Document ID: EPA-HQ-OPP-2003-0349-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-04-13T04:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
CERTIFIED
MAIL
Dear
Registrant:

This
is
to
inform
you
that
the
Environmental
Protection
Agency
(
hereafter
referred
to
as
EPA
or
the
Agency)
has
completed
its
review
of
the
available
data
and
public
comments
received
related
to
the
preliminary
risk
assessment
for
the
dimethylurea
herbicide
diuron.
The
Agency
has
revised
the
human
health
and
environmental
effects
risk
assessments
based
on
the
comments
received
during
the
public
comment
period
and
additional
data
from
the
registrant.
Based
on
the
Agency's
revised
risk
assessments
for
diuron,
EPA
has
identified
risk
mitigation
measures
that
the
Agency
believes
are
necessary
to
address
the
human
health
and
environmental
risks
associated
with
the
current
use
of
diuron.
EPA
is
now
publishing
its
reregistration
eligibility,
and
risk
management
decision.
The
Agency's
decision
on
the
individual
chemical
diuron
can
be
found
in
the
attached
document
entitled,
"
Reregistration
Eligibility
Decision
for
Diuron"
which
was
approved
on
September
30,
2003.
A
tolerance
reassessment
was
completed
in
July
of
2002.
This
RED
document
contains
that
tolerance
reassessment
decision
as
well
as
the
Agency's
decisions
on
the
mitigation
needed
for
other
human
health
and
environmental
risks.

A
Notice
of
Availability
for
the
Reregistration
Eligibility
Decision
for
Diuron
is
being
published
in
the
Federal
Register.
To
obtain
copies
of
the
RED
document,
please
contact
the
Pesticide
Docket,
Public
Response
and
Program
Resources
Branch,
Field
and
External
Affairs
Division
(
7506C),
Office
of
Pesticide
Programs
(
OPP),
USEPA,
Washington,
DC
20460,
telephone
(
703)
305­
5805.
Electronic
copies
of
the
RED
and
all
supporting
documents
are
available
on
the
Internet.
See
www.
epa.
gov/
pesticides/
reregistration/
status.
htm.

As
part
of
the
Agency's
effort
to
involve
the
public
in
the
implementation
of
the
Food
Quality
Protection
Act
of
1996
(
FQPA),
the
Agency
is
undertaking
a
special
effort
to
maintain
open
public
dockets
and
to
engage
the
public
in
the
reregistration
and
tolerance
reassessment
processes.
During
the
public
comment
period,
comments
on
the
risk
assessment
were
submitted
by
Griffin
L.
L.
C.,
the
technical
registrant.
A
close­
out
conference
call
with
interested
stakeholders
was
conducted
on
September
29,
2003,
to
discuss
the
risk
management
decisions
and
resultant
changes
to
the
diuron
labels.
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
July
9,
2003).
For
purposes
of
this
risk
assessment,
EPA
has
assumed
that
diuron
does
not
have
a
common
mechanism
of
toxicity
with
other
substances.

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.
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
14,
2002
(
67
FR
2210­
2214),
and
is
available
from
the
OPP
Website
at:
http://
www.
epa.
gov/
oppfod01/
trac/
science/
cumulative_
guidance.
pdf.

This
RED
contains
the
necessary
labeling
changes
for
diuron.
Product
labels
must
be
revised
by
the
manufacturer
to
adopt
the
changes
set
forth
in
Section
IV
of
this
document.
Instructions
for
registrants
on
submitting
revised
labeling
and
the
time
frame
established
to
do
so
can
be
found
in
Section
V
of
this
document.

Should
a
registrant
fail
to
implement
any
of
the
risk
mitigation
measures
outlined
in
this
document,
the
Agency
will
continue
to
have
concerns
about
the
risks
posed
by
diuron.
Where
the
Agency
has
identified
any
unreasonable
adverse
effect
to
human
health
and
the
environment,
the
Agency
may
at
any
time
initiate
appropriate
regulatory
action
to
address
this
concern.
At
that
time,
any
affected
person(
s)
may
challenge
the
Agency's
action.
If
you
have
questions
on
this
document
or
the
proposed
label
changes,
please
contact
the
Special
Review
and
Reregistration
Division
representative,
Diane
Isbell
at
(
703)
308­
8154.

Betty
Shackleford,
Acting
Director
Special
Review
and
Reregistration
Division
Attachment
Reregistration
Eligibility
Decision
for
Diuron
List
A
Case
0046
Table
of
Contents
Executive
Summary
.
.
.
.
.
.
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.
iv
I.
Introduction
.
.
.
.
.
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.
.
1
II.
Chemical
Overview
.
.
.
.
.
.
.
.
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.
2
A.
Regulatory
History
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
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.
.
.
2
B.
Chemical
Identification
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
2
C.
Use
Profile
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
4
D.
Estimated
Usage
of
Pesticide
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
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.
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.
.
.
.
.
.
.
.
6
III.
Summary
of
Diuron
Risk
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
9
A.
Human
Health
Risk
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
9
1.
Dietary
Risk
From
Food
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
9
a.
Toxicity
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
9
b.
FQPA
Safety
Factor
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
12
c.
Endpoints
and
Doses
for
Risk
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
13
d.
Endocrine
Disruption
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
14
e.
3,4­
dichloroaniline
(
3,4­
DCA)
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
15
f.
Potential
Tetrachloroazobenzene
Contamination
.
.
.
.
.
.
.
.
.
15
g.
Exposure
Assumptions
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
16
h.
Dietary
(
Food)
Risk
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
17
(
1)
Acute
Dietary
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
17
(
2)
Chronic
(
Non­
Cancer)
Dietary
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
17
(
3)
Cancer
Dietary
Risk
from
Food
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
18
2.
Dietary
Risk
from
Drinking
Water
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
19
a.
Surface
Water
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
.
.
.
.
.
20
b.
Ground
Water
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
22
c.
Drinking
Water
Risk
Estimates
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
23
3.
Diuron:
Residential
Exposure
and
Risk
.
.
.
.
.
.
.
.
.
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.
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.
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.
.
24
a.
Toxicity
.
.
.
.
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.
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.
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.
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.
.
.
.
24
b.
Residential
Handler
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
26
(
1)
Exposure
Scenarios,
Data,
&
Assumptions
.
.
.
.
.
.
.
.
.
26
(
2)
Residential
Handler
Risk
Characterization
.
.
.
.
.
.
.
.
28
c.
Residential
Postapplication
Risk
Characterization
.
.
.
.
.
.
.
.
29
(
1)
Exposure
Scenarios,
Data,
&
Assumptions
.
.
.
.
.
.
.
.
.
29
(
2)
Residential
Postapplication
Risk
Characterization
.
.
30
4.
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
.
.
.
.
.
.
31
a.
Acute
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
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.
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.
.
.
.
.
.
31
b.
Short­
Term
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
31
c.
Chronic
(
Non­
Cancer)
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
32
d.
Cancer
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
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.
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.
.
.
.
.
.
.
33
5.
Occupational
Risk
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
.
34
a.
Toxicity
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
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.
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.
.
.
.
.
36
b.
Agricultural
Handler
Exposure
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
36
c.
Agricultural
Handler
Non­
Cancer
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
39
d.
Agricultural
Handler
Cancer
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
47
e.
Handler
Exposure
from
Antimicrobial
Use:
Mildewcide
in
Paints,
Stains,
Solvents,
Adhesives,
and
Coatings
.
.
.
.
.
.
.
.
.
53
f.
Handler
Risk
from
Antimicrobial
Use:
Mildewcide
in
Paints,
Stains,
Solvents,
Adhesives,
and
Coatings
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
55
g.
Handler
Exposures:
Algaecide
Use
for
Use
in
Commercial
Fish
Ponds
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
58
h.
Handler
Risks:
Algaecide
Use
for
Use
in
Commercial
Fish
Ponds
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
60
i.
Postapplication
Occupational
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
60
(
1)
Data
Sources
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
61
(
2)
Assumptions
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
62
j.
Human
Incident
Data
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
64
B.
Environmental
Risk
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
64
1.
Environmental
Fate
and
Transport
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
64
2.
Toxicity
(
Hazard)
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
66
a.
Toxicity
to
Terrestrial
Organisms
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
66
b.
Toxicity
to
Aquatic
Organisms
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
67
c.
Toxicity
to
Non­
target
Plants
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
68
3.
Exposure
and
Risk
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
69
a.
Risk
Calculation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
69
b.
Exposure
and
Risk
to
Non­
target
Terrestrial
Organisms
.
.
.
70
(
1)
Avian
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
70
(
2)
Mammalian
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
72
(
3)
Risk
to
Non­
target
Insects
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
73
c.
Exposure
and
Risk
to
Non­
target
Aquatic
Organisms
.
.
.
.
.
73
(
1)
Surface
Water
Resources
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
74
(
2)
Risk
to
Fish
and
Aquatic
Invertebrates
.
.
.
.
.
.
.
.
.
.
.
.
.
.
74
d.
Exposure
and
Risk
to
Non­
target
Terrestrial
and
Aquatic
Plants
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
76
4.
Ecological
Incidents
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
79
5.
Endangered
Species
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
80
IV.
Risk
Management,
Reregistration
and
Tolerance
Reassessment
Decisions
.
.
.
.
.
.
81
A.
Determination
of
Reregistration
Eligibility
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
81
B.
Public
Comments
and
Responses
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
81
C.
Regulatory
Position
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
82
1.
FQPA
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
82
a.
"
Risk
Cup"
Determination
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
82
b.
Determination
of
Safety
for
U.
S.
Population
.
.
.
.
.
.
.
.
.
.
.
.
.
82
c.
Determination
of
Safety
for
Infants
and
Children
.
.
.
.
.
.
.
.
.
83
d.
Endocrine
Disruptor
Effects
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
83
e.
Cumulative
Risks
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
84
f.
Tolerance
Summary
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
84
(
1)
Codex
Harmonization
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
90
D.
Risk
Management
and
Rationale
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
91
1.
Human
Health
Risk
Management
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
92
a.
Dietary
(
Food)
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
92
b.
Drinking
Water
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
93
c.
Residential
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
93
(
1)
Residential
Handler
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
94
(
2)
Residential
Postapplication
Risk
Mitigation
.
.
.
.
.
.
.
94
d.
Aggregate
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
94
(
1)
Acute
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
94
(
2)
Short­
term
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
94
(
3)
Chronic
(
Non­
Cancer)
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
94
(
4)
Chronic
(
Cancer)
Aggregate
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
95
e.
Occupational
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
95
(
1)
Handler
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
95
(
2)
Post­
application
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
98
2.
Environmental
Risk
Mitigation
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
98
3.
Other
Labeling
Requirements
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
99
a.
Endangered
Species
Statement
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
99
b.
Spray
Drift
Management
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
100
V.
What
Registrants
Need
to
Do
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
101
A.
Manufacturing
Use
Products
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
103
1.
Additional
Generic
Data
Requirements
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
103
2.
Labeling
for
Manufacturing­
Use
Products
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
104
B.
End­
Use
Products
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
104
1.
Additional
Product­
Specific
Data
Requirements
.
.
.
.
.
.
.
.
.
.
.
.
.
.
104
2.
Labeling
for
End­
Use
Products
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
104
C.
Existing
Stocks
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
104
i
Diuron
Reregistration
Eligibility
Decision
Team
Office
of
Pesticide
Programs:

Biological
and
Economic
Analysis
Assessment
Bill
Chism
Alan
Halvorson
Environmental
Fate
and
Effects
Risk
Assessment
Ibrahim
Abdel­
Saheb
William
Eckel
Richard
Lee
Dana
Spatz
Health
Effects
Risk
Assessment
Carol
Christensen
Ken
Dockter
Sherrie
Kinard
Yung
Yang
Registration
Support
Dan
Rosenblatt
Jim
Tompkins
Risk
Management
Diane
Isbell
ii
Glossary
of
Terms
and
Abbreviations
AGDCI
Agricultural
Data
Call­
In
ai
Active
Ingredient
aPAD
Acute
Population
Adjusted
Dose
AR
Anticipated
Residue
BCF
Bioconcentration
Factor
CFR
Code
of
Federal
Regulations
cPAD
Chronic
Population
Adjusted
Dose
CSF
Confidential
Statement
of
Formula
CSFII
USDA
Continuing
Surveys
for
Food
Intake
by
Individuals
DCI
Data
Call­
In
DEEM
Dietary
Exposure
Evaluation
Model
DFR
Dislodgeable
Foliar
Residue
DWLOC
Drinking
Water
Level
of
Comparison.
EC
Emulsifiable
Concentrate
Formulation
EEC
Estimated
Environmental
Concentration
EPA
Environmental
Protection
Agency
EUP
End­
Use
Product
FDA
Food
and
Drug
Administration
FIFRA
Federal
Insecticide,
Fungicide,
and
Rodenticide
Act
FFDCA
Federal
Food,
Drug,
and
Cosmetic
Act
FQPA
Food
Quality
Protection
Act
FOB
Functional
Observation
Battery
G
Granular
Formulation
GENEEC
Tier
I
Surface
Water
Computer
Model
GLN
Guideline
Number
HAFT
Highest
Average
Field
Trial
IR
Index
Reservoir
LC50
Median
Lethal
Concentration.
A
statistically
derived
concentration
of
a
substance
that
can
be
expected
to
cause
death
in
50%
of
test
animals.
It
is
usually
expressed
as
the
weight
of
substance
per
weight
or
volume
of
water,
air
or
feed,
e.
g.,
mg/
l,
mg/
kg
or
ppm.
LD50
Median
Lethal
Dose.
A
statistically
derived
single
dose
that
can
be
expected
to
cause
death
in
50%
of
the
test
animals
when
administered
by
the
route
indicated
(
oral,
dermal,
inhalation).
It
is
expressed
as
a
weight
of
substance
per
unit
weight
of
animal,
e.
g.,
mg/
kg.
LOC
Level
of
Concern
LOD
Limit
of
Detection
LOAEL
Lowest
Observed
Adverse
Effect
Level
MATC
Maximum
Acceptable
Toxicant
Concentration

g/
g
Micrograms
Per
Gram

g/
L
Micrograms
Per
Liter
mg/
kg/
day
Milligram
Per
Kilogram
Per
Day
mg/
L
Milligrams
Per
Liter
MOE
Margin
of
Exposure
MRID
Master
Record
Identification
(
number).
EPA's
system
of
recording
and
tracking
studies
submitted.
MUP
Manufacturing­
Use
Product
NA
Not
Applicable
NAWQA
USGS
National
Water
Quality
Assessment
NCFAP
National
Center
for
Food
and
Agricultural
Policy
NPDES
National
Pollutant
Discharge
Elimination
System
iii
NR
Not
Required
NOAEL
No
Observed
Adverse
Effect
Level
OP
Organophosphate
OPP
EPA
Office
of
Pesticide
Programs
OPPTS
EPA
Office
of
Prevention,
Pesticides
and
Toxic
Substances
PAD
Population
Adjusted
Dose
PCA
Percent
Crop
Area
PDP
USDA
Pesticide
Data
Program
PHED
Pesticide
Handler's
Exposure
Data
PHI
Preharvest
Interval
ppb
Parts
Per
Billion
PPE
Personal
Protective
Equipment
ppm
Parts
Per
Million
PRZM/
EXAMS
Tier
II
Surface
Water
Computer
Model
Q1*
The
Carcinogenic
Potential
of
a
Compound,
Quantified
by
the
EPA's
Cancer
Risk
Model
RAC
Raw
Agriculture
Commodity
RED
Reregistration
Eligibility
Decision
REI
Restricted
Entry
Interval
RfD
Reference
Dose
RQ
Risk
Quotient
SCI­
GROW
Tier
I
Ground
Water
Computer
Model
SAP
Science
Advisory
Panel
SF
Safety
Factor
SLC
Single
Layer
Clothing
SLN
Special
Local
Need
(
Registrations
Under
Section
24
©
)
of
FIFRA)
TGAI
Technical
Grade
Active
Ingredient
TRED
Tolerance
Reassessment
Progress
and
Risk
Management
Decision
TRR
Total
Radioactive
Residue
USDA
United
States
Department
of
Agriculture
USGS
United
States
Geological
Survey
UF
Uncertainty
Factor
UV
Ultraviolet
WPS
Worker
Protection
Standard
iv
Executive
Summary
EPA
has
completed
its
review
of
public
comments
on
the
preliminary
risk
assessments
and
is
issuing
its
risk
management
decision
for
diuron.
The
revised
risk
assessments
are
based
on
a
review
of
the
required
target
data
base
supporting
the
use
patterns
of
currently
registered
products
and
additional
information
received
during
the
public
comment
periods.
After
considering
the
risks
identified
in
the
revised
risk
assessment,
EPA
developed
its
risk
management
decision
for
uses
of
diuron
that
pose
risks
of
concern.
Risks
from
N'­(
3­
chlorophenyl)­
N,
Ndimethyl
urea
(
MCPDMU)
(
water
only)
3,4­
dichlorophenylurea
(
DCPU)
and
3­(
3,4­
dichlorophenyl)­
1­
methylurea
(
DCPMU),
the
primary
metabolites
of
diuron,
are
also
considered
in
the
assessment.
The
decision
is
discussed
fully
in
this
document.
A
tolerance
reassessment
was
completed
in
July
of
2002.
For
completeness,
the
results
of
the
tolerance
reassessment
are
incorporated
in
this
document,
including
additional
information
on
surface
water
monitoring.

Diuron
is
registered
for
pre­
and
post­
emergent
herbicide
treatment
of
both
crop
and
noncrop
areas,
as
a
mildewcide
and
preservative
in
paints
and
stains,
and
as
an
algaecide
in
commercial
fish
production,
residential
ponds
and
aquariums.
Diuron
was
first
registered
in
1967.

Estimates
for
total
annual
domestic
use
average
approximately
nine
to
ten
million
pounds
of
active
ingredient.
Approximately
two
thirds
is
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
citrus,
berries,
asparagus
and
pineapple.
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.

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
July
9,
2003).
For
purposes
of
this
risk
assessment,
EPA
has
assumed
that
diuron
does
not
have
a
common
mechanism
of
toxicity
with
other
substances.
v
Dietary
Risk
­
Food
EPA's
dietary
risk
analysis
evaluated
acute,
chronic
(
non­
cancer)
and
cancer
risk
for
diuron.
Anticipated
residues
from
field
trial
data
were
used
to
estimate
the
dietary
exposure
to
diuron
from
the
diets
of
the
U.
S.
population
as
well
as
certain
population
subgroups.
The
field
trials
were
conducted
at
the
highest
application
rates
for
the
crop
tested
and
therefore,
the
residues
from
these
trials
are
considered
high
end.
It
should
be
noted
that
the
U.
S.
Department
of
Agriculture's
Pesticide
Data
Program
(
PDP)
monitoring
data
are
available
for
diuron
alone,
indicating
no
detectable
residues
of
the
parent
compound
in
citrus,
milk
and
other
sampled
commodities
monitored
for
diuron.
However,
these
data
have
not
been
used
in
the
risk
assessment
because
the
PDP
program
only
monitored
for
diuron,
the
parent
compound,
and
did
not
monitor
for
the
metabolites.

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.
The
chronic
non­
cancer
dietary
analysis
indicates
all
risk
estimates
are
below
EPA's
level
of
concern
for
all
population
subgroups.
The
chronic
dietary
risk
estimate
for
food
is
about
3%
of
the
chronic
PAD
for
the
U.
S.
population
and
about
7%
of
the
chronic
PAD,
for
the
highest
exposed
population
subgroup,
children
(
1­
6
years).
The
estimated
cancer
dietary
risk
associated
with
the
use
of
diuron
shows
a
lifetime
risk
estimate
of
1.68
x
10­
6
for
the
general
population.
However,
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.

Dietary
Risk
­
Drinking
Water
Drinking
water
exposure
to
pesticides
can
occur
through
groundwater
and
surface
water
contamination.
For
chronic
risk
from
diuron,
drinking
water
monitoring
data
from
South
Florida
Water
Management
District
and
the
California
Department
of
Pesticide
Regulation
were
used
in
addition
to
USGS
NAWQA
data
from
the
South
Florida,
Georgia­
Florida
Coastal
Plain
and
Apalachicola­
Chattahoochee­
Flint
River
were
used
to
determine
the
estimated
environmental
concentrations
(
EECs)
in
surface
water.
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
not
of
concern.

The
estimated
environmental
concentrations
(
EECs)
for
surface
water
from
monitoring
data
(<
1
ppb)
do
not
exceed
the
drinking
water
level
of
comparison
(
DWLOC)
of
28
ppb
and
are
not
of
concern
for
the
general
population
or
any
sub­
group.

For
diuron
potential
cancer
risk,
EPA
has
considered
average
values
from
monitoring
data
ranging
from
0.16
to
0.28
ppb,
yielding
risk
estimates
in
the
1
x
10­
6
range.
vi
For
the
degradate
MCPDMU,
the
EEC
for
surface
water
has
been
estimated
to
be
<
1ppb,
using
monitoring
data.
The
drinking
water
assessment
for
MCPDMU
can
be
further
refined
with
additional
environmental
fate
data.
These
data
are
required.

Residential
Risk
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
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.

There
are
no
residential
uses
that
would
result
in
chronic
exposure
to
diuron.
Because
less
than
1
percent
of
all
paint
contains
diuron,
cancer
risk
from
residential
use
is
expected
to
be
negligible.

Diuron
Aggregate
Risk
An
aggregate
risk
assessment
looks
at
the
combined
risk
from
dietary
exposure
(
food
and
drinking
water
pathways)
as
well
as
exposures
from
non­
occupational
sources
(
e.
g.,
residential
uses).

Acute
Aggregate
Risk.
There
are
no
adverse
effects
expected
from
a
single
exposure
to
diuron;
therefore,
an
acute
risk
assessment
was
not
conducted.

Short­
term
Aggregate
Risk.
Short­
term
aggregate
exposure
takes
into
account
residential
exposure
plus
chronic
exposure
to
food
and
water.
Short­
term
aggregate
risks
from
food,
residential
inhalation,
and
drinking
water
are
not
of
concern.

Chronic
(
Non­
cancer)
Aggregate
Risk.
The
chronic
(
non­
cancer)
aggregate
risk
assessment
addresses
exposure
to
diuron
residues
in
food
and
water;
there
are
no
diuron
uses
that
vii
could
result
in
chronic
residential
exposure.
Monitoring
data
from
the
South
Florida
Water
Management
District
and
the
California
Department
of
Pesticide
Regulation
were
used
in
addition
to
USGS
NAWQA
data
from
the
South
Florida,
Georgia­
Florida
Coastal
Plain
and
Apalachicola­
Chattahoochee­
Flint
River.
The
estimated
environmental
concentration
(
EEC)
for
surface
water
(<
1
ppb)
does
not
exceed
the
drinking
water
level
of
comparison
(
DWLOC)
of
28
ppb
for
the
most
sensitive
population
subgroup
(
children
1­
6).
Therefore,
the
chronic
non­
cancer
DWLOCs
are
greater
than
the
surface
water
EECs
indicating
that
chronic
dietary
(
food
+
water)
risks
are
below
EPA's
level
of
concern.
Chronic
aggregate
risk
is
also
below
EPA's
level
of
concern.

Chronic
(
Cancer)
Aggregate
Risk.
Dietary
risk
from
food
is
estimated
at
1.68
x
10­
6
based
on
field
trial
data
and
assuming
maximum
application
rates.
This
estimate
can
be
refined
with
additional
residue
data.
Based
on
monitoring
data,
drinking
water
cancer
risk
is
estimated
in
the
1
x
10­
6
range.
Exposure
from
residential
uses
is
negligible.
Although
the
combined
risk
exceeds
1
x
10­
6,
EPA
believes
that,
given
the
weight
of
evidence,
diuron
cancer
risk
is
not
of
concern.
The
Agency
does
not
apply
the
negative
risk
standard
for
cancer
(
1
x
10­
6
or
one
in
a
million)
as
a
bright
line
test
because
of
the
lack
of
precision
in
the
quantitative
cancer
risk
assessment.
There
are
protective
assumptions
in
both
the
toxicological
data
used
to
derive
the
cancer
potency
of
a
substance
and
in
the
exposure
calculations.

MCPDMU
Aggregate
Risk
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.

Monitoring
data,
adjusted
to
account
for
all
potential
metabolites,
indicate
that
environmental
concentrations
of
MCPDMU
would
be
<
1
ppb,
which
is
less
than
the
calculated
DWLOC
of
2
ppb.
Thus,
the
aggregate
risk
of
MCPDMU
is
not
of
concern.

Occupational
Risk
The
Agency
has
identified
31
handler
scenarios
resulting
from
mixing/
loading
and
applying
diuron
for
crop
and
non­
crop
uses.
Of
the
31
scenarios,
all
short­
and
intermediate­
term
exposures
resulted
in
a
Margin
of
Exposure
(
MOE)
at
or
near
the
target
of
100
with
personal
protective
equipment
(
PPE)
and
engineering
controls
(
e.
g.,
closed
mixing
and
loading
systems),
as
appropriate.

For
the
occupational
paint
assessment,
painters
using
an
airless
sprayer
(
MOE
=
56)
is
of
concern
(
with
PPE).

For
the
cancer
assessment,
the
following
scenarios
are
potentially
of
concern
(
with
PPE):
viii
applying
with
a
right­
of­
way
sprayer
(
risk
=
1.3e­
4);
applying
in
an
industrial/
commercial
setting
with
a
high­
pressure
handwand
(
risk
=
2.4e­
4);
mixing/
loading/
applying
wettable
powder
products
with
a
low­
pressure
handwand
(
risk
=
1.5e­
4);
loading
and
applying
with
a
gravity
feed
backpack
spreader
(
risk
=
1.6e­
4);
and
loading
and
applying
with
a
belly
grinder
(
risk
=
3.1e­
4).

Ecological
Risk
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.

Most
of
the
RQ
values
are
9
or
below,
including
birds
(
acute),
mammals,
freshwater
fish,
estuarine
fish,
freshwater
invertebrates,
and
estuarine
invertebrates.
The
highest
RQ
value
for
non­
target
aquatic
plants
from
railroad/
right­
of­
way
treatment
at
the
maximum
application
rate
is
172.
The
RQs
for
non­
target
terrestrial
plants
range
from
1
to
77
for
acute
risk.

Endangered
Species
EPA
has
completed
an
"
Effects
Determination"
for
endangered
and
threatened
salmon
and
steelhead
species
and
the
potential
for
indirect
effects
on
these
fish
from
damage
to
their
aquatic
plant
cover
in
water
bodies
in
California
and
the
Pacific
Northwest.

The
Agency
has
concluded
that
agricultural
crop
uses
of
diuron
will
have
no
effect
on
Pacific
salmon
and
steelhead
except
at
certain
high
use
rates,
on
walnuts,
filberts,
and
peaches,
and
that
non­
crop
uses
may
affect
25
salmon
and
steelhead
evolutionarily
significant
units
(
ESUs).
For
those
ESUs
that
may
be
affected
by
diuron
use,
EPA
will
consult
with
the
National
Marine
Fisheries
Service
to
determine
what
protective
measures
are
needed.
The
protective
measures
are
communicated
to
the
public
in
county­
specific
bulletins.
Other
species
and
geographic
areas
have
not
yet
been
evaluated.
For
additional
information,
please
see
the
document
titled,
"
Diuron,
Analysis
of
Risks
to
Endangered
and
Threatened
Salmon
and
Steelhead,"
dated
July
30,
2003.
See
http://
www.
epa.
gov/
oppfead1/
endanger/
effects/
diuron_
analysis_
final2.
pdf.
ix
Risk
Mitigation
Summary
To
mitigate
risks
of
concern
posed
by
the
use
of
diuron,
EPA
considered
the
mitigation
proposed
by
the
technical
registrant,
as
well
as
risk
mitigation
ideas
from
other
interested
parties,
and
has
decided
on
a
number
of
label
amendments
to
address
the
worker,
residential
and
ecological
concerns.
A
summary
of
the
risk
mitigation
is
listed
below.
A
complete
discussion
of
the
risk
assessments,
and
the
necessary
label
amendments
to
mitigate
risks
posed
by
the
use
of
diuron,
are
presented
in
Chapter
IV
of
this
RED.

°
All
wettable
powder
products
will
be
voluntarily
canceled.

°
Reduction
in
application
rate
and
increased
treatment
intervals,
and
limit
the
number
of
applications
for
some
crops.

°
Use
of
the
backpack
sprayer
is
prohibited.

°
Implement
use
of
PPE
and
engineering
controls
for
some
workers.

°
Eliminate
aerial
applications
except
for
rights­
of­
way,
alfalfa,
cotton,
winter
barley,
winter
wheat,
sugarcane,
and
grass
seed
crops.

°
Best
management
practices
to
reduce
spray
drift.

Conclusions
The
Agency
is
issuing
this
Reregistration
Eligibility
Document
(
RED)
for
diuron,
as
announced
in
a
Notice
of
Availability
published
in
the
Federal
Register.
This
RED
document
includes
guidance
and
time
frames
for
complying
with
any
required
label
changes
for
products
containing
diuron.
With
the
addition
of
the
label
restrictions
and
amendments
detailed
in
this
document,
the
Agency
has
determined
that
all
currently
registered
uses
of
diuron
are
eligible
for
reregistration.

The
risk
assessments
for
diuron
are
based
on
the
best
scientific
data
currently
available
to
the
Agency
and
are
adequate
for
regulatory
decision
making.
1
I.
Introduction
The
Federal
Insecticide,
Fungicide,
and
Rodenticide
Act
(
FIFRA)
was
amended
in
1988
to
accelerate
the
reregistration
of
products
with
active
ingredients
registered
prior
to
November
1,
1984.
The
amended
Act
calls
for
the
development
and
submission
of
data
to
support
the
reregistration
of
an
active
ingredient,
as
well
as
a
review
of
all
submitted
data
by
the
U.
S.
Environmental
Protection
Agency
(
referred
to
as
EPA
or
"
the
Agency").
Reregistration
involves
a
thorough
review
of
the
scientific
database
underlying
a
pesticide's
registration.
The
purpose
of
the
Agency's
review
is
to
reassess
the
potential
hazards
arising
from
the
currently
registered
uses
of
the
pesticide,
to
determine
the
need
for
additional
data
on
health
and
environmental
effects,
and
to
determine
whether
or
not
the
pesticide
meets
the
"
no
unreasonable
adverse
effects"
criteria
of
FIFRA.

On
August
3,
1996,
the
Food
Quality
Protection
Act
of
1996
(
FQPA)
was
signed
into
law.
This
Act
amends
FIFRA
to
require
tolerance
reassessment
during
reregistration.
It
also
requires
that
by
2006,
EPA
must
review
all
tolerances
in
effect
on
the
day
before
the
date
of
the
enactment
of
the
FQPA.
The
FQPA
also
amends
the
FFDCA
to
require
a
safety
finding
in
tolerance
reassessment
based
on
factors
including
an
assessment
of
cumulative
effects
of
chemicals
with
a
common
mechanism
of
toxicity.

Diuron
is
used
as
a
pre­
and
post­
emergent
herbicide
treatment
on
a
variety
of
both
crop
and
non­
crop
areas.
It
is
also
used
as
a
mildewcide
in
paints
and
stains,
and
as
an
algaecide
in
commercial
fish
production.
At
this
time,
the
Agency
does
not
have
data
available
to
determine
with
certainty
whether
diuron
has
a
common
mechanism
of
toxicity
with
other
pesticides.
Therefore,
for
the
purposes
of
this
risk
assessment,
the
Agency
has
assumed
that
diuron
does
not
share
a
common
mechanism
of
toxicity
with
other
pesticides.
If
the
Agency
identifies
other
substances
that
share
a
common
mechanism
of
toxicity
with
diuron,
EPA
will
consider
whether
a
cumulative
assessment
is
warranted.
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/
oppfod01/
trac/
science/
cumulative_
guidance.
pdf.

This
document
consists
of
six
sections.
Section
I,
Introduction,
contains
the
regulatory
framework
for
reregistration/
tolerance
reassessment.
Section
II,
Chemical
Overview,
provides
a
profile
of
the
use
and
usage
of
the
chemical
and
its
regulatory
history.
Section
III,
Summary
of
Diuron
Risk
Assessments,
gives
an
overview
of
the
revised
human
health
and
environmental
effects
risk
assessments
resulting
from
public
comments
and
other
information.
Section
IV,
Risk
Management:
Reregistration
and
Tolerance
Reassessment,
presents
the
Agency's
reregistration
eligibility
and
risk
management
decisions.
Section
V,
What
Registrants
Need
to
Do,
summarizes
label
changes
needed
to
implement
the
risk
mitigation
measures
outlined
in
Section
IV.
The
Appendices,
provide
information
on
how
to
access
related
documents,
and
list
Data
Call­
In
(
DCI)
information.
The
revised
risk
assessments
and
related
addenda
are
not
included
in
this
document,
but
are
available
on
the
Agency's
web
page
www.
epa.
gov/
pesticides,
and
in
the
Public
Docket.
II.
Chemical
Overview
2
A.
Regulatory
History
Diuron
has
been
registered
in
the
United
States
since
1967
for
use
as
an
herbicide,
mildewcide
and
algaecide.

A
Registration
Standard,
titled
"
Guidance
for
the
Reregistration
of
Pesticide
Products
Containing
Diuron
as
the
Active
Ingredient"
was
released
in
1983.
The
Registration
Standard
involved
a
thorough
review
of
the
scientific
data
base
underlying
pesticide
registrations
and
an
identification
of
essential
but
missing
studies
which
may
not
have
been
required
when
the
product
was
initially
registered
or
studies
that
were
considered
insufficient.
Subsequent
Data
Call­
Ins
(
DCIs)
were
issued
in
1990,
and
1995
for
diuron.
This
Reregistration
Eligibility
Decision
(
RED)
reflects
a
reassessment
of
all
data
submitted
to
date.

There
is
a
Section
18,
Emergency
Exemption
registration
for
diuron
use
on
catfish
in
the
states
of
Arkansas,
Louisiana,
and
Mississippi.
The
Agency
is
considering
the
catfish
use
for
registration
under
Section
3
of
FIFRA.
Therefore,
the
risks
from
the
catfish
use
have
been
assessed
and
are
discussed
in
this
document.

This
Reregistration
Eligibility
Decision
document
evaluates
risks
from
all
currently
registered
uses,
including
agricultural
food
and
non­
food
crops;
ornamental
trees,
flowers,
and
shrubs;
paints
and
coatings;
ornamental
fish
and
catfish
production;
rights­
of­
way
and
industrial
sites.
Residential
uses
include
ponds,
aquariums,
and
paints.

In
an
effort
to
promote
transparency
of
the
reregistration
process
and
public
acceptance
of
regulatory
decisions,
the
Agency,
in
cooperation
with
the
U.
S.
Department
of
Agriculture
(
USDA),
is
working
to
modify
the
reregistration
process.
An
interim
process
has
been
established
to
provide
opportunities
for
stakeholders
to
ask
questions
and
provide
input
on
the
risk
assessment
and
risk
mitigation
strategies,
via
conference
calls
and
other
formats.
See
Chapter
IV,
Section
B
for
a
detailed
description
of
the
modified
process.
A
Tolerance
Reassessment
Progress
and
Risk
Management
Decision
(
TRED)
was
issued
in
July
2002.
This
RED
document
contains
the
tolerance
reassessment
decision
as
well
as
the
Agency's
decisions
on
the
mitigation
needed
for
other
human
health
and
environmental
risks.

A
risk
mitigation
meeting
was
held
with
stakeholders
on
August
6,
2003.
Stakeholders
and
research
organizations
provided
new
information
regarding
use
rates,
acreage,
application
frequency,
application
equipment,
etc.,
which
enabled
EPA
to
significantly
refine
the
occupational
risk
assessment.
Also,
a
close­
out
conference
call
was
conducted
on
September
29,
2003,
with
EPA,
USDA,
the
registrants,
and
other
stakeholders
(
e.
g.,
growers,
commodity
groups,
land
grant
universities),
to
discuss
the
risk
management
decisions
and
resultant
changes
to
the
diuron
labels.

B.
Chemical
Identification
The
Agency
has
reviewed
the
metabolism
of
diuron
in
plants
and
animals
from
the
results
3
NH
N
O
Cl
Cl
CH
3
CH
3
NH
NH
O
Cl
Cl
CH
3
NH
NH
2
O
Cl
Cl
of
wheat,
corn,
orange,
ruminant,
and
poultry
studies
together
with
the
environmental
fate
studies
conducted
in
soil
and
water
and
has
identified
the
following
14C­
containing
residues
in
plants:
diuron,
3,4­
dichlorophenylurea
(
DCPU),
and
3­(
3,4­
dichlorophenyl)­
1­
methylurea
(
DCPMU).
No
other
dichloroaniline­
containing
metabolites
were
identified.
The
majority
of
radioactivity
in
the
aqueous/
organic
fractions
was
characterized
as
polar
unknowns.
Radiovalidation
of
a
GC/
ECD
data
collection
method
which
is
similar
to
the
enforcement
method
suggested
that
a
good
portion
of
these
polar
metabolites
can
be
converted
to
3,4­
DCA.
The
chemical
names
and
structures
of
these
compounds
are
depicted
in
Figure
A.

Figure
A.
Chemical
structures
of
diuron
residues
of
concern.

Diuron:
3­(
3,4­
dichlorophenyl)­
1,1­
dimethylurea
DCPMU;
IN­
15654:
3­(
3,4­
dichlorophenyl)­
1­
methylurea
DCPU;
IN­
R915:
3,4­
dichlorophenylurea
°
Common
Name:
Diuron
°
Chemical
Name:
3­(
3,4­
dichlorophenyl)­
1,1­
dimethylurea
°
Chemical
Family:
dimethylurea
°
CAS
Registry
Number:
330­
54­
1
°
OPP
Chemical
Code:
035505
°
Empirical
Formula:
C
9
H
10
Cl
2
N
2
O
°
Molecular
Weight
233.1
°
Vapor
Pressure:
2
x
10­
7
mm
Hg
at
30

C
°
Basic
Manufacturer:
Griffin
LLC
Table
1.
Diuron
Physical
and
Chemical
Properties
4
Guideline
Number
Physical
and
Chemical
Property
Data
830­
6302
Color
White
830­
6303
Physical
State
Crystal
830­
6304
Odor
None
830­
7200
Melting
Point
158o
C
830­
7840
Water
Solubility
42
ppm
@
25o
C
830­
7950
Vapor
Pressure
2
x
10­
7
mm
Hg
@
30o
C
830­
7550
Partition
Coefficient
(
Log
P
ow)
2.68
830­
6320
Corrosion
characteristics
Not
corrosive
830­
6313
Stability
to
normal
and
elevated
temperatures,
metals,
and
metal
ions
Stable
for
2
yrs.
in
double
polyethylene
bag
inside
a
fiber
drum
under
warehouse
conditions.
Metals
and
metal
ion
data
not
given.

C.
Use
Profile
The
following
is
information
on
the
currently
registered
uses
including
an
overview
of
use
sites
and
application
methods.
A
detailed
table
of
the
uses
of
diuron
eligible
for
reregistration
is
contained
in
Appendix
A.

Type
of
Pesticide
Diuron
is
a
substituted
urea
herbicide
for
the
control
of
a
wide
variety
of
annual
and
perennial
broad
leaved
and
grassy
weeds
on
both
crop
and
non­
crop
sites.
The
mechanism
of
herbicidal
action
is
the
inhibition
of
photosynthesis.

Use
Sites
Products
containing
diuron
are
intended
for
both
occupational
and
residential
uses.
Occupational
uses
include
agricultural
food
and
non­
food
crops;
ornamental
trees,
flowers,
and
shrubs;
paints
and
coatings;
ornamental
fish
ponds,
and
catfish
production;
rights­
of­
way
and
industrial
sites.
Residential
uses
include
ponds,
aquariums,
and
paints.

Use
Limitations
The
plantback
intervals
for
the
various
crops
on
diuron
labels
range
from
2
to
12
months.
5
In
addition,
rotational
crop
restrictions
are
listed
on
individual
labels,
and
further
restrictions
limit
applications
to
crops
grown
in
certain
soils
or
soil
types.

For
more
information
about
the
plantback
interval,
please
see
the
document
titled,
"
Residue
Chemistry
Chapter
For
The
Diuron
Reregistration
Eligibility
Decision
(
RED)
Document,"
dated
7/
29/
2001.

Target
Pests
Diuron
is
used
for
pre­
emergence
control
of
annual
grass
and
broadleaf
weeds
and
some
perennial
weeds.

Formulation
Types
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
use
solution
(
0.67%
to
19%
ai).

Methods
and
Rates
of
Application
Diuron
is
applied
using
the
following
equipment:
groundboom
sprayer,
aerial
equipment,
chemigation,
rights­
of­
way
sprayer,
high­
pressure
handwand,
low­
pressure
handwand,
tractordrawn
spreader,
granular
backpack
spreader,
push­
type
spreader,
airless
sprayer,
paintbrush,
shaker­
type
applicator,
backpack
sprayer,
belly
grinder,
and
by
hand.
Products
intended
for
residential
use
may
be
applied
using
a
spoon,
by
hand,
by
airless
sprayer,
or
by
paintbrush/
roller.

For
agricultural
uses,
labeled
single
application
rates
range
from
0.2
to
6.4
lbs
active
ingredient
(
ai)
per
acre
(
A).
For
citrus,
a
yearly
maximum
of
9.6
lbs
ai/
A
is
on
current
labels.
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.
6
Timing
of
Application
One
to
four
applications
per
season
may
be
applied
in
60­
day
intervals
(
on
current
labels);
for
most
uses
only
one
application
is
used.

D.
Estimated
Usage
of
Pesticide
Estimates
for
total
annual
domestic
use
of
diuron
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.
Crops
with
the
highest
percent
crop
treated
are
the
citrus,
various
berries,
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.
These
estimates
were
derived
from
a
variety
of
published
and
proprietary
sources
available
to
the
Agency.
Table
2
summarizes
the
best
available
estimates
for
the
pesticide
usage
of
diuron.

Table
2.
Diuron
Crop
Usage
Summary
Site
Acres
Grown
(
000)
Acres
Treated
(
000)
%
of
Crop
Treated
Pounds
AI
Applied
(
000)
Average
Application
Rate
States
of
Most
Usage
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Pounds
ai/
Acre
Per
Year
Pounds
Applied
Per
Year
Pounds
ai
Per
Acre
Applied
(%
of
total
lb
ai
used
on
this
site)

Blackberries
5
3
4
53%
73%
5
7
1.7
1.1
1.5
OR
100%

Blueberries
59
17
22
29%
37%
21
29
1.2
1.1
1.1
MI
NJ
OR
84%

Raspberries
13
2
4
13
29
2
4
1.2
1.1
1.1
WA
OR
100%

Grapes
869
87
155
10
18
100
200
1.2
1.0
1.2
CA
NY
PA
81%

Grapefruit
189
89
147
47
78
240
462
2.7
1.7
1.6
FL
TX
92%

Lemons
67
18
35
26
53
39
86
2.2
1.3
1.7
CA
AZ
98%

Oranges
927
470
578
51
62
1,210
1,710
2.6
1.7
1.5
FL
CA
97%

Citrus,
Other
62
24
39
38
63
65
118
2.8
1.7
1.6
FL
AZ
93%

Limes
6
2
3
33
49
5
7
2.4
1.8
1.3
­

Tangelos
12
6
7
47
58
17
26
2.9
2.1
1.4
FL
100%

Tangerines
37
11
16
30
43
22
31
2.0
1.7
1.1
FL
CA
100%

Temples
7
3
5
51
80
9
18
2.6
1.9
1.4
FL
100%

Apples
520
65
113
13
22
100
188
1.5
1.1
1.4
NY
WA
PA
ID
OH
65%

Pears
74
7
15
9
20
15
31
2.2
1.2
1.8
OR
CA
WA
81%
Site
Acres
Grown
(
000)
Acres
Treated
(
000)
%
of
Crop
Treated
Pounds
AI
Applied
(
000)
Average
Application
Rate
States
of
Most
Usage
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Pounds
ai/
Acre
Per
Year
Pounds
Applied
Per
Year
Pounds
ai
Per
Acre
Applied
(%
of
total
lb
ai
used
on
this
site)

7
Pome
Fruit,
Other
31
4
6
13
19
10
15
2.6
1.8
1.5
FL
98%

Avocados
80
1
2
1
2
1
3
1.7
1.3
1.3
FL
100%

Cherries,
Sweet
52
0.2
0.8
0.3
2
0.3
1.7
2.1
1.9
1.1
MI
OR
93%

Cherries,
Tart
49
1
4
3
8
3
9
2.1
1.2
1.8
MI
88%

Nectarines
36
0.1
0.5
0.3
1
0.2
0.8
1.6
1.0
1.6
­

Olives
36
8
12
24
35
14
19
1.6
1.2
1.4
­

Peaches
260
25
56
10
21
38
81
1.5
1.0
1.4
GA
SC
NJ
PA
WV
CA
74%

Plums/
Prunes
147
4
6
3
4
2
3
0.6
1.2
0.5
CA
OR
GA
85%

Almonds
489
3
10
1
2
6
15
2.2
1.2
1.8
CA
100%

Hazelnuts/
Filberts
29
4
8
14
28
5
9
1.2
1.0
1.2
OR
100%

Macadamia
&
Pistachio
75
4
7
5
10
9
18
2.5
2.4
1.0
­

Pecans
452
13
26
3
6
28
58
2.1
1.0
2.1
GA
AZ
NM
CA
80%

Walnuts
215
26
43
12
20
51
98
2.0
1.1
1.8
CA
98%

Asparagus
83
45
56
53
68
74
80
1.7
1.2
1.3
CA
MI
WA
96%

Barley
6612
8
38
0.1
1
1
6
0.2
1.0
0.2
­

Corn
77779
19
79
0.02
0.1
18
83
0.9
1.0
0.9
LA
MS
PA
TX
87%

Mint
167
68
91
41
54
22
29
0.3
­
­
CA
ID
90%

Oats
2667
3
8
0.1
0.3
2
5
1.6
­
­
OR
WA
100%

Seed
Crops
1249
547
683
44
55
678
848
1.2
­
­
OR
ID
88%

Sorghum
10216
14
52
0.1
1
9
37
0.6
1.0
0.6
TX
NM
91%

Sugarcane
882
36
76
4
9
42
89
1.2
1.1
1.0
LA
93%

Wheat,
Spring
20599
14
38
0.1
0.2
8
20
0.5
1.0
0.5
ID
OR
88%

Wheat,
Winter
43721
150
319
0.3
1
140
380
0.9
1.0
0.9
OR
OK
WA
87%

Alfalfa
23665
190
380
1
2
240
350
1.3
1.0
1.3
CA
KS
AZ
NV
MT
81%

Hay,
Other
25983
30
81
0.1
0.3
36
95
1.2
1.0
1.2
CA
TX
KS
OR
NC
81%

Cotton
13188
145
0
232
2
11
18
770
1224
0.5
1.3
0.4
TX
MS
LA
AR
GA
85%

Cropland
for
Pasture
63687
3
6
­
­
4
8
1.3
1.0
1.3
OR
CA
80%
Site
Acres
Grown
(
000)
Acres
Treated
(
000)
%
of
Crop
Treated
Pounds
AI
Applied
(
000)
Average
Application
Rate
States
of
Most
Usage
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Pounds
ai/
Acre
Per
Year
Pounds
Applied
Per
Year
Pounds
ai
Per
Acre
Applied
(%
of
total
lb
ai
used
on
this
site)

8
Pasture/
Rangeland,
Other
35872
4
26
78
0.01
0.02
62
187
2.4
1.0
2.4
OR
83%

Fallow,
Summer
24699
17
52
0.1
0.2
10
29
0.6
1.0
0.6
NE
TX
84%

Idle
Cropland,
Other
7366
4
13
0.1
0.2
9
28
2.1
1.1
1.8
OR
92%

Lots/
Farmsteads/
Etc.
23987
21
37
0.1
0.2
66
134
3.1
1.3
2.4
CA
AR
WA
UT
OR
NC
70%

Building/
Structures
­
­
­
­
­
2
5
­
­
­
­

Roads/
Ditches/
Misc.
­
­
­
­
­
64
129
­
­
­
­

Ornamentals
­
47
70
­
­
54
80
1.2
1.1
1.1
OR
CA
MT
87%

Non­
Farm
Industrial
Facilities/
Pipelines
4312
­
­
­
­
518
1047
­
­
615
­

Wholesale/
Manufacturing
30149
­
­
­
­
166
218
­
­
­
­

Lawn/
Landscape
Operator
30419
­
­
­
­
46
100
­
­
2.0
­

Residential
­
­
­
­
­
13
25
­
­
­
­

Office/
Retail
(
for
hire)
­
­
­
­
­
28
42
­
­
­
­

Nurseries/
Greenhouses
409
8
24
2
6
10
29
1.2
1.0
1.2
­

Office/
Retail
(
not
for
hire)
­
­
­
­
­
71
106
­
­
­
­

Pest
Control
Operator
­
5
15
­
­
­
­
­
­
­
­

Railroads
1577
­
­
­
­
2,007
2,907
­
­
4.7
­

Recreation
­
­
­
­
­
12
23
­
­
­
­

Roadways
11400
­
­
­
­
426
800
­
­
2.3
­

Sanitation/
Utilities
­
­
­
­
­
617
1051
­
­
­
­

Electric
Utilities
9669
­
­
­
­
167
288
­
­
3.6
­

Crops
Grown
Outside
the
Continental
United
States
With
Limited
Usage
Data
Pineapple
no
data
no
data
Bananas
14
18
Papaya
13
19
Site
Acres
Grown
(
000)
Acres
Treated
(
000)
%
of
Crop
Treated
Pounds
AI
Applied
(
000)
Average
Application
Rate
States
of
Most
Usage
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Wtd
Avg
Est
Max
Pounds
ai/
Acre
Per
Year
Pounds
Applied
Per
Year
Pounds
ai
Per
Acre
Applied
(%
of
total
lb
ai
used
on
this
site)

9
Total
7,914
10,429
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
1990
­
1999.
Calculations
of
the
above
numbers
may
not
appear
to
agree
because
they
are
displayed
as
rounded
to
the
nearest
1,000
for
acres
treated
or
lb.
a.
i.
(
therefore
0
=
<
500),
and
rounded
to
one
decimal
percentage
point
for
%
of
crop
treated
and
pounds
of
a.
i..
SOURCES:
EPA,
USDA
,
and
National
Center
for
Food
and
Agricultural
Policy.

III.
Summary
of
Diuron
Risk
Assessment
The
following
is
a
summary
of
EPA's
human
health
and
ecological
risk
findings
and
conclusions
for
diuron,
as
presented
fully
in
the
documents,
"
Diuron:
the
Revised
HED
Chapter
of
the
Reregistration
Eligibility
Decision
Document
(
RED),"
dated
July
9,
2003,
"
Environmental
Risk
Assessment
for
the
Reregistration
of
Diuron,"
dated
August
27,
2001,
and
"
Surface
Water
Monitoring
Data
for
Diuron,"
dated
August
5,
2003.
Since
the
completion
of
the
preliminary
risk
assessments,
the
Agency
has
calculated
new
surface
water
concentrations
for
diuron
based
on
monitoring
data.
Also,
new
information
provided
by
stakeholders
enabled
the
Agency
to
characterize
worker
cancer
risk
estimates.

The
purpose
of
this
section
of
the
decision
document
is
to
summarize
the
key
features
and
findings
of
the
risk
assessment
in
order
to
help
the
reader
better
understand
the
risk
management
decisions
reached
by
the
Agency.
While
the
risk
assessments
and
related
addenda
are
not
included
in
this
document,
they
are
available
in
the
public
docket.

A.
Human
Health
Risk
Assessment
Risks
from
dietary
exposure
(
food
and
drinking
water),
residential
exposure,
aggregate
exposures,
and
occupational
exposures
have
been
evaluated
for
diuron.
1.
Dietary
Risk
From
Food
a.
Toxicity
The
toxicity
database
for
diuron
is
adequate
to
assess
the
potential
hazard
to
humans,
including
special
sensitivity
of
infants
and
children.
The
database
will
support
a
reregistration
eligibility
decision
for
the
currently
registered
uses.
However,
EPA
is
requiring
that
a
28­
day
inhalation
study
be
submitted
to
address
the
concern
for
inhalation
exposure
potential
based
on
the
use
pattern.
For
more
information
on
the
toxicity
of
diuron,
please
see
the
document
titled
10
"
Diuron
­
Phase
2:
Revised
Toxicology
Disciplinary
Chapter
for
the
Reregistration
Eligibility
Decision,"
dated
March
6,
2002.

Acute
Toxicity:

Diuron
has
low
acute
toxicity
(
Toxicity
Category
3
or
4)
by
the
oral,
dermal,
or
inhalation
exposure
routes.
Diuron
is
not
an
eye
or
skin
irritant,
and
not
a
skin
sensitizer.
A
rat
metabolism
study
indicated
that
diuron
is
rapidly
absorbed
and
metabolized
within
24
hours
post­
dose
at
the
low
dose
and
within
48
hours
post­
dose
at
the
high
dose.
The
urine
is
the
major
route
of
excretion
in
both
sexes.
A
small
amount
of
diuron
is
detected
in
the
feces.
The
highest
tissue
residue
levels
were
found
in
the
liver
and
kidneys
4
days
post
14C­
diuron
dose.
The
metabolism
of
diuron
involved
N­
oxidation,
some
ring
hydroxylation,
demethylation,
dechlorination,
and
conjugation
to
sulfate
and
glucuronic
acid.
Acute
toxicity
values
and
categories
for
the
technical
grade
of
diuron
are
summarized
in
Table
3.

Table
3.
Acute
Toxicity
of
Diuron
Guideline
No.
Study
Type
Results
Toxicity
Category
870.1100
Acute
Oral
LD
50
=
4721
mg/
kg
(
M)
>
5000
mg/
kg
(
F)
III
870.1200
Acute
Dermal
LD
50
>
2000
mg/
kg
III
870.1300
Acute
Inhalation
LC
50
>
7.1
mg/
L
IV
870.2400
Primary
Eye
Irritation
At
48
hrs,
all
irritation
had
cleared.
III
870.2500
Primary
Skin
Irritation
All
irritation
had
cleared
by
72
hrs.
IV
870.2600
Dermal
Sensitization
Nonsensitizer
N/
A
870.6200
Acute
Neurotoxicity
Not
available
N/
A
Subchronic/
Chronic
Systemic
Toxicity:
The
primary
diuron
target
sites
are
blood,
bladder,
and
kidney.
Erythrocyte
(
red
blood
cell)
damage
resulted
in
hemolytic
anemia
and
compensatory
hematopoiesis,
which
are
manifested
as
significantly
decreased
erythrocyte
counts,
hemoglobin
levels,
and
hematocrit,
and
increased
mean
corpuscular
volume
(
MCV),
mean
corpuscular
hemoglobin
(
MCH),
abnormal
erythrocyte
forms,
reticulocyte
counts,
and
leukocyte
count.
Consistent
observations
of
erythocytic
regeneration
are
seen
in
chronic
toxicity
studies
in
rats,
mice
and
dogs.
Gross
pathology
findings
in
chronic
rat
and
mouse
studies
showed
increased
incidences
of
urinary
bladder
swelling
and
wall
thickening
at
high
doses.
Microscopic
evaluation
showed
dose­
related
increases
in
the
severity
of
epithelial
focal
hyperplasia
of
the
urinary
bladder
and
renal
pelvis
(
kidney)
in
both
sexes.
11
Although
the
developmental
toxicity
study
in
rats
is
classified
as
unacceptable,
the
data
base
as
a
whole
is
adequate
for
pre­
and
post­
natal
toxicity
evaluation
and
did
not
reveal
developmental
or
reproductive
toxicity.
The
NOAELs
for
maternal/
parental
toxicity
were
either
less
than
or
equal
to
the
NOAELs
for
fetal
or
reproductive
toxicity.
A
complete
summary
of
the
toxicity
database
is
discussed
in
the
document
titled
"
Diuron
­
Phase
2:
Revised
Toxicology
Disciplinary
Chapter
for
the
Reregistration
Eligibility
Decision,"
dated
March
6,
2002.

Carcinogenicity:
Diuron
has
been
characterized
as
a
"
known/
likely"
human
carcinogen,
based
on
urinary
bladder
carcinomas
in
both
sexes
of
the
Wistar
rat,
kidney
carcinomas
in
the
male
rat
(
a
rare
tumor),
and
mammary
gland
carcinomas
in
the
female
NMRI
mouse.
The
Agency
has
used
a
low
dose
linear
extrapolation
model
with
a
Q
1
*
of
1.91
x
10­
2
(
mg/
kg/
day)­
1
to
be
applied
to
the
animal
data
for
the
quantification
of
human
risk,
based
on
the
urinary
bladder
carcinomas
in
the
rat.
Tumors
were
observed
only
at
doses
in
excess
of
600
mg/
kg/
day.

Mechanism
of
Carcinogenicity:
The
registrant
has
requested
that
the
Agency
reconsider
the
1996
carcinogenicity
assessment
for
the
following
reasons:
1)
there
is
a
plausible
mode
of
action
that
discounts
the
relevance
of
the
rat
bladder
carcinomas
to
humans,
2)
the
mouse
historical
data
were
not
considered
in
their
entirety
and
should
be
considered
`
spontaneous,"
3)
the
structure
activity
relationships
actually
decrease
the
weight­
of­
the­
evidence
of
diuron
carcinogenicity
rather
than
increase
the
weight,
4)
new
guidelines
are
in
place
that
separate
the
`
known'
from
`
likely'
category
and
5)
there
is
no
history
of
human
carcinogenesis
as
a
result
of
diuron
exposure.

The
Agency
reviewed
the
submitted
information/
data
and
mutagenicity
studies,
considered
the
registrant's
proposed
mechanism
of
action
and
determined
that
diuron
will
not
be
re­
classified
at
this
time.
The
Agency
based
its
decision
on:
1)
the
registrant
did
not
submit
any
data
or
information
to
support
its
claim
that
there
is
no
evidence
of
human
carcinogenesis;
2)
the
submitted
information
is
insufficient
to
support
a
mode
of
action
on
bladder
carcinogenicity
for
diuron;
3)
the
mouse
historical
data
have
been
reviewed
­
the
Agency
concluded
that
a
positive
oncogenic
response
was
seen
in
high­
dose
female
mice
compared
to
the
control
group;
4)
there
is
insufficient
evidence
to
support
the
notion
that
the
structure
activity
relationships
actually
decrease
the
weight­
of­
the­
evidence
of
diuron
carcinogenicity
rather
than
increase
the
weight;
and
5)
preliminary
reviews
have
been
conducted
on
newly
submitted
in
vivo
cytogenetic
mutagenicity
studies
(
mouse
bone
marrow
micronucleus
assays)
and
no
evidence
of
cytogenetic
effect
was
seen
in
mice
administered
either
technical
grade
or
formulated
diuron.
However,
these
studies
provide
little
additional
information
since
EPA
has
already
concluded
that
there
is
little
or
no
concern
for
the
mutagenic
activity
of
diuron.
The
registrant
has
indicated
their
intention
to
submit
a
study
on
the
cancer
mechanism
of
action
for
diuron.
The
study
is
scheduled
for
completion
in
2004
and
will
be
submitted
to
the
Agency
for
further
consideration.

Mutagenicity:
Diuron
was
not
mutagenic
in
bacteria
or
in
cultured
mammalian
cells
and
no
indication
of
DNA
damage
in
primary
rat
hepatocytes
was
observed.
There
were
marginal
statistically
significant
increases
in
cells
with
structural
aberrations
in
a
Sprague
Dawley
rat
in
vivo
bone
marrow
chromosomal
aberration
assay.
However,
the
levels
of
aberrations
were
within
12
the
historical
control
range
and
assessed
negative.

Developmental/
Reproductive
Toxicity:
There
is
an
acceptable
developmental
toxicity
study
in
rabbits
and
an
acceptable
two­
generation
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
Agency
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
and
concluded
that
a
developmental
neurotoxicity
(
DNT)
study
is
not
required.

There
is
no
indication
of
increased
susceptibility
to
young
exposed
to
diuron
in
the
available
studies.
In
the
developmental
toxicity
study
in
rabbits,
there
were
no
developmental
effects
at
the
highest
dose
tested.
In
the
developmental
toxicity
study
in
rabbits
and
in
the
2­
generation
rat
reproduction
study,
developmental/
offspring
effects
were
observed
only
at
maternally/
parentally
toxic
dose
levels.

Neurotoxicity:
No
acute
or
subchronic
neurotoxicity
data
are
available.
However,
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.

Dermal
Absorption:
No
systemic
toxicity
was
seen
following
repeated
dermal
dosing
at
1200
mg/
kg/
day
in
the
rabbit
dermal
toxicity
study.
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%.

b.
FQPA
Safety
Factor
The
FQPA
safety
factor
is
intended
to
provide
up
to
an
additional
10­
fold
safety
factor
(
10X),
to
protect
for
special
sensitivity
in
infants
and
children
to
specific
pesticide
residues
in
food.
The
FQPA
Safety
Factor
Committee
concluded
that
the
safety
factor
could
be
removed
(
i.
e.,
reduced
to
1x)
for
diuron
for
the
following
reasons:

°
There
is
no
indication
of
quantitative
or
qualitative
increased
susceptibility
of
rats
or
rabbits
to
in
utero
or
postnatal
exposure;
°
A
DNT
study
with
diuron
is
not
required;
and
°
The
dietary
(
food
and
drinking
water)
and
non­
dietary
(
residential)
exposure
assessments
will
not
underestimate
the
potential
exposures
for
infants
and
children.

c.
Endpoints
and
Doses
for
Risk
Assessment
The
doses,
toxicity
endpoints
selected
and
supporting
studies
for
various
exposure
scenarios
are
summarized
in
Table
5.
13
Table
5.
Summary
of
Doses
and
Toxicological
Endpoints
for
Diuron
EXPOSURE
SCENARIO
DOSE
(
mg/
kg/
day)
ENDPOINT
STUDY
Acute
Dietary
No
appropriate
endpoint
attributed
to
a
single
dose
was
identified.
Therefore,
an
acute
RfD
was
not
established.

Chronic
Dietary
LOAEL
=
1.0
UF
=
300
FQPA
SF
=
1
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis
(
significantly
decreased
erythrocyte
counts,
hemoglobin
levels,
and
hematocrit,
and
increased
MCV,
MCH,
abnormal
erythrocyte
forms,
reticulocyte
counts,
and
leukocyte
count)
Combined
chronic
toxicity/
carcinogenicity
study
in
rats
MRID
40886501,
43871901,
43804501,
44302003
Chronic
RfD
=
0.003
mg/
kg/
day
cPAD
=
0.003
mg/
kg/
day
Incidental
Oral,
short­
term
(
1­
30
days)
NOAEL=
10
UF
=
100
FQPA
SF
=
1
Decreased
body
weight
and
food
consumption
at
maternal
LOAEL
of
50
mg/
kg/
day.
Developmental
toxicity
study
in
rabbits
MRID
40228802
Level
of
Concern
for
residential
MOE
=
100
Incidental
Oral,
Intermediate­
Term
(
1­
6
months)
NOAEL
=
1.0
UF
=
100
FQPA
SF
=
1
Altered
hematological
parameters
at
LOAEL
of
10
mg/
kg/
day,
observed
at
6
months.
Chronic
toxicity/
carcinogenicity
study
in
rats
MRID
40886501,
43871901,
43804501,
44302003
Level
of
Concern
for
residential
MOE
=
100
Dermal,
Short­
Intermediate­
Term
No
systemic
toxicity
was
seen
following
repeated
dermal
dosing
at
1200
mg/
kg/
day
in
the
rabbit
dermal
toxicity
study.
No
hazard
was
identified
and
no
quantitative
assessment
is
required.

Dermal,
Long­
Term
(
6
months
to
life­
time)

Absorption
factor
of
4%
used
for
conversion
from
oral
to
dermal
route
LOAEL
=
1.0
UF
=
300
FQPA
SF
=
1
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis
(
significantly
decreased
erythrocyte
counts,
hemoglobin
levels,
and
hematocrit,
and
increased
MCV,
MCH,
abnormal
erythrocyte
forms,
reticulocyte
counts,
and
leukocyte
count).
Chronic
toxicity/
carcinogenicity
study
in
rats
MRID
40886501,
43871901,
43804501,
44302003
Level
of
Concern
for
occupational/
residential
MOE
=
300
Inhalation,
Short­
Term
(
1­
30
days)
NOAEL
=
10
UF
=
100
FQPA
SF
=
1
Decreased
body
weight
and
food
consumption
at
maternal
LOAEL
of
50
mg/
kg/
day.
Developmental
toxicity
study
in
rabbits
MRID
40228802
Level
of
Concern
for
occupational/
residential
MOE
=
100
EXPOSURE
SCENARIO
DOSE
(
mg/
kg/
day)
ENDPOINT
STUDY
14
Inhalation,
Intermediate­
Term
(
1­
6
months)**
NOAEL
=
1.0
UF
=
100
FQPA
SF
=
1
Altered
hematological
parameters
at
LOAEL
of
10
mg/
kg/
day,
observed
at
6
months.
Chronic
toxicity/
carcinogenicity
study
in
rats
MRID
40886501,
43871901,
43804501,
44302003
Level
of
Concern
for
occupational/
residential
MOE
=
100
Inhalation,
Long­
Term
(
6
months
to
life­
time)**
LOAEL
=
1.0
UF
=
300
FQPA
SF
=
1
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis
(
significantly
decreased
erythrocyte
counts,
hemoglobin
levels,
and
hematocrit,
and
increased
MCV,
MCH,
abnormal
erythrocyte
forms,
reticulocyte
counts,
and
leukocyte
count).
Chronic
toxicity/
carcinogenicity
study
in
rats
MRID
40886501,
43871901,
43804501,
44302003
Level
of
Concern
for
occupational/
residential
MOE
=
300
Cancer
Known/
likely
human
carcinogen
Urinary
bladder
carcinoma
in
both
sexes
of
the
Wistar
rat,
kidney
carcinomas
in
the
male
rat
(
a
rare
tumor),
and
mammary
gland
carcinomas
in
the
female
NMRI
mouse
Carcinogenicity
studies
in
rats
and
mice
MRID
40886501,
43871901,
43804501,
44302003
and
42159501,
43349301
Q1*
=
1.91
x
10­
2
(
mg/
kg/
day)­
1
UF
=
Uncertainty
Factor
PAD
=
Population
Adjusted
Dose
(
includes
UF
and
FQPA
safety
factor)
MOE
=
Margin
of
Exposure
d.
Endocrine
Disruption
EPA
is
required
under
the
FFDCA,
as
amended
by
FQPA,
to
develop
a
screening
program
to
determine
whether
certain
substances
(
including
all
pesticide
active
and
other
ingredients)
"
may
have
an
effect
in
humans
that
is
similar
to
an
effect
produced
by
a
naturally
occurring
estrogen,
or
other
such
endocrine
effects
as
the
Administrator
may
designate."
Following
the
recommendations
of
its
Endocrine
Disruptor
Screening
and
Testing
Advisory
Committee
(
EDSTAC),
EPA
determined
that
there
was
scientific
bases
for
including,
as
part
of
the
program,
the
androgen
and
thyroid
hormone
systems,
in
addition
to
the
estrogen
hormone
system.
EPA
also
adopted
EDSTAC's
recommendation
that
the
Program
include
evaluations
of
potential
effects
in
wildlife.
As
the
science
develops
and
resources
allow,
screening
of
additional
hormone
systems
may
be
added
to
the
Endocrine
Disruptor
Screening
Program
(
EDSP).
When
the
appropriate
screening
and/
or
testing
protocols
being
considered
under
the
Agency's
EDSP
have
been
developed,
diuron
may
be
subjected
to
additional
screening
and/
or
testing
to
better
characterize
effects
related
to
endocrine
disruption.

At
this
time,
neither
the
available
submitted
studies
on
diuron
nor
the
literature
show
any
indication
of
endocrine
disruption
effects.
15
e.
3,4­
dichloroaniline
(
3,4­
DCA)

3,4­
dichloroaniline
(
3,4­
DCA)
is
a
metabolite
of
diuron
as
well
as
two
other
pesticides,
linuron
and
propanil.
However,
EPA's
Metabolism
Assessment
Review
Committee
(
MARC)
concluded
that
residues
of
3,4­
DCA
should
not
be
aggregated
for
the
diuron,
linuron,
and
propanil
risk
assessments
because
3,4­
DCA
is
significant
residue
of
concern
for
propanil,
but
is
not
a
residue
of
concern
per
se
for
diuron
or
linuron.
Although
the
analytical
method
for
quantifying
residues
of
concern
from
diuron
converts
all
residues
to
3,4­
DCA
as
a
convenience,
3,4­
DCA
was
not
a
significant
residue
in
any
metabolism
or
hydrolysis
study.

f.
Potential
Tetrachloroazobenzene
Contamination
Diuron
has
been
reported
to
contain
trace
amounts
of
a
manufacturing
impurity,
3,3',
4,4'­
tetrachloroazobenzene,
(
TCAB),
which
has
been
shown
to
be
a
cytochrome
P450
enzyme
inducer.
A
summary
of
short­
term
bioassays
compiled
by
the
National
Toxicology
Program
states
that
(
TOX­
65,
1998),

"
3,3',
4,4'­
tetrachloroazobenzene
caused
typical
dioxin­
like
effects,
such
as
thymic
atrophy,
an
increase
in
liver
weights,
induction
of
hepatic
cytochrome
P4501A,
and
decreased
mean
body
weight
gains.
Furthermore,
in
the
13­
week
studies,
a
sharp
decrease
in
circulating
thyroxine
concentrations
was
observed
even
at
the
lowest
dose
(
0.1
mg/
kg)
tested
in
rats.
Other
effects
included
a
decrease
in
epididymal
spermatozoal
concentration
in
mice,
major
effects
on
the
hematopoietic
system,
and
increased
incidence
of
hyperplasia
of
the
forestomach
in
3
and
30
mg/
kg
males
and
30
mg/
kg
females.
A
no­
observable­
adverse­
effect­
level
(
NOAEL)
was
not
reached
in
rats.
The
NOAEL
in
mice
was
0.1
mg/
kg.
Comparison
of
various
dioxin­
like
effects
in
these
studies
with
those
reported
in
the
literature
indicate
that
3,3',
4,4'­
tetrachloroazobenzene
is
two
to
six
orders
of
magnitude
less
potent
than
2,3,7,8­
tetrachlorodibenzo­
p­
dioxin."

Chronic
toxicity/
carcinogenicity
studies
are
not
available
for
TCAB.
The
specific
endpoint(
s)
and
related
dose
levels
that
may
be
observed
in
chronic
toxicity
studies,
or
the
specific
carcinogenic
potential
of
this
compound
is
not
known.
However,
since
it
is
assumed
that
TCAB
may
have
been
present
in
all
diuron
toxicological
test
materials,
including
the
test
material
for
the
chronic
toxicity/
carcinogenicity
studies,
the
Agency
concludes
that
the
risks
from
exposure
to
diuron
and
TCAB
resulting
from
use
of
diuron
products
(
including
carcinogenic
potential)
have
not
been
underestimated.

g.
Exposure
Assumptions
Diuron
is
not
acutely
toxic.
No
adverse
effects
attributed
to
a
single
exposure
were
identified
in
any
available
study.
Therefore,
no
acute
dietary
risk
assessment
was
conducted.
A
chronic
exposure
analysis
for
diuron
and
its
metabolites
that
are
hydrolyzable
to
3,4­
DCA
was
performed
utilizing
the
Dietary
Exposure
Evaluation
Model
(
DEEMTM)
software
Version
7.73.
16
DEEMTM,
developed
by
Novigen
Sciences,
Inc.
This
model
calculates
acute
and
chronic
dietary
exposure
and
risk
estimates
for
residues
in
food
for
the
U.
S.
general
population
and
various
population
subgroups.
The
software
contains
food
consumption
data
from
the
USDA
Continuing
Survey
of
Food
Intake
by
Individuals
(
CFSII)
from
1989­
1992.
For
chronic
and
cancer
dietary
risk
assessments,
the
1989­
1992
data
are
based
on
the
reported
consumption
patterns
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
proprietary
recipe
translation
files
within
DEEM.
Consumption
data
are
averaged
for
the
entire
U.
S.
population
and
within
population
subgroups
for
chronic
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.
The
calculated
chronic
exposure
(
residue
x
consumption)
was
compared
to
a
cPAD
of
0.003
mg/
kg/
day,
which
reflects
an
FQPA
factor
of
1x.
Noncancer
dietary
exposure
estimates
are
expressed
in
milligrams
per
kilogram
of
body
weight
per
day
(
mg/
kg/
day).

Diuron
is
used
on
a
wide
variety
of
food
and
feed
crops.
Residue
levels
from
United
States
Department
of
Agriculture
(
USDA)
and
Food
and
Drug
Administration
(
FDA)
monitoring
programs
do
not
include
all
the
residues
of
concern
needed
for
the
Agency's
diuron
risk
assessment
(
diuron
and
metabolites
convertible
to
3,4­
DCA)
and
were
not
used
for
this
analysis.
Instead,
anticipated
residues
(
ARs)
from
field
trial
data
were
utilized
to
estimate
the
dietary
exposure
to
diuron
from
the
diets
of
the
U.
S.
population
as
well
as
certain
population
subgroups.
The
field
trials
were
conducted
at
the
highest
application
rates
for
the
crop
tested
and
therefore,
the
residues
from
these
trials
are
considered
high
end.

Available
processing
data
for
apple,
citrus
and
grapes
indicated
that
there
was
no
concentration,
nor
reduction,
in
residue
values
for
these
processed
commodities
(
i.
e.,
juice,
dried
fruit).
The
sugarcane
processing
study
showed
a
reduction
of
residues
in
refined
sugar
but
a
concentration
of
residues
in
molasses.
With
the
exception
of
residue
data
from
the
processing
of
sugarcane
into
refined
sugar
and
molasses,
the
only
additional
refinements
to
the
residue
data
are
the
use
of
averaged
percent
crop
treated
(%
CT)
information.
Percent
crop
treated
data
were
available
for
blackberries,
blueberries,
raspberries,
grapes,
grapefruit,
lemons,
oranges,
limes,
tangelos,
tangerines,
temples,
apples,
pears,
avocados,
sweet
cherries,
tart
cherries,
nectarines,
olives
peaches,
plums/
prunes,
almonds,
hazelnuts,
macadamia
nuts,
pistachio
nuts,
pecans,
walnuts,
asparagus,
barley
corn,
mint
oats,
seed
crops,
sorghum,
sugarcane,
wheat,
alfalfa,
hay,
cotton,
cropland
for
pasture,
pasture/
rangeland,
fallow,
idle
cropland,
lots/
farmsteads,
and
nurseries/
greenhouses.
These
data
were
used
for
the
chronic
dietary
assessment.

The
reregistration
requirements
for
magnitude
of
the
residue
in
plants
are
not
fulfilled
for:
alfalfa
forage;
globe
artichoke;
barley
hay;
cotton
gin
byproducts;
field
corn
aspirated
grain
17
fractions;
field
corn
forage
and
stover;
filbert;
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;
wheat
forage
and
hay.
Additional
crop
field
trial
data
are
required
for
these
commodities.

h.
Dietary
(
Food)
Risk
Assessment
(
1)
Acute
Dietary
Risk
There
are
no
adverse
effects
attributed
to
a
single
exposure
identified
in
any
available
studies.
In
addition,
diuron
has
low
acute
toxicity
and
no
developmental
or
neurotoxic
concerns.
Therefore,
no
acute
dietary
endpoint
was
chosen
and
no
acute
dietary
risk
assessment
was
conducted.

(
2)
Chronic
(
Non­
Cancer)
Dietary
Risk
Chronic
dietary
risk
is
calculated
by
using
an
average
consumption
value
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.

As
shown
in
Table
6,
non­
cancer
chronic
risk
estimates
for
all
population
subgroups
are
below
the
Agency's
level
of
concern
(<
100%
cPAD).
Estimated
chronic
dietary
(
food)
risk
estimates
associated
with
the
use
of
diuron
do
not
exceed
the
Agency's
level
of
concern
(>
100%
cPAD)
for
any
population
subgroup
including
the
most
highly
exposed
population
subgroup,
children
ages
1­
6
years.
The
chronic
dietary
risk
for
children
ages
1­
6
years
is
7%
of
the
chronic
PAD
and
3%
for
the
general
U.
S.
population.
Orange
juice
and
orange
juice
concentrate
are
the
largest
contributors
to
dietary
exposure
from
diuron.
18
Table
6.
Summary
of
Chronic
Dietary
Exposure
and
Risk
for
Diuron
Population
Exposure
mg/
kg/
day
%
Chronic
PAD
U.
S.
Population
0.000088
3
All
Infants
(<
1
year)
0.000077
3
Children
1­
6
years
0.00020
7
Children
7­
12
years
0.000118
4
Females
13­
50
years
0.000069
2
Males
13­
19
years
0.000098
3
Males
20+
years
0.000066
2
Seniors
55+
years
0.000083
3
(
3)
Cancer
Dietary
Risk
from
Food
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
(
Q
1*)
approach
to
determine
the
lifetime
(
cancer)
risk
estimate.
The
Agency
generally
considers
risks
greater
than
1
x
10­
6
(
i.
e.,
probability
greater
than
one
in
one
million)
to
be
of
potential
concern
for
dietary
cancer
exposure.
Table
7
presents
the
lifetime
(
70
year)
cancer
risk
estimates
for
the
U.
S.
general
population.
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
but,
is
not
of
concern.
As
discussed
earlier,
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.
Again,
the
Agency
assumed
that
exposure
was
to
diuron
and
its
metabolites
that
are
hydrolyzable
to
3,4­
DCA.
19
Table
7
.
Summary
of
Diuron
Dietary
Exposure
and
Risk
Population
Acute
Dietary
Chronic
Dietary
Cancer
Dietary
NA
Exposure
(
mg/
kg/
day)
Risk
(%
cPAD)
Exposure
(
mg/
kg/
day)
Lifetime
Risk
(
Q1*=
0.0191)

U.
S.
Population
0.000088
3
0.000088
1.68
x
10­
6
All
Infants
<
1
year
0.000077
3
Not
Applicable
Children
1­
6
years
0.000200
7
Children
7­
12
years
0.000118
4
Females
13­
50
years
0.000069
2
MCPDMU
Cancer
Dietary
Risk
Environmental
laboratory
studies
have
shown
that
in
drinking
water
only,
diuron
partially
degrades
to
another
chemical
referred
to
as
MCPDMU
(
N'­(
3­
chlorophenyl)­
N,
N­
dimethyl
urea).
However,
the
environmental
fate
and
persistence
of
MCPDMU
are
uncertain.
MCPDMU
is
structurally
similar
to
monuron
[
N'­(
4­
chlorophenyl)­
N,
N­
dimethyl
urea],
a
pesticide
no
longer
registered
in
the
United
States.
Monuron
produces
tumors
in
the
kidney
and
liver
in
male
rats
and
has
a
Q
1*
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
degradate,
MCPDMU.

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

Based
on
a
Q
1*
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.

2.
Dietary
Risk
from
Drinking
Water
20
Drinking
water
exposure
to
pesticides
can
occur
through
ground
and
surface
water
contamination.
EPA
considers
acute
(
one
day)
and
chronic
(
lifetime)
drinking
water
risks
and
uses
either
modeling
or
actual
monitoring
data,
if
available,
to
estimate
those
risks.
For
diuron,
monitoring
data
were
available
for
states
with
a
high
percent
of
diuron
use.
Therefore,
monitoring
data
from
Florida
and
California
were
used
to
estimate
surface
water
concentrations,
and
SCI­
GROW
was
used
to
estimate
groundwater
concentrations.
The
Screening
Concentration
in
Ground
Water
Program
(
SCI­
GROW),
model
is
considered
a
screening
tool.

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
DWLOC
represents
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.

Neither
diuron
nor
monuron
are
regulated
under
the
Safe
Drinking
Water
Act.
As
a
result,
neither
Maximum
Contaminant
Levels
(
MCLs)
nor
drinking
water
health
advisories
(
HAs)
for
these
chemicals
have
been
established
by
the
EPA
Office
of
Water.
However,
diuron
was
placed
on
a
list
of
contaminants
to
be
monitored
during
2001
and
2002.
This
information
will
be
used
to
support
EPA
decisions
concerning
whether
or
not
to
regulate
and
establish
standards
for
diuron
in
drinking
water.

a.
Surface
Water
In
this
case,
only
chronic
(
non­
cancer)
and
cancer
drinking
water
risks
have
been
assessed
since
no
acute
endpoint
was
identified.

Diuron
can
be
transported
to
surface
water
at
application
via
run­
off
and
spray
drift
from
aerial
and
ground
applications.
In
the
preliminary
assessment
for
surface
water,
chronic
and
cancer
drinking
water
risks
were
potentially
of
concern
based
on
modeled
estimates.
Based
on
information
gathered
after
the
initial
risk
assessment
was
prepared,
the
Agency
has
decided
to
use
surface
water
monitoring
data
to
estimate
risks
from
drinking
water.
Conservative
models
were
used
to
determine
that
the
diuron
degradates
would
add
an
additional
20
percent
to
the
concentration
of
the
parent
compound.
The
drinking
water
assessment
includes
surface
water
monitoring
data
from
Florida,
the
scenario
which
is
anticipated
to
represent
the
highest
potential
drinking
water
concern.
The
following
information
was
used
in
the
revised
surface
water
assessment.
21
­
South
Florida
Surface
Water
Monitoring
Data
Data
collected
by
the
South
Florida
Water
Management
District
(
SFWMD)
between
December,
1998
and
August,
2001
indicate
that
diuron
was
detected
in
only
17
of
438
samples
(
4%
detection
rate).
The
37
monitoring
stations
were
in
south
Florida,
from
Lake
Okeechobee
south
to
the
Everglades.
Diuron
is
used
on
citrus,
bananas,
and
sugarcane
in
this
area.
The
highest
reported
concentration
was
1.2
ppb.
The
90th
and
95th
percentile
concentrations
were
below
the
detection
limit
(
0.2
to
0.4
ppb).
The
data
are
available
at
www.
sfwmd.
gov/
curre/
pest/
pestindex.
htm.

­
US
Geological
Survey
(
USGS)
National
Water
Quality
Assessment
Program
(
NAWQA)
data
for
Southeastern
U.
S.

USGS
NAWQA
data
for
3
study
units
(
South
Florida,
Georgia­
Florida
Coastal
Plain,
and
Appalachicola­
Chattahoochee­
Flint
River)
show
a
22%
detection
rate
(
185
of
858
samples)
for
diuron
over
the
period
1993
to
1998.
Most
of
the
latter
study
area
was
around
Atlanta.
All
detects
were
less
than
or
equal
to
1
ppb.
The
median,
90th
percentile,
and
95th
percentile
concentrations
were
0.05
ppb.
The
99th
percentile
was
approximately
0.3
ppb.
The
detection
limit
was
0.02
ppb,
about
ten
times
lower
than
SFWMD's
detection
limit
of
0.2
to
0.4
ppb,
which
may
explain
the
higher
detection
rate.

­
NAWQA
Data
The
USGS
NAWQA
Program
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.

­
California
Dormant
Spray
Monitoring
Study
The
California
Department
of
Pesticide
Regulation
(
DFR)
conducted
a
Dormant
Spray
Monitoring
Study
at
three
locations
(
82
samples)
in
the
Sacramento
River
and
two
locations
(
54
samples)
in
the
San
Joaquin
River,
over
the
period
December
2000
to
March
2001.
About
one
million
pounds
of
diuron
are
used
in
these
two
watersheds
per
year.
Diuron
is
used
on
a
number
of
crops
in
California,
including
alfalfa,
oranges,
grapes,
walnuts,
asparagus,
lemons,
olives,
cotton,
grapefruit,
and
tangerines.
Non­
agricultural
uses
include
rights­
of­
way,
landscape
maintenance,
and
uncultivated
areas.

Each
of
the
five
locations
was
sampled
at
least
once
a
week.
100%
of
the
samples
on
the
San
Joaquin
River
had
detectable
diuron,
with
a
maximum
concentration
of
8.45
ppb
in
the
Orestimba
Creek
tributary.
The
average
concentration
at
the
two
San
Joaquin
River
stations
was
22
1.7
ppb.
About
75%
of
the
samples
in
the
Sacramento
River
had
detectable
diuron.
The
maximum
concentration
was
1.42
ppb
at
the
Alamar
Marina
dock,
9
miles
downstream
of
the
confluence
of
the
Feather
River.
The
average
concentration,
assuming
that
all
non­
detects
were
equal
to
the
detection
limit
of
0.05
ppb,
was
0.16
ppb.

­
California
DFR
Summary,
July
8,
2003
California
DFR
has
provided
EPA
with
a
summary
of
historical
surface
water
monitoring
data
in
their
SURF
database
through
July,
2000.
The
total
amount
of
diuron
used
in
California
from
1990
to
1998
was
just
over
ten
million
pounds.
Diuron
was
the
most
frequently
detected
(
57.2%
or
350
of
612
samples)
of
the
146
chemicals
in
the
SURF
database.
The
median
concentration
was
0.281
ppb,
the
75th
percentile
was
0.719
ppb,
and
the
95th
percentile
was
3.6
ppb.

­
Texas
Playa
Lakes
Study
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.

b.
Ground
Water
In
the
absence
of
monitoring
data,
the
Screening
Concentration
in
Ground
Water
(
SCIGROW
model,
which
is
a
Tier
I
assessment,
was
used
to
estimate
potential
ground
water
concentrations.
SCI­
GROW
estimates
likely
groundwater
concentrations
if
the
pesticide
is
used
at
the
maximum
allowable
rate
in
areas
where
groundwater
is
exceptionally
vulnerable
to
contamination.
This
assessment
represents
a
conservative
estimate
and
in
most
cases,
a
large
majority
of
the
use
area
will
have
groundwater
that
is
less
vulnerable
to
contamination
than
the
areas
used
to
derive
the
SCIGROW
estimate.
Application
of
diuron
to
citrus
in
Florida
was
modeled.
These
scenarios
represent
high
application
rates
and
areas
vulnerable
to
ground
water
contamination.
The
modeled
estimates
indicate
that
ground
water
concentrations
of
diuron
and
its
metabolites
are
below
the
chronic
DWLOC.

For
more
information
on
drinking
water
risks
and
the
DWLOC
calculations,
see
the
Water
Exposure
section
of
the
July
9,
2003,
Human
Health
Risk
Assessment,
the
March
11,
2002
memorandum
entitled,
"
Drinking
Water
Reassessment
for
Diuron
and
its
Degradates"
and
the
August
5,
2003
memorandum
entitled,
"
Surface
Water
Monitoring
Data
for
Diuron."
23
c.
Drinking
Water
Risk
Estimates
To
determine
the
maximum
allowable
contribution
of
pesticide
residues
in
water,
EPA
first
looks
at
how
much
of
the
overall
allowable
risk
is
contributed
by
food
and
then
determines
a
"
drinking
water
level
of
comparison"
(
DWLOC)
to
determine
whether
modeled
or
monitoring
levels
exceed
this
level.
The
Agency
uses
the
DWLOC
as
a
surrogate
to
capture
risk
associated
with
exposure
from
pesticides
in
drinking
water.
The
DWLOC
is
the
maximum
concentration
in
drinking
water
which,
when
considered
together
with
dietary
exposure,
does
not
exceed
a
level
of
concern.

The
results
of
the
Agency's
drinking
water
analysis
are
summarized
in
Table
8.
Details
of
the
drinking
water
analysis
are
found
in
the
Human
Health
Risk
Assessment
for
Diuron,
dated
September
8,
2003.

Table
8.
Estimated
Environmental
Concentrations
and
Chronic
DWLOCs
for
Diuron
and
its
Degradates
Estimated
Environmental
Concentrations
in
Surface
and
Ground
Water
for
Diuron
and
its
Degradates
from
Diuron
Use
on
Citrus
Estimated
Environmental
Concentrations
(

g/
L)

Diuron
MCPDMU
DWLOC4
Surface
Water
Monitoring
Data
<
11,2
<
11,3
28
Groundwater
(
peak
and
longterm
average)
9.12
0.593
1
Increased
20%
to
account
for
degradates,
as
indicated
by
modeling
work.
2
Includes
modeled
values
for
the
following
degradates:
DCPMU;
DCPU;
and
3,4­
DCA.
3
Based
on
modeling,
using
6.4
lbs
ai/
A
application
rate
for
citrus.
4
For
the
most
sensitive
subpopulation,
children
1
­
6
years.

Cancer
Drinking
Water
Risk
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
residue
and
processing
data.
To
better
characterize
both
potential
cancer
risks
from
surface
water,
EPA
has
used
monitoring
data
from
Florida,
an
area
of
high
diuron
use,
and
other
states.
These
data
indicate
detections
generally
one
to
two
orders
of
magnitude
lower
than
modeled
estimates
for
diuron
(
parent
compound).
Based
on
this
new
data,
the
Agency
has
concluded
that
cancer
risk
from
diuron
in
drinking
water
is
not
a
concern.
The
monitoring
data
for
Florida
can
be
found
on
the
following
website:
www.
sfwmd.
gov/
curre/
pest/
pestindex.
htm.
For
more
information
on
cancer
risks
from
drinking
24
water,
please
see
the
Aggregate
Risk
Section
below.
MCPDMU
Risk
For
the
degradate
MCPDMU,
the
Agency
calculated
the
EEC
using
drinking
water
monitoring
data.
The
monitoring
data
indicates
the
EEC
for
diuron
is
<
1
ppb,
including
all
of
the
degradates.
Although
the
water
monitoring
data
do
not
include
data
on
the
degradates
of
diuron,
the
Agency
has
increased
the
EECs
by
20
percent,
as
indicated
by
conservative
modeling,
to
account
for
the
degradates.
The
<
1ppb
calculation
includes
the
estimation
for
the
degradates.
The
<
1
ppb
EEC
for
MCPDMU
is
below
the
cancer
DWLOC
and
is
not
of
concern.
In
addition,
environmental
fate
data
are
required
to
confirm
estimates
of
the
concentrations
and
persistence
of
MCPDMU
in
water.

As
a
comparison,
the
Agency
used
modeling
to
calculate
the
EECs
with
the
revised
maximum
application
rate
(
6.4
lb
ai/
A)
for
citrus.
The
modeled
EEC
for
MCPDMU
is
6.94
ppb,
consistent
with
the
monitoring
results.

3.
Diuron:
Residential
Exposure
and
Risk
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.

a.
Toxicity
Table
9
details
the
results
of
the
hazard
assessment
for
the
non
dietary
risk
assessment
for
diuron.
25
Table
9.
Toxicity
Endpoints
Selected
for
Assessing
Residential
Risks
for
Diuron
Route
/
Duration
NOAEL
(
mg/
kg/
day)
Effect
Study
Uncertainty
Factors
and
Safety
Factors
Short­
term
Incidental
Oral
(
1
to
30
days)
10
Decreased
body
weight
and
food
consumption
Developmental
toxicity
study
in
rabbits
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Intermediateterm
Incidental
Oral
(
one
month
to
six
months)
1.0
Altered
hematological
parameters
observed
at
six
months.
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Short­
and
intermediateterm
Dermal
No
systemic
toxicity
following
repeated
dermal
dosing
at
1200
mg/
kg/
day
was
seen
in
the
dermal
toxicity
study.
Also,
there
is
no
developmental
concern.
No
hazard
was
identified
and
no
quantitative
assessment
is
required.

Long­
term
Dermala
(
greater
than
six
months)
1.0
(
LOAEL)
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis.
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Use
of
LOAEL
instead
of
a
NOAEL:
3x
Short­
term
Inhalationb
10
Decreased
body
weight
and
food
consumption
Developmental
toxicity
study
in
rabbits
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Intermediateterm
Inhalationb
1.0
Altered
hematological
parameters
observed
at
six
months
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Long­
term
Inhalationb
1.0
(
LOAEL)
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Use
of
a
LOAEL
instead
of
a
NOAEL:
3x
Cancer
Known/
likely
human
carcinogen
Q1*
=
1.91
x
10­
2
Urinary
bladder
carcinoma
in
both
sexes
of
the
Wistar
rat,
kidney
carcinomas
in
the
male
rat
(
a
rare
tumor),
and
mammary
gland
carcinomas
in
the
female
NMRI
mouse
Carcinogenicity
study
in
rats
and
mice
a
An
oral
endpoint
was
used
for
dermal
exposure:
dermal
absorption
factor
of
4%
of
oral
exposure
shall
be
used.
b
An
oral
endpoint
was
used
for
inhalation
exposure:
inhalation
exposure
assumed
equivalent
to
oral
exposure.

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
(
Q
1*)
approach
to
determine
the
lifetime
(
cancer)
risk
estimate.
26
b.
Residential
Handler
Risk
(
1)
Exposure
Scenarios,
Data,
&
Assumptions
There
are
potential
residential
exposures
from
activities
associated
with
pond
and
aquarium
use
and
paint
and
stain
use.
Though
there
are
existing
labels
for
applications
of
granular
formulations
of
diuron
to
turf,
most
are
limited
to
industrial
and
non­
crop
uses.
Others
products
are
either
pending
cancellation
by
the
registrant
or
the
registrant
has
agreed
to
place
language
specifically
eliminating
residential
uses
on
the
label.
Since
residential
turf
uses
are
being
canceled
for
diuron,
a
residential
assessment
for
turf
was
not
conducted.

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
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.
For
more
information,
see
"
Diuron:
the
Revised
HED
Chapter
of
the
Reregistration
Eligibility
Decision
Document
(
RED),"
dated
September
8,
2003.

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
following
three
residential
handler
scenarios
were
evaluated:

(
1)
Loading
ready
to
use
liquids;

(
2)
Applying
paints
or
stains
with
a
paintbrush;
and
(
3)
Applying
paints
with
an
airless
sprayer.

The
following
assumptions
were
used
in
the
non­
cancer
exposure
calculations:

°
Average
body
weight
of
an
adult
handler
is
70
kg.

°
The
average
residential
aquarium
is
assumed
to
be
50
gallons
and
the
average
residential
pond
is
assumed
to
be
1,000
gallons.
The
No
More
Algae
liquid
label
also
states
that
the
maximum
residential
pond
that
can
be
treated
is
3,000
gallons,
so
this
volume
was
assessed
as
a
high
end,
maximum
exposure
value.
27
°
The
amount
of
paint
used
per
day
for
residential
handlers
is
15
gallons
for
airless
sprayer,
two
gallons
for
paintbrush
applying
paint
and
five
gallons
for
paintbrush
applying
stain.
For
homeowners,
the
airless
sprayer
is
assumed
to
be
used
for
outdoor
applications
only.
Homeowner
use
of
diuron
treated
paint
indoors
is
restricted
to
small
rooms
such
as
bathrooms,
laundry
rooms,
etc.
where
the
use
of
an
airless
sprayer
is
unlikely
to
occur.

°
In
addition
to
diuron's
mildewcide
use
in
paints
and
stains,
it
is
also
used
in
plaster,
stuccos,
sealants,
caulking,
and
fillers.
Unit
exposure
data
only
exists
for
the
use
of
paints/
stains
with
airless
sprayer
and
paintbrush.
These
exposure
scenarios
are
assumed
to
have
a
higher
exposure
than
use
of
diuron
in
plaster,
stucco,
sealants,
caulking
and
fillers,
since
less
material
would
be
applied
in
a
day.
Therefore,
the
paint/
stain
assessment
will
also
be
considered
an
estimate
of
the
exposure
resulting
from
the
use
of
diuron
in
plaster,
stucco,
sealants,
caulking,
and
fillers.

°
Application
rates
­
The
concentration
of
diuron
in
the
paint,
caulking,
and
other
products
is
0.2
to
2.5
percent.
The
maximum
amount
of
diuron
per
gallon
of
paint
is
0.0532
lbs
ai/
gallon
paint.

°
Exposure
frequency
­
The
secondary
residential
handlers
are
expected
to
be
of
a
short­
term
duration
(
less
than
30
days).

The
following
assumptions
and
factors
were
used
in
addition
to
previously
stated
residential
non­
cancer
handler
assumptions
in
order
to
complete
this
cancer
risk
assessment:

°
The
average
lifetime
is
assumed
to
be
70
years.

°
Exposure
duration
is
assumed
to
be
50
years.
.
°
The
number
of
exposures
per
year
for
the
pond
and
aquarium
uses
are
based
on
the
label
recommendations.
The
"
No
More
Algae"
liquid
label
states
that
"
For
regular
maintenance,
use
once
a
month
or
as
algae
starts
to
reappear."
Therefore,
12
exposures
per
year
were
assumed.

°
Homeowners
applying
diuron
treated
paint
are
exposed
two
days
per
year.
Since
it
would
be
unusual
for
homeowners
to
paint
their
houses
every
year
with
diuron
treated
paint,
this
is
considered
to
be
a
high­
end
estimate.

°
Homeowners
are
assumed
to
be
wearing
short­
sleeved
shirt
and
short
pants
and
no
personal
protective
equipment
(
PPE).

No
chemical
specific
handler
exposure
data
have
been
submitted
to
determine
the
extent
28
of
these
exposures.
Secondary
residential
handlers
are
assessed
using
an
airless
sprayer
and
a
paint
brush.
The
Pesticide
Handler
Exposure
Database
(
PHED)
was
used
to
estimate
homeowner
exposure
while
using
diuron­
treated
paint.
For
comparative
purposes,
the
Agency
calculated
homeowner
exposure
to
diuron
while
using
a
paint
brush
and
an
airless
sprayer
using
data
submitted
for
another
pesticide.
These
calculations
indicate
risks
similar
to
those
that
were
derived
from
using
the
PHED.

Although
there
is
potential
exposure
during
the
application
of
the
other
treated
materials
(
caulks
and
sealants),
they
are
not
included
in
this
assessment
because
no
data
are
available
to
assess
these
uses.
There
is
also
a
potential
for
exposure
from
applying
paint
with
a
roller.
However,
it
is
the
Agency's
conclusion
that
the
airless
sprayer
and
paintbrush
scenarios
represent
the
high
end
exposures
for
diuron
antimicrobial
secondary
handler
uses.

(
2)
Residential
Handler
Risk
Characterization
Summary
of
Non­
Cancer
Risk
Concerns
for
Residential
Handlers
The
short
term
inhalation
NOAEL
of
10
mg/
kg/
day
was
used
for
all
non­
cancer
exposures
and
had
a
target
MOE
of
100.
The
calculations
of
short­
term
inhalation
risk
from
exposure
to
the
liquid
formulation
of
diuron
indicate
that
inhalation
MOEs
are
more
than
100
for
the
all
the
assessed
exposure
scenarios
and
are
not
considered
risks
of
concern.
Although
no
data
are
available
to
assess
exposures
and
risks
from
the
block/
tablet
form
of
diuron,
exposure
from
the
block/
tablet
forms
of
diuron
are
expected
to
be
less
than
exposure
from
the
liquid
formulation,
and
therefore
are
not
a
risk
of
concern.
For
more
information,
see
"
Diuron:
the
Revised
HED
Chapter
of
the
Reregistration
Eligibility
Decision
Document
(
RED),"
dated
September
8,
2003.

Residential
Cancer
Risk
Characterization
The
applicator
assessment
for
paints
and
stains
applied
with
a
brush
or
an
airless
sprayer
is
based
on
a
Q
1*
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%.
Usage
information
gathered
subsequent
to
the
risk
assessment
indicates
that
less
than
1%
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.
The
diuron
cancer
risk
estimates
are
presented
in
Table
10
below.

Table
10.
Diuron
Cancer
Exposure
and
Risk
Estimates
for
Homeowner
Pond/
Aquarium,
Paint
and
Stain
Application
29
Exposure
Scenario
(
Scenario
#)
Use
site
Application
Rate
Amount
Treated
Total
Daily
Dosea
Baseline
Daily
LADDb,
c
Baseline
Riskd
Mixer/
Loader
(
12
days/
year)

(
1)
Loading
Ready
to
Use
Liquids
pond
0.0000074
lb
ai
per
gallon
3000
Gallons
per
day
0.000037
8.7
E­
7
1.7
E­
8
pond
0.0000074
lb
ai
per
gallon
1000
Gallons
per
day
0.000012
2.9
E­
7
5.5
E­
9
aquarium
0.0000074
lb
ai
per
gallon
50
Gallons
per
day
0.00000062
1.5
E­
8
3.0
E­
10
Applicator
(
2
days/
year)

(
2)
Applying
Paint/
Stains
with
Paintbrush
Paint
0.0532
lb
ai
per
gallon
2
Gallons
per
day
0.014
5.5
E­
5
1.1
E­
6
Stains
0.0532
lb
ai
per
gallon
5
Gallons
per
day
0.036
1.4
E­
4
2.7
E­
6
(
3)
Applying
Paint
with
Airless
Sprayer
Paint
0.0532
lb
ai
per
gallon
15
Gallons
per
day
0.045
1.8
E­
4
3.4
E­
6
a
Total
Daily
Dose
(
mg/
kg/
day)
=
Daily
Dermal
Dose
(
mg/
kg/
day)
*
Dermal
Absorption
(
4%)
+
Daily
Inhalation
Dose
(
mg/
kg/
day).
See
Table
13
for
daily
dermal
and
inhalation
doses.
b
The
number
of
exposures
per
year
are
based
on
the
label
recommendations.
The
No
More
Algae
Liquid
label
states
that
"
For
regular
maintenance,
use
once
a
month
or
as
algae
starts
to
reappear."
Therefore,
12
exposures
per
year
were
assumed.
Two
exposure
per
year
assumed
for
residential
person
painting
their
home.
c
Lifetime
average
daily
dose
(
LADD)
(
mg/
kg/
day)
=
Total
Daily
Dose
(
mg/
kg/
day)
*
(
number
of
days
of
exposure
per
year
/
365
days/
year)
*
(
50
years
exposed
/
70
years
in
a
lifetime).
d
Cancer
risk
=
LADD
(
mg/
kg/
day)
*
Q1
(
1.91E­
2
mg/
kg/
day).

c.
Residential
Postapplication
Risk
Characterization
(
1)
Exposure
Scenarios,
Data,
&
Assumptions
Residential
postapplication
inhalation
and
dermal
exposure
is
expected
to
occur
from
the
use
of
diuron
in
ponds
and
aquariums
and
from
the
indoor
use
of
paints
and
stains.
The
following
residential
postapplication
scenarios
were
evaluated:

(
1)
Inhalation
exposure
from
diuron
use
in
ponds
and
aquariums;

(
2)
Dermal
exposure
from
diuron
use
in
ponds
and
aquariums;

(
3)
Inhalation
exposure
from
the
indoor
use
of
diuron
paints
or
stains;
and
(
4)
Dermal
exposure
from
the
indoor
use
of
diuron
paints
or
stains.

Note
that
postapplication
exposure
to
turf
is
no
longer
considered
in
the
residential
postapplication
risk
assessment.
The
registrants
have
agreed
to
prohibit
turf
treatment
in
residential
areas.
30
The
following
assumptions
were
used:

°
Typical
homeowner
clothing
indoors
is
represented
by
short
pants,
short
sleeve
shirt,
no
gloves.

°
The
average
body
weight
of
70
kg
was
used.

°
Diuron
products
applied
to
ponds
or
aquariums
is
in
tablet/
block
or
a
ready­
to­
use
liquid
form.

°
Two
tablet
products
were
assessed,
one
product
that
requires
using
one
tablet
for
every
10
gallons
of
aquarium
or
pond
water
and
one
product
that
requires
using
one
tablet
for
every
250
gallons
of
pond
water.

°
Short­
term
exposure
of
one
to
30
days
for
pond/
aquarium
treatment
and
for
paint/
stain
use.

(
2)
Residential
Postapplication
Risk
Characterization
Postapplication
inhalation
and
dermal
exposure
resulting
from
the
use
of
diuron
in
ponds
and
aquariums
is
expected
to
be
minimal
and
not
of
concern.
Diuron
is
applied
to
ponds/
aquariums
in
the
form
of
a
liquid
and
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
and
not
of
concern.
HED
has
conducted
a
screening­
level
inhalation
assessment
using
the
Multi­
Chamber
Concentration
and
Exposure
Model
(
MCCEM).
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
results
of
this
model,
coupled
with
diuron's
low
vapor
pressure
(
2
x
10­
7
mm
Hg
at
30

C),
show
minimal
postapplication
inhalation
exposure.
Furthermore,
diuron­
treated
paint
is
only
likely
to
be
used
in
rooms
where
high
humidity
is
expected
(
i.
e.
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.

4.
Aggregate
Risk
31
The
Food
Quality
Protection
Act
amendments
to
the
Federal
Food,
Drug,
and
Cosmetic
Act
(
FFDCA,
Section
408(
b)(
2)(
A)(
ii))
require
"
that
there
is
reasonable
certainty
that
no
harm
will
result
from
aggregate
exposure
to
pesticide
chemical
residue,
including
all
anticipated
dietary
exposures
and
other
exposures
for
which
there
are
reliable
information."
Aggregate
exposure
will
typically
include
exposures
from
food,
drinking
water,
residential
uses
of
a
pesticide,
and
other
non­
occupational
sources
of
exposure.
For
diuron,
aggregate
risk
assessments
were
conducted
for
short­
term
(
one
to
thirty
days),
and
chronic
(
several
months
to
lifetime)
exposures.
The
aggregate
risk
assessments
for
chronic
exposures
include
a
non­
cancer
and
a
cancer
risk
assessment.
No
acute
or
intermediate­
term
aggregate
risks
were
assessed
because
there
was
no
systemic
toxicity
seen
in
the
acute
oral
or
21­
day
dermal
toxicity
study.

a.
Acute
Aggregate
Risk
No
adverse
effects
attributed
to
a
single
exposure
to
diuron
were
identified
in
any
available
studies.
Therefore,
no
acute
dietary
risk
assessment
was
warranted.

b.
Short­
Term
Aggregate
Risk
When
potential
food
and
residential
inhalation
exposures
are
combined
they
result
in
aggregate
short­
term
MOEs
of
1043
and
1045
for
adult
males
and
females,
respectively,
which
are
not
of
concern.
Based
on
labeled
uses,
no
intermediate­
or
long­
term
residential
handler,
or
substantial
postapplication
exposures
of
any
duration,
are
expected.

Aggregate
short­
term
risk
estimates
for
diuron
and
its
metabolites
hydrolyzable
to
3,4­
DCA
would
combine
exposures
from
food
(
average),
water,
and
residential
inhalation
only.
Estimates
of
allowable
levels
of
diuron
in
drinking
water
were
calculated
using
DWLOCs.
The
Agency
determined
that
it
was
unlikely
that
more
than
one
of
the
residential
handler
activities
would
occur
concurrently
during
a
short­
term
time
period.
Therefore,
the
Agency
took
the
protective
approach
of
including
the
exposures
from
the
activity
which
could
potentially
result
in
the
most
exposure
to
the
homeowner,
applying
paint
with
an
airless
sprayer,
in
the
aggregate
assessment.
As
noted
previously,
residential
exposures
are
calculated
using
short­
sleeved
shirt
and
short
pants
(
no
personal
protective
equipment,
no
engineering
controls).

An
MOE
was
calculated
to
estimate
the
short­
term
aggregate
risk,
combining
food
and
inhalation
exposures,
and
using
a
NOAEL
of
10
mg/
kg/
day.
A
UF
of
100
(
10x
for
interspecies
extrapolation,
10x
for
intraspecies
variability)
and
the
1x
FQPA
safety
factor
for
diuron
were
applied
to
the
assessment;
therefore,
an
MOE
of
greater
than
100
is
not
of
concern.
As
shown
in
Table
11,
the
surface
water
and
groundwater
EECs
are
below
the
DWLOCs
and
are
not
of
concern.
Table
11.
Diuron
Aggregate
DWLOCs
for
Short­
Term
Exposures
32
Population
Subgroup1
Aggregate
Risk
MOE
2
(
food
and
residential)
Surface
Water
EEC
3
(
ppb)
Ground
Water
EEC
3
(
ppb)
Short­
Term
DWLOC
4
(
ppb)

Adult
Males
1043
104
9.1
3153
Adult
Females
1045
2700
1
Only
adults
are
included
in
aggregate
risk
assessment;
it
is
assumed
that
only
adults
will
apply
paint
2
Aggregate
MOE
=
[
NOAEL
÷
(
Avg
Food
Exposure
+
Residential
Exposure)]
3
The
crop
producing
the
highest
level
was
used
to
assess
exposure
to
diuron,
DCPMU,
DCPU,
3,4­
DCA,
total.
4DWLOC(

g/
L)
=
[
maximum
water
exposure
(
mg/
kg/
day)
x
body
weight
(
kg)]
[
water
consumption
(
L)
x
10­
3
mg/

g]

c.
Chronic
(
Non­
Cancer)
Aggregate
Risk
Aggregate
chronic
(
noncancer)
risk
estimates
include
the
contribution
of
exposure
from
dietary
sources
(
food
+
water)
and
residential
sources.
However,
based
on
the
labeled
uses,
no
long­
term
or
chronic
residential
exposures
are
expected.
Chronic
risk
estimates
from
exposures
to
food,
associated
with
the
use
of
diuron
do
not
exceed
the
Agency's
level
of
concern
for
the
most
highly
exposed
population
subgroup,
children
ages
1­
6
years
of
age.
The
chronic
dietary
(
food
only)
risk
estimate
for
children
ages
1­
6
years
of
age
was
<
7%
of
the
chronic
PAD.

The
original
Tier
2
drinking
water
assessment
was
based
on
the
PRZM/
EXAMS
model
and
identified
chronic
drinking
water
concerns.
Since
that
time,
the
registrant
has
submitted
an
analysis
of
surface
water
supplies
identified
using
Geographic
Information
Systems
information
from
Florida,
coupled
with
water
monitoring
data.
The
submitted
data,
combined
with
additional
monitoring
data
that
was
subsequently
identified,
was
reviewed
and
determined
to
have
enough
samples
and
be
of
sufficient
quality
to
allow
the
Agency
to
refine
the
drinking
water
analysis.
The
revised
chronic
EEC
is
<
1
ppb.
Conservative
models
were
used
to
determine
that
the
diuron
degradates
would
add
an
additional
20
percent
to
the
concentration
of
the
parent
compound.
The
<
1
ppb
estimation
includes
the
estimation
for
the
degradates.
Based
on
this
new
data,
the
Agency
has
concluded
that
chronic
risk
of
diuron
in
drinking
water
is
not
a
concern.
For
more
information,
please
see
the
document
titled
"
Environmental
Risk
Assessment
for
the
Reregistration
of
Diuron,"
dated
August
27,
2001.
Table
12
presents
the
DWLOCs
for
various
subpopulations.
33
Table
12
.
DWLOCs
for
Chronic
Non­
Cancer
Aggregate
Dietary
Exposure
Population
Subgroup
Surface
Water
EECs
(
ppb)
Chronic
DWLOC
(
ppb)

Non­
Cancer
U.
S.
Population
1
102
Females
(
13­
50
years)
88
Infants
(<
1
Year)
29
Children
(
1­
6
years)
28
d.
Cancer
Aggregate
Risk
The
cancer
aggregate
risk
assessment
includes
chronic
dietary
exposures
from
residues
in
food
and
water
and
a
consideration
of
potential
exposures
from
the
residential
uses
of
a
chemical.
In
the
case
of
diuron,
separate
cancer
risk
assessments
have
been
conducted
for
the
parent
diuron
and
for
its
water
metabolite,
MCPDMU.
EPA
considers
separate
cancer
assessments
to
be
warranted
because
the
target
organs
and
Q
1*
are
different
for
parent
and
metabolite.
The
MCPDMU
assessment
relies
on
toxicity
data
from
monuron,
a
structurally
similar
molecule
that
was
formerly
a
registered
pesticide.
Like
chronic
dietary
risk,
potential
cancer
risk
is
calculated
by
using
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
(
Q
1*)
approach
to
determine
the
lifetime
(
cancer)
risk
estimate.

Aggregate
Cancer
Risk
from
Diuron
Although
estimated
exposure
to
diuron
residues
in
food
alone
results
in
a
cancer
risk
estimate
of
1.68
x
10­
6
for
the
general
population,
the
Agency
believes
that
this
estimate
is
not
of
concern
based
on
several
protective
assumptions
in
the
assessment.
The
estimates
of
exposure
from
food
are
based
largely
on
field
trial
data
conducted
at
the
maximum
application
rates,
with
adjustments
only
for
percent
crop
treated
and
some
processing
data.
Further,
even
though
PDP
monitoring
data
show
no
detectable
residues
of
diuron
parent
in
any
food
commodity,
EPA
has
made
the
protective
assumption
that
all
diuron
converts
to
metabolites
and
has
determined
that
these
metabolite
residues
are
as
toxic
as
the
parent
compound.
Drinking
water
monitoring
data
for
several
states
with
high
usage
of
diuron,
indicate
average
detections
in
the
0.05­
0.28
ppb
range.
These
levels,
if
sustained
over
a
lifetime
of
exposure
would
result
in
risk
estimates
in
the
1
x
10­
6
range.
Thus,
combined
food
and
drinking
water
risks
would
be
<
3
x
10­
6.
34
The
residential
uses
of
diuron
result
in
only
short­
term
exposures,
generally
less
than
7
days
per
year,
therefore
the
diuron
cancer
assessment
based
on
Residential
SOP
provides
a
very
conservative
estimate
of
potential
cancer
risk.
The
assessment
assumes
an
upper
bound
dermal
absorption
factor,
even
though
no
dermal
toxicity
was
observed
in
a
28­
day
rabbit
dermal
toxicity
study.
Further,
EPA
has
assumed
100%
absorption
by
the
inhalation
route.
Given
the
low
vapor
pressure
of
diuron,
2
x
10­
7mm
Hg
@
30
C,
absorption
by
the
inhalation
route
is
likely
to
be
low.
Finally,
because
of
the
low
percent
of
paint
containing
diuron
(<
1%
),
lifetime
exposure
to
home
applicators
of
diuron­
containing
products
is
likely
to
be
negligible.

Aggregate
Risk
from
MCPDMU
For
the
MCPDMU
aggregate
assessment,
EPA
considered
the
potential
contributions
from
drinking
water
and
consumption
of
catfish.
Because
MCPDMU
is
only
formed
in
water,
these
are
the
only
potential
sources
of
exposure
to
MCPDMU.
Based
on
modeled
estimates,
the
EEC
for
MCPDMU
is
6.94
ppb,
and
represents
a
slight
exceedance
of
the
cancer
DWLOC
of
2
ppb.
However,
as
mentioned
in
the
Dietary
Risk
from
Drinking
Water
Section,
drinking
water
monitoring
data
was
used
to
estimate
the
EECs
of
diuron
and
its
degradates
in
drinking
water.
The
monitoring
data
indicates
the
EEC
for
diuron
is
<
1
ppb,
including
the
degradates.
Although
the
water
monitoring
data
do
not
include
data
on
the
degradates
of
diuron,
the
Agency
has
increased
the
EECs
by
20
percent,
as
suggested
by
modeling,
to
account
for
the
degradates.
In
addition,
environmental
fate
data
are
required
to
confirm
estimates
of
the
concentrations
and
persistence
of
MCPDMU
in
water.

Table
13.
Summary
of
Cancer
DWLOC
Calculations
for
MCPDMU
Population
Subgroup
Surface
Water
EECs
(
ppb)
Ground
Water
EECs
(
ppb)
DWLOCcancer
(
ppb)

U.
S.
Population
<
1*
1.4
2.0
*
For
comparative
purposes,
the
modeled
estimate
for
the
surface
water
EEC
is
6.94
ppb.

5.
Occupational
Risk
Occupational
workers
can
be
exposed
to
a
pesticide
through
mixing,
loading,
and/
or
applying
a
pesticide,
or
re­
entering
treated
sites.
Occupational
handlers
of
diuron
include:
workers
in
right­
of­
way
areas
or
industrial
sites,
workers
in
agricultural
environments,
workers
applying
paints
or
stains,
workers
in
ornamental
fish
and
catfish
production
and
workers
applying
diuron
to
ornamental
plants
and
trees
in
nurseries.
Non­
cancer
risk
for
all
of
these
potentially
exposed
populations
is
measured
by
a
Margin
of
Exposure
(
MOE)
which
determines
how
close
the
occupational
exposure
comes
to
a
No
Observed
Adverse
Effect
Level
(
NOAEL).
In
the
case
of
diuron,
MOEs
greater
than
100
do
not
exceed
the
Agency's
level
of
concern.
When
evaluating
cancer
risks
for
the
occupational
population,
EPA
closely
examines
risks
in
the
1x10­
4
to
1x10­
6
range
and
seeks
cost
effective
ways
to
reduce
occupational
cancer
risks
to
the
greatest
extent
feasible,
preferably
1x10­
6
or
less.
35
Calculations
of
noncancer
risk
based
on
inhalation
exposure
indicate
that
the
inhalation
margins
of
exposure
(
MOEs)
are
more
than
100
with
PPE
or
engineering
controls
for
all
of
the
short­
term
occupational
exposure
scenarios
except
applying
sprays
with
a
high
pressure
handwand.
Sixteen
of
the
31
occupational
scenarios
were
identified
as
having
intermediate­
term
durations
of
exposure.
Of
these,
none
have
a
non­
cancer
risk
of
concern
for
intermediate­
term
inhalation
exposure
with
PPE
or
engineering
controls.
A
noncancer
postapplication
risk
assessment
was
not
conducted,
since
no
systemic
toxicity
by
the
dermal
route
is
expected
for
the
short­
or
intermediate­
term
durations.
Postapplication
cancer
risks
for
private
growers
were
calculated
at
both
the
typical
application
rate
and
the
maximum
application
rate
for
each
crop
grouping.

Occupational
risk
assessments
were
conducted
for
the
use
of
diuron
as
a
mildewcide
in
paint.
Four
occupational
handler
scenarios
were
identified
for
the
use
of
diuron
in
paint
and
are
expected
to
be
of
short­
and
intermediate­
term
exposure
duration.
The
calculations
of
short­
and
intermediate­
term
inhalation
risk
from
the
use
of
diuron
in
paint
indicate
that
MOEs
are
more
than
100
at
the
assessed
level
of
mitigation
for
all
the
exposure
scenarios,
except
applying
paints
with
an
airless
sprayer
(
indoors).
At
the
assessed
level
of
mitigation,
all
paint
scenarios
have
potential
cancer
risks
between
1
x
10­
4
and
1
x
10­
6.
Occupational
postapplication
exposures
to
paint
containing
diuron
may
occur
in
industrial
settings
around
open
vats
used
in
paint
processing.
Inhalation
and
dermal
exposures
may
also
occur
while
maintaining
industrial
equipment.
No
postapplication
exposure
data
have
been
submitted
to
determine
the
extent
of
postapplication
exposures
in
the
industrial
settings.
Nonetheless,
inhalation
exposures
are
expected
to
be
minimal
because
of
the
low
vapor
pressure
of
diuron
(
2
x
10­
7
mm
Hg
at
30

C)
and
aerosol
formation
is
not
expected.
Dermal
postapplication
exposures
are
expected
to
be
lower
than
when
handling/
loading
the
formulated
product.
Therefore,
postapplication
exposures
in
the
industrial
settings
are
expected
to
be
minimal
and
not
of
concern.

Occupational
risk
assessments
were
also
conducted
for
the
use
of
diuron
as
an
algaecide
in
commercial
fish
ponds.
Four
short­
term
occupational
handler
scenarios
were
identified
for
the
use
of
diuron
in
commercial
fish
production
and
the
inhalation
MOEs
from
all
four
of
the
commercial
fish
production
scenarios
were
greater
than
100
at
the
baseline
level
of
mitigation
and
are
not
of
concern.
With
maximum
mitigation
measures
(
engineering
control
level),
all
four
scenarios
have
estimated
cancer
risks
of
less
than
1
x
10­
6
and
are
not
of
concern.
Occupational
postapplication
exposure
to
diuron
in
treated
fish
production
ponds
is
not
likely
to
result
in
a
risk
of
concern
based
on
the
extremely
high
dilution
rate
36
a.
Toxicity
The
acute
toxicity
profiles
for
diuron
is
listed
previously
in
Table
3.
Table
14
details
the
toxicity
endpoints
used
in
the
occupational
risk
assessment
for
diuron.

Table
14:
Toxicity
Endpoints
for
Diuron
Risk
Assessment
Route
/
Duration
NOAEL
(
mg/
kg/
day)
Effect
Study
Uncertainty
Factors
and
Safety
Factors
Short­
and
intermediateterm
Dermal
No
systemic
toxicity
following
repeated
dermal
dosing
at
1200
mg/
kg/
day
was
seen
in
the
dermal
toxicity
study.
Also,
there
is
no
developmental
concern.
No
hazard
was
identified
and
no
quantitative
assessment
is
required.

Long­
term
Dermala
(
greater
than
six
months)
1.0
(
LOAEL)
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis.
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Use
of
LOAEL
instead
of
a
NOAEL:
3x
Short­
term
Inhalationb
10
Decreased
body
weight
and
food
consumption
Developmental
toxicity
study
in
rabbits
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Intermediateterm
Inhalationb
1.0
Altered
hematological
parameters
observed
at
six
months
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Long­
term
Inhalationb
1.0
(
LOAEL)
Evidence
of
hemolytic
anemia
and
compensatory
hematopoiesis
Chronic
toxicity/
carcinogenicity
study
in
rats
Interspecies:
10x
Intraspecies:
10x
FQPA:
1x
Use
of
a
LOAEL
instead
of
a
NOAEL:
3x
Cancer
Known/
lik
ely
human
carcinogen
Q1*
=
1.91
x
10­
2
Urinary
bladder
carcinoma
in
both
sexes
of
the
Wistar
rat,
kidney
carcinomas
in
the
male
rat
(
a
rare
tumor),
and
mammary
gland
carcinomas
in
the
female
NMRI
mouse
Carcinogenicity
study
in
rats
and
mice
a
An
oral
endpoint
was
used
for
dermal
exposure:
dermal
absorption
factor
of
4%
of
oral
exposure
shall
be
used.
b
An
oral
endpoint
was
used
for
inhalation
exposure:
inhalation
exposure
assumed
equivalent
to
oral
exposure.

b.
Agricultural
Handler
Exposure
Based
on
the
registered
use
patterns,
EPA
has
identified
31major
exposure
scenarios
for
which
there
is
potential
occupational
handler
exposure
during
mixing,
loading,
and
applying
products
containing
diuron.
These
scenarios
are
as
follows:

(
1a)
mixing/
loading
liquid
formulations
for
aerial
application;
(
1b)
mixing/
loading
liquid
formulations
for
chemigation;
(
1c)
mixing/
loading
liquid
formulations
for
groundboom
application;
37
(
1d)
mixing/
loading
liquid
formulations
for
rights­
of­
way
sprayers;
(
1e)
mixing/
loading
liquid
formulations
for
high­
pressure
hand
wand;
(
2a)
mixing/
loading
dry
flowables
for
aerial
application;
(
2b)
mixing/
loading
dry
flowables
for
chemigation;
(
2c)
mixing/
loading
dry
flowables
for
groundboom
application;
(
2d)
mixing/
loading
dry
flowables
for
rights­
of­
way
spray
application;
(
2e)
mixing/
loading
dry
flowables
for
high­
pressure
hand
wand;
(
3a)
mixing/
loading
wettable
powders
for
aerial
application;
(
3b)
mixing/
loading
wettable
powders
for
chemigation;
(
3c)
mixing/
loading
wettable
powders
for
groundboom
application;
(
3d)
mixing/
loading
wettable
powders
for
rights­
of­
way
spray
application;
(
3e)
mixing/
loading
wettable
powders
for
high­
pressure
hand
wand;
(
4)
loading
granulars
for
tractor­
drawn
spreaders;
(
5)
applying
sprays
for
aerial
application;
(
6)
applying
sprays
for
groundboom
application;
(
7)
applying
sprays
with
a
rights­
of­
way
sprayer;
(
8)
applying
sprays
with
a
high­
pressure
hand
wand;
(
9)
applying
granulars
for
a
tractor­
drawn
spreader;
(
10)
applying
granulars
with
a
spoon;
(
11)
applying
granulars
for
hand
application;
(
12)
flagging
aerial
spray
applications;
(
13)
mixing/
loading/
applying
liquids
with
a
low­
pressure
hand
wand;
(
14)
mixing/
loading/
applying
liquids
with
a
backpack
sprayer;
(
15)
mixing/
loading/
applying
wettable
powders
with
a
low­
pressure
hand
wand;
(
16)
loading/
applying
granulars
with
a
pump
feed
backpack
spreader;
(
17)
loading/
applying
gravity
feed
backpack
spreader;
(
18)
loading/
applying
granulars
for
a
belly
grinder
application;
and
(
19)
loading/
applying
granulars
with
a
push­
type
spreader.

Since
granulars
are
only
used
on
non­
crop/
utility
areas,
aerial
application
of
granulars
and
flaggers
supporting
aerial
granular
applications
were
not
assessed.

For
agricultural
handlers,
the
estimated
exposures
initially
are
assessed
assuming
handlers
are
using
baseline
attire
(
i.
e.,
long­
sleeve
shirt,
long
pants,
shoes,
and
socks).
If
risk
estimates
exceed
the
level
of
concern
for
a
given
scenario
with
baseline
attire,
then
exposures
are
assessed
with
the
addition
of
personal
protective
equipment
(
i.
e.,
chemical­
resistant
gloves,
double­
layer
body
protection,
and/
or
a
respirator)
as
required.
In
general,
the
Agency
uses
the
least
PPE
necessary
to
achieve
risk
estimates
that
do
not
exceed
the
level
of
concern.
If
the
risk
estimates
exceed
the
Agency's
level
of
concern
(
i.
e.,
if
MOE
<
100)
for
a
given
scenario
even
with
the
addition
of
PPE,
then
the
risks
are
assessed
with
the
use
of
engineering
controls
(
i.
e.,
closed
system
mixing/
loading
and
enclosed
cabs
or
cockpits
for
applying
and
flagging).
38
Agricultural
Handler
Data
Sources
The
analyses
for
the
diuron
risk
assessment
were
performed
using
the
following
sources
of
data:

°
Outdoor
Residential
Exposure
Task
Force
(
ORETF).
The
task
force
recently
submitted
proprietary
data
to
the
Agency
on
hose­
end
sprayers,
push­
type
granular
spreaders,
and
handgun
sprayers
(
MRID
#
44972201).
The
ORETF
data
were
used
in
this
assessment
in
place
of
PHED
data
for
the
"
loading/
applying
granulars
using
a
push­
type
spreader"
scenario.

°
Available
data
were
used
to
assess
exposures
and
risks
to
occupational
handlers
loading
and
applying
granulars
using
a
scoop
and
bucket,
these
estimates
are
used
as
range­
finding
estimates
for
the
applications
made
with
a
spoon
or
by
hand.

°
Pesticide
Handlers
Exposure
Database
(
PHED).
PHED
was
designed
by
a
task
force
of
representatives
from
the
US
EPA,
Health
Canada,
the
California
Department
of
Pesticide
Regulation,
and
member
companies
of
the
American
Crop
Protection
Association,
now
known
as
Crop
Life
America.
It
is
a
software
system
consisting
of
two
parts
­
a
database
of
measured
exposure
values
for
workers
involved
in
the
handling
of
pesticides
under
actual
field
conditions
and
a
set
of
computer
algorithms
used
to
subset
and
statistically
summarize
the
selected
data.
Currently,
the
database
contains
values
for
over
1,700
monitored
individuals
(
i.
e.,
replicates).
The
quality
of
the
data
and
exposure
factors
represents
the
best
sources
of
data
currently
available
to
the
Agency
for
completing
these
kinds
of
assessments.

Agricultural
Handler
Exposure
Assumptions
The
following
assumptions
and
factors
were
used
in
order
to
complete
the
exposure
and
risk
assessments
for
occupational
handlers/
applicators:

Calculations
were
completed
for
a
range
of
maximum
application
rates
for
crops
specified
on
current
diuron
labels
and
in
the
Label
Usage
and
Information
System
(
LUIS)
report.
These
rates
were
assessed
in
order
to
bracket
risk
levels
associated
with
the
various
use
patterns.

°
Average
body
weight
of
an
adult
handler
was
assumed
to
be
70
kg.

°
Daily
(
8­
hour
workday)
acres
and
volumes
(
as
appropriate)
to
be
treated
in
each
scenario
include:

°
Exposures
were
estimated
for
handlers
using
1,200
and
350
acres
per
day
for
aerial
equipment.
The
use
of
1,200
acres
treated
in
one
day
by
either
the
mixer/
loader
or
the
applicator
is
considered
a
reasonable
high­
end
estimate,
because
these
crops
are
high
acreage
field
crops.
This
maximum
acres
treated
aerially
per
day
is
based
on
published
scientific
literature,
surveys,
knowledge
of
agricultural
practices,
and
calculated
acreage
estimates.
39
°
350
acres
for
aerial
applications
to
all
agricultural
crops,
except
for
cotton,
and
alfalfa;

°
350
acres
for
flaggers
supporting
aerial
applications;

°
For
groundboom
equipment
use
on
high
acreage
crops
such
as
cotton,
small
grains
(
wheat,
barley,
and
oats),
alfalfa
and
corn,
a
range
of
200
acres
per
day
to
80
acres
per
day
was
used.
For
all
other
crops,
80
acres
was
used;

°
1000
gallons
for
high­
pressure
hand
wands
and
rights­
of­
way
sprayers;

°
350
acres
for
chemigation;

°
40
gallons
for
low­
pressure
hand
wands
and
backpack
sprayers;

°
80
acres
for
tractor­
drawn
spreader;

°
5
acres
for
a
push­
type
spreader
and
backpack
spreaders,
1
acre
for
a
belly­
grinder
and
100
square
feet
for
granular
hand
and
spoon
application;
and
°
50
gallons
for
airless
sprayer
and
5
gallons
for
paintbrush.

°
If
scenario­
specific
data
are
lacking,
the
Agency
will
calculate
unit
exposure
values
using
generic
protection
factors
that
are
applied
to
represent
the
use
of
personal
protective
equipment
(
PPE)
and
engineering
controls.
This
assessment
used
an
80
percent
protection
factor
applied
to
baseline
inhalation
unit
exposure
values
to
represent
use
of
a
dust/
mist
respirator
(
currently
required
on
some
labels).

°
The
duration
of
exposure
for
handlers
of
diuron
is
assumed
to
be
mostly
shortterm
(
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.
Since
only
aerial
and
chemigation
equipment,
and
groundboom
sprayers
are
used
to
treat
these
crops,
only
the
scenarios
with
this
equipment
and
the
supporting
flagger
scenario
were
assessed
for
the
intermediate
term.
Only
for
the
highest
application
rate
for
the
four
crops,
cotton
at
2.2
lbs
ai/
acre,
was
assessed
for
the
intermediate
term.

°
Rights­
of­
way
sprayer
scenarios
for
utility
and
industrial
areas
are
assumed
to
be
intermediate­
term
duration,
because
utility
workers
could
possibly
treat
rights­
ofway
areas
(
roadsides,
railroads,
etc)
all
summer
long.

c.
Agricultural
Handler
Non­
Cancer
Risk
The
duration
of
exposure
is
expected
to
be
short­,
and
intermediate­
term
for
occupational
handlers.
The
exposure
duration
for
short­
term
assessments
is
1
to
30
days,
while
intermediate­
40
term
durations
are
1
to
6
months.
Non­
cancer
risk
estimates
are
expressed
in
terms
of
the
Margin
of
Exposure
(
MOE).
For
occupationally
exposed
workers,
MOEs
greater
than
or
equal
to
100
and
are
not
of
concern.
A
summary
of
Occupational
Handler
Non­
Cancer
Risks
are
shown
in
Table
15.
41
Table
15.
Diuron:
Summary
of
Occupational
Handler
Non­
Cancer
Risks
Exposure
Scenario
Crop
Type
or
Target
Acres
Treated
or
Gallons
per
Application
Application
Rate
(
lbs
a.
i./
A)
Inhalation
MOEs
Necessary
Level
of
PPE
or
Engineering
Controls
Short
Term
<
7
days
Intermediate
Term
<
30
days
Occupational
Mixer/
Loader
Estimates
for
MOE
100
or
Highest
Achievable
MOE
(
1a)
Mixing/
Loading
Liquids
for
Aerial
Application
Sugarcane
350
acres/
day
6
lb
ai/
acre
280
­
Baseline
Alfalfa
1200
acres/
day
3.2
lb
ai/
acre
150
­
Baseline
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
380
Minimum
Cotton
1200
acres/
day
2.2
lb
ai/
acre
­
110
Minimum
(
1b)
Mixing/
Loading
Liquids
for
Chemigation
Application
Sugarcane
350
acres/
day
6
lb
ai/
acre
280
­
Baseline
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
380
Minimum
(
1c)
Mixing/
Loading
Liquids
for
Groundboom
Application
Grapes
80
acres/
day
9.6
lb
ai/
acre
760
­
Baseline
Alfalfa
200
acres/
day
3.2
lb
ai/
acre
910
­
Baseline
Cotton
80
acres/
day
2.2
lb
ai/
acre
­
330
Baseline
Cotton
200
acres/
day
2.2
lb
ai/
acre
­
130
Baseline
(
1d)
Mixing/
Loading
Liquids
for
Rights­
of­
Way
Application
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
3000
­
Baseline
Utility/
industrial
areas
1000
gallons/
day
0.9
lb
ai/
gallon
650
­
Baseline
Utility/
industrial
areas
1000
gallons/
day
0.9
lb
ai/
gallon
­
320
Minimum
(
1e)
Mixing/
Loading
Liquids
for
High­
Pressure
Handwand
Application
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
3000
Not
Applicable
Baseline
Utility/
industrial
areas
1000
gallons/
day
0.9
lb
ai/
gallon
650
Not
Applicable
Baseline
Exposure
Scenario
Crop
Type
or
Target
Acres
Treated
or
Gallons
per
Application
Application
Rate
(
lbs
a.
i./
A)
Inhalation
MOEs
Necessary
Level
of
PPE
or
Engineering
Controls
Short
Term
<
7
days
Intermediate
Term
<
30
days
42
(
2a)
Mixing/
Loading
Dry
Flowables
for
Aerial
Application
Sugarcane
350
acres/
day
6.4
lb
ai/
acre
410
­
Baseline
Alfalfa
1200
acres/
day
3.2
lb
ai/
acre
240
­
Baseline
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
120
Baseline
1200
acres/
day
­
180
Minimum
(
2b)
Mixing/
Loading
Dry
Flowables
for
Chemigation
Application
Sugarcane
350
acres/
day
6.4
lb
ai/
acre
410
­
Baseline
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
120
Baseline
(
2c)
Mixing/
Loading
Dry
Flowables
for
Groundboom
Application
Grapes
80
acres/
day
9.6
lb
ai/
acre
1200
­
Baseline
Alfalfa
1200
acres/
day
3.2
lb
ai/
acre
1400
­
Baseline
Cotton
80
acres/
day
2.2
lb
ai/
acre
­
520
Baseline
1200
acres/
day
­
210
Baseline
(
2d)
Mixing/
Loading
Dry
Flowables
for
Rights­
of­
Way
Sprayer
Application
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
4700
­
Baseline
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
gallon
950
­
Baseline
­
490
Minimum
(
2e)
Mixing/
Loading
Dry
Flowables
for
High­
Pressure
Handwand
Application
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
4700
­
Baseline
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
gallon
950
­
Baseline
Exposure
Scenario
Crop
Type
or
Target
Acres
Treated
or
Gallons
per
Application
Application
Rate
(
lbs
a.
i./
A)
Inhalation
MOEs
Necessary
Level
of
PPE
or
Engineering
Controls
Short
Term
<
7
days
Intermediate
Term
<
30
days
43
(
3a)
Mixing/
Loading
Wettable
Powders
for
Aerial
Application
Sugarcane
350
acres/
day
6.4
lb
ai/
acre
1300
­
Engineering
Controls
Alfalfa
1200
acres/
day
3.2
lb
ai/
acre
760
­
Engineering
Controls
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
380
Engineering
Controls
Cotton
1200
acres/
day
2.2
lb
ai/
acre
­
110
Engineering
Controls
(
3b)
Mixing/
Loading
Wettable
Powders
for
Chemigation
Application
Sugarcane
350
acres/
day
6.4
lb
ai/
acre
1300
­
Engineering
Controls
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
380
Engineering
Controls
(
3c)
Mixing/
Loading
Wettable
Powders
for
Groundboom
Application
Grapes
80
acres/
day
9.6
lb
ai/
acre
110
­
Minimum
Alfalfa
200
acres/
day
3.2
lb
ai/
acre
130
­
Minimum
Cotton
80
acres/
day
2.2
lb
ai/
acre
­
1700
Engineering
Controls
200
acres/
day
2.2
lb
ai/
acre
­
660
Engineering
Controls
(
3d)
Mixing/
Loading
Wettable
Powders
for
Rights­
of­
Way
Sprayer
Application
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
gallon
170
­
Maximum
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
420
­
Minimum
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
gallon
300
Engineering
Controls
Exposure
Scenario
Crop
Type
or
Target
Acres
Treated
or
Gallons
per
Application
Application
Rate
(
lbs
a.
i./
A)
Inhalation
MOEs
Necessary
Level
of
PPE
or
Engineering
Controls
Short
Term
<
7
days
Intermediate
Term
<
30
days
44
(
3e)
Mixing/
Loading
Wettable
Powders
for
High­

Pressure
Handwand
Applications
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
420
­
Minimum
Utility/
Industrial
Areas
0.96
lb
ai/
gallon
170
­
Maximum
(
4)
Loading
Granulars
for
Tractor­
Drawn
Spreaders
Application
Utility/
Industrial
Areas
80
acres/
day
87.1
lb
ai/
acre
300
Not
Applicable
Minimum
Applicator
(
5)
Applying
Sprays
for
Aerial
Application
Sugarcane
350
acres/
day
6.4
lb
ai/
acre
4600
­
Engineering
Controls
Alfalfa
1200
acres/
day
3.2
lb
ai/
acre
2700
­
Engineering
Controls
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
1300
Engineering
Controls
1200
acres/
day
2.2
lb
ai/
acre
­
390
Engineering
Controls
(
6)
Applying
Sprays
for
Groundboom
Application
Grapes
80
acres/
day
9.6
lb
ai/
acre
1200
­
Baseline
Alfalfa
200
acres/
day
3.2
lb
ai/
acre
1500
­
Baseline
Cotton
80
acres/
day
2.2
lb
ai/
acre
­
540
Baseline
200
acres/
day
2.2
lb
ai/
acre
­
210
Baseline
Exposure
Scenario
Crop
Type
or
Target
Acres
Treated
or
Gallons
per
Application
Application
Rate
(
lbs
a.
i./
A)
Inhalation
MOEs
Necessary
Level
of
PPE
or
Engineering
Controls
Short
Term
<
7
days
Intermediate
Term
<
30
days
45
(
7)
Applying
Sprays
for
Rights­
Of­
Way
Grapes
1000
gallons/
day
0.19
lb
ai/
gallon
930
­
Baseline
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
gallon
190
­
Baseline
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
gallon
­
190
Maximum
(
8)
Applying
Sprays
for
High­
Pressure
Handwand
Application
Grapes
1000
gallons/
day
0.19
lb
ai/
acre
230
Not
Applicable
Minimum
Utility/
Industrial
Areas
1000
gallons/
day
0.96
lb
ai/
acre
92
Not
Applicable
Maximum
(
9)
Applying
Granulars
for
Tractor­
Drawn
Spreaders
Application
Utility/
Industrial
Areas
80
acres/
day
87.1
lb
ai/
acre
420
Not
Applicable
Minimum
(
10)
Applying
Granulars
with
a
Spoon
Industrial
Areas
100
sq.
feet/
day
87.1
lb
ai/
acre
78000
Not
Applicable
Baseline
(
11)
Applying
Granulars
for
Hand
Application
Industrial
Areas
100
sq.
feet/
day
87.1
lb
ai/
acre
740
Not
Applicable
Baseline
Flagger
(
12)
Flagging
for
Sprays
Application
Sugarcane
350
acres/
day
6.4
lb
ai/
acre
890
­
Baseline
Cotton
350
acres/
day
2.2
lb
ai/
acre
­
260
Baseline
Mixer/
Loader/
Applicator
(
13)
Mixing/
Loading/
Applying
Liquids
for
Low
Pressure
Handwand
Application
Industrial
Areas
40
gallons/
day
0.9
lb
ai/
gallon
650
Not
Applicable
Baseline
(
14)
Mixing/
Loading/
Applying
Liquids
for
Backpack
Sprayer
Application
Industrial
Areas
40
gallons/
day
0.9
lb
ai/
gallon
650
Not
Applicable
Baseline
(
15)
Mixing/
Loading/
Applying
Wettable
Powders
For
Low
Pressure
Handwand
Application
Industrial
Areas
40
gallons/
day
0.96
lb
ai/
gallon
170
Not
Applicable
Maximum
Exposure
Scenario
Crop
Type
or
Target
Acres
Treated
or
Gallons
per
Application
Application
Rate
(
lbs
a.
i./
A)
Inhalation
MOEs
Necessary
Level
of
PPE
or
Engineering
Controls
Short
Term
<
7
days
Intermediate
Term
<
30
days
46
(
16)
Loading/
Applying
Granulars
with
a
Pump
Feed
Granular
Spreader
Industrial
Areas
5
acres/
day
87.1
lb
ai/
acre
380
Not
Applicable
Baseline
(
17)
Loading/
Applying
Granulars
with
Gravity
Feed
Backpack
Spreader
Industrial
Areas
5
acres/
day
87.1
lb
ai/
acre
180
Not
Applicable
Minimum
(
18)
Loading/
Applying
Granulars
for
Belly
Grinder
Application
Industrial
Areas
1
acres/
day
87.1
lb
ai/
acre
130
Not
Applicable
Baseline
(
19)
Loading/
Applying
Granulars
for
Push­
type
Spreader
Application
Industrial
Areas
5
acres/
day
87.1
lb
ai/
acre
210
Not
Applicable
Baseline
a
Crops
named
are
index
crops
which
are
chosen
to
represent
all
other
crops
at
or
near
that
application
rate
for
that
use.

See
the
application
rates
listing
in
the
use
summary
section
of
this
document
for
further
information
on
application
rates
used
in
this
assessment.

b
Application
rates
are
based
on
the
maximum
application
rates
listed
on
the
marketed
diuron
labels
c
Amount
handled
per
day
from
Science
Advisory
Council
on
Exposure's
Policy
#
9.1
d
Short­
term
MOE
=
Short­
term
NOAEL
(
mg/
kg/
day)
/
Daily
Inhalation
Dose
(
mg/
kg/
day)

e
Baseline:
long
pants,
long­
sleeved
shirt
shoes
and
socks
(
no
respirator)

f
Minimum
PPE:
baseline
plus
dust
mist
respirator
g
Maximum
PPE:
baseline
plus
organic
vapor
respirator
h
Engineering
controls:
closed
mixing/
loading,
enclosed
cab,
truck,
or
cockpit.

See
the
appendix,
Tables
A,
B,
C,
and
D
for
the
inputs
and
dermal
and
inhalation
does
calculations.

­
Scenario's
calculated
MOE
exceeds
the
target
MOE
at
the
previous
level
of
mitigation.

(
MOE
>
100),
NF
=
Not
feasible
for
this
scenario
(
no
available
engineering
controls).
47
d.
Agricultural
Handler
Cancer
Risk
Cancer
risk
estimates
are
presented
as
a
probability
of
developing
cancer.
The
cancer
handler
exposure
scenarios
are
identical
to
those
assessed
in
the
noncancer
handler
assessment.
However,
it
should
be
noted
that
the
cancer
assessment
assumes
4
percent
dermal
absorption
since
exposures
may
be
of
duration
longer
than
six
months.
A
28­
day
dermal
toxicity
study
showed
no
adverse
effects
from
diuron
up
to
the
limit
dose
of
1200
mg/
kg/
day.
To
assess
cancer
risk,
a
total
daily
dose,
a
lifetime
daily
dose
and
a
total
cancer
risk
are
calculated.
The
total
daily
dose
is
calculated
to
include
both
dermal
and
inhalation
exposure
(
dermal
dose
includes
dermal
absorption
since
an
oral
cancer
endpoint
was
used)
and
used
a
Q
1*=
1.91
x
10­
2
(
mg/
kg/
day)­
1
in
human
equivalents.
For
occupational
risks
between
1x10­
6
and
1x10­
4,
the
Agency
will
pursue
risk
mitigation
where
feasible
and
cost
effective
to
reduce
the
risks
to
1x10­
6
or
less.

The
assessment
assumed
that
the
average
lifetime
is
70
years,
exposure
duration
is
35
years,
and
that
the
exposures
per
year
are:
10
days
per
year
for
the
private
grower
and
30
days
per
year
for
a
commercial
applicator.
Maximum
application
rates
were
used
in
the
private
grower
assessment.
Typical
application
rates
were
used
in
both
the
private
grower
and
commercial
applicator
assessments.
It
was
assumed
that
as
the
frequency
of
exposure
increased,
the
probability
of
being
exposed
to
a
maximum
application
rate
would
decrease.
Therefore,
maximum
application
rates
were
not
assessed
for
the
commercial
applicator.
Tables
16
and
17
summarize
the
cancer
risks
associated
with
the
handling
of
diuron
for
the
baseline,
maximum
PPE
and
engineering
control
level
of
mitigation
for
commercial
and
private
farmers,
respectively.
In
general,
the
Agency
is
concerned
when
occupational
cancer
risk
estimates
exceed
1
x
10­
4.
The
Agency
will
seek
ways
to
mitigate
the
risks,
to
the
extent
that
it
is
practical
and
economically
feasible,
to
lower
the
risks
to
1
x
10­
6
or
less.

Five
of
the
assessed
scenarios
have
cancer
risks
greater
than
1
x
10­
4
at
the
highest
feasible
level
of
mitigation
(
private
farmer/
commercial
applicator,
typical/
max
rate)
and
are
of
concern.
Twenty­
six
of
the
scenarios
have
cancer
risks
between
1
x
10­
4
and
1
x
10­
6
at
the
highest
feasible
level
of
mitigation
(
private
farmer/
commercial
applicator,
typical/
max
rate).

Table
16.
Diuron:
Summary
of
Occupational
Handler
Cancer
Risks
for
Commercial
Applicators
Diuron:
Occupational
Handler
Cancer
Risk
Estimates
Commercial
Applicator/
30
Exposures
Per
Year/
Typical
Application
Rate
Exposure
Scenario
Cancer
Risk
Baseline
(
single
layer)
Cancer
Risk
(
double
layer
+
gloves
+
half­
face
respirator
w/
P
95
filter)
Cancer
Risk
Engineering
Controls
Mixer/
Loader
(
1a)
Mixing/
Loading
Liquids
for
Aerial
Application
1.8
E­
3
­
3.9
E­
3
1.3
E­
5
­
2.7
E­
5
6.7
E­
6
­
1.4
E­
5
(
1b)
Mixing/
Loading
Liquids
for
Chemigation
Application
1.8
E­
3
1.3
E­
5
6.7
E­
6
Diuron:
Occupational
Handler
Cancer
Risk
Estimates
Commercial
Applicator/
30
Exposures
Per
Year/
Typical
Application
Rate
Exposure
Scenario
Cancer
Risk
Baseline
(
single
layer)
Cancer
Risk
(
double
layer
+
gloves
+
half­
face
respirator
w/
P
95
filter)
Cancer
Risk
Engineering
Controls
48
(
1c)
Mixing/
Loading
Liquids
for
Groundboom
Application
4.2
E­
4
­
6.6
E­
4
2.9
E­
6
­
4.5
E­
6
1.5
E­
6
­
2.4
E­
6
(
1d)
Mixing/
Loading
Liquids
for
Rights­
of­
Way
Application
8.4
E­
5
­
1.2
E­
3
5.7
E­
7
­
8.1
E­
6
3.1
E­
7
­
4.3
E­
6
(
1e)
Mixing/
Loading
Liquids
for
High­
Pressure
Handwand
Application
8.4
E­
5
­
1.2
E­
3
5.7
E­
7
­
8.1
E­
6
3.1
E­
7
­
4.3
E­
6
(
2a)
Mixing/
Loading
Dry
Flowable
for
Aerial
Application
5.4
E­
5
­
1.2
E­
4
3.1
E­
5
­
6.6
E­
5
1.1
E­
6
­
2.3
E­
6
(
2b)
Mixing/
Loading
Dry
Flowable
for
Chemigation
Application
5.4
E­
5
3.1
E­
5
1.1
E­
6
(
2c)
Mixing/
Loading
Dry
Flowable
for
Groundboom
Application
1.2
E­
5
­
1.9
E­
5
7.0
E­
6
­
1.1
E­
5
2.4
E­
7
­
3.8
E­
7
(
2d)
Mixing/
Loading
Dry
Flowable
for
Rights­
of­
Way
Sprayer
Application
2.5
E­
6
­
3.7
E­
5
1.4
E­
6
­
2.1
E­
5
4.8
E­
8
­
7.2
E­
7
(
2e)
Mixing/
Loading
Dry
Flowable
for
High­
Pressure
Handwand
Application
2.5
E­
6
­
3.7
E­
5
1.4
E­
6
­
2.1
E­
5
4.8
E­
8
­
7.2
E­
7
(
3a)
Mixing/
Loading
Wettable
Powders
for
Aerial
Application
3.0
E­
3
­
6.4
E­
3
1.5
E­
4
­
3.2
E­
4
9.9
E­
6
­
2.1
E­
5
(
3b)
Mixing
/
Loading
of
Wettable
Powders
for
Chemigation
Application
3.0
E­
3
1.5
E­
4
9.9
E­
6
(
3c)
Mixing/
Loading
of
Wettable
Powders
for
Groundboom
Application
6.9
E­
4
­
1.1
E­
3
3.4
E­
5
­
5.3
E­
5
2.3
E­
6
­
3.5
E­
6
(
3d)
Mixing/
Loading
Wettable
Powders
for
Rights­
of­
Way
Sprayer
Application
1.4
E­
4
­
2.1
E­
3
6.8
E­
6
­
1.0
E­
4
4.5
E­
7
­
6.8
E­
6
(
3e)
Mixing/
Loading
Wettable
Powders
for
High­
Pressure
Handwand
Application
1.4
E­
4
­
2.1
E­
3
6.8
E­
6
­
1.0
E­
4
4.5
E­
7
­
6.8
E­
6
(
4)
Loading
Granular
Formulation
For
Tractor­
Drawn
Spreader
Application
1.6
E­
4
2.4
E­
5
3.2
E­
6
Applicator
(
5)
Applying
Sprays
Aerially
See
Engineering
Controls
See
Engineering
Controls
4.2
E­
6
­
9.0
E­
6
(
6)
Applying
Sprays
with
Groundboom
4.7
E­
6
­
7.3
E­
6
1.8
E­
6
­
2.9
E­
6
8.7
E­
7
­
1.4
E­
6
(
7)
Applying
with
a
Rights­
of­
Way
Sprayer
4.0
E­
5
­
6.0
E­
4
8.6
E­
6
­
1.3
E­
4
NF
(
8)
Applying
with
a
High­
Pressure
Handwand
1.1
E­
4
­
1.6
E­
3
1.6
E­
5
­
2.4
E­
4
NF
(
9)
Applying
Granular
Formulations
with
a
Tractor­
Drawn
Spreader
1.3
E­
4
2.3
E­
5
2.4
E­
5
(
10)
Applying
Granulars
with
a
Spoon
2.8
E­
7
2.0
E­
7
NF
(
11)
Applying
Granulars
by
Hand
7.4
E­
5
3.7
E­
5
NF
Flagger
Diuron:
Occupational
Handler
Cancer
Risk
Estimates
Commercial
Applicator/
30
Exposures
Per
Year/
Typical
Application
Rate
Exposure
Scenario
Cancer
Risk
Baseline
(
single
layer)
Cancer
Risk
(
double
layer
+
gloves
+
half­
face
respirator
w/
P
95
filter)
Cancer
Risk
Engineering
Controls
49
(
12)
Flagging
for
Spray
Application
1.2
E­
5
6.8
E­
6
2.5
E­
7
Mixer/
Loader/
Applicator
(
13)
Mixing/
Loading/
Applying
Liquids
using
Low
Pressure
Handwand
1.6
E­
3
7.2
E­
6
NF
(
14)
Mixing/
Loading/
Applying
Liquids
using
Backpack
Sprayer
5.3
E­
5
2.7
E­
5
NF
(
15)
Mixing/
Loading/
Applying
Wettable
Powder
Formulations
using
Low
Pressure
Handwand
6.2
E­
4
1.5
E­
4
NF
(
16)
Loading/
Applying
Granulars
using
a
Pump
Feed
Backpack
Spreader
4.0
E­
5
2.4
E­
5
NF
(
17)
Loading/
Applying
Granulars
using
a
Gravity
Feed
Backpack
Spreader
3.3
E­
4
1.6
E­
4
NF
(
18)
Loading/
Applying
Granulars
with
a
Belly
Grinder
4.5
E­
4
3.1
E­
4
NF
(
19)
Loading/
Applying
Granules
using
a
Push­
type
Spreader
1.1
E­
4
1.7
E­
5
NF
NF
=
Not
feasible
50
Table
17.
Diuron:
Summary
of
Occupational
Handler
Cancer
Risks
for
Private
Farmer
Diuron:
Handler
Risk
Estimates
for
Cancer
Private
Farmer/
10
Exposures
Per
Year
Exposure
Scenario
Typical
Application
Rate
Maximum
Application
Rate
Cancer
Risk
Baseline
(
i.
e.,

single
layer)
Cancer
Risk
(
double
layer
+

gloves
+
respirator)
Cancer
Risk
Engineering
Controls
Cancer
Risk
Baseline
(
i.
e.,

single
layer)
Cancer
Risk
(
double
layer
+

gloves
+
respirator)
Cancer
Risk
Engineering
Controls
Mixer
/
Loader
(
1a)
Mixing/
Loading
Liquids
for
Aerial
Application
6.1
E­
4
­
1.3
E­
3
4.2
E­
6
­
9.0
E­
6
2.2
E­
6
­
4.8
E­
6
9.2
E­
4
­
1.7
E­
3
6.3
E­
6
­
1.2
E­
5
6.1
E­
6
­
3.4
E­
6
(
1b)
Mixing/
Loading
Liquids
for
Chemigation
Application
6.1
E­
4
4.2
E­
6
2.2
E­
6
9.2
E­
4
6.3
E­
6
3.4
E­
6
(
1c)
Mixing/
Loading
Liquids
for
Groundboom
Application
1.4
E­
4
­
2.2
E­
4
9.6
E­
7
­
1.5
E­
6
5.1
E­
7
­
8.0
E­
7
2.8
E­
4
­
3.4
E­
4
1.9
E­
6
­
2.3
E­
6
1.0
E­
6
­
1.2
E­
6
(
1d)
Mixing/
Loading
Liquids
for
Rights­
of­
Way
Application
2.8
E­
5
­
3.9
E­
4
1.9
E­
7
­
2.7
E­
6
1.0
E­
7
­
1.4
E­
6
8.4
E­
5
­
3.9
E­
4
5.7
E­
7
­
2.7
E­
6
3.1
E­
7
­
1.4
E­
6
(
1e)
Mixing/
Loading
Liquids
for
High­
Pressure
Handwand
Application
2.8
E­
5
­
3.9
E­
4
1.9
E­
7
­
2.7
E­
6
1.0
E­
7
­
1.4
E­
6
8.4
E­
5
­
3.9
E­
4
5.7
E­
7
­
2.7
E­
6
3.1
E­
7
­
1.4
E­
6
(
2a)
Mixing/
Loading
Dry
Flowable
for
Aerial
Application
1.8
E­
5
­
3.8
E­
5
1.0
E­
5
­
2.2
E­
5
3.5
E­
7
­
7.5
E­
7
2.9
E­
5
­
4.9
E­
5
1.6
E­
5
­
2.8
E­
5
5.6
E­
7
­
9.6
E­
7
(
2b)
Mixing/
Loading
Dry
Flowable
for
Chemigation
Application
1.8
E­
5
1.0
E­
5
3.5
E­
7
2.9
E­
5
1.6
E­
5
5.6
E­
7
(
2c)
Mixing/
Loading
Dry
Flowable
for
Groundboom
Application
4.1
E­
6
­
6.4
E­
6
2.3
E­
6
­
3.7
E­
6
8.0
E­
8
­
1.3
E­
7
8.2
E­
6
­
9.8
E­
6
4.7
E­
6
­
5.6
E­
6
1.3
E­
7
­
1.9
E­
7
(
2d)
Mixing/
Loading
Dry
Flowable
for
Rights­
of­

Way
Sprayer
Application
8.2
E­
7
­
1.2
E­
5
4.7
E­
7
­
7.0
E­
6
1.6
E­
8
­
2.4
E­
7
2.5
E­
6
­
1.2
E­
5
1.4
E­
6
­
7.0
E­
6
4.8
E­
8
­
2.4
E­
7
(
2e)
Mixing/
Loading
Dry
Flowable
for
High­

Pressure
Handwand
Application
8.2
E­
7
­
1.2
E­
5
4.7
E­
7
­
7.0
E­
6
1.6
E­
8
­
2.4
E­
7
2.5
E­
6
­
1.2
E­
5
1.4
E­
6
­
7.0
E­
6
4.8
E­
8
­
2.4
E­
7
Diuron:
Handler
Risk
Estimates
for
Cancer
Private
Farmer/
10
Exposures
Per
Year
Exposure
Scenario
Typical
Application
Rate
Maximum
Application
Rate
Cancer
Risk
Baseline
(
i.
e.,

single
layer)
Cancer
Risk
(
double
layer
+

gloves
+
respirator)
Cancer
Risk
Engineering
Controls
Cancer
Risk
Baseline
(
i.
e.,

single
layer)
Cancer
Risk
(
double
layer
+

gloves
+
respirator)
Cancer
Risk
Engineering
Controls
51
(
3a)
Mixing/
Loading
Wettable
Powders
for
Aerial
Application
10.0
E­
4
­
2.1
E­
3
5.0
E­
5
­
1.1
E­
4
3.3
E­
6
­
7.1
E­
6
1.6
E­
3
­
2.7
E­
3
8.0
E­
5
­
1.4
E­
4
5.3
E­
6
­
9.1
E­
6
(
3b)
Mixing
/
Loading
of
Wettable
Powders
for
Chemigation
Application
1.0
E­
3
5.0
E­
5
3.3
E­
6
1.6
E­
3
8.0
E­
5
5.3
E­
6
(
3c)
Mixing/
Loading
of
Wettable
Powders
for
Groundboom
Application
2.3
E­
4
­
3.6
E­
4
1.1
E­
5
­
1.8
E­
5
7.6
E­
7
­
1.2
E­
6
4.6
E­
4
­
5.5
E­
4
2.3
E­
5
­
2.7
E­
5
1.5
E­
6
­
1.8
E­
6
(
3d)
Mixing/
Loading
Wettable
Powders
for
Rights­
of­
Way
Sprayer
Application
4.6
E­
5
­
6.9
E­
4
2.3
E­
6
­
3.4
E­
5
1.5
E­
7
­
2.3
E­
6
1.4
E­
4
­
6.9
E­
4
6.8
E­
6
­
3.4
E­
5
4.5
E­
7
­
2.3
E­
6
(
3e)
Mixing/
Loading
Wettable
Powders
for
High­

Pressure
Handwand
Application
4.6
E­
5
­
6.9
E­
4
2.3
E­
6
­
3.4
E­
5
1.5
E­
7
­
2.3
E­
6
1.4
E­
4
­
6.9
E­
4
6.8
E­
6
­
3.4
E­
5
4.5
E­
7
­
2.3
E­
6
(
4)
Loading
Granular
Formulation
For
Tractor­

Drawn
Spreader
Application
5.3
E­
5
8.0
E­
6
1.1
E­
6
5.3
E­
5
8.0
E­
6
1.1
E­
6
Applicator
(
5)
Applying
Sprays
Aerially
See
Engineering
Controls
See
Engineering
Controls
1.4
E­
6
­
3.0
E­
6
See
Engineering
Controls
See
Engineering
Controls
2.2
E­
6
­
3.9
E­
6
(
6)
Applying
Sprays
with
Groundboom
1.6
E­
6
­
2.4
E­
6
6.2
E­
7
­
9.6
E­
7
2.9
E­
7
­
4.5
E­
7
3.1
E­
6
­
3.7
E­
6
1.2
E­
6
­
1.5
E­
6
5.8
E­
7
­
7.0
E­
7
(
7)
Applying
with
a
Rights­
of­
Way
Sprayer
1.3
E­
5
­
2.0
E­
4
2.9
E­
6
­
4.3
E­
5
NF
4.0
E­
5
­
2.0
E­
4
8.6
E­
6
­
4.3
E­
5
NF
(
8)
Applying
with
a
High­
Pressure
Handwand
3.6
E­
5
­
5.4
E­
4
5.3
E­
6
­
8.0
E­
5
NF
1.1
E­
4
­
5.2
E­
4
1.6
E­
5
­
8.0
E­
5
NF
(
9)
Applying
Granular
Formulations
with
a
Tractor­
Drawn
Spreader
4.2
E­
5
7.5
E­
6
7.9
E­
6
4.2
E­
5
7.5
E­
6
7.9
E­
6
(
10)
Applying
Granulars
with
a
Spoon
9.3
E­
8
2.0
E­
7
NF
9.3
E­
8
2.0
E­
7
NF
(
11)
Applying
Granulars
by
Hand
2.5
E­
5
1.2
E­
5
NF
2.5
E­
5
1.2
E­
5
NF
Diuron:
Handler
Risk
Estimates
for
Cancer
Private
Farmer/
10
Exposures
Per
Year
Exposure
Scenario
Typical
Application
Rate
Maximum
Application
Rate
Cancer
Risk
Baseline
(
i.
e.,

single
layer)
Cancer
Risk
(
double
layer
+

gloves
+
respirator)
Cancer
Risk
Engineering
Controls
Cancer
Risk
Baseline
(
i.
e.,

single
layer)
Cancer
Risk
(
double
layer
+

gloves
+
respirator)
Cancer
Risk
Engineering
Controls
52
Flagger
(
12)
Flagging
for
Spray
Application
4.1
E­
6
2.3
E­
6
8.3
E­
8
6.6
E­
6
3.6
E­
6
1.3
E­
7
Mixer/
Loader/
Applicator
(
13)
Mixing/
Loading/
Applying
Liquids
using
Low
Pressure
Handwand
5.4
E­
4
2.4
E­
6
NF
5.4
E­
4
2.4
E­
6
NF
(
14)
Mixing/
Loading/
Applying
Liquids
using
Backpack
Sprayer
1.8
E­
5
9.0
E­
6
NF
1.8
E­
5
9.0
E­
6
NF
(
15)
Mixing/
Loading/
Applying
Wettable
Powder
Formulations
using
Low
Pressure
Handwand
2.1
E­
4
5.1
E­
5
NF
2.1
E­
4
5.1
E­
5
NF
(
16)
Loading/
Applying
Granulars
using
a
Pump
Feed
Backpack
Spreader
1.3
E­
5
7.8
E­
6
NF
1.3
E­
5
7.8
E­
6
NF
(
17)
Loading/
Applying
Granulars
using
a
Gravity
Feed
Backpack
Spreader
1.1
E­
4
5.4
E­
5
NF
1.1
E­
4
5.4
E­
5
NF
(
18)
Loading/
Applying
Granulars
with
a
Belly
Grinder
1.5
E­
4
7.6
E­
5
NF
1.5
E­
4
7.6
E­
5
NF
(
19)
Loading/
Applying
Granules
using
a
Push­
type
Spreader
3.5
E­
5
5.5
E­
6
NF
3.5
E­
5
5.5
E­
6
NF
NF
=
Not
feasible
53
e.
Handler
Exposure
from
Antimicrobial
Use:
Mildewcide
in
Paints,
Stains,
Solvents,
Adhesives,
and
Coatings
Diuron
is
used
as
a
mildewcide
in
paints,
solvents,
adhesives,
stains,
polymer
latices,
plaster,
stuccos,
sealants,
caulking,
fillers,
and
coatings.
These
products
are
formulated
as
a
flowable
concentrate,
a
tablet,
an
emulsifiable
concentrate,
and
a
paste
form.
These
pesticide
products
are
incorporated
into
paint
at
0.20
to
2.5
percent
during
the
initial
phase
of
the
manufacturing
process.

For
the
antimicrobial
use
of
diuron,
EPA
considers
both
"
primary"
and
"
secondary"
handler
exposure.
The
primary
handlers
are
defined
as
those
individuals
exposed
to
the
formulated
product
(
i.
e.,
adding
the
diuron
product
into
vats
of
paint
during
its
manufacturing).
The
secondary
handlers
are
defined
as
those
individuals
exposed
to
the
active
ingredient
as
a
direct
result
of
its
incorporation
into
an
end
use
product
(
i.
e.,
individuals
using
the
caulk
or
paint
that
in
itself
is
not
a
registered
product).
The
Agency
has
identified
and
assessed
the
primary
handlers
as
those
individuals
who
mix
and
load
diuron
formulation
at
the
manufacturing
facility
for
use
as
a
mildewcide
in
adhesives,
caulks,
sealants,
and
paints.
The
secondary
handlers
are
commercial
applicators
who
apply
adhesives,
caulks,
sealants,
and
paints.

No
handler
exposure
data
have
been
submitted
to
determine
the
extent
of
these
exposures.
The
Agency
assessed
the
risks
to
the
primary
handlers
using
the
dermal
and
inhalation
exposure
data
for
loading
liquids
and
tablet
formulations
from
the
proprietary
Chemical
Manufacturers
Association
(
CMA)
antimicrobial
exposure
study.
No
unit
exposure
data
exists
to
assess
the
mixing
and
loading
of
the
paste
formulation
into
paint.
It
is
assumed
that
this
exposure
would
be
similar
to
mixing
and
loading
liquids
into
paint
products.
Two
primary
handler
exposure
scenarios
have
been
identified
and
include:

(
1)
Mixing/
Loading
liquids
(
2)
Mixing/
loading
tablets
In
addition
to
the
primary
handlers,
secondary
handlers
are
assessed
using
an
airless
sprayer
and
a
paint
brush.
Unit
exposure
data
used
to
assess
the
exposure
resulting
from
applying
paint
containing
diuron
with
an
airless
sprayer
and
a
paintbrush
were
taken
from
a
previous
chlorothalonil
risk
assessment.
These
data
were
merged
with
data
contained
in
PHED
to
increase
the
number
of
replicates
and
the
quality
of
the
unit
exposure
data.
The
surrogate
data
are
assumed
to
be
representative
of
the
exposure
from
the
use
of
diuron
using
the
same
equipment,
since
the
two
chemicals
are
formulated
together
in
three
out
of
the
four
currently
registered
diuron
paint
products.
The
clothing
and
PPE
scenarios
for
each
type
of
exposure
reflect
the
clothing
and
PPE
worn
in
the
study
from
which
the
unit
exposure
values
were
derived.
Although
there
is
potential
exposure
during
the
application
of
the
other
treated
materials
(
e.
g.,
caulks
and
sealants),
they
are
not
included
because
no
data
are
available
to
assess
the
uses.
Although
it
is
reasonable
to
assume
that
the
exposure
from
these
uses
would
be
no
greater
than
the
exposure
from
use
of
diuron­
treated
paints.
There
is
also
potential
for
exposure
from
applying
paint
with
a
54
roller.
The
Agency
believes
that
the
airless
sprayer
and
paintbrush
scenarios
represent
the
high
end
exposures
for
diuron
antimicrobial
secondary
uses.
Two
secondary
handler
exposure
scenarios
have
been
identified
and
include:

(
3)
Applying
paints
with
an
airless
sprayer,
and
(
4)
Applying
paints
with
a
paint
brush.

Assumptions
for
the
Antimicrobial
Assessment:

The
following
additional
assumptions
were
used
in
this
assessment:

°
Application
rates
­
The
concentration
of
diuron
is
in
the
paint,
caulking,
and
other
products
is
0.2
to
2.5
percent.
The
maximum
amount
of
diuron
per
gallon
of
paint
is
0.0532
lbs
ai/
gallon
paint.

°
Amount
handled
­
The
amount
of
general
preservatives
treated
per
day
is
100
to
1000
gallons
for
treated
paint.
The
amount
of
paint
used
in
the
secondary
exposure
scenarios
is
50
gallons
for
commercial
airless
sprayers
and
five
gallons
of
paint
for
commercial
painters
using
paint
brushes/
rollers.

°
CMA
exposure
data
­
The
CMA
data
for
liquid
products
are
based
on
transferring
liquids
from
large
containers
to
smaller
containers
for
measuring
and
pouring.
These
products
were
applied
from
five
to
78
minutes
per
application
during
metal
cutting
operations.
Gloves
were
worn
for
all
eight
of
the
replicates.
The
CMA
data
for
solid
place
(
tablets,
water
soluble
packets)
had
only
one
replicate
for
tablets.
Again,
the
data
used
the
metal
fluid
from
a
metal
cutting
operation.
The
tableted
solid
place
data
is
considered
low
quality
since
there
is
only
one
replicate.
No
other
data
on
adding
tablets
to
paint
or
during
other
anti­
microbial
uses
exists.

°
In
addition
to
diuron's
mildewcide
use
in
paints
and
stains,
it
is
also
used
in
plaster,
stuccos,
sealants,
caulking,
and
fillers.
Unit
exposure
data
only
exist
for
the
use
of
paints/
stains
with
airless
sprayer
and
paintbrush.
These
exposure
scenarios
are
assumed
to
have
a
higher
exposure
than
use
of
diuron
in
plaster,
stucco,
sealants,
caulking
and
fillers,
since
less
material
would
be
applied
in
a
day.
Therefore,
the
paint/
stain
assessment
will
also
be
considered
an
estimate
of
the
exposure
resulting
from
the
use
of
diuron
in
plaster,
stucco,
sealants,
caulking,
and
fillers.

°
Exposure
frequency
­
The
industrial
and
commercial
painter
exposure
scenarios
are
believed
to
have
a
short
(
one
to
30
days)
and
intermediate­
term
(
one
month
to
180
days)
exposure
duration.
It
is
assumed
that
diuron
would
only
be
mixed
into
paint
every
other
week,
five
days
a
week.
This
type
of
intermittent
exposure
frequency
is
not
considered
a
chronic
exposure
scenario
(
greater
then
180
days)
because
diuron
is
not
believed
to
be
used
continuously
for
at
least
180
days
and
urinary
and
fecal
excretion
of
diuron
is
nearly
55
complete
within
24
hours
at
low­
dose
groups(
10
mg/
kg/
day)
and
within
48
hours
within
high­
dose
groups
(
400
mg/
kg/
day)
in
the
rat
metabolism
study.

°
For
the
cancer
risk
assessment,
workers
handling
diuron
in
the
industrial
setting
(
mixing
diuron
into
paints)
are
assumed
to
be
exposed
to
diuron
in
paints
125
days
per
year
(
50
weeks
worked/
year
x
0.5
"
every
other
week"
x
5
days/
week)
and
commercial
painters
applying
diuron
treated
paint
are
assumed
to
be
exposed
50
days
per
year
(
only
in
paints
needing
mildewcide
and
less
than
one
percent
of
all
paint
is
treated
with
diuron).

f.
Handler
Risk
from
Antimicrobial
Use:
Mildewcide
in
Paints,
Stains,
Solvents,
Adhesives,
and
Coatings
The
following
scenarios
have
cancer
risks
between
1
x
10­
4
and
1
x
10­
6
at
the
assessed
level
of
mitigation:

°
Mixing/
loading
of
liquids
into
paint
products;

°
Loading
of
tablets
into
paint
products;

°
Applying
paints
with
an
airless
sprayer;
and
°
Applying
paints
with
a
paint
brush.

Usage
information
gathered
subsequent
to
the
risk
assessment
indicates
that
less
than
1%
of
all
paint
contains
diuron.
All
scenarios
were
assessed
at
the
maximum
rate
of
application.
Because
conservative
assumptions
were
used
to
develop
this
assessment
and
it
is
unlikely
that
paint
containing
diuron
would
be
applied
for
35
years.
Because
the
Agency
believes
a
35­
year
exposure
to
diuron­
treated
paint
is
unlikely
and
believes
the
risks
to
workers
applying
paints
with
an
airless
sprayer
is
not
of
concern.
Tables
18
and
19
summarize
the
non­
cancer
and
cancer
risks,
respectively
from
the
antimicrobial
use
of
diuron.
56
Table
18.
Non­
Cancer
Risks
from
Short­
and
Intermediate­
term
Antimicrobial
Uses
of
Diuron
Exposure
Scenario
(
Scenario
#)
Clothing
Attire
Inhalation
Unit
Exposure
(

g/
lb
ai)
a
Max
Application
Rateb
(
lb
ai/
gal)
Amount
Treatedc
Short­
term
Inhalation
MOEd,
e
Intermediate.­
term
Inhalation
MOEd,
e
Primary
Handlers
(
1)
Mixing/
loadin
g
of
Liquids
into
Paint
Products
Open
pour,
long
pants,
long­
sleeved
shirt,
chemical
resistant
gloves,
and
a
5­
fold
PF
dust/
mist
type
respirator
1.7
0.0532
100
gal
77000
7700
1,000
gal
7700
770
(
2)
Loading
of
Tablets
into
Paint
Products
11.8
0.0532
100
gallons
11000
1100
1,000
gal
1100
110
Secondary
Handlers
(
3)
Applying
Paints
with
an
Airless
Sprayer
Indoor
Long
pants,
long
sleeved
shirt,
and
a
5­
fold
PF
dust/
mist
type
respirator
470
0.0532
50
gallons
560
56
Long
pants,
long
sleeved
shirt,
gloves,
and
a
5­
fold
PF
dust/
mist
type
respirator
470
560
56
Outdoor
Long
pants,
long
sleeved
shirt,
and
a
5­
fold
PF
dust/
mist
type
respirator
86.6
0.0532
50
gallons
3000
300
Long
pants,
long
sleeved
shirt,
gloves,
and
a
5­
fold
PF
dust/
mist
type
respirator
86.6
3000
300
(
4)
Applying
Paints
with
a
Paint
Brush
Long
pants,
long
sleeved
shirt,
and
a
5­
fold
PF
dust/
mist
type
respirator
101
0.0532
5
gallons
26000
2600
Footnotes:
a
Inhalation
unit
exposures
are
from
CMA
and
Chlorothalonil
studies.
b
Application
rates
are
based
on
diuron
paint
labels
c
Amount
treated
is
based
on
assumptions
from
EPA's
Antimicrobial
Division
and
HED
Expo
SAC
Policy
#
9.1.9
d
Inhalation
dose
(
mg/
kg/
day)
=
[
unit
exposure
(

g/
lb
ai)
*
0.001
mg/

g
unit
conversion
*
max
appl
rate
(
lb
ai/
gal)
*
gallons
handled]
/
Body
weight
(
70
kg).
e
MOE
=
NOAEL
(
mg/
kg/
day)
/
Daily
Dose
[
Short­
term
inhalation
NOAEL=
10
mg/
kg/
day,
Intermediate­
term
inhalation
NOAEL
=
1.0
mg/
kg/
day].
Target
MOE
is
100
for
occupational/
commercial.
57
Table
19.
Diuron
Cancer
Assessment
for
Antimicrobial
Uses
Exposure
Scenario
Clothing
Maximum
Application
Ratea
(
lb
ai/
gal)
Amount
Treatedb
Total
Absorbed
Dose
(
mg/
kg/
day)
c
LADD
(
mg/
kg/
day)
d
Riske
Primary
Handlers
(
125
day/
year)

(
1)
Mixing/
loading
of
Liquids
into
Paint
Products
Open
pour,
long
pants,
long­
sleeved
shirt,
chemical
resistant
gloves,
and
a
5­
fold
PF
dust/
mist
type
respirator
0.0532
100
gal
6.9
E­
4
1.2
E­
4
2.3
E­
6
1,000
gal
6.9
E­
3
1.2
E­
3
2.3
E­
5
(
2)
Loading
of
Tablets
into
Paint
Products
0.0532
100
gallons
2.1
E­
3
3.7
E­
4
7.0
E­
6
1,000
gallons
2.1
E­
2
3.7
E­
3
7.0
E­
5
Secondary
Handlers
(
50
day/
year)

(
3)
Applying
Paints
with
an
Airless
Sprayer
Indoor
Long
pants,
long
sleeved
shirt,
and
a
5­
fold
PF
dust/
mist
type
respirator
0.0532
50
gallons
7.3
E­
2
5.0
E­
3
9.5
E­
5
Long
pants,
long
sleeved
shirt,
gloves,
and
a
5­
fold
PF
dust/
mist
type
respirator
3.6
E­
2
2.5
E­
3
4.7
E­
5
Outdoor
Long
pants,
long
sleeved
shirt,
and
a
5­
fold
PF
dust/
mist
type
respirator
0.0532
50
gallons
5.4
E­
2
3.7
E­
3
7.1
E­
5
Long
pants,
long
sleeved
shirt,
gloves,
and
a
5­
fold
PF
dust/
mist
type
respirator
1.7
E­
2
1.1
E­
3
2.2
E­
5
Exposure
Scenario
Clothing
Maximum
Application
Ratea
(
lb
ai/
gal)
Amount
Treatedb
Total
Absorbed
Dose
(
mg/
kg/
day)
c
LADD
(
mg/
kg/
day)
d
Riske
58
(
4)
Applying
Paints
with
a
Paint
Brush
Long
pants,
long
sleeved
shirt,
and
a
5­
fold
PF
dust/
mist
type
respirator
0.0532
5
gallons
4.4
E­
2
3.0
E­
3
5.8
E­
5
a
Application
rates
are
based
on
diuron
paint
labels
b
Amount
treated
is
based
on
assumptions
from
EPA's
Antimicrobial
Division
and
HED
Expo
SAC
Policy
#
9.1.9
c
Total
daily
absorbed
dose
(
mg/
kg/
day)
=
[(
dermal
dose
(
mg/
lb
ai)
*
dermal
absorption
(
4%)+
inhalation
dose
(
mg/
lb
ai)].
See
Table
6
for
the
corresponding
dermal
dose
and
inhalation
dose.
d
LADD
(
Lifetime
average
daily
dose)
mg/
kg/
day
=
Total
daily
absorbed
dose
(
mg/
kg/
day)
*
(
days
worked
per
year/
365
days
per
year)
*
(
35
years
worked/
70
year
lifetime).
Days
worked
per
year
are
estimates.
e
Risk
=
LADD
(
mg/
kg/
day)
*
Q
1
*
=
1.91e­
2
(
mg/
kg/
day
g.
Handler
Exposures:
Algaecide
Use
for
Use
in
Commercial
Fish
Ponds
Occupational
risk
assessments
were
conducted
for
the
use
of
diuron
as
an
algaecide
in
commercial
fish
ponds.
Four
short­
term
occupational
handler
scenarios
were
identified
for
the
use
of
diuron
in
commercial
fish
production
and
the
inhalation
MOEs
from
all
four
of
the
commercial
fish
production
scenarios
were
greater
than
100
at
the
baseline
level
of
mitigation
and
are
not
of
concern.

Diuron
is
used
as
an
algaecide
in
the
commercial
production
of
ornamental
fish,
bait
fish,
and
catfish.
For
these
uses,
there
are
two
state
labels
(
FL99000200
and
AR99000800),
a
section
18,
and
several
other
Griffin
labels
pending
approval.

Based
on
the
use
patterns
of
diuron
as
an
algaecide,
four
occupational
exposure
scenarios
were
identified:

(
1a)
Mixing/
loading
dry
flowables
for
catfish
production;
(
1b)
Mixing/
loading
dry
flowables
for
ornamental
fish
production;
(
2a)
Mixing/
loading
wettable
powders
for
catfish
production;
and
(
2b)
Mixing/
loading
wettable
powders
for
ornamental
fish
production.

The
assumptions
used
for
catfish
production
in
this
assessment
are
assumed
to
be
applicable
to
ornamental
fish
production
as
well,
since
no
other
data
exist
at
this
time.
They
are:

°
Use
instructions:

Weigh
the
correct
amount
of
Diuron
80W
into
a
five
gallon
bucket
and
fill
the
bucket
half
full
with
pond
water.
Stir
the
contents
of
the
bucket.
Pour
the
contents
of
the
stirred
59
bucket
into
the
outflow
side
of
the
aerator
and
rinse
the
bucket
in
the
pond
water.
Operate
the
aerator
for
one
hour
after
the
addition
of
the
Diuron
80W
to
the
pond.

°
The
Agency
assumed
an
average
pond
size
of
15
acres,
4
feet
deep,
with
20
ponds
per
farm
(
no
more
than
25%
would
be
expected
to
be
treated
per
day).
The
assumptions
on
pond
size
and
numbers
of
ponds
per
farm
are
based
on
telephone
conversations
between
EPA
staff
(
Pilot
Interdisciplinary
Risk
Assessment
Team)
and
contacts
at
Auburn
and
Mississippi
State
Universities
in
1996.

°
For
commercial
fish
ponds
treated
with
wettable
powders,
the
application
rates
were
calculated
as
follows.
Diuron
80W,
for
use
in
catfish
ponds,
may
be
applied
at
a
rate
of
0.5
oz/
acre
ft
(
0.025
lb
ai/
acre
ft)
every
seven
days
for
a
total
of
9
applications.
Therefore,
it
was
estimated
that
handlers
would
mix
up
to
7.5
lb
ai/
day
(
15
acres/
pond
x
4
ft
x
5
ponds/
day
x
0.025
lb
ai/
acre
foot
=
7.5
lb
ai/
day).
The
label
AR99000800,
for
use
in
ornamental
fish
ponds,
states
an
application
rate
of
1.0
oz/
acre
ft
(
0.05
lbs
ai/
acre
ft).
Therefore
it
was
estimated
that
handlers
would
mix
up
to
15.0
lbs
ai/
day
(
15
acres/
pond
x
4
ft
x
5
ponds/
day
x
0.050
lb
ai/
acre
foot
=
15.0
lb
ai/
day).

°
For
commercial
fish
ponds
treated
with
dry
flowables,
the
application
rates
were
calculated
as
follows.
The
Nautillus
Aquatic
Herbicide
label,
for
use
in
catfish
ponds,
states
that
it
may
be
applied
at
a
rate
of
0.5
oz/
acre
ft
(
0.025
lb
ai/
acre
ft)
every
seven
days
for
a
total
of
9
applications.
Therefore,
it
was
estimated
that
handlers
would
mix
up
to
7.5
lb
ai/
day
(
15
acres/
pond
x
4
ft
x
5
ponds/
day
x
0.025
lb
ai/
acre
foot
=
7.5
lb
ai/
day).
The
label
FL99000200,
for
use
in
ornamental
fish
ponds,
states
an
application
rate
of
0.0038
grams
ai/
gallon
(
2.73
lbs
ai/
acre
ft),
applied
up
to
three
times
a
year.
Therefore,
it
was
estimated
that
handlers
would
mix
up
to
819
lbs
ai/
day
(
15
acres/
pond
x
4
ft
x
5
ponds/
day
x
2.73
lb
ai/
acre
foot
=
819
lb
ai/
day).

°
Unit
exposure
data
from
PHED
were
used
to
assess
the
mixing
and
loading
of
wettable
powders
and
dry
flowables
into
commercial
fish
ponds.
60
h.
Handler
Risks:
Algaecide
Use
for
Use
in
Commercial
Fish
Ponds
With
maximum
PPE,
(
long
pants,
long
sleeved
shirt,
socks,
shoes,
coveralls,
gloves,
and
respirator)
all
four
scenarios
have
estimated
cancer
risks
of
that
range
from
1.8
x
10­
6
to
4.94
x
10­
8
and
are
not
of
concern.
Occupational
postapplication
exposure
to
diuron
in
treated
fish
production
ponds
is
not
likely
to
result
in
a
risk
of
concern
based
on
the
extremely
high
dilution
rate.

i.
Postapplication
Occupational
Risk
Occupational
Non­
Cancer
Postapplication
Exposure
and
Risk
Estimates
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
and
no
post­
application
inhalation
exposure
is
expected.

Occupational
Cancer
Postapplication
Agricultural
Exposure
Only
crops
that
can
receive
direct
foliar
treatments
were
assessed
for
postapplication
risks.
These
crops
are
not
damaged
by
foliar
treatments
of
diuron.
Many
of
the
applications
of
diuron
are
soil
directed
or
pre­
plant,
since
the
application
of
diuron
to
most
of
the
registered
crops
would
result
in
plant
damage.
The
crops
assessed
are
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.

EPA
has
determined
that
there
are
potential
postapplication
exposures
to
individuals
entering
treated
fields.
In
the
Worker
Protection
Standard,
a
restricted
entry
interval
(
REI)
is
defined
as
the
duration
of
time
which
must
elapse
before
residues
decline
to
a
level
so
entry
into
a
previously
treated
area
and
engaging
in
any
task
or
activity
would
not
result
in
exposures
which
are
of
concern.
Typically,
the
activity
with
the
highest
risk
will
drive
the
selection
of
the
appropriate
REI
for
the
crop.
The
current
diuron
labels
have
a
REI
requirement
of
12
hours
with
the
following
early
entry
PPE
required:
coveralls
over
long
sleeved
shirt
and
long
pants,
waterproof
gloves,
chemical
resistant
footwear
plus
socks,
protective
eye
wear
and
chemical
resistant
headgear
for
overhead
exposures.

Significant
exposure
to
diuron
may
result
from
contact
with
treated
soil
when
planting
seedlings,
moving
irrigation
lines,
or
other
soil
related
activities
since
diuron
is
applied
directly
to
the
soil.
At
this
time,
no
transfer
coefficients
exist
for
activities
resulting
in
contact
with
treated
soil.
There
are
also
no
data
on
the
soil
residue
dissipation
of
diuron.
A
worker
exposure
study
and
a
diuron
soil
residue
dissipation
study
would
be
needed
to
assess
this
risk.
Transfer
coefficients
do
not
exist
for
the
mechanical
harvesting
of
alfalfa
and
asparagus
and
these
activities
61
are
considered
of
special
concern
according
to
the
Agriculture
Transfer
Coefficient
Exposure
SAC
policy
3.1.
Significant
worker
exposure
is
possible
from
mechanical
harvesting
these
crops.

Since
diuron
can
be
applied
as
a
defoliant
soon
before
harvest,
exposure
to
cotton
harvesters
is
of
special
concern
for
this
chemical.
According
to
data
recently
submitted
to
the
Agency,
there
is
exposure
during
the
mechanical
harvesting
of
cotton.
Exposure
can
result
from
the
following
occupational
job
functions:
picker
operator,
module
builder,
tramper,
and
raker.
A
picker
operator
is
the
individual
that
drives
the
harvesting
machine,
usually
with
an
enclosed
cab.
A
module
builder
operator
is
the
individual
that
operates
the
controls
of
the
module
builder
that
the
picker
dumps
the
cotton
into.
The
module
builder
is
used
to
receive
the
cotton
and
then
compact
it
into
modules
or
bales.
A
tramper
is
the
individual
who
stands
on
top
of
the
module
builder
and
helps
direct
the
cotton
out
of
the
picker
and
into
the
module
builder.
The
tramper
than
jumps
into
the
module
builder
and
redistributes
the
cotton
around
inside.
A
raker
is
the
individual
who
rakes
up
the
spilled
cotton
and
puts
it
back
into
the
module
builder.
The
models
presently
used
to
assess
occupational
postapplication
exposure
cannot
be
used
since
the
foliage
has
dropped
off
of
the
cotton
plants
by
the
time
of
harvest.
There
are
no
standard
default
transfer
coefficients
for
these
activities
at
this
time.

Chemical­
specific
postapplication
exposure
and/
or
environmental
fate
data
have
not
yet
been
submitted
by
the
registrant
in
support
of
reregistration
of
diuron.
In
lieu
of
these
data,
a
surrogate
postapplication
assessment
was
conducted
to
determine
potential
risks.
The
surrogate
assessment
is
based
on
both
the
typical
and
maximum
application
rates
that
a
private
farmer/
grower
may
reasonably
be
expected
to
be
exposed
to
for
a
short­
term
duration
(
10
days),
and
on
the
typical
application
rates
that
a
commercial
applicator
may
be
reasonably
expected
to
be
exposed
to
for
a
longer­
term
duration
(
30
days).
The
maximum
application
rates
are
not
included
in
the
postapplication
assessment
for
the
commercial
applicator,
as
it
is
unlikely
that
a
commercial
applicator
would
be
exposed
at
the
maximum
application
rate
for
30
days
a
year.

Occupational
Data
Sources
and
Assumptions
(
1)
Data
Sources
°
Typical
application
rates
were
supplied
by
the
primary
registrant,
Griffin.
The
sources
of
the
data
were
quoted
as
Doane,
the
National
Center
for
Food
and
Agricultural
Policy
(
NCFAP),
the
U.
S.
Department
of
Agriculture,
and
Griffin.
A
range
of
the
typical
application
rates
was
given.
The
highest
value
of
the
typical
range
of
application
rates
was
used
in
this
assessment.
BEAD
has
evaluated
the
typical
application
rates
and
determined
that
they
are
typical
to
high
end.
No
data
on
the
typical
application
rates
of
paints,
ponds,
and
non­
crop/
industrial
areas
were
supplied.
Therefore,
only
the
maximum
application
rates
were
used
in
the
cancer
assessments
for
these
uses.

°
No
chemical
specific
DFR
data
exists
for
diuron.
Therefore,
the
DFR
values
are
derived
from
using
an
estimated
20
percent
of
the
rate
applied
as
initial
dislodgeable
residues
for
cotton
and
an
estimated
10
percent
dissipation
rate
per
day.
62
°
The
transfer
coefficients
used
in
this
assessment
are
from
the
Agricultural
Re­
entry
Task
Force
(
ARTF)
database.
An
interim
transfer
coefficient
policy
was
developed
by
HED's
Science
Advisory
Council
for
Exposure
using
the
ARTF
database
(
policy
#
3.1).
It
is
the
intention
of
HED's
Science
Advisory
Council
for
Exposure
that
this
policy
will
be
periodically
updated
to
incorporate
additional
information
about
agricultural
practices
in
crops
and
new
data
on
transfer
coefficients.
Much
of
this
information
will
originate
from
exposure
studies
currently
being
conducted
by
the
ARTF,
from
the
further
analysis
of
studies
already
submitted
to
the
Agency,
and
from
the
studies
in
the
published
scientific
literature.

(
2)
Assumptions
The
following
assumptions
were
used
in
the
occupational
postapplication
assessment.

°
The
maximum
transfer
coefficients
for
each
crop
were
used
to
determine
the
highest
possible
postapplication
exposure.
Other
activities,
such
as
scouting
and
irrigation,
were
also
assessed
to
determine
possible
exemptions
to
the
restricted
entry
intervals
calculated
for
the
highest
postapplication
exposures.

°
Exposure
time
is
assumed
to
be
8
hours
per
day.
This
represents
a
typical
work
day.

°
The
average
body
weight
of
70
kg
is
used.

°
Exposures
per
year:
Ten
days
of
exposure
per
year
was
assumed
for
the
private
grower
and
30
days
of
exposure
per
year
was
assumed
for
a
commercial
applicator.

°
Maximum
application
rates
were
used
in
the
private
grower
assessment.
Typical
application
rates
were
used
in
both
the
private
grower
and
commercial
applicator
assessments.
It
is
assumed
that
as
the
frequency
of
exposure
increases,
the
probability
of
being
exposed
to
a
maximum
residue
resulting
from
the
maximum
application
rate
decreases.
Therefore,
maximum
application
rates
were
only
assessed
for
the
professional
grower.

Occupational
Postapplication
Cancer
Risk
Summary
When
evaluating
cancer
risks
for
the
occupational
population,
EPA
closely
examines
risks
in
the
1x10­
4
to
1x10­
6
range
and
seeks
cost
effective
ways
to
reduce
occupational
cancer
risks
to
the
greatest
extent
feasible,
preferably
1x10­
6
or
less.
This
diuron
postapplication
cancer
assessment
assumes
that
a
worker
would
contact
residues
on
the
day
of
application
for
ten
or
thirty
days
a
year,
every
year
for
35
years.
Since
it
is
unlikely
that
a
postapplication
worker
would
contact
the
highest
possible
residue
value
for
that
length
of
time,
this
assessment
is
considered
very
conservative.
63
Private
Growers
(
10
Days
Exposure
Per
Year)

Postapplication
cancer
risks
for
private
growers
were
calculated
at
both
the
typical
application
rate
and
the
maximum
application
rate
for
each
crop
grouping.
As
mentioned
previously,
the
occupational
cancer
risk
assessment
is
a
conservative
assessment;
therefore,
all
cancer
risks
to
private
growers
were
less
than
1
x
10­
4
on
the
day
of
treatment
and
are
not
of
concern.

Commercial
Farm
Workers
(
30
Days
Exposure
Per
Year)

Postapplication
cancer
risks
for
commercial
farm
workers
were
calculated
at
the
typical
application
rate
only
for
each
crop
grouping.
All
cancer
risks
to
commercial
farm
workers
were
less
than
1
x
10­
4
on
the
day
of
treatment
and
are
not
of
concern.

Historically,
setting
REIs
on
cancer
endpoints
has
been
difficult
because
of
the
need
for
lifetime
use
assumptions.
To
estimate
the
LADD
(
Life­
time
Average
Daily
Dose)
the
typical
application
rate,
the
number
of
days
worked
per
year,
and
the
number
of
years
one
would
be
exposed
during
a
working
lifetime
are
needed.
Each
one
of
these
variables
is
dependent
upon
many
factors.
For
example,
the
number
of
days
worked
per
year
must
correspond
to
the
days
worked
when
the
pesticide
of
concern
has
been
applied.
Additionally,
the
residue
dissipation
over
the
work
interval
should
be
estimated.
Without
an
estimate
for
residue
dissipation
one
needs
to
assume
(
conservatively)
that
the
worker
travels
from
one
treated
field
to
another
so
that
the
highest
residue
value
is
always
contacted.
In
the
case
of
diuron,
a
screening
estimate
was
developed
because
lifetime
use
data
are
not
available.

Occupational
Postapplication
Exposures
to
Paint
Containing
Diuron
Postapplication
exposures
may
occur
in
industrial
settings
around
open
vats
used
in
paint
processing.
Inhalation
and
dermal
exposures
may
also
occur
while
maintaining
industrial
equipment.
No
postapplication
exposure
data
have
been
submitted
to
determine
the
extent
of
postapplication
exposures
in
the
industrial
settings.
However,
usage
information
gathered
subsequent
to
the
risk
assessment
indicates
that
less
than
1
%
of
all
paint
contains
diuron.
Inhalation
exposures
are
expected
to
be
minimal
because
of
the
low
vapor
pressure
of
diuron
(
2
x
10­
7
mmHg
at
30

C)
and
aerosol
formation
is
not
expected
to
be
registered.
Dermal
postapplication
exposures
are
expected
to
be
lower
than
when
handling/
loading
the
formulated
product.
Therefore,
postapplication
exposures
in
the
industrial
settings
are
expected
to
be
minimal
and
not
of
concern.

Occupational
Postapplication
Exposures
to
Commercial
Fish
Ponds
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.
64
Furthermore,
postapplication
activities
in
and
around
ponds/
aquariums
treated
with
diuron
are
assumed
to
be
infrequent.

j.
Human
Incident
Data
The
Agency
searched
several
databases
for
reports
of
incidents
resulting
from
exposures
to
diuron.
The
databases
searched
were
the
Incident
Data
System
(
IDS),
American
Association
of
Poison
Control
Centers
(
AAPCC),
California
Pesticide
Illness
Surveillance
Program,
and
National
Pesticide
Telecommunication
Network
(
NPTN).
There
were
incidents
reported
involving
both
adults
and
children.
Most
were
treated
on
an
outpatient
basis
but
a
few
required
hospitalization
and
one
death
occurred.
A
direct
connection
between
exposure
to
diuron
as
the
cause
and
the
reported
death
has
not
been
made.
Some
incident
reports
described
symptoms
such
as
eye
irritation,
rash,
dizziness,
respiratory
irritation
and
headaches
for
both
agricultural
and
nonagricultural
exposures.
Specific
details
may
be
found
in,
"
Review
of
Diuron
Poisoning
Incident
Data.
Chemical:
#
035505,"
dated
October
11,
2001.

The
incident
data
show
that
the
number
of
poisoning
incidents
for
diuron
alone
is
relatively
small
in
any
one
surveillance
system.
Also,
the
incidents
are
scattered
in
time
and
location,
and
many
of
the
incidents
involve
diuron
use
in
mixtures.
Therefore,
few
conclusions
can
be
drawn.
However,
a
1995
Louisiana
elementary
school
incident
in
which
diuron
was
associated
with
the
illnesses
of
23
children
and
9
adults,
remains
unexplained.
There
are
no
known
recreational
or
school
building
registered
uses
of
diuron.

B.
Environmental
Risk
Assessment
A
summary
of
the
Agency's
environmental
risk
assessment
is
presented
below.
For
detailed
discussions
of
all
aspects
of
the
environmental
risk
assessment,
see
the
"
Environmental
Risk
Assessment
for
the
Reregistration
of
Diuron",
dated
August
27,
2001,
the
"
Drinking
Water
Reassessment
for
Diuron
and
its
Degradates",
dated
March
11,
2002,
and
the
memorandum
entitled,
"
Surface
Water
Monitoring
Data
for
Diuron"
dated
August
5,
2003.
These
documents
are
also
available
in
the
OPP
public
docket
and
on
the
Agency's
website
at:
http://
cfpub.
epa.
gov/
oppref/
rereg/
status.
cfm?
show=
rereg.

1.
Environmental
Fate
and
Transport
The
environmental
fate
database
for
diuron
is
essentially
complete.
Diuron
is
mobile
and
has
the
potential
to
leach
to
ground
and
to
contaminate
surface
waters.
An
upgradable
adsorption/
desorption/
leaching
study
(
MRID
44490501)
showed
that
diuron
has
low
to
medium
K
oc
values
(
468­
1666)
and
Freundlich
K
ads
values
(
7.9­
28).
In
addition,
diuron
has
relatively
low
water
solubility
(
42
ppm)
and
low
volatility
(
2
x
10­
7
mm
Hg
at
30
°
C).

Diuron
is
persistent
in
terrestrial
environments.
The
major
routes
of
dissipation
for
diuron
in
the
environment
is
microbial
degradation
in
water.
Diuron
also
degrades
through
photolysis
in
both
water
and
soil,
but
at
a
slower
rate.
65
Diuron
is
stable
to
hydrolysis
at
pH
5,
7,
and
9.
The
minor
degradate
3,4­
dichloroaniline
(
3,4­
DCA)
was
identified
in
all
hydrolysis
test
solutions
(
0.5%
of
applied).
In
aqueous
and
soil
photolysis
studies
with
diuron,
calculated
half­
lives
were
43
and
173
days,
respectively.
In
water,
photolysis
degradates
were
carbon
dioxide
(
CO
2)
and
at
least
13
minor
(
each
<
9%
of
applied)
polar
products.
In
soil,
the
major
photolysis
degradate
was
N'­(
3,4­
dichlorophenyl)­
N­
methylurea
(
DCPMU),
and
the
minor
degradates
were
demethylated
DCPMU
(
DCPU),
dichloroaniline
(
DCA),
and
3,3',
4,4'­
tetrachlorobenzene
(
TCAB).
The
calculated
half­
lives
in
aerobic
and
anaerobic
soil
metabolism
studies
were
372
(
aerobic)
and
1000
(
anaerobic)
days.
Under
aerobic
conditions,
the
major
degradate
was
DCPMU
(
20.9­
22.5
%
of
the
amount
applied
at
365
days),
and
minor
degradates
were
DCPU
and
CO
2.
Under
anaerobic
conditions,
the
only
degradate
identified
was
DCPMU,
which
accounted
for
a
maximum
of
10.3%
of
applied
(
at
45
days).

In
contrast
to
its
persistence
in
laboratory
studies
of
hydrolysis,
aqueous
and
soil
photolysis,
and
aerobic
and
anaerobic
soil
metabolism,
diuron
degraded
relatively
quickly
in
aquatic
metabolism
laboratory
studies,
with
a
half­
life
of
33
days
under
aerobic
conditions
and
of
5
days
under
anaerobic
conditions.
The
major
metabolism
degradate
under
aerobic
conditions
was
N'­(
3­
chlorophenyl)­
N,
N­
dimethylurea
(
MCPDMU)
which
reached
25
%
of
the
applied
dose
by
the
end
of
the
study
and
was
evenly
distributed
between
the
soil
and
aqueous
phase.
The
minor
degradates
identified
were
DCPMU
and
CPMU
and
were
primarily
associated
with
the
soil
phase.
The
major
degradate
under
anaerobic
conditions
was
MCPDMU,
which
was
mainly
associated
with
the
aqueous
phase.
The
two
minor
degradates
were
PDMU
and
MCPMU.

In
terrestrial
field
dissipation
studies
in
FL,
MS,
and
CA
with
sand,
silt
loam,
and
silty
clay
loam
soils,
diuron
dissipated
in
bare
ground
plots
with
half­
lives
of
73,
139,
and
133
days,
respectively.
The
major
degradate
DCPMU
dissipated
in
the
same
plots
with
half­
lives
of
217,
1733,
and
630
days.
In
aquatic
field
dissipation
studies,
half­
lives
were
115­
177
days
and
the
major
degradate
was
DCPMU.

The
major
degradate
formed
in
laboratory
studies
of
soil
photolysis,
aerobic
soil
metabolism,
and
anaerobic
soil
metabolism,
and
in
all
field
dissipation
studies
was
DCPMU.
The
major
degradate
formed
in
laboratory
studies
of
aerobic
and
anaerobic
aquatic
metabolism
studies
was
MCPDMU.
The
major
and
minor
degradates
of
diuron
are
shown
in
Table
20.
The
environmental
degradates
of
toxicological
concern
to
humans
and
other
non­
target
species
are
shown
in
italics.

The
degradate
3,4­
DCA
is
of
toxicological
concern
for
human
health
and
is
a
common
degradate
for
diuron,
linuron,
and
propanil.
Based
on
limited
environmental
fate
data
(
three
hydrolysis
studies),
3,4­
DCA
is
formed
at
<
1%
of
applied
diuron.
Although
the
environmental
risk
assessment
for
diuron
noted
the
lack
of
fate
and
transport
data
on
3,4­
DCA,
additional
data
will
not
be
required
for
diuron
since
this
degradate
is
formed
at
such
a
low
percent
of
applied
parent.

Tetrachloroazobenzene
(
TCAB),
also
a
degradate
of
concern
for
human
health,
was
identified
as
one
of
the
minor
degradates
of
diuron
in
a
soil
photolysis
study
with
a
maximum
concentration
of
0.038
ppm.
66
Table
20.
Major
and
Minor
Degradates
of
Diuron
in
Environmental
Fate
Studies
Environmental
Fate
Study
Major
degradate
Minor
degradates
Hydrolysis
(
MRID
41418804)
None
3,4­
DCA
Photodegradation
in
Water
(
MRID
41418805)
CO2
13
polar
products
Photodegradation
in
Soil
(
MRID
41719302)
DCPMU
DCPU,
3,4­
DCA,
TCAB
Aerobic
Soil
Metabolism
(
MRID
4179303)
DCPMU
DCPU,
CO2
Anaerobic
Soil
Metabolism
(
MRID
41418806)
DCPMU
None
Aerobic
Aquatic
Metabolism
(
MRID
44221002)
MCPDMU
DCPMU,
CPMU
Anaerobic
Aquatic
Metabolism
(
MRID
44221001)
MCPDMU
PDMU,
MCPMU
Terrestrial
Field
Dissipation
(
MRIDs
44654001,
44865001)
DCPMU
Not
Measured
Aquatic
Field
Dissipation
(
MRIDs
43762901,
43978901)
DCPMU
Not
Measured
2.
Toxicity
(
Hazard)
Assessment
a.
Toxicity
to
Terrestrial
Organisms
Diuron
is
sightly
toxic
to
bobwhite
quail
and
practically
nontoxic
to
mallard
duck
on
an
acute
oral
basis.
It
is
practically
nontoxic
to
bobwhite
quail
and
slightly
toxic
to
mallard
duck
on
a
subacute
dietary
basis.
Diuron
is
relative
nontoxic
to
both
honey
bees
and
laboratory
rats
(
acute
basis).
In
a
2­
generation
rat
reproduction
study,
diuron
caused
pup
body
weight
loss.
No
avian
reproduction
study
was
submitted
by
the
registrant
and
one
is
required
because
diuron
is
persistent
in
the
environment
and
has
the
potential
to
cause
chronic
effects.
In
Table
21,
the
toxicity
endpoints
used
in
calculating
risk
are
shaded.
67
Table
21.
Summary
of
Acute
and
Chronic
Toxicity
Values
for
Terrestrial
Organisms
Species
Acute
Toxicity
Chronic
Toxicity
Acute
LD50
(
mg/
kg)
Acute
Oral
Toxicity
(
MRID)
Subacute
LC50
(
ppm)
Subacute
Dietary
Toxicity
(
MRID)
NOEC/
LOEC
(
ppm)
(
MRID)
Affected
endpoint
Northern
bobwhite
quail
Colinus
virgianus
940
Slightly
toxic
(
50150170)
>
5000
Practically
nontoxic
(
00022923)
 
­
­

Mallard
duck
Anas
platyrhynchous
>
2000
Practically
nontoxic
(
00160000)
1730
Slightly
toxic
(
00022923)
­­
­­

Honey
bee
Apis
meliferus
1451
Practically
nontoxic
(
00036935)
 
 
 
­
­

Laboratory
rat
Rattus
norvegicus
Male:
5,000
Female:
10,000
Class.
III
(
00146145)
 
­
­
NOEC
=
250
LOEC
=
1750
(
00146145)
Pup
body
weight
b.
Toxicity
to
Aquatic
Organisms
Diuron
is
moderately
toxic
to
the
majority
of
aquatic
animals
tested,
including
rainbow
trout,
bluegill
sunfish,
water
flea,
striped
mullet,
sheepshead
minnow,
Eastern
oyster,
and
brown
shrimp.
However,
it
is
highly
toxic
to
cutthroat
trout
and
scuds.
Diuron
is
only
slightly
acutely
toxic
to
fathead
minnows.
In
chronic
studies,
diuron
reduced
the
number
of
surviving
fathead
minnows,
the
growth
and
survival
of
sheepshead
minnows,
and
the
growth
and
reproduction
of
mysid
shrimp.
Chronic
studies
on
water
fleas
and
sheepshead
minnows
will
need
to
be
repeated
because
they
failed
to
provide
a
LOEC
(
water
flea,
no
observed
effect
at
all
doses
tested)
or
a
NOEC
(
sheepshead
minnow,
reduced
growth
and
survival
at
all
doses
tested).
In
Table
22,
the
toxicity
endpoints
used
in
calculating
risk
are
shaded.
68
Table
22.
Summary
of
Acute
and
Chronic
Toxicity
Values
for
Aquatic
Organisms
Species
Acute
Toxicity
Chronic
Toxicity
48­
h
EC50
(
ppm)
96­
hr
LC50
(
ppm)
Acute
Toxicity
(
MRID)
NOEC/
LOEC
(
ppm)
Affected
Endpoint
(
MRID)

Cutthroat
trout
Oncerynchus
clarki
(
freshwater
fish)
 
0.71
Highly
toxic
(
40098001)
 
­
­

Fathead
minnows
Pimephales
promelas
(
freshwater
fish)
 
14
Slightly
toxic
(
00141636)
NOEC
=
0.
026
LOEC
=
0.062
No.
of
survivors
(
00141636)

Scud
Gammmarus
fasciatus
(
freshwater
invertebrate)
0.16
 
Highly
toxic
(
40094602)
 
­
­

Water
flea
Daphnia
magna
(
freshwater
invertebrate)
1.4
 
Moderately
toxic
(
40094602)
NOEC
=
0.
2
No
LOEC
No
effect
(
STODIV05)

Striped
mullet
Mugil
cephalus
(
marine/
estuarine
fish)
 
6.3
Moderately
toxic
(
40228401)
 
­
­

Sheepshead
minnow
Cypprinoden
varieggatus
(
marine/
estuarine
fish)
 
6.7
Moderately
toxic
(
41418805)
No
NOEC
LOEC
=
0.44
Reduced
growth,
survival
(
42312901)

Brown
shrimp
Penaeus
aztecus
(
marine/
estuarine
invertebrate)
1
 
Moderately
toxic
(
40228401)
 
 
Mysid
shrimp
Americamysis
bahia
(
marine/
estuarine
invertebrate)
 
­
­
 
NOEC
=
0.27
LOEC
=
0.56
Growth
Reproduction
c.
Toxicity
to
Non­
target
Plants
Tier
II
terrestrial
plant
seedling
emergence
and
vegetative
vigor
toxicity
studies
were
conducted
with
four
species
of
monocotyledonous
plants
(
corn,
onion,
sorghum,
and
wheat)
and
six
species
of
dicotyledonous
plants
(
soybean,
pea,
rape,
cucumber,
sugar
beet,
and
tomato).
Onion
and
tomato
were
most
sensitive
species
for
seedling
emergence;
and
wheat
and
tomato
were
most
sensitive
species
for
plant
vegetative
vigor.
Tier
II
aquatic
plant
toxicity
testing
was
conducted
on
fifteen
species
of
nonvascular
plants
including
aquatic
algae
and
diatoms.
However,
only
one
study
on
green
algae
(
Selenastrum
capricornutum)
was
acceptable
because
the
other
69
submitted
studies
tested
inappropriate
species.
No
vascular
aquatic
plant
studies
were
submitted
for
diuron;
an
aquatic
plant
study
on
four
species
including
the
vascular
plant
Lemna
gibba
(
duckweed)
is
required.
Tables
23
and
24
show
a
summary
of
acute
toxicity
values
for
non­
target
terrestrial
plants
and
non­
target
aquatic
plants,
respectively.

Table
23.
Summary
of
Acute
Toxicity
Values
for
Non­
Target
Terrestrial
Plants
(
Endpoint
=
Shoot
Dry
Weight).

Classification
Toxicity
test
Crop
(
MRID)
EC25/
EC05
(
lbs.
ai/
A)

Monocot
Seedling
emergence
Onion
(
MRID
44114301)
0.099/
0.089
Vegetative
vigor
Wheat
(
MRID
44113401)
0.021/
0.002
Dicot
Seedling
emergence
Tomato
(
MRID
44113401)
0.08
/
0.047
Vegetative
vigor
Tomato
(
MRID
42398501)
0.002/
0.001
Table
24.
Summary
of
Acute
Toxicity
Values
for
Non­
Target
Aquatic
Plants
Classification
Species
(
MRID)
EC50
(
ppb)

Non­
vascular
Green
algae
Selenastrum
capricornutum
(
MRID
42218401)
2.4
Vascular
Duckweed
Lemna
Gibba
(
No
study
available)
None
available
3.
Exposure
and
Risk
Assessment
a.
Risk
Calculation
Levels
of
Concern
To
evaluate
the
potential
ecological
risk
to
non­
target
organisms
from
the
use
of
diuron
products,
risk
quotients
(
RQs)
are
calculated
from
the
ratio
of
estimated
environmental
concentrations
(
EEC)
to
ecotoxicity
values.
The
Agency
calculates
risk
quotients
(
RQs)
by
dividing
exposure
estimates
by
acute
and
chronic
ecotoxicity
values:

RQ
=
EXPOSURE/
TOXICITY
RQs
are
then
compared
to
OPP's
levels
of
concern
(
LOCs).
These
LOCs
are
criteria
used
by
OPP
to
indicate
potential
risk
to
nontarget
organisms
and
the
need
to
consider
regulatory
action.
The
criteria
indicate
that
a
pesticide
used
as
directed
has
the
potential
to
cause
adverse
effects
on
non­
70
target
organisms.
Risk
presumptions,
along
with
the
corresponding
LOCs,
are
given
in
Table
25.

Table
25.
Risk
Presumptions
for
Terrestrial
and
Aquatic
Animals
Risk
Presumption
LOC
terrestrial
animals
LOC
aquatic
animals
LOC
terrestrial
plants
LOC
aquatic
plants
Acute
High
Risk
there
is
potential
for
acute
risk;
regulatory
action
may
be
warranted
in
addition
to
restricted
use
classification,
0.5
0.5
1
1
Acute
Restricted
Use
­
there
is
potential
for
acute
risk,
but
may
be
mitigated
through
restricted
use
classification,
0.2
0.1
1
1
Acute
Endangered
Species
­
endangered
species
may
be
adversely
affected;
regulatory
action
may
be
warranted,
0.1
0.05
1
1
Chronic
Risk
­
there
is
potential
for
chronic
risk;
regulatory
action
may
be
warranted.
1
1
NA
NA
When
available,
field
studies
and
incident
data
are
used
to
further
characterize
the
risk
to
non­
target
organisms.
Risk
characterization
integrates
the
results
of
all
available
data
to
evaluate
the
likelihood
of
adverse
ecological
effects.

b.
Exposure
and
Risk
to
Non­
target
Terrestrial
Organisms
(
1)
Avian
Risk
In
order
to
assess
risk
to
birds,
estimated
environmental
concentrations
(
EECs)
on
food
items
following
product
application
are
compared
to
LC
50
values
to
assess
risk
by
the
Risk
Quotient
(
RQ)
method.
Estimates
of
maximum
and
average
residue
levels
(
EECs)
of
diuron
on
avian
food
items
were
based
on
the
nomograph
of
Hoerger
and
Kenega
(
1972),
as
modified
by
Fletcher
et
al.
(
1994).
The
upper
limit
values
from
the
nomograph
represent
the
95th
percentile
of
residues
from
actual
field
measurements
(
Hoerger,
1972).
The
Fletcher
et
al.
(
1994)
modification
to
the
Kenaga
nomograph
are
based
on
measured
field
residues
from
249
published
research
papers,
including
118
various
species
of
plants,
121
pesticides,
and
17
chemical
classes.
These
modifications
represent
the
95th
percentile
of
the
expanded
data
set.
71
Avian
risk
quotients
are
calculated
using
the
most
sensitive
LC
50
(
acute
risk)
and
NOEC
(
chronic
risk)
for
birds.
In
this
instance,
the
mallard
duck
5­
day
LC
50
of
1730
ppm
was
used
to
calculate
acute
risk.
Short
grass
represents
the
food
items
with
the
highest
residue
concentration
and
therefore,
the
highest
RQ,
conversely,
seeds
represent
the
foodstuffs
with
the
lowest
RQs.
Other
food
items
fall
within
this
range.
Chronic
risk
to
birds
could
not
be
calculated
because
no
chronic
avian
toxicity
data
were
available
for
diuron;
an
avian
reproduction
study
is
required.

The
highest
calculated
avian
acute
RQ
is
1.7
and
is
based
on
a
single
application
of
diuron
at
12
lbs
a.
i./
A
to
rights­
of­
way.
The
highest
RQ
associated
with
an
agricultural
use
is
1.3,
based
on
a
single
ground
application
of
9.6
lbs
a.
i./
A
to
grapes,
or
two
applications
of
4.8
lbs
a.
i./
A
to
citrus.
Acute
(
LOC
=
0.5),
acute
high
risk
(
LOC
=
0.2),
and
acute
endangered
species
(
LOC
=
0.1)
levels
of
concern
are
exceeded
for
birds
feeding
on
short
grass,
tall
grass
(
not
shown)
and
broadleaf
plants
and
insects
(
not
shown).
However,
LOCs
are
not
exceeded
if
RQs
are
calculated
using
mean
EECs
(
not
shown)
based
on
mean
residues
from
Hoerger
and
Kenega
1972
as
modified
by
Fletcher
et
al.
1994.
Table
26
shows
the
range
of
acute
avian
RQs
based
on
maximum
EECs
and
maximum
labeled
application
rates
for
birds
feeding
on
short
grass
and
seeds,
only.

Table
26:
Avian
Acute
Risk
Quotients
for
Single
and
Multiple
Applications
Based
on
Maximum
Residues
(
LC50
=
1730
ppm).

Use
site/
application
methods
(
number
of
applications)
Rate
(
lbs
ai/
A)
Food
Items
Single
Application
Multiple
Applications
Acute
only
Acute
only
Rights­
of­
way/
aerial
(
1)
12
Short
grass
1.7
­­

Seeds
0.1
 
Grapes/
ground
(
1)
9.6
Short
grass
1.3
­­

Seeds
0.08
 
Citrus/
ground
(
2)
6.4
(
4.8
for
2
applications)
Short
grass
0.9
1.3
Seeds
0.06
0.08
Fruits/
ground
(
1)
4.0
Short
grass
0.6
­­

Seeds
0.03
­­

Sugarcane/
aerial
(
3)
3.2
Short
grass
0.4
0.8
Seeds
0.03
0.05
Cotton/
aerial
(
2)
1.6
(
1.2
for
2
applications)
Short
grass
0.2
0.3
Seeds
0.01
0.02
72
(
2)
Mammalian
Risk
In
order
to
assess
risk
to
small
mammals,
estimated
environmental
concentrations
(
EECs)
of
diuron
on
food
items
are
compared
to
LC
50
values
from
laboratory
studies
on
small
mammals
(
rats,
mice)
to
calculate
risk
quotients
(
RQs).
Wild
mammal
toxicity
studies
are
required
on
a
case­
by­
case
basis,
depending
on
the
results
of
laboratory
mammalian
studies,
intended
chemical
use
patterns
and
pertinent
environmental
fate
characteristics.
For
most
chemicals,
including
diuron,
rat
or
mouse
toxicity
values
obtained
from
the
Agency's
Health
Effects
Division
substitute
for
wild
mammal
testing.

To
calculate
acute
risk
and
maximum
chronic
risk
values,
estimates
of
maximum
residue
levels
(
EECs)
of
diuron
on
mammalian
food
items
were
based
on
the
model
of
Hoerger
and
Kenega
(
1972),
as
modified
by
Fletcher
et
al.
(
1994).
In
addition,
a
second
estimate
of
maximum
chronic
risk
values
and
an
estimate
of
average
chronic
risk
values
were
calculated
using
the
LFATE
model.

The
concentration
of
diuron
in
the
diet
that
is
expected
to
be
acutely
lethal
to
50%
of
the
test
population
(
LC
50)
is
determined
by
dividing
the
LD
50
value
(
in
this
case,
the
male
rat
5­
day
LD
50
of
5,000
mg/
kg)
by
the
%
(
decimal
of)
body
weight
consumed
(
95%
for
grass,
forage,
and
insects,
and
21%
for
seeds).
An
acute
risk
quotient
is
then
determined
by
dividing
the
EEC
by
the
derived
LC
50
value.
Chronic
risk
quotients
are
calculated
in
a
similar
manner
using
the
most
sensitive
chronic
endpoint,
in
this
case,
a
NOEC
of
250
ppm
from
a
2­
generation
rat
reproduction
study
(
chronic
effect
=
pup
body
weight
loss).
Risk
quotients
are
calculated
for
three
separate
weight
classes
of
mammals
(
15,
35,
and
1000
g),
each
presumed
to
consume
four
different
kinds
of
food
(
grass,
forage,
insects,
and
seeds).

The
acute
level
of
concern
(
LOC
=
0.5)
for
mammals
is
only
exceeded
for
15
g
mammals
feeding
on
short
grass
following
a
12
lb
a.
i./
A
application
of
diuron
to
rights­
of­
way,
a
use
which
results
in
the
highest
calculated
RQ
for
mammals,
0.6.
The
highest
calculated
RQ
associated
with
an
agricultural
use
is
0.4,
for
a
single
ground
application
to
grapes
of
9.6
lbs
a.
i./
A,
two
ground
applications
of
4.8
lbs
a.
i./
A
to
citrus,
or
three
applications
of
3.2
lbs
a.
i./
A
to
sugarcane.
Acute
high
risk
(
LOC
=
0.2)
and
acute
endangered
species
(
LOC
=
0.1)
levels
of
concern
are
exceeded
for
small
(
15
g)
and
medium­
sized
(
35
g)
mammals
for
some
use­
sites
and
application
rates.

The
chronic
level
of
concern
(
LOC
=
1)
for
mammals
is
exceeded
for
small
(
15
g)
mammals
feeding
on
short
grass,
tall
grass,
and
broadleaf
plants
and
insects,
for
all
crops
with
multiple
diuron
applications
(
citrus,
sugarcane,
and
cotton).
The
highest
calculated
chronic
RQ
value
is
9.2,
based
on
2
ground
applications
(
4.8
lbs
a.
i./
A
per
application)
to
citrus
and
3
aerial
applications
(
3.2
lbs
a.
i./
A
per
application)
to
sugarcane.

Table
27
shows
the
acute
and
chronic
risk
quotients
for
the
smallest
mammals
(
15
g,
most
sensitive,
highest
risk)
feeding
on
seeds
(
lower
residues
and
risk)
and
short
grass
(
highest
residues
and
risk)
calculated
using
maximum
Kenaga
nomogram
residues,
only.
These
values
represent
the
73
most
conservative
estimate
of
risk
(
highest
RQs).

Table
27:
Mammalian
(
15
g
mammal)
Acute
and
Chronic
Risk
Quotients
for
Single
and
Multiple
Applications
Based
on
Maximum
Residues
(
LD50
=
5,000
mg/
kg,
NOEC
=
250
ppm).

Use
site/
application
methods
(
number
of
applications)
Rate
(
lbs
ai/
A)
Food
Items
Single
Application
Multiple
Applications
Acute
Chronic
Acute
Chronic
Rights­
of­
way/
aerial
(
1)
12
Short
grass
0.6
­­
­­
­­

Seeds
0.01
­­
­­
­­

Grapes/
ground
(
1)
9.6
Short
grass
0.4
­­
­­
­­

Seeds
<
0.01
­­
­­
­­

Citrus/
ground
(
2)
6.4
(
4.8
for
2
applications
Short
grass
0.3
­­
0.4
9.2
(
3.1)
1
Seeds
<
0.01
­­
<
0.01
0.6
(
0.3)
1
Fruits/
ground
(
1)
4.0
Short
grass
0.2
­­
­­
­­

Seeds
<
0.01
­­
­­
­­

Sugarcane/
aerial
(
3)
3.2
Short
grass
0.2
­­
0.4
9.2
(
2.1)
1
Seeds
<
0.01
­­
<
0.01
0.6
(
0.2)
1
Cotton/
aerial
(
2)
1.6
(
1.2
for
2
applications)
Short
grass
0.07
­­
0.1
2.1
(
0.8)
1
Seeds
<
0.01
­­
<
0.01
0.1
(
0.06)
1
1Value
in
parentheses
is
the
average
chronic
RQ,
calculated
using
average
residue
values
from
the
FATE
model.

(
3)
Risk
to
Non­
target
Insects
Diuron
is
practically
non­
toxic
to
honeybees
and
risk
to
non­
target
insects
is
expected
to
be
minimal.

c.
Exposure
and
Risk
to
Non­
target
Aquatic
Organisms
74
(
1)
Surface
Water
Resources
Assessment
Diuron
aquatic
estimated
environmental
concentrations
(
EECs)
were
generated
using
the
Tier
I
surface
water
model
GENEEC
II,
a
screening
level
model
generating
upper­
bound
EECs.
Diuron
EEC
values
were
calculated
based
on
applications
to
various
crops
using
aerial
or
ground
equipment.
In
addition,
the
Tier
II
surface
water
model
PRZM/
EXAMS
was
used
to
generate
less
conservative
EEC
values
for
the
grape
(
CA),
citrus
(
FL)
and
apple
(
NY)
diuron
use
scenarios.
These
scenarios
were
chosen
to
reflect
a
wide
range
of
diuron
application
rates
and
regional
weather
conditions.

(
2)
Risk
to
Fish
and
Aquatic
Invertebrates
Risk
to
freshwater
fish
and
invertebrates
To
calculate
acute
RQs
for
freshwater
aquatic
organisms,
peak
EEC
values
were
divided
by
the
most
sensitive
acute
toxicity
endpoints:
the
cutthroat
trout
LC
50
(
0.71
ppm)
for
fish,
and
the
scud
LC
50
(
0.16
ppm)
for
invertebrates.
Chronic
RQ
values
were
calculated
by
dividing
21­
day
average
EECs
(
for
invertebrates)
and
60­
day
average
EECs
(
for
fish)
by
the
most
sensitive
chronic
toxicity
endpoints:
the
fathead
minnow
NOEC
(
0.0264
ppm)
for
fish,
and
the
water
flea
NOEC
(
0.2
ppm)
for
invertebrates.

The
acute
level
of
concern
for
aquatic
organisms
(
LOC
=
0.5)
is
not
exceeded
for
freshwater
fish
except
for
the
12
lbs
a.
i./
A
right­
of­
way
use,
which
results
in
the
highest
calculated
RQ
for
freshwater
fish,
0.6
(
Table
28).
However,
the
acute
restricted
use
level
of
concern
(
LOC
=
0.1)
is
exceeded
for
freshwater
fish
for
all
uses
except
sugarcane
(
multiple
applications)
and
cotton
(
single
and
multiple
applications).
The
acute
endangered
species
level
of
concern
(
LOC
=
0.05)
is
exceeded
for
freshwater
fish
for
all
uses
except
multiple
applications
to
cotton.

The
highest
acute
RQ
for
freshwater
invertebrates
is
2.6
and
is
associated
with
the
use
of
diuron
on
rights­
of­
way.
The
acute
LOC
(
0.5)
is
exceeded
for
freshwater
invertebrates
for
all
uses
except
sugarcane
(
multiple
applications)
and
cotton
(
single
and
multiple
applications).
The
acute
restricted
use
(
0.2)
and
acute
endangered
species
(
0.05)
levels
of
concern
are
exceeded
for
all
uses.

The
highest
calculated
chronic
RQs
for
freshwater
fish
are
9.0
(
rights­
of­
way)
and
7.2
(
grapes),
and
the
highest
calculated
RQs
for
freshwater
invertebrates
are
1.8
(
rights­
of­
way)
and
1.3
(
grapes).
The
chronic
level
of
concern
for
aquatic
organisms
(
LOC
=
1)
is
exceeded
for
freshwater
fish
for
all
uses
except
multiple
applications
to
cotton.
For
invertebrates,
the
chronic
LOC
(
1)
is
exceeded
for
single
applications
to
rights­
of­
way
and
grapes,
and
for
multiple
applications
to
citrus.

Table
28.
Freshwater
Fish
and
Invertebrate
Acute
and
Chronic
Risk
Quotients
75
Use
site/
application
methods
(
number
of
applications)
Rate
(
lbs
ai/
A)
Acute
Risk
Quotients
Chronic
Risk
Quotients
Freshwater
Fish
Freshwater
Invertebrates
Freshwater
Fish
Freshwater
Invertebrates
Rights­
of­
way/
aerial
(
1)
12
0.
6
2.
6
9.0
1.8
Grapes/
ground
(
1)
9.6
0.5
(
0.05)
1
2.
1
(
0.2)
1
7.
2
(
1.4)
1
1.3
(
0.2)
1
Citrus/
ground
(
1)
6.4
0.3
(
0.2)
1
1.4
(
0.9)
1
4.8
(
4.9)
1
0.9
(
0.7)
1
Citrus/
ground
(
2)
4.8
0.1
0.6
2.0
1.2
Fruits/
ground
(
1)
4.0
0.2
(
0.07)
1
0.9
(
0.3)
1
3.0
(
1.9)
1
0.5
(
0.3)
1
Alfalfa,
sugarcane,
grass
seeds/
aerial
(
1)
3.2
0.2
0.7
2.5
0.6
Sugarcane/
aerial
(
3)
3.2
0.09
0.4
1.4
0.8
Cotton/
aerial
(
1)
1.6
0.08
0.4
1.3
0.2
Cotton/
aerial
(
2)
1.2
0.03
0.1
0.5
0.3
1
RQ
values
in
parentheses
were
calculated
using
Tier
II
PRZM/
EXAMS
modeling.

Risk
to
estuarine/
marine
fish
and
invertebrates
To
calculate
acute
RQ
values
for
estuarine/
marine
aquatic
organisms,
peak
EEC
values
were
divided
by
the
most
sensitive
acute
toxicity
endpoints:
the
striped
mullet
LC
50
(
6.3
ppm)
for
fish,
and
the
brown
shrimp
LC
50
(>
1
ppm)
for
invertebrates.
Chronic
RQ
values
were
calculated
by
dividing
21­
day
average
EECs
(
for
invertebrates)
and
60­
day
average
EECs
(
for
fish)
by
the
most
sensitive
chronic
toxicity
endpoints:
the
sheepshead
minnow
NOEC
(
0.44
ppm)
for
fish,
and
the
mysid
shrimp
NOEC
(
0.27
ppm)
for
invertebrates.

The
acute
(
LOC
=
0.5)
and
acute
restricted
use
(
LOC
=
0.1)
levels
of
concern
for
aquatic
organisms
are
not
exceeded
for
estuarine/
marine
fish
(
Table
29).
The
acute
endangered
species
level
of
concern
(
LOC
=
0.05)
is
exceeded
for
estuarine/
marine
fish
only
for
the
uses
on
rights­
ofway
(
RQ
=
0.07)
and
grapes
(
RQ
=
0.05).
The
acute
LOC
(
0.5)
is
not
exceeded
for
estuarine/
marine
invertebrates.
The
calculated
RQs
associated
with
a
single
application
of
diuron
to
rights­
of­
way
(
RQ
=
0.4),
grapes
(
RQ
=
0.3),
and
citrus
(
RQ
=
0.2)
exceed
the
acute
restricted
use
level
of
concern
(
0.2)
for
invertebrates.
The
acute
endangered
species
(
0.05)
level
of
concern
is
exceeded
for
estuarine/
marine
invertebrates,
for
all
uses
except
multiple
applications
to
cotton.

The
highest
calculated
chronic
RQ
for
estuarine/
marine
fish
is
0.5
(
rights­
of­
way
use),
which
does
not
exceed
the
chronic
level
of
concern
(
1).
The
highest
calculated
chronic
RQs
for
estuarine/
marine
invertebrates
are
1.3
(
rights­
of­
way)
and
1.0
(
grapes);
these
are
the
only
uses
with
76
RQs
that
exceed
the
chronic
LOC
of
1.

Table
29.
Estuarine/
Marine
Fish
and
Invertebrate
Acute
and
Chronic
Risk
Quotients
Use
site/
application
methods
(
number
of
applications)
Rate
(
lbs
ai/
A)
Acute
Risk
Quotients
Chronic
Risk
Quotients
Estuarine/
Marine
Fish
Estuarine/
Marine
Invertebrates
Estuarine/
Marine
Fish
Estuarine/
Marine
Invertebrates
Rights­
of­
way/
aerial
and
ground
(
1)
12
0.
07
0.4
0.5
1.3
Grapes/
ground
(
1)
9.6
0.05
(
0.006)
1
0.3
(
0.04)
1
0.4
(
0.08)
1
1.0
(
0.1)
1
Citrus/
ground
(
1)
6.4
0.03
(
0.02)
1
0.2
(
0.1)
1
0.3
(
0.3)
1
0.06
(
0.5)
1
Citrus/
ground
(
2)
4.8
0.01
0.09
0.1
0.9
Fruits/
ground
(
1)
4.0
0.02
(
0.008)
1
0.1
(
0.05)
1
0.2
(
0.1)
1
0.4
(
0.2)
1
Alfalfa,
sugarcane,
grass
seeds/
aerial
and
ground
(
1)
3.2
0.02
0.1
0.2
0.4
Sugarcane/
aerial
(
3)
3.2
0.01
0.06
0.08
0.6
Cotton/
aerial
(
1)
1.6
0.01
0.06
0.08
0.2
Cotton/
aerial
(
2)
1.2
0.01
0.
02
0.03
0.2
1
RQ
values
in
parentheses
were
calculated
using
Tier
II
PRZM/
EXAMS
modeling.

d.
Exposure
and
Risk
to
Non­
target
Terrestrial
and
Aquatic
Plants
Risk
to
non­
target
terrestrial
plants
Terrestrial
plants
inhabiting
dry
and
semi­
aquatic
areas
may
be
exposed
to
diuron
from
runoff,
spray
drift.
Semi­
aquatic
areas
are
those
low­
lying
wet
areas
that
may
be
dry
at
certain
times
of
the
year.
The
run­
off
scenario
used
for
dry
areas
is
characterized
as
"
sheet
run­
off";
the
run­
off
scenario
for
semi­
aquatic
areas
is
characterized
as
"
channelized
run­
off".
EECs
are
calculated
for
ground
and
aerial
applications.
Spray
drift
exposure
from
ground
application
is
assumed
to
be
1%
of
the
application
rate,
whereas
spray
drift
from
aerial
applications
is
assumed
to
be
5%
of
the
application
rate.
The
total
loading
to
dry
areas
adjacent
to
treatment
sites
is
the
sum
of
sheet
run­
off
and
drift
(
EEC
dry).
The
total
loading
to
semi­
aquatic
areas
is
the
sum
of
channelized
run­
off
and
drift
(
EEC
semi­
aquatic).

In
order
to
calculate
the
acute
RQs
for
terrestrial
plants
in
dry
areas
adjacent
to
diuron
application
sites,
the
EEC
dry
was
divided
by
the
EC
25
value
of
the
most
sensitive
species
in
the
seedling
emergence
study
(
tomatoes,
EC
25
=
0.08
lbs
a.
i./
A).
The
acute
RQs
for
terrestrial
plants
77
in
semi­
aquatic
areas
were
calculated
by
dividing
the
EEC
semi­
aquatic
by
the
EC
25
value
of
the
most
sensitive
species
in
the
seedling
emergence
study
(
tomatoes,
EC
25
=
0.08
lbs
a.
i./
A).

Acute
RQs
for
endangered
terrestrial
plants
are
calculated
in
the
same
manner
as
for
nonendangered
plants,
except
that
the
EC
05
values
for
the
most
sensitive
species
in
the
seedling
emergence
(
tomato,
EC
05
=
0.047
lbs
a.
i./
A)
and
vegetative
vigor
(
tomato,
EC
05
=
0.001
lbs
a.
i./
A)
studies
are
used
instead
of
the
EC
25
values.

The
acute
RQs
calculated
for
terrestrial
and
endangered
terrestrial
plants
are
shown
in
Table
30
for
plants
in
dry
areas
adjacent
to
the
application
site,
and
semi­
aquatic
areas.
The
acute
levels
of
concern
for
terrestrial
(
LOC
=
1)
and
endangered
terrestrial
(
LOC
=
1)
plants
are
exceeded
for
both
dry
and
semi­
aquatic
areas.
The
acute
RQs
range
from
0.6
to
9.3
for
terrestrial
plants
in
dry
areas
and
from
3.4
to
77
for
terrestrial
plants
in
semi­
aquatic
areas.
The
acute
RQs
for
endangered
terrestrial
plants
range
from
5.0
to
48
for
endangered
plants
in
dry
areas
and
from
29
to
306
for
endangered
plants
in
semi­
aquatic
areas,
as
shown
in
Table
30.

Table
30.
Risk
Quotients
for
Terrestrial
and
Endangered
Terrestrial
Plants
in
Dry
and
Semi­
Aquatic
Areas.

Use
site/
application
method
Rate
(
lbs
a.
i./
A)
Acute
Risk
Acute
Endangered
Species
Risk
Dry
Areas
Semiaquatic
Areas
Vegatative
Vigor
Dry
Areas
Semiaquatic
Areas
Vegatative
Vigor
Rights­
of­
way/
ground
12
4.5
31.5
60
7.7
53.6
120
Grapes/
ground
9.6
3.6
25.3
50
6.1
42.8
100
Citrus/
ground
6.4
2.4
16.8
30
41
28.6
60
Alfalfa,
Sugarcane,
Grass
seeds/
ground
3.2
1.1
8.4
15
2.0
14.3
30
Cotton/
ground
1.6
0.6
4.3
10
1.0
7.1
20
Rights­
of­
way/
aerial
12
9.3
25.5
300
15.8
43.4
600
Alfalfa,
Sugarcane/
aerial
3.2
2.5
6.8
80
4.2
11.6
160
Cotton/
aerial
1.6
1.3
3.4
40
2.1
5.8
80
Risk
to
non­
target
aquatic
plants
Exposure
to
non­
target
aquatic
plants
may
occur
through
runoff
or
spray
drift
from
78
adjacent
treated
sites.
Diuron
aquatic
estimated
environmental
concentrations
(
EECs)
were
generated
using
the
Tier
I
surface
water
model
GENEEC
II,
a
screening
level
model
generating
upper­
bound
EECs.
Diuron
EEC
values
were
calculated
based
on
applications
to
various
crops
using
aerial
or
ground
equipment.

The
acute
RQs
for
aquatic
vascular
plants
are
usually
calculated
by
dividing
the
aquatic
EECs
by
the
EC
50
for
the
duckweed
Lemna
gibba.
In
the
case
of
diuron,
no
vascular
plant
toxicity
study
was
available
(
one
is
required).
Acute
RQs
for
aquatic
non­
vascular
plants
were
calculated
by
dividing
the
aquatic
EECs
by
the
acute
EC
50
(
0.0024
ppm)
for
the
green
alga
Selenastrum
capricornutum.

The
acute
RQs
for
endangered
aquatic
vascular
plants
are
usually
calculated
by
dividing
the
aquatic
EECs
by
the
EC
05
for
the
duckweed
Lemna
gibba.
Since
no
vascular
plant
toxicity
study
was
available
for
diuron,
risk
to
endangered
aquatic
vascular
plants
could
not
be
calculated.
To
date,
there
are
no
known
non­
vascular
plant
species
on
the
endangered
species
list.

Acute
RQs
for
aquatic
non­
vascular
plants
ranged
from
9.6
(
based
on
two
aerial
application
to
cotton)
to
172
(
based
on
one
aerial
application
to
rights­
of­
way)
(
Table
31).
The
acute
level
of
concern
for
aquatic
non­
vascular
plants
(
LOC
=
0.1)
plants
is
exceeded
for
all
uses
of
diuron.
79
Table
31.
Risk
Quotients
for
Non­
Vascular
Aquatic
Plants.

Use
site/
application
methods
(
number
of
applications)
Rate
(
lbs
ai/
A)
Single
Application
Multiple
Applications
Acute
only
Acute
only
Rights­
of­
way/
aerial
(
1)
12
172
­­

Grapes/
ground
(
1)
9.6
138
­­

Citrus/
ground
(
2)
6.4
(
4.8
for
2
applications)
92
38
Fruits/
ground
(
1)
4.0
57
­­

Sugarcane/
aerial
(
3)
3.2
48
25
Cotton/
aerial
(
2)
1.6
(
1.2
for
2
applications)
24
9.6
4.
Ecological
Incidents
There
are
29
ecological
incident
reports
involving
diuron
and
non­
target
organisms;
most
of
these
reports
are
from
the1990s.
Of
the
29
incidents,
one
involved
birds,
16
involved
fish,
and
12
involved
plants.
One
incident
report
included
tissue
analysis
for
both
fish
and
plants.

Of
20
reported
incidents
where
fish
were
killed,
16
resulted
from
direct
application
to
ponds,
which
is
not
allowed
as
a
legal
use
in
the
U.
S.
Two
incidents
were
from
use
on
unidentified
agricultural
crops
where
diuron
subsequently
ran
off
into
adjacent
waters.
In
one
instance
12
bass
and
catfish
were
killed
in
Oklahoma,
and
in
the
other,
3000
unidentified
fish
were
killed
in
Maryland.
It
is
considered
"
probable"
that
diuron
caused
these
kills,
but
it
is
unknown
if
the
diuron
was
applied
according
to
the
label.
Another
incident
resulted
from
spraying
fence
rows,
with
subsequent
runoff
into
a
pond,
killing
all
of
the
algae
within
two
days
and
30­
40
fish
two
days
later.
Diuron
was
applied
by
a
pressure
spray
in
combination
with
imazapyr
and
metsulfuronmethyl
It
is
likely
that
the
spray
application
was
the
causative
event,
but
it
seems
very
likely
that
the
cause
of
the
fish
deaths
was
low
dissolved
oxygen
which
was
found
to
be
markedly
reduced;
fish
were
observed
"
groping
for
air."
The
fourth
incident
was
associated
with
application
of
a
bromacil­
diuron
product
to
an
electrical
substation.
It
appears
to
be
unlikely
to
have
resulted
from
diuron
because
copper
sulfate
had
been
applied
several
days
previously,
and
measured
amounts
of
diuron
and
bromacil
in
the
pond
were
very
low,
whereas
copper
concentrations
were
above
median
lethal
levels
for
several
fish
species.

The
absence
of
additional
documented
incidents
does
not
necessarily
mean
that
such
incidents
did
not
occur.
Mortality
incidents
must
be
seen,
reported,
investigated,
and
submitted
to
the
Agency
in
order
to
be
recorded
in
the
incident
database.
Incidents
may
not
be
noticed
because
the
carcasses
decayed,
were
removed
by
scavengers,
or
were
in
out­
of­
the­
way
or
hard­
to­
see
locations.
Due
to
the
voluntary
nature
of
incident
reporting,
an
incident
may
not
be
reported
to
80
appropriate
authorities
capable
of
investigating
it.

5.
Endangered
Species
Endangered
species
LOCs
for
diuron
are
exceeded
for
terrestrial
plants,
herbivorous
mammals
and
herbivorous
and
insectivorous
birds
from
all
uses;
freshwater
fish
and
crustaceans
from
all
uses
but
cotton;
and
mollusks
and
estuarine
fish
from
the
uses
on
grapes
and
nonagricultural
sites.
The
Agency
consulted
with
the
US
Fish
and
Wildlife
Service
(
FWS
or
the
Service)
on
the
agricultural
uses
of
diuron
in
the
"
reinitiation"
of
the
cluster
assessments
in
1988.
The
resulting
1989
opinion
found
jeopardy
to
the
Wyoming
toad
(
extirpated
in
the
wild
except
on
FWS
refuges).
The
Service
proposed
a
Reasonable
and
Prudent
Alternative
(
RPA)
(
no
spray
zone
within
100
yards
of
occupied
habitat
for
ground
applications
and
1/
4
mile
for
aerial
application)
to
avoid
the
likelihood
of
jeopardizing
the
continued
existence
of
this
species.
In
addition,
the
Service
had
Reasonable
and
Prudent
Measures
(
RPM)
to
reduce
incidental
take
of
20
fish
and
two
aquatic
invertebrate
species.
The
details
of
the
RPM
recommendations
are
provided
in
the
FWS
1989
biological
opinion.

Many
additional
species,
especially
aquatic
species,
have
been
federally
listed
as
endangered/
threatened
since
the
biological
opinion
of
1989
was
written;
determination
of
potential
effect
to
most
of
these
species
has
not
yet
been
assessed
for
diuron.
Species­
and
site­
specific
assessments
have
been
done
for
the
various
uses
of
diuron
with
respect
to
listed
Pacific
salmon
and
steelhead,
in
accordance
with
a
court
order,
and
consultation
has
been
requested
of
the
National
Marine
Fisheries
Service
for
those
that
exceed
criteria
of
concern;
these
latter
include
nonagricultural
uses
and
the
highest
rates
of
certain
agricultural
uses
of
diuron.
These
assessments
should
not
be
extrapolated
to
other
species
and
other
parts
of
the
U.
S.
In
addition,
endangered
plants,
birds,
and
mammals
were
not
considered
in
the
1989
Biological
Opinion
or
the
consultation
request
for
salmon
and
steelhead.
These
need
to
be
addressed
along
with
newly
listed
aquatic
species
and
the
non­
crop
uses
of
diuron
for
all
species
other
than
Pacific
salmon
and
steelhead
because
the
1989
biological
opinion
dealt
only
with
crop
uses.
Finally,
not
only
are
more
refined
methods
to
define
ecological
risks
of
pesticides
being
used,
but
also
new
data
that
did
not
exist
in
1989,
such
as
that
for
spray
drift,
are
now
available.
The
RPMs
in
the
1989
opinion
may
need
to
be
re­
assessed
and
consultation
reinitiated,
as
appropriate.
For
additional
information,
please
see:
http://
www.
epa.
gov/
oppfead1/
endanger/
effects/
diuron_
analysis_
final2.
pdf
81
IV.
Risk
Management,
Reregistration
and
Tolerance
Reassessment
Decisions
A.
Determination
of
Reregistration
Eligibility
Section
4(
g)(
2)(
A)
of
FIFRA
calls
for
the
Agency
to
determine,
after
submission
of
relevant
data
concerning
an
active
ingredient,
whether
or
not
products
containing
the
active
ingredient
are
eligible
for
reregistration.
The
Agency
has
previously
identified
and
required
the
submission
of
the
generic
(
i.
e.,
active
ingredient­
specific)
data
to
support
reregistration
of
products
containing
the
active
ingredient
diuron.

The
Agency
has
completed
its
assessment
of
the
occupational,
residential,
and
ecological
risks
associated
with
the
use
of
pesticide
products
containing
the
active
ingredient
diuron,
as
well
as
a
diuron­
specific
dietary
risk
assessment.
Based
on
a
review
of
these
data
and
on
public
comments
on
the
Agency's
assessments
for
the
active
ingredient
diuron,
EPA
has
sufficient
information
on
the
human
health
and
ecological
effects
of
diuron
to
make
decisions
as
part
of
the
tolerance
reassessment
process
under
FFDCA
and
reregistration
process
under
FIFRA,
as
amended
by
FQPA.
EPA's
tolerance
reassessment
decision
was
completed
in
July
2002,
and
has
been
included
in
this
document.
The
Agency
has
determined
that
diuron
products
are
eligible
for
reregistration
provided
that:
(
i)
current
data
gaps
and
confirmatory
data
needs
are
addressed;
(
ii)
the
risk
reduction
measures
outlined
in
this
document
are
adopted;
and
(
iii)
label
amendments
are
made
to
reflect
these
measures.
Label
changes
are
described
in
Section
V.
Appendix
A
summarizes
the
uses
of
diuron
that
are
eligible
for
reregistration.
Appendix
B
identifies
the
generic
data
requirements
that
the
Agency
reviewed
as
part
of
its
determination
of
reregistration
eligibility
of
diuron,
and
lists
the
submitted
studies
that
the
Agency
found
acceptable.
Data
gaps
are
identified
as
generic
data
requirements
that
have
not
been
satisfied
with
acceptable
data.

Based
on
its
evaluation
of
diuron,
the
Agency
has
determined
that
diuron
products,
unless
labeled
and
used
as
specified
in
this
document,
would
present
risks
inconsistent
with
FIFRA.
Accordingly,
should
a
registrant
fail
to
implement
any
of
the
risk
mitigation
measures
identified
in
this
document,
the
Agency
may
take
regulatory
action
to
address
the
risk
concerns
from
use
of
diuron.
If
all
changes
outlined
in
this
document
are
incorporated
into
the
product
labels,
then
all
current
risks
for
diuron
will
be
adequately
mitigated
for
the
purposes
of
this
determination.

B.
Public
Comments
and
Responses
When
making
its
reregistration
decision,
the
Agency
took
into
account
all
comments
received
after
opening
of
the
public
docket.
These
comments
in
their
entirety
are
available
in
the
docket
(
OPP­
2002­
0249).
Comments
on
the
risk
assessment
were
submitted
by
the
registrant,
Griffin
LLC.
A
formal
Agency
response
to
these
comments
can
be
found
in
the
following
document
which
is
available
in
the
public
docket:
"
HED
Response
to
Public
Comments
on
the
Diuron
Preliminary
Risk
Assessment"
dated
July
9,
2003.
No
other
comments
were
received
on
the
preliminary
risk
assessments
for
diuron.
82
C.
Regulatory
Position
1.
FQPA
Assessment
a.
"
Risk
Cup"
Determination
As
part
of
the
FQPA
tolerance
reassessment
process,
EPA
assessed
the
risks
associated
with
this
pesticide.
EPA
has
determined
that
risk
from
dietary
(
food
sources
only)
exposure
to
diuron
is
within
its
own
"
risk
cup."
An
aggregate
assessment
was
conducted
for
exposures
through
food,
drinking
water,
and
residential
uses.
The
Agency
has
determined
that
the
human
health
risks
from
these
combined
exposures
are
within
acceptable
levels.
In
other
words,
EPA
has
concluded
that
the
tolerances
for
diuron
meet
the
FQPA
safety
standards.
In
reaching
this
determination,
EPA
has
considered
the
available
information
on
the
special
sensitivity
of
infants
and
children,
as
well
as
the
chronic
and
acute
food
exposure.
The
Tolerance
Reassessment
Decision
was
completed
in
July
2002,
and
can
be
found
on
the
EPA
website:
http://
www.
epa.
gov/
oppsrrd1/
REDs/
diuron_
tred.
pdf.

Some
tolerances
will
change
because
the
data
indicate
either
that
a
lower
or
higher
tolerance
is
needed.
Some
will
be
revoked
because
they
are
no
longer
a
regulated
commodity
or
significant
livestock
feed
items.
Some
will
be
deleted
because
a
crop
group
tolerance
will
be
established.

b.
Determination
of
Safety
for
U.
S.
Population
In
its
July
2002,
TRED,
EPA
determined
that
the
established
uses
for
diuron,
with
amendments
and
changes
as
specified
in
that
document,
met
the
safety
standard
under
the
FQPA
amendments
to
section
408(
b)(
2)(
D)
of
the
FFDCA,
that
there
is
a
reasonable
certainty
of
no
harm
for
the
general
population.
In
reaching
this
determination,
EPA
considered
all
available
information
on
the
toxicity,
use
practices,
and
scenarios,
and
the
environmental
behavior
of
diuron.
As
discussed
in
chapter
3,
an
acute
dietary
risk
assessment
was
not
performed
because
no
adverse
effects
attributed
to
a
single
exposure
were
identified
in
any
available
study.
For
chronic
(
noncancer
risk
from
food
alone,
the
risks
from
diuron
are
not
of
concern.
The
estimated
cancer
dietary
risk
associated
with
the
use
of
diuron
indicates
a
slight
exceedance
above
1
x
10­
6
and
shows
a
lifetime
risk
estimate
of
1.68
x
10
­
6
for
the
general
population.
However,
the
Agency
has
determined
that
potential
dietary
cancer
risk
is
not
of
concern
because
the
residues
used
in
the
calculations
are
from
field
trials
conducted
at
the
highest
application
rates
and
some
residue
processing
data
are
still
outstanding.
Therefore,
the
exposure
calculation
is
a
conservative
estimate.

Acute
risks
from
drinking
water
exposures
are
not
of
concern.
For
chronic
drinking
water
risk,
drinking
water
monitoring
data
from
Florida,
California,
and
the
U.
S.
Geological
Survey
National
Water
Quality
Assessment
(
NAWQA)
Program
were
used
to
determine
the
estimated
environmental
concentrations
(
EECs)
in
surface
water.
These
monitoring
data
confirm
that
actual
concentrations
of
diuron
are
substantially
less
than
previous
model
estimates.
Although
modeled
83
estimates
showed
only
a
marginal
exceedance
of
the
DWLOC,
monitoring
data
show
concentrations
substantially
below
the
chronic
DWLOC.
Short­
term
residential
exposures
to
diuron
are
not
of
concern.
The
Agency
has
concluded
that
the
potential
cancer
risk
from
residential
use
is
negligible
because
of
the
low
volume
of
diuron
used
in
paint
and
the
sporadic,
short­
term
duration
of
homeowner
exposures.

c.
Determination
of
Safety
for
Infants
and
Children
In
its
July
2002
TRED,
EPA
determined
that
the
established
tolerances
for
diuron,
meet
the
safety
standards
under
the
FQPA
amendments
to
section
408(
b)(
2)(
C)
of
the
FFDCA,
that
there
is
a
reasonable
certainty
of
no
harm
for
infants
and
children.
The
safety
determination
for
infants
and
children
considered
the
factors
noted
above
for
the
general
population,
but
also
takes
into
account
the
possibility
of
increased
dietary
exposure
due
to
the
specific
consumption
patterns
of
infants
and
children,
as
well
as
the
possibility
of
increased
susceptibility
to
the
toxic
effects
of
diuron
residues
in
this
population
subgroup.

In
determining
whether
or
not
infants
and
children
are
particularly
susceptible
to
toxic
effects
from
diuron
residues,
EPA
considered
the
completeness
of
the
database
for
developmental
and
reproductive
effects,
the
nature
of
the
effects
observed,
and
other
information.
The
FQPA
Safety
Factor
has
been
removed
(
i.
e.,
reduced
to
1x)
for
diuron
because:
1)
there
is
no
indication
of
quantitative
or
qualitative
increased
susceptibility
of
rats
or
rabbits
to
in
utero
or
postnatal
exposure;
2)
a
DNT
study
with
diuron
is
not
required;
and
3)
the
dietary
(
food
and
drinking
water)
and
non­
dietary
(
residential)
exposure
assessments
will
not
underestimate
the
potential
exposures
for
infants
and
children.

d.
Endocrine
Disruptor
Effects
EPA
is
required
under
the
FFDCA,
as
amended
by
FQPA,
to
develop
a
screening
program
to
determine
whether
certain
substances
(
including
all
pesticide
active
and
other
ingredients)
"
may
have
an
effect
in
humans
that
is
similar
to
an
effect
produced
by
a
naturally
occurring
estrogen,
or
other
endocrine
effects
as
the
Administrator
may
designate."
Following
recommendations
of
its
Endocrine
Disruptor
Screening
and
Testing
Advisory
Committee
(
EDSTAC),
EPA
determined
that
there
was
scientific
basis
for
including,
as
part
of
the
program,
the
androgen
and
thyroid
hormone
systems,
in
addition
to
the
estrogen
hormone
system.
EPA
also
adopted
EDSTAC's
recommendation
that
EPA
include
evaluations
of
potential
effects
in
wildlife.
For
pesticides,
EPA
will
use
FIFRA
and,
to
the
extent
that
effects
in
wildlife
may
help
determine
whether
a
substance
may
have
an
effect
in
humans,
FFDCA
authority
to
require
the
wildlife
evaluations.
As
the
science
develops
and
resources
allow,
screening
of
additional
hormone
systems
may
be
added
to
the
Endocrine
Disruptor
Screening
Program
(
EDSP).

When
the
appropriate
screening
and/
or
testing
protocols
being
considered
under
the
EDSP
have
been
developed,
diuron
may
be
subject
to
additional
screening
and/
or
testing
to
better
characterize
effects
related
to
endocrine
disruption.
84
e.
Cumulative
Risks
The
Food
Quality
Protection
Act
(
FQPA)
requires
that,
when
considering
whether
to
establish,
modify,
or
revoke
a
tolerance,
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."
Diuron
is
a
dimethylurea
herbicide.
The
Agency
does
not
currently
have
data
available
to
determine
with
certainty
whether
diuron
has
a
common
mechanism
of
toxicity
with
any
other
substances.
Therefore
for
purposes
of
this
Reregistration
Eligibility
Decision,
the
Agency
has
assumed
that
diuron
does
not
have
a
common
mechanism
of
toxicity
with
any
other
pesticides.

f.
Tolerance
Summary
A
summary
of
EPA's
July
2002
diuron
tolerance
reassessment
is
presented
in
Table
24.
The
tolerance
reassessment
information
is
presented
in
this
RED
document
for
the
sake
of
completeness
and
for
the
convenience
of
the
reader.
A
full
description
of
the
tolerance
reassessment
can
be
found
in
the
Residue
Chemistry
Assessment
for
diuron
dated
July
9,
2003.
Diuron
tolerances
are
currently
expressed
as
diuron
per
se.
The
Agency
is
recommending
that
the
tolerance
expression
for
diuron
be
revised
to
include
metabolites
hydrolyzable
to
3,4­
dichloroaniline
(
3,4­
DCA).
This
determination
is
based
on
the
results
of
the
reviewed
plant
and
animal
metabolism
studies.
Tolerances
for
residues
of
diuron
in/
on
plant
and
animal
commodities
are
established
under
40
CFR
§
180.106.

Table
24.
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]

Apples
1
0.10
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.
[
Apple]

Artichokes
1
1/(
TBD3)
[
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]
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
85
Barley,
grain
1
Reassign;
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
Reassign;
2
Barley,
straw
2
1.5
Birdsfoot
trefoil,
forage
2
0.10
T
hese
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
15
Cattle,
meat
1
15
Cattle,
meat
byproducts
1
15
Citrus
fruits
1
1/(
TBD3)
[
Fruit,
citrus,
group]

Citrus
pulp,
dried
4
4/(
TBD3)
[
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.
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
86
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.

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.

Corn,
sweet,
fodder
2
Revoke
There
are
no
registered
uses
of
diuron
on
sweet
corn.
Corn,
sweet,
forage
2
Corn,
field
fodder
2
2/(
TBD3)
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/(
TBD3)
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/(
TBD3)
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]
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
87
Corn,
pop,
forage
2
2/(
TBD3)
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
15
[
Goat,
fat]

Goats,
meat
1
15
[
Goat,
meat]

Goats,
meat
byproducts
1
15
[
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
3
)
[
Grass,
forage,
except
Bermuda
grass]

Grass,
hay
(
other
than
Bermuda
grass
hay)
2
2/(
TBD
3
)
[
Grass,
hay,
except
Bermuda
grass]

Hogs,
fat
1
15
[
Hog,
fat]

Hogs,
meat
1
15
[
Hog,
meat]

Hogs,
meat
byproducts
1
15
[
Hog,
meat
byproducts]

Horses,
fat
1
15
[
Horse,
fat]

Horses,
meat
1
15
[
Horse,
meat]

Horses,
meat
byproducts
1
15
[
Horse,
meat
byproducts]

Nuts
0.1
0.1/(
TBD3)
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.
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
88
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/(
TBD3)
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/(
TBD3)

Oats,
straw
2
1.5
Olives
1
1/(
TBD3)
[
Olive]

Papayas
0.5
0.50
[
Papayas]

Peaches
0.1
0.10
[
Peach]

Pears
1
1/(
TBD3)
[
Pear]

Peas
1
0.10
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
0.10
ppm.
[
Pea,
field,
seed]

Peas,
forage
2
2/(
TBD3)
[
Pea,
field,
vines]

Peas,
hay
2
2/(
TBD3)
[
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
15
Sheep,
meat
1
15
Sheep,
meat
byproducts
1
15
Sorghum,
fodder
2
2/(
TBD3)
[
Sorghum,
grain,
stover]

Sorghum,
forage
2
2/(
TBD3)
[
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]
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
89
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/(
TBD3)

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

Wheat,
hay
2
2/(
TBD3)

Wheat,
straw
2
1.5
The
available
data
indicate
that
the
tolerance
should
be
reduced
to
1.5
ppm.

Tolerance
Listed
Under
40
CFR
§
180.106(
b)

Catfish
fillets
2.03
2.0
Expiration
date
of
06/
30/
05
[
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
TBD3
Cotton,
gin
byproducts
N/
A
TBD3
Eggs
N/
A
TBD3
Grass,
seed
screenings
N/
A
TBD3
Grass,
straw
N/
A
TBD3
Milk
N/
A
TBD3
Pineapple,
process
residue
N/
A
0.40
Poultry,
meat
byproducts
N/
A
TBD3
Prickly
pear
N/
A
0.05
Commodity
Established
Tolerance
(
ppm)
1
Reassessed
Tolerance
(
ppm)
2
Comment
Correct
Commodity
Definition
90
Spearmint
N/
A
1.5
Sugarcane,
molasses
N/
A
0.70
Wheat,
bran
N/
A
0.70
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.

(
1)
Codex
Harmonization
The
Codex
Alimentarius
Commission
has
not
established
or
proposed
Codex
MRLs
for
residues
of
diuron;
therefore,
there
are
no
issues
pertaining
to
harmonization
of
U.
S.
tolerances
with
Codex
MRLs.

Canadian
tolerances
(
from
PMRA
web
site)
include
the
following:

7
ppm
in/
on
asparagus
1
ppm
in/
on
citrus,
corn,
grapes,
pineapple,
potatoes,
and
wheat.

Mexican
tolerances
(
from
1992
Diuron
Residue
Chemistry
Registration
Standard
Update)
are
established
for
diuron
as
follows:

7
ppm
in/
on
asparagus
4
ppm
in/
on
dry
citrus
pulp
2
ppm
in/
on
alfalfa,
corn
(
forage),
sorghum
(
forage),
wheat
(
straw,
forage)
1
ppm
in/
on
artichoke,
cottonseed,
sugarcane,
citrus
fruit,
apple,
corn
grain,
peaches,
potatoes,
pears,
pineapple,
sorghum
(
grain),
wheat
(
grain
and
straw),
and
grapes.
0.5
ppm
in/
on
papaya
0.1
ppm
in/
on
nuts
91
D.
Risk
Management
and
Rationale
The
following
is
a
summary
of
the
rationale
for
managing
risks
associated
with
the
use
of
diuron.
Where
labeling
revisions
are
warranted,
specific
language
is
set
forth
in
the
summary
tables
of
Section
V
of
this
document.
Application
rates
have
been
reduced
and
retreatment
intervals
have
been
increased
for
ten
crops.
The
risk
reduction
by
these
actions
have
not
been
quantified
but
will
reduce
exposure
to
diuron.
Table
25
lists
all
the
crops
that
have
revised
application
rates
and
retreatment
intervals.

Table
25.
Revised
Crop
Parameters
Crop
Current
Maximum
Application
Rate
Current
Number
of
Applications/
Retreatment
Interval
Revised
Application
Rate
(
Annual
Rate)
Number
of
Applications/
Other
Revisions
Non­
Crop
Areas/
Rights­
of
Way
12
lb
ai/
A
(
typically
18
lb
ai/
A
year)
Not
Specified
(
Typically
2)
8
lb
ai/
A
except
in
areas
of
high
rainfall
or
dense
vegetation1
(
12
lb
ai/
A
per
year)
2
applications,
with
a
90­
day
retreatment
interval
Citrus
(
other
than
Flatwood
area)
3.2
lb
ai/
A
No
Limit
(
1.6
­
3.2
lb/
A
per
application
to
max
of
6.4
lb/
A
per
year)
3.2
lb
ai/
A
(
6.4
lb
ai/
A
per
year)
2
applications,
with
a
60­
day
retreatment
interval
(
Trees
<
4
years)

2
applications,
with
a
80­
day
retreatment
interval
(
Trees
>
4
years)

Citrus
(
Flatwood
area)
6.4
lb
ai/
A
(
9.6
lb
ai/
A
per
year)
No
Limit
(
1.6
­
6.4
lb/
A
per
application
to
max
of
9.6
lb/
A
per
year)
6.4
lb
ai/
A
(
6.4lb
ai/
A
per
year)
2
applications,
with
a
60­
day
retreatment
interval
(
Trees
<
4
years)

2
applications,
with
a
80­
day
retreatment
interval
(
Trees
>
4
years)

Apple
3.2
lb
ai/
A
1­
2
(
1.6
­
3.2
lb/
A
to
max
of
3.2
lb/
A
per
year)
3.2
lb
ai/
A
per
year
1­
2
applications,
(
1.6
­
3.2
lb/
A
to
max
of
3.2
lb
ai/
A
per
year),
with
a
90­
day
retreatment
interval
Alfalfa
3.2
lb
ai/
A
1
application/
year
2.4
lb
ai/
A
per
year
1
application
Crop
Current
Maximum
Application
Rate
Current
Number
of
Applications/
Retreatment
Interval
Revised
Application
Rate
(
Annual
Rate)
Number
of
Applications/
Other
Revisions
92
Cotton
2.2
lb
ai/
A
Not
Specified
Preplant/
Preemergence
(
0.8
­
1.6
lb
ai/
A)
3
applications,
with
total
ai
per
season
limited
to
0.8
lb
ai/
A
on
coarse
soils,
1.5
lb
ai/
A
on
medium
soils
and
2.2
lb
ai/
A
on
fine
soils,
with
a
21­
day
retreatment
interval
Post­
emergence:
(
0.8
­
1.2
lb
ai/
A,
depending
upon
soil
texture)

Grapes
9.6
lb
ai/
A
2
4
lb
ai/
A
(
8
lb
ai/
A
per
year)
2
applications,
with
a
90­
day
retreatment
interval
Filberts
4
lb
ai/
A
Not
Specified
(
typically
2)
2.2
lb
ai/
A/
year
1.6
lb
ai/
A
(
3.2
lb
ai/
A
maximum)
2
applications,
with
a
150­
day
retreatment
interval
Walnuts
4
lb
ai/
A
Not
Specified
(
typically
2)
2.2
lb
ai/
A/
year
1.6
lb
ai/
A
3.0
lb
ai/
A
maximum
in
CA
(
3.2
lb
ai/
A
maximum)
2
applications
with
a
150­
day
retreatment
interval
Peaches
4
lb
ai/
A
Not
Specified
(
typically
2)
1.6
­
2.2
lb
ai/
A
1.6
­
3.0
lb
ai/
A
in
CA
Do
not
apply
within
3
months
of
harvest
Do
not
apply
within
8
months
of
harvest
in
the
western
U.
S.

Grass
Seed
Crops
3.2
lb
ai/
A
1
2.4
lb
ai/
A
1
application,
aerial
applications
are
limited
to
the
pacific
northwestern
U.
S.

1
High
rainfall
is
defined
as
>
40
inches
per
year;
high
density
vegetation
is
defined
as
>
90%
weed
ground
cover.

1.
Human
Health
Risk
Management
a.
Dietary
(
Food)
Risk
Mitigation
Diuron
is
not
acutely
toxic.
No
adverse
effects
attributed
to
a
single
exposure
were
identified
in
any
available
study.
Therefore,
no
acute
dietary
risk
assessment
was
conducted
and
no
mitigation
is
needed.
93
The
chronic
non­
cancer
dietary
analysis
indicates
all
risk
estimates
are
below
the
Agency's
level
of
concern
for
all
population
subgroups
for
diuron.
The
highest
chronic
dietary
risk
estimates
are
7%
of
the
chronic
PAD,
for
diuron,
with
the
highest
exposed
population
subgroup
being
children
(
1­
6
years).
Therefore,
the
chronic
dietary
(
food)
risk
estimate
is
not
of
concern,
and
no
risk
reduction
measures
are
necessary.

In
accordance
with
the
EPA
Draft
Guidelines
for
Carcinogen
Risk
Assessment,
the
Cancer
Assessment
Review
Committee
has
classified
diuron
as
"
known/
likely
to
be
carcinogenic
to
humans."
The
lifetime
dietary
cancer
risk
estimate
is
1.68x10­
6
for
diuron,
representing
a
borderline
exceedance.
Generally,
the
Agency
is
concerned
when
cancer
risk
estimates
exceed
the
range
of
1x10­
6
or
one
in
one
million,
although
this
negligible
risk
standard
should
not
be
viewed
as
a
brightline
standard.
As
discussed
previously,
the
residues
used
in
the
calculations
are
from
field
trials
conducted
at
the
highest
application
rates
and
from
tolerance
level
residues
from
certain
commodities.
In
addition,
some
processing
data
are
still
outstanding,
which
would
enable
further
refinement
to
the
risk
assessment.
Therefore,
the
exposure
calculation
is
a
conservative
estimate
and
the
Agency
is
not
concerned
with
the
dietary
cancer
risk
from
diuron
use.

b.
Drinking
Water
Risk
Mitigation
In
the
preliminary
risk
assessment
for
diuron,
surface
and
groundwater
concentrations
were
modeled
based
on
application
to
citrus
in
Florida;
the
crop
with
the
highest
application
rate.
An
application
rate
of
6.4
lbs
ai/
acre
could
be
applied,
with
a
second
application
of
diuron
applied
at
a
rate
of
3.2
lbs
ai/
acre
applied
later
for
the
seasonal
maximum
application
of
9.6
lbs
ai/
acre.
Based
on
information
gathered
after
the
initial
risk
assessment
was
prepared,
the
Agency
has
analyzed
surface
water
monitoring
data
from
Florida
and
California
that
has
enabled
us
to
conduct
a
more
refined
drinking
water
assessment.
In
addition,
the
registrant
has
agreed
to
reduce
the
application
rate
and
increase
the
retreatment
interval
for
citrus.
The
application
rate
on
Florida
citrus
(
Flatwood
area)
is
reduced
to
6.4
lbs
ai/
acre
per
year,
with
a
60­
day
retreatment
interval
for
trees
less
than
4
years
old
and
an
80­
day
retreatment
interval
for
trees
older
than
4
years.
Application
rate
reductions
in
other
crops
(
Table
25)
will
also
serve
to
reduce
drinking
water
exposure
to
diuron
in
drinking
water.

c.
Residential
Risk
Mitigation
Residential
exposure
to
diuron
can
occur
when
homeowners
apply
diuron­
treated
paints
or
stains
or
apply
diuron
to
ornamental
ponds
or
aquariums.
For
residential
paint
and
stain
uses,
the
short­
term
inhalation
risk
from
exposure
to
the
liquid
formulation
of
diuron
indicates
that
inhalation
MOEs
are
more
than
the
target
of
100
with
baseline
level
of
clothing.
Therefore,
the
short­
term
risks
to
homeowners
from
paint
and
stain
use
is
not
of
concern.
Diuron
application
to
ponds
and
aquariums
is
not
of
concern
and
does
not
require
further
mitigation.
In
addition,
the
registrant
has
agreed
to
eliminate
diuron
application
to
home
lawns.
94
(
1)
Residential
Handler
Mitigation
The
lifetime
cancer
risk
estimates
for
applying
diuron­
treated
paint
and
stain
products
once
per
year
for
50
years
range
from
9.5x10­
7
to
1.1x10­
6.
However,
the
Agency
believes
these
exposures
are
not
of
concern
because
it
is
unlikely
that
a
homeowner
would
apply
diuron
treated
paint
or
stain
every
year
for
50
years.
In
addition,
approximately
one
percent
of
all
paint
contains
diuron
and
that
paint
contains
a
maximum
of
0.0532
lbs.
of
diuron
per
gallon.
Therefore,
the
Agency
believes
the
risks
to
homeowners
from
applying
diuron­
treated
paints
and
stains
are
negligible
and
not
of
concern.
No
further
risk
mitigation
is
necessary.

(
2)
Residential
Postapplication
Risk
Mitigation
Post­
application
exposure
to
diuron­
treated
paints,
and
stains
is
anticipated
to
be
only
by
the
inhalation
route,
as
the
treated
materials
will
have
dried
and
be
relatively
inert.
The
results
of
Multi­
Chamber
Concentration
and
Exposure
Model,
as
discussed
previously,
coupled
with
diuron's
low
vapor
pressure
(
2
x
10­
7
mm
Hg
at
30

C),
show
negligible
postapplication
inhalation
exposure.
Furthermore,
diuron­
treated
paint
is
only
likely
to
be
used
in
rooms
where
high
humidity
is
expected,
such
as
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
diurontreated
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.
No
risk
mitigation
is
necessary
for
postapplication
exposure
to
homeowners.

d.
Aggregate
Risk
Mitigation
(
1)
Acute
Aggregate
Risk
There
are
no
adverse
effects
expected
from
a
single
exposure
to
diuron;
therefore,
an
acute
aggregate
risk
assessment
was
not
conducted.

(
2)
Short­
term
Aggregate
Risk
Short­
term
aggregate
exposure
takes
into
account
residential
exposure
plus
chronic
exposure
to
food
and
water.
Short­
term
aggregate
risks
from
food,
residential
inhalation,
and
drinking
water
are
not
of
concern;
therefore,
no
mitigation
is
required.

(
3)
Chronic
(
Non­
Cancer)
Aggregate
Risk
The
chronic
(
non­
cancer)
aggregate
risk
assessment
addresses
exposure
to
diuron
residues
in
food
and
water;
there
are
no
diuron
uses
that
could
result
in
chronic
residential
exposure.
The
estimated
environmental
concentration
(
EEC)
for
surface
water
(<
1
ppb)
does
not
exceed
the
drinking
water
level
of
comparison
(
DWLOC)
of
28
ppb
for
the
most
sensitive
population
subgroup
(
children
1­
6).
Chronic
dietary
(
food
+
water)
risks
are
below
EPA's
level
of
concern.
Chronic
aggregate
risk
is
also
below
EPA's
level
of
concern;
therefore,
no
mitigation
is
required.
95
(
4)
Chronic
(
Cancer)
Aggregate
Risk
As
mentioned
previously,
dietary
risk
from
food
is
estimated
to
slightly
exceed
1
x
10­
6,
based
on
field
trial
data
and
assuming
maximum
application
rates.
This
estimate
can
be
refined
with
additional
residue
data.
Based
on
monitoring
data,
drinking
water
cancer
risk
is
estimated
in
the
1
x
10­
6
range.
Lifetime
exposure
from
residential
uses
is
negligible.
Although
the
combined
risk
slightly
exceeds
1
x
10­
6,
EPA
believes
that,
given
the
weight
of
evidence,
diuron
cancer
risk
is
not
of
concern.
The
Agency
does
not
apply
the
negligible
risk
standard
for
cancer
(
1
x
10­
6
or
one
in
a
million)
as
a
bright
line
test
because
of
the
lack
of
precision
in
the
quantitative
cancer
risk
assessment.
There
are
protective
assumptions
in
both
the
toxicological
data
used
to
derive
the
cancer
potency
of
a
substance
and
in
the
exposure
calculations.
In
addition,
other
risk
mitigation
measures
discussed
in
this
document
will
result
in
lower
aggregate
risks.

e.
Occupational
Risk
Mitigation
The
Agency
met
with
the
registrant
to
discuss
occupational
risk
mitigation
on
August
6,
2003
and
September
10,
2003.
Stakeholders
submitted
information
regarding
use
rates,
acreage,
and
use
practices
to
the
Agency
in
order
to
further
refine
the
cancer
risk
assessment.
This
information
was
confirmed
and
used
by
the
Agency
to
further
characterize
the
occupational
risks.

(
1)
Handler
Risk
Mitigation
Handler
exposure
assessments
are
completed
by
EPA
using
a
baseline
exposure
scenario
and,
if
required,
increasing
levels
of
mitigation
(
PPE
and
engineering
controls)
to
achieve
an
adequate
margin
of
exposure
(
MOE).
For
diuron
the
target
MOE
for
workers
is
100.
Analyses
for
handler/
applicator
exposures
were
performed
using
PHED,
ORETF,
and
available
studies.
The
non­
cancer
calculations
indicate
that
the
MOEs
for
many
handler
scenarios
including
all
agricultural
applicator
scenarios
are
above
100
at
the
baseline
level
and
are
not
of
concern.
Generally
for
diuron,
the
worker
risk
mitigation
is
driven
by
the
cancer
assessment.

For
occupational
cancer
risks
between
1x10­
6
and
1x10­
4,
EPA
carefully
evaluates
exposure
scenarios
to
seek
cost
effective
ways
to
reduce
cancer
risks
to
the
greatest
extent
feasible,
preferably
to
a
risk
of
1x10­
6
or
less.
For
the
scenarios
listed
below,
EPA
has
determined
that
the
use
of
PPE
or
engineering
controls
would
further
reduce
exposure
to
handlers
but
for
some
scenarios,
such
as
mixing/
loading
and
applying
with
a
backpack
sprayer,
and
applying
with
a
rightsof
way
sprayer,
engineering
controls
are
not
available.
For
other
scenarios,
such
as
applying
granular
formulations
with
a
tractor­
drawn
spreader,
some
engineering
controls
may
be
available
but
they
are
not
universally
used
for
this
type
of
application.
The
Agency
encourages
the
use
of
engineering
controls
in
all
settings
where
practical
and
feasible,
and
allows
for
handlers
to
reduce
PPE
when
engineering
controls
are
used.
However,
EPA
concludes
that
the
risk
reduction
potential
of
requiring
engineering
controls
for
additional
scenarios
would
not
be
commensurate
with
the
costs
and
difficulties
associated
with
implementing
the
requirement.
96
To
address
cancer
risks
to
occupational
handlers,
the
registrant
has
agreed
to
the
following
mitigation
measures,
which
are
necessary,
reasonable,
and
cost­
effective:

°
Eliminate
aerial
applications
except
for
rights­
of­
way,
alfalfa,
cotton,
winter
barley,
winter
wheat,
sugarcane,
and
grass
seed
crops
(
in
the
pacific
northwestern
U.
S.
only).

°
All
wettable
powder
products
will
be
voluntarily
canceled.

°
Use
of
the
pump­
feed
backpack
spreader
and
the
gravity­
feed
backpack
spreader
will
be
prohibited.

°
Cancel
use
of
diuron
on
home
lawns.

°
Application
of
diuron
using
a
spoon
will
be
prohibited.

EPA
has
determined
that
worker
risks
from
exposure
to
diuron
in
the
scenario
listed
below
would
be
adequately
mitigated
through
the
use
of
the
following
PPE:
long
pants,
long­
sleeved
shirt,
socks,
shoes,
and
gloves.

°
Applying
Granular
Formulations
by
Hand;
°
Loading/
Applying
Granular
Formulations
with
a
Belly
Grinder;
and
°
Loading/
Applying
Granular
Formulations
with
a
Push­
Type
Spreader.

EPA
has
determined
that
worker
risks
from
exposure
to
diuron
in
the
scenarios
listed
below
would
be
adequately
mitigated
through
the
use
of
the
following
PPE:
long
pants,
long­
sleeved
shirt,
dust
mist
respirator,
socks,
shoes,
and
gloves:

°
Loading
Granular
Formulation
for
Tractor­
Drawn
Spreader
Application;
°
Applying
Granular
Formulations
with
a
Tractor­
Drawn
Spreader;
°
Applying
Sprays
Using
a
Rights­
of­
Way
Sprayer
(
no
PPE
required
in
closed
cab);
°
Applying
Sprays
Using
a
High­
Pressure
Handwand;
°
Mixing/
Loading/
Applying
Liquids
Using
a
Low
Pressure
Handwand;
and
°
Mixing/
Loading/
Applying
Liquids
Using
a
Backpack
Sprayer.

EPA
has
determined
that
worker
risks
from
exposure
to
diuron
in
the
scenarios
listed
below
would
be
adequately
mitigated
through
the
use
of
the
following
PPE:
long
pants,
long­
sleeved
shirt,
dust
mist
respirator,
socks,
shoes,
gloves,
and
apron:

°
Mixing/
Loading
Liquids
for
Aerial
Application;
°
Mixing/
Loading
Liquids
for
Chemigation
Application;
°
Mixing/
Loading
Liquids
for
Groundboom
Application;
°
Mixing/
Loading
Liquids
for
Rights­
of­
Way
Application;
°
Mixing/
Loading
Liquids
for
High­
Pressure
Handwand
Application;
°
Mixing/
Loading
Dry
Flowable
for
Aerial
Application;
97
°
Mixing/
Loading
Dry
Flowable
for
Chemigation
Application
°
Mixing/
Loading
Dry
Flowable
for
Groundboom
Application;
°
Mixing/
Loading
Dry
Flowable
for
Rights­
of­
Way
Application;
and
°
Mixing/
Loading
Dry
Flowable
for
High­
Pressure
Handwand
Application.

EPA
has
determined
that
worker
risks
from
exposure
to
diuron
in
the
scenario
listed
below
would
be
adequately
mitigated
through
the
use
of
an
enclosed
cockpit
or
enclosed
cab.

°
Applying
Sprays
Aerially;
and
°
Flagging
for
Spray
Applications.

°
Applying
sprays
with
rights­
of­
way
sprayers
for
commercial
applicators
(
scenario
7),
the
assessment
is
based
on
the
worker
applying
1000
gallons
of
liquid
with
a
rightsof
way
sprayer.
The
Agency
has
received
information
indicating
that
workers
typically
use
4.8
­
6.4
lbs
ai/
A.
Higher
application
rates
are
used
on
less
than
10
percent
of
the
acreage
and
are
limited
to
difficult
to
treat
areas
where
longer
residual
control
is
necessary.
In
addition,
the
Agency
has
concluded
that
the
estimate
of
applying
1000
gallons
of
product
per
day
with
30
days
of
exposure
per
year
to
be
a
high
estimate
that
would
not
reflect
actual
exposure
to
workers.
Typically,
the
truck
where
the
applicator
rides
has
the
controls
for
operating
the
sprayer
inside
the
cab.
With
the
windows
closed,
the
driver
of
the
truck
would
not
be
required
to
wear
any
PPE.
However,
an
applicator
outside
the
truck
operating
the
spray
equipment,
would
be
required
to
wear
maximum
PPE.
EPA
has
concluded
that
with
the
addition
of
maximum
PPE,
this
scenario
would
not
require
additional
risk
mitigation.

°
Applying
sprays
for
high
pressure
handwand
application
for
commercial
applicators
(
scenario
8),
the
assessment
is
based
on
the
worker
applying
1000
gallons
of
liquid
with
a
high
pressure
handwand.
The
Agency
has
received
information
about
high
pressure
handwand
use.
The
information
indicates
that
most
non­
crop
applications
would
be
made
by
a
truck­
mounted
boom.
The
high
pressure
handwand
would
be
used
only
around
fence
or
sign
posts
or
other
areas
that
are
not
accessible
with
the
truck­
mounted
boom.
It
is
estimated
that
the
high
pressure
handwand
is
used
in
less
than
10
percent
of
rights­
of­
way
treatment.
Therefore,
the
Agency
has
determined
that
the
estimate
of
applying
1000
gallons
of
product
per
day
with
30
days
of
exposure
per
year
to
be
a
high
estimate
that
would
not
reflect
actual
exposure
to
workers
and
would
not
require
additional
risk
mitigation
beyond
maximum
PPE.

°
Loading/
applying
granulars
for
belly
grinder
applications
for
commercial
applicators
(
scenario
18),
the
application
rate
used
in
the
assessment
is
87.1
lbs
ai/
A,
much
higher
than
any
product
labels
currently
on
the
market.
The
highest
application
rate
on
a
marketed
label
is
12
lbs
ai/
A.
The
registrant
has
agreed
to
limit
the
application
rates
for
non­
crop
uses
to
12
lbs
ai/
A.
In
addition,
the
registrant
has
agreed
to
limit
the
percent
active
ingredient
in
all
granular
products
to
no
more
than
8
%.
The
98
Agency
has
received
information
about
belly
grinder
use;
this
information
indicates
that
most
non­
crop
applications
would
be
applied
by
a
truck­
mounted
boom.
The
belly
grinder
would
mostly
be
used
around
fence
or
sign
posts
or
other
areas
that
are
not
accessible
with
the
truck­
mounted
boom.
In
this
type
of
treatment,
the
applicator
typically
applies
7.2
lb
ai/
A.
In
a
typical
day
an
applicator
would
apply
diuron
on
eight
to
twelve
small
sites
equaling
approximately
two
acres.
Therefore,
the
Agency
has
concluded
that
the
estimate
of
applying
diuron
at
the
high
application
rate
to
be
a
high
estimate
that
would
not
reflect
actual
exposure
to
workers.
No
additional
risk
mitigation
is
required
beyond
maximum
PPE.

(
2)
Post­
application
Risk
Mitigation
The
Restricted
Entry
Interval
(
REI)
represents
the
amount
of
time
required
for
residues
to
dissipate
in
treated
areas
prior
to
beginning
a
job
or
task
in
that
area
such
that
the
resulting
exposures
do
not
exceed
the
Agency's
level
of
risk
concern.
In
order
to
determine
the
REI
for
a
crop,
EPA
calculates
the
number
of
days
that
must
elapse
after
pesticide
application
until
residues
dissipate
and
risk
to
a
worker
falls
below
the
target
risk
level.
For
a
specific
crop/
pesticide
combination,
the
duration
required
to
achieve
the
target
risk
estimate
can
vary
depending
on
the
activity
assessed.

Only
the
crops
whose
foliage
can
be
sprayed
without
damage
were
assessed
for
postapplication
exposure.
The
crops
that
can
be
sprayed
without
foliage
damage
are
oats,
wheat,
birdsfoot
trefoil,
clover,
grass
grown
for
seed,
alfalfa,
asparagus,
pineapple
and
sugarcane.

In
general,
the
Agency
is
concerned
when
postapplication
occupational
cancer
risk
estimates
exceed
1
x10­
4.
Postapplication
cancer
risks
for
commercial
and
private
farm
workers
were
calculated
at
the
typical
application
rate
only
for
each
crop
that
received
foliar
applications.
All
cancer
risks
to
commercial
and
private
farm
workers
were
less
than
1
x
10­
4
on
the
day
of
treatment
and
not
of
concern.
Therefore,
no
additional
risk
mitigation
is
necessary,
the
REI
for
diuron
labels
will
remain
at
12­
hours
with
the
following
early
entry
PPE
required:
coveralls
over
long
sleeved
shirt
and
long
pants,
waterproof
gloves,
chemical
resistant
footwear
plus
socks,
protective
eye
wear
and
chemical
resistant
headgear
for
overhead
exposures.

2.
Environmental
Risk
Mitigation
EPA's
ecological
risk
assessment
shows
minimal
exceedance
of
the
levels
of
concern
for
acute
risk
to
birds.
Chronic
risk
to
birds
could
not
be
calculated
due
to
a
lack
of
chronic
avian
toxicity
data;
these
data
are
required.
Chronic
RQs
for
very
small
mammals
(
15
grams)
range
from
0.1
to
9.2;
all
other
mammalian
RQs
are
below
levels
of
concern.
Acute
RQs
for
freshwater
fish
and
invertebrates
are
relatively
low
ranging
from
0.03
to
2.6;
however,
limited
incident
data
suggest
that
diuron
may
pose
an
acute
risk
to
fish.
Chronic
RQs
for
freshwater
fish
range
from
0.3
to
9.
Acute
and
chronic
risk
quotients
for
estuarine
and
marine
fish
and
invertebrates
are
low,
with
the
highest
RQ
of
1.3
for
chronic
risk
to
marine
invertebrates,
based
on
the
12
lb.
application
rate
to
rights­
of­
way.
Of
greatest
concern
is
the
potential
acute
risk
to
non­
target
plants,
with
RQs
for
99
terrestrial
plants
ranging
from
1
to
77
and
RQs
for
endangered
terrestrial
plants
ranging
from
5
to
over
300.
Acute
RQs
for
aquatic
non­
vascular
plants
range
from
10
to
172.
RQs
for
aquatic
vascular
and
endangered
aquatic
vascular
plants
could
not
be
calculated
because
no
toxicity
data
were
available;
these
data
are
required.
Acute
risk
to
non­
target
plants
is
further
supported
by
available
incident
data.

Many
of
the
mitigation
measure
mentioned
earlier
in
this
section
will
also
serve
to
decrease
risk
to
non­
target
species.
These
include:

°
Eliminate
aerial
applications
except
for
rights­
of­
way,
alfalfa,
cotton,
winter
barley,
winter
wheat,
sugarcane,
and
grass
seed
crops
(
in
the
pacific
northwestern
U.
S.
only).

°
Reducing
applications
rates
and
increasing
interval
between
applications
for
numerous
crops
as
shown
in
Table
25;

°
Implementing
labeling
with
best
management
practices
to
reduce
spray
drift;
and
°
Reducing
application
rates
on
walnuts,
filbert,
and
peaches
to
address
risk
to
endangered
salmon
and
steelhead
in
California
and
the
Pacific
northwest.

3.
Other
Labeling
Requirements
In
order
to
be
eligible
for
reregistration,
various
use
and
safety
information
must
also
be
placed
on
the
labeling
of
all
end­
use
products
containing
diuron.
For
the
specific
labeling
statements,
refer
to
Section
V
of
this
document.

a.
Endangered
Species
Statement
The
Agency
has
developed
the
Endangered
Species
Protection
Program
to
identify
pesticides
whose
use
may
cause
adverse
impacts
on
endangered
and
threatened
species,
and
to
implement
mitigation
measures
that
address
these
impacts.
EPA
is
not
requiring
specific
label
language
at
the
present
time
relative
to
threatened
and
endangered
species.
The
general
risk
mitigation
required
through
this
RED
will
serve
to
protect
listed
species
of
potential
concern
until
such
time
as
the
agency
refines
its
risk
assessment
for
birds,
mammals,
aquatic
species
and
plants
from
the
uses
of
diuron.
If
in
the
future,
specific
measures
are
necessary
for
the
protection
of
listed
species,
the
Agency
will
implement
them
through
the
Endangered
Species
Protection
Program.

The
Endangered
Species
Protection
Program
as
described
in
a
Federal
Register
notice
(
54
FR
27984­
28008,
July
3,
1989)
is
currently
being
implemented
on
an
interim
basis.
As
part
of
the
interim
program,
the
Agency
has
developed
County
Specific
Pamphlets
that
articulate
many
of
the
specific
measures
outlined
in
the
Biological
Opinions
issued
to
date.
The
Pamphlets
are
available
for
voluntary
use
by
pesticide
applicators
on
EPA's
website
at
www.
epa.
gov/
espp.
A
final
Endangered
Species
Protection
Program,
which
may
be
altered
from
the
interim
program,
was
proposed
for
public
comment
in
the
Federal
Register
December
2,
2002.
b.
Spray
Drift
Management
100
The
Agency
has
been
working
closely
with
stakeholders
to
develop
improved
approaches
for
mitigating
risks
to
human
health
and
the
environment
from
pesticide
spray
and
dust
drift.
As
part
of
the
reregistration
process,
we
will
continue
to
work
with
all
interested
parties
on
this
important
issue.

From
its
assessment
of
diuron,
as
summarized
in
this
document,
the
Agency
concludes
that
certain
measures
are
needed
to
address
the
potential
for
off­
target
drift
from
use
of
diuron
products.
Label
statements
implementing
these
measures
are
listed
in
the
"
spray
drift
management"
section
of
the
label
table,
which
will
be
issued
separately.
In
the
future,
diuron
product
labels
may
need
to
be
revised
to
include
additional
or
different
drift
label
statements.

The
following
label
language
is
required
to
address
the
risks
from
off­
target
drift
for
diuron
products.

For
non­
WPS
products:

"
Do
not
apply
this
product
in
a
way
that
will
contact
workers
or
other
persons
either
directly
or
through
drift."

For
all
diuron
products
applied
as
a
liquid
(
including
non­
WPS
products):

"
Requirements
for
reducing
spray
drift
for
diuron
ground
and
aerial
applications"

"
Use
best
practices
to
avoid
drift
to
all
other
crops
and
non­
target
areas.
Do
not
apply
when
conditions
favor
drift
from
target
areas.
The
interaction
of
many
equipment­
and
weather­
related
factors
determine
the
potential
for
spray
drift.
Avoiding
spray
drift
at
the
application
site
is
the
responsibility
of
the
applicator.
The
applicator
must
follow
the
most
restrictive
precautions
to
avoid
drift,
including
those
found
in
this
labeling
as
well
as
applicable
state
and
local
regulations
and
ordinances."

"
Do
not
make
aerial
or
ground
applications
when
the
wind
speed
exceeds
10
miles
per
hour."

"
Do
not
make
aerial
or
ground
applications
into
temperature
inversions."

"
Apply
as
a
medium
or
coarser
spray
(
according
to
ASAE
standard
572)
for
standard
nozzles."

Additional
requirements
for
ground
applications:

"
When
applying
to
crops,
apply
with
nozzle
height
no
more
than
6
feet
above
the
ground
or
crop
canopy.
When
applying
to
non­
crop
areas,
use
lowest
nozzle
height
consistent
with
safety
and
efficacy.
Direct
spray
into
target
vegetation."
101
Additional
requirements
for
aerial
applications:

"
The
boom
length
must
not
exceed
75%
of
the
wingspan
or
90%
of
rotor
blade
diameter."

"
When
aerial
applications
are
made
with
cross­
wind,
the
swath
will
be
displaced
downwind.
The
applicator
must
compensate
for
this
displacement
at
the
downwind
edge
of
the
application
area
by
adjusting
the
path
of
the
aircraft
upwind."

"
When
applying
to
crops,
do
not
release
spray
at
a
height
greater
than
6
to
10
feet
above
the
ground
or
crop
canopy.
When
applying
to
non­
crop
areas,
apply
at
a
minimum
safe
altitude
above
the
area
being
treated."

"
Release
spray
at
the
lowest
height
consistent
with
efficacy
and
flight
safety."

"
Do
not
apply
by
air
if
drift
can
occur
to
sensitive
non­
target
crops
or
plants
that
are
within
100
feet
of
the
application
site."

V.
What
Registrants
Need
to
Do
The
Agency
has
determined
that
diuron
is
eligible
for
reregistration
provide
that:
(
i)
additional
data
that
the
Agency
intends
to
require
confirm
this
interim
decision;
and
(
ii)
the
risk
mitigation
measures
outlined
in
this
document
are
adopted,
and
label
amendments
are
made
to
reflect
these
measures.
To
implement
the
risk
mitigation
measures,
the
registrants
must
amend
their
product
labeling
to
incorporate
the
label
statements
set
forth
in
the
Label
Summary
Table
in
Section
D
below.
The
additional
data
requirements
that
the
Agency
intends
to
obtain
will
include,
among
other
things,
submission
of
the
following:

A.
For
diuron
technical
grade
active
ingredient
products,
the
registrant
needs
to
submit
the
following
items.

Within
90
days
from
receipt
of
the
generic
data
call­
in
(
DCI):

(
1)
completed
response
forms
to
the
generic
DCI
(
i.
e.,
DCI
response
form
and
requirements
status
and
registrant's
response
form);
and
(
2)
submit
any
time
extension
and/
or
waiver
requests
with
a
full
written
justification.

Within
the
time
limit
specified
in
the
generic
DCI:

(
1)
cite
any
existing
generic
data
which
address
data
requirements
or
submit
new
generic
data
responding
to
the
DCI.
102
Please
contact
Diane
Isbell
at
(
703)
308­
8154
with
questions
regarding
generic
reregistration.

By
US
mail:
By
express
or
courier
service:
Document
Processing
Desk
(
DCI/
SRRD)
Document
Processing
Desk
(
DCI/
SRRD)
Diane
Isbell
Diane
Isbell
US
EPA
(
7508C)
Office
of
Pesticide
Programs
(
7508C)
1200
Pennsylvania
Ave.,
NW
Room
266A,
Crystal
Mall
2
Washington,
DC
20460
1921
Jefferson
Davis
Highway
Arlington,
VA
22202
B.
For
products
containing
the
active
ingredient
diuron,
the
registrant
needs
to
submit
the
following
items
for
each
product.

Within
90
days
from
the
receipt
of
the
product­
specific
data
call­
in
(
PDCI):

(
1)
completed
response
forms
to
the
PDCI
(
i.
e.,
PDCI
response
form
and
requirements
status
and
registrant's
response
form);
and
(
2)
submit
any
time
extension
or
waiver
requests
with
a
full
written
justification.

Within
eight
months
from
the
receipt
of
the
PDCI:

(
1)
two
copies
of
the
confidential
statement
of
formula
(
EPA
Form
8570­
4);

(
2)
a
completed
original
application
for
reregistration
(
EPA
Form
8570­
1).
Indicate
on
the
form
that
it
is
an
"
application
for
reregistration";
(
3)
five
copies
of
the
draft
label
incorporating
all
label
amendments
outlined
in
Table
39
of
this
document;
(
4)
a
completed
for
certifying
compliance
with
data
compensation
requirements
(
EPA
Form
8570­
34);
(
5)
if
applicable,
a
completed
for
certifying
compliance
with
cost
share
offer
requirements
(
EPA
Form
8570­
32);
and
(
6)
the
product­
specific
data
responding
to
the
PDCI.

Please
contact
Barbara
Briscoe
at
(
703)
308­
8178
with
questions
regarding
product
reregistration
and/
or
the
PDCI.
All
materials
submitted
in
response
to
the
PDCI
should
be
addressed
as
follows:
103
By
US
mail:
By
express
or
courier
service:
Document
Processing
Desk
(
PDCI/
PRB)
Document
Processing
Desk
(
PDCI/
PRB)
Barbara
Briscoe
Barbara
Briscoe
US
EPA
(
7508C)
Office
of
Pesticide
Programs
(
7508C)
1200
Pennsylvania
Ave.,
NW
Room
266A,
Crystal
Mall
2
Washington,
DC
20460
1921
Jefferson
Davis
Highway
Arlington,
VA
22202
A.
Manufacturing
Use
Products
1.
Additional
Generic
Data
Requirements
The
generic
data
base
supporting
the
reregistration
of
diuron
for
the
above
eligible
uses
has
been
reviewed
and
determined
to
be
substantially
complete.
However,
the
following
data
requirements
are
necessary
to
confirm
the
reregistration
eligibility
decision
documented
in
this
RED.

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:
globe
artichoke;
barley
hay;
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;
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
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
104
Environmental
Fate
and
Ecological
Effects
Data:

°
Avian
reproduction
study
­
diuron
°
Freshwater
aquatic
invertebrate
life­
cycle
toxicity
study
­
diuron
°
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
2.
Labeling
for
Manufacturing­
Use
Products
To
ensure
compliance
with
FIFRA,
manufacturing
use
product
(
MUP)
labeling
should
be
revised
to
comply
with
all
current
EPA
regulations,
PR
Notices
and
applicable
policies.
The
MUP
labeling
should
bear
the
labeling
contained
in
the
labeling
table,
which
will
be
issued
separately.

B.
End­
Use
Products
1.
Additional
Product­
Specific
Data
Requirements
Section
4(
g)(
2)(
B)
of
FIFRA
calls
for
the
Agency
to
obtain
any
needed
product­
specific
data
regarding
the
pesticide
after
a
determination
of
eligibility
has
been
made.
The
Registrant
must
review
previous
data
submissions
to
ensure
that
they
meet
current
EPA
acceptance
criteria
and
if
not,
commit
to
conduct
new
studies.
If
a
registrant
believes
that
previously
submitted
data
meet
current
testing
standards,
then
the
study
MRID
numbers
should
be
cited
according
to
the
instructions
in
the
Requirement
Status
and
Registrants
Response
Form
provided
for
each
product.

A
product­
specific
data
call­
in,
outlining
specific
data
requirements,
accompanies
this
RED.

2.
Labeling
for
End­
Use
Products
Labeling
changes
are
necessary
to
implement
measures
outlined
in
Section
IV
above.
Specific
language
to
incorporate
these
changes
is
specified
in
Table
26.

C.
Existing
Stocks
Registrants
may
generally
distribute
and
sell
products
bearing
old
labels/
labeling
for
12
months
from
the
date
of
the
issuance
of
this
Reregistration
Eligibility
Decision
document.
Persons
other
than
the
registrant
may
generally
distribute
or
sell
such
products
for
24
months
from
the
date
of
the
issuance
of
this
RED.
However,
existing
stocks
time
frames
will
be
established
case­
by­
case,
105
depending
on
the
number
of
products
involved,
the
number
of
label
changes,
and
other
factors.
Refer
to
"
Existing
Stocks
of
Pesticide
Products;
Statement
of
Policy";
Federal
Register,
Volume
56,
No.
123,
June
26,
1991.