Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1994
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: study was carried out according to test guideline and under GLP-conditions. Reporting was done in a simplified version.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

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:
yes
Remarks:
Experimentel performance and documention of lab reports done under GLP conditions, but no certificate of analysis available for the tested sample and no storage of a retained sample

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Sampling and analysis

Analytical monitoring:
no

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.
Tested substance in the test flasks was homogenized by ultra sonic treatment for 30 min.
Concentration of the tested substance was in the range of 7.8 mg/L to 1000 mg/L.

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
Origin: Municipal sewage treatment plant Frankfurt-Sindlingen, Germany
Pretreatment: according to data in guideline
Preconditions: not pre-adapted to the test chemical and the reference chemical

Study design

Limit test:
no
Total exposure duration:
3 h

Test conditions

Test temperature:
20°C +/-2
pH:
7.2 +/-0.2 prior to start of test
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol at 3 different concentrations (5, 20, 30 mg/L)

Results and discussion

Effect concentrationsopen allclose all
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: EC20
Effect conc.:
44 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

Conclusions:
The tested substance is not toxic to activated sludge bacteria. EC50 value amounts to > 1000 mg/L at 3 hours exposure time.