1,4-bis(p-tolylamino)anthraquinone

Endpoint summary

Description of key information

Biodegradation in water

Biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical (Experimental study report, 1992).The study was performed in accordance with OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))under aerobic conditions at a temperature of 24°C. Activated sludge, domestic (adaptation not specified) obtained from a domestic waste water sewage plant was used as a test inoculum for the study. Initial test substance conc. used in the study was 30 mg/l. Flasks were used as a test vessel for the study. An amount of sludge from a domestic waste water sewage plant corresponding to 7.5 mg dry material for positive control ANILINE and 25 mg dry material for the test article were added to 250 ml of the final test medium. The test flasks was incubated on a SAPROMAT D12 (Voith GmbH) supplied with an evaluation program. The biodegradation of the test article was followed by exposing it to microorganisms from the secondary effluent of a domestic waste water sewage plant and determined by means of the biochemical oxygen demand (BOD) for 28 days. At the end of the incubation period, samples of atleast 10 ml from all flasks were centrifuged and thereafter directly analysed. TOC analyses were performed with the various filtrates, using a Shimadzu TOC Analyser (Shimadzu TOC 500). Aniline (positive control) was used as a reference substance for the study. Untreated inoculum was used as an inoculum blank. It degraded by 67.8% and 71.5% after 7 and 14 days respectively. A slight degradation was observed in the flask without inoculum, allowing the assumption that the test article was not only degraded by microorganisms. The percentage degradation of test chemical was determined to be 29.9% by BOD parameter in 28 days. Thus, based on percentage degradation,test chemical is considered to be inherently biodegradable in nature.

Additional information

Biodegradation in water

Various experimental key and supporting study of the test chemical were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from study report (1992),biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed in accordance with OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))under aerobic conditions at a temperature of 24°C. Activated sludge, domestic (adaptation not specified) obtained from a domestic waste water sewage plant was used as a test inoculum for the study. Initial test substance conc. used in the study was 30 mg/l. Flasks were used as a test vessel for the study. An amount of sludge from a domestic waste water sewage plant corresponding to 7.5 mg dry material for positive control ANILINE and 25 mg dry material for the test article were added to 250 ml of the final test medium. The test flasks was incubated on a SAPROMAT D12 (Voith GmbH) supplied with an evaluation program. The biodegradation of the test article was followed by exposing it to microorganisms from the secondary effluent of a domestic waste water sewage plant and determined by means of the biochemical oxygen demand (BOD) for 28 days. At the end of the incubation period, samples of atleast 10 ml from all flasks were centrifuged and thereafter directly analysed. TOC analyses were performed with the various filtrates, using a Shimadzu TOC Analyser (Shimadzu TOC 500). Aniline (positive control) was used as a reference substance for the study. Untreated inoculum was used as an inoculum blank. It degraded by 67.8% and 71.5% after 7 and 14 days respectively. A slight degradation was observed in the flask without inoculum, allowing the assumption that the test article was not only degraded by microorganisms. The percentage degradation of test chemical was determined to be 29.9% by BOD parameter in 28 days. Thus, based on percentage degradation, test chemical is considered to be inherently biodegradable in nature.

 

In a supporting study,28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical (Experimental study report, 2018. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used as a test inoculum for the study. 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 73.49%. Degradation of Sodium Benzoate exceeds 39.15% on 7 days & 70.48% on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1 mgO2/mg. ThOD was calculated as 2.37 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 42.19%. Based on the results, the test item, under the test conditions, was considered to be inherently biodegradable in nature.

 

On the basis of above results, the test chemicalcan be considered to beinherently biodegradable in nature.