3,4-dichlorophenyl isocyanate

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2022

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
Individual model MPBPWIN included in the Estimation Programs Interface (EPI) Suite.

2. MODEL (incl. version number)
MPBPWIN v1.44, 2000 - 2015 (February, 2015) 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: A 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 the substance is a solid, the model uses the melting point and the boiling point for estimation:
The following parameters were applied:
- Melting point: 42 °C (experimentally determined)
- Boiling point: 228 °C at 1013 hPa (experimentally determined)

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 188.011 g/mol the substance is within the applicable range of 16 - 943 g/mol. Regarding the structure, 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):
3,4-Dichlorophenylisocyanate 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 188.011 g/mol 3,4-dichlorophenylisocyanate is within the range of the training set (16 -– 943 g/mol).
ii. Structural fragment domain: Regarding the structure, 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. Adequacy of prediction: The result for 3,4-dichlorophenylisocyanate falls within the applicability domain described above and the estimation rules applied for the substance appears appropriate. Therefore the predicted value can be considered reliable yielding a useful result for further assessment.
e. 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 initially online in November 2012.

GLP compliance:

no

Type of method:

other: QSAR

Key result

Temp.:

25 °C

Vapour pressure:

7.62 Pa

Remarks on result:

other: Modified Grain method

Validity of the model:

1. Defined Endpoint: Vapour pressure

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

3. Applicability domain: Because an experimental boiling and melting point is available for the substance the applicablity domain is just described by the molecular weight range. With a molecular weight of 188.011 g/mol the substance is within the applicable range of 16 - 943 g/mol.

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.

Adequacy of prediction: The result for 3,4-dichlorophenylisocyanate falls within the applicability domain described above and the estimation rules applied for the substance appears 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 3,4-dichlorophenylisocyanate using the model MPBPWIN included in the Estimation Program Interface (EPI) Suite v4.11 revealed a value of 7.62 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Executive summary:

The vapour pressure of 3,4-dichlorophenylisocyanate was predicted using the QSAR calculation of the Estimation Programm Interface EPI-Suite v4.11. The experimental melting point of 42°C (experimentally determined; Weight of evidence: ChemSafe, 2008; Six C., Richter F., 2005 (Ullmann's); Daubert, T.E. et. al, 1989) and boiling point of 228°C (experimentally determined; Weight of evidence: ChemSafe, 2008; Six C., Richter F., 2005 (Ullmann's); Daubert, T.E. et. al, 1989) were taken into account for estimation. Using the modified Grain method, the vapour pressure was estimated to be 7.62 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Reference 2

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Due to insufficient reporting of the experimental details, this study was rated with a Klimisch score of 4 ("not assignable"). As none of the available studies can serve as a key study with sufficiently detailed reporting justifying a Klimisch score of 1 or 2 for the given endpoint, several independent sources were used in a weight of evidence approach. The combinied data from handbooks or collection of data provided experimental values in a similar range, supporting the reliability of the result.

Principles of method if other than guideline:

no data

Type of method:

other: no data

Specific details on test material used for the study:

purity not specified

Key result

Temp.:

43 °C

Vapour pressure:

0.746 hPa

Executive summary:

The vapour pressure for 3,4 -dichlorophenyl isocyanatobenzene is 0.746 hPa (74.6 Pa) at 43°C (Daubert, 1989).

Description of key information

QSAR (Seel, Currenta, 2022)

The vapour pressure of 3,4-dichlorophenylisocyanate was predicted using the QSAR calculation of the Estimation Programm Interface EPI-Suite v4.11. The experimental melting point of 42°C (experimentally determined; Weight of evidence: ChemSafe, 2008; Six C., Richter F., 2005 (Ullmann's); Daubert, T.E. et. al, 1989) and boiling point of 228°C (experimentally determined; Weight of evidence: ChemSafe, 2008; Six C., Richter F., 2005 (Ullmann's); Daubert, T.E. et. al, 1989) were taken into account for estimation. Using the modified Grain method, the vapour pressure was estimated to be 7.62 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Daubert, 1989

The vapour pressure for 3,4-dichlorophenylisocyanate was experimentally determined as 74.6 Pa at 43°C.

EPI-Suite v4.11 cites an exptrapolated value of 66.7 Pa at 25 °C (extrapolated from an experimental vapour pressure reported in the reference: Daubert, 1989)

As the value obtained by QSAR calculation and the experimental value reported by Daubert, 1989 differ in an order of magnitude, the highest value (worst case assumption) is chosen as key value for chemical safety assessment.

Key value for chemical safety assessment

Vapour pressure:

74.6 Pa

at the temperature of:

43 °C