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 August 10, 2017 to August 22, 2017
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:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Batch No.: WD0066442; Purity: 100 % (UVCB); Appearance: amber liquid; Homogeneity: homogeneous
Key result
Water solubility:
> 25.3 - < 88.3 mg/L
Conc. based on:
test mat. (dissolved fraction)
Loading of aqueous phase:
1 002 mg/L
Incubation duration:
7 d
Temp.:
20 °C
pH:
>= 4.12 - <= 4.86
Details on results:
As solubility was dependent on nominal concentration, no exact value for the solubility of the test substance in water can be stated. The solubility range for the tested nominal concentration 100 – 1002 mg/L is 25.3 – 88.3 mg/L at 20.0 ± 0.5 °C, corresponding to 25 – 9 % of the test substance relating to the nominal concentration of the test substance.

Dependency of solubility on amount of the test substance (nominal load) was perceived in the main test, too:

Flask

Measured Conc. test sub. [mg/L]

Nominal Conc. test sub. [mg/L]

Dissolved Part [%]

pH value

2

25.3

100.0

25

4.86

3

51.5

300.0

17

4.44

1*

59.6

500.3

12

-**

4

78.2

602.0

13

4.28

5

76.8

801.0

10

4.21

6

88.3

1002.0

9

4.12

*mean value of flasks 1A – 1C (days 4 – 7)

**value was not measured via pH meter

Conclusions:
Under the study conditions, at the plateau, the concentration of the test substance in water lay in the range of 25.3 – 88.3 mg/L at 20.0 ± 0.2 °C for the following nominal load range of the test substance in water: 100 – 1002 mg/L. Therefore, 25 – 9 % of the test substance was dissolved in water relating to the nominal concentration of the test substance. As the DOC method measures the sum of all dissolved parts of the test substance, this study does not provide any insights on the stability of the test substance in aqueous medium.
Executive summary:

A study was conducted to determine the solubility of the test substance according to OECD Guideline 105 and EU Method A.6, in compliance with GLP. The solubility of the test substance in water was determined by measurement of DOC concentration in the filtrated test solutions using TOC analyser. Based on the results of the pre-test, the flask method was selected for the main study. In the main test, six different loading rates of the test substance were chosen to study the effect of the loading rate on the measured water solubility: 100, 300, 500, 602, 801 and 1002 mg/L. Three flasks 1A - C with the same loading rate (500 mg/L) were used during equilibration. Seven vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature (20.0 ± 0.5 °C). Then, flasks 1A - 1C were taken from the shaker, samples were taken, membrane filtered and analysed for DOC via TOC analyser. Because of a difference of more than 15 % between the concentrations on days 2 and 3 the test was prolonged and the flasks 1A – 1C were further measured to get the values on days 4 – 7. Due to a difference of less than 15 % between the concentrations on days 6 and 7 and no upward tendency, the test was finished on day 7. Therefore, on day 7, vessels 2 – 6 were sampled and analysed for TOC in the same fashion. No Tyndall effect could be observed indicating that no colloidal dispersed particles or micells are present. Under the study conditions, at the plateau, the concentration of the test substance in water lay in the range of 25.3 – 88.3 mg/L at 20.0 ± 0.2 °C for the following nominal load range of the test substance in water: 100 – 1002 mg/L. Therefore, 25 – 9 % of the test substance was dissolved in water relating to the nominal concentration of the test substance. As the DOC method measures the sum of all dissolved parts of the test substance, this study does not provide any insights on the stability of the test substance in aqueous medium (Affolter, 2017).

Description of key information

The water solubility was determined according to OECD Guideline 105 and EU Method A.6 (Affolter, 2017).

Key value for chemical safety assessment

at the temperature of:
20 °C

Additional information

25.3 – 88.3 mg/L