Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
yes

Test material

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

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
- Laboratory culture: Activated sludge from the municipal wastewater treatment plant of Mannheim, Germany was collected from the aeration tank of the plant
- Preparation of inoculum for exposure: The activated sludge suspension was sieved with a fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. At the next day the sludge suspension was washed once with tap water and the suspension was adjusted to 7.5 g/L dry matter.
- Pretreatment: None
- Initial biomass concentration: 1.5 g/L dry mass

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
180 min

Test conditions

Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer-flasks (nominal volume 250 mL)
- Type (delete if not applicable): closed
- Aeration: incubation was started by aeration of the test vessels with pressure air
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates):2
- No. of vessels per vehicle control (replicates):0

OTHER TEST CONDITIONS
- Adjustment of pH: no

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline:
- Test concentrations: 62.5, 125, 250, 500, 1000 mg/L
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
180 min
Dose descriptor:
EC10
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:
180 min
Dose descriptor:
other: EC20
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:
180 min
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
Results with reference substance (positive control):
The EC50 of 3,5-dichlorophenol is in the range of 5 - 30 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes