Fatty acids C8-18 (even numbered), mono- and diesters with sucrose

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:

17 Oct - 14 Nov 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids C8-18 (even numbered), mono- and diesters with sucrose

EC Number:

947-862-2

Molecular formula:

not applicable, substance is UVCB

IUPAC Name:

Fatty acids C8-18 (even numbered), mono- and diesters with sucrose

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): Kurume central sewage treatment center (Kururne-shi, Fukuoka, Japan); sampled on 17 Oct 2017
- Storage conditions: After collection, the activated sludge was aerated at the test temperature until it was used for the test.
- Concentration of sludge: 1950 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Test temperature: 22 °C
- pH: 7.4 (start), 7.3 - 7.7 (end)
- pH adjusted: yes; the pH of the mineral medium was adjusted to 7.4
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes
- Other: Each test solution was stirred with a stirrer.

TEST SYSTEM
- Culturing apparatus: Glass exposure vessels with a fill volume of 300 mL
- Number of culture flasks/concentration: 2
- Measuring equipment: Automated oxygen consumption measuring equipment
- Details of trap for CO2 and volatile organics if used: Soda lime was used to absorb CO2.

SAMPLING
- Sampling frequency: O2 consumption was measured continuously.
- Sampling method: Automated measuring system.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, two bottles
- Toxicity control: yes, one bottle
- Abiotic sterile control: no
- Reference substance: yes, one bottle

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

88

Sampling time:

28 d

Remarks on result:

other: Mean of two replicates.

Details on results:

At the end of the 10-day window the substance was degraded to 64%: Thus, the pass level is reached and the substance is considered to be readily biodegradable according to the OECD criteria.
No insoluble particles were observed in the test solutions throughout the test.

BOD5 / COD results

Results with reference substance:

The reference substance was degraded to 79% after 14 d and 90% after 28 d.

Any other information on results incl. tables

Table 1: Degradation of test item, reference substance and toxicity control

Vessel	7th day	14th day	21st day	28th day	Mean
	% degradation
Test item 1	53	71	83	89	88
Test item 2	54	73	82	86
Toxicity control	68	79	85	90	-
Reference substance	86	92	94	95	-

In the toxicity control 79% degradation was recorded after 14 d. Since the trigger value of 25% degradation after 14 d is reached the substance is not considered to be inhibitory to the inoculum.

Table 2: Validity criteria for OECD 301F.

Criterion from the guideline	Outcome	Validity criterion fulfilled
Difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20%.	3%	yes
Percentage degradation of the reference compound has reached the pass levels by day 14.	92%	yes
The oxygen uptake of the inoculum blank is normally 20-30 mg O2/L and should not be greater than 60 mg/L in 28 days.	29 mg/L	yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Interpretation of results:

readily biodegradable