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Endpoint:
adsorption / desorption, other
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Accepted calculation method, but substance not within applicability domain of model
Justification for type of information:
For QSAR justification please refer to QPRF and QMRF description.
Principles of method if other than guideline:
KOCWIN (v2.00): estimation using estimated or experimentally derived log Kow
GLP compliance:
no
Type of method:
other: QSAR estimation: KOCWIN v2.00: Koc estimate from log Kow
Test temperature:
25 °C
Computational methods:
- Other: log Kow used for estimation: -4.67 (estimated by KOWWIN )
Type:
Koc
Value:
0.002 L/kg
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.
Type:
log Koc
Value:
-2.667
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.

Koc Estimate from Log Kow:

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

 

Log Kow (Kowwin estimate) ......................... : -4.67

Non-Corrected Log Koc (0.55313 logKow + 0.9251) .... : -1.6580

Fragment Correction(s):

9 Nitrogen to Carbon (aliphatic) (-N-C).. : -0.1961

2 Aliphatic Alcohol (-C-OH) ........... : -0.8229

Corrected Log Koc .................................. : -2.6770

Estimated Koc: 0.002104 L/kg <===========

Executive summary:

QPRF: KOCWIN v. 2.00 (18. Nov. 2013) 

1. 

Substance

See "Test material identity"

2. 

General information

2.1

Date of QPRF

See "Data Source (Reference)"

2.2

QPRF author and contact details

See "Data Source (Reference)"

3.

Prediction

3.1

Endpoint
(OECD Principle 1)

Endpoint

Adsorption to solid phase of
soils etc.

Dependent variable

Organic carbon normalised
adsorption coefficient (Koc)

3.2

Algorithm (OECD Principle 2)

Model or submodel name

KOCWIN

Model version

v. 2.00

Reference to QMRF

QMRF: Estimation of
Soil Adsorption Coefficient using KOCWIN v2.00 (EPI Suite v4.11): Estimation using log Kow

Predicted value (model result)

See “Results and discussion”

Input for prediction

- Chemical structure via CAS number or SMILES

Descriptor values

 

- Chemical structure

- Correction factors

3.3

Applicability domain
(OECD principle 3)

Domains

1) Molecular weight
(range of test data set: 32.04 to 665.02 g/mol; On-Line KOCWIN User’s Guide, Ch. 6.2.4 Domain)

Substance within
range (219 g/mol)

2) log Kow (range of test data set: -2.11 to 8.12; On-Line KOCWIN User’s Guide, Appendices E & F)

No experimental log Kow

 

 

3) Correction factors: Number of
instances of the identified correction factor does not exceed the maximum number as listed in Appendix D (On-Line KOCWIN User’s Guide)

Not fulfilled

3.4

The uncertainty
of the prediction (OECD principle 4)

 

Nonpolar compounds: n = 68; r2=0.478, average dev. = 0.371

Polar compounds: n = 447, r²=0.855, std. dev.= 0.396, average dev. = 0.307

3.5

The chemical mechanisms
according to the model underpinning the predicted result (OECD principle 5)

 

Adsorption is caused by temporary (reversible) or permanent bonding between the substance and a surface (e.g. due to van der Waals interactions, hydrogen bonding to hydroxyl groups, ionic interactions, covalent bonding, etc.). The organic carbon normalized adsorption coefficient (Koc) is the ratio of a substance concentration sorbed in the organic matter component of soil or sediment to that in the aqueous phase at equilibrium.

Estimation using log Kow: The model is based on the high correlation of log Kow and the adsorption potential.

References

- US EPA (2012). On-Line KOCWIN User’s Guide.

- Meylan, W., P.H. Howard and R.S. Boethling. 1992. Molecular topology/fragment contribution method for predicting soil sorption coefficients. Environ. Sci. Technol. 26: 1560-1567.

 

 

Assessment of estimation domain (molecular weight, fragments, correction factors):

Please refer to attached background material.

 

Endpoint:
adsorption / desorption, other
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other:
Remarks:
Accepted calculation method, but substance not within applicability domain of model
Justification for type of information:
For QSAR justification please refer to QPRF and QMRF description.
Principles of method if other than guideline:
KOCWIN (v2.00): estimation using first-order Molecular Connectivity Index (MCI)
GLP compliance:
no
Type of method:
other: QSAR estimation: KOCWIN v2.00: Koc estimate from MCI
Test temperature:
25 °C
Key result
Type:
Koc
Value:
10 L/kg
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.
Key result
Type:
log Koc
Value:
1 dimensionless
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.

KOCWIN Program (v2.00) Results:

==============================

SMILES : OCCN(CN(CN1CCO)CCO)C1

CHEM : Grotan BK

MOL FOR: C9 H21 N3 O3

MOL WT : 219.29

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

Koc Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 7.296

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 4.4030

Fragment Correction(s):

9 Nitrogen to Carbon (aliphatic) (-N-C).. : -1.9146

2 Aliphatic Alcohol (-C-OH) ........... : -2.6358

Corrected Log Koc .................................. : -0.1474

Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

Executive summary:

QPRF: KOCWIN v2.00 (18 Nov. 2013)

 

QPRF: KOCWIN v. 2.00 (18. Nov. 2013) 

1. 

Substance

See "Test material identity"

2. 

General information

2.1

Date of QPRF

See "Data Source (Reference)"

2.2

QPRF author and contact details

See "Data Source (Reference)"

3.

Prediction

3.1

Endpoint
(OECD Principle 1)

Endpoint

Adsorption to solid phase of
soils etc.

Dependent variable

Organic carbon normalised
adsorption coefficient (Koc)

3.2

Algorithm (OECD Principle 2)

Model or submodel name

KOCWIN

Model version

v. 2.00

Reference to QMRF

QMRF: Estimation of
Soil Adsorption Coefficient using KOCWIN v2.00 (EPI Suite v4.11): MCI methodology

Predicted value (model result)

See “Results and discussion”

Input for prediction

- Chemical structure via CAS number or SMILES

Descriptor values

- MCI (first order molecular connectivity index)
- Correction factors

3.3

Applicability domain
(OECD principle 3)

Domains

1) Molecular weight
(range of test data set: 32.04 to 665.02 g/mol; On-Line KOCWIN User’s Guide, Ch. 6.2.4 Domain)

Substance within range (219 g/mol)

2) Correction factors: Number of
instances of the identified correction factor does not exceed the maximum number as listed in Appendix D (On-Line KOCWIN User’s Guide)

Not fulfilled

3.4

The uncertainty
of the prediction (OECD principle 4)

Statistical accuracy for training dataset:
n = 516, r² = 0.916, std. dev.
= 0.330, average dev. = 0.263

3.5

The chemical mechanisms
according to the model underpinning the predicted result (OECD principle 5)

Adsorption is caused by temporary (reversible) or permanent bonding between the substance and a surface (e.g. due to van der Waals interactions, hydrogen bonding to hydroxyl groups, ionic interactions, covalent bonding, etc.). The organic carbon normalized adsorption coefficient (Koc) is the ratio of a substance concentration sorbed in the organic matter component of soil or sediment to that in the aqueous phase at equilibrium.
MCI methodology: The first-order molecular connectivity index is a measure to describe a variety of properties of chemicals. According to Sabljic (1984; cited in Meylan et al., 1992), the soil sorption potential is highly correlated with the first order MCI. Therefore, it has been used to derive the adsorption coefficient.

 

References

- US EPA (2012). On-Line KOCWIN User’s Guide.

- Meylan, W., P.H. Howard and R.S. Boethling. 1992. Molecular topology/fragment contribution method for predicting soil sorption coefficients. Environ. Sci. Technol. 26: 1560-1567.

 

 

Assessment of estimation domain (molecular weight, fragments, correction factors):

Please refer to attached background material.

 

Description of key information

Based upon a calculated log Koc adsorption to solid soil phase is not expected. The log Koc value was determined to be 1 and the Koc value was determined to be 10.

 

Key value for chemical safety assessment

Koc at 20 °C:
10

Additional information

A QSAR estimation was performed to fulfill this endpoint. KOCWIN version 2.00 was used as model with the the MCI and Kow method to calculate the Koc value. The Koc value was determined to be 10, the log Koc was determined to be 1 with the MCI method. The calculated Koc in the Kow method was 0.002104 L/kg, the calculated log Koc value was -2.6770. As a worst case presumption the Koc value was determined to be 10 and the log Koc value was determined to be 1.

A further supporting study according to OECD guideline 121 is available. The Koc was determined using the HPLC estimation method. The log Koc was determined to be > 0.47.

[LogKoc: 1.0]