Registration Dossier

Physical & Chemical properties

Water solubility

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From November 03, 2017 to February 09, 2018
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose:
reference to same study
Qualifier:
according to
Guideline:
other: OECD Guideline 115: Surface Tension of Aqueous Solutions
Version / remarks:
27 July 1995
Deviations:
no
Qualifier:
according to
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:
< 1.7 mg/L
Conc. based on:
test mat.
Incubation duration:
ca. 15.75 h
Temp.:
20 °C
pH:
ca. 5.505
Remarks on result:
other: CMC - water solubility equivalent for surfactants; value rounded off to 7 mg/L
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)

1.068 x 103

40.5

20.0

40.5

20.0

40.5

20.0

320.4

41.5

20.0

41.5

20.0

41.5

20.0

106.8

43.5

20.0

45.0

20.0

45.5

20.0

46.0

20.0

46.0

20.0

47.0

20.0

47.0

20.0

47.0

20.0

32.04

50.5

20.0

50.5

20.0

50.5

20.0

10.68

52.5

20.0

52.5

20.0

52.5

20.0

3.204

54.0

20.0

55.5

20.0

56.5

20.0

57.0

20.0

57.0

20.0

58.0

20.0

58.5

20.0

58.5

20.0

58.5

20.0

1.068

60.0

20.0

60.0

20.0

60.0

20.0

0.3204

70.0

20.0

70.0

20.0

70.0

20.0

0.1068

72.5

20.0

72.5

20.0

72.5

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

1.068 x 103

3.029

40.5

3.56

320.4

2.506

41.5

3.99

106.8

2.029

47.0

4.37

32.04

1.506

50.5

4.80

10.68

1.029

52.5

5.13

3.204

0.506

58.5

5.36

1.068

0.029

60.0

5.49

03204

-0.494

70.0

5.52

0.1068

-0.971

72.5

5.56

The plot of log10 [concentration (mg/L)] versus surface tension (mN/m) was drafted. For graph, kindly refer the attached background material section.

The green line was generated from linear regression of 7 sample solution concentrations. The red line was not allocated any samples as there was no definitive CMC. However, there was a possibly event between 0.3 and 1.0 mg/L where the surface tension jumps by 10 mN/m and the largest step in half a log unit.

Considering this, the CMC was determined to be less than 1.07 mg/L.

Conclusions:
Under the study conditions, the the CMC or water solubility of the test substance was determined to be <1.7 mg/L at 20.0 ± 0.5°C.
Executive summary:

A study was conducted to determined the water solubility of the test substance based on critical micelle concentration (CMC), according to OECD Guideline 115 and EU Method A.5, in compliance with GLP. 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 study conditions, the CMC of the test substance was determined to be <1.7 mg/L 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).

Key value for chemical safety assessment

Water solubility:
1.7 mg/L
at the temperature of:
20 °C

Additional information

(<1.7 mg/L, based on CMC)