Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13 Dec 1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
Version / remarks:
1986
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
Basic Blue 45 MeSO4

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
Direct weighing into stock solution (1000 mg/L)
Dilution with test medium and addition of inoculum

Test organisms

Test organisms (species):
activated sludge, industrial
Details on inoculum:
Laboratory wastewater treatment plant
6.0 g dry particulate mater /L in stock solution

Study design

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

Test conditions

Nominal and measured concentrations:
10, 18, 32, 56, 100 mg/L
Reference substance (positive control):
yes
Remarks:
dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
4.71 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
60.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Details on results:
Respiration inhibition (compared to negative control): 24.5% (10 mg/L), 24.5% (18 mg/L), 32.1% (56 mg/L), 69.8% (100 mg/L)
Results with reference substance (positive control):
77% inhibition at 5 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The substance caused significant respiration inhibition to activated sludge. The EC10 was determined at ca. 4.71 mg/L, the EC50 at ca. 60.5 mg/L.