Sc e t c ssues ssoc ated t 

ientific Issues Associated with 

Proposed Cancellation & Deni

Certain Rodenticide Produc

Sc e t c ssues ssoc ated t 

Proposed Cancellation & Deni

Ce ta ode t c de oduc

rtain Rodenticide Produc

Charge Questions
Risks to Humans

Question 1

• Does the A

gy y enc

y’s anal

ysis of the mammal

toxicity studies and human incident reports provide a reasonable basis for concluding exposure to warfarin brodifacoum difethiaexposure to warfarin, brodifacoum, difethia

and/or bromethalin can cause health effectindividuals who ingest these rodenticides? 

the adverse effects described in the childre

incident reports [e.g., anemia, melena (bloostool), ( g )], hematemesis 

(vomitin

g of blood)], c

consequences of exposure to these active ingredients? Please provide the basis for yconclusions.
Risks to Humans

Question 2

• The human incident report summarizes a number of 

and information sources used in the analyses and rconducted. Based on the incident report analysis, 

h l d d th t th l b f d has conclu

d

e

d th

a

t there are a large num

ber o

f ro

de

exposure incidents that involve children less than 6 old. While exposure generally results in no clinical 

children the exposures to rodenticides have the pochildren, the exposures to rodenticides have the po

to result in severe outcomes and/or require medical follow-up. Does the SAP concur with the EPA’s 

conclusions regarding the extent of exposures poteconclusions regarding the extent of exposures, pote

severity of effects, and degree of risks posed to humAre the conclusions reached reasonably supported data anal

y p yp sis? Please ex

plain the basis of 

your 

pos
Risks to Humans

Question 

3

• Based on the human incident report, EPA 

concludes that the use of conforming rodenproducts will reduce the risk rodenticides pproducts will reduce the risk rodenticides p

humans by reducing the opportunity for exposure. Is it reasonable to expect that lim

consumer use to conforming rodenticide products will generally reduce the opportunex

posure of humans to commensal rodenti

products? Please provide the basis for youconclusions.
Risks to Pets

Question 

4

• The pet incident report summarizes a number of dat

The pet incident report summarizes

a number of dat

information sources used in the analyses and reviewconducted. The EPA concludes that there is a high 

frequency of reported pet incidents involving rodenfrequency of reported pet incidents involving roden

many of which result in severe outcomes; this concis further supported by the information reported in tliterature as well as the characterization of 

p y rimar

y a

risk. Does the SAP concur with EPA’s conclusions orisks posed to pets by non-conforming rodenticide products? Are the conclusions reached reasonably supported by the data analysis? Please explain the your position.
Risks to Pets

Question 

5

• The pet analysis has relied on the assessm

risks to wildlife from primary exposure as oline of evidence to characterize primary aculine of evidence to characterize primary acu

to pets from non-conforming rodenticide products. Is it reasonable to conclude that 

to pets are similar to risks to non-target mammalian wildlife, assuming comparable ex

p py osures? Please ex

plain the basis of 

yo

conclusions.
Risks to Pets

Question 6

• Based on the pet incident report, EPA conc

that the use of conformin

g p rodenticide 

prod

will reduce the opportunity for exposure of to rodenticides. Is it reasonable to expect tlimiting consumer use to conforming rodenlimiting consumer use to conforming roden

products will generally reduce the opportunexposure of pets to commensal rodenticide 

prod ? Pl id h b i f ducts

? Please provide t

he 

basis 

for you

conclusions.
Risks to Wildlife

Question 

7

• Th EPA h d t d d t i i ti i k 

The EPA

has con

duc

t

e

d a 

d

e

terministic ris

k assessme

evaluate the risks of acute toxicity to non-target mammbirds from primary exposure to non-conforming roden

products In its assessment EPA calculated risk quotproducts. In its assessment, EPA calculated risk quot

an acute oral dose and acute dietary exposure basis foand mammals and further characterized the opportuni

exposure at lethal levels based on factors including thexposure at lethal levels based on factors including th

of days required to feed and the mass of pesticide reqbe consumed to reach lethal thresholds. Using the beavailable data, p 

 EPA made assum

ptions relative to toxic

accumulation, and clearance of the pesticides that are to the exposure and effects modeling in the determinisprimary risk assessment. 
Risks to Wildlife

Question 7 CONT.

a

) Please comment on the reasonableness of th

following aspects of EPA’s primary exposure deterministic risk assessment: 

• Selection of toxicity endpoints for species commo

Selection of toxicity endpoints for species commo

assessed chemicals in light of the incomplete overacross available data sets; 

• The use of allometric toxicity scaling approaches f

The use of allometric toxicity scaling approaches f

• The reliance on mammalian first order liver or plas

elimination half lives to estimate whole body wildli

and mammals) elimination rates for anticoagulants and mammals) elimination rates for anticoagulants 

bromethalin, respectively;

• The use of the time required and the consumption 

rodenticide mass required to reach lethal thresholdrodenticide mass required to reach lethal threshold

means of comparing the relative risks of acute morfollowing consumption of rodenticide bait; 
Risks to Wildlife

Question 7 CONT.

b) In addition does the Panel concur with EPA In addition, does the Panel concur with EPA 

analysis and conclusion that use of non-conrodenticide products (i.e., not in bait station

cause ad ff t t dverse effec

ts 

to non-t t ildlif ? 

targe

t wildlif

e

? 

provide a basis for your conclusions. 

c) Is it reasonable to expect that placing roden

Is it reasonable to expect that placing roden

products in tamper resistant bait stations wformulations expected to remain in the bait 

will generally reduce the opportunity for primwill generally reduce the opportunity for prim

exposure of wildlife to commensal rodent coproducts? Please provide a basis for your 

conclusions.
Risks to Wildlife

Question 8

• The EPA has conducted a deterministic risk assessmen

The EPA has conducted

a deterministic risk assessmen

evaluate risks of acute toxicity to non-target mammals afrom secondary exposure to non-conforming rodenticid

products. In its exposure estimate, EPA used both calcproducts. In its exposure estimate, EPA used both calc

theoretical contamination levels in prey and available edata. EPA also characterized the secondary exposure rsecondar

yg g feedin

g studies and factors includin

g the nu

contaminated animals required to be consumed to reacexposure thresholds. For these analyses, using the besdata, EPA made assumptions relative to toxicity, accumand clearance of the pesticide that are material to the exand effects modeling in the deterministic secondary expassessment.
Risks to Wildlife

Question 8 CONT.

a) Please comment on the reasonableness of the follo

aspects of EPA’s secondary exposure deterministic assessment: 

• The use of theoretical body burden calculation together w

empirical whole body residue data to produce a reasonabestimated exposures for secondary exposure pathways; 

• The use of the number of prey items required to reach let

thresholds as a means of comparing the relative risks acrthresholds as

a means of comparing the relative risks acr

assessed rodenticides of acute mortality following consucontaminated prey; 

• The conclusion that the results of 

p g

redator / scaven

ger fe

studies are consistent with the findings of the determinissecondary risk assessment;

• The use of a standardized set of avian toxicity endpoints 

t t d ll th d h i l ) i li ht f i f tes

t

e

d across all the assesse

d c

hemicals

) in li

ght o

f in

for

diphacinone suggesting that raptors may be more sensitsurrogate avian species used in the risk assessment.
Risks to Wildlife

Question 8 CONT.

b) Does the Panel concur with EPA’s analysis and co

that consumption of living or dead rodents poisonebrodifacoum or difethialone presents a greater opp

for adverse effects to non-target wildlife compared rodenticides warfarin, diphacinone, chlorophacinobromethalin? Please provide a basis for your conclusions. Does the Panel concur that cancellatproducts containing brodifacoum and difethialone residential consumers will reduce the opportunity fsecondary exposure for wildlife to rodenticides? Psecondary exposure for wildlife to rodenticides? P

provide a basis for your conclusions.
Risks to Wildlife

Question 9

• Incident data demonstrate that rodenticide u

result in wildlife mortality, and that such wildmortalities occur in urban and suburban aremortalities occur in urban and suburban are

Based on this incident data, EPA has concluthat consumer use of rodenticides in urban 

suburban areas may be a significant contribthe wildlife mortalities attributable to rodentThe EPA also determined that both 

p y rimar

y 

secondary poisonings have been document
Risks to Wildlife

Question 9 CONT.

a

) A t f it l i f i id t EPA l d t

As par

t o

f its analysis o

f inciden

ts, EPA analyze

d t

available incident data in order to associate incidenspecific land use categories, i.e., agricultural, urba

suburban areas In performing this analysis EPA rsuburban areas. In performing this analysis, EPA r

the information in incident reports identifying assohabitat or on the address reported for the incident 

then used remote sensing information to assign a then used remote sensing information to assign

a 

category with the incident. Please comment on the reasonableness of this approach to using location information to support the conclusion that use of t

commensal rodenticides addressed in the draft NOcauses wildlife mortalities in urban and suburban awell as rural areas. 
Risks to Wildlife

Question 9 CONT.

b) EPA analyzed the available incident data in order to 

diff ti t i d d ildlif t ldifferenti

a

te primary an

d secon

dary wildlife mor

t

al

this analysis, EPA relied on information on the dietrequirements of the moribund species and any ide

gut contents when available Does the Panel find tgut contents when available. Does the Panel find t

approach a reasonable way to evaluate the occurreprimary and secondary toxicity as causes of wildlif

mortality? Please provide the basis for your conclmortality? Please provide the basis for your concl
Efficacy of Conforming 

Rodenticide Products

Question 10

• EPA i i t t f l d t t 

EPA requires regis

tran

ts o

f commensal ro

den

t con

t

products to demonstrate that their products meet crfor efficacy. The registrants of conforming rodentic

products have submitted such data to EPA and EPA products have submitted such data to EPA, and EPA 

determined that their products meet these criteria. meeting of these efficacy performance criteria and E

analysis of the effectiveness of conforming rodenticanalysis of the effectiveness of conforming rodentic

products reasonably support conclusions that confrodenticide products provide effective options for ccontrol of commensal rodents b

y p non

professional u

If you conclude that conforming rodenticide producnot provide effective options for chemical control of commensal rodents by nonprofessional users, pleadiscuss to what extent the following requirements aavailability to consumers of effective options for cocommensal rodents:
Efficacy of Conforming 

Rodenticide Products

Question 10 CONT.

• The requirement that rodenticides sold to res

The requirement that rodenticides sold to res

consumers must include tamper-resistant bastations;

• The requirement that rodenticides sold to res

consumers must be in forms (e.g. bait blocksare reasonably expected to remain within the are reasonably expected to remain within the 

station; and 

• The requirement that rodenticides sold to res

consumers not t i th ti i di t t con

t

ain the active ingredien

ts 

brodifacoum, difethialone, bromadiolone, or difenacoum.

Please provide the basis for your conclusions. 
Efficacy of Conforming 

Rodenticide Products

Question 11

• Are conforming rodenticide products conta

the active ingredients warfarin, diphacinonchlorophacinone, or bromethalin, along witchemical rodent control methods available chemical rodent control methods available 

consumers and other options, capable of providing effective control of commensal 

rodents? Please provide the basis for your rodents? Please provide the basis for your

conclusions.