Amaryllidaceae, Allium Cepa L. (fresh bulb), Rutaceae, Citrus Limon (L.) Burm. F. (fresh pulp), extract, sodium chloride

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:

14/11/2017-12/12/2017

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 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Amaryllidaceae, Allium Cepa L. (fresh bulb), Rutaceae, Citrus Limon (L.) Burm. F. (fresh pulp), extract, sodium chloride

EC Number:

944-860-3

IUPAC Name:

Amaryllidaceae, Allium Cepa L. (fresh bulb), Rutaceae, Citrus Limon (L.) Burm. F. (fresh pulp), extract, sodium chloride

Test material form:

solid

Specific details on test material used for the study:

Appearance: Colourless liquid
Batch number: OC15014 after rotavapor
Sample code: 109/BF-81/17
Composition provided by the Sponsor: NaCl (~ 4%) dry matter (9.3%)

The solvents, water and ethanol were completely evaporated from the extract to constant mass of solid reside, under vacuum from 300 to 1 torr and at temperature of 65-67°C. The resulted dry residue was dissolved in double distilled water and examined in biodegradation test.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic (adaptation not specified)

Remarks:

from the Sewage Treatment Plant ”Czajka” , Warsaw

Details on inoculum:

Inoculum as a sample of secondary efluent was taken from the Sewage Treatment Plant ”Czajka and was pre-conditioned by aerating, without other treatment or addition, for 7 days at the test temperature.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 2 mg/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

Expressed as a percentage of COD.

Details on study design:

TEST CONDITIONS :

Initial concentration of test item in medium, C : 2 mg/L as organic matter in dried solid
Initial concentration of reference item in medium, C : 2 mg/L
Volume of test solution in flask, V : 0.300 L
Test item COD : 1.275 ± 0.12 mg O2/mg test item
Reference item ThOD : 0.78 mg O2/mg reference item
Amount of effluent in 1 L of mineral solution : 0.2 ml/L
Initial concentration in toxicity control test : 2.0 mg/L test item + 2.0 mg/L reference item
Concentration of test item as organic matter in dried solid in stock solution : 81.45 g/L
Concentration of reference item in stock solution : 10 g/L

- Test temperature: 22 +/- 5°C
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: full closed bottle

NUMBER OF FLASKS:
Inoculum blanks: 18 flasks (two parallel samples for each oxygen concentration measurement) containing inoculum and mineral medium.
Procedure control: 18 flasks (two parallel samples for each oxygen concentration measurement) containing inoculum, reference item (2 mg/l) and mineral medium.
Test: 18 flasks (two parallel samples for each oxygen concentration measurement) containing inoculum, test item (2 mg/l) and mineral medium.
Toxicity control: 18 flasks (two parallel samples for each oxygen concentration measurement) containing inoculum, test item (2 mg/l), reference item (2 mg/l) and mineral medium.

STATISTICAL METHODS:The calculations and the graphs will be performed using SigmaPlot 9.0 software of SYSTAT Software, Inc

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Test performance:

Validity of test
1. The difference of extremes of replicate values of the removal of the test chemical at the plateau. at the end of the test is less than 20% and the percentage degradation of the reference compound has reached on the 2nd day the pass level (60%) for the limit of day 14.
2. In a toxicity test containing both the test item and a reference item. on the 14th test day the biodegradation (based on ThOD of reference item and on COD of test item) attained 58.9 % and the test item cannot be assumed to be inhibitory.
3. Oxygen depletion in the inoculum (0.91 mg/L) did not exceed the limit of 1.5 mg dissolved oxygen/litre after 28 days.
4. The residual concentration of oxygen in the test bottles did not fall below 0,5 mg/litre at any time.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 62.94

Sampling time:

28 d

Details on results:

oxygen depletion: % degradation (toxicity test, 28 days) : 71.53% (mean of the two bottles)

BOD5 / COD results

BOD5 / COD

Key result

Parameter:

ThOD

Value:

ca. 1.275 g O2/g test mat.

Results with reference substance:

oxygen depletion: % degradation (reference substance, 28 days) : 87.50% (mean of the two bottles)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Executive summary:

The biodegradability attained 62.9 % within twenty-eight days.

The pass level for ready biodegradability of 60% of COD was reached on 24th day, but not in 10-day window, in which the biodegradability attained 49%.

Thus, the test item can not be considered as readily biodegradable. This negative result in a test for ready biodegradability does not necessarily mean that the chemical will not be degraded under relevant environmental conditions, but it means that the next level of testing, i.e. either a simulation test or an inherent biodegradability test, should be considered