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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Testing appears to have been performed well and in accordance with guidelines. However, the work does not appear to be to GLP and the report lacks some key information. However, the results are backed up by other earlier work (supporting studies)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report Date:
2005

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sample tested was commercial grade material with approximately 35% active, containing a measured 22.6% w/w C.
Dosing levels took this into account

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Duration of test (contact time):
28 d
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
ca. 70
Sampling time:
9 d
Parameter:
% degradation (CO2 evolution)
Value:
ca. 96
Sampling time:
28 d
Details on results:
Two concentrations tested, but lower concentration (approx 10 mg/l C) gave a % degradation over over 100% and has been disregarded.
The higher concentration of approximately 30 mg/l C resulted in a plateau of about 100% degradation after day 22. The 10 day window was achieved.
The positive control group reached a plateau of about 80% after 22 days, but failed to reach the 60% in 10 day criteria.

BOD5 / COD results

Results with reference substance:
The positive control group reached a plateau of about 80% after 22 days, but failed to reach the 60% in 10 day criteria.

Applicant's summary and conclusion

Validity criteria fulfilled:
no
Interpretation of results:
readily biodegradable
Executive summary:

There are obvious flaws in the testing, such as exceeding 100% for one of the concentrations tested and the poor performance of the positive control. However, earlier studies (albeit with less detail on methods and limited reporting) and estimations based on modelling and considering the class of substance suggests that the the substance is readily biodegradable.