9-Octadecenoic acid (Z)-, reaction products with diethylenetriamine, di-Me sulfate-quaternized

Endpoint summary

Description of key information

BIODEGRADATION

Six studies in total are included for consideration of the biodegradation potential of the test substance 9-Octadecenoic acid (Z)-, reaction products with diethylenetriamine, di-Me sulfate-quaternized. Only one study, a screening study, used the test substance itself, in which the test substance was found to have 0% biodegradation after 28 days and was classified as not readily biodegradable. Four other screening tests are included, and one simulation study (design similar to an OECD 303) which assessed the biodegradation of two different read-across substances, although some studies comprised of more than one constituent. A range of results are presented with very limited biodegradation observed in three studies and significant biodegradation observed in two others. A summary of the data is presented in the biodegradation summary section as the basis for a weight of evidence (WoE) assessment. Based on WoE, the test substance is classified as not readily biodegradable.

HYDROLYSIS

Two studies are available investigating the hydrolysis of two read-across substances. A reliable Klimisch 2 (OECD Guideline, to GLP standards) study assessed hydrolysis of the read-across substance, Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sulfates (CAS number 931 -745 -8), based on the C18:1/C18:1 imidazolinium quat constituent. The half-life (DT50, 50% decline times) of the test item were determined at > 1 year at 25°C at pH 4 and as 2.9 days at 20°C, 2.5 days at 25°C, 27 hours at 50°C and 16 hours at 60°C (all at pH 7). The other study is for the read-across substance fatty acids, C16-18 (even numbered) and C18 unsatd., reaction products with diethylene triamine, di-Me sulfate quaternized (CAS number 937 -237 -2), however the hydrolysis of this substance was not able to be assessed due to the substance being insoluble.

In conclusion (based on a WoE approach) from the data on the read-across substances it is evident that some of the constituents of the test substance are likely to undergo hydrolysis, however this may not be an important process for other constituents that are largely insoluble, at least at the concentrations required in hydrolysis tests.

ADSORPTION

Three reliable studies are included on the read-across substances, fatty acids, C16-18 (even numbered) and C18 unsatd., reaction products with diethylene triamine, di-Me sulfate quaternized and Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sul. oleic-acid based IQAC, DMS quaternised. Two of these studies assessed adsorption using the HPLC method and both determined adsorption coefficients of >427,000 (KOC) and >5.63 (Log Koc) at 25˚C and 35˚C. A third study used the batch equilibrium method and demonstrated that the compound adsorbed to all tested soils with Koc values above 135000. The test item showed a low desorption (0.05 to 0.7 %) during desorption kinetic experiments.

Based on this the test substance is expected to be highly adsorptive in soils and sediment, the adsorption will not be reversible and overall is immobile.

However, a cautionary note is added regarding the applicability of this method to surface active substances, such as these two read-across substances.