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Endpoint:
adsorption / desorption: screening
Type of information:
(Q)SAR
Adequacy of study:
supporting study
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 adequate and reliable documentation / justification
Justification for type of information:
- QMRF: see 'Overall remarks, attachments'.
- QPRF: see 'Executive summary'.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation using KOCWIN (v2.00) log Kow Method
GLP compliance:
no
Type of method:
other: QSAR estimation: KOCWIN v2.00: Koc estimate from log Kow
Specific details on test material used for the study:
- SMILES Code: CCCCCCCCCCCCN(CCC(=O)O)CCC(=O)O([Na])
Test temperature:
25 °C
Computational methods:
log Kow used for estimation: -2.08 (KOWWIN estimate).
Type:
Koc
Value:
0.087 L/kg
Temp.:
25 °C
Type:
log Koc
Value:
-1.06 dimensionless
Temp.:
25 °C

Koc Estimate from Log Kow:

Log Kow (Kowwin estimate)

-2.08

Non-Corrected Log Koc (0.55313 logKow + 0.9251)

-0.2254

Fragment Correction(s):

3 Nitrogen to Carbon (aliphatic) (-N-C)

-0.0654

Organic Acid (-CO-OH)

-0.7694

Corrected Log Koc

-1.0601

Estimated Koc

0.08707 L/kg

Executive summary:

QPRF: KOCWIN v2.00 (using log Kow method) (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

- log Kow (for log Kow method; optional)

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 (351.47 g/mol)

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

Substance within range (-2.08)

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)

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):

Training set: Molecular weights

Training set

Validation set

Minimum

32.04

73.14

Maximum

665.02

504.12

Average

224.4

277.8

Assessment of molecular weight

Molecular weight within range of training set

Training set: Log Kow

Training set

Validation set

Minimum

-2.11

-5.98

Maximum

8.12

8.68

Assessment of log Kow

Log Kow within range of training set

 

Appendix D. MCI & Log Kow Correction Factors for 447 Compound Training Set

Correction Factor Descriptor

Coefficient for log Kow Regression Methodology

Occurrence

No. of instances

of each bond

found for the

current substance

(number of compounds

(max. per structure)

Nitrogen to Carbon (aliphatic) (-N-C)

-0.021787

133

5

3

Organic Acid (-CO-OH)

-0.769374

21

1

1

Endpoint:
adsorption / desorption: screening
Type of information:
(Q)SAR
Adequacy of study:
supporting study
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 adequate and reliable documentation / justification
Justification for type of information:
- QMRF: see 'Overall remarks, attachments'.
- QPRF: see 'Executive summary'.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation using KOCWIN (v2.00) Molecular Connectivity Index (MCI)
GLP compliance:
no
Type of method:
other: QSAR estimation: KOCWIN v2.00: Koc estimate from MCI
Specific details on test material used for the study:
- SMILES Code: CCCCCCCCCCCCN(CCC(=O)O)CCC(=O)O([Na])
Test temperature:
25 °C
Type:
Koc
Value:
12 620 L/kg
Temp.:
25 °C
Type:
log Koc
Value:
4.101 dimensionless
Temp.:
25 °C

Koc Estimate from MCI:

First Order Molecular Connectivity Index

11.058

Non-Corrected Log Koc (0.5213 MCI + 0.60)

6.3642

Fragment Correction(s):

3 Nitrogen to Carbon (aliphatic) (-N-C)

-0.6382

Organic Acid (-CO-OH)

-1.6249

Corrected Log Koc

4.1011

Estimated Koc

1.262E+004 L/kg

Executive summary:

QPRF: KOCWIN v2.00 (MCI methodology) (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 (351.47)

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)

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):  

Training set: Molecular weights

Training set

Validation set

Minimum

32.04

73.14

Maximum

665.02

504.12

Average

224.4

277.8

Assessment of molecular weight

Molecular weight within range of training set

 

Appendix D. MCI & Log Kow Correction Factors for 447 Compound Training Set

Correction Factor Descriptor

Coefficient for Molecular Connectivity Index (MCI) Regression Methodology

Occurrence

No. of instances

of each bond

found for the

current substance

(new model)

Remark

(number of compounds

(max. per structure)

Nitrogen to Carbon (aliphatic) (-N-C)

-0.21273

c

-0.021787

133

5

Organic Acid (-CO-OH)

-1.624874

(f)

-0.769374

21

1

(c) Any nitrogen attached to double bond is not counted; also, carbonyl and thiocarbonyl are not counted as carbons.

(f) Counted only once per structure, regardless of number of occurrences.

Description of key information

In accordance with column 2 of REACH Annex VII, the adsorption/desorption test does not need to be conducted as the substance has a low potential for sorption (log Kow < 3). The Log POW is : -2.12.

Nvertheless, for sodium 3-[(2-carboxyethyl)(dodecyl)amino]propanoate Koc values were calculated to be 12620 L/kg (log Koc = 4.1011) and 0.08707 L/kg (log Koc = -1.0601) when based on the MCI method and the log Kow method, respectively.

Key value for chemical safety assessment

Additional information

QSAR-disclaimer:

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met.

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

For the assessment of sodium 3-[(2-carboxyethyl)(dodecyl)amino]propanoate (CAS 14960-06-6) (Q)SAR results were used for adsorption / desorption. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.