Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

A biodegradability study has been carried out according to the method described in the appendix C.4-C of EEC Directive 92/69/CEE (Boutonnet, 1994). This protocol is compliant with OECD Guideline nº 301B adopted on 17/7/92. Under the test conditions, the percentage of biodegradation of the substance was 20% at the end of the test (28 days). Under tests conditions, the test substance is assessed not readily biodegradable. However, two other studies have been performed according to the OECD guideline 301 D “Ready biodegradability - Closed Bottle Test” and GLP requirements (Gancet, 2009). Under the test conditions, the percentage of biodegradation of 2 mg/L of test item reached 75 % of the ThOD at the end (28 days) of the first test and 60% in the second one . All the validity criteria were fulfilled. The 10-day window condition was reached in the first test. In the second test, this criterion was not reached but since this surfactant cationic is a fatty amine derivative and an UVCB, this criterion can be waived.

The difference of biodegradation observed between these different tests can be explained by the highest test concentration (26.7 mg/L) used in the OECD 301B test compared to the OECD 301D (2 mg/L). This hypothesis is confirmed in the inhibition control of the OECD 301B test. Indeed, some inhibition of the test substance on the reference substance was observed in the toxicity control flasks.

Therefore, the low level of biodegradation of the test substance in the OECD 301B test could be explained by toxicity toward microorganisms.

To conclude, Amides, C18 -unsatd., N-[3 -(dimethylamine)propyl] was assessed to be readily biodegradable.