Dihydrogen (ethyl)[4-[[4-[ethyl(3-sulphonatobenzyl)amino]phenyl](2-sulphonatophenyl)methylene]cyclohexa-2,5-dien-1-ylidene](3-sulphonatobenzyl)ammonium, aluminium salt

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

Justification for type of information:

Experimental result using OECD guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

other: Mixed inoculum

Details on inoculum:

Mixed Inoculum Preparation:Polyseed were used for this study. Polyseed capsule is a blend of broad spectrum bacteria designed specifically as seed inoculum for the BOD test. Polyseed is an EPA approved BOD seed inoculum. 15 mg of polyseed from the capsule was weighed and added in 50 ml D.I water and then stirred for 1 h. This gave the bacterial count as 10E4 to 10E6 CFU/L. A further concentration of 1ml/L of polyseed solution is prepared and from this working inoculum 0.125 mL solution is added to every bottles of 125 ml.

Duration of test (contact time):

42 d

Initial conc.:

4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: OECD mineral medium was used for the study
- Test temperature: 20°C
- Continuous darkness: Yes
- Other: The water used in this study is deionized water.

TEST SYSTEM
- Culturing apparatus: The apparatus used in this study is BOD bottles; with glass stoppers (125 ml), BOD incubator & oxygen electrode and meter.

CONTROL AND BLANK SYSTEM
- Inoculum blank: it contains only test inoculum
- Procedure control: contains reference compound and inoculum

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

47.54

Sampling time:

42 d

Remarks on result:

other: Other details not known

Details on results:

The oxygen consumed by the test systems was corrected for oxygen consumption occurring in the blank test systems. The BOD Values (mgO2/mg) and percent biodegradation results for each test system are reported in tables, respectively. The BOD42 value of test chemical was observed to be 0.87 mgO2/mg. ThOD was determined by calculation as 1.83 mgO2/mg. % degradation was calculated using the values of BOD and ThOD for test chemical and was determined to be 47.54% at 20 ± 1°C. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 85.54%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 76.5% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid.

Results with reference substance:

The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 85.54%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 76.5% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid.

TABLE 1: D.O Values (mg/L)

No. of Days	Inoculum Blank (Control)	Test Suspension	Procedure Control (Reference Item)	Toxicity control
0	8.8	8.5	8.6	8.4
7	8.2	6.2	3.3	7.3
14	7.8	5.5	2.5	3.7
21	7.7	4.7	1.8	2.1
28	7.3	4	1.4	2.4
35	6.9	3.2	1	1
42	6.6	2.8	0.7	0.8

TABLE 2: BOD Values (mg O2/mg)

 

No. of Days	Test Suspension	Procedure Control (Reference Item)	Toxicity control
0	0	0	0
7	0.42	1.17	0.12
14	0.5	1.27	0.92
21	0.67	1.42	1.3
28	0.75	1.42	1.12
35	0.85	1.42	1.37
42	0.87	1.42	1.37

 

TABLE 3: PERCENT BIODEGRDATION RESULTS

No. of Days	Test Suspension	Procedure Control (Reference Item)	Toxicity control
0	0	0	0
7	22.95	70.48	6.55
14	27.32	76.5	50.27
21	36.61	85.54	71.03
28	40.98	85.54	61.2
35	46.44	85.54	74.86
42	47.54	85.54	74.86

 

Table 4: BOD42, THOD AND % BIODEGRADATION VALUES

 

Method details	BOD42 (mgO2/mg)	ThOD (mgO2/mg)	%Biodegradation
Test Item	0.87	1.83	47.54
Reference Item	1.42	1.66	85.54
Toxicity control	1.37	1.83	74.86

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test chemical undergoes 47.54% biodegradation after 42 days in the test condition. Thus, the test chemical was considered to be inherently biodegradable.

Executive summary:

Biodegradation study was conducted for 42-days using Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test chemical and reference substance. Polyseed were used for this study. The concentration of test and reference substance (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 1 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference chemical was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 85.54%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 76.5% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD42 value of test chemical was observed to be 0.87 mgO2/mg. ThOD was calculated as 1.83 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 47.54%. Based on the results, the test item, under the test conditions, was considered to be inherently biodegradable in nature.

Description of key information

Biodegradation study was conducted for 42-days using Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical (Experimental study report, 2019). The study was performed at a temperature of 20°C. The test system included control, test chemical and reference substance. Polyseed were used for this study. The concentration of test and reference substance (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 1 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference chemical was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 85.54%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 76.5% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD42 value of test chemical was observed to be 0.87 mgO2/mg. ThOD was calculated as 1.83 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 47.54%. Based on the results, the test item, under the test conditions, was considered to be inherently biodegradable in nature.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Additional information

Biodegradation study was conducted for 42-days using Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical (Experimental study report, 2019). The study was performed at a temperature of 20°C. The test system included control, test chemical and reference substance. Polyseed were used for this study. The concentration of test and reference substance (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 1 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference chemical was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 85.54%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 76.5% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD42 value of test chemical was observed to be 0.87 mgO2/mg. ThOD was calculated as 1.83 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 47.54%. Based on the results, the test item, under the test conditions, was considered to be inherently biodegradable in nature.