2-fluoro-6-trifluoromethylpyridine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Substance ID: F6TF
Lot #: AF0460
Purity: 99.5%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all
- Sampling method: high performance liquid chromatography method; at the start of the test, the excess test solutions were sampled, and at the end of the test the A replicate of each test solution was sampled.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION: This study was run with a dilution water control together with nominal test substance concentrations of 10, 18, 32, 56 and 120 mg/L. Test solutions were prepared by the direct addition of the required amount of test substance to 1000 mL of dilution water. A 180 mg/L solution was prepared in the same way. These solutions were then stirred thoroughly for 24 hours to allow complete dissolution of the test substance. After stirring, a 120 mg/L test solution was prepared by dilution of the 180 mg/L solution. All test solutions were observed to be clear and colourless. These test solutions were not changed or aerated during the 48 hour exposure period.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM:
- Strain: Daphnia magna
- Age at study initiation: <24 hours
- Feeding during test: None

ACCLIMATION
- Acclimation period: The parent animals were 19 ± 1 days old

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Total hardness as CaC03: 197.7 mg/L

Test temperature:

20 ± 1°C

pH:

7.78 - 8.00

Dissolved oxygen:

8.6 - 9.2 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0, 10, 18, 32, 56 and 120 mg/L
Mean Measured concentrations: 0, 12, 16, 36, 57 and 120 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Borosilicate hypo-vials of 60 mL nominal capacity
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Conductivity: 586 µS/cm

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours dark, with 20 minute transition periods

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Assessments of the response of the Daphnia were made at 24 and 48 hours after commencement of the study. Each Daphnia was viewed by eye, and was defined as affected if showing no whole body movement relative to the water within a period of 15 seconds, even if movement of individual appendages was visible. Daphnia so affected were termed immobile. Any overt symptoms of toxicity were also recorded.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

82 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 56 -120 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: symptom of toxicity

Details on results:

Mean measured values ranged from 89 to 120% of the nominal values.

The 48 hour lowest nominal concentration at which there was 100% immobilisation was 120 mg/L. Although activity was reduced, immobilisation was not observed at any other test concentration or in the controls.

Reported statistics and error estimates:

The numbers of Daphnia immobilised in the replicates of the dilution water control and the test concentrations were summed for each time period. The 24 and 48 hour EC50 values, and their 95% confidence intervals, were calculated by the testing facility computer program "LC50", using Stephan's method.

Validity criteria fulfilled:

yes

Conclusions:

48-hour EC50 (Daphnia magna) = 82 mg/L
48-hour NOEC (Daphnia magna)= 56 mg/L

Executive summary:

An acute, static 48-hour test was conducted at nominal concentrations of 10, 18, 32, 56 and 120 mg/L on Daphnia magna according to the guideline OECD 202. Exposure after 48 hours resulted in 100% immobility at 120 mg/L. Based on nominal concentrations, the EC₅₀ was 82 mg/L.

Description of key information

Based on nominal concentrations because mean measured concentrations were within 80-120% of nominal:
48-hour EC50 = 82 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

82 mg/L