­
1­
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
March
30,
2005
MEMORANDUM
SUBJECT:
SETHOXYDIM:
Occupational
and
Residential
Exposure
Assessment
and
Recommendations
for
the
Reregistration
Eligibility
Decision
Document
(
RED)

FROM:
Wade
Britton,
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

THROUGH:
Catherine
Eiden,
Chief
and
Danette
Drew,
Branch
Senior
Scientist
Reregistration
Branch
3
Health
Effects
Division
(
7509C)

TO:
William
Donovan,
Risk
Assessor
Reregistration
Branch
3
Health
Effects
Divisions
(
7509C)

DP
Barcode:

Pesticide
Chemical
Codes:
­
2­
TABLE
OF
CONTENTS
1.0
Occupational
and
Residential
Exposure
Assessment
for
Sethoxydim
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5
1.1
Purpose
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5
1.2
Criteria
for
Conducting
Exposure
Assessments
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5
1.3
Summary
of
Hazard
Concerns
for
Sethoxydim
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5
1.4
Incident
Reports
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8
1.5
Summary
of
Use
Patterns
and
Formulations
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8
1.5.1
End
Use
Products
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8
1.5.2
Registered
Use
Categories
and
Sites
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8
1.5.3
Application
Methods
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9
2.0
Occupational
Exposures
and
Risks
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10
2.1
Occupational
Handler
Exposures
&
Risks
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10
2.1.1
Data
and
Assumptions
For
Handler
Exposure
Scenarios
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12
2.1.1.1
Assumptions
for
Handler
Exposure
Scenarios
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12
2.1.1.2
Exposure
Data
for
Handler
Exposure
Scenarios
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13
2.1.2
Sethoxydim
Handler
Exposure
Scenarios
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14
2.1.3
Non­
cancer
Sethoxydim
Handler
Exposure
and
Assessment
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15
2.1.3.1
Non­
cancer
Sethoxydim
Handler
Exposure
and
Risk
Calculations
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15
2.1.3.2
Sethoxydim
Non­
cancer
Risk
Summary
(
using
PHED,
ORETF,
and
proprietary
data)
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16
2.1.4
Cancer
Sethoxydim
Handler
Exposure
and
Risk
Assessment
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19
2.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Occupational
Handlers
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19
2.1.5.1
Summary
of
Risk
Concerns
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19
2.1.5.2
Summary
of
Data
Gaps
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19
2.1.6
Recommendations
For
Refining
Occupational
Handler
Risk
Assessment
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19
2.2
Occupational
Postapplication
Exposures
and
Risks
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19
2.2.1
Occupational
Postapplication
Exposures
and
Risks
Estimates
For
Cancer
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20
3.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
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20
3.1
Residential
Handler
Exposures
and
Risks
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20
3.1.1
Handler
Exposure
Scenarios
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21
3.1.2
Data
and
Assumptions
For
Handler
Exposure
Scenarios
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21
3.1.3
Residential
Handler
Exposure
and
Non­
Cancer
Risk
Estimates
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22
3.1.4
Residential
Handler
Exposure
and
Risk
Estimates
for
Cancer
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23
3.1.5
Recommendations
For
Refining
Residential
Handler
Risk
Assessment
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23
3.2
Residential
Postapplication
Exposures
and
Risks
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24
3.2.1
Residential
Postapplication
Exposure
Scenarios
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24
3.2.2
Data
and
Assumptions
for
Residential
Postapplication
Exposure
Scenarios
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26
3.2.3
Residential
Postapplication
Exposure
and
Noncancer
Risk
Estimates
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26
3.2.4
Residential
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
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29
3.2.5
Recommendations
For
Refining
Residential
Postapplication
Risk
Estimates
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29
­
3­
Executive
Summary
Sethoxydim
is
a
selective,
systemic,
postemergence
herbicide
used
for
the
control
of
annual
and
perennial
grass
weeds
in
broadleaf
crops.
Registered
use
sites
for
sethoxydim
include
agricultural
crops
such
as
various
fruits,
tree
nuts,
vegetables
and
herbs,
as
well
as
non­
agricultural
sites,
including
ornamental
and
flowering
plants,
recreational
areas,
rights­
of­
way,
along
fences
and
hedgerows,
and
public
and
commercial
buildings/
structures
(
outdoor).

Hazard
Concerns:
The
HED
HIARC
(
US
EPA,
March
19,
2003)
did
not
identify
dermal
toxicity
endpoints
for
sethoxydim,
therefore,
only
exposure
from
inhalation
and
ingestion
was
used
to
assess
short­
and
intermediate­
term
(
non­
cancer)
occupational
and
short­
term
residential
risk.
Inhalation
risk
was
estimated
using
the
NOAEL
of
81
mg/
kg/
day
from
a
28­
day
rat
inhalation
study.
The
NOAEL
was
based
on
increased
liver
weight,
clinical
chemistry
(
increased
total
serum
bilirubin),
and
liver
histopathology.
An
inhalation
factor
of
100%
was
applied.
The
adverse
effects
for
the
short­
and
intermediate­
term
inhalation
endpoints
are
based
on
a
study
where
the
effects
were
observed
in
males
and
females,
therefore,
the
body
weight
of
an
average
adult
(
i.
e.,
70
kg)
was
used
to
estimate
exposure.

Short­
term
incidental
ingestion
risk
to
toddlers
was
estimated
using
a
NOAEL
of
180
mg/
kg/
day
and
LOAEL
of
650
mg/
kg/
day
from
a
rat
developmental
toxicity
study.
The
endpoint
was
based
on
irregular
gait
observed
in
the
dams
on
the
first
day
of
dosing.
The
body
weight
of
the
average
toddler
(
i.
e.,
15
kg)
was
used
to
estimate
short­
term
incidental
toddler
ingestion
exposure.
No
endpoint
was
selected
for
intermediate­
term
incidental
ingestion
exposures
which
are
considered
unlikely.
This
decision
is
based
upon
the
frequency
(
no
more
than
twice
per
year)
and
method
of
application
(
spot­
treatment)
allowed
by
product
labeling.

Endpoints
were
also
selected
by
the
HIARC
for
chronic
(
long­
term)
exposures,
however,
these
endpoints
were
not
used
in
this
assessment
because
chronic
occupational
and
residential
exposure
to
sethoxydim
are
not
expected
to
occur
based
upon
patterns
of
registered
uses.

HEDs
level
of
concern
(
LOC)
for
sethoxydim
inhalation
exposures
is
100
(
i.
e.,
a
margin
of
exposure
(
MOE)
less
than
100
is
a
risk
concern)
for
occupational
scenarios.
The
level
of
concern
is
based
on
10X
to
account
for
interspecies
extrapolation
(
differences
between
humans
and
animals)
to
humans
from
the
animal
test
species
and
10X
to
account
for
intraspecies
sensitivity
(
differences
among
humans).
The
LOC
for
residential
scenarios
is
also
100.

Use
Patterns:
Sethoxydim
is
formulated
for
use
in
occupational
and
residential
settings
as
a
liquid
product.
It
is
applied
with
several
types
of
application
equipment
including
aerial
and
groundboom
sprayer
applications.
Applications
to
smaller
areas
may
be
performed
with
handheld
­
4­
equipment,
including
low
pressure
handwand,
backpack
sprayers,
and
garden
hose­
end
sprayers.

Occupational
Handler
Risks:
HED
determined
that
the
potential
for
occupational
exposure
to
sethoxydim
exists
in
a
variety
of
occupational
environments.
The
anticipated
use
patterns
and
current
labeling
indicate
several
occupational
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
for
sethoxydim
applications.

Short­
and
intermediate­
term
inhalation
estimated
occupational
MOEs
range
from
2,400
for
mixing/
loading
liquid
for
high
pressure
handwand
to
3.2E+
7
for
mixing/
loading/
applying
liquids
with
a
handgun
sprayer.
The
resulting
MOEs
are
above
the
target
MOE
of
100
and,
therefore,
are
not
a
risk
concern.

Occupational
Postapplication
Risks:
There
is
a
potential
for
postapplication
dermal
exposure
to
scouts,
harvesters,
and
other
field
workers.
However,
because
a
dermal
endpoint
of
concern
was
not
identified,
and
postapplication
inhalation
exposure
is
expected
to
be
negligible,
a
quantitative
occupational
postapplication
risk
assessment
was
not
conducted.
Based
upon
the
acute
toxicity
of
sethoxydim,
the
current
labels
for
sethoxydim
have
a
12­
hour
restricted
entry
interval
per
the
Worker
Protection
Standard
(
WPS).

Residential
Handler
Risks:
HED
determined
that
residential
(
non­
occupational)
handlers
of
sethoxydim
may
be
exposed
for
short­
term
durations
via
the
dermal
and
inhalation
routes.
Sethoxydim
is
labeled
for
consumer
use
to
control
grass
weeds
in
ornamental
gardens
and
turf.
The
HED
HIARC
did
not
identify
dermal
toxicity
endpoints,
therefore,
only
handler
inhalation
scenarios
were
assessed.
MOEs
estimated
for
handlers
range
from
1.4E+
6
for
mixing/
loading/
applying
liquids
for
backpack
sprayer
application
and
garden
hose­
end
sprayer
and
1.6E+
6
for
mixing/
loading/
applying
liquids
for
low
pressure
handwand
application.
The
resulting
MOEs
are
above
the
target
MOE
of
100
and,
therefore,
are
not
a
risk
concern.

Residential
Postapplication
Risks:
HED
determined
that
short­
term
postapplication
exposures
may
result
from
incidental
oral
exposures
(
children
only)
due
to
dermal
contact
with
turf.
The
HED
HIARC
did
not
identify
dermal
toxicity
endpoints,
therefore,
only
postapplication
exposure
scenarios
for
toddler
incidental
ingestion
(
i.
e.,
hand­
to­
mouth,
object­
to­
mouth,
and
soil
ingestion)
were
estimated.
MOEs
estimated
range
from
26,000
for
hand­
to­
mouth
incidental
exposures
to
7.6E+
6
for
soil
ingestion
incidental
exposures.
The
resulting
MOEs
are
above
the
target
MOE
of
100
and,
therefore,
are
not
of
concern
to
HED.
­
5­
1.0
Occupational
and
Residential
Exposure
Assessment
for
Sethoxydim
1.1
Purpose
This
document
is
the
occupational
and
residential
non­
dietary
exposure
and
risk
assessment
for
sethoxydim
from
its
use
as
an
herbicide.
In
this
document,
which
is
for
use
in
EPA's
development
of
the
HED
chapter
of
the
sethoxydim
RED
Document,
EPA
presents
the
results
of
its
review
of
the
potential
human
health
effects
of
occupational
and
residential
(
non­
occupational)
exposure
to
sethoxydim.

1.2
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
a
potential
for
exposure
to
handlers
(
mixers,
loaders,
applicators)
during
use
or
to
persons
entering
treated
sites
or
exposed
to
vapors
after
application
is
complete.
Toxicological
endpoints
were
selected
for
short­
and
intermediateterm
inhalation
exposures
to
sethoxydim.
There
is
a
significant
potential
for
exposure
in
a
variety
of
occupational
agricultural
and
commercial
settings
as
well
as
in
residential
settings.
Therefore,
risk
assessments
are
required
for
occupational
and
residential
handlers
as
well
as
for
occupational
and
residential
postapplication
exposures
that
can
occur
as
a
result
of
sethoxydim
use.

1.3
Summary
of
Hazard
Concerns
for
Sethoxydim
Dermal
Route
(
non­
cancer):
The
HED
HIARC
(
US
EPA,
March
19,
2003)
concluded
that
for
all
durations
of
dermal
exposure
quantification
of
non­
cancer
risk
is
not
required
based
on
the
following
factors:

°
No
dermal
or
systemic
toxicity
was
seen
following
repeated
dermal
applications
at
the
limit
dose
in
rabbits.
°
There
is
no
concern
for
pre­
natal
toxicity
in
rabbits
(
the
fetus
in
not
susceptible).
Although
there
is
a
concern
for
developmental
effects
in
rats,
they
occurred
in
the
presence
of
maternal
toxicity
at
a
high
dose
(
650
mg/
kg/
day)
that
is
close
to
the
Limit
Dose
(
1000
mg/
kg/
day).
°
The
physical
and
chemical
properties
of
sethoxydim
indicate
low
dermal
absorption
of
sethoxydim.

For
these
reasons,
only
exposure
from
inhalation
was
used
to
assess
short­
and
intermediate­
term
(
non­
cancer)
occupational
and
short­
term
residential
risk
Inhalation
Route
(
non­
cancer):
For
short­
and
intermediate­
term
inhalation
exposures
an
­
6­
endpoint
was
selected
based
upon
a
28­
day
rat
study
(
MRID
44021202).
A
NOAEL
of
81
mg/
kg/
day
and
a
LOAEL
of
651
mg/
kg/
day
were
selected,
based
upon
liver
weight,
clinical
chemistry
(
bilirubin)
and
histology.
The
dose/
endpoint
is
derived
from
a
study
conducted
via
the
appropriate
route
of
concern
and
used
for
all
inhalation
exposure
durations,
age
groups,
and
for
both
sexes.

Oral
Route
(
non­
cancer):
An
endpoint
was
selected
for
short­
term
incidental
oral
ingestion
exposures
based
upon
a
rat
developmental
toxicity
study.
A
NOAEL
of
180
mg/
kg/
day
and
a
LOAEL
of
650
mg/
kg/
day
was
selected
due
to
irregular
gait
and
excessive
salivation.
No
endpoint
was
selected
for
intermediate­
term
incidental
ingestion
exposures
which
are
considered
unlikely.

Non­
Cancer
Level
of
Concern
(
LOC)
:
HEDs
level
of
concern
(
LOC)
for
sethoxydim
inhalation
exposures
is
100
(
i.
e.,
a
margin
of
exposure
(
MOE)
less
than
100
exceeds
HED's
level
of
concern)
for
occupational
scenarios.
The
level
of
concern
is
based
on
10X
to
account
for
interspecies
extrapolation
(
differences
between
humans
and
animals)
to
humans
from
the
animal
test
species
and
10X
to
account
for
intraspecies
sensitivity
(
differences
among
humans).
The
LOC
for
residential
scenarios
is
also
100.

Carcinogenicity
of
Sethoxydim:
Sethoxydim
is
characterized
as
"
not
likely"
to
be
a
human
carcinogen
based
on
the
lack
of
increased
tumor
incidence
in
the
rat
and
mouse
carcinogenicity
studies.
Therefore,
a
cancer
risk
assessment
was
not
conducted.

Acute
Toxicity:
The
acute
toxicity
data
indicate
that
sethoxydim
is
minimally
toxic
(
Category
III)
via
oral,
dermal,
and
inhalation
routes
of
exposure.
Oral
and
inhalation
routes
of
exposure
observed
resulted
in
induced
hepatotoxicity.
Sethoxydim
is
neither
irritating
to
the
eye
nor
the
skin.
It
is
not
a
sensitizer.
The
acute
toxicity
and
endpoint
selection
for
sethoxydim
is
presented
in
Tables
1.3.1
and
1.3.2,
respectively.

Body
Weight:
The
adverse
effects
for
the
short­
and
intermediate­
term
inhalation
endpoints
are
based
on
studies
where
the
effects
were
observed
in
males
and
females,
therefore,
the
body
weight
of
an
average
adult
(
i.
e.
70
kg)
was
used
to
estimate
exposure.

Table
1.3.1
Acute
Toxicity
of
Technical
Sethoxydim
Study
Type
MRID
#(
s)
Results
Toxicity
Category
Acute
Oral
00045847
HED
Doc
#
903
LD50
=
M:
3125
mg/
kg
F:
2676
mg/
kg
III
Acute
Dermal
00045848
HED
Doc
#
903
LD50
=
>
5000
mg/
kg
III
­
7­
Acute
Inhalation
00045849
HED
Doc
#
903
LC50
=
M:
603
m/
L
F:
6.28
m/
L
Aerosol
composed
of
NP­
55
(
25%),
DMSO
(
75%).
III
Primary
Eye
Irritation
00045850
HED
Doc
#
903
No
Irritation
IV
Primary
Skin
Irritation
00045851
HED
Doc
#
903
No
Irritation
IV
Dermal
Sensitization
00045852
HED
Doc
#
903
Study
waved
based
on
lack
of
sensitization
in
guinea
pigs
treated
with
the
formulation
(
Poast)

Table
1.3.2
Summary
of
Toxcological
Doses
and
Endpoints
for
Sethoxydim
Exposure
Scenario
Dose
Used
in
Risk
Assessment,
UF
Special
FQPA
SF
and
Level
of
Concern
for
Risk
Assessment
Study
and
Toxicological
Effects
Short­
Term
Incidental
Oral
(
1­
30
days)
NOAEL=
180
mg/
kg/
day
Residential
LOC
for
MOE
=
100
Occupational
=
NA
Rat
Developmental
Toxicity
Maternal
LOAEL
=
650
mg/
kg/
day
based
on
irregular
gait
that
was
observed
in
12/
34
dams
on
the
first
day
of
dosing.

Short­
(
1
to
30
days),
Intermediate­
(
1
to
6
months),
and
Long­
Term
Dermal
(>
6
months)
Dermal
(
or
oral)
study
NOAEL=
NA
Residential
LOC
for
MOE
=
NA
Occupational
LOC
for
MOE
NA
Quantification
of
dermal
exposure
risk
assessment
is
not
required
Short­
(
1
to
30
days)
and
Intermediate­
Term
Inhalation
(
1
to
6
months)
Inhalation
study
NOAEL=
81
mg/
kg/
day
Residential
LOC
for
MOE
=
100
Occupational
LOC
for
MOE
=
100
28­
day
rat
inhalation
LOAEL
=
651
mg/
kg/
day
based
on
increased
liver
weight,
clinical
chemistry
(
increased
total
serum
bilirobin),
and
liver
histopathology.

Long­
Term
Inhalation
(>
6
months)
Inhalation
study
NOAEL=
81
mg/
kg/
day
Residential
LOC
for
MOE
=
300
Occupational
LOC
for
MOE
=
300
28­
day
rat
inhalation
LOAEL
=
651
mg/
kg/
day
based
on
increased
liver
weight,
clinical
chemistry
(
increased
total
serum
bilirobin),
and
liver
histopathology.

Cancer
(
oral,
dermal,
inhalation)
"
Not
likely
human
carcinogen"
based
on
the
lack
of
evidence
of
carcinogenicity
in
rats
and
mice.

UF
=
uncertainty
factor,
FQPA
SF
=
Special
FQPA
safety
factor,
NOAEL
=
no
observed
adverse
effect
level,
­
8­
LOAEL
=
lowest
observed
adverse
effect
level,
PAD
=
population
adjusted
dose
(
a
=
acute,
c
=
chronic),
RfD
=
reference
dose,
MOE
=
margin
of
exposure,
LOC
=
level
of
concern,
NA
=
Not
Applicable
1.4
Incident
Reports
Sethoxydim
exposure
could
potentially
lead
to
symptoms
in
unprotected
applicators
and
other
handlers.
Of
the
databases
consulted
for
incident
reports
relating
to
sethoxydim
exposure,
the
data
collected
by
the
California
Department
of
Pesticide
Regulation
and
Poison
Control
Centers
were
the
only
that
offered
enough
documentation
to
warrant
any
conclusions
about
the
health
effects
of
sethoxydim.
The
most
common
symptoms
reported
included
rash,
eye
and
throat
irritation,
gastrointestinal
symptoms,
headache,
and
dizziness.
Two
of
the
more
serious
cases
reported
eye
problems
including
visual
defect
and
nonreactive
pupils.
However,
these
incident
reports
only
state
that
sethoxydim
was
present
and
the
exposure
was
likely
in
the
presence
of
pesticides
mixtures
(
unknown
origins).

1.5
Summary
of
Use
Patterns
and
Formulations
1.5.1
End
Use
Products
Sethoxydim
is
a
selective,
systemic,
postemergence
herbicide
used
for
the
control
of
annual
and
perennial
grass
weeds
in
broadleaf
crops.
Registered
use
sites
for
sethoxydim
include
agricultural
crops
such
as
various
fruits,
tree
nuts,
vegetables
and
herbs,
as
well
as
non­
agricultural
sites,
including
ornamental
and
flowering
plants,
recreational
areas,
rights­
of­
way,
along
fences
and
hedgerows,
and
public
and
commercial
buildings/
structures
(
outdoor).
Registered
residential
uses
include
the
application
of
sethoxydim
to
ornamental
gardens
and
turf.
Based
upon
label
rates,
maximum
application
of
sethoxydim
ranges
from
1­
3
times
per
year,
based
upon
crop
or
use
site.

Sethoxydim
is
formulated
for
use
in
occupational
and
residential
settings
as
a
liquid
product.
It
is
applied
with
several
types
of
application
equipment
including
aerial
and
groundboom
sprayer
applications.
Applications
to
smaller
areas
(
lawns,
ornamentals)
may
be
performed
with
handheld
equipment,
including
low
pressure
handwand,
backpack
sprayers,
and
garden
hose­
end
sprayers.
Use
instructions
on
product
labeling
suggest
only
spot­
treatment.
However,
no
recommendation
against
broadcast
use
(
residential)
appears
on
the
label.

Sethoxydim
is
an
acetyl
CoA
carboxylase
(
fatty
acid
synthesis)
inhibitor,
which
acts
to
inhibit
mitosis.
It
rapidly
enters
the
target
grasses
through
its
foliage
and
translocates
throughout
the
plant.
The
effects
range
from
slowing
or
stopping
growth
(
generally
within
2
days),
to
foliage
reddening
and
leaf
tip
burn.
Subsequently,
foliage
burnback
may
occur.
These
symptoms
will
generally
be
observed
within
3
weeks
depending
on
environmental
conditions.
Essentially
all
grass
crops,
as
well
as
ornamental
grasses,
such
as
turf,
are
susceptible
to
sethoxydim.
­
9­
1.5.2
Registered
Use
Categories
and
Sites
Sethoxydim
is
registered
for
use
in
a
variety
of
occupational
and
residential
scenarios
and
thus
both
occupational
and
residential
populations
could
be
potentially
exposed
while
performing
sethoxydim
applications.
It
is
also
possible
for
occupational
and
residential
populations
to
be
exposed
to
sethoxydim
during
postapplication
time
periods.
A
summary
of
maximum
application
rates
for
registered
sethoxydim
commercial
and
residential
uses
is
presented
in
Tables
1.6.2.1
and
1.6.2.2,
respectively.

Table
1.6.2.1
Maximum
Application
Rates
for
Registered
Sethoxydim
Commercial
Uses
Crop
or
Target
Maximum
Application
Rate
(
lb
ai/
acre)

Alfalfa,
Amaranth,
Argula,
Beans
(
dry,
succulent),
Broccoli
(
including
Chinese
and
Raab),
Brussel
Sprouts,
Cabbage
(
Bok
Choy,
Chinese
Mustard,
Napa),
Canteloupes,
Cardoon,
Cauliflower,
Celery,
Celery
(
Chinese),
Celtuce,
Chervil,
Chrysanthemum
(
Edible,
Garland),
Cilantro,
Collard,
Corn
(
Poast
protected
field
corn
only),
Corn
(
Poast
protected
sweet
corn
only),
Corn
Salad,
Cotton,
Cress
(
Garden,
Upland),
Cucumber,
Dandelion,
Dock,
Eggplant,
Endive
(
Escarole),
Fennel
(
Florence),
Flax
(
not
in
CA),
Garlic,
Gherkin,
Groundcherry,
Honeydew
Melon,
Kale,
Kohlrabi,
Leek,
Lettuce
(
Head),
Lettuce
(
Leaf),
Muskmelons,
Mustard
Greens,
Onion
(
Dry
Bulb
and
Green),
Orach,
Parsley,
Pepino,
Peppers,
Potato,
Pumpkin,
Purslane
(
Garden,
Winter),
Radiccio,
Rape
Greens,
Rhubarb,
Shallot,
Soybean
(
not
in
CA),
Spinach
(
including
New
Zealand
and
Vine),
Squash,
Strawberry
(
not
in
FL,
CA),
Sunflower,
Sweet
Potato
(
West
US),
Swiss
Chard,
Tobacco,
Tomatillo,
Tomato,
Watermelon
0.28
Crop
or
Target
Maximum
Application
Rate
(
lb
ai/
acre)

­
10­
Apricot,
Arracacha,
Artichoke
(
Chinese,
Globe,
Jerusalem),
Asparagus,
Avacado
(
Nonbearing),
Beet
(
garden),
Blackberry,
Blueberry
(
not
in
CA),
Birdsfoot
Trefoil,
Canna
(
Edible),
Canola
(
not
in
CA),
Carrot,
Cassava
(
Bitter,
Sweet),
Chayote
Root,
Cherries
(
Sweet
and
Sour),
Christmas
Tree
Farms,
Chufa,
Citrus,
Clover,
Clover
Hay,
Crabapples,
Crambe
(
not
in
CA),
Cranberry
(
not
in
CA),
Dasheen
(
Taro),
Date
(
Nonbearing),
Deciduous
Trees,
Fallow
Land,
Fescue
(
Tall),
Field
Potatoes,
Fig
(
Nonbearing),
Ginger,
Grape,
Horseradish
(
not
in
CA),
Juneberry,
Lentil
(
not
in
CA),
Leren,
Lingonberry,
Loganberry,
Mint,
Non­
bearing
Food
Crops,
Nursery
Plantings,
Olives,
Ornamentals,
Peach,
Peanut,
Pears,
Peas
(
Dry,
Succulent),
Pistacio,
Plum,
Pomegranate
(
Nonbearing),
Prune
(
Nonbearing),
Quince,
Raspberry
(
Red,
Black),
Rapeseed
(
not
in
CA),
Rights
of
Way,
Roadsides,
Sainfoin,
Safflower,
Salal,
Set­
aside
Conservation
Land,
Sugar
Beet,
Sunflower
(
not
recommended
for
inbred
lines
grown
for
seed),
Sweet
Potatoes
(
East
US),
Tanier,
Tree
Nuts,
Tumeric,
Turf/
Lawn,
Wildflowers,
Yam
Bean,
Yam
(
True),
Younberry
0.47
Tobacco
Seedbeds
(
not
in
CA)
0.18
Orchard
Floor
Middles
0.09
Table
1.6.2.2
Maximum
Application
Rates
for
Registered
Sethoxydim
Residential
Uses
Crop
or
Target
Maximum
Application
Rate
(
lb
ai/
acre)

Ornamentals
0.47
Turf/
Lawn
0.47
1.5.3
Application
Methods
Sethoxydim
can
be
applied
by
aerial
spray,
backpack
sprayer,
garden
hose­
end
sprayer,
groundboom,
handgun
(
lawn)
sprayer,
and
high/
low
pressure
handwand
sprayers.

2.0
Occupational
Exposures
and
Risks
­
11­
HED
determined
that
the
potential
for
occupational
exposure
to
sethoxydim
exists
in
a
variety
of
occupational
environments.
The
anticipated
use
patterns
and
current
labeling
indicate
several
occupational
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
for
sethoxydim
applications.
These
include
the
handling
of
sethoxydim
during
mixing,
loading,
and
applying
processes
(
i.
e.
mixer/
loaders,
applicators,
flaggers,
and
mixer/
loader/
applicators).
In
addition,
there
is
potential
for
postapplication
worker
exposure
from
entering
into
areas
previously
treated
with
sethoxydim.
As
a
result,
risk
assessments
have
been
completed
for
occupational
handler
scenarios
as
well
as
occupational
postapplication
scenarios.
Short­
term
(
1
to
30
days)
and
intermediate­
term
exposures
(
1
to
6
months)
may
occur,
however,
long­
term
exposures
(
greater
than
6
months)
are
not
expected.

2.1
Occupational
Handler
Exposures
and
Risks
HED
uses
the
term
"
handlers"
to
describe
those
individuals
who
are
involved
in
the
pesticide
application
process.
HED
believes
that
there
are
distinct
job
functions
or
tasks
related
to
applications
and
that
exposures
can
vary
depending
on
the
specifics
of
each
task.
Job
requirements
(
e.
g.,
amount
of
chemical
to
be
used
in
an
application),
the
kinds
of
equipment
used,
the
target
being
treated,
and
the
level
of
protection
used
by
a
handler
can
cause
exposure
levels
to
differ
in
a
manner
specific
to
each
application
event.

HED
uses
exposure
scenarios
to
describe
the
various
types
of
handler
exposures
that
may
occur
for
a
specific
active
ingredient.
The
use
of
scenarios
as
a
basis
for
exposure
assessment
is
described
in
the
U.
S.
EPA
Guidelines
For
Exposure
Assessment
(
U.
S.
EPA;
Federal
Register
Volume
57,
Number
104;
May
29,
1992).
Information
from
the
current
labels,
use
and
usage
information,
toxicology
data,
and
exposure
data
were
all
key
components
in
the
development
of
the
exposure
scenarios.
HED
has
developed
a
series
of
general
descriptions
for
tasks
that
are
associated
with
pesticide
applications.
Tasks
associated
with
occupational
pesticide
handlers
are
categorized
using
one
of
the
following
terms:

°
Mixers
and/
or
Loaders:
these
individuals
perform
tasks
in
preparation
for
an
application.
For
example,
prior
to
application,
mixer/
loaders
would
mix
the
sethoxydim
and
load
it
into
the
holding
tank
of
the
airplane
or
groundboom.


Applicators:
these
individuals
operate
application
equipment
during
the
release
of
a
pesticide
product
into
the
environment.
These
individuals
can
make
applications
using
equipment
such
as
airplanes
or
groundboom.

°
Mixer/
Loader/
Applicators
and
or
Loader/
Applicators:
these
individuals
are
involved
in
the
entire
pesticide
application
process
(
i.
e.,
they
do
all
job
functions
related
to
a
pesticide
application
event).
These
individuals
would
transfer
sethoxydim
into
the
application
equipment
and
then
also
apply
it.

°
Flaggers:
these
individuals
guide
aerial
applicators
during
the
release
of
a
pesticide
­
12­
product
onto
an
intended
target.

A
chemical
can
produce
different
effects
based
on
how
long
a
person
is
exposed,
how
frequently
exposures
occur,
and
the
level
of
exposure.
HED
classifies
exposures
up
to
30
days
as
short­
term
and
exposures
greater
than
30
days
up
to
six
months
as
intermediate­
term.
HED
completes
both
short­
and
intermediate­
term
assessments
for
occupational
scenarios
in
essentially
all
cases,
because
these
kinds
of
exposures
are
likely
and
acceptable
use/
usage
data
are
not
available
to
justify
deleting
intermediate­
term
scenarios.
Based
on
use
data
and
label
instructions,
HED
believes
that
occupational
sethoxydim
exposures
may
occur
over
a
single
day
or
up
to
weeks
at
a
time
for
many
use­
patterns
and
that
intermittent
exposures
over
several
weeks
also
may
occur.
Some
applicators
may
apply
sethoxydim
over
a
period
of
weeks,
because
they
are
custom
or
commercial
applicators
who
are
completing
a
number
of
applications
for
a
number
of
different
clients.
Long­
term
handler
exposures
are
not
expected
to
occur
for
sethoxydim.

Other
parameters
are
also
defined
from
use
and
usage
data
such
as
application
rates
and
application
frequency.
HED
always
completes
non­
cancer
risk
assessments
using
maximum
application
rates
for
each
in
order
to
ensure
there
are
no
concerns
for
each
specific
use.

Occupational
handler
exposure
assessments
are
completed
by
HED
using
different
levels
of
risk
mitigation.
Typically,
HED
uses
a
tiered
approach.
The
lowest
tier
is
designated
as
the
baseline
exposure
scenario
(
i.
e.,
long­
sleeve
shirt,
long
pants,
shoes,
socks,
and
no
respirator).
If
risks
are
of
concern
at
baseline
attire,
then
increasing
levels
of
personal
protective
equipment
or
PPE
(
e.
g.,
gloves,
double­
layer
body
protection,
and
respirators)
are
evaluated.
If
risks
remain
a
concern
with
maximum
PPE,
then
engineering
controls
(
e.
g.,
enclosed
cabs
or
cockpits,
water­
soluble
packaging,
and
closed
mixing/
loading
systems)
are
evaluated.
This
approach
is
used
to
ensure
that
the
lowest
level
of
risk
mitigation
that
provides
adequate
protection
is
selected,
since
the
addition
of
PPE
and
engineering
controls
involves
an
additional
expense
to
the
user
and
 
in
the
case
of
PPE
 
also
involves
an
additional
burden
to
the
user
due
to
decreased
comfort
and
dexterity
and
increased
heat
stress
and
respiratory
stress.

2.1.1
Data
and
Assumptions
For
Handler
Exposure
Scenarios
2.1.1.1
Assumptions
for
Handler
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
occupational
handler
risk
assessments.
Each
assumption
and
factor
is
detailed
below
on
an
individual
basis.
The
assumptions
and
factors
used
in
the
risk
calculations
include:


Occupational
handler
exposure
estimates
were
based
on
surrogate
data
from:
(
1)
the
Pesticide
Handlers
Exposure
Database
(
PHED),
and
(
2)
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF).
­
13­

The
adverse
effects
for
the
short­
and
intermediate­
term
inhalation
endpoints
are
based
on
a
study
where
the
effects
were
observed
in
males
and
females,
therefore
the
average
body
weight
of
an
adult
handler
(
i.
e.,
70
kg)
is
used
to
complete
the
non­
cancer
risk
assessment.


Exposure
factors
used
to
calculate
daily
exposures
to
handlers
are
based
on
applicable
data,
if
available.
For
lack
of
appropriate
data,
values
from
a
scenario
deemed
similar
enough
by
the
assessor
might
be
used.


For
non­
cancer
assessments,
HED
assumes
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments.


The
average
occupational
workday
is
assumed
to
be
8
hours.


The
daily
areas
treated
were
defined
for
each
handler
scenario
(
in
appropriate
units)
by
determining
the
amount
that
can
be
reasonably
treated
in
a
single
day
(
e.
g.,
acres,
square
feet,
cubic
feet,
or
gallons
per
day).
When
possible,
the
assumptions
for
daily
areas
treated
are
taken
from
the
Health
Effects
Division
Science
Advisory
Committee
on
Exposure
SOP
#
9:
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,
which
was
completed
on
July
5,
2000.

2.1.1.2
Exposure
Data
for
Handler
Exposure
Scenarios
HED
uses
unit
exposures
to
assess
handler
exposures
to
pesticides.
Unit
exposures
are
estimates
of
the
amount
of
exposure
to
an
active
ingredient
a
handler
receives
while
performing
various
handler
tasks
and
are
expressed
in
terms
of
micrograms
or
milligrams
of
active
ingredient
per
pounds
of
active
ingredient
handled.
HED
has
developed
a
series
of
unit
exposures
that
are
unique
for
each
scenario
typically
considered
in
our
assessments
(
i.
e.,
there
are
different
unit
exposures
for
different
types
of
application
equipment,
job
functions,
and
levels
of
protection).
The
unit
exposure
concept
has
been
established
in
the
scientific
literature
and
also
through
various
exposure
monitoring
guidelines
published
by
the
U.
S.
EPA
and
international
organizations
such
as
Health
Canada
and
OECD
(
Organization
For
Economic
Cooperation
and
Development).

Pesticide
Handler
Exposure
Database
(
PHED)
Version
1.1
(
August
1998):
PHED
was
designed
by
a
task
force
of
representatives
from
the
U.
S.
EPA,
Health
Canada,
the
California
Department
of
Pesticide
regulation,
and
member
companies
of
the
American
Crop
Protection
Association.
PHED
is
a
software
system
consisting
of
two
parts
 
a
database
of
measured
exposures
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).

Users
select
criteria
to
subset
the
PHED
database
to
reflect
the
exposure
scenario
being
evaluated.
The
subsetting
algorithms
in
PHED
are
based
on
the
central
assumption
that
the
­
14­
magnitude
of
handler
exposures
to
pesticides
are
primarily
a
function
of
activity
(
e.
g.,
mixing/
loading,
applying),
formulation
type
(
e.
g.,
liquids,
granulars),
application
method
(
e.
g.,
aerial,
groundboom),
and
clothing
scenarios
(
e.
g.,
gloves,
double
layer
clothing).

Once
the
data
for
a
given
exposure
scenario
have
been
selected,
the
data
are
normalized
(
i.
e.,
divided
by)
by
the
amount
of
pesticide
handled
resulting
in
standard
unit
exposures
(
milligrams
of
exposure
per
pound
of
active
ingredient
handled).
Following
normalization,
the
data
are
statistically
summarized.
The
distribution
of
exposure
for
each
body
part
(
e.
g.,
chest,
upper
arm)
is
categorized
as
normal,
lognormal,
or
"
other"
(
i.
e.,
neither
normal
nor
lognormal).
A
central
tendency
value
is
then
selected
from
the
distribution
of
the
exposure
for
each
body
part.
These
values
are
the
arithmetic
mean
for
normal
distributions,
the
geometric
mean
for
lognormal
distributions,
and
the
median
for
all
"
other"
distributions.
Once
selected,
the
central
tendency
values
for
each
body
part
are
composited
into
a
"
best
fit"
exposure
value
representing
the
entire
body.

The
unit
exposures
calculated
by
PHED
generally
range
from
the
geometric
mean
to
the
median
of
the
selected
data
set.
To
add
consistency
and
quality
control
to
the
values
produced
from
this
system,
the
PHED
Task
Force
has
evaluated
all
data
within
the
system
and
has
developed
a
set
of
grading
criteria
to
characterize
the
quality
of
the
original
study
data.
The
assessment
of
data
quality
is
based
on
the
number
of
observations
and
the
available
quality
control
data.
These
evaluation
criteria
and
the
caveats
specific
to
each
exposure
scenario
are
summarized
in
Appendix
B,
Table
B1.
While
data
from
PHED
provide
the
best
available
information
on
handler
exposures,
it
should
be
noted
that
some
aspects
of
the
included
studies
(
e.
g.,
duration,
acres
treated,
pounds
of
active
ingredient
handled)
may
not
accurately
represent
labeled
uses
in
all
cases.
HED
has
developed
a
series
of
tables
of
standard
unit
exposure
for
many
occupational
scenarios
that
can
be
utilized
to
ensure
consistency
in
exposure
assessments.
Unit
exposures
are
used
which
represent
different
levels
of
personal
protection
as
described
above.
Protection
factors
were
used
to
calculate
unit
exposures
for
varying
levels
of
personal
protection
if
data
were
not
available.

ORETF
Handler
Studies
(
MRID
449722­
01):
A
report
was
submitted
by
the
ORETF
(
Outdoor
Residential
Exposure
Task
Force)
that
presented
data
in
which
the
application
of
various
products
used
on
turf
by
homeowners
and
lawncare
operators
(
LCOs)
was
monitored.
All
of
the
data
submitted
in
this
report
were
completed
in
a
series
of
studies.
These
studies
are
summarized
in
the
HED
Memorandum
"
Summary
of
HED's
Reviews
of
ORETF
Chemical
Handler
Exposure
Studies:
MRID
449722­
01",
DP
Barcode
D261948
of
April
30,
2001.
The
studies
performed
used
Dacthal
as
a
surrogate
compound
with
a
target
application
rate
of
2.0
lbs/
ai.
All
studies
were
conducted
in
accordance
with
current
Agency
guidelines,
have
been
reviewed
by
HED
and
Health
Canada,
and
the
data
generated
were
of
high
quality.

2.1.2
Sethoxydim
Handler
Exposure
Scenarios
­
15­
Daily
Exposure
mg
ai
day

Unit
Exposure
mg
ai
lb
ai
handled
x
Application
Rate
lbs
ai
area
x
Daily
Area
Treated
area
day
HED
has
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
occupational
use
of
sethoxydim
in
a
variety
of
occupational
environments.
The
anticipated
use
patterns
and
current
labeling
indicate
several
occupational
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
for
sethoxydim
applications.
The
quantitative
exposure/
risk
assessment
developed
for
occupational
handlers
is
based
on
the
following
scenarios.

Mixer/
Loaders:
(
1a)
Liquids
for
Aerial
Applications
(
1b)
Liquids
for
Groundboom
Applications
(
1c)
Rights­
of­
Way
Sprayer
Applications
Applicators:
(
2)
Aerial
Spray
Applications
(
3)
Groundboom
Spray
Applications
(
4)
Rights­
of­
Way
Sprayer
Applications
Flaggers:
(
4)
Flagging
for
Aerial
Spray
Applications
Mixer/
Loader/
Applicators:
(
5)
Liquids
for
Low
Pressure
Handwand
Sprayer
(
6)
Liquids
for
Backpack
Sprayer
(
7)
Liquids
for
High
Pressure
Handwand
Sprayer
(
8)
Liquids
for
Handgun
(
lawn)
Sprayer
(
ORETF)

2.1.3
Non­
cancer
Sethoxydim
Handler
Exposure
and
Assessment
2.1.3.1
Non­
cancer
Sethoxydim
Handler
Exposure
and
Risk
Calculations
Daily
Exposure:
Daily
inhalation
handler
exposures
are
estimated
for
each
applicable
handler
task
with
the
application
rate,
the
area
treated
in
a
day,
and
the
applicable
inhalation
unit
exposure
using
the
following
formula:

Where:

Daily
Exposure
=
Amount
(
mg
or

g
ai/
day)
deposited
on
the
surface
of
the
skin
­
16­
Average
Daily
Dose
mg
/
kg
/
day

Daily
Exposure
mg
ai
day
x
Absorption
Factor
(%
/
100)
Body
Weight
(
kg)

MOE

NOAEL

LOAEL
mg/
kg/
day
Average
Daily
Dose
mg/
kg/
day
that
is
available
for
inhalation
absorption;
Unit
Exposure
=
Unit
exposure
value
(
mg
or

g
ai/
lb
ai)
derived
from
August
1998
PHED
data,
from
ORETF
data,
study
data;
Application
Rate
=
Normalized
application
rate
based
on
a
logical
unit
treatment,
such
as
acres,
square
feet,
or
gallons.
Maximum
values
are
generally
used
(
lb
ai/
A,
lb
ai/
sq
ft,
lb
ai/
gal)
and
Daily
Area
Treated
=
Normalized
application
area
based
on
a
logical
unit
treatment
such
as
acres
(
A/
day),
square
feet
(
sq
ft/
day),
OR
gallons
per
day
(
gal/
day).

Daily
Dose:
The
daily
inhalation
dose
is
calculated
by
normalizing
the
daily
exposure
by
body
weight
and
adjusting,
if
necessary,
with
an
appropriate
inhalation
absorption
factor.
The
HED
HIARC
did
not
identify
dermal
toxicity
endpoints
for
sethoxydim,
therefore,
only
inhalation
exposures
were
assessed.
For
all
short­
and
intermediate­
term
exposure
scenarios
for
sethoxydim,
an
average
adult
body
weight
of
70
kilograms
was
used,
since
the
toxicological
endpoint
of
concern
is
not
sex­
specific.
An
absorption
factor
of
100%
was
used
for
inhalation
dose
calculations.
Daily
dose
was
calculated
using
the
following
formula:

Where:

Average
Daily
Dose
=
Absorbed
dose
received
from
exposure
to
a
pesticide
in
a
given
scenario
(
mg
pesticide
active
ingredient/
kg
body
weight/
day);
Daily
Exposure
=
Amount
(
mg
ai/
day)
inhaled
that
is
available
for
inhalation
absorption;
Absorption
Factor
=
A
measure
of
the
amount
of
chemical
that
crosses
a
biological
boundary
such
as
the
skin
or
lungs
(%
of
the
total
available
absorbed);
and
Body
Weight
=
Body
weight
determined
to
represent
the
population
of
interest
in
a
risk
assessment
(
kg).

Margins
of
Exposure:
Non­
cancer
inhalation
risks
for
each
applicable
handler
scenario
are
calculated
using
a
Margin
of
Exposure
(
MOE),
which
is
a
ratio
of
the
toxicological
endpoint
to
the
daily
dose
of
concern.
All
MOE
values
were
calculated
for
inhalation
exposure
levels.

Where:

MOE
=
Margin
of
Exposure,
value
used
by
HED
to
represent
risk
or
how
close
a
chemical
exposure
is
to
being
a
concern
(
unitless);
­
17­
ADD
=
Average
Daily
Dose
or
the
absorbed
dose
received
from
exposure
to
a
pesticide
in
a
given
scenario
(
mg
pesticide
active
ingredient/
kg
body
weight/
day);
and
NOAEL
or
LOAEL
=
Dose
level
in
a
toxicity
study,
where
no
observed
adverse
effects
(
NOAEL)
or
where
the
lowest
observed
adverse
effects
(
LOAEL)
occurred
in
the
study
Risk
values
are
presented
for
the
route
of
exposure
(
i.
e.,
inhalation)
in
each
scenario,
because
risk
mitigation
measures
are
specific
to
the
route
of
exposure.

2.1.3.2
Sethoxydim
Non­
cancer
Risk
Summary
(
using
PHED
and
ORETF
data)

Short­
and
Intermediate­
term
Total
Risks:
Occupational
handler
exposure
estimates
were
calculated
with
MOEs
ranging
from
2,400
for
Mixing/
Loading
Liquids
for
High
Pressure
Handwand
to
3.2E+
7
for
Mixing/
Loading/
Applying
lLiquids
with
a
Handgun
Sprayer.
The
resulting
MOEs
are
above
the
target
MOE
of
100
and,
therefore,
are
not
a
risk
concern.
A
summary
of
the
MOEs
estimated
for
handlers
are
presented
in
Table
2.1.3.2.

Table
2.1.3.2:
Short­
and
Intermediate­
term
Baseline
Exposures
and
Risks
for
Occupational
Handlers
Exposure
Scenario
(
Scenario
#)
Dermal
Unit
Exposure
(
mg/
lb
ai)
1
Inhalation
Unit
Exposure
(
Ug/
lb
ai)
2
Crop3
Application
Rate4
Daily
Area
Treated5
Inhalation
Dose
(
mg/
kg/
day)
6
Inhalation
MOE7
Mixer/
Loader
Mixing/
Loading
Liquids
for
Aerial
application
2.9
1.2
Berry,
Field
Crops,
Tree
(
fruit,
nut),
Vegetable,
Vine
0.47
lb
ai
per
acre
350
Acres
per
day
0.0028
29000
Mixing/
Loading
Liquids
for
Aerial
application
2.9
1.2
High
Acreage
Field
Crops10
0.47
lb
ai
per
acre
1200
Acres
per
day
0.0097
8400
Mixing/
Loading
Liquids
for
Groundboom
application
2.9
1.2
Berry,
Field
Crops,
Tree
(
fruit,
nut),
Vegetable,
Vine
0.47
lb
ai
per
acre
80
Acres
per
day
0.00064
130000
Mixing/
Loading
Liquids
for
Groundboom
application
2.9
1.2
High
Acreage
Field
Crops8
0.47
lb
ai
per
acre
200
Acres
per
day
0.0016
50000
Exposure
Scenario
(
Scenario
#)
Dermal
Unit
Exposure
(
mg/
lb
ai)
1
Inhalation
Unit
Exposure
(
Ug/
lb
ai)
2
Crop3
Application
Rate4
Daily
Area
Treated5
Inhalation
Dose
(
mg/
kg/
day)
6
Inhalation
MOE7
­
18­
Mixing/
Loading
Liquids
for
Rightsof
Way
Sprayer
application
2.9
1.2
Rights­
of­
Way
0.47
lb
ai
per
gallon
1000
Gallons
per
day
0.0081
10000
Applicator
Sprays
for
Aerial
application
No
Data
No
Data
Berry,
Field
Crops,
Tree
(
fruit,
nut),
Vegetable,
Vine
0.47
lb
ai
per
acre
350
Acres
per
day
No
Data
No
Data
Sprays
for
Aerial
application
No
Data
No
Data
High
Acreage
Field
Crops8
0.47
lb
ai
per
acre
1200
Acres
per
day
No
Data
No
Data
Sprays
for
Groundboom
application
0.014
0.74
Berry,
Field
Crops,
Tree
(
fruit,
nut),
Vegetable,
Vine
0.47
lb
ai
per
acre
80
Acres
per
day
0.00040
200000
Sprays
for
Groundboom
application
0.014
0.74
High
Acreage
Field
Crops18
0.47
lb
ai
per
acre
200
Acres
per
day
0.00099
82000
Sprays
for
Rights­
of­
Way
Sprayer
application
1.3
3.9
Rights­
of­
Way
0.47
lb
ai
per
gallon
1000
Gallons
per
day
0.026
3100
Flagger
Flagging
for
Sprays
application
0.011
0.35
Berry,
Field
Crops,
Tree
(
fruit,
nut),
Vegetable,
Vine
0.47
lb
ai
per
acre
350
Acres
per
day
0.00082
98000
Mixer/
Loader/
App
Mixing/
Loading/
App
lying
Liquids
for
Low
Pressure
Handwand
application
100
30
Misc
Crops
0.02
lb
ai
per
gallon
5
Gallons
per
day
0.000043
1900000
Mixing/
Loading/
App
lying
Liquids
for
Backpack
sprayer
application
2.5
30
Misc
Crops
0.02
lb
ai
per
gallon
5
Gallons
per
day
0.000043
1900000
Exposure
Scenario
(
Scenario
#)
Dermal
Unit
Exposure
(
mg/
lb
ai)
1
Inhalation
Unit
Exposure
(
Ug/
lb
ai)
2
Crop3
Application
Rate4
Daily
Area
Treated5
Inhalation
Dose
(
mg/
kg/
day)
6
Inhalation
MOE7
­
19­
Mixing/
Loading/
App
lying
Liquids
for
High­
Pressure
HandWand
application
3.5
120
Rights­
ofway
0.02
lb
ai
per
gallon
1000
Gallons
per
day
0.034
2400
Mixing/
Loading/
App
lying
Liquids
for
Handgun
(
lawn)
Sprayer
(
ORETF)
application
No
Data
1.8
Turf/
Lawn
0.02
lb
ai
per
acre
5
Acres
per
day
0.0000026
32000000
1Baseline
dermal
unit
exposures
represent
long
pants,
long
sleeved
shirts,
shoes,
and
socks.
Values
are
reported
in
the
PHED
Surrogate
Exposure
Guide
dated
August
1998
or
are
from
data
submitted
by
the
Outdoor
Residential
Exposure
Task
Force
dated
May
2000.
2Baseline
inhalation
unit
exposures
represent
no
respirator.
Values
are
reported
in
the
PHED
Surrogate
Exposure
Guide
dated
August
1998
or
are
from
data
submitted
by
the
Outdoor
Residential
Exposure
Task
Force
dated
May
2000.
3Crops
and
use
patterns
are
from
the
labels.
4Application
rates
are
based
on
maximum
values
found
in
various
sources
including
LUIS
and
various
labels.
In
most
scenarios,
a
range
of
maximum
application
rates
is
used
to
represent
the
range
of
rates
for
different
crops/
sites/
uses.
Most
application
rates
upon
which
the
analysis
is
based
are
presented
as
lb
ai/
A.
In
some
cases,
the
application
rate
is
based
on
applying
a
solution
at
concentrations
specified
by
the
label
(
i.
e.,
presented
as
lb
ai/
gallon).
5Amount
treated
is
based
on
the
area
or
gallons
that
can
be
reasonably
applied
in
a
single
day
for
each
exposure
scenario
of
concern
based
on
the
application
method
and
formulation/
packaging
type.
(
Standard
EPA/
OPP/
HED
values).
6Inhalation
dose
(
mg/
kg/
day)
=
[
unit
exposure
(
ug/
lb
ai)
*
0.001
mg/
g
unit
conversion
*
Inhalation
absorption
(
100%)
*
Application
rate
(
lb
ai/
acre
or
lb
ai/
gallon)
*
Daily
area
treated
(
acres
or
gallons)]
/
Body
weight
(
70
kg).
7Inhalation
MOE
=
(
81
mg/
kg/
day)
/
Daily
Inhalation
Dose.
Target
Inhalation
MOE
is
100.
8
High
Acreage
Crops
include:
Alfalfa,
Corn,
Cotton,
and
Soybean
2.1.4
Cancer
Sethoxydim
Handler
Exposure
and
Risk
Assessment
No
cancer
endpoints
of
concern
for
sethoxydim
were
identified,
therefore
cancer
risks
to
handlers
were
not
assessed.

2.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Occupational
Handlers
2.1.5.1
Summary
of
Risk
Concerns
No
occupational
handler
scenarios
for
sethoxydim
have
risks
associated
with
them
that
are
above
HED's
level
of
concern
for
non­
cancer
risk
assessments.
MOEs
resulting
from
risk
estimation
are
above
the
target
MOE
of
100
and,
therefore,
are
not
a
risk
concern.

2.1.5.2
Summary
of
Data
Gaps
There
are
no
occupational
handler
scenarios
for
sethoxydim
that
have
data
gaps.

2.1.6
Recommendations
For
Refining
Occupational
Handler
Risk
Assessment
In
order
to
refine
this
occupational
risk
assessment,
data
on
actual
use
patterns
including
rates,
­
20­
timing,
and
areas
treated
would
better
characterize
sethoxydim
risks.
Exposure
studies
for
equipment
types
that
lack
data
or
that
are
not
well
represented
in
PHED
(
e.
g.,
because
of
low
replicate
numbers
or
data
quality)
should
also
be
considered
based
on
a
review
of
the
quality
of
the
data
used
in
this
assessment.

2.2
Occupational
Postapplication
Exposures
and
Risks
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
(
also
referred
to
as
reentry
exposure).
HED
believes
that
there
are
distinct
job
functions
or
tasks
related
to
the
kinds
of
activities
that
occur
in
previously
treated
areas.
Job
requirements
(
e.
g.,
the
kinds
of
jobs
to
cultivate
a
crop),
the
nature
of
the
crop
or
target
that
was
treated,
and
how
the
chemical
residues
degrade
in
the
environment
can
cause
exposure
levels
to
differ
over
time.
While
the
proposed
use
for
sethoxydim
is
to
control
grass
weeds
in
broadleaf
crops,
accomplishing
this
task
can
involve
limited
foliar
application.
Therefore,
there
is
a
potential
for
dermal
exposure
to
scouts,
harvesters,
and
other
field
workers.
However,
because
a
dermal
endpoint
of
concern
was
not
identified,
and
postapplication
inhalation
exposure
is
expected
to
be
negligible,
an
occupational
postapplication
risk
assessment
was
not
conducted.

The
sethoxydim
technical
material
has
been
classified
in
Toxicity
Category
III
for
acute
oral,
dermal,
and
inhalation
and
Toxicity
Category
IV
for
primary
eye
irritation
and
primary
skin
irritation.
Per
the
Worker
Protection
Standard
(
WPS),
a
12­
hour
restricted
entry
interval
(
REI)
is
required
for
chemicals
classified
under
Toxicity
Category
III
or
IV.
Therefore,
the
REI
of
12
hours
appearing
on
the
label
is
in
compliance
with
the
WPS.

2.2.1
Occupational
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
No
toxicological
endpoint
of
concern
was
identified
for
cancer
for
sethoxydim,
cancer
risks
from
occupational
postapplication
exposures
were
not
assessed.

3.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
Sethoxydim
is
labeled
for
residential
(
consumer)
use
on
ornamental
gardens
and
turf
for
the
control
of
annual
and
perennial
grass
weeds.
Residents
or
consumers
applying
sethoxydim
products
may
be
exposed
for
short­
term
durations
via
the
dermal
and
inhalation
routes.
In
addition,
short­
term
postapplication
exposures
may
result
from
incidental
oral
exposures
(
children
only)
due
to
contact
with
sethoxydim­
treated
turf
in
public
(
recreational)
and
residential
settings.

Use
instructions
on
product
labeling
suggest
only
spot­
treatment,
which
is
not
considered
by
HED
to
result
in
consequential
exposures.
However,
because
no
recommendation
against
broadcast
lawn
use
appears
on
product
labeling,
it
is
assumed
that
such
a
use
could
occur
and,
­
21­
therefore,
an
assessment
of
residential
postapplication
turf
exposure
was
performed.
The
estimation
of
short­
term
oral
postapplication
exposures
for
residential
settings
are
recognized
to
be
conservative
in
nature.
No
endpoint
was
selected
for
intermediate­
term
incidental
ingestion
exposures
which
are
considered
unlikely.
This
decision
is
based
upon
the
frequency
(
no
more
than
twice
per
year)
and
method
of
application
(
spot­
treatment)
specified
by
product
labeling.

The
HED
HIARC
did
not
identify
dermal
toxicity
endpoints
for
sethoxydim,
therefore,
only
exposure
from
inhalation
(
adult
handlers)
and
incidental
ingestion
(
children,
postapplication)
were
assessed.

3.1
Residential
Handler
Exposures
and
Risks
HED
uses
the
term
"
handlers"
to
describe
those
individuals
who
are
involved
in
the
pesticide
application
process.
HED
believes
that
there
are
distinct
tasks
related
to
applications
and
that
exposures
can
vary
depending
on
the
specifics
of
each
task
as
was
described
above
for
occupational
handlers.

3.1.1
Handler
Exposure
Scenarios
Scenarios
are
used
to
define
risks
based
on
the
U.
S.
EPA
Guidelines
For
Exposure
Assessment
(
U.
S.
EPA;
Federal
Register
Volume
57,
Number
104;
May
29,
1992).
Assessing
exposures
and
risks
resulting
from
residential
uses
is
very
similar
to
assessing
occupational
exposures
and
risks,
with
the
following
exceptions:

$
Residential
handler
exposure
scenarios
are
considered
to
be
short­
term
only,
due
to
the
infrequent
use
patterns
associated
with
homeowner
products.

$
A
tiered
approach
for
personal
protection
using
increasing
levels
of
PPE
is
not
used
in
residential
handler
risk
assessments.
Homeowner
handler
assessments
are
based
on
the
assumption
that
individuals
are
wearing
shorts,
short­
sleeved
shirts,
socks,
and
shoes.

$
Homeowner
handlers
are
expected
to
complete
all
tasks
associated
with
the
use
of
a
pesticide
product
including
mixing/
loading
if
needed
as
well
as
the
application.

$
Label
use
rates
and
use
information
specific
to
residential
products
serve
as
the
basis
for
the
risk
calculations.

$
Area/
volumes
of
spray
or
chemical
used
in
the
risk
assessment
are
based
on
HED's
guidance
specific
to
residential
use
patterns.

HED
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
residential
use
of
sethoxydim
in
a
variety
of
outdoor
environments.
The
anticipated
use
patterns
and
current
labeling
indicate
several
residential
handler
scenarios
based
on
the
types
of
equipment
and
­
22­
techniques
that
can
potentially
be
used
to
make
sethoxydim
applications.
The
quantitative
exposure/
risk
assessment
developed
for
residential
handlers
is
based
on
these
scenarios:

$
Inhalation
exposure
from
mixing/
loading/
applying
liquids
for
low
pressure
handwand
application.

$
Inhalation
exposure
from
mixing/
loading/
applying
liquids
for
backpack
sprayers.

$
Inhalation
exposure
from
mixing/
loading/
applying
liquids
for
garden
hose­
end
sprayers
(
spot
treatment).

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,
these
unit
exposure
values
were
taken
from
the
Pesticide
Handlers
Exposure
Database
(
PHED)
and
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
studies.
Both
PHED
and
the
individual
studies
are
presented
below.
[
Note:
Several
of
the
assumptions
and
factors
used
for
the
assessment
are
similar
to
those
used
in
the
occupational
assessment
presented
above.
As
such,
only
factors
that
are
unique
to
the
residential
scenarios
are
presented
below.]

Assumptions
and
Factors:
The
assumptions
and
factors
used
in
the
risk
calculations
include:


Exposure
factors
used
to
calculate
daily
exposures
to
handlers
were
based
on
applicable
data
if
available.
When
appropriate
data
is
unavailable,
values
from
a
scenario
deemed
similar
might
be
used.


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.


Residential
risk
assessments
are
based
on
estimates
of
what
homeowners
would
typically
treat,
such
as
the
size
of
a
lawn
or
the
size
of
a
garden.
The
factors
used
for
the
sethoxydim
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
maximum
application
rate
used
for
each
residential
scenario
are
provided
in
Table
1.6.2.2.

3.1.3
Residential
Handler
Exposure
and
Non­
Cancer
Risk
Estimates
­
23­
Noncancer
risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
as
described
in
Section
2.1.3.
Assessing
exposures
and
risks
resulting
from
residential
uses
is
very
similar
to
assessing
occupational
exposures
and
risks,
except
as
described
in
Section
3.1.1.
The
overall
uncertainty
factor
applied
to
sethoxydim
handler
risk
assessments
is
an
MOE
of
100,
which
is
based
on
10X
for
inter­
species
extrapolation,
and
10X
for
intra­
species
variation.

Noncancer
Risk
Summary:
Calculations
of
daily
inhalation
exposure
to
sethoxydim
were
used
to
calculate
short­
term
inhalation
doses
and,
in
turn,
the
risks
for
residential
handlers.
Table
3.1.3
presents
the
residential
inhalation
short­
term
doses
and
the
MOEs
associated
with
the
residential
handling
of
sethoxydim.

Residential
(
non­
occupational)
handler
risks
range
from
1.4E+
6
to
1.6E+
6
and,
therefore,
do
not
exceed
HED's
level
of
concern.

Table
3.1.1:
Short­
term
Exposures
and
Risks
for
Residential
(
Non­
occupational)
Handlers
Exposure
Scenario
(
Scenario
#)
Inhalation
Unit
Exposure
(
Ug/
lb
ai)
1
Crop2
Application
Rate3
Daily
Area
Treated4
Inhalation
Dose
(
mg/
kg/
day)
5
Inhalation
MOE6
Mixer/
Loader/
App
Mixing/
Loading/
Applyi
ng
Liquids
for
Low
Pressure
Handwand
application
(
1)
30
Ornamentals,
Flowering
Plants,
Turf/
Lawn
0.02
lb
ai
per
gallon
5
Gallons
per
day
0.000049
1600000
Mixing/
Loading/
Applyi
ng
Liquids
for
Backpack
sprayer
application
(
2)
30
Ornamentals,
Flowering
Plants,
Turf/
Lawn
0.02
lb
ai
per
gallon
5
Gallons
per
day
0.000049
1600000
Mixing/
Loading/
Applyi
ng
Liquids
for
Garden
hose­
end
sprayer(
ORETF
­
conventional)
application
(
2)
17
Ornamentals,
Flowering
Plants,
Turf/
Lawn
0.47
lb
ai
per
acre
0.5
Acres
per
day
0.000057
1400000
1Baseline
inhalation
unit
exposures
represent
no
respirator.
Values
are
reported
in
the
PHED
Surrogate
Exposure
Guide
dated
August
1998
or
are
from
data
submitted
by
the
Outdoor
Residential
Exposure
Task
Force
dated
May
2000.
2Crops
and
use
patterns
are
from
various
sources
including
LUIS
and
labels.
3Application
rates
are
based
on
maximum
values
found
in
various
sources
including
LUIS
and
various
labels.
In
most
scenarios,
a
range
of
maximum
application
rates
is
used
to
represent
the
range
of
rates
for
different
crops/
sites/
uses.
Most
application
rates
upon
which
the
analysis
is
based
are
presented
as
lb
ai/
A.
In
some
cases,
the
application
rate
is
based
on
applying
a
solution
at
concentrations
specified
by
the
label
(
i.
e.,
presented
as
lb
ai/
gallon).
4Amount
treated
is
based
on
the
area
or
gallons
that
can
be
reasonably
applied
in
a
single
day
for
each
exposure
scenario
of
concern
based
on
the
application
method
and
formulation/
packaging
type.
(
Standard
EPA/
OPP/
HED
values).
5Inhalation
dose
(
mg/
kg/
day)
=
[
unit
exposure
(
ug/
lb
ai)
*
0.001
mg/
g
unit
conversion
*
Inhalation
absorption
(
100%)
*
Application
rate
(
lb
ai/
acre
or
lb
ai/
gallon)
*
Daily
area
treated
(
acres
or
gallons)]
/
Body
weight
(
70
kg).
6Inhalation
MOE
=
NOAEL
(
81
mg/
kg/
day)
/
Daily
Inhalation
Dose.
Target
Inhalation
MOE
is
100.
­
24­
3.1.4
Residential
Handler
Exposure
and
Risk
Estimates
for
Cancer
Residential
handler
cancer
risks
were
not
assessed,
since
no
toxicological
endpoint
of
concern
for
cancer
was
selected.

3.1.5
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
sethoxydim
risks.
Exposure
studies
for
many
equipment
types
that
lack
data
or
that
are
not
well
represented
in
PHED
(
i.
e.,
because
of
low
replicate
numbers
or
data
quality)
should
also
be
considered
based
on
a
review
of
the
quality
of
the
data
used
in
this
assessment.

3.2
Residential
Postapplication
Exposures
and
Risks
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.
Sethoxydim
can
be
used
in
areas
that
can
be
frequented
by
the
general
population
including
residential
areas
(
i.
e.,
home
lawns).
There
is
potential
for
dermal
(
adults
and
children)
and
incidental
oral
exposure
(
children)
following
the
application
of
sethoxydim.
The
potential
for
incidental
oral
exposures
of
short­
term
duration
exist
from
the
day
of
application
to
turf.
Intermediate­
term
incidental
oral
exposures
are
not
expected
due
to
a
maximum
of
two
applications
to
ornamental
gardens
and
turf
allowed
per
year
as
specified
by
product
labels.
The
HED
HIARC
did
not
identify
dermal
endpoints
of
concern
for
sethoxydim
and,
because
inhalation
is
considered
negligible
for
postapplication
exposure,
only
toddler
incidental
oral
exposures
were
assessed.

3.2.1
Residential
Postapplication
Exposure
Scenarios
A
wide
array
of
individuals
of
varying
ages
can
potentially
be
exposed
to
sethoxydim
when
they
are
in
areas
that
have
been
previously
treated.
Postapplication
exposure
scenarios
were
developed
for
each
residential
setting
where
sethoxydim
can
be
used.
Assessing
postapplication
exposures
and
risks
resulting
from
residential
uses
are
very
similar
to
assessing
occupational
postapplication
exposures
and
risks
(
Section
2.2),
except
in
residential
assessments
non­
dietary
ingestion
exposures
to
toddlers
are
calculated
(
i.
e.,
soil
ingestion,
hand­
to­
mouth
ingestion,
and
object­
to­
mouth
ingestion).
It
may
also
be
noted
that
for
this
particular
assessment,
because
of
the
lack
of
a
dermal
endpoint
and
that
inhalation
is
considered
negligible
for
postapplication
exposure,
exposures
were
calculated
for
children
of
differing
ages
while
no
exposures
were
assessed
for
adults.

HED
relies
on
a
standardized
approach
for
completing
residential
risk
assessments
that
is
based
on
current
sethoxydim
labels
and
guidance
contained
in
the
following
five
documents:
­
25­
$
Series
875,
Residential
and
Residential
Exposure
Test
Guidelines:
Group
B
­
Postapplication
Exposure
Monitoring
Test
Guidelines
(
V
5.4,
Feb.
1998)
This
document
provides
general
risk
assessment
guidance
and
criteria
for
analysis
of
residue
dissipation
data.

$
Standard
Operating
Procedures
For
Residential
Exposure
Assessment
(
Dec.
1997)
This
document
provides
the
overarching
guidance
for
developing
residential
risk
assessments
including
scenario
development,
algorithms,
and
values
for
inputs.

$
Science
Advisory
Council
For
Exposure
Policy
003.1
(
Aug.
2000):
Agricultural
Transfer
Coefficients
This
document
provides
transfer
coefficients
which
have
been
used
to
assess
exposures
in
home
gardens.

$
Science
Advisory
Council
For
Exposure
Policy
12
(
Feb.
2001):
Recommended
Revisions
To
The
Standard
Operating
Procedures
(
SOPs)
For
Residential
Exposure
Assessment
This
document
provides
additional,
revised
guidance
for
completing
residential
exposure
assessments.

°
Overview
of
Issues
Related
To
The
Standard
Operating
Procedures
For
Residential
Exposure
Assessment
(
August
1999
Presentation
To
The
FIFRA
SAP)
This
document
provides
rationale
for
Agency
changes
in
SOPs.

When
the
guidance
in
current
labels
and
these
documents
is
considered,
it
is
clear
that
HED
should
consider
children
of
differing
ages
as
well
as
adults
in
its
assessments.
It
is
also
clear
that
different
age
groups
should
be
considered
in
different
situations.
Due
to
the
lack
of
a
dermal
endpoint
and
negligible
inhalation
postapplication
risk,
the
populations
that
were
considered
in
this
assessment
are
limited
to
children

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,
in
gardens,
on
carpets
and
hard
flooring,
or
from
contact
with
treated
pets).
These
kinds
of
exposures
are
attributable
to
a
variety
of
activities
such
as
playing
outside,
home
gardening,
playing
on
carpeting
or
hard
flooring,
and
playing
with
a
companion
animal.
Toddlers
have
been
selected
as
the
sentinel
(
representative)
population
for
turf,
indoor
flooring,
and
companion
animal
assessments.
Children
are
addressed
by
HED
in
risk
assessments
by
considering
representative
activities
for
each
age
group
in
an
exposure
calculation.

The
SOPs
For
Residential
Exposure
Assessment
define
several
scenarios
that
apply
to
uses
specified
in
current
labels.
These
scenarios
served
as
the
basis
for
the
residential
postapplication
assessment
along
with
the
modifications
to
them
and
the
additional
data
and
approaches
described
above.
HED
used
this
guidance
to
define
the
exposure
scenarios
that
essentially
include
the
nondietary
ingestion
exposure
to
toddlers
on
treated
lawns.
The
SOPs
and
the
associated
scenarios
are
presented
below:
­
26­

Dose
from
hand­
to­
mouth
activity
from
treated
turf:
Postapplication
dose
calculations
for
toddlers
from
incidental
nondietary
ingestion
of
pesticide
residues
on
treated
turf
from
hand­
to­
mouth
transfer
(
i.
e.,
those
residues
that
are
swallowed
when
toddlers
get
pesticide
residues
on
their
hands
from
touching
treated
turf
and
then
put
their
hands
in
their
mouth);


Dose
from
object­
to­
mouth
activity
from
treated
turf:
Postapplication
dose
calculations
for
toddlers
from
incidental
nondietary
ingestion
of
pesticide
residues
on
treated
turf
from
object­
to­
mouth
transfer
(
i.
e.,
those
residues
that
are
swallowed
when
toddlers
put
treated
turf
in
their
mouths);
and

Dose
from
soil
ingestion
activity
from
treated
turf:
Postapplication
dose
calculations
for
toddlers
from
incidental
nondietary
ingestion
of
pesticide
residues
from
ingesting
soil
in
a
treated
turf
area
(
i.
e.,
those
soil
residues
that
are
swallowed
when
toddlers
get
pesticide
residues
on
their
hands
from
touching
treated
soil
and
then
put
their
hands
in
their
mouth);.
3.2.2
Data
and
Assumptions
for
Residential
Postapplication
Exposure
Scenarios
Assumptions
and
Exposure
Factors:
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:


There
are
many
factors
that
are
common
to
the
occupational
and
residential
postapplication
risk
assessments,
such
as
body
weights
for
adults,
and
analysis
of
residue
dissipation
data.


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.
However,
because
the
HED
HIARC
did
not
identify
a
dermal
endpoint
for
sethoxydim,
risk
was
not
combined.


Exposures
to
adults
and
children
on
treated
turf
have
been
addressed
using
the
latest
HED
standard
operating
procedures
for
this
scenario
including:


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
transfer
factor
of
5%,
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
transfer
factor
of
20%
and
a
25
cm2
surface
area;
­
27­

exposure
durations
for
turfgrass
scenarios
are
estimated
to
be
2
hours
based
on
information
in
HED's
Exposure
Factors
Handbook;
and

soil
residues
are
contained
in
the
top
centimeter
and
soil
density
is
0.67
mL/
gram;


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

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
source
of
exposure
(
i.
e.,
TTRs
on
lawns),
then
calculating
nondietary
ingestion
exposures.

Nondietary
Ingestion
Exposure
From
Treated
Turf:
Nondietary
ingestion
exposure
from
treated
turf
was
calculated
using
the
following
equations.
These
values
were
then
used
to
calculate
MOEs.

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

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

ADD
=
(
TTR0
*
SA
*
FQ
*
ET
*
SE
*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day);
TTRt
=
transferable
residue
on
day
"
0"
(

g/
cm2
)
 
assumed
to
be
5%
of
the
application
rate;
SA
=
surface
area
of
the
hands
(
20
cm2/
event);
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

g
units
in
the
DFR
value
to
mg
for
the
daily
exposure
(
0.001
mg/

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);
­
28­
TTRt
=
transferable
residue
on
day
"
0"
(

g/
cm2)
 
assumed
to
be
20%
of
the
application
rate;
IgR
=
ingestion
rate
of
grass
(
25
cm2/
day);
CF1
=
weight
unit
conversion
factor
to
convert
the

g
of
residues
on
the
grass
to
mg
to
provide
units
of
mg/
day
(
1E­
3
mg/

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
=
(
SR0
*
IgR
*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day);
SR0t
=
soil
residue
on
day
"
0"
(

g/
g);
IgR
=
ingestion
rate
of
soil
(
100
mg/
day);
CF1
=
weight
unit
conversion
factor
to
convert
the

g
of
residues
on
the
soil
to
grams
to
provide
units
of
mg/
day
(
1E­
6
g/

g);
and
BW
=
body
weight
(
15
kg).

and
SRt
=
TTRt
*
F
*
CF2
*
CF3
*
CF4
Where:
APP
=
application
rate
(
lb
ai/
A)
F
=
fraction
of
ai
available
in
uppermost
cm
of
soil
(
1
fraction/
cm);
CF2
=
conversion
from
pounds
active
ingredient
to
micrograms
active
ingredient
(
4.54E+
08);
CF3
=
conversion
from
acres
to
centimeters
squared
(
2.47E­
08);
and
CF4
=
volume
to
weight
unit
conversion
factor
to
convert
the
volume
units
(
cm3)
to
weight
units
for
the
SR
value
(
U.
S.
EPA,
1992)
(
0.67
cm3/
g
soil);

Noncancer
Risk
Summary:
HED
considered
exposure
scenarios
resulting
from
the
application
of
sethoxydim
to
residential
areas.
There
is
potential
for
dermal
(
adults
and
children)
and
incidental
oral
exposure
(
children)
following
the
application
of
sethoxydim.
HED
HIARC
did
not
identify
dermal
endpoints
of
concern
for
sethoxydim
and,
because
inhalation
is
considered
negligible
for
postapplication
exposure,
only
toddler
incidental
oral
exposures
were
assessed.
The
residential
postapplication
exposure
and
risk
assessment
indicates
that
for
all
short­
term
incidental
oral
exposures
to
toddlers
estimated,
none
are
a
risk
of
concern
(
i.
e.,
MOE
less
than
100).
Results
from
incidental
short­
term
oral
exposures
to
toddlers
are
presented
in
Tables
3.2.3.1,
3.2.3.2,
and
3.2.3.3.

Incidental
Oral
Ingestion:
The
residential
postapplication
exposure
and
risk
assessment
indicates
that
residential
postapplication
incidental
short­
term
oral
exposures
to
toddlers
are
not
a
risk
of
concern
for
all
exposure
scenarios.
MOEs
estimated
range
from
26,000
for
hand­
to­
mouth
incidental
exposures
to
7.6E+
6
for
soil
ingestion
incidental
exposures.
­
29­
Combined
Risks
to
Toddlers:
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.
The
combined
risk
assessment
for
exposures
to
toddlers
following
home
lawn
applications
is
calculated
using
the
following
equation:

Combined
MOE
=
NOAEL/(
ADDhand­
to­
mouth
+
ADDobject­
to­
mouth
+
ADDincidental
soil
ingestion
+
ADDdermal)

Since
the
HED
HIARC
did
not
identify
dermal
toxicity
endpoints
for
sethoxydim,
dermal
average
daily
dose
(
ADD)
cannot
be
calculated.
ADD
dermal
is
required
for
calculation
of
the
combined
risk
to
toddlers.
In
turn,
the
combined
risk
to
toddlers
cannot
be
determined.

3.2.4
Residential
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
Residential
postapplication
cancer
risks
were
not
assessed
for
sethoxydim
since
no
toxicological
endpoint
of
concern
was
selected
for
cancer.

3.2.5
Recommendations
for
Refining
Residential
Postapplication
Risk
Assessments
In
order
to
refine
the
residential
postapplication
assessment,
data
on
actual
use
patterns
including
rates,
timing,
and
the
kinds
of
tasks
performed
are
required
to
better
characterize
sethoxydim
risks.
­
30­

Table
3.2.3.1:
Short­
Term
Oral
Hand­
to­
Mouth
Exposure
and
Risk
for
Children
from
Treated
Lawns
Exposure
Scenario
Formulation
Application
Rate
(
lbai/
A)
Percent
ai
dislodgeable
TTR1
(

g/
cm2)
Surface
Area
(
cm2)
Hand
to
Mouth
(
events/
hr)
Extraction
by
Saliva
Exposure
Time
(
hrs/

day)
Body
Weight
(
kg)
Daily
Dose2
(
mg/
kg/
day)
Short­
Term3
MOE
Hand­
to­

Mouth
(
using
5%

defalt)
Spray
0.47
5
%
0.26
20
20
50%
2
15
0.007
26000
1
Turf
Transferrable
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Turf
Transferrable
Residue
(
ug/
cm2)
x
Extraction
by
Saliva
x
Hand
Surface
Area
(
cm2/
event)
x
Frequency
(
events/
hr)
x
1E­
3
mg/
ug
x
ET
(
hrs/
day)]
/
[
Body
Weight
(
kg)]

3
MOE
=
Short­
Term
Oral
NOAEL
(
180
mg/
kg/
day)
/
Daily
Dose.

Table
3.2.3.2:
Short­
Term
Oral
Object­
to­
Mouth
(
Turfgrass)
Exposure
and
Risk
for
Children
from
Treated
Lawns
Exposure
Scenario
Formulation
Application
Rate
(
lbai/
A)
Percent
ai
dislodgeable
TTR1
(

g/
cm2)
Surface
Area
Mouthed
(
cm2/
day)
Body
Weight
(
kg)
Daily
Dose2
(
mg/
kg/
day)
Short­
Term
MOE3
Object­
to­

Mouth
(
turf)
Spray
0.47
20
%
1.05
25
15
0.0018
100000
1Grass
residue
(
ug/
cm2)
=
[
Application
Rate
(
lbs
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2]
­
31­
2
Daily
Dose
=
[
Grass
reside
(
ug/
cm2)
x
Surface
Area
Mouthed
(
cm2/
day)
x
1E­
3
mg/
ug]
/
[
Body
Weight
(
kg)]
3
MOE
=
Short­
Term
Oral
NOAEL
(
180
mg/
kg/
day)
/
Daily
Dose.

Table
3.2.3.3:
Short­
Term
Exposure
and
Risk
for
Children
from
Ingestion
of
Soil
Exposure
Scenario
Formulation
Application
Rate
(
lbai/
A)
Fraction
of
ai
available
Soil
Residue1
(

g/
g)
Ingestion
Rate
(
mg/
day)
Body
Weight
(
kg)
D
(

Soil
Ingestion
Spray
0.47
100%
3.5
100
15
1
Soil
residue
(
ug/
g)
=
[
Application
Rate
(
lbs
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
x
0.67
cm3/
g
soil]
2
Daily
Dose
=
[
Soil
reside
(
ug/
g)
x
Ingestion
rate
(
mg/
day)
x
1E­
6
g/
ug]
3
MOE
=
Short­
Term
Oral
NOAEL
(
180
mg/
kg/
day)
/
Daily
Dose.
