Reaction products of C18 (unsaturated) fatty acids and dimethyl sulfate and triethanolamine

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar (eco)toxicological properties because
• they share structural similarities with common functional groups: One quaternised ethanolamine moiety, one to three, mainly two ester groups with a typical UVCB distribution with long-chain fatty acids of natural origin. The molecular structure is almost identical.
• they are manufactured from similar resp. identical precursors (triethanolamine, long-chain fatty acids, dimethyl sulphate) under similar conditions. Therefore, common breakdown products via physical and biological processes, which result in structurally similar chemicals are evident
• A constant pattern in the changing of the potency of the properties across the TEA-Esterquats by chain-length and the grade of esterification is not observed, because the fatty acid chain-length distribution is too narrow and similar and the distribution of mono-, di-, and tri-esters is identical. Some variation caused by variation in C=C double bonds may occur and will be discussed at the relevant endpoint.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See justification for read-across attached to chapter 13 of this IUCLID file.

3. ANALOGUE APPROACH JUSTIFICATION
See justification for read-across attached to chapter 13 of this IUCLID file.

4. DATA MATRIX
See justification for read-across attached to chapter 13 of this IUCLID file.

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across source

Water solubility:

2 171 mg/L

Temp.:

10 °C

pH:

3.73

Water solubility:

2 244 mg/L

Temp.:

20 °C

pH:

3.86

Water solubility:

2 359 mg/L

Temp.:

30 °C

pH:

3.83

Results of the preliminary test (ambient temperature/bi-distilled water): A solution with a nominal concentration of 10 mg test item/L was totally dissolved or dispersed with no apparent precipitate or phase separation after 24 h of shaking. A solution with a nominal concentration of 100 mg test item/L showed un-dissolved solid particles after 24 h of shaking.

Results of the main test

1. Time course of the solubility of partially unsaturated TEA-Esterquat at 10, 20, and 30°C in distilled water (pH not adjusted) in equilibrium to atmospheric carbon dioxide

	Temperature in °C
Time in h	10		20		30
	mg/L	pH	mg/L	pH	mg/L	pH
0 24 48 72	1830 2564 2434 1857	- 3.70 3.74 3.75	1385* 2862 2625 2105	- 3.71 3.90 3.97	1775 2792 2677 2193	- 3.90 3.81 3.78
Mean	2171	3.73	2244	3.86	2359	3.83
Std. Dev.	382	0.03	387	0.13	468	0.06
RSD in %	17.6	0.80	15.3	3.37	19.8	1.57

*regarded as outliner

The water solubility was not found to be temperature dependent.

2. Time course of the solubility of partially unsaturated TEA-Esterquat at 20°C in citric acid buffer (pH 4)

	Temperature in °C
Time in h	20
	mg/L	pH
0 24 48 72	5.73 5.01 5.37 5.10	- 4.05 4.05 4.04
Mean	5.30	4.05
Std. Dev.	0.32	0.01
RSD in %	6.0	0.25

3. Time course of the solubility of partially unsaturated TEA-Esterquat at 20°C in phosphate buffer (pH 7)

	Temperature in °C
Time in h	20
	mg/L	pH
0 24 48 72	2.93 4.74 2.30 3.57	- 7.09 7.08 7.08
Mean	3.39	7.08
Std. Dev.	1.04	0.01
RSD in %	30.7	0.14

4. Time course of the solubility of partially unsaturated TEA-Esterquat at 20°C in borate buffer (pH 9)

	Temperature in °C
Time in h	20
	mg/L	pH
0 24 48 72	5.03* 20.2 19.8 18.3	- 9.06 9.11 9.15
Mean	19.40	9.11
Std. Dev.	1.0	0.05
RSD in %	5.2	0.55

*regarded as outliner

Based on the results in buffered systems it can be assumed that the water solubility is dependent on pH. However, due to the bipolarity of the molecules, it is noted that the counter ions phosphate, citrate and borate, respectively obviously have a more distinct influence on solubility than pH, since the solubility is almost three orders of magnitude below that in pure water. Finally, at higher pH values, a change in composition due to hydrolysis may have a greater influence on the absolute solubility of the test item (see chapter 5.1.2).

Conclusions:

Interpretation of results (migrated information): soluble (1000-10000 mg/L)
The water solubility of the analogue source test substance "partially unsaturated TEA-Esterquat" was investigated in a study conducted according to OECD Guideline 105 and EU-Method A.6 and using HPLC/MS/MS for quantification. In the main test, on the one hand the test item was dissolved in distilled water and the water solubility was measured at 10, 20, and 30°C without adjustment of the pH and on the other hand the water solubility of the test item was determined in buffered systems (pH 4, 7, and 9) at 20°C. In distilled water the water solubility was not found to be temperature dependent (ws at 10°Cand pH 3.73: 2171 mg/L; ws at 20°C and pH 3.86: 2244 mg/L; ws at 30°C and pH 3.83: 2359 mg/L). Based on the results in buffered systems (ws at 20°C and pH 4.05: 5.30 mg/L; ws at 20°C and pH 7.08:3.39 mg/L; ws at 20°C and pH 9.11: 19.4 mg/L) it can be assumed that the water solubility is dependent on pH. However, due to the bipolarity of the molecules, it is noted that the counter ions phosphate, citrate and borate, respectively obviously have a more distinct influence on solubility than pH, since the solubility is almost three orders of magnitude below that in pure water. Finally, at higher pH values, a change in composition due to hydrolysis may have a greater influence on the absolute solubility of the test item

Executive summary:

The water solubility of the analogue source test substance "partially unsaturated TEA-Esterquat" was investigated in a study conducted according to OECD Guideline 105 and EU-Method A.6 and using HPLC/MS/MS for quantification. HPLC/MS/MS proved to be a suitable analytical tool. Based on the results of the preliminary test, the flask method was used for the determination of the water solubility. In the main test, on the one hand the test item was dissolved in distilled water and the water solubility was measured at 10, 20, and 30°C without adjustment of the pH and on the other hand the water solubility of the test item was determined in buffered systems (pH 4, 7, and 9) at 20°C. The following results were obtained:

1. Solubility in water without pH adjustment (distilled water being in equilibrium with atmospheric carbon dioxide) at 10, 20, and 30°C: 2171 (pH 3.73, 10°C), 2244 (pH 3.86, 20°C), and 2359 mg/L (pH 3.83, 30°C). The water solubility was not found to be temperature dependent.

2. Solubility in buffered water at pH 4-9 and 20°C: 5.30 (pH 4.05), 3.39 (pH 7.08), and 19.4 mg/L (pH 9.11; at 20°C each). Based on the results in buffered systems it can be assumed that the water solubility is dependent on pH. However, due to the bipolarity of the molecules, it is noted that the counter ions phosphate, citrate and borate, respectively obviously have a more distinct influence on solubility than pH, since the solubility is almost three orders of magnitude below that in pure water. Finally, at higher pH values, a change in composition due to hydrolysis may have a greater influence on the absolute solubility of the test item (see chapter 5.1.2).

It can be expected that the study results are also applicable to the target substance Fatty acids, C18 unsatd., reaction products with triethanolamine, di-Me sulfate-quaternized.

Description of key information

Solubility in water at 20°C: 2244 mg/L (pH 3.86 )
                                                  5.30 mg/L (pH 4.05)
                                                  3.39 mg/L (pH 7.08)

Key value for chemical safety assessment

Water solubility:

3.39 mg/L

at the temperature of:

20 °C

Additional information

No experimental data are available for the target substance oleic acid-based TEA-Esterquat. However, the water solubility was determined for the source substance partially unsaturated TEA-Esterquat. A justification for read-across is attached to Iuclid section 13.

The water solubility of partially unsaturated TEA-Esterquat was investigated in a study conducted according to OECD Guideline 105 and EU-Method A.6 and using HPLC/MS/MS for quantification. HPLC/MS/MS proved to be a suitable analytical tool. Based on the results of the preliminary test, the flask method was used for the determination of the water solubility. In the main test, on the one hand the test item was dissolved in distilled water and the water solubility was measured at 10, 20, and 30°C without adjustment of the pH and on the other hand the water solubility of the test item was determined in buffered systems (pH 4, 7, and 9) at 20°C. The following results were obtained:

1. Solubility in water without pH adjustment (distilled water being in equilibrium with atmospheric carbon dioxide) at 10, 20, and 30°C: 2171 (pH 3.73, 10°C), 2244 (pH 3.86, 20°C), and 2359 mg/L (pH 3.83, 30°C).The water solubility was not found to be temperature dependent.

2. Solubility in buffered water at pH 4-9 and 20°C: 5.30 (pH 4.05), 3.39 (pH 7.08), and 19.4 mg/L (pH 9.11; at 20°C each). Based on the results in buffered systems it can be assumed that the water solubility is dependent on pH.

 

Supporting data on the structurally related source substance MDEA-Esterquat C16-18 and C18 unsatd. are included to justify read-across: the water solubility of the source substance was estimated to be 17.6 mg/L at 19.7°C based on the results of turbidity measurements.