Sodium hydrogen N-(1-oxododecyl)-L-glutamate

Endpoint summary

Additional information

The aquatic hazard assessment of Sodium hydrogen N-(1-oxododecyl)-L-glutamate (CAS No. 29923 -31 -7) was performed using test results with available data for the source substances l-Glutamic acid, N-coco acyl derivs., monosodium salts (CAS No. 68187-32-6) and L-Glutamic acid, N-coco acyl derivs., disodium salts (CAS No. 68187-30-4), which was used in a read across approach in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5. The read across is considered valid as the target substance is the major component, and the central member of an homologous series of components, of the source substances, possessing identical functional groups and extremely similar structures.  It is reasonable to expect that the toxicological properties of the target and source substances will not be markedly different.  On this basis, experimental data on the source substances are expected to be directly applicable to the target substance, and can be used to adequately predict its properties. Further details are provided in the in the field “Attached documents”.

Two studies investigating the short-term toxicity on fish and on aquatic invertebrates of Sodium hydrogen N-(1-oxododecyl)-L-glutamate (CAS No. 29923 -31 -7) are available. These studies have been conducted according to international guidelines however they have not been considered as key studies but only as supporting studies as the study on fish reported some issue on the concentration of the substance monitored during the study that has not been considered adequately investigated while the study on the aquatic invertebrated has been carried out at a concentration of the substance of ca 36.6% that is much lower of the concentration of the substance uesd in the read-across study.

Thus data for the source substance l-Glutamic acid, N-coco acyl derivs., monosodium salts (CAS No. 68187-32 -6) and L-Glutamic acid, N-coco acyl derivs., disodium salts (CAS No. 68187-30-4 were used for the assessment. The key studies showed a 96h-LC50 of 62.4 mg/L for fish, a 48h-EC50 of 49 mg/L for aquatic invertebrates and a 72h-EC50 of 32.56 mg/L for algae. Giving these results Sodium hydrogen N-(1-oxododecyl)-L-glutamate is considered to be harmful to aquatic organisms. Algae are identified as most sensitive organisms

Regarding chronic data, one 72h-EC10 value for freshwater algae is available and determined to be 11.25 mg/L. Results of long-term toxicity test with fish and Daphnia are not available. In Annex IX, column II (9.1) of Regulation (EC) No 1907/2006, it is laid down that a long-term toxicity test shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on aquatic organisms. The hazard assessment of Sodium hydrogen N-(1-oxododecyl)-L-glutamate

reveals that aquatic invertebrates are more sensitive than fish. However, the 48h-EC50 is measured to be > 10 mg/L indicating that the substance is not acute toxic but harmful to aquatic invertebrates. Given the very fast biodegradation of the substance in the environment (> 80% in 7 days) and the very low bioaccumulation potential (log Kow = -1.77) chronic toxicity of the substance leading to chronic classification is not indicated. An exposure assessment performed using PNECs derived on the basis of the available aquatic short-term toxicity tests (including a conservative assessment factor of 1000) indicate no risk for the aquatic environment. Therefore, it is not considered to be necessary to perform a long-term toxicity test with aquatic invertebrates to improve the safe handling of the substance.

One study investigating the toxicity of Sodium hydrogen N-(1-oxododecyl)-L-glutamate (CAS No. 29923 -31 -7)

to aquatic microorganisms is available. A 3h-EC10 is determined to be > 1000 mg/L. As the substance is readily biodegradable no toxicity was expected for microorganisms. The test result confirmed this assumption. Thus, inhibition of the biodegradation activity of activated sludge in STPs is not anticipated.