Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

BIODEGRADATION IN WATER: SCREENING TESTS

Test on Ready biodegradability

The registration substance was tested in a ready biodegradability test (OECD 301B, Closed Bottle Test). The inoculum was prepared according OECD 301C test guidleine from municipal activated sludge (4 different STPs), river water, lake water and estuary water The degradation rate based on O2 consumption reached a maxium of 53% at a test item concentration of 10 mg/L. Based on the degradation rate the registration substance is not readily biodegradable under the test conditions chosen.

Test on Inherent biodegradability

In an OECD 302B test the registration substance was inherent primary biodegradable, but not inherently biodegradable under the test conditions chosen. The maximum degradation rate of 57% was reached at day 21.

BIODEGRADATION: SIMULATION TESTS

SEWAGE TREATMENT PLANT

The registration substance was tested in an OECD 303A Sewage Treatment Plant Simulation Test over 37d using a test item concentration of 24.8 mg/L. After the run-in phase the test item was monitored over 17d using 24h composite samples and DOC Analysis. Based on these measurements a Biodegradation rate of 62% +/- 3% was determined. This biodegradation rate is in line with the degradation found in a ready and in an inherent test (see IUCLID Chapter 5.2.1).

SEDIMENT

Considering the full life cycle of the substance no direct exposure to sediment is expected.

Based on the Log Kow of 1.1 -1.6 at pH 7 (see IUCLID Chapter 4.7) the Exposure Modelling Program EUSES 2.1 calculates a low Koc of 10.4 L/kg (QSAR for organic acids) which corresponds to a Kd sediment of 0.5 L/kg (2% organic carbon) . Due to this very low sorption of the registration substance transfer from freshwater to sediment and thereby indirect exposure to sediment can be neglected. Therefore a simulation study on sediment biodegradation is not warranted.

SOIL

Considering the full life cycle of the substance no direct exposure to soil is expected.

Based on the Log Kow of 1.1 -1.6 at pH 7 (see IUCLID Chapter 4.7) the Exposure Modelling Program EUSES 2.1 calculates a low Koc of 10.4 L/kg (QSAR for organic acids) which corresponds to a Kd soil of 0.2 L/kg (2% organic carbon) and a Kd sewage sludge of 3.8 L/kg (37% organic carbon). Due to the very low sorption of the registration substance transfer from sewage sludge to agricultural soil via sludge amendment and thereby indirect exposure to soil can be neglected. Therefore a simulation study on soil biodegradation is not warranted.