UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
Date:
October
06,
2005
SUBJECT:
Imazaquin:
Residential
Exposure
Assessment
and
Recommendations
for
the
Tolerance
Reassessment
Eligibility
Decision
(
TRED)

FROM:
Seyed
Tadayon,
Chemist
Reregistration
Branch
III
Health
Effect
Division
(
7509C)

THRU:
William
Donovan,
Acting
Branch
Senior
Scientist
Reregistration
Branch
III
Health
Effect
Division
(
7509C)

TO:
Susan
Stanton,
Risk
Assessor
Reregistration
Branch
III
Health
Effect
Division
(
7509C)

PC
Code:
128848
DP
Barcode:
D302942
The
attached
assessment
shows
the
non­
occupational
(
residential)
exposure
and
risk
estimates
for
imazaquin
to
support
HED's
tolerance
reassessment
eligibility
decision
(
TRED).
Page
2
of
25
Table
of
Contents
1.0
EXECUTIVE
SUMMARY
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3
2.0
BACKGROUND
INFORMATION
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4
2.1
Purpose
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4
2.2
Criteria
for
Conducting
Exposure
Assessments
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4
2.3
Summary
of
Toxicity
Concerns
Related
to
Residential
Exposures
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4
2.4
FQPA
Safety
Factor
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6
2.5
Incident
Reports
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7
2.6
Summary
of
Physical
and
Chemical
Properties
of
imazaquin
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7
2.7
Summary
of
Use
Pattern
and
Formulations
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7
3.0
RESIDENTIAL
EXPOSURE
AND
RISKS
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7
3.1
Residential
Handler
Exposures
and
Risks
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7
3.1.1
Handler
Exposure
Scenarios
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7
3.1.2
Data
and
Assumptions
For
Handler
Exposure
Scenarios
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8
3.1.3
Residential
Handler
Exposure
and
Non­
Cancer
Risk
Estimates
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10
3.1.4
Residential
Handler
Exposure
and
Risk
Estimates
for
Cancer
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11
3.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Handlers
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11
3.1.6
Recommendations
For
Refining
Residential
Handler
Risk
Assessment
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11
3.2
Residential
Postapplication
Exposures
and
Risks
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11
3.2.1
Residential
Postapplication
Exposure
Scenarios
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12
3.2.2
Data
and
Assumptions
for
Residential
Postapplication
Exposure
Scenarios
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12
3.2.3
Residential
Postapplication
Exposure
and
Noncancer
Risk
Estimates
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13
3.2.4
Residential
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
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3.2.5
Summary
of
Residential
Postapplication
Risk
Concerns
and
Data
Gaps
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17
3.2.6
Recommendations
For
Refining
Residential
Postapplication
Risk
Assessment
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17
3.3
Spray
Drift
from
Agricultural
Uses
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18
Appendix
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19
Page
3
of
25
1.0
EXECUTIVE
SUMMARY
This
document
supports
the
Tolerance
Reassessment
Eligibility
Decision
(
TRED)
for
imazaquin
and
addresses
risks
resulting
from
non­
occupational
(
residential)
exposures
only.
Occupational
exposures
will
not
be
addressed
in
this
document.

At
this
time,
products
containing
imazaquin
are
intended
for
both
occupational
and
nonoccupational
uses.
Imazaquin
is
a
selective
herbicide
used
in
the
post­
emergent
control
of
grasses
in
agricultural,
ornamental,
residential
and
recreational
(
golf
courses)
settings.
Imazaquin
has
occupational
uses
that
will
not
be
addressed
in
this
TRED.
The
imazaquin
end­
use
products
are
formulated
as
liquid
concentrates
and
ready­
to­
use
liquids
formulations.

In
residential
settings,
imazaquin
is
used
on
residential
turfgrass,
on
ornamentals,
and
for
golf
courses.
The
current
maximum
application
rate
for
application
to
residential
turfgrass
is
0.5
pounds
active
ingredient
per
acre
by
lawn
care
operators
(
LCOs),
and
0.38
pounds
active
ingredient
per
acre
by
homeowner
application.
The
maximum
application
rate
for
application
to
residential
ornamentals
and
turf
spot
treatment
is
0.006
pounds
active
ingredient
per
gallon.

Short­
term
exposures
(
defined
as
exposures
from
1
to
30
days
in
duration)
may
occur
for
residents
applying
imazaquin
products
and
for
residents
exposed
to
imazaquin
following
applications
in
residential
settings.
Intermediate­
and
long­
term
exposures
are
not
anticipated
for
residential
handling
or
postapplication
exposures.
For
short,
intermediate
and
long­
term
dermal
and
inhalation
a
NOAEL
of
25
mg/
kg/
day
(
1000
ppm)
based
on
body
weight
loss,
clinical
chemistry/
hematology
differences,
slight
anemia
and
the
presence
of
skeletal
muscle
myopathy
at
a
dose
of
125
mg/
kg/
day
(
5000
ppm)
was
selected.
For
inhalation
assessment,
100%
absorption
of
inhaled
imazaquin
in
the
atmosphere
is
assumed.
For
dermal
assessment,
50%
dermal
absorption
is
assumed.
The
same
end
point
(
25
mg/
kg/
day)
was
selected
for
incidental
oral
ingestion.

The
exposure
and
risk
for
residential
handlers
were
assessed
using
the
revised
draft
Standard
Operating
Procedures
(
SOPs)
for
Residential
Exposure
Assessment
and
the
2001
Recommended
Revisions
by
the
Science
Advisory
Council
for
Exposure
(
Policy
#
12).
Exposures
were
estimated
using
surrogate
unit
exposure
values
from
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
data
base.

Short­
term
postapplication
exposures
may
occur
following
applications
at
residential
sites.
Residential
exposures
were
estimated
based
on
HED's
1997
draft
Standard
Operating
Procedures
for
Residential
Exposure
Assessments
and
the
2001
Recommended
Revisions
by
the
Science
Advisory
Council
for
Exposure
(
Policy
#
12).
Short­
term
risks
estimated
for
Handler
and
postapplication
exposure
do
not
exceed
HED's
level
of
concern
for
any
of
the
assessed
scenarios.

2.0
BACKGROUND
INFORMATION
Page
4
of
25
2.1
Purpose
This
document
supports
the
Tolerance
Reassessment
Eligibility
Decision
(
TRED)
document
for
imazaquin
and
addresses
risks
resulting
from
non­
occupational
(
residential)
exposures
only.
Occupational
exposures
and
risks
are
not
addressed
in
this
document.

2.2
Criteria
for
Conducting
Exposure
Assessments
An
occupational
and/
or
residential
exposure
assessment
is
required
for
an
active
ingredient
if
(
1)
certain
toxicological
criteria
are
triggered
and
(
2)
there
is
potential
exposure
to
handlers
(
mixers,
loaders,
applicators,
etc.)
during
use
or
to
persons
entering
treated
sites
after
application
is
complete.
For
imazaquin,
both
criteria
are
met.

2.3
Summary
of
Toxicity
Concerns
Related
to
Residential
Exposures
Short­
term
Dermal
and
inhalation
(
non­
cancer)

Short­
term
exposures
(
defined
as
exposures
from
1
to
30
days
in
duration)
may
occur
for
residents
applying
imazaquin
products
and
for
residents
exposed
to
imazaquin
following
applications
in
residential
settings.
For
short
­
term
dermal
and
short­
term
inhalation
a
NOAEL
of
25
mg/
kg/
day
(
1000
ppm)
based
on
body
weight
loss,
clinical
chemistry/
hematology
differences,
slight
anemia
and
the
presence
of
skeletal
muscle
myopathy
at
a
dose
of
125
mg/
kg/
day
(
5000
ppm)
was
selected.
For
inhalation
assessment,
100%
absorption
of
the
inhaled
imazaquin
in
the
atmosphere
is
assumed.
For
dermal
assessment,
50%
dermal
absorption
is
assumed.

Intermediate­
term
and
Long­
term
(
Chronic)
Dermal
and
Inhalation
(
noncancer)

The
same
endpoint
of
concern
was
chosen
for
intermediate­
term
and
long­
term
dermal
and
inhalation
exposures
as
was
chosen
for
short­
term
dermal
and
inhalation
exposures.
No
Intermediate­
term
or
long­
term
exposures
are
expected
for
residential
use­
patterns,
therefore,
no
risks
were
assessed.

Short­
term
Oral
Ingestion
(
non­
cancer)

For
short
­
term
oral
ingestion
assessment
a
NOAEL
of
25
mg/
kg/
day
(
1000
ppm)
based
on
body
weight
loss,
clinical
chemistry/
hematology
differences,
slight
anemia
and
the
presence
of
skeletal
muscle
myopathy
at
a
dose
of
125
mg/
kg/
day
(
5000
ppm)
was
selected.

Dermal
Absorption
A
dermal
penetration
study
was
not
available.
When
the
NOAEL
of
1000
mg/
kg/
day
for
the
rabbit
21­
day
dermal
toxicity
study
was
compared
with
the
LOAEL
for
body
weight
effects
in
the
rabbit
oral
prenatal
developmental
toxicity
study
a
crude
estimate
of
50%
dermal
absorption
was
made.
It
is
noted
that
a
LOAEL
for
the
rabbit
oral
study
is
being
compared
with
a
NOAEL
Page
5
of
25
for
a
dermal
study
when
LOAEL
for
both
studies
should
normally
be
compared.
However,
since
no
LOAEL
for
the
rabbit
dermal
study
was
established,
the
highest
dose
tested
(
1000
mg/
kg/
day)
is
being
compared
for
a
conservative
estimate
based
on
the
possibility
that
toxicity
may
develop
at
doses
slightly
higher
than
the
NOAEL.
Otherwise
the
default
assumption
of
100%
dermal
absorption
would
have
to
be
assumed
for
imazaquin
since
there
is
no
dermal
absorption
study.

Non­
cancer
Level
of
Concern
(
LOC)

HED's
level
of
concern
for
imazaquin
exposures
is
100
 
a
margin
of
exposure
(
MOE)
less
than
100
exceeds
HED's
level
of
concern
for
residential
scenarios.
The
level
of
concern
is
based
on
10X
to
account
for
interspecies
extrapolation
to
humans
from
the
animal
test
species
and
10X
to
account
for
intraspecies
sensitivity.

Aggregation
The
dermal
and
inhalation
margins
of
exposure
were
combined
for
the
imazaquin
risk
assessment,
because
the
toxicity
endpoints
for
the
dermal
and
inhalation
routes
of
exposure
are
the
same.

Cancer
Imazaquin
is
classified
as
not
likely
to
be
carcinogenic
to
humans,
based
on
the
lack
of
evidence
of
carcinogenicity
in
mice
rats
or
dogs.

Acute
Toxicity
Imazaquin
is
classified
as
category
IV
for
acute
oral,
and
category
III
for
dermal,
and
inhalation
toxicity.
It
is
classified
as
category
IV
for
eye
irritation
potential
and
skin
irritation
potential.
Results
were
negative
for
dermal
sensitization
in
guinea
pigs.

Table
1
Acute
Toxicity
Profile
­
Imazaquin
Guideline
No.
Study
Type
MRID(
s)
Results
Toxicity
Category
870.1100
Acute
oral
[
rat]
00144178*
00144180*
00144617*
LD50
=
>
5000
mg/
kg
IV
870.1200
Acute
dermal
[
rabbit]
00144178*
00144180*
00144617*
LD50
>
2000
mg/
kg
III
870.1300
Acute
inhalation
[
rat]
00073679*
>
5.5
mg/
L
(
4
hours)
III
Page
6
of
25
870.2400
Acute
eye
irritation
[
rabbit]
00144178*
00144180*
00144617*
Non­
irritating
IV
870.2500
Acute
dermal
irritation
[
rabbit]
00144178*
00144180*
00144617*
Mildly
irritating
IV
870.2600
Skin
sensitization
[
guinea
pig]
00073680*
Negative
­
not
a
sensitizer
A
summary
of
toxicological
endpoints
for
imazaquin
is
presented
in
Table
2.

Table
2.
Summary
of
Toxicological
Doses
and
Endpoints
for
Imazaquin
Use
in
Human
Residential
Risk
Assessments
Exposure
Scenario
Dose
Used
in
Risk
Assessment,
UF
Special
FQPA
SF*
and
Level
of
Concern
for
Risk
Assessment
Study
and
Toxicological
Effects
Incidental
Oral
Short­
Term
(
1
­
30
days)
NOAEL
=
25
mg/
kg/
day
acceptable
MOE
=
100
(
residential,
FQPA
SF
=
1).
Chronic
toxicity
­
dog
LOAEL
=
125
mg/
kg/
day
based
on
weight
loss,
slight
anemia,
evidence
of
skeletal
muscle
myopathy
and
supporting
hematology/
clinical
chemistry
differences
Incidental
Oral
Intermediate­
Term
(
1
­
6
months)
NOAEL
=
25
mg/
kg/
day
acceptable
MOE
=
100
(
residential,
FQPA
SF
=
1)
Same
as
above
Dermal
­
all
exposures.
NOAEL
=
25
mg/
kg/
day.
Assume
50%
dermal
absorption.
acceptable
MOE
=
100
Same
as
above
Inhalation
­
all
exposures.
NOAEL
=
25
mg/
kg/
day
Assume
100%
absorption.
acceptable
MOE
=
100
(
occupational)
acceptable
MOE
=
100
(
residential,
FQPA
SF
=
1)
Same
as
above
Cancer
(
oral,
dermal,
inhalation)
Classification:
no
evidence
of
carcinogenicity
in
mice
or
rats.
"
Not
Likely
To
Be
Carcinogenic
To
Humans"
was
evaluated
by
imazaquin
risk
assessment
team.

UF
=
uncertainty
factor,
FQPA
SF
=
Special
FQPA
safety
factor,
NOAEL
=
no
observed
adverse
effect
level,
LOAEL
=
lowest
observed
adverse
effect
level,
MOE
=
margin
of
exposure.

2.4
FQPA
Safety
Factor
The
imazaquin
risk
assessment
team
evaluated
the
potential
for
increased
susceptibility
of
infants
and
children
from
exposure
to
imazaquin
as
required
by
the
Food
Quality
Protection
Act
Page
7
of
25
(
FQPA)
of
1996
according
to
the
2002
OPP
10x
Guidance
Document.
Based
on
the
hazard
data,
the
team
concluded
that
the
special
FQPA
SF
can
be
removed
(
1X),
since
there
are
no
concerns
and
not
residual
uncertainties
for
pre­
and/
or
postnatal
toxicity.

2.5
Incident
Reports
See
a
separate
memo
from
J
Blondell
2.6
Summary
of
Physical
and
Chemical
Properties
of
Imazaquin
See
product
chemistry
chapter.

2.7
Summary
of
Use
Pattern
and
Formulations
Imazaquin
is
formulated
as
soluble
concentrate
and
ready­
to­
use
liquid
concentrate.
It
is
registered
for
use
in
a
variety
of
agricultural,
occupational
and
residential
scenarios.
However,
this
assessment
addresses
risk
resulting
from
non­
occupational
(
residential)
exposures
only.
Occupational
exposures
will
not
be
addressed
in
this
document.
Imazaquin
is
registered
for
use
by
residential
applicators
therefore,
risks
to
residential
handlers
will
be
assessed
as
well
as
postapplication
risks
to
residential
populations.
Table
3
summarizes
the
use­
patterns
that
could
impact
nonoccupational
(
residential)
populations.

Table
3.
Summary
of
Maximum
Application
Rates
for
Imazaquin
Uses
in
Residential
Settings
Target
Application
Rate
Application
Equipment
Area
Treated
Daily
Commercial
Uses
at
Residential
Sites
Lawn
Turf*
0.38
lb
ai/
A
Garden
Hose­
end
sprayer
0.5A
Ornamental
or
shade
trees
0.006
lb
ai/
gal
Hand
Held
Pump
Sprayer
1
gal
Lawn
Turf
(
spot
treatment)
0.006
lb
ai/
gal
Ready
to
Use
Sprayer
1
gal
*
For
all
post
application
activities
an
application
rate
of
0.5
lb
ai/
A
(
commercial
rate
applied
by
LCOs)
is
used
in
this
assessment.

3.0
RESIDENTIAL
EXPOSURE
AND
RISKS
Residential
Handler
Exposures
and
Risks
3.1.1
Handler
Exposure
Scenarios
It
has
been
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
residential
use
of
imazaquin
in
a
variety
of
outdoor
environments,
including
on
lawns
and
ornamentals.
The
anticipated
use
patterns
and
current
labeling
indicate
several
residential
handler
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
to
make
Page
8
of
25
imazaquin
applications.
The
quantitative
exposure/
risk
assessment
developed
for
residential
handlers
is
based
on
these
scenarios.

Mixer/
Loader/
Applicators:
(
1)
Liquid
Concentrate:
Hose­
end
Sprayer
(
ORETF
data)
(
2)
Liquid
Concentrate:
Hand
Held
Pump
Sprayer
(
ORETF
data)
(
3)
Liquid
Concentrate:
Ready
to
Use
Sprayer
(
ORETF
data)

3.1.2
Data
and
Assumptions
For
Handler
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
residential
handler
risk
assessments.
Each
assumption
and
factor
is
detailed
below.
In
addition
to
these
factors,
unit
exposure
values
were
used
to
calculate
risk
estimates.
Mostly,
the
unit
exposure
value
was
taken
from
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
studies
Assumptions
and
Factors:
The
assumptions
and
factors
used
in
the
risk
calculations
include:

C
HED
always
considers
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments.
If
additional
information
such
as
average
or
typical
rates
are
available,
these
values
also
may
be
used
to
allow
risk
managers
to
make
a
more
informed
risk
management
decision.
Average/
typical
application
rates
were
not
available
for
residential
scenarios.

C
Residential
risk
assessments
are
based
on
estimates
of
what
homeowners
would
typically
treat,
such
as
the
size
of
a
lawn.
The
factors
used
for
the
imazaquin
assessment
were
from
the
Health
Effects
Division
Science
Advisory
Committee
Policy
12:
Recommended
Revisions
To
The
Standard
Operating
Procedures
For
Residential
Exposure
Assessment
which
was
completed
on
February
22,
2001,
and
on
professional
judgement.
The
daily
volumes
handled
and
area
treated
used
in
each
residential
scenario
are
provided
in
Table
3.

Residential
Handler
Exposure
Studies:
No
chemical­
specific
data
were
submitted
for
use
in
the
residential
handler
risk
assessment.
The
unit
exposure
values
that
were
used
in
this
assessment
were
based
on
PHED
database
and
Outdoor
Residential
Exposure
Task
Force
studies.
Summaries
of
the
studies
are
presented
below:

ORETF
Hose
End
Sprayer
Study:
A
mixer/
loader/
applicator
study
was
performed
by
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
using
diazinon
as
a
surrogate
compound
to
determine
"
generic"
exposures
to
individuals
applying
a
pesticide
to
turf
with
a
dial
type
hose
end
sprayer.
Dermal
and
inhalation
exposures
were
estimated
using
whole­
body
passive
dosimeters
and
breathing­
zone
air
samples
on
OVS
tubes.
Inhalation
exposure
was
calculated
using
an
assumed
respiratory
rate
of
17
liters
per
minute
for
light
work
(
NAFTA,
1999),
the
actual
sampling
time
for
each
individual,
and
the
pump
flow
rate.
All
results
were
normalized
for
Page
9
of
25
pounds
active
ingredient
handled.
A
total
of
30
replicates
were
monitored
throughout
the
study.
Diazinon
(
25%
emulsifiable
concentrate)
was
applied
by
homeowners
to
actual
residential
lawns
at
a
site
in
Maryland.
A
target
application
rate
of
4
pounds
active
ingredient
was
used
for
all
replicates.
Each
replicate
monitored
the
test
subject
treating
5,000
ft2
of
turf
and
handling
a
total
of
0.5
lb
ai/
replicate.
The
exposure
periods
(
mixing/
loading/
applying)
averaged
seventy­
five
minutes.
Dermal
exposure
was
measured
using
inner
and
outer
whole
body
dosimeters,
hand
washes,
face/
neck
washes,
and
personal
air
monitoring
devices.
In
general,
concurrent
lab
spikes
produced
mean
recoveries
in
the
range
of
87­
103
percent.
Adjustment
for
recoveries
from
field
fortifications
(
79­
104%)
were
performed
on
each
dosimeter
section
or
sample
matrix
for
each
study
participant,
using
the
mean
recovery
for
the
closest
field
spike
level
for
each
matrix
and
correcting
the
value
to
100
percent.
The
unit
exposures
are
presented
below
in
Table
4.
[
Note
the
data
were
found
to
be
lognormally
distributed.
As
a
result,
all
exposures
are
geometric
means.]

Table
4:
Unit
Exposures
Obtained
From
ORETF
Hose
End
Sprayer
Studies
(
MRID
449722­
01)

Type
Dermal:
Short
Pants,
Short
Sleeves
(
mg
ai/
lb
handled)
Inhalation
(
µ
g
ai/
lb
handled)

Hose­
end
(
Mix­
your­
own)
11
17
All
unit
exposures
are
geometric
means.

ORETF
Hand
Held
Pump
Sprayer
(
MRID
#
444598­
01):
The
data
collected
reflect
the
dermal
and
respiratory
exposure
of
homeowners
mixing,
loading
and
applying
RP­
2
Liquid
(
21%),
a
carbaryl
end­
use
product.
Applications
were
made
by
volunteers
to
two
18
foot
rows
of
tomatoes
and
one
18
foot
row
of
cucumber.
The
only
test
field
was
located
in
Florida.
For
this
study,
RP­
2
Liquid
(
21%)
exposures
were
monitored
using
hose­
end
sprayers
and
low­
pressure
handwand
sprayers.
Exposures
to
Sevin
®
10
Dust,
using
a
separate
duster
device
that
required
transfer
from
the
package
and
Sevin
®
Ready
To
Use
Insect
Spray
(
RTU)
in
a
trigger
sprayer
package
were
also
monitored.
Exposure
for
each
spray
method/
product
combination
was
monitored
using
40
handlers
(
replicates).
Of
the
40
replicates
per
spray
method/
product
combination,
20
wore
household
latex
gloves
and
20
performed
tasks
without
gloves.
The
20
dust
product
replicates
loaded
the
dusters
and
applied
without
gloves
only.

Each
replicate
opened
the
end­
use
product,
added
it
to
the
application
implement
(
except
the
RTU
product),
adjusted
the
setting
and
applied
it
to
the
vegetable
rows.
After
application
to
the
vegetable
rows,
dosimeters
were
collected.
Inhalation
exposure
was
monitored
with
personal
air
sampling
pumps
with
OVS
tubes
attached
to
the
shirt
collar
in
the
breathing
zone.
Dermal
exposure
was
assessed
by
extraction
of
carbaryl
from
inner
and
outer
100
percent
cotton
dosimeters,
face/
neck
wipes,
and
glove
and
hand
washes.
The
inner
and
outer
dosimeters
were
segmented
into:
lower
and
upper
arms,
lower
and
upper
legs,
front
and
back
torso.

Field
fortification
recoveries
for
passive
dosimeters
averaged
84.3
percent
for
inner
and
77.7
percent
for
outer
dosimeters.
Face
and
neck
wipe
fortifications
average
84.8
percent.
Handwash
and
Inhalation
OVS
tube
field
fortification
averaged
>
90
percent.
Inner
and
outer
Page
10
of
25
dosimeter
and
face
and
neck
wipe
residues
were
adjusted
for
field
fortification
results.
Handwash
and
inhalation
residues
were
not
adjusted.

Laboratory
method
validation
for
each
matrix
fell
within
the
acceptable
range
of
70
to
120
percent.
The
limit
of
quantitation
(
LOQ)
was
1.0
µ
g/
sample
for
all
media
except
the
inhalation
monitors
where
the
LOQ
was
0.01
µ
g/
sample.
The
limit
of
detection
(
LOD)
was
0.5
µ
g/
sample
for
all
media
except
the
inhalation
monitors
where
the
LOD
was
0.005
µ
g/
sample.

Dermal
exposure
was
determined
by
adding
the
values
from
the
bare
hand
rinses,
face/
neck
wipes
to
the
outer
dosimeter
lower
legs
and
lower
arms
plus
the
inner
dosimeter
front
and
rear
torso,
upper
legs,
lower
legs,
lower
arms,
and
upper
arms.
This
accounts
for
the
residential
handlers
with
barehands
wearing
short­
sleeved
shirt
and
short
pants.
Unit
exposures
for
this
scenario
in
each
application
method
are
presented
below
in
Table
5.
[
Note:
The
geometric
mean
values
were
used
for
risk
assessment
purposes.]

Table
5:
Unit
Exposure
Values
Obtained
From
ORETF
Study
(
(
MRID
444598­
01)

Scenario
Monitored
Dermal
Unit
Exposure
(
mg
ai/
lb
handled)
Inhalation
Unit
Exposure
(
µ
g
ai
/
lb
handled)

Hand
Held
Pump­
Spray
38
9
Ready­
to­
Use
Spray
54
67
All
unit
exposures
are
geometric
means.

3.1.3
Residential
Handler
Exposure
and
Non­
Cancer
Risk
Estimates
Residential
risk
assessments
must
include
the
determination
of
an
appropriate
Food
Quality
Protection
Act
(
FQPA)
safety
factor
to
be
applied
to
the
overall
safety
factor
or
level
of
concern.
In
the
case
of
imazaquin,
it
was
decided
that
the
factor
should
be
1X.
Therefore,
the
overall
uncertainty
factor
applied
to
imazaquin
for
residential
handler
risk
assessments
is
100,
which
is
based
on
the
FQPA
safety
factor
of
1X
along
with
the
10X
for
inter­
species
extrapolation,
and
the
10X
for
intra­
species
sensitivity.

Dermal
and
inhalation
potential
doses
for
residential
handlers
are
calculated
as
follows:

Exposure
Dose
(
mg/
kg/
day)
=
UE
x
AR
x
A
x
AB
BW
Where,
UE
=
unit
exposure
from
ORETF
study
data
(
mg/
lb
ai
or
µ
g/
lb
ai)
AR
=
maximum
application
rate
(
lb
ai/
acre
or
lb
ai/
gal)
A
=
maximum
area
treated
(
acres/
day
or
gal/
day)
AB
=
absorption
value
(
Dermal
absorption
50%
inhalation
absorption
=
100%)
BW
=
body
weight
(
70
kg)

For
handler
short­
term
exposure,
the
margin
of
exposure
(
MOE)
was
calculated
as
follows:

Inhalation
MOE
=
NOAEL
(
25
mg/
kg/
day)
Page
11
of
25
Inhalation
Exposure
Dose
Dermal
MOE=
NOAEL
(
25
mg/
kg/
day)
Dermal
Exposure
Dose
MOE
TOTAL
=
1
(
1/
Dermal
MOE
)
+
(
1/
Inhalation
MOE)

Noncancer
Risk
Summary:
All
of
the
noncancer
risk
calculations
for
residential
imazaquin
handlers
completed
in
this
assessment
are
included
in
Table
6.
The
results
of
the
residential
handler
noncancer
risk
assessment
indicate
that
none
of
the
residential
handler
risks
exceed
HED's
level
of
concern
(
i.
e.,
MOEs
are
all
greater
than
100).

Table
6:
Summery
of
Residential
Handler
Noncancer
Risks
from
Imazaquin
Exposure
Scenario
Target
Application
Rate
Area
Treated
Daily
MOE
(
HED's
level
of
concern
=
100)

Dermal
Inhalation
Dermal
+
Inhalation
Mixer/
Loader/
Applicator
Mixing/
Loading/
Applying
Liquid
Concentrates
with
Hose­
End
Sprayer
(
Residential
ORETF
data)
(
1)
Turf
0.38/
A
0.5
acre
1700
550000
1700
Mixing/
Loading/
Applying
Liquid
Concentrates
with
a
Hand
Held
Pump
(
ORETF
)
sprayer(
2)
Ornamental
or
shade
trees
0.006
lb
ai/
gal
1
gal
15400
12500000
15400
Applying
Ready
to
Use
sprayer
(
ORETF)(
3)
Turf
0.006
lb
ai/
gal
1
gal
11000
15625000
11000
3.1.4
Residential
Handler
Exposure
and
Risk
Estimates
for
Cancer
Residential
handler
cancer
risks
are
not
assessed,
since
no
toxicological
endpoint
of
concern
for
cancer
was
selected.

3.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Handlers
Noncancer
risks
(
i.
e.,
MOEs)
associated
with
the
residential
handler
scenarios
do
not
exceed
HED's
level
of
concern
of
100.

HED
has
no
data
to
assess
exposures
from
applications
using
a
sprinkling
can.
Therefore,
ORETF
residential
hose­
end
data
were
used
in
the
assessment
as
a
surrogate.

3.1.6
Recommendations
For
Refining
Residential
Handler
Risk
Assessment
In
order
to
refine
this
residential
risk
assessment,
more
data
on
actual
use
patterns
including
rates,
timing,
and
areas
treated
would
better
characterize
imazaquin
risks.

3.2
Residential
Postapplication
Exposures
and
Risks
Page
12
of
25
HED
uses
the
term
"
postapplication"
to
describe
exposures
to
individuals
that
occur
as
a
result
of
being
in
an
environment
that
has
been
previously
treated
with
a
pesticide.
Imazaquin
can
be
used
in
many
areas
that
can
be
frequented
by
the
general
population
including
residential
areas
(
e.
g.,
home
lawns).
As
a
result,
individuals
can
be
exposed
by
entering
these
areas
if
they
have
been
previously
treated.

3.2.1
Residential
Postapplication
Exposure
Scenarios
Individuals
of
varying
ages
can
potentially
be
exposed
to
imazaquin
when
they
are
in
areas
that
have
been
previously
treated.
Postapplication
exposure
scenarios
were
developed
for
each
residential
setting
where
imazaquin
can
be
used.
The
scenarios
assessed
include:

Residential
Adults:
these
individuals
are
members
of
the
general
population
that
are
exposed
to
chemicals
by
engaging
in
activities
at
their
residences
(
e.
g.,
in
their
lawns)
and
also
in
areas
not
limited
to
their
residence
(
e.
g.,
golf
courses
or
parks)
previously
treated
with
a
pesticide.
These
kinds
of
exposures
are
attributable
to
a
variety
of
activities
and
are
usually
addressed
by
HED
in
risk
assessments
by
considering
a
representative
activity
as
the
basis
for
the
exposure
calculation.

Residential
Children:
children
are
members
of
the
general
population
that
can
also
be
exposed
in
their
residences
(
e.
g.,
on
lawns
and
other
residential
turfgrass
areas).
These
kinds
of
exposures
are
attributable
to
a
variety
of
activities
such
as
playing
outside.
Toddlers
have
been
selected
as
the
sentinel
(
representative)
population
for
turf.
Children
are
addressed
by
HED
in
risk
assessments
by
considering
representative
activities
for
each
age
group
in
an
exposure
calculation.

3.2.2
Data
and
Assumptions
for
Residential
Postapplication
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
residential
postapplication
risk
assessments.
The
assumptions
and
factors
used
in
the
risk
calculations
are
consistent
with
current
Agency
policy
for
completing
residential
exposure
assessments
(
i.
e.,
SOPs
For
Residential
Exposure
Assessment).
The
values
used
in
this
assessment
include:

C
The
body
weight
of
an
average
adult
(
70
kilograms)
is
used
for
assessing
dermal
risks
to
adults.

C
HED
combines
risks
resulting
from
exposures
to
individual
applications
when
it
is
likely
they
can
occur
simultaneously
based
on
the
use
pattern
and
the
behavior
associated
with
the
exposed
population.
For
imazaquin,
HED
has
combined
risks
(
i.
e.,
MOEs)
for
turf
scenarios
involving
toddlers
 
dermal
plus
hand­
to­
mouth
plus
object­
to­
mouth
plus
soil
ingestion.

C
Exposures
to
adults
and
children
on
treated
turf
have
been
addressed
using
the
latest
HED
standard
operating
procedures
for
this
scenario
including:
Page
13
of
25
<
A
dermal
absorption
value
of
50%
was
used
for
estimating
risk
in
this
assessment.

<
5
percent
of
the
application
rate
has
been
used
to
calculate
the
day­
zero
TTR
residue
levels
used
for
assessing
risks
from
dermal
and
hand­
to­
mouth
exposures,
since
imazaquin­
specific
turf
transferable
residue
study
data
are
not
available;

<
20
percent
of
the
application
rate
has
been
used
to
calculate
the
day­
zero
residue
levels
used
for
assessing
risks
from
object­
to­
mouth
behaviors
(
a
higher
percent
transfer
has
been
used
for
object­
to­
mouth
behaviors,
because
it
involves
a
teething
action
believed
to
be
more
analogous
to
DFR/
leaf
wash
sample
collection
where
20
percent
is
also
used);

<
the
transfer
coefficients
used
are
those
presented
during
the
1999
Agency
presentation
before
the
FIFRA
Science
Advisory
Panel
that
have
been
adopted
in
routine
practice
by
HED;

<
3
year
old
toddlers
are
expected
to
weigh
15
kilograms
(
representing
an
average
weight
from
years
one
to
six);

<
hand­
to­
mouth
exposures
are
based
on
a
frequency
of
20
events/
hour
and
a
surface
area
per
event
of
20
cm2,
representing
the
palmar
surfaces
of
three
fingers;

<
saliva
extraction
efficiency
is
50
percent
meaning
that
every
time
the
hand
goes
in
the
mouth
approximately
½
of
the
residues
on
the
hand
are
removed;

<
object­
to­
mouth
exposures
are
based
on
a
25
cm2
surface
area;

<
exposure
durations
for
turfgrass
scenarios
are
estimated
to
be
2
hours
based
on
information
in
HED's
Exposure
Factors
Handbook;

<
soil
residues
are
contained
in
the
top
centimeter
and
soil
density
is
0.67
mL/
gram;
and
<
dermal,
hand­
and
object­
to­
mouth,
and
soil
ingestion
are
combined
to
represent
an
overall
risk
from
exposure
to
turf.

C
Postapplication
residential
risks
are
based
on
maximum
application
rates
or
values
specified
in
the
SOPs
For
Residential
Exposure
Assessment.

C
The
Jazzercize
approach
is
the
basis
for
the
dermal
transfer
coefficients
from
turfgrass
as
described
in
HED's
Series
875
guidelines,
SOPs
For
Residential
Exposure
Assessment,
and
the
1999
FIFRA
SAP
Overview
document.

3.2.3
Residential
Postapplication
Exposure
and
Noncancer
Risk
Estimates
Noncancer
risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
approach,
which
is
a
ratio
of
the
body
burden
to
the
toxicological
endpoint
of
concern.
Exposures
were
calculated
by
considering
the
potential
sources
of
exposure
(
i.
e.,
TTRs
on
lawns),
then
calculating
dermal
and
nondietary
ingestion
exposures.
Page
14
of
25
Nondietary
Ingestion
Exposure
From
Treated
Turf:
Nondietary
ingestion
exposure
from
treated
turf
were
calculated
using
the
following
equations.
These
values
were
then
used
to
calculate
MOEs.

Estimating
Turf
Transferrable
Residues
and
Dislodgeable
Foliar
Residues
To
estimate
turf
transferrable
residue
(
TTR)
values
when
no
chemical­
specific
TTR,
HED
assumes
that
5
percent
of
the
turf
application
rate
is
available
for
transfer
on
day
0.
Then
HED
converts
the
application
rate
(
in
pounds
active
ingredient
per
acre)
to
micrograms
per
square
centimeter
using
conversion
factors.

TTR
=
AR
x
F
x
CF2
x
CF
3
where:
AR
=
application
rate
F
=
fraction
of
ai
available
on
turf
CF2
=
weight
unit
conversion
factor
to
convert
the
lbs
ai
in
the
application
rate
to
ug
for
TTR
value
(
4.54E8
ug/
lb)
CF3
=
area
unit
conversion
factor
to
convert
the
surface
are
units
(
acres)
in
the
application
rate
to
cm2
for
the
TTR
value
(
2.47E­
8
acre/
cm2)

Dermal
Exposure
from
Treated
Lawns
(
adult
and
toddler)

The
approach
used
to
calculate
the
dermal
exposures
that
are
attributable
to
exposure
from
contacting
treated
lawns
is:

ADD
=
(
TTR0
*
ET
*
TC
*
DA
*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day);
TTRt
=
turf
transferable
residue
on
day
"
0"
(
µ
g/
cm2);
ET
=
exposure
time
(
2
hr/
day)
for
lawn
and
(
4
hr.
day)
for
golf;
TC
=
transfer
coefficient
(
14,500
cm2/
hr
for
adults
and
5,200
cm2/
hr
for
toddlers
for
high
contact
lawn
activities;
500
cm2/
hr
for
golf
or
mowing);
DA
=
dermal
absorption
factor
(
50%
for
high
contact
lawn
activities
(
high
exposure)
and
golfing
or
mowing
(
low
exposure));
CF1
=
weight
unit
conversion
factor
to
convert
µ
g
units
to
mg
for
the
daily
exposure
(
0.001
mg/
µ
g);
and
BW
=
body
weight
(
70
kg
for
adults
and
15
kg
for
toddlers).

Hand­
to­
mouth
Transfer
of
Pesticide
Residues
on
Lawns
(
toddler)

The
approach
used
to
calculate
the
nondietary
ingestion
exposures
that
are
attributable
to
hand­
to­
mouth
behavior
on
treated
turf
is:

ADD
=
(
TTR0
*
SA
*
FQ
*
ET
*
SE
*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day);
TTRt
=
turf
transferable
residue
on
day
"
0"
(
µ
g/
cm2
);
SA
=
surface
area
of
the
hands
(
20
cm2/
event);
Page
15
of
25
FQ
=
frequency
of
hand­
to­
mouth
activity
(
20
events/
hr);
ET
=
exposure
time
(
2
hr/
day);
SE
=
extraction
by
saliva
(
50%);
CF1
=
weight
unit
conversion
factor
to
convert
µ
g
units
in
the
TTR
value
to
mg
for
the
daily
exposure
(
0.001
mg/
µ
g);
and
BW
=
body
weight
(
15
kg).

Object­
to­
mouth
Transfer
of
Pesticide
Residues
on
Lawns
(
toddler)

The
approach
used
to
calculate
exposures
that
are
attributable
to
object­
to­
mouth
behavior
on
treated
turf
that
is
represented
by
a
child
mouthing
on
a
handful
of
turf
is:

ADD
=
(
TTR0
*
IgR*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day);
TTRt
=
turf
transferable
residue
on
day
"
0"
(
µ
g/
cm2);
IgR
=
ingestion
rate
of
grass
(
25
cm2/
day);
CF1
=
weight
unit
conversion
factor
to
convert
the
µ
g
of
residues
on
the
grass
to
mg
to
provide
units
of
mg/
day
(
1E­
3
mg/
µ
g);
and
BW
=
body
weight
(
15
kg).

Incidental
Ingestion
of
Soil
from
Pesticide­
Treated
Residential
Areas
(
toddler)

The
approach
used
to
calculate
exposures
that
are
attributable
to
soil
ingestion
is:

ADD
=
SR
*
IgR
*
CF1/
BW
where:
ADD
=
Average
daily
l
dose
rate
on
day
"
t"
(
mg/
day)
SR
=
soil
residue
on
day
"
t"
(
Fg/
g)
IgR
=
ingestion
rate
of
soil
(
mg/
day)
CF1
=
weight
unit
conversion
factor
to
convert
the
Fg
of
residues
on
the
soil
to
grams
to
provide
units
of
mg/
day
(
1E­
6
g/
Fg)
and
SR
=
AR
*
F
*
(
1­
D)
t
*
CF2
*
CF3
*
CF4
where:
AR
=
application
rate
(
lbs
ai/
ft2
or
lb
ai/
acre)
F
=
fraction
of
ai
available
in
uppermost
cm
of
soil
(
fraction/
cm)
D
=
fraction
of
residue
that
dissipates
daily
(
unitless)
t
=
postapplication
day
on
which
exposure
is
being
assessed
CF2
=
weight
unit
conversion
factor
to
convert
the
lbs
ai
in
the
application
rate
to
Fg
for
the
soil
residue
value
(
4.54E8
Fg/
lb)
CF3
=
area
unit
conversion
factor
to
convert
the
surface
area
units
(
ft2)
in
the
application
rate
to
cm2
for
the
SR
value
(
1.08E­
3
ft2/
cm2
or
2.47E­
8
acre/
cm2
if
the
application
rate
is
per
acre)
CF4
=
volume
to
weight
unit
conversion
factor
to
convert
the
volume
units
(
cm3)
to
weight
units
for
the
SR
value
(
0.67
cm3/
g
soil)

Adults
Page
16
of
25
Table
7
presents
the
imazaquin
postapplication
MOE
values
calculated
for
adults
after
applications
to
golf
courses,
to
established
lawns
and
to
lawns
slated
for
renovation.
All
MOEs
are
$
100
on
the
day
of
application.

Table
7.
Adult
Residential
Risk
Estimates
for
Postapplication
Exposure
to
imazaquin
Exposure
Scenario
Route
of
Exposure
Application
Rate
(
lb
ai/
acre)
MOE
at
Day
0
(
HED's
level
of
concern
=
100)

High
Contact
Lawn
Activities
Dermal
0.5
430
Mowing
Turf
12500
Golf
Course
6250
Toddler
(
3
year
old)

Risks
(
MOEs)
to
toddlers
were
calculated
for
postapplication
risks
following
the
application
of
imazaquin
to
established
home
lawns
and
to
lawns
slated
for
renovation.
Table
8
summarizes
the
risk
assessment
for
toddlers.
All
MOEs
are
greater
than
HED's
level
of
concern
of
100
on
day
0.

Table
8.
Toddler
Residential
Postapplication
Risk
Estimates
for
Imazaquin
Exposure
Scenario
Route
of
Exposure
Application
Rate
(
lb
ai/
acre)
MOE
on
Day
0
(
HED's
level
of
concern
=
100)

Residential
Turf
(
High
Contact
Activities)
Dermal
0.5
260
Hand
to
Mouth
Activity
on
Turf
Oral
3400
Object
to
Mouth
Activity
on
Turf
13400
Incidental
Soil
Ingestion
1000000
Combined
Risk
Assessment
for
Residential
Scenarios
HED
combines
risk
values
resulting
from
separate
postapplication
exposure
scenarios
when
it
is
likely
they
can
occur
simultaneously
based
on
the
use­
pattern
and
the
behavior
associated
with
the
exposed
population.
Table
9
presents
a
summary
of
the
combined
MOE
estimates.

The
combined
risk
assessment
for
exposures
to
toddlers
following
home
lawn
applications
was
calculated:

Combined
MOE
=
NOAEL/(
ADDhand­
to­
mouth
+
ADDobject­
to­
mouth
+
ADDincidental
soil
ingestion
+
ADDdermal)
Page
17
of
25
The
results
of
the
combined
postapplication
risk
assessment
for
toddlers
indicates
that
the
combined
risks
to
toddlers
on
day
0
following
applications
to
established
lawns
and
to
lawns
slated
for
renovation
are
greater
than
HED's
level
of
concern
of
100
(
i.
e.,
MOE
=
260).

Table
9:
Imazaquin
Residential
Scenarios
for
Combined
Risk
Estimates
Postapplication
Exposure
Scenario
Margins
of
Exposure
(
MOEs)
(
HED's
level
of
concern
=
100)

ADD
(
mg/
kg/
day)
Combined
Non­
Dietary
Risk
Toddler
Risks
following
spray
applications
to
lawns
Hand
to
Mouth
0.007
260
Object
to
Mouth
0.0019
Incidental
Soil
Ingestion
0.00003
High
Contact
Dermal
0.10
3.2.4
Residential
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
Residential
postapplication
cancer
risks
were
not
assessed
for
imazaquin,
since
no
toxicological
endpoint
of
concern
was
selected
for
cancer.

3.2.5
Summary
of
Residential
Postapplication
Risk
Concerns
and
Data
Gaps
HED
considered
a
number
of
exposure
scenarios
for
products
that
can
be
used
in
the
residential
environment
representing
different
segments
of
the
population
including
toddlers,
youth­
aged
children,
and
adults.
Short­
term
noncancer
MOEs
were
calculated
for
all
scenarios.
Cancer
risks
were
not
calculated,
since
no
toxicological
endpoint
for
cancer
was
selected.
In
residential
settings,
HED
does
not
use
restricted­
entry
intervals
or
other
mitigation
approaches
to
limit
postapplication
exposures,
because
they
are
viewed
as
impractical
and
not
enforceable.
As
such,
risk
estimates
on
the
day
of
application
are
the
key
concern.

In
the
assessment
for
residential
postapplication
exposure
and
risk,
HED
has
no
postapplication
risk
concerns
following
the
use
of
imazaquin
in
residential
settings.

3.2.6
Recommendations
For
Refining
Residential
Postapplication
Risk
Assessment
In
order
to
refine
this
residential
assessment,
data
on
actual
use
patterns
including
rates,
timing,
and
the
kinds
of
tasks
performed
are
required
to
better
characterize
imazaquin
risks.
3.3
Spray
Drift
from
Agricultural
Uses
HED
has
concerns
for
the
potential
for
children's
exposure
in
the
home
as
a
result
of
agricultural
uses
of
imazaquin.
Environmental
concentrations
of
imazaquin
in
homes
may
result
from
spray
drift,
track­
in,
or
from
redistribution
of
residues
brought
home
on
the
farm
worker's
clothing.
Potential
routes
of
exposure
for
children
may
include
incidental
ingestion
and
dermal
contact
with
residues
on
carpets/
hard
surfaces.
Further
research
into
children's
exposures
resulting
from
agricultural
uses
of
pesticides
are
being
conducted
by
the
Agency's
Office
of
Research
and
Development
through
the
STAR
(
Science
to
Achieve
Results)
grant
program.
The
STAR
program
can
be
accessed
at
http://
es.
epa.
gov/
ncerqa/
grants/
Modifications
to
this
assessment
shall
be
incorporated
as
updated
guidance
becomes
available.
This
will
include
expanding
the
scope
of
the
residential
exposure
assessments
by
developing
guidance
for
characterizing
exposures
from
other
sources
not
addressed
such
as
from
spray
drift
and
exposures
to
farm
worker
children.
Page
19
of
25
IMAZAQUIN
APPENDIX
POSTAPPLICATION
EXPOSURE
AND
RISK
CALCULATIONS
Page
20
of
25
Appendix
Table
1:
Residential
Handler
Noncancer
Risks
from
Imazaquin
Exposure
Scenario
Target
Application
Ratea
Area
Treated
Dailyb
Dermal
Unit
Exposure
(
mg/
lb
ai)
Inhalation
Unit
Exposure
(
Ug/
lb
ai)
Dermal
Dose
d
(
mg/
kg/
day)
Inhalation
Dose
e
(
mg/
kg/
day)
MOE
(
HED's
level
of
concern
=
100)

Dermalf
Inhalation
g
Dermal
+

Inhalation
h
Mixer/
Loader/
Applicator
Mixing/
Loading/
Applying
Liquid
Concentrates
with
Hose­
End
Sprayer
(
Residential
ORETF
data)
(
1)
Turf
0.38/
A
0.5
acre
11
17
0.015
0.000046
1700
550000
1700
Mixing/
Loading/
Applying
Liquid
Concentrates
with
a
Hand
Held
Pump
(
ORETF
)
sprayer(
2)
Ornamental
0.006
lb
ai/
gal
1
gal
38
2.7
0.0016
0.0000002
15400
12500000
15400
Applying
Ready
to
Use
sprayer
(
ORETF)(
3)
Turf
0.006
lb
ai/
gal
1
gal
54
19
0.0023
0.0000016
11000
15625000
11000
Footnotes
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
imazaquin.

b
Amount
handled
per
day
values
are
EPA
estimates.

c
Attire
is
short­
sleeve
shirt,
short
pants,
and
no
gloves
and
no
respirator.

d
Dermal
Dose
=
application
rate
x
area
treated
x
dermal
unit
exposure
x
%
DA
(
50)
÷
70
e.
Inhalation
Dose
=
application
rate
x
area
treated
x
inhalation
unit
exposure
÷
70
f.
Dermal
MOE
=
NOAEL
(
25mg/
kg/
day)
/
dermal
daily
dose
(
mg/
kg/
day),

g.
Inhalation
MOE
=
NOAEL
(
25
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day)

h
MOE
TOTAL
=
1
(
1/
Dermal
MOE
)
+
(
1/
Inhalation
MOE)
Page
21
of
25
Appendix
Table
2
­
Oral
Exposure
from
Hand­
to­
Mouth
Activity
on
Imazaquin
Treated
Turf
Exposure
Scenario
Application
Rate
(
lb
ai/
acre)
Percent
active
ingredient
dislodgeable
Surface
area
(
cm2)
Hand
to
Mouth
(
events/
hr)
Extraction
by
Saliva
Exposure
Time
Body
Weight
(
kg)
Average
Daily
Dose
(
mg/
kg/
day)
Oral
MOE
(
HED's
level
of
concern
=
100)

Hand
to
Mouth
(
turf)
0.5
5%
20
20
50%
2
15
0.007
3400
Oral
Dose
(
mg/
kg/
day)
=
AR
(
lb
ai)
x
CF1
x
CF2
x
CF3
x
F
x
SA
(
cm2)
x
EXT
x
FQ(
events/
hr)
x
ET(
hrs/
day)
x
(
0.001mg/
µ
g)

BW
(
kg)

Where:

Dose
=
oral
dose
on
day
of
application
(
mg/
kg/
day)

AR
=
application
rate
(
lb
ai/
A)

CF1
=
conversion
factor
to
convert
µ
g
to
mg
(
1.00
x
10­
3
µ
g/
mg)

CF2
=
weight
unit
conversion
factor
to
convert
the
lbs
ai
in
the
application
rate
to
µ
g
for
the
soil
residue
value
(
4.54
x
108
µ
g/
lb)

CF3
=
area
unit
conversion
factor
to
convert
the
surface
area
units
(
acres)
in
the
application
rate
to
cm2
for
the
SR
value
(
2.47
x
10­
8
acre/
cm2)

F
=
fraction
of
residue
dislodgeable
from
wet
hands
(
unitless)

SA
=
surface
area
of
1
to
3
fingers
(
cm2)

EXT
=
extraction
rate
by
saliva
(
unitless)

FQ
=
frequency
of
hand­
to­
mouth
events
(
events/
hour)

ET
=
exposure
duration
(
hours/
day)

BW
=
body
weight
(
kg)

Assumptions:

SA
­
The
surface
area
of
1
to
3
finger
is
20
cm2
FQ
­
The
frequency
of
hand­
to­
mouth
events
is
20
events
per
hour
F
­
The
fraction
of
residue
dislodgeable
from
wet
hands
is
5%

EXT
­
The
extraction
rate
by
saliva
is
50%.

ET
­
The
time
spent
outdoors
is
2
hours/
day
MOE
=
NOAEL
(
25g/
kg/
day)
÷
Dermal
Dose
Page
22
of
25
Appendix
Table
3
­
Oral
Exposure
from
Mouthing
Imazaquin
Treated
Turf
Exposure
Scenario
Application
Rate
(
lb
ai/
acre)
Percent
Active
Ingredient
Dislodgeable
Surface
Area
(
cm2)
Body
Weight
(
kg)
Average
Daily
Dose
(
mg/
kg/
day)
Oral
MOE
(
HED's
level
of
concern
=

100)

Object
(
turf)
to
Mouth
0.5
20%
25
15
0.0019
13400
Oral
Dose
(
mg/
kg/
day)
=
AR
(
lb
ai)
x
CF1
x
CF2
x
CF3
x
F
x
SA
(
cm2)

BW
(
kg)

Where:

Dose
=
oral
dose
on
day
of
application
(
mg/
kg/
day)

AR
=
application
rate
(
lb
ai/
A)

CF1
=
conversion
factor
to
convert
µ
g
to
mg
(
1.00
x
10­
3
µ
g/
mg)

CF2
=
weight
unit
conversion
factor
to
convert
the
lbs
ai
in
the
application
rate
to
µ
g
for
the
soil
residue
value
(
4.54
x
108
µ
g/
lb)

CF3
=
area
unit
conversion
factor
to
convert
the
surface
area
units
(
acres)
in
the
application
rate
to
cm2
for
the
SR
value
(
2.47
x
10­
8
acre/
cm2)

F
=
fraction
of
residue
dislodgeable
from
wet
hands
(
unitless)

SA
=
surface
area
of
1
to
3
fingers
(
cm2/
day)

BW
=
body
weight
(
kg)

Oral
MOE
=
NOAEL
(
25
mg/
kg/
day)
÷
Daily
Dose
Assumptions:

SA
­
The
surface
area
of
1
to
3
finger
is
25
cm2/
day
F
­
The
fraction
of
residue
dislodgeable
from
wet
hands
is
20%
Page
23
of
25
Appendix
Table
4
­
Oral
Exposure
from
Incidental
Soil
Ingestion
Exposure
Scenario
Application
Rate
(
lb
ai/
acre)
%
of
rate
in
uppermost
1
cm
of
soil
Body
Weight
(
kg)
Ingestion
Rate
(
IgR)

(
mg/
day)
Average
Daily
Dose
mg/
kg/
day
Oral
MOE
(
HED's
level
of
concern
=
100)

Soil
Ingestion
0.5
100%
15
100
0.00003
1000000
Oral
Dose
=
AR
(
lb
ai/
A)
x
F
(
1.0/
cm)
x
IgR(
mg/
day)
x
CF1(
4.54E­
8
µ
g/
lb)
x
CF2
(
2.47E­
8
A/
cm2)
x
CF3
(
0.67
cm3/
g)
x
CF4
(
1E­
6
g/
µ
g)

BW
(
kg)

Where:

Dose
=
oral
dose
on
day
of
application
(
mg/
kg/
day)

AR
=
application
rate
(
lb
ai/
A)

F
=
fraction
or
residue
retained
on
uppermost
1
cm
of
soil
IgR
=
ingestion
rate
of
soil
(
mg/
day)

CF1
=
weight
unit
conversion
factor
to
convert
the
lbs
ai
in
the
application
rate
to
µ
g
for
the
soil
residue
value
(
4.54
x
108
µ
g/
lb)

CF2
=
area
unit
conversion
factor
to
convert
the
surface
area
units
(
acres)
in
the
application
rate
to
cm2
for
the
SR
value
(
2.47
x
10­
8
acre/
cm2)

CF3
=
volume
to
weight
unit
conversion
factor
to
convert
the
volume
units
(
cm3)
to
weight
units
for
the
soil
residue
value
(
0.67
cm3/
g
soil)

CF4
=
weight
unit
conversion
factor
to
convert
the
µ
g
of
residues
on
the
soil
to
grams
to
provide
units
of
mg/
day
(
1E­
6
g/
µ
g)

BW
=
body
weight
(
kg)

MOE
=
NOAEL
(
25
mg/
kg/
day)
÷
Daily
Dose
Assumptions:

F
­
The
fraction
or
residue
retained
on
uppermost
1
cm
of
soil
is
100
percent
based
on
soil
incorporation
into
top
1
cm
of
soil
after
application
(
1.0/
cm)

IgR
­
The
ingestion
rate
of
soil
is
100
mg/
day
Page
24
of
25
Appendix
Table
5
­
Dermal
Exposure
from
Imazaquin
Treated
Turfgrass
Exposure
Scenario
Application
Rate
(
lb
ai/
acre)
Hours
of
Exposure
Body
Weight
(
kg)
Percent
available
TTR
(
µ
g/
cm2)

(
normalized)

DAT
0
Transfer
Coefficient
(
cm2/
hr)
Dermal
Absorption
(%)
Absorbed
Dermal
Dose
(
mg/
kg/
day)
Dermal
MOE
(
HED's
level
of
concern
=
100)

High
Contact
Lawn
Activities
Adult
0.5
2
70
5%
0.549
14,500
50
0.06
430
Toddler
2
15
5%
0.549
5,200
50
0.1
260
Mowing
Turf
Adult
2
70
5%
0.050
500
50
0.002
12500
Golf
Course
Adults
4
70
5%
0.050
500
50
0.004
6250
Dermal
Dose
(
mg/
kg/
day)
=
TTR
(
µ
g/
cm2)
x
0.001
(
mg/
µ
g)
x
TC
(
cm2/
hr)
x
ET
(
hr/
day)
x
DA
(%)

BW
(
kg)

Where:

Dose
=
Dermal
exposure
at
on
day
of
application
attributable
for
activity
in
a
previously
treated
area
(
mg/
kg/
day)

TTR
=
Turf
Transferable
Residue
on
day
of
application
(
µ
g/
cm2)

TC
=
Transfer
Coefficient;

ET
=
Exposure
Time
(
hours);

DA
=
Dermal
Absorption;
and
BW
=
Body
Weight
(
70
kg)

TTR
(
µ
g/
cm2)
=
AR
(
lb
ai/
acre)
x
CF1(
4.54E­
8
µ
g/
lb)
x
CF2
(
2.47E­
8
A/
cm2)
x
PA
Where:

AR
=
Application
rate
(
lb
ai/
acre)

CF1
=
weight
unit
conversion
factor
to
convert
the
lbs
ai
in
the
application
rate
to
µ
g
for
the
soil
residue
value
(
4.54
x
108
µ
g/
lb)

CF2
=
area
unit
conversion
factor
to
convert
the
surface
area
units
(
acres)
in
the
application
rate
to
cm2
for
the
SR
value
(
2.47
x
10­
8
acre/
cm2)

PA
=
Percent
available
(%)

Assumptions:

TC
­
The
assumed
transfer
coefficients
(
TCs)
for
adults
and
children
performing
short­
term
high
contact
activities
on
treated
turf
are
14,500
and
5,200,
respectively.
Golfing,
mowing
and
other
low
contact
activities
were
assumed
to
have
a
TC
of
500
µ
g/
cm2.
Page
25
of
25
ET
­
The
exposure
time
for
high
contact
activities
on
residential
lawns
is
2
hours.
The
exposure
time
for
golfers
is
4
hours.
The
exposure
time
for
mowing
is
2
hours.

DA
­
The
dermal
absorption
is
50%
