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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Details on test solutions:
The stock solution (100 mg/L test item was weighed out) was freshly prepared with dilution water.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Test organism: Daphnia magna STRAUS (Clone 5)
Culture medium: Elendt M4, according to ELENDT (1990), modified to a total hardness of 160 to 180 mg CaCO3/L
Culture feeding: At least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata, Desmodesmus
subspicatus and Chlorella vulgaris, with an algae cell density of > 10E6 cells/mL.

Study design

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

Test conditions

Hardness:
288 mg CaCO3/L
Test temperature:
20.9 °C
pH:
7.76-7.78
Dissolved oxygen:
8.38-8.60 mg O2/L
Nominal and measured concentrations:
Nominal: 100 mg/L
Details on test conditions:
Culture: In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 +/- 2 °C, in an incubator, 16 h illumination, light intensity
of max. 20 µE*m-2 * s-1
Test duration: 48 h
Test vessels: Glass beakers (4 cm ID x 7 cm H), 50 mL capacity
Test volume per vessel: 20 mL
Dilution water: ISO Test water, according to OECD 202, Annex 3
Number of daphnids and replicates: 20 daphnids, divided into 4 replicates, each with 5 daphnids per limit concentration solution and control
Age of daphnids at experimental starting: 2 to 24 h old daphnids were used for the study. They were obtained by removing the mother animals twice
within 22 h.
Acclimatization: At least 2 h in dilution water
Application: Per replicate, 20 g test solution was weighed out into the test vessels. This corresponds to 20 mL per test vessel. The daphnids were
inserted with a small amount of dilution water by a pipette.
Test temperature: 18 - 22 °C, ± 1 °C constant
Illumination/Photoperiod: Diffuse light, light intensity max. 20 µE*m-2 * s-1 / 16/8 h light/dark cycle
Feeding: The daphnids were not fed during the study.

Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Results with reference substance (positive control):
The percentage immobility for the reference item was determined after 24 h. The EC50-value with 95 % confidence interval (CI) was calculated by
sigmoidal dose-response regression. The EC50-value for the most recent of the monthly performed reference tests was:
EC50: 1.74 mg/L (CI 1.49 - 2.00 mg/L)
The EC50-value of the reference item potassium dichromate after 24 h is within the prescribed concentration range of 1.0 - 2.5 mg/L of quality
criteria according to AQS P 9/2 (05/1996) for daphnids clone 5 cultured in Elendt M4 medium. The EC50-value of the reference item is also within therecommended range of 0.6 - 2.1 mg/L according to OECD-Guideline 202.
Reported statistics and error estimates:
EC10 / 50 /100-values after 24 and 48 h and the NOEC and LOEC after 48 h were estimated directly from the observation data, without mathematical calculation.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
At the limit concentration of 100 mg/L of the test item 1,3-Dimethyl-1H-imidazol-3-iumpropanoate, no effect was observed on Daphnia magna.