Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1994-08-04 to 1994-08-04
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Short summary report of well conducted GLP study performed to OECD guideline 209

Data source

Reference
Reference Type:
other: short summary report incl. all critical study information e.g. OECD guideline, test item identity, result, study dates, etc.
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
yes
Remarks:
Test carried out to principles of GLP; but, the testing was carried out without inspection by the QA unit.The report was prepared in simplified summary form and contains no GLP certificate. Details of test material summarised in report but CofA not avail

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Batch: 1 (7.93) 331302
Purity: 68.7%
Impurities: 25% (coconut fatty acid and stearic acid)
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: in the range of 62.5mg/L and 1000mg/L
- Sampling method: no data
- Sample storage conditions before analysis: no data

Test solutions

Vehicle:
no
Details on test solutions:
Due to low solubility, there was no stock solution (no solvent). The test item was weighed directly into the vessels. Better solubility was achieved in the test vessels by ultrasound treatment 30 minutes before the beginning of the test.

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
Amount of activated sludge used: 1600mg/L (dry weight)
Origin: Municipal wastewater treatment plant, Frankfurt/M-Sindlingen
Preparation: As specified in cited test guidelines
Acclimation state: Not acclimatised to the test substance or reference substance in the lab.

Study design

Test type:
not specified
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Post exposure observation period:
no data

Test conditions

Hardness:
no data
Test temperature:
20 +/- 2 degrees C
pH:
7.2 +/- 0.2
Dissolved oxygen:
no data
Salinity:
not applicable
Nominal and measured concentrations:
The concentrations of the test item were checked to be in the range of 62.5mg/L to 1000mg/L.
Details on test conditions:
The incubation with the test item was performed before the measurement of respiratory activity at 20 +/- 2°C over a period of 3 hours. The composition of the reaction medium is equivalent to that specified in the cited EEC Directive. The pH value of the culture solution was 7.2 +/- 0.2 and was determined prior to the depletion measurements. The sensitivity of the activated sludge was tested with a reference approach. A reference substance of 3,5-Dichlorphenol at the concentrations 5, 20 & 30 mg/L. As a control, an inoculated approach was used without addition of a test material. The control was filled with water to achieve a uniform volume.

The specified testing ranges were kept with both the reference substance as well as the control.
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorphenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC20
Effect conc.:
ca. 639 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC80
Effect conc.:
> 1 000 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no data
- Effect concentrations exceeding solubility of substance in test medium: no
Results with reference substance (positive control):
The specified testing ranges were kept with both the reference substance as well as the control.

- Results with reference substance valid? no data
- Relevant effect levels: no data
Reported statistics and error estimates:
No data

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test item was found to be harmless to the organisms in activated sludge.
The EC50 is in the range: >1000mg/L
Executive summary:

In a OECD 209 Activated sludge, respiration inhibition test, the inoculum (mainly domestic activated sludge) was exposed to the test item for 3 hours. Due to low solubility, there was no stock solution. The test item was weighed directly into the vessels. Better solubility was achieved in the test vessels by ultrasound treatment 30 minutes before the beginning of the test. The EC50 of the test item was found to be >1000mg/L, which means the test item is harmless to the organisms in activated sludge.