Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2004
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report Date:
2005

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
- Laboratory culture: origin: the water treatment plant of Evreux (France)
- Method of cultivation: activated sludge collected from a water treatment works containing effluent from a predominantly domestic
origin.
- Preparation of inoculum for exposure: the inoculum was left to settle and the supernatant rejected. it was then filtered and washed once with
dechlorinated water. Four samples were taken to determine the conten tin the suspended matter
(dry weight). concentration of sludge: 4 g / l ± 10 %. (Initial biomass concentration)

Study design

Test type:
other: aerobic
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
3 h

Test conditions

Hardness:
280 ± 20 mg / l (as CaCO3 (dechlorinated tap water for dilution)
Test temperature:
21-23 °C
Dissolved oxygen:
air bubbling through each solution at arate of 0.5 to 1 l / min. until the start of oxygenconcentation measurement.
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
other: including the dissolved and undissolved fractions of the test item
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
No observed effect after 3 hours.
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: 3-hour EC50: 13.0 mg / l

Any other information on results incl. tables

Conclusion: non-toxic for microorganisms of a water treatment plant.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Conclusion: non-toxic for microorganisms of a water treatment plant.