1,1,2,2,3,3,4,4-octafluoro-1,4-diiodobutane

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:

From June 2017 to April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Appearance: Pink liquid
- Test item storage: At room temperature protected from light
- Purity/Composition correction factor: No correction factor required

Analytical monitoring:

yes

Details on sampling:

For the analysis of the actual test substance concentration, 30ml of the stock solution was taken and measured while preparing the fresh test solutions, and 30ml of test solution from each test vesse! at the beginning of the test.

Vehicle:

no

Details on test solutions:

A nominal concentration of 200 mg/L of the test substance was prepared in dechlorinated tap water and stirred (via magnetic stirrer) in the dark for 72h (the vortex depth was 1/3 of that of the mixture column) followed by filtration using a 0.45 µm nitrocellulose membrane to make the stock solution of the test substance. The test solutions were prepared by dilution of the stock solution with dechlorinated tap water.

Test organisms (species):

other: Gobiocypris rarus

Details on test organisms:

TEST ORGANISM
- Common name: Gobiocypris rarus
- Source: in-house culture
- Length at study initiation: 2.3 ± 0.1cm (mean ± SD)
- Weight at study initiation: 0.22 ± 0.029 (mean ± SD)

ACCLIMATION
- Acclimation period: more than 14 days:
- Temperature: 21-25°C (constant within a range of 2°C)
- pH: 6.0-8.5
- Dissolved oxygen concentration: > 80% of air saturation value (ASV)
- Photoperiod: light/dark = 12 hours/12 hours;
- Feeding: fish were fed with brine shrimp flake (O.S.I®, USA) daily until 24 hours before the test was started.
- Health during acclimation (any mortality observed): no diseases were observed during the acclimation period and no mortality was observed within the 7 days before the start of the test

FEEDING DURING TEST : none

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

22.0 - 22.4°C

pH:

7.44 - 7.93.

Dissolved oxygen:

80.9 - 93.5% air saturation value

Nominal and measured concentrations:

Nominal concentrations (final test): solutions containing 0 (control), 1, 1.8, 3.2, 5.6% and 10% of the stock solution

Details on test conditions:

TEST SYSTEM
- Test vessel: 10-liter litre glass vessels with seals, without headspace
- Aeration: continuous over 24h
- Renewal rate of test solution: every 24h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: about 0.2 g fish/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water dechlorinated by activated carbon and sterilized by UV lamp

OTHER TEST CONDITIONS
- Photoperiod: light/dark = 12 hours/12 hours

EFFECT PARAMETERS MEASURED:
The fish were inspected at 0, 3, 24, 48, 72 and 96 hours after test initiation and dead fish were removed when observed and mortalities and any abnormalities observed were recorded. At the end of the test, the body length and body weight of the test fish of the control group were measured. The loading rate was also calculated with the body weight at the same time.

OTHER PARAMETERS MEASURED
Measurements of the pH, dissolved oxygen concentration and temperature in the test solutions were made at the beginning, before and after each renewal, and at the end of the test.

RANGE FINDING TEST CONCENTRATIONS
- Range finding study : yes (solutions containing 0 (control), 1, 10 and 100% of the stock solution)
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

1,4 diiodoperfluorobutane

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

<= 0.192 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

The mortalities were plotted against each test concentration (geometric mean measured) and control for each exposure period (24h, 48h, 72h and 96h). The 24 hours LC50 was calculated using the method of Linear Interpolation; and the 48, 72 and 96 hours LC50 with 95% confidence limits were calculated using the method of Spearman-Karber. The data analysis was carried out with software TOXCALC­Toxicity Data Analysis Software (v5.0.32).

Sublethal observations / clinical signs:

Measured Concentrations

Based on the results of the range-finding test, five treatment groups and one control group were included in the definitive test. The concentrations of the treatment groups were 1.0%, 1.8%, 3.2%, 5.6% and 10% of the stock solution (the geometric mean measured concentration of the stock solution was 4.52mg/L during the period of the test). The measured concentrations of the test substance for all the treatment groups were below the limit of detection (LOD = 0.540mg/L) and therefore, the concentration of the test substance for each treatment was estimated from the concentration in the stock solution, i.e., 0.0452mg/L, 0.0814mg/L, 0.145mg/L, 0.253mg/L and 0.452mg/L, respectively.

Mortality

The maximum concentration causing no mortality and the minimum concentration causing 100 percent mortality within the period of the test was 1.8% stock solution (estimated: 0.0814mg/L) and 10% stock solution (estimated: 0.452mg/L), respectively (see below table). There were no mortalities or abnormalities observed in fish of the control group during the test

Group	Duration(h)	Mortalities	Cumulative Mortalities	Abnormalities
Control	0	0	0	none
1.0%	3	0	0	none
	24	0	0	none
	48	0	0	none
	72	0	0	none
	96	0	0	none
1.8%	0	0	0	none
	3	0	0	none
	24	0	0	none
	48	0	0	none
	72	0	0	none
	96	0	0	none
3.5%	0	0	0	none
	3	0	0	none
	24	0	0	none
	48	1	1	1SA
	72	0	1	2LE
	96	0	1	4LE
5.6%	0	0	0	none
	3	0	0	none
	24	0	0	none
	48	2	2	2SA
	72	4	6	2SA, 2LE
	96	0	6	4LE
10%	0	0	0	none
	3	0	0	none
	24	2	2	2LE
	48	4	6	1LE
	72	1	7	/
	96	/	7	/

SA: swim abnormally

LE : loss of equilibrium

The 96h-LC50 for Gobiocypris rarus exposed to the test item was estimated to be 0.192mg/L (95% confidence limits: 0.155 – 0.237mg/L) based on the concentrations in test solutions estimated from the concentration in stock solution. Considering the uncertainties about the stability of the test substance in test solutions, the 96h-LC50 for the test item to Gobiocypris rarus is reported as ≤ 0.192 mg/L.

Acceptability of the Test

1. No mortality was observed in the control during the test.

2. The dissolved oxygen concentrations in test solutions were between 80.9%- 93.5% ASV, which was greater than 60.0%of the air saturation value, throughout the test.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the test, the 96h-LC50 for Gobiocypris rarus exposed to the test item was estimated to be 0.192 mg/L (95% confidence interval between 0.155 and 0.237 mg/L) based on measured concentrations in the stock solution. Considering the uncertainties about the stability of the test item in test solutions, the 96h-LC50 for Gobiocypris rarus exposed to the test item is reported as ≤ 0.192 mg/L.

Executive summary:

The acute toxicity of the test item to the freshwater fish Gobiocypris rarus was investigated in a GLP-compliant study performed in accordance with OECD Guidelines No. 203. Under the conditions of the test, the 96h-LC50 for Gobiocypris rarus exposed to the test item was estimated to be 0.192 mg/L (95% confidence interval between 0.155 and 0.237 mg/L) based on measured concentrations in the stock solution. Considering the uncertainties about the stability of the test item in test solutions, the 96h-LC50 for Gobiocypris rarus exposed to the test item is reported as ≤ 0.192 mg/L.

Description of key information

The acute toxicity of the test item to the freshwater fish Gobiocypris rarus was investigated in a GLP-compliant study performed in accordance with OECD Guidelines No. 203. Under the conditions of the test, the 96h-LC50 for Gobiocypris rarus exposed to the test item was estimated to be 0.192 mg/L (95% confidence interval between 0.155 and 0.237 mg/L) based on measured concentrations in the stock solution. Considering the uncertainties about the stability of the test item in test solutions, the 96h-LC50 for Gobiocypris rarus exposed to the test item was reported as ≤ 0.192 mg/L. Alternatively, the 96h-LC50 could also have been reported as < LOD/2, i.e.< 0.270 mg/L.

As it was not possible to determine with precision the 96h-LC50 for fish, a safety factor of 10 is applied, for the assessment, to the estimated value of 0.192 mg/L, which means that a 96h-LC50 value of 0.0192 mg/L was used, as a worst-case, for environmental hazard assessment.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.019 mg/L

Additional information

The toxicity of the test item to freshwater fish was investigated in one GLP-compliant study performed in accordance with standard methods, without deviations. The study is considered as reliable (Klimisch 1) and is selected as a key study for the endpoint.