Tall oil, polymd., oxidized

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2018

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

Justification for type of information:

1. SOFTWARE
EPI Suite v. 4.11

2. MODEL (incl. version number)
KOCWIN version 2.00 (September 2010)
(Estimation Using Log Kow)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
Tall Oil, polymerized, oxidized is a complex mixture (UVCB substance). In order to estimate the organic carbon normalized adsorption coefficient (Koc) of the substance, Koc values were estimated for its following main components:

1) Fatty acids, polymerized, oxidized (products of the reaction of crude tall oil fatty acids with oxygen, containing C-O-C and C-C cross links, hydroxyl and carboxyl functional groups).
Dimer containing C-O-C cross link
SMILES: OC(CCCCCCCC(=O)O)C(CCCCCCCC)OC(CCCCCCCC)C(O)CCCCCCCC(=O)O

2) Resin acids (such as Abietic acid)
Abietic acid (CAS 514-10-3)
SMILES: O=C(O)C(C(C(C(C(=C1)C=C(C2)C(C)C)C2)(CC3)C)C1)(C3)C

3) Fatty acids (such as Oleic acid and Linoleic acid)
Oleic acid (CAS 112-80-1)
SMILES: CCCCCCCCC=CCCCCCCCC(=O)O
Linoleic acid (CAS 60-33-3)
SMILES: CCCCCC=CCC=CCCCCCCCC(=O)O

4) Sterols (such as Campesterol, Stigmasterol, Sitosterol)
Campesterol (CAS 474-62-4)
SMILES: OC(CC(=CCC1C(CC2)C3(C2C(CCC(C(C)C)C)C)C)C4(C)C1CC3)CC4
Stigmasterol (CAS 83-48-7)
SMILES: OC(CC(=CCC1C(CC2)C3(C2C(C=CC(C(C)C)CC)C)C)C4(C)C1CC3)CC4
Sitosterol (CAS 83-46-5)
SMILES: OC(CC(=CCC1C(CC2)C3(C2C(CCC(C(C)C)CC)C)C)C4(C)C1CC3)CC4

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
A traditional method of estimating soil adsorption Koc involves correlations developed with log octanol-water partition coefficient (log Kow) (Doucette, 2000). Since an expanded experimental Koc database was available from the new MCI (Molecular Connectivity Index) regression, it was decided to develop a log Kow estimation methodology that was potentially more accurate than existing log Kow QSARs for diverse structure datasets.
Effectively, the new log Kow methodology simply replaces the MCI descriptor with log Kow and derives similar equations. The derivation uses the same training and validation data sets. The training set is divided into the same non-polar (no correction factors) and correction factor sets. The same correction factors are also used.
Separate equations correlating log Koc with log Kow were derived for nonpolar and polar compounds because it was statistically more accurate to do so than to use the approach taken with the MCI-based method. The equation derived by the non-polar (no correction factor) regression is:

log Koc = 0.8679 Log Kow - 0.0004
(n = 68, r2 = 0.877, std dev = 0.478, avg dev = 0.371)

One non-polar compound was removed from the regression (hexabromobiphenyl) because it was the only compound without a recommended experimental log Kow and the accuracy of its estimated log Kow (9.10) is suspect. This equation is used for any compound having no correction factors.
For the multiple-linear regression using correction factors, log Kow was included as an individual descriptor. For compounds having correction factors, the equation is:
log Koc = 0.55313 Log Kow + 0.9251 + ΣPfN
where ΣPfN is the summation of the products of all applicable correction factor coefficients multiplied by the number of times (N) that factor is counted for the structure
The statistics pertain to the experimental log Koc and the Log Kow estimated log Koc:

Log Kow Methodology

Training Training Validation
No Corrections with Corrections Data set

number 68 447 150 **
r2 corr coef 0.877 0.855 0.778
std deviation 0.478 0.396 0.679
avg deviation 0.371 0.307 0.494
** eight ammonium and metal salt compounds were removed from the Validation dataset

5. APPLICABILITY DOMAIN
The minimum and maximum values for molecular weight are the following:
Training Set Molecular Weights:
Minimum MW: 32.04
Maximum MW: 665.02
Average MW: 224.4

Validation Molecular Weights:
Minimum MW: 73.14
Maximum MW: 504.12
Average MW: 277.8

Currently there is no universally accepted definition of model domain. However, the log Koc estimates are less accurate for compounds outside the MW range of the training set compounds, and/or that have more instances of a given fragment than the maximum for all training set compounds.

6. ADEQUACY OF THE RESULT
The estimate values have been generated by a valid model. The model is applicable to the selected components of Tall Oil, polymerized, oxidized with the necessary level of reliability and is sufficiently relevant for the regulatory purpose.
These estimated values of Koc supports the qualitative evaluation of the adsorption/desorption property for Tall Oil, polymerized, oxidized.

Guideline:

other: KOCWIN

Version / remarks:

version 2.00

Principles of method if other than guideline:

- Software tool(s) used including version: EPI SUITE v.4.11
- Model(s) used: KOCWIN v.2.00 (September 2010)
- Model description: see field 'Justification for type of information'.

Specific details on test material used for the study:

Fatty acids
Oleic acid SMILES: CCCCCCCCC=CCCCCCCCC(=O)O
Linoleic acid SMILES: CCCCCC=CCC=CCCCCCCCC(=O)O

Resin acids
Abietic acid SMILES: O=C(O)C(C(C(C(C(=C1)C=C(C2)C(C)C)C2)(CC3)C)C1)(C3)C

Sterols
Campesterol SMILES: OC(CC(=CCC1C(CC2)C3(C2C(CCC(C(C)C)C)C)C)C4(C)C1CC3)CC4
Stigmasterol SMILES: OC(CC(=CCC1C(CC2)C3(C2C(C=CC(C(C)C)CC)C)C)C4(C)C1CC3)CC4
Sitosterol SMILES: OC(CC(=CCC1C(CC2)C3(C2C(CCC(C(C)C)CC)C)C)C4(C)C1CC3)CC4

Fatty acids, polymerized, oxidized (products of the reaction of crude tall oil fatty acids with oxygen, containing C-O-C and C-C cross links, hydroxyl and carboxyl functional groups).
Dimer containing C-O-C cross link SMILES: OC(CCCCCCCC(=O)O)C(CCCCCCCC)OC(CCCCCCCC)C(O)CCCCCCCC(=O)O

Key result

Type:

log Koc

Value:

> 3.5 - < 6 dimensionless

Remarks on result:

other: (Q)SAR predicted value

Tall Oil, polymerized, oxidized is a complex mixture (UVCB substance). In order to estimate the organic carbon normalized adsorption coefficient (Koc) of the substance, Koc values were estimated for its following main components:

1) Fatty acids, polymerized, oxidized (products of the reaction of crude tall oil fatty acids with oxygen, containing C-O-C and C-C cross links, hydroxyl and carboxyl functional groups).

Dimer containing C-O-C cross link: LogKoc: 5.27

 

2) Resin acids

Abietic acid: LogKoc: 3.73

2) Fatty acids

Oleic acid: LogKoc: 4.38

Linoleic acid: LogKoc: 4.05

3) Sterols

Campesterol: LogKoc: 5.06

Stigmasterol: LogKoc: 5.72

Sitosterol: LogKoc: 5.85

Based on the above predictions and the composition the adsorption coefficient of the test item was estimated to be high.

Conclusions:

The LogKoc of Tall oil, polymerized, oxidized was estimated to be high (estimated values for the main components > 4).

Description of key information

The LogKoc of Tall oil, polymerized, oxidized was estimated to be high (estimated values for the main components > 4).

Key value for chemical safety assessment

Koc at 20 °C:

4