Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1999-11-23
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study, GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Adipic acid, Cyclicester with diethylenglycol
- Analytical purity: ca. 90%
- Impurities (identity and concentrations): Diethylenglycol < 10% ; water< 2%
- Purity test date: Report of the sponsor of 18 Feb. 1999
- Lot/batch No.: B47

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
- Preparation of inoculum for exposure: The inoculum was washed, brought to a concentration of 5 g/l dry substance and aerated for 24 hours.
- Initial biomass concentration: 50 ml were added to a total volume of 250 ml to obtain a concentration of 1 g/I dry substance in the test.

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:
7.1-7.2 at test start, 7.3 at test end
Dissolved oxygen:
- Oxygen concentration during aeration: >2.5 mg/I
- Oxygen concentration immediately before measurement: >6.5 mg/I
Nominal and measured concentrations:
1000 mg/l, in addition a blanc control and a reference control were tested
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, Erlenmeyer-flask (250 ml nominal), liquid volume: 250 ml
- Aeration: sparged with air
- No. of vessels per concentration (replicates; test substance, TS): 1
- No. of vessels per control (replicates; blanc, BC): 3
- No. of vessels per concentration (replicates; positive control, reference substance, RS): 3

TEST MEDIUM / WATER PARAMETERS
- Culture medium: OECD test medium

OTHER TEST CONDITIONS
- Adjustment of pH: no pH adjustments during test

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
O2: on line measurement for 6 min
pH: at test start and test end


Reference substance (positive control):
yes
Remarks:
3.5-dichlorophenol (CAS 591-35-5)

Results and discussion

Effect concentrations
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
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- Relevant effect levels: EC20 (30 min): 2.2 mg/L (nominal); EC50 (30 min): 6.5 mg/L (nominal); EC80 (30 min): 55 mg/L (nominal)

Any other information on results incl. tables

The EC20 in the activated sludge respiration inhibition test is >1000 mg/l. The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
Deviation of blank controls < 15 %; EC50 of 3,5-dichlorophenol in the range of 5-30 mg/I