Registration Dossier

Administrative data

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2018-02-07 to 2018-03-01
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7840 (Water Solubility)
Deviations:
no
Principles of method if other than guideline:
The solubility of the test item is below 0.01 g/L, so the column elution method should be applied according to the guideline. However, column elution method is not feasible with this test item, because coating of the support material is not possible due to the low solubility of the test item in any solvent. Therefore, the flask method was applied.
GLP compliance:
yes (incl. certificate)
Type of method:
flask method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Test Item: Leuco Sulfur Blue 15
Appearance: Dark, near black powder

Results and discussion

Water solubilityopen allclose all
Key result
Water solubility:
>= 1.36 - <= 5.2 mg/L
Conc. based on:
act. ingr.
Incubation duration:
24 h
Temp.:
20 °C
pH:
>= 2.97 - <= 2.99
Key result
Water solubility:
>= 3.17 - <= 5.1 mg/L
Conc. based on:
act. ingr.
Incubation duration:
48 h
Temp.:
20 °C
pH:
> 2.92 - <= 3
Key result
Water solubility:
4.1 mg/L
Conc. based on:
act. ingr.
Incubation duration:
72 h
Temp.:
20 °C
pH:
>= 2.89 - <= 2.99
Details on results:
The measured concentrations were contant within +/- 15% and thus within the range required by the guidelines.

Any other information on results incl. tables

Table 1: Results of the determination of the test item concentrations

Sampling time   Measured concentration of the test item [mg/L] Measured pH
Test vessels Mean with the 95% confidence intervals
After 24 hours

3.44

3.85

4.46

3.92 ± 1.28

2.97

2.99

3.00

After 48 hours

3.70

4.45

4.27

4.14 ± 0.97

2.98

2.95

3.00 

 After 72 hours

4.48

3.98

*

4.23

2.89

2.91

2.99

Solubility of the test item (mg/L)

4.08 ± 0.33

4.1  ± 0.4    

RSD%

 10

4

Ultra-pure water   

< LOQ

6.73

* outlier data

Applicant's summary and conclusion

Conclusions:
The water solubility of the test item was assessed according to OECD Guideline 105, EU Method A.6 and US EPA OPPTS 830.7840 under GLP conditions. The water solubility of the test item was determined to be 4.1  ± 0.4 mg/L (95% confidence interval) at 20 °C +/- 1 °C using the shake-flask method.
Executive summary:

The water solubility of the test item was assessed according to OECD Guideline 105, EU Method A.6 and US EPA OPPTS 830.7840 under GLP conditions. The solubility of the test item is below 10 E-2 g/L, so the column elution method should be applied according to the guideline. However, column elution method is not feasible with this test item, because coating of the support material is not possible due to the low solubility of the test item in any solvent. Therefore, the shake-flask method was applied. In result, the water solubility of the test item was determined to be 4.1 ± 0.4 mg/L (95% confidence interval) at 20 °C +/- 1 °C.