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Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study performed under GLP and in accordance with Czechian testing methods (similar to OECD-/EU-testing guidelines)
Cross-reference
Reason / purpose for cross-reference:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report date:
2005

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: Method XI Determination of biodegradability - Activated Sludge Respiration Inhibition test, Regulation of the Ministery of Environment of the Czech republic No. 222/2004, Annex 2. (identical with Method C.11 of Directive 67/548/EEC):
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Details on test material:
- Name of test material (as cited in study report): 4-butyrobetain (BUBET)
- Molecular formula: C7H15NO2
- Molecular weight: 145.20 g/mol
- Physical state: colourless solution

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
The following test item concentrations were tested:
- 100 mg/l
- 180 mg/l
- 320 mg/l
- 560 mg/l
- 1000 mg/l

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h

Test conditions

Hardness:
not measured
Test temperature:
20°C
pH:
The pH was 7.51-8.0 during the test.
Dissolved oxygen:
not measured
Salinity:
freshwater used
Nominal and measured concentrations:
The following nominal test item concentrations were tested:
- 100 mg/l
- 180 mg/l
- 320 mg/l
- 560 mg/l
- 1000 mg/l
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorphenol

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
IC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
The rate of inhibition for the test item ranged from 0 to 4.4%.
Results with reference substance (positive control):
The rate of inhibition for the reference compound ranged from 0 to 83.1%; the IC50 was determined to be 10.1 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The IC50 of the aqueous solution on waste water bacteria was found to be > 1000 mg/l. The IC50 for the pure material was extrapolated to be > 400 mg/l.