4,6-Dichloro-5-fluoropyrimidine

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:

28 Feb - 05. Apr 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.063, 0.125, 0.25, 0.5 and 1 mg/L
- Sampling method: Sampling done daily on both test solution and control
- Sample storage conditions before analysis: Direct analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test concentrations were prepared daily by diluting a stock solution (1 mg/L), which was treated with an ultra turrax for 60 seconds and afterwards stirred for 24 hours on a magnetic stirrer. Finally undissolved particles of the test substance were removed by filtration.
- Controls: One control
- Test concentration separation factor: 2
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None after filtration

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra fish
- Source: Di Mamma (Netherlands)
- Length at study initiation (length definition, mean, range and SD): 3.08 cm (S.D. = 0.29 cm)
- Method of breeding: Well-established stock
- Maintenance of the brood fish: Test conditions have been established in the brood.

ACCLIMATION
- Acclimation period: Stock held since Jan. 23, 2002 and acclimatised to the test conditions since then.
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food during acclimation: Commercial fish food
- Feeding frequency during acclimation: Fed daily
- Health during acclimation (any mortality observed): Mortality < 2%

FEEDING DURING TEST (as applicable)
No feeding during exposure

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

13.4 °dH (= 239.2 mg/1 CaCO3)

Test temperature:

20 - 24 °C

pH:

7.5 - 7.9

Dissolved oxygen:

> 5 mg/L (8-5 - 8.8 mg/L)

Nominal and measured concentrations:

Nominal: 0.063, 0.125, 0.25, 0.5 and 1 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria holding 5 L of test media
- Aeration: gentle aeration via narrow glass tubes
- Renewal rate of test solution (frequency/flow rate): Daily renewal of test medium
- No. of organisms per vessel: 0.78 g/L loading rate, 10 animals per concentration
- No. of vessels per concentration (replicates): 1 vessel
- No. of vessels per control (replicates): 1 vessel
- Biomass loading rate: 0.78 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water prepared according to the recommendations of ISO 7346. This freshly prepared standard dilution water is used for both, the maintenance of the test animals under flow-through conditions and the preparation of stock and test solutions of the test substance.
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality observed every 24 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

>= 0.2 - <= 0.42 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

0.424 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

0.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: 0%

Sublethal observations / clinical signs:

Validity criteria for the measurement of the fish toxicity

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
In the control(s) (dilution water control, solvent control), the mortality should not exceed 10% (or one fish, if fewer than 10 control fish are tested) at the end of the exposure.	Mortality of control: 0 fish died	Yes
All fish should be held in the laboratory for at least 9 days before they are used for testing. The first 48 hours constitute a settling-in period. Then, fish should be acclimatised for at least 7 days (48 hours settling-in + 7 days acclimatisation = 9 days) in water similar to test water immediately before the start of the test.	Acclimation period was from 23 Jan 2002 while the test was performed at 28 Feb 2002 (acclimation period over 9 days).	Yes
During the acclimatisation period, mortalities are recorded, and the following criteria are applied: - mortalities of greater than 10% of the population in seven days: reject the entire batch; - mortalities between 5 and 10% of the population: acclimatisation is continued for seven additional days; and if there is more than 5% mortality during the second seven day period, reject the entire batch; - mortalities of less than 5% of population in seven days: accept the batch.	Health during acclimation (~ 1 month): Mortality < 2%	Yes
Temperature: the water temperature should not differ by more than 2°C	During the test a temperature range of 20 - 24°C was maintained in the test vessels, with a maximum temperature fluctuation of +/- 1°C in each individual test.	Yes
Duration: 96 hours.	Duration was 96 h.	Yes

 

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'.

Conclusions:

LC50 (96 h): >0.2 - <0.424 mg/L (mean measured).

Executive summary:

Groups of ten fish of the recommended size were exposed to a range of concentrations, nominally 0.063, 0.125, 0.25, 0.5 and 1 mg/L of the test substance dissolved in water. Auxiliaries used to prepare the test media were an ultra turrax, a magnetic stirrer and folded filters. Observations were made on the numbers of dead fish and the incidence of sub-lethal effects after 2, 24, 48, 72 and 96 hours of exposure. The following values were determined: LC0 = 0.2 mg/L, LC50 (96 h): >0.2 - <0.424 mg/L, LC 100 = 0.424 mg/L. All results are expressed in terms of mean measured concentrations. Measured concentrations ranged from 81-95.2% of nominal values in the freshly prepared medium and from 42.9-81.9% of nominal values after 24 hours of exposure.

Description of key information

Groups of ten fish of the recommended size were exposed to a range of concentrations, nominally 0.063, 0.125, 0.25, 0.5 and 1 mg/L of the test substance dissolved in water. Auxiliaries used to prepare the test media were an ultra turrax, a magnetic stirrer and folded filters. Observations were made on the numbers of dead fish and the incidence of sub-lethal effects after 2, 24, 48, 72 and 96 hours of exposure. The following values were determined: LC0 = 0.2 mg/L, LC50 (96 h): >0.2 - <0.424 mg/L, LC 100 = 0.424 mg/L. All results are expressed in terms of mean measured concentrations. Measured concentrations ranged from 81-95.2% of nominal values in the freshly prepared medium and from 42.9-81.9% of nominal values after 24 hours of exposure.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 0.2 - < 0.424 mg/L