Diphenylacetonitrile

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. 1 polyseed capsule was added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum.

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:

28.4

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 2 and 3, respectively. The BOD42 value of test chemical was observed to be 0.75 mgO2/mg. ThOD was determined by calculation as 2.64 mgO2/mg. % degradation was calculated using the values of BOD and ThOD for test chemical and was determined to be 28.4% at 20 ± 1°C. The % degradation of procedure control (reference chemical) was also calculated using BOD & ThOD and was determined to be 66.26%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 73.49% on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid.

Results with reference substance:

The % degradation of procedure control (reference chemical) was also calculated using BOD & ThOD and was determined to be 66.26%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 73.49% on 14th day. The activity of the inoculum was 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)
0	6.8	6.7	6.7
7	6.5	5.1	1.7
14	6.3	4.7	1.2
21	6	3.8	0.8
28	5.6	2.9	0.7
35	5.3	2.4	0.6
42	5.1	2	0.6

TABLE 2: BOD Values (mg O2/mg)

 

No. of Days	Test Suspension	Procedure Control (Reference Item)
0	0	0
7	0.32	1.17
14	0.37	1.22
21	0.52	1.27
28	0.65	1.2
35	0.7	1.15
42	0.75	1.1

 

TABLE 3: PERCENT BIODEGRDATION RESULTS

No. of Days	Test Suspension	Procedure Control (Reference Item)
0	0%	0%
7	12.12%	70.48%
14	14.01%	73.49%
21	19.69%	76.5%
28	24.62%	72.28%
35	26.51%	69.27%
42	28.4%	66.26%

 

Table 4: BOD42, THOD AND % BIODEGRADATION VALUES

 

Method details	BOD42(mgO2/mg)	ThOD (mgO2/mg)	%Biodegradation
Test Item	0.75	2.64	28.4
Reference Item	1.10	1.66	66.26

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

Test chemical undergoes 28.4% biodegradation after 42 days in the test condition. Thus, the test chemical was considered to be not readily biodegradable in nature.

Executive summary:

42-days 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 chemical. Polyseed were used as a test inoculum for the study.The concentration of test and reference chemical (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 chemical and reference chemical. The % degradation of procedure control (reference chemical) was also calculated using BOD & ThOD and was determined to be 66.26%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 73.49% 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 0.75 mgO2/mg. ThOD was calculated as 2.64 mgO2/mg. Accordingly, the % degradation of the test chemical after 42 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 28.4. Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable in nature.

Description of key information

42-days 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 chemical. Polyseed were used as a test inoculum for the study.The concentration of test and reference chemical (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 chemical and reference chemical. The % degradation of procedure control (reference chemical) was also calculated using BOD & ThOD and was determined to be 66.26%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 73.49% 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 0.75 mgO2/mg. ThOD was calculated as 2.64 mgO2/mg. Accordingly, the % degradation of the test chemical after 42 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 28.4%. Based on the results, the test item, under the test conditions, was considered to be inherently biodegradable in nature.

Estimation Programs Interface Suite was run to predict the biodegradation potential of the test compound. The screening testsready biodegradability of the test substance was calculated using the software BIOWIN v4.10. The results indicate that Diphenylacetonitrileis not expectedto be readily biodegradablein nature.

Biodegradation study was conducted according to OECD TG 301 C guideline for evaluating the percentage biodegradability of test substance Benzonitrile.Initial test substance conc. used in the study was 100 mg/l. Water, acetone or DMSO solution (0.1 ml) of the test chemicals was added to a mixture of river/sea water (4.9 ml) from an unpolluted area and an autoclaved solution (5.0ml) of 0.2% peptone in a sterile test tube with a tight plug. After sealed with film and fixed at an angle of 30°in a dark box, the test tubes were incubated at 30°C and shaked at 120rpm. Inoculum used for the study was mixed culture obtained from different sources (Sea water from Tama river and River water from Enoshima Beach). The percentage degradation of test substance was found to be 7% and 0% in 14 days, respectively. Thus, the substance Benzonitrile was determined to be not readily biodegradable in nature.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Additional information

42-days 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 chemical. Polyseed were used as a test inoculum for the study.The concentration of test and reference chemical (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 chemical and reference chemical. The % degradation of procedure control (reference chemical) was also calculated using BOD & ThOD and was determined to be 66.26%. Degradation of Sodium Benzoate exceeds 70.48% on 7 days & 73.49% 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 0.75 mgO2/mg. ThOD was calculated as 2.64 mgO2/mg. Accordingly, the % degradation of the test chemical after 42 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 28.4%. Based on the results, the test item, under the test conditions, was considered to be inherently biodegradable in nature.

Estimation Programs Interface Suite was run to predict the biodegradation potential of the test compound. The screening testsready biodegradability of the test substance was calculated using the software BIOWIN v4.10. The results indicate that Diphenylacetonitrileis not expectedto be readily biodegradablein nature.

Biodegradation study was conducted according to OECD TG 301 C guideline for evaluating the percentage biodegradability of test substance Benzonitrile.Initial test substance conc. used in the study was 100 mg/l. Water, acetone or DMSO solution (0.1 ml) of the test chemicals was added to a mixture of river/sea water (4.9 ml) from an unpolluted area and an autoclaved solution (5.0ml) of 0.2% peptone in a sterile test tube with a tight plug. After sealed with film and fixed at an angle of 30°in a dark box, the test tubes were incubated at 30°C and shaked at 120rpm. Inoculum used for the study was mixed culture obtained from different sources (Sea water from Tama river and River water from Enoshima Beach). The percentage degradation of test substance was found to be 7% and 0% in 14 days, respectively. Thus, the substance Benzonitrile was determined to be not readily biodegradable in nature.

Over all the test chemical is considered to be not readily biodegradable in water.