Fatty acids, C16-18 (even numbered), reaction products with diethylene triamine, di-Me sulfate quaternized

Endpoint summary

Description of key information

- study conducted according to OECD 111,GLP, RL1, half-life (lives)/DT50 (50% decline times)of the test item were at pH 4: > 1 year at 25°C, at pH7: 2.9 days at 20°C, 2.5 days at 25°C, 27 hours at 50°C and 16 hours at 60°C and at pH 9 : 1.2 days at 20°C, read-across key-study

- study conducted according to OECD 111, substance insoluble in water, test not performed, read-across supporting study

- study conducted according to OECD guideline 301D,GLP, RL1, closed bottle test, not readily biodegradable

- study conducted according to DIN38412_part 25,non-GLP, RL3, readily biodegradable, read-across

- study conducted according to OECD 121, GLP, RL1, HPLC, Koc = 427000 at 20°C, read-across

Additional information

Hydrolysis:

Experimental data on hydrolysis of hydrogenated tallow/nortallow based IQACs as well as the structurally similar partially unsaturated IQAC, DMS quaternised are not available. However, a study is available for the source substance oleic acid based IQACs. A detailed justification for read-across is attached to IUCLID section 13.

Partially unsaturated IQAC, DMS quaternised is easily forming emulsions with water. It was not possible to remove the suspension of excess undissolved test substance by either centrifugation or filtration techniques to isolate a suitable aqueous solution for a hydrolysis study. In the guidelines (EC Guideline C.7 and OECD Guideline 111) it is outlined, that the hydrolysis test is only applicable to water soluble substances. In the frame of determing physico-chemical properties, among others the water solubility of Partially unsaturated IQAC, DMS quaternised was determined to be 2.6 mg/l using a slow stirring method (see Chapter 4.8). Based on these findings and the requirements of the guidelines, the test on hydrolysis is technically not feasible and was therefore not performed.Instead, a read across test from the closely related Oleic-acid based IQAC, DMS quaternised is available. Hydrolysis of the IQAC based on oleic acid was studied in the dark at 20ºC, 50 ºC and 60 ºC in sterile aqueous buffered solutions at pH 4 (acetate buffer), pH 7 (phosphate buffer) and pH 9 (borate buffer) for 5 days according to EC C.7 (OECD 111). The half-lives of the test item were at pH 4: > 1 year at 25 °C, at pH 7 2.9 days at 20°C, 2.5 days at 25°C, 27 hours at 50 °C and 16 hours at 60 °C, respectively. At pH 9 the half life was 1.2 days at 20 °C. The results are deemed to be also reliable for the target substance because the differneces between the substances are limited to alkyl-chain length and unsaturation and these structural properties are not considered to have any influence on hydrolysis.

Biodegradation:

The biodegradation of hydrogenated tallow/nortallow based IQACs (5% aqueous dispersion) was investigated over a 28-day period in a Closed Bottle Test according to OECD guideline 301 D (1992). The test medium was inoculated with activated sludge from a sewage treatment plant mainly fed with municipal wastewater. The rate of degradation was monitored by measuring the oxygen consumption over the 28-d period.

The test item was tested with a concentration of 20 and 40 mg/L in duplicates, corresponding to a carbon content (ThOC) of 2.83 and 5.66 mg C/L in the test vessels.

Degradation is followed by analysis of dissolved oxygen over a 28-day period. The amount of oxygen taken up by the microbial population during biodegradation of the test item (corrected for uptake by blank inoculum, run in parallel) is expressed as a percentage of ThOD.

The 10 % level (beginning of biodegradation of the test item) was reached within an adaptation phase of 3 days for the procedural control. The percentage of degradation of the functional control reached the pass level of 60 % after 3 days.

The highest mean biodegradation rate of hydrogenated tallow/nortallow based IQAC aqueous dispersion (5 %) within the 28 days of incubation in the static test was found to be 6 % (day 6) in the assays with 20 mg/L and 3 % (day 21) in the assays with 40 mg/L. Thus, no biodegradation within a 10-day-window could be obtained. The biodegradation of the item mixture in the toxicity control was found to be 28 % after 14 days of incubation. Thus, the demanded threshold value of 25 % is exceeded and the test item IS-2017-761 aqueous dispersion (5 %) can be identified as non-toxic in a ready biodegradability test. The reference item sodium benzoate was degraded to 97 % within the first 14 days, which was the highest degradation rate found within the test duration. In conclusion, according to the guideline, the test item hydrogenated tallow/nortallow based IQAC aqueous dispersion (5 %) must be identified as not readily biodegradable under the chosen test conditions.

Additionally, in a study conducted according to DIN 380412 Teil 25, the test item Rewoquat W1599 was tested for biodegradability by COD-Elimination. 2.4 g test item/L were incubated with 50 mL inoculum from a local sewage traetment plant for 28 days. Over 90% of the substance was degraded after 28 days, thus, the substance was considered to be readily biodegradable.

Based on the available information hydrogenated tallow/nortallow based IQACs is considered to be not readily biodegradable.

Adsorption/desorption:

There are no data for the target substance hydrogenated tallow/nortallow based IQACs regarding sorption to soil. No experimental data on soil sorption are available for the target substance hydrogenated tallow/nortallow based IQACs. However, a study is available for the source substance partially unsaturated IQACs, DMS quaternised. A detailed justification for read-across is attached to IUCLID section 13. In a study to determine the soil sorption with the HPLC-Method it was found that the structurally similar substance Partially unsaturated IQAC, DMS quaternised strongly interacted with the analytical column. Based on the results obtained it was concluded that the test substance has a Koc value of higher than the reference substance 2,4-DDT. It corresponds with Koc and log Koc value for the test substance of > 427000 and > 5,63, respectively.

From these findings it can be concluded that partially unsaturated IQAC, DMS quaternised will strongly interact with soils, sediment and suspended matter in natural environment. It is technically not feasible to determine a concrete soil sorption coefficient.