 Pa.
The vapour pressure of the substance at 25°C was determined to be 6.0E-8 Pa.
Executive summary:

The vapour pressure of the substance was determined using the isothermal thermogravimetric effusion method in a GLP study according to EC A.4, OECD 104 and OPPTS 830.7950.

The constants specific for the experimental arrangement were determined using a set of 5 reference compounds. A vapour pressure curve for the test item was constructed from duplicate measurements at 140°C, 150°C, 160°C and 170°C. The vapour pressure of the substance at 20°C and 25°C was calculated by extrapolation to be 2.2E-8 Pa and 6.0E-8 Pa, resp.