R d ti id R

o

denticides: 

P t I id t A l 

R

o

denticides: 

P t I id t A l Pe

t

Inciden

t

Ana

ly

Presentation to the SAP

November 29, 2011

Sarah Winfield

Health Effects Division
Presentation Outlin

• Introduction• Lines of Evidence

• Hazard• Exposure• Risk Characterization• Incident Analysis• Literature Review

• Conclusions
Pet Behaviors/Vulnerab

• H d t ti l Hazar

d po

tenti

al

• Rodenticides are acute poisons

• Exposure potential Exposure potential

• Placement of baits allows them to 

accessed

• Size and shape of baits are easily 

consumed

• Canine feeding behavior
Risk Characterizati

• Mammalian wildlife deterministic, 

dose

-based risk assessment based risk assessment

reflecting primary exposure 

•

Acute concern identified across all rodenticides

• Rodenticides can kill mammals:

• 1 k (2 2 lb) i l 1

kg (2.2 lb) generic mammal

• 4-16 g of bait is a lethal dose

• 1.8 k

g( ) 4 lb

) chihuahua

• 6-24 g of bait is a lethal dose

• 29.5 kg (65 lb) labrador

• 45

-196 g of bait is a lethal dose 196

g of bait is

a lethal dose
Risk Characterization: Con

• Given comparable exposure ri

Given comparable exposure, ri

comparable between wildlife an

pet mammals
Incident Analysis

• Data Sources

• OPP Incident Data System (IDS) • National Pesticide Information Center (NP• National Animal Poison Control Center (A

National Animal Poison Control Center (A

• Pet Poison Helpline

• Types of incidents

• Primarily involved dogs• Primarily involved direct exposure to bait

• Uncertainties

• Market share• Reporting bias• Unde

r-reporting
Incident Analysis: I

• IDS pet exposures involving IDS pet exposures involving rodenticides rodenticides, 1999

Rodenticide Death Major Total E

Co

Brodifacoum 516 194 Bromethalin 175 117 Diphacinone and diphacinone, sodium salt 172 90 Warfarin and warfarin, sodium salt 29 4 Difethi l a one 10

9 

Chlorophacinone 3 3 Grand Total 905 417 
Incident Analysis: I

• IDS pet exposures involving rodenticides 1999

Rodenticide

Percentage of Death 

and Major out of Total 

IDS pet exposures involving rodenticides, 1999 

j

Exposure Count 

Brodifacoum 22% Di

p p hacinone and di

phacinone, sodium salt 22% 

Warfarin and warfarin, sodium salt 22% Chlorophacinone 21% Difethialone 13% Bromethalin 12% Grand Total - 
Incident Analysis: N

• NPIC pet exposures involving rodenticides, 1

Rodenticide Total Exposure Count

Diphacinone 521Bromethalin 254 Brodifacoum 125 Chlorophacinone 123Warfarin 84 Difethialone 56 Grand Total 1,163 
Incident Analysis: AP

• APCC pet exposures involving rodenticides 20

Rodenticide 2008 2009 2010 Total (’08-’

Bromethalin 2,220 1,590 1,249 5

APCC pet exposures involving rodenticides, 20

, , , 

Brodifacoum 1,415 1,429 1,426 4Difethialone 379 502 695 1Di

phacinone 239 210 201 

Warfarin 71 45 54 Chlorophacinone 60 55 45 Grand Total 4,384 3,831 3,670 11

• In 2010, rodenticides were the 3rd most freque

i l di t

, , , 

involve

d in pe

t exposures
Incident Analysis: Pet Poison 

• In 2009 In 2009, rodenticides rodenticides were identifie

were identifie

• the 3rd most common toxin involved in 

p g oisonin

g

s

• the 4th most common toxin involved in 

poisonings
Incident Analysis: Concl

• Across data sources: Across data sources:

• Rodenticides are likely to be 

associated with reported pet exposures, many of which resusevere outcomes

• Pets are in

g g estin

g toxic and leth

doses of rodenticides
Literature Review

• Case studies and series support Case studies and series support

findings from the risk characterizat

and incident data and incident data

• Exposure and hazard potential• S t i t t ith d f 

Symp

toms consis

ten

t with mo

de o

f a

• Severe outcomes
Literature Review

• Meadows & Meadows

& Gwaltney Gwaltney

-Brant 20

Brant, 20

• Using APCC data from 2001 to 2

id tifi d d ti id th 4th identifi

e

d ro

denti

cides as the 

4

th m

common substance involved in d

poi i son ngs
Literature Review

• Cope et al 2006 Cope et. al, 2006

• Rodenticides most common 

substance involved in dog poisonsubstance involved in dog poison

• Costly outcomes• Long exposure to treatment inter
Literature Review: Conclus

• Exposure to rodenticides have the pote

result i t (i l di d 

lt in severe ou

tcomes (including 

de

and necessitate veterinary care

• S t t d i th lit t Symp

toms repor

t

e

d in the litera

ture are 

consistent with toxicological mode of ac

• Rodenticides are common substances are common substances

involved in pet poisonings
Summary

• A lti l li f id Across multiple lines of evidenc

• Pets are gaining access and bein

exposed to rodenticides

• Pe s e posed o ts exposed to rode c des nticides ma

experience severe adverse sympand death
Risk Mitigation

• Risk Mitigation Risk Mitigation

• EPA is requiring that all rodenticide pro

available for sale to residential consum

sold only in bait stations sold only in bait stations

• Loose rodenticide bait such as pellets w

prohibited 

• Bait Station Requirements

• Tier 1 and Tier 2 bait stations are tamp

resistant for dogs; tested according to E

resistant for dogs; tested according to E

protocols
Conclusions

• Current label directions intended t

Current label directions intended t

keep bait away from pets are not effective at preventing exposures 

pets.

• EPA expects that RMD conformin

rodenticide products (i.e., those in 

tamper

-resistant bait stations) will resistant bait stations) will

mitigate pet incidents.