Page
1
of
6
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
August
29,
2005
MEMORANDUM:

SUBJECT:
Dicofol.
Revised,
Refined
Post­
Application
Exposure
Estimates
(
Citrus,
Stonefruit,
Tree­
nut
Crops
Re­
revised)

FROM:
Robert
Travaglini,
Chemist
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

THRU:
Steven
Weiss,
Senior
Scientist
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

TO:
Mika
Hunter,
Chemical
Review
Manager
Reregistration
Branch
3
Special
Review
and
Reregistration
Division
(
7508C)

DP
Barcode:
D
321184
PC
Code:
010501
MRID
44685603;
45290602
This
memorandum
addresses
the
error­
correction
response
dated
August
17,
2005
from
Dow
Agrosciences
pertaining
to
the
HED
document
of
July
29,
2004
(
D
305650)
which
concerned
post­
application
exposures
and
risk
estimates
for
the
insecticide/
miticide
dicofol
on
apples/
pears,
beans,
cotton,
cucurbits,
grapes,
sod/
turf
farms
and
tomatoes/
peppers.
A
memorandum
which
addresses
the
Dow
Agrosciences
comments
is
attached.

This
document
reflects
current
HED
policy.
This
memorandum
addresses
post­
application
exposures
and
risk
estimates
for
the
insecticide/
miticide
dicofol,
in
continuation
of
the
reregistration
(
RED)
process
for
this
pesticide.
Attachments
for
this
document
are
the
appendices
for
the
short
and
intermediate­
term
postapplication
re­
entry
interval
(
REI)
calculations,
which
include
data
inputs
and
tables.

Background
The
registrant
at
the
time
the
RED
process
began
for
dicofol
was
Rohm
&
Haas
Co.
which
had
submitted
several
Dislodgeable
Foliar
Residue
(
DFR)
studies
in
support
of
the
chemical.

In
November,
1999
HED
issued
a
revised
Occupational
Exposure
Assessment
for
the
miticide
dicofol
(
DD260940).
A
short­
term
NOAEL
of
75
mg
and
intermediate­
term
NOAEL
of
3
mg
were
used
as
the
endpoints
in
the
assessment.
Since
these
endpoints
were
taken
from
dermal
studies,
a
dermal
absorption
factor
of
100%
was
utilized.
The
submitted
DFR
studies
were
deemed
in
compliance
with
Agency
guidelines,
scientifically
valid
and
were
utilized
in
assessing
post­
application
exposures.
The
target
MOE
for
dermal
exposures
is
100.

In
the
1999
assessment
and
in
subsequent
reviews
which
followed
a
recurring
problem
involving
intermediate­
term
Re­
entry
Intervals
(
REIs)
presented
itself
(
D260198
&
D271793).
In
the
preceding
dicofol
documents
acceptable
intermediate­
term
MOEs
for
several
crops,
in
particular
citrus
and
peaches,
were
not
achieved
for
as
many
as
104
and
100
days
respectively
for
high
exposure
type
activities
such
as
harvesting
and
pruning
the
crops.

In
the
intervening
time
since
these
aforementioned
documents
were
published,
the
Agency
and
The
Agricultural
Re­
entry
Task
Force
(
ARTF)
have
developed
some
new
transfer
coefficients
(
Tc)
for
use
in
estimating
post­
application
exposures.

A
July
16,
2004
memorandum
concerning
dicofol
crop
usage
by
the
Biological
and
Economic
Analysis
Division
(
BEAD)
identified
nine
(
9)
crops
which
constitute
5%
or
greater
of
the
total
percentage
of
those
treated
crops.
These
crops
were
identified
as
grapefruit,
oranges,
tangelos,
and
tangerines
(
citrus
crops);
apricots,
nectarines
and
peaches
(
stone
fruit
crops),
as
well
as
pecans
(
tree
nut
crop).
In
conjunction
with
the
July
16,
2004
BEAD
memo,
SRRD
requested
for
HED
to
estimate
post­
application
occupational
exposures
only
pertinent
to
the
identified
crops
using
application
rates
of
3.0
lbs.
ai/
acre
and
1.5
lbs.
ai/
acre
applied
twice
at
seven
day
intervals.

HED
re­
evaluated
the
submitted
DFR
studies,"
Dissipation
of
Dislodgeable
Foliar
Residues
of
Dicofol
Applied
to
Peaches
in
California"
(
MRID
45290602)
and
"
Dissipation
of
Dislodgeable
Foliar
Residues
of
Dicofol
Applied
to
Citrus"
(
MRID
44685603).
For
the
citrus
study,
the
registrant
conducted
DFR
studies
on
grapefruit
in
Florida
as
well
as
oranges
on
California.
These
studies
were
again
determined
to
be
acceptable
and
would
be
the
best
available
data
to
use
in
estimating
the
REIs
and
fulfilling
SRRD's
request.
Page
3
of
6
The
REI
estimates
in
this
document
then
are
based
on
the
submitted
chemical
specific
DFR
data
and
updated
transfer
coefficients
using
the
HED
developed
REI
software
calculator.
The
REI
Calculator's
calculations
are
based
on
the
semi­
log
regression
of
the
actual
submitted
DFR
data.

Post­
Application
Exposure
&
Risk
Estimates
Summary
results
of
the
short
and
intermediate­
term
post­
application
exposure
and
REI
estimates
are
presented
in
Tables
1
&
2.
The
REI
Calculator
supporting
documents
are
included
as
Appendices
A
&
B.
(
Note
that
the
REI
Calculator
arranges
the
selected
crops
into
crop
groupings
analysis.)

For
short­
term
exposures,
all
post­
application
activities
MOEs
of
100
are
reached
within
zero
days
at
the
application
rate
of
1.5
lbs.
ai/
acre.
For
the
3.0
lbs.
ai/
acre
rate,
target
MOEs
for
medium
exposure
activities
are
achieved
within
3
days
and
within
fifteen
days
for
higher
activities.

For
intermediate­
term
exposures,
at
the
lower
application
rate
(
1.5
lbs.
ai/
acre
2x):

Target
MOEs
for
low
exposure
post­
application
activities
range
from
13
(
pecans)
to
39
(
citrus)
days
after
treatment
(
DAT).

Target
MOEs
for
medium
exposure
post­
application
activities
are
achieved
at
46
(
citrus)
DAT.

Target
MOES
for
high
and
very
high
exposure
post­
application
activities
range
from
33
(
stone
fruit)
to
58
(
citrus)
DAT.

For
intermediate­
term
exposures,
at
the
higher
application
rate
(
3.0
lbs.
ai/
acre):

Target
MOEs
for
low
exposure
post­
application
activities
range
from
26
(
pecans)
to
62
(
citrus)
DAT.

Target
MOEs
for
medium
exposure
post­
application
activities
are
achieved
at
71
(
citrus)
DAT.

Target
MOES
for
high
and
very
high
exposure
post­
application
activities
range
from
47
(
stone
fruit)
to
87
(
citrus)
DAT.
Page
4
of
6
Table
1.
Summary
of
'
Days
After
Treatment'
to
Reach
the
Target
MOE
for
Short­
term
Exposure
Crop
Grouping
(
1)
Dicofol
Specific
Crops
(
2)
Max
Foliar
Rate
(
lb
ai/
acre)
(
2)
Days
After
Treatment
Target
MOE
Achieved
(
Target
MOE
=
100)

Exposure
Activity
Levels
(
3,4)

Very
Low
Low
Medium
High
Very
High
Trees,
fruit,
deciduous
Apricots,
Peaches
1.5
­
3
0
0
N/
A
0
0
Trees,
fruit,
evergreen
Citrus,
Grapefruit,

Oranges
1.5
­
3
0
0
0
­
3
0
­
15
N/
A
Trees,
nut
Pecans
1.5
­
3
N/
A
0
N/
A
0
N/
A
Footnote:

1.
Crop
groupings
and
transfer
coefficients
from
Science
Advisory
Council
for
Exposure:
Policy
Memo
#
003.1
'
Agricultural
Transfer
Coefficients',
August
17,
2000.

2.
Maximum
label
rates
from
end
use
product
labels.

3.
DAT
=
Days
after
treatment;
DAT0
=
On
the
day
of
treatment,
after
sprays
have
dried;
assumed
approximately
12
hours.

4.
MOE
=
Dermal
toxicity
endpoint
(
mg/
kg­
day)/
absorbed
dermal
dose
(
mg/
kg­
d)
where
the
absorbed
dose
=
DFR
(
ug/
cm2)
x
TC
(
cm2/
hr)
x
conversion
factor
(
1
mg/
1,000
ug)
x
exposure
time
(
hrs)
x
dermal
absorption
/
body
weight
(
kg).
Page
5
of
6
Table
2.
Summary
of
'
Days
After
Treatment'
to
Reach
the
Target
MOE
for
Intermediate­
term
Exposure
Crop
Grouping
(
1)
Dicofol
Specific
Crops
(
2)
Max
Foliar
Rate
(
lb
ai/
acre)
Days
After
Treatment
Target
MOE
Achieved
(
Target
MOE
=
100)

Exposure
Activity
Levels
(
3,4)

Very
Low
Low
Medium
High
Very
High
Trees,
fruit,
deciduous
Apricots,
Peaches
1.5
­
3
0
26
­
39
N/
A
33
­
47
47
­
60
Trees,
fruit,
evergreen
Citrus,
Grapefruit,

Oranges
1.5
­
3
0
­
12
39
­
62
46
­
71
58
­
87
N/
A
Trees,
nut
Pecans
1.5
­
3
N/
A
13
­
26
N/
A
43
­
56
N/
A
Footnote:

1.
Crop
groupings
and
transfer
coefficients
from
Science
Advisory
Council
for
Exposure:
Policy
Memo
#
003.1
'
Agricultural
Transfer
Coefficients',
August
17,
2000.

2.
Maximum
label
rates
from
end
use
product
labels.

3.
DAT
=
Days
after
treatment;
DAT0
=
On
the
day
of
treatment,
after
sprays
have
dried;
assumed
approximately
12
hours.

4.
MOE
=
Dermal
toxicity
endpoint
(
mg/
kg­
day)/
absorbed
dermal
dose
(
mg/
kg­
d)
where
the
absorbed
dose
=
DFR
(
ug/
cm2)
x
TC
(
cm2/
hr)
x
conversion
factor
(
1
mg/
1,000
ug)
x
exposure
time
(
hrs)
x
dermal
absorption
/
body
weight
(
kg).
Page
6
of
6
