Appendix E. 

Ecotoxicity Information 

Freshwater Fish Acute Toxicity Data. 

Common Name %AI Study parameters Test Results MRID Classification/ 

Category

Bluegill sunfish 

Lepomis 

macrochirus

100 96 hour study 

10 fish/treatment 

Static study. 

96-h LC50 = 0.710

 

43249501 Acceptable/ 

Highly toxic 

Rainbow trout 

Onchorhynchus 

mykiss

100 96 hour study 

10 fish/treatment 

Static study. 

96-h LC50 = 0.450 43249502 Acceptable/ 

Highly toxic 

Freshwater Invertebrate Acute Toxicity Data 

Common 

Name

%AI Study parameters Test Results MRID Classification/ 

Category

Water flea 

Daphnia 

magna

N/A 48-h flow-through 

study 

Nominal treatments: 

110, 180 ,310, 510 

and 850 μg/L. 

48-h EC50: 0.640 mg a.i./L

NOAEC: 0.280 mg a.i./L 

42356101 Acceptable/ 

Highly toxic 

Avian Acute Oral Toxicity 

Species Toxicity Value Used in 

Risk Assessment 1 

Citation MRID # 

(Author & Date) 

Comments 

Northern 

bobwhite 

quail 

(Colinus 

virginianus) 

LD50 = 258 mg a.i./kg-bw2 41513101 

Acceptable/Highly Toxic 

1 birds were observed for 30 days after dosing 

2 all mortality (28 of birds dosed) occurred within 5 days 

1
Avian Subacute Dietary Toxicity 

Species Toxicity Value Used 

in Risk Assessment 1 

Citation MRID # 

(Author & Date) 

Comments 

Northern bobwhite 

quail (Colinus 

virginianus) 

5-day LC50 = 56 mg 

a.i./kg-diet2

41513102 Acceptable/Highly Toxic 

Mallard duck 

(Anas 

platyrhynchos) 

5-day LC50 = 172 mg 

a.i./kg-diet3

41513103 Acceptable/Highly Toxic 

Secondary Exposure Toxicity to Birds 

Predator/ 

scavenger 

(p/s) 

Prey offered 

to p/s 

No. prey 

offered daily 

per p/s 

No. days 

p/s 

exposed 

No. 

p/s 

exposed 

No. 

p/s 

dead 

No. survivors 

with signs of 

chlorophacinone 

toxicitya Reference 

Barn owl 

(Tyto alba) 

rats fed choice of 

0.005% bait or 

untreated bait for 

5 days 

1-2 10 2 0 0 Mendenhal

l and Pank 

1980 

Black-billed 

magpie (Pica 

hudsonia) 

rats fed 0.005% 

bait for 5 days 

ad lib. 5 20 0 0 Baroch 

1997 

American 

kestrel 

(Falco 

sparverius) 

voles fed 0.01% 

bait until dead 

1 

1 every 3 

days 

21 

61 

10 

10 

0 

0 

10 (eb/ih) 

10 (eb/ih) 

Radvanyi 

et al. 1988 

Red-tailed 

hawk (Buteo 

jamaicensis) 

voles fed 10 g 

0.005% bait daily 

for up to 9 days 

2 6 5 0 0 Askham 

and Poché 

1992 

Great horned 

owl (Bubo 

viriginianus) 

voles fed 10 g 

0.005% bait daily 

for 

 up to 9 days 

2 6 1 0 0 Askham 

and Poché 

1992 

Red-tailed 

hawk 

voles fed 0.005% 

bait for up to 

 9 days 

2 6 5 0 0 Askham 

1988 

Great horned 

owl 

voles fed 0.005% 

bait for up to 

 9 days 

2 6 1 0 0 Askham 

1988 

Tawny owl 

(Strix aluco) 

mice fed 

0.0075% baitb

ad lib. 10 4 0 (ct) Riedel et 

al. 1991c

2
Secondary Exposure Toxicity to Birds 

Predator/ 

scavenger 

(p/s) 

Prey offered 

to p/s 

No. prey 

offered daily 

per p/s 

No. days 

p/s 

exposed 

No. 

p/s 

exposed 

No. 

p/s 

dead 

No. survivors 

with signs of 

chlorophacinone 

toxicitya Reference 

Eurasian 

buzzard 

(Buteo buteo) 

mice fed 

0.0075% baitb

ad lib. 7 

10 

5+5+5d

40 

4 

6 

3 

3 

0 

0 

0 

0 

(ct) 

(ct) 

(ct)

(ct) 

Riedel et 

al. 1991c

Eurasian 

buzzard 

mice fed 

0.0075% baitb

4 7 4 0 0 Anonymou

s 1978c

Carrion crow 

(Corvus 

corone) 

mice fed 

0.0075% baitb

ad lib. 10 4 0 (ct) Riedel et 

al. 1991c

Carrion crow mice fed 

0.0075% baitb

3-4 3 

5 

12 

12 

0 

0 

0 

0 

Sterner 

1978c

White stork 

(Ciconia 

ciconia) 

mice fed 

0.0075% baitb

ad lib. 

(treated 

/untreated ) 

3 

14 

3 

3 

0 

0 

1 or 2 (ct) 

1 or 2 (ct) 

Sterner 

1981c

a

 eb = external bleeding; ih = internal hematoma; bl = bleeding (unspecified); ct = increased blood coagulation time; 

nr = not reported 

b

 ground squirrels were fed no-choice for 3 days followed by 3 days in which they had a choice of bait or untreated 

laboratory chow 

c

 baits registered in the U.S. are either 0.005% or 0.01% ai 

d

 individual was sacrificed but considered ‘dead’ based on coagulation index 

3
Mammal Acute Toxicity 

Species LD50, mg a.i./kg-bw 

(95% CI)

LC50, mg a.i./kgdiet (95% CI) Citation MRID # 

(Author & Date) 

Laboratory rat 

(Rattus norvegicus)

1.14 (1.02-1.36) 

1.14 (0.98-1.35) 

1.26 (1.11-1.47) 

1.26 (0.97-1.64) 

EPA 

unpublished 

dataa

Laboratory rat 

(Rattus norvegicus) 6.2 

3.1 (1.5-6.7) 

11.0 (6.5-18.5) 

41875301 

Laboratory rat 

(Rattus norvegicus)

0.95 (5-day dose @ 0.19/day) Jackson and 

Ashton 1992 

Norway rat 

(wild)

0.80 (5-day dose @ 0.16/day) Jackson and 

Ashton 1992 

 House mouse 1.0 

 6

Hone and 

Mulligan 

1982b

 Laboratory 

mouse 

5.95 (5-day dose @ 1.19/day) Jackson and 

Ashton 1992 

 Deer mouse 0.49 Clark 1994 

 Deer mouse 1.0-3.75c Schafer and 

Bowles 1985 

 Norway rat 5.0 Clark 1994 

 Pine vole 14.2 (11.4-17.6) Byers 1978 

 Roof rat 15.0 Clark 1994 

 Dog 50-100 Labe and 

Lorgue 

1977 a

 the 5 dietary tests for brodifacoum and 4 dietary tests for bromadiolone were conducted at 

 EPA's former Toxicology Unit, Beltsville, MD; methodology follows that described in 

 McCann et al. 1981 

b

 cited in Hyngstrom et al. 1994 

c

 an approximate lethal dose (ALD); the ALD is estimated from an acute oral test that uses too 

 few concentrations and test animals to statistically derive an LD50 

4
Secondary Exposure Toxicity to Mammals 

Predator/ 

scavenger 

(p/s) 

Prey offered 

to p/s 

No. prey 

offered daily 

per p/s 

No. days 

p/s 

exposed 

No. 

p/s 

exposed 

No. 

p/s 

dead 

No. survivors 

with signs of 

chlorophacinone 

toxicitya Reference 

Mongoose 

(Galidictis 

sp.) 

rats fed 0.005% 

bait for 5 days 

1 1 

3 

5 

6 

7 

9 

10 

1 

1 

2 

1 

1 

1 

1 

0 

1 

2 

1 

1 

1 

1 

nr 

no survivors 

no survivors 

no survivors 

no survivors 

no survivors 

no survivors 

Pank and 

Hirata 

1976 

Coyote 

(Canis 

latrans) 

ground squirrels 

fed 15 g of 0.01% 

bait for 6 daysb

1 5 7 3 0 Marsh and 

Howard 

1986 

Red fox 

(Vulpes 

vulpes) 

mice fed 

0.0075% baitc

20 total 4 1 1d no survivors Bachhuber 

and Beck 

1988e

European 

ferret 

(Mustela 

putorius) 

rats fed 0.005% 

bait for 5 days 

ad lib. 5 20 11 nr Ahmed et 

al. 1996 

European 

ferret 

prairie dogs fed 

25 g of 0.0025% 

bait daily for 6 

daysc

4 (1 every 

other day) 

8 6 5 nr Fisher and 

Timm 

1987 

European 

ferret 

voles/mice fed 

0.0075% baitc

5 total 4 2 1f (ct) Bachhuber 

and Beck 

1988e

European 

ferret 

muskrats fed 

0.005% bait 

ad lib. 4 

8 

2 

1 

0 

1 

1 (bl) 

no survivors 

Jobsen 

1978e

European 

ferret 

voles fed 

0.0075% baitc

ad lib. 3 4 0 (ct) Anonymou

s 1983e

Weasel 

(Mustela 

erminea) 

mice fed 0.005% 

bait 

ad lib. 90 4 3 0 Anonymou

s 1981e

a

 eb = external bleeding; ih = internal hematoma; bl = bleeding (unspecified); ct = increased blood coagulation time; 

nr = not reported 

b

 ground squirrels were fed no-choice for 3 days followed by 3 days in which they had a choice of bait or untreated 

laboratory chow 

c

 baits registered in the U.S. are either 0.005% or 0.01% ai d

 individual was sacrificed but considered ‘dead’ based on coagulation index 

5
Terrestrial and Simulated Field Tests 

Common Name %AI Nontarget kill MRID Classification/C

ategory

California Ground Squirrel 

(Spermophilus beecheyi)

0.01% 

and 

0.005% 

grain 

baits 

Poisoning confirmed in 14/15 

mice and 2/2 woodrats examined 

on 5 0.01% bait plots and 9/13 

mice and 3/3 wood rats on 5 

0.005% bait plots 

43922201 Supplemental2 

California Ground Squirrel Bait 

station 

with 

0.005% 

grain 

bait 

poisoning confirmed in 3/3 mice 

examined on 2 bait plots1 

43922202 Supplemental2

California Ground Squirrel 0.005% 

pelleted 

bait 

Poisoning confirmed in 2 dead 

rabbits (residue levels of 0.011 and 

1.16 ppm in GI tract) 

41649301 Supplemental2

Pine vole (Microtus 

pinetorum) 

1 ground 

spray at 

0.3 lb/ac 

No mortality or adverse affects 

were observed in six captive 

opossums exposed for 14 days to 

sprayed ground vegetation in an 

orchard 

234579 Supplemental3

1poisoning was indicated by blue-dyed bait in the GI tract, blue stain in fatty tissues, subdermal hematomas, 

and/or 

internal hemorrhaging 

2the study was an efficacy test that provided some information on nontarget hazards 

3sample size (6 opossums) was small 

REFERENCES 

Ahmed, M.S., J. Baroch, L. Carlet, and D. Whaley. 1996. Secondary hazard study using 

chlorophacinone-killed laboratory rats fed to domestic ferrets (Mustela putorius furo). 

Unpubl. report submitted to EPA by LiphaTech, Inc., Milwaukee, WI. 84 pp. 

Anonymous. 1981. Environmental and vertebrate chemistry - rodenticides. Agricultural 

Science Service, Research and Development Report, pp. 36-38. 

Anonymous. 1983. Unpubl. Report Niedersächsische Forstliche Versuchsanstalt, Göttingen 

(DE) (in German). 

Bachhuber, E. and C. Beck. 1988. [The effect of some anticoagulants on mice relevant in 

forestry and on mice predators.] Thesis, Munchen (DE) (in German). 

Byers, R.E. 1978. Performance of rodenticides for the control of pine voles in orchards. J. 

Amer. Soc. Hort. Sci. 103:65-69. 

6
Clark, J.P. 1994. Vertebrate Pest Control Handbook. (4th ed.) California Dept. Food and 

Agriculture, Sacramento. 803 pp. 

Fisher, D.D. and R.M. Timm. 1987. Laboratory trial of chlorophacinone as a prairie dog 

toxicant. Proc. Great Plains Wildl. Damage Workshop 8:67-69. 

Hone, J. and H. Mulligan. 1982. Vertebrate pesticides. Science Bull. 89, Dept. of Agriculture, 

NSW, Australia. 130 pp. 

Hygnstrom, S.E., R.M. Timm, and G.E. Larson. 1994. Prevention and Control of Wildlife 

Damage. Univ. Nebraska Cooperative Extension, USDA Animal Damage Control, and 

Great Plains Agric. Council. 

Jackson, W.B. and A.D. Ashton. 1992. A review of available anticoagulants and their use in the 

United States. Proc. Vertebr. Pest Conf. 15:156-160. 

Jobsen, J.A. 1978. [Study on the possibility of secondary poisoning of ferrets by 

chlorophacinone-poisoned muskrats.] Internal report of the Dutch Plant Protection 

Service, Wageningen (NL). 

Labe, J. and G. Lorgue. 1977. Intoxication des carnivores domestiques par les raticides 

anticoagulants. pp128-140. Notes de Toxicologie Veterinaire, No. 3. Centre 

d'Informations Toxicologiques Veterinaire, Ecole Nationale Veterinaire, Marcy L'Etoile, 

France. 

Marsh, R.E. and W.E. Howard. 1986. Ground squirrel--coyote secondary toxicity studies with 

chlorophacinone and bromadiolone (an administrative report of laboratory findings). 

Unpubl. report submitted to EPA by LiphaTech, Inc., Milwaukee, WI. 

McCann, J.A., W. Teeters, D.J. Urban and N. Cook. 1981. A short-term dietary toxicity test on 

small mammals. Pages 132-142 in D.W. Lamb and E.E. Kenaga (eds): Avian and 

Mammalian Wildlife Toxicology: Second Conference, ASTM STP 757, American 

Society for Testing Materials. 

Pank, L.F. and D.N. Hirata. 1976. Primary and secondary toxicity of anticoagulant rodenticides. 

Unpubl. report, Denver Wildlife Research Center. 23 pp. 

Schafer, E.W., Jr. and W.A. Bowles, Jr. 1985. Acute oral toxicity and relellency of 933 

chemicals to house and deer mice. Arch. Environ. Contam. Toxicol. 14:111-129. 

7