Registration Dossier

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: The respiration inhibition test with sewage sludge was performed to national standards (DIN 8192:2007-005)

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
Deviations:
yes
Remarks:
In the today's methods no industrial but municipal wastewater sludge is used
Qualifier:
equivalent or similar to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Deviations:
yes
Remarks:
In the today's methods no industrial but municipal wastewater sludge is used
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
no

Test solutions

Details on test solutions:
Preparation of stock solution: 2 g/L were dissolved, pH adjusted from 5.1 to 7.3. The batch was stirred over a period of 24 h at room temperature and the pH again adjusted to 7.2. Some loss of substance occured in the stock solution, possibly by incomplete solution of the substance.

DOC analysis: 474 mg/L (according to 908.4 mg/L test substance)
COD analysis: 1292 mg/L (according to 929.4 mg/L test substance)

The result of the DOC analysis was taken for the calculations of the substance concentrations in the test.

Test organisms

Test organisms (species):
activated sludge, industrial
Details on inoculum:
- Origin: sewage treatment of Hoechst AG, site Kelsterbach (industrial activated sludge)
- Pretreatment: corresponding to the cited test guideline
- Content of suspended solids in the sewage sludge suspension: 1 g/L (dry matter)

Study design

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

Test conditions

Test temperature:
21.2 - 21.5°C
pH:
8.0 - 8.1
Nominal and measured concentrations:
28.4, 56.8, 114, 227 and 454 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

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
EC0
Effect conc.:
> 454 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 454 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
The highest concentration in the test, 454 mg/L showed no inhibition.

Applicant's summary and conclusion

Conclusions:
The test item is not toxic at concentration < 454 mg/L to activated sludge of a industrial sewage treatment plant.
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 > 454 mg/L to industrial activated sludge.