N-methyl-N-[C18-(unsaturated)alkanoyl]glycine

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 2

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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:

1. SOFTWARE
ChemProp(TM) Main Module 6.5, Public OSIRIS Edition

2. MODEL (incl. version number)
Franco, Fu & Trapp (Partitioning, soil sorption coefficient, Koc), ionizable substances, acids and bases

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer. Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on results incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other: REACh Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: ChemProp v6.5
- Model(s) used: Franco, Fu & Trapp
Full reference and details of the used formulas can be found in:
1. Franco A, Fu W, Trapp S 2009. Influence of soil pH on the sorption of ionizable chemicals: Modeling advances. Environ. Toxicol. Chem. 28: 458-464.
2. Franco A, Trapp S 2008. Estimation of the soil-water partition coefficient normalized to organic carbon for ionizable organic chemicals. Environ. Toxicol. Chem. 27: 1995-2004.
- Model description: see field 'attached justification' and 'any other information on material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Type of method:

other: calculation

Media:

soil

Details on test conditions:

BASIS FOR CALCULATION OF Koc:
- Estimation software: ChemProp v6.5, Franco, Fu and Trapp 2009 model for acids
- Log Kow: 3.5 and 4.2
- pKa: 5.0
- pH: 4, 7, and 9

Type:

Koc

Value:

119.204 L/kg

pH:

7

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 3.5

Type:

log Koc

Value:

2.08 dimensionless

pH:

7

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 3.5

Type:

Koc

Value:

188.036 L/kg

pH:

7

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 4.2

Type:

log Koc

Value:

2.27 dimensionless

pH:

7

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 4.2

Type:

Koc

Value:

977.558 L/kg

pH:

4

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 3.5

Type:

log Koc

Value:

2.99 dimensionless

pH:

4

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 3.5

Type:

Koc

Value:

2 331.764 L/kg

pH:

4

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 4.2

Type:

log Koc

Value:

3.37 dimensionless

pH:

4

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 4.2

Type:

Koc

Value:

84.503 L/kg

pH:

9

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 3.5

Type:

log Koc

Value:

1.93 dimensionless

pH:

9

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 3.5

Type:

Koc

Value:

101.371 L/kg

pH:

9

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 4.2

Type:

log Koc

Value:

2.01 dimensionless

pH:

9

% Org. carbon:

5

Remarks on result:

other: constituent 1-3

Remarks:

log Kow = 4.2

For detailed information on the results please refer to the attached report.

Description of key information

log Koc (constituent 1-3) = 2.99 – 3.37 (pH 4, ChemProp v6.5, Franco, Fu & Trapp acid model)

log Koc (constituent 1-3) = 2.08 - 2.27 (pH 7, ChemProp v6.5, Franco, Fu & Trapp acid model)

log Koc (constituent 1-3) = 1.93 – 2.01 (pH 9, ChemProp v6.5, Franco, Fu & Trapp acid model)

Additional information

There is no study available investigating the log Koc of N-methyl-N-(C18-(unsaturated)alkanoyl)glycine (EC 701-177-3). Therefore, the log Koc was calculated for three constituents, N-methyl-N-oleoylglycine and N-[methyl-[(9Z,12Z)-1-oxo-9,12octadecadienyl glycine as main components and oleic acid, which is of minor importance due to a lower percentage, with the Franco, Fu and Trapp model (2009) for ionisable acids at the environmentally relevant pH values 4, 7 and 9. The required model input parameters are the pH value (4, 7, and 9), the pKa value (5.0, 20 °C, OECD 112) and the log Pn (3.5 and 4.20), corresponding to the log Kow for the neutral molecule (≥ 3.5 ≤ 4.2, 20 °C, EU A.8, HPLC).

All molecules fall within the applicability domain of the model (pKa and log Kow). The obtained log Koc is 2.99 – 3.37 (Koc = 977.56 – 2331.76 L/kg) at pH 4, 2.08 – 2.27 (Koc = 119.20 – 188.04 L/kg) at pH 7, and 1.93 – 2.01 (Koc = 84.50 – 101.37 L/kg) at pH 9. The log Koc at pH 7 is considered as key value and indicates that the substance is low to moderately adsorptive.

Based on low water solubility (0.44 mg/L), low vapour pressure (1.31E-4 Pa at 20 °C) and a moderate log Koc of 2.08 - 2.27 at pH7, the substance will distribute mainly into water. However, due to its ready biodegradability, the substance will not persist in these compartments.