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Endpoint:
adsorption / desorption, other
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 limited documentation / justification
Justification for type of information:
1. SOFTWARE
US EPA. 2008. Estimation Programs Interface Suite™ for Microsoft® Windows, v3.20. United States Environmental Protection Agency, Washington, DC, USA.

2. MODEL (incl. version number)
PCKOCWIN v1.66

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
[R]C(NCCN(CCO)CCC(O[Na])=O)=O / [R]C(NCCN(CCO)CCC(O)=O)=O

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
see attachment

5. APPLICABILITY DOMAIN
Currently there is no universally accepted definition of model domain. However, users may wish to consider the possibility that log Koc estimates are less accurate for compounds outside the MW range of the training set compounds, and/or that have more instances of a given fragment than the maximum for all training set compounds. It is also possible that a compound may have a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient or correction factor was developed. These points should be taken into consideration when interpreting model results.

6. ADEQUACY OF THE RESULT
Due to missing information about the applicability of the calculation model in respect to the substance under investigation the results and the conclusions thereoff should be treated with care.
Principles of method if other than guideline:
Amphopropionates C12-18 is a UVCB substance containing C8-, C10-, C12-, C14-, C16-, and C18-alkyl side chains. Based on this and the variable composition of the compound (alkyl chain distribution dependent on origin of the coco fatty acid) the calculation of physico-chemical properties for the mixture is not feasible. To get a hint on the physico-chemical data, the EPIWIN calculation was conducted for the C8 and the C18 derivatives. The soil sorption coefficients Koc of the substance were calculated using EPIWIN v3.20, PCKOCWIN v1.66.
Type of method:
other: calculation
Media:
soil
Type:
Koc
Value:
23.57 L/kg
Remarks on result:
other: C8 -derivative
Type:
Koc
Value:
10 740 L/kg
Remarks on result:
other: C18 -derivative
Conclusions:
Amphopropionates C12-18 is a UVCB substance containing C8-, C10-, C12-, C14-, C16-, and C18-alkyl side chains. Based on this and the variable composition of the compound (alkyl chain distribution dependent on origin of the coco fatty acid) the calculation of physico-chemical properties for the mixture is not feasible. To get a hint on the physico-chemical data, the EPIWIN calculation was conducted for the C8 and the C18 derivatives. The soil sorption coefficients Koc of the substance were calculated using EPIWIN v3.20, PCKOCWIN v1.66. The calculation yielded Koc values in the range between 23.57 (log Koc=1.372) (C8 -derivate) and 10740 (log Koc=4.494) (C18 -derivate). Based on these results and taking into account the classification scheme of Blume & Ahlsdorf (1993), a very low sorption onto soil organic matter is to be expected for the short chain compound (C8-derivative) and a very high for the long chain compound (C18 -derivative). Due to missing information about the applicability of the calculation model in respect to the substance under investigation the results and the conclusions thereoff should be treated with care.
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))
Version / remarks:
August 21, 2001
Deviations:
yes
Remarks:
see "Principles of method if other than guideline"
Qualifier:
according to
Guideline:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Version / remarks:
January 22, 2001
Deviations:
yes
Remarks:
see "Principles of method if other than guideline"
Principles of method if other than guideline:
According to guidelines, the determination of the Pow of the test substance should be performed in its non-ionised form. Therefore, the pKa values of the test substance were calculated using Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International). These calculations show that there is not a pH at which all ionisable groups are in their non-ionised form. At pH 2, net charge of the test substance is zero and therfore it was descided to perform a test at this pH. However, this pH was not in the environmentally relevant range of pH 5.0-9.0. Thus, an additional test was performed at neutral pH. Under these conditions, the net charge will deviate from zero.
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Radiolabelling:
no
Test temperature:
35±5°C
Details on study design: HPLC method:
EQUIPMENT
- Apparatus: Alliance Separation Module 2695, detector: Dual λ Absorbance Detector 2487 (Waters), column: 150 mm x 4.6 mm i.d. Hypersil BDS-CN; dp = 5 pm (Thermo, San Jose, CA, USA); column temp.: 35 ± 5.0°C; flow: 1 mL/min; Injection volume: 10 µL
- Detection system: UV detection (210nm)

MOBILE PHASES
Mobile phase pH 2.0: 55/45 (v/v) methanol/0.05 M phosphate buffer at pH 2.0
Mobile phase neutral pH: 55/45 (vlv) methanollMilli-Q water

DETERMINATION OF DEAD TIME
- Method: by inert substance which is not retained by the column (formamide)

REFERENCE SUBSTANCES
- Identity: Phenol, N, N-Dimethylbenzamide, Methylbenzoate, 3,5-Dinitrobenzamide, Naphthalene, Fenthion, Phenanthrene, 2,4-DDT

REPETITIONS
- Number of determinations: duplicates
Details on test conditions:
A 1294 mg/L or 1482 mg/L stock solution of the test substance was prepared in mobile phase pH 2.0 or mobile phase neutral pH. The test solutions were diluted with mobile phase pH 2.0 or mobile phase neutral pH, to a final concentration corrected for a purity of 50.60% of 253 mg/L. As test substance blank solution mobile phase pH 2.0 or mobile phase neutral pH was used.
Type:
log Koc
Value:
< 1.32 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 7; component 1
Type:
log Koc
Value:
3.47 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 7; component 2
Type:
log Koc
Value:
> 5.63 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 7; component 3+4+5
Type:
log Koc
Value:
< 1.32 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 2; component 1
Type:
log Koc
Value:
1.45 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 2; component 2
Type:
log Koc
Value:
3.42 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 2; component 6
Type:
log Koc
Value:
3.57 dimensionless
Temp.:
35 °C
Remarks on result:
other: pH 2; component 7
Transformation products:
not measured

Koc at pH 2

log Koc at pH 2

area%

Koc at pH7

log Koc at pH 7

area%

component 1

<2.1E1

<1.32

26

<2.1E1

<1.32

24

component 2

2.80E+01

1.45

69

2.90E+03

3.47

1.7

component 3

2.00E+02

2.3

0.7

>4.3E05

>5.63

25

component 4

5.90E+02

2.77

0.1

>4.3E05

>5.63

3.8

component 5

1.60E+03

3.2

0.6

>4.3E05

>5.63

45

component 6

2.60E+03

3.42

1.4

component 7

3.70E+03

3.57

1.8

Validity criteria fulfilled:
yes
Conclusions:
The log Koc of Amphopropionate C8 is, for the different components, in the range of < 2.1 to 3.57 at pH 2.0 and < 2.1 to >5.63 at pH 7.0.
Executive summary:

In a screening study conducted according to OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)) the log Koc value of Amphopropionate C8 was determined at pH 2 and pH 7.

According to guidelines, the determination of the Koc of the test substance should be performed in its non-ionised form. Therefore, the pKa values of the test substance were calculated using Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International). These calculations show that there is not a pH at which all ionisable groups are in their non-ionised form. At pH 2, net charge of the test substance is zero and, thus, the test was performed at this pH. However, because this pH was not in the environmentally relevant range of pH 5.0-9.0, an additional test was performed at neutral pH. Under these conditions, the net charge will deviate from zero.

In the chromatograms of the test substance solutions, several test substance peaks were observed. Some peaks were broad indicating not pure reverse phase retention as required for accurate determination of Koc. Because a different method to determine Koc is not applicable, these values were reported as a range. The log Koc of Amphopropionate C8 is, for the different components, in the range of < 2.1 to 3.57 at pH 2.0 and < 2.1 to >5.63 at pH 7.0.

Description of key information

< 2.1 to >430000 at pH 7.0 (OECD TG 121; RL1; GLP), read-across: Amphopropionate C8

Key value for chemical safety assessment

Additional information

In a screening study conducted according to OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)) the log Koc value of Amphopropionate C8 was determined at pH 2 and pH 7.

According to guidelines, the determination of the Koc of the test substance should be performed in its non-ionised form. Therefore, the pKa values of the test substance were calculated using Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International). These calculations show that there is not a pH at which all ionisable groups are in their non-ionised form. At pH 2, net charge of the test substance is zero and, thus, the test was performed at this pH. However, because this pH was not in the environmentally relevant range of pH 5.0-9.0, an additional test was performed at neutral pH. Under these conditions, the net charge will deviate from zero.

In the chromatograms of the test substance solutions, several test substance peaks were observed. Some peaks were broad indicating not pure reverse phase retention as required for accurate determination of Koc. Because a different method to determine Koc is not applicable, these values were reported as a range. The Koc of Amphopropionate C8 is, for the different components, in the range of < 2.1 to 37000 at pH 2.0 and < 2.1 to >430000 at pH 7.0.

The results indicate a high adsorption potential for the main components at neutral pH (Koc = >4.3E05).

 

Similar results were obtained for the target substance itself from a calculation using the individual chain lengths:

Amphopropionates C12-18 is a UVCB substance containing C8-, C10-, C12-, C14-, C16-, and C18-alkyl side chains. Based on this and the variable composition of the compound (alkyl chain distribution dependent on origin of the coco fatty acid) the calculation of physico-chemical properties for the mixture is not feasible. To get a hint on the physico-chemical data, the EPIWIN calculation was conducted for the C8 and the C18 derivatives. The soil sorption coefficients Koc of the substance were calculated using EPIWIN v3.20, PCKOCWIN v1.66. The calculation yielded Koc values in the range between 23.57 (log Koc=1.372) (C8 -derivative) and 10740 (log Koc=4.494) (C18 -derivative). Based on these results and taking into account the classification scheme of Blume & Ahlsdorf (1993), a very low sorption onto soil organic matter is to be expected for the short chain compound (C8-derivative) and a very high for the long chain compound (C18 -derivative).

 

Justification for read-across

For details on substance identity and detailed (eco)toxicological profiles, please refer also to the general justification for read-across given at the beginning of the CSR and attached as pdf document to IUCLID section 13.

This read-across approach is justified based on structural similarities. The target and source substances contain the same functional groups. Thus a common mode of action can be assumed.

 

Structural similarity and functional groups

The target substance Amphopropionates C12-18 is manufactured from fatty acids (C12-18, C18unsatd.) and aminoethylethanolamie (AEEA) to form 1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-(C11-C17 odd-numbered, C17unsatd. alkyl) derivs. This is further reacted with 2-propenoic acid in the presence of sodium hydroxide (alternatively, sodium 2-propenoate can be used) and water. The molar relation between 1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-(C11-C17, C17unsatd. alkyl) derivs. and 2-propenoic acid is somewhat below 1:1. Most of the excess 2-propenoic acid is stripped off by distillation. However, a small amount remains in the aqueous solution.

 

The source substance Amphopropionate C8 is manufactured from capric acid and aminoethylethanolamine (AEEA) to form 1-(2-Hydroxyethyl)-2-Heptylimidazoline. Excess AEEA is removed from the reaction mixture by distillation at elevated temperature. In a further step 2-propenoic acid is added to form Amphopropionate C8. Most of the excess 2-propenoic acid is stripped off by distillation. However, a small amount remains in the aqueous solution.

 

Differences

Chain length:

The source substance Amphopropionate C8 contains shorter C chains, whereas the major C chain in the target substance is C12.

Compounds with higher chains lengths are expected to show a higher sorption potential to the organic matter of soils and sediments.

 

Comparison of data on adsorption

 

 

Target substance

Source substance

Endpoint

Amphopropionates C12-18

Amphopropionate C8

Adsorption / Desorption

WoE_Adsorption / desorption.93820-52-1_9.3.1_CFCS_EPIWIN (C8/C18)_2008

 

Calculation, EPIWIN v3.20, PCKOCWIN v1.66

 

Koc = 23.57 (C8-derivative)

log Koc=1.372 (C8-derivative)

Koc = 10740 (C18-derivative)

log Koc=4.494 (C18-derivative)

 

4 (not assignable)

WoE_RA_Adsorption / desorption: 64265-45-8_9.3.1_Evonik_2007_121

 

OECD TG 121, HPLC screening method

 

Koc < 2.1 to 37000 at pH 2.0

Log Koc <1.32 – 3.57 at pH 2

(main component: Koc = 2.8 at pH 2)

Koc < 2.1 to >430000 at pH 7.0

Log Koc <1.32 – 5.63 at pH 7.0

(main components: Koc = >4.3E05 at pH 7)

 

 

1 (reliable without restriction), GLP

 

No experimental data are available for the target substance Amphopropionates C12-18. A calculation using EPIWIN v3.20, PCKOCWIN v1.66 is used as supporting information.

In the screening study conducted with the source substance Amphopropionate C8 the Koc was in the range of < 2.1 to 37000 at pH 2.0 and < 2.1 to >430000 at pH 7.0 for the different components.

 

Quality of the experimental data of the analogues:

The available data are adequate and sufficiently reliable to justify the read-across approach.

The study was conducted according to OECD Guideline 121, and is reliable without restrictions (RL1).

The test materials used in the respective studies represent the source substance as described in the hypothesis in terms of substance identity and minor constituents.

Overall, the study results are adequate for the purpose of classification and labelling and risk assessment.

 

Conclusion

The structural similarities between the source and the target substances presented above and in more detail in the general justification for read-across support the read-across hypothesis.

The screening study conducted with the source substance Amphopropionate C8 indicates a high adsorption potential for the main components at neutral pH (Koc = >4.3E05). Based on the even longer C chains present in the target substance, high adsorption should be assumed for the target substance Amphopropionates C12-18.