2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione

Endpoint summary

Additional information

Biodegradation in water

The predicted data for the test compound2-Octadecyl-1H-thioxantheno(2,1,9-def)isoquinoline-1,3(2H)-dione(CAS No. 27870-92-4) and the study for its read across substance were reviewed for the biodegradation end point which are summarized as below:

Biodegradation in water ability was predicted (SSS QSAR Prediction model, 2016) for the test substance2-Octadecyl-1H-thioxantheno

(2,1,9-def)isoquinoline-1,3(2H)-dione (CAS no. 27870-92-4) using the SSS QSAR prediction model. The ready biodegradability of the test substance 2-Octadecyl-1H-thioxantheno(2,1,9-def)isoquinoline-1,3(2H)-dione was estimated as 0.166% in 28 days by using BOD parameter. This result indicates that 2-Octadecyl-1H-thioxantheno(2,1, 9 -def)isoquinoline-1, 3(2H)-dione was estimated to be not readily biodegradable in water.

 

Estimation Programs Interface Suite (EPI suite, 2016) was run to predict the biodegradation potential of the test compound 2-Octadecyl-1H- thioxantheno(2,1,9-def)isoquinoline-1,3(2H)-dione (CAS No. 27870 -92 -4). The screening test ready biodegradability of the substance was calculated using the software BIOWIN v4.10. The results indicate that 2-Octadecyl-1H-thioxantheno(2,1,9-def)isoquinoline-1,3(2H)- dione is not expected to be readily biodegradable in nature.

Biodegradation study was conducted for 15 days (K. YOSHIMURA et. al; 1980) for evaluating the percentage biodegradability of test substanceTri-n-octylamine. Biodegradation tests were carried out with an oxygen consumption measuring apparatus (Ohkura Coulometer) at 25°C. The basal medium was the JIS (Japanese Industrial Standards) BUD diluent prepared by adding 3 ml each of solution A, B, C and D to 987 ml of deionized water. The incubation chamber includes an incubation flask with a magnetic stirrer and a small vessel for carbon dioxide absorbent.Colorimetric, total organic carbon (TOC) and CO 2 production measurements. The colorimetric measurement was carried out according to Auerbach's method (Bromophenol Blue), whereas the TOC measurement was with a Beckman TOC analyzer.C02production was measured according to Ito's method. Activated sludge was obtained from a municipal sewage plant that treated domestic sewage in Tokyo. Concentration of inoculum i.e, activated sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l. The percentage degradation of test substance was found to be in the range of 0% by BOD/ThOD in 15 days. Thus, the substanceTri-n-octylamineis not expected to be readily biodegradable in water.

Biodegradation study was conducted (J-CHECK, 2016) for 14 days for evaluating the percentage biodegradability of test substance Tri-n-octylamine. Concentration of inoculum i.e; sludge used was 100 mg/l and initial test substance conc. used in the study was 30 mg/l. The percentage degradation of test substancewas found to be 0% by BOD and 12% by GC in 14 days. Thus, the substance Tri-n-octylamine is not expected to be readily biodegradable in water.

 

Biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of test substanceTri-n-octylamine [Environmental Fate Data Base (EFDB), 2016]. Concentration of inoculum i.e; activated sludge used was 30 mg/l and intial test substance concentration used in the study was 100 mg/l. The percentage degradation of test substance was found to be in the range of 0-29% by BOD in 14 days at a temperature of 25°C and pH 7.0. Thus, the substance Tri-n-octylamineis not expected to be readily biodegradable in water.

 

On the basis of above results for target and read across substance, it can be concluded that the test substance 2-Octadecyl-1H-thioxantheno

(2,1,9-def)isoquinoline-1,3(2H)-dione can be expected to be not readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI) Suite (2016) prediction model was run to predict the half-life in water and sediment for the test compound 2-Octadecyl-1H-thioxantheno(2,1,9-def)isoquinoline-1,3(2H)-dione(CAS No. 27870 -92 -4). Half-life of 2 -Octadecyl-1H-thioxantheno(2,1, 9 -def)iso quinoline-1, 3(2H)-dione in water is estimated to be 37.5 days (900 hrs) while in sediment it is 337.5 days (8100 hrs). Based on these half-life value of 2-Octadecyl-1H-thioxantheno(2,1,9-def)isoquinoline-1,3(2H)-dione, it is concluded that the chemical is not persistent in water while it is persistent in sediment.

Biodegradation in soil

Based on EPI prediction Level III Fugacity Model (EPI suite, 2016), the estimated half-life period of 2 -Octadecyl-1H-thioxantheno(2, 1, 9 -def)isoquino line-1,3(2H)-dione (CAS No. 27870-92-4) in soil was obtained to be 75 days (1800 hrs). Based on this half-life value of 2 -Octadecyl-1H-thioxantheno (2,1,9-def)isoquinoline-1,3(2H)-dione, it is concluded that the chemical is not persistent in the soil environment.

On the basis of available information, the test substance 2-Octadecyl-1H-thioxantheno(2,1,9-def)isoquinoline-1,3(2H)-dione can be considered to be not readilybiodegradable in nature.