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Diss Factsheets

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP- and Guideline Study with no deviations.

Data source

Reference Type:
study report

Materials and methods

Test guideline
according to guideline
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
ethyl 2-{[4-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)phenyl]amino}acetate
EC Number:
Cas Number:
Molecular formula:
C12 H13 N3 O4
ethyl 2-{[4-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)phenyl]amino}acetate
Test material form:

Sampling and analysis

Analytical monitoring:
Details on sampling:
At 0 h, 24 h and 48 h, samples were taken from the test concentrations and from the negative control from separate test vessels without animals.

Test solutions

Details on test solutions:
A stock solution of 100 mg/L test item was prepared with M4 medium and stirred for 18 h. Since the test solution was not clear after stirring,
it was filtered with a 0.45 μm membrane filter. The filtered 100 mg/L test solution was diluted with M4 medium to obtain following five test
concentrations 100, 76.9, 59.2, 45.5 and 35.0 mg/L with a (spacing factor 1.3).
Four replicates per test concentration each containing 20 mL test solution and four replicates with 20 mL medium serving as controls were
prepared in 50 mL beakers. The pH and the oxygen content were determined and five daphnids were inserted into each beaker.
In addition, test vessels without daphnids were prepared for all test concentrations and the control in order to analyse the TOC (total organic carbon) content without any interference from the test organisms.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Daphnia magna Straus originates from a clone breeding of the German Federal Environmental Agency, department V 3.2, Berlin.
The current breeding has been held at Hydrotox GmbH since October 2012. Twice a week the animals are placed into fresh Elendt
medium M4 (according to OECD 202). They are kept at approximately 10 animals / 200 mL. Daily, they are fed with a suspension of
the algae Desmodesmus subspicatus in order to keep the C-content in the incubation beakers at 0.1 mg C per Daphnia and day. The Ccontent
of the algal suspension is measured photometrical. The daphnids are held at 20 ±2°C with a light : dark cycle of 16 : 8 h.
According to OECD 202 daphnids aged less than 24 h should be tested. In the present test animals of an age of maximal 23 h were used.

Study design

Test type:
Water media type:
Limit test:
Total exposure duration:
48 h

Test conditions

Test temperature:
19.5 to 21.1°C
Dissolved oxygen:
7.5 to 7.9 mg/L and did not fall below 3 mg/L during the time of exposure
Reference substance (positive control):

Results and discussion

Effect concentrationsopen allclose all
48 h
Dose descriptor:
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
48 h
Dose descriptor:
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
48 h
Dose descriptor:
Effect conc.:
>= 100 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:

Applicant's summary and conclusion

Validity criteria fulfilled:
Based on the results of the static Daphnia Acute immobilisation test according to OECD 202 and on the classification criteria of Regulation EU No.
1272/2008 the substance must not be classified as toxic to aquativ invertebrates.
Executive summary:

A static Daphnia, Acute immobilisation test with five nominal concentrations between 35 and

100 mg/L was performed with Oxa-Ester. The following ECx values were determined:

24 h                 48 h

EC10       >100 mg/L       >100 mg/L

EC20       >100 mg/L       >100 mg/L

EC50       >100 mg/L        >100 mg/L

LOEC       >100 mg/L       >100 mg/L

NOEC       ≥100 mg/L    ≥100 mg/L

Accompanying TOC-analysis resulted in mean recovery rates of 83.5 to 90.3%, indicating

that the test item was stable during the test period of 48 h.