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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014
Report date:
2014

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Qualifier:
according to guideline
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
Trimethyl benzene-1,2,4-tricarboxylate
EC Number:
219-547-3
EC Name:
Trimethyl benzene-1,2,4-tricarboxylate
Cas Number:
2459-10-1
Molecular formula:
C12H12O6
IUPAC Name:
trimethyl benzene-1,2,4-tricarboxylate
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): 1,2,4-Trimethylbenzenetricarboxylate
- Physical state: liquid, viscous / amber
- Analytical purity: 99.9 area-% (207 nm)

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:

- Laboratory culture: Activated sludge from the municipal wastewater treatment plant of Mannheim, Germany was collected from the aeration tank of the plant
- Preparation of inoculum for exposure: The activated sludge suspension was sieved with a fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. At the next day the sludge suspension was washed once with tap water and the suspension was adjusted to 3 g/L dry matter.
- Pretreatment: None
- Initial biomass concentration: 1.5 g/L dry mass

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
180 min

Test conditions

pH:
7.6 - 8.1
Nominal and measured concentrations:
1000, 500, 250, 125, 62.5 mg/L as nominal concentration based on test substance without correction of purity and blank controls.
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer-flasks (nominal volume 1000 mL)
- Test volume: 500 mL
- Synthetic medium: 16 mL/test vessel of 100-fold concentrated OECD medium
- Oxygen concentration during aeration: > 2 mg/L
- Oxygen concentration immediately before measurement: > 7 mg/L
- Duration of the measurement of oxygen consumption: about 8 - 10 min
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per reference substance concentration (replicates): 2

Reference substance (positive control):
yes
Remarks:
3,5 dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
160 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:
other: EC20
Effect conc.:
350 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):
The EC50 of 3,5-dichlorophenol is in the range of 2 - 25 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes