Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Melamine is not readily biodegradable and also not inherently biodegradable.
Melamine can be degraded by adapted microorganisms or if additional energy is supplied to the microorganisms.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

No data are available. As the substance is a water soluble salt of phosphate, effects can be read-across from the cation, which is likely to have the more important effects.Inbiological systems, phosphate is an abundant in cells and body fluids.In ecological terms, because of its important role in biological systems, phosphate is a highly sought-after resource. Thus, read-across from component CAS Reg.-No. 108-78-1, melamine, is justified.

Test results on a MITI test for ready biodegradability, 3 Zahn-Wellens assays for inherent biodegradability and 2 studies on the Biochemical Oxygen Demand are reported. A weight of evidence approach is applied. Each of the individual studies points to the same result: Melamine is not readily biodegradable and also not inherently biodegradable.

With activated sludge taken from an industrial waste water treatment plant as the inoculum, a degradation of DOC of up to 16 % was observed within 20 d (Pagga 1991). A rapid and complete primary degradation of the molecule within 8 h was detected with an activated sludge taken from an industrial waste water treatment plant from a producer of melamine (Fimberger 1997).

Addition of glucose, in the absence of NH4+, enables the microorganisms to use melamine as the only nitrogen source (Fimberger 1997).

Degradation occurs by hydrolytic deamination to ammeline, ammelide and cyanuric acid, and lastly to CO2 and NH4+ (Fimberger 1997).