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:
other information
Study period:
2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well documented GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Duration of test (contact time):
28 d

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Value:
48
Sampling time:
14 d
Parameter:
% degradation (O2 consumption)
Value:
57
Sampling time:
21 d
Parameter:
% degradation (O2 consumption)
Value:
60
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
Boldenone (ZK5320) was degraded to 60% after 28 days. However, it is not ready biodegradable according to the stringetn criteria of the guidlein,
although significant degradation was observed.
Executive summary:

The testsubstance ZK 5320 was incubated in an aqueous solution including nutrients with microorganisms from a municipal sewage treatment plant for 28 days.

The biological degradation of the test and reference substances was evaluated by measurement of the O2consumption during the test period. O2consumption was continuously monitored and recorded by an automated device. The O2consumption was calculated as the percentage of total O2that the test material could theoretically have consumed, based on the molecular formula. The blank O2consumption was subtracted for correction.

In accordance with the OECD 301F(1), the test compound boldenone (ZK 5320) is not readily biodegradable under the conditions of the test and it was not toxic to the microbes of activated sludge. However, significant degradation up to 60 % occurred, but the 10 -day window was not passed.