Warfarin

Toxicity to birds

Administrative data

Endpoint:

toxicity to birds

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Modification of guideline. No mention of GLP.

Data source

Reference

Reference Type:

publication

Title:

An interpretation of Toxicity Response of Bobwhite Quail with Respect to Duration of Exposure

Author:

Shirazi, M. A., R. S. Bennett, and R. K. Ringer

Year:

1994

Bibliographic source:

Archives of Environmental Contamination and Toxicology, 26: 417-424

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: USEPA Pesticide Assessment Guidelines, Subdivision E, Hazard Evaluation: Wildlife and Aquatic Organisms. EPA-540/9-82-024

Deviations:

yes

Remarks:

No 3 day post exposure period.

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.
- Analytical purity: 98%.

Dose method:

feed

Analytical monitoring:

yes

Vehicle:

yes

Details on preparation and analysis of diet:

DIET PREPARATION
- Description and nutrient analysis of basal diet provided in study report: No.
- Preparation of doses: Test substance was dissolved or suspended in corn oil.
- Type and function of solvent/vehicle: Corn oil.
- Amount of vehicle: 2:98 w/w.


HOMOGENEITY AND STABILITY OF TEST MATERIAL IN DIET
- How often was homogeneity and stability tested: Not specified.
- When and at what dose levels were samples of treated food analyzed for stability and concentration during the study: Aliquots of each concentration were analyzed.
- Results of homogeneity analysis (range of values):
- Nominal concentration (mg/kg feed): 298-5000 mg/kg.
- Concentration analysed (mg/kg feed): All.
- % of nominal: Within 20%.
- Mixing procedure adequate and variance between nominal and actual dosage acceptable (yes/no): Not used unless concentration was within 20% of nominal.

Test organisms

Test organisms (species):

Colinus virginianus

Details on test organisms:

TEST ORGANISM
- Common name: Northern Bobwhite Quail.
- Source: Inhouse colony at USEPA Corvalis Laboratory.
- Age at test initiation (mean and range, SD): One test group 14 days, one test group 16 weeks.
- Sexes used: Juveniles too young to determine sex, adults not specified.

Study design

Limit test:

no

Total exposure duration (if not single dose):

28 d

Remarks:

5 day and 28 day tests

Post exposure observation period:

5-day chemical treatment group had a 3 day post exposure observation period.

No. of animals per sex per dose and/or stage:

10.

Control animals:

yes

Nominal and measured doses / concentrations:

Juvenile 5 day test-298-5000 mg/kg.
Juvenile 28 day test-263-2000 mg/kg.
Adult 28 day test- 263-2000 mg/kg.
All concentrations nominal.

Details on test conditions:

ACCLIMATION
- Acclimation period: Not specified.


PEN SIZE AND CONSTRUCTION MATERIALS
- Description: 71 x 92 x 22 cm galvanized steel brooders for juveniles, 50 x 75 x 25 cm galvinized steel pens for adults.
- Floor covering: Not specified.
- Suitable to avoid crowding stress: Yes.
- Caging: Grouped by dose.


NO. OF BIRDS PER REPLICATE
- For treated: 10.


NO. OF REPLICATES PER GROUP
- For treated: 1.


TEST CONDITIONS (range, mean, SD as applicable)
- Temperature:
- Brooder temperature: 35° Celcius for the first week, reduced by 2.5°Celcius each week thereafter (juveniles.)
- Room temperature: 25° Celcius.
- Photoperiod: 12 hours light, 12 hours dark for juveniles, 8 hours light, 16 hours dark for adults.

Examinations

Reference substance (positive control):

no

Results and discussion

Effect levels

Effect levels 1

Duration (if not single dose):

5 d

Dose descriptor:

LC50

Effect level:

3 109 mg/kg diet

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: juvenile

Effect levels 2

Duration (if not single dose):

28 d

Dose descriptor:

LC50

Effect level:

238.5 mg/kg diet

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: juvenile

Effect levels 3

Duration (if not single dose):

28 d

Dose descriptor:

LC50

Effect level:

819.3 mg/kg diet

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: adult

Further details on results:

ALC50 values also calculated for all tests.

Reported statistics and error estimates:

LC50s were calculated after Shirazi and Lowrie, 1990, and bootstrap calculations.

Applicant's summary and conclusion

Conclusions:

The LC50 for 5-day test in juvenile birds was 3109 mg/kg, for 28 day test in juvenile birds it was 238.5 mg/kg and a 28 day test in adult birds it was 819.3 mg/kg.