Decan-5-olide

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. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism.

Duration of test (contact time):

28 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:

49.4

Sampling time:

28 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 arereported in Tables 2 and 3, respectively. The BOD28 value of test chemical was observed to be 1.25 mgO2/mg. ThOD was determined by calculation as 2.53 mgO2/mg. % Degradation was calculated using the values of BOD and ThOD for test item and was determined to be 49.4% at 20 ± 1°C. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 73.49% at 20 ± 1°C. Degradation of Sodium Benzoate exceeds 43.37% on 7th days & 58.43% 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 item) was also calculated using BOD & ThOD and was determined to be 73.49% at 20 ± 1°C. Degradation of Sodium Benzoate exceeds 43.37% on 7th days & 58.43% 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	6.7	6.5	6.6
7	6.2	3.9	3.2
14	6	2	2
21	5.7	1	1
28	5.5	0.3	0.5

TABLE 2: BOD Values (mg O2/mg)

 

No. of Days	Test Suspension	Procedure Control (Reference Item)
0	0	0
7	0.52	0.72
14	0.95	0.97
21	1.12	1.15
28	1.25	1.22

 

TABLE 3: PERCENT BIODEGRDATION RESULTS

No. of Days	Test Suspension	Procedure Control (Reference Item)
0	0%	0%
7	20.55%	43.37%
14	37.54%	58.43%
21	44.26%	69.27%
28	49.4%	73.49%

 

Table 4: BOD28, THOD AND % BIODEGRADATION VALUES

 

Method details	BOD28 (mgO2/mg)	ThOD (mgO2/mg)	%Biodegradation
Test Item	1.25	2.53	49.4
Reference Item	1.22	1.66	73.49

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test chemical undergoes 49.4% biodegradation after 28 days in the test condition. Thus, the test chemical was considered to be inherently biodegradable in nature.

Executive summary:

Biodegradation study was conducted for 28-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 substance. 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 chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 73.49% at 20 ± 1°C. Degradation of Sodium Benzoate exceeds 43.37% on 7th days & 58.43% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.25 mgO2/mg. ThOD was calculated as 2.53 mgO2/mg. Accordingly, the % degradation of the test chemical after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 49.4%. Based on the results, the test chemical, under the test conditions, was considered to be inherently biodegradable in nature.

Description of key information

Biodegradation study was conducted for 28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical (Experimental study report, 2017). The study was performed at a temperature of 20°C. The test system included control, test chemical and reference substance. 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 chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 73.49% at 20 ± 1°C. Degradation of Sodium Benzoate exceeds 43.37% on 7th days & 58.43% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.25 mgO2/mg. ThOD was calculated as 2.53 mgO2/mg. Accordingly, the % degradation of the test chemical after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 49.4%. Based on the results, the test chemical, 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 28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical (Experimental study report, 2017). The study was performed at a temperature of 20°C. The test system included control, test chemical and reference substance. 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 chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 73.49% at 20 ± 1°C. Degradation of Sodium Benzoate exceeds 43.37% on 7th days & 58.43% on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.25 mgO2/mg. ThOD was calculated as 2.53 mgO2/mg. Accordingly, the % degradation of the test chemical after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 49.4%. Based on the results, the test chemical, under the test conditions, was considered to be inherently biodegradable in nature.