Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1994 - 1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well performed OECD study with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
not specified
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
purity: 95 +- 1 % contains residual water

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
Aktivated sludge from the predominantly domestic waste water treatment plant Frankfurt-Sindlingen; not adapted to the test substance and the reference substance

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Post exposure observation period:
no

Test conditions

Test temperature:
19.2 - 20.6 °C
pH:
7.0 - 7.1
Nominal and measured concentrations:
nominal concentrations : 500 mg/L and 1000 mg/L
Details on test conditions:
480 ml glass bottles (diameter 60 mm, height 170 mm), placed in a thermostated water bath.
Measuring the consumption rate of oxygen with an oximeter WTW Oxi 537.
Reference substance (positive control):
yes

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: respiration inhibition
Results with reference substance (positive control):
The EC50 with the positive control (3,5-dichlorophenol) was between 5 mg/L and 30 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The EC50 for toxicity to bacteria is greater 1000 mg/L
Executive summary:

The toxicity to bacteria of the test substance was determined according to OECD guideline 209. Activated not adapted sludge from the predominantly domestic waster water treatment plant Frankfurt-Sindlingen was used as inoculum. Nominal concentrations of 500 mg/L and 1000 mg/L were used in duplicate. The average value for the respiration inhibition was 7.4% (1000 mg/L) and 7.6% (500 mg/L).

3,5 -dichlorophenol was used as rferene substance in the concentrations 5, 20, 30 mg/L showing inhibition rates of 22.8, 66.9, 71.3%.