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Physical & Chemical properties

Partition coefficient

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Endpoint:
partition coefficient
Data waiving:
study technically not feasible
Justification for data waiving:
other:
Justification for type of information:
The substance is a complex mixture, which contains a large number of constituents, which are mostly unkown but which have different solubility (often low solubility) and volatility. In addition its physical state leads to difficulties for physico-chemical testing: It is described a brown red solid.

Endpoint:
partition coefficient
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
run on 2018
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 limited documentation / justification
Justification for type of information:
QSAR prediction : The values obtained on known constituents of the substance are not experimental results, however the QSAR model is recommended by the ECHA guidance document on information requirements, is well documented with regard to validation parameters according to OECD principles. Moreover, the constituents of the substance are fully characterised towards the applicability domain.
Reason / purpose:
reference to other study
Principles of method if other than guideline:
QSAR estimation
Partition coefficient type:
octanol-water
Type:
log Pow
Partition coefficient:
>= -0.14 - <= 6.27
Remarks on result:
other: Temperature and pH not provided (QSAR estimation)
Remarks:
Range of logKow estimated on a the known constituents of the substance

Temperature and pH values are not considered in this model.

The estimation is based on the non-ionised form of the molecule.

No Experimental Value Adjustment was made.

The molecular weight of the constituents are between 46.07 and 222.37 g/mol, hence within the estimation domain of the validation set (27.03 -991.15 g/mol), all the functional groups are included in the list of descriptors, and, the occurence of each fragment is below or very closed to the maximum number in the training/validation sets (Appendix D), such as:

    Training Set Validation Set
Fragment Descriptor & Correction Factor Descriptor Coef Max Number Max Number
-CH3 [aliphatic carbon] 0,5473 13 1401 20 7413
-CH2-   [aliphatic carbon] 0,4911 18 1083 28 7051
-CHO    [aldehyde, aliphatic attach] -0,9422 1 8 2 30
-CH   [aliphatic carbon] 0,3614 16 460 23 3864
 =CH- or =C<  [olefinc carbon] 0,3836 10 239 10 1847
-COOH   [acid, aliphatic attach]  -0,6895 3 126 3 672
-tert Carbon [3 ot more carbon attach] 0,2676 4 130 8 1381
Fused aliphatic ring unit correction  -0,3421 8 41 8 684
-OH   [hydroxy, aliphatic attach] -1,4086 6 187 9 1525
 -O- [oxygen, aliphatic attach] -1,2566 5 108 12 1235
Aromatic carbon 0,294 24 1790 30 8792
-O-   [oxygen, one aromatic attach]  -0,4664 3 203 5 1770
-OH     [hydroxy, aromatic attach] -0,4802 3 193 4 611
Ketone in a ring [olefin, aromatic attach]  -0,5497 -0,5497 2 11 2 104
Ortho-Hydroxy to misc. -C(=O)- correction  0,777 2 11 2 82
-C(=O)O [ester, aliphatic attach] -0,9505 3 113 6 1178
-C(=O)- [carbonyl, aliphatic attach] -1,5586 2 54 2 241
Cyclic ester  correction  -1,0577 1 14 2 144
Conclusions:
Log Kow of known constituents of the substance, representing a limited fraction of the composition, were estimated to be between -0.14 and 6.27 (estimated by QSAR)
Executive summary:

The partition coefficient of the known constituents of the substance were estimated using the recommended QSAR model KOWWIN v1.68, based on Atom/Fragment Contribution (AFC) method. The constituents of the test item were within the applicability domain (MW, descriptors).

This range of logKow was estimated between -0.14 and 6.27, with a standard deviation provided by the model of 0.48.

Description of key information

No range of logKow representative of the test item can be determined (neither with an experimental approach nor with an estimation approach)

Key value for chemical safety assessment

Additional information

The substance is a complex mixture, which contains a large number of constituents, which are mostly unkown but which have different solubility (often low solubility) and volatility. In addition its physical state leads to difficulties for physico-chemical testing: It is described as a brown red solid.

For such complex substances, the standard tests for partition coefficient endpoint are considered as not appropriate because of the limited knowledge of composition and the physical state of the substance. That is why the test has been waived.

In addition calculated values were provided on known constituents of the substance. However, only a range of logKow on a limited part of the composition of the substance can be calculated using QSAR estimations.

Therefore it is considered that no range logKow representative of the whole test item can be determined (neither with an experimental approach nor with an estimation approach).