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Endpoint:
adsorption / desorption
Remarks:
adsorption
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
April 19, 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation method using accepted and valid (Q)SAR method.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Soil Adsorption Coefficient Program (KOCWIN) estimates the soil adsorption coeffiecient (Koc) of organic compounds. Koc can be defined as "the ratio of the amount of chemical adsorbed per unit weight of organic carbon (oc) in the soil or sediment to the concentration of the chemical in solution at equilibrium" (Lyman, 1990); it is represented by the following equation (Lyman, 1990):

Koc = (ug adsorbed/g organic carbon) / (ug/mL solution)

The units of Koc are typically expressed as either L/kg or mL/g.

Koc provides an indication of the extent to which a chemical partitions between solid and solution phases in soil, or between water and sediment in aquatic ecosystems. Estimated values of Koc are often used in environmental fate assessment because measurement of Koc is expensive. Traditional estimation methods rely upon the octanol/water partition coefficient or related parameters, but the first-order molecular connectivity index (MCI) has been used successfully to predict Koc values for hydrophobic organic compounds (Sabljic, 1984, 1987; Bahnick and Doucette, 1988). The original KOCWIN program (PCKOC) used MCI and a series of group contribution factors to predict Koc (Meylan et al., 1992). This group contribution method was shown to outperform traditional estimation methods based on octanol/water partition coefficients and water solubility.

Since the introduction of the original PCKOC program in 1992, the number of available experimental Koc values has grown significantly. Using an expanded experimental dataset and the original PCKOC methodology, the QSAR equations were re-regressed to derive updated coefficient values. In addition, several new group contribution factors (correction factors) were added to improve estimation accuracy. Also, the updated KOCWIN program includes a separate Koc estimate based upon Log Kow (rather than MCI).
Type of method:
other: in silico
Computational methods:
- Adsorption coefficient per organic carbon (Koc)
Type:
Koc
Value:
85 850 000
Remarks on result:
other: L/Kg
Type:
log Koc
Value:
7.934

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

Compound Being Estimated:

SMILES: O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

CHEM: trioctyl benzene-1,2,4-tricarboxylate

MOL FOR: C33 H54 O6

MOL WT: 546.79

Koc Estimate from MCI:

---------------------

First Order Molecular Connectivity Index ........... : 19.044

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 10.5277

Fragment Correction(s):

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

Corrected Log Koc ........................... : 7.9338

Estimated Koc: 8.585e+007 L/kg <===========

Koc Estimate from Log Kow:

-------------------------

Log Kow (User entered ) ............................ : 9.30

Non-Corrected Log Koc (0.55313 logKow + 0.9251) .... : 6.0692

Fragment Correction(s):

2 Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -0.1312

Corrected Log Koc ........................... : 5.9380

Estimated Koc: 8.67e+005 L/kg <===========

Validity criteria fulfilled:
yes
Conclusions:
Overall, the MCI methodology is somewhat more accurate than the Log Kow methodology, although both methods yield good results, thus the Koc estimate value from MCI was selected.
It is predicted that the substance has a Koc equal to 85850000 L/Kg.
According to the McCall classification scheme, this means that DIPLAST TM 8 is expected to be immobile (Koc > 5000) on soil.
Executive summary:

Koc has been calculated using the computer program KOCWIN (v2.00). It is predicted that DIPLAST TM 8 has a Koc equal to 85850000 L/Kg.

According to the McCall classification scheme, this means that the above substance is expected to be immobile (Koc > 5000) on soil.

Endpoint:
adsorption / desorption
Remarks:
other: in silico
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
April 19, 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation method using accepted and valid (Q)SPR method.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May 2008
Principles of method if other than guideline:
The Soil Adsorption Coefficient Program (KOCWIN) estimates the soil adsorption coefficient (Koc) of organic compounds. Koc can be defined as "the ratio of the amount of chemical adsorbed per unit weight of organic carbon (oc) in the soil or sediment to the concentration of the chemical in solution at equilibrium" (Lyman, 1990); it is represented by the following equation (Lyman, 1990):

Koc = (μg adsorbed/g organic carbon) / (μg/mL solution)

The units of Koc are typically expressed as either L/kg or mL/g.

Koc provides an indication of the extent to which a chemical partitions between solid and solution phases in soil, or between water and sediment in aquatic ecosystems. Estimated values of Koc are often used in environmental fate assessment because measurement of Koc is expensive. Traditional estimation methods rely upon the octanol/water partition coefficient or related parameters, but the first-order molecular connectivity index (MCI) has been used successfully to predict Koc values for hydrophobic organic compounds (Sabljic, 1984, 1987; Bahnick and Doucette, 1988). The original KOCWIN program (PCKOC) used MCI and a series of group contribution factors to predict Koc (Meylan et al., 1992). This group contribution method was shown to outperform traditional estimation methods based on octanol/water partition coefficients and water solubility.

Since the introduction of the original PCKOC program in 1992, the number of available experimental Koc values has grown significantly. Using an expanded experimental dataset and the original PCKOC methodology, the QSAR equations were re-regressed to derive updated coefficient values. In addition, several new group contribution factors (correction factors) were added to improve estimation accuracy. Also, the updated KOCWIN program includes a separate Koc estimate based upon Log Kow (rather than MCI).
Type:
Koc
Value:
ca. 867 000
Remarks on result:
other: L/Kg
Type:
log Koc
Value:
5.938
Statistics:
The following table gives statistical information for the log Kow-based regression training and validation sets. The statistics pertain to the experimental log Koc and the Log Kow estimated log Koc:

Training No Corrections Validation with Corrections Validation 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

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

Compound Being Estimated:

SMILES: O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

CHEM: trioctyl benzene-1,2,4-tricarboxylate

MOL FOR: C33 H54 O6

MOL WT: 546.79

 

 Koc Estimate from Log Kow:

 -------------------------

        Log Kow (User entered  ) ......................... : 9.30

        Non-Corrected Log Koc (0.55313 logKow + 0.9251) .. : 6.0692

        Fragment Correction(s):

                 2  Ester (-C-CO-O-C-) or (HCO-O-C) ..... : -0.1312

        Corrected Log Koc ................................ : 5.9380

 

                        Estimated Koc: 8.67e+005 L/kg  <===========

Validity criteria fulfilled:
yes
Conclusions:
The estimated value of Koc (from log Pow) is predicted to be about 867000 L/Kg.
Executive summary:

The estimated value of Koc (from log Pow) is predicted to be about 867000 L/Kg.

Endpoint:
adsorption / desorption
Remarks:
other: in silico
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
April 19, 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation method using accepted and valid (Q)SPR method.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May 2008
Principles of method if other than guideline:
The Soil Adsorption Coefficient Program (KOCWIN) estimates the soil adsorption coefficient (Koc) of organic compounds. Koc can be defined as "the ratio of the amount of chemical adsorbed per unit weight of organic carbon (oc) in the soil or sediment to the concentration of the chemical in solution at equilibrium" (Lyman, 1990); it is represented by the following equation (Lyman, 1990):

Koc = (μg adsorbed/g organic carbon) / (μg/mL solution)

The units of Koc are typically expressed as either L/kg or mL/g.

Koc provides an indication of the extent to which a chemical partitions between solid and solution phases in soil, or between water and sediment in aquatic ecosystems. Estimated values of Koc are often used in environmental fate assessment because measurement of Koc is expensive. Traditional estimation methods rely upon the octanol/water partition coefficient or related parameters, but the first-order molecular connectivity index (MCI) has been used successfully to predict Koc values for hydrophobic organic compounds (Sabljic, 1984, 1987; Bahnick and Doucette, 1988). The original KOCWIN program (PCKOC) used MCI and a series of group contribution factors to predict Koc (Meylan et al., 1992). This group contribution method was shown to outperform traditional estimation methods based on octanol/water partition coefficients and water solubility.

Since the introduction of the original PCKOC program in 1992, the number of available experimental Koc values has grown significantly. Using an expanded experimental dataset and the original PCKOC methodology, the QSAR equations were re-regressed to derive updated coefficient values. In addition, several new group contribution factors (correction factors) were added to improve estimation accuracy. Also, the updated KOCWIN program includes a separate Koc estimate based upon Log Kow (rather than MCI).
Type:
Koc
Value:
ca. 85 862 000
Remarks on result:
other: L/Kg
Type:
log Koc
Value:
7.934
Statistics:
The following table gives statistical information for the MCI (Molecular Connectivity Index, first-order) training and validation Datasets.  The statistics pertain to the experimental log Koc and the MCI estimated log Koc:

Training No Corrections Validation with Corrections Validation Data set

number 69 447 158
r2 corr coef 0.967 0.900 0.850
std deviation 0.247 0.340 0.583
avg deviation 0.199 0.273 0.459

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

Compound Being Estimated:

SMILES: O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

CHEM: trioctyl benzene-1,2,4-tricarboxylate

MOL FOR: C33 H54 O6

MOL WT: 546.79

 

 

 Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index ....... : 19.044

        Non-Corrected Log Koc (0.5213 MCI + 0.60) ...... : 10.5277

        Fragment Correction(s):

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

        Corrected Log Koc ............................... : 7.9338

 

                        Estimated Koc: 8.585e+007 L/kg  <===========

Validity criteria fulfilled:
yes
Conclusions:
The estimated value of Koc (from MCI) is predicted to be about 85862000 L/Kg.
Executive summary:

The estimated value of Koc (from MCI) is predicted to be about 85862000 L/Kg.

Endpoint:
adsorption / desorption: screening
Remarks:
other: in silico
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
April 19, 2012
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:
See the cross-reference
Reason / purpose:
other: (Q)SAR: supporting information
Remarks:
KOCWIN v2_00 (Sep2010)_QSAR Method and Domain.pdf
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals
Principles of method if other than guideline:
See the justification for type of information.
Type:
log Koc
Value:
5.94 dimensionless
Statistics:
See the justification for type of information.

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

Compound Being Estimated:

SMILES: O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

CHEM: trioctyl benzene-1,2,4-tricarboxylate

MOL FOR: C33 H54 O6

MOL WT: 546.79

 

 Koc Estimate from Log Kow:

 -------------------------

        Log Kow (User entered  ) ......................... : 9.30

        Non-Corrected Log Koc (0.55313 logKow + 0.9251) .. : 6.0692

        Fragment Correction(s):

                 2  Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -0.1312

        Corrected Log Koc ................................. : 5.9380

 

        Estimated Koc: 8.67e+005 L/kg

Validity criteria fulfilled:
yes
Conclusions:
The estimated value of log Koc (from log Pow) is predicted to be 5.94.
According to the McCall classification scheme, this means that the test material is immobile (Koc > 5000) on soil.
Executive summary:

The estimated value of log Koc (from log Pow) is predicted to be 5.94.

According to the McCall classification scheme, this means that the test material is immobile (Koc > 5000) on soil.

Endpoint:
adsorption / desorption: screening
Remarks:
in silico
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
April 19, 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source
Justification for type of information:
See the attached justification.
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals
Principles of method if other than guideline:
See the justification for type of information.
Type:
log Koc
Value:
7.934 dimensionless
Statistics:
See the justification for type of information.

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

Compound Being Estimated:

SMILES: O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

CHEM: trioctyl benzene-1,2,4-tricarboxylate

MOL FOR: C33 H54 O6

MOL WT: 546.79

 

 

 Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index ... : 19.044

        Non-Corrected Log Koc (0.5213 MCI + 0.60) .. : 10.5277

        Fragment Correction(s):

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

        Corrected Log Koc ............................ : 7.9338

 

        Estimated Koc: 8.585e+007 L/kg

Validity criteria fulfilled:
yes
Conclusions:
The estimated value of log Koc (from MCI) is predicted to be 7.934
According to the McCall classification scheme, this means that the test material is immobile (Koc > 5000) on soil.
Executive summary:

The estimated value of log Koc (from MCI) is predicted to be 7.934

According to the McCall classification scheme, this means that the test material is immobile (Koc > 5000) on soil.

Description of key information

Koc = 8.59E7 L/Kg

Log Koc = 7.934

Key value for chemical safety assessment

Koc at 20 °C:
85 900 000

Additional information

The Soil Adsorption Coefficient (Koc) of the test material, estimated using the software KOCWIN v2.00, leads to the following results:

Log Koc= 7.93 (from MCI)

Log Koc= 5.94 (from Log Kow)

Overall, the MCI methodology is somewhat more accurate than the Log Kow methodology, although both methods yield good results, then the Koc estimate value from MCI was selected for the environmental assessment.

According to the McCall classification scheme, this means that the above substance is immobile (Koc > 5000) on soil.

[LogKoc: 7.93]