Registration Dossier

Administrative data

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08 January 2009 to 07 February 2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Deviations:
not specified
GLP compliance:
yes (incl. certificate)
Remarks:
Date of inspection: 19 August 2008; Date of signature: 04 March 2009
Type of method:
flask method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sponsor's identification : H-CB sodium salt
Description : blue solid
Purity : 94.8%
Lot number : MB-2
Date received : 04 December 2008
Storage conditions : room temperature in the dark

Results and discussion

Water solubility
Water solubility:
31.6 - 34 other: % w/w
Temp.:
20 °C
pH:
> 7.6 - < 7.7

Any other information on results incl. tables

Preliminary test

The sample concentration, observations and solution pH, on completion of the 20oC equilibration period, are shown in the following table:

 

Sample Number

Concentration (% w/w)

Observations

Solution pH

1

10.1

Dark blue solution with no visible excess test material

7.4

2

20.0

Dark blue solution with excess test material

7.8

3

29.9

Dark blue viscous solution with no visible excess test material

7.3

4

39.7

Dark blue very viscous solution with excess test material

-

5

49.1

Dark blue very viscous solution with excess test material

-

6

59.8

No solution present but damp test material

-

 

Result: Solubility in the range 29.9 to 39.7% w/w of solution at 20oC +/- 0.5oC.

 

Definitive test

The sample concentration, observations and solution pH, on completion of the 20oC equilibration period, are shown in the following table:

 

Sample Number

Concentration (% w/w)

Observations

Solution pH

1

29.7

Dark blue viscous solution with no visible excess test material

7.7

2

31.6

Dark blue viscous solution with no visible excess test material

7.6

3

34.0

Dark blue immobile paste, no visible excess test material

-

4

35.1

Dark blue immobile paste, no visible excess test material

-

5

37.8

Dark blue immobile paste, no visible excess test material

-

6

40.0

Dark blue immobile paste, no visible excess test material

-

 

Result: Solubility in the range 31.6 to 34.0% w/w of solution at 20oC +/- 0.5oC.

 

Discussion

The EC A6 Method and OECD Method 105 were not applicable due to extremely high water solubility of the test material. It was therefore not possible to prepare samples at five times saturation level as specified in the guidelines. Therefore a number of individual samples were prepared at increasing nominal concentrations and the solubility determined by visual assessment of the resulting solutions.

 

 Although no excess test material was visible for Samples 3 to 6 in the definitive test, they formed an immobile paste which did not move or pour when held horizontally. The solubility range was therefore taken between the highest mobile concentration and the lowest stationary concentration.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): very soluble (> 10000 mg/L)
The water solubility of the test material has been determined to be in the range 31.6 to 34.0% w/w of solution at 20 Deg C +/- 0.5 Deg C by visual assessment.
Executive summary:

In the range 31.6 to 34.0% w/w of solution at 20oC +/- 0.5oC, based on the flask method, Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008.