Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The inherent biodegradability of the test item was determined in the Modified MITI Test (II) with non adapted activated sludge for a period of 28 days. The study was conducted according to OECD Guideline 302 C and compliant to GLP. The test item concentration selected as appropriate was 40 mg/L, corresponding to a ThOD of 54 mgO2/L. The oxygen was depleted by respiration of bacteria and the degradation was followed by measuring the oxygen concentration. The biodegradation is therefore expressed as the percentage BOD depletion and was calculated for each study day


Two test item replicates did not reach the 10 % level (beginning of biodegradation) within the test duration of 28 days. The 3rd test item replicate reached the 10 % level after 16 days. The pass level > 70 % for evidence of inherent, ultimate biodegradability was not reached within 28 days. After 28 days the mean biodegradation rate was 5 %.


 


To estimate BCF of the submission substance by QSAR, besides the key study (reliability category 2) performed using the CAESAR BCF model v.  v. 1.0.0.11 supporting calculations were performed using BCFBAF v. 3.01 and the Arnot & Gobas (2003) model on bioconcentration. The following results were achieved:


BCF according to CAESAR (key study): 5 L/kg whole body wet weight


BCF according to BCFBAF (supporting study): 10 L/kg whole body wet weight


BCF according to Arnot & Gobas model, upper trophic level (10.7% lipid content): 213 L/kg whole body wet weight


BCF according to Arnot & Gobas model, standard test fish species (5% lipid content): 100 L/kg whole body wet weight


 


In a reliable study using the HPLC-method according to OECD 121 for estimating the adsorption coefficient Koc on soil and sewage sludge, for the test item a log Koc of 5.8 was determined. The calculated log Koc value of the test substance is outside but close to the calibrated range. 4,4'-DDT is


the reference substance with highest log Koc value available (5.63). Therefore only an extrapolated value for the test substance can be obtained.


 

Additional information