Fatty acids, C18 (even numbered) and C18 unsatd., reaction products with triethanolamine, di-Me sulfate quaternized

Endpoint summary

Description of key information

Physical state

C18 and C18 unsatd. TEA-Esterquat is a yellow to brown pasty solid at 20°C and 1013 hPa (visual assessment).

 

Melting point

The melting point of C18 and C18 unsatd. TEA-Esterquat was determined according to EU method A.1 using differential scanning calorimetry. The test item showed a melting range of crystalline subcomponents between 28°C and 58°C in the 1st heating run. Additionally the test item showed a glass transition temperature at -27°C in the 1st heating run. The melting range of C18 and C18 unsatd. TEA-Esterquat was determined to be 28 - 58°C.

 

Water solubility

The water solubility of C18 and C18 unsatd. TEA-Esterquat was determined according to OECD Guideline 105 using the flask method. The water solubility was determined to be 878.4 mg/L at 20°C and pH 2.9.

 

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. 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.

 

A relatively high water solubility was observed in both, the target and the source substance without pH adjustment of 878.4 mg/L at pH 2.9 and 2244 mg/L at pH 3.86, respectively. As buffered systems are more relevant in the environment, the value of 3.39 mg/L at 20°C and pH 7.01 will be used as key value.

 

log Kow

The n-Octanol/water partitioning coefficient (log Kow) of C18 and C18 unsatd. TEA-Esterquat was calculated from the individual solubilities in 1-octanol and water at 20 °C, respectively. The log Kow is reported to be 1.9 at 20°C.

However, due to the surface-active properties of the test substance, the 'real' water solubility is overestimated. Therefore the result should be treated with care.

 

Comparable results were also obtained with the source substance partially unsaturated TEA-Esterquat:

In the frame of a study conducted according to OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method) and EU Method A.8 (Partition Coefficient), the n-octanol/water partition coefficient log Kow of the test substance was estimated via the 'apparent' water solubility. The calculation yielded a log Kow=1.9 (Kow=200 g/L/2.5 g/L; 'apparent' water solubility=2.5 g/L at 20°C, solubility in n-octanol=200 g/L at 20°C). Due to the surface-active properties of the test substance, the 'real' water solubility is overestimated. Therefore the result should be treated with care.

 

Due to these uncertainties, a further approach was selected: A calculation of the n-octanol/water-partition coefficient (log Kow) was performed using theSoftware ACD/Labs12 from the companyAdvanced Chemistry Development, incand experimental data of [Me-¹⁴C] MDEA Esterquat (NOTOX 489708). This programme is useful to determine log Kow values of ionic substances. For experimental data input to ACD/Labs, adsorption coefficients of [Me-¹⁴C] MDEA Esterquat were used for calculation of the log Kow according to the Lyman-method. Kow values for the most lipophilic Mono-, Di- and Triesterquat species (C18chain-length, saturated) were calculated separately. Outputs were then weighted to calculate a mean log Kow. The calculated log Kow of MDEA Esterquat was 5.38. Mole fractions of Mono-, Di- and Triesterquats used for calculation were 0.403, 0.495 and 0.1015, respectively. The geometric weighted mean of the inverse logarithm of log Kow is 4.77. This value was used as a reasonable worst case for the assessment.

 

No experimental data are available for boiling point, density, vapour pressure, surface tension and self-ignition temperature of the target substance C18 and C18 unsatd. TEA-Esterquat. However, physicochemical studies are available for the closely related source substance partially unsaturated TEA-Esterquat. A justification for read-across is given below.

 

Boiling point

At atmospheric pressure the boiling point ofpartially unsaturated TEA-Esterquatcannot be determined as the test item decomposes at temperatures above 260°C.

 

Density

Density and relative density for partially unsaturated TEA-Esterquat were determined to be 1.059 g/cm³ at 20 °C and 1.059 (20/4), respectively.

 

Particle size distribution

According to the REACH Regulation, Annex VII, column 2 a study on particle size distribution does not need to be conducted if the substance is marketed or used in a non solid or granular form: the test item is a waxy, viscous solidified liquid at ambient temperature.

 

Vapour pressure

Based on experimentally derived results and using the Antoine equation, the vapour pressure at 20 and 25 °C of partially unsaturatedTEA-Esterquatwas calculated to be 4.4E-06 hPa/ 4.4E-04 Pa (at 20 °C) and 6.7E-06 hPa/6.7E-04 Pa (at 25 °C). In addition, the substance is a salt with ionic structure of one long-chained organic ammonium cation and the anionic counter ion. For these substances, a vapour pressure of almost zero is expected.

 

Surface tension

The mean surface tension of an aqueous solution of 1 g/L ofpartially unsaturated TEA-Esterquatwas determined to be 41.8 mN/m at 20 °C and can therefore be considered as a surface active substance.

 

Flash point

According to REACH Annex XI, 1. a test for the determination of the flash point of the substance is not scientifically necessary because the flash point refers to liquids (Reach R7.1.9). The substance is solid at ambient temperature; therefore a determination of the flash point is not required.

 

Flammability, auto-flammability

No self-ignition temperature was observed forpartially unsaturated TEA-Esterquatup to the maximum temperature of 402°C.

The flammability of partially unsaturated TEA-Esterquat was investigated in a study conducted according to EU-Method A.10. In a preliminary test, the test item could not be ignited with a flame. Therefore the main test was not necessary. Based on the results, the test substance is not a highly flammable solid.

 

Explosive and oxidizing properties

As indicated by structural aspects and underlined by estimated thermodynamic properties forpartially unsaturated TEA-Esterquat, the substance isnot considered to have explosive and oxidising properties. Based on the results obtained with the capillary method, the decomposition of the substance starts at 260 °C at atmospheric pressure.

 

 

 

JUSTIFICATION FOR READ-ACROSS

For details on substance identity and detailed substance profiles, please refer also to the general justification for read-across given at the beginning of the CSR and attached as pdf document to IUCLID section 13.

This read-across approach is justified based on structural similarities. The target and source substances contain the same functional groups. The target and source substance vary only marginally in the fatty acid chain-length distribution and the distribution of mono-, di-, and tri-esters is very similar. Therefore their physico-chemical properties are assumed to be within the variation of measured results. Differences are expected according to the amount of C=C double bonds. This is expressed by the fact thatthe target substanceC18 and C18 unsatd. TEA-Esterquatas well as the source substances fully saturated TEA-Esterquat and partially unsaturated TEA-Esterquatare solids, while oleic acid-based TEA-Esterquatis a liquid at room temperature.

The composition of the source substance partially unsaturated TEA-Esterquat is very similar to the target substanceC18 and C18 unsatd. TEA-Esterquat. Thus, the data obtained with this source substance are used to fulfill the information requirements of the target substance C18 and C18 unsatd. TEA-Esterquat.

The data obtained with the source substances fully saturated TEA-Esterquat, oleic acid-based TEA-Esterquat and DODMAC, if available, are included into the dossier to justify the read-across approach for other endpoints.

 

a. Structural similarity and functional groups

The target substance C18 and C18 unsatd. TEA-Esterquat is a UVCB substance manufactured from fatty acids (C18 and C18 unsatd) and triethanolamine. Subsequently the product is reacted with dimethyl sulphate for quaternisation. 

 

The source substance partially unsaturated TEA-Esterquat is a UVCB substance manufactured from fatty acids (C16-18 (even numbered) and C18 unsatd.) and triethanolamine. Subsequently the product is reacted with dimethyl sulphate for quaternisation. 

 

b. Differences

Differences in physicochemical properties of the target and source substances could potentially arise from the following facts:

 

Degree of esterification: The lipophilic properties increase with the degree of esterification. As the distribution of mono-, di and tri-esters of the target and source substances is very similar, no significant differences in lipophilicity are expected.

 

Chain-length distribution: Lipophilic properties of molecules also increase with increasing fatty acid chain-length. The amounts of chain-lengths lower than C16 and higher than C18 are comparably low in both the target and the source substance. In contrast to the target substanceC18 and C18 unsatd. TEA-Esterquat, the source substance partially unsaturated TEA-Esterquat contains considerable amounts of C16. However, no relevant differences are expected since the relative difference in chain length between C16 and C18 is only marginal.

 

Amount of unsaturated fatty ester moieties: The amount of unsaturated fatty acid moieties is slightly higher in the source substancepartially unsaturated TEA-Esterquat compared to the target substanceC18 and C18 unsatd. TEA-Esterquat.As the difference in the degree of unsaturation is rather small,no significant differences in physicochemical properties are expected. With respect to flammability endpoints, a higher amount of unsaturated fatty acid moieties may be regarded as a worst case due to in general higher reactivity.

 

 

Comparison of physico-chemical data

Endpoints	C18 and C18 unsatd. TEA-Esterquat	Partially unsaturated TEA-Esterquat
Physical state at 20°C / 1013 hPa	Solid (paste)	Solid (waxy)
Melting point	range: 28 – 58°C	range: > 85-110 °C
Boiling point	No data, read-across	decomposition >= 260 °C
Density	No data, read-across	density: 1.059 g/cm³ at 20 °C relative density (20/4): 1.059
Vapour pressure	No data, read-across	at 20 °C: 4.4 x 10E-4 Pa at 25 °C: 6.7 x 10E-4 Pa
Log Kow	1.9 (calculated from individual solubilities in n-octanol and water)	1.9 (calculated from individual solubilities in n-octanol and water)
	Log Kow= 4.77 at 25 °C (calculation using Software ACD, weighted mean)	Log Kow= 4.725 at 25 °C (calculation using Software ACD, weighted mean)
Water solubility	878.4 mg/L (pH 2.9 and 20°C)	at 20 °C: 2244 mg/L (pH 3.86) 3.39 mg/L (pH 7.1 at 20 °C)
Surface tension	No data, read-across	41.8 mN/m at 20 °C   36.46 -39.4 mN/m at 24.7°C
Auto flammability	No data, read-across	self-ignition temperature: > 402 °C at ambient air pressure (1013 hPa)
Flammability	No data, read-across	The test item could not be ignited with a flame.

 

The target and source substances vary only marginally in the fatty acid chain-length distribution and the distribution of mono-, di-, and tri-esters is identical. Therefore their physico-chemical properties are assumed to be within the variation of measured results.

 

Experimental data for the targetsubstance C18 and C18 unsatd. TEA-Esterquatare only available for the endpoints melting point, water solubility and log Kow.

The measured log Kow (using the individual solubilities in n-octanol and water) lead to the same result of 1.9. However, due to the surface active properties of both substances, a calculation approach was applied using weighted mean calculated values.

The water solubility of both substances was relatively high without pH adjustment. However, as buffered systems or systems closer to neutral pH are more relevant in the environment, the value of 3.39 mg/L at 20°C and pH 7.01 obtained with the source substance partially unsaturated TEA-Esterquat will be used as key value.

 

All other physico-chemical endpoints are read across from the source substance partially unsaturated TEA-Esterquat.

At atmospheric pressure the boiling point ofpartially unsaturated TEA-Esterquatcannot be determined as the test item decomposes at temperatures above 260 °C. It is concluded that also the target substance should behave in the same way caused by their highly similar structure.

Density and relative density for partially unsaturated TEA-Esterquat were determined to be 1.059 g/cm³ at 20°C and 1.059 (20/4), respectively. The density and the relative density of the target substance is assumed to be similar.

Based on experimentally derived results and using the Antoine equation, the vapour pressure at 20 and 25 °C of partially unsaturatedTEA-Esterquatwas calculated to be 4.4E-6 hPa/ 4.4E-4 Pa at 20 °C and 6.7E-6 hPa/6.7E-4 Pa at 25 °C.

A calculation of the n-octanol/water-partition coefficient was performed using theSoftware ACD/Labs12. The weighted mean log Kow forTEA-Esterquat (C18, satd) is4.725.

 

Solubility in buffered water at pH 4-9 and 20°C was determined to be 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

The mean surface tension of an aqueous solution of 1 g/L ofpartially unsaturated TEA-Esterquatwas determined to be 41.8 mN/m at 20°C and can therefore be considered as a surface active substance.

Due to close structural similarities to the source substancepartially unsaturated TEA-Esterquatand identical functional groupsno self-ignition up to the limit temperature and no high flammability is expected for the target substance.

 

 

Quality of the experimental data of the analogues:

The available data are adequate and sufficiently reliable to justify the read-across approach.

The target substance has been tested in reliable and GLP-compliant studies according to EU method A.1 and OECD TG 105.

The source substance partially unsaturated TEA-Esterquat has been tested in reliable (RL1) and GLP-compliant studies according to OECD TG 102 (melting point), 103 (boiling point), 109 (density), 104 (vapour pressure), 105 (water solubility), 115 (surface tension), EU method A.16 (auto flammability) and EU method A.10 (flammability). The n-octanol/water partition coefficient was calculated using a generally accepted calculation method suitable for ionic substances (RL2).

The test materials used in the respective studies represent the source substance as described in the hypothesis in terms of substance identity and minor constituents.

Overall, the study results are adequate for the purpose of classification and labelling and risk assessment.

 

Conclusion

Based on structural similarities of the target and source substanceas presented above and in more detail in the general justification for read across, it can be concluded that the available data from the source substancepartially unsaturated TEA-Esterquatare also valid for the target substance C18 and C18 unsatd. TEA-Esterquat.

The physicochemical properties of the target substance are expected to be in the same range as the source substance since the minor variability in the fatty acid moiety is not expected to be relevant for the physicochemical properties of the substances as described above.