Diethyl sulphate, compound with 2-(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1)

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

Study period:

4 September 2021 - 22 December 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted on 1 June 2019

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- lot number of test material: 10419
- Purity, including information on contaminants, isomers, etc.: 93%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient (21 to 29˚C), dry and dark
- Date of Manufacture : 2021/4/23
- Date of Expiry : 2023/4/2

Analytical monitoring:

yes

Remarks:

- during main study, samples from test item stock solution was collected at 0 hour and at 96 hours; - analytical method: HPLC - test concentrations during main study were prepared by diluting the stock solution

Details on sampling:

- Concentrations:
- DRF: 0.25 mg/L, 1.10 mg/L, 4.84 mg/L, 21.30 mg/L and 93.70 mg/L
- main study: 0.129 mg/L, 0.270 mg/L, 0.567 mg/L, 1.190 mg/L and 2.5 mg/L
- Sampling method: collection at 0 hour (fresh solution) and at 96 hours (spent solution). A volume of 9 mL of test samples was collected in duplicates from stock solution.

Vehicle:

yes

Remarks:

tap water

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: common carp
- Source: in-housed maintained procured from Fisheries Research and Information Center (Inland), Hesaraghatta, Bangalore, Karnataka, India.
- Age at study initiation: juvenile
- Length at study initiation: 2.5 to 3.5 cm (dose range finding study) and 3.1 to 3.8 cm (main study)

ACCLIMATION
- Acclimation period: 9 days (48 hours settling-in + 7 days acclimatization) prior to test initiation
- Acclimation conditions: Water temperature during acclimatization was between 22.0 °C to 22.9 °C during dose range finding study and 22.2 °C to 22.9 °C during main study. CaCO3/L and 177.6 mg CaCO3/L and dissolved oxygen content of ˃82.3 and ˃83.9% was maintained during dose range finding study and main study respectively.
- Type and amount of food during acclimation: ad libitum with commercial feed pellets (Kijaro Grow)
- Feeding frequency during acclimation: daily
- Health during acclimation (any mortality observed): No mortality was observed during acclimatization of both dose range finding study and main study.

Test type:

static

Water media type:

other: Reverse osmosis purified water (Tap water)

Limit test:

yes

Total exposure duration:

96 h

Hardness:

176.7 mg/L CaCO3

Test temperature:

maintained between 22.1 °C to 22.9 °C

pH:

6.79 to 6.99

Dissolved oxygen:

86.9 to 95.4 %

Nominal and measured concentrations:

Nominal Conc. (mg/mL) Obtained Conc. (mg/mL) Recovery (%)
Date of Analysis: 29/10/2021
Sample 1 0.00 BLOQ -
Sample 2 10.00 8.97 89.66
Date of Analysis: 02/11/2021
Sample 1 0.00 BLOQ -
Sample 2 10.00 9.81 98.07

Details on test conditions:

TEST SYSTEM
- Test vessel: thoroughly cleaned rectangular glass aquaria having the water holding capacity of 50 liters. Test vessels were labeled for identification (study no., test item code, study code, group no. and concentration, exposure start and exposure end) prior to experiment initiation.
- No. of organisms per vessel: 7
- Biomass loading rate: 0.27 g and 0.28 g wet weight of fish/L during dose range finding study and main study respectively

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: inhouse
- Total organic carbon: ≤ 2 mg/L

OTHER TEST CONDITIONS
- Photoperiod: 12 hours light and 12 hours darkness
- Light intensity: 574 to 686 lux (during dose range finding study), 584 to 722 lux (during main study)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 4.4 for dose range finding study; 2.1 for main study
- Range finding study: 0.25 mg/L, 1.10 mg/L, 4.84 mg/L, 21.30 mg/L and 93.70 mg/L
- Test concentrations: 1.10 mg/L, 4.84 mg/L, 21.30 mg/L and 93.70 mg/L
- Results used to determine the conditions for the definitive study: during dose range finding study, no mortalities were recorded in control group and at the tested concentration of 0.25 mg/L. Mortalities of 85.7 %, 100.0 %, 100.0 % and 100 % were observed at the tested concentrations of 1.10 mg/L, 4.84 mg/L, 21.30 mg/L and 93.70 mg/L, respectively

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.497 mg/L

95% CI:

0.344 - 0.72

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Other abnormalities:
Dose Range Finding Study: Clinical signs of hypoactivity, abnormal surface distribution/behavior and abnormal bottom istribution/behavior were observed during the 5 hours observation period at the tested concentration of 4.84 mg/L.

Clinical signs of abnormal surface distribution/behavior and corkscrew swimming were observed during the 2 hours observation period at the tested concentration of 21.30 mg/L.
Clinical signs of surface distribution/behavior were observed during 2 hours observation period at the tested concentrations of 93.70 mg/L.

Main study:
Clinical signs of abnormal bottom distribution/behavior were observed at the tested concentration of 0.270 mg/L during 96 hours of exposure period.
Clinical signs of hypoactivity and abnormal bottom distribution/behavior were observed at the tested concentrations of 0.567 mg/L and 1.190 mg/L during the 96 hours exposure period.
Clinical signs of abnormal bottom distribution/behavior and abnormal surface distribution/behavior were observed at the tested concentration of 2.5 mg/L during the first 30 hours of the exposure period.

- Mortality of control: No mortality was observed at control group

Reported statistics and error estimates:

The acute Median Lethal Concentration (LC50) of Diethyl sulphate, compound with 2-
(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1) was evaluated by using the Probit analysis (Finney, 1971) with 95% confidence limits based on the nature of the mortality data. The LC50 values were evaluated with fiducial limits and graph was plotted with percent mortality against test concentration for recommended exposure periods of 96 hours.

Sublethal observations / clinical signs:

During the main study, no clinical signs of toxicity were observed at the control group and at the tested concentration of 0.129 mg/L during the 96 hours of observation period.

Clinical signs of abnormal bottom distribution/behavior were observed at the tested concentration of 0.270 mg/L during 96 hours of exposure period.

Clinical signs of hypoactivity and abnormal bottom distribution/behavior were observed at the tested concentrations of 0.567 mg/L and 1.190 mg/L during the 96 hours exposure period.

Clinical signs of abnormal bottom distribution/behavior and abnormal surface distribution/behavior were observed at the tested concentration of 2.5 mg/L during the first 30 hours of the exposure period.

No mortality was observed in control group and at the tested concentration of 0.129 mg/L during the 96 hours exposure period. Percent mortalities of 14.3 %, 71.4 %, 85.7 % and 100.0 % were observed at the tested concentrations of 0.270 mg/L, 0.567 mg/L, 1.190 mg/L and 2.5 mg/L of test item respectively during the 96 hours exposure period.

Validity criteria fulfilled:

yes

Conclusions:

The 96 hours acute Median Lethal Concentration (LC50) value of Diethyl sulphate, compound with 2-(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1) is 0.497 mg/L.

Executive summary:

In accordance to OECD 203, the acute toxicity of Diethyl sulphate, compound with 2-(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1) has been assessed on fish (Cyprinus carpio (Common carp)).

Percent mortalities of 14.3 %, 71.4 %, 85.7 % and 100.0 % were observed at the tested concentrations of 0.270 mg/L, 0.567 mg/L, 1.190 mg/L and 2.5 mg/L. The 96 hours acute Median Lethal Concentration (LC50) value of Diethyl sulphate, compound with 2-(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1) is 0.497 mg/L, with 95 % confidence limits, lower limit of 0.344 mg/L and upper limit of 0.720 mg/L.

Description of key information

In accordance to OECD 203, the acute toxicity of Diethyl sulphate, compound with 2-(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1) has been assessed on fish (Cyprinus carpio (Common carp). The 96 hours acute Median Lethal Concentration (LC50) value of Diethyl sulphate, compound with 2-(heptadec-8-enyl)-4,5-dihydro-1H-imidazole-1-ethanol (1:1) is 0.497 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

0.497 mg/L