Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The biodegradation potential of the 1-methylpiperazine has been assessed in closed bottle tests according OECD TG 301D and in Zahn-Wellens tests according to OECD 302B. The results obtained show no or only limited degradation when non-acclimated sludge was used. When however acclimated or sligthly acclimated sludge is used as inoculum, the microorganisms are capable of growing at high rates because N-methylpiperazine was degraded within a week. Fast degradation is thus observed in a standard ready test (OECD TG 301D) when using adapted sludge or sessile micro-organisms which were for 4 weeks exposed to low  concentrations (10 and 100 µg/L) of substance.

Based on the results of this test with adapted sludge it can be concluded that 1-methylpiperazine should be considered as non-persisitent. The results with micro-organisms exposed to low concentrations (1, 10 and 100 µg/L) indicate that in the GLP tests where no degradation occured, an insufficient number of competent microorganisms in the inoculum was likely the reason for this absence of degradation.

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable

Additional information

1-methyl piperazine was found to be rapidly and completely biodegraded in closed bottle test using sludge which was acclimated in a SCAS test. Also when using sessile microorganisms (which settled on glass beads during flow through of river water containing low µg/L test substance) similar results were obtained. Thus also when using extremely low concentrations during acclimation, complete degradation was observed within 28 days in closed bottle tests. Based on these results with adapted or slightly adapted microorganisms it is very likely that the number of competent microorganisms, in the available tests with negative results, was not sufficient and that based on the rapid degradation when using a slightly acclimated inoculum n-methylpiperazine should be considered to be Non persistent.