N,N'-ethylenebis[N-acetylacetamide]

Biodegradation in water and sediment: simulation tests

Description of key information

STP SIMULATION TEST according OECD 303A
For TAED a STP Simulation test according OECD 303A was carried out which resulted in an elimination of 98% based on DOC. As no substance specific analysis was applied biodegradation could not be measured. On the other hand as TAED has only a very low potential to sorb to sewage sludge it can be assumed that the eliminated amount of TAED was biodegraded. This is supported by the Sturm test according OECD 301B. Based on the REACH Guidance on information requirements and chemical safety assessment Chapter R.16.4.4.4 a degradation rate of readily biodegradable substances of 1 1/h can be assumed which corresponds to a DT50 STP TAED of 0.7 h.
For DAED such a study is not available but due to the structural similarity and the similar inherent properties e.g. fate and ecotoxicity it can be assumed that a read across to the TAED study is appropriate means DT50 STP DAED 0.7 h.
SURFACE WATER SIMULATION TEST e.g. according OECD 309
SEDIMENT SIMULATION TEST e.g. according OECD 308
TAED
According 1907/2006/EC Annex IX, Column 2, 9.2.13 Simulation studies for surface water and sediment need not to be carried out for readily biodegradable substances. But according to the REACH Guidance on information requirements and chemical safety assessment Chapter R.16.4.4.5 a DT50 for biodegradation may be derived from a test on ready biodegradability alone (surface water) or in conjunction with the Koc of the substance. For TAED the Koc is < 100 L/kg .
This results in the following DT50 for TAED which can be regarded as conservative:
DT50 Surface water TAED    15d
DT50 Sediment TAED           30 d
DAED	
Due to the structural similarity and the similar inherent properties e.g. fate and toxicity it can be assumed that the DT50 for TAED as mentioned above may also be applied for DAED (read across).