Document ID: EPA-HQ-OPP-2002-0250-0010
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2002-09-24T04:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
May
8,
2002
MEMORANDUM
SUBJECT:
HED
Response
to
Registrants
30
Day
Error
Only
Comments
Concerning
the
Preliminary
Residential
Risk
and
Exposure
Assessment
for
Fenarimol,
as
Part
of
the
Human
Health
Assessment
for
the
Tolerance
Reassessment
Eligibility
Decision
(
TRED)
Document.
Chemical
No.
206600.
No
MRID
#.
DP
Barcode
No.
D282386.

FROM:
Barry
O'Keefe,
Residential
Exposure
Assessor
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

THRU:
Catherine
Eiden,
Branch
Senior
Scientist
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

TO:
Tom
Myers,
Chemical
Review
Manager
Special
Review
and
Reregistration
Division
(
7508C)

This
review
is
in
response
to
Gowan
Company's
comments
and
questions
concerning
the
residential
risk
and
exposure
assessment
portion
of
the
Health
Effects
Division's
(
HED's)
Tolerance
Reassessment
Eligibility
Decision
(
TRED)
document
for
fenarimol.
Gowan
Company
made
several
comments
and
asked
several
questions
concerning
this
assessment.
Gowan
Company's
comments
and
questions,
and
the
HED's
responses
are
as
follows:

Comment/
Question
#
1:
Gowan
Company
agreed
with
the
Agency
that
the
two
methods
of
applying
the
Riverdale
Chemical
Company's
granular
product
(
EPA
Reg.
No.
228­
298)
should
be
prohibited
on
the
label;
i.
e.
the
bellygrinder
for
broadcast
application
or
hand
application
for
spot
treatments.
Gowan
commented
that
the
possibility
of
either
a
homeowner
or
professional
applicator
choosing
either
one
of
these
application
methods
is
remote
given
the
fact
that
up
to
350
lb
of
product
per
acre
can
be
applied.

HED
Response:
The
HED
is
required
to
assess
these
two
application
method
scenarios,
since
the
label
does
not
prohibit
handlers
from
applying
this
granular
product
using
these
application
methods.
The
HED
does
not
consider
the
application
of
350
lb
of
product
per
acre
to
be
a
remote
possibility.
However,
the
preliminary
risk
assessment
was
based
upon
0.5
acres
treated
for
the
bellygrinder
scenario,
and
0.023
(
1000
ft2)
acres
treated
for
the
hand
application
spot
treatment
scenario.
HED
recommends
prohibition
of
these
two
types
of
application
for
granular
products;
i.
e.
broadcast
by
2
belly
grinder,
and
spot
treatment
by
hand.

Comment/
Question
#
2:
Gowan
agreed
with
the
Agency's
recommendation
that
prompt
watering
in
should
be
required
for
the
granular
product
used
on
residential
turf.

HED
Response:
HED
actually
recommended
that
label
language
should
be
strengthened
to
ensure
that
watering­
in
occurs
immediately
after
application
for
all
end
use
products
used
on
turf.
This
recommendation
was
not
exclusive
only
to
the
granular
product,
nor
was
it
exclusive
only
to
residential
turf.
HED
recommends
that
all
end
use
products
be
watered­
in
immediately
after
application
on
turf,
lawns
and
playing
fields.
However,
watering­
in
immediately
after
application
cannot
be
mandated
on
the
labels,
because
there
is
no
way
to
ensure
that
applicators
will
adhere
to
this
direction.
Also,
watering­
in
would
probably
be
a
lot
more
difficult
to
do
on
playing
fields,
than
on
home
lawns.

Comment/
Question
#
3:
Gowan
stated
that
the
Agency's
exposure
calculations
compounded
a
number
of
conservative
default
assumptions,
as
follows:

Comment/
Question
#
3a:
Gowan
stated
that
the
Agency
used
a
5%
transfer
coefficient
from
turf
that
is
two
orders
of
magnitude
higher
than
the
transfer
coefficients
observed
with
other
liquid
products
on
turf.

HED
Response:
As
stated
in
the
preliminary
risk
assessment,
HED
used
the
Agency's
SOP
default
transfer
efficiency
rate
(
percent
of
application
rate)
of
5%;
i.
e.
5%
of
application
rate
available
for
transfer
from
treated
turf
to
wet
hands.
HED
will
continue
to
use
this
5%
transfer
efficiency
rate
until
data
indicate
that
a
different
rate
should
be
used.
Data
from
the
registrant
submitted
turf
transfer
residue
(
TTR)
study
showed
that
6.1%,
0.85%
and
0.59%
(
for
CA,
IN
and
MS,
respectively)
of
the
applied
fenarimol
was
detected
on
turf
immediately
after
application.
This
study
itself
was
of
poor
quality,
and
therefore
the
data
were
not
used
to
generate
risk
estimates
because
the
data
were
too
variable,
and
because
no
relevant
transfer
coefficient
exists
for
the
California
roller
method
that
was
used
in
this
study.

There
is
interdependence
of
the
transferable
residue
value
and
the
human
activity
expressed
in
the
transfer
coefficient
(
TC).
The
TC
for
short­
term
exposures
is
based
on
a
study
by
Formoli
(
1996)
evaluated
by
the
California
Department
of
Pesticide
Regulation
(
CDPR),
in
which
propetamaphos
was
applied
to
carpets.
The
transferable
residues
in
that
study
were
approximately
1%
of
the
application
rate.
The
TTR
method
used
to
measure
concurrent
transferable
residues
was
the
California
roller
(
also
referred
to
as
the
cloth
roller
and
CDFA
roller).
Other
proprietary
studies
using
this
method
suggest
1.6­
3%
transferability.
The
California
EPA,
in
a
letter
to
the
USEPA
during
the
time
the
SOPs
were
taken
to
the
USEPA
Science
Advisory
Panel
(
SAP)
also
affirm
that
the
transferability
of
this
method
is
less
than
5%.

TTR
data
generated
by
members
of
the
Outdoor
Residential
Entry
Task
Force
(
ORETF)
rely
on
a
modified
version
of
the
California
roller
(
ORETF
roller)
that
appears
to
have
a
much
lower
transfer
efficiency
(
percent
of
application
rate)
than
the
original
version.
Many
TTR
data
submitted
by
ORETF
members
show
transfer
efficiencies
of
<
1%
for
sprayable
3
formulations
and
<
0.5%
for
granular
formulations.
The
USEPA
Office
of
Research
and
Development
(
ORD)
has
conducted
a
round
robin
test
of
TTR
methods
that
included
the
ORETF
roller
(
Fortune
1997).
While
ORD
concluded
that
the
ORETF
roller
method
performed
the
best
of
all
methods,
transfer
efficiency
for
three
liquid
herbicide
formulations
indicated
a
transfer
efficiency
of
approximately
0.5%.
The
ORETF
data
should
not
be
used
with
the
revised
transfer
coefficients
of
approximately
1
to
5%.
The
ORETF
is
generating
task
force
specific
transfer
coefficients
to
be
used
with
the
ORETF
member
TTR
data.
ORETF
post
application
exposure
data
has
been
submitted
and
is
being
reviewed.

Comment/
Question
#
3b:
Gowan
believes
that
the
assumed
20%
dermal
absorption
number
used
by
HED
should
be
reduced
by
an
order
of
magnitude.
Gowan
submitted
rationale
and
numerous
literature
to
support
their
rationale.

HED
Response:
HED
toxicologists
will
address
these
comments
and
questions.
Please
refer
to
that
formal
response
for
further
details.

Comment
#
3c:
Gowan
commented
that
they
had
"
observed
in
two
other
studies
that
presumably
persistent
compounds
are
rapidly
removed
from
home
lawns
for
the
simple
reason
that
grass
is
mowed."

HED
Response:
HED
suggests
that
Gowan
Company
submit
copies
of
these
studies
to
the
Agency.

Comment
#
3d:
Gowan
commented
that
the
safety
factors
(
target
MOEs
of
1000
for
intermediate­
term
exposure
and
3000
for
short­
term
exposure)
are
very
conservative.

HED
Response:
HED
toxicologists
will
address
this
comment.
Please
refer
to
that
formal
response
for
further
details.
4
Internal
Points
for
SRRD
(
i.
e.
not
meant
to
be
part
of
the
formal
response
to
comments)

1.
Watering­
In
Is
it
practical
and/
or
enforceable
to
require
registrants
to
add
a
requirement
or
recommendation
to
their
end
use
labels
to
water­
in
the
product
immediately
after
it
is
applied
to
turf,
lawns
or
playing
fields?
In
the
real
world,
does
this
truly
mean
anything?
What
percentage
of
applicators
will
actually
adhere
to
this
requirement
or
recommendation?

Fenarimol
is
a
systemic
fungicide.
Therefore,
in
order
to
be
efficacious,
it
must
enter
the
root
zone
so
that
it
can
be
taken
up
by
the
grass.
The
current
labels
advise
users
to
irrigate
if
precipitation
does
not
occur
within
24
hours.

Whether
by
precipitation
and/
or
irrigation
the
watering­
in
of
fenarimol
product
will
undoubtedly
remove
fenarimol
residues
from
the
surface
of
grass
blades,
and
therefore
reduce
the
amount
of
fenarimol
residues
transferable
to
individuals
contacting
treated
grass.
The
question
is,
by
how
much
is
the
potentially
transferrable
residue
reduced
by
watering­
in?
Based
upon
data
from
other
pesticides
applied
to
turf,
watering­
in
may
provide
an
average
reduction
in
residues
of
2
to
5
fold
for
granular
formulations.
Watering­
in
liquid
formulations
after
application
to
turf
result
in
greater
reductions
in
dislodgeable
residues,
e.
g.
residues
of
the
herbicide
diazinon
were
reduced
by
80
fold.
For
the
liquid
herbicide
pronamide,
watering­
in
resulted
in
a
13
fold
reduction
in
residues.
For
the
nematicide
fenamiphos
(
emulsifiable
concentrate),
watering­
in
resulted
in
a
30
fold
reduction
in
residues.
Unfortunately,
OPP/
ORE
scientists
cannot
provide
SRRD
with
a
quantitative
reduction
factor
or
range.
However,
common
sense
dictates
that
a
sizable
reduction
in
residues
and
associated
risk
will
occur
with
watering­
in.
Therefore,
SRRD
can
use
this
knowledge
to
discuss
why
mitigation
is
not
being
required
while
MOEs
of
concern
remain
(
i.
e.
MOEs
somewhat
below
our
targets).

2.
Episodic
Ingestion
of
Fenarimol
Granules
by
Toddlers
In
the
preliminary
residential
risk
assessment,
a
short­
term
MOE
of
220
was
estimated
for
episodic
ingestion
of
fenarimol
product
granules.
This
is
well
below
the
target
MOE
of
3000.
However,
based
upon
the
particle
sizes
of
these
granules,
HED
characterized
this
potential
risk
to
be
less
likely
or
difficult
to
occur,
and
therefore,
not
of
great
concern.
Is
this
a
valid
characterization?
The
characterization
in
the
preliminary
residential
risk
assessment
is
as
follows:

"
Information
was
received
from
Riverdale
Chemical
Company
regarding
the
size
and
distribution
of
the
granular
formulation
they
manufacture.
This
information
is
helpful
in
refining
or
characterizing
the
estimate
of
potential
risk
from
episodic
incidental
ingestion
of
granules
beyond
the
current
screening
level.
For
example,
the
granules
would
be
considered
more
attractive
and
more
likely
to
be
consumed
if
readily
visible
and
easily
picked
up
by
a
child.
The
Riverdale
Chemical
Company
product
information,
provided
to
HED
by
telephone
conversation
on
July
18,
2001,
indicates
that
93%
of
the
product
has
a
particle
diameter
range
of
0.594
to
0.841
mm,
with
the
remaining
7%
in
the
0.841
to
2
mm
size.
The
granules
are
white
in
color.
If
evenly
distributed,
individual
grains
would
be
difficult
to
pick
up,
or
even
to
see
when
applied
on
a
lawn,
and
if
used
according
to
label
directions
and
soil
5
incorporated
by
watering
in.
Therefore,
given
proper
application
this
product
would
be
difficult
for
a
small
child
to
grasp
and
then
mouth
or
ingest."

Additionally,
if
hand
dispersal
application
is
prohibited,
then
unevenly
distributed
granules
will
be
much
less
likely.
Also,
watering­
in,
whether
recommended
or
required
will
reduce
the
chances
of
toddlers
grasping
granules.