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Biodegradation in water

Estimation Programs Interface Suite (2018) was run to predict the biodegradation potential of the test compound  1,4-phenylene bis[(4-phenoxyphenyl)-methanone]  (CAS no. 54299 -17 -1) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 1,4-phenylene bis[(4-phenoxyphenyl)-methanone] is expected to be not readily biodegradable.

Additional information

Biodegradation in water

Predicted data for the target compound 1,4-phenylene bis[(4-phenoxyphenyl)-methanone](CAS No. 54299-17-1) and various supporting weight of evidence studies for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction using the Estimation Programs Interface Suite (2018), the biodegradation potential of the test compound1,4-phenylene bis[(4-phenoxyphenyl)-methanone](CAS No. 54299-17-1) in the presence of mixed populations of environmental microorganisms was estimated. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 1,4-phenylene bis[(4-phenoxyphenyl)-methanone]is expected to be not readily biodegradable.

 

In a supporting weight of evidence study from experimental study report (2018),42-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test item. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 107 to 108 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 75.3%. Degradation of Sodium Benzoate exceeds 46.38% on 7 days & 61.44% on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD42 value of test chemical was observed to be 0.62 mgO2/mg. ThOD was calculated as 2.31 mgO2/mg. Accordingly, the % degradation of the test item after 42 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 26.83%. Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable in nature.

 

For the test chemical, biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test substance (authoritative database J-CHECK, 2018). Activated sludge was used as a test inoculums for the study. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance was determined to be 0% by BOD and HPLC parameter in 28 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

On the basis of above results for target chemical 1,4-phenylene bis[(4-phenoxyphenyl)-methanone] (from modelling database, 2018), it can be concluded that the test substance 1,4-phenylene bis[(4-phenoxyphenyl)-methanone] can be expected to be not readily biodegradable in nature.