Document ID: EPA-HQ-OPP-2002-0249-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2002-02-11T05:00Z

Page
1
of
30
Overview
of
the
Diruon
Risk
Assessment
July
29,
2002
Introduction
This
document
summarizes
the
Environmental
Protection
Agency's
(
EPA)
human
health,
environmental
fate
and
transport,
and
ecological
risk
findings
for
the
pesticide
diuron,
as
presented
fully
in
the
documents,
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002,
and
"
Environmental
Risk
Assessment
for
the
Reregistration
of
Diuron,"
dated
March
11,
2002.
The
purpose
of
this
overview
is
to
help
the
reader
understand
the
conclusions
reached
in
the
risk
assessments
by
identifying
the
key
features
and
findings
of
the
assessments.
References
to
relevant
sections
in
the
complete
documents
are
provided
for
a
more
detailed
explanation.
This
overview
was
developed
in
response
to
comments
from
the
public
which
indicated
that
EPA's
risk
assessments
were
difficult
to
understand,
that
they
were
too
lengthy,
and
that
it
was
not
easy
to
compare
the
assessments
for
different
chemicals
due
to
the
use
of
different
formats.

These
diuron
risk
assessments
and
additional
supporting
documents,
are
posted
on
EPA's
Internet
website
(
http://
www.
epa.
gov/
pesticides/
reregistration/
diuron)
and
are
available
in
the
Pesticide
Docket
for
public
viewing.
Meetings
with
stakeholders
(
i.
e.,
growers,
extension
officials,
public
interest
groups,
commodity
group
representatives
and
other
government
officials)
will
be
held
to
discuss
the
risk
assessments,
the
identified
risks
and
solicit
input
on
risk
mitigation
strategies,
if
needed.
This
feedback
will
be
used
to
complete
the
Reregistration
Eligibility
Decision
(
RED)
document,
which
will
include
the
resulting
risk
management
decisions.
The
Agency
plans
to
conduct
a
close­
out
conference
call
with
interested
stakeholders
to
describe
the
regulatory
decisions
presented
in
the
RED.
In
the
case
of
diuron,
the
Agency
intends
to
proceed
with
finalizing
the
tolerance
reassessment
now
and
completing
the
RED,
including
any
necessary
mitigation
for
worker
and
ecological
risks
in
2003.

Risks
summarized
in
this
document
are
those
that
result
only
from
the
use
of
diuron.
The
Food
Quality
Protection
Act
(
FQPA)
requires
that
the
Agency
consider
"
available
information"
concerning
the
cumulative
effects
of
a
particular
pesticide's
residues
and
"
other
substances
that
have
a
common
mechanism
of
toxicity."
The
reason
for
consideration
of
other
substances
is
due
to
the
possibility
that
low­
level
exposures
to
multiple
chemical
substances
that
cause
a
common
toxic
effect
by
a
common
mechanism
could
lead
to
the
same
adverse
health
effect
as
would
a
higher
level
of
exposure
to
any
of
the
other
substances
individually.
The
Agency
did
not
perform
a
cumulative
risk
assessment
as
part
of
this
reregistration
review
of
diuron
because
the
Agency
has
not
yet
determined
if
there
are
any
other
chemical
substances
that
share
a
common
mechanism
of
toxicity
with
diuron
(
see
Section
6
of
the
Human
Health
Risk
Assessment,
dated
March
13,
2002).
For
purposes
of
this
risk
assessment,
EPA
Page
2
of
30
has
assumed
that
diuron
does
not
have
a
common
mechanism
of
toxicity
with
other
substances.

Available
data
indicate
that
3,4­
DCA
is
a
metabolite
of
linuron,
diuron,
and
propanil.
EPA
has
not
aggregated
residues
of
3,4­
DCA
for
the
linuron,
diuron
and
propanil
risk
assessments
because
neither
linuron
nor
diuron
metabolize
to
3,4­
DCA
in
appreciable
amounts
(
less
than
1%
of
the
parent
compound
for
diuron)
in
animal,
plant
and
environmental
(
soil
and
water)
metabolism
studies.
Therefore,
3,4­
DCA
is
a
significant
residue
of
concern
for
propanil,
it
is
not
a
residue
of
concern
per
se
for
linuron
or
diuron.
The
registered
uses
for
linuron,
diuron,
and
propanil
result
in
minimal
cooccurrence
of
use.
That
is,
there
is
very
little
overlap
of
use
patterns
and
the
use
patterns
are
geographically
limited
for
each
active
chemical.
Therefore,
the
risk
assessments
for
each
individual
chemical
fully
assess
the
risks
posed
by
the
parent
compound
and
the
relevant
metabolites.

In
the
future,
the
registrant
may
be
asked
to
submit,
upon
EPA's
request
and
according
to
a
schedule
determined
by
the
Agency,
such
information
as
the
Agency
directs
to
be
submitted
in
order
to
evaluate
issues
related
to
whether
diuron
shares
a
common
mechanism
of
toxicity
with
any
other
substance
and,
if
so,
whether
any
tolerances
for
diuron
need
to
be
modified
or
revoked.
If
the
Agency
identifies
other
substances
that
share
a
common
mechanism
of
toxicity
with
diuron,
we
will
perform
aggregate
exposure
assessments
on
each
chemical,
and
will
begin
to
conduct
a
cumulative
risk
assessment.
The
Agency
has
developed
a
framework
for
conducting
cumulative
risk
assessments
on
substances
that
have
a
common
mechanism
of
toxicity.
This
guidance
was
issued
on
January
16,
2002
(
67
FR
2210­
2214),
and
is
available
from
the
OPP
Website
at:
http://
www.
epa.
gov/
pesticides/
trac/
science/
cumulative_
guidance.
pdf.

The
risk
assessment,
and
documents
pertaining
to
the
Agency's
report
on
FQPA
tolerance
reassessment
progress
and
risk
management
decision
for
diuron
are
available
on
the
Internet
at
http://
www.
epa.
gov/
pesticides/
reregistration/
status.
htm
and
the
public
docket
for
viewing.
Because
the
dietary
risks
posed
by
the
use
of
diuron
are
low
and
drinking
water
concerns
are
being
addressed
by
mitigation
and
the
development
of
confirmatory
data,
the
Agency
is
proceeding
with
its
decision
on
the
tolerance
reassessment
at
this
time.
The
Agency's
tolerance
reassessment
decision
for
diuron
will
be
announced
in
the
Federal
Register.
The
complete
RED
for
diuron
will
be
issued
later
this
year.

Use
Profile
°
Herbicide,
Mildewcide
and
Algaecide:
Registered
for
pre­
and
post­
emergent
herbicide
treatment
of
both
crop
and
non­
crop
areas,
as
a
mildewcide
and
preservative
in
paints
and
stains,
and
as
an
algaecide
in
commercial
fish
production,
residential
ponds
and
aquariums.

°
Formulations:
Formulated
as
wettable
powder
(
25%
to
80%
ai),
liquid
(
up
to
40%
ai),
emulsifiable
concentrate
(
2%
to
80%
ai),
dry
flowable
(
40%
to
80
%
ai),
flowable
concentrate
(
19%
to
47.5%
ai),
granular
(
0.2%
to
20%
ai),
pellet/
tablet
(
0.51%
to
19%
ai),
and
ready­
to­
Page
3
of
30
use
solution
(
0.67%
to
19%
ai).

°
Methods
of
Application:
Applied
by
groundboom
sprayer,
aerial
equipment,
chemigation,
right­
of­
way
sprayer,
high­
and
low­
pressure
handwands,
tractor­
drawn
spreader,
push­
type
spreader,
airless
paint
sprayer,
paintbrush,
paintbrush/
roller,
shaker­
type
applicator,
backpack
sprayer,
backpack
granular
spreader,
belly
grinder,
spoon,
or
hand.

°
Use
Rates:
For
agricultural
uses,
labeled
single
application
rates
range
from
0.2
to
9.6
lbs
active
ingredient
(
ai)
per
acre.
One
to
four
applications
per
season
may
be
applied
in
60­
day
intervals,
for
most
crops
only
one
application
is
used.
For
non­
agricultural
uses
labeled
rates
range
from
0.8
lbs
to
87
lbs
ai/
acre;
however,
the
highest
application
rate
on
an
actively
marketed
label
is
12
lbs
ai/
acre.
The
risk
assessments
evaluate
a
range
of
rates;
however,
this
overview
will
focus
on
application
rates
of
12
lbs
ai/
A
or
lower.
The
higher
rates
on
the
other
products
are
not
being
supported
by
the
registrant
and
will
be
removed
from
product
labels.
Diuron
may
be
applied
to
non­
agricultural
areas
1
to
2
times
per
year.
For
the
mildewcide
and
preservative
in
paint
uses,
label
rates
go
up
to
0.053
lbs
ai/
gal.
and
for
algaecidal
uses
labeled
rates
are
less
than
1/
100th
%
ai/
gal.

°
Annual
Poundage:
Estimates
for
total
annual
domestic
use
average
approximately
nine
to
ten
million
pounds
of
active
ingredient.
Approximately
two
thirds
are
used
on
agricultural
crops
and
the
remaining
one
third
on
non­
crop
areas.
Diuron
is
used
on
33
crops.
Crops
with
the
highest
percent
crop
treated
are
the
citrus
fruit
group,
dried
citrus
pulp,
blackberries,
blueberries,
boysenberries,
currants,
dewberries,
gooseberries,
huckleberries,
loganberries,
raspberries,
pineapple,
and
asparagus.
In
terms
of
pounds
applied,
oranges
and
cotton
account
for
the
greatest
agricultural
use.
Right­
of­
way
applications
(
e.
g.,
the
area
around
railroad
tracks)
are
the
greatest
non­
agricultural
use
of
diuron,
with
approximately
2
to
3
million
pounds
applied
annually.

°
Registrants:
Griffin
Corporation,
Drexel,
DuPont,
Staveley,
United
Phosphorus,
and
Makhteshim­
Agan
of
North
America
Page
4
of
30
Human
Health
Risk
Assessment
Dietary
Diuron
is
an
herbicide
that
is
not
applied
directly
to
most
agricultural
crops,
but
is
applied
to
the
area
around
the
crop
to
kill
weeds.
However,
the
following
crops
can
be
treated
with
foliar
applications
of
diuron:
oats;
forage;
oats,
grain;
oats,
hay;
oats,
straw;
wheat,
forage;
wheat,
grain;
wheat,
hay;
wheat
straw;
birdsfoot
trefoil,
forage;
birdsfoot
trefoil,
hay;
grass,
forage,
except
Bermuda
grass;
grass,
hay,
except
Bermuda
grass;
alfalfa,
forage;
alfalfa,
hay;
asparagus;
clover,
forage;
clover,
hay;
pineapple;
and
sugarcane.
The
residue
data
for
diuron,
which
does
not
indicate
dietary
concerns,
is
consistent
with
this
use
pattern.

Acute
Dietary
Risk
(
Food)

For
a
complete
discussion,
see
section
4.2
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

Acute
dietary
risk
is
calculated
considering
foods
eaten
in
one
day
(
consumption)
and
diuron
residue
values
in
or
on
the
food
eaten
by
the
general
population
and
each
population
subgroup
of
interest.
The
consumption
distribution
can
either
be
multiplied
by
a
residue
point
estimate
for
a
deterministic­
type
(
i.
e.,
Tier
I/
II)
exposure
assessment,
or
used
with
a
residue
distribution
in
a
Tier
III
probabilistic­
type
(
Monte
Carlo)
exposure
assessment.
A
risk
estimate
that
is
less
than
100%
of
the
acute
Population
Adjusted
Dose
(
aPAD)
(
the
dose
at
which
an
individual
could
be
exposed
on
any
given
day
that
would
not
be
expected
to
result
in
adverse
health
effects)
does
not
exceed
the
Agency's
level
of
concern.
The
aPAD
is
the
acute
reference
dose
(
aRFD)
adjusted
for
the
FQPA
safety
factor.

The
Agency
has
not
performed
an
acute
dietary
risk
assessment
of
diuron
because
no
adverse
effects
attributed
to
a
single
exposure
were
identified
in
any
available
study.

Chronic
(
non­
cancer)
Dietary
Risk
(
Food)

For
a
complete
discussion,
see
section
4.2
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

Chronic
dietary
risk
is
calculated
by
using
an
average
consumption
value
(
based
on
a
survey)
for
food
and
average
residue
values
on
those
foods
consumed
over
a
70­
year
lifetime.
A
risk
estimate
that
is
less
than
100%
of
the
chronic
PAD
(
the
dose
at
which
an
individual
could
be
exposed
over
the
course
of
a
lifetime
and
no
adverse
health
effects
would
be
expected)
does
not
exceed
the
Agency's
level
of
concern.
The
cPAD
is
the
chronic
reference
dose
(
cRfD)
adjusted
for
the
FQPA
Safety
Factor.
Page
5
of
30
Chronic
risk
estimates
from
exposures
to
food
do
not
exceed
the
Agency's
level
of
concern.
The
chronic
risk
estimate
for
food
is
about
3%
of
the
cPAD
for
the
U.
S.
Population
and
about
7%
for
children
from
1­
6
years,
the
most
sensitive
population
subgroup.

°
The
toxicity
endpoint
for
the
chronic
dietary
assessment
is
from
a
combined
chronic/
carcinogenicity
study
in
rats.
It
is
based
on
evidence
of
hemolytic
anemia
(
an
effect
that
reduces
the
oxygen
carrying
capacity
of
the
blood
cells)
and
compensatory
hematopoiesis
(
regeneration
of
red
blood
cells).
A
No
Observable
Adverse
Effect
Level
(
NOAEL)
was
not
established
and
these
effects
were
observed
at
1.0
mg/
kg/
day
(
Lowest
Observable
Adverse
Effect
Level
or
LOAEL).

°
The
Uncertainty
Factor
(
UF)
is
300X:
10X
for
inter­
species
variation,
10X
for
intra­
species
extrapolation,
and
3X
for
the
lack
of
a
NOAEL.

°
There
is
an
acceptable
developmental
toxicity
study
in
rabbits
and
an
acceptable
twogeneration
reproduction
study
in
rats.
A
developmental
toxicity
study
in
rats
was
classified
as
unacceptable
due
to
deficiencies
in
analytical
data
on
the
sample
analysis.
However,
the
Hazard
Identification
Assessment
Review
Committee
(
HIARC)
considered
the
developmental
toxicity
study
in
rats
adequate
for
the
FQPA
susceptibility
assessment
based
on
the
observation
that
the
developmental
toxicity
NOAEL
was
higher
than
the
maternal
NOAEL.

°
There
are
no
neurotoxic
signs
in
any
of
the
submitted
subchronic
or
chronic
studies
and
a
literature
search
did
not
reveal
any
studies
relevant
for
assessing
the
potential
neurotoxicity
of
diuron.

°
The
10X
FQPA
Special
Safety
Factor
is
reduced
to
1X
(
i.
e.,
removed)
because
there
is
no
indication
of
increased
susceptibility
of
rats
or
rabbits
to
in
utero
or
postnatal
exposure,
and
the
dietary
and
non­
dietary
assessments
are
not
likely
to
underestimate
potential
exposure
to
infants
and
children.
A
developmental
neurotoxicity
study
(
DNT)
with
diuron
is
not
required.

°
The
chronic
Population
Adjusted
Dose
(
cPAD)
is
0.003
mg/
kg/
day
and
is
equal
to
the
LOAEL
(
1.0
mg/
kg/
day)
divided
by
the
uncertainty
factor
(
UF)
of
300X.

°
Anticipated
residues
from
field
trial
data
were
utilized
to
estimate
dietary
exposure.
The
field
trials
were
conducted
at
the
highest
application
rates
allowed
for
the
crop
tested;
therefore,
the
residues
from
these
trials
are
considered
high
end.
Available
processing
data
for
apples,
citrus,
grapes
and
sugarcane
refined
into
sugar
and
molasses
were
used
in
the
assessment.
In
addition,
averaged
percent
crop
treated
information
was
included
in
the
assessment.

°
USDA
Pesticide
Data
Program
(
PDP)
food
monitoring
data
are
available
for
diuron
(
parent
Page
6
of
30
compound)
only.
These
data
indicate
no
detectable
residues
of
the
parent
compound
in
any
of
the
foods
sampled,
PDP
data
were
not
used
in
the
dietary
assessment
because
metabolites
were
not
monitored.

Cancer
Dietary
Risk
(
Food)

For
a
complete
discussion,
see
section
4.2
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

Like
chronic
dietary
risk,
potential
dietary
cancer
risk
is
calculated
by
using
the
average
consumption
values
for
food
and
average
residue
values
for
those
foods
over
a
70­
year
lifetime.
The
chronic
exposure
value
is
typically
combined
with
a
linear
low­
dose
(
Q1*)
approach
to
determine
the
lifetime
(
cancer)
risk
estimate.
The
Agency
generally
considers
risks
lower
than
1
x
10­
6
(
i.
e.,
probability
less
than
one
in
one
million)
to
be
of
potential
concern
for
dietary
cancer
exposure.

°
Two
separate
cancer
risk
assessments
were
completed
for
diuron
and
MCPDMU
(
N'­(
3­
chlorophenyl)­
N,
N­
dimethyl
urea),
a
degradate
of
diuron
in
water.
Because
the
cancer
effects
(
i.
e.,
target
organs)
for
the
two
compounds
differ,
the
risks
from
diuron
and
MCPDMU
are
not
combined.

°
Diuron
is
classified
as
"
known/
likely
human
carcinogen"
(
See
Carcinogenicity
Peer
Review
of
Diuron,
5/
8/
97).
Carcinogenicity
studies
in
the
rat
showed
urinary
bladder
carcinoma
in
both
sexes
of
Wistar
rat,
and
kidney
carcinomas
in
the
male
rat
(
a
rare
tumor).
Mammary
gland
carcinomas
were
observed
in
the
female
mouse.

°
Based
on
a
Q1*
of
1.91
x
10­
2
(
mg/
kg/
day)­
1,
the
potential
dietary
cancer
risk
estimate
for
diuron
is
1.68
x
10­
6
(
mg/
kg/
day)­
1.

°
The
estimated
cancer
dietary
risk
associated
with
the
use
of
diuron
indicates
a
borderline
exceedance
above
1
x
10­
6
and
shows
a
lifetime
risk
estimate
of
1.68
x
10
­
6
for
the
general
population.
The
Agency
does
not
believe
potential
dietary
cancer
risk
to
be
of
concern
because
the
residues
used
in
the
calculations
are
from
field
trials
conducted
at
the
highest
application
rates
and
some
processing
data
are
still
outstanding.
Therefore,
the
exposure
calculation
is
a
conservative
estimate.

°
Information
provided
by
the
registrant
related
to
the
cancer
mechanism
of
action
was
insufficient
to
support
reclassification
of
the
cancer
category
for
diuron
at
this
time.
The
information
suggested
the
reversibility
of
possible
precancerosis
but
did
not
present
or
propose
a
mode
of
action
for
bladder
tumors
from
diuron
exposure.
The
Agency
agrees
that
there
is
little
or
no
concern
for
mutagenic
activity
of
diuron
(
See
the
Agency
HIARC
report,
dated
August
28,
2001).
Page
7
of
30
°
Based
on
a
Q1*
of
a
similar
compound,
monuron,
the
estimated
dietary
risk
for
MCPDMU
is
1.02
x
10­
7,
which
includes
catfish
consumption
only.
The
anticipated
residue
of
MCPDMU
in
catfish
was
calculated
using
the
2
ppm
tolerance
for
catfish,
the
fraction
of
applied
radioactive
diuron
converted
to
MCPDMU
in
an
aerobic
aquatic
metabolism
study
(
see
the
Environmental
Risk
Assessment)
and
the
percent
crop
treated
for
catfish.

°
Based
upon
environmental
laboratory
studies,
it
is
known
that
in
drinking
water
only,
diuron
partially
degrades
to
another
chemical
referred
to
as
MCPDMU
(
N'­(
3­
chlorophenyl)­
N,
Ndimethyl
urea).
However,
the
environmental
fate
and
persistence
of
MCPDMU
are
uncertain.
MCPDMU
is
structurally
similar
to
monuron
[
N'­(
4­
chlorophenyl)­
N,
N­
dimethyl
urea].
Monuron
produces
tumors
in
the
kidney
and
liver
in
male
rats
and
has
a
Q1*
of
1.52
x
10­
2.
Due
to
the
structural
similarity
between
MCPDMU
and
monuron,
the
Agency
believes
it
is
prudent
to
evaluate
the
carcinogenic
risk
associated
with
MCPDMU
based
upon
the
hazard
information
concerning
the
chemical
monuron.
The
Agency
believes
MCPDMU
is
likely
less
toxic
than
monuron,
but
is
unable
to
quantify
this
difference
without
further
information.
The
approach
used
in
this
assessment
yields
a
high­
end
estimate.
Absent
information
specifically
about
the
carcinorgenic
potential
of
MCPDMU,
the
Agency
has
taken
this
conservative,
health
protective
approach
in
its
assessment.
The
Agency
is
addressing
this
uncertainty
by
requiring
additional
information
about
the
behavior
and
fate
of
diuron
and
its
drinking
water
degradates.
This
exposure
information
will
permit
refinement
of
the
drinking
water
assessment.

Drinking
Water
Dietary
Risk
For
a
complete
discussion,
see
section
4.3
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

Drinking
water
exposure
to
pesticides
can
occur
through
ground
water
and
surface
water
contamination.
EPA
considers
both
acute
(
one
day)
and
chronic
(
lifetime)
drinking
water
risks
and
uses
either
modeling
or
actual
monitoring
data,
if
available,
to
estimate
those
risks.
To
determine
the
maximum
allowable
contribution
of
pesticide
residue
in
water
allowed
in
the
diet,
EPA
first
looks
at
how
much
of
the
overall
allowable
risk
is
contributed
by
food,
then
calculates
a
drinking
water
level
of
comparison
(
DWLOC)
to
determine
whether
modeled
or
monitoring
levels
exceed
this
level.

The
DWLOCs
represent
the
maximum
contribution
to
the
human
diet
(
in
ppb
or
µ
g/
L)
that
may
be
attributed
to
residues
of
a
pesticide
in
drinking
water
after
dietary
exposure
is
subtracted
from
the
aPAD
or
cPAD.
Risks
from
drinking
water
are
assessed
by
comparing
the
DWLOCs
to
the
estimated
environmental
concentrations
(
EECs)
in
surface
water
and
ground
water.
Drinking
water
modeling
is
considered
to
be
an
unrefined
assessment
and
provides
conservative
estimates
based
on
maximum
labeled
rates
and
number
of
applications.
In
this
case,
only
chronic
(
non­
cancer)
and
cancer
drinking
water
risks
have
been
assessed
since
no
acute
endpoint
was
identified
and
there
are
no
acute
risks
of
concern.
Page
8
of
30
°
Estimated
drinking
water
concentrations
for
ground
water
are
based
on
the
SCI­
GROW
model,
which
is
a
Tier
I
assessment
that
provides
a
conservative
estimate.
The
modeled
estimates
indicate
that
ground
water
concentrations
of
diuron
and
its
metabolites
are
below
the
chronic
DWLOC.

°
For
surface
water,
the
following
Tier
II
screening
models
PRZM
and
EXAMS
were
run
using:
the
maximum
labeled
rates
for
citrus
(
6.4
lb
ai/
A);
the
Index
Reservoir;
and,
the
Percent
Crop
Area
(
PCA)
adjustment
(
to
determine
estimated
surface
water
concentrations
of
diuron
and
its
degradates).
The
drinking
water
assessment
is
based
on
using
the
maximum
rates
on
citrus
crops
in
Florida
because
this
scenario
is
anticipated
to
represent
the
highest
potential
drinking
water
concern.

°
The
index
reservoir
model
represents
a
vulnerable
drinking
water
source
from
a
specific
area
with
specific
cropping
patterns,
weather,
soils,
and
other
factors.
The
PCA
is
a
generic
watershed­
based
adjustment
factor
which
represents
the
portion
of
a
watershed
planted
with
a
crop
or
crops.
The
model
indicates
that
diuron
and
its
degradates
have
the
potential
to
contaminate
surface
water
by
runoff
in
areas
with
large
amounts
of
annual
rainfall.

°
Drinking
water
derived
from
surface
water
is
not
of
concern
except
for
chronic
risk
in
the
flatwood
area
of
Florida
at
the
maximum
application
rate.
In
this
area,
the
EECs
at
the
maximum
application
rate
of
6.4
lbs
ai/
A
(
9.6
lbs
ai/
A
per
year)
are
42
ppb,
with
a
DWLOC
of
28
ppb.
The
registrant
for
diuron
has
provided
a
Geographic
Information
System
watershed
analysis
that
may
allow
for
refinement
of
the
modeling
estimates
for
this
area.
Residue
data
to
support
the
9.6
lbs
ai/
A
per
year
rate
are
required.
The
registrant
may
provide
data
to
support
this
use
rate
or
change
the
labels
to
reflect
the
use
rate
of
6.4
lbs
ai/
A
per
year,
as
supported
by
current
residue
data.

°
For
other
areas
of
Florida
where
the
citrus
application
rate
is
3.2
lbs
ai/
A
(
up
to
two
applications
per
year)
the
EECs
are
30
ppb,
with
a
DWLOC
of
28
ppb
for
the
most
sensitive
subpopulation,
children
1­
6.
This
represents
a
slight
exceedance
and,
given
the
protective
assumptions
in
the
dietary
assessment,
does
not
pose
a
risk
of
concern.
It
should
be
noted
that
the
original
risk
assessment
used
the
maximum
yearly
rate
for
citrus
(
9.6
lbs
ai/
A)
to
calculate
the
EECs
instead
of
the
maximum
single
application
rate
of
6.4
lbs
ai/
A
for
citrus.
The
information
presented
in
this
overview
is
based
on
the
6.4
lbs
ai/
A
rate.

°
For
diuron
potential
cancer
risk,
no
DWLOC
has
been
calculated.
Food
alone
shows
a
slight
exceedance
for
cancer
risk
(
1.68
x
10­
6)
based
on
field
trial
data
using
maximum
application
rates.
These
estimates
can
be
refined
with
additional
processing
data
and
monitoring
data.
To
better
characterize
both
potential
cancer
risks
from
surface
water,
EPA
has
evaluated
monitoring
data
from
Florida,
an
area
of
high
diuron
use.
These
data
indicate
detections
Page
9
of
30
generally
one
to
two
orders
of
magnitude
lower
than
modeled
estimates
for
diuron
(
parent
compound).
The
monitoring
data
for
Florida
can
be
found
on
the
following
website:
www.
sfwmd.
gov/
curre/
pest/
pestindex.
htm.

°
For
the
degradate
MCPDMU,
the
EEC
for
surface
water
using
PRZM/
EXAMS
is
5
ppb,
and
exceeds
the
calculated
DWLOC
of
2.0
ppb,
based
on
the
3.2
lbs
ai/
A
rate
for
citrus.
The
drinking
water
assessment
for
MCPDMU
can
be
refined
with
additional
environmental
fate
data.
These
data
are
required.

°
Additional
monitoring
data
on
diuron
and
its
degradates
evaluated
for
this
assessment
are
listed
below.
­
A
study
on
the
occurrence
of
cotton
herbicides
and
insecticides
in
the
Playa
Lakes
area
of
the
high
plains
of
western
Texas
was
evaluated.
Diuron
and
metabolites
were
found
in
71%
of
the
samples
collected
from
32
lakes
at
a
mean
concentration
of
2.7
ppb.
This
study
did
not
have
sufficient
frequency
of
sampling
or
a
long
enough
sampling
period
to
be
used
for
regulatory
purposes.
In
addition,
the
study
has
limited
use
in
a
National
assessment
because
western
Texas
is
not
expected
to
be
one
of
the
most
vulnerable
use
areas
for
runoff,
the
method
of
contamination
expected
with
diuron.
However,
because
samples
were
taken
within
2
days
of
application,
the
results
provide
an
indication
of
concentrations
that
could
occur
in
drinking
water
in
that
area.

­
The
US
Geological
Survey
National
Water
Quality
Assessment
Program
(
NAWQA)
collected
1420
surface
water
samples
from
62
agricultural
stream
sites
during
a
6
year
period
from
1992
­
1998.
Diuron
was
detected
in
7.32%
of
the
samples
at
a
mean
concentration
of
0.13
ppb.

Residential
Risk
For
a
complete
discussion,
see
section
4.4
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

There
are
two
potential
sources
of
exposure
to
diuron
in
a
residential
setting
­
as
an
algaecide
in
ponds
and
aquariums,
and
as
a
preservative
or
a
mildewcide
in
paints.
Exposure
from
the
dermal
and
inhalation
routes
are
combined
for
each
residential
use.

°
The
algaecide
products
are
formulated
as
tablets/
blocks
and
as
a
liquid.
There
are
no
exposure
data
for
the
use
of
the
algaecide
tablets/
blocks.
Since
the
products
are
formulated
as
tablets/
blocks
and
dissolve
in
less
than
5
minutes,
minimal
exposure
is
expected
and
was
not
quantified.
The
liquid
is
used
at
a
rate
of
one
teaspoon
(
5
ml)
for
every
10
gallons
of
aquarium
or
pond
water,
once
a
month
or
when
algae
growth
reappears.
Residential
exposure
may
Page
10
of
30
result
from
measuring
the
liquid
and
pouring
the
liquid
into
the
aquarium
or
pond.
Exposure
is
expected
to
be
short­
term
(
1
to
30
days).
These
risks
are
not
of
concern.

°
Residential
painters
using
paints
and
stains
were
assumed
to
use
airless
sprayers
and
paint
brushes.
Exposure
is
expected
to
be
short­
term
(
1
to
30
days).
For
homeowners,
the
airless
sprayer
is
assumed
to
be
used
for
outdoor
applications
only.
For
indoor
applications,
EPA
assumed
that
painting
would
be
restricted
to
small
rooms
such
as
bathrooms
(
high
potential
for
moisture)
where
an
airless
sprayer
is
unlikely
to
be
used.
These
risks
are
not
of
concern.

The
only
potential
residential
exposure
scenario
of
concern
is
due
to
the
cancer
risk
to
applicators
using
diuron
treated
paints
or
stains
applied
with
airless
paint
sprayer
or
paint
brush.
Depending
on
the
exposure
data
used,
application
method
employed
and
the
amount
applied,
calculated
risk
to
applicators
range
from
3
x
10­
10
to
3.4
x
10­
6
over
a
lifetime
of
70
years.

Similar
to
dietary
cancer
risk,
potential
residential
cancer
risk
is
calculated
by
using
the
average
exposure
over
a
70­
year
lifetime.
The
lifetime
exposure
value
is
typically
combined
with
a
linear
low­
dose
(
Q1*)
approach
to
determine
the
lifetime
(
cancer)
risk
estimate.
The
Agency
generally
considers
risks
lower
than
1
x
10­
6
(
i.
e.,
greater
than
one
in
one
million)
to
exceed
its
level
of
concern
for
potential
residential
cancer
risk.

°
The
applicator
assessment
for
paints
and
stains
applied
with
a
brush
or
an
airless
sprayer
is
based
on
a
Q1*
of
1.91
x
10­
2
(
mg/
kg/
day)­
1,
and
an
application
rate
of
0.053
lb
ai
per
gallon.
This
is
the
maximum
application
rate.
For
a
cancer
risk
assessment,
typical
rates
would
ordinarily
be
used
but
these
were
not
available.
The
assessment
also
assumes
two
gallons
for
paints
to
five
gallons
for
stains
applied
with
a
brush
per
day
or
fifteen
gallons
applied
per
day
with
an
airless
sprayer,
2
applications
per
year,
50
years
of
use
over
a
70
year
lifetime,
and
a
high­
end
dermal
absorption
factor
of
4%
calculated
from
submitted
studies.
Usage
information
gathered
subsequent
to
the
risk
assessment
indicates
that
less
than
5%
of
all
paint
contains
diuron.
Therefore,
it
is
unlikely
that
a
homeowner
would
only
apply
paint
containing
diuron
two
times
per
year
for
50
years.

Postapplication
Risk
Diuron
is
applied
to
ponds/
aquariums
in
the
form
of
a
liquid
or
an
effervescent
tablet.
Due
to
the
high
dilution
rate
of
the
liquid
in
pond
and
aquarium
water
(
0.0000074
lb
ai
per
gallon
of
water),
and
the
effervescent
nature
of
the
tablet
(
expected
to
dissolve
in
less
than
five
minutes),
postapplication
exposure
to
diuron
in
pond
and
aquarium
water
is
expected
to
be
minimal.
Furthermore,
postapplication
activities
in
and
around
ponds/
aquariums
treated
with
diuron
are
assumed
to
be
infrequent.

Postapplication
inhalation
and
dermal
exposure
resulting
from
the
indoor
use
of
diuron
in
paints
is
also
expected
to
be
minimal.
The
Agency
has
conducted
a
screening­
level
inhalation
assessment
Page
11
of
30
using
the
Multi­
Chamber
Concentration
and
Exposure
Model
(
MCCEM).
The
MCCEM
uses
air
infiltration
and
interzonal
air
flow
rates,
together
with
user
inputs
for
emission
rates,
decay
rates,
and
outdoor
concentrations
to
calculate
time­
varying
indoor
concentrations
and
associated
indoor
inhalation
exposure
due
to
product
or
material
emissions
in
several
zones
or
chambers
within
a
residence.
The
result
of
this
model,
coupled
with
diuron's
low
vapor
pressure
(
2
x
10­
7
mm
Hg
at
30
E
C),
shows
minimal
postapplication
inhalation
exposure
is
likely.
Furthermore,
diuron­
treated
paint
is
most
likely
to
be
used
in
rooms
where
high
humidity
is
expected
(
e.
g.,
a
bathroom),
and
would
rarely
be
used
in
the
entire
house.
It
is
unlikely
that
a
homeowner
would
receive
a
significant
amount
of
postapplication
inhalation
exposure
from
diuron­
treated
paint,
as
the
very
nature
of
its
use
is
as
a
mildewcide,
and
any
substantial
loss
of
the
active
ingredient
from
the
paint
would
render
the
product
ineffective.

Aggregate
Risk
For
a
complete
discussion,
see
section
5.0
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

The
aggregate
risk
assessment
for
diuron
examines
the
combined
risk
from
exposure
through
food,
drinking
water
and
residential
use.

°
There
are
no
adverse
effects
expected
from
a
single
exposure
to
diuron;
therefore,
an
acute
risk
assessment
was
not
conducted.
Short­
term
aggregate
risks
from
food,
residential
inhalation,
and
drinking
water
are
not
of
concern.

°
Estimated
aggregate
chronic
risk
(
noncancer)
concentrations
of
diuron
and
its
metabolites
in
surface
water
slightly
exceed
the
chronic
DWLOC
in
the
Flatwood
area
of
Florida.
Because
field
trial
residue
levels
(
from
maximum
labeled
rates)
were
used
in
the
assessments,
dietary
risks
are
high
end
estimates
and
may
be
refined
further.

°
An
aggregate
cancer
estimate
has
not
been
calculated
since
conservative
assumptions
were
used
in
both
the
dietary
and
drinking
water
assessments.
Thus,
aggregation
of
these
assessments
would
result
in
an
even
more
conservative
expression
of
risk.

°
Dietary
risk
estimates
can
be
further
refined
with
processing
data
and
monitoring
data
that
accounts
for
diuron
and
its
metabolites.

°
Additional
targeted
drinking
water
monitoring
will
be
required
to
fully
characterize
drinking
water
risk
of
diuron
and
its
metabolites.

°
Because
of
the
low
percent
of
paint
containing
diuron,
exposure
to
home
applicators
is
not
likely
to
be
a
significant
contributor
to
aggregate
risk.

°
Calculated
diuron
potential
cancer
risks
from
food
and
residential
applicator
exposure
(
paints
Page
12
of
30
and
stains)
show
a
slight
exceedance
of
the
Agency's
level
of
concern,
1
x
10­
6.
As
noted
previously,
both
assessments
include
conservative
exposure
assumptions.
In
both
cases
additional
data
will
allow
for
refinement
of
the
exposure
portion
of
the
assessment.

°
As
discussed
above
(
under
Drinking
Water
Dietary
Risk),
diuron
degrades
in
water
to
MCPDMU.
Because
no
toxicology
data
are
available
for
MCPDMU,
the
Agency
used
data
from
a
structurally
similar
compound,
monuron,
to
assess
the
potential
cancer
risk
from
MCPDMU.
Based
on
the
algaecidal
use
in
commercial
fish
ponds,
the
dietary
cancer
risk
from
catfish
alone
is
1.02
x
10­
7
and
is
not
of
concern.

°
For
surface
water
contamination
from
the
degradate
MCPDMU,
crop
and
non­
crop
uses
are
potentially
of
concern
based
on
tier
II
modeling
EEC
estimate
of
5
ppb
exceeding
the
DWLOC
of
2.0
ppb,
based
on
a
3.2
lbs
ai/
A
(
up
to
two
applications
per
year).
For
the
Flatwood
area
in
Florida,
where
the
maximum
application
rate
of
6.4
lbs
ai/
A
(
9.6
lbs
ai/
A
per
year)
is
used,
the
EEC
is
8
ppb,
exceeding
the
DWLOC
of
2.0
ppb.
These
estimates
can
be
refined
with
additional
environmental
fate
data
on
the
metabolite
and/
or
monitoring
data.
Residue
data
to
support
the
9.6
lbs
ai/
A
per
year
rate
are
required.
The
registrant
may
provide
data
to
support
this
use
rate
or
change
the
labels
to
reflect
the
use
rate
of
6.4
lbs
ai/
A
per
year,
as
supported
by
current
residue
data.

Occupational
Risk
For
a
complete
discussion,
see
section
7.0
of
the
"
Diuron:
HED
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
March
13,
2002.

People
can
be
exposed
to
a
pesticide
while
working
through
mixing,
loading,
or
applying
a
pesticide,
and
reentering
a
treated
site.
Handler
and
worker
risks
(
non­
cancer)
are
measured
by
a
Margin
of
Exposure
(
MOE)
which
determines
how
close
the
occupational
exposure
comes
to
a
No
Observed
Adverse
Effect
Level
(
NOAEL)
taken
from
animal
studies.
Generally,
MOEs
greater
than
100
are
not
of
concern.
Potential
cancer
risks
are
measured
in
terms
of
the
increased
chance
that
an
effect
would
occur
over
the
course
of
a
life­
time.

In
the
case
of
diuron,
dermal
and
inhalation
risks
for
handlers
are
assessed.
Handler
exposures
to
diuron
are
expected
to
be
short­,
intermediate­
and
long­
term.
However,
no
dermal
endpoints
were
identified
for
short­
and
intermediate­
term
exposures.
Potential
life­
time
cancer
risk
is
also
calculated
for
the
various
handler
scenarios.
The
assessment
also
includes
risks
to
postapplication
workers
who
enter
treated
areas
to
perform
certain
agricultural
activities,
such
as
harvesting.

Occupational
Handler
Summary
Page
13
of
30
EPA
identified
31
handler
exposure
scenarios
resulting
from
mixing/
loading
and
applying
(
liquid
and
dry)
diuron
for
crop
and
non­
crop
areas,
based
on
diuron's
labeled
use
directions.
The
assessment
evaluated
mixing,
loading,
and
applying
liquid,
dry
flowable,
wettable
powder,
and
granular
formulations
with
aircraft,
groundboom
sprayer,
chemigation,
high
and
low
pressure
handwands,
tractor
drawn
spreader,
push­
type
spreader,
gravity
feed
spreader,
pump
feed
spreader,
and
belly
grinder.
In
addition,
two
scenarios
are
assessed
for
those
mixing
and
loading
diuron
in
the
manufacture
of
paints
and
stains
(
primary
handlers),
two
scenarios
for
commercial
painters
(
secondary
handlers),
and
four
scenarios
for
mixing
and
loading
diuron
algaecides
for
commercial
fish
ponds.

°
Handler
exposures
to
diuron
are
expected
to
be
mainly
of
short­
term
duration
(
one
day
to
one
month).
Intermediate­
term
exposure
(
one
month
to
several
months)
for
handlers
is
possible
for
large
field
crops,
including
corn,
wheat,
oats
and
cotton,
because
of
their
long
planting
seasons.
Right­
of­
way
sprayer
scenarios
for
utility
and
industrial
areas
are
assumed
to
be
of
intermediate­
term
duration,
because
utility
workers
could
possibly
treat
right­
of­
way
areas
(
roadsides,
railroads,
etc)
all
summer
long.
However,
for
most
uses
diuron
is
only
applied
one
to
two
times
per
season.

°
Of
the
31
handler
exposure
scenarios,
all
short­
and
intermediate­
term
exposure
scenarios
resulted
in
MOEs
at
or
near
the
target
of
100
with
PPE
and
engineering
controls,
as
appropriate.

°
No
systemic
toxicity
following
repeated
dermal
dosing
at
1200
mg/
kg/
day
was
seen
in
the
rabbit
dermal
toxicity
study;
therefore,
a
quantitative
non­
cancer
dermal
risk
assessment
(
shortand
intermediate­
term)
is
not
required.

°
For
the
long­
term
dermal
toxicity
endpoint,
a
LOAEL
of
1.0
mg/
kg/
day
is
based
on
evidence
of
hemolytic
anemia
(
an
effect
that
reduces
the
oxygen
carrying
capacity
of
the
blood
cells)
and
compensatory
hematopoiesis
(
regeneration
of
red
blood
cells)
from
the
chronic
toxicity/
carcinogenicity
study
in
the
rat.
Because
a
NOAEL
was
not
established,
an
additional
3x
uncertainty
factor
is
included
resulting
in
a
300x
UF.

°
For
estimating
dermal
risks
in
the
cancer
assessment,
EPA
uses
oral
animal
studies
in
the
absence
of
appropriate
dermal
toxicity
studies
and
adjusts
for
the
amount
of
pesticide
absorbed
through
the
skin.
For
diuron,
no
dermal
absorption
study
is
available.
However,
there
is
a
21­
day
dermal
toxicity
study
in
the
rabbit
and
an
oral
developmental
toxicity
study
in
the
rabbit.
An
upper­
bound
estimation
of
dermal
absorption
of
4%
was
extrapolated
using
the
maternal
LOAEL
of
50
mg/
kg/
day
from
the
oral
developmental
toxicity
study
in
the
rabbit
and
the
NOAEL
of
1200
mg/
kg/
day
(
HDT)
from
the
21­
day
dermal
toxicity
study
in
the
rabbit:
the
ratio
is
50/
1200
or
4%.
Page
14
of
30
°
For
estimating
short­,
intermediate­,
and
long­
term
inhalation
risks,
EPA
uses
oral
animal
studies
in
the
absence
of
appropriate
inhalation
toxicity
studies.
EPA
assumes
100%
of
the
inhaled
diuron
dose
is
absorbed
by
the
body.

°
For
the
short­
term
inhalation
toxicity
endpoint,
a
NOAEL
of
10
mg/
kg/
day
is
based
on
decreased
body
weight
and
food
consumption
at
the
maternal
LOAEL
of
50
mg/
kg/
day
from
a
developmental
toxicity
study
in
the
rabbit.

°
For
the
intermediate­
term
inhalation
risk
assessment,
a
NOAEL
of
1.0
mg/
kg/
day
is
based
on
altered
hematological
parameters
at
the
LOAEL
of
10
mg/
kg/
day,
observed
at
6
months
in
the
chronic
toxicity/
carcinogenicity
study
in
the
rat.

°
For
the
cancer
assessment,
a
linear
low­
dose
approach
is
used
based
a
Q1*
of
1.91
x
10­
2
(
mg/
kg/
day)­
1
from
carcinogenicity
studies
in
rats
and
mice.

°
No
diuron­
specific
exposure
studies
are
available
for
the
occupational
assessment.
Surrogatebased
exposure
assessments
for
each
scenario
are
used
from
the
Pesticide
Handler
Exposure
Database
(
PHED),
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
and
other
available
data.

Handler
Risk
Scenarios/
Assumptions
Handler
risk
is
assessed
with
a
variety
of
assumptions
concerning
protection
equipment:
baseline
clothing;
minimum
personal
protective
equipment(
PPE);
maximum
PPE;
and,
when
feasible,
engineering
controls.
Baseline
assessments
assume
long
pants,
long­
sleeve
shirt,
shoes,
socks,
and
for
some
scenarios
chemical
resistant
gloves.
Currently,
diuron
handlers
are
required
to
wear
baseline
clothing
with
chemical
resistant
gloves.
Generally,
minimum
PPE
is
baseline
plus
gloves
and
dust
mist
respirator
and
maximum
PPE
adds
coveralls
and
organic
vapor
respirator.
Engineering
controls
typically
include
exposure
reducing
equipment,
such
as
closed
mixing/
loading
systems,
water
soluble
bags,
closed
cabs,
and
closed
cockpits.

The
results
of
the
non­
cancer
assessments
for
crop
and
non­
crop
areas
indicate
that
all
scenarios
are
at
or
near
the
target
MOE
with
PPE
or
engineering
controls.
The
diuron
cancer
risk
assessment
for
crop
and
non­
crop
areas
indicates
five
scenarios
are
of
potential
concern
with
calculated
risks
lower
than
1
x
10­
4
even
with
maximum
PPE
or
engineering
controls.
Primary
and
secondary
handler
estimates
to
diuron
in
paints
and
stains,
and
commercial
fish
ponds
are
in
the
10­
5
to
10­
6
range.
Below
is
a
summary
of
the
handler
risks
of
concern.

The
following
assumptions
and
factors
were
used
when
performing
the
handler(
non­
cancer)
risk
assessment:
Page
15
of
30
°
The
average
body
weight
of
70
kg
is
used,
representing
a
typical
adult.
°
Daily
(
8­
hour
work
day)
acres
and
volumes
to
be
treated
in
each
scenario
include:
­
350
acres
for
aerial
applications
to
all
agricultural
crops;
­
350
acres
for
flaggers
supporting
aerial
applications;
­
80
acres
for
most
groundboom
crops,
unless
otherwise
specified;
­
1,000
gallons
for
high
­
pressure
hand
wands
and
rights­
of­
way
sprayers;
­
350
acres
for
chemigation;
­
40
gallons
for
low­
pressure
handwands
and
backpack
sprayers;
­
80
acres
for
tractor­
drawn
spreader;
­
5
acres
for
a
push­
type
spreader
and
backpack
spreader;
­
1
acre
for
a
belly
grinder;
­
100
square
feet
for
granular
hand
and
spoon
application;
and
­
50
gallons
for
airless
sprayer
and
5
gallons
for
paintbrush.

°
The
duration
of
exposure
for
handlers
of
diuron
is
assumed
to
be
mostly
short­
term
(
one
day
to
one
month).
Intermediate­
term
exposure
(
one
month
to
several
months)
is
possible
for
large
field
crops.
However
most
crops
only
receive
one
application
of
diuron
per
season.

The
following
assumptions
and
factors
were
used
when
performing
the
handler
cancer
risk
assessment:

°
The
average
body
weight
of
70
kg
is
used,
representing
a
typical
adult;
°
Exposure
duration
is
assumed
to
be
35
years.
This
represents
a
typical
working
lifetime;
°
Lifetime
is
assumed
to
be
70
years;
°
Exposure
frequencies
used
in
the
calculations
are,
125
days
per
year
formulating
paints,
30
to
180
days
per
year
for
painters
using
an
airless
sprayer
or
paint
brush;
and
°
The
daily
volumes
used
in
the
calculations
are,
100
to
1,000
gallons
of
paints
treated,
50
gallons
for
painters
using
airless
sprayers,
5
gallons
using
a
paint
brush.

Short­
term
Worker
Assessment
for
Crop/
Non­
crop
Areas
°
All
mixer/
loader
scenarios
with
wettable
powder
products
are
of
concern
at
baseline;
the
risks
estimated
in
these
scenarios
can
be
mitigated
with
engineering
controls.
°
Loading
and
applying
is
of
concern
with
gravity
feed
equipment
at
high
rate
(
87
lbs
ai/
A)
at
baseline
(
MOE=
36).
This
exposure
is
not
of
concern
at
the
highest
rate
currently
marketed
(
12
lbs
ai/
A).
°
Both
loading
and
applying
granular
products
for
tractor
drawn
spreaders
are
of
concern
with
high
rate
(
87
lbs
ai/
A).
When
using
the
highest
rate
(
12
lbs
ai/
A)
on
a
currently
marketed
label,
this
exposure
is
not
of
concern.
°
All
aerial
application
scenarios
are
not
of
concern
provided
a
closed
cockpit
is
used.
°
Applying
with
high­
pressure
handwand
is
of
concern
with
baseline
PPE.
With
maximum
PPE,
Page
16
of
30
the
MOE
is
92.
°
Mixer/
loader/
applicator
risk
is
of
concern
for
low­
pressure
handwand
using
baseline
PPE.
With
PPE,
this
risk
is
not
of
concern
(
83
at
min
PPE
and
170
at
max
PPE).

Intermediate­
term
Risks
for
Crop/
Non­
crop
Areas
°
All
mixer/
loader
scenarios
with
wettable
powders
are
not
of
concern
with
engineering
controls.
°
All
aerial
application
scenarios
are
not
of
concern
provided
a
closed
cockpit
is
used.
°
Mixing/
loading
liquids
is
not
of
concern
with
minimum
PPE.
°
Mixing/
loading
dry
flowable
products
is
of
concern
at
baseline
for
high
acreage
crops
(
1200
A)
with
a
MOE
=
34.
With
minimum
PPE
this
risk
is
not
of
concern.
°
Applying
sprays
for
right­
of­
ways
with
minimum
PPE,
the
MOE=
93,
but
is
not
of
concern.

Cancer
Risks
for
Crop/
Non­
crop
Areas
°
Twenty­
six
scenarios
have
cancer
risks
of
concern
between
1
x
10­
4
and
1
x
10­
6
with
maximum
feasible
PPE/
engineering
controls.
°
At
currently
marketed
rates,
all
risks
are
less
than
1
x
10­
4
with
maximum
feasible
PPE/
engineering
controls.

Risks
for
Occupational
Paints
°
Intermediate­
term
risk
calculations
for
indoor
painters
using
airless
sprayers
result
in
an
MOE
of
56.
°
Cancer
risk
for
primary
handlers
in
paint
manufacturing
facilities
range
from
7
x10­
5
to
2.3
x
10­
6.
°
Cancer
risk
for
commercial
painters
using
an
airless
sprayer
range
from
9.5
x
10­
5
to
2.2
x
10­
5.
°
Cancer
risk
for
commercial
painters
using
a
brush
is
5.8
x
10­
5.

Risks
for
Commercial
Fish
Ponds
°
No
risks
of
concern
(
cancer/
non­
cancer)
with
use
of
a
closed
mixing
loading
system.

Postapplication
Occupational
Cancer
Risk
EPA
has
determined
that
there
are
potential
cancer
risks
for
both
private
and
commercial
growers
entering
treated
areas
to
perform
certain
agricultural
activities
after
a
diuron
application.
It
should
be
noted
that
a
non­
cancer
postapplication
assessment
was
not
conducted
since
no
systemic
toxicity
by
the
dermal
route
is
expected
for
the
short­
or
intermediate­
term
durations.

°
Only
crops
that
can
receive
direct
foliar
treatments
were
assessed
for
postapplication
risks.
These
crops
are
not
damaged
by
foliar
treatments
of
diuron.
The
crops
assessed
are
oats;
forage;
oats,
grain;
oats,
hay;
oats,
straw;
wheat,
forage;
wheat,
grain;
wheat,
hay;
wheat
straw;
Page
17
of
30
birdsfoot
trefoil,
forage;
birdsfoot
trefoil,
hay;
grass,
forage,
except
Bermuda
grass;
grass,
hay,
except
Bermuda
grass;
alfalfa,
forage;
alfalfa,
hay;
asparagus;
clover,
forage;
clover,
hay;
pineapple;
and
sugarcane.
°
The
postapplication
assessment
is
based
on
the
current
12­
hour
restricted
entry
interval.
An
assessment
was
performed
using
both
typical
and
maximum
application
rates.
For
private
growers,
10
days
of
exposure
per
year
is
assumed.
For
commercial
growers,
30
days
of
annual
exposure
is
assumed.

°
For
field
and
row
crops,
medium
exposure
activities,
such
as
moving
irrigation
equipment
and
scouting
mature
plants
are
of
concern
for
cancer
(
private:
1.0
x
10­
5;
commercial:
3.0
x
10­
5)
at
the
typical
application
rate
and
current
12­
hour
restricted
entry
interval
(
REI).

°
For
sugarcane,
medium
exposure
activities,
such
as
scouting
mature
plants
are
potentially
of
concern
for
cancer
(
private:
6.4
x
10­
6;
commercial:
1.9
x
10­
5)
at
the
typical
application
rate
and
current
12
hour
REI.

°
For
asparagus
and
pineapple,
all
activities
assessed
are
potentially
of
concern
at
typical
application
rates
and
the
12­
hour
REI.
The
estimated
risks
for
private
growers
performing
high,
medium,
and
low
exposure
activities
are
1.1
x
10­
5,
5.4
x
10­
6,
and
3.2
x
10­
6,
respectively.
The
estimated
risks
for
commercial
growers
performing
high,
medium,
and
low
exposure
activities
are
3.2
x
10­
5,
1.6
x
10­
5,
and
9.7
x
10­
6,
respectively.
Low
exposure
activities
include
moving
irrigation
pipe,
scouting,
thinning,
and
weeding
immature
plants.
Medium
exposure
activities
include
moving
irrigation
pipe
and
scouting
mature
plants.
High
exposure
activities
include
hand
harvesting
and
pruning.

Ecological
Risk
For
a
complete
discussion,
see
the
"
Environmental
Risk
Assessment
for
the
Reregistration
of
Diuron"
document,
dated
March
11,
2002.

To
estimate
potential
ecological
risk,
EPA
integrates
the
results
of
exposure
and
ecotoxicity
studies
using
the
quotient
method.
Risk
quotients
(
RQs)
are
calculated
by
dividing
exposure
estimates
by
ecotoxicity
values,
both
acute
and
chronic,
for
various
wildlife
species.
RQs
are
then
compared
to
levels
of
concern
(
LOCs).
Generally,
the
higher
the
RQ,
the
greater
the
potential
risk.
Risk
characterization
provides
further
information
on
the
likelihood
of
adverse
effects
occurring
by
considering
the
fate
of
the
chemical
in
the
environment,
communities
and
species
potentially
at
risk,
their
spatial
and
temporal
distributions
and
the
nature
of
the
effects
observed
in
studies.

Environmental
Fate
and
Transport
Page
18
of
30
°
Diuron
is
persistent
and
is
stable
to
hydrolysis.
Calculated
half­
lives
in
aqueous
and
soil
photolysis
are
43
and
173
days,
respectively.
Half
lives
in
laboratory
aerobic
and
anaerobic
soil
metabolism
studies
are
372
and
1000
days,
respectively.
However,
in
a
viable
laboratory
aquatic
system,
degradation
occurred
with
half­
lives
of
33
and
5
days
in
aerobic
and
anaerobic
systems,
respectively.
In
soil,
the
half
lives
of
diuron
and
its
degradate
DCPMU
range
from
73
to
139
days
and
217
to
1733
days,
respectively.

°
Diuron
has
been
detected
in
ground
and
surface
water
monitoring.
Ground
water
samples
were
taken
from
wells
showing
detections
of
diuron
with
a
mean
concentration
of
2.44
ppb.
Surface
water
samples
were
taken
in
a
study
of
pesticides
in
the
Playa
Lakes
area
of
the
high
plains
of
Texas,
from
32
lakes
with
a
mean
concentration
of
2.7
ppb.
The
United
States
Geological
Survey
(
USGS)
National
Water
Quality
Assessment
Program
(
NAWQA)
program
collected
1420
surface
water
samples
from
62
agricultural
streams
with
an
average
concentration
of
0.13ppb.
Monitoring
data
are
also
available
for
California
and
Florida.

Endangered
Species
The
Endangered
Species
Act
requires
Federal
agencies
to
ensure
that
their
actions
are
not
likely
to
jeopardize
listed
species
or
adversely
modify
designated
critical
habitat.
To
analyze
the
potential
of
registered
pesticide
uses
to
affect
any
particular
species,
EPA
puts
basic
toxicity
and
exposure
data
into
context
for
individual
listed
species
and
their
locations
by
evaluating
important
ecological
parameters,
pesticide
use
information,
the
geographic
relationship
between
specific
pesticides
uses
and
species
locations,
and
biological
requirements
and
behavioral
aspects
of
the
particular
species.
A
determination
that
there
is
a
likelihood
of
potential
impact
to
a
listed
species
may
result
in
limitations
on
use
of
the
pesticide,
other
measures
to
mitigate
any
potential
impact,
or
consultations
with
the
Fish
and
Wildlife
Service
and/
or
the
National
Marine
Fisheries
Service
as
necessary.
For
diuron,
EPA
has
identified
potential
concerns
for
some
endangered
species
in
California
and
Florida.

Terrestrial
and
Aquatic
Organism
Risk
The
impact
to
non­
target
terrestrial
and
aquatic
plants
is
the
main
ecological
concern
from
the
use
of
diuron,
which
is
consistent
with
herbicide
use.
Table
1
compares
the
range
of
RQs
for
terrestrial
and
aquatic
organisms
to
the
level
of
concern
for
those
organisms.
Page
19
of
30
Table
1:
Terrestrial
and
Aquatic
Organism
Risk
Quotients
Organism
Crop
Range
of
Application
Rate
(
lbs
ai/
A)
a
Level
of
Concern
Range
of
RQ
Values
Birds
(
acute)
Cotton,
Rights
of
way
1.6
­
12
0.5
0.01
­
1.66
Mammals
(
acute)
Rights
of
way
12
0.5
<
0.01
­
0.55
Mammals
(
chronic)
Cotton,
Citrus
1.2
­
4.8
1
0.06
­
9.22
Terrestrial
Plants
(
acute)
Cotton,
Rights
of
way
1.6
­
12
1
1.25
­
77
Aquatic
Plants
(
acute)
Cotton,
Rights
of
way
1.6
­
12
1
9.6
­
171.7
Freshwater
fish
(
acute)
Cotton,
Rights
of
way
1.2
­
12
0.5
0.03
­
0.58
Freshwater
Fish
(
chronic)
Cotton,
Rights
of
way
1.2
­
12
1
0.50
­
9
Estuarine
Fish
(
acute)
Cotton,
Sugarcane,
Citrus,
Rights
of
way
1.2
­
12
0.5
0.01
­
0.07
Estuarine
Fish
(
chronic)
Cotton,
Rights
of
way
1.2
­
12
1
0.03
­
0.53
Freshwater
Invertebrates
(
acute)
Cotton,
Rights
of
way
1.2
­
12
0.5
0.14
­
2.58
Freshwater
Invertebrates
(
chronic)
Cotton,
Rights
of
way
1.6
­
12
1
0.24
­
1.77
Estuarine
Invertebrates
(
acute)
Cotton,
Rights
of
way
1.2
­
12
0.5
0.023
­
0.412
Estuarine
Invertebrates
(
chronic)
Cotton,
Rights
of
way
1.6
­
12
1
0.17
­
1.31
a
The
assessment
is
based
on
one
application
per
season
except
for
the
following
uses:
citrus,
2
applications;
cotton,
2
applications;
and
sugarcane,
3
applications.
Page
20
of
30
Incident
Data
There
are
29
ecological
incident
reports
for
nontarget
organisms,
reported
primarily
in
the
1990s.
Of
these
incidents,
one
involved
birds,
16
involved
fish,
and
12
involved
plants.
Of
the
29
incidents,
19
were
associated
with
misuse,
three
were
from
a
registered
use,
and
seven
were
not
identified
as
being
from
a
misuse
nor
a
registered
use.

Tolerance
Reassessment
Summary
For
a
complete
discussion,
see
Residue
Chemistry
Chapter
For
The
Diuron
Reregistration
Eligibility
Decision
(
RED)
Document,
dated
7/
29/
2001.

The
Agency
has
reassessed
all
81
existing
permanent
tolerances
for
diuron
and
can
make
an
FQPA
safety
determination,
provided
that
the
registrant
revises
the
product
labels
consistent
with
the
changes
outlined
in
the
Residue
Chemistry
Chapter
and
submits
the
required
residue
data
to
support
the
9.6
lbs
ai/
A
per
year
rate
for
citrus.
In
addition,
two
new
tolerances
are
proposed
for
use
on
prickly
pear
(
0.05
ppm),
and
spearmint
(
1.5
ppm).
The
Agency
has
sufficient
residue
data
for
reassessing
the
tolerances
for
diuron
and
is
requiring
additional
confirmatory
data
for
alfalfa
forage;
globe
artichokes;
barley
hay;
citrus
(
9.6
lbs
ai/
A
per
year
rate),
cotton
gin
byproducts;
field
corn
aspirated
grain
fractions,
forage
and
stover;
sweet
corn,
stover;
sweet
corn,
forage;
filberts;
grass
forage,
hay
seed
screenings
and
straw;
lemon;
pear;
oat
forage,
hay;
olive;
field
pea
vines
and
hay;
sorghum
aspirated
grain,
fractions,
stover,
and
forage;
and
wheat
forage
and
hay.
For
commodities
that
require
additional
residue
data,
the
current
tolerance
value
will
continue
to
be
used
for
enforcement
purposes
until
new
data
are
received.
If
the
new
data
indicate
that
adjustments
to
tolerances
are
warranted,
adjustments
will
be
made
at
that
time.
Anticipated
residues
for
all
commodities
were
calculated
from
field
trial
data
and
subsequently
utilized
to
estimate
the
dietary
exposure
to
diuron.
Dietary
risks
from
exposure
to
diuron
do
not
exceed
the
Agency's
level
of
concern.
Final
tolerances
for
most
crops
are
being
proposed
as
part
of
this
tolerance
reassessment.
Additional
tolerances
may
be
revised
once
the
confirmatory
field
trial
data
have
been
submitted
to
and
reviewed
by
the
Agency.
In
addition,
processing
data
for
field
corn
and
olives
and
a
metabolism
study
in
fish
are
required.

Table
2:
Tolerance
Reassessment
Summary
for
Diuron
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Tolerances
Listed
Under
40
CFR
§
180.106(
a)

Alfalfa
2
2/(
TBD3)
[
Alfalfa,
forage]

2.0
[
Alfalfa,
hay]
Page
21
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Apples
1
0.10
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.
[
Apple]

Artichokes
1
1/(
TBD)
[
Artichoke,
globe]

Asparagus
7
7.0
Treatment
of
asparagus
is
restricted
to
early
season,
prior
to
the
appearance
of
asparagus
spears.

Bananas
0.1
0.05
This
tolerance
should
be
reclassified
under
180.106(
c),
as
use
of
diuron
on
banana
will
be
restricted
to
HI.
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.05
ppm.
[
Banana]

Barley,
grain
1
0.20
These
tolerances
should
be
reclassified
under
180.106(
c),
as
use
of
diuron
on
barley
is
restricted
to
western
OR
and
WA.
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.20
ppm
for
barley,
grain;
and
to
1.5
ppm
for
barley,
straw.
Barley,
hay
2
2/(
TBD)

Barley,
straw
(
2)
6
1.5
Birdsfoot
trefoil,
forage
2
0.10
These
tolerances
should
be
reclassified
under
180.106(
c),
as
use
of
diuron
on
trefoil
is
restricted
to
western
OR.
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm
for
birdsfoot
trefoil,
forage
and
to
0.15
ppm
for
birdsfoot
trefoil,
hay.
Birdsfoot
trefoil,
hay
2
0.15
Blackberries
1
Reassign;
0.10
The
established
tolerances
for
blackberries,
blueberries,
boysenberries,
currants,
dewberries,
gooseberries,
huckleberries,
loganberries,
and
raspberries
should
be
revoked
concomitant
with
the
establishment
of
a
tolerance
for:
The
available
data
indicate
that
these
tolerances
should
be
reduced
to
0.10
ppm.
[
Berry
Group].
Blueberries
1
Boysenberries
1
Currants
1
Dewberries
1
Gooseberries
1
Huckleberries
1
Loganberries
1
Raspberries
1
Cattle,
fat
1
16
Page
22
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Cattle,
meat
1
16
Cattle,
meat
byproducts
1
16
Citrus
fruits
1
1/(
TBD3,
6)
[
Fruit,
citrus,
group]

Citrus
pulp,
dried
4
4/(
TBD)
[
Citrus,
dried
pulp]

Clover,
forage
2
0.10
These
tolerances
should
be
reclassified
under
180.106(
c),
as
use
of
diuron
on
clover
is
restricted
to
western
OR.
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm
for
clover,
forage
and
to
1
ppm
for
clover,
hay.
Clover,
hay
2
1
Corn
in
grain
or
ear
form
(
including
sweet
corn,
field
corn,
popcorn)
1
0.10
Concomitant
with
the
reassignment
of
this
tolerance,
a
separate
tolerance
should
be
established
for
[
Corn,
field,
grain].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.

1
0.10
Concomitant
with
the
reassignment
of
this
tolerance,
a
separate
tolerance
should
be
established
for
[
Corn,
pop,
grain].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.

1
0.10
Concomitant
with
the
reassignment
of
this
tolerance,
a
separate
tolerance
should
be
established
for
[
Corn,
sweet,
grain].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.

1
0.10
Concomitant
with
the
reassignment
of
this
tolerance,
a
separate
tolerance
should
be
established
for
[
Corn,
field,
ear].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.

1
0.10
Concomitant
with
the
reassignment
of
this
tolerance,
a
separate
tolerance
should
be
established
for
[
Corn,
pop
ear].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.
Page
23
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
1
0.10
Concomitant
with
the
reassignment
of
this
tolerance,
a
separate
tolerance
should
be
established
for
[
Corn,
sweet
ear].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.
Page
24
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Corn,
sweet,
fodder
2
Revoke
There
are
no
registered
uses
of
diuron
on
sweet
corn.
Corn,
sweet,
forage
2
Corn,
field
fodder
2
2/(
TBD)
This
tolerance
was
inadvertently
omitted
from
the
1/
14/
98
Final
Rule
technical
amendment
consolidating
40
CFR
parts
185­
186
to
40
CFR
part
180.
This
action
will
reinstate
this
tolerance
to
40
CFR
part
180.106.
[
Corn,
field,
stover]

Corn,
pop,
fodder
2
2/(
TBD)
This
tolerance
was
inadvertently
omitted
from
the
1/
14/
98
Final
Rule
technical
amendment
consolidating
40
CFR
parts
185­
186
to
40
CFR
part
180.
This
action
will
reinstate
this
tolerance
to
40
CFR
part
180.106.
[
Corn,
pop,
stover]

Corn,
field
forage
2
2/(
TBD)
This
tolerance
was
inadvertently
omitted
from
the
1/
14/
98
Final
Rule
technical
amendment
consolidating
40
CFR
parts
185­
186
to
40
CFR
part
180.
This
action
will
reinstate
this
tolerance
to
40
CFR
part
180.106.
[
Corn,
field,
forage]

Corn,
pop,
forage
2
2/(
TBD)
This
tolerance
was
inadvertently
omitted
from
the
1/
14/
98
Final
Rule
technical
amendment
consolidating
40
CFR
parts
185­
186
to
40
CFR
part
180.
This
action
will
reinstate
this
tolerance
to
40
CFR
part
180.106.
[
Corn,
pop,
forage]

Cottonseed
1
0.20
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.20
ppm.
[
Cotton,
undelinted
seed]

Goats,
fat
1
16
[
Goat,
fat]

Goats,
meat
1
16
[
Goat,
meat]

Goats,
meat
byproducts
1
16
[
Goat,
meat
byproducts]

Grapes
1
0.05
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.05
ppm.
[
Grape]

Grass
crops
(
other
than
Bermuda
grass)
2
2/(
TBD)
[
Grass,
forage,
except
Bermuda
grass]

Grass,
hay
(
other
than
Bermuda
grass
hay)
2
2/(
TBD)
[
Grass,
hay,
except
Bermuda
grass]

Hogs,
fat
1
16
[
Hog,
fat]
Page
25
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Hogs,
meat
1
16
[
Hog,
meat]

Hogs,
meat
byproducts
1
16
[
Hog,
meat
byproducts]

Horses,
fat
1
16
[
Horse,
fat]

Horses,
meat
1
16
[
Horse,
meat]

Horses,
meat
byproducts
1
16
[
Horse,
meat
byproducts]

Nuts
0.1
0.1/(
TBD)
Concomitant
with
the
reassignment
of
this
tolerance,
separate
a
separate
tolerance
should
be
established
for
[
Filbert
].

0.05
Concomitant
with
the
reassignment
of
this
tolerance,
separate
a
separate
tolerance
should
be
established
for
[
Nut,
macadamia].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.05
ppm.

0.05
Concomitant
with
the
reassignment
of
this
tolerance,
separate
a
separate
tolerance
should
be
established
for
[
Pecan].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.05
ppm.

0.05
Concomitant
with
the
reassignment
of
this
tolerance,
separate
a
separate
tolerance
should
be
established
for
[
Walnut].
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.05
ppm.

Oats,
forage
2
2/(
TBD)
These
tolerances
should
be
reclassified
under
180.106(
c),
as
use
of
diuron
on
oats
is
restricted
to
ID,
OR,
and
WA.
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm
for
oats,
grain;
and
to
1.5
ppm
for
oats,
straw.
Oats,
grain
1
0.10
Oats,
hay
2
2/(
TBD)

Oats,
straw
2
1.5
Olives
1
1/(
TBD)
[
Olive]

Papayas
0.5
0.50
[
Papayas]

Peaches
0.1
0.10
[
Peach]

Pears
1
1/(
TBD)
[
Pear]

Peas
1
0.10
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.
[
Pea,
field,
seed]
Page
26
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Peas,
forage
2
2/(
TBD)
[
Pea,
field,
vines]

Peas,
hay
2
2/(
TBD)
[
Pea,
field,
hay]

Peppermint,
hay
2
1.5
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
1.5
ppm.
[
Peppermint,
tops]

Pineapple
1
0.10
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.

Potatoes
1
Revoke
There
are
no
registered
uses
of
diuron
on
potatoes.

Rye,
forage
2
Revoke
There
are
no
registered
uses
of
diuron
on
rye.
Rye,
grain
1
Rye,
hay
2
Rye,
straw
2
Sheep,
fat
1
16
Sheep,
meat
1
16
Sheep,
meat
byproducts
1
16
Sorghum,
fodder
2
2/(
TBD)
[
Sorghum,
grain,
stover]

Sorghum,
forage
2
2/(
TBD)
[
Sorghum,
grain,
forage]

Sorghum,
grain
1
0.50
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.50
ppm.
[
Sorghum,
grain,
grain]

Sugarcane
1
0.20
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.20
ppm.

Vetch,
forage
2
0.10
These
tolerances
should
be
reclassified
under
180.106(
c),
as
use
of
diuron
on
vetch
is
restricted
to
ID,
OR,
and
WA.
The
available
data
indicate
that
these
tolerances
should
be
reduced
to
0.10
ppm
for
vetch,
forage
and
to
1.5
ppm
for
vetch,
hay.
Vetch,
hay
2
1.5
Vetch,
seed
1
Revoke
No
longer
considered
a
significant
livestock
feed
item.

Wheat,
forage
2
2/(
TBD)

Wheat,
grain
1
0.50
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.50
ppm.

Wheat,
hay
2
2/(
TBD)
Page
27
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
Wheat,
straw
2
1.5
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
1.5
ppm.
Page
28
of
30
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
1.
Expressed
as
diuron
per
se,
unless
otherwise
stated.

2.
To
be
expressed
as
the
combined
residues
of
diuron
and
its
metabolites
convertible
to
3,4­
DCA,
expressed
as
diuron.
The
residues
of
3,4­
DCA
are
low
but
diuron
residues
are
converted
to
3,4­
DCA
for
the
tolerance
expression
based
on
the
assumption
that
the
metabolites
would
not
be
any
more
toxic
than
diuron
and
the
consideration
that
the
analytical
methods
used
to
collect
the
field
trial
data
are
not
capable
of
measuring
each
metabolite
individually.
The
reassessed
tolerances
are
contingent
upon
the
recommended
label
revisions
outlined
in
Table
B
of
the
Residue
Chemistry
Chapter
For
The
Diuron
Reregistration
Eligibility
Decision
(
RED)
Document,
dated
7/
29/
2001.

3.
TBD
=
To
be
determined.
These
commodities
were
included
in
the
dietary
risk
assessment
using
the
Current
Tolerance
level.
Additional
confirmatory
field
trial
residue
data
are
required;
therefore,
the
final
tolerance
may
be
revised.

4.
Expressed
as
combined
residues
of
diuron
and
its
metabolites
convertible
to
3,4­
DCA.

5.
Feeding
study
data
have
been
submitted
to
reassess
the
established
tolerances
for
the
fat,
meat,
and
meat
byproducts
of
cattle,
goats,
hogs,
horses,
and
sheep.
Residue
data
are
not
available
for
several
potential
feed
items.
If
the
maximum
dietary
burden
does
not
increase
when
recalculated
from
all
potential
feed
items
after
acceptable
field
trial
data
are
submitted
then
the
established
tolerances
for
residues
in
fat,
meat,
and
meat
byproducts
of
cattle,
goats,
hogs,
horses,
and
sheep
can
be
lowered.
Tolerance
Listed
Under
40
CFR
§
180.106(
b)

Catfish
fillets
2.04
2.0
Expiration
date
of
06/
30/
03
[
Catfish]

Tolerances
To
Be
Proposed
Under
40
CFR
§
180.106(
a)

Aspirated
grain
fractions
N/
A
5.0
Barley,
bran
N/
A
0.7
Citrus,
oil
N/
A
TBD
Cotton,
gin
byproducts
N/
A
TBD
Eggs
N/
A
TBD
Grass,
seed
screenings
N/
A
TBD
Grass,
straw
N/
A
TBD
Milk
N/
A
TBD
Pineapple,
process
residue
N/
A
0.40
Poultry,
meat
byproducts
N/
A
TBD
Prickly
pear
N/
A
0.05
Spearmint
N/
A
1.5
Sugarcane,
molasses
N/
A
0.70
Wheat,
bran
N/
A
0.70
Page
29
of
30
6.
Residue
data
to
support
the
9.6
lbs
ai/
A
per
year
rate
for
citrus
are
required.
The
registrant
may
provide
data
to
support
this
use
rate
or
change
the
labels
to
reflect
the
use
rate
of
6.4
lbs
ai/
A
per
year,
as
supported
by
current
residue
data.

No
maximum
residue
limits
(
MRLs)
for
diuron
have
been
established
by
Codex
for
any
agricultural
commodity.

Summary
of
Pending
Data
The
following
additional
confirmatory
data
have
been
identified.

Toxicology
Data:

°
28­
day
inhalation
study
Product
and
Residue
Chemistry
Data:

°
New
confidential
statements
of
formula
reflecting
preliminary
analyses
of
current
products
together
with
discussions
of
formation
of
impurities
°
UV/
Visible
absorption
data/
spectra
°
Independent
lab
validation
for
analytical
method
°
Multiresidue
methods
for
diuron
and
metabolites
in
plants
and
livestock
°
Magnitude
of
residue
field
trial
data
for:
alfalfa
forage;
globe
artichoke;
barley
hay;
citrus
(
at
the
9.6
lbs
ai/
A
rate),
cotton
gin
byproducts;
field
corn
aspirated
grain
fractions,
forage
and
stover;
sweet
corn,
stover;
sweet
corn,
forage;
filbert;
grass
forage,
hay,
seed
screenings,
and
straw;
lemon
(
in
review);
pear;
oat
forage,
hay;
olive;
field
pea
vines
and
hay;
sorghum
aspirated
grain,
fractions,
stover,
and
forage;
and
wheat
forage
and
hay
°
Processing
data
for
field
corn
and
olives
°
Metabolism
study
in
fish
Occupational
Exposure
Data:

°
Exposure
study
of
mixing/
loading/
applying
wettable
powder
or
dry
flowable
with
backpack
sprayer
°
Exposure
study
of
mixing/
loading/
applying
dry
flowable
with
low­
pressure
handwand
°
Worker
exposure
resulting
from
contact
with
treated
soil
and
soil
dissipation
study
°
Exposure
study
for
mechanical
harvesting
alfalfa
and
asparagus
Environmental
Fate
and
Ecological
Effects
Data:

°
Avian
reproduction
study
­
diuron
°
Freshwater
aquatic
invertebrate
life­
cycle
toxicity
study
­
diuron
Page
30
of
30
°
Estuarine/
marine
fish
early
life­
cycle
toxicity
study
­
diuron
°
Nontarget
aquatic
plant
toxicity
study
­
diuron
°
Upgrade
of
leaching­
adsorption­
desorption
study
­
diuron
°
Hydrolysis
of
MCPDMU
°
Aerobic
Soil
Metabolism
of
MCPDMU
°
Aerobic
Aquatic
Metabolism
of
MCPDMU
°
Anaerobic
Aquatic
Metabolism
of
MCPCMU
°
Leaching­
Adsorption­
Desorption
of
MCPDMU
°
Drinking
water
monitoring
study
on
diuron
and
its
major
degradates
(
reserved).