Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
1
of
10
Primary
Evaluator:
Sarah
J.
Levy,
Chemist
Registration
Action
Branch
1
(
RAB1)
Health
Effects
Division
(
HED;
7509C)
Date:
06­
APR­
2006
Approved
by:
George
Kramer,
Ph.
D.,
Chemist
RAB1/
HED
(
7509C)
Date:
06­
APR­
2006
This
DER
was
originally
prepared
under
contract
by
Dynamac
Corporation
(
1910
Sedwick
Road,
Building
100,
Suite
B,
Durham,
NC
27713;
submitted
10/
17/
2005.
The
DER
has
been
reviewed
by
HED
and
revised
to
reflect
current
Office
of
Pesticide
Programs
(
OPP)
policies.

STUDY
REPORTS:

45794202.
Schwarts,
N.
Heitcamp,
J.
(
2001)
[
14C]
Bifenthrin:
Nature
of
the
Residue
in
the
Potato
Tubers
Following
an
At­
planting
Soil
Application
and
Two
Pre­
Harvest
Foliar
Applications.
Lab
Project
Number:
46249.
Study
No.
182POTOOM1
Unpublished
study
prepared
by
ABC
Laboratories.
134
pages.

EXECUTIVE
SUMMARY:

The
metabolism
of
bifenthrin
in
potatoes
was
examined
in
two
trials
using
either
[
cyclopropyl­
1­
14C]­
or
[
U­
phenyl­
14C]­
labeled
bifenthrin
(
14C­
CP
or
14C­
PH).
Each
14C­
label
was
formulated
as
an
EC
and
applied
to
potatoes
as
a
single
in­
furrow
application
at
0.3
lb
ai/
A,
followed
by
two
broadcast
foliar
applications
at
0.1
lb
ai/
A/
application,
for
a
total
of
0.5
lb
ai/
A.
The
foliar
applications
were
made
late
in
the
season
during
the
vegetative
stage,
at
a
retreatment
interval
(
RTI)
of
14
days.
Samples
of
potato
tubers
and
foliage
were
collected
at
2­
and
14­
day
preharvest
intervals
(
PHIs).
An
exaggerated
treatment
rate
study
for
the
in­
furrow
application
was
also
performed;
however,
samples
were
not
analyzed
as
there
were
sufficient
levels
of
14Cresidues
in
samples
conducted
from
the
non­
exaggerated
rate
study
(
total
application
rate
0.5
lb
ai/
A).

The
levels
of
radioactivity
in
foliage
and
tubers
were
similar
for
the
[
14C­
CP]
and
[
14C­
PH]
labeled
samples.
Total
radioactive
residues
(
TRR)
in
foliage
were
2.89­
3.29
ppm
at
2­
day
PHI
and
declined
to
1.94­
2.70
ppm
by
14­
day
PHI.
TRR
were
substantially
lower
in
tubers
(
0.020­
0.068
ppm)
at
both
sampling
intervals,
indicating
that
translocation
of
[
14C]
bifenthrin
from
leaves
to
the
tubers
was
minimal.

Mature
(
14­
day
PHI)
samples
of
tubers
and
foliage
were
extracted
with
acetonitrile
(
ACN),
releasing
91.4­
95.7%
of
the
TRR
from
each
matrix.
Solubilized
residues
were
subsequently
partitioned
into
hexane,
ether/
ACN,
and
aqueous
fractions.
Radioactivity
remaining
in
the
residual
solids
accounted
for
7.5­
8.6%
TRR
in
tubers
and
4.3%
of
the
TRR
in
foliage.

With
the
exception
of
several
minor
metabolites,
the
14C­
residue
profiles
in
tubers
and
foliage
were
similar
for
the
two
14C­
labels,
with
identified
residues
accounting
for
75­
81%
of
the
TRR
in
tubers
and
95%
of
the
TRR
in
foliage.
In
all
matrices,
bifenthrin
was
the
major
14C­
residue
accounting
for
73.3­
81.1
%
of
the
TRR
in
tubers
and
94.7­
95.1%
of
the
TRR
in
foliage.
Minor
amounts
( 
1.2%
TRR,
<
0.001
ppm)
of
the
following
metabolites
were
also
tentatively
identified
by
high­
performance
liquid
chromatography
(
HPLC)
in
tubers:
4­
OH­
bifenthrin,
biphenyl
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
2
of
10
alcohol
or
acid
metabolites,
a
biphenyl
aldehyde
metabolite,
and
TFP
acid.
No
metabolites
were
detected
in
foliage.
Considering
the
type
of
metabolites
detected,
the
metabolism
of
bifenthrin
in
potatoes
appears
to
involve
hydrolytic
cleavage
of
the
ester
linkage
and
hydroxylation
of
the
biphenyl
moiety.

STUDY/
WAIVER
ACCEPTABILITY/
DEFICIENCIES/
CLARIFICATIONS:

Under
the
conditions
and
parameters
used
in
the
study,
the
potato
metabolism
data
are
classified
as
scientifically
acceptable.
The
acceptability
of
this
study
for
regulatory
purposes
is
addressed
in
the
forthcoming
U.
S.
EPA
Residue
Chemistry
Summary
Document
[
DP#:
310089].

COMPLIANCE:

Signed
and
dated
Good
Laboratory
Practice
(
GLP),
Quality
Assurance
and
Data
Confidentiality
statements
were
provided.
No
deviations
from
GLP
standards
were
reported
for
this
substance.

A.
BACKGROUND
INFORMATION
Bifenthrin
is
a
broad
spectrum,
non­
systemic
insecticide/
miticide
in
the
class
of
synthetic
pyrethroids
(
MOA
Group
3).
It
is
registered
to
FMC
Corporation
for
use
as
foliar
applications
on
a
variety
of
field,
fruit
and
vegetable
crops.
Bifenthrin
is
formulated
for
use
on
crop
plants
as
a
2.0
lb/
gal
emulsifiable
concentrate
(
EC;
Capture
®
2
EC;
EPA
Reg.
No.
279­
3069)
and
as
a
1.15%
granule
(
G;
Capture
1.15G;
EPA
Reg.
No.
279­
3244).

TABLE
A.
1.
Nomenclature
of
Bifenthrin
Compound
O
O
Cl
F
3
C
CH
3
CH
3
C
H
3
Common
name
Bifenthrin
Company
experimental
names
Capture
®
Insecticide/
Miticide
IUPAC
name
2­
methylbiphenyl­
3­
ylmethyl(
Z)­(
1RS,
3RS)­
3­(
2­
chloro­
3,3,3­
trifluoroprop­
1­
enyl)­
2,2dimethylcyclopropanecarboxylate
or
2­
methylbiphenyl­
3­
ylmethyl(
Z)­(
1RS)­
cis­
3­(
2­
chloro­
3,3,3­
trifluoroprop­
1­
enyl)­
2,2dimethylcyclopropanecarboxylate
CAS
name
rel­
2­
methyl(
1,1'­
biphenyl)­
3­
yl)
methyl(
1R,
3R)­
3­((
1Z)­
2­
chloro­
3,3,3­
trifluoro­
1­
propenyl)­
2,2­
dimethylcyclopropanecarboxylate
CAS
#
82657­
04­
03
End­
use
products/
EPs
2.0
lb/
gal
EC
(
Capture
®
2EC;
EPA
Reg
No.
279­
3069)

1.15%
G
(
Capture
®
1.15G;
EPA
Reg
No.
279­
3244)
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
3
of
10
TABLE
A.
2.
Physicochemical
Properties
of
the
Technical
Grade
Bifenthrin
Parameter
Value
Reference
Melting
point/
range
68­
70.6
°
C
pH
NA
Density
at
24
°
C
1.26
g/
mL
Water
solubility
<
0.1
Fg/
L
Solvent
solubility
(
g/
100
mL)
8.9
in
heptane
and
methanol
125
in
acetone,
chloroform,
ether,
methylene
chloride,
and
toluene
Vapor
pressure
(
Pa)
at
25
°
C
2.41
x
10­
5
Dissociation
constant
(
pKa)
NA
Octanol/
water
partition
coefficient)
Kow
>
1
x
10
6
UV/
visible
absorption
spectrum
NA
Product
Chemistry
Chapter
of
the
Tolerance
Reassessment
Eligibility
Decision
(
TRED)

B.
EXPERIMENTAL
DESIGN
B.
1.
Trial
Site
and
Crop
Information
The
in­
life
phase
of
the
study
was
conducted
by
ABC
Laboratories,
Columbia,
MO
from
23­
JAN­
2001
to
14­
JUN­
2001.
Potato
plants
were
grown
in
a
loam
soil
in
oval
galvanized
stock
tanks
with
interior
coatings
of
fiberglass
resin
(
Table
B.
1.1).
One
furrow
was
made
at
the
top
of
each
tank
and
seed
potatoes
were
planted
following
the
initial
in­
furrow
application
of
[
14C]
bifenthrin.
Tanks
were
separated
by
a
minimum
of
5
ft
to
prevent
cross­
contamination
due
to
spray
drift
from
foliar
applications.
The
potato
plants
were
maintained
indoors
in
a
greenhouse
throughout
the
study
and
grown
in
accordance
with
typical
agricultural
practices.
There
were
no
deviations
noted.

TABLE
B.
1.1.
Test
Site
Information.

Soil
characteristics1
Testing
Environment
Type
%
OM
pH
CEC
Potatoes
were
grown
in
fiberglass
coated
galvanized
stock
tanks
in
a
greenhouse
Loam
1.6
5.6
11.4
1
OM
=
Organic
matter,
CEC
=
Cation­
exchange
capacity.
These
parameters
are
only
required
for
studies
involving
a
soil
treatment.

TABLE
B.
1.2.
Crop
Information.

Crop;
crop
group
Variety
Growth
stage
at
applications
Growth
stage
at
harvest
Harvested
Matrix
Potato;
Crop
group
1
Atlantic
The
initial
application
was
made
prior
to
planting
seed
potatoes
and
the
foliar
applications
were
made
at
approximately
28
and
14
days
prior
to
normal
maturity.
Maturity
Foliage
was
cut
at
ground
level
and
tubers
dug
from
the
soil
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
4
of
10
B.
2.
Test
Materials
The
14C­
test
materials
(
Table
B.
2.1)
were
directly
mixed
with
a
blank
EC
formulation
and
diluted
with
water
for
application.

TABLE
B.
2.1.
Test
Material
Characteristics.
Chemical
structure
O
O
Cl
F
3
C
CH
3
CH
3
C
H
3
*
O
O
Cl
F
3
C
CH
3
CH
3
C
H
3
*

Radiolabel
position
The
1­
position
of
the
cyclopropyl
ring
Uniformly
in
the
phenyl
ring
Lot
No.
PR­
2030­
PC
PR­
2030­
PC
Purity
99.1%
99.1%
Specific
activity
29,051dpm/
µ
g
(
5.54
mCi/
mmol)
30,814
dpm/
µ
g
(
5.87
mCi/
mmol)

B.
3.
Study
Use
Pattern
TABLE
B.
3.1.
Use
Pattern
Information.
Chemical
name
[
14C­
PH]
Bifenthrin
[
14C­
CP]
Bifenthrin
Application
method
In
Furrow
Broadcast
Foliar
In
Furrow
Broadcast
Foliar
Application
rate
0.3
lb
ai/
A
0.1
lb
ai/
A
0.3
lb
ai/
A
0.1
lb
ai/
A
Number
of
applications
1
2
1
2
Timing
of
applications
Pre­
planting
28
and
14
days
PHI
Pre­
planting
28
and
14
days
PHI
PHI
2
and
14
days
2
and
14
days
B.
4.
Identification/
Characterization
of
Residues
B.
4.1.
Sample
Handling,
Preparation,

Samples
of
potato
foliage
and
tubers
were
harvested
at
2­
and
14­
day
PHIs.
Foliage
was
removed
close
to
the
ground
and
placed
unwashed
into
sample
bags.
Tubers
were
dug
from
the
soil
and
rinsed
in
distilled
water
to
remove
excess
soil
residue.
Tubers
were
then
cut
into
smaller
pieces
with
a
knife,
and
placed
into
sample
bags.
All
samples
were
directly
transported
to
the
freezer
( 
20
°
C)
until
analysis.
Foliage
and
tuber
samples
were
ground
with
dry
ice,
and
the
TRR
in
each
sample
was
determined
in
triplicate
using
combustion/
liquid­
scintillation
counting
(
LSC)
analysis.
The
limit
of
detection
(
LOD)
for
the
radioassay
was
0.001
ppm
For
identification
and
characterization
of
14C­
residues
in
tubers,
samples
were
initially
extracted
with
ACN
and
centrifuged.
The
ACN
fraction
was
then
partitioned
sequentially
with
hexane
and
ethyl
ether,
resulting
in
a
hexane
fraction,
an
ether/
ACN
fraction,
and
residual
aqueous
fraction.
The
hexane
and
ether/
ACN
fractions
were
concentrated,
redissolved
in
ACN
and
analyzed
by
HPLC.
The
post­
extraction
solids
were
solubilized
using
5.25%
sodium
hypochlorite
and
analyzed
by
LSC
to
determine
%
TRR
remaining
as
non­
extractable
residues.

Potato
foliage
samples
were
extracted
three
times
with
ACN
and
centrifuged.
The
ACN
extracts
were
combined
and
partitioned
three
times
with
hexane,
with
the
ACN
fraction
being
acidified
*
indicates
position
of
14C
label
*
indicates
position
of
14C
label
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
5
of
10
for
the
third
partition.
The
resulting
hexane
fractions
were
combined,
concentrated,
and
analyzed
using
HPLC
and
thin­
layer
chromatography
(
TLC).
The
ACN/
water
fraction
was
not
further
analyzed.

B.
4.2.
Analytical
Methodology
Radioactive
residues
in
solvent
fractions
were
analyzed
and
quantified
by
reverse­
phase
HPLC.
The
HPLC
system
used
a
C18
column
with
a
mobile
phase
gradient
of
water
to
ACN.
The
system
included
both
an
in­
line
radioactivity
monitor
and
a
variable
wavelength
detector.
Retention
times
of
the
HPLC
peaks
were
compared
with
the
retention
time
of
the
standards.
Including
parent,
a
total
of
six
reference
standards
were
used
for
comparison.
The
identity
of
parent
in
hexane
fractions
was
confirmed
by
one­
dimensional
normal­
phase
TLC
using
a
solvent
system
of
hexane/
toluene/
ethyl
ether/
acetic
acid
(
11.5:
8.5:
2:
0.3,
v/
v/
v/
v).
Radioactivity
in
extracts
and
HPLC
fractions
was
determined
by
LSC.

C.
RESULTS
AND
DISCUSSION
C.
1.
Storage
Stability
Potato
tubers
and
foliage
were
stored
frozen
at
­
20
°
C
for
up
to
3
and
4
months
prior
to
analysis
(
Table
C.
1).
As
analyses
were
completed
within
6
month
of
sampling,
no
supporting
storage
stability
data
are
required.
In
addition,
the
identification
of
parent
as
the
major
component
of
the
TRR
in
tubers
(
73­
81%
TRR)
and
foliage
(
95­
96%
TRR)
indicates
that
14C­
residues
were
stable
in
frozen
storage.

TABLE
C.
1.
Summary
of
Storage
Conditions.
Potato
Matrix
Storage
Temperature
(
°
C)
Actual
Storage
Duration
(
Months)
Interval
of
Demonstrated
Storage
Stability
(
Months)
Tubers
3
NR
Foliage
­
20
°
C
4
NR
1
NR=
Not
required
as
samples
analyses
were
completed
within
6
months.

C.
2.
Identification,
Characterization,
and
Distribution
of
Residues
The
distribution
and
levels
of
radioactivity
in
the
tubers
and
foliage
were
similar
of
the
two
14Clabels
TRR
in
foliage
were
2.89­
3.29
ppm
at
2­
day
PHI
and
declined
to
1.94­
2.70
ppm
by
14­
day
PHI.
TRR
were
substantially
lower
in
tubers
(
0.020­
0.068
ppm)
at
both
sampling
intervals,
indicating
minimal
translocation
of
14C­
residues
from
leaves
to
the
tubers
(
Table
C.
2.1).

TABLE
C.
2.1.
TRR
in
Potato
Tubers
and
Foliage.
14C­
CP­
label
14C­
PH­
label
Matrix
Timing
and
Applic.
No.
PHI
(
days)
ppm
ppm
Immature
Tubers
2
0.0681
0.0201
Immature
Foliage
2
3.29
2.89
Mature
Tubers
14
0.0468
0.0379
Mature
Foliage
One
In­
furrow
treatment
at
planting
and
two
broadcast
foliar
treatments
at
approximately
28
and
14
days
prior
to
normal
harvest.
14
2.70
1.94
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
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45794202
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6
of
10
For
both
14C­
labels,
solvent
extraction
released
91.4­
95.7%
of
the
TRR
from
mature
samples
of
foliage
and
tubers.
Radioactivity
in
the
residual
solids
accounted
for
7.5­
8.6%
TRR
in
tubers
and
4.3%
of
the
TRR
in
foliage
(
Table
C.
2.2).
Identified
residues
accounted
for
75­
81%
of
the
TRR
in
mature
tubers
and
95%
of
the
TRR
in
foliage.

The
14C­
residue
profiles
in
tuber
and
foliage
were
also
similar
for
the
two
14C­
labels
(
Table
C.
2.3).
Bifenthrin
(
parent)
was
the
major
14C­
residue
detected
in
both
tubers
and
foliage.
At
14­
day
PHI,
bifenthrin
accounted
for
73.3­
81.1
%
of
the
TRR
in
tubers
and
94.7­
95.1%
of
the
TRR
in
foliage.
The
identity
of
parent
in
tubers
and
foliage
was
confirmed
by
TLC.
Minor
amounts
( 
1.2%
TRR,
<
0.001
ppm)
of
the
following
metabolites
were
also
tentatively
identified
by
HPLC
in
tubers:
4­
OH­
bifenthrin,
biphenyl
alcohol
or
acid
metabolite,
a
biphenyl
aldehyde
metabolite,
and
TFP
acid.
Other
minor
unknowns
and
polar
residues
in
tubers
accounted
for
3.4­
12.6%
of
the
TRR,
with
each
individual
metabolite/
fraction
accounting
for
<
8%
of
the
TRR.
No
metabolites
were
detected
in
foliage,
and
all
unknown
fractions
or
metabolites
accounted
for
 
1.2%
of
the
TRR.

TABLE
C.
2.2.
Distribution
of
the
14C­
Residues
in
Mature
Potato
Tubers
and
Foliage
Harvested
14
Days
Following
the
Final
Application
of
[
14C]
Bifenthrin.
[
14C­
CP]
14­
day
PHI
[
14C­
PH]
14­
day
PHI
Tuber
Foliage
Tuber
Foliage
TRR
=
0.0468
ppm
TRR
=
2.70
ppm
TRR
=
0.0379
ppm
TRR
=
1.94
ppm
Metabolite/
Fraction
%
TRR
ppm
%
TRR
ppm
%
TRR
ppm
%
TRR
ppm
ACN
Extracts
(
solvent
partitioning)
92.5
0.0433
95.7
2.58
91.4
0.0346
95.7
1.85
Hexane
(
HPLC
analysis)
Parent
74.4
71.7
0.0348
0.0336
94.5
95.1
2.55
2.56
87.3
80.9
0.0331
0.0307
95.7
94.7
1.85
1.83
Ethyl
ether/
ACN
(
HPLC
analysis)
Parent
Polar
residues
TFP
acid
4'
OH­
bifenthrin
Biphenyl
Alcohol
and/
or
Acid
Biphenyl
Aldehyde
Total
unknowns
(
each
 
0.8%
TRR)
14.2
1.61
7.62
0.93
1.20
ND
ND
1.05
0.0067
0.0008
0.0036
0.0004
0.0006
­­­
­­­
0.0005
NA
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
1.91
0.16
0.55
ND
0.10
0.09
0.07
0.72
0.0007
<
0.0001
0.0002
­­­
<
0.0001
<
0.0001
<
0.0001
0.0003
NA
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­
­­

Aqueous
(
not
further
analyzed)
3.89
0.0018
1.20
0.03
2.17
0.0008
<
0.1
­­
Post­
extraction
solids
(
PES)
7.51
0.0035
4.27
0.12
8.62
0.0033
4.29
0.08
NA
=
not
applicable.
ND
=
not
detected.
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
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310089/
MRID#:
45794202
Page
7
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10
Table
C.
2.3.
Summary
of
Characterization
and
Identification
of
14C­
Residues
in
Mature
Potato
Matrices
Harvested
14­
day
PHI
Following
Applications
of
[
14C]
Bifenthrin
totaling
0.5
lb
ai/
A.
[
14C­
CP]
Bifenthrin
[
14C­
PH]
Bifenthrin
TRR
=
0.0468
ppm
TRR
=
0.0379
ppm
Compound/
Fractions
%
TRR
ppm
%
TRR
ppm
Tubers
Parent
73.3
0.0344
81.1
0.0308
4­
OH­
Bifenthrin
1.20
0.0006
0.10
<
0.0001
Biphenyl
Alcohol
or
Acid
ND
­­­
0.09
<
0.0001
Biphenyl
Aldehyde
ND
­­­
0.07
<
0.0001
TFP
acid
0.93
0.0004
ND
­­­
Total
identified
75.43
0.0354
81.36
0.0308
Minor
unknowns
(
Each
 
0.8%
TRR)
1.05
0.0005
0.72
0.0003
Minor
Polar
components1
11.51
0.0054
2.72
0.0010
Total
characterized
87.99
0.0412
84.80
0.0321
Total
extractable
92.5
0.0433
91.4
0.0346
Unextractable
(
PES)
2
7.51
0.0035
8.62
0.0033
Accountability3
100.0
100.0
Foliage
TRR
=
2.70
ppm
TRR
=
1.94
ppm
Compound
%
TRR
ppm
%
TRR
ppm
Parent
95.1
2.56
94.7
1.83
Total
identified
95.1
2.56
94.7
1.83
Minor
aqueous
fraction
1.2
0.03
<
0.01
­­­
Total
characterized
96.3
2.59
94.7
1.83
Total
extractable
95.7
2.58
95.7
1.85
Unextractable
(
PES)
2
4.27
0.12
4.29
0.08
Accountability3
100.0
100.0
1
Includes
polar
HPLC
fractions
and
minor
aqueous
fractions
2
Post­
extraction
solids.
3
Accountability
=
(
Total
extractable
+
Total
unextractable)/(
TRR
from
combustion
analysis;
see
TABLE
C.
2.1)
*
100.
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
8
of
10
C.
3.
Proposed
Metabolic
Profile
FIGURE
C.
3.1.
Proposed
Metabolic
Profile
of
Bifenthrin
in
Potatoes.

O
O
Cl
F
3
C
CH
3
CH
3
C
H
3
Cl
O
OH
F
3
C
CH
3
C
H
3
OH
C
H
3
O
O
Cl
F
3
C
OH
CH
3
C
H
3
CH
3
O
C
H
3
OH
O
C
H
3
Bifenthrin
cis­
TFP
acid
BP
alcohol
4'­
Hydroxy­
bifenthrin
BP
aldehyde
BP
acid
Polar
Products
Hydrolysis
Oxidation
Oxidation
Oxidation
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
9
of
10
TABLE
C.
3.1.
Bifenthrin
Metabolites
from
Potato
Metabolism
Study
Common
name/
code
Figure
C.
3.1
ID
No.
Chemical
name
Chemical
structure
TFP
Acid
Cis­
3­(
2­
chloro­
3,
3,
3­
trifluoroprop­
1­
enyl)­
2,
2­
dimethylcyclopropanecarboxylic
acid
Cl
O
OH
F
3
C
CH
3
C
H
3
Biphenyl
Aldehyde
2­
methylbiphenyl­
3­
carboxaldehyde
O
C
H
3
Biphenyl
Acid
2­
methylbiphenyl­
3­
carboxylic
acid
OH
O
C
H
3
4'
Hydroxy
bifenthrin
4'­
hydroxy­
2­
methylbiphenyl­
3­
ylmethyl
(
Z)
cis
3­(
2­
chloro­
3,
3,
3­
trifluoroprop­
1­
enyl)­
2,
2­
dimethylcyclopropanecarboxylate
O
O
Cl
F
3
C
OH
CH
3
C
H
3
CH
3
Biphenyl
Alcohol
2­
methylbipheny­
3­
methanol
OH
C
H
3
Bifenthrin/
128825/
IR­
4
DACO
6.3/
OPPTS
860.1300/
OECD
II
6.2.2,
6.2.3
&
IIIA
8.2,
8.4.1,
8.4.2
Nature
of
the
Residues
in
Plants
­
Potato
DP#:
310089/
MRID#:
45794202
Page
10
of
10
D.
CONCLUSION
The
potato
metabolism
study
is
adequate.
Following
a
single
in­
furrow
application
at
planting
and
two
foliar
applications
totaling
0.50
lb
ai/
A,
TRR
were
0.0379­
0.0468
ppm
in/
on
tubers
and
1.94­
2.70
ppm
in/
on
foliage
collected
at
a
14­
day
PHI.
The
14C­
residue
profiles
in
tubers
and
foliage
were
similar
between
the
two
14C­
labels,
with
the
exception
of
several
trace
metabolites
in
tubers.

The
metabolism
of
bifenthrin
in
potatoes
was
minimal.
Bifenthrin
(
parent)
was
the
only
compound
detected
in
foliage,
accounting
for
94.7­
95.1%
of
the
TRR
and
was
the
major
residue
in
tubers,
accounting
for
73.3­
81.1%
of
the
TRR.
The
minor
metabolites
detected
in
tubers
suggest
that
the
metabolism
of
bifenthrin
in
potatoes
involves
hydrolysis
of
the
ester
linkage
prior
to
or
after
hydroxylation
of
the
biphenyl
moiety
(
Figure
C.
3.1).

E.
REFERENCES
DP#:
283808
Subject:
Bifenthrin.
Residue
and
Product
Chemistry
Considerations
for
the
Tolerance
Reassessment
Eligibility
Decision
(
TRED)
From:
S.
Levy
To:
T.
Myers
Dated:
21­
AUG­
2002
MRID(
s):
None
F.
DOCUMENT
TRACKING
RDI:
RAB1
Chemists
(
16­
NOV­
2005)
Petition#:
3E6882
DP#:
310089
PC
Code:
128825
Template
Version
June
2005
