Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Version / remarks:
April 1984
Deviations:
yes
Remarks:
Instead of a centrifuged sludge a settled sludge was used.
GLP compliance:
no
Remarks:
However, Quality Assurance Statement available

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
not applicable

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
other: activated sludge, domestic, non-adapted
Details on inoculum:
- Preparation of inoculum for exposure: The preparation was carried out according to the method described in the guideline, except the settling instead of centrifuging.
- Initial biomass concentration: the sludge concentrations in the test bottles was 1.6 g/L

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Post exposure observation period:
none

Test conditions

Hardness:
no data
Test temperature:
20+/- 2 °C
pH:
no data
Dissolved oxygen:
no data
Salinity:
no data
Nominal and measured concentrations:
Reference substance : 32, 10 and 3.2 mg/L (nominal)
Test substance: 100, 32, 10, 3.2 ans 1 mg/L (nominal)
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 mL BOD flasks with gas inlet
- Biomass loading rate: the sludge concentration in the test bottles was 1.6 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated drinking water


TEST CONCENTRATIONS
- Test concentrations: Reference substance: 32, 10 and 3.2 mg/L (nominal), test substance: 100, 32, 10, 3.2, 1 mg/L
Reference substance (positive control):
yes
Remarks:
3,5-Diclorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
IC50
Effect conc.:
> 100 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: IC80
Effect conc.:
> 100 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: IC20
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Results with reference substance (positive control):
- Relevant effect levels: IC50 = 11mg/L
Reported statistics and error estimates:
no data

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The inhibition of the degradation activity of activated sludge is not anticipated when introduced to biological treatment plants in appropriate low concentrations.