2,5-dioxopyrrolidin-1-yl N-{[methyl[[2-(1-methylethyl)-4-thiazolyl]methyl]amino]carbonyl}-.sc.l.sc.-valinate

Toxicity to microorganisms

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

Test material information

Constituent 1

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:

2,5-dioxopyrrolidin-1-yl (2S)-3-methyl-2-{[methyl({[2-(propan-2-yl)-1,3-thiazol-4-yl]methyl})carbamoyl]amino}butanoate

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