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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2020
Report Date:
2020

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 was prepared by measuring 150.34 mg of test item into 1 000 ml Elendt M4 growth medium. The suspension was stirred till complete dilution. After stirring the stock solution was clear and colourless. The measured concentration of stock solution was 153.51 mg/L.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Test species: Daphnia magna Straus
Age: < 24 hours neonates
Origin: National Institute of Environmental Health
Date of arriving: 16 May 2013
Culture conditions: The test species is maintained in Elendt M4 medium with culture conditions at 21±1 °C and a light/dark cycle of 16/8 hours with light intensities of less than 1000 Lux. The cultures are fed with centrifugalized green alga (Pseudokirchneriella subcapitata) cells daily at weekdays.

Study design

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

Test conditions

pH:
The test vessels were covered with plastic lids and were kept in thermostat at 21 ± 1 °C with a 16/8 hours light/dark cycle.
Nominal and measured concentrations:
The toxic property of test item was investigated at six concentrations which were prepared by different dilutions of stock solution of test item. Elendt M4 medium was used for dilution of stock solution. In the test the following nominal concentrations were applied: 15.4; 30.7; 51.2; 76.8; 102.3 and 153.5 mg/L.
The concentration of test item was measured at each concentration level at start and at the end of the test by a validated HPLC method. The geometric means of measured concentrations were determined.
The following actual concentrations were calculated from the measured values in the test: 15.07; 30.10; 50.11; 76.03; 101.21 and 152.89 mg test item/L.
Details on test conditions:
Selection of young daphnids:
On the first day of the test, all of juvenile daphnids were removed from the selected breeding cultures by sieving. Juvenile daphnids were disposed.
Next day the neonates (which are younger than 24 hours) were separated from the parental culture by filtering and were transferred into test vessels.
reparation of stock solution:
The preparation of stock and test solutions was based on the preliminary non GLP range finding test [9]. As the Range Finding Test was not performed in compliance with the GLP-Regulations it is excluded from the Statement of Compliance in the final report, but the raw data of this test are archived under the study code of present study. For the stock solution 150.34 mg of test item was measured into 1 000 ml Elendt M4 medium. The suspension was stirred and ultrasonicated till complete dissolution. After stirring the stock solution was clear and colourless. The measured concentration of stock solution was 153.5 mg/L.
Preparation of test solutions:
Seven dilution levels were prepared by mixing appropriate volume of Elendt M4 medium and stock solution of the test item. The maximum separation factor between of test vessels was 2.00. The following table shows the preparation of the different dilution levels. The volume of the prepared test solutions was 300 ml.
Test procedure:
The test was maintained under static conditions for a period of 48 hours. At the start of the study each test vessels contained 50 ml of test solutions and five young daphnids. In the test four replicates total of 20 animals at each test concentration level were investigated. The test vessels were covered with plastic lids and were kept in thermostat at 21 ± 1 °C with a 16/8 hours light/dark cycle. Each control vessels containing five young daphnids in Elendt M4 medium were
prepared in four replicates and kept under the same static conditions. The number of immobilised and abnormally behaved daphnids was recorded after 24 and 48h. A daphnia is considered to be immobile if it is not able to swim within 15 seconds after a gentle agitation of the test vessel. The daphnids were not fed during the test.

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
29.62 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
68.99 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In this Daphnia sp., Acute Immobilisation Test for Methyl-guanidyl-thiazole dihydrochloride monohydrate the results indicated that the test item is hazardous to the aquatic environment and classified into the third acute toxic hazardous category. [48 hr EC50 (for Crustacea) > 10 mg/L but ≤ 100 mg/L]