Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
19.03.1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report date:
1997

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Version / remarks:
1993
Qualifier:
according to guideline
Guideline:
ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
Version / remarks:
1986
Qualifier:
according to guideline
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Version / remarks:
1987
GLP compliance:
yes
Remarks:
BASF AG, Ökologie und Umweltanalytik, Labor für Mikrobiologie, 67056 Ludwigshafen (Germany)

Test material

Constituent 1
Chemical structure
Reference substance name:
3,7-dimethyloctane-1,7-diol
EC Number:
203-517-1
EC Name:
3,7-dimethyloctane-1,7-diol
Cas Number:
107-74-4
Molecular formula:
C10H22O2
IUPAC Name:
3,7-dimethyloctane-1,7-diol
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
- Laboratory culture: yes
- Method of cultivation: Activated sludge from laboratory stp treating municipal and synthetic sewage
- Preparation of inoculum for exposure: the inoculum was washed, the concentration of dry matter adjusted to 5 g/L and aerated for 24 h
- Initial biomass concentration: 1 g/L dry matter

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:
7.0-7.1
Dissolved oxygen:
during aeration: >2.5 mg/L
immediately before measurement respiration inhibition measurement: >6.5 mg/L
Nominal and measured concentrations:
509 and 1027 mg/L nominal
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrations
Key result
Duration:
30 min
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: EC50 ca. 15 mg/L 3,5-dichlorophenol

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The respiration of activated sludge was not inhibited by hydroxyciol concentrations up to 1000 mg/L nominal.
Executive summary:

The activated sludge respiration inhibition of hydroxyciol was investigated in a study conducted according to EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test; 1987), OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test; 1993), and ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation; 1986). Respiration inhibition was not observed at test substance concentrations up to 1000 mg/L nominal.

The study is regarded as reliable without restrictions and satisfying the guideline requirements an activated sludge respiration inhibition test.

Results Synopsis

Test organism size/age: activated sludge

Test Type: static

30 min NOEC: 1000 mg/L (nominal)

Endpoint(s) Effected: respiration