Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-02-09 - 1988-04-15
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Version / remarks:
(Paris 1984)
Deviations:
yes
Remarks:
, instead a centrifuged sludge a settled sludge was used
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Physical state: red powder (solid)

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
Activated sludge from a sewage treatment plant (CH - 4153 Reinach)

Study design

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

Test conditions

Test temperature:
20 ± 2 °C
Nominal and measured concentrations:
100, 32, 10, 3.2 and 1 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 mL BOD flasks with gas inlet
- Source: Activated sludge from a sewage treatment plant
- Material, size, headspace, fill volume: the sudge concentration in the test bottles was 1.6 g/L

TEST CONCENTRATIONS
- Test concentrations: 100, 32, 10, 3.2 and 1 m/L
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
IC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: IC20
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: IC80
Effect conc.:
> 100 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 IC50 of the reference substance 3,5-Dichlorophenol is: 11 mg/L
Reported statistics and error estimates:
none

Any other information on results incl. tables

 Test item (mg/L)  oxygen-comsumption (mg/L/h)  Inhibition (%)
 1.0  37.0 27 
 3.2  45.00  11
 10.0  48.00  5
 32.0  43.50 14 
 100.0  45.60  10
 3,5 -Dichlorophenol    
 3.2  47.10
 10.0  24.90 51 
 32.0  9.96  80
 Control K1, K2  52.60; 48.75  -4; 4

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The inhibition of the degradation activity of activated sludge is not anticipated when introduced to biological treatment plants in appropriate low concentrations.