Registration Dossier

Administrative data

Endpoint:
vapour pressure
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 104 (Vapour Pressure Curve)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.4 (Vapour Pressure)
Deviations:
no
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
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 1,2,4-Benzenetricarboxylic acid, decyl octyl ester (CAS No. 67989-23-5) / 1,2,4-Benzenetricarboxylic acid, mixed decyl and octyl triesters (CAS No. 90218-76-1)
- Molecular weight: 546 - 630 g/mol
- Substance type: not mentioned
- Physical state: liquid
- Analytical purity: > 97.5%
- Impurities (identity and concentrations): not mentioned
- Composition of test material, percentage of components: 97.5% 1,2,4-Benzenetrecarboxylic acid, decyl octyl ester
- Isomers composition: not mentioned
- Purity test date: not mentioned
- Lot/batch No.: 3103
- Sampling date: not mentioned
- Expiration date of the lot/batch: 1 years after production (2009-06-11)
- Stability under test conditions: not known
- Storage condition of test material: room temperature (20 ± 5°C)
- Other:
Production date: 2007-06-12

Results and discussion

Vapour pressureopen allclose all
Temp.:
ca. 20 °C
Vapour pressure:
ca. 0 Pa
Remarks on result:
other: Calculated from the regression equation
Temp.:
ca. 25 °C
Vapour pressure:
ca. 0 Pa
Remarks on result:
other: Calculated from the regression equation

Any other information on results incl. tables

Findings and Results

The vapour pressure of the stuctural related substance 1,2,4-Benzenetricarboxylic acid, decyl octyl ester (CAS No 67989 -23 -5) / 1,2,4 -Benzenetricarboxylic acid, mixed decyl and octyl triesters (CAS No 90218 -76 -1) was determined following EU A.4 using the effusion method (weight loss)

Two runs were performed.

In the first run with seven experiments, vapour pressure was determined at seven different temperatures. At lower temperatures no weight loss was detected. At the temperaures 125 and 140 °C (nominal), weight loss was found, but it was badly reproducible. It was suspected that other test items wich hat shown weight loss at lower temperatures might have influenced the result by contaminating the Knudsen cells. Therefore, it was decided to repeat the experiment.

In the second run with two experimens, vapour pressure was determined at the nominal temperatures 125 °C and 140 °C only. Significant and better reproducible weight loss was found. As higher temperatures could not be measured due to the limits of the test system and lower temperatures would not yield significant weight loss, regression was performed over these two temperatures.

The following values were determined experimentally:

Vapour Pressures (Effusion Method)

 Experiment  T  P  Stand. Dev. P  RSD P
 No.  K  Pa  Pa  %
1  389.3 3.79E-04   1.59E-04  41.8%
 2  403.5  9.47E-04  2.67E-04  28.2%

In this table, E-04 represents multiplication with 10 -4.

Evaluation

Vapour pressures at 20 °C and 25 °C were calculated from the regression equation with:

Vapour pressure at 20 °C: 7.50 * 10 -8 Pa

Vapour pressure at 25 °C: 1.34 * 10 -7 Pa

Both experiments showed medium repeatability within the four replicates. Both values lie below the threshold of 10 -5 Pa.

Discussion

All measured values show medium reproducibility: relative standard deviation was approx. 30 - 40%: This is attributed to the low vapour pressure as well as to the composition of the test item (mixture). The calculated value for the vapour pressure at 20°C using the estimation by the software EpiWin is almost the same as the value which was determined using the regression linear. Both values lie below the threshold of 10 -5 Pa.

No significant impact on the assessment of the test item's behaviour in the environment is expected from the remaining uncertainty in vapour pressure.

The result of the test is considered valid.

Applicant's summary and conclusion

Conclusions:
The vapour pressure of 1,2,4 -benzenetricarboxylic acid, mixed dodecyl and octyl triesters was not specifically determined. However, data are available for a structurally related material (1,2,4-Benzenetricarboxylic acid, decyl octyl ester), the only difference being the presence of esters with a shorter alkyl chain (C10 instead of C12). Due to the structural similarity of the test substance compared to the submission substance the available data can be used for read-across.