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other: GLP-compliant guideline study available as unpublished report, no restrictions, fully adequate for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
2006

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Qualifier:
according to
Guideline:
ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
GLP compliance:
yes (incl. certificate)
Remarks:
BASF AG Experimental Toxicology and Ecology

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test substance: 1,2,3,4-Tetrahydroisoquinoline
- Molecular formula: C9 H11 N
- Molecular weight (g/mol): 133.1929
- Water solubility (mg/L): 20000
- Purity: 87.3 % (area)
- Physical state: liquid
- Colour: redish-yellow
- Homogeneity: homogeneous
- Special conditions for storage: storage at room temperature
- Stability: The stability of the test substance under storage conditions over the test perio d is guaranteed by the sponsor
- Test substance number: 05/0797-1
- Batch identification: LJ 32741/75
- Date of production: 10 October 2005

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
Because the test substance is sufficiently soluble in water a stock solution was prepared. Iherefore a adequate amount of the test substance was stirred with deionized water at room temperature until the test substance was dissolved completely. After that the pH value of the stock solution was measured and adjusted.

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
BIOLOGICAL TEST SYSTEM
Activated sludge from the municipal wastewater treatment plant of the city Mannheim/Baden Württemberg (Germany). lt was collected at 19 Apr 2006 from the aeration tank of the plant. The activated sludge Suspension was washed with tap water, sieved with a fine woven mesh (mesh size about 1 mm). This Suspension was adjusted to a concentration of 5.0 g/L dry weight and pre-aerated for 24 hours. This suspension was added to the test vesseis to obtain a sludge concentration of 1.0 g/L dry substance.

Study design

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

Test conditions

Test temperature:
20±2°C
pH:
7.0 - 7.3
Dissolved oxygen:
- Oxygen concentration during aeration: > 2.5 mg/L;
- Oxygen concentration immediatelybefore measurement: > 6.5 mg/L;
Nominal and measured concentrations:
- Nominal concentrations: 10, 100, 240, 500 and 1000 mg/L
Details on test conditions:
EXPERIMENTAL PROCEDURE
The test substance was added in the required amount to the test vessel with about 180 mL deionized water. Then synthetic medium was added, the pH-value was adjusted to 7.5 ± 0.5, the inoculum was added and the aeration was started. After 30 minutes the mixture was given in a measuring cell without oxygen addition. Oxygen consumption rates are measured using an oxygen electrode. The percentage inhibition of the oxygen consumption is estimated by comparison of the rate with that of a control mixture containing no test material (blank control).

- lncubation time: 30 min
- Test temperature: 20 ± 2 0C
- Test vesseis: Erlenmeyer-vessel (nominal volume 250 mL)
- Test volume: 250 mL
- Synthetic medium: 8 mL/vessel 100-fold concentrated OECD medium
- Oxygen concentration during aeration: > 2.5 mgIL
- Oxygen concentration immediately before measurement: > 6.5 mg/L
Duration of the measurement of oxygen consumption: 8 - 10 min
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenole

Results and discussion

Effect concentrations
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
Results with reference substance (positive control):
30-min EC50 = 14.8 mg/L

Applicant's summary and conclusion