[(3aS*,4R*,5S*,7R*,7aS*)-4,7-methano-2,3,3a,4,5,6,7,7a-octahydro-1H-inden-5-yl]methyl acetate

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 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: municipal sewage treatment plant, hardly receiving any industrial chemical waste.
- Pretreatment: the activated sludge was washed twice with autoclaved tap water. Then, the settled sludge was filled up with a mineral salts medium, and it was kept under aerobic conditions by aeration for 4 hours. Afterwards, the sludge was homogenized with a blender, the supernatant was decanted and maintained under aerobic conditions by aeration with CO2 free air for 7 days.
- Concentration of sludge: 0.2 mL inoculum per test vessel

Duration of test (contact time):

28 d

Initial conc.:

3 mg/L

Based on:

test mat.

Initial conc.:

7.8 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral salts medium
- Test temperature: 20 - 24°C (± 1°C)
- pH: 7.4 ± 0.2 for mineral salts medium; pH range of both test item and controls 7.23 - 7.31 and 6.83 - 7.44 at the beginning and at the end of the test, respectively
- Aeration of dilution water: yes, until oxygen saturation
- Continuous darkness: yes
- Oxygen concentration measurements: 5 measurements every 7 days for inoculum control, test item and functional control; 3 measurements every 14 days (approx.) for the toxicity control
- Replicates: duplicates

TEST SYSTEM
- Test vessels: BOD bottles of 300 mL with glass stoppers, and without headspace.
- Method used to create aerobic conditions: aeration
- Measurement equipment: Oximeter, HQ 40d multi

CONTROL AND BLANK SYSTEM
- Inoculum blank: test medium without test and/or reference item
- Functional control: 5 mg/L reference item (ThOD 8.4 mg oxygen/L)
- Toxicity control: 1.5 mg/L test item + 2.5 mg/L reference item (ThOD 8.1 mg oxygen/L)

Reference substance:

benzoic acid, sodium salt

Remarks:

CAS No. 532-32-1

Test performance:

The biodegradation was followed by measuring the oxygen concentration in the test solutions, which was depleted by the respiration of the bacteria of the inoculum. For the calculation of the Biological Oxygen Demand (BOD), the oxygen depletion of the control was taken into account. The % biodegradation is calculated by dividing the specific BOD by the specific ThOD of test item and controls at each oxygen consumption measurement.

Key result

Parameter:

% degradation (O2 consumption)

Value:

16

Sampling time:

28 d

Details on results:

10% biodegradation of the test item after 5 days. 16% biodegradation of the test item after 28 days. At the end of the test, the 60% pass level was not reached for the test item.

Results with reference substance:

81% biodegradation of the reference substance after 28 days. The pass level > 60% was reached after 6 days.
46% biodegradation of the toxicity control after 13 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control.

Validity criteria fulfilled:

yes

Remarks:

All validity criteria fulfilled

Interpretation of results:

not readily biodegradable

Conclusions:

The test item is classified as not readily biodegradable in the 10-d window and after 28 days. 10% biodegradation of the test item was reached after 5 days, with a maximum of 19% biodegradation after 21 days. At the end of the test, the 60% pass level was not reached for the test item.

Executive summary:

The ready biodegradability of the test item was determined by Closed Bottle method, according to OECD TG 301 D. Degradation was followed by analysis of dissolved oxygen over a 28-d period.

An inoculum control, functional control with a reference substance, and toxicity control were also assessed during the test. 81% biodegradation of the reference substance was reached after 28 days. The biodegradation of the reference item was not found to be inhibited by the test item in the toxicity control.

10% biodegradation of the test item was reached after 5 days, with a maximum of 19% biodegradation after 21 days. At the end of the test, the 60% pass level was not reached for the test item. The test item is not readily biodegradable in the 10-d window and after 28 days.

The study is reliable without restrictions, being GLP compliant and having followed a standard guideline.

Description of key information

10% biodegradation of the test item was reached after 5 days, with a maximum of 19% biodegradation after 21 days. At the end of the test, the 60% pass level was not reached for the test item. The test item is not readily biodegradable in the 10-d window and after 28 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The biodegradability of the test item was determined by Closed Bottle method, according to OECD TG 301 D. Degradation was followed by analysis of dissolved oxygen over a 28-d period. An inoculum control, functional control with a reference substance, and toxicity control were also assessed during the test (2011). 81% biodegradation of the reference substance was reached after 28 days. The biodegradation of the reference item was not found to be inhibited by the test item in the toxicity control.

The study is reliable without restrictions, being GLP compliant and having followed a standard guideline.