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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:
2018
Report Date:
2018

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
Test material form:
solid: crystalline

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes
Details on test solutions:
The stock solution was prepared by measuring 18.05 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 nominal concentration of stock solution was 18 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.
Breeding conditions: The stock, breeding and test cultures were kept at the same conditions in thermostat (temperature: 21 ± 1 °C; light/dark cycle: 16/8 hour). These conditions ensure that the reproduction was by parthenogenesis.
Stock cultures: The stock cultures contained Daphnia magna of different age. Occasionally the adult animals were separated by sieving to start a new breeding culture.
Breeding cultures: Adult daphnids which were able to give birth to neonates were kept in breeding cultures. The volume of breeding cultures was 1 500 ml and each vessel contained 20-60 adult daphnids. The pH and oxygen concentration of these cultures were measured weekly. The progeny was separated at least weekly from adults by sieving. The first progeny of a new breeding culture was not used for the test.
Neonates: Young daphnids were used in the test were less than 24 hours old and were not first brood progeny.

Study design

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

Test conditions

Test temperature:
The temperature of thermostat was recorded daily and registered continuously by Extech datalogger. The temperature inside the thermostat at the test vessels was measured and registered continuously by Extech SD200 thermometer and datalogger.
pH:
The pH and dissolved oxygen were measured at the beginning and at the end of the test. At the beginning of the test the pH and the dissolved oxygen were measured from the remaining test solutions of the concurrent test vessels at each dilution levels. At the end of the test the pH and the dissolved oxygen were measured in each test vessel.
Dissolved oxygen:
The pH and dissolved oxygen were measured at the beginning and at the end of the test. At the beginning of the test the pH and the dissolved oxygen were measured from the remaining test solutions of the concurrent test vessels at each dilution levels. At the end of the test the pH and the dissolved oxygen were measured in each test vessel.
Nominal and measured concentrations:
Elendt M4 medium was used for dilution of stock solution. In the test the following nominal concentrations were applied: 18; 9; 5.4; 3.6; 2.7; 1.44 and 0.72 mg/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.
Preparation 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 18.05 mg of test item was measured into 1 000 ml Elendt M4 medium. The suspension was stirred till complete dissolution. After stirring the stock solution was clear and colourless. The nominal concentration of stock solution was 18
mg/L. The measured concentration of the stock solution was 16.00 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. The volume of the prepared test solutions was 300 ml.
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.:
1.36 mg/L
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
other: EC20
Effect conc.:
1.55 mg/L
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
1.98 mg/L
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) of the test item were determined with Fisher’s exact binominal test with Bonferroni correction by ToxRat® software. The results were not applicable to the data obtained.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The EC50 was 1.98 mg/L at 48 h. In this Daphnia sp., Acute Immobilisation Test for Tetrahydro-pyridine-tosilate the results indicated that the test item is hazardous to the aquatic environment and classified into the second acute toxic hazardous category [GHS Acute aquatic hazard Category Acute II. – 48 hr EC50 (for Crustacea) > 1 mg/L but ≤ 10 mg/L]