2,2-dimethylpropane-1,3-diyl dibenzoate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Accepted calculation method

Justification for type of information:

Justification for type of information
1. SOFTWARE
Individual model MPBPWIN included in the Estimation Programs Interface (EPI) Suite.

2. MODEL (incl. version number)
MPBPWIN v1.43 included in EPISuite v 4.11, 2000 - 2012
The modified Grain method.

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
a. Input for prediction:
The CAS Number was entered in the initial data entry screen. In the structure window, the molecular weight, structural formula and the structure of the input SMILES notation is shown. If available, experimental determined values of melting point and boiling point are taken for input.
b. Descriptor values:
As 2,2-dimethylpropane-1,3-diyl dibenzoate is a solid, the model uses the melting point and the boiling point for estimation.
The following parameters were applied:
Melting point: 46.5°C (experimental, see Study report 2014/00243)
Boiling point: 375.86°C (estimated, EPIWIN v4.11)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
a. Defined endpoint:
Vapour pressure
b. Unambigous algorithm:
The modified Grain method equation was used for calculation.
c. Applicability domain:
With a molecular weight of 312.37 g/mole 2,2-dimethylpropane-1,3-diyl dibenzoate is within the range of the training set (16 - 943). Regarding the structure of 2,2-dimethylpropane-1,3-diyl dibenzoate, the fragment descriptors used by the program for the estimation of the boiling point are complete and listed in Appendix F of the MPBPWIN help file.
d. Statistical characteristics:
Correlation coefficient of the total test set is r2= 0.949.
e. Mechanistic interpretation:
The vapour pressure is related to fugacity models describing the distribution of the substance in the environment.
f. The uncertainty of the prediction (OECD principle 4):
2,2-dimethylpropane-1,3-diyl dibenzoate is not highly complex and the rules applied for the substance appear appropriate. An individual uncertainty for the investigated substance is not available.

5. APPLICABILITY DOMAIN
a. Domains:
i. Molecular weight:
With a molecular weight of 312.37 g/mole 2,2-dimethylpropane-1,3-diyl dibenzoate is within the range of the training set (16 - 943).
ii. Structural fragment domain:
Regarding the structure of 2,2-dimethylpropane-1,3-diyl dibenzoate, the fragment descriptors used by the program for the estimation of the boiling point are complete and listed in Appendix F of the MPBPWIN help file.
iii. Mechanism domain:
No information available
iv. Metabolic domain, if relevant:
Not relevant
b. Structural analogues:
No information available
c. Considerations on structural analogues:
No information available

6. ADEQUACY OF THE RESULT
a. Regulatory purpose:
The data may be used under any regulatory purpose.
b. Approach for regulatory interpretation of the model result:
If no experimental data are available the estimated value may be used to fill data gaps needed for hazard and risk assessment. Further the value is used for other calculations.
c. Outcome:
The prediction of vapour pressure yields a useful result for further evaluation.
d. Conclusion:
The result is considered as useful for regulatory purposes.

Guideline:

other: REACH guidance on QSARs R.6, May 2008

Principles of method if other than guideline:

The Estimation Program Interface (EPI) Suite v4.11 includes the model MPBPWIN for estimating the vapour pressure of organic compounds. The Estimation Programs Interface was developed by the US Environmental Agency's Office of Pollution Prevention and Toxics and Syracuse Research Corporation (SRC). © 2000 - 2012 U.S. Environmental Protection Agency for EPI SuiteTM. Published online in November 2012.

GLP compliance:

no

Type of method:

other: QSAR

Specific details on test material used for the study:

DESCRIPTOR VALUES APPLIED IN THE MODEL:
- SMILES: O=C(OCC(C)(C)COC(=O)c(cccc1)c1)c(cccc2)c2 (values relate to the pure substance)
- Melting point: 46.5°C (exp.)
- Boiling point: 375.86°C (calc.)

Temp.:

25 °C

Vapour pressure:

0.003 Pa

Remarks on result:

other: modified Grain method

VALIDITY OF THE MODEL:

1. Defined Endpoint: Vapour pressure

2. Unambigous algorithm: The modified Grain methodequation was used for calculation.

3. Applicability domain: Because an experimental melting point is available for 2,2-dimethylpropane-1,3-diyl dibenzoate the applicablity domain is just described by the molecular weight range. With a molecular weight of 312.37 g/mole 2,2-dimethylpropane-1,3-diyl dibenzoate is within the applicable range of 16 - 943 g/mole.

4. Statistical characteristics: Correlation coefficient of the total test set is r2= 0.949.

5. Mechanistic interpretation: The vapour pressure is related to fugacity models describing the distribution of the substance in the environment.

6. Adequacy of prediction: The result for 2,2-dimethylpropane-1,3-diyl dibenzoate falls within the applicability domain described above and the estimation applied rules appear appropriate. Therefore the predicted value can be considered reliable yielding a useful result for further assessment.

 

Conclusions:

The QSAR determination of the vapour pressure of 2,2-dimethylpropane-1,3-diyl dibenzoate using the model MPBPWIN included in the Estimation Program Interface (EPI) Suite v4.11 revealed a value of 0.0027 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Executive summary:

The vapour pressure of 2,2-dimethylpropane-1,3-diyl dibenzoate was predicted using the QSAR calculation of the Estimation Programm Interface (EPI) Suite v4.11. The experimental melting point of 46.5°C and the calculated boiling point of 375.86°C were taken into account for estimation. Using the modified Grain method, the vapour pressure was estimated to be 0.0027 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Description of key information

The QSAR determination of the vapour pressure of 2,2-dimethylpropane-1,3-diyl dibenzoate using the model MPBPWIN included in the Estimation Program Interface (EPI) Suite v4.11 revealed a value of 0.0027 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Key value for chemical safety assessment

Vapour pressure:

0.003 Pa

at the temperature of:

25 °C

Additional information

No experimental data on vapour pressure for 2,2-dimethylpropan-1,3-diyl dibenzoate are available.

In order to predict the thermodynamic equilibrium of 2,2-dimethylpropan-1,3-diyl dibenzoate the vapour pressure was calculated using estimation methods following the recommendations of the ECHA guidance on information requirements and chemical safety assessment, chapter R.7a: Endpoint specific guidance document R.7a (ECHA, 2014).

The vapour pressure of 2,2-dimethylpropane-1,3-diyl dibenzoate was predicted using the QSAR calculation of the Estimation Programm Interface (EPI) Suite v4.11. The experimental melting point of 46.5°C was taken into account for estimation. Using the modified Grain method, the vapour pressure was estimated for 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.