Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
March 20th - October 25 1996
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
424-660-8
EC Name:
-
Cas Number:
224631-15-6
Molecular formula:
Hill formula: C18H26N4O5S CAS formula: C18H26N4O5S
IUPAC Name:
(S)-2,5-dioxopyrrolidin-1-yl 2-(3-((2-isopropylthiazol-4-yl)methyl)-3-methylureido)-3-methylbutanoate

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
after 3 hours contact time with the test material, the contents of each vessell are transferred to the measuring apparthus, dissolved oxygen meter.

Test solutions

Details on test solutions:
synthetic sewage mix:
peptone 16 g/l
meat extract 11 g/l
Urea 3 g/l
Sodium chloride 0.7 g/l
Calcium chloride 0.4 g/l
magnesium sulphate 0.2 g/l
dipotassium hydrogen phosphate 2.8 g/l
water 1000 ml

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
On collection, the activated sludge was transferred to the testing laboratory and agitated. after agititation the dry weight of the mixed liquor suspended solids (MLSS) was determined. A volume of MLSS with a known volume of Milli-Q water to give a sludge suspension of a known concentration of ca 2.2 g/l

Study design

Test type:
other: aerobic
Total exposure duration:
3 h

Test conditions

Test temperature:
27oc (+/- 1oC)
Nominal and measured concentrations:
A-133816.0 nominal concentration = 78 mg/l (78 ppm)
Details on test conditions:
to each test vessel of chemcially defined medium, add a pre-determined quantity of the test material and avolume of the activated sludge inoculum. aerate (3h) at a constant room temperature (20oC +/- 2oC). using a pre-calibrated dissolved oxygen meter measure the respiraton rate of the activated sludge in the presence of the test material after the contact time (3h).

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
78 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
The result was determined as an EC 50 value for the inhibition of respiration of activated sludge.  The results were accepted as valid on the basis of an experimentally determined EC 50 for the recommended reference material, 3,5-Dichlorophenol, of 14ppm.  The two control respiration rate results were within 15% of each other.
Results with reference substance (positive control):
a

Applicant's summary and conclusion

Conclusions:
A-133816.0 is determinded to show an EC50 of 78 ppm