1
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
01/
15/
2002
MEMORANDUM
SUBJECT:
Linuron.
Anticipated
Residues
and
Dietary
Exposure
Assessment
(PC
Code
035506);
DP
Barcode
D279340;
Case
0047.

FROM:
John
S.
Punzi,
Ph.
D.,
Chemist
Reregistration
Branch
II
Health
Effects
Division
(7509C)

THROUGH:
Alan
Nielsen,
Branch
Senior
Scientist
Reregistration
Branch
II
Health
Effects
Division
(7509C)

Dietary
Exposure
Science
Advisory
Council
(DE
SAC)
12/
20/
2001
Chemistry
Science
Advisory
Council
(DE
SAC)
12/
19/
2001
Health
Effects
Division
(7509C)

TO:
Carol
Christensen,
Risk
Assessor
Reregistration
Branch
II
Health
Effects
Division
(7509C)

Executive
Summary
This
exposure
assessment
was
conducted
for
the
herbicide
linuron
to
estimate
the
dietary
risk
associated
with
registered
uses
of
this
product.
A
refined
tier
3
analysis
was
done
for
the
chronic
assessment
and
a
refined
tier
3
probalistic
analysis
was
perfomed
for
the
acute
assessment.
Residue
levels
from
USDA
and
FDA
monitoring
programs
do
not
include
all
residues
of
concern
needed
for
this
assessment
(linuron
and
metabolites
converted
to
3,4­
dichloroanaline)
and
would
underestimate
residue
values
for
this
analysis.
Anticipated
residues
(ARs)
were
computed
from
field
trial
data
and
subsequently
utilized
to
estimate
the
dietary
exposure
to
linuron
from
the
diets
of
the
U.
S.
population,
as
well
as
certain
population
subgroups.
In
addition
to
percent
crop
treated
(%
CT)
data,
residue
reduction
data
from
2
washing,
cooking
and
various
processing
studies
were
used
as
refinements
to
the
residue
data.
USDA
PDP
data
shows
that
up
to
70%
of
the
carrot
samples
have
detectable
residues
of
linuron
up
to
0.3
ppm.
This
suggests
that
the
ARs
used
for
this
assessment
are
not
unrealistic.

Estimated
chronic
dietary
exposure
associated
with
the
use
of
linuron
does
not
exceed
HED's
level
of
concern
(>
100%
cPAD
1
)
for
the
U.
S.
population
or
any
population
subgroup
examined.
The
chronic
dietary
risk
estimates
for
the
US
population
and
children
aged
1­
6
years
(the
highest
exposed
group)
are
approximately
15
%
and
35
%
of
cPAD,
respectively.
Approximately
30
%
of
the
chronic
exposure
to
linuron
from
food
is
from
meats
and
milk
however
the
ARs
for
these
foods
are
based
on
extremely
conservative
livestock
diets.

Estimates
for
acute
dietary
exposures
associated
with
the
use
of
linuron
does
not
exceed
HED's
level
of
concern
(>
100%
aPAD
1
at
the
99
th
percentile)
for
the
population
subgroup
comprised
of
females
aged
13
to
50
years.
The
acute
dietary
risk
exposure
estimate
for
this
population
is
approximately
10
%
of
aPAD.
Approximately
37
%
of
the
acute
exposure
to
linuron
from
food
is
from
asparagus
and
milk.
As
stated
above
the
AR
for
milk
is
extremely
conservative.

1
cPAD/
aPAD=
acute/
chronic
Population
Adjusted
Dose=
Acute
or
Chronic
RfD
FQPA
Safety
Factor
The
data
and
results
for
this
analysis
are
organized
into
9
Sections
with
4
Appendices;

1.
DEEM™
Program
and
Consumption
Information
2.
Anticipated
Residues
3.
Crop
Use
Information
and
Field
Trial
Data
4.
Processing
Studies
5.
Residue
Reduction
6.
Residues
in
Meat
and
Milk
7.
Toxicology
Data
8.
Chronic
Exposure
Results
9.
Acute
Exposure
Results
Appendix
1;
Residue
Distribution
Files
(asparagus.
rdf,
carrot.
rdf,
celery.
rdf,
parsely.
rdf,
potato.
rdf,
sweetcorn.
rdf).
Appendix
2;
Chronic
DEEM
input
files
(linuron_
chronic.
rs7,
linuron_
chronic.
CH1).
Appendix
3;
Acute
DEEM
input
files
(linuron_
acute.
rs7,
linuron_
acute.
AC1)
Appendix
4;
BEAD
%
Crop
Treated
Data.

1.
DEEM™
Program
and
Consumption
Information
3
Linuron
acute
and
chronic
dietary
exposure
assessments
were
conducted
using
the
Dietary
Exposure
Evaluation
Model
(DEEM™)
software
Version
7.73,
which
incorporates
consumption
data
from
USDA's
Continuing
Surveys
of
Food
Intake
by
Individuals
(CSFII),
1989­
1992.
The
1989­
92
data
are
based
on
the
reported
consumption
of
more
than
10,000
individuals
over
three
consecutive
days,
and
therefore
represent
more
than
30,000
unique
person
days
of
data.
Foods
as
consumed
(e.
g.,
apple
pie)
are
linked
to
raw
agricultural
commodities
and
their
food
forms
(e.
g.,
apples­
cooked/
canned
or
wheat­
flour)
by
recipe
translation
files
internal
to
the
DEEM
software.
Consumption
data
are
averaged
for
the
entire
U.
S.
population
and
within
population
subgroups
for
chronic
exposure
assessment,
but
are
retained
as
individual
consumption
events
for
acute
exposure
assessment.

For
chronic
exposure
and
risk
assessment,
an
estimate
of
the
residue
level
in
each
food
or
food­
form
(e.
g.,
orange
or
orange­
juice)
on
the
commodity
residue
list
is
multiplied
by
the
average
daily
consumption
estimate
for
that
food/
food
form.
The
resulting
residue
consumption
estimate
for
each
food/
food
form
is
summed
with
the
residue
consumption
estimates
for
all
other
food/
food
forms
on
the
commodity
residue
list
to
arrive
at
the
total
estimated
exposure.
Exposure
estimates
are
expressed
in
mg/
kg
body
weight/
day
and
as
a
percent
of
the
cPAD.
This
procedure
is
performed
for
each
population
subgroup.

For
acute
exposure
assessments,
individual
one­
day
food
consumption
data
are
used
on
an
individual­
byindividual
basis.
The
reported
consumption
amounts
of
each
food
item
can
be
multiplied
by
a
residue
point
estimate
and
summed
to
obtain
a
total
daily
pesticide
exposure
for
a
deterministic
(Tier
1
or
Tier
2)
exposure
assessment,
or
matched
in
multiple
random
pairings
with
residue
values
and
then
summed
in
a
probabilistic
(Tier
3/
4)
assessment.
The
resulting
distribution
of
exposures
is
expressed
as
a
percentage
of
the
aPAD
on
both
a
user
(i.
e.,
those
who
reported
eating
relevant
commodities/
food
forms)
and
a
percapita
(i.
e.,
those
who
reported
eating
the
relevant
commodities
as
well
as
those
who
did
not)
basis.
In
accordance
with
HED
policy,
per
capita
exposure
and
risk
are
reported
for
all
tiers
of
analysis.
However,
for
tiers
1
and
2,
significant
differences
in
user
vs.
per
capita
exposure
and
risk
are
identified
and
noted
in
the
risk
assessment.

2.
Anticipated
Residues
Table
1
Residue
data
to
be
used
in
exposure
calculations.

Crop
Tolerence
Percent
of
Crop
Treated
Anticipated
Residue
s
1
Processing/
Reduction
factor(
s)
Average
Maximum
Chronic
Acute
Asparagus
7.0
20
33
0.541750
0.893888b
2
RDF1
nb,
pb
Washing
(0.4)
3
Boiled
(0.25)

Carrot
1.0
75
100
0.276250
0.368333b
RDF2
nb,
pb
Boiled
(0.35)
4
Celery
0.5
24
33
0.030150
0.041456b
RDF3
nb,
pb
Boiled
(0.35)

Corn,
grain
0.01
1
1
0.000633
0.000633
oil
1x
bran
1x
flour
1x
Boiled
(0.35)

Corn,
sweet
0.25
1
1
0.000138
0.000138b
RDF4
nb,
pb
Boiled
(0.35)

Cotton
0.05
1
2
0.000500
0.000500
meal
1x
oil
1x
Parsley
0.25
3
6
0.003400
0.006800b
RDF5
nb,
pb
Boiled
(0.35)

Parsnip
0.05
2
3
0.001000
0.001500b
RDF6
nb,
pb
Boiled
(0.35)

Potato
0.20
7
11
0.003700
0.005814b
RDF7
nb,
pb
Baked
(1.5x)
Boiled
(0.48)

Sorghum
0.25
1
1
0.002500
0.002500
Boiled
(0.35)

Soybean
1.0
1
1
0.002796
0.002796
oil
(0.2)
meal
(1.2)
tofu
(0.3)
Boiled
(0.35)

Wheat
0.05
1
1
0.000450
0.000450
bran
1x
flour
1x
germ
1x
Boiled
(0.35)

Beef­
lean
0.10
NA
100
0.012567
0.067391
NA
Beef­
fat
0.20
NA
100
0.085405
0.114493
NA
Beef­
liver
0.10
NA
100
0.337838
1.775362
NA
Pork­
lean
0.05
NA
100
0.002435
0.003039
NA
Pork­
fat
0.05
NA
100
0.004136
0.005130
NA
Pork­
liver
0.01
NA
100
0.065445
0.081169
NA
Milk
0.05
NA
100
0.010000
0.053623
boiled
0.35
5
footnotes:

1.
The
anticipated
residues
have
been
corrected
for
%
CT
in
this
Table.

2.
b
=blended,
nb=
not
blended,
pb=
partially
blended.

3.
Washing
factor
from
asparagus
study
was
applied
to
asparagus
only
since
washing
study
from
celery
did
not
show
residue
reduction.

4.
An
average
boiling
factor
was
derived
from
asparagus,
carrot
and
potato
cooking
studies
and
translated
to
all
appropriate
food
forms
(exception
of
meats).

3.
Crop
Use
Information
and
Field
Trial
The
reregistration
requirements
for
magnitude
of
the
residue
in
plants
are
fulfilled
for
asparagus,
carrots;
field
corn
grain;
field
corn
forage
and
fodder;
cottonseed;
parsley;
parsnips;
potatoes;
sorghum
grain;
sorghum
aspirated
grain
fractions;
soybeans;
soybean
forage
and
hay;
soybean
aspirated
grain
fractions;
and
wheat
grain.

The
reregistration
requirements
for
magnitude
of
the
residue
in
plants
are
not
fulfilled
for:
celery;
corn,
field,
aspirated
grain
fractions;
corn,
sweet
(K+
CWHR);
corn,
sweet,
forage;
corn,
sweet,
stover;
cotton
gin
byproducts;
sorghum
forage
and
stover;
wheat
forage,
hay,
and
straw.
The
unsatisfied
data
requirements
are
generally
either
storage
stability
information
or
additional
geographic
representation.

The
data
collection
method
for
linuron
and
metabolites
of
concern
involves
hydrolysis
of
the
sample
and
measurement
of
3,4­
DCA.
The
analytical
methods
used
by
monitoring
programs
rely
on
methods
that
will
detect
only
the
parent
linuron
compound.
Since
the
MARC
has
determined
that
linuron
and
compounds
hydrolyzable
to
3,4­
DCA
are
the
residues
of
concern
the
monitoring
programs
(USDA,
FDA)
do
not
collect
the
appropriate
data.
It
is
noteworthy
that
parent
linuron
was
detected
in
nearly
70
%
of
the
carrot
samples
from
1999
USDA
PDP
sampling
program
and
that
values
up
to
0.3
ppm
have
been
measured.
This
indicates
that
the
ARs
generated
herein
are
not
unrealistically
high.

Root
and
Tuber
Vegetables
Group
Carrot:
Data
from
carrot
field
trials
(MRID
40537601)
indicate
that
linuron
residues
ranged
from
0.28­
0.50
ppm
and
0.30­
0.60
ppm
in/
on
samples
of
washed
and
unwashed
carrots,
respectively,
harvested
14
days
following
either
a
single
postemergence
application
of
a
50%
WP
or
50%
DF
formulation
at
2.0
lb
ai/
A
(1x
the
maximum
seasonal
application
rate)
or
two
applications
for
a
total
rate
of
2.0
or
4.0
lb
ai/
A
(1x
or
2x
the
maximum
seasonal
application
rate).
Data
for
anticipated
residues
are
from
6
unwashed
carrot
samples;
(0.30,
0.28,
0.40,
0.50,
0.39,
0.34
ppm).
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
blended
food
forms
is;
(0.30
+
0.28
+
0.40
+
0.50
+
0.39
+
0.34)/
6
*
%
CT=
0.368333(%
CT)
ppm.
Note
that
the
%
CT
value
is
an
estimated
maximum
for
acute
assessment
and
a
weighted
average
for
the
chronic
assessment.
The
rdf
file
to
be
used
in
the
acute
exposure
assesment
for
6
non
blended
and
partially
blended
food
forms
contains
the
residue
values
only
since
the
maximum
%
CT
is
100%.

Parsnip:
Data
from
6
parsnip
field
trials
(MRID
00018171)
indicate
that
the
linuron
residues
of
concern
were
<0.05
ppm
in/
on
parsnips
harvested
155,
169,
and
182
days
following
a
single
application
of
the
50%
WP
at
1.0
or
2.0
lb
ai/
A
(0.7x
or
1.3x
the
maximum
seasonal
rate).
Linuron
residues
of
concern
were
nondetectable
(<
0.05
ppm).
In
the
absence
of
reliable
analytical
data
concerning
the
limits
of
detection
(LOD),
the
residue
value
to
be
used
for
chronic
assessments
is;
(0.05
+
0.05
+
0.05
+
0.05
+
0.05
+
0.05)/
6
*
%
CT=
0.050000(%
CT)
ppm.
The
rdf
file
to
be
used
in
the
acute
exposure
assesment
for
non
blended
and
partially
blended
food
forms
contains
the
residue
values
and
194
zeros
to
reflect
3%
CT.

Potato:
Data
from
7
potato
field
trials
(MRID
00163267)
indicate
that
residues
were
nondetectable
(<
0.05
ppm)
in/
on
all
but
one
sample
(0.07
ppm)
of
potato
harvested
125
to
155
days
after
planting.
A
single
preeemergence
or
postemergence
application
of
the
WP
or
DF
formulation
was
made
at
1.0­
4.0
lb
ai/
A
(0.5­
2x
the
maximum
seasonal
application
rate)
using
ground
equipment.
Data
for
anticipated
residues
are;
0.05,
0.05,
0.05,
0.05,
0.05,
0.05,
0.07
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
blended
food
forms
is;
(0.05
+
0.05
+
0.05
+0.05
+
0.05
+
0.05
+0.07)/
7*
%
CT=
0.052857(%
CT)
ppm.
The
rdf
file
to
be
used
in
the
acute
exposure
assesment
for
non
blended
and
partially
blended
food
forms
contains
the
residue
values
and
57
zeros
to
reflect
11%
CT.

Leafy
Vegetables
Group
Celery:
Residue
data
from
celery
field
trials
(MRID
41501501)
indicate
that
linuron
residues
of
concern
were
0.04­
0.42
ppm
in/
on
six
celery
samples
harvested
68­
102
days
following
a
single
posttransplant
application
of
the
4
lb/
gal
FlC
or
50%
DF
formulation
at
1.5
lb
ai/
A
(1x
the
maximum
seasonal
rate)
in
tests
performed
in
FL,
MI,
and
NY.
Data
from
additional
celery
field
trials
(MRID
40537601)
indicate
that
linuron
residues
of
concern
were
nondetectable
(<
0.05
ppm)
to
0.32
ppm
in/
on
celery
(washed/
unwashed
and
trimmed
/untrimmed)
harvested
44­
82
days
following
postemergence
application
of
either
the
4
lb/
gal
FlC,
50%
WP,
or
50%
DF
formulation
at
(i)
0.5­
1.5
lb
ai/
A
(0.33­
1x
the
maximum
single
application
rate)
and
(ii)
two
or
four
applications
at
consecutive
intervals
of
22,
13,
and
19
days
for
a
total
seasonal
rate
of
1.5
or
3.0
lb
ai/
A
(1
or
2x
the
maximum
registered
seasonal
rate)
in
tests
performed
in
CA,
FL,
and
MI.

Currently,
the
Griffin
labels
for
the
4
lb/
gal
FlC
and
50%
DF
formulation
permit
use
on
celery
in
all
states
including
CA.
Griffin
Corporation
submitted
Interregional
Research
Project
No.
4
(IR­
4)
residue
data
(MRID
43681401)
in
support
of
a
request
for
amended
use
of
the
4
lb/
gal
FlC
and
50%
DF
formulations
on
celery
grown
west
of
the
Rocky
Mountains.
Linuron
residues
of
concern
were
0.04­
0.12
ppm
in/
on
celery
grown
in
CA
or
OR
and
harvested
66
or
77
days
following
posttransplant
application
at
1.5
lb
ai/
A
(1x
the
maximum
seasonal
rate
for
all
states
except
CA;
1.5x
the
maximum
seasonal
rate
for
CA).

The
data
for
the
anticipated
residues
are
taken
from
MRIDs
40537601,
43681401,
and
41501501
and
7
reflect
1.5
lb/
ai/
A
and
PHI
range
of
60­
83
days.

Data
for
anticipated
residues
are;
0.08,
0.07,
0.10,
0.12,
0.05,
0.06,
0.04,
0.04,
0.12,
0.14,
0.42,
0.18,
0.32,
0.17,
<0.05,
<0.05
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
blended
food
forms
is;
(0.08
+
0.07
+
0.10
+
0.12
+
0.05
+
0.06
+
0.04
+
0.04
+
0.12
+
0.14
+
0.42
+
0.18
+
0.32
+
0.17
+
0.05
+
0.05)/
16*%
CT=
0.125625(%
CT)
ppm.
The
rdf
file
to
be
used
in
acute
exposure
assesment
for
non
blended
and
partially
blended
food
forms
contains
the
16
residue
values
and
17
zeros.

Parsley:
Data
reported
in
MRID
41189801
indicate
that
linuron
residues
of
concern
from
a
single
preemergence
application
at
1x
were
0.08­
0.11
ppm
in/
on
samples
of
parsley
harvested
52­
90
days
after
treatment.
Linuron
residues
of
concern
from
a
single
preemergence
plus
a
postemergence
application
at
1.3x
total
were
0.09­
0.18
ppm
in/
on
parsley
24
days
after
the
last
application.
Data
for
anticipated
residues
are;
0.08,
0.18,
0.08,
0.12,
0.11,
0.11
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
blended
food
forms
is;
(0.08,
0.18,
0.08,
0.12,
0.11,
0.11)/
6*
(%
CT)=
0.113333(%
CT)
ppm.
The
rdf
file
to
be
used
in
the
acute
exposure
assesment
for
non
blended
and
partially
food
forms
contains
the
6
residue
values
and
94
zeros.

Legume
Vegetables
Group
Soybean:
Data
reported
in
MRID
43039101
indicate
that
the
linuron
residues
of
concern
from
were
<0.01­
1.0
ppm
in/
on
9
samples
of
soybeans
harvested
56­
132
days
following
a
single
preemergence
application
of
the
DF
formulation
at
2.5
lb
ai/
A
followed
by
a
single
directed
postemergence
application
at
1.0
lb
ai/
A
for
a
total
rate
of
3.5
lb
ai/
A
(-1x
the
maximum
seasonal
rate).

Data
for
anticipated
residues
are;
0.31,
0.29,
0.31,
0.23,
0.087,
0.11,
0.10,
0.80
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
the
blended
food
forms
is;
(0.31,
0.29,
0.31,
0.23,
0.087,
0.11,
0.10,
0.80)/
8*
(%
CT)=
0.279625(%
CT)
ppm.

Cereal
Grain
Group
Corn,
field,
grain:
Data
from
field
corn
grain
field
trial
(MRID
40537601)
indicate
that
linuron
residues
were
nondetectable
(<
0.05
ppm)
to
0.11
ppm
in/
on
five
samples
of
field
corn
grain
harvested
between
47
and
116
days
following
a
single
postemergence
application
of
the
4
lb/
gal
FlC
formulation
at
1.5
lb
ai/
A
(1x
the
maximum
application
rate).

Corn
field
trial
data
(MRIDs
00018171,
00018206,
and
40210901)
indicate
that
linuron
residues
were:
(i)
nondetectable
(<
0.05
ppm)
in/
on
corn
grain
harvested
56­
65
days
following
a
single
postemergence
application
of
the
WP
formulation
at
0.75­
6.0
lb
ai/
A;
and
(ii)
nondetectable
(<
0.05
ppm)
in/
on
corn
grain
harvested
116­
125
days
following
a
single
preemergence
application
of
the
WP
formulation
at
1.5
lb
ai/
A.
One
sample
of
corn
harvested
150
days
following
0.75
lb/
ai
/A
(0.5x)
showed
detectable
residues
(0.06
8
ppm).

Data
for
anticipated
residues
are;
8@<
0.05,
0.11,0.09,0.10,0.06,
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
the
blended
food
forms
is;
((
8*
0.05)+
0.11
+
0.09
+
0.10
+
0.06)/
12*
(%
CT)=
0.063333(%
CT)
ppm.

Corn,
sweet
(K+
CWHR):
Crop
field
trial
data
for
sweet
corn
were
submitted
by
Griffin;
these
data
are
inadequate
to
fulfill
reregistration
requirements
because
of
incomplete
geographic
representation.
Although
inadequate,
the
field
trial
data
indicate
that
linuron
residues
of
concern
were
below
the
LOQ
(<
0.01
ppm)
to
0.048
ppm
in/
on
sweet
corn
K+
CWHR
harvested
at
maturity
following
a
single
soil
directed
application
of
the
50%
DF
or
4
lb/
gal
FlC
formulation
at
1.48­
1.57
lb
ai/
A
(~
1x
the
maximum
application
rate)
made
when
sweet
corn
plants
were
at
least
15
inches
tall.

Data
for
anticipated
residues
are;
16@<
0.01,
0.048,
0.04,
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
the
blended
food
forms
is;
((
16*
0.01)+
0.048
+
0.04)/
18*
(%
CT)=
0.013777(%
CT)
ppm.
The
rdf
file
to
be
used
in
acute
exposure
assessment
for
non
blended
and
partially
blended
food
forms
contains
the
18
residue
values
and
1584
zeros.

Sorghum:
Since
linuron
is
used
on
less
than
1%
of
the
US
sorghum
crop
the
tolerance
of
0.25
ppm
(corrected
for
%
CT)
will
be
used.

Wheat,
grain:
There
are
three
linuron
EPs
(EPA
Reg.
Nos.
1812­
245,
19713­
97,
and
51036­
78)
currently
registered
for
use
on
winter
wheat
(drill
planted)
in
ID,
OR,
and
WA..
Data
reported
in
MRID
42605901
indicate
that
the
linuron
residues
of
concern
were
nondetectable
(<
0.03
ppm
to
0.08
ppm)
in/
on
two
samples
of
wheat
grain
harvested
128
days
following
a
single
postemergence
application
of
the
DF
formulation
at
2.5
or
5.0
lb
ai/
A
(1.4x
or
2.9x
the
maximum
seasonal
rate
for
areas
west
of
the
Cascade
Range
and
3.3x
or
6.7x
the
maximum
seasonal
rate
for
areas
east
of
the
Cascade
Range).
Data
for
anticipated
residues
are;
4@
0.03,
5@
0.05,
0.08
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
the
blended
food
forms
is;
((
4*
0.03)+
5*(
0.05)
+
0.08)/
10*
(%
CT)=
0.045(%
CT)
ppm.

Miscellaneous
Commodities
Asparagus:
Residure
data
for
asparagus
(MRID
41452601)
indicate
that
linuron
residues
of
concern
were
0.4­
5.0
ppm
in/
on
asparagus
harvested
1
day
following
four
applications
(one
at
preemergence,
a
second
at
early
emergence,
followed
by
two
postemergence
applications)
at
1.0
lb
ai/
A/
application
for
a
total
rate
of
4.0
lb
ai/
A
(1x
the
maximum
seasonal
rate)
of
L
or
DF
formulations.
Data
for
anticipated
residues
are
from
8
samples;
6.75,
5.95,
1.74,
1.74,
1.13,
0.86,
2.0,
1.5
ppm.
The
residue
value
to
be
used
for
chronic
and
acute
assessments
for
blended
food
forms
is;
(6.75
+
5.95
+
1.74
+
1.74
+
1.13
+
0.86
+
2.0
+
1.5)/
8
(*%
CT)=
2.708750
(%
CT)
ppm.
The
rdf
file
to
be
used
in
the
acute
exposure
assessment
for
non
blended
and
partially
blended
food
forms
contains
the
residue
values
and
17
zeros.
9
Cotton,
seed:
Since
linuron
is
used
on
less
than
1%
of
the
U.
S.
cotton
crop
the
tolerance
of
0.05
ppm
(corrected
for
%
CT)
will
be
used.

4.
Processing
Studies
The
reregistration
requirements
for
the
magnitude
of
the
residue
in
processed
food/
feed
are
fulfilled
for
field
corn,
cotton,
soybeans,
and
wheat.

Corn,
field:
An
acceptable
field
corn
processing
study
has
been
submitted
(MRID
42560001).
The
data
indicate
that
linuron
residues
of
concern
do
not
concentrate
in
starch,
grits,
meal,
flour,
or
crude
or
refined
oil
(from
both
wet
and
dry
milling)
processed
from
field
corn
grain
bearing
trace
residues
following
treatment
at
5x.

Cotton:
Acceptable
residue
data
are
available
for
cotton
processed
commodities
(DP
Barcode
D271950).
No
concentration
of
linuron
residues
of
concern
was
observed
in
cotton
meal,
hulls,
and
refined
oil
processed
from
cottonseed
bearing
detectable
linuron
residues
of
concern.

Potato:
The
processing
data
indicate
that
linuron
residues
of
concern
concentrate
in
wet
peel
waste
(processing
factor
of
5.5x),
chips
(2.0x),
dehydrated
granules
(3.4x),
and
oven­
baked
potatoes
(2.1x)
but
do
not
concentrate
in
peeled
potato
(0.82x)
or
mashed
potato
(0.61x).

Sorghum,
grain:
Sorghum
processing
data
(DP
Barcode
D187993,
11/
18/
93,
D.
McNeilly)
indicate
that
linuron
residues
of
concern
do
not
concentrate
in
sorghum
flour
(processing
factor
of
<0.44x)
or
starch
(<
0.44x).

Soybean:
The
available
soybean
processing
data
(
DP
Barcode
D182595)
indicate
that
linuron
residues
of
concern
do
not
concentrate
significantly
in
hulls
(processing
factor
of
0.5x),
meal
(1.2x),
soapstock
(0.7x),
crude
oil
(0.2x),
refined
oil
(0.2x),
degummed
oil
(0.2x),
tofu
(0.3x),
light
impurities
(0.9x),
soybean
milk
(0.15x),
or
soybean
kernels
(0.9x).
Residues
were
found
to
concentrate
in
soybean
isolate
(1.6x)
and
lecithin
(2.3x).

Wheat:
HED
granted
a
waiver
for
a
wheat
processing
study
for
linuron
(DP
Barcode
D185892,
1/
15/
93,
R.
Perfetti)
based
on
the
fact
that
linuron
residues
of
concern
were
below
the
LOQ
(<
0.03
ppm)
in/
on
wheat
grain
treated
at
an
exaggerated
rate
of
6.7x.

5.
Reduction
of
Residues
All
data
for
reduction
of
residues
have
been
evaluated
and
deemed
adequate
except
that
additional
information
is
required
to
upgrade
existing
potato
and
carrot
cooking
studies.

The
asparagus
cooking
study
shows
washing
with
water
reduces
residues
by
40%.
Boiling
removes
an
10
additional
25%
of
the
residues,
while
steaming
had
little
or
no
effect
on
reducing
residue
levels
in
or
on
asparagus
(D182590,
3/
18/
93,
D.
McNeilly).

A
carrot
cooking
study
indicated
that
linuron
residues
of
concern
concentrate
in
peels
(3.3x)
but
reduce
after
boiling
(0.3x)
or
steaming
(0.4x).
Additional
information
pertaining
to
how
the
carrots
were
cooked
and
how
the
LOQs
were
determined
is
required
to
upgrade
this
study
(D181455,
9/
8/
92,
S.
Knizner).

The
potato
cooking
study
shows
that
linuron
residues
concentrate
in
oven­
baked
potatoes
(1.5x)
and
microwave­
baked
potatoes
(1.6x),
but
are
reduced
in
boiled
potatoes
(0.48x).
Additional
information
pertaining
to
the
cooking
procedures,
LOQ
determination,
and
sample
handling/
storage
is
required
to
upgrade
this
study
(D181454,
9/
2/
92,
S.
Knizner).

The
appropriate
reduction
factor
will
be
used
in
the
DEEM
input
files.
For
commodities
not
specifically
tested
a
boiling
factor
will
be
employed
using
an
average
of
the
three
cooking
studies
listed
above
(0.35x).

6.
Residues
in
Meat
and
Milk
Two
cows
were
fed
50
ppm
linuron
(6.9x)
for
30
days.
Residues
were
12.0
and
13.0
ppm
in
kidney,
11.0
and
13.0
in
liver,
0.45
and
0.48
ppm
in
lean
muscle,
and
0.48
and
1.10
ppm
in
subcutaneous
fat.
Milk
residues
were
0.05­
0.37
ppm,
with
the
highest
value
observed
on
Day
27
of
dosing;
milk
samples
were
collected
every
other
day
during
dosing
(MRID
00018210).
Tolerances
are
not
required
for
poultry.

Table
2
Cattle
diet
for
acute
exposure
assessment
(6.9x):

Feed
Item
%
Dry
Matter
%
Diet
Residues
Contibution
(ppm)

Carrot,
culls
12
25
1.00
2.08
Corn,
sweet,
forage
48
40
3.00*
2.50
Cotton,
gin
byproducts
90
20
9.00*
2.00
Cottonseed,
meal
89
15
0.10
0.017
Total
6.60
*Estimated
tolerance
(additional
field
trial
data
required).

Anticipated
residues
for
acute
exposure
assessments
were
computed
as
follows;

Fat
(0.48+
1.10)/
2
/
6.9=
0.114493
ppm
Muscle
(0.45+
0.48)/
2
/6.9
=
0.067391ppm.
Liver/
kidney
(12.0+
13.0+
11.0+
13.0)/
4/
6.9=
1.775362ppm.
Milk
0.37/
6.9=
0.053623
ppm
11
Table
3
Cattle
diet
for
chronic
exposure
assessment
(37x).

Feed
Item
%
Dry
Matter
%
Diet
Residues
Contibution
(ppm)

Carrot,
culls
12
25
0.368333
0.767354
Corn,
sweet,
forage
48
40
0.277139
0.230949
Cotton,
gin
byproducts
90
20
1.491475
0.331439
Cottonseed,
meal
89
15
0.10
0.017
Total
100
1.34672
Fat
(0.48+
1.10)/
2
/37=
0.085405
ppm
Muscle
(0.45+
0.48)/
2
/37
=0.012567
ppm.
Liver/
kidney
(12.0+
13.0+
11.0+
13.0)/
4/
37=
0.337838
ppm.
Milk
0.37/
37=
0.010000
These
values
are
used
for:
liver,
kidney,
meat
byproducts,
and
other
organ
meats
of
beef,
goat,
horses,
sheep,
and
veal.

Table
4
Swine
diet
for
acute
exposure
assessment
(153x).

Feed
Item
Carrot,
culls
NA
10
1.0
0.10
Sorghum,
grain
NA
90
0.25
0.225
Total
100
0.325
Fat
(0.48+
1.10)/
2
/153=
0.005163
ppm
Muscle
(0.45+
0.48)/
2
/153
=
0.003039
ppm.
Liver/
kidney
(12.0+
13.0+
11.0+
13.0)/
4/
153=
0.080065
ppm.

Table
5
Swine
diet
for
chronic
exposure
assessment
(191x).

Feed
Item
Carrot,
culls
NA
10
0.368333
0.036833
Sorghum,
grain
NA
90
0.25
0.225
Total
100
0.261833
Fat
(0.48+
1.10)/
2
/191=
0.004136
ppm
Muscle
(0.45+
0.48)/
2
/191=
0.002435
ppm.
Liver/
kidney
(12.0+
13.0+
11.0+
13.0)/
4/
191=
0.065445
ppm.
12
7.
Toxicology
Data
On
September
13
and
27,
2001
the
Hazard
Identification
Assessment
Review
Committee
(HIARC)
reviewed
the
toxicology
data
base
of
linuron
and
selected
endpoints/
doses
for
various
exposure
assessments.
The
HIARC
also
evaluated
the
potential
for
increased
susceptibility
of
infants
and
children
from
exposure
to
linuron
as
required
by
the
Food
Quality
Protection
Act
(FQPA)
of
1996.
The
doses
and
toxicological
endpoints
selected
for
various
exposure
scenarios
are
summarized
below
(HED
DOC.
No.
0050286).

Table
6
Toxicology
data.

EXPOSURE
SCENARIO
DOSE
(mg/
kg/
day)
ENDPOINT
STUDY
Acute
Dietary
(Females
13­
50)
NOAEL=
12.1
UF
=
100
Increased
post­
implantation
loss
and
fetal/
litter
resorptions
at
49.8
mg/
kg/
day
(LOAEL).
Rat
Prenatal
Developmental
Toxicity
(MRID
00018167)

Acute
RfD
(Females
13­
50
years
old)
=
0.121
mg/
kg
Acute
Dietary
(General
Population)
No
appropriate
effects
attributed
to
a
single
exposure
was
identified.

Chronic
Dietary
NOAEL
=
0.77
UF
=
100
Increased
met­
and
sulfhemoglobin
levels
at
LOAEL
(4.17
mg/
kg/
day,
males;
3.49
mg/
kg/
day,
females).
Chronic
Oral
/
Dog
(MRID
40952601)

Chronic
RfD
=
0.0077
mg/
kg/
day
The
FQPA
committee
met
on
11/
26/
2001
and
reduced
the
safety
factor
to
3x
for
acute
dietary
and
retained
a
10x
safety
factor
for
chronic
exposure
assessment.
The
cPAD
and
aPAD
are:
12.1
mg/
kg/
300=
0.0403333
mg/
kg
and
0.77
mg/
kg/
1000=
0.00077
mg/
kg
respectively
(TXR
No.
0050322).

The
rationale
for
requiring
the
FQPA
Safety
Factor
is
listed
below;

1.
A
qualitative
increase
in
susceptibility
seen
in
the
F1
males
in
the
rat
reproductive
toxicity
study.
2.
A
developmental
neurotoxicity
study
in
rats
is
required
for
the
chemical
because
linuron
is
a
potential
endocrine
disruptor
and
there
is
evidence
for
testicular
lesions
and
decreased
fertility
in
the
rat
reproductive
toxicity
study.
3.
The
toxicology
database
is
complete;
4.
The
dietary
(food
and
water)
exposure
assessments
will
not
underestimate
the
potential
exposures
for
infants,
children,
and/
or
women
of
childbearing
age;
and,
5.
There
are
no
residential
uses.
13
8.
Results
The
chronic
exposure
to
linuron
from
the
diets
of
the
U.
S.
population
and
a
number
of
populations
was
computed
using
the
latest
version
of
DEEM,
anticipated
residues
discribed
above,
1989­
1992
USDA
consumption
data
and
current
percent
crop
treated
data
provided
by
BEAD.
These
results
are
presented
in
Table
4.
Estimated
chronic
dietary
exposure
associated
with
the
use
of
linuron
does
not
exceed
HED's
level
of
concern
(>
100%
cPAD)
for
the
US
population
or
any
population
subgroup
examined.
The
chronic
dietary
risk
estimates
for
the
US
population
and
children
aged
1­
6
years
(the
highest
exposed
group)
are
approximately
15
%
and
35
%
of
cPAD,
respectively.
Approximately
30
%
of
the
chronic
exposure
to
linuron
from
food
is
from
meats
and
milk.
The
AR
for
meats
and
milk
are
based
on
an
extremely
conservative
animal
diets
and
is
likely
overestimated.

Table
7.
The
chronic
exposure
of
linuron
from
the
diets
for
a
variety
of
subpopoulations.

Population
subgroup
Exposure
(mg/
kg/
day)
%
cPAD
U.
S.
Population
(total)
0.000114
14.8
Infants
(<
1
year)
0.000179
23.3
Children
1­
6
yrs
0.000268
34.7
Children
7­
12
yrs
0.000173
22.4
Females
13­
50
yrs
0.000083
10.8
Males
13­
19
yrs
0.000102
13.2
Males
20+
yrs
0.000088
11.4
Seniors
55+
0.000094
12.2
The
acute
exposure
to
linuron
from
the
diet
for
a
subgroup
of
the
U.
S.
population
was
computed
using
a
Monte­
Carlo
approach
with
1000
iterations
in
the
latest
version
of
DEEM,
anticipated
residues
discribed
above,
1989­
1992
USDA
consumption
data
and
current
percent
crop
treated
data
provided
by
BEAD.
These
results
are
presented
in
Table
5.
Estimates
for
acute
dietary
exposures
associated
with
the
use
of
linuron
does
not
exceed
HED's
level
of
concern
(>
100%
aPAD)
for
the
population
subgroup
comprised
of
14
females
aged
13
years
to
50
years.
The
acute
dietary
risk
exposure
estimate
for
this
population
is
approximately
10
%
of
aPAD.
Approximately
37
%
of
the
acute
exposure
to
linuron
from
food
is
from
asparagus
and
milk.
The
AR
for
milk
is
based
on
an
extremely
conservative
animal
diet
and
is
likely
overestimated.

Table
8.
Acute
dietary
exposure
of
linuron
from
the
diets
for
a
variety
of
subpopoulations.

Population
subgroup
95
th
percentile
99
th
percentile
99.9
th
percentile
exposure
(mg/
kg/
day)
%aPAD
exposure
(mg/
kg/
day)
%aPAD
exposure
(mg/
kg/
day
%aPAD
Females
13­
50
yrs
0.000605
1.50
0.001177
2.92
0.003839
9.52
Appendix
1;
Residue
Distribution
Files
(asparagus.
rdf,
carrot.
rdf,
celery.
rdf,
parsely.
rdf,
potato.
rdf,
sweetcorn.
rdf).
Appendix
2;
Chronic
DEEM
input
files
(linuron_
chronic.
rs7,
linuron_
chronic.
AC1).
Appendix
3;
Acute
DEEM
input
files
(linuron_
acute.
rs7,
linuron_
acute.
AC1)
Appendix
4;
BEAD
%
Crop
Treated
Data.

Asparagus.
rdf
totalnz=
8
totalz=
17
totallod=
0
lodres=
0.05
6.75
5.95
1.74
1.74
1.13
0.86
2.0
1.5
End
of
File
(EOF)

Parsnip.
rdf
totalnz=
6
15
totalz=
194
totallod=
0
lodres=
0.05
0.05
0.05
0.05
0.05
0.05
0.05
EOF
Potato.
rdf
totalnz=
7
totalz=
57
totallod=
0
lodres=
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.07
EOF
Celery.
rdf
totalnz=
16
totalz=
17
totallod=
0
lodres=
0.05
0.08
0.07
0.10
0.12
0.05
0.06
0.04
0.04
0.12
16
0.14
0.42
0.18
0.32
0.17
0.05
0.05
EOF
Parsely.
rdf
totalnz=
6
totalz=
94
totallod=
0
lodres=
0.05
0.08
0.18
0.08
0.12
0.11
0.11
EOF
Carrot.
rdf
totalnz=
6
totalz=
0
totallod=
0
lodres=
0.05
0.30
0.28
0.40
0.50
0.39
0.34
EOF
Sweetcarn.
rdf
totalnz=
18
17
totalz=
1584
totallod=
0
lodres=
0.05
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.048
0.04
EOF
Acute.
AC1
Chronic.
CH1
Quantitative
Usage
Analysis
for
Linuron
Case
Number:
0047
PC
Code:
35506
Date:
October
22,
2001
Analyst:
Frank
Hernandez
Based
on
available
usage
information
from
pesticide
surveys
for
the
years
of
1992
through
2000,
total
annual
domestic
usage
of
linuron
averaged
approximately
over
four
hundred
thousand
pounds
of
active
ingredient
(a.
i.)
for
just
under
four
hundred
thousand
acres
treated.
Linuron
is
a
herbicide
with
its
largest
markets
in
terms
of
total
pounds
of
active
ingredient
allocated
to
carrots
(35%),
potatoes
(20%),
and
cotton
(17%).
Most
of
the
usage
is
in
IL,
IN,
MD,
MI,
OH,
and
WA.
Crops
with
a
high
percentage
of
the
total
U.
S.
planted
acres
treated
include
carrots
(75%),
celery
(24%),
18
asparagus
(20%),
and
potatoes
(7%).
Crops
with
less
than
1
percent
of
the
crop
treated
include
alfalfa,
barley,
dry
beans,
corn,
cotton,
lettuce,
melons,
peanuts,
rice,
rye,
sorghum,
soybeans,
sweet
corn,
and
wheat.

Site
Acres
Grown
(000)
Acres
Treated
(000)
%
of
Crop
Treated
LB
AI
Applied
(000)
Average
Application
Rate
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
lb
ai/
A/
yr
#appl
/
yr
lb
ai/
A/
appl
Alfalfa
23,701
1
4
0.00
0.02
1
2
0.7
1.0
0.7
Asparagus
90
18
30
20.39
33.29
18
36
1.0
1.0
1.0
Barley
7,326
0
0
0.00
0.00
0
0
0.5
1.0
0.5
Beans/
Peas,
Dry
2,190
3
12
0.14
0.54
2
10
0.8
2.5
0.3
Beans/
Peas,
Green
709
1
2
0.10
0.28
0
1
0.4
1.0
0.4
Carrots
104
79
104
75.31
100.00
145
210
1.8
1.0
1.8
Celery
34
8
11
23.67
32.54
4
8
0.5
1.0
0.5
Corn
72,425
7
10
0.01
0.01
15
29
2.1
1.3
1.7
Cotton
12967
88
233
0.68
1.80
72
123
0.8
1.0
0.8
Lettuce
274
2
8
0.61
2.98
1
5
0.6
1.0
0.6
Melons
375
1
2
0.25
0.5051
1
2
1.0
1.0
1.0
Site
Acres
Grown
(000)
Acres
Treated
(000)
%
of
Crop
Treated
LB
AI
Applied
(000)
Average
Application
Rate
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
lb
ai/
A/
yr
#appl
/
yr
lb
ai/
A/
appl
19
Oats/
Rye
6,184
0
1
0.01
0.01
0
1
0.7
1.0
0.7
Parsley
5
0
0
3.00
6.00
0
2
2.7
3.5
0.8
Parsnips
4
0
0
1.55
2.33
0
0
1.0
1.0
1.0
Peanuts
1,582
0
1
0.03
0.06
1
1
1.1
1.0
1.1
Potatoes
1,433
100
158
6.98
11.03
85
180
0.8
1.0
0.8
Rice
2,992
5
20
0.18
0.66
3
13
0.5
1.1
0.5
Rye
4,364
0
1
0.01
0.02
0
1
0.7
1.0
0.7
Sorghum
11,140
33
107
0.30
0.96
13
52
0.4
1.0
0.4
Soybeans
63,141
25
41
0.04
0.07
53
100
2.1
1.1
2.0
Sweet
Corn
732
3
10
0.47
1.37
4
8
1.19
1.6
0.8
Wheat,
Spring
21,311
0
2
0.00
0.01
0
1
0.5
1.0
0.5
Wheat,
Winter
44,907
7
13
0.01
0.03
3
6
0.4
2.0
0.2
Total
383
577
421
605
COLUMN
HEADINGS
Wtd
Avg
=
Weighted
average­­
the
most
recent
years
and
more
reliable
data
are
weighted
more
heavily.
Est
Max
=
Estimated
maximum,
which
is
estimated
from
available
data.
Average
application
rates
are
calculated
from
the
weighted
averages.

NOTES
ON
TABLE
DATA
Usage
data
primarily
covers
1992
­
2000.
Calculations
of
the
above
numbers
may
not
appear
to
agree
because
they
are
displayed
as
rounded
to
the
nearest
1000
for
acres
treated
or
lb.
a.
i.
(therefore
0
=
<
500),
and
to
two
decimal
percentage
points
for
%
of
crop
treated.

Other/
Crop
Groups
Melons
include
cantaloupe,
watermelon,
honeydew,
muskmelon,
and
winter
melon.

SOURCES:
EPA
data,
USDA,
and
National
Center
for
Food
and
Agricultural
Policy.
20
cc:
JSPunzi
(RRB2),
Linuron
Reg.
Std.
File,
Linuron
SF,
RF,
LAN.
RD/
I:
RRB2
Chem
Review
Team
(12/
10/
2001),
Alan
Nielsen
(12/
30/
2001),
ChemSac
(12/
12/
2001),
DeSac
(12/
18/
2001).
7509C:
RRB2:
John
S.
Punzi:
CM2:
Rm
804E:
703­
305­
7727:
12/
20/
2001.
