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Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

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Description of key information

Simulation study in sediment (similar to OECD 308):

The half-life of the parent compound in water and sediment was 95 days (Lienden) and 76 days (IJzendoorn).

Key value for chemical safety assessment

Half-life in freshwater sediment:
95 d

Additional information

Aminotriazole® is a quickly acting herbicide which is taken up predominantly through the leaves. From there the active ingredient is transported with the assimilation stream into the roots and the underground stolons.

 The active ingredient 1H-1,2,4-triazole-3-amine was given the common name amitrole. The degradation of[3-14C]amitrole was investigated in two water-sediment systems using an aquatic, aerobic test model especially developed for this purpose. Immediately prior to the start of the test, water and sediment were taken from a fish pond near Lienden (NL) and from a ditch in a fruit-growing area near Ijzendoorn (NL). The amount of active ingredient applied was 5.0mg/I and the incubation period was determined to be 91 days.

 The active ingredient was degraded to CO2 and incorporated into the sediment. The mineralization rates after 91 days of incubation amounted to 19% of the applied active ingredient in the Lienden system (the sediment with the lower amount of organic carbon) and 10 % in the Ijzendoorn system. The half-life of the parent compound in the water and sediment was 95days (Lienden) and 76 days (IJzendoorn).

 Metabolites occurred only in low concentrations (=<3%). Two metabolites, triazole and urea were identified by mass spectroscopy.

[Type of water: other: Lienden]