Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
adsorption / desorption, other
Remarks:
adsorption
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 with 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 prediction is evaluated on the basis of the model performance on similar substances. For more details see section `overall remarks, attachments´.
Qualifier:
according to
Guideline:
other: REACh Guidance on QSARs R.6
Principles of method if other than guideline:
- Software tool(s) used including version: EPI Suite v4.11
- Model(s) used: KOCWIN v2.00, MCI based method
Full reference and details of the used formulas can be found in:
Meylan, W., P.H. Howard and R.S. Boethling, "Molecular Topology/Fragment Contribution Method for Predicting Soil Sorption Coefficients", Environ. Sci. Technol. 26: 1560-7 (1992)
- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on Material and methods'
- Justification of QSAR prediction: see field 'Justific ation for type of information', 'Attached justification' and/or 'overall remarks'
GLP compliance:
no
Type of method:
other: calculation
Media:
soil
Details on test conditions:
BASIS FOR CALCULATION OF Koc:
- Estimation software: EPI Suite™ v 4.11, KOCWIN v2.00, MCI based method
- Water solubility: -
- Vapour pressure: -
Type:
log Koc
Value:
>= 12.34 - <= 21.47 dimensionless
Temp.:
25 °C
Remarks on result:
other: MCI based estimate for the main constituents reported in section 1.2
Details on results (Batch equilibrium method):
For detailed description on on the prediction see "Any other information on results incl. tables".

Result refers to the uncharged molecule, for the main constituents reported in section 1.2.

 

--------------------------- KOCWIN v2.00 Results ---------------------------

 

 Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index ........... : 27.490 - 47.535

        Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 14.9301 - 25.3797

        Fragment Correction(s):

                 2  Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -2.5939

        Corrected Log Koc .................................. : 12.3362  - 21.4679

 

                        Estimated Koc: 1e+010 L/kg  <===========

Description of key information

log Koc > 5.0 (25 °C, EPI Suite v4.11, KOCWIN v2.00)

Key value for chemical safety assessment

Additional information

There are no experimental studies available assessing the adsorption/desorption of Isohexadecyl 12-[(1-oxooctadecyl)oxy]octadecanoate (CAS 97338-28-8). Therefore, the log Koc was calculated by (Q)SAR (EPI Suite v4.11) using the KOCWIN v2.00 model based on the Molecular Connectivity Index (MCI) and the log Kow method.

Since the substance only partially falls within the applicability domain of both models due to the high molecular weights of its constituents (> 665.02 g/mol) and high estimated log Kow (above the applicability domain limit values of 8.12/8.68 of the models, KOWWIN v1.68), the reported results are not fully reliable and should be treated with caution.

The estimation based on the MCI method resulted in log Koc values of 12.34 – 21.47 (25 °C), indicating a high potential for adsorption, which is in line with the high, estimated log Kow.