Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The standard OECD ready biodegradability pass level is 70 % removal of dissolved oxygen concentration (DOC). This pass level is reached with DOPA-Glycinate within 10 days and thus also fulfils the criterion of ready biodegradability within the 10-day window as outlined in OECD guideline 301. In view of the results obtained in the valid DOC die-away test with DOPA-Glycinate, the substance should be considered as readily biodegradable.

 

The biodegradability of DOPA-Glycinate under anaerobic conditions was hindered by the antibacterial effect of the test substance under the chosen test conditions. As the test results showed, there was no anaerobic biodegradation of DOPA-Glycinate within 60 days. Due to these results the test item must be identified as non-biodegradable under anaerobic conditions because of its potentially toxic effects to bacteria, at least at the concentration recommended by the test guideline. Nevertheless, DOPA-Glycinate must be assumed to quickly degrade aerobically in the STP.

 

In view of the verified aerobic ready biodegradability, further biodegradation tests (e.g. aerobic degradation in soil) are not considered necessary. However, an STP simulation test is available. In view of the established ready biodegradability this study is presented as supportive data. The simulation test corroborates the excellent degradability of DOPA-Glycinate in sewage treatment plants, with a reported removal rate of 81 ± 5 %.

 

The experimental determination of the degradation half-life (DT50) of DOPA-Glycinate in soil is not considered to be required in view of the ready biodegradability and overall limited direct release to soil. Instead, the half-life in soil may be determined by default allocation according to the TGD (chapter 2.3.6.5, Table 8), based on the ready biodegradability and the soil adsorption characteristics (soil partition coefficient: Kpsoil= 1240, see Chapter Adsorption/desorption below). A soil half-life of 3000 days (degradation ratek= 0.000231) at 12 °C is therefore allocated by default.

 

Conclusion:

DT50(surface water) = 15 days

DT50(sediment) = 3000 days

DT50(soil) = 3000 days

DT50(STP) =0.693 hours