Document ID: EPA-HQ-OPP-2002-0049-0016
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2002-12-24T05:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
December17,
2002
MEMORANDUM
SUBJECT:
EFED
response
to
HACCO's
errors­
only
comments
on
the
Agency
document
"
Comparative
Risks
of
Nine
Rodenticides
to
Birds
and
Nontarget
Mammals"

TO:
John
Pates,
Chemical
Review
Manager
Susan
Lewis,
Branch
Chief
FROM:
William
Erickson,
Biologist
Douglas
Urban,
Senior
Biologist
Environmental
Risk
Branch
III,
Environmental
Fate
and
Effects
Division
THRU:
Stephanie
Irene,
Acting
Chief
Environmental
Risk
Branch
III,
Environmental
Fate
and
Effects
Division
The
Environmental
Fate
and
Effects
Division
(
EFED)
has
reviewed
HACCO's
"
errors­
only"
response
to
the
Agency
document
"
Comparative
Risks
of
Nine
Rodenticides
to
Birds
and
Nontarget
Mammals"
dated
October
3,
2001.
HACCO's
comments
of
December
6,
2001
were
prepared
by
J.
A.
Thompson,
Registration
Manager,
Rodenticides.
As
stated
in
the
Agency's
October
23,
2001
cover
letter
for
the
assessment,
the
registrants'
30­
day
response
should
address
only
mathematical,
computational,
typographic,
or
other
similar
errors.
Matters
of
policy,
interpretation,
or
applicability
of
data
will
be
addressed
after
the
public
comment
period
in
accordance
with
the
Agency's
reregistration
process
for
pesticides.

In
response
to
error
comments
by
HACCO,
other
rodenticide
registrants,
and
the
Rodenticide
Registrants
Task
Force,
EFED
has
made
necessary
computational
and/
or
typographical
corrections.
However,
EFED
notes
that
many
comments
relate
to
policy,
interpretation,
or
applicability
of
data,
and
those
comments
will
be
addressed
along
with
public
comments
after
the
60­
day
public­
comment
period.
2
Re:
Preliminary
Comparative
Ecological
Risk
Assessment
for
Rodenticides
Dear
Mr.
Pates:

I
am
writing
to
address
several
very
serious
concerns
that
HACCO,
Inc
has
with
EPA*
s
"
Preliminary
Comparative
Ecological
Risk
Assessment
for
Nine
Rodenticides"
(
PRA)
dated
October
3,
2001.
The
compounds
included
in
the
assessment
are:
brodifacoum,
difethethialone,
bromadiolone,
diphacinone,
chlorophacinone,
warfarin,
zinc
phosphide,
bromethalin
and
cholecalciferol.
HACCO,
Inc.
holds
active
registrations
for
the
following
rodenticide
active
ingredients
included
in
this
Assessment:
Diphacinone,
Brodifacoum,
Warfarin
and
Zinc
Phosphide.

We,
HACCO,
Inc,.
are
members
of
the
Rodenticide
Registrants
Task
Force
(
RRTF)
and
of
the
Zinc
Phosphide
Consortium
along
with
many
other
rodenticide
registrants.
We
have
been
active
in
presenting
the
Agency
with
added
information
in
regards
to
rodenticide
benefits,
usage,
toxicity,
and
relative
safety.
However,
the
present
version
of
the
PRA
contains
significant
errors
and
does
not
incorporate
many
of
the
RRTF*
s
comments
submitted
in
response
to
EPA*
s
October
19,
1999,
meeting
regarding
risks
to
birds
and
non­
target
mammals.
HACCO
strongly
urges
that
the
Agency
does
not
release
this
PRA
to
the
public.
This
PRA
needs
to
be
revised
substantially
before
it
can
be
released
to
the
public.

HAZARD
COMPARISON
VERSUS
RISK
ASSESSMENT
In
reading
this
document,
the
overall
concern
is
that
this
PRA
is
a
hazard
comparison
and
not
a
risk
assessment.
EPA
does
not
address
and
characterize
exposure.
EPA
does
not
address
the
facts
that
these
active
ingredients
are
used
differently
and
that
formulations
of
these
compounds
may
vary
the
characterization
of
exposure.
Certain
formulations
and
bait
forms
may
reduce
exposure
under
certain
use
patterns.
The
Agency
assumes
that
all
exposures
are
equal
in
its
equations
to
evaluate
risk.
In
examining
field
uses,
however,
the
Agency
in
the
PRA
gives
an
example
of
how
a
bait
form
could
vary
a
"
risk"
through
limiting
"
exposure"
when
it
addresses
the
desirability
of
broadcasting
a
6
gram
pellet
to
protect
birds
from
primary
exposure.
As
another
example
of
how
formulation
and
form
will
affect
exposure,
a
broadcast
use
of
grain
bait
might
be
preferred
where
the
concern
is
primary
exposure
of
non
target
canines.
The
Agency
gave
the
first
example
listed
above,
but
the
Agency
does
not
characterize
exposure
components
in
its
equations
to
evaluate
risk.
The
Agency
needs
to
address
exposure
to
do
a
"
risk"
assessment.
The
Agency
needs
to
broaden
the
way
it
looks
at
rodenticides
to
include
use
patterns
in
the
United
States,
sales
volume,
formulations
and
bait
forms,
identification
and
behavior
of
non
targets
within
the
vicinity
of
an
application,
so
that
an
examination
of
the
actual
exposure
of
non
targets
can
be
made.
Risk
should
not
be
estimated
without
an
adequate
characterization
of
exposure.

EFED
response:
This
has
been
addressed
in
the
revised
document.
It
is
well
known
that
rodenticide
baits
are
formulated
to
be
lethal
to
rodents
and
a
few
other
small
mammals,
and
they
are
not
selective
to
the
target
species.
Although
many
factors
influence
which
nontarget
animals
might
be
exposed
to
baits,
many
nontarget
organisms
are
attracted
to
1
See
December
8­
9,
1998
http://
www.
epa.
gov/
scipoly/
sap/
1998/
index.
htm
2
See
Guidelines
for
Ecological
Risk
Assessment
(
EPA/
630/
R­
95/
002F,
1998)
at
http://
cfpub.
epa.
gov/
ncea/
cfm/
recordisplay.
cfm?
deid=
12460
3
and
consume
grain­
based
baits.
Predators
and
scavengers
also
feed
on
rats
and
mice
or
other
target
species,
and
they
are
not
likely
to
avoid
feeding
on
those
that
have
eaten
rodenticide
bait.
Thus,
rodenticide
baits
also
pose
potential
secondary
risks.
EFED
believes
that
the
potential
for
risks
to
birds
and
nontarget
mammals
is
well
established
for
some
of
these
rodenticides.

The
risk
assessment
is
based
on
the
available
data.
Registrants
have
not
submitted
the
data
that
would
be
needed
to
assess
the
probability
of
exposure.
These
data
have
been
outlined
in
a
section
on
Uncertainty
and
Data
Needs
in
the
revised
assessment.
The
methodology
used
is
similar
to
that
used
in
the
Agency's
"
Comparative
Analysis
of
Acute
Risk
From
Granular
Pesticides"
(
EPA
1992)
and
"
A
Comparative
Analysis
of
Ecological
Risks
from
Pesticides
and
Their
Use:
Background,
Methodology,
Case
Study"
(
EPA
1998)
1;
both
were
reviewed
by
a
FIFRA
Scientific
Review
Panel.
Concerning
the
latter
analysis,
the
Panel
noted
the
many
scientific
uncertainties
in
the
method,
yet
agreed
that
it
was
a
useful
screening
tool
that
provides
a
rough
estimate
of
relative
risk.
The
Panel
made
a
number
of
helpful
suggestions
to
improve
the
utility
of
the
method,
most
of
which
are
included
here.

Risk
conclusions
are
presented
in
tabular
and
graphical
form
based
on
two
analyses
of
the
available
data.
The
first
is
a
comparative
ranking
of
the
potential
risk
based
on
a
comparative­
analysis
model,
and
the
second
is
a
tabular
comparative
rating
of
potential
risk
based
on
a
qualitative
"
weight­
of­
evidence"
assessment.
Quantitative
estimates
of
risk
are
used
in
both;
however,
the
"
weight­
of
evidence"
assessment
includes
qualitative
assessments
of
secondary
risk
based
on
mortality
and
other
adverse
effects
reported
in
laboratory
and
field
studies,
operational
control
programs,
and
incident
reports,
as
well
as
toxicokinetic
data
and
residue
levels
reported
in
primary
consumers.
This
approach
is
in
concert
with
EPA's
risk­
assessment
guidelines2,
where
professional
judgement
or
other
qualitative
evaluation
techniques
may
be
used
to
rank
risks
using
categories
such
as
low,
medium,
and
high
when
exposure
and
effects
data
are
limited
or
are
not
easily
expressed
in
quantitative
terms.

COST/
BENEFITS
OF
USING
RODENTICIDES
Since
FIFRA
is
a
cost/
benefit
statute,
EPA
should
address
the
benefits
of
using
rodenticides
in
this
document.
EPA
summarized
in
its
Rodenticide
Cluster
RED
of
July,
1998,
the
benefits
of
rodenticides
specifically
to
include
1)
health
benefits
­
prevention
of
disease
transmission,
2)
4
prevention
of
property
damage
and
3)
prevention
of
rodent
attacks
on
humans.
I
would
like
to
add
the
benefit
of
rodenticides
in
restoring
threatened
and
endangered
species
to
island
ecological
systems.

In
regards
to
item
1),
the
CDC
presented
a
report
at
the
Rodenticide
Stakeholder*
s
working
group,
June,
1999,
that
rodents
directly
cause
hantavirus
pulmonary
syndrome,
leptospirosis,
ratbite
fever,
salmonellosis,
yersinia
pseudotuberculosis,
lymphocytic
choriomeningitis,
trichinosis
and
toxoplasmosis.
Rodents
indirectly
(
through
harboring
hosts
such
as
fleas
and
mites)
cause
plague,
rickettsialpox,
Colorado
tick
fever,
Rocky
Mountain
spotted
fever,
Lyme*
s
disease,
relapsing
fever,
babesiosis,
western
equine
encephalitis,
California
encephalitis,
murine
typhus,
human
granulocytic
ehrlichiosis
and
cutaneous
leishmaniasis.

Concerning
item
2)
rodents
are
estimated
to
consume
or
contaminate
with
urine
or
droppings
$
1
billion
of
food
in
the
U.
S.
annually.
As
noted
in
the
above
mentioned
RED,
rodents
damage
structures
by
gnawing
on
integral
parts
and
contaminating
them
with
bodily
excretions.
Rodents
are
also
believed
to
account
for
50%
of
fires
of
unknown
origin
by
gnawing
on
electrical
wiring.
This
was
discussed
by
Dr.
Robert
Corrigan
at
a
meeting
of
the
above
mentioned
Rodenticide
Stakeholder*
s
Working
Group
In
regards
to
item
3)
per
the
above
mentioned
RED,
the
number
of
cases
of
rats
biting
humans
is
estimated
to
be
14,000
per
year.
The
CDC
collected
data
showed
that
between
1986
and
1994,
809
non­
work
related
rat
bites
were
reported
to
the
New
York
City
Department
of
Health.
Two
percent
of
rat
bites
require
hospitalization
and
95%
require
treatment.

Finally,
I
would
like
to
mention
that
Rodenticides
are
used
in
the
restoration
of
natural
ecosystems.
Uninhabited
islands
in
the
United
States
have
used
brodifacoum
to
control
rats.
Hawaii
is
currently
using
diphacinone
in
its
ecosystem
restoration
program.
Non
indigenous
rodents
(
often
rats)
threaten
indigenous
birds
and
plants.
Rodenticides
have
been
used
and
plans
are
being
made
to
use
them
in
the
future
to
protect
threatened
indigenous
birds
and
plants.

EFED
response:
The
Agency
will
be
considering
benefits
later
in
the
reregistration
process,
and
the
document
has
been
modified
to
clarify
that
this
is
EFED's
assessment
of
potential
risks.

OTHER
ERROR
CORRECTIONS
In
conclusion,
I
would
like
to
add
that
HACCO
has
given
its
page
by
page
review
to
the
RRTF
for
inclusion
with
the
RRTF*
s
comments
and
believes
that
itemization
in
this
correspondence
would
be
unnecessary
repetition.
However,
we
do
want
to
emphasize,
once
again,
that
diphacinone*
s
acute
oral
toxicity
for
rats
should
be
listed
as
7.0
mg/
Kg.
This
is
the
number
that
should
be
used
in
EPA*
s
equations
for
ecological
effects.
It
shows
a
bias
on
the
Agency*
s
part
to
continue
to
list
and
to
always
use
in
its
equations
the
rat
acute
oral
LD50
of
2.5
and
2.1
mg/
Kg,
the
results
of
an
unacceptable
study.
The
Agency
notified
the
registrants
that
this
study
was
unacceptable.
Our
letter
from
EPA
on
the
unacceptability
of
this
study
is
dated
February
6,
1992.
5
In
the
letter,
it
was
stated
that
if
the
Agency*
s
question
could
not
be
answered,
the
Agency
required
that
a
replacement
study
be
done.
The
accepted
replacement
study
found
the
combined
acute
oral
LD50
in
rats
to
be
7.0
mg/
Kg.

EFED
response:
HACCO
provides
no
supporting
documentation
that
this
study
is
"
unacceptable".
The
study
is
categorized
as
"
supplementary"
in
the
EPA/
OPP
Health
Effects
Division's
toxicity
database;
data
from
supplementary
studies
are
used
in
OPP
risk
assessments.

IN
SUMMARY
We
urge
EPA
not
to
issue
publicly
this
erroneous
and
incomplete
document
as
EPA*
s
current
statement
of
its
Ecological
Risk
Assessment
of
Rodenticides,
but
rather
to
review
our
comments
and
the
comments
soon
to
be
submitted
by
the
RRTF
and
to
make
revisions
accordingly.