Page
1
of
44
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
Date:
August
12,
2005
MEMORANDUM
SUBJECT:
REVISED
OCCUPATIONAL
AND
RESIDENTIAL
EXPOSURE
ASSESSMENT
AND
RECOMMENDATIONS
FOR
THE
REREGISTRATION
ELIGIBILITY
DECISION
DOCUMENT
FOR
ENDOTHALL
FROM:
Seyed
Tadayon,
Chemist
Reregistration
Branch
III
Health
Effect
Division
(
7509C)

THRU:
Steven
Weiss,
Branch
Senior
Scientist
Reregistration
Branch
III
Health
Effect
Division
(
7509C)

TO:
Robert
P.
Zendzian,
Risk
Assessor
Toxicology
Branch
Health
Effects
Division
(
7509C)

Please
find
the
review
of
endothall
DP
Barcode:
D319373
PC
Codes:
038901
EPA
Reg
Nos:
4581­
206,
4581­
257,
4581­
284,
4581­
174,
4581­
172,
4581­
388,
4581­
204,
AL81000900
AZ79001000,
AZ87001800,
AZ98000900,
CA87003100,
CA99000300,
FL77000100,
ID87001500,
ID87001900,
ID98001300,
IN80000800,
NV87000800,
NV98000200,
OK81002300,
OR87000400,
TX81003200,
TX99000500,
TX99000600,
WA87001100,
WA87003600,
WA98002900
EPA
MRID
No:
434701­
01
LUIS
Report:
4/
13/
04
PHED:
Yes,
Version
1.1
Page
2
of
44
Table
of
Contents
Executive
Summary
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4
1.0
Occupational
and
Residential
Exposure/
Risk
Assessment
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7
1.1
Purpose
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7
1.2
Criteria
for
Conducting
Exposure
Assessments
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7
1.3
Summary
of
Hazard
Concerns
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7
1.3.1
Endothall
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7
1.4
Incident
Reports
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10
1.5
Summary
of
Physical
and
Chemical
Properties
of
Endothall
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10
1.6
Summary
of
Use
Patterns
and
Formulations
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10
1.6.1
End­
Use
Products
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10
1.6.2
Registered
Use
Categories
and
Sites
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11
1.6.3
Application
Methods
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11
2.0
Occupational
Exposures
and
Risks
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12
2.1
Occupational
Handler
Exposures
and
Risks
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12
2.1.1
Data
and
Assumptions
For
Handler
Exposure
Scenarios
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14
2.1.1.1
Assumptions
for
Handler
Exposure
Scenarios
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14
2.1.1.2
Exposure
Data
for
Handler
Exposure
Scenarios
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15
2.1.2
Endothall
Handler
Exposure
Scenarios
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18
2.1.3
Endothall
Handler
Exposure
and
Assessment
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18
2.1.3.1
Endothall
Handler
Exposure
and
Risk
Calculations
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18
2.1.3.2
Endothall
Risk
Summary
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20
2.1.4
Cancer
Endothall
Handler
Exposure
and
Risk
Assessment
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25
2.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Occupational
Handlers
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25
2.1.5.1
Summary
of
Data
Gaps
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25
2.1.6
Recommendations
For
Refining
Occupational
Handler
Risk
Assessment
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25
2.2
Occupational
Postapplication
Exposures
and
Risks
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25
3.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
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26
3.1
Residential
Handler
Exposures
and
Risks
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26
3.1.1
Handler
Exposure
Scenarios
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26
3.1.2
Data
and
Assumptions
For
Handler
Exposure
Scenarios
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27
3.1.3
Residential
Handler
Exposure
and
Risk
Estimates
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28
3.1.4
Summary
of
Risk
Concerns
and
Data
Gaps
for
Handlers
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28
3.1.5
Recommendations
For
Refining
Residential
Handler
Risk
Assessment
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28
3.2
Residential
Postapplication
Exposures
and
Risks
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29
Page
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44
3.2.1
Residential
Postapplication
Exposure
Scenarios
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29
3.2.2
Residential
Postapplication
Exposure
and
Risk
Estimates
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29
3.3
Residential
Risk
Characterization
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30
3.3.1
Characterization
Of
Residential
Handler
Risks
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30
3.3.2
Characterization
Of
Residential
Postapplication
Risks
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30
APPENDIX
A
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32
Page
4
of
44
Executive
Summary
This
is
a
revision
of
the
Occupational
and
Residential
Exposure
Assessment
and
Recommendations
Document
for
endothall,
(
S.
Tadayon
April
1st,
2005).
This
chapter
has
been
revised
to
address
comments
made
during
public
comment
period
by
Cerexagri
Arkema
Group
LLC.
Also
after
further
consultation
with
Army
Corp
of
Engineers
some
assumptions
for
aquatic
uses
have
been
refined.

This
document
contains
the
occupational
and
residential
exposure
assessment
for
various
uses
of
endothall.
The
document
also
considers
potential
risk
mitigation
measures
such
as
personal
protective
equipment
(
PPE)
and
engineering
controls
for
handlers
and
proposed
restricted
entry
intervals
(
REIs)
for
postapplication
activities.
The
scope
of
the
document
covers
all
registered
endothall
uses.

Endothall
is
registered
as
a
harvest­
aid
chemical
(
i.
e.,
defoliant,
desiccant,
vine
killer)
used
to
reduce
or
eliminate
foliage
and
thereby
aid
in
the
efficiency
of
mechanical
harvesting
for
alfalfa
grown
for
seed,
clover
grown
for
seed,
cotton,
and
potatoes.
Endothall
is
also
registered
as
a
sucker
suppressant
in
hops.
Endothall
is
registered
as
an
aquatic
herbicide
used
to
control
a
wide
range
of
aquatic
plants
in
ponds,
lakes,
reservoirs,
marshes,
bayous,
drainage
ditches,
irrigation
and
other
canals,
rivers,
streams,
and
other
bodies
of
water
that
are
quiescent
or
moving.
When
used
as
an
aquatic
herbicide,
the
use
of
endothall
is
expected
to
result
in
both
occupational
and
residential
exposures.

Endothall
is
applied
as
a
spray
with
aerial
and
groundboom
equipment
when
used
as
a
harvest­
aid
agent
and
when
used
as
a
sucker
suppressant
on
hops,
endothall
is
applied
with
ground
equipment
only.
When
used
as
an
aquatic
herbicide,
a
variety
of
equipment
may
be
used.
Boats
used
to
treat
aquatic
weeds
are
normally
designed
to
apply
sprays
and
granular
applications
from
the
bow.
For
occupational
applications
of
liquid
formulations
to
water,
endothall
may
be
sprayed
onto
the
water
surface
using
hand­
held
or
boat­
mounted
equipment.
Endothall
may
also
be
directly
metered
into
the
suction
side
of
a
pump
and
injected
below
the
surface
of
the
water.
This
technique
is
the
only
method
of
application
to
flowing
waters,
but
is
also
used
for
applications
to
quiescent
waters.
For
occupational
applications
of
granular
formulations
to
water,
two
types
of
equipment
are
commonly
used,
centrifugal
granular
spreader.
For
residential
applications
of
granular
formulations
to
water,
HED
assumes
that
a
belly­
grinder­
type
granular
spreader
is
used.

The
Hazard
Identification
Assessment
Review
Committee
(
HIARC)
dated
June
14,
2004
selected
the
following
endpoints
for
exposure
risk
assessment:

Dermal
No
dermal
endpoint
was
selected.
A
21­
day
dermal
toxicity
study
was
submitted
and
reviewed
based
on
dermal
irritation
and
body
weight
gain
inhibition.
Body
weight
losses
were
Page
5
of
44
observed
in
females
at
Days
14
and
20
and
therefore
a
LOAEL
of
30
mg/
kg/
day
was
established
for
systemic
toxicity.
No
NOAEL
for
systemic
toxicity
was
established.
There
were
also
severe
local
dermal
effects
at
30
mg/
kg/
day
based
on
erythema,
edema,
fissuring
of
the
dose
site
and
sloughing
of
the
skin
at
the
dose
sites.
No
NOAEL
for
dermal
irritation
was
established.
Because
of
the
systemic
and
local
effects
were
co­
occurrent,
it
is
more
likely
that
the
weight
loss
was
a
consequence
of
the
severe
local
toxicity.
Therefore
Risk
Assessment
Review
Committee
(
RARC)
determined
that
endothall
should
be
regulated
as
a
severe
dermal
irritant
and
not
on
systemic
effects,
and
recommended
against
conducting
a
dermal
risk
assessment
because
the
severe
localized
irritation
effects
of
endothall
on
the
skin
would
be
self­
limiting
as
to
dermal
exposures.

Inhalation
The
short­
term
inhalation
risk
assessment
for
endothall
is
based
on
a
NOAEL
of
9.4
mg/
kg/
day
based
on
decreased
pup
body
weight
(
both
sexes)
on
Day
0
F
1
and
F
2
generations
in
a
2­
generation
rat
reproduction
(
oral
feeding)
study.
HED's
level
of
concern
(
LOC)
for
short­
term
occupational
inhalation
risk
is
100
(
i.
e.,
an
MOE
less
than
100,
exceeds
HED's
level
of
concern)
and
the
LOC
for
short­
term
residential
inhalation
risk
is
100
(
i.
e.,
an
MOE
less
than
100,
exceeds
HED's
level
of
concern).
The
intermediate­
term
inhalation
risk
assessment
for
endothall
is
based
on
an
LOAEL
of
2
mg/
kg/
day
and
is
based
on
proliferative
lesions
of
the
gastric
epithelium
(
both
sexes)
in
a
2­
generation
rat
reproduction
(
oral
feeding)
study.
HED's
level
of
concern
(
LOC)
for
intermediate­
term
occupational
inhalation
risk
is
300
and
the
LOC
for
intermediate­
term
residential
inhalation
risks
is
300.
For
residential
exposures,
another
3X
is
added
to
account
for
the
lack
of
a
NOAEL.
Long­
term
exposures
to
endothall
(
i.
e.
greater
than
6
months)
are
not
expected
for
current
registered
uses.

For
agricultural
uses,
HED
relied
almost
completely
on
surrogate
data
from
the
Pesticide
Handlers
Exposure
Database
(
PHED)
Version
1.1.
For
aquatic
uses
data
from
the
Pesticide
Handlers
Exposure
Database
(
PHED)
and
ORETF
were
study
used.
For
residential
handler
exposure
HED
used
the
ORETF
study
data
and
the
Residential
SOPs.

The
short­
term
inhalation
handler
risk
assessments
for
endothall
agricultural
crop
applications
indicate
no
risk
concerns
(
MOEs

100)
at
baseline
(
i.
e.,
no
respirator)
for
most
scenarios.
For
aerial
applications,
there
are
no
risk
concerns
(
MOEs

100)
with
engineering
controls.
The
short­
term
inhalation
handler
risk
assessments
for
endothall
aquatic
applications
indicate
no
risks
concerns
(
MOEs

100)
at
baseline
(
i.
e.,
no
respirator)
for
most
scenarios.
However,
the
addition
of
a
respirator
(
i.
e.,
quarter­
face
dust/
mist
respirator)
is
needed
to
achieve
short­
term
MOEs
of
greater
than
or
equal
to
100
for
some
handlers
scenarios.
For
mixing/
loading/
applying
liquid
formulations
with
direct
metering,
there
is
no
risk
of
concern
(
MOEs

100)
with
closed
system
engineering
controls.

For
residential
handlers,
short­
term
inhalation
MOEs
are
not
of
concern
for
the
pond
scenarios,
because
they
do
not
exceed
the
Agency's
uncertainty
factor
(
i.
e.,
MOE

100)
for
risk
assessments
in
nonoccupational
settings.
For
treating
ponds,
the
inhalation
MOEs
range
from
Page
6
of
44
470
to
2700.
Short­
term
inhalation
risks
to
residential
handlers
are
not
a
concern
for
treating
garden
pools,
the
inhalation
MOE
is
2,700.

Oral
The
short­
term
oral
risk
assessment
for
endothall
is
based
on
a
NOAEL
of
9.4
mg/
kg/
day
based
on
decreased
pup
body
weight
(
both
sexes)
on
Day
0
F
1
and
F
2
generations
in
a
2­
generation
rat
reproduction
(
oral
feeding)
study.
This
end
point
was
utilized
to
calculate
the
risk
from
oral
exposure
for
swimmers.
Short­
term
oral
ingestion
MOE
is
not
of
concern
for
the
swimmers
,
because
they
do
not
exceed
the
Agency's
uncertainty
factor
(
i.
e.,
MOE

100).

Overall
Risk
Summary
This
risk
assessment
applied
the
latest
exposure
data,
toxicology
information,
and
use
data.
The
overall
results
indicate
that
the
Agency
has
no
risk
concerns
for
most
endothall
usepatterns
involving
agricultural
crops,
aquatic
and
residential
uses.
Page
7
of
44
1.0
Occupational
and
Residential
Exposure/
Risk
Assessment
1.1
Purpose
This
document
is
the
occupational
and
residential
non­
dietary
exposure
and
risk
assessment
for
endothall
from
its
use
as
a
harvest
aid
in
certain
agricultural
crops
and
as
an
aquatic
plant
control
agent
in
lakes,
ponds,
canals,
and
other
waters.
In
this
document,
which
is
for
use
in
EPA's
development
of
the
endothall
RED
Document,
EPA
presents
the
results
of
its
review
of
the
potential
human
health
effects
of
occupational
and
residential/
non­
occupational
exposure
to
endothall.

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
intermediate­
term
inhalation
exposures
to
endothall.
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
endothall
use.

1.3
Summary
of
Hazard
Concerns
HED's
Hazard
Identification
Assessment
Review
Committee
(
HIARC)
met
to
determine
appropriate
toxicological
endpoints
of
concern
for
endothall.
The
toxicological
endpoints
that
were
used
to
complete
the
occupational
and
residential
risk
assessments
are
summarized
below
which
have
been
extracted
from
the
latest
endothall
HIARC
report
(
6/
14/
04).
Adverse
effects
were
identified
at
all
durations
of
exposure
ranging
from
short­
term
(
up
to
30
days)
to
chronic
durations
(
every
working
day).
Currently,
endothall
is
not
classified
for
carcinogenic
potential.

1.3.1
Endothall
Endothall
is
registered
as
a
harvest­
aid
chemical
(
i.
e.,
defoliant,
desiccant,
vine
killer)
used
to
reduce
or
eliminate
foliage
and
thereby
aid
in
the
efficiency
of
mechanical
harvesting
for
alfalfa
grown
for
seed,
clover
grown
for
seed,
cotton,
and
potatoes.
When
used
as
a
harvest­
aid
chemical,
the
use
of
endothall
is
expected
to
result
in
occupational
exposures
only,
since
the
label
requires
that
the
crops
must
be
mechanically
harvested
and
residential
users
do
not
mechanically
harvest
crops.
Endothall
is
also
registered
as
a
sucker
suppressant
in
hops.

Endothall
also
is
registered
as
an
aquatic
herbicide
used
to
control
a
wide
range
of
aquatic
plants
in
ponds,
lakes,
reservoirs,
marshes,
bayous,
drainage
ditches,
irrigation
and
other
canals,
rivers,
streams,
and
other
bodies
of
water
that
are
quiescent
or
moving.
When
used
as
an
aquatic
herbicide,
the
use
of
endothall
is
expected
to
result
in
both
occupational
and
residential
exposures.
Page
8
of
44
Endothall
use
patterns
are
likely
to
result
in
short­
and
intermediate­
term
exposure
durations.
Long­
term
(
chronic)
exposures
are
not
expected
with
the
present
use­
patterns.

Dermal
Route
No
dermal
endpoint
was
selected.
A
21­
day
dermal
toxicity
study
was
submitted
and
reviewed
based
on
dermal
irritation
and
body
weight
gain
inhibition.
Body
weight
losses
were
observed
in
females
at
Days
14
and
20
and
therefore
a
LOAEL
of
30
mg/
kg/
day
was
established
for
systemic
toxicity.
No
NOAEL
for
systemic
toxicity
was
established.
There
were
also
severe
local
dermal
effects
at
30
mg/
kg/
day
based
on
erythema,
edema,
fissuring
of
the
dose
site
and
sloughing
of
the
skin
at
the
dose
sites.
No
NOAEL
for
dermal
irritation
was
established.
Because
of
the
systemic
and
local
effects
were
co­
occurrent,
it
is
more
likely
that
the
weight
loss
was
a
consequence
of
the
severe
local
toxicity.
Therefore
Risk
Assessment
Review
Committee
(
RARC)
determined
that
endothall
should
be
regulated
as
a
severe
dermal
irritant
and
not
on
systemic
effects,
and
recommended
against
conducting
a
dermal
risk
assessment
because
the
severe
localized
irritation
effects
of
endothall
on
the
skin
would
be
self­
limiting
as
to
dermal
exposures.

Inhalation
Route
The
short­
term
inhalation
risk
assessment
for
endothall
is
based
on
a
NOAEL
of
9.4
mg/
kg/
day
based
on
decreased
pup
body
weight
(
both
sexes)
on
Day
0
F
1
and
F
2
generations
in
a
2­
generation
rat
reproduction
(
oral
feeding)
study
(
MRID
43152101).
HED's
level
of
concern
(
LOC)
for
short­
term
occupational
inhalation
risk
is
100
(
i.
e.,
an
MOE
less
than
100,
exceeds
HED's
level
of
concern)
and
the
LOC
for
short­
term
residential
inhalation
risk
is
100
(
i.
e.,
an
MOE
less
than
100,
exceeds
HED's
level
of
concern).
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.

The
intermediate­
term
inhalation
risk
assessment
for
endothall
is
based
on
an
LOAEL
of
2
mg/
kg/
day)
based
on
proliferative
lesions
of
the
gastric
epithelium
(
both
sexes)
in
a
2­
generation
rat
reproduction
(
oral
feeding)
study
(
MRID
43152101).
HED's
level
of
concern
(
LOC)
for
intermediate­
term
occupational
inhalation
risk
is
300
(
i.
e.,
an
MOE
less
than
300,
exceeds
HED's
level
of
concern)
and
the
LOC
for
intermediate­
term
residential
inhalation
risks
is
300
(
i.
e.,
an
MOE
less
than
300,
exceeds
HED's
level
of
concern).
The
level
of
concern
is
based
on
10X
to
account
for
interspecies
extrapolation
to
humans
from
the
animal
test
species,
10X
to
account
for
intraspecies
sensitivity,
and
3X
is
added
to
account
for
the
lack
of
a
NOAEL.

Long­
term
exposures
to
endothall
(
i.
e.
greater
than
6
months)
are
not
expected
for
current
registered
uses.

Body
Weight
Page
9
of
44
Since
the
adverse
effects
for
the
inhalation
studies
utilized
in
the
endothall
risk
assessments
are
from
reproductive
studies,
the
average
weight
of
an
adult
female
(
i.
e.,
60
kg)
was
used
to
estimate
inhalation
doses.

Cancer
In
accordance
with
the
1999
Draft
Guidelines
for
Cancer
Risk
Assessment,
the
HIARC
classified
endothall
as
"
not
likely
to
be
carcinogenic
to
humans"
based
on
the
lack
of
evidence
of
carcinogenicity
in
mice
or
rats.

Table
1:
Summary
of
Toxicology
Endpoint
Selection
for
Endothall
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)
Offspring
NOAEL
=
9.4
mg/
kg/
day
Residential
LOC
for
MOE
=
100
2­
generation
reproduction
study
in
rats
LOAEL
=
60
mg/
kg/
day
based
on
decreased
pup
body
weight
(
both
sexes)
on
Day
0
F1and
F2
generations
Intermediate­
Term
Incidental
Oral
(
1­
6
months)
LOAEL=
2
mg/
kg/
day
Residential
LOC
for
MOE
=
300
Occupational
=
NA
2­
generation
reproduction
study
in
rats
LOAEL
=
2
mg/
kg/
day
based
on
proliferative
lesions
of
the
gastric
epithelium
in
both
sexes
Short­
Term
Dermal
(
1
to
30
days)
NA
Intermediate
(
1
to
6
months)­
and
Long­
Term
(>
6
months)
Dermal
NA
Short­
Term
Inhalation
(
1
to
30
days)
Offspring
NOAEL
=
9.4
mg/
kg/
day
(
inhalation
absorption
rate
=
100%)
Residential
LOC
for
MOE
=
100
Occupational
LOC
for
MOE
=
100
2­
generation
reproduction
study
in
rats
LOAEL
=
2
mg/
kg/
day
based
on
proliferative
lesions
of
the
gastric
epithelium
in
both
sexes
Intermediate­
(
1
to
6
months)
and
Long
(>
6
months)
­
Term
Inhalation
LOAEL=
2
mg/
kg/
day
Residential
LOC
for
MOE
=
300
Occupational
LOC
for
MOE
=
300
2­
generation
reproduction
study
in
rats
LOAEL
=
2
mg/
kg/
day
based
on
proliferative
lesions
of
the
gastric
epithelium
in
both
sexes
Cancer
(
oral,
dermal,
inhalation)
Not
likely
to
be
carcinogenic
to
humans
UF
=
uncertainty
factor,
FQPA
SF
=
Special
FQPA
safety
factor,
NOAEL
=
no
observed
adverse
effect
level,
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
Page
10
of
44
Acute
Toxicity
Endothall
is
classified
as
category
I
for
acute
oral
toxicity
and
for
eye
irritation
potential
and
skin
irritation
potential.
It
is
classified
as
category
III
for
acute
dermal
toxicity
and
acute
inhalation
toxicity.
Results
were
positive
for
dermal
sensitization
in
guinea
pigs.

Table
2:
Acute
Toxicity
of
Endothall
Guideline
No.
Study
Type
MRID
#(
S).
Results
Toxicity
Category
81­
1
Acute
Oral
42289201
LD50
=
males
50.2,
females
44.4
mg/
kg
I
81­
2
Acute
Dermal
42289202
LD50
=
males
>
2000,
females
>
2000,
combined
>
2000
mg/
kg
III
81­
3
Acute
Inhalation
42169501
LC50
=
males
1.27,
females
2.20,
combined
1.51
m/
L
III
81­
4
Primary
Eye
Irritation
422889203
extremely
irritating
lethal
4/
6
rabbits
I
81­
5
Primary
Skin
Irritation
42289204
unacceptable
study
I
a
81­
6
Dermal
Sensitization
41871901
positive
N/
A
a
Endothall
has
been
shown
to
be
a
skin
irritant
in
a
preliminary
range
finding
study
of
the
dermal
absorption
study
(
MRID
42169503)
at
single
doses
of
50

g/
cm2
and
higher
and
in
the
21­
day
dermal
toxicity
study
(
MRID
43465201)
after
one
application
at
doses
of
30
mg/
kg
or
higher.
This
information
is
considered
sufficient
to
classify
endothall
as
a
severe
dermal
irritant.

1.4
Incident
Reports
An
analysis
of
incidence
reports
will
be
included
in
a
separate
memo
by
Jerrold
Blondell.

1.5
Summary
of
Physical
and
Chemical
Properties
of
Endothall
Technical
endothall
is
a
colorless
or
white
crystal
which
is
stable
to
light,
weak
acidic
media
and
weak
alkaline
media.
It
is
stable
to
temperatures
up
to
about
90
degrees
C.
Above
that
temperature,
it
undergoes
a
slow
conversion
to
anhydride.
Vapor
pressure
of
endothall
is
2.09
x
10­
5
mm
Hg
at
24.3
degrees
C.

1.6
Summary
of
Use
Patterns
and
Formulations
Endothall
products
are
described
in
this
section.

1.6.1
End­
Use
Products
Endothall
is
formulated
as
a
soluble
concentrate
for
use
as
a
harvest­
aid
agent
or
sucker
suppressant
on
certain
agricultural
crops.
It
also
is
formulated
as
a
soluble
concentrate
and
Page
11
of
44
granular
product
for
use
as
an
aquatic
herbicide.
Note,
however,
that
only
granular
products
are
available
for
residential
use.

1.6.2
Registered
Use
Categories
and
Sites
Endothall
is
registered
for
use
in
a
variety
of
occupational
and
residential
scenarios
and
thus
both
occupational
and
residential
populations
could
be
potentially
exposed
while
making
endothall
applications.
It
is
also
possible
for
occupational
and
residential
populations
to
be
exposed
to
endothall
during
postapplication
time
periods.

1.6.3
Application
Methods
Agricultural
Crop
Applications
When
used
as
a
harvest­
aid
agent,
endothall
is
applied
as
a
spray
with
aerial
and
groundboom
equipment.
When
used
as
a
sucker
suppressant
on
hops,
endothall
is
applied
with
ground
(
i.
e.,
groundboom)
equipment
only.

Aquatic
Herbicide
Applications
When
used
as
an
aquatic
herbicide,
a
variety
of
equipment
may
be
used.
Boats
used
to
treat
aquatic
weeds
are
normally
designed
to
apply
sprays
(
sprayer
located
in
the
rear)
and
granular
application
(
spreader
located
on
the
side).

For
occupational
applications
of
liquid
formulations
to
water,
endothall
may
be
sprayed
onto
the
water
surface
using
hand­
held
or
boat­
mounted
equipment
handgun
sprayers.
Endothall
may
also
be
directly
metered
into
the
suction
side
of
a
pump
and
injected
below
the
surface
of
the
water.
This
technique
is
the
only
method
of
application
to
flowing
waters,
but
is
also
used
for
applications
to
quiescent
waters.

For
occupational
applications
of
granular
formulations
to
water,
two
types
of
equipment
are
commonly
used,
centrifugal
granular
spreader
and
a
blower­
type
granular
spreader.
Centrifugal
spreaders
use
a
mechanical
rotor
to
strike
the
granules
and
disperse
them
in
a
30­
to
40­
feet
swath.
When
the
rotor
strikes
the
granules,
dust
is
created.
Blower­
type
spreaders
use
air
pressure
to
disperse
the
granules
and
create
relatively
little
dust
as
compared
to
centrifugal
spreaders.

For
residential
applications
of
granular
formulations
to
water,
HED
assumes
that
a
bellygrinder
type
granular
spreader
is
used.

Table
3:
Summary
of
Maximum
Application
Rates
for
Endothall
Agricultural
Crop
Uses
Crop
Type/
Use
Site
Application
Equipment
Acres
Treated
Per
Day
Maximum
Application
Rate
Section
3
SLN
Table
3:
Summary
of
Maximum
Application
Rates
for
Endothall
Agricultural
Crop
Uses
Crop
Type/
Use
Site
Application
Equipment
Acres
Treated
Per
Day
Maximum
Application
Rate
Page
12
of
44
Alfalfa
Grown
for
Seed
aerial
350
0.8
lb
ai/
A
1.0
lb
ai/
A
groundboom
200
Clover
Grown
for
Seed
aerial
350
0.8
lb
ai/
A
N/
A
groundboom
80
Cotton
aerial
1200
0.1
lb
ai/
A
0.13
lb
ai/
A
groundboom
200
Hops
groundboom
40
1.0
lb
ai/
A
N/
A
Potatoes
aerial
350
1.0
lb
ai/
A
N/
A
groundboom
80
Acers
Treated
/
day
obtained
from
Expo
SAC
policy
9.1
Table
4:
Summary
of
Maximum
Application
Rates
for
Endothall
Aquatic
Herbicide
Commercial
Uses
Aquatic
Site
Application
Equipment
Area
Treated
Per
Day
Application
Rate
Maximum
Ponds/
Lakes
Handgun
30
acres
surface
area
&
5
feet
deep
13.5
lbs
ai/
acre­
foot
Direct
metering
30
acres
surface
area
&
5
feet
deep
Canals
Handgun
10
miles
&
5
feet
deep
&
20
feet
wide
1.7
lbs
ai
at
1
mile
&
1
foot
wide
&
1
foot
deep
10
miles
&
5
feet
deep
&
5
feet
wide
Direct
metering
10
miles
&
5
feet
deep
&
20
feet
wide
10
miles
&
5
feet
deep
&
5
feet
wide
Flowing
Water
Direct
metering
300
minutes
metering
@
50
cfs;
120
minutes
metering
@
200
cfs
0.56
lb
ai/
minute
@
50
cfs
Area
treated/
day
provided
by
Kurt
Getsinger
of
Army
Corp
of
Engineers.

Table
5:
Summary
of
Maximum
Application
Rates
for
Endothall
Aquatic
Herbicide
Residential
Uses
Aquatic
Site
Application
Equipment
Area
Treated
Per
Day
Maximum
Application
Rate
Ponds/
Lakes
Bellygrinder
43,560
sq
ft
&
2
feet
deep
0.00022
lb
ai/
cubic
feet
10,000
sq
feet
&
2
feet
deep
Garden
Pools
Hand
1,000
sq
feet
&
2
feet
deep
2.0
Occupational
Exposures
and
Risks
It
has
been
determined
that
there
is
a
potential
for
exposure
to
endothall
in
occupational
scenarios
from
handling
endothall
products
during
the
application
process
(
i.
e.,
mixer/
loaders,
applicators,
flaggers,
and
mixer/
loader/
applicators)
and
a
potential
for
postapplication
worker
exposure
from
entering
into
areas
previously
treated
with
endothall.
As
a
result,
risk
assessments
have
been
completed
for
occupational
handler
scenarios
as
well
as
occupational
postapplication
scenarios.

2.1
Occupational
Handler
Exposures
and
Risks
Page
13
of
44
Tasks
associated
with
occupational
pesticide
use
(
i.
e.,
for
"
handlers")
can
generally
be
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
endothall
and
load
it
into
the
holding
tank
of
the
airplane
or
groundboom
sprayer.


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
endothall
into
the
application
equipment
and
then
also
apply
it.

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

HED
always
completes
risk
assessments
using
maximum
application
rates
for
each
scenario,
because
what
is
possible
under
the
label
must
be
evaluated,
for
complete
stewardship,
in
order
to
ensure
there
are
no
concerns
for
each
specific
use.

A
chemical
can
produce
different
effects
based
on
how
long
a
person
is
exposed,
how
frequently
exposures
occur,
and
the
level
of
exposure.
It
is
likely
that
endothall
exposures
can
occur
in
a
variety
of
patterns.
HED
believes
that
occupational
endothall
exposures
can
occur
over
a
single
day
or
up
to
weeks
at
a
time
for
many
use­
patterns
and
intermittent
exposures
over
several
weeks
are
also
anticipated.
Some
applicators
may
apply
endothall
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.
HED
classifies
exposures
up
to
30
days
as
short­
term
and
exposures
greater
than
30
days
up
to
several
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.
Long­
term
handler
exposures
are
not
expected
to
occur
for
endothall.
Different
toxicological
endpoints
of
concern
(
from
an
oral
study)
have
been
selected
for
short­
and
intermediate­
term
inhalation
exposures
to
endothall,
therefore
the
risk
results
for
all
inhalation
durations
of
exposure
are
numerically
distinct.

Occupational
handler
exposure
assessments
are
completed
by
HED
using
different
levels
of
personal
protection.
HED
typically
evaluates
all
exposures
with
a
tiered
approach.
The
lowest
tier
is
represented
by
the
baseline
exposure
scenario
(
i.
e.,
long­
sleeve
shirt,
long
pants,
shoes,
and
socks)
followed
by
increasing
the
levels
of
personal
protective
equipment
or
PPE
(
e.
g.,
gloves,
double­
layer
body
protection,
and
respirators)
and
engineering
controls
(
e.
g.,
enclosed
cabs
and
closed
mixing/
loading
systems).
This
approach
is
always
used
by
HED
in
order
to
be
able
to
Page
14
of
44
define
label
language
using
a
risk­
based
approach.
In
addition,
the
minimal
level
of
adequate
protection
for
a
chemical
is
generally
considered
by
HED
to
be
the
most
practical
option
for
risk
reduction
(
i.
e.,
over­
burdensome
risk
mitigation
measures
are
not
considered
a
practical
alternative).

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).


The
average
body
weight
of
an
adult
female
handler
(
i.
e.,
60
kilograms)
is
used
for
assessing
inhalation
dose,
because
the
toxicity
endpoint
values
used
for
the
inhalation
assessments
are
from
a
reproductive
study
and,
therefore,
are
female­
specific.


Generic
protection
factors
(
PFs)
were
used
to
calculate
exposures
when
data
were
not
available.
For
example,
an
80
percent
protection
factor
was
assumed
for
the
use
of
a
quarter­
face
dust/
mist
respirator.


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
the
endothall
handler
exposure
assessment,
the
following
surrogate
data
was
used
for
certain
application
methods,
since
the
nature
of
these
application
methods
are
believed
to
be
similar
enough
to
bridge
the
data:


for
occupational
large
scale
spray
applications
to
water
using
boat­
mounted
boom
sprayers,
PHED
data
for
mixing/
loading
and
applying
with
ground
boom
were
used;


for
occupational
larger­
scale
spray
applications
to
water
using
boat­
mounted
spray
tanks
equipped
with
a
handgun,
ORETF
data
for
loading/
applying
with
handgun
equipment
were
used;


for
occupational
direct
metering
of
liquid
formulations
to
water,
PHED
data
for
mixing/
loading
liquid
formulations
were
used;


for
occupational
boat­
mounted
granular
applications
to
water
using
blower­
type
spreaders,
PHED
data
for
loading
granulars
were
used;
and

for
residential
granular
applications
to
water,
PHED
data
for
loading/
applying
granulars
with
bellygrinder
equipment
were
used.
Page
15
of
44

For
occupational
assessments,
HED
assumes
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments
(
see
tables
3
and
4).


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
is
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.
The
Agency
also
met
with
Army
Corp
Of
Engineers
on
July
27th
2005
to
discuss
assumptions
used
in
aquatic
risk
assessment.
The
Corp
view
was
that
the
original
assumptions
were
an
over
estimate
and
suggested
to
use
lower
values.
The
suggested
values
were
captured
in
a
memo
and
received
by
Health
effect
Division(
SRRD,
Mika
Hunter,
July
27th
2005).
The
revised
assessment
includes
values
suggested
by
the
Army
Corp
of
Engineers.
However,
no
standard
values
are
available
for
numerous
scenarios.
Assumptions
for
these
scenarios
are
based
on
HED
estimates
and
could
be
further
refined
from
input
from
affected
sectors.

S
Aerial
equipment:
350
acres
for
most
crops
on
which
endothall
is
registered,
except
1200
acres
for
high
acreage
crops
(
i.
e.,
cotton);

S
Groundboom
equipment:
80
acres
for
most
crops
on
which
endothall
is
registered,
except
200
acres
for
high
acreage
crops
(
i.
e.,
cotton)
and
40
acres
for
hops;
 
Flaggers:
350
acres
for
all
crops
on
which
endothall
is
registered;
 
Pond/
Lake
spray
and
granular
applications:
30­
acre
surface
area
and
5­
feet
depth;
 
Canal
spray
and
granular
applications:
10
miles
in
length,
5­
feet
depth,
and
20­
or
5­
feet
width;
and
 
Flowing
water
applications:
5
hours,
if
water
is
flowing
50
cubic
feet
per
second
and
2
hours,
if
water
is
flowing
200
cubic
feet
per
second.

2.1.1.2
Exposure
Data
for
Handler
Exposure
Scenarios
For
endothall
handler
exposure
assessments,
all
analyses
were
completed
using
data
that
were
deemed
to
be
a
source
of
acceptable
surrogate
exposure
data
for
the
scenario
in
question.

HED
uses
a
concept
known
as
unit
exposure
as
the
basis
for
the
scenarios
used
to
assess
handler
exposures
to
pesticides.
Unit
exposures
numerically
represent
the
exposures
one
would
receive
related
to
an
application.
They
are
generally
presented
as
milligrams
of
active
ingredient
exposure
per
pound
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
Page
16
of
44
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
exposure
values
for
workers
involved
in
the
handling
of
pesticides
under
actual
field
conditions
and
a
set
of
computer
algorithms
used
to
subset
and
statistically
summarize
the
selected
data.
Currently,
the
database
contains
values
for
over
1,700
monitored
individuals
(
i.
e.,
replicates).

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
magnitude
of
handler
exposures
to
pesticides
are
primarily
a
function
of
activity
(
e.
g.,
mixing/
loading,
applying),
formulation
type
(
e.
g.,
wettable
powders,
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
values
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
values
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
exposure
values
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
A
,
Table
A7.
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
values
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
exposure
values
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.
The
study
that
Page
17
of
44
monitored
LCO
exposure
scenarios
using
a
low
pressure,
high
volume
turf
handgun
(
ORETF
Study
OMA002)
is
summarized
below.

LCO
Handgun
Sprayer:
A
mixer/
loader/
applicator
study
was
performed
by
ORETF
using
Dacthal
as
a
surrogate
compound
to
determine
"
generic"
exposures
to
individuals
applying
a
pesticide
to
turf
with
a
low­
pressure
"
nozzle
gun"
or
"
handgun"
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
pounds
active
ingredient
handled.
A
total
of
90
replicates
were
monitored
using
17
different
subjects.
Four
different
formulations
of
dacthal
[
75%
wettable
powder
(
packaged
in
4
and
24
pound
bags),
75%
wettable
powder
in
water
soluble
bags
(
3
pound
bag),
75%
water
dispersable
granules
(
2
pound
bag)
and
55%
liquid
flowable
(
2.5
gallon
container)]
were
applied
by
five
different
LCOs
to
actual
residential
lawns
at
each
site
in
three
different
locations
(
Ohio,
Maryland,
and
Georgia)
for
a
total
of
fifteen
replicates
per
formulation.
An
additional
ten
replicates
at
each
site
were
monitored
while
they
performed
spray
application
only
using
the
75
percent
wettable
powder
formulation.
A
target
application
rate
of
2
pounds
active
ingredient
was
used
for
all
replicates
(
actual
rate
achieved
was
about
2.2
pounds
active
ingredient
per
acre).
Each
replicate
treated
a
varying
number
of
actual
client
lawns
to
attain
a
representative
target
of
2.5
acres
(
1
hectare)
of
turf.
The
exposure
periods
averaged
five
hours
twenty­
one
minutes,
five
hours
thirty­
nine
minutes,
and
six
hours
twenty­
four
minutes,
in
Ohio,
Maryland
and
Georgia,
respectively.
Average
time
spent
spraying
at
all
sites
was
about
two
hours.
All
mixing,
loading,
application,
adjusting,
calibrating,
and
spill
clean
up
procedures
were
monitored,
except
for
typical
end­
of­
day
clean­
up
activities
(
e.
g.
rinsing
of
spray
tank,
etc).
Dermal
exposure
was
measured
using
inner
and
outer
whole
body
dosimeters,
hand
washes,
face/
neck
washes,
and
personal
air
monitoring
devices.
All
test
subjects
wore
one­
piece,
100
percent
cotton
inner
dosimeters
beneath
100
percent
cotton
long­
sleeved
shirt
and
long
pants,
rubber
boots
and
nitrile
gloves.
Gloves
are
typically
worn
by
most
LCOs,
and
required
by
many
pesticide
labels
for
mixing
and
loading.

Overall,
residues
were
highest
on
the
upper
and
lower
leg
portions
of
the
dosimeters.
In
general,
concurrent
lab
spikes
produced
mean
recoveries
in
the
range
of
78­
120
percent,
with
the
exception
of
OVS
sorbent
tube
sections
which
produced
mean
recoveries
as
low
as
65.8
percent.
Adjustment
for
recoveries
from
field
fortifications
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
exposure
values
are
presented
below.
[
Note
the
data
were
found
to
be
lognormally
distributed.
As
a
result,
all
exposure
values
are
geometric
means.]

Table
6:
Unit
Exposure
Values
Obtained
From
ORETF
LCO
Handgun
Studies
(
MRID
449722­
01)

Application
Method
Inhalation
Unit
Exposure
(

g/
lb
ai)
1
LCO
Handgun
Spray
Mixer/
Loader/
Applicator
Liquid
Flowable3
1.8
Page
18
of
44
1Air
concentration
(
mg/
m3/
lb
ai)
calculated
using
NAFTA
`
99
standard
breathing
rate
of
17
lpm
(
1
m3/
hr).
2Exposure
calculated
using
OPP/
HED
50%
protection
factor
(
PF)
for
cotton
coveralls
on
torso,
arms,
legs.
3All
commercial
handlers
wore
long
pants,
long­
sleeved
shirt,
nitrile
gloves
and
shoes.

2.1.2
Endothall
Handler
Exposure
Scenarios
It
has
been
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
occupational
use
of
endothall
in
two
distinct
occupational
environments
 
applying
endothall
to
crops
as
a
harvest­
aid
and
applying
endothall
to
water
for
aquatic
plant
control.
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
during
endothall
applications.
The
quantitative
exposure/
risk
assessment
developed
for
occupational
handlers
is
based
on
the
following
scenarios.
[
Note:
The
scenario
numbers
correspond
to
the
tables
of
risk
calculations
included
in
the
occupational
risk
calculation
sections
of
the
appendices.
Endothall
inhalation
exposure
was
estimated
using
PHED
or
ORETF
data.]

Mixer/
Loaders
Supporting
Applications
to
Crops:
(
1a)
Liquids
for
Aerial
Applications;
(
1b)
Liquids
for
Groundboom
Applications;

Applicators
Applying
to
Crops:
(
2)
Aerial
Applications
(
Sprays);
(
3)
Groundboom
Applications;

Flaggers
Supporting
Applications
to
Crops:
(
4)
Flagging
for
Sprays;

Mixer/
Loader/
Applicators
Applying
to
Water:
(
5)
Liquid:
Handgun
Sprayer;
(
6)
Liquid:
Direct
Metering
(
using
data
for
mixing/
loading
liquid
formulations);
(
7)
Granular:
Blower­
type
Spreader
(
using
data
for
loading
granules).

2.1.3
Endothall
Handler
Exposure
and
Assessment
The
occupational
handler
exposure
and
risk
calculations
are
presented
in
this
section.

2.1.3.1
Endothall
Handler
Exposure
and
Risk
Calculations
risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
which
is
a
ratio
of
the
daily
dose
to
the
toxicological
endpoint
of
concern.
Daily
dose
values
are
calculated
by
first
calculating
exposures
by
considering
application
parameters
(
i.
e.,
rate
and
area
treated)
along
with
unit
exposure
values.
Exposures
were
then
normalized
by
body
weight
and
adjusted
for
absorption
factors
as
appropriate
to
calculate
dose
levels.
MOEs
then
were
calculated.

Daily
Exposure:
The
daily
exposure
and
daily
dose
to
handlers
were
calculated
as
Page
19
of
44
Daily
Exposure
mg
ai
day

Unit
Exposure
mg
ai
lb
ai
handled
x
Application
Rate
lbs
ai
area
x
Daily
Area
Treated
area
day
Average
Daily
Dose
mg
/
kg
/
day

Daily
Exposure
mg
ai
day
x
Absorption
Factor
(%
/
100)
Body
Weight
(
kg)
described
below.
The
first
step
was
to
calculate
daily
exposure
(
inhalation)
using
the
following
formula:

Where:

Daily
Exposure
=
Amount
(
mg
ai/
day)
inhaled
that
is
available
for
inhalation
absorption;
Unit
Exposure
=
Unit
exposure
value
(
mg
ai/
lb
ai)
derived
from
August
1998
PHED
data
and
from
ORETF
data;
Application
Rate
=
Normalized
application
rate
based
on
a
logical
unit
treatment,
such
as
acres,
square
feet,
gallons,
or
cubic
feet.
Maximum
values
are
generally
used
(
lb
ai/
A,
lb
ai/
sq
ft,
lb
ai/
gal,
lb
ai/
cu
ft);
and
Daily
Area
Treated
=
Normalized
application
area
based
on
a
logical
unit
treatment
such
as
acres
(
A/
day),
square
feet
(
sq
ft/
day),
gallons
per
day
(
gal/
day),
or
cubic
feet
(
cu
ft/
day).

Daily
Dose:
Daily
dose
(
inhalation)
was
calculated
by
normalizing
the
daily
inhalation
exposure
value
by
body
weight
and
accounting
for
inhalation
absorption.
For
assessing
an
average
body
weight
of
60
kilograms
was
used
 
representing
the
body
weight
of
an
average
adult
female
handler.
Since
the
inhalation
toxicological
endpoint
of
concern
is
based
on
an
oral
study,
an
inhalation
absorption
rate
is
needed
and
is
assumed
to
be
100
percent.
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:
Finally,
the
calculations
of
daily
inhalation
dose
received
by
handlers
were
then
compared
to
the
appropriate
endpoint
(
i.
e.,
NOAEL
or
LOAEL)
to
assess
the
total
risk
to
handlers
for
each
exposure
route
within
the
scenarios.
All
MOE
values
were
calculated
inhalation
exposure
levels
using
the
formula
below:
Page
20
of
44
MOE

NOAEL
mg/
kg/
day
Average
Daily
Dose
mg/
kg/
day
Where:

MOE
=
Margin
of
exposure,
value
used
by
HED
to
represent
risk
or
how
close
a
chemical
exposure
is
to
being
a
concern
(
unitless);
ADD
=
(
Average
Daily
Dose)
or
the
amount
as
absorbed
dose
received
from
exposure
to
a
pesticide
in
a
given
scenario
(
mg
pesticide
active
ingredient/
kg
body
weight/
day);
and
NOAEL
=
Dose
level
in
a
toxicity
study,
where
no
observed
adverse
effects
occurred
(
NOAEL
or
LOAEL)
in
the
study
2.1.3.2
Endothall
Risk
Summary
(
using
PHED
and
ORETF)

All
of
the
risk
calculations
for
occupational
endothall
handlers
completed
in
this
assessment
are
included
in
Appendix
A.
A
summary
of
the
short­
and
intermediate­
term
risks
for
each
exposure
scenario
are
presented
below
in
Tables
7
and
8.

.

Table
7.
Summery
of
Endothall
Occupational
Short­
and
Intermediate­
Term
Inhalation
Handler
Risks
for
Agricultural
Crops
Uses
Page
21
of
44
Exposure
Scenario
Crop
or
Target
Application
Ratea
(
lb
ai/
acre)
Area
Treated
Dailyb
(
acres)
Inhalation
MOEf,
g
(
Target
Short­
Term
MOE
=
100;
Target
Intermediate­
Term
MOE
=
300)

Baseline
Attirec
PPE
­
80%
Respiratord
Engineering
Controlse
Short­
term
Intermediateterm
Short­
term
Intermediateterm
Short­
term
Intermediate­
term
Mixer/
Loader
Mixing/
Loading
Emulsifiable
Concentrates
(
Liquids)
for
Aerial
Applications
Alfalfa
(
SLN)
1
1,200
390
83
2,000
420
5,700
1,200
Alfalfa
0.8
1,200
490
100
2,400
520
7,100
1,500
Potatoes
1
350
1,300
290
6,700
1,400
19,000
4,100
Clover
0.8
350
1,700
360
8,400
1,800
24,000
5,200
Cotton
(
SLN)
0.13
1,200
3,000
640
15,000
3,200
44,000
9,300
Cotton
0.1
1,200
3,900
830
20,000
4,200
57,000
12,000
Mixing/
Loading
Emulsifiable
Concentrates
(
Liquids)
for
Groundboom
Applications
Alfalfa
(
SLN)
1
200
2,400
500
12,000
2,500
34,000
7,200
Alfalfa
0.8
200
2,900
630
15,000
3,100
42,000
9,000
Potatoes
1
80
5,900
1,300
29,000
6,300
85,000
18,000
Hops
1
40
12,000
2,500
59,000
36,000
170,000
36,000
Clover
0.8
80
7,300
1,600
37,000
7,800
110,000
23,000
Cotton
(
SLN)
0.13
200
18,000
3,800
90,000
19,000
260,000
56,000
Cotton
0.1
200
24,000
5,000
120,000
25,000
340,000
72,000
Applicator
Applying
Sprays
via
Aerial
Equipment
Alfalfa
(
SLN)
1
1,200
No
Data
No
Data
No
Data
No
Data
6,900
1,500
Alfalfa
0.8
1,200
No
Data
No
Data
No
Data
No
Data
8,600
1,800
Potatoes
1
350
No
Data
No
Data
No
Data
No
Data
24,000
5,000
Clover
0.8
350
No
Data
No
Data
No
Data
No
Data
30,000
6,300
Cotton
(
SLN)
0.13
1,200
No
Data
No
Data
No
Data
No
Data
53,000
11,000
Cotton
0.1
1,200
No
Data
No
Data
No
Data
No
Data
69,000
15,000
Applying
Sprays
via
Groundboom
Equipment
Alfalfa
(
SLN)
1
200
3,800
810
19,000
4,100
66,000
14,000
Alfalfa
0.8
200
4,800
1,000
24,000
5,100
82,000
17,000
Potatoes
1
80
9,500
2,000
48,000
10,000
160,000
35,000
Hops
1
40
19,000
4,100
95,000
20,000
330,000
70,000
Exposure
Scenario
Crop
or
Target
Application
Ratea
(
lb
ai/
acre)
Area
Treated
Dailyb
(
acres)
Inhalation
MOEf,
g
(
Target
Short­
Term
MOE
=
100;
Target
Intermediate­
T
Baseline
Attirec
PPE
­
80%
Respiratord
Short­
term
Intermediateterm
Short­
term
Intermediateterm
Page
22
of
44
Clover
0.8
80
12,000
2,500
60,000
13,000
Cotton
(
SLN)
0.13
200
29,000
6,200
150,000
31,000
Cotton
0.1
200
38,000
8,100
190,000
140,000
Flagger
Flagging
for
Sprays
via
Aerial
Equipment
Alfalfa
(
SLN),
Potatoes
1
350
4,600
980
23,000
4,900
Alfalfa,
Clover
0.8
350
5,800
1,200
29,000
6,100
Cotton
(
SLN)
0.13
350
35,000
7,500
180,000
38,000
Cotton
0.1
350
46,000
9,800
230,000
49,000
Footnotes
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
endothall.
b
Amount
handled
per
day
values
are
HED
estimates
of
acres
treated
daily
based
on
Exposure
SAC
SOP
#
9
"
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,"
industry
sources,
and
HED
estimates.
c
Baseline
attire
is
no
respirator.
d
PPE­
80%
Respirator
is
quarter­
face
dust/
mist
respirator
(
that
provides
an
80%
protection
factor)
e
Engineering
Controls
is
closed
mixing/
loading
system,
enclosed
cab,
or
enclosed
cockpit.
f
Short­
term
inhalation
MOE
=
NOAEL
(
9.4
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g)
/
body
weight
(
60
kg
adult
female).
g
Intermediate­
term
inhalation
MOE
=
LOAEL
(
2
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g)
/
body
weight
(
60
kg
adult
female).
Page
23
of
44
Table
8.
Summery
of
Endothall
Short­
and
Intermediate­
Term
Occupational
Inhalation
Handler
Risks
for
Aquatic
Uses
Exposure
Scenario
Crop
or
Target
Application
Rate
Surface
Area
or
Length
of
Water
Body
(
acres
or
miles)
Depth
of
Water
Body
(
feet)
Width
of
Water
Body
(
feet)
Inhalation
MOE
(
Target
Short­
Term
MOE
=
100;
Target
Intermediate­
Term
MOE
=
300)

Baseline
Attire
PPE
­
80%
Respirator
Engineering
Controls
Short­
term
Intermediateterm
Short­
term
Intermediateterm
Short­
term
Intermediateterm
Mixer/
loader
Mixing/
loading
liquid
for
groundboom
application
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
230
50
1150
250
500
(
half
face
respirator
90%

protection)
3150
670
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
400
85
2000
425
4700
1000
Mixing/
Loading
Emulsifiable
Concentrate
with
Direct
Metering
(
PHED:

mixing/
loading
liquid
)
Flowing
Water
0.56
lb
ai
/
minute
at
50
cfs
300
minutes/
day
NA
NA
2800
600
14000
3000
40000
8600
Flowing
Water
0.15
lb
ai
/
minute
at
200
cfs
120
minutes/
day
NA
NA
26000
5500
130000
27500
380000
80000
Applicator
Applying
liquid
with
groundboom
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
375
80
1900
400
NF
NF
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
625
135
3150
675
NF
NF
Mixer/
Loader/
Applicator
Ponds/
Lakes
13.5
lb
ai/
A­
ft
10
Acres/
day
2
NA
1160
245
5900
1250
NF
NF
Ponds/
Lakes
8
lb
ai/
A­
ft
10
Acres/
day
2
NA
1880
400
9800
2100
NF
NF
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
20
470
100
2300
500
NF
NF
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
5
1880
400
9400
2000
NF
NF
Canals
1lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
20
785
165
4000
850
NF
NF
Canals
1
lb
ai/
canal­­
1
mile
X
10
miles
long
2
5
3135
670
16000
3400
NF
NF
Table
8.
Summery
of
Endothall
Short­
and
Intermediate­
Term
Occupational
Inhalation
Handler
Risks
for
Aquatic
Uses
Exposure
Scenario
Crop
or
Target
Application
Rate
Surface
Area
or
Length
of
Water
Body
(
acres
or
miles)
Depth
of
Water
Body
(
feet)
Width
of
Water
Body
(
feet)
Inhalation
MOE
(
Target
Short­
Term
MOE
=
100;
Target
Intermediate­
Term
MOE
=
300)

Baseline
Attire
PPE
­
80%
Respirator
Engineering
Controls
Short­
term
Intermediateterm
Short­
term
Intermediateterm
Short­
term
Intermediateterm
Page
24
of
44
1
ft
wide
x
1
ft
deep
Loading/
Applying
Granulars
(
PHED:
open
loading
granulars)
Ponds/
Lakes
9.8
lb
ai/
A­
ft
30
Acres/
day
5
NA
230
48
1100
240
480
(
half
face
respirator
90%

protection)
NF
NF
Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
20
208
45
1050
220
450
(
half
face
respirator
90%

protection)
NF
NF
Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
5
860
180
4100
870
NF
NF
2.1.4
Cancer
Endothall
Handler
Exposure
and
Risk
Assessment
Page
25
of
44
No
occupational
handler
cancer
risk
assessment
is
needed
for
endothall,
since
no
cancer
endpoint
of
concern
was
identified.

2.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Occupational
Handlers
There
occupational
handler
scenarios
for
endothall
have
no
risks
associated
with
them
and
are
above
HED's
level
of
concern
for
inhalation
risk
assessments.
The
assessment
involving
the
aquatic
herbicide
scenarios
uses
substitute
inhalation
unit
exposure
values,
since
no
data
are
available
for
assessing
inhalation
exposures
from
the
use
of
boat­
mounted
application
equipment.
These
occupational
handler
scenarios
for
endothall
could
be
better
refined
with
equipment­
specific
exposure
data.

2.1.5.1
Summary
of
Data
Gaps
Several
data
gaps
were
identified
for
endothall
in
many
different
use
areas
that
include:

°
mixing/
loading/
applying
liquid
formulations
to
aquatic
areas
using
handheld
equipment;

$
loading/
applying
liquid
formulations
to
aquatic
areas
using
direct
metering;
and
$
loading/
applying
granular
formulations
to
aquatic
areas
using
centrifugal
or
blower­
type
equipment.

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,
timing,
and
areas
treated
would
better
characterize
endothall
risks.
Exposure
studies
for
many
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
the
data
gaps
identified
above
and
based
on
a
review
of
the
quality
of
the
data
used
in
this
assessment.

2.2
Occupational
Postapplication
Exposures
and
Risks
Agricultural
Crop
Uses:

EPA
did
not
assess
occupational
postapplication
risks
to
agricultural
workers
following
treatments
to
agricultural
crops,
since
no
dermal
endpoint
of
concern
was
identified.

The
Environmental
Protection
Agency's
requirements
regarding
Restricted­
entry
Intervals
(
REIs)
are
included
in
the
40
CFR
156.208.
Guidance
on
applying
these
requirements
are
also
included
in
Chapter
11
of
the
Office
of
Pesticide
Programs'
Label
Review
Manual.
In
accordance
with
the
40
CFR
156.208,
the
REI
is
based
on
the
acute
toxicity
of
the
"
technical
active
ingredient
material".

The
toxicity
categories
of
the
active
ingredient
for
acute
dermal,
eye
irritation,
and
skin
irritation
potential
are
used
to
determine
the
interim
REI.
If
one
or
more
of
the
three
acute
toxicity
effects
are
in
Page
26
of
44
toxicity
category
I,
the
interim
REI
is
established
at
48
hours.
If
none
of
the
acute
toxicity
effects
are
in
category
I,
but
one
or
more
of
the
three
is
classified
as
category
II,
the
interim
REI
is
established
at
24
hours.
The
acute
toxicity
classification
for
primary
eye
irritation
of
endothall
is
category
I
which
requires
a
48­
hour
REI.

Aquatic
Uses:
Postapplication
occupational
exposures
following
endothall
application
to
aquatic
areas
is
likely
limited
to
persons
who
contact
the
treated
water
to
perform
tests,
such
as
testing
the
levels
of
endothall,
or
persons
such
as
agricultural
workers
or
irrigation
water
suppliers
who
contact
treated
water
in
irrigation
canals.
Worse­
case
postapplication
exposures
to
endothall
following
application
in
aquatic
sites
is
likely
to
be
to
persons
who
swim
in
the
treated
waters.
The
swimmer
exposure
to
endothall
followed
the
guidance
provided
in
the
Agency's
draft
SOP.
The
standard
exposure
factors
provided
in
the
residential
SOP
were
used
to
assess
noncompetitive
swimmer
exposure.
The
exposure
to
competitive
swimming
was
not
assessed
since
endothall
is
not
used
in
swimming
pools.

Refer
to
residential
postapplication
section
for
postapplication
exposure
assessment
to
aquatic
uses
of
endothall
for
noncompetitive
swimmers
(
i.
e.,
recreational).

3.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
It
has
been
determined
that
there
is
a
potential
for
exposure
in
residential
settings
during
the
application
process
for
homeowners
who
use
endothall
products
to
control
aquatic
weeds
and
algae
in
ponds
and
garden
pools.
There
is
also
a
potential
for
exposure
to
adults
and
children
from
contacting
water
treated
with
endothall
through
swimming,
wading,
water
skiing,
etc.
As
a
result,
risk
assessments
have
been
completed
for
both
residential
handler
and
postapplication
scenarios.

3.1
Residential
Handler
Exposures
and
Risks
Residential
handlers
are
addressed
somewhat
differently
by
the
Agency
as
homeowners
are
assumed
to
complete
all
elements
of
an
application
with
little
use
of
protective
equipment.

3.1.1
Handler
Exposure
Scenarios
The
purpose
of
this
section
is
to
describe
how
the
exposure
scenarios
were
defined.
Much
of
the
process
for
residential
uses
is
identical
to
that
considered
for
the
occupational
assessment
with
a
few
notable
exceptions
that
include:

°
Residential
handler
exposure
scenarios
are
only
considered
to
be
short­
term
in
nature
due
to
the
episodic
uses
associated
with
homeowner
products.

°
A
tiered
approach
for
personal
protection
using
increasing
levels
of
personal
protective
equipment
(
PPE)
is
not
used
in
residential
handler
risk
assessments.
Rather
than
using
PPE,
homeowner
handler
assessments
are
completed
based
on
individuals
using
shorts
and
shortsleeved
shirts.
°
Homeowner
handlers
are
expected
to
complete
all
tasks
associated
with
the
use
of
a
pesticide
Page
27
of
44
product
including
loading
as
well
as
the
application.

°
Label
use
rates
and
use
information
specific
to
residential
products
serve
as
the
basis
for
the
risk
calculations
as
opposed
to
the
rates
used
in
the
occupational
assessment.;

°
Area
treated
per
day
in
the
risk
assessment
is
based
on
Agency
guidance
specific
to
residential
use
patterns.

It
has
been
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
residential
use
of
endothall
granular
products
in
ponds
and
garden
pools.
The
anticipated
use
patterns
and
current
labeling
indicate
two
likely
residential
exposure
scenarios
 
loading/
applying
granules
with
a
bellygrinder
and
applying
granules
by
hand.
The
quantitative
exposure/
risk
assessment
developed
for
residential
handlers
is
based
on
these
two
scenarios.
[
Note:
The
scenario
numbers
correspond
to
the
tables
of
risk
calculations
included
in
the
occupational
risk
calculation
sections
of
the
appendices.]

(
1)
Granular
formulation:
loading/
applying
with
bellygrinder;
and
(
2)
Granular
formulation:
applying
by
hand.

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.
These
unit
exposure
values
were
taken
from
the
Pesticide
Handlers
Exposure
Database
(
PHED).
[
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:


The
Agency
always
considers
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments
to
consider
what
is
legally
possible
based
on
the
label.


Residential
risk
assessments
were
not
based
on
what
could
be
applied
in
a
typical
workday
as
with
the
occupational
risk
assessments
presented
above.
Instead,
the
Agency
based
calculations
on
what
would
reasonably
be
treated
by
homeowners,
such
as
the
size
of
a
pond,
or
the
size
of
a
garden
pool.
This
information
was
used
by
the
Agency
to
define
chemical
throughput
values
for
handlers
which
in
turn
were
coupled
with
unit
exposure
values
to
calculate
risks.
The
daily
area
treated,
based
on
HED's
professional
judgement,
used
in
each
residential
scenario,
include:

°
typical
pond
application:
rangefinder
calculation
using
1
acre
of
surface
area
and
2­
feet
depth
and
10,000
square
feet
surface
area
and
2­
feet
depth.
°
typical
garden
pool
application:
1,000
square
feet
of
surface
area
and
2
feet
depth.

Residential
Handler
Exposure
Studies:
The
unit
exposure
values
that
were
used
in
this
Page
28
of
44
assessment
were
based
on
studies
completed
by
the
Pesticide
Handler
Exposure
Database
(
PHED,
Version
1.1
August
1998).
[
Note:
PHED
studies
are
described
above
in
Section
2.1.2,
refer
to
that
section
for
further
information.]

3.1.3
Residential
Handler
Exposure
and
Risk
Estimates
The
residential
handler
exposure
and
risk
calculations
are
presented
in
this
section.
Risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
as
described
in
Section
2.1.3.
Much
of
the
process
for
residential
uses
is
identical
to
that
considered
for
the
occupational
assessment
with
a
few
notable
exceptions
as
described
above
in
Section
3.1.1
(
e.
g.,
all
are
short­
term
exposures
and
assume
homeowners
wear
shorts
and
short­
sleeved
shirts
with
no
gloves).

Risk
Summary:
The
risk
calculations
for
residential
endothall
handlers
are
included
in
Appendix
A
and
summarized
below.

Table
9.
Endothall
Short­
and
Intermediate­
Term
Risks
to
Residential
Handler
Exposure
Scenario
Crop
or
Target
Application
Rate
(
lb
ai/
cubic
feet)
Surface
Area
Treated
Daily
(
square
feet)
Depth
of
Water
(
feet)
Short­
Term
Inhalation
MOE
(
no
respirator)

Mixer/
Loader/
Applicator
Loading/
Applying
Granulars
via
Belly
Grinder
Ponds/
Lakes
0.00022
43,560
2
470
Ponds/
Lakes
0.00022
10,000
2
1900
Applying
Granulars
via
Hand
Garden
pool
0.00022
1,000
2
2700
In
residential
settings,
the
Agency
does
not
use
personal
protective
equipment
(
PPE)
to
limit
exposures,
because
PPE
are
viewed
as
impractical
and
not
enforceable.

For
residential
handlers,
short­
term
inhalation
MOEs
are
not
of
concern
for
any
of
the
scenarios
and
does
not
exceed
the
Agency's
uncertainty
factor
(
i.
e.,
MOE

100).

3.1.4
Summary
of
Risk
Concerns
and
Data
Gaps
for
Handlers
In
summary,
the
assessment
for
residential
handler
exposure
presented
in
this
section
concludes
that
there
are
no
risk
concerns
for
endothall
as
it
is
currently
used
in
a
residential
environment.

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
endothall
risks.

3.2
Residential
Postapplication
Exposures
and
Risks
Page
29
of
44
3.2.1
Residential
Postapplication
Exposure
Scenarios
Postapplication
exposures
to
adults
and
children
are
expected
following
applications
of
endothall
to
ponds
and
lakes.
Of
the
possible
postapplication
exposures,
swimming
in
treated
water
is
considered
by
HED
to
be
worse­
case
and
is
used
as
a
surrogate
for
all
other
possible
postapplication
exposures,
such
as
wading,
water
skiing,
etc.

The
Agency
considered
residential
postapplication
exposure
for
different
segments
of
the
population.
Risks
were
calculated
for
swimming
in
treated
lakes
or
ponds
(
see
section
2.2.1Occupational
Postapplication
Exposure
Scenarios).

3.2.2
Residential
Postapplication
Exposure
and
Risk
Estimates
The
residential
postapplication
exposure
and
risk
calculations
are
presented
in
this
section.
Risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
which
is
a
ratio
of
the
body
burden
to
the
toxicological
endpoint
of
concern.
Exposures
were
calculated
using
the
SWIM
model.

Risk
Summary:
The
Agency
has
addressed
residential
postapplication
exposures
to
endothall
using
the
SWIM
model.

The
following
assumptions
have
used
to
assess
postapplication
exposure
to
swimmers.

S
Body
Weights
22kg
for
children
(
6
year
old)
and
70kg
for
adults
S
Body
surface
area
9000
cm2
and
21000
cm2
for
adults
S
Exposure
Time
3hrs/
day
S
Water
Intake
5
liter
or
5000
ml
in
and
out
of
the
mouth
per
hour
S
Water
ingested
0.05
L
or
50
ml
per
hour
S
Application
rate
1
to
5
ppm
or
1
to
5
mg/
L
or
1
to
5
mg/
1000
cm3
S
Permeability
coefficient
K
p
8.82
x10­
7
cm/
hr
S
Octanol/
water
partition
coefficient
K
ow
0.0008
S
Vapor
pressure
3.92x10­
5
mg/
day
Table
10
provides
the
individual
exposure
through
various
routes
based
on
the
standard
factors
and
physical
constant.
The
estimates
provided
by
the
SOP
are
the
absorbed
doses
and
risks
using
endothall
for
recreational
swimming
from
to
all
routes
of
exposure.

Table
10
Summary
of
Endothall
Swimmer
Postapplication
Risk
Exposure
Children
(
6
to
10)
Adult
Daily
Dose
mg/
kg/
day
MOE
Daily
Dose
mg/
kg/
day
MOE
Oral
0.0341
280
0.0107
900
Dermal
NA
NA
NA
NA
Buccal
Insignificant*
NA
Insignificant
NA
Page
30
of
44
Orbital/
Nasal
Insignificant
NA
Insignificant
NA
Total
280
900
*
Dosage
is
insignificant
according
to
the
SOP
because
endothall
is
lipophobic
(
K
OW
=
0.0008)

For
significant
absorption
through
buccal/
sublingual,
orbital
and
nasal
exposure
the
chemical
must
be
lipophilic
with
a
high
K
OW.
Since
endothall
has
a
low
K
ow
Value,
therefore
no
significant
risk
is
expected.
Also
due
to
low
vapor
pressure,
inhalation
exposure
is
expected
to
be
negligible.

Risk
Summary:

The
Agency
considered
one
residential
postapplication
exposure
scenario
 
swimming
 
for
different
segments
of
the
population
including
children,
and
adults.
risks
were
calculated.
In
residential
settings,
the
Agency
does
not
use
REIs
or
other
mitigation
approaches
to
limit
exposures,
because
they
are
viewed
as
impractical
and
not
enforceable.
As
such,
risk
estimates
on
the
day
of
application
are
the
key
concern.
However,
several
of
the
Special
Local
Needs
labels
do
having
swimming
restrictions
following
commercial
applications
of
endothall.

3.3
Residential
Risk
Characterization
3.3.1
Characterization
of
Residential
Handler
Risks
The
data
that
were
used
in
the
endothall
residential
handler
assessment
represent
the
best
data
and
approaches
that
are
currently
available.
For
each
use
pattern,
the
Pesticide
Handlers
Exposure
Database
(
PHED)
was
used
to
develop
the
unit
exposure
values.
All
data
that
have
been
used
may
not
be
of
optimal
quality,
but
represent
the
best
available
data.

The
inputs
for
application
rate
and
other
use/
usage
information
(
e.
g.,
area
treated)
used
by
the
Agency
were
supported
by
the
available
endothall
labels.
There
are
also
many
uncertainties
in
the
assessment
that
are
common
with
the
occupational
assessment
as
well.
These
factors
and
their
impacts
on
the
results
should
be
considered
as
well
in
the
interpretation
of
the
results
for
residential
handlers.
Section
2.3.1
provides
a
summary
of
these
issues.

In
summary,
with
respect
to
residential
handler
risks,
the
Agency
believes
that
the
values
presented
in
this
assessment
represent
the
highest
quality
results
that
could
be
produced
given
the
exposure,
use,
and
toxicology
data
that
are
available.

3.3.2
Characterization
Of
Residential
Postapplication
Risks
The
data
that
were
used
in
the
endothall
residential
postapplication
assessment
represent
the
best
data
and
approaches
that
are
currently
available.

The
Agency
believes
that
the
values
presented
in
this
assessment
represent
the
highest
quality
results
that
could
be
produced
based
on
the
currently
available
postapplication
exposure
data.
The
Page
31
of
44
Agency
believes
that
the
risks
represent
reasonable
worse­
case
estimates
of
exposure
because
maximum
application
rates
are
used
to
define
residue
levels
upon
which
the
calculations
are
based.
Page
32
of
44
APPENDIX
A
Tables
1A­
7A
Page
33
of
44
Table
1A.
Endothall
Occupational
Short­
and
Intermediate­
Term
Inhalation
Handler
Risks
for
Agricultural
Crops
Uses
Exposure
Scenario
Crop
or
Target
Application
Ratea
(
lb
ai/
acre)
Area
Treated
Dailyb
(
acres)
Inhalation
Unit
Exposure
(

g/
lb
ai)
Inhalation
MOEf,
g
(
Target
Short­
Term
MOE
=
100;
Target
Intermediate­
Term
MOE
=
300)

Baseline
PPE
­
80%
Respiratord
Engineering
Controlxe
Baseline
Attirec
PPE
­
80%
Respiratord
Engineering
Controlse
Shortterm
Intermediateterm
Shortterm
Intermediateterm
Shortterm
Intermediateterm
Mixer/
Loader
Mixing/
Loading
Emulsifiable
Concentrates
(
Liquids)
for
Aerial
Applications
Alfalfa
(
SLN)
1
1,200
1.2
0.24
0.083
390
83
2,000
420
5,700
1,200
Alfalfa
0.8
1,200
1.2
0.24
0.083
490
100
2,400
520
7,100
1,500
Potatoes
1
350
1.2
0.24
0.083
1,300
290
6,700
1,400
19,000
4,100
Clover
0.8
350
1.2
0.24
0.083
1,700
360
8,400
1,800
24,000
5,200
Cotton
(
SLN)
0.13
1,200
1.2
0.24
0.083
3,000
640
15,000
3,200
44,000
9,300
Cotton
0.1
1,200
1.2
0.24
0.083
3,900
830
20,000
4,200
57,000
12,000
Mixing/
Loading
Emulsifiable
Concentrates
(
Liquids)
for
Groundboom
Applications
Alfalfa
(
SLN)
1
200
1.2
0.24
0.083
2,400
500
12,000
2,500
34,000
7,200
Alfalfa
0.8
200
1.2
0.24
0.083
2,900
630
15,000
3,100
42,000
9,000
Potatoes
1
80
1.2
0.24
0.083
5,900
1,300
29,000
6,300
85,000
18,000
Hops
1
40
1.2
0.24
0.083
12,000
2,500
59,000
36,000
170,000
36,000
Clover
0.8
80
1.2
0.24
0.083
7,300
1,600
37,000
7,800
110,000
23,000
Cotton
(
SLN)
0.13
200
1.2
0.24
0.083
18,000
3,800
90,000
19,000
260,000
56,000
Cotton
0.1
200
1.2
0.24
0.083
24,000
5,000
120,000
25,000
340,000
72,000
Applicator
Applying
Sprays
via
Aerial
Equipment
Alfalfa
(
SLN)
1
1,200
No
Data
No
Data
0.068
No
Data
No
Data
No
Data
No
Data
6,900
1,500
Alfalfa
0.8
1,200
No
Data
No
Data
0.068
No
Data
No
Data
No
Data
No
Data
8,600
1,800
Potatoes
1
350
No
Data
No
Data
0.068
No
Data
No
Data
No
Data
No
Data
24,000
5,000
Clover
0.8
350
No
Data
No
Data
0.068
No
Data
No
Data
No
Data
No
Data
30,000
6,300
Cotton
(
SLN)
0.13
1,200
No
Data
No
Data
0.068
No
Data
No
Data
No
Data
No
Data
53,000
11,000
Cotton
0.1
1,200
No
Data
No
Data
0.068
No
Data
No
Data
No
Data
No
Data
69,000
15,000
Applying
Sprays
via
Groundboom
Equipment
Alfalfa
(
SLN)
1
200
0.74
0.148
0.043
3,800
810
19,000
4,100
66,000
14,000
Alfalfa
0.8
200
0.74
0.148
0.043
4,800
1,000
24,000
5,100
82,000
17,000
Potatoes
1
80
0.74
0.148
0.043
9,500
2,000
48,000
10,000
160,000
35,000
Exposure
Scenario
Crop
or
Target
Application
Ratea
(
lb
ai/
acre)
Area
Treated
Dailyb
(
acres)
Inhalation
Unit
Exposure
(

g/
lb
ai)
Inhalation
MOEf,
g
(
Target
Short­
Term
MOE
=
100;
Target
Intermediate­
Term
MOE
=
300)

Baseline
PPE
­
80%
Respiratord
Engineering
Controlxe
Baseline
Attirec
PPE
­
80%
Respiratord
Engineering
Controlse
Shortterm
Intermediateterm
Shortterm
Intermediateterm
Shortterm
Intermediateterm
Page
34
of
44
Hops
1
40
0.74
0.148
0.043
19,000
4,100
95,000
20,000
330,000
70,000
Clover
0.8
80
0.74
0.148
0.043
12,000
2,500
60,000
13,000
200,000
44,000
Cotton
(
SLN)
0.13
200
0.74
0.148
0.043
29,000
6,200
150,000
31,000
500,000
110,000
Cotton
0.1
200
0.74
0.148
0.043
38,000
8,100
190,000
140,000
660,000
140,000
Flagger
Flagging
for
Sprays
via
Aerial
Equipment
Alfalfa
(
SLN),

Potatoes
1
350
0.35
0.07
0.043
4,600
980
23,000
4,900
37,000
8,000
Alfalfa,

Clover
0.8
350
0.35
0.07
0.043
5,800
1,200
29,000
6,100
47,000
10,000
Cotton
(
SLN)
0.13
350
0.35
0.07
0.043
35,000
7,500
180,000
38,000
290,000
61,000
Cotton
0.1
350
0.35
0.07
0.043
46,000
9,800
230,000
49,000
370,000
80,000
Footnotes
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
endothall.

b
Amount
handled
per
day
values
are
HED
estimates
of
acres
treated
daily
based
on
Exposure
SAC
SOP
#
9
"
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,"
industry
sources,
and
HED
estimates.

c
Baseline
attire
is
no
respirator.

d
PPE­
80%
Respirator
is
quarter­
face
dust/
mist
respirator
(
that
provides
an
80%
protection
factor)

e
Engineering
Controls
is
closed
mixing/
loading
system,
enclosed
cab,
or
enclosed
cockpit.

f
Short­
term
inhalation
MOE
=
NOAEL
(
9.4
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g)
/
body
weight
(
60
kg
adult
female).

g
Intermediate­
term
inhalation
MOE
=
LOAEL
(
2
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g)
/
body
weight
(
60
kg
adult
female).
Page
35
of
44
Table
2A.
Occupational
Aquatic
Use
Handler
Baseline
Attire
Risks
Exposure
Scenario
Crop
or
Target
Application
Ratea
Area
Treated
Dailyb
Depth
of
Water
Body
(
feet
deep)
Width
of
Body
of
Water
(
feet
wide)
Baseline
Attirec
B
Inhalation
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/

kgday
Short­
term
MOEd
Intermediate­
term
MOEe
Mixer/
Loader
Mixing/
loading
liquid
for
groundboom
application
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
1.2
2.43
0.041
230
50
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
1.2
1.44
0.024
400
85
Mixing/
Loading
Emulsifiable
Concentrate
with
Direct
Metering
(
PHED:
mixing/
loading
liquid
­
open
system)
Flowing
Water
0.56
lb
ai
/
minute
at
50
cfs
300
minutes/
day
NA
NA
1.2
0.20
0.003
3200
670
Flowing
Water
0.15
lb
ai
/
minute
at
200
cfs
120
minutes/
day
NA
NA
1.2
0.022
0.0004
26000
5500
Applicator
Applying
liquid
with
groundboom
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
0.74
1.50
0.025
375
80
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
0.74
0.89
0.015
625
135
Mixer/
Loader/
Applicator
Mixing/
Loading/
Applyin
g
Emulsifiable
Concentrates
with
a
Handgun
Sprayer
(
LCO
ORETF
data)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
10
Acres
2
NA
1.8
0.49
0.008
1160
245
Ponds/

Lakes
8
lb
ai/
A­
ft
10
Acres
2
NA
1.8
0.29
0.005
1880
400
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
20
1.8
1.22
0.020
470
100
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
5
1.8
0.31
0.0051
1880
400
Canals
1
lb
ai/
canal­­
1
mile
X
1
ft
wide
10
miles
long
2
20
1.8
0.72
0.012
785
165
Exposure
Scenario
Crop
or
Target
Application
Ratea
Area
Treated
Dailyb
Depth
of
Water
Body
(
feet
deep)
Width
of
Body
of
Water
(
feet
wide)
Baseline
Attirec
B
Inhalation
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/

kgday
Short­
term
MOEd
Intermediate­
term
MOEe
Page
36
of
44
x
1
ft
deep
Canals
1
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
5
1.8
0.18
0.003
3135
670
Loading/

Applying
Granulars
(
PHED:
open
loading
granulars)
Ponds/

Lakes
9.8
lb
ai/
A­
ft
30
Acres/

day
5
NA
1.7
2.5
0.042
230
48
Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
20
1.7
2.72
0.045
208
45
Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
5
1.7
0.68
0.011
860
180
Footnotes
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
endothall.

b
Amount
handled
per
day
values
are
HED
estimates
of
acres,
miles,
or
feet
treated
per
day
based
on
industry
sources
and
HED
estimates.

c
Baseline:
no
respirators.

d
Short­
term
inhalation
MOE
=
NOAEL
(
9.4
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g
/
body
weight
(
60
kg
adult
female).

e
Intermediate­
term
inhalation
MOE
=
LOAEL
(
2
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g
/
body
weight
(
60
kg
adult
female).
Page
37
of
44
Table
3A.
Occupational
Aquatic
Use
Handler
PPE
Inhalation
Risks
Exposure
Scenario
Crop
or
Target
Application
Ratea
Area
Treated
Dailyb
Depth
of
Water
Body
(
feet
deep)
Width
of
Body
of
Water
(
feet
wide)
PPE
­
80%
Respiratorc
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/

kgday
Short­
term
MOEd
Intermediate­
term
MOEe
Mixer/
Loader
Mixing/
loading
liquid
for
groundboom
application
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
0.24
0.49
0.0082
1150
250
500
(
half
face
respirator
90%

protection)

Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
0.24
0.29
0.0048
2000
425
Mixing/
Loading
Emulsifiable
Concentrate
with
Direct
Metering
(
PHED:

mixing/
loading
liquid
­
open
system)
Flowing
Water
0.56
lb
ai
/
minute
at
50
cfs
300
minutes/
day
NA
NA
0.24
0.040
0.0007
14000
3000
Flowing
Water
0.15
lb
ai
/
minute
at
200
cfs
120
minutes/
day
NA
NA
0.24
0.004
0.00007
130000
27500
Applicator
Applying
liquid
with
groundboom
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
0.15
0.30
0.005
1900
400
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
0.15
0.18
0.003
3150
675
Mixer/
Loader/
Applicator
Mixing/
Loading/

Applying
Emulsifiable
Concentrates
with
a
Handgun
Sprayer
(
LCO
ORETF
data)
Ponds/
Lakes
13.5
lb
ai/
A­
ft
10
Acers
2
NA
0.36
0.097
0.0016
5900
1250
Ponds/
Lakes
8
lb
ai/
A­
ft
10
Acres
2
NA
0.36
0.058
0.00096
9800
2100
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
20
0.36
0.245
0.0041
2300
500
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
5
0.36
0.061
0.001
9400
2000
Canals
1
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
20
0.36
0.144
0.0024
4000
850
Canals
1
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
2
5
0.36
0.036
0.0006
16000
3400
Exposure
Scenario
Crop
or
Target
Application
Ratea
Area
Treated
Dailyb
Depth
of
Water
Body
(
feet
deep)
Width
of
Body
of
Water
(
feet
wide)
PPE
­
80%
Respiratorc
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/

kgday
Short­
term
MOEd
Intermediate­
term
MOEe
Page
38
of
44
Loading/
Applying
Granulars
(
PHED:

open
loading
granulars)
Ponds/
Lakes
9.8
lb
ai/
A­
ft
30
Acres/
day
5
NA
0.34
0.4998
0.0083
1100
240
480
(
half
face
respirator
90%

protection)

Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
20
0.34
0.544
0.0091
1050
220
450
(
half
face
respirator
90%

protection)

Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
5
0.34
0.136
0.0023
4100
870
Footnotes
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
endothall.

b
Amount
handled
per
day
values
are
HED
estimates
of
acres,
miles,
or
feet
treated
per
day
based
on
industry
sources
and
HED
estimates.

c
PPE­
80%
Respirator
is
quarter­
face
dust/
mist
respirator
(
that
provides
an
80%
protection
factor).

d
Short­
term
inhalation
MOE
=
NOAEL
(
9.4
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g
/
body
weight
(
60
kg
adult
female).

e
Intermediate­
term
inhalation
MOE
=
LOAEL
(
2
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g
/
body
weight
(
60
kg
adult
female).
Page
39
of
44
Table
4A.
Occupational
Aquatic
Use
Handler
Engineering
Control
Risks
Exposure
Scenario
Crop
or
Target
Application
Ratea
Area
Treated
Dailyb
Depth
of
Water
Body
(
feet
deep)
Width
of
Body
of
Water
(
feet
wide)
Engineering
Controlsc
 
Inhalation
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/

kgday
Short­
term
MOEd
Intermediate­
term
MOEe
Mixer/
Loader
Mixing/
loading
liquid
for
groundboom
application
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
0.083
0.17
0.003
3150
670
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
0.083
0.10
0.002
4700
1000
Mixing/
Loading
Emulsifiable
Concentrate
with
Direct
Metering
(
PHED:

mixing/
loading
liquid
­
closed
system)
Flowing
Water
0.56
lb
ai
/
minute
at
50
cfs
300
minutes/
day
NA
NA
0.083
0.013944
0.00023
40000
8600
Flowing
Water
0.15
lb
ai
/
minute
at
200
cfs
120
minutes/
day
NA
NA
0.083
0.001494
0.000025
380000
80000
Applicator
Applying
liquid
with
groundboom
(
subsurface
use)
Ponds/

Lakes
13.5
lb
ai/
A­
ft
30
Acres
5
NA
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Ponds/

Lakes
8
lb
ai/
A­
ft
30
Acres
5
NA
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Mixer/
Loader/
Applicator
Ponds/

Lakes
13.5
lb
ai/
A­
ft
10
Acres
5
NA
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Ponds/

Lakes
8
lb
ai/
A­
ft
10
Acres
5
NA
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
20
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Canals
1.7
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
5
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Canals
1
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
20
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Canals
1
10
5
5
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Exposure
Scenario
Crop
or
Target
Application
Ratea
Area
Treated
Dailyb
Depth
of
Water
Body
(
feet
deep)
Width
of
Body
of
Water
(
feet
wide)
Engineering
Controlsc
 
Inhalation
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/

kgday
Short­
term
MOEd
Intermediate­
term
MOEe
Page
40
of
44
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
miles
long
Loading/
Applying
Granulars
(
PHED:

open
loading
granulars)
Ponds/

Lakes
9.8
lb
ai/
A­
ft
30
Acres/

day
5
NA
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
20
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Canals
1.6
lb
ai/
canal­­
1
mile
X
1
ft
wide
x
1
ft
deep
10
miles
long
5
5
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Not
Feasible
Footnotes
Not
Feasible
 
no
engineering
controls
are
available
for
this
scenario.

NA
­
not
applicable
for
that
scenario
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
endothall.

b
Amount
handled
per
day
values
are
HED
estimates
of
acres,
miles,
or
feet
treated
per
day
based
on
industry
sources
and
HED
estimates.

c
Engineering
Controls
is
closed
mixing/
loading
system,
enclosed
cab,
or
enclosed
cockpit.

d
Short­
term
inhalation
MOE
=
NOAEL
(
9.4
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g
/
body
weight
(
60
kg
adult
female).

e
Intermediate­
term
inhalation
MOE
=
LOAEL
(
2
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g
/
body
weight
(
60
kg
adult
female).
Page
41
of
44
Table5A.
Residential
Use
Handler
Baseline
Attire
Risks
Baseline
Attirec
B
Inhalation
Exposure
Scenario
Crop
or
Target
Application
Ratea
(
lb
ai/
cubic
feet)
Area
Treated
Dailyb
(
feet
square)
Depth
of
Water
(
feet)
Unit
Exposure
(

g/
lb
ai)
Exposure
(
mg/
day)
Dose
(
mg/
kg­
day)
Short­
term
MOEd
Intermediate­
term
MOEe
Mixer/
Loader/
Applicator
Loading/

Applying
Granulars
via
Belly
Grinder
Ponds/
Lakes
0.00022
43,560
2
62
1.2
0.02
470
100
Ponds/
Lakes
0.00022
10,000
2
62
0.27
0.005
1900
400
Applying
Granulars
via
Hand
Garden
pool
0.00022
1,000
2
467
0.21
0.003
2700
670
Footnotes
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
endothall.

b
Amount
handled
per
day
values
are
EPA
estimates.

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

d
Short­
term
inhalation
MOE
=
NOAEL
(
9.4
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
Conversion
factor
(
1mg/
1,000

g)
/
body
weight
(
60
kg
adult
female).

e
Intermediate­
term
inhalation
MOE
=
LOAEL
(
2
mg/
kg/
day)
/
inhalation
daily
dose
(
mg/
kg/
day),
where
inhalation
dose
=
daily
unit
exposure
(

g/
lb
ai)
x
application
rate
x
amount
handled
per
day
x
conversion
factor
(
1mg/
1,000

g)
/
body
weight
(
60
kg
adult
female).
Page
42
of
44
Table
6A:
Sources
of
Exposure
Data
Used
In
The
Occupational
Endothall
Handler
Exposure
And
Risk
Calculations
Exposure
Scenario
Data
Source
Standard
Assumptions
(
8­
hr
work
day)
a
Commentsb,
c
Mixer/
Loader
Descriptors
Mixing/
Loading
Liquid
Formulations
PHED
V1.1
Aerial:
1,200
acres
for
high
acreage
agricultural
crops
and
350
acres
for
all
other
crops;

Groundboom:
200
acres
for
high
acreage
agricultural
crops,
40
acres
for
hops,
and
80
acres
for
all
other
crops;

Direct
metering
to
aquatic
treatments:
30
acres
for
5feet
deep
ponds/
lakes;
10
miles
long,
5
feet
deep,
&
5
and
20
feet
wide
canals;
300
and
120
minutes/
day
of
flowing
water
Baseline:
inhalation
=
acceptable
grades.
Inhalation
=
85
replicates.
High
confidence
in
inhalation
data.
No
protection
factor
was
needed
to
define
the
unit
exposures.

PPE:
A
respirator
protection
factor
of
5
is
applied
to
estimate
the
use
of
a
quarter­
face
respirator
(
dust/
mist
filtering
only).
A
respirator
protection
factor
of
10
is
applied
to
estimate
the
use
of
a
halfface
negative
pressure
respirator
or
a
powered
air
purifying
respirator
(
dust/
mist
filtering
and/
or
organic
vapor­
removing).

Engineering
Controls:
Inhalation
=
27
replicates.
High
confidence
in
inhalation
data.

Loading
Granular
Formulations
PHED
V1.1
Loading/
Applying
for
Boat­
Mounted
Aquatic
treatments:
30
acres
for
5
feet
deep
ponds/
lakes;
10
miles
long,
5
feet
deep,
&
5
and
20
feet
wide
canals
Baseline:
Inhalation
=
58
replicates.
High
confidence
in
inhalation
data.
No
protection
factor
was
needed
to
define
the
unit
exposure
value.

PPE:
A
respirator
protection
factor
of
5
is
applied
to
estimate
the
use
of
a
quarter­
face
respirator
(
dust/
mist
filtering
only).
A
respirator
protection
factor
of
10
is
applied
to
estimate
the
use
of
a
halfface
negative
pressure
respirator
or
a
powered
air
purifying
respirator
(
dust/
mist
filtering
and/
or
organic
vapor­
removing).

Engineering
Controls:
Not
feasible
for
this
scenario.

Applying
Descriptors
Applying
Sprays
via
Fixed­
wing
Aircraft
PHED
V1.1
1,200
acres
for
high
acreage
agricultural
crops
and
350
acres
for
all
other
crops
Engineering
Controls:
Inhalation
=
23
replicates.
Medium
confidence
in
inhalation
data.
No
protection
factor
was
needed
to
define
the
unit
exposure
value.

EPA
has
no
data
for
this
scenario,
other
than
enclosed
cockpits
 
the
engineering
control.

Applying
Sprays
via
Groundboom
Sprayer
PHED
V1.1
200
acres
for
high
acreage
agricultural
crops,
40
acres
for
hops,
and
80
acres
for
all
other
crops
Baseline:
inhalation
=
AB
grades.
Inhalation
=
22
replicates.
High
confidence
in
halation
data.
No
protection
factors
were
needed
to
define
the
unit
exposure
values.

PPE:
A
respirator
protection
factor
of
5
is
applied
to
estimate
the
use
of
a
quarter­
face
respirator
(
dust/
mist
filtering
only).
A
respirator
protection
factor
of
10
is
applied
to
estimate
the
use
of
a
halfface
negative
pressure
respirator
or
a
powered
air
purifying
respirator
(
dust/
mist
filtering
and/
or
organic
vapor­
removing).

Engineering
Controls:
Inhalation
=
AB
grades.
Inhalation
=
16
replicates.
High
confidence
in
inhalation
data.

Flagging
Descriptors
Flagging
for
Aerial
Spray
Applications
PHED
V1.1
350
acres
for
all
crops
Baseline:
inhalation
=
AB
grades.
Inhalation
=
28
replicates.
High
confidence
inhalation
data.
No
protection
factor
was
required
to
calculate
unit
exposures.

PPE:
A
respirator
protection
factor
of
5
is
applied
to
estimate
the
use
of
a
quarter­
face
respirator
(
dust/
mist
filtering
only).
A
respirator
protection
factor
of
10
is
applied
to
estimate
the
use
of
a
halfface
negative
pressure
respirator
or
a
powered
air
purifying
respirator
(
dust/
mist
filtering
and/
or
organic
vapor­
removing).

Engineering
Controls:
The
same
data
are
used
as
for
baseline
coupled
with
a
98%
protection
factor
to
account
for
the
use
of
an
engineering
control
(
e.
g.,
sitting
in
a
vehicle).
Table
6A:
Sources
of
Exposure
Data
Used
In
The
Occupational
Endothall
Handler
Exposure
And
Risk
Calculations
Exposure
Scenario
Data
Source
Standard
Assumptions
(
8­
hr
work
day)
a
Commentsb,
c
Page
43
of
44
Mixing/
Loading/
Applying
Descriptors
Mixing/
Loading/
Applying
Emulsifiable
Concentrates
via
Handgun
Sprayer
(
ORETF
data)
ORETF
Chemical
Handler
Exposure
Studies
Aquatic
treatments:
10
acres
for
2feet
deep
ponds/
lakes;
10
miles
long,
5
feet
deep,
&
5
and
20
feet
wide
canals
Baseline:
Inhalation
=
B
grade
and
15
replicates.
Moderate
to
high
confidence
in
inhalation
data.

PPE:.
A
respirator
protection
factor
of
5
is
applied
to
estimate
the
use
of
a
quarter­
face
respirator
(
dust/
mist
filtering
only).
A
respirator
protection
factor
of
10
is
applied
to
estimate
the
use
of
a
halfface
negative
pressure
respirator
or
a
powered
air
purifying
respirator
(
dust/
mist
filtering
and/
or
organic
vapor­
removing).

Engineering
Controls:
Not
considered
feasible
for
this
exposure
scenario.

a
All
Standard
Assumptions
are
based
on
an
8­
hour
work
day
as
estimated
by
the
Agency.

b
All
handler
exposure
assessments
in
this
document
are
based
on
the
"
Best
Available"
data
as
defined
by
the
HED
SOP
for
meeting
Subdivision
U
Guidelines
(
i.
e.,

completing
exposure
assessments).
Best
available
grades
are
assigned
to
data
as
follows:
matrices
with
A
and
B
grade
data
(
i.
e.,
Acceptable
Grade
Data)
and
a
minimum
of
15
replicates;
if
not
available,
then
grades
A,
B
and
C
data
and
a
minimum
of
15
replicates;
if
not
available,
then
all
data
regardless
of
the
quality
(
i.
e.,
All
Grade
Data)
and
number
of
replicates.
High
quality
data
with
a
protection
factor
take
precedence
over
low
quality
data
with
no
protection
factor.
Generic
data
confidence
categories
are
assigned
as
follows:

High
=
grades
A
and
B
and
15
or
more
replicates
per
body
part
Medium
=
grades
A,
B,
and
C
and
15
or
more
replicates
per
body
part
Low
=
grades
A,
B,
C,
D
and
E
or
any
combination
of
grades
with
less
than
15
replicates.

c
PHED
grading
criteria
do
not
reflect
overall
quality
of
the
reliability
of
the
assessment.
Sources
of
the
exposure
factors
should
also
be
considered
in
the
risk
Page
44
of
44
Table7A:
Sources
of
Exposure
Data
Used
In
The
Residential
Endothall
Handler
Exposure
And
Risk
Calculations
Exposure
Scenario
Data
Source
Standard
Assumptions
(
8­
hr
work
day)
a
Commentsb,
c
Mixer/
Loader/
Applicator
Descriptors
Loading/
Applying
Granular
Formulations
with
a
Belly
Grinder
PHED
V1.1
Loading/
Applying
for
Boat­
Mounted
Aquatic
treatments:
43,560
sq
ft
and
2
feet
deep
ponds/
lakes;
10,000
sq
ft
and
2
feet
deep
ponds/
lakes
Baseline:
Hands
=
Inhalation
=
AB
grades.
inhalation
=
40
replicates.

Loading/
applying
granules
using
a
spoon,
measuring
scoop,

shaker
can,
or
by
hand
Review
of
fipronil
granular
mixer/
loader/
applicator
study
as
a
source
of
surrogate
data,
MRID
45250701.
J.
Dawson
memo,

D270065,
1/
5/
01.
Aquatic
treatments:
1,000
sq
ft
and
2
feet
deep
garden
pools
Baseline:
A
90%
protection
factor
was
applied
to
gloved
hands
data
to
back
calculate
"
no
glove"
hand
exposure.
A
standard
50%
protection
factor
was
used
for
the
torso.
A
10%

protection
factor
was
used
to
represent
the
protection
afforded
by
shorts
and
a
short­
sleeved
shirt.

PPE
and
Engineering
Controls
data
are
not
required
for
this
assessment.

a
All
Standard
Assumptions
are
based
on
an
8­
hour
work
day
as
estimated
by
HED.
BEAD
data
were
not
available.

b
All
handler
exposure
assessments
in
this
document
are
based
on
the
"
Best
Available"
data
as
defined
by
the
PHED
SOP
for
meeting
Subdivision
U
Guidelines
(
i.
e.,

completing
exposure
assessments).
Best
available
grades
are
assigned
to
data
as
follows:
matrices
with
A
and
B
grade
data
(
i.
e.,
Acceptable
Grade
Data)
and
a
minimum
of
15
replicates;
if
not
available,
then
grades
A,
B
and
C
data
and
a
minimum
of
15
replicates;
if
not
available,
then
all
data
regardless
of
the
quality
(
i.
e.,
All
Grade
Data)
and
number
of
replicates.
High
quality
data
with
a
protection
factor
take
precedence
over
low
quality
data
with
no
protection
factor.
Generic
data
confidence
categories
are
assigned
as
follows:

High
=
grades
A
and
B
and
15
or
more
replicates
per
body
part
Medium
=
grades
A,
B,
and
C
and
15
or
more
replicates
per
body
part
Low
=
grades
A,
B,
C,
D
and
E
or
any
combination
of
grades
with
less
than
15
replicates.

c
PHED
grading
criteria
do
not
reflect
overall
quality
of
the
reliability
of
the
assessment.
Sources
of
the
exposure
factors
should
also
be
considered
in
the
risk
management
decision.
