Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
adsorption / desorption, other
Remarks:
adsorption
Type of information:
(Q)SAR
Adequacy of study:
other information
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:
Please refer to "Overall remarks and attachments".
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 (experimental value; BASF SE, 2015)
Type:
Koc
Value:
0.134 L/kg
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.
Type:
log Koc
Value:
-0.874 dimensionless
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.

Log Kow (User entered ): -4.0

Non-Corrected Log Koc (0.55313 logKow + 0.9251): -1.2874

Fragment Corrections:

2  N-CO-C (aliphatic carbon): -0.0076

1  Urea (N-CO-N) : -0.0102

1  Azo (-N=N-): 0.4310

1  Sulfonic acid (-S(=O)-OH): 0.0000

Corrected Log Koc: -0.8742

Estimated Koc: 0.1336 L/kg  

 

Remarks:

The Koc of this structure may be sensitive to pH! The estimated Koc represents a best-fit to the majority of experimental values however, the Koc may vary significantly with pH.

Executive summary:

QPRF: KOCWIN v2.00 (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

- 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 (465.39 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 not within range (-4.0)

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):

Model:  KOCWIN v2.00 MCI & Log Kow method
Substance:  DEA
CAS-#:  35342-16-6 
SMILES:  Cc3c(c2c(cc3)nc(s2)c4ccc(cc4)N=NC1C(=O)NC(=O)NC1(=O))S(=O)(=O)O([Li])
Molecular weight (g/mol): 465.39
Log Kow (experimental data): -4 Reference: EPISUITE - KOWWIN data base match
           
  Molecular weight (g/mol)   log Kow
Minimum Maximum Average   Minimum Maximum
Training set 32.04 665.02 224.4   -2.11 8.12
Validation set 73.14 504.12 277.8   -5.98 8.68
Assessment of molecular weight Molecular weight within range of training and validation set.
 
             
Assessment of log Kow (only relevant for log Kow method) Log Kow within range of validation set, but not within training set. Therefore, the estimate may be less accurate.
             
Appendix D. MCI & Log Kow Correction Factors for 447 Compound Training Set    
Correction Factor Descriptor Coefficient for Molecular Connectivity Index (MCI) Regression Methodology Coefficient for log Kow Regression Methodology Occurrence No. of instances
of each bond
found for the
current substance
(new model)  Remark (number of compounds (max per structure)  
N-CO-C (aliphatic carbon)  -1.027725 (a) -0.00379 39 1 2
Urea (N-CO-N)  -1.003794 (a) -0.01023 57 1 1
Azo (-N=N-) -0.647525   0.431031 3 1 1

(a) Counted up to twice per structure, regardless of number of occurrences.

The number of instances of the identified correction factor does exceed the maximum number as listed in Appendix D. Therefore, the estimate may be less accurate.

Endpoint:
adsorption / desorption, other
Remarks:
adsorption
Type of information:
(Q)SAR
Adequacy of study:
key study
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:
Please refer to "Overall remarks and attachments".
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:
330.9 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:
2.52 dimensionless
Temp.:
25 °C
Remarks on result:
other: The substance is not within the applicability domain of the model.

KOCWIN v2.00 Results 

Koc Estimate from MCI:

First Order Molecular Connectivity Index: 14.630

Non-Corrected Log Koc (0.5213 MCI + 0.60): 8.2264

Fragment Corrections:

2  N-CO-C (aliphatic carbon): -2.0554

1  Urea (N-CO-N): -1.0038

1  Azo (-N=N-): -0.6475

1  Sulfonic acid (-S(=O)-OH): -2.0000

Corrected Log Koc: 2.5197

Estimated Koc: 330.9 L/kg

 

Executive summary:

QPRF: KOCWIN v2.00 (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 (465.39 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):

Model:  KOCWIN v2.00 MCI & Log Kow method
Substance:  DEA
CAS-#:  35342-16-6 
SMILES:  Cc3c(c2c(cc3)nc(s2)c4ccc(cc4)N=NC1C(=O)NC(=O)NC1(=O))S(=O)(=O)O([Li])
Molecular weight (g/mol): 465.39
Log Kow (experimental data): -4 Reference: EPISUITE - KOWWIN data base match
           
  Molecular weight (g/mol)   log Kow
Minimum Maximum Average   Minimum Maximum
Training set 32.04 665.02 224.4   -2.11 8.12
Validation set 73.14 504.12 277.8   -5.98 8.68
Assessment of molecular weight Molecular weight within range of training and validation set.
 
             
Assessment of log Kow (only relevant for log Kow method) Log Kow within range of validation set, but not within training set. Therefore, the estimate may be less accurate.
             
Appendix D. MCI & Log Kow Correction Factors for 447 Compound Training Set    
Correction Factor Descriptor Coefficient for Molecular Connectivity Index (MCI) Regression Methodology Coefficient for log Kow Regression Methodology Occurrence No. of instances
of each bond
found for the
current substance
(new model)  Remark (number of compounds (max per structure)  
N-CO-C (aliphatic carbon)  -1.027725 (a) -0.00379 39 1 2
Urea (N-CO-N)  -1.003794 (a) -0.01023 57 1 1
Azo (-N=N-) -0.647525   0.431031 3 1 1

 (a) Counted up to twice per structure, regardless of number of occurrences.

The number of instances of the identified correction factor does exceed the maximum number as listed in Appendix D. Therefore, the estimate may be less accurate.

Description of key information

The Koc and the Log Koc of the substance at 20 °C is considered to be 330.9 L/kg and 2.5197, respectively. Adsorption to solid soil phase is not expected.

Key value for chemical safety assessment

Koc at 20 °C:
330.9

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. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort.

 

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 Lithium 2-[4-[(hexahydro-2,4,6-trioxopyrimidin-5-yl)azo]phenyl]-6-methylbenzothiazole-7-sulphonate (CAS 35342-16-6) (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 sufficiently covered and suitable for risk assessment.

 

Therefore, further experimental studies on adsorption/desorption are not provided.

Remarks:

The test substance is a multiconstituent substance.

Since 2-[4-[(Hexahydro-2,4,6-trioxo-5-pyrimidyl)azo]phenyl]-6-methylbenzothiazole-7-sulphonic acid, compound with 2,2',2''-nitrilotris[ethanol] (1:1) (CAS 65036-46-6 ) is a Quaternary Ammonium Compound (QAC), adsorption of QACs seem to occur mainly by an ion-exchange mechanism and depends on cation-exchange capacity of the sorbent and variety of other parameters (Boethling, 1994). The training set for the Koc estimation of the used program did not include any QACs. Therefore, the Koc estimate would be outside the program's prediction domain. Therefore, the estimation of Koc and Log Koc is based on Lithium 2-[4-[(hexahydro-2,4,6-trioxopyrimidin-5-yl)azo]phenyl]-6-methylbenzothiazole-7-sulphonate (CAS 35342-16-6).  The number of instances of the identified correction factor does exceed the maximum number as listed in Appendix D. Therefore, the estimate may be less accurate. The Log Kow was within range of validation set, but not within training set. Therefore, the estimate may be less accurate. The estimated Koc represents a best-fit to the majority of experimental values. However, the Koc may vary significantly with pH.  

Following a worst case approach, the Koc and the Log Koc of the substance at 20 °C is considered to be 330.9 L/kg and 2.5197, respectively (Koc estimation via MCI method).

[LogKoc: 2.5197]