2,6-dibromo-4-cyanophenyl octanoate

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:

10 Aug - 11 Sep, 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

not specified

Remarks:

the percentage of air saturation in water is not reported

GLP compliance:

yes (incl. QA statement)

Remarks:

From THE DEPARTMENT OF HEALTH OF THE GOVERNMENT OF THE UNITED KINGDOM

Analytical monitoring:

yes

Details on sampling:

Samples of the test solutions were taken for analysis at 0, 24, and 96 hours. All samples were taken from the centre of the test vessels and were analysed directly after sampling.

Vehicle:

yes

Remarks:

dimethylformamide

Details on test solutions:

A stock concentrate was prepared by weighing 0.30 g of the test material into a beaker and adding 300 ml of dimethylformamide to give a nominal concentration of 1.0 g/1. The resulting solution was clear and colourless. The stock solutions were prepared by adding the appropriate amount of stock concentrate, diluted with 150 ml of dimethylformamide, to the stock jars to give the correct nominal concentrations in the test vessels. All the stock solutions were clear
and colourless. Stock solutions were replaced with freshly prepared solutions on day 2. The stock solutions were fed to the glass mixing chambers by a pump and the dilution water was supplied using a capillary flow control system. Magnetic stirrers in the mixing chambers were used to ensure mixing before the
test solutions passed into the fish exposure vessels. The dilution ratio of the stock solutions to dilution water was nominally 1:10,000 in all concentrations.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

There were no mortalities during the 4 weeks prior to the test. The pretest diet used for the fish was Promin. The fish were not fed during the exposure period or for 24 hours prior to the test start. The batch of fish used for this study was held for 28 days at 15 ± 1 °C before the start of the test. The fish were held in fibre glass tanks under daylight and artificial lighting.
No medication was given to the fish during the holding period.
The range in weight was 0.61 to 1.88 g with a mean of 1.21 g and the range in length was 38 to 52 mm with a mean of 45 mm. The fish loading in the dilution water control was 0.27 g/l.
Ten rainbow trout were used in each test concentration and in the solvent and dilution water controls. The fish were randomly assigned to the test vessels

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

38.7 - 50.0 mg/L as CaCO3

Test temperature:

14.6 - 15.0 °C

pH:

7.04 - 7.47

Dissolved oxygen:

9.2 - 10.0 mg/L

Salinity:

Not applicable

Conductivity:

158 - 236 µS/cm

Nominal and measured concentrations:

Nominal concentrations: 3, 6, 12, 24, 48 and 96 µg/L
Mean measured concentrations: 2.6, 5.4, 11, 24, 40 and 89 (83 to 100 % of nominal)

Details on test conditions:

The apparatus used in this study was a dynamic, continuous flowthrough system. The test vessels, dosing lines, mixing chambers and stock vessels were all constructed of glass. A minimum quantity of silicone rubber tubing was used to connect the components together.
Glass vessels with external dimensions of 610 mm x 305 mm x 310 mm, a maximum capacity of 54 litres and a working volume of 45 litres were used to hold the test fish. The test solutions were renewed at a nominal rate of 250 mL/minute so that a 95 % exchange of the test solutions was calculated to occur within 9 hours.
A continual measurement of temperature in the dilution water control noted it to have remained within 15 ± 1 °C.
The photoperiod in this study was 16 hours light and 8 hours darkness with 10 minute transition periods at 06:00 and 21:50 hrs.
Observations of mortalities and symptoms of toxicity were made at 24, 48, 72 and 96 hours.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

41 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

The symptoms of toxicity noted in this study were in general behaviour, swimming, pigmentation and respiration, and were observed at the mean measured concentrations of 24, 40 and 89 ug/L.

Sublethal observations / clinical signs:

Please refer to "overall remark/ attached background material" field for result tables.

Validity criteria for OECD 203 (2019) table

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	0%	Yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	Ranged between 9.2 to 10.0 mg/L	No information
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20 per cent, results should be based on the measuredconcentration.	The measured values were greater than 80 % of the nominal value in all aquaria over the whole test period	Yes

The validity criteria according to the OECD 203 guideline (2019) are met except that the air saturation percentage is missing. According to the level of dissolved oxygen in the solution (9.2 mg/L as a minimum), it could be expected that the air saturation was higher than 60% throughout the test duration.

Validity criteria fulfilled:

not specified

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, the LC50 96 h for Oncorhynchus mykiss was 0.041 mg/L.

Description of key information

From short-term key study, the 96-hour LC50 for fish exposed to the present test material was 0.041 mg a.i./L, freshwater.

From short-term supportive study, the 96-hour LC50 for fish exposed to the present test material was 0.170 mg a.i./L, saltwater.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

ca. 0.041 mg/L

Marine water fish

Marine water fish

Dose descriptor:

LC50

Effect concentration:

ca. 0.17 mg/L

Additional information

Three GLP-studies are available for short-term toxicity testing in fish and one of them was identified as key study. Three additional non GLP-studies were also included.

In the key study (1992), the acute toxicity of test substance to fish was investigated in a 96-hours flow-through test with the rainbow trout (Oncorhynchus mykiss) according to guideline OECD 203. Ten fish per replicate and three replicate per concentration were exposed for 96 hours under flow-through conditions to nominal test item concentrations of 3, 6, 12, 24, 48 and 96 µg a.i./L, alongside with a control. Mean measured concentrations from days 0 and 4 ranged from 83 to 100 % of nominal concentrations. The 96-hour LC₅₀was determined to be 0.041 mg a.i./L, based on mean measured concentration values.

There are two additional GLP studies available, conducted with Oncorhynchus mykiss (rainbow trout) and Cyprinodon variegatus (sheepshead minnow); the resulting LC₅₀values were≥0.17 mg a.i./L. These studies were considered suitable for supporting purpose.

In the first supporting study (1992), the acute toxicity of test material to sheepshead minnow was determined in a 96-h flow-through test according to US EPA-72.3 guideline.The 96-hour LC50 of the technical active ingredient was determined to be 0.170 mg a.i./L based on the mean measured concentration.

In the second supporting study (2003), the acute toxicity of test material to rainbow trout was determined in a 96-h-static test according to guidelines OECD 203 and OECD 219. The 96-hour LC50 of the technical active ingredient was determined to be 0.180 mg a.i./L, based on the initial measured concentration.

There are three additional non-GLP studies available, conducted with Oncorhynchus mykiss (rainbow trout) and Lepomis macrochirus (bluegill sunfish); the resulting LC₅₀values were ≥ 0.061 mg/L.

Additionally, one study on Lepomis macrochirus was conducted with the substance, the resulting LC₅₀value was 0.034 mg/L over 2 to 7 days.