Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: 87/302/EEC page 118-122 Activated sludge respiration inhibition test
Deviations:
yes
Remarks:
Instead of a centrifuged sludge a settled sludge was used
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
Activated sludge collected from the sewage treatment plant of CH-4153 Reinach on 14/09/92. The pH after collection was 7.2.
The preparation was carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. The pH of the sludge before use was 7.8
The sludge concentration in the test bottles was 1.62 g/L (dry weight).

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
180 min

Test conditions

Test temperature:
20 +/- 2°C
pH:
8.2
Nominal and measured concentrations:
- Concentrations of the test substance (nominal): 1, 3.2, 10, 32.1 and 100.4 mg/L
- Concentrations of the reference substance (nominal): 3.2, 10 and 32 mg/L
Details on test conditions:
- Vessels: 250 ml BOD flasks with gas inlet
- Water: Dechlorinated drinking water
- Nutrien Solution (dissolved in one liter):
16 g Peptone
11 g Meat extract
3.0 g Urea
0.7 g NaCl
0.4 g CaCl2 x 2H2O
0.2 g MgSO4 x 7H2O
2.8 g K2HPO4
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrations
Duration:
180 min
Dose descriptor:
other: EC20
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
EC50 (180 min) > 100 mg/L
Results with reference substance (positive control):
EC50 (180 min) = 15.4 mg/L

Applicant's summary and conclusion