1-ethyl-3-methyl-3H-imidazolium dicyanidoamide(1-)

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Sampling: Samples were collected from each test chamber of each treatment and control group at 0h, 48h and 96h (±1h) to measure concentrations of the test substance.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Standard stock solution: The test item (63.28mg) was dissolved in acetonitrile and made up to the mark in a 100mL volumetric flask to prepare a stock solution with a concentration of 616.3mg/L (The purity is 97.4%).
- Calibration solutions: Defined volumes of the standard stock solution were further diluted with 50% acetonitrile to obtain calibration solutions of the test item in the range of 0.5778-46.23mg/L.
- Test substance solutions: 0.615g test substanee was dissolved in 300mL test water, transferred to 1000mL volumetrie flask and diluted with the test water to 1000mL, then transferred into 5L-jar, diluted with the test water to 5000mL by 1000mL volumetrie flask and stirred well. After that, the nominal concentration of 123mg/L test substanee solution (120mg/L calculated based on 97.4% purity of the main constituent) was obtained.
- Test concentration: The nominal concentration of active constituent of 10 mg/L, 50 mg/L and 100 mg/L test substance solution, and a blank control containing no test substance was set. Based on the results of range-finding test, the Iimit test was conducted with the nominal concentration of 123 mg/L test substance solution and a blank control under semi-static test (renewal at every 48h).
- Control: A blank control (test water without test substance) was set in parallel to the test concentration.
- Volume of test solutions: 5L/test vessel

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra Fish
- Source: Kangda Breeding Farm
- body length: 28.59 mm± 1.10mm
- body weight: 0.329 g ± 0.067 g
- Feeding during test: None

ACCLIMATION
- for 88 days by flow-through under the same conditions of water quality (Dechlorinated tap water), temperature (23 °C±2°C), light and dark period ( 14h light/10h dark). The dissolved oxygen concentration during acclimation was kept at least 80 % of the air Saturation value. The test fish were fed at least 3 times per week until 24 hours before the start of the test. The mortality was 1.3% during 7 days before the start of the test, which met the requirement.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

127 mg CaCO3/L

Test temperature:

21.3-22.3 °C

pH:

7.81-8-31

Dissolved oxygen:

79-102%

Nominal and measured concentrations:

- The actual concentration of test substance in blank control were all <0.1597mg/L (LOD) at 0h, 96h and 48h (before and after the renewal) after the start of the test.
- The measured concentrations of test substance in the nominal concentration of 123 mg/L test substance solution at 0h, 96h and 48h (after and before the renewal) after the start of the test were 119.5 mg/L (0h), 125.6 mg/L (48h old), 127.4 mg/L (48h new) and 129.5 mg/L (96h), respectively.
- During the test, the actual concentrations of test substance in old solutions were maintained within ±20% of the nominal concentration of main constituent in new test substance solutions.

Details on test conditions:

TEST SYSTEM
- Test vessel 15L-jar: 30 cm X 20 cm X 30 cm
- Renewal rate of test solution: After 48 and after 96 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration: 1
- No. of vessels per control: 1
- Biomass loading rate: 0.658 g/ L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The chlorine of drinking water was removed by aeration

OTHER TEST CONDITIONS
- Photoperiod: 14h:10h light/dark cycle

EFFECT PARAMETERS MEASURED:
- Mortality and visible abnonnality of the test fish were recorded at 24h, 48h, 72h and 96h after the start of the test during test period. The dead fish were removed as soon as they were found. A fish was considered dead if there was no visible movement (e.g. gill movements) and if touching ofthe caudal peduncle produces no reaction.

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 10, 50, 100 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 123 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

123 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 123 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No abnormal response was observed in blank control and test substance group.
- Mortality of control: None
- During the test, the actual concentrations of test substance in old solutions were maintained within ±20% of the nominal concentration of main constituent in new test substance solutions. Therefore, effect concentrations are exporessed as nominal.

Description of key information

The 96-h LC50 value is >123 mg/L in species Danio rerio.

Additional information

The short-term toxicity to freshwater fish was determined in a limit test according to OECD TG 203 and in compliance with GLP criteria (Guangdong Detection Center of Microbiology, 2013). In this study, groups of 10 zebrafish (Danio rerio) were exposed to nominal test concentrations of 0 (control) and 123 mg/L for 96 hours under semi-static conditions. The nominal test concentration was analytically verified at the start, after 48 hours (after and before the renewal) and after 96 hours and remained within ±20% of nominal. Therefore, the effect value is expressed as nominal. Fish mortality and general symptoms of toxicity were recorded after 24, 48, 72 and 96 hours exposure. No abnormal response was observed in the blank control and the test substance group. No mortality occurred in the blank. Based on these findings the 96-h LC50 value was determined at >123 mg/L.