Barium(2+) 12-hydroxyoctadecanoate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

key study

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:

Please refer to the QMRF and QPRF files provided under the section 'Attached justification'.

Qualifier:

according to guideline

Guideline:

other: ECHA Guidance on information requirements and chemical safety assessment Chapter R.6: QSARs and grouping of chemicals

Version / remarks:

May 2008

Deviations:

no

Principles of method if other than guideline:

Estimates the log octanol-water partition coefficient, log KOW, of chemicals using an atom/fragment contribution method.

GLP compliance:

no

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SMILES: O[C@@H](CCCCCC)CCCCCCCCCCC([O-])=O.O[C@@H](CCCCCC)CCCCCCCCCCC([O-])=O.[Ba+2]

Key result

Type:

log Pow

Partition coefficient:

6.41

Temp.:

25 °C

Remarks on result:

other: QSAR predicted value. The substance is within the applicability domain of the model.

Log Kow (version 1.68 estimate): 6.41

 

SMILES : OC(CCCCCC)CCCCCCCCCCC(=O)(O)

CHEM  :

MOL FOR: C18 H36 O3

MOL WT : 300.49

 

TYPE	NUM	LOGKOW FRAGMENT DESCRIPTION	COEFF	VALUE
Frag	1	-CH3   [aliphatic carbon]	0.5473	0.5473
Frag	15	-CH2-  [aliphatic carbon]	0.4911	7.3665
Frag	1	-CH    [aliphatic carbon]	0.3614	0.3614
Frag	1	-OH    [hydroxy, aliphatic attach]	-1.4086	-1.4086
Frag	1	-COOH  [acid, aliphatic attach]	-0.6895	-0.6895
Const		Equation Constant		0.2290

                                                        Log Kow  =  6.4061

Conclusions:

Using KOWWIN v1.68 the logPow of the test item was calculated to be 6.41 at 25 °C. The substance is within the applicability domain of the model.

Executive summary:

The logPow was calculated using KOWWIN v1.68 as part of EPISuite v4.11 from US Environmental Protection Agency.

Using KOWWIN v1.68 the log Kow of the test item was calculated to be 6.41 at 25 °C (EPI Suite, 2014).

 

The adequacy of a prediction depends on the following conditions:

a) the (Q)SAR model is scientifically valid: the scientific validity is established according to the OECD principles for (Q)SAR validation;

b) the (Q)SAR model is applicable to the query chemical: a (Q)SAR is applicable if the query chemical falls within the defined applicability domain of the model;

c) the (Q)SAR result is reliable: a valid (Q)SAR that is applied to a chemical falling within its applicability domain provides a reliable result;

d) the (Q)SAR model is relevant for the regulatory purpose.

 

For assessment and justification of these 4 requirements the QMRF and QPRF files were developed and attached to this study record.

 

Description of the prediction Model

The prediction model was descripted using the harmonised template for summarising and reporting key information on (Q)SAR models. For more details please refer to the attached QSAR Model Reporting Format (QMRF) file. 

 

Assessment of estimation domain

The assessment of the estimation domain was documented in the QSAR Prediction Reporting Format file (QPRF). Please refer to the attached document for the details of the prediction and the assessment of the estimation domain.

Description of key information

Using KOWWIN v1.68 the logPow of the test item was calculated to be 6.41 at 25 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

6.41

at the temperature of:

25 °C

Additional information

Using KOWWIN v1.68 the logPow of the test item was calculated to be 6.41 at 25 °C. The substance is within the applicability domain of the model.

Based on the ionic bindings of the Barium, it is assumed, that the molecule dissociates in aqueous solution. Therefore, calculation of the log Pow is based on the structure of 12-Hydroxyoctadecanoic acid (CAS 106-14-9) as scientific plausible approximation.

 

In addition, a study was conducted in accordance with OECD TG 107 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the shake flask method. It was technically not feasible to establish a substance specific method for the complex test substance. Thus, the equilibrium concentration of the test substance in both phases was determined by means of ICP. The samples in the octanol phase and the water phase were diluted and analysed using ICP-OES. Based on the measured barium content in the aqueous phase the Pow of the test substance was determined to be 0.6 ± 0.1 (95 % confidence interval) at 20 °C, the log Pow calculated to be -0.23, respectively.

Since the test material could not be brought into solution, the analysis of the barium content was the only experimental possibility. A microwave digestion was carried out and the barium content was analysed. Since only free barium ions and not an organic compound can be determined in this way, the result obtained does not represent the properties of the whole substance. According to Annex VII, point 7.8, column 2 of the REACH Regulation, the study does not need to be conducted if the substance does not dissolve in water or in octanol. Against this background, the result of the QSAR calculation was considered as key study, since here the complete substance is taken into account. The experimental determination was added as a supporting study.