Tall Oil Fatty Acids, compounds with 2-(2-aminoethoxy) ethanol

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 June 2015 to 05 February 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EU Method A.5 (Surface Tension)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: ring method

Key result

Water solubility:

31 mg/L

Temp.:

22 °C

pH:

>= 5.4 - <= 7.9

Remarks on result:

other: Based on calculation of critical micelle concentration after determination of surface tension for a range of aqueous sample solutions of differing concentration.

Details on results:

- Readings, times and temperatures for the sample solutions are shown in Tables 3.16 to 3.23 (attached).
- The concentration (g/L), Log10 of the concentration and mean surface tension values are shown in Table 3.24 (attached).
- The plot of Log10 concentration (g/L) versus surface tension (mN/m) is shown in Figure 3.6 (attached).
- Line 1 was generated from linear regression of four sample solution concentrations for which the surface tension was shown to be concentration dependent.
- Line 2 was generated from linear regression of two sample solution concentrations for which the surface tension was observed to be essentially independent of concentration.
- The intersection of the two lines gave the critical micelle concentration and was calculated by solving two equations where y = -12.6x + 14.4 (Line 1 equation) and y = -1.00x + 32.0 (Line 2 equation).
- The CMC was determined to be 3.1 x 10E-02 g/L.
- Sample solutions at 0.03 and 0.001 g/L were not used in generating the two lines.
- At a concentration of 0.001 g/L the surface tension was only slightly affected and was approaching that of purified water.

DISCUSSION

- The citical micelle concentration (CMC) is an important characteristic of a surfactant.

- At low concentrations of surfactant the surface tension of water is only slightly affected but increasing the concentration before reaching the CMC causes the surface tension to change significantly. After reaching the CMC, and above, the surface tension remains relatively constant or changes with a much more gradual slope.

- Below the CMC, the surfactant is considered to be thermodynamically soluble in the water. Above the CMC, the solubility of the surfactant in water has been exceeded and the excess surfactant aggregates to form micelles. These micelles have significantly less effect on the surface tension of a solution and are considered not to be in solution. Thus the water solubility of a surfactant may be expressed in terms of the CMC.

- The CMC test was performed because the test item was a complex mixture containing highly surface active components and it was not possible to obtain a definitive result from the water solubility test. The test used to determine CMC is designed to measure surface active materials and is not significantly affected by complex mixtures. The test also generates a single result, which can be used as a more definitive solubility limit of the test item in water.

Conclusions:

The critical micelle concentration of the test item was assessed in accordance with EU Method A5. The critical micelle concentration test is designed to measure surface active materials and is not significantly affected by complex mixtures. The critical micelle concentration of the test item was determined to be 3.1 x 10E-02 g/L at 22.0 ± 0.5 °C and this single result is considered to be the definitive solubility limit of the test item in water. The test item is considered to be slightly soluble (0.1-100 mg/L).

Executive summary:

GUIDELINE

Experimental procedure was based on Method A.5 Surface Tension of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 115 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

RESULTS

Critical micelle concentration was found to be 3.1 x 10E-02 g/L at 22.0 ± 0.5 °C by determinining the surface tension of a range of aqueous sample solutions of differing concentration.

CONCLUSION The critical micelle concentration test is designed to measure surface active materials and is not significantly affected by complex mixtures. The critical micelle concentration of the test item was determined to be 3.1 x 10E-02 g/L at 22.0 ± 0.5 °C and this single result is considered to be the definitive solubility limit of the test item in water.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

03 June 2015 to 05 February 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

0 g/L

Temp.:

20 °C

pH:

>= 6.8 - <= 7

Remarks on result:

other: Positive mode

Water solubility:

0.002 g/L

Temp.:

20 °C

pH:

>= 6.8 - <= 7

Remarks on result:

other: Negative mode

Details on results:

PRELIMINARY TEST
- Preliminary estimates of water solubility at 20.0 ± 0.5 °C for the two loading rates are shown in Table 3.9 (below).

DEFINITIVE TEST
- Typical chromatograms for the 10.0 mg/L standard, matrix blank and Sample 1B are attached.
- Mean total peak areas for the standard and sample solutions are shown in Table 3.10 (attached).
- Calibration plots constructed from the standard data and from which the sample concentrations were interpolated are shown in Figures 3.3 and 3.4 (attached).
- Concentration of test item in the sample solutions is shown in Table 3.11 (below).

Table 3.9 – Preliminary estimates of water solubility
Nominal Loading Rate (g/L)	Concentration (g/L)		pH
	Positive mode	Negative mode
0.1	2.29 x 10E-03	2.97 x 10E-02	8.2
1	0.158	0.485	9.1

Table 3.11 – Concentration of test item in sample solutions
Sample number	Shaking at 30 °C (hours)	Equilibration at 20 °C (hours)	Concentration (g/L)		Solution pH
			Positive mode	Negative mode
1	24	24	3.57 x 10E-04	2.98 x 10E-03	7.0
2	48	24	3.17 x 10E-04	2.94 x 10E-03	7.0
3	72	24	1.44 x 10E-04	1.15 x 10E-03	6.8
Overall concentration (positive mode): 2.73 x 10E-04 g/L at 20.0 ± 0.5 °C
Overall concentration (negative mode): 2.36 x 10E-03 g/L at 20.0 ± 0.5 °C

Conclusions:

The water solubility of the test item was assessed in accordance with OECD Guideline 105. Water solubility of the test item at 20.0 ± 0.5 °C was determined at a nominal loading rate of 0.01 g/L and found to be 2.73 x 10E-04 g/L (positive mode) and 2.36 x 10E-03 g/L (negative mode). Due to the complexity of the test item, water solubility was loading rate dependent. At higher loading rates it became difficult to remove the excess dispersed test item from solution, which meant a single definitive result was not possible.

Executive summary:

GUIDELINE

 

The assessment was carried out by the flask method using a procedure designed to be compatible with Method A.6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

 

RESULTS

 

Water solubility of the test item at 20.0 ± 0.5 °C was determined at a nominal loading rate of 0.01 g/L and found to be 2.73 x 10E-04 g/L (positive mode) and 2.36 x 10E-03 g/L (negative mode).

 

CONCLUSION

 

Due to the complexity of the test item, water solubility was loading rate dependent. At higher loading rates it became difficult to remove the excess dispersed test item from solution, which meant a single definitive result was not possible.

Description of key information

The critical micelle concentration of the test item was assessed in accordance with EU Method A5.  The critical micelle concentration test is designed to measure surface active materials and is not significantly affected by complex mixtures. The critical micelle concentration of the test item was determined to be 3.1 x 10E-02 g/L at 22.0 ± 0.5 °C and this single result is considered to be the definitive solubility limit of the test item in water.  The test item is considered to be slightly soluble (0.1-100 mg/L).

Key value for chemical safety assessment

Water solubility:

0.031 g/L

at the temperature of:

22 °C

Additional information

No additional data.