Warfarin

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline modified.

Data source

Reference

Reference Type:

publication

Title:

A Comparison of the Toxicity of 50 Reference Chemicals to Freshly Isolated Rainbow Trout Hepatocytes and Daphnia magna

Author:

Lilius H, Isomaa B, Holmstrom T

Year:

1994

Bibliographic source:

Aquatic Toxicology 30:47-60

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Not specified

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Warfarin

EC Number:

201-377-6

EC Name:

Warfarin

Cas Number:

81-81-2

Molecular formula:

C19H16O4

IUPAC Name:

4-hydroxy-3-(3-oxo-1-phenylbutyl)-2H-chromen-2-one

Details on test material:

- Name of test material (as cited in study report): Warfarin.

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

yes

Details on test solutions:

Warfarin first disolved in methanol.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna.
- Source: Department of Biology, University of Turku.
- Age at study initiation (mean and range, SD): < 24 hours.
- Feeding during test
- Frequency: Not fed during test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Post exposure observation period:

None.

Test conditions

Hardness:

Not specified.

Test temperature:

21 ± 1° Celcius.

pH:

7.6 SU.

Dissolved oxygen:

Not specified.

Salinity:

Not applicable.

Nominal and measured concentrations:

5 concentrations, not specified.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): Closed.
- Material, size, headspace, fill volume: 100 ml polystyrene, 50 ml test solution volume.
- Aeration: No.
- No. of organisms per vessel: 20.
- No. of vessels per concentration (replicates): 3.
- Culture medium different from test medium: Yes.

OTHER TEST CONDITIONS
- Photoperiod: 12 hours light, 12 hours dark.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Observations made for immobilization at 24 hours.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.288 other: mM

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: ± 0.007 mM

Reported statistics and error estimates:

The GraphPad 4 statistical program was used to calculate the LC50.

Applicant's summary and conclusion

Conclusions:

The 24 hour LC50 for Warfarin to Daphnia magna was found to be 0.288 ± 0.007 mM.