Octadecanoic acid, C16-18-alkyl esters

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

The substance is not fully compliant with the applicability domain of the model. However, this calculation is used in a weight of evidence approach, in accordance to the REACh Regulation (EC) No 1907/2006, Annex XI General rules for adaptation of the standard testing regime set out in Annexes VII to X, 1.2. It is adequately documented and justified: the overall internal quality check in VEGA v1.1.4 indicates that the prediction is reliable with a Klimisch score of 2.

Justification for type of information:

1. SOFTWARE
VEGA version 1.1.4

2. MODEL (incl. version number)
ALogP Model v. 1.0.0

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer. Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on results incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: VEGA v1.1.4
- Model(s) used: ALogP Model version 1.0.0
The model is based on the Ghose-Crippen-Viswanadhan LogP (ALogP) and consists of a regression equation based on the hydrophobicity contribution of 120 atom types as described in: A.K. Ghose and G.M. Crippen, J. Comput. Chem. 1986, 7, 565-577; V.N. Viswanadhan et al., J. Comput. Chem. 1993, 14, 1019-1026; A.K. Ghose, V.N. Viswanadhan, J.J. Wendoloski, J. Phys. Chem. A 1998, 102, 3762-3772. For the purpose of applicability domain assessment, the training set of the Meylan LogP model (9,961 compounds) has been considered, setting all molecules as belonging to the test set.
- Model description: see field 'Justification for type of information', 'Attached justification' and 'any other information on Material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Type of method:

other: QSAR

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

> 10

Remarks on result:

other: QSAR result, no information on temperature and pH available.

For detailed information on the results please refer to the attached report.

Reference 2

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

The substance is not fully compliant with the applicability domain of the model. However, this calculation is used in a weight of evidence approach, in accordance to the REACh Regulation (EC) No 1907/2006, Annex XI General rules for adaptation of the standard testing regime set out in Annexes VII to X, 1.2. It is adequately documented and justified: the overall internal quality check in VEGA v1.1.4 indicates that the prediction is reliable with a Klimisch score of 2.

Justification for type of information:

1. SOFTWARE
VEGA version 1.1.4

2. MODEL (incl. version number)
ALogP Model v. 1.0.0

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer. Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on results incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: VEGA v1.1.4
- Model(s) used: ALogP Model version 1.0.0
The model is based on the Ghose-Crippen-Viswanadhan LogP (ALogP) and consists of a regression equation based on the hydrophobicity contribution of 120 atom types as described in: A.K. Ghose and G.M. Crippen, J. Comput. Chem. 1986, 7, 565-577; V.N. Viswanadhan et al., J. Comput. Chem. 1993, 14, 1019-1026; A.K. Ghose, V.N. Viswanadhan, J.J. Wendoloski, J. Phys. Chem. A 1998, 102, 3762-3772. For the purpose of applicability domain assessment, the training set of the Meylan LogP model (9,961 compounds) has been considered, setting all molecules as belonging to the test set.
- Model description: see field 'Justification for type of information', 'Attached justification' and 'any other information on Material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Type of method:

other: QSAR

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

> 10

Remarks on result:

other: QSAR result, no information on temperature and pH available.

For detailed information on the results please refer to the attached report.

Reference 3

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Remarks:

Estimation based on solubility on 1-octanol and in water

Adequacy of study:

weight of evidence

Study period:

27 Mar 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The water solubility used for the estimation of log Pow is below the detection limit of the analytical method. A clear log Pow cannot therefore estimated.

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: EU Method A.8 - Appendix 1 (Partition Coefficient - Estimation method)

Version / remarks:

May 2008

Qualifier:

according to guideline

Guideline:

other: Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint specific guidance

Version / remarks:

Version 4.1, October 2015

GLP compliance:

no

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

> 5.76

Temp.:

20 °C

pH:

6.3

Remarks on result:

other: estimated from solubility in water and 1-octanol

Details on results:

Solubility in water and 1-octanol were both performed at 20 °C
pH 6.3 was measured during the water solubility study.

Pow = solubility of test item in 1-octanol / solubility of test item in water

Pow = 2.9 g/L / <5µg/L > 2.9 g/L / 0.000005 g/L = 5.8E5

log Pow > 5.76

 

The partition coefficient of the test item was calculated from the individual solubilities in 1-octanol and water at 20 °C, respectively. The log Pow value can be reported as:

log Pow > 5.76

Description of key information

Log Pow > 10 (Weight of Evidence: Estimation method according to EU A.8 and QSAR calculation (EPI Suite / KOWWIN version 1.68))

Additional information

A log Pow > 5.76 has been estimated for the target substance, based on its measured solubility in 1-octanol and in water. The estimated value is a lower limit, because the water solubility was not clearly determined (< 5µg/L), as it was below the quantification limit of the analytical method. The octanol/water partition coefficient has been further evaluated based on the QSAR estimates for two representative structures of the target substance: “Octadecanoic acid, octadecyl ester” and “Octadecanoic acid, octadecyl ester”. The following log Pow were calculated by VEGA ALogP model v1.0.0: 16.58 and 15.6. Experimental and predicted log Pow values of similar molecules retrieved by the VEGA software support the reliability of the obtained values, in terms of log Pow being higher than 10.

Considering the available results, a log Pow > 10 is considered as a reasonable estimation for the substance as a whole.