5-octylbicyclo[2.2.1]hept-2-ene

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

Study period:

21 June to 19 July 2018 (Test period).

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

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Materia, Inc., 60 N San Gabriel Blvd, Pasadena, CA 91107, USA; Batch No. RP367_ONB-D
- Expiration date of the lot/batch: 09 August 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient (15±10ºC), in the dark
- Stability under test conditions: Not known
- Solubility and stability of the test substance in the solvent/vehicle: Not known

OTHER SPECIFICS:
- Purity / Composition: ONB Isomers (2) 93.26%; TCPD Isomers (3 major) 3.92%; Other individual impurities <0.99 ea% (taken from CoA)
- Appearance (observed): Colourless liquid
- Solubility (specified): <0.001g/L
- Homogeneity (observed): Homogeneous

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Cambridge STW, Cowley Road, Cambridge, UK
- Date of collection: 15 June 2018
- Pre-treatment: Filtered (Whatman No. 54)
- Temperature at start of test: 20.8°C
- Concentration of inoculum: 1ml/l

Duration of test (contact time):

28 d

Initial conc.:

2 g/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: The dilution water was prepared by the addition of mineral nutrient stock solutions to deionised water, aerating it strongly for 20 minutes, allowing to stand for 24 hours and 22 minutes and adding inoculum.

TEST SYSTEM
- Number of culture flasks/concentration: 0 days (1 replicate), 7 days (2 replicates), 14 days (2 replicates), 21 days (3 replicates), 28 days (3 replicates); Blank and control (1 replicate)
- Measuring equipment: Dissolved oxygen meter

SAMPLING
- Sampling frequency: Dissolved oxygen concentration measurements were made on bottles removed after 7, 14, 21 and 28 days.
- Sampling method: The test material was stated to be soluble in water at ≤0.001g/l, therefore it was treated as insoluble and a stock solution of 0.5004g of 5- Octyl- 2- Norbornene was made to 500ml with deionised water to produce a concentration of 1.002g/l. Replicate standard BOD bottles were filled with the sample stock solution, prepared by addition of the 1.002g/l sample stock solution to mineral medium at 2.0ml/l to give a final test concentration of 2.00g/l. A series of bottles were prepared with only inoculated mineral medium, for the determination of "blank" losses.
- Other: The bottles were incubated in the dark at 20.2-21.3 degrees C for the duration of the test period.

Reference substance:

other: Sodium acetate

Remarks:

Tested at 5.00mg/l by preparing a 1.000g/l stock solution (0.1000g Sodium acetate made to 100ml with deionised water), added to the mineral media at 5ml/l.

Preliminary study:

No

Key result

Parameter:

% degradation (O2 consumption)

Value:

108

Sampling time:

28 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

29

Sampling time:

7 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

94

Sampling time:

14 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

107

Sampling time:

21 d

Details on results:

Values are for a test concentration of 2.00mg/l and a Theoretical Oxygen Demand (ThOD) of 3115mgO2/g.

Key result

Parameter:

ThOD

Value:

3 115 mg O2/g test mat.

Results with reference substance:

% degradation of sodium acetate: 80.
ThOD of sodium acetate 780mgO2/g.

5 -Octyl-2 -Norbornene was found to be insoluble in water. Therefore a surfactant (IGEPAL CA 630) was used to emulsify the sample. The effects of surfactant degradation were taken into account when calculating the degradation of the test material. The OECD 301D guideline requires that the reference material degrades by at least 60% of its ThOD, and that the blank dissolved oxygen loss does not exceed 1.5mg/l after 28 days. Both of these criteria were satisfied for this test; a maximum value of 105% degradation of the sodium acetate was achieved, and the blank DO loss was 1.36mg/l. Degradation values in excess of 100% are considered a result of analytical variation.

The conclusion of this study is therefore that 5 -Octyl-2 -Norbornene is readily biodegradable under the conditions of this test.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Under the conditions of this study, this substance was found to be readily biodegradable.

Description of key information

5 -Octyl-2 -Norbornene was found to be insoluble in water. Therefore a surfactant (IGEPAL CA 630) was used to emulsify the sample. The effects of surfactant degradation were taken into account when calculating the degradation of the test material. The OECD 301D guideline requires that the reference material degrades by at least 60% of its ThOD, and that the blank dissolved oxygen loss does not exceed 1.5mg/l after 28 days. Both of these criteria were satisfied for this test; a maximum value of 105% degradation of the sodium acetate was achieved, and the blank DO loss was 1.36mg/l. Degradation values in excess of 100% are considered a result of analytical variation.

The conclusion of this study is therefore that 5 -Octyl-2 -Norbornene is readily biodegradable under the conditions of this test.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater