Imidazolium compounds, 2-(C9-19 and C9-19-unsatd. alkyl)-1-[(C10-20 and C10-20-unsatd. amido)ethyl]-4,5-dihydro-1-Me, Me sulfates

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

From March 07, 2018 to March 15, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 115: Surface Tension of Aqueous Solutions

Version / remarks:

27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EU Method A5: Surface tension

Version / remarks:

30 May 2008

Deviations:

no

Principles of method if other than guideline:

Below the CMC, a surfactant is considered to be thermodynamically soluble in the water; whereas above the CMC, the solubility of a surfactant in water has been exceeded and the excess surfactant aggregates to form micelles. These micelles have significantly less effect on the surface tension of a solution and are considered not to be in solution. Thus, the water solubility of a surfactant may be expressed in terms of the CMC.

GLP compliance:

no

Remarks:

The study was conducted in a facility which operates in accordance with Good Laboratory Practice principles; however no claim of GLP compliance was intended nor is made for this study

Type of method:

other: by determining the surface tension of a range of aqueous sample solutions of differing concentration

Key result

Conc. based on:

test mat.

Incubation duration:

ca. 17.5 h

Temp.:

20 °C

pH:

ca. 4.85 - ca. 5.84

Remarks on result:

other: The critical micelle concentration of the test substance at 20.0 ± 0.5 °C could not be determined

Details on results:

Please see below table.

Results

The readings and temperatures for the sample solutions are shown in the following table:

Table1: Surface tension values

Concentration (mg/L)	Reading (mN/m)	Temperature (°C)
1.011 x 10^4	40.5	20.0
	38.0	20.0
	38.0	20.0
	38.0	20.0
3.034 x 10^3	45.0	20.0
	44.0	20.0
	44.0	20.0
	44.0	20.0
1.011 x 10^3	49.0	20.0
	48.0	20.0
	48.0	20.0
	48.0	20.0
303.4	54.0	20.0
	52.5	20.0
	52.0	20.0
	52.0	20.0
	52.0	20.0
101.1	58.0	20.0
	56.5	20.0
	56.5	20.0
	58.5	20.0
	59.0	20.0
	59.0	20.0
	61.0	20.0
	60.0	20.0
	60.0	20.0
	60.0	20.0
30.34	61.0	20.0
	61.0	20.0
	61.0	20.0
10.11	66.5	20.0
	65.5	20.0
	68.0	20.0
	67.0	20.0
	67.0	20.0
	67.0	20.0
3.034	71.5	20.0
	69.5	20.0
	70.5	20.0
	69.5	20.0
	69.5	20.0
	69.5	20.0
1.011	72.5	20.0
	70.5	20.0
	70.5	20.0
	70.5	20.0

Mean surface tension values were based on the last three readings for a particular concentration which were considered to be constant.

The concentration (mg/L), log₁₀ [concentration (mg/L)] and mean surface tension values for the sample solutions are shown in the following table:

 

Table 2: The concentration (mg/L), log₁₀ [concentration (mg/L)] and mean surface tension values

Concentration (mg/L)	Log10Concentration	Mean Surface Tension (mN/m)	Solution pH
1.011 x 10^4	4.005	38.0	5.71
3.034 x 10^3	3.482	44.0	5.40
1.011 x 10^3	3.005	48.0	5.17
303.4	2.482	52.0	5.09
101.1	2.005	60.0	4.85
30.34	1.482	61.0	5.24
10.11	1.005	67.0	5.44
3.034	0.482	69.5	5.57
1.011	0.005	70.5	5.84

The greenlinewasgenerated from linear regression of7sample solution concentrations. The red line was not allocated any samples as there was no definitive CMC event observed.

GreenLine equation: y =-9.49x +76.5

Thesample solutionsat 3.034 and 1.011mg/L were not used in generating the line.

Overall, no value for the CMC could be determined.

The surface tension at 1 g/L was determined to be 48.0 ± 0.5mN/m.

Conclusions:

Under the study conditions, the CMC or water solubility of the test substance could not be determined in the study at 20.0 ± 0.5°C.

Executive summary:

A study was conducted to determine the critical micelle concentration (i.e., water solubility equivalent for surfactants) of the test substance, 'di-C16 and C18 -unsatd. AAEMIM-MS', by determining the surface tension of a range of aqueous sample solutions of differing concentration, according to OECD Guideline 115 and EU Method A.5. Due to the surface activity of the test substance, the CMC value was considered as a water soluibility equivalent in accordance with the ECHA R.7a Guidance. Under the study conditions, the CMC or water solubility of the test substance could not be determined in the study at 20.0 ± 0.5°C (Envigo, 2018).

Reference 2

Endpoint:

water solubility

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, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction from an well known and acknowledged tool. See below under 'Overall remarks, attachments' for applicability domain.

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs: Chapter R.6. QSARs and grouping of chemicals

Principles of method if other than guideline:

Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the partition coefficient values were estimated for the individual components followed by the determination of an overall weighted-average value using the mole fractions of all the individual components.

Key result

Water solubility:

ca. 0.015 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: Weighted average water solubility estimation using WSKOWWIN v1.42

Key result

Water solubility:

ca. 0.123 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: Weighted average water solubility estimation using WATERNT v1.01

QSAR full test results

(A) WSKOWWIN v1.42

Chemical names	SMILES	Mole fraction Xi = (mi/Mi)/∑ (mi/Mi)	WSKOW	WSKOW*xi	Domain evaluation
Glyceryl monoester C16	CCCCCCCCCCCCCCCC(=O)OCC(O)CO	0.069569	1.25E-01	8.71E-03	ID - Molecular weight, partition coefficient
hexadecanoic acid	CCCCCCCCCCCCCCCC(O)=O	0.089667	4.07E-02	3.65E-03	ID - Molecular weight, partition coefficient
Glyceryl monoester C18:1	CCCCCCCCC=CCCCCCCCC(=O)OCC(O)CO	0.058626	1.93E-02	1.13E-03	ID - Molecular weight, partition coefficient
Oleic acid (C18:1)	CCCCCCCCC=CCCCCCCCC(O)=O	0.074001	1.15E-02	8.52E-04	ID - Molecular weight, partition coefficient
Glyceryl monoester C18:2	CCCCCC=CCC=CCCCCCCCC(=O)OCC(O)CO	0.014740	3.03E-02	4.47E-04	ID - Molecular weight, partition coefficient
(9Z,12Z)-octadeca-9,12-dienoic acid	CCCCCC=CCC=CCCCCCCCC(O)=O	0.018633	3.77E-02	7.03E-04	ID - Molecular weight, partition coefficient
Fatty quaternized imidazolines C16/C16	COS([O])(=O)=OCCCCCCCCCCCCCCCC(=O)NCC[N]1(C)CCN=C1CCCCCCCCCCCCCCC	0.298770	1.27E-09	3.81E-10	OD - Molecular weight, ID- partition coefficients
Fatty quaternized imidazolines C18:1/C18:1	COS([O])(=O)=OCCCCCCCCC=CCCCCCCCC(=O)NCC[N]1(C)CCN=C1CCCCCCCC=CCCCCCCCC	0.252500	2.74E-11	6.92E-12	OD - Molecular weight, ID- partition coefficients
Fatty quaternized imidazolines C18:2/C18:2	COS([O])(=O)=OCCCCCC=CCC=CCCCCCCCC(=O)NCC[N]1(C)CCN=C1CCCCCCCC=CCC=CCCCCC	0.063471	6.80E-11	4.31E-12	OD - Molecular weight, ID- partition coefficients
Glycerated imidazolines of combinations of C16:0 and C18:1	CCCCCCCCCCCCCCCC1=NCCN1CCN(CC(O)CO)C(=O)CCCCCCCC=CCCCCCCCC	0.041255	5.77E-10	2.38E-11	OD - Molecular weight, partition coefficients
Diamidoamine intermediates of combinations of C16:0, C18:1, and C18:2	CCCCCCCCCCCCCCCC(=O)NCCNCCNC(=O)CCCCCCCC=CCCCCCCCC	0.018767	4.87E-09	9.15E-11	ID - Molecular weight, OD- partition coefficients
		1.0000000		0.015

ID - In domain, MW - Molecular weight

WSKOW
Water Sol: 0.1252 mg/L
SMILES : CCCCCCCCCCCCCCCC(=O)OCC(O)CO
CHEM  :
MOL FOR: C19 H38 O4							Molecular weight
MOL WT : 330.51						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 5.63
Log Kow (experimental): not available from database							Log Kow
Log Kow used by Water solubility estimates: 5.63						ID	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -6.422
Water Solubility at 25 deg C (mg/L): 0.1252
Water Sol: 0.04073 mg/L
Experimental Water Solubility Database Match:
Name    : PALMITIC ACID
CAS Num : 000057-10-3
Exp WSol : 0.04 mg/L (25 deg C)
Exp Ref : ROBB,ID (1966)
SMILES : CCCCCCCCCCCCCCCC(=O)(O)
CHEM  :
MOL FOR: C16 H32 O2							Molecular weight
MOL WT : 256.43						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 6.96
Log Kow (experimental): 7.17							Log Kow
Cas No: 000057-10-3						ID	-3.89	8.27
Name : PALMITIC ACID
Refer : SANGSTER (1993)
Log Kow used by Water solubility estimates: 7.17
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
Acid, aliphatic      0.395
Log Water Solubility (in moles/L) : -6.799
Water Solubility at 25 deg C (mg/L): 0.04073
Water Sol: 0.01931 mg/L
SMILES : CCCCCCCCC=CCCCCCCCC(=O)OCC(O)CO
CHEM  :
MOL FOR: C21 H40 O4							Molecular weight
MOL WT : 356.55						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 6.40
Log Kow (experimental): not available from database							Log Kow
Log Kow used by Water solubility estimates: 6.40						ID	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -7.266
Water Solubility at 25 deg C (mg/L): 0.01931
Water Sol: 0.01151 mg/L
SMILES : CCCCCCCCC=CCCCCCCCC(=O)(O)
CHEM  :
MOL FOR: C18 H34 O2							Molecular weight
MOL WT : 282.47						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 7.73
Log Kow (experimental): 7.64							Log Kow
Cas No: 002027-47-6						ID	-3.89	8.27
Name : 9-OCTADECENOIC ACID
Refer : SANGSTER (1993)
Log Kow used by Water solubility estimates: 7.64
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
Acid, aliphatic      0.395
Log Water Solubility (in moles/L) : -7.390
Water Solubility at 25 deg C (mg/L): 0.01151
Water Sol: 0.03031 mg/L
SMILES : CCCCCC=CCC=CCCCCCCCC(=O)OCC(O)CO
CHEM  :
MOL FOR: C21 H38 O4							Molecular weight
MOL WT : 354.53						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 6.19
Log Kow (experimental): not available from database							Log Kow
Log Kow used by Water solubility estimates: 6.19						ID	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -7.068
Water Solubility at 25 deg C (mg/L): 0.03031
Water Sol: 0.03771 mg/L
SMILES : CCCCCC=CCC=CCCCCCCCC(=O)(O)
CHEM  :
MOL FOR: C18 H32 O2							Molecular weight
MOL WT : 280.45						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 7.51
Log Kow (experimental): 7.05							Log Kow
Cas No: 000060-33-3						ID	-3.89	8.27
Name : LINOLEIC ACID
Refer : SANGSTER (1993)
Log Kow used by Water solubility estimates: 7.05
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
Acid, aliphatic      0.395
Log Water Solubility (in moles/L) : -6.871
Water Solubility at 25 deg C (mg/L): 0.03771
Water Sol: 1.247e-009 mg/L
SMILES : CCCCCCCCCCCCCCCC(=O)NCCN1(C)(OS(=O)(=O)OC)CCN=C1CCCCCCCCCCCCCCC
CHEM  :
MOL FOR: C38 H77 N3 O5 S1						Molecular weight
MOL WT : 688.11					OD	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 12.33
Log Kow (experimental): not available from database						Log Kow
Log Kow used by Water solubility estimates: 12.33					ID	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -14.742
Water Solubility at 25 deg C (mg/L): 1.247e-009
Water Sol: 2.742e-011 mg/L
SMILES : CCCCCCCCC=CCCCCCCCC(=O)NCCN1(C)(OS(=O)(=O)OC)CCN=C1CCCCCCCC=CCCCCCCCC
CHEM  :						Molecular weight
MOL FOR: C42 H81 N3 O5 S1					OD	27.03	627.62
MOL WT : 740.19
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 13.86						Log Kow
Log Kow (experimental): not available from database					ID	-3.89	8.27
Log Kow used by Water solubility estimates: 13.86
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -16.431
Water Solubility at 25 deg C (mg/L): 2.742e-011
Water Sol: 6.795e-011 mg/L
SMILES : CCCCCC=CCC=CCCCCCCCC(=O)NCCN1(C)(OS(=O)(=O)OC)CCN=C1CCCCCCCC=CCC=CCCC
CC
CHEM  :
MOL FOR: C42 H77 N3 O5 S1							Molecular weight
MOL WT : 736.16						OD	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 13.43
Log Kow (experimental): not available from database							Log Kow
Log Kow used by Water solubility estimates: 13.43						ID	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -16.035
Water Solubility at 25 deg C (mg/L): 6.795e-011
Water Sol: 5.774e-010 mg/L
SMILES : CCCCCCCCCCCCCCCC1=NCCN1CCN(CC(O)CO)C(=O)CCCCCCCC=CCCCCCCCC
CHEM  :
MOL FOR: C41 H79 N3 O3							Molecular weight
MOL WT : 662.11						OD	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 12.92
Log Kow (experimental): not available from database							Log Kow
Log Kow used by Water solubility estimates: 12.92						OD	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -15.059
Water Solubility at 25 deg C (mg/L): 5.774e-010
SMILES : CCCCCCCCCCCCCCCC(=O)NCCNCCNC(=O)CCCCCCCC=CCCCCCCCC
CHEM  :
MOL FOR: C38 H75 N3 O2							Molecular weight
MOL WT : 606.04						ID	27.03	627.62
---------------------------------- WSKOW v1.42 Results ------------------------
Log Kow (estimated) : 12.27
Log Kow (experimental): not available from database							Log Kow
Log Kow used by Water solubility estimates: 12.27						OD	-3.89	8.27
Equation Used to Make Water Sol estimate:
Log S (mol/L) = 0.796 - 0.854 log Kow - 0.00728 MW + Correction
(used when Melting Point NOT available)
Correction(s):        Value
--------------------  -----
No Applicable Correction Factors
Log Water Solubility (in moles/L) : -14.095
Water Solubility at 25 deg C (mg/L): 4.873e-009

(B) WATERNT v1.01

Chemical names	SMILES	Mole fraction Xi = (mi/Mi)/∑ (mi/Mi)	WATERNT	WATERINT*xi	Domain evaluation
Glyceryl monoester C16	CCCCCCCCCCCCCCCC(=O)OCC(O)CO	0.069569	1.27E+00	8.85E-02	ID - Molecular weight, OD- molecular fragments
hexadecanoic acid	CCCCCCCCCCCCCCCC(O)=O	0.089667	9.99E-02	8.95E-03	ID - Molecular weight, molecular fragments
Glyceryl monoester C18:1	CCCCCCCCC=CCCCCCCCC(=O)OCC(O)CO	0.058626	2.56E-01	1.50E-02	ID - Molecular weight, OD- molecular fragments
Oleic acid (C18:1)	CCCCCCCCC=CCCCCCCCC(O)=O	0.074001	2.05E-02	1.52E-03	ID - Molecular weight, molecular fragments
Glyceryl monoester C18:2	CCCCCC=CCC=CCCCCCCCC(=O)OCC(O)CO	0.014740	5.63E-01	8.30E-03	ID - Molecular weight, molecular fragments
(9Z,12Z)-octadeca-9,12-dienoic acid	CCCCCC=CCC=CCCCCCCCC(O)=O	0.018633	4.51E-02	8.40E-04	ID - Molecular weight, molecular fragments
Fatty quaternized imidazolines C16/C16	COS([O])(=O)=OCCCCCCCCCCCCCCCC(=O)NCC[N]1(C)CCN=C1CCCCCCCCCCCCCCC	0.298770	6.88E-07	2.06E-07	OD - Molecular weight, molecular fragments
Fatty quaternized imidazolines C18:1/C18:1	COS([O])(=O)=OCCCCCCCCC=CCCCCCCCC(=O)NCC[N]1(C)CCN=C1CCCCCCCC=CCCCCCCCC	0.252500	7.40E-07	1.87E-07	OD - Molecular weight, molecular fragments
Fatty quaternized imidazolines C18:2/C18:2	COS([O])(=O)=OCCCCCC=CCC=CCCCCCCCC(=O)NCC[N]1(C)CCN=C1CCCCCCCC=CCC=CCCCCC	0.063471	7.36E-07	4.67E-08	OD - Molecular weight, molecular fragments
Glycerated imidazolines of combinations of C16:0 and C18:1	CCCCCCCCCCCCCCCC1=NCCN1CCN(CC(O)CO)C(=O)CCCCCCCC=CCCCCCCCC	0.041255	6.62E-07	2.73E-08	OD - Molecular weight, molecular fragments
Diamidoamine intermediates of combinations of C16:0, C18:1, and C18:2	CCCCCCCCCCCCCCCC(=O)NCCNCCNC(=O)CCCCCCCC=CCCCCCCCC	0.018767	6.06E-07	1.14E-08	ID - Molecular weight, OD- molecular fragments
		1.0000000		0.123

ID - In domain, OD - Out domain, MW - Molecular weight

WATERINT
Water Sol (v1.01 est): 1.2721 mg/L
SMILES : CCCCCCCCCCCCCCCC(=O)OCC(O)CO
CHEM  :						Domain evaluation
MOL FOR: C19 H38 O4							Molecular weight
MOL WT : 330.51						ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 1 | -CH3   [aliphatic carbon]               |-0.3213  | -0.3213							ID	6
Frag | 16 | -CH2-  [aliphatic carbon]               |-0.5370  | -8.5923							OD	14
Frag | 1 | -CH    [aliphatic carbon]               |-0.5285  | -0.5285							ID	6
Frag | 2 | -OH    [hydroxy, aliphatic attach]      | 1.6012  | 3.2025							ID	4
Frag | 1 | -C(=O)O [ester, aliphatic attach]       | 0.5757  | 0.5757							ID	5
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C =  -5.4147
Water Solubility (mg/L) at 25 dec C =  1.2721
Water Sol (v1.01 est): 0.099869 mg/L
Experimental Water Solubility Database Match:
Name    : PALMITIC ACID
CAS Num : 000057-10-3
Exp WSol : 0.04 mg/L (25 deg C)
Exp Ref : ROBB,ID (1966)
SMILES : CCCCCCCCCCCCCCCC(=O)(O)
CHEM  :						Domain evaluation
MOL FOR: C16 H32 O2							Molecular weight
MOL WT : 256.43						ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 1 | -CH3   [aliphatic carbon]               |-0.3213  | -0.3213							ID	1
Frag | 14 | -CH2-  [aliphatic carbon]               |-0.5370  | -7.5183							ID	14
Frag | 1 | -COOH  [acid, aliphatic attach]         | 1.1808  | 1.1808							ID	1
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C =  -6.4095
Water Solubility (mg/L) at 25 dec C = 0.099869
Water Sol (v1.01 est): 0.25601 mg/L
SMILES : CCCCCCCCC=CCCCCCCCC(=O)OCC(O)CO
CHEM  :							Domain evaluation
MOL FOR: C21 H40 O4								Molecular weight
MOL WT : 356.55							ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 1 | -CH3   [aliphatic carbon]               |-0.3213  | -0.3213							ID	6
Frag | 16 | -CH2-  [aliphatic carbon]               |-0.5370  | -8.5923							OD	14
Frag | 1 | -CH    [aliphatic carbon]               |-0.5285  | -0.5285							ID	6
Frag | 2 | =CH- or =C< [olefinc carbon]            |-0.3646  | -0.7292							ID	6
Frag | 2 | -OH    [hydroxy, aliphatic attach]      | 1.6012  | 3.2025							ID	4
Frag | 1 | -C(=O)O [ester, aliphatic attach]       | 0.5757  | 0.5757							ID	5
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C =  -6.1439
Water Solubility (mg/L) at 25 dec C = 0.25601
Water Sol (v1.01 est): 0.020522 mg/L
SMILES : CCCCCCCCC=CCCCCCCCC(=O)(O)
CHEM  :							Domain evaluation
MOL FOR: C18 H34 O2								Molecular weight
MOL WT : 282.47							ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 1 | -CH3   [aliphatic carbon]               |-0.3213  | -0.3213							ID	6
Frag | 14 | -CH2-  [aliphatic carbon]               |-0.5370  | -7.5183							ID	14
Frag | 2 | =CH- or =C< [olefinc carbon]            |-0.3646  | -0.7292							ID	6
Frag | 1 | -COOH  [acid, aliphatic attach]         | 1.1808  | 1.1808							ID	1
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C =  -7.1387
Water Solubility (mg/L) at 25 dec C = 0.020522
Water Sol (v1.01 est): 0.56317 mg/L
SMILES : CCCCCC=CCC=CCCCCCCCC(=O)OCC(O)CO
CHEM  :							Domain evaluation
MOL FOR: C21 H38 O4								Molecular weight
MOL WT : 354.53							ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 1 | -CH3   [aliphatic carbon]               |-0.3213  | -0.3213							ID	6
Frag | 14 | -CH2-  [aliphatic carbon]               |-0.5370  | -7.5183							ID	14
Frag | 1 | -CH    [aliphatic carbon]               |-0.5285  | -0.5285							ID	6
Frag | 4 | =CH- or =C< [olefinc carbon]            |-0.3646  | -1.4584							ID	6
Frag | 2 | -OH    [hydroxy, aliphatic attach]      | 1.6012  | 3.2025							ID	4
Frag | 1 | -C(=O)O [ester, aliphatic attach]       | 0.5757  | 0.5757							ID	5
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C =  -5.7990
Water Solubility (mg/L) at 25 dec C = 0.56317
Water Sol (v1.01 est): 0.045077 mg/L
SMILES : CCCCCC=CCC=CCCCCCCCC(=O)(O)
CHEM  :							Domain evaluation
MOL FOR: C18 H32 O2								Molecular weight
MOL WT : 280.45							ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 1 | -CH3   [aliphatic carbon]               |-0.3213  | -0.3213							ID	6
Frag | 12 | -CH2-  [aliphatic carbon]               |-0.5370  | -6.4442							ID	14
Frag | 4 | =CH- or =C< [olefinc carbon]            |-0.3646  | -1.4584							ID	6
Frag | 1 | -COOH  [acid, aliphatic attach]         | 1.1808  | 1.1808							ID	1
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C =  -6.7939
Water Solubility (mg/L) at 25 dec C = 0.045077
Water Sol (v1.01 est): 6.8811e-007 mg/L
SMILES : CCCCCCCCCCCCCCCC(=O)NCCN1(C)(OS(=O)(=O)OC)CCN=C1CCCCCCCCCCCCCCC
CHEM  :							Domain evaluation
MOL FOR: C38 H77 N3 O5 S1								Molecular weight
MOL WT : 688.11							OD	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 4 | -CH3   [aliphatic carbon]               |-0.3213  | -1.2851							ID	6
Frag | 30 | -CH2-  [aliphatic carbon]               |-0.5370  |-16.1106							OD	14
Frag | 1 | C    [aliphatic carbon - No H, not tert] |-1.0516  | -1.0516							ID	2
Frag | 1 | -O-    [oxygen, aliphatic attach]       | 1.2746  | 1.2746							ID	3
Frag | 1 | -NH-   [aliphatic attach]               | 2.1357  | 2.1357							ID	2
Frag | 1 | -C(=O)N [aliphatic attach]              |-0.2426  | -0.2426							ID	2
Frag | 2 | -CH2- [aliphatic carbon, cyclic]        |-0.3308  | -0.6617							ID	8
Frag | 1 | >N< [+5 valence; single bonds;no H attach]| 0.0000  | 0.0000							ID	5
Frag | 1 | -O-SO2-O-    [sulfate, linear]          |-2.6175  | -2.6175
Frag | 1 | -N=C    [aliphatic attach]              | 0.0000  | 0.0000
Frag | 1 | {-O- or -S-} to nitrogen (+5 valence)]   | 0.0000 **| 0.0000
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
NOTE |    | An estimated coefficient (**) used                  |
-------+-----+--------------------------------------------+----------+---------
NOTE |    | Minimum Solubility (log S = -12.00) Applied!        |
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C = -12.0000
Water Solubility (mg/L) at 25 dec C =6.8811e-007
Water Sol (v1.01 est): 7.4019e-007 mg/L
SMILES : CCCCCCCCC=CCCCCCCCC(=O)NCCN1(C)(OS(=O)(=O)OC)CCN=C1CCCCCCCC=CCCCCCCCC
							Domain evaluation
CHEM  :								Molecular weight
MOL FOR: C42 H81 N3 O5 S1							OD	30.3	627.62
MOL WT : 740.19
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------							ID	6
Frag | 4 | -CH3   [aliphatic carbon]               |-0.3213  | -1.2851							OD	14
Frag | 30 | -CH2-  [aliphatic carbon]               |-0.5370  |-16.1106							ID	2
Frag | 1 | C    [aliphatic carbon - No H, not tert] |-1.0516  | -1.0516							ID	6
Frag | 4 | =CH- or =C< [olefinc carbon]            |-0.3646  | -1.4584							ID	3
Frag | 1 | -O-    [oxygen, aliphatic attach]       | 1.2746  | 1.2746							ID	2
Frag | 1 | -NH-   [aliphatic attach]               | 2.1357  | 2.1357							ID	2
Frag | 1 | -C(=O)N [aliphatic attach]              |-0.2426  | -0.2426							Id	8
Frag | 2 | -CH2- [aliphatic carbon, cyclic]        |-0.3308  | -0.6617							Id	5
Frag | 1 | >N< [+5 valence; single bonds;no H attach]| 0.0000  | 0.0000
Frag | 1 | -O-SO2-O-    [sulfate, linear]          |-2.6175  | -2.6175
Frag | 1 | -N=C    [aliphatic attach]              | 0.0000  | 0.0000
Frag | 1 | {-O- or -S-} to nitrogen (+5 valence)]   | 0.0000 **| 0.0000
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
NOTE |    | An estimated coefficient (**) used                  |
-------+-----+--------------------------------------------+----------+---------
NOTE |    | Minimum Solubility (log S = -12.00) Applied!        |
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C = -12.0000
Water Solubility (mg/L) at 25 dec C =7.4019e-007
Water Sol (v1.01 est): 7.3616e-007 mg/L
SMILES : CCCCCC=CCC=CCCCCCCCC(=O)NCCN1(C)(OS(=O)(=O)OC)CCN=C1CCCCCCCC=CCC=CCCC
CC							Domain evaluation
CHEM  :								Molecular weight
MOL FOR: C42 H77 N3 O5 S1							OD	30.3	627.62
MOL WT : 736.16
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------							ID	6
Frag | 4 | -CH3   [aliphatic carbon]               |-0.3213  | -1.2851							OD	14
Frag | 26 | -CH2-  [aliphatic carbon]               |-0.5370  |-13.9625							ID	2
Frag | 1 | C    [aliphatic carbon - No H, not tert] |-1.0516  | -1.0516							OD	6
Frag | 8 | =CH- or =C< [olefinc carbon]            |-0.3646  | -2.9168							ID	3
Frag | 1 | -O-    [oxygen, aliphatic attach]       | 1.2746  | 1.2746							ID	2
Frag | 1 | -NH-   [aliphatic attach]               | 2.1357  | 2.1357							ID	2
Frag | 1 | -C(=O)N [aliphatic attach]              |-0.2426  | -0.2426							ID	8
Frag | 2 | -CH2- [aliphatic carbon, cyclic]        |-0.3308  | -0.6617							ID	5
Frag | 1 | >N< [+5 valence; single bonds;no H attach]| 0.0000  | 0.0000
Frag | 1 | -O-SO2-O-    [sulfate, linear]          |-2.6175  | -2.6175
Frag | 1 | -N=C    [aliphatic attach]              | 0.0000  | 0.0000
Frag | 1 | {-O- or -S-} to nitrogen (+5 valence)]   | 0.0000 **| 0.0000
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
NOTE |    | An estimated coefficient (**) used                  |
-------+-----+--------------------------------------------+----------+---------
NOTE |    | Minimum Solubility (log S = -12.00) Applied!        |
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C = -12.0000
Water Solubility (mg/L) at 25 dec C =7.3616e-007
Water Sol (v1.01 est): 6.6211e-007 mg/L
SMILES : CCCCCCCCCCCCCCCC1=NCCN1CCN(CC(O)CO)C(=O)CCCCCCCC=CCCCCCCCC							Domain evaluation
CHEM  :
MOL FOR: C41 H79 N3 O3								Molecular weight
MOL WT : 662.11							OD	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 2 | -CH3   [aliphatic carbon]               |-0.3213  | -0.6425							ID	6
Frag | 32 | -CH2-  [aliphatic carbon]               |-0.5370  |-17.1846							OD	14
Frag | 1 | -CH    [aliphatic carbon]               |-0.5285  | -0.5285							ID	6
Frag | 1 | C    [aliphatic carbon - No H, not tert] |-1.0516  | -1.0516							ID	2
Frag | 2 | =CH- or =C< [olefinc carbon]            |-0.3646  | -0.7292							ID	6
Frag | 2 | -OH    [hydroxy, aliphatic attach]      | 1.6012  | 3.2025							ID	4
Frag | 2 | -N<    [aliphatic attach]               | 1.9643  | 3.9286							ID	2
Frag | 1 | -C(=O)N [aliphatic attach]              |-0.2426  | -0.2426							ID	2
Frag | 2 | -CH2- [aliphatic carbon, cyclic]        |-0.3308  | -0.6617							ID	8
Frag | 1 | -N=C    [aliphatic attach]              | 0.0000  | 0.0000
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
NOTE |    | Minimum Solubility (log S = -12.00) Applied!        |
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C = -12.0000
Water Solubility (mg/L) at 25 dec C =6.6211e-007
Water Sol (v1.01 est): 6.0604e-007 mg/L
SMILES : CCCCCCCCCCCCCCCC(=O)NCCNCCNC(=O)CCCCCCCC=CCCCCCCCC
CHEM  :							Domain evaluation
MOL FOR: C38 H75 N3 O2								Molecular weight
MOL WT : 606.04							ID	30.3	627.62
-------+-----+--------------------------------------------+----------+---------
TYPE | NUM |   WATER SOLUBILITY FRAGMENT DESCRIPTION  | COEFF  | VALUE
-------+-----+--------------------------------------------+----------+---------
Frag | 2 | -CH3   [aliphatic carbon]               |-0.3213  | -0.6425							ID	6
Frag | 32 | -CH2-  [aliphatic carbon]               |-0.5370  |-17.1846							OD	14
Frag | 2 | =CH- or =C< [olefinc carbon]            |-0.3646  | -0.7292							ID	6
Frag | 3 | -NH-   [aliphatic attach]               | 2.1357  | 6.4071							OD	2
Frag | 2 | -C(=O)N [aliphatic attach]              |-0.2426  | -0.4852							ID	2
Const |    | Equation Constant                        |         | 0.2492
-------+-----+--------------------------------------------+----------+---------
NOTE |    | Minimum Solubility (log S = -12.00) Applied!        |
-------+-----+--------------------------------------------+----------+---------
Log Water Sol (moles/L) at 25 dec C = -12.0000
Water Solubility (mg/L) at 25 dec C =6.0604e-007

Conclusions:

The estimated weighted average water solubility values of the test substance were calculated to be 0.015 and 0.123 mg/L, in WSKOWIN v1.42 and WATERNT v1.01 models, respectively.

Executive summary:

The water solubility values for the test substance, 'di-C16 and C18 -unsatd. AAEMIM-MS', was estimated using the WSKOWIN v1.42 and WATERNT v1.01 programs of EPI Suite v4.11. Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the partition coefficient values were estimated for the individual components followed by the determination of an overall weighted-average value using the mole fractions of all the individual components. SMILES codes were used as the input parameter for the partition coefficient estimation for the individual constituents. The estimated water solubility values for the constituents ranged from 2.74E-11 to 1.25E-01 and 6.06E-07 to 1.27 mg/L using WSKOWIN v1.42 and WATERNT v1.01 models, respectively. The estimated weighted average water solubility values for the overall test substance were calculated to be 0.015 and 0.123 mg/L using WSKOWIN v1.42 and WATERNT v1.01 models, respectively (US EPA, 2018). The estimates for the major constituents from WSKOWIN v1.42 and WATERNT v1.01 models are considered to be reliable with restrictions, as they do not completely fall within of the applicability domain.

Reference 3

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

From November 09, 2017 to March 01, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Refer to section 13 of IUCLID for details on the read-across justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 115: Surface Tension of Aqueous Solutions

Version / remarks:

27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EU Method A5: Surface tension

Version / remarks:

30 May 2008

Deviations:

no

Principles of method if other than guideline:

Below the CMC, a surfactant is considered to be thermodynamically soluble in the water; whereas above the CMC, the solubility of a surfactant in water has been exceeded and the excess surfactant aggregates to form micelles. These micelles have significantly less effect on the surface tension of a solution and are considered not to be in solution. Thus, the water solubility of a surfactant may be expressed in terms of the CMC.

GLP compliance:

no

Remarks:

The study was conducted in a facility which operates in accordance with Good Laboratory Practice principles; however no claim of GLP compliance was intended nor is made for this study

Type of method:

other: by determining the surface tension of a range of aqueous sample solutions of differing concentration

Key result

Water solubility:

ca. 600 mg/L

Conc. based on:

test mat.

Incubation duration:

ca. 19.25 h

Temp.:

20 °C

pH:

ca. 4.7 - ca. 5.29

Remarks on result:

other: Water solubility determined as CMC

Details on results:

Please see below table.

Results

The readings and temperatures for the sample solutions are shown in the following table:

Table1: Surface tension values

Concentration (mg/L)	Reading (mN/m)	Temperature (°C)
1.050 x 10^4	50.5	20.0
	53.5	20.0
	55.5	20.0
	55.5	20.0
	55.5	20.0
3.151 x 10^3	49.0	20.0
	50.5	20.0
	53.5	20.0
	55.5	20.0
	56.0	20.0
	56.0	20.0
	56.0	20.
1.575 x 10^3	48.0	20.0
	50.5	20.0
	53.0	20.0
	55.0	20.0
	55.5	20.0
	56.0	20.0
	56.0	20.0
	56.0	20.
1.050 x 10^3	51.0	20.0
	54.0	20.0
	56.5	20.0
	56.5	20.0
	56.5	20.0
630.1	51.5	20.0
	56.0	20.0
	57.0	20.0
	57.0	20.0
	57.0	20.0
472.7	56.0	20.0
	58.0	20.0
	60.0	20.0
	62.0	20.0
	63.5	20.0
	64.0	20.0
	64.0	20.0

472.7	65.0	20.0
	65.0	20.0
	65.0	20.0
393.8	53.0	20.0
	57.0	20.0
	58.5	20.0
	60.0	20.0
	61.5	20.0
	64.0	20.0
	65.0	20.0
	66.0	20.0
	66.0	20.0
	66.0	20.0
315.1	56.5	20.0
	59.0	20.0
	61.0	20.0
	62.5	20.0
	64.5	20.0
	67.0	20.0
	67.0	20.0
	67.0	20.0
210.0	56.0	20.0
	62.0	20.0
	66.5	20.0
	69.0	20.0
	69.0	20.0
	69.0	20.0
105.0	57.0	20.0
	60.5	20.0
	64.0	20.0
	67.5	20.0
	69.0	20.0
	70.0	20.0
	71.0	20.0
	71.0	20.0
	71.0	20.0

31.51	68.0	20.0
	69.0	20.0
	72.0	20.0
	72.0	20.0
	72.0	20.0
10.50	69.5	20.0
	73.0	20.0
	73.0	20.0
	73.0	20.0

Mean surface tension values were based on the last three readings for a particular concentration which were considered to be constant.

The concentration (mg/L), log₁₀ [concentration (mg/L)] and mean surface tension values for the sample solutions are shown in the following table:

 

Table 2: The concentration (mg/L), log₁₀ [concentration (mg/L)] and mean surface tension values

Concentration (mg/L)	Log10Concentration	Mean Surface Tension (mN/m)	Solution pH
1.050 x 10^4	4.021	55.5	4.77
3.151 x 10^3	3.498	56.0	4.72
1.575 x 10^3	3.197	56.0	4.74
1.050 x 10^3	3.021	56.5	4.74
630.1	2.799	57.0	4.74
472.7	2.675	65.0	4.83
393.8	2.595	66.0	4.99
315.1	2.498	67.0	4.77
210.0	2.322	69.0	4.94
105.0	2.021	71.0	4.91
31.51	1.498	72.0	5.14
10.50	1.021	73.0	5.29

Line 1 (red) was not allocated any samples due to the line angle that would have been generated from the available sample concentrations. However, Line 2 (green) was generated from linear regression of 5 sample solution concentrations for which the surface tension was observed to be essentially independent of concentration. The intersection of these two lines would have given the critical micelle concentration and been calculated by solving the two equations. The graph attached in the àttached background material section`.

Line 1 equation: y = not applicable

Line 2 equation: y = -1.12x + 59.9

Instead, as it appears the CMC would be between the two concentrations of 472.7 and 630.1, a result of approx. 600 mg/L will be used.

Conclusions:

Under the study conditions, the the CMC or water solubility of the read across substance was determined to be 600 mg/L at 20.0 ± 0.5°C.

Executive summary:

A study was conducted to determine the critical micelle concentration (i.e., water solubility equivalent for surfactants) of the read across substance, 'di-C18-22 AAEMIM-MS' by determining the surface tension of a range of aqueous sample solutions of differing concentration, according to OECD Guideline 115 and EU Method A.5. Due to the surface activity of the test substance, the CMC value was considered as a water solubility equivalent in accordance with the ECHA R.7a Guidance. Under the study conditions, the CMC or water solubility of the test substance was determined to be 600 mg/L at 20.0 ± 0.5°C (Envigo, 2018).

Reference 4

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

From November 09, 2017 to February 16, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Refer to section 13 of IUCLID for details on the read-across justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 115: Surface Tension of Aqueous Solutions

Version / remarks:

27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EU Method A5: Surface tension

Version / remarks:

30 May 2008

Deviations:

no

Principles of method if other than guideline:

Below the CMC, a surfactant is considered to be thermodynamically soluble in the water; whereas above the CMC, the solubility of a surfactant in water has been exceeded and the excess surfactant aggregates to form micelles. These micelles have significantly less effect on the surface tension of a solution and are considered not to be in solution. Thus, the water solubility of a surfactant may be expressed in terms of the CMC.

GLP compliance:

no

Remarks:

The study was conducted in a facility which operates in accordance with Good Laboratory Practice principles; however no claim of GLP compliance was intended nor is made for this study

Type of method:

other: by determining the surface tension of a range of aqueous sample solutions of differing concentration

Key result

Conc. based on:

test mat.

Incubation duration:

ca. 16.25 - ca. 20.25 h

Temp.:

20 °C

pH:

ca. 4.88 - ca. 6.12

Remarks on result:

other: The critical micelle concentration of the test substance at 20.0 ± 0.5 °C could not be determined

Details on results:

Please see below table.

Results

The readings and temperatures for the sample solutions are shown in the following table:

Table1: Surface tension values

Concentration (mg/L)	Reading (mN/m)	Temperature (°C)
1.001 x 10^5	36.0	20.0
	36.0	20.0
	36.0	20.0
3.336 x 10^4	40.0	20.0
	40.0	20.0
	40.0	20.0
9.928 x 10^3	42.0	20.0
	43.0	20.0
	44.5	20.0
	44.5	20.0
	44.5	20.0
3.309 x 10^3	48.0	20.0
	49.5	20.0
	50.5	20.0
	50.5	20.0
	50.5	20.0
1.016 x 10^3	38.0	20.0
	44.0	20.0
	45.0	20.0
	48.0	20.0
	50.0	20.0
	52.0	20.0
	52.0	20.0
	52.0	20.0
304.9	55.0	20.0
	58.5	20.0
	60.5	20.0
	61.5	20.0
	62.0	20.0
	62.0	20.0
	62.0	20.0
101.6	59.0	20.0
	63.0	20.0
	65.0	20.0
	66.0	20.0
	66.0	20.0
	67.5	20.0
	68.5	20.0
	68.5	20.0
	68.5	20.0
30.49	67.0	20.0
	71.0	20.0
	71.0	20.0
	71.0	20.0
10.16	69.0	20.0
	72.0	20.0
	72.0	20.0
	72.0	20.0
3.049	73.0	20.0
	73.0	20.0
	73.0	20.0

Mean surface tension values were based on the last three readings for a particular concentration which were considered to be constant.

The concentration (mg/L), log₁₀ [concentration (mg/L)] and mean surface tension values for the sample solutions are shown in the following table:

 

Table 2: The concentration (mg/L), log₁₀ [concentration (mg/L)] and mean surface tension values

Concentration (mg/L)	Log10Concentration	Mean Surface Tension (mN/m)	Solution pH
1.001 x 10^5	5.000	36.0	6.12
3.336 x 10^4	4.523	40.0	5.64
9.928 x 10^3	3.997	44.5	5.53
3.309 x 10^3	3.520	50.5	5.06
1.016 x 10^3	3.007	52.0	4.96
304.9	2.484	62.0	4.88
101.6	2.007	68.5	4.92
30.49	1.484	71.0	5.07
10.16	1.007	72.0	5.30
3.049	0.484	73.0	5.44

The greenline was generated from linear regression of 7 sample solution concentrations. The red line was not allocated any samples as there was no definitive CMC event observed.

Green Line equation: y =-10.6x +87.7

Thesample solutions at 30.49, 10.16 and 3.049 mg/L were not used in generating the line. At these concentrations the surface tension was only slightly affected and was approaching that of purified water.

Overall, no value for the CMC could be determined.

The surface tension at 1 g/L was determined to be 52.0 ± 0.5mN/m.

Conclusions:

Under the study conditions, the CMC or water solubility of the read across substance could not be determined in the study at 20.0 ± 0.5°C.

Executive summary:

A study was conducted to determine the critical micelle concentration (i.e., water solubility equivalent for surfactants) of the read across substance, 'di-C16-18-satd. and C18-24-unsatd. AAEMIM-MS', by determining the surface tension of a range of aqueous sample solutions of differing concentration, according to OECD Guideline 115 and EU Method A.5. Due to the surface activity of the test substance, the CMC value was considered as a water soluibility equivalent in accordance with the ECHA R.7a Guidance. Under the study conditions, the CMC or water solubility of the read across substance could not be determined in the study at 20.0 ± 0.5°C (Envigo, 2018).

Description of key information

The water solubility of the test substance was determined based on critical micelle concentration (a water solubility equivalent of surfactant), according to OECD Guideline 115 and EU Method A.5 (Envigo, 2018), as well as using QSAR models, WSKOW and WATERINT (US EPA, 2018).

Key value for chemical safety assessment

Water solubility:

1 mg/L

at the temperature of:

25 °C

Additional information

In absence of an experimental water solubility/CMC value for the test substance, which is surface active, the endpoint has been assessed using a weight of evidence (WoE) approach, as presented below:

- Experimental water solubility (based on CMC): could not be concluded based on the CMC study;

- Weighted average QSAR based water solubility of test substance 'di-C16 and C18-unsatd. AAEMIM-MS': 0.015 and 0.123 mg/L at 25°C using WSKOWIN v1.42 and WATERNT v1.01 models, respectively (US EPA, 2018); indicating slight solubility. The estimates for the major constituents from both the models are considered to be reliable with restrictions, as they do not completely fall within the applicability domain.

- Experimental water solubility of similar Croda substances: 

(a) Fatty acids, rape-oil, hydrogenated, reaction products with diethylenetriamine, di-Me sulfate-quaternized ('di-C18-22 AAEMIM-MS'): 600 mg/L at 20°C (based on CMC) - result was considered to be questionable; overall concluded to have slight solubility (1-100 mg/L) based on structure/nature of the substance along with weight of evidence from other similar substances and QSAR predictions (REACH dossier, CAS: 97281-29-3);

(b) Rape oil, reaction products with diethylenetriamine, di-Me sulfate-quaternized (di-C16-18 satd. and C18-24 unsatd. AAEMIM-MS): CMC could not be concluded; expected to be <=1 mg/L based on QSAR, indicating slight solubility; overall concluded to have slight solubility (≤1 mg/L) based on structure/nature of the substance along with weight of evidence from other similar substances and QSAR predictions (REACH dossiers; CAS: 98219-63-7).

- Experimental water solubility of other similar substances: (a) Fatty acids, C16-18 (even numbered) and C18 unsatd., reaction products with diethylene triamine, di-Me sulfate quaternized (di-C16-18 and C18-unsatd. AAEMIM-MS): 2.6 mg/L at 22°C (using slow stirring method) (REACH dossier, EC: 937-237-2); (b) Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sulfates (di-C18-unsatd. AAEMIM-MS): 2.2 mg/L at 22°C (using slow stirring method) (REACH dossier, EC: 98219-63-7); indicating slight solubility. 

Based on the above weight of evidence information, and given the overall structure of the substance, the water solubility of the test substance would be expected to be slightly soluble (i.e., ≤1 mg/L). Therefore, a water solubility value of 1 mg/L has been taken forward for the hazard assessment.