Registration Dossier

Administrative data

Endpoint:
vapour pressure
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2 December 1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method A.4 (Vapour Pressure)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
effusion method: vapour pressure balance

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: solid mass
Details on test material:
MMBC
Physical state: light brown solid

Results and discussion

Vapour pressure
Temp.:
25 °C
Vapour pressure:
0.34 Pa

Any other information on results incl. tables

Vapour Pressure Measurement by Mass Difference

 

RUN 1

A plot of Log(Vapour Pressure / Pa) vs Reciprocal Temperature (K / T) for Run 1 gives the following statistical data using an unweighted least squares treatment:

Slope: -3623.325

Intercept: 11.751

Standard deviation in Slope: 376.294

above as % of Slope: 10.385

Standard deviation in Intercept: 1.261

above as % of Intercept: 10.730

 

The results obtained indicate the following Vapour Pressure relationship:

Log Vp(Pa) = (-3623.325 (± 376.294) / Temp (K)) + 11.751 (± 1.261)

This yields a calculated vapour pressure of Vp(298.15 K) = 3.964^-01 Pa (-1.124^-03 / + 1.127^-03)

 

RUN 2

Slope: -2870.947

Intercept: 9.079

Standard deviation in Slope: 67.042

above as % of Slope: 2.335

Standard deviation in Intercept: 0.223

above as % of Intercept: 2.451

 

The results obtained indicate the following Vapour Pressure relationship:

Log Vp(Pa) = (-2870.947 (± 67.042) / Temp (K)) + 9.079 (± 0.23)

This yields a calculated vapour pressure of Vp(298.15 K) = 2.818^-01 Pa (-1.500^-03 / + 1.508^-03)

 

RUN 3

Slope: -913.376

Intercept: 1.742

Standard deviation in Slope: 77.903

above as % of Slope: 8.529

Standard deviation in Intercept: 0.260

above as % of Intercept: 14.927

 

The results obtained indicate the following Vapour Pressure relationship:

Log Vp(Pa) = (-913.376 (± 77.903) / Temp (K)) + 1.742 (± 0.260)

This yields a calculated vapour pressure of Vp(298.15 K) = 4.771^-02 Pa (-1.375E-04 / + 1.379^-04)

 

DISCUSSION

The solid sample was maintained below 39.5 °C during experiments and the small amount remaining showed no signs of melting or decomposition. The sample did not condense onto the balance pan. For stability reasons the temperature range was restricted.

 

The initial measured mass difference of Run 1 was 162.5 ug at 15.1 °C (equivalent to about 2.1 x 10^-1 Pa) with values rising to a maximum of 993 µg (equivalent to around 1.3 Pa) at 37.25 °C. Run 1 measured mass difference data gave a vapour pressure relationship yielding the rounded value Vp (25 °C) = 3.96 ± 0.01 x 10^-1 Pa as the interpolated vapour pressure.

 

After pumping during recooling, the initial measured mass difference of Run 2 was 128 µg at 18.35 °C (equivalent to about 1.7 x 10^-1 Pa) with values rising ultimately to 547 µg at 38.35 °C (equivalent to around 7.1 x 10^-1 Pa). Run 2 measured mass difference data gave a vapour pressure relationship yielding the rounded value Vp (25 °C) = 2.82 ± 0.015 x 10^-1 Pa as the interpolated vapour pressure.

 

After pumping during recooling, the initial measured mass difference of Run 3 was 27.2 µg at 15.5 °C (equivalent to about 3.5 x 10^-2 Pa) with values rising to 50 µg at 39.5 °C. Run 3 measured mass difference data gave a vapour pressure relationship yielding the rounded value Vp (25 °C) = 4.77 ± 0.015 x 10^-2 Pa as the interpolated vapour pressure.

 

Taking into account the small amount remaining on final inspection after Run 3 the rounded mean of the Run 1 and 2 values, Vp (25 °C) = 3.40 x 10^-1 Pa is the recommended vapour pressure.

Applicant's summary and conclusion

Conclusions:
The vapour pressure of the test substance at 25 °C was determined to be 3.40 x 10^-1 Pa.
Executive summary:

The vapour pressure of the test substance was determined in accordance with standardised guideline EU Method A.4 using the vapour pressure balance. Under the conditions of the test, the vapour pressure of the test substance at 25 °C was determined to be 3.40 x 10^-1 Pa.