UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
December
9,
2004
MEMORANDUM:

SUBJECT:
Dicofol.
Crop­
Specific
Refined
Post­
Application
Exposure
Estimates:
Pecans
FROM:
Robert
Travaglini,
Chemist
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

THRU:
Danette
Drew,
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
305651
PC
Code:
010501
MRID
45290602
&
41884604
Background
In
response
to
HED's
previous
memorandum
concerning
intermediate­
term
postapplication
exposure
to
the
insecticide/
miticide
dicofol,
dated
July
29,
2004
(
D
305650),
the
Special
Review
and
Reregistration
Division
in
conjunction
with
the
Biological
and
Economic
Analysis
Division
(
BEAD)
requested
that
HED
re­
examine
the
scenarios
used
in
the
assessment
and
in
particular,
activities
involving
pecan
harvesting.
In
the
previous
assessment
for
pecans,
HED
examined
scenario
activities
such
as
irrigation
and
hand­
harvesting
which
had
exposure
potentials
ranging
from
low
to
very
high
using
correlating
transfer
coefficients
of
500
and
2500
cm2
/
hr.
respectively.
HED
evaluated
potential
post­
application
exposures
for
the
targeted
crops
using
the
dislodgeable
foliar
residue
(
DFR)
studies
(
peaches
and
oranges)
submitted
by
the
registrant
and
transfer
coefficients
from
the
Science
Advisory
Council
for
Exposure
Policy#
003.1
to
translate
the
residue
data
to
the
post­
application
activities.

For
the
revised
crop­
specific
assessment
on
pecans
contained
herein,
HED
utilized
a
worker
exposure
study
of
the
insecticide/
aracicide
propargite
on
almonds
(
MRID
41884604).
In
this
study
dermal
exposure
was
monitored
for
tree
shaking
activities,
considered
a
very
low
potential
exposure
activity,
using
a
transfer
coefficient
of
48
cm2
/
hr.
Adding
the
tree
shaker
activity
scenario
and
attendant
transfer
coefficient,
HED
re­
evaluated
post­
application
exposures
based
on
the
aforementioned
dicofol
DFR
study
on
peaches
(
MRID
45290602)
and
employing
the
BEAD
requested
application
of
rate
of
2.0
lbs
ai/
acre
for
pecans.

Revised
Post­
Application
Intermediate­
Term
Exposure
&
Risk
Estimates
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.

For
intermediate­
term
exposures,
at
the
application
rate
of
2.0
lbs.
ai/
acre
on
pecans,
the
estimated
Margins
of
Exposure
(
MOEs)
[
MOE
=
NOAEL/
Dose]:

­
are
greater
than
400
and
exceed
the
target
MOE
(
100)
for
very
low
exposure
postapplication
activities
,
i.
e.
tree
shakers,
on
the
day
of
application
(
0
DAT);

­
achieve
the
target
MOE
for
medium
exposure
post­
application
activities
at
18
DAT.

­
reach
target
MOES
for
high
exposure
post­
application
activities
at
49
DAT.

Summary
results
of
the
days
after
treatment
to
reach
the
target
MOE
(
100)
for
intermediate­
term
post­
application
exposure
and
REI
estimates
are
presented
in
Table
1.
Table
2
lists
the
exposures
and
MOEs
up
the
target
MOE
for
all
activities.
The
REI
Calculator
supporting
documents
are
included
as
Appendices
1
&
2.

2
3
Table
1.
Summary
of
'
Days
After
Treatment'
to
Reach
the
Target
MOE
for
Intermediate­
term
Exposure
Crop
Grouping
(
1)
DICOFOL(
P.
B)

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,
nut
Pecans
2
0
18
N/
A
49
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).
4
Table
2.
Residues,
Dose
&
MOEs
for
Post­
Application
Activities
on
Dicofol
Treated
Pecans
DAT
(
3)
DFR
LEVELS
(
ug/
cm2)
DOSE
(
mg/
kg/
day)
(
4)
MOEs
(
5)

Not
Adjusted
Adjusted
for
Rate
Very
Low
Low
Medium
High
Very
High
Very
Low
Low
Medium
High
Very
High
0
1.000
1.333
0.0073
0.076
N/
A
0.38
N/
A
410
39
N/
A
7.9
N/
A
1
0.948
1.265
0.0069
0.072
N/
A
0.36
N/
A
430
42
N/
A
8.3
N/
A
2
0.900
1.199
0.0066
0.069
N/
A
0.34
N/
A
460
44
N/
A
8.8
N/
A
3
0.853
1.138
0.0062
0.065
N/
A
0.33
N/
A
480
46
N/
A
9.2
N/
A
4
0.809
1.079
0.0059
0.062
N/
A
0.31
N/
A
510
49
N/
A
9.7
N/
A
5
0.768
1.023
0.0056
0.058
N/
A
0.29
N/
A
530
51
N/
A
10
N/
A
6
0.728
0.971
0.0053
0.055
N/
A
0.28
N/
A
560
54
N/
A
11
N/
A
7
0.691
0.921
0.0051
0.053
N/
A
0.26
N/
A
590
57
N/
A
11
N/
A
8
0.655
0.873
0.0048
0.050
N/
A
0.25
N/
A
630
60
N/
A
12
N/
A
9
0.621
0.828
0.0045
0.047
N/
A
0.24
N/
A
660
63
N/
A
13
N/
A
10
0.589
0.786
0.0043
0.045
N/
A
0.22
N/
A
700
67
N/
A
13
N/
A
11
0.559
0.745
0.0041
0.043
N/
A
0.21
N/
A
730
70
N/
A
14
N/
A
12
0.530
0.707
0.0039
0.040
N/
A
0.20
N/
A
770
74
N/
A
15
N/
A
13
0.503
0.670
0.0037
0.038
N/
A
0.19
N/
A
820
78
N/
A
16
N/
A
14
0.477
0.636
0.0035
0.036
N/
A
0.18
N/
A
860
83
N/
A
17
N/
A
15
0.452
0.603
0.0033
0.034
N/
A
0.17
N/
A
910
87
N/
A
17
N/
A
DAT
(
3)
DFR
LEVELS
(
ug/
cm2)
DOSE
(
mg/
kg/
day)
(
4)
MOEs
(
5)

Not
Adjusted
Adjusted
for
Rate
Very
Low
Low
Medium
High
Very
High
Very
Low
Low
Medium
High
Very
High
5
16
0.429
0.572
0.0031
0.033
N/
A
0.16
N/
A
960
92
N/
A
18
N/
A
17
0.407
0.542
0.0030
0.031
N/
A
0.15
N/
A
1000
97
N/
A
19
N/
A
18
0.386
0.515
0.0028
0.029
N/
A
0.15
N/
A
1100
100
N/
A
20
N/
A
19
0.366
0.488
0.0027
0.028
N/
A
0.14
N/
A
1100
110
N/
A
22
N/
A
20
0.347
0.463
0.0025
0.026
N/
A
0.13
N/
A
1200
110
N/
A
23
N/
A
21
0.329
0.439
0.0024
0.025
N/
A
0.13
N/
A
1200
120
N/
A
24
N/
A
22
0.312
0.416
0.0023
0.024
N/
A
0.12
N/
A
1300
130
N/
A
25
N/
A
23
0.296
0.395
0.0022
0.023
N/
A
0.11
N/
A
1400
130
N/
A
27
N/
A
24
0.281
0.375
0.0021
0.021
N/
A
0.11
N/
A
1500
140
N/
A
28
N/
A
25
0.266
0.355
0.0019
0.020
N/
A
0.10
N/
A
1500
150
N/
A
30
N/
A
26
0.253
0.337
0.0018
0.019
N/
A
0.096
N/
A
1600
160
N/
A
31
N/
A
27
0.240
0.320
0.0018
0.018
N/
A
0.091
N/
A
1700
160
N/
A
33
N/
A
28
0.227
0.303
0.0017
0.017
N/
A
0.087
N/
A
1800
170
N/
A
35
N/
A
29
0.216
0.288
0.0016
0.016
N/
A
0.082
N/
A
1900
180
N/
A
37
N/
A
30
0.205
0.273
0.0015
0.016
N/
A
0.078
N/
A
2000
190
N/
A
39
N/
A
31
0.194
0.259
0.0014
0.015
N/
A
0.074
N/
A
2100
200
N/
A
41
N/
A
32
0.184
0.245
0.0013
0.014
N/
A
0.070
N/
A
2200
210
N/
A
43
N/
A
33
0.175
0.233
0.0013
0.013
N/
A
0.066
N/
A
2400
230
N/
A
45
N/
A
DAT
(
3)
DFR
LEVELS
(
ug/
cm2)
DOSE
(
mg/
kg/
day)
(
4)
MOEs
(
5)

Not
Adjusted
Adjusted
for
Rate
Very
Low
Low
Medium
High
Very
High
Very
Low
Low
Medium
High
Very
High
6
34
0.166
0.221
0.0012
0.013
N/
A
0.063
N/
A
2500
240
N/
A
48
N/
A
35
0.157
0.209
0.0011
0.012
N/
A
0.060
N/
A
2600
250
N/
A
50
N/
A
36
0.149
0.199
0.0011
0.011
N/
A
0.057
N/
A
2800
260
N/
A
53
N/
A
37
0.141
0.188
0.0010
0.011
N/
A
0.054
N/
A
2900
280
N/
A
56
N/
A
38
0.134
0.179
0.00098
0.010
N/
A
0.051
N/
A
3100
290
N/
A
59
N/
A
39
0.127
0.169
0.00093
0.0097
N/
A
0.048
N/
A
3200
310
N/
A
62
N/
A
40
0.121
0.161
0.00088
0.0092
N/
A
0.046
N/
A
3400
330
N/
A
65
N/
A
41
0.114
0.152
0.00084
0.0087
N/
A
0.044
N/
A
3600
340
N/
A
69
N/
A
42
0.108
0.145
0.00079
0.0083
N/
A
0.041
N/
A
3800
360
N/
A
73
N/
A
43
0.103
0.137
0.00075
0.0078
N/
A
0.039
N/
A
4000
380
N/
A
77
N/
A
44
0.098
0.130
0.00071
0.0074
N/
A
0.037
N/
A
4200
400
N/
A
81
N/
A
45
0.093
0.123
0.00068
0.0070
N/
A
0.035
N/
A
4400
430
N/
A
85
N/
A
46
0.088
0.117
0.00064
0.0067
N/
A
0.033
N/
A
4700
450
N/
A
90
N/
A
47
0.083
0.111
0.00061
0.0063
N/
A
0.032
N/
A
4900
470
N/
A
95
N/
A
48
0.079
0.105
0.00058
0.0060
N/
A
0.030
N/
A
5200
500
N/
A
100
N/
A
49
0.075
0.100
0.00055
0.0057
N/
A
0.029
N/
A
5500
530
N/
A
110
N/
A
Footnote:

1.
Crop
groupings
and
transfer
coefficients
from
Science
Advisory
Council
for
Exposure:
Policy
Memo
#
003.1
'
Agricultural
Transfer
Coefficients',
August
7
17,
2000.

2.
Maximum
label
rates
from
end
use
product
labels.

Appendix
1.
Occupational
Post­
Application
Risk
Assessment
Calculator
(
12/
7/
01)

Chemical:
DICOFOL(
P.
B)

Reason:
TC
Policy
3.1
Date:
12­
7­
04
Assessor:
travagl
Applicable
TC
Groups:

Trees,
nut
[
Note:
Only
applicable
TCGroups
are
included
above.]

DFR/
TTR
Data
Defaults:

Initial
Percent
of
Rate
as
DFR
(%):
20
Dissipation
Rate
per
day
(%):
10
Initial
Percent
of
Rate
as
TTR
(%):
5
Dissipation
Rate
per
day
(%):
10
Toxicology
&
Exposure
Factor
Inputs:

Uncertainty
Factor:

Adult
Exposure
Duration
(
hrs/
day):

Dermal
Abs.
(%):
N/
A
Short­
term
NOAEL
(
mg/
kg/
day):
75
Source
of
Short­
term
NOAEL:
dog
Adult
Body
Weight
(
kg):
70
Intermediate­
term
NOAEL
(
mg/
kg/
day):
3
Source
of
Intermediate­
term
NOAEL:
dog
Adult
Body
Weight
(
kg):
70
Note:
If
a
dermal
administration
toxicity
study
is
the
source
of
the
endpoint
used
for
risk
assessment,
then
the
dermal
absorption
factor
is
set
to
100%
to
satisfy
the
calculations
in
this
program.
8
Appendix
1.
Occupational
Post­
Application
Risk
Assessment
Calculator
(
12/
7/
01)
(
cont.)
(
1,
2)

Short­
term
Results
Chemical:
DICOFOL(
P.
B)

Date:
12­
7­
04
Assessor:
travagl
Transfer
Coefficient
Group:
Trees,
nut
Specific
Crop
Considered:
Pecans
Application
Rate
of
Crop
(
lb
ai/
A):
2
DFR
Data
Summary
Source:
Ca
peaches
Slope
of
Semilog
Regression:
­
0.0529
Day
0
Concentration
(
ug/
cm):
1
Study
Application
Rate
(
lb
ai/
A):
1.5
Limit
of
Quantification
(
ug/
cm2):
0
Exposure
Inputs
Summary
Exposure
Potential
Transfer
Coefficients
(
cm2/
hr)
(
1)
Activities
(
1)

Used
for
RA
Range
Very
Low
48
TBD
tree
shakers
Low
500
197
­
2,302
Scouting,
Thinning,
Irrigation,
Weeding
(
hand)

Medium
N/
A
N/
A
N/
A
High
2500
1,121
­
4,929
Harvest
(
hand),
Pruning
(
hand),
Thinning,

Harvest
(
hand)
(
net)

Very
High
N/
A
N/
A
N/
A
9
