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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
Study period:
1988
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: According to national standards (DIN 8192:2007-05)

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Qualifier:
equivalent or similar to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
no

Test solutions

Details on test solutions:
Due to the low solubility no stock solution was used. The test item was weighed out directly into the test vessels.

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
- Origin: sewage treatment plant at Frankfurt am Main, Sindlingen (domestic activated sludge)
- Pretreatment: corresponding to the cited test guideline
- Content of suspended solids in the sewage sludge suspension: 2 g/L (dry matter)

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
3 h

Test conditions

Test temperature:
22.0 - 22.5 °C
pH:
8.0
Nominal and measured concentrations:
Nominal concentrations: 63, 125 and 250 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Glasbottles with a diameter of 60 mm and a grounded neck (NS 29), height 170 mm, total volume appr. 480 ml. The bottles contained magnetic stirrer bars and were incubated in a water bath on magnetic stirrers.
- Test volume: 200 ml each batch
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
EC0
Effect conc.:
> 250 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.:
> 250 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
Effect concentrations exceeding solubility of substance in test medium. No inhibition but 2.6 fold increase of activity was observed at all concentration levels.

Any other information on results incl. tables

Table 1: Concentrations and results

Controls and Test batches

Activity

mg O2/L

in 25 min

Respiration inhibition

pH value

Temperature

Control 1

1.6

 

8.0

22.0

Control 2

no value

 

8.0

22.0

250 mg/L

4.2

No inhibition, but 2.6 fold increase of activity

8.0

22.5

125 mg/L

4.2

8.0

22.5

63 mg/L

4.2

8.0

22.5

Applicant's summary and conclusion

Conclusions:
The test item is not toxic at concentration
Executive summary:

A Respiration Inhibition Test according to OECD Guideline No. 209 was performed with the test item at Hoechst AG, Abteilung Umweltschutz, Frankfurt. The respiration rate of test item was measured after a contact time of three hours. The EC0 is > 250 mg/L to activated sludge.

An increase of activity was observed at all concentration levels.