Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
other information
Study period:
2007-11-29 to 2007-11-30 (experimental phase)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Batch-Identification: 76584075L0
- Purity: 99.8 area-%
- Homogeneity: Homogeneous
- Storage stability: Expiry date: 17 January 2009
- Physical state/ Appearance: Liquid / colorless, clear

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: 2 g of the test substance were added to about 800 mL of demineralized water and stirred at room temperature until the test substance was completely dissolved. The stock solution was made up to 1 L with demineralised water. The stock solution appeared colorless and clear.


Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
- Source and preparation of the inoculum: Activated sludge from the municipal wastewater treatment plant of the city Mannheim/Baden Württemberg (Germany). It was collected at 29 Nov 2007 from the aeration tank of the plant. The activated sludge suspension was washed thrice with tap water, sieved with a fine woven mesh (mesh size about 1 mm). This suspension was adjusted to a concentration of 7.5 g/L dry weight and pre-aerated over night. After the pre-aeration the lost water was replaced. This suspension was added to the test vessels to obtain a sludge concentration of 1.5 g/L dry substance.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
180 min

Test conditions

Test temperature:
20 ± 2 °C
pH:
Adjusted to 7.2
Dissolved oxygen:
Oxygen concentration during aeration: > 2.5 mg/L
Oxygen concentration immediately before measurement: > 6.5 mg/L
Nominal and measured concentrations:
Nominal concentrations: 62.4, 125, 250, 500 and 1000 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer-vessel (nominal volume 250mL)
- Fill volume: 250 mL
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of medium: According to guideline
- Intervals of water quality measurement: At test start and at test end

EFFECT PARAMETERS MEASURED: Respiration inhibition

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
Reference substance (positive control):
yes
Remarks:
3,5 dichlorophenole

Results and discussion

Effect concentrationsopen allclose all
Duration:
180 min
Dose descriptor:
EC10
Effect conc.:
120 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
180 min
Dose descriptor:
other: EC20
Effect conc.:
230 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
180 min
Dose descriptor:
EC50
Effect conc.:
740 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
180 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

Validity criteria fulfilled:
yes