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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
Title:
Unnamed
Year:
2021
Report date:
2021

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1'-{2-(2,4-difluorophenyl)-2-[(trimethylsilyl)oxy]propane-1,3-diyl}bis(1H-1,2,4-triazole)
EC Number:
928-141-1
Molecular formula:
C16H20F2N6OSi
IUPAC Name:
1,1'-{2-(2,4-difluorophenyl)-2-[(trimethylsilyl)oxy]propane-1,3-diyl}bis(1H-1,2,4-triazole)

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Details on test solutions:
The test organism was bred and held in Elendt M4 medium which was also used for preparing of test item solutions. Young daphnids aged less than 24 hours at the start of the experiment were exposed to the test item for a period of 48 hours and acute toxic effect displayed as immobilization of test organism recorded at 24 and 48 hours after the start of test. The stock solution was prepared by measuring 159.95 mg of test item into 1 000 ml Elendt M4 growth medium. The suspension was ultrasonicated for 15 minutes and then stirred till complete dilution. As the correction factor of the test item is 1.328, the nominal concentration of the stock solution was 120.44 mg/L. The measured concentration of the stock solution was 108.80 mg/L.
The toxic property of test item was investigated at five 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: 18.13; 29.01; 43.52; 72.53 and 108.80 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
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Nominal and measured concentrations:
The toxic property of test item was investigated at five 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: 18.13; 29.01; 43.52; 72.53 and 108.80 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.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
105.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
not determinable
Details on results:
The effective concentrations (ECx) were calculated with Probit analysis using linear max. Likelihood regression. The EC10, EC20 and EC50 were calculated for immobility at both 24 h and 48 h period.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®

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Acute toxic effect of Silyl-fluconazole was investigated in Daphnia sp. Acute Immobilisation test (according to OECD 202 guideline).
The EC50 was >105.10 mg/L at 48 h. (EC10 was 105.10 mg/L at 48 h) In this Daphnia sp., Acute Immobilisation Test for Silyl-fluconazole the results indicated that the test item is not hazardous to the aquatic environment