Octanoic acid, monoester with glycerol

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Remarks:

- critical micellization concentration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

other: ISO 4311: Anionic and non-ionic surface active agents - Determination of the critical micellization concentration - Method by measuring surface tension with a plate, stirrup or ring

Version / remarks:

1979

GLP compliance:

no

Type of method:

other: Method by measuring surface tension with a ring

Water solubility:

5.8 g/L

Temp.:

20 °C

Remarks on result:

other: This result refers to the critical micellization concentration (c.m.c.) according to ISO 4311 (1979).

Results

For both the preliminary test and the main test, the surface tension (σ [mN/m]) was plotted as a function of the logarithm of the concentration (log c).

From the preliminary test the c.m.c. was estimated to be between 2 g/L and 10 g/L.

The results of the main test are summarized in Table 1.

 

Table 1: Results of the main test

Concentration of test item [mg/L]	log c	σ [mN/m]	mean σ [mN/m]
2284	3.36	26.28	26.39
		26.54
		26.36
2936	3.47	25.29	25.29
		25.28
		25.30
3639	3.56	24.79	24.59
		24.44
		24.55
4601	3.66	24.34	24.40
		24.33
		24.54
5767	3.76	24.30	24.24
		24.17
		24.25
7334	3.87	24.44	24.40
		24.42
		24.35
9262	3.97	24.55	24.59
		24.60
		24.61

The results of the preliminary test were plotted in the same graph as the main test results - see illustration.

In the resulting curve the c.m.c. corresponds to the point on the curve at which the surface tension is considerably lower than that at higher concentration. The c.m.c. is defined at the abscissa of the minimum of the curve, which is 5.8 g/L in this case.

 

Final result

According to ISO 4311 (1979) the critical micellization concentration of the test item SOFTISAN GC8 at 20 ⁰C was determined to be: 

c.m.c.: 5.8 g/L

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: OECD Guideline study without GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Water solubility:

ca. 330 g/L

Temp.:

20 °C

pH:

3.52

Details on results:

Due to the formation of a gel, the investigation was stopped after the preliminary test, and the water solubility was approximated to 330 g/L.
Please note:
It is likely that it is possible to create a gel with even higher concentrations of the test item.

Conclusions:

Interpretation of results (migrated information): very soluble (> 10000 mg/L)
It is shown that the water solubility of the substance is below 1 mg/L.

Executive summary:

With 1.0 g of test item being mixed into 2 g of water, a gel with a total weight of 3.0 g has been formed. This is equivalent to 33% (w/w) of test item in solution/gel. Due to the fact, that the density of the gel is not known and that the formation of the gel is a continuous process and no discrete point can be identified at which dissolution in water switches to gelling, the water solubility can only be approximated to 330 g/L.

Please note:

It is likely that it is possible to create a gel with even higher concentrations of the test item.

The pH value of a 5% solution of the test item in water was 3.52, the tests were performed at 20 °C.

Description of key information

Due to formation of a gel, the water solubility could only be approximated to 330 g/L. For a better understanding of the behaviour of this surface active substance in a water solution, the critical micellization concentration (c.m.c) was determined and found to be 5.8 g/L at 20 °C.

Key value for chemical safety assessment

Water solubility:

330 g/L

at the temperature of:

20 °C

Additional information

With 1.0 g of test item being mixed into 2 g of water, a gel with a total weight of 3.0 g has been formed. This is equivalent to 33% (w/w) of test item in solution/gel. Due to the fact that the density of the gel is not known and that the formation of the gel is a continuous process and no discrete point can be identified at which dissolution in water switches to gelling, the water solubility can only be approximated to 330 g/L.

The critical micellization concentration (c.m.c.) at 20 °C of the test item was determined to be 5.8 g/L (ISO 4311, Method by measuring surface tension with a ring).