Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
not applicable
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid
Details on test material:
dark clear liquid
Specific details on test material used for the study:
Hydrolyzed Quinoa
Lot# P9243

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
natural water: freshwater
Details on inoculum:
inoculum: Surface water from Skokie, IL water district.
- proportion and nature of industrial waste water in sewage: unknown, discharge from waste treatment facility within 1 mile.
- test duration and temperature: 28 days or as indicated, 22C +/- 2C
- bacterial inoculum -1E5 CFU/ml
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
20 mg/L
Based on:
TOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
72
Sampling time:
28 d
Details on results:
Sodium acetate control achieved 76% degradation after 28 days.

Any other information on results incl. tables

The OECD 301B method is designed to provide the screening of chemicals for ready biodegradability in an aerobic aqueous medium. Samples are required to achieve a threshold of 60% degradation based on the maximum available carbon from a given sample formulation. Total carbon is determined analytically for each sample and used as the reference for the determination of the percentage of carbon dioxide (% ThCO2) produced by microbiological degradation.

 

For the purpose of determining biological degradation, two criteria can be achieved. Ready Biodegradability can be achieved by obtaining the 60% threshold within a 10 day-window within the 28 days of testing. The second criteria, Ultimate Biodegradation, can be achieved if the amount of biodegradation meets or exceeds the 60% threshold at a time point determined in the test (e.g. when the rate of degradation reaches a plateau). For each of these criteria, when achieved, the sample also achieves the requirements needed for classification as 'Inherent Biodegradability'.

 

One test sample was submitted for OECD 301B biodegradation testing. The result data and graphs were analyzed by curve fit to establish a plateau for the rate of biodegradation.

Sample 1 - Quinoa Pro NPNF, INCI: Hydrolyzed Quinoa, Lot# P9243 -was a dark clear liquid and was introduced into the test system as received. The test sample achieved the requirements for Ready Biodegradability by the OECD 301B standard for degradation of 60% (+/- 5%) ThCO2 within a 10-day window of the test timeframe (day 2 to day 12). The test sample achieved inherent biodegradation of 60% ThCO2 by day 12 of the testing and 72% at day 28 of testing. A degradation plateau was not achieved within the 28 days of testing.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
The test sample achieved the requirements for Ready Biodegradability