Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
April 15, 2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Test conducted according to internationally accepted Guideline and in according to the GLP Principles

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
yes
Remarks:
Different temperature range; measurement period was partly less than five minutes.
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Qualifier:
according to
Guideline:
other: Internal Procedure: SOP 118 007 01
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Sampling and analysis

Details on sampling:
- Concentrations: 1, 10.6, 100.8, 1002.8, 1001, 1000.4, 1001.4, 1000.2 mg/l
- Sampling method: Due to the poor solubility of the test item, the test item was weighed directly into the test vessels
- Sample storage conditions before analysis: The test item was stored in a closed glass vessel dry at room temperature (20 ± 5 °C)

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method:
In the control vessels, 16 ml nutrient solution was mixed with 234 ml water. The positive control vessels and the treatments were prepared by putting the appropriate amount of positive control solution respectively test item into the respective test vessel, adding 16 ml nutrient solution and water to give 250 ml. Then, 250 ml inoculum was added in five-minute-intervals and the mixtures were aerated.

- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Water

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
Laboratory culture: ESN (Stadtentsorgung Neustadt) sewage treatment plant D-67435 NW-Lachen-Speyerdorf
Collection of inoculum: one day before the start of the test

Preparation of inoculum for exposure:
The sludge has been filtrated, washed with tap water and re-suspendenin tap water. The activated sludge was aerated until usage in the test and fed daily with 50 ml/l synthetic sewage feed.

On the day before the experiment, the inoculum was taken from its source, washed, aerated and the dry matter was determined. Volume was adapted to the desired content of dry matter. The nutrient solution was thawed and the sludge was fed with 50 ml/l sludge.
On the day of the experiment, the dry matter was determined once more. The stock solu-tion of the positive control was prepared.

Study design

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

Test conditions

Hardness:
1.10 mmol/l
Test temperature:
21.1 – 22.6 °C
pH:
7.1 - 7.5
Nominal and measured concentrations:
Test item: 1, 10.6, 100.8, 1002.8, 1001, 1000.4, 1001.4, 1000.2 mg/l
Positive Control: 5.0, 10.1, 20.2, 40.3 mg/l
Details on test conditions:
TEST SYSTEM
- Test vessel: Glass beakers cleaned before use.
- measuring flasks: Narrow-neck glass bottles with flat bottoms (250 ml)
- Aeration: purified air, using Pateur pipettes
- No. of vessels per concentration: one replicate for lower concentrations 1 – 100 mg/l, five replicates for test item treatment 1000 mg/L
- No. of vessels per control: two replicates before and two after measuring positive control and test item, respectively;
- No. of vessels per positive control: 1 replicate (5.0, 10.1, 20.2, 40.3 mg/l)
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
NOEC
Effect conc.:
ca. 1 000 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:
EC50
Effect conc.:
> 1 000 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):
Results with reference substance:
Valid (the calculated value for the positive control 3,5-dichlorophenole is 7.6 mg/l; the value lies within the recommended range of 2 – 25 mg/l)

Any other information on results incl. tables

The coefficient of variation of oxygen uptake rate in control replicates should not be more than 30 % at the end of the test. The registered value during the test is 2.7 %; this value lies below the recommended limit of 30 %.

The blank controls oxygen uptake rate should not be less than 20 mg oxygen per gram of activated sludge (dry weight of suspended solids) in an hour. The Oxygen Uptake Rate in mg/per gram activated sludge/hour during the test is: 31.52 mg oxygen per gram sludge in one hour. All values meet the required limit.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
EC50(3h) > 1000 mg/l
NOEC(3h) = 1000 mg/l
Executive summary:

Method

The test has been conducted according to the OECD Guidelines 209, the EU-Method C.11, during the test were been used the following concentrations of the substance: 1, 10.6, 100.8, 1002.8, 1001, 1000.4, 1001.4, 1000.2 mg/l.

Activated sludge was used as inoculum. It was taken from a domestic sewage treatment plant and washed before usage.

3,5-Dichlorophenole was used as positive control. Four concentrations were tested (5.0, 10.1, 20.2, 40.3 mg/l);

Results

No significant inhibition was observed at the highest test concentration 1000 mg/l, therefore the NOEC value after 3 hours is 1000mg /l and the EC50 value after 3 hours is greater then 1000 mg/l.