Document ID: EPA-HQ-OPP-2004-0142-0008
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-10-19T04:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
May
5,
2004
MEMORANDUM
SUBJECT:
Residential
Exposure
Assessment
and
Recommendations
for
the
Tolerance
Reassessment
Evaluation
Decision
(
TRED)
Document
for
Trifluralin
FROM:
Shanna
Recore,
Industrial
Hygienist
Reregistration
Branch
II
Health
Effects
Division
(
7509C)

TO:
Richard
Griffin,
Biologist
Risk
Assessor
Reregistration
Branch
II
Health
Effects
Division
(
7509C)

THROUGH:
Alan
Nielsen,
Branch
Senior
Scientist
Reregistration
Branch
II
Health
Effects
Division
(
7509C)

Please
find
the
review
of
Trifluralin.

DP
Barcode:
D296625
Pesticide
Chemical
Codes:
036101
EPA
Reg
Numbers:
Residential
Labels:
228­
208,
228­
209,
228­
254,
228­
255,
228­
257,
572­
200,
961­
280,
961­
283,
961­
335,
961­
348,
1812­
430,
5887­
171,
7401­
349,
8378­
41,
8660­
143,
8660­
149,
8660­
165,
8660­
166,
9198­
60,
9198­
79,
9198­
91,
9198­
94,
9198­
98,
9198­
101,
9198­
149,
9688­
133,
32802­
35,
32802­
40,
32802­
77,
49585­
25,
54705­
6,
59823­
3,
62719­
137,
62719­
280,
62719­
327,
62719­
331,
62719­
332,
72620­
1
2
Occupational
Labels:
228­
207,
228­
256,
961­
370,
8378­
37,
10404­
57,
32802­
35,
32802­
40,
62719­
97,
62719­
150,
62719­
151,
62719­
152,
62719­
175,
32719­
192
PHED:
Yes,
Version
1.1
3
Table
of
Contents
Executive
Summary
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4
1.0
Residential
Exposure/
Risk
Assessment
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6
1.1
Purpose
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6
1.2
Criteria
for
Conducting
Exposure
Assessments
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6
1.3
Summary
of
Hazard
Concerns
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6
1.4
Summary
of
Use
Patterns
and
Formulations
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10
1.4.1
End­
Use
Products
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10
1.4.2
Mode
of
Action
and
Targets
Controlled
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10
1.4.3
Registered
Use
Categories
and
Sites
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11
2.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
.
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11
2.1
Residential
Handler
Exposures
and
Risks
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11
2.1.1
Handler
Exposure
Scenarios
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11
2.1.2
Data
and
Assumptions
For
Handler
Exposure
Scenarios
.
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12
2.1.3
Residential
Handler
Exposure
and
Non­
Cancer
Risk
Estimates
.
.
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.
.
18
2.1.4
Summary
of
Non­
Cancer
Risk
Concerns
for
Residential
Handlers
.
.
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.
20
2.2
Residential
Cancer
Trifluralin
Handler
Exposure
and
Risk
Assessment
.
.
.
.
.
.
.
22
2.2.1
Data
and
Assumptions
For
Residential
Cancer
Handler
Exposure
Scenarios
22
2.2.2
Residential
Cancer
Trifluralin
Handler
Exposure
and
Risk
Calculations
.
22
2.3
Residential
Postapplication
Exposures
and
Risks
.
.
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26
2.3.1
Residential
Postapplication
Exposure
Scenarios
.
.
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.
26
2.3.2
Data
&
Assumptions
for
Residential
Noncancer
Postapplication
Exposure
Scenarios
.
.
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27
2.3.3
Residential
Postapplication
Exposure
and
Noncancer
Risk
Estimates
.
.
.
29
2.4
Combined
Residential
Handler
and
Postapplication
Exposures
and
Risks
.
.
.
.
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38
3.0
Trifluralin
Poisoning
Incidents
Information
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38
Appendices
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41
4
RESIDENTIAL
EXPOSURE/
RISK
ASSESSMENT
AND
CHARACTERIZATION
Executive
Summary
The
Federal
Food,
Drug,
and
Cosmetic
Act
(
FFDCA),
as
amended,
requires
the
U.
S.
Environmental
Protection
Agency
to
reassess
all
the
tolerances
for
the
registered
chemicals
in
effect
on
or
before
August
3,
1996,
the
date
of
the
enactment
of
the
Food
Quality
Protection
Act
(
FQPA),
against
the
new
safety
standard
adopted
in
the
FQPA.
A
reregistration
eligibility
decision
(
RED)
for
trifluralin
was
completed
in
April
1996,
prior
to
the
enactment
of
FQPA.
Therefore,
EPA
is
issuing
a
tolerance
reassessment
evaluation
decision
(
TRED)
to
reassess
the
tolerances
under
the
FQPA
standard.
Occupational
exposure
assessments
are
not
included
in
TRED
documents;
however,
potential
occupational
exposure
to
trifluralin
was
assessed
in
the
April
1996
RED
document.

At
this
time,
products
containing
trifluralin
are
intended
for
both
occupational
and
nonoccupational
uses.
Trifluralin
is
a
pre­
emergent
herbicide
used
to
control
annual
grasses
and
broadleaf
weeds
on
a
variety
of
residential
food
and
non­
food
uses.
There
are
also
several
occupational
uses
which
will
not
be
addressed
in
this
TRED.
For
residential
uses,
trifluralin
is
formulated
as
a
granular
(
0.17
­
2.0
percent
active
ingredient)
and
an
emulsifiable
concentrate
liquid
(
43
percent
active
ingredient).

In
May
2003,
the
Hazard
Identification
Assessment
and
Review
Committee
(
HIARC)
reassessed
toxicological
endpoints
for
non­
dietary
exposures
to
trifluralin.
The
duration
of
exposure
for
residential
populations
is
assumed
to
be
short­
term
(
1­
30
days)
only.
No
exposure
or
risk
assessment
is
required
for
short­
term
dermal
exposures,
since
there
was
no
systemic
toxicity
at
the
limit
dose
in
the
dermal
toxicity
study
and
there
are
no
developmental
toxicity
concerns.
The
short­
term
(
1­
30
days)
inhalation
toxicological
endpoint
was
established
at
81
mg/
kg/
day,
based
on
the
no­
observed­
adverse­
effect
level
(
NOAEL)
from
a
30­
day
inhalation
rat
study.
Trifluralin
is
classified
as
a
"
Group
C,"
possible
human
carcinogen
with
a
Q*
of
0.00579
(
mg/
kg/
day)­
1.
HED
notes
that
the
HIARC
recommends
that
products
containing
trifluralin
should
be
labeled
as
a
dermal
sensitizer
and
should
state
that
skin
contact
should
be
avoided.

Short­
term
inhalation
risks
to
residential
handlers
and
dermal
and
inhalation
cancer
risks
to
residential
handlers
were
calculated
using
surrogate
data
from
the
Pesticide
Handler
Exposure
Database
(
PHED),
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF),
and
a
proprietary
study
using
fipronil1
with
MRID
452507­
01
.

HED
has
determined
that
there
are
potential
exposures
to
residential
handlers
(
i.
e.,
mixer/
loader/
applicators)
during
the
usual
use­
patterns
associated
with
trifluralin.
Based
on
the
use
patterns,
seven
major
residential
exposures
were
identified
for
trifluralin:
(
1)
loading/
applying
granulars
with
a
belly
grinder;
(
2)
loading/
applying
granulars
with
a
push­
type
spreader;
(
3)
loading/
applying
granulars
with
a
spoon,
measuring
scoop,
shaker
can,
or
by
hand;
(
4)
mixing/
loading/
applying
liquids
with
a
hose­
end
sprayer;
(
5)
mixing/
loading/
applying
liquids
with
a
low
5
pressure
handwand;
(
6)
mixing/
loading/
applying
liquids
with
a
backpack
sprayer;
and
(
7)
applying
trifluralin
impregnated
fabric
squares
to
soil.

For
short­
term
noncancer
risks
to
residential
handlers,
a
margin
of
exposure
(
MOE)
of
less
than
100
exceeds
the
Agency's
level
of
concern.
For
residential
handlers,
the
calculations
of
shortterm
inhalation
noncancer
risk
indicate
that
the
MOEs
are
greater
than
100
for
all
residential
handler
scenarios.

For
residential
handler
scenarios,
cancer
risks
greater
than
1x10­
6
are
considered
to
be
of
concern.
The
calculations
of
residential
handler
cancer
risk
indicate
that
all
scenarios
have
a
cancer
risk
of
less
than
1x10­
6.

HED
has
determined
that
there
are
potential
postapplication
exposures
to
adults
and
children
in
residential
settings
during
the
usual
use­
patterns
associated
with
trifluralin.
Based
on
the
use
patterns,
seven
potential
residential
postapplication
exposures
were
identified
for
trifluralin:
(
1)
dermal
exposure
from
residue
on
lawns
(
adult
and
toddler);
(
2)
dermal
exposure
from
residue
on
golf
course
turfgrass
(
adult
and
youth);
(
3)
dermal
exposure
from
residue
on
home
gardens
(
adult
and
youth);
(
4)
hand­
to­
mouth
transfer
of
residue
on
lawns
(
toddler);
(
5)
object­
to­
mouth
transfer
of
residues
on
lawns
(
toddler);
(
6)
incidental
ingestion
of
soil
from
pesticide
treated
residential
areas
(
toddler);
and
(
7)
incidental
ingestion
of
granules
from
pesticide­
treated
residential
areas.

For
noncancer
postapplication
risks,
since
there
is
no
short­
term
dermal
toxicological
endpoint
of
concern
for
trifluralin
and
no
intermediate­
term
dermal
exposure
is
anticipated,
the
only
assessment
is
for
incidental
ingestion
by
toddlers.

For
short­
term
noncancer
residential
postapplication
risks,
a
margin
of
exposure
(
MOE)
of
less
than
100
exceeds
the
Agency's
level
of
concern.
For
residential
postapplication,
the
calculations
of
noncancer
risk
based
on
the
incidental
oral
NOAEL
endpoint
indicate
that
the
MOEs
were
more
than
100
for
the
following
residential
postapplication
scenarios:

$
hand­
to­
mouth
transfer
of
residues
on
lawns
(
toddler),
°
object­
to­
mouth
transfer
of
residues
on
lawns
(
toddler),
and
°
incidental
ingestion
of
residues
of
soil
from
pesticide
treated
residential
areas
(
toddler).

In
addition,
HED
determined
that
a
combined
risk
assessment
was
necessary
for
the
following
noncancer
residential
postapplication
scenarios
listed
above.
The
combined
MOE
for
these
scenarios
is
greater
than
100
and
is
not
considered
a
risk
concern.

The
Agency
also
assesses
the
exposure
and
risk
to
toddlers
from
incidental
ingestion
of
granules
in
pesticide­
treated
residential
areas.
Since
this
exposure
is
episodic
and
likely
to
occur,
at
most,
only
once
following
an
application,
an
acute
dietary
NOAEL
endpoint
is
used
to
assess
the
risks.
Since
6
no
acute
dietary
endpoint
for
trifluralin
has
been
identified
for
the
general
population,
including
infants
and
children,
acute
dietary
risks
from
ingestion
of
pesticide
granules
were
not
assessed.

HED
has
determined
that
there
are
potential
postapplication
cancer
risks
for
adults
in
residential
areas
treated
with
trifluralin.
The
following
scenarios
were
assessed:
(
1)
dermal
exposure
to
residue
on
lawns,
(
2)
dermal
exposure
to
golf
course
turfgrass,
and
(
3)
dermal
exposure
to
residue
on
home
gardens.
For
residential
postapplication
scenarios,
cancer
risks
greater
than
1x10­
6
are
considered
to
be
of
concern.
The
calculation
of
residential
postapplication
cancer
risk
indicate
that
all
scenarios
have
a
cancer
risk
of
less
than
1
x10­
6
and
are
not
considered
a
risk
concern.

For
the
residential
turfgrass
scenario,
HED
combined
the
cancer
risks
for
residential
handlers
applying
granular
formulation
to
lawns
with
postapplication
cancer
risks
to
adults
from
exercising
on
just­
treated
lawns.
This
combined
two
screening­
level
calculations.
The
combined
risks
are
less
than
1
x10­
6
and
are
not
considered
a
risk
concern.

1.0
Residential
Exposure/
Risk
Assessment
1.1
Purpose
The
Federal
Food,
Drug,
and
Cosmetic
Act
(
FFDCA),
as
amended,
requires
the
U.
S.
Environmental
Protection
Agency
to
reassess
all
the
tolerances
for
the
registered
chemicals
in
effect
on
or
before
August
3,
1996,
the
date
of
the
enactment
of
the
Food
Quality
Protection
Act
(
FQPA),
against
the
new
safety
standard
adopted
in
the
FQPA.
A
reregistration
eligibility
decision
(
RED)
for
trifluralin
was
completed
in
April
1996,
prior
to
the
enactment
of
FQPA.
Therefore,
EPA
has
issued
a
tolerance
reassessment
evaluation
decision
(
TRED)
to
reassess
the
tolerances
under
the
FQPA
standard.

In
this
document,
which
is
for
use
in
EPA's
development
of
the
trifluralin
TRED
Document,
EPA
presents
the
results
of
its
review
of
the
potential
human
health
effects
of
residential/
non­
occupational
exposure
to
trifluralin.
Occupational
exposure
assessments
are
not
included
in
TRED
documents;
however,
potential
occupational
exposure
to
trifluralin
was
briefly
assessed
in
the
April
1996
RED
document.

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
after
application
is
complete.
Toxicological
endpoints
were
identified
for
short­
term
inhalation
exposures
and
for
short­
term
incidental
ingestion.
In
addition,
trifluralin
has
been
classified
as
a
Category
C
possible
human
carcinogen
with
a
Q
1*
of
0.00579
(
mg/
kg/
day)­
1.2
Handler
and
postapplication
exposure
scenarios
have
been
identified.
7
1.3
Summary
of
Hazard
Concerns
The
toxicological
endpoints
that
were
used
to
complete
the
residential
risk
assessments
are
summarized
below
and
in
Table
1
which
has
been
extracted
from
the
latest
HIARC
document
dated
May
2,
2003.
Adverse
effect
were
identified
at
different
durations
of
exposure
ranging
from
short­
term
(
up
to
30
days)
to
chronic
durations
(
every
working
day).
However,
for
residential
exposure
assessments,
only
short­
term
exposures
and
risks
are
evaluated
because
trifluralin
is
a
pre­
emergent
herbicide
where
the
use
patterns
in
residential
settings
are
limited
to
a
few
widely
spaced
applications
each
year.
No
short­
term
dermal
endpoint
was
identified,
since
there
was
no
systemic
toxicity
at
the
limit
dose
in
the
dermal
toxicity
study
and
there
are
no
developmental
toxicity
concerns.
The
short­
term
inhalation
risk
assessment
for
trifluralin
is
based
on
an
NOAEL
of
81
mg/
kg/
day,
which
was
defined
in
a
30­
day
inhalation
study
in
rats.
The
short­
term
incidental
oral
risk
assessments
for
trifluralin
are
based
on
an
NOAEL
of
10
mg/
kg/
day,
which
was
defined
in
a
two­
generation
reproductive
study
in
rats.
The
acute
dietary
(
toddler
ingestion
of
granules)
risks
for
trifluralin
were
not
assessed,
since
no
acute
dietary
endpoint
of
concern
was
identified
for
the
general
population,
including
infants
and
toddlers.

The
Agency's
level
of
concern
for
noncancer
risks
(
i.
e.,
target
level
for
MOEs
or
Margins
of
Exposure)
is
defined
by
the
uncertainty
factors
that
are
applied
to
the
assessment.
The
Agency
applies
a
factor
of
100
to
account
for
inter­
species
extrapolation
to
humans
from
the
animal
test
species
and
to
account
for
intra­
species
sensitivity.
Based
on
the
requirements
of
the
1996
Food
Quality
Protection
Act,
the
Agency
must
also
consider
sensitive
populations
in
its
nonoccupational
risk
assessments.
The
Agency
has
reduced
the
FQPA
safety
factor
for
trifluralin
to
1x
for
all
residential
populations.
2
The
total
uncertainty
factors
that
have
been
applied
to
noncancer
risk
assessments
is
100
for
the
residential
assessment.

In
addition,
trifluralin
has
been
classified
as
a
Category
C
B
possible
human
carcinogen,
based
on
increased
incidences
of
combined
malignant
and
benign
tumors
of
the
renal
pelvis
and
benign
tumors
of
the
urinary
bladder.
Quantification
of
human
risk
using
a
low
dose
model
extrapolation
was
recommended.
Trifluralin
has
a
Q
1*
of
0.00579
(
mg/
kg/
day)­
1.2
For
residential
handler
and
postapplication
scenarios,
cancer
risks
greater
than
1x10­
6
are
considered
by
EPA
to
be
of
concern.

Trifluralin
is
also
classified
as
a
skin
sensitizer,
but
EPA
has
no
method
of
quantifying
risk
due
to
skin
sensitization.
Therefore,
the
HIARC
recommends
that
all
products
containing
trifluralin
should
be
labeled
as
SENSITIZER
and
also
recommend
that
human
contact
should
be
avoided.
8
Table
1.
Hazard
Endpoints
and
Uncertainty
Factors.

Exposure
Scenario
Dose
Used
in
Risk
Assessment,
UF
Special
FQPA
SF*
and
Level
of
Concern
for
Risk
Assessment
Study
and
Toxicological
Effects
Acute
Dietary
(
General
population
including
infants
and
children)
No
appropriate
single
dose
endpoint
was
found
for
this
population
sub
group
Residential
NA
No
appropriate
single
dose
endpoint
was
found
for
this
population
sub
group
Short­
Term
Incidental
Oral
(
1­
30
days)
NOAEL=
10
mg/
kg/
day
Residential
LOC:
MOE
=
100
Occupational
=
NA
Two­
generation
Reproduction
Study
­
Rat
LOAEL
=
32.5
mg/
kg/
day
based
on
decreased
pup
weights
in
both
generations
Intermediate­
Term
Incidental
Oral
(
1­
6
months)
NOAEL=
10
mg/
kg/
day
Residential
LOC:
MOE
=
100
Occupational
=
NA
Special
Urinalysis
Study
­
Rat
LOAEL
=
40
mg/
kg/
day
based
on
based
on
the
presence
of
tubular
cytoplasmic
hyaline
droplets;
increased
total
protein,
AST,
and
LDH
in
the
urine;
albumin
 1­
globulin
and
 2­
globulin
observed
by
urine
electrophoresis;
and
increased
urinary
volume
Short­
Term
Dermal
(
1
to
30
days)
No
quantification
required
since
there
was
no
systemic
toxicity
at
the
limit
dose
in
the
dermal
toxicity
study.
There
are
no
developmental
toxicity
concerns.
Also,
because
risk
cannot
be
quantified,
the
HIARC
also
recommends
that
the
products
containing
trifluralin
should
be
labeled
as
SENSITIZER
and
should
avoid
human
contact.

Intermediate­
Term
Dermal
(
1
to
6
months)
Oral
study
NOAEL
=
10
mg/
kg/
day
(
dermal
absorption
rate
=
3
%
Residential
LOC:
MOE
=
100
Occupational
LOC:
MOE
=
100
Special
Urinalysis
Study
­
Rat
LOAEL
=
40
mg/
kg/
day
based
on
based
on
the
presence
of
tubular
cytoplasmic
hyaline
droplets;
increased
total
protein,
AST,
and
LDH
in
the
urine;
albumin
 1­
globulin
and
 2­
globulin
observed
by
urine
electrophoresis;
and
increased
urinary
volume
Long­
Term
Dermal
(>
6
months)
Oral
study
NOAEL=
2.4
mg/
kg/
day
(
dermal
absorption
rate
=
3
%
when
appropriate)
Residential
LOC:
MOE
=
100
Occupational
LOC:
MOE
=
100
Chronic
Toxicity
(
capsule)
­
Dog
LOAEL
=
mg/
kg/
day
based
on
based
on
increased
frequency
of
abnormal
stool,
decreased
body
weights
and
body
weight
gains,
and
on
decreased
erythrocytes
and
hemoglobin
and
increased
thrombocytes
in
males
Short­
Term
Inhalation
(
1
to
30
days)
Inhalation
study
NOAEL=
81
mg/
kg/
day
Residential
LOC:
MOE
=
100
Occupational
LOC:
MOE
=
100
30­
Day
Inhalation
Study
­
Rat
LOAEL
=
270
mg/
kg/
day
based
on
increased
methemoglobin
and
bilirubin
in
females
and
incidences
of
dyspnea
and
ruffled
fur
in
males
and
females
Table
1.
Hazard
Endpoints
and
Uncertainty
Factors.

Exposure
Scenario
Dose
Used
in
Risk
Assessment,
UF
Special
FQPA
SF*
and
Level
of
Concern
for
Risk
Assessment
Study
and
Toxicological
Effects
9
Intermediate­
Term
Inhalation
(
1
to
6
months)
Oral
study
NOAEL
=
10
mg/
kg/
day
(
inhalation
absorption
rate
=
100%)
Residential
LOC:
MOE
=
100
Occupational
LOC:
MOE
=
100
Special
Urinalysis
Study
­
Rat
LOAEL
=
40
mg/
kg/
day
based
on
based
on
the
presence
of
tubular
cytoplasmic
hyaline
droplets;
increased
total
protein,
AST,
and
LDH
in
the
urine;
albumin
 1­
globulin
and
 2­
globulin
observed
by
urine
electrophoresis;
and
increased
urinary
volume
Long­
Term
Inhalation
(>
6
months)
Oral
study
NOAEL=
2.4
mg/
kg/
day
(
inhalation
absorption
rate
=
100%)
Residential
LOC:
MOE
=
100
Occupational
LOC:
MOE
=
100
Chronic
Toxicity
(
capsule)
­
Dog
LOAEL
=
mg/
kg/
day
based
on
based
on
increased
frequency
of
abnormal
stool,
decreased
body
weights
and
body
weight
gains,
and
on
decreased
erythrocytes
and
hemoglobin
and
increased
thrombocytes
in
males
Cancer
(
oral,
dermal,
inhalation)
Q1*
=
5.79
X
10­
3
(
mg/
kg/
day)­
1
"
Group
C"
(
limited
evidence
of
carcinogenicity)

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
NOTE:
The
Special
FQPA
Safety
Factor
recommended
by
the
HIARC
assumes
that
the
exposure
databases
(
dietary
food,
drinking
water,
and
residential)
are
complete
and
that
the
risk
assessment
for
each
potential
exposure
scenario
includes
all
metabolites
and/
or
degradates
of
concern
and
does
not
underestimate
the
potential
risk
for
infants
and
children.

A
series
of
acute
toxicity
tests
were
also
conducted
using
trifluralin
(
see
Table
2).
The
results
indicate
that
trifluralin
is
a
category
IV
toxicant
via
the
oral
route,
and
category
III
via
the
dermal
route.
It
is
also
a
category
IV
for
acute
inhalation
toxicity
and
a
category
III/
IV
eye
and
skin
irritant.
Results
were
positive
for
dermal
sensitization
and
the
HIARC
document
recommends
that
dermal
exposure
to
trifluralin
should
be
minimized
and
the
products
labeled
to
provide
instructions
to
avoid
contact
with
skin.

Table
2:
Acute
Toxicity
of
Trifluralin
(
technical)

Guideline
No.
Study
Type
MRID
No.
Results
Toxicity
Category
81.1
870.1100
Acute
Oral
(
Rat)
00157486
(
1985)
TXR
006174
Acceptable/
Guideline
LD50
>
5000
mg/
kg
IV
Table
2:
Acute
Toxicity
of
Trifluralin
(
technical)

Guideline
No.
Study
Type
MRID
No.
Results
Toxicity
Category
10
81.2
870.1200
Acute
Dermal
(
Rat)
00157482
(
1985)
TXR
006174
Acceptable/
Guideline
LD50
>
2000
mg/
kg
III
81.3
870.1300
Acute
Inhalation
(
Rat)
00155261
(
1982)
TXR
006174
Acceptable/
guideline
LC50
>
4660
mg/
m3,
4.66
mg/
L
IV
81.4
870.2400
Primary
Eye
Irritation
(
Rabbit)
00157483
(
1985)
TXR
006174
Acceptable/
Guideline
Conjunctival
redness
at
24
hr,
cleared
by
day
4
III
81.5
870.2500
Primary
Skin
Irritation
00157485
(
1985)
TXR
006174
Acceptable/
Guideline
Not
an
irritant
IV
81.6
870.2600
Dermal
Sensitization
00157484
(
1985)
TXR
006174
Acceptable/
Guideline
Sensitizing
agent
N/
A
1.4
Summary
of
Use
Patterns
and
Formulations
At
this
time,
products
containing
trifluralin
are
intended
for
both
occupational
and
residential
uses.
However,
in
this
TRED
only
residential
(
i.
e.,
non­
occupational)
exposures
will
be
assessed.
Trifluralin
is
a
pre­
emergent
herbicide
registered
for
weed
control
on
home
lawns,
vegetable
gardens,
ornamental
gardens
(
including
planting
beds,
flowers,
shrubs,
and
trees),
and
at
other
residential
sites,
such
as
golf
courses,
recreational
parks,
bike/
golf
cart
paths,
and
cemeteries.
Trifluralin
has
several
registrants
including,
Dow
AgroSciences,
Griffin
LLC
and
Riverdale
Chemical
Company.

1.4.1
End­
Use
Products
Based
on
a
review
of
the
Office
of
Pesticide
Programs
 
Pesticide
Product
Label
System
(
PPLS),
residential
trifluralin
formulations
include
liquid
concentrates
and
granular
formulations.

1.4.2
Mode
of
Action
and
Targets
Controlled
Trifluralin
is
a
pre­
emergent
herbicide
used
in
commercial/
residential
settings
for
preemergent
weed
control
of
annual
grasses
and
broadleaf
weeds
which
include,
but
are
not
limited
to,
the
following:
11
°
Grass
Weeds:
annual
bluegrass,
barnyardgrass,
brachiaria,
bromegrass,
cheat,
crabgrass,
foxtail,
guineagrass,
itchgrass,
johnsongrass,
junglerice,
panicum,
ryegrass,
Texas
panicum,
red
rice,
sandbur,
sprangletop,
stinkgrass,
shattercane,
woolly
cupgrass;
and
°
Broadleaf
Weeds:
carpetweed,
chickweed,
field
bindweed,
goosefoot,
henbit,
knotweed,
kochi,
lambsquater,
pigweed,
puncturevine,
purslane,
Russian
thistle,
stinging
nettle.

Trifluralin
is
applied
during
the
growing
season
to
established
plants
and
transplants.
It
is
applied
one
to
two
weeks
prior
to
the
anticipated
germination
of
annual
grass
weed
seeds,
since
established
weeds
will
not
be
controlled.
Treated
areas
should
be
irrigated
or
soil
incorporated
soon
after
application.

1.4.3
Registered
Use
Categories
and
Sites
An
analysis
of
the
current
labeling
and
available
use
information
was
completed.
Trifluralin
is
registered
for
use
in
a
variety
of
occupational
and
homeowner/
residential
scenarios.
This
TRED
deals
only
with
homeowner/
residential
uses.

Homeowner/
Residential
Use
Sites
Trifluralin
can
be
purchased
and
used
by
homeowners
in
residential
settings.
The
following
is
a
list
of
use
sites
in
the
residential
environment.

°
vegetable
gardens
°
residential,
golf
course,
and
recreational
turf
°
ornamentals:
flowers,
trees,
and
shrubs,
preplant
ornamentals
2.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
It
has
been
determined
there
is
a
potential
for
exposure
in
residential
settings
during
the
application
process
for
homeowners
who
use
products
containing
trifluralin.
There
is
also
a
potential
for
exposure
from
entering
areas
treated
with
trifluralin
that
could
lead
to
exposures
for
adults
and
children.
As
a
result,
risk
assessments
have
been
completed
for
both
residential
handler
and
postapplication
scenarios.

2.1
Residential
Handler
Exposures
and
Risks
The
Agency
uses
the
term
"
handlers"
to
describe
those
individuals
who
are
involved
in
the
pesticide
application
process.
Residential
handlers
are
assumed
to
complete
all
elements
of
an
application
(
i.
e.,
mixing,
loading,
and
application)
without
the
use
of
personal
protective
equipment
and
are
assumed
to
be
attired
in
short­
sleeve
shirts,
short
pants,
shoes,
and
socks.
12
2.1.1
Handler
Exposure
Scenarios
Scenarios
are
used
to
define
risks
based
on
the
U.
S.
EPA
Guidelines
For
Exposure
Assessment
(
U.
S.
EPA;
Federal
Register
Volume
57,
Number
104;
May
29,
1992).
The
purpose
of
this
section
is
to
describe
how
the
exposure
scenarios
were
defined.

°
For
residential
scenarios,
homeowner
handlers
are
expected
to
complete
all
tasks
associated
with
the
use
of
a
pesticide
product,
including
mixing/
loading
as
well
as
application;

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

°
Label
use
rates
and
use
information
specific
to
residential
products
serve
as
the
basis
for
the
risk
calculations;
and
°
Area/
volumes
of
spray
or
chemical
used
in
the
risk
assessment
are
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
trifluralin
in
a
variety
of
environments
including
on
turf,
vegetable
gardens,
and
ornamentals.
The
anticipated
use
patterns
and
current
labeling
indicate
several
major
residential
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
to
make
trifluralin
applications.
The
quantitative
exposure
and
risk
assessment
developed
for
residential
handlers
is
based
on
these
scenarios.
[
Note:
The
scenario
numbers
correspond
to
the
tables
of
risk
calculations
included
in
the
residential
risk
calculation
aspects
of
the
appendices.]

(
1)
loading/
applying
granulars
with
a
belly
grinder;
(
2)
loading/
applying
granulars
with
a
push­
type
spreader;
(
3)
loading/
applying
granulars
using
a
spoon,
measuring
scoop,
shaker
can,
or
via
hand;
(
4)
mixing/
loading/
applying
liquids
with
a
hose­
end
sprayer;
(
5)
mixing/
loading/
applying
liquids
with
low
pressure
handwand
sprayer;
(
6)
mixing/
loading/
applying
liquids
with
backpack
sprayer;
and
(
7)
applying
trifluralin
impregnated
fabric
squares
to
soil.

2.1.2
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
3
(
PHED),
from
Outdoor
Residential
Exposure
Task
Force
4
(
ORETF)
data,
or
from
other
surrogate
data.
Both
PHED
and
the
individual
studies
are
presented
below.
13
Assumptions
and
Factors:
The
assumptions
and
factors
used
in
the
risk
calculations
include:

°
For
noncancer
assessments,
the
Agency
always
considers
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments:

S
Vegetable
gardens:
The
maximum
label
application
rate
using
a
granular
formulation
is
4.0
lbs
a.
i./
A
and
using
a
liquid
formulation
is
4.1
lbs
a.
i./
A
or
0.047
lbs
ai/
gallon.

S
Flowers,
shrubs,
trees:
The
maximum
label
application
rate
using
a
granular
formulation
is
4.0
lbs
a.
i./
A
and
using
a
liquid
formulation
is
4.1
lbs
a.
i./
A
or
0.047
lbs
ai/
gallon.

S
Preplant
Ornamentals:
The
maximum
label
application
rate
is
20
lbs
a.
i./
A
(
granular
only).

S
Turf
(
residential
lawns,
golf
courses,
recreation
parks,
etc):
The
maximum
label
application
rate
is
3.0
lbs
a.
i./
A
(
granular
only).

$
For
cancer
assessments,
the
Agency
considers
the
typical
application
rate
for
a
given
use
site,
if
known.
The
typical
application
rate
is
not
known
for
most
trifluralin
applications
in
residential
settings,
therefore
B
with
one
exception
B
the
maximum
application
rate
was
used
in
the
cancer
exposure
and
risk
assessment.
However,
since
the
labeled
rate
for
established
ornamentals
is
2
to
4
pounds
active
ingredient
per
acre,
EPA
used
3
pounds
active
ingredient
per
acre
as
a
typical
rate
for
ornamentals
in
the
cancer
assessment.

°
Average
body
weight
of
an
adult
handler
is
70
kilograms.
Since
the
noncancer
and
cancer
endpoints
of
concern
are
not
sex­
specific,
the
body
weight
of
an
average
adult
is
used
in
the
assessments.

°
PHED
values
represent
a
handler
wearing
typical
residential
clothing
attire
of
short­
sleeved
shirt,
short
pants,
socks,
shoes,
and
no
gloves.
Generally,
the
use
of
personal
protective
equipment
(
PPE)
and
engineering
controls
are
not
considered
acceptable
risk
mitigation
options
for
products
sold
for
use
by
homeowners.

°
Residential
risk
assessments
are
based
on
what
would
reasonably
be
treated
by
homeowners
such
as
the
size
of
a
lawn,
or
the
size
of
a
garden.
The
factors
used
for
the
trifluralin
assessment
were
those
dictated
in
the
Health
Effects
Division
Science
Advisory
Committee
Standard
Operating
Procedure
12:
Recommended
Revisions
To
The
Standard
Operating
Procedures
For
Residential
Exposure
Assessment5
which
was
completed
on
February
22,
2001.
The
following
daily
volumes
handled
and
area
treated,
excerpted
from
the
SOP
and
used
in
each
residential
scenario,
include:

S
The
amount
of
dilute
pesticide
used
per
day
or
area
treated
per
day
for
liquid
formulations:
>
5
gallons
for
a
low­
pressure
handwand
and
a
backpack
sprayers,
and
14
>
1,000
ft2
for
applications
to
gardens
(
vegetables
and
ornamentals)
with
a
hose­
end
sprayer.

S
The
area
treated
with
granules
by
a
homeowner
is
assumed
to
be:
>
0.5
acres
for
broadcast
applications
with
a
belly
grinder
or
push­
type
spreader
to
lawns,
>
1,000
ft2
for
spot
treatments
to
lawns
with
a
belly
grinder,
spoon,
measuring
scoop,
shaker
can,
or
by
hand;
and
>
1,000
ft2
for
flower
or
vegetable
garden
applications
with
a
belly
grinder,
spoon,
measuring
scoop,
shaker
can,
or
by
hand.

Pesticide
Handler
Exposure
Database
(
PHED)
Version
1.1
(
August
1998):
Chemical­
specific
data
for
assessing
human
exposures
during
pesticide
handling
activities
were
not
submitted
to
the
Agency
in
support
of
the
reregistration
of
trifluralin.
It
is
the
policy
of
the
HED
to
use
data
from
the
Pesticide
Handlers
Exposure
Database
(
PHED)
Version
1.1
to
assess
handler
exposures
for
regulatory
actions
when
chemical­
specific
monitoring
data
are
not
available.
6
PHED
was
designed
by
a
task
force
of
representatives
from
the
U.
S.
EPA,
Health
Canada,
the
California
Department
of
Pesticide
Regulation,
and
member
companies
of
the
American
Crop
Protection
Association.
PHED
is
a
software
system
consisting
of
two
parts
­­
a
database
of
measured
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.,
liquid
concentrates,
granulars),
application
method
(
e.
g.,
low­
pressure
handwand
sprayer,
push­
type
spreader),
and
clothing
scenarios
(
e.
g.,
short­
sleeve
shirt
and
short
pants).

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.
15
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
Table
6.
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
residential
scenarios
that
can
be
utilized
to
ensure
consistency
in
exposure
assessments.
5
EPA
MRID
449722­
01
(
ORETF
Handler
Studies):
A
report
was
submitted
by
the
ORETF
(
Outdoor
Residential
Exposure
Task
Force4)
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
monitored
homeowner
exposure
scenarios
using
a
push­
type
spreader
(
ORETF
Study
OMA003)
is
summarized
below.

Homeowner
Push­
Type
Spreader
(
OMA003):
A
mixer/
loader/
applicator
study
was
performed
by
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
using
Dacthal
(
active
ingredient
DCPA,
dimethyl
tetrachloroterephthalate)
as
a
surrogate
compound
to
determine
"
generic"
exposures
of
individuals
applying
a
granular
pesticide
formulation
to
residential
lawns.
A
total
of
30
volunteers
were
monitored
using
passive
dosimetry
(
inner
and
outer
whole
body
dosimeters,
hand
washes,
face/
neck
wipes,
and
personal
inhalation
monitors).
Each
volunteer
carried,
loaded,
and
applied
two
25­
lb
bags
of
fertilizer
(
0.89%
active
ingredient)
with
a
rotary
type
spreader
to
a
lawn
covering
10,000
ft2.
The
target
application
rate
was
2
lb
ai/
acre
(
actual
rate
achieved
was
about
1.9
lbs
ai/
acre).
The
average
application
time
was
22
minutes,
including
loading
the
rotary
push
spreader
and
disposing
of
the
empty
bags.
Each
replicate
handled
approximately
0.45
lbs
ai.
Dermal
exposure
was
measured
using
inner
and
outer
whole
body
dosimeters,
hand
washes,
face/
neck
washes,
and
personal
air
monitoring
devices
with
OVS
tubes.
The
study
results
are
normalized
to
kg
ai
handled.
The
US
EPA
HED
typically
assumes
that
residential
applicators
wear
short
pants
and
short­
sleeved
shirts,
as
described
in
the
Residential
SOPs
(
1997).
Therefore,
the
table
reports
the
dermal
exposures
for
the
short
pants
and
shortsleeve
shirt
clothing
scenario
only.
16
Table
3:
Unit
Exposure
Values
Obtained
From
ORETF
Study
MRID
449722­
01
Scenario
Monitored
Push­
Type
Spreader
Applied
(
lb
ai)
Dermal
(
mg
ai/
lb
handled)
Inhalation
(

g
ai/
lb
handled)

Geometric
Mean
0.45
0.67
0.88
EPA
MRID
44518501
(
ORETF
Handler
Studies):
A
report
was
submitted
by
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
that
presented
data
in
which
the
application
of
various
products
used
on
ornamentals
by
homeowners
was
monitored.
All
of
the
data
submitted
in
this
report
were
completed
in
a
series
of
studies.
The
study
that
monitored
homeowner
exposure
scenarios
using
a
hose­
end
sprayer
and
a
low­
pressure
handwand
are
summarized
below.

Homeowner
Hose­
end
and
Hand­
held
Sprayer:
Applications
of
Sevin
Liquid
®
Carbaryl
insecticide
[
RP­
2
liquid
(
21%)]
were
made
by
volunteers
to
two
young
citrus
trees
and
two
shrubs
in
each
replicate
that
was
monitored
in
the
study.
The
test
field
was
located
only
in
Florida.
Twenty
(
20)
replicates
were
monitored
using
hose­
end
sprayer
(
Ortho
®
DIAL
or
Spray
®
hose
end
sprayer),
and
20
replicates
were
monitored
using
hand
held
pump
sprayers
(
low
pressure
handwands).

Each
replicate
opened
the
end­
use
product,
added
it
to
the
hose­
end
sprayer
or
hand
held
pump
and
then
applied
it
to
the
trees
and
shrubs.
After
application
to
two
trees
and
two
shrubs
dosimeters
were
collected.
Inhalation
exposure
was
monitored
with
personal
air
sampling
pumps
with
OVS
tubes
attached
to
the
shirt
collar
in
the
breathing
zone.
Dermal
exposure
was
assessed
by
extraction
of
carbaryl
from
inner
and
outer
100
percent
cotton
dosimeters.
The
inner
and
outer
dosimeters
were
segmented
into:
lower
and
upper
arms,
lower
and
upper
legs,
front
and
back
torso.
No
gloves
were
worn
therefore
hand
exposure
was
assessed
with
400
ml
handwash
with
0.01
percent
Aerosol
OT­
75
sodium
dioctyl
sulfosuccinate
(
OTS).
One
hundred
percent
cotton
handkerchiefs
wetted
with
25
ml
OTS
were
used
to
wipe
face
and
neck
to
determine
exposure.

Field
fortification
recoveries
for
passive
dosimeters
averaged
88.3
percent
for
inner
and
76.2
percent
for
outer
dosimeters.
Face
and
neck
wipe
fortifications
average
82.5
percent.
Handwash
and
inhalation
OVS
tube
field
fortification
averaged
>
90
percent.
Inner
and
outer
dosimeter
and
face
and
neck
wipe
residues
were
adjusted
for
field
fortification
results.
Handwash
and
inhalation
residues
were
not
adjusted.

Laboratory
method
validation
for
each
matrix
fell
within
the
acceptable
range
of
70
to
120
percent.
The
limit
of
quantitation
(
LOQ)
was
1.0

g/
sample
for
all
media
except
the
inhalation
monitors
where
the
LOQ
was
0.01

g/
sample.
The
limit
of
detection
(
LOD)
was
0.5

g/
sample
for
all
media
except
the
inhalation
monitors
where
the
LOQ
was
0.005

g/
sample.
17
For
use
in
reregistration
documents,
the
dermal
exposure
was
calculated
by
adding
the
values
from
the
hand
rinses,
face/
neck
wipes
to
the
outer
dosimeter
lower
legs
and
lower
arms
plus
the
inner
dosimeter
front
and
rear
torso,
upper
legs
and
upper
arms.
This
accounts
for
the
residential
handler
wearing
short­
sleeved
shirt
and
short
pants.
The
results
for
the
low
pressure
handwand
are
summarized
in
Table
3
below.

The
distribution
of
the
unit
exposure
values
is
categorized
as
normal,
lognormal,
or
"
other"
(
i.
e.,
neither
normal
nor
lognormal).
A
central
tendency
value
is
selected
from
the
distribution
of
the
exposure
values.
These
values
are
the
arithmetic
mean
for
normal
distributions,
the
geometric
mean
for
lognormal
distributions,
and
the
median
for
all
"
other"
distributions.
The
dermal
exposure
had
a
lognormal
distribution
so
the
geometric
mean
value
was
used
to
determine
dermal
exposure
to
trifluralin.
The
inhalation
exposure
had
neither
a
normal
or
lognormal
distribution
so
the
median
was
used
to
determine
inhalation
exposure
to
trifluralin.

Table
4:
Unit
Exposure
Values
Obtained
ORETF
Study
MRID
44518501)

Scenario
Monitored
Hose
End
Pump
Sprayer
Applied
(
lb
ai)
Dermal
(
mg
ai/
lb
handled)
Inhalation
(

g
ai/
lb
handled)
Applied
(
lb
ai)
Dermal
(
mg
ai/
lb
handled)
Inhalation
(

g
ai/
lb
handled)

Geometric
Mean
0.033
39.0
1.6
0.017
56.0
2.6
Proprietary
Studies
One
proprietary
study
was
used
to
obtain
unit
exposure
values
for
handlers
loading/
applying
with
a
bucket
and
spoon.
This
study
is
summarized
below.

Worker
Exposure
Study
During
Application
of
Regent
20GR
In
Banana
Plantation1,
EPA
MRID
452507­
02
(
Fipronil
Study):
Handler
exposure
data
from
a
proprietary
granular
mixer/
loader/
applicator
study
(
MRID
452507­
02)
in
bananas
using
fipronil
(
Regent
20GR)
were
used
in
place
of
PHED
data
for
the
"
loading/
applying
granulars
using
a
spoon,
measuring
scoop,
shaker
can
or
by
hand"
scenario.
This
fipronil
study
is
considered
to
be
an
appropriate
source
of
surrogate
handler
exposure
data
for
trifluralin
because
formulation
types
are
similar
(
granular)
and
application
methods
are
similar
(
applying
granulars
with
a
spoon).
The
study
is
considered
to
be
of
sufficient
quality
for
use
in
risk
assessment.
1
Data
compensation
for
these
data
should
be
determined.

Several
factors
should
be
considered
when
using
fipronil
data
in
the
trifluralin
exposure
assessment.
Protection
factors
used
to
calculate
trifluralin
dermal
unit
exposure
values,
based
on
the
fipronil
unit
exposure
values,
include
a
standard
50%
protection
factor
for
the
torso,
a
10%
protection
factor
for
legs,
based
on
shorts,
and
a
10%
protection
factor
for
arms,
based
on
a
shortsleeved
shirt.
These
protection
factors
represent
the
typical
attire
assumed
to
be
worn
by
a
homeowner
during
pesticide
application
(
shorts
and
short­
sleeved
shirt).
The
10%
protection
factor
for
shorts
and
the
10%
protection
factor
for
a
short­
sleeved
shirt
are
not
standard
protection
18
factors
used
by
the
Agency;
rather,
these
values
are
based
on
the
best
professional
judgement
of
Agency
scientists
and
are
appropriate
for
calculating
range­
finding
estimates
only.

Some
other
issues
and
limitations
to
be
considered
when
using
the
fipronil
study
include
the
following:

°
Agency
guidelines
require
that
15
replicates
be
completed
in
exposure
studies
in
three
different
locations.
In
the
fipronil
study,
only
ten
replicates
were
completed
using
spoons,
and
at
only
one
location.
However,
the
events
that
were
monitored
seemed
to
be
reasonable
representations
of
actual
agricultural
practices,
so
it
is
unlikely
that
additional
replicates
would
significantly
alter
the
final
unit
exposure
results.
Additionally,
it
is
unlikely
that
cultural
practices
would
significantly
vary
if
the
study
was
completed
at
different
locations.

°
The
individual
amounts
of
chemical
applied
were
not
recorded
in
this
study.
Instead,
the
investigators
determined
how
much
product
was
applied
by
the
application
teams
used.
Using
this
information,
the
investigators
calculated
the
amount
used
for
each
individual
by
assuming
that
each
was
equally
productive
(
i.
e.,
dividing
the
total
amount
used
per
team
by
the
number
of
team
members).

°
One
applicator
using
the
spoons
had
a
spoon
with
no
handle.
The
results
for
this
individual
were
included
with
the
other
spoon
applicators
as
it
is
a
plausible
variation
of
that
application
method.

Table
5:
Unit
Exposure
Values
Obtained
From
Fipronil
Study
MRID
452507­
02
Scenario
Monitored
Spoon
Applications
Handled
(
mg
exposure/
lb
ai
handled)
Dermal
(
mg
ai/
lb
handled)
Inhalation
(

g
ai/
lb
handled)

Geometric
Mean
0.045
3.5
45.0
2.1.3
Residential
Handler
Exposure
and
Non­
Cancer
Risk
Estimates
The
residential
handler
exposure
and
non­
cancer
risk
calculations
are
presented
in
this
section.
Non­
cancer
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
were
then
calculated.

Daily
Inhalation
Exposure:
The
daily
inhalation
exposure,
daily
inhalation
dose
and
hence
the
inhalation
risks,
to
handlers
were
calculated
as
described
below.
The
first
step
was
to
calculate
daily
exposure
(
dermal
or
inhalation)
using
the
following
formula:
19
Daily
Inhalation
Exposure
mg
ai
day

Unit
Exposure

g
ai
lb
ai
x
Conversion
Factor
1mg
1,000

g
x
Use
Rate
lb
ai
Sq
ft,
Gallons
x
Amount
Treated
Sq
ft,
Gallons
day
Average
Daily
Dose
mg
ai
kg/
day

Daily
Exposure
mg
ai
day
x
AbsorptionFactor(%/
100)
Body
Weight
(
kg)
Where:

Daily
Exposure
=
Amount
that
is
inhaled,
also
referred
to
as
potential
dose
(
mg
ai/
day);
Unit
Exposure
=
Normalized
exposure
value
derived
from
August
1998
PHED
Surrogate
Exposure
Table
and
various
referenced
exposure
studies
noted
above
(
mg
ai/
lb
ai);
Application
Rate
=
Normalized
application
rate
based
on
a
logical
unit
treatment
such
as
square
feet
or
gallons,
maximum
values
are
generally
used
(
lb
ai/
sq
ft,
lb
ai/
gal)
and
Daily
Area
Treated
=
Normalized
application
area
based
on
a
logical
unit
treatment
such
as
square
feet
(
sq
ft/
day),
or
gallons
per
day
(
gal/
day).

Daily
Inhalation
Dose:
Daily
dose
was
calculated
by
normalizing
the
daily
inhalation
exposure
value
by
body
weight.
For
adult
handlers
using
trifluralin,
an
average
adult
body
weight
of
70
kg
was
used
for
all
exposure
scenarios.
Since
there
is
no
specific
inhalation
absorption
factor
that
is
available
for
trifluralin,
a
factor
of
100
percent
has
been
used
for
all
calculations.
Daily
dose
was
calculated
using
the
following
formula:

Where:

Average
Daily
Dose
=
The
amount
as
absorbed
dose
received
from
exposure
to
a
pesticide
in
a
given
scenario
(
mg
pesticide
active
ingredient/
kg
body
weight/
day,
also
referred
to
as
ADD);
Daily
Exposure
=
Amount
deposited
on
the
surface
of
the
skin
that
is
available
for
dermal
absorption
or
amount
that
is
inhaled,
also
referred
to
as
potential
dose
(
mg
ai/
day);
Absorption
Factor
=
A
measure
of
the
flux
or
amount
of
chemical
that
crosses
a
biological
boundary
such
as
the
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)
to
assess
the
total
risk
to
handlers
for
each
exposure
route
within
the
scenarios.
Inhalation
MOEs
for
all
durations
were
calculated
using
a
NOAEL
of
81
mg/
kg/
day
(
Table
1).
All
MOE
values
were
calculated
for
inhalation
exposure
levels
using
the
formula
below:
20
MOE

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

MOE
=
Margin
of
exposure,
value
used
by
the
Agency
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)
in
the
study
or
the
lowest
dose
level
where
an
adverse
effect
occurred.

A
margin
of
exposure
(
MOE)
uncertainty
factor
of
100
is
considered
an
appropriate
risk
level
for
the
residential
risk
assessments.
2
Noncancer
Risk
Summary:
All
of
the
noncancer
risk
calculations
for
residential
trifluralin
handlers
completed
in
this
assessment
are
included
in
Appendix
A.
A
summary
of
the
results
for
each
exposure
scenario
is
also
provided
below.

Appendix
A/
Table
A1:
Sources
of
Exposure
Data
Used
in
the
Short­
Term
Residential
Trifluralin
Handler
Exposure
and
Risk
Calculations
Describes
the
sources
and
quality
of
the
exposure
data
used
in
all
of
the
residential
handler
calculations.

Appendix
A/
Table
A2:
Margins
of
Exposure
For
Short­
Term
Trifluralin
Residential
Handler
Risk
Assessment
Unit
exposure
values,
daily
doses,
and
risks
are
presented
for
residential
handlers
for
short­
term
exposures.

2.1.4
Summary
of
Non­
Cancer
Risk
Concerns
for
Residential
Handlers
Short­
term
exposures
and
risks
were
not
assessed
for
trifluralin,
since
no
short­
term
dermal
endpoint
was
identified.
For
the
applications
in
residential
settings,
the
inhalation
risks
are
not
a
concern
for
all
mixing/
loading/
applying
scenarios.
Note
that
there
is
assumed
to
be
no
inhalation
risk
data
for
applying
ready­
to­
use
trifluralin
impregnated
squares
to
soil.
Due
to
the
low
vapor
pressure
of
trifluralin
(
4
x
10­
5
mm
Hg
at
25

C),
the
inhalation
risk
from
this
exposure
pattern
is
not
expected
to
be
a
concern.
21
Table
6.
Residential
Handler
Short­
Term
Inhalation
Exposure
and
Risks
to
Trifluralin
Exposure
Scenario
(
Scenario
#)
Use
Site
Inhalation
Unit
Exposure
(

g/
lb
ai)
a
Application
Rateb
Amount
Used
or
Area
Treated
per
Dayc
Daily
Inhalation
Dose
(
mg/
day/
day)
d
Inhalation
MOEe
MIXER/
LOADER/
APPLICATOR
EXPOSURE
Loading/
applying
granulars
with
a
belly
grinder
(
1)
ornamental
(
pre­
plant)
62
20
lbs
ai/
acre
0.023
acres
4.10e­
03
2.00e+
05
ornamental
(
post­
plant)
4.0
lbs
ai/
acre
0.023
acres
8.20e­
05
9.90e+
05
turf
3.0
lbs
ai/
acre
0.5
acres
1.30e­
03
6.10e+
04
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
8.30e­
05
9.70e+
05
Loading/
applying
granulars
with
a
push­
type
spreader
(
2)
ornamental
(
pre­
plant)
0.88
20
lbs
ai/
acre
0.023
acres
5.80e­
06
1.40e+
07
ornamental
(
post­
plant)
4.0
lbs
ai/
acre
0.023
acres
1.20e­
06
7.00e+
07
turf
3.0
lbs
ai/
acre
0.5
acres
1.90e­
05
4.30e+
06
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
1.20e­
06
6.90e+
07
Loading/
applying
granulars
using
a
spoon,
measuring
scoop,
shaker
can,

or
by
hand(
3)
ornamental
(
pre­
plant)
45
20
lbs
ai/
acre
0.023
acres
3.00e­
04
2.70e+
05
ornamental
(
post­
plant)
4.0
lbs
ai/
acre
0.023
acres
5.90e­
05
1.40e+
07
turf
3.0
lbs
ai/
acre
0.023
acres
4.40e­
05
1.80e+
06
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
6.00e­
05
1.30e+
06
rose
bushes
0.00043
lbs
ai/
bush
50
bushes
1.40e­
05
5.90e+
06
Mixing/
loading/
applying
liquids
with
a
hose­
end
sprayer
(
4)
flowers,
trees
and
shrubs
1.5
4.1
lbs
ai/
acre
0.023
acres
2.00e­
06
4.00e+
07
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
2.00e­
06
4.00e+
07
Mixing/
loading/
applying
liquids
with
low
pressure
hand
wand
(
5)
flowers,
trees,
and
shrubs
3.8
0.047
lbs
ai/
gallon
5
gallons
1.30e­
05
6.30e+
06
vegetable
gardens
0.047
lbs
ai/
gallon
5
gallons
1.30e­
05
6.30e+
06
Mixing/
loading/
applying
liquids
with
back
pack
sprayer
(
6)
flowers,
trees,
and
shrubs
30
0.047
lbs
ai/
gallon
5
gallons
1.00e­
04
8.00e+
05
vegetable
gardens
0.047
lbs
ai/
gallon
5
gallons
1.00e­
04
8.00e+
05
Applying
trifluralin
impregnated
fabric
squares
to
soil
(
7)
No
data
are
available
for
this
scenario.

Footnotes:

a
Inhalation
unit
exposure
values
from
PHED
represent
no
respirator.
3
b
Application
Rates
are
based
on
the
maximum
application
rates
listed
on
the
trifluralin
labels.
22
c
Amount
handled
per
day
are
from
EPA
estimates
of
acres
treated,
or
square
feet
treated,
in
a
single
day
based
on
the
application
method.
For
ready
to
use
formulations,
the
whole
container
is
assumed
to
be
used
in
one
day.

d
Daily
Inhalation
dose
(
mg/
kg/
day)
=
(
Inhalation
Unit
Exposure
(

g/
lb
ai)
x
(
1mg/
1000

g)
Conversion
Factor
x
Application
Rate
(
lb
ai/
A
or
lb
ai/
gal
or
lb
ai/
bush)
x
Area
Treated
per
day
(
acres,
gallons,
or
bushes))/
body
weight
(
70
kg).

e
Short­
term
Inhalation
MOE
=
Inhalation
NOAEL
(
81
mg/
kg/
day)/
Daily
Inhalation
Dose
(
mg/
kg/
day).
23
2.2
Residential
Cancer
Trifluralin
Handler
Exposure
and
Risk
Assessment
This
section
presents
the
residential
handler
exposure
and
cancer
risk
assessment
for
trifluralin.

2.2.1
Data
and
Assumptions
For
Residential
Cancer
Handler
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
residential
handler
risk
assessments.

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

°
The
Agency
always
considers
the
typical
application
rates
allowed
for
its
cancer
risk
assessments,
however,
no
typical
rates
were
available
for
residential
trifluralin
uses.
As
a
result,
the
maximum
rates
were
used,
except
for
the
post­
plant
applications
to
ornamentals.
The
label
rates
for
this
use
pattern
varied
from
2
to
4
lb
ai/
acre
and
an
average
rate
of
3
lb
ai/
acre
was
utilized
for
the
cancer
assessment.

$
Residential
applications
per
year
(
5
total)
for
the
granular
scenarios
were
as
follows:

S
one
pre­
plant
application
to
ornamentals
(
at
20
lb
ai/
acre,
treat
1,000
sq
ft);

S
one
post­
plant
application
to
ornamentals
(
at
3
lb
ai/
acre,
treat
1,000
sq
ft
­
label
rates
range
from
2
to
4
lb
ai/
acre);

S
one
application
to
vegetable
gardens
(
4.1
lb
ai/
acre,
treat
1,000
sq
ft);
and
S
two
applications
to
turf
per
year
for
all
granular
equipment
(
3
lb
ai/
acre,
treat
0.5
acres).

$
Residential
applications
per
year
for
the
liquid
scenarios
were
set
at
5
per
year.

2.2.2
Residential
Cancer
Trifluralin
Handler
Exposure
and
Risk
Calculations
Cancer
risks
resulting
from
exposures
to
trifluralin
were
calculated
using
a
linear
low­
dose
extrapolation
approach
in
which
a
Lifetime
Average
Daily
Dose
(
LADD)
is
first
calculated
and
then
compared
with
a
Q1*
that
has
been
calculated
for
trifluralin
based
on
dose
response
data
(
Q1*
=
5.79
x
10­
3
(
mg/
kg/
day)­
1).
Absorbed
average
daily
dose
(
ADD)
levels
were
used
as
the
basis
for
calculating
the
LADD
values.
Section
2.1.3
describes
how
the
ADD
values
for
inhalation
exposures
were
calculated
for
the
non­
cancer
MOEs.
These
values
also
serve
as
the
basis
for
the
cancer
risk
estimates.
In
the
cancer
assessment
both
dermal
and
inhalation
ADD
values
are
calculated
and
then
added
together
to
obtain
combined
dermal
plus
inhalation
ADD
values.
Dermal
ADD
values
are
calculated
as
described
in
Section
2.1.3.
To
assess
cancer
risks,
LADD
values
are
calculated
and
then
compared
to
the
Q1*
selected
for
trifluralin.

Lifetime
Average
Daily
Dose:
To
calculate
the
carcinogenic
risk
from
absorbed
average
daily
dose,
the
values
must
be
amortized
over
the
lifetime
of
residential
handlers.
Current
use
24
LADD
mg
ai
kg/
day

Total
Daily
Dose
mg
ai
kg/
day
x
days
exposed
365
days
per
year
x
50
years
exposed
70
year
lifetime
Cancer
Risk

LADD
mg
ai
kg/
day
x
Q
1

patterns
indicate
that
application
occurs
only
a
few
times
per
year.
HED
does
not
expect
homeowner
handler
exposures
to
exceed
five
times
per
year
for
this
cancer
risk
assessment:

Finally,
a
50­
year
exposure
and
a
70­
year
lifespan
were
used
to
complete
the
calculations.
LADD
values
were
calculated
using
the
following
equation:

Where:

Lifetime
Average
Daily
Dose
=
The
amount
as
absorbed
dose
received
from
exposure
to
a
pesticide
or
degradate
in
a
given
scenario
over
a
lifetime
(
mg/
kg/
day,
also
referred
to
as
LADD);
Average
Daily
Dose
=
The
amount
as
absorbed
dose
received
from
exposure
to
a
pesticide
or
degradate
in
a
given
scenario
on
a
daily
basis
(
mg/
kg/
day,
also
referred
to
as
ADD);
Exposure
Frequency
=
The
annual
frequency
of
exposure
to
an
individual
(
days/
year);
Exposure
Duration
=
The
amount
of
a
lifetime
that
an
individual
is
exposed
(
50
years);
and
Lifetime
=
The
average
life
expectancy
of
an
individual
(
70
years).

Cancer
Risks
:
Finally,
cancer
risk
calculations
were
completed
by
comparing
the
LADD
values
to
the
Q
1*
for
trifluralin
(
Q1*
=
5.97
x
10­
3
(
mg/
kg/
day)­
1).
Individual
cancer
risks
were
calculated
using
the
following
equation:

Where:

Cancer
Risk
=
Probability
of
excess
cancer
cases
over
a
lifetime
(
unitless);
Lifetime
Average
Daily
Dose
=
The
amount
as
absorbed
dose
received
from
exposure
to
a
pesticide
or
degradate
in
a
given
scenario
over
a
lifetime
(
mg/
kg/
day);
and
Q1*
=
Quantitative
dose
response
factor
used
for
linear,
low­
dose
response
cancer
risk
calculations
(
mg/
kg/
day)­
1.

After
calculating
all
of
the
individual
cancer
risks,
a
total
combined
cancer
risk
was
calculated
by
adding
together
all
the
individual
cancer
risks
for
a
particular
scenario.

HED
has
defined
a
range
of
acceptable
cancer
risks
based
on
a
policy
memorandum
issued
in
1996
by
then
Office
of
Pesticide
Programs
director,
Mr.
Dan
Barolo.
This
memo
refers
to
a
predetermined
quantified
"
level
of
concern"
for
residential
carcinogenic
risk.
In
summary,
this
25
policy
memo
indicates
risks
less
than
1
x
10­
6
are
not
considered
to
be
of
concern
and
require
no
risk
management
action.

Cancer
Risk
Summary:
A
summary
of
the
results
for
each
exposure
scenario
is
provided
below
in
Table
7.
In
addition,
the
cancer
risk
calculations
for
residential
trifluralin
handlers
completed
in
this
assessment
are
included
in
Appendix
A:
Table
A3:
Trifluralin
Residential
Handler
Cancer
Risk
Assessment.

Summary
of
Risk
Concerns
for
Cancer
The
target
risk
for
cancer
is
1
x
10­
6.
Risks
greater
than
1
x
10­
6
for
the
general
population
are
considered
to
be
of
concern
and
risks
less
than
1
x
10­
6
are
not
considered
to
be
of
concern.
Homeowner
exposure
to
trifluralin
is
not
expected
to
occur
more
than
five
days
per
year.
All
scenarios
have
cancer
risks
of
less
than
1
x
10­
6.
Note
that
there
is
no
inhalation
risk
data
for
applying
ready­
to­
use
trifluralin
impregnated
squares
to
soil,
but
inhalation
exposure
is
expected
to
be
negligible.
HED
expects
the
cancer
risks
for
this
scenario
to
be
far
less
than
applying
granular
formulations
using
a
spoon,
measuring
scoop,
shaker
can,
or
by
hand.
26
Table
7.
Baseline
Residential
Handler
Dermal
and
Inhalation
Cancer
Exposure
to
Trifluralin
Exposure
Scenario
(
Scenario
#)
Use
Site
Application
Rate
a
Area
Treated
Dermal
Unit
Exposure
(
mg/
lb
ai)
Inhalation
Unit
Exposure
(
ug/
lb
ai)
Residential
Handler
Treatments
/
Year
b
Daily
Total
Dose
(
mg/
kg/
day)
c
Residential
Handler
Total
LADD
(
mg/
kg/
day)
d
Residential
Handler
Cancer
Risk
e
Combined
Residential
Handler
Cancer
Riskf
MIXER/
LOADER/
APPLICATOR
EXPOSURE
Loading/
applying
granulars
with
a
belly
grinder
(
1)
ornamental
(
pre)
20
lb
ai/
acre
0.023
acres
110
62
1
0.022
4.4E­
05
2.5E­
07
8.85E­
07
ornamental
(
post)
3
lb
ai/
acre
0.023
acres
110
62
1
0.0033
6.5E­
06
3.8E­
08
turf
3
lb
ai/
acre
0.5
acres
110
62
2
0.024
9.4E­
05
5.4E­
07
vegetable
gardens
4.1
lb
ai/
acre
0.023
acres
110
62
1
0.0045
8.8E­
06
5.1E­
08
Loading/
applying
granulars
with
a
push
type
spreader
(
2)
ornamental
(
pre)
20
lb
ai/
acre
0.023
acres
0.67
0.88
1
0.00014
2.7E­
07
1.6E­
09
5.52E­
09
ornamental
(
post)
3
lb
ai/
acre
0.023
acres
0.67
0.88
1
0.000021
4.0E­
08
2.3E­
10
turf
3
lb
ai/
acre
0.5
acres
0.67
0.88
2
0.00015
5.9E­
07
3.4E­
09
vegetable
gardens
4.1
lb
ai/
acre
0.023
acres
0.67
0.88
1
0.000028
5.5E­
08
3.2E­
10
Loading/
applying
granulars
using
a
spoon,
measuring
scoop,
shaker
can,
or
by
hand(
3)
ornamental
(
pre)
20
lb
ai/
acre
0.023
acres
3.5
45
1
0.00099
1.9E­
06
1.1E­
08
1.68E­
08
ornamental
(
post)
3
lb
ai/
acre
0.023
acres
3.5
45
1
0.00015
2.9E­
07
1.7E­
09
turf
3
lb
ai/
acre
0.023
acres
3.5
45
2
0.000049
1.9E­
07
1.1E­
09
vegetable
gardens
4.1
lb
ai/
acre
0.023
acres
3.5
45
1
0.0002
3.9E­
07
2.3E­
09
Mixing/
loading/
applying
liquids
with
a
hose­
end
sprayer
(
4)
flowers,
trees,
shrubs,

vegetable
gardens
4.1
lb
ai/
acre
0.023
acres
39
1.5
5
0.0016
1.5E­
05
8.9E­
08
Mixing/
loading/
applying
liquids
with
low
pressure
hand
wand
(
5)
flowers,
trees,
shrubs,

vegetable
gardens
0.047
lb
ai/
gal
5
gallons
56
3.8
5
0.0057
5.5E­
05
3.2E­
07
Mixing/
loading/
applying
liquids
with
back
pack
sprayer
(
6)
flowers,
trees,
shrubs,

vegetable
gardens
0.047
lb
ai/
gal
5
gallons
100
30
5
0.01
1.0E­
04
5.8E­
07
Applying
trifluralin
impregnated
fabric
squares
to
soil
(
7)
No
data
are
available
for
this
scenario.

Footnotes:

a
Maximum
application
rates
were
utilized
for
all
use
sites
except
for
the
granular,
post­
plant
application.
The
label
rates
for
this
use
ranged
from
2
to
4
lb
ai/
acre
so
the
average
rate
of
3
lb
ai/
acre
was
utilized
for
the
cancer
assessment.

b
The
number
of
exposures
per
year
are
based
on
the
label
recommendations.

c
Total
Daily
Dose
(
mg/
kg/
day)
=
Daily
Dermal
Dose
(
mg/
kg/
day)
*
Dermal
Absorption
(
3%)
+
Daily
Inhalation
Dose
(
mg/
kg/
day).

d
LADD
(
mg/
kg/
day)
=
Total
Daily
Dose
(
mg/
kg/
day)
*
(#
days
of
exposure
per
year/
365
days/
year)
*
(
50
years
exposed/
70
years
in
a
lifetime).

e
Cancer
Risk
=
LADD
(
mg/
kg/
day)
*
Q1*
(
0.00579)

f
Combined
Cancer
Risk
by
Equipment
Type
=
Cancer
risks
for
each
crop
in
the
equipment
scenario
added
to
one
another.
27
2.3
Residential
Postapplication
Exposures
and
Risks
2.3.1
Residential
Postapplication
Exposure
Scenarios
Trifluralin
residential
uses
(
vegetable
gardens,
ornamentals,
and
turf)
indicate
that
individuals
of
varying
ages
potentially
can
be
exposed
during
activities
in
areas
that
have
been
previously
treated.
The
Agency
is
concerned
about
these
kinds
of
postapplication
exposures.
Postapplication
exposure
scenarios
were
developed
for
each
residential
setting
where
trifluralin
can
be
used.

The
Agency
considered
a
number
of
residential
postapplication
exposure
scenarios
for
different
segments
of
the
population
including
toddlers,
youth­
aged
children,
and
adults.
Noncancer
risks
were
calculated
for
only
a
few
scenarios,
since
no
short­
term
dermal
endpoint
of
concern
has
been
identified.
In
general,
postapplication
inhalation
risks
following
outdoor
applications
are
considered
negligible.
Therefore,
at
this
time,
EPA
is
only
assessing
non­
dietary
ingestion
exposures
for
toddlers
(
i.
e.,
soil
ingestion,
hand­/
object­
to­
mouth,
and
granule
ingestion).

The
Agency
relies
on
a
standardized
approach
for
completing
residential
risk
assessments
that
is
based
on
current
trifluralin
labels
and
guidance
contained
in
the
following
four
documents:

°
Series
875,
Residential
and
Residential
Exposure
Test
Guidelines:
Group
B
­
Postapplication
Exposure
Monitoring
Test
Guidelines
(
V
5.4,
Feb.
1998)
This
document
provides
general
risk
assessment
guidance
and
criteria
for
analysis
of
residue
dissipation
data.

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

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

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

When
the
guidance
in
current
labels
and
these
documents
is
considered,
it
is
clear
that
the
Agency
should
consider
children
of
differing
ages
as
well
as
adults
in
its
assessments.
However,
since
no
short­
term
dermal
endpoint
of
concern
has
been
identified,
the
only
population
that
was
considered
in
the
assessment
was:
28

Residential
Children:
children
are
members
of
the
general
population
that
can
also
be
exposed
in
their
residences
(
e.
g.,
on
lawns
or
in
gardens),
as
well
as
other
areas
treated
with
a
pesticide
(
e.
g.,
parks).
These
kinds
of
exposures
are
attributable
to
a
variety
of
activities
such
as
playing
outside,
or
playing
indoors
on
carpet
or
hard
flooring.
Toddlers
have
been
selected
as
a
sentinel
(
or
representative)
population
for
turf.

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

Dose
from
incidental
ingestion
of
granulars
from
treated
turf
calculated
using
SOP
1.3.1:
Postapplication
dose
among
toddlers
from
incidental
nondietary
ingestion
of
granulars
in
a
treated
turf
area
(
i.
e.,
those
granular
particles
that
end
up
in
the
mouth
from
a
child
touching
treated
turf
then
putting
their
hands
in
their
mouth).

Dose
from
hand­
to­
mouth
activity
from
treated
turf
calculated
using
SOP
1.3.2:
Postapplication
dose
among
toddlers
from
incidental
nondietary
ingestion
of
pesticide
residues
on
treated
turf
from
hand­
to­
mouth
transfer
(
i.
e.,
those
residues
that
end
up
in
the
mouth
from
a
child
touching
turf
and
then
putting
their
hands
in
their
mouth);

Dose
from
object­
to­
mouth
activity
from
treated
turf
calculated
using
SOP
1.3.3:
Postapplication
dose
among
toddlers
from
incidental
nondietary
ingestion
of
pesticide
residues
on
treated
turf
from
object­
to­
mouth
transfer
(
i.
e.,
those
residues
that
end
up
in
the
mouth
from
a
child
mouthing
a
handful
of
treated
turf);
and

Dose
from
soil
ingestion
activity
from
treated
turf
calculated
using
SOP
1.3.4:
Postapplication
dose
among
toddlers
from
incidental
nondietary
ingestion
of
pesticide
residues
from
ingesting
soil
in
a
treated
turf
area
(
i.
e.,
those
soil
residues
that
end
up
in
the
mouth
from
a
child
touching
treated
soil
and
turf
then
putting
their
hands
in
their
mouth).

The
detailed
residential
postapplication
calculations
are
presented
in
Appendix
B
of
this
document.

2.3.2
Data
&
Assumptions
for
Residential
Noncancer
Postapplication
Exposure
Scenarios
29
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
residential
noncancer
postapplication
risk
assessments.
Each
assumption
and
factor
are
detailed
below.

The
assumptions
and
factors
used
in
the
risk
calculations
are
consistent
with
current
Agency
Standard
Operating
Procedures
for
completing
residential
exposure
assessments
(
i.
e.,
SOPs
For
Residential
Exposure
Assessment5).
[
Note:
More
detail
about
the
origin
of
each
factor
can
be
obtained
in
the
SOP
document
and
associated
documents
such
as
the
Agency's
1999
Overview
document
presented
to
the
FIFRA
SAP.]
The
values
used
in
this
assessment
include:

°
The
Agency
combines
risks
resulting
from
exposures
to
individual
chemicals
when
it
is
likely
they
can
occur
simultaneously
based
on
the
use
pattern
and
the
behavior
associated
with
the
exposed
population.
For
this
residential
postapplication
assessment,
risks
from
individual
exposure
scenarios
resulting
from
an
application
to
turf
are
combined
for
the
toddler
hand­
to­
mouth,
object­
to­
mouth,
and
soil
ingestion
scenarios,
because
they
can
cooccur

°
Exposures
to
children
playing
on
treated
turf
have
been
addressed
using
the
latest
Agency
approaches
for
this
scenario
including:

S
the
TTR
value
at
day
zero
from
the
trifluralin­
specific
turf
transferable
residue
study7
(
MRID
#
457456­
01)
was
used
in
each
scenario;

S
3
year
old
toddlers
are
expected
to
weigh
15
kg;

S
short­
term
hand­
to­
mouth
exposures
are
based
on
a
frequency
of
20
events/
hour;

S
a
surface
area
per
event
of
20
cm2
representing
the
palmar
surfaces
of
three
fingers
is
used
for
short­
term
exposure
durations;

S
saliva
extraction
efficiency7
is
50
percent
 
meaning
that
every
time
the
hand
goes
in
the
mouth
approximately
½
of
the
residues
on
the
hand
are
removed;

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

S
exposure
durations
are
expected
to
be
2
hours
based
on
information
in
the
Agency's
Exposure
Factors
Handbook;

S
soil
residues
are
contained
in
the
top
centimeter
and
soil
density
is
0.67
mL/
gram;

S
The
assumed
ingestion
rate
of
dry
pesticide
formulations
(
i.
e.,
pellets
and
granules)
is
0.3
grams/
day
for
children
(
age
3
years);

S
hand­
and
object­
to­
mouth,
and
soil
ingestion
are
added
together
to
represent
an
overall
risk
from
exposure
to
turf;
and
S
Postapplication
noncancer
residential
risks
are
based
generally
on
maximum
application
rates
or
values
specified
in
the
SOPs
For
Residential
Exposure
Assessment.

Dissipation
of
Transferable
Residues
of
Benefin
and
Trifluralin
on
Turf
Treated
with
a
Formulation
of
the
Pesticides8
 
EPA
MRID
457456­
01:
The
registrant
submitted
a
transferable
residue
study
of
benefin
and
trifluralin
on
turf.
The
study
is
designed
to
fulfill
the
30
requirements
of
the
EPA
Series
875:
Occupational
and
Residential
Exposure
Test
Guidelines
in
accordance
with
EPA
FIFRA
Good
Laboratory
Practices
Standards.
The
study
was
conducted
from
June
to
September,
1997
at
three
geographical
locations
(
California,
Indiana,
and
Mississippi)
that
are
said
to
be
representative
of
the
climatic
and
turf
growing
conditions
expected
in
the
intended
use­
areas.
Turf
varieties
used
were
common
bermuda
in
California,
tall
fescue
in
Indiana,
and
a
mixture
of
bermuda
and
barnyard
grasses
in
Mississippi.
The
turf
was
mowed
to
its
normal
cutting
height
prior
to
pesticide
application
and
no
irrigation,
mowing,
or
maintenance
chemical
applications
were
performed
for
the
duration
of
the
study.
A
granular
product
containing
1.33%
benefin
and
0.67%
trifluralin
was
applied
to
the
turf
in
a
single
application
at
the
maximum
label
rate
of
two
pounds
benefin
active
ingredient
per
acre
and
one
pound
trifluralin
active
ingredient
per
acre
using
a
drop
granule
spreader
or
an
air­
powered
granular
applicator.
Sampling
was
performed
using
the
California
Roller
technique
and
the
sampling
medium
was
a
percale
cloth
sheet.
Samples
were
collected
at
days
0,
1,
2,
4,
and
7
following
application.
For
trifluralin,
the
study
limit
of
detection
(
LOD)
was
0.001

g/
cm2
and
the
limit
of
quantitation
(
LOQ)
was
0.003

g/
cm2.
Initial
transferable
residues
of
trifluralin
were
less
than
the
LOQ
and
ranged
from
not
detectable
to
0.002

g/
cm2.
The
average
transferable
residues
at
day
0
were
0.0011

g/
cm2,
just
slightly
higher
than
the
limit
of
detection.
After
day
0,
no
residues
were
detectable.

2.3.3
Residential
Postapplication
Exposure
and
Noncancer
Risk
Estimates
The
residential
postapplication
exposure
and
noncancer
risk
calculations
are
presented
in
this
section.
Noncancer
risks
were
calculated
using
the
Margin
of
Exposure
(
MOE),
which
is
a
ratio
of
the
daily
dose
to
the
toxicological
endpoint
of
concern.
Exposures
were
calculated
by
considering
the
potential
sources
of
exposure
then
calculating
nondietary
ingestion
exposures
to
toddlers.
The
major
difference
with
residential
risk
assessments
is
that
the
uncertainty
factor
which
defines
the
level
of
risk
concern
also
has
to
consider
application
of
the
additional
FQPA
safety
factor
specified
by
the
legislation.
The
overall
uncertainty
factor
applied
to
trifluralin
for
residential
postapplication
risk
assessments
is
100.

Nondietary
Ingestion
Exposure
From
Treated
Turf:
Nondietary
ingestion
exposure
levels
from
turf
are
calculated
using
the
following
equations.

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

ADD
=
(
TTR
0
*
SA
*
FQ
*
ET
*
SE
*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day)
TTRt
=
turf
transferable
residue
on
day
"
0"
(
0.0033

g/
cm2
)
SA
=
surface
area
of
the
hands
(
20
cm2/
event)
FQ
=
frequency
of
hand­
to­
mouth
activity
(
20
events/
hr)
ET
=
exposure
time
(
2
hr/
day)
SE
=
extraction
by
saliva
(
50%)
31
CF1
=
weight
unit
conversion
factor
to
convert

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

g)
BW
=
body
weight
(
15
kg)

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

ADD
=
(
TTR
0
*
IgR*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day)
TTRt
=
turf
transferable
residue
on
day
"
0"
(
0.0033

g/
cm2)
IgR
=
ingestion
rate
of
grass
(
25
cm2/
day)
CF1
=
weight
unit
conversion
factor
to
convert
the

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

g)
BW
=
body
weight
(
15
kg)

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

ADD
=
(
SR
0
*
IgR
*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day)
SR0t
=
soil
residue
on
day
"
0"
(
0.0022

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

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

g)
BW
=
body
weight
(
15
kg)

and
SRt
=
TTRt
*
F
*
CF2
Where:
TTRt
=
turf
transferable
residue
on
day
"
0"
(
0.0033

g/
cm2)
F
=
fraction
of
ai
available
in
uppermost
cm
of
soil
(
1
fraction/
cm)
CF2
=
volume
to
weight
unit
conversion
factor
to
convert
the
volume
units
(
cm3)
to
weight
units
for
the
SR
value
(
U.
S.
EPA,
1992)
(
0.67
cm3/
g
soil)

Residential
Postapplication
Noncancer
Short­
Term
Oral
Risk
Calculations:
For
postapplication
oral
exposures
to
toddlers
from
contact
with
treated
turfgrass
and
soil,
the
margin
of
exposure
(
MOE)
is
calculated
as
follows:

Oral
MOE
=
Short­
Term
Incidental
Oral
NOAEL
Exposure
Dose
32
Episodic
Exposure
From
Ingesting
Granules
or
Pellets:
The
Agency
assesses
risks
to
toddlers
resulting
from
incidental
ingestion
of
pesticide
granules
or
pellets
in
pesticide­
treated
residential
areas.
Since
this
exposure
is
likely
to
occur,
at
most,
only
once
following
a
residential
application,
the
acute
dietary
NOAEL
toxicological
endpoint
of
concern
is
used
to
assess
the
risks.
The
following
illustrates
the
approach
used
to
calculate
the
nondietary
ingestion
exposures
that
are
attributable
to
toddlers
ingesting
pesticide
granules
or
pellets:

Incidental
ingestion
of
granules
from
pesticide­
treated
residential
areas
(
toddler)

ADD
=
IgR*
F*
CF1/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day)
IgR
=
ingestion
rate
of
dry
pesticide
formulation
(
0.3
g/
day)
F
=
fraction
of
ai
in
dry
formulation
(
0.0175
unitless)
CF1
=
weight
unit
conversion
factor
to
convert
g
units
in
the
ingestion
rate
value
to
mg
for
the
daily
exposure
(
1,000
mg/
g)
BW
=
body
weight
(
15
kg)

Residential
Postapplication
Noncancer
Acute
Oral
Risk
Calculations:
For
postapplication
exposures
to
toddlers
from
a
one­
time
incident
involving
ingestion
of
pesticide
granules,
the
margin
of
exposure
(
MOE)
is
calculated
as
follows:

Oral
MOE
=
Acute
Dietary
NOAEL
Exposure
Dose
However,
no
acute
dietary
endpoint
of
concern
for
trifluralin
was
identified
for
the
general
population,
including
infants
and
toddlers,
therefore
no
acute
oral
risks
were
assessed
for
toddlers
ingesting
pesticide
granules.

Noncancer
Postapplication
Risk
Summary:
A
summary
of
the
results
for
each
exposure
scenario
is
also
provided
below
in
Table
8.
In
addition,
the
noncancer
residential
risk
calculations
for
the
trifluralin
assessment
are
included
in
Appendix
A:
Table
A4:
NonCancer
Postapplication
Risk
Assessment
for
Trifluralin.

The
Agency
has
addressed
residential
postapplication
exposures
to
trifluralin
using
the
standard
set
of
scenarios
that
are
prescribed
in
current
guidance.
There
are
many
issues
associated
with
the
development
of
these
scenarios
and,
in
general,
residential
exposure
methods.
The
shortterm
incidental
oral
endpoint
of
10
mg/
kg/
day
was
used
for
the
hand­
to­
mouth,
object­
to­
mouth,
soil
ingestion
scenarios,
granular
ingestion
since
these
are
oral
exposures.
The
FQPA
safety
factor
was
reduced
to
1x
for
all
residential
populations2.
The
target
MOE
for
the
oral
short­
term
exposures
is
100.
33
The
calculations
of
short­
term
oral
risk
indicate
that
oral
MOEs
are
more
than
100
for
all
of
the
assessed
exposure
scenarios.

Table
8:
Residential
Risk
Estimates
for
Postapplication
Exposure
to
Trifluralin
Exposure
Scenario
Route
of
Exposure
Population
Application
Ratea
MOEb
Short­
term
Postapplication
Exposures
Outdoors
Hand
to
Mouth
Activity
on
Turfc
Oral
Toddler
3.0
lb
ai/
acre
110,000
Object
to
Mouth
Activity
on
Turfd
Oral
Toddler
3.0
lb
ai/
acre
1,800,000
Incidental
Soil
Ingestione
Oral
Toddler
3.0
lb
ai/
acre
680,000,000
Incidental
Ingestion
of
Granulesf
Oral
Toddler
1.75
%
ai
NA
Footnotes:

a
Application
rates
represent
maximum
label
rates
from
current
EPA
registered
labels
(
Granular
rate
is
3.0
lb
ai/
acre),
except
for
ingestion
of
granules
where
the
highest
percent
active
ingredient
product
is
utilized.
b
MOEs
calculated
using
residues
which
would
be
found
on
day
of
treatment.
Short­
term
Oral
MOE
(
S­
T)
=
Short­
term
Incidental
Oral
NOAEL
(
10
mg/
kg/
day
/
short­
term
Oral
Dose
(
mg/
kg/
day)
with
a
target
MOE
of
100;
c
Hand­
to­
mouth
Dose
Calculation:
oral
dose
to
child
(
1­
6
year
old)
on
the
day
of
treatment
(
mg/
kg/
day)
=
TTR
at
day
0
normalized
to
application
rate
(
0.0033
ug/
cm2)
x
median
surface
area
for
1­
3
fingers
(
20
cm2/
event)
x
hand­
tomouth
rate
(
20
events/
hour)
x
exposure.
time
(
2
hr/
day)
x
50%
saliva
extraction
factor
x
0.001
mg/
µ
g]
/
bw
(
15
kg
child).
d
Object
to
Mouth
Activity
on
­
Turf
Dose
Calculation:
oral
dose
to
child
(
1­
6
year
old)
on
the
day
of
treatment
=
TTR
at
day
0
normalized
to
application
rate
(
0.0033
ug/
cm2)
x
median
surface
area
for
1­
3
fingers
(
25
cm2/
event)
x
hand­
tomouth
rate
(
20
events/
hour)
x
0.001
mg/
µ
g]]
/
bw
(
15
kg
child).
e
Incidental
Soil
ingestion
­
Dose
Calculation:
oral
dose
to
child
(
1­
6
year
old)
on
the
day
of
treatment
(
mg/
kg/
day)
=
[
TTR
at
day
0
normalized
to
application
rate
(
0.0033
ug/
cm2)
x
fraction
of
residue
retained
on
uppermost
1
cm
of
soil
(
100%
or
1.0/
cm)
x
0.67
cm3/
g
soil
conversion
factor]
x
100
mg/
day
ingestion
rate
x
1.0E­
06
g/

g
conversion
factor]
/
bw
(
15
kg).
Note:
Assumptions
used
in
dose
calculations
(
e.
g.,
transfer
coefficients)
are
from
Residential
SOPs
(
revised
2/
01).

Combined
Risk
Assessment
for
Residential
Scenarios
The
Agency
combines
risk
values
resulting
from
separate
postapplication
exposure
scenarios
when
it
is
likely
they
can
occur
simultaneously
based
on
the
use­
pattern
and
the
behavior
associated
with
the
exposed
population.
For
trifluralin,
HED
combined
risk
values
(
i.
e.,
MOEs)
for
postapplication
exposures
to
toddlers
associated
with
turf
applications
by
combining
risks
from
oral
exposures
via
transfer
of
residues
from
turf
to
hands
to
mouth
with
risks
from
oral
exposures
via
transfer
from
turf
to
directly
to
mouth,
and
risks
from
oral
exposures
via
incidental
soil
ingestion.

The
combined
risk
assessment
was
calculated
as
follows:

Combined
MOE
=
NOAEL/(
ADD
hand­
to­
mouth
+
ADD
object­
to­
mouth
+
ADD
incidental
soil
ingestion)
34
The
combined
MOE
for
the
above
scenario
is
180
(
see
Table
9)
and
is
greater
than
the
target
MOE
of
100
and
thus
is
not
a
risk
concern.

Table
9:
Trifluralin
Residential
Scenarios
for
Combined
Risk
Estimates
Postapplication
Exposure
Scenario
Margins
of
Exposure
(
MOEs)
(
UF=
100)
Short­
Term
Oral
(
Non­
Dietary)
Total
Non­
Dietary
Riska
Toddler
Turf:
granules
on
turf
(
3
lb
ai/
acre)
Hand
to
Mouth
110,000
110,000
Object
to
Mouth
1,800,000
Incidental
Soil
Ingestion
680,000,000
2.4
Residential
Postapplication
Cancer
Exposures
and
Risks
2.4.1
Residential
Postapplication
Cancer
Exposure
Scenarios
HED
has
determined
that
there
are
potential
postapplication
exposures
to
residents
entering
the
areas
where
trifluralin
has
been
applied.
Although
postapplication
exposures
to
youths
and
toddlers
are
expected,
when
assessing
cancer
risk,
the
only
postapplication
residential
scenarios
that
are
applicable,
using
the
current
methods,
are
the
following:

S
Dermal
exposure
to
residues
on
lawns
(
adults);

S
Dermal
exposure
to
golf
course
turfgrass
(
adults);
and
S
Dermal
exposure
in
home
vegetable
gardens.

2.4.2
Residential
Postapplication
Cancer
Trifluralin
Exposure
and
Risk
Calculations
The
Agency
has
trifluralin­
specific
turf
transferrable
residue
data
upon
which
to
base
the
postapplication
cancer
assessment
resulting
from
dermal
exposures
to
adults
in
residential
settings.

For
cancer
assessments,
it
is
necessary
to
estimate
the
number
of
days
per
year
an
adult
would
be
exposed
to
a
treated
surface.
Trifluralin­
specific
turf
transferable
residue
data
indicate
that
residues
are
not
detectable
after
the
day
of
application
and
two
applications
are
permitted
each
year.
Therefore
for
postapplication
exposures
to
residential
turfgrass
and
golf
course
turfgrass,
and
for
postapplication
exposures
to
residential
vegetable
gardens,
EPA
estimated
cancer
risks
to
adults
using
the
assumption
that
adults
might
be
exposed
on
the
day
of
application
(
day
zero)
following
both
the
permitted
applications
each
year.

For
the
exposure
duration,
standard
default
values5
were
used:

S
Two
hours
of
exposure
while
exercising
on
a
treated
lawn;
35
S
Four
hours
of
exposure
while
playing
golf;
and
S
Forty
minutes
of
exposure
while
working
in
a
vegetable
garden.

Exposure
duration
was
assumed
to
be
50
years
in
a
70
year
lifespan.

The
exposure
length
(
hours/
day)
and
exposure
frequency
(
days/
year)
assumptions
are
assumed
to
be
worst­
case,
since
it
is
unlikely
that
B
for
50
years
B
an
adult
would
spend:

S
two
hours
exercising
on
a
treated
lawn
on
day
0
for
two
applications
per
year;

S
4
hours
playing
golf
on
a
treated
golf
course
on
day
0
for
two
applications
per
year;
or
S
2/
3
hours
working
in
the
vegetable
garden
on
day
0
for
two
applications
per
year.

In
addition,
the
label
recommends
watering­
in
following
application,
which
would
further
reduce
the
potential
exposure
in
treated
areas.

For
the
postapplication
cancer
risk
assessment,
EPA
used
the
following
transfer
coeffients:

S
7300
for
exposures
to
lawns
while
exercising;
(
This
is
the
transfer
coefficient
in
the
revised
Residential
Standard
Operating
Procedures
for
intermediate­
term
B
and
presumably
long­
term
B
exposures
by
adults
to
turfgrass.
5)

S
500
for
exposures
to
treated
turfgrass
while
golfing;
(
This
is
the
transfer
coefficient
in
the
draft
standard
operating
procedure
for
golfer
exposure
assessment
for
adults
and
children
and
has
been
used
in
other
golfer
exposure
assessments.)

S
1000
for
exposures
to
treated
vegetables
in
a
residential
garden.
(
This
is
the
transfer
coefficient
in
the
Agricultural
Default
Transfer
Coefficient
SOP10
as
high
exposure
to
fruiting
vegetables.)

Postapplication
cancer
risks
resulting
from
exposures
to
trifluralin
were
calculated
using
a
linear
low­
dose
extrapolation
approach
in
which
a
Lifetime
Average
Daily
Dermal
Dose
(
LADD)
is
first
calculated
and
then
compared
with
a
Q1*
that
has
been
calculated
for
trifluralin
based
on
dose
response
data
(
Q1*
=
5.79
x
10­
3
(
mg/
kg/
day)­
1).
Absorbed
average
daily
dermal
dose
(
ADD)
levels
were
used
as
the
basis
for
calculating
the
LADD
values.
LADD
values
were
then
calculated
and
compared
to
the
Q1*
to
obtain
cancer
risk
estimates.

Lifetime
Average
Daily
Dose:
To
calculate
the
carcinogenic
risk
from
absorbed
average
daily
dermal
dose,
the
values
must
be
amortized
over
the
lifetime
of
residential
handlers.
Current
use
patterns
indicate
that
application
occurs
only
a
few
times
per
year.
36
LADD
mg
ai
kg/
day

Total
Daily
Dose
mg
ai
kg/
day
x
days
exposed
365
days
per
year
x
50
years
exposed
70
year
lifetime
Cancer
Risk

LADD
mg
ai
kg/
day
x
Q
1

LADD
values
were
calculated
using
the
following
equation:

Where:

Lifetime
Average
Daily
Dose
=
The
amount
as
absorbed
dose
received
from
exposure
to
a
pesticide
or
degradate
in
a
given
scenario
over
a
lifetime
(
mg/
kg/
day,
also
referred
to
as
LADD);
Average
Daily
Dermal
Dose
=
The
amount
as
absorbed
dose
received
from
dermal
and
inhalation
exposure
to
a
pesticide
or
degradate
in
a
given
scenario
on
a
daily
basis
(
mg/
kg/
day,
also
referred
to
as
ADD);
Exposure
Frequency
=
The
annual
frequency
of
exposure
to
an
individual
(
days/
year);
Exposure
Duration
=
The
amount
of
a
lifetime
that
an
individual
is
exposed
(
50
years);
and
Lifetime
=
The
average
life
expectancy
of
an
individual
(
70
years).

Cancer
Risks
:
Cancer
risk
calculations
were
completed
by
comparing
the
LADD
values
to
the
Q1*
for
trifluralin
(
Q1*
=
5.97
x
10­
3
(
mg/
kg/
day)­
1).
Individual
cancer
risks
were
calculated
using
the
following
equation:

Where:

Cancer
Risk
=
Probability
of
excess
cancer
cases
over
a
lifetime
(
unitless);
Lifetime
Average
Daily
Dose
=
The
amount
as
absorbed
dermal
dose
received
from
exposure
to
a
pesticide
or
degradate
in
a
given
scenario
over
a
lifetime
(
mg//
kg/
day);
and
Q1*
=
Quantitative
dose
response
factor
used
for
linear,
lowdose
response
cancer
risk
calculations
(
mg/
kg/
day)­
1.

Table
10
presents
the
residential
lifetime
average
daily
doses
and
cancer
risks
associated
with
postapplication
exposures
to
trifluralin.

Summary
of
Cancer
Risk
Concerns
for
Residential
Postapplication
HED
has
defined
a
range
of
acceptable
cancer
risks
based
on
a
policy
memorandum
issued
in
1996
by
then
Office
of
Pesticide
Programs
director,
Mr.
Dan
Barolo.
This
memo
refers
to
a
predetermined
quantified
"
level
of
concern"
for
residential
carcinogenic
risk.
In
summary,
this
policy
memo
indicates
risks
less
than
1
x
10­
6
are
not
considered
to
be
of
concern
and
require
no
risk
management
action.
Risks
greater
than
1
x
10­
6
for
the
general
population
are
considered
to
be
of
concern.
37
Dermal
contact
with
residential
turf
for
adults
when
assessed
at
two
days
of
exposure
per
year
 
each
on
the
day
of
application
 
had
risks
of
less
than
1
x
10­
6
and
are
not
considered
to
be
a
risk
concern.
Dermal
contact
with
golf
course
turfgrass
for
adults
when
assessed
at
two
days
of
exposure
per
year
 
each
on
the
day
of
application
 
had
risks
less
than
1
x
10­
6
and
are
not
considered
to
be
of
concern.
Dermal
contact
with
vegetable
gardens
for
adults
when
assessed
at
two
days
of
exposure
per
year
 
each
on
the
day
of
application
after
sprays
have
dried
 
had
risks
of
less
than
1
x
10­
6
and
are
not
considered
to
be
a
risk
concern.
38
Table
10.
Residential
Postapplication
Scenarios
and
Cancer
Risks
from
Trifluralin
Exposure
Scenario
Application
Rate
(
lb
ai/
acre)
a
TTR/
DFR
(

g/
cm2)
b
Transfer
Coefficient
(
Tc)

(
cm2/
hr)
Exposure
Time
(
ET)

(
hrs/
day)
ADD
(
mg/
kg/
day)
c
Days
of
Exposure
LADD
(
mg/
kg/
day)
d
Cancer
Riske
Dermal
contact
with
turf
(
adults)
3.0
0.0033
(
at
day
0)
7300
2
2.06
x
10­
5
2
8.08
x
10­
8
4.7
x
10­
10
Dermal
contact
with
golf
course
turfgrass
(
adults)
0.0033
(
at
day
0)
500
4
2.83
x
10­
6
2
1.11
x
10­
8
6.4
x
10­
11
Dermal
contact
with
vegetable
gardens
(
adults)
4.0
0.0044
(
at
day
0)
1000
0.67
1.26
x
10­
6
2
7.42
x
10­
8
4.3
x
10­
10
a
Application
rate
for
turf
is
the
maximum
label
rate
for
turfgrass
use
patterns;
application
rate
for
vegetable
gardens
is
maximum
label
rate
for
use
on
vegetable
gardens.

b
Turf
transfer
residue
at
day
zero
(

g/
cm2)
=
[
AR
(
3
lbs
ai/
A)
*
TTR
residue
on
day
0
from
the
trifluralin­
specific
study;
Dislodgeable
foliar
residue
for
vegetable
gardens
at
day
zero
(

g/
cm2)
=
[
AR
(
4
lbs
ai/
A)
*
TTR
residue
on
day
0
from
the
trifluralin­
specific
study;

c
Average
daily
dermal
dose
(
ADD)
(
mg/
kg/
day)
=
[
DFR/
TTR
(

g/
cm2)
*
TC
(
cm2/
hr)
*
mg/
1,000

g
*
ET
(
hrs/
day)
*
Dermal
Absorption
(
3%)]
/
[
BW
(
70
kg)]

d
Lifetime
average
daily
dose
(
LADD)
=
Average
Daily
Dermal
Dose
(
mg/
kg/
day)
*
(
number
of
days
of
exposure
per
year
/
365
days/
year)
*
(
50
years
exposed
/
70
years
in
a
lifetime).

e
Cancer
Risk
=
LADD
(
mg/
kg/
day)
x
Q1*
(
mg/
kg/
day)
where
Q1*
=
0.00579.
39
2.4
Combined
Residential
Handler
and
Postapplication
Exposures
and
Risks
The
Agency
combines
risk
values
resulting
from
separate
exposure
scenarios
when
it
is
likely
they
can
occur
simultaneously
based
on
the
use­
pattern
and
the
behavior
associated
with
the
exposed
population.
For
trifluralin,
HED
combined
cancer
risk
values
for
residential
handler
and
residential
postapplication
exposures
associated
with
turf
applications.
(
Note
that
since
both
the
residential
handler
and
residential
postapplication
exposures
were
estimated
using
a
worse­
case
rangefinder
approach,
combining
these
risk
values
may
result
in
exaggerated
cancer
risks.)
The
combined
handler
plus
postapplication
cancer
risk
associated
with
applications
to
residential
turfgrass
is
5.4
x10­
7.
This
below
EPA's
level
of
concern
for
cancer.
Note
that
combining
shortterm
risks
was
not
done,
since
there
are
no
short­
term
postapplication
risks
because
there
is
no
short­
term
dermal
endpoint
of
concern.

3.0
Trifluralin
Poisoning
Incidents
Information
HED
tracks
pesticide­
related
incidents
involving
humans
through
four
main
resources:

$
OPP
Incident
Data
System
(
IDS)

$
Poison
Control
Centers
$
California
Department
of
Pesticide
Regulation
$
National
Pesticide
Information
Center
(
NPIC)

OPP
Incident
Data
System
(
IDS):
The
Office
of
Pesticide
Programs
(
OPP)
Incident
Data
System
consists
of
reports
of
incidents
from
various
sources,
including
registrants,
other
federal
and
state
health
and
environmental
agencies
and
individual
consumers,
submitted
to
OPP
since
1992.
Reports
submitted
to
the
Incident
Data
System
represent
anecdotal
reports
or
allegations
only,
unless
otherwise
stated.
Typically
no
conclusions
can
be
drawn
implicating
the
pesticide
as
a
cause
of
any
of
the
reported
health
effects.
Nevertheless,
sometimes
with
enough
cases
and/
or
enough
documentation
risk
mitigation
measures
may
be
suggested.
For
trifluralin,
it
appears
that
the
majority
of
cases
involved
skin
and
eye
illnesses.

Poison
Control
Centers:
As
the
result
of
a
data
purchase
by
EPA,
Office
of
Pesticide
Programs
received
Poison
Control
Center
data
covering
the
years
1993
through
1998
for
all
pesticides.
Most
of
the
national
Poison
Control
Centers
(
PCCs)
participate
in
a
national
data
collection
system,
the
Toxic
Exposure
Surveillance
System
which
obtains
data
from
about
65­
70
centers
at
hospitals
and
universities.
PCCs
provide
telephone
consultation
for
individuals
and
health
care
providers
on
suspected
poisonings,
involving
drugs,
household
products,
pesticides,
etc.
Poison
Control
Center
data
indicates
that,
in
general,
trifluralin
is
less
likely
to
cause
minor,
moderate,
or
life­
threatening
symptoms
than
other
pesticides,
except
among
nonoccupational
cases
where
moderate
effects
are
more
likely.
There
were
no
major
or
life­
threatening
cases
or
cases
requiring
hospitalization
or
intensive
care,
except
for
one
case
involving
a
two
year
old
child
who
ingested
trifluralin
and
was
hospitalized
even
through
asymptomatic.
It
appears
likely
this
case
was
kept
in
the
hospital
overnight
for
observation.
Symptoms
most
commonly
reported
in
ten
or
more
reports
were
eye
irritation/
pain
(
25
reports),
nausea
(
16
reports),
vomiting
(
13
reports),
and
skin
irritation/
pain
(
10
reports).
Of
the
symptomatic
cases,
one­
quarter
involved
exposure
to
residue
rather
than
direct
spray
or
spill.
40
California
Department
of
Pesticide
Regulation:
California
has
collected
uniform
data
on
suspected
pesticide
poisonings
since
1982.
Physicians
are
required,
by
statute,
to
report
to
their
local
health
officer
all
occurrences
of
illness
suspected
of
being
related
to
exposure
to
pesticides.
The
majority
of
the
incidents
involve
workers.
Information
on
exposure
(
worker
activity),
type
of
illness
(
systemic,
eye,
skin,
eye/
skin
and
respiratory),
likelihood
of
a
causal
relationship,
and
number
of
days
off
work
and
in
the
hospital
are
provided.
Detailed
descriptions
of
77
trifluralin­
related
cases
submitted
to
the
California
Pesticide
Illness
Surveillance
Program
(
1982­
2001)
were
reviewed.
In
57
of
these
cases,
trifluralin
was
used
alone
or
was
judged
to
be
responsible
for
the
health
effects.
Only
cases
with
a
definite,
probable
or
possible
relationship
were
reviewed.
Trifluralin
ranked
72nd
as
a
cause
of
systemic
poisoning
in
California
based
on
data
for
1982
through
2001.
Pesticide
handler
(
i.
e.,
mixer/
loader
and
applicator)
were
associated
with
31
exposure
incidents
and
field
workers
were
associated
with
12
incidents.
The
reported
illnesses
included
symptoms
of
conjunctivitis,
swollen
arms,
hand,
and
face
and
a
rash,
eye
irritation,
tearing
and
red
eyes,
headache,
skin
irritation,
and
abdominal
pain.

National
Pesticide
Information
Center
(
NPIC):
NPIC
is
a
toll­
free
information
service
supported
by
the
Office
of
Pesticide
Programs.
A
ranking
has
been
prepared
of
the
top
200
active
ingredients
for
which
telephone
calls
were
received
during
the
calendar
years
of
1984
through­
1991.
The
total
number
of
calls
was
tabulated
for
the
categories
human
incidents,
animal
incidents,
calls
for
information,
and
others.
On
the
list,
trifluralin
was
ranked
53rd
with
75
incidents
involving
humans
and
17
incidents
involving
animals
(
mostly
pets).

Incident
Reported
in
the
Scientific
Literature:
Pentel
et
al.
(
1994)
reported
that
a
sixty­
one
year
old
male
laboratory
supervisor
at
a
chemical
pesticide
company
since
1951
was
patch
tested
for
trifluralin
along
with
eight
other
pesticides.
The
man
had
a
positive
reaction
to
trifluralin.
The
authors
concluded
that
exposure
to
this
chemical
caused
him
to
have
allergic
contact
dermatitis.

Conclusions:
Based
on
California
data
and
the
Incident
Data
System,
it
appears
that
the
majority
of
cases
involved
skin
and
eye
illnesses.
Poison
Control
Center
data
would
tend
to
support
these
results,
dermal
and
ocular
effects
were
some
of
the
most
common
effects
reported.
41
References
1)
Dawson,
J.
(
2001)
Ethoprop.
Review
of
fipronil
granular
mixer/
loader/
applicator
study
(
MRID
452507­
01)
in
bananas
as
a
source
of
surrogate
data
and
accompanying
ethoprop
risk
assessment.
Washington,
D.
C.:
U.
S.
Environmental
Protection
Agency,
Office
of
Pesticide
Programs.
January
5,
2001.

2)
Fricke,
R.
F.
(
2003)
Trifulralin
­
Report
of
the
Hazard
Identification
Assessment
Review
Committee.
Washington,
D.
C.:
U.
S.
Environmental
Protection
Agency,
Office
of
Pesticide
Programs.
May
2,
2003.

3)
U.
S.
EPA
(
1998)
PHED
Surrogate
Exposure
Guide.
Version
1.1.
Health
Effects
Division,
Office
of
Pesticide
Programs,
August
1998.

4)
Bangs,
G.
(
2001)
Summary
of
HED's
Reviews
of
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
Chemical
Handler
Exposure
Studies;
MRID
449722­
01.
Memorandum
from
Gary
Bangs
(
HED)
to
Demson
Fuller
(
Special
Review
and
Reregistration
Division),
April
30,
2001.

5)
U.
S.
EPA
(
1997)
Draft
Standard
Operating
Procedures
(
SOPs)
for
Residential
Exposure
Assessments.
December
1997
with
revisions
stated
in
the
HED
Science
Advisory
Council
for
Exposure,
SOP
12.
Recommended
Revisions
to
the
Standard
Operating
Procedures
(
SOPs)
for
Residential
Exposure
Assessments.
February
22,
2001.

6)
U.
S.
EPA
(
1998)
HED
Exposure
Science
Advisory
Council
SOP
Memo
No.
7.
Use
of
Values
from
the
PHED
Surrogate
Table
and
Chemical
Specific
Data.
Health
Effects
Division,
Office
of
Pesticide
Programs,
December
1998.

7)
Clothier,
J.
M.
(
2000)
Dermal
Transfer
Efficiency
of
Pesticides
from
Turf
Grass
to
Dry
and
Wetted
Palms.
U.
S.
Environmental
Protection
Agency,
National
Exposure
Research
Laboratory,
Research
Triangle
Park,
NC.

8)
Trifluralin.
Dissipation
of
transferable
residues
of
benefin
and
trifluralin
on
turf
treated
with
a
formulation
of
the
pesticides
(
MRID
457456­
01).
Washington,
D.
C.:
U.
S.
Environmental
Protection
Agency,
Office
of
Pesticide
Programs.
Study
completed
July
26,
2002.

9)
U.
S.
EPA
(
2000)
HED
Science
Advisory
Council
for
Exposure,
SOP
003.1.
Agricultural
Default
Transfer
Coefficients.
Health
Effects
Division,
Office
of
Pesticide
Programs,
August
7,
2000.

10)
U.
S.
EPA
(
2000)
HED
Science
Advisory
Council
for
Exposure,
SOP
003.1.
Agricultural
Default
Transfer
Coefficients.
Health
Effects
Division,
Office
of
Pesticide
Programs,
August
7,
2000.
42
Appendices
43
Table
A1:
Sources
of
Exposure
Data
Used
in
the
Short­
Term
Residential
Trifluralin
Handler
Exposure
and
Risk
Calculations
Exposure
Scenario
(
Scenario
#)
Data
Source
Standard
Assumptiona
Commentsb
Mixer/
Loader/
Applicator
Descriptors
Loading/
applying
granules
with
a
belly
grinder
(
1)
PHED
V1.1
0.5
acres/
day
for
use
on
turf,
1000
ft2/
day
for
use
on
ornamentals
(
both
pre­
plant
and
post­
plant
)
and
vegetable
gardens.
Baseline:
Dermal
data
=
A,
B,
C
grades;
20­
45
replicates
(
medium
confidence).
Hands
data
=
A,
B,
C
grades;
23
replicates
(
medium
confidence).
Inhalation
data
=
A,
B
grades;
40
replicates
(
high
confidence).

PPE
and
Engineering
Controls:
Not
required
for
assessment.

Loading/
applying
granules
with
a
push­
type
spreader
(
2)
PHED
V1.1
0.5
acres/
day
for
use
on
turf,
1000
ft2/
day
for
use
on
ornamentals
(
both
pre­
plant
and
post­
plant
)
and
vegetable
gardens.
Baseline:
Dermal
data
=
C
grade;
0­
15
replicates
(
low
confidence).
Hands
data
=
C
grades;
15
replicates
(
low
confidence);
Inhalation
data
=
B
grades;
15
replicates
(
high
confidence).

PPE
and
Engineering
Controls:
Not
required
for
assessment.

Loading/
applying
granules
using
a
spoon,
measuring
scoop,
shaker
can,
or
by
hand
(
3)
Review
of
fipronil
granular
mixer/
loader/
applicator
study
as
a
source
of
surrogate
data,

MRID
452507­
01.
J.
Dawson
memo,
D270065,
1/
5/
01.
1000
ft2/
day
for
use
on
ornamentals
(
both
pre­
plant
and
post­
plant
),
turf
and
vegetable
gardens.
50
bushes/
day
for
use
on
roses.
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:
Not
required
for
assessment.

Mixing/
loading/
applying
liquids
using
a
hose
end
sprayer
(
4)
ORETF
Chemical
Handler
Exposure
Studies
1000
ft2/
day
Baseline:
Dermal,
inhalation,
and
hands
=
A
grade.
Dermal,
inhalation,
and
hands
=

20
replicates
each.
High
confidence
in
all
data.

PPE
and
Engineering
Controls:
Not
required
for
assessment.

Mixing/
loading/
applying
liquids
with
a
low
pressure
handwand
(
5)
ORETF
Chemical
Handler
Exposure
Studies
5
gallons
spray/
day
Baseline:
Dermal,
inhalation,
and
hands
=
A
grade.
Dermal,
inhalation,
and
hands
=

20
replicates
each.
High
confidence
in
all
data.

PPE
and
Engineering
Controls:
Not
required
for
assessment.

Mixing/
loading/
applying
liquids
with
a
backpack
sprayer
(
6)
PHED
V1.1
5
gallons
spray/
day
Baseline:
Dermal
data
=
A,
B
grades;
9­
11
replicates
(
low
confidence).
Hands
data
=

C
grade,
11
replicates
(
low
confidence).
Inhalation
data
=
A
grade;
11
replicates
(
low
confidence).

PPE
and
Engineering
Controls:
Not
required
for
assessment.

Applying
trifluralin
impregnated
fabric
squares
to
soil
(
7)
No
data
is
available
for
this
scenario.

Footnotes:

a
Standard
Assumptions
from
Residential
SOPs.

b
"
Best
Available"
grades
are
defined
by
HED
SOP
for
meeting
Subdivision
U
Guidelines.
Best
available
grades
are
assigned
as
follows:
matrices
with
grades
A
and
B
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
and
number
of
replicates.
Data
confidence
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
44
Table
A2:
Margins
of
Exposure
For
Short­
Term
Trifluralin
Residential
Handler
Risk
Assessment
Exposure
Scenario
(
Scenario
#)
Crop
or
Target
Application
Rate
a
Area
Treated
Daily
b
Baseline
Inhalation
Unit
Exposure
(
ug/
lb
ai)
c
Baseline
Inhalation
Exposure
d
Baseline
Inhalation
Dose
e
Baseline
Inhalation
MOE
f
Loading/
applying
granules
with
a
belly
grinder
(
1)
ornamental
(
pre)
20
lbs
ai/
acre
0.023
acres
62
0.029
0.00041
200,000
ornamental
(
post)
4.0
lbs
ai/
acre
0.023
acres
62
0.0057
0.000082
990,000
turf
1.0
lbs
ai/
acre
0.5
acres
62
0.031
0.00044
180,000
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
62
0.0058
0.000083
970,000
Loading/
applying
granules
with
a
push­
type
spreader
(
2)
ornamental
(
pre)
20
lbs
ai/
acre
0.023
acres
0.88
0.00041
0.0000058
14,000,000
ornamental
(
post)
4.0
lbs
ai/
acre
0.023
acres
0.88
0.000081
0.0000012
70,000,000
turf
1.0
lbs
ai/
acre
0.5
acres
0.88
0.00044
0.0000063
13,000,000
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
0.88
0.000083
0.0000012
69,000,000
Loading/
applying
granules
using
a
spoon,
measuring
scoop,
shaker
can,
or
by
hand
(
3)
ornamental
(
pre)
20
lbs
ai/
acre
0.023
acres
45
0.021
0.0003
270,000
ornamental
(
post)
4.0
lbs
ai/
acre
0.023
acres
45
0.0041
0.000059
1,400,000
turf
1.0
lbs
ai/
acre
0.023
acres
45
0.001
0.000015
5,500,000
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
45
0.0042
0.00006
1,300,000
rose
bushes
0.000425
lbs
ai/
bush
50
bushes
45
0.00096
0.000014
5,900,000
Mixing/
loading/
applying
liquids
using
a
hose
end
sprayer
(
4)
flowers,
trees,
shrubs
4.1
lbs
ai/
acre
0.023
acres
1.5
0.00014
0.000002
40,000,000
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
1.5
0.00014
0.000002
40,000,000
Mixing/
loading/
applying
liquids
with
a
low
pressure
handwand
(
5)
flowers,
trees,
shrubs
0.047
lb
ai/
gallon
5
gallons
3.8
0.00089
0.000013
6,300,000
vegetable
gardens
0.047
lb
ai/
gallon
5
gallons
3.8
0.00089
0.000013
6,300,000
Mixing/
loading/
applying
liquids
with
a
backpack
sprayer
(
6)
flowers,
trees,
shrubs
0.047
lb
ai/
gallon
5
gallons
30
0.0071
0.0001
800,000
vegetable
gardens
0.047
lb
ai/
gallon
5
gallons
30
0.0071
0.0001
800,000
Footnotes:

a
Application
Rates
are
based
on
the
maximum
application
rates
listed
on
the
trifluralin
labels.

b
Amount
handled
per
day
are
from
EPA
estimates
of
acres
treated,
or
square
feet
treated,
in
a
single
day
based
on
the
application
method.
For
ready
to
use
formulations,
the
whole
container
is
assumed
to
be
used
in
one
day.

c
Baseline
inhalation
unit
exposure
represents
no
respirator.

d
Daily
Inhalation
Exposure
(

g/
day)
=
(
Inhalation
Unit
Exposure
(

g/
lb
ai)
x
(
1mg/
1000

g)
Conversion
Factor
x
Application
Rate
(
lb
ai/
A)
x
Area
Treated
per
day
(
acres
and
square
feet)).
45
e
Daily
Inhalation
Exposure
(

g/
day)
=
(
Daily
Inhalation
Exposure
(

g/
day)
x
Inhalation
Absorption
Factor
(%))/
Body
Weight
(
70
kg).

f
Short­
term
Inhalation
MOE
=
Inhalation
NOAEL
(
81
mg/
kg/
day)/
Daily
Inhalation
Dose
(
mg/
kg/
day).
46
Table
A3:
Cancer
Risks
For
Trifluralin
Residential
Handler
Risk
Assessment
Exposure
Scenario
Crop
Type
Application
Rate
a
Area
Treated
Daily
b
Baseline
Dermal
Unit
Exposure
(
mg/
lb
ai)
Baseline
Inhalation
Unit
Exposure
(
ug/
lb
ai)
Days
/
Yr
Baseline
Daily
Total
Dose
(
mg/
kg/
day)
Residential
Applicator
Total
Baseline
LADD
(
mg/
kg/
day)
Residential
Applicator
Baseline
Cancer
Risk
Loading/
applying
granules
with
a
belly
grinder
(
1)
ornamental
(
pre)
20
lbs
ai/
acre
0.023
acres
110
62
1
0.022
4.4E­
05
2.5E­
07
ornamental
(
post)
4.0
lbs
ai/
acre
0.023
acres
110
62
1
0.0033
6.5E­
06
3.8E­
08
turf
1.0
lbs
ai/
acre
0.5
acres
110
62
2
0.024
9.4E­
05
5.4E­
07
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
110
62
1
0.0045
8.8E­
06
5.1E­
08
Loading/
applying
granules
with
a
push­
type
spreader
(
2)
ornamental
(
pre)
20
lbs
ai/
acre
0.023
acres
0.67
0.88
1
0.00014
2.7E­
07
1.6E­
09
ornamental
(
post)
4.0
lbs
ai/
acre
0.023
acres
0.67
0.88
1
0.000021
4.0E­
08
2.3E­
10
turf
1.0
lbs
ai/
acre
0.5
acres
0.67
0.88
2
0.00015
5.9E­
07
3.4E­
09
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
0.67
0.88
1
0.000028
5.5E­
08
3.2E­
10
Loading/
applying
granules
using
a
spoon,
measuring
scoop,
shaker
can,
or
by
hand
(
3)
ornamental
(
pre)
20
lbs
ai/
acre
0.023
acres
3.5
45
1
0.00099
1.9E­
06
1.1E­
08
ornamental
(
post)
4.0
lbs
ai/
acre
0.023
acres
3.5
45
1
0.00015
2.9E­
07
1.7E­
09
turf
1.0
lbs
ai/
acre
0.023
acres
3.5
45
2
0.000049
1.9E­
07
1.1E­
09
vegetable
gardens
4.1
lbs
ai/
acre
0.023
acres
3.5
45
1
0.0002
3.9E­
07
2.3E­
09
rose
bushes
0.000425
lb
ai/
bush
50
bushes
3.5
45
1
0.000046
8.9E­
08
5.2E­
10
Mixing/
loading/
applying
liquids
using
a
hose
end
sprayer
(
4)
flowers,
trees,
shrubs,

vegetable
gardens
4.1
lb
ai/
acre
0.023
acres
39
1.5
5
0.0016
1.5E­
05
8.9E­
08
Mixing/
loading/
applying
liquids
with
a
low
pressure
handwand
(
5)
flowers,
trees,
shrubs
0.047
lb
ai/
gal
5
gallons
56
3.8
5
0.0057
5.5E­
05
3.2E­
07
Mixing/
loading/
applying
liquids
with
a
backpack
sprayer
(
6)
flowers,
trees,
shrubs
0.047
lb
ai/
gal
5
gallons
100
30
5
0.01
1.0E­
04
5.8E­
07
Footnotes:

a
Application
Rates
are
based
on
the
typical
application
rates
listed
on
the
trifluralin
labels
when
available.
If
no
typical
rate
was
provided,
maximum
applications
rates
were
used.

b
Amount
handled
per
day
are
from
EPA
estimates
of
acres
treated,
or
square
feet
treated,
in
a
single
day
based
on
the
application
method.
For
ready
to
use
formulations,
the
whole
container
is
assumed
to
be
used
in
one
day.

c
Baseline
inhalation
unit
exposure
represents
no
respirator.
47
Table
A4
­
Short­
Term
Oral
Exposure
from
Hand­
to­
Mouth
Activity
on
Trifluralin
Treated
Turf
Exposure
Scenario
Maximum
Application
Rate
TTR
at
day
0
(
normalized
to
max
appl.
rate)
Surface
Area
(
cm2)
Hand
to
Mouth
(
events/
hr)
Extraction
by
Saliva
Exposure
Time
(
hours)
Body
Weight
(
kg)
Average
Daily
Dose
(
mg/
kg/
day)
MOE
Hand
to
Mouth
(
turf)
3.0lb
ai/
acre
0.0033

g/
cm2
20
20
50%
2
15
0.000088
110,000
Oral
Dose
(
mg/
kg/
day)
TTR(

g/
cm2)
x
CF
(
0.001mg/

g)
x
SA
(
cm2)
x
EXT
x
FQ
(
events/
hr)
x
ET
(
hrs/
day)

BW
(
kg)

Where:

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

TTR
=
turf
transferable
residue
normalized
to
maximum
application
rate
(

g/
cm2)

CF
=
conversion
factor
from

g
to
mg
(
0.001)

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

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

EXT
=
extraction
rate
by
saliva
(
unitless)

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

ET
=
exposure
duration
(
hours/
day)

BW
=
body
weight
(
kg)

Assumptions:

SA
­
The
surface
area
of
1
to
3
finger
is
20
cm2
FQ
­
The
frequency
of
hand­
to­
mouth
events
is
20
events
per
hour
for
short­
term
EXT
­
The
extraction
rate
by
saliva
is
50%.

ET
­
The
time
spent
outdoors
is
2
hours/
day
Endpoint
of
Concern
=
Short­
Term
Incidental
Oral
NOAEL
(
10
mg/
kg/
day)
48
Table
A5
­
Short­
Term
Oral
Exposure
from
Mouthing
Trifluralin
Treated
Turf
Exposure
Scenario
Application
Rate
TTR
at
day
0
(
normalized
to
max
appl.
rate)
Surface
Area
(
cm2)
Body
Weight
(
kg)
Average
Daily
Dose
(
mg/
kg/
day)
MOE
Object
(
turf)
to
Mouth
3.0
lb
ai/
acre
0.0033

g/
cm2
25
15
0.0000055
1,800,000
Short­
Term
Oral
Dose
(
mg/
kg/
day)
=
(
TTRt
*
IgR*
CF1)
/
BW
Where:
ADD
=
average
daily
dose
(
mg/
kg/
day)

TTRt
=
turf
transferable
residue
on
day
"
0"
(

g/
cm2)
normalized
to
maximum
application
rate
IgR
=
ingestion
rate
of
grass
(
25
cm2/
day)

CF1
=
weight
unit
conversion
factor
to
convert
the

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

g)

BW
=
body
weight
(
15
kg)

Endpoint
of
Concern
=
Short­
Term
Incidental
Oral
NOAEL
(
10
mg/
kg/
day)
49
Table
A6
­
Short­
Term
Oral
Exposure
from
Incidental
Soil
Ingestion
Exposure
Scenario
Application
Rate
Application
Rate
Units
%
of
Application
Rate
in
Uppermost
1
cm
of
Soil
(
fraction/
cm)
Ingestion
Rate
(
IgR)
mg/
day
Body
Weight
(
kg)
Average
Daily
Dose
(
mg/
kg/
day)
MOE
Incidental
Soil
Ingestion
3.0lb
ai/
acre
100%
100
15
1.47
x
10­
8
680,000,000
Oral
Dose
=
TTR
(
ug/
cm2)
x
F(
1.0/
cm)
x
IgR(
mg/
day)
x
(
0.67
cm3/
g)
x
(
1E­
6
g/

g)

BW
(
kg)

Where:

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

AR
=
application
rate
(
lb
ai/
A)

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

CF2
=
volume
to
weight
unit
conversion
factor
to
convert
the
volume
units
(
cm3)
to
weight
units
for
the
soil
residue
value
(
0.67
cm3/
g
soil)

CF3
=
weight
unit
conversion
factor
to
convert
the

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

g)

BW
=
body
weight
(
kg)

Assumptions:

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

IgR
­
The
ingestion
rate
of
soil
is
100
mg/
day
Endpoint
of
Concern
=
Short­
Term
Incidental
Oral
NOAEL
(
10
mg/
kg/
day)
50
Table
A8:
Cancer
Risks
For
Trifluralin
Residential
Postapplication
Risk
Assessment
Scenario
TC
cm2/
hr
Hours
of
Exposure
Days
of
Exposure
TTR/
DFR
ug/
cm2
Absorbed
Dose
(
mg/
kg/
day)
LADD
Cancer
Residential
Turfa
­
adults
(
2
days
of
exposure
using
TTR
at
day
0)
7,300
2
2
0.0033
2.06E­
05
8.08E­
08
4.7E­
10
Golf
Course
Turfa
­
adults
(
2
days
of
exposure
using
TTR
at
day
0)
500
4
2
0.0033
2.83E­
06
1.11E­
08
6.4E­
11
Vegetable
gardensa
­
adults
(
2
days
of
exposure
using
DFR
at
day
0)
1,000
0.67
2
0.0044
1.26E­
06
7.42E­
08
4.3E­
10
a
Application
rate
for
turf
is
the
maximum
label
rate
for
turfgrass
use
patterns;
application
rate
for
vegetable
gardens
is
maximum
label
rate
for
use
on
vegetable
gardens.

b
Turf
transfer
residue
at
day
zero
(

g/
cm2)
=
data
from
the
trifluralin­
specific
TTR
study
normalized
to
maximum
application
rate;
Dislodgeable
foliar
residue
for
vegetable
gardens
at
day
zero
(

g/
cm2)
=
data
from
the
trifluralin­
specific
TTR
study
normalized
to
maximum
application
rate;

c
Average
daily
dermal
dose
(
ADD)
(
mg/
kg/
day)
=
[
DFR/
TTR
(

g/
cm2)
*
TC
(
cm2/
hr)
*
mg/
1,000

g
*
ET
(
hrs/
day)
*
Dermal
Absorption
(
3%)]
/
[
BW
(
70
kg)]

d
Lifetime
average
daily
dose
(
LADD)
=
Average
Daily
Dermal
Dose
(
mg/
kg/
day)
*
(
number
of
days
of
exposure
per
year
/
365
days/
year)
*
(
50
years
exposed
/
70
years
in
a
lifetime).

e
Cancer
Risk
=
LADD
(
mg/
kg/
day)
x
Q1*
(
mg/
kg/
day)
where
Q1*
=
0.00579.