Registration Dossier

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:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Version / remarks:
Cited as Directive 88/302/EEC, C.11
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report):1,3-dimethylurea
- Lot/batch No.: 00001075-0
- Analytical purity: 97.7 %
Water-solubility: 1000 g/l

Sampling and analysis

Analytical monitoring:
no

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
Activated sludge taken from a laboratory wastewater plant fed with municipal sewage.
- Initial biomass concentration: 1 g/l

Study design

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

Test conditions

Test temperature:
20 ± 2 °C
pH:
7.2
Nominal and measured concentrations:
Test substance concentration: 1000 mg/l
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer-vessel (nominal volume 250 ml)
- Fill volume: 250 ml


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: 8 ml/vessel 100-fold concentrated OEC D


OTHER TEST CONDITIONS
- Adjustment of pH: yes (6.9 before correction)

Results and discussion

Effect concentrationsopen allclose all
Duration:
30 min
Dose descriptor:
other: EC20
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
30 min
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
Duration:
30 min
Dose descriptor:
other: EC80
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

Applicant's summary and conclusion