Registration Dossier

Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 104 (Vapour Pressure Curve)
GLP compliance:
yes (incl. certificate)
Type of method:
effusion method: by loss of weight or by trapping vaporisate

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline

Results and discussion

Vapour pressure
Key result
Remarks on result:
other: Vapor pressure could not be determined. The results given by the measurements indicate vapor pressure values at temperatures of 50°C and lower below (2±1 )*10-6hPa.
Vapour pressure at 50°C (if relevant for classification of gas under pressure)
Key result
Vapour pressure:
< 0 hPa

Any other information on results incl. tables

Vapor pressure could not be determined.

The results given by the measurements indicate vapor pressure values at temperatures of 50°C and lower below (2±1 )*10 -6hPa.

Molar mass used: 106.39 g/mol.

The data given by the measurements were inconclusive. The mass differences recorded seem to be caused by water adhering to the test item while it was cooling down from the measuring temperature in order to weigh the measuring cells.

So an error analysis was conducted for the measurements at approximately 116°C.

The vapor pressures are calculated assuming a weighing error of + 1 mg. The assumption is based on the measured weight gain of 1 mg at measurement 2 due to the hygroscopic characteristic of the test item.

Furthermore, it is supposed that the weighing error only occurs while the test item is removed from the measuring equipment and cooled down in order to weigh it, since bringing the test item into the measuring equipment is much faster.

Furthermore, it is assumed that the water absorbed during removal is completely evaporated in the following measurement step within a short time. This is justified by the first measurement with a

running time of 1186 minutes. More than 2wt% of the test item used escaped during this time. The further total measuring time of 21398 minutes results in a maximum of 0.12wt% mass lass and the measurement time of each of these measurements is at least 2.5 times langer than that of the first (1186 minutes). So it is stated that a mass of 1 mg water, which is less than 0.1 wt% of the test items mass, will evaporate in much less than 1186 minutes.

With these assumptions and assuming the weighing error occurs statistically distributed the maximum possible vapor pressure of the test item can be estimated to be (2±1)*10-6hPa at t = 116 ° C.

As the vapor pressure decreases with decreasing temperature, this maximum value does also apply for temperatures below 116°C.

Applicant's summary and conclusion