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Physical & Chemical properties

Water solubility

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Reference
Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
April 13, 2018 - May 02, 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Deviations:
no
GLP compliance:
no
Type of method:
flask method
Key result
Water solubility:
507 g/L
Conc. based on:
test mat.
Loading of aqueous phase:
764 g/L
Temp.:
20 °C
pH:
> 7.9 - < 8.1

Preliminary  test

In a stepwise procedure, increasing volumes of demineralized water were added at room temperature to a defined amount of the test item. After each addition of an amount of water the mixture was treated with ultrasound for 15 minutes and visually checked for any undissolved particles.

Table4: Results of the preliminary test

Amount of test item

/ mg

Added volume of demineralized water / mL

Total volume of demineralized water / mL

Appearance of mixture

108.6

0.1

0.1

not dissolved

0.4

0.5

dissolved

The preliminary test showed that the water solubility of the test item is > 10 mg/L. According to the preliminary test the water solubility was determined by the flask method in the main test.

Flask method

The flask method was performed as described above. The data for the evaluation are given in Table5. After the equilibration time precipitate was observed in the flasks of the experiments excluding in the blank experiment.Asthe resulting solutions of the experiments were too concentrated for pipetting aliquots were weighted in graduated flasks and filled up to 10 mL with demin. water. Therefore the measured density of 1.14 was used to calculate the volume of the aliquots of the flasks. The water solubility was calculated from the measured and unrounded concentration values and not from the rounded values given in Table5.

Table5: Water solubility experiments of the test item

Experiment

24 h experiment

48 h experiment

72 h experiment

168 h experiment

Blank

experiment (72 h)

Amount of test item / g

15.277

15.007

15.087

15.298

--

Amount of demineralized water / mL

20

20

20

20

20

Stirring time at 30 °C / h

24

48

72

168

72

pH at 24 °C

8.1

8.0

7.9

8.0

6.2

Aliquots of the flasks / mg

61.8

80.5

75.8

61.3

750

Aliquots of the flasks / mL

0.054

0.071

0.066

0.054

0.750

1st Dilution / mL

10

10

10

10

10

Aliquot of the flasks / mL

0.05

0.05

0.05

0.05

0.05

2nd Dilution / mL

1.0

1.0

1.0

1.0

1.0

Dilution factor

3700

2817

3030

3704

267

Measured concentration / mg/L

137.48 / 136.99

162.36 / 162.24

96.69 / 96.58

73.30 / 72.94

-- / --

Mean concentration / mg/L

137.2

162.3

96.6

73.1

--

Water solubility / g/L

507

460

291

272

--

The water solubilities showed a decreasing tendency. As a conservative approach the highest value was stated. The water solubility of the test item at 20 °C was determined to be 507 g/L.

Executive summary:

The water solubility cS of the test item Acid Orange 166 at a temperature of 20 °C was determined according to the flask method. It was found to be without correction of the purity:

                                                                 cS = 507 g/L

Description of key information

The water solubility cS of the test item Acid Orange 166 at a temperature of 20 °C was determined according to the flask method. It was found to be without correction of the purity:

                                                                 cS = 507 g/L

Key value for chemical safety assessment

Water solubility:
507 g/L
at the temperature of:
20 °C

Additional information