[No public or meaningful name is available]

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:

May 2021

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

No claim of GLP A leak was encountered in one of the vessels so the study should be treated with caution.

Justification for type of information:

Information derived from R&D process and deemed reliable

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

no

Remarks:

This study experience methodological definciencies

Test material

Test material information

Constituent 1

Reference substance name:

Sophorolipids: fermentation products of glucose and fatty acids, C18 (unsaturated), glycerol esters with yeast Starmerella Bombicola

IUPAC Name:

Sophorolipids: fermentation products of glucose and fatty acids, C18 (unsaturated), glycerol esters with yeast Starmerella Bombicola

Test material form:

liquid

Details on test material:

Batch release

Specific details on test material used for the study:

Name HoneySurf LF
Batch no. H20310-02
Expiry date 30. Nov. 2021

Study design

Oxygen conditions:

aerobic

Remarks:

The test vessels were aerated with purified (by activated charcoal), CO2-scrubbed, moistened air. The scrubbing of carbon dioxide was achieved by bubbling the purified air through a flask containing 1.5 M NaOH. To control the absence of CO2, the air was t

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly domestic sewage.
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, 67435 NW-L
The sludge was filtrated, washed with test medium (2x) and resuspended in test medium. It was then aerated until use. The dry matter was determined with 3.50 g suspended solids/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

20.1 mg/L

Based on:

COD

Remarks:

Test 2

Initial test substance concentration 2

Initial conc.:

20.7 mg/L

Based on:

COD

Remarks:

Test 1

Initial test substance concentration 3

Initial conc.:

51.1 mg/L

Based on:

test mat.

Remarks:

Test 2

Initial test substance concentration 4

Initial conc.:

52.6 mg/L

Based on:

test mat.

Remarks:

Test 1

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

2000 mL-SCHOTT-flasks were used as test vessels, 100 mL scrubber flasks as absorbent
vessels.
The medium was prepared from the stock solutions. The stock solution of the positive control
was prepared and its organic carbon was measured. The inoculum was taken from its
source, washed, aerated and the dry matter was determined.
The test vessels were filled with medium and inoculum. Then all flasks were aerated for
72 hours with purified, CO2-free, moistened air to purge the system of CO2.
Flask volume 1500 mL
Apparatus blanks 2, containing mineral medium only
Controls 2, containing mineral medium and inoculum
Positive control flasks 2, containing positive control, mineral medium and inoculum
Test flasks 2, containing test item, mineral medium and inoculum
Abiotic control 1, containing test item, mineral medium and HgCl2
Toxicity control 1, containing test item, positive control, mineral medium and inoculum
Inoculum concentration: 25.0 mg/L
Temperature 19.4 – 21.9 °C without direct lighting
Duration 28 days
The test was performed with a nominal start concentration of 20 mg organic carbon/L.
From each front scrubber flask, 10 samples were taken in order to determine the emitted
CO2. (on days 0, 2, 4, 7, 9, 11, 14, 18, 23 and 29). The sample volume was 1 mL. The
resulting change in the volume of the front flask was considered in the calculation of emitted
CO2 (see also chapter 3.2.1).
On day 28, 5 mL HCl 2 M. were added to each test flask in order to drive off dissolved CO2.
On day 29, samples from both scrubber flasks were taken.

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

69.2

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

81.1 % on day 14

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

NB leak on one vessel line, treat results with some degree of caution