Undecanolactone

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study conducted between 16 February and 17 March 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

UK Department of Health, inspected 01-03 December 2015, certificate issued 15 February 2016

Test material

Test material information

Constituent 1

Reference substance name:

Undecanolactone

EC Number:

254-399-3

EC Name:

Undecanolactone

Cas Number:

39282-36-5

Molecular formula:

C11H20O2

IUPAC Name:

(5E,13E)-icosa-5,13-dienoic acid; 6-tetradecyloxan-2-one

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 1383Q12001
- Expiration date of the lot/batch: 29 April 2016

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: No data
- Solubility and stability of the test substance in the solvent/vehicle: Insoluble in water/Soluble in acetone, chloroform & hexane

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Worlingworth sewage treatment works, Suffolk, UK
- Storage conditions: Aerated in laboratory
- Storage length: 2 days before test initiation
- Preparation of inoculum for exposure: None
- Pretreatment: Sieved to 1 mm2
- Concentration of sludge: Adjusted to give 30 mg/L solids

Duration of test (contact time):

<= 28 d

Initial test substance concentration

Initial conc.:

<= 50 mg/L

Based on:

COD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Test temperature: 22 +/-2oC
- pH adjusted: No
- Suspended solids concentration: Adjusted to 30 mg/L
- Continuous darkness: No data

TEST SYSTEM
- Number of culture flasks/concentration: 2 replicates of test item, 1 replicate each for reference substance and toxicity control
- Method used to create aerobic conditions: Magnetic stirrer to creat vortex in each test vessel
- Test performed in open system: No
- Details of trap for CO2 and volatile organics if used: Electrolytic cell assembly (electrolyte, 1M CuSO4, CO2 absorber, 2M KOH)

CONTROL AND BLANK SYSTEM
- Inoculum blank: Inoculated mineral salts medium only
- Abiotic sterile control: No
- Toxicity control: Test item (50 mg/L) and sodium benzoate (50 mg/L)

Reference substance

Reference substance:

other: Sodium benzoate

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

91

Sampling time:

28 d

Details on results:

The test item can be classed as a substance of unknown or variable composition, therefore, under EC regulation 286/2011 the 60% pass level can be determined after 28 days and the 10-day window pass level can be waived.

Any other information on results incl. tables

Day	% Biodegradation
	Test item	Toxicity control	Reference item
0	0	0	0
5	60	62	74
10	79	82	85
15	84	86	92
20	87	86	97
25	90	88	102
28	91	91	104

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item attained 81% biodegradation within the 10-day window and 91% biodegradation after 28 days, and can be classified as readily biodegradable under the conditions of the test.
The reference item attained 87% biodegradation within the 10-day window and a maximimum of 104%, indicating the sewage sludge inoculum was responding normally
The toxidity control attained 83% biodegradation within the 10-day window and a maximum of 91% biodegradtion after 28 days, indicating that the test item was not toxic to the sewge treatment micro-organisms used in the test

Executive summary:

A study was performed to determine the ready biodegradability of the test item when exposed to sewage treatment micro-organisms under aerobic conditions. The test was conducted according to the principles of GLP and followed internationally accepted test guidelines.

Sewage sludge was exposed to an aqueous dispersion of the test item at the nominal test concentration of 50 mg/L over a period of 28 days. The respiration rate (CO2 evolution) was measured daily throughout the test period and the % biodegradation calculated. The test validity criteria were met and the study is therefore acceptable.

The reference item attained 87% biodegradation within the 10-day window, indicating the sewage sludge inoculum was responding normally.

The toxicity control attained 83% biodegradation with the 10-day window, indicating that the test item was not toxic to the sewage treatment micro-organisms used in the test.

The test item can be classed as a substance of unknown or variable composition, therefore, under EC regulation 286/2011 the 60% pass level can be determined after 28 days and the 10-day window pass level can be waived. The test item attained 81% biodegradation within the 10-day window and 91% biodegradation after 28 days, and can be classified as readily biodegradable under the conditions of the test.