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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
Study period:
January 22, 2003 to March 4, 2003
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Specific details on test material used for the study:
Test material name (as stated in the report): Cetonal
Batch No.: 9000439021
Expiry date: December 28, 2004

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
Fresh activated sludge from a biological waste water treatment plant treating predominantly domestic sewage (City of Geneva, Peney-Dessous) was used. The sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 1000 g for 10 minutes, discarding the supernatant and resuspending in mineral medium) and kept aerobic until being used on the same day.
Duration of test (contact time):
35 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Reference substance
Reference substance:
other: Sodium benzoate

Results and discussion

% Degradation
Key result
Parameter:
% degradation (O2 consumption)
Value:
70
Sampling time:
28 d
Details on results:
The 10-day window criterion is fulfilled. Biodegradation starts on day 5 and reaches 60% at the end of the 10-day window (days 5 to 15).

Any other information on results incl. tables

The curves obtained with the reference substance alone and with CETONAL + reference substance show no toxic effect of CETONAL to the micro-organisms at the test concentration (100 mg/l).

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
CETONAL undergoes 70% biodegradation after 28 days (72% after 35 days) in the test conditions. Biodegradation starts on day 5 and reaches 60% at the end of the 10-day window (days 5 to 15). Hence, the 10-day window criterion is fulfilled.
Executive summary:

The Ready Biodegradability of CETONAL was determined by the Manometric Respirometry Test according to the OECD Guidelines for Testing of Chemicals, Method No. 301 F.

CETONAL undergoes 70% biodegradation after 28 days (72% after 35 days) in the test conditions. Biodegradation starts on day 5 and reaches 60% at the end of the 10-day window (days 5 to 15). Hence, the 10-day window criterion is fulfilled.

 The curves obtained with the reference substance alone and with CETONAL + reference substance show no toxic effect of CETONAL to the micro-organisms at the test concentration (100 mg/l).

 Thus, CETONAL should be regarded as readily biodegradableaccording to this test.