Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study was carried out according to OECD 209

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
GLP compliance:
no
Remarks:
experimental part acc. to GLP standards but no quality control, sample storage and GLP certificate

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test solutions

Details on test solutions:
Due to the low solubility of the tested substance no stock solution was prepared. The tested substance was added directly to the test flasks.
Concentration of the tested substance was 1000 mg/L (2 tests at 1000 mg/L).

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
Origin of inoculum: municipal sewage treatment plant Frankfurt- Sindlingen, Germany
Source: activated sludge of municipal sewage treatment
Preparation of suspension: activated sludge sediment centrifugated twice and resuspended.
Used quantity of inoculum: 90 ml/L suspended sludge
Pretreatment: pre-aeration of the inoculum for 1 - 4 days
Preconditions: not pre-adapted to the test substance and the reference material

Study design

Limit test:
yes
Total exposure duration:
3 h

Test conditions

Test temperature:
20.3 - 20.5°C (prior to measurement)
pH:
7.1 - 7.2 (prior to measurement)
Reference substance (positive control):
yes
Remarks:
3,5-dichlorphenol at 3 different concentrations (5, 20, 30 mg/L)

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
other: EC0
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC80
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The tested substance is not toxic to bacteria in an actived sludge respiration inhibition test. EC50 value amounts to > 1000 mg/L at 3 hours exposure time.