Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2003
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
collected from a water treatment works, containing effluent from a predominantly domestic origin.

Study design

Test type:
other: Respiration of activated sewage sludge – 3h static test
Total exposure duration:
3 h
Post exposure observation period:
None.

Test conditions

Hardness:
280 +/- 20 mg/L as CaCO3
Test temperature:
20 to 24 °C
pH:
6.0 to 8.0
Details on test conditions:
- 2 groups containing inoculum at 1.6 mg/L
- 5 test concentrations at 10, 31.6, 100, 316 and 100mg/L and inoculum at 1.6 mg/L
- 3 reference concentrations (3,5-dichlorophenol) at 4, 12 and 36 mg/L and inoculum at 1.6 mg/L
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:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Results with reference substance (positive control):
3h EC50 for 3,5-dichlorophenol : 13.3 mg/L

Applicant's summary and conclusion

Conclusions:
The 3h EC50 of Thiofestermet on activated sludge is > 1000mg/L. Thiofestermet considered as non-toxic for the micro-organisms of a water treatment plant.