1,4-bis(p-tolylamino)anthraquinone

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Principles of method if other than guideline:

The test chemical was assessed for its biodegradability by waste water bacteria in the ''Modified MITI-TEST (II)'' for 28 days.

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Test organism: Microorganisms (activated bacterial sludge) from a domestic waste water sewage plant.
- Source of inoculum/activated sludge: ARA, Sissach/Switzerland
- Test Medium: The stock solutions were:
a) 8.5 g KH2PO4, 21.75 g K2HPO4,
44.6 g Na2PO4 x 12 H2O, 1.7 g NH4Cl dissolved upto 1000 ml bidistilled water.
b) 22.5 g MgSO4 x 7H2O dissolved upto 1000 ml bidistilled water.
c) 27.5 g CaCl2 dissolved upto 1000 ml bidistilled water.
d) 0.25 g FeCL3 x 6H20 dissolved upto 1000 ml bidistilled water.

3ml each of the stock solutions (a-d) were addede upto 1000 ml bidistilled water (final test medium pH adjusted to 7.0).

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.

Duration of test (contact time):

28 d

Initial conc.:

0 mg/L

Based on:

other:

Remarks:

Untreated inoculated control

Initial conc.:

30 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: Biochemical oxygen demand (BOD)

Details on study design:

Incubation
Apparatus: The test flasks was incubated on a SAPROMAT D12 (Voith GmbH) supplied with an evaluation program.
Temperature: 24.0 degC, checked once per week, held with a built in thermostat.
Illumination: Protected from light
Samples: Flask 1: 250 ml bidistilled water and 7.3 mg test article
Flask 2+3+4: 250 ml final test medium,
7.4 mg test article (flask 2)
7.5 mg test article (flask 3)
7.3 mg test article (flask 4) and
25 mg inoculum.

Flask 9+10+11: 250 ml final test medium,
25.0 mg ANILINE (flask 9)
25.1 mg ANILINE (flask 10)
25.5 mg ANILINE (flask 11) and
7.5 mg inoculum.

Flask 12: 250 ml final test medium amd 25 mg inoculum.

Analyses:
Sample Preparation: At the end of the incubation period, samples of atleast 10 ml from all flasks were centrifuged and thereafter directly analysed.

TOC analyses: TOC analyses were performed with the various filtrates, using a Shimadzu TOC Analyser (Shimadzu TOC 500).

Reference substance:

aniline

Remarks:

(100 mg/l)

Key result

Parameter:

other: BOD

Value:

29.9

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

The test chemical was degradable by 29.9% (BOD/ThOD) within 28 days. A degradation of 7.2% was observed in the flask without inoculum.

Key result

Parameter:

ThOD

Value:

237 other: mg/100 mg

Remarks on result:

other: For test substance

Key result

Parameter:

ThOD

Value:

241 other: mg O2/100 mg

Remarks on result:

other: For Aniline

Results with reference substance:

The standard compound, ANILINE, was degraded within 7 and 14 days by 67.8% and 71.5% (BOD/ThOD), respectively.

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable

Conclusions:

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 water.

Executive summary:

Biodegradation study 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.

Description of key information

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.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Additional information

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 chemical can be considered to be inherently biodegradable in nature.