Reaction mass of N-2-hydroxyethylacetamide and N,O-diacetyl-2-aminoethanol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From October 18, 2017 to February 13, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

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: modified flask method

Key result

Water solubility:

> 17 314 g/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

94.5 other: %w/w

Incubation duration:

ca. 72 h

Temp.:

20 °C

pH:

ca. 6.24

Results

The sample concentrations, observations and solution pH are shown in the following table:

Table2

Sample	Concentration (% w/w)	Observations	Solution pH
1	5.1	Clear, colourless, single-phase liquid	5.11
2	25.0	Clear, very pale yellow, single-phase liquid	5.25
3	49.7	Clear, pale yellow, single-phase liquid	5.45
4	74.9	Clear, yellow, single-phase liquid	5.96
5	94.5	Clear, yellow, slightly viscous, single-phase liquid	6.24

Overall result: Miscible with water in all proportions at 20.0 ± 0.5°C.

Discussion

The study was commenced to determine the critical micelle concentration. However, a solution in purified water of the test substance at 1.0 x 10³ mg/L had a surface tension of 73.0 mN/m. This indicated that the test substance did not significantly interfere with the surface tension of water and would therefore not be applicable to the method used to measure the critical micelle concentration. The study was then amended to determine the water solubility. The standard EC A.6 / OECD 105 methodology was not applicable to this test substance due to its miscibility with water. Therefore, a range of sample concentrations from a nominal 5 to 95% w/w were prepared for visually assessment.

Conclusion

The test substance has been determined to be miscible with water in all proportions at 20.0 ± 0.5°C.

Conclusions:

Under the study conditions, the water solubility of the test substance was determined to be >95.4% (i.e., 2.8482 g of test substance added to 0.1645 g of water), which is equivalent to >17314 g/L at 20°C and pH 6.24

Executive summary:

A study was conducted to determine the water solubility of the test substance according to the OECD Guideline 105 and EU Method A.6, using modified flask method. Mixtures of test substance (i.e., 0.15, 0.75, 1.5, 2.25, 2.85 g) and purified water (i.e., 2.85, 2.27, 1.5, 0.75, 0.165 g) were added to five separate flasks. This resulted in nominal loading rate concentrations of 5, 25, 50, 75 and 95% w/w. After preparation, the samples were shaken (200 rpm) at 30.0 ± 1.0°C for 72¼ h followed by static equilibration at 20.0 ± 0.5°C for a period of 26 h and then the contents of the flasks were visually assessed. The pH of each solution was measured where possible. The test substance has been determined to be miscible with water in all proportions at 20.0 ± 0.5°C. Under the study conditions, the water solubility of the test substance was determined to be >95.4% (i.e., 2.8482 g of test substance added to 0.1645 g of water), which is equivalent to >17314 g/L at 20°C and pH 6.24 (Envigo, 2018).

Description of key information

The water solubility of the test substance was determined using visual inspection according to OECD Guideline 105 and EU Method A.6 (Envigo, 2018).

Key value for chemical safety assessment

Water solubility:

17 314 g/L

at the temperature of:

20 °C

Additional information

The test substance was found to be miscible with water in all proportions at 20°C (i.e. >17314 g/L)