UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
December
9,
2005
MEMORANDUM
SUBJECT:
Occupational
and
Residential
Exposure/
Risk
Assessment
of
1,2,4­
Triazole
(
DP
Barcode:
322240;
PC
Code:
600074)

FROM:
Jack
Arthur,
Environmental
Scientist
Registration
Action
Branch
3
Health
Effects
Division
(
7509C)

TO:
Michael
Doherty,
Risk
Assessor
Registration
Action
Branch
2
Health
Effects
Division
(
7509C)

THRU:
Stephen
Dapson,
BSS
Registration
Action
Branch
3
Health
Effects
Division
(
7509C)

HED
has
determined
that
risks
from
the
residues
of
1,2,4­
triazole,
triazole
alanine
and
triazole
acetic
acid
should
be
assessed
for
their
contribution
to
the
risk
resulting
from
the
use
of
1,2,4­
triazole­
derivative
fungicides.
The
U.
S.
Triazole
Task
Force
(
USTTF)
has
submitted
an
assessment
entitled,
"
1,2,4­
Triazole
Aggregate
Exposure
Assessment"
(
Syngenta
Study
T022748­
04,
N.
Heard,
May
20,
2005)
which
includes
an
assessment
of
the
residential
exposure
to
1,2,4­
triazole
from
triazole­
derivative
fungicides.
In
addition,
the
USTTF
presented
an
occupational
handler
and
postapplication
exposure
assessment
to
EPA
(
meeting
held
at
EPA,
June
2,
2003),
which
included
a
hardcopy
submission
of
its
overhead
slides.
This
document
presents
HED's
occupational
and
residential
exposure/
risk
assessment
for
the
use
of
triazole­
derivative
fungicides,
including
references
to
the
USTTF
submissions,
where
appropriate.
Page
2
of
14
1.0
Executive
Summary
The
use
of
1,2,4­
triazole­
derivative
(
T­
D)
fungicides
results
in
potential
occupational
and
residential
exposures
to
certain
break­
down
products
that
are
of
concern
to
HED.
Specifically,
1,2,4­
triazole
(
1,2,4­
T)
can
be
formed
in
soil
following
application
of
T­
D
fungicides.
In
addition,
dermal,
inhalation
and
incidental
oral
exposure
to
a
T­
D
fungicide
can
lead
to
an
absorbed
dose
of
the
parent
compound
which
can
be
metabolically
transformed
to
1,2,4­
triazole.
Two
other
important
degradates
of
T­
D
fungicides,
i.
e.,
triazole
alanine
(
TA)
and
triazole
acetic
acid
(
TAA),
are
primarily
formed
through
metabolic
conversion
in
plant
tissues.
Because
TA
and
TAA
residues
are
believed
to
remain
inside
crop
commodities,
they
are
not
a
concern
for
occupational
or
residential
exposure
scenarios.

A
separate
1,2,4­
T
risk
assessment
is
necessary
because,
under
the
Food
Quality
Protection
Act
(
FQPA),
regulatory
decisions
for
an
individual
T­
D
fungicide
also
must
take
into
account
the
dietary
contribution
of
1,2,4­
T
from
other
T­
D
fungicides
used
on
food
crops
or
in
residential
settings.
This
same
FQPA
concern
is
not
applicable
to
occupational
exposure.
Instead,
it
is
presumed
that
workers
will
be
exposed
only
to
the
1,2,4­
T
contribution
from
a
single
T­
D
fungicide
at
any
given
time.
The
toxicity
endpoints
for
the
particular
parent
T­
D
fungicide
being
assessed
are
considered
to
account
for
the
toxicity
of
any
1,2,4­
T
that
has
formed
in
the
exposed
worker
as
a
result
of
metabolic
conversion.
Under
FQPA,
other
indirect
sources
of
1,2,4­
T
(
i.
e.,
from
food
or
residential
T­
D
fungicide
uses)
are
not
aggregated
with
worker
exposures
to
1,2,4­
T
from
the
use
of
a
single
T­
D
fungicide
in
their
workday
An
assessment
of
residential
exposure
to
1,2,4­
T
was
performed
for
T­
D
fungicide
use
on
turf.
There
are
a
number
of
T­
D
fungicides
currently
registered
for
turf
use,
with
others
in
the
proposal
stage.
Rather
than
assess
each
turf
T­
D
fungicide
individually,
worst­
case
assessments
(
based
on
currently
registered
turf
products,
as
well
as,
a
hypothetical
worst­
case
composite
product)
were
performed
for
residential
handlers
and
postapplication
activities
that
will
stand
as
screens
for
all
currently
registered
turf
products
and,
potentially,
for
any
future
turf
use
registration
requests.

Occupational
Handler/
Postapplication
Exposure
and
Risk
A
separate
1,2,4­
T
assessment
is
not
necessary
(
see
discussion
in
above
section).

Residential
Handler
Residential
handler
risks
from
short­
term
exposure
to
1,2,4­
T
do
not
exceed
HED's
level
of
concern
(
LOC)
for
lawn
use
of
triadimefon
(
the
worst­
case
currently
registered
turf­
use
TD
fungicide).
Likewise,
the
screening
level
assessment,
using
a
composite
of
high­
end
exposure
input
values,
results
in
risks
that
do
not
exceed
HED's
LOC
(
MOEs
range
from
1500
to
6400).
Page
3
of
14
Residential
Postapplication
The
MOEs
for
short­
term
postapplication
exposure
to
the
T­
D
fungicide
turf
product,
triadimefon
are
all
$
1000
for
individual
routes
of
exposure,
and
therefore
do
not
exceed
HED's
level
of
concern.
Likewise,
for
triadimefon,
if
individual
routes
of
exposure
(
e.
g.,
toddler
dermal
and
incidental
ingestion
activities)
are
combined,
the
MOE
is
2200,
and
therefore
does
not
exceed
HED's
LOC.

The
MOEs
for
postapplication
exposure
to
a
hypothetical
screening
level
T­
D
fungicide
are
less
than
1000
for
the
dermal
route
of
exposure
(
e.
g.,
adult
dermal
MOE
=
270;
toddler
dermal
MOE
=
160),
and
therefore
exceed
HED's
LOC.

2.0
Hazard
Summary
The
acute
toxicity
of
1,2,4­
T
is
presented
in
Table
1,
and
a
summary
of
toxicity
endpoints
in
Table
2.
All
residential
exposure
scenarios
are
expected
to
be
short­
term
(
1
­
30
days
duration).

Table
1
Acute
Toxicity
Profile
­
Test
Substance
Note
that
values
on
this
table
are
based
on
submitted
summary
data;
full
study
reports
are
not
available.

Guideline
No.
Study
Type
MRID(
s)
Results
Toxicity
Category
870.1100
Acute
oral
[
rat]
45284004,
45284001
LD50
=
1648­
3080
mg/
kg
III
870.1100
Acute
oral
[
mice]
45284001
LD50
=
3650
mg/
kg
III
870.1100
Acute
oral
[
rabbit]
45324301
LD50
=
666
mg/
kg
III
870.1200
Acute
dermal
[
rat]
45284004
LD50
=
3129­
4200
mg/
kg
III
870.1200
Acute
dermal
[
rabbit]
45324301,
45284006
LD50
=
<
2000
mg/
kg
II
870.1300
Acute
inhalation
[
mice]
45284011
LC50
4
h
=
2200
mg/
m3
870.1300
Acute
inhalation
[
rats]
45284011
LC50
4
h
=
2050
mg/
m3
870.2400
Acute
eye
irritation
[
rabbit]
45284004,
45324301,
45284006
severe
870.2500
Acute
dermal
irritation
[
rabbit]
45284004,
45324301,
45284006
not
irritating
to
slightly
irritating
IV
870.2600
Skin
sensitization
[
species]
No
studies
available
unknown
Page
4
of
14
Table
2
Summary
of
Toxicological
Doses
and
Endpoints
for
Chemical
for
Use
in
Human
Risk
Assessments
Exposure
Scenario
Dose
Used
in
Risk
Assessment,
UF
Special
FQPA
SF
and
Level
of
Concern
for
Risk
Assessment
Study
and
Toxicological
Effects
Acute
Dietary
(
females
13­
49)
NOAEL
=
30
mg/
kg
UF=
1000
Acute
RfD=
0.03
mg/
kg
FQPA
SF
=
1
aPAD
=
acute
RfD
FQPA
SF
=
0.03
mg/
kg/
day
Developmental
Toxicity
study
in
rabbits
LOAEL=
45
mg/
kg
based
on
urinary
tract
malformations
in
fetuses
Acute
Dietary
(
general
population)
NOAEL
=
30
mg/
kg
UF=
1000
Acute
RfD=
0.03
mg/
kg
FQPA
SF
=
1
aPAD
=
acute
RfD
FQPA
SF
=
0.03
mg/
kg/
day
Developmental
Toxicity
study
in
rabbits
LOAEL=
45
mg/
kg
based
clinical
signs
and
mortality
in
does
starting
on
GD
6
or
7
Chronic
Dietary
(
all
populations)
LOAEL
=
15
mg/
kg/
day
UF
=
3000
Chronic
RfD
=
0.005
mg/
kg/
day
FQPA
SF
=
1
cPAD
=
chronic
RfD
FQPA
SF
=
0.005
mg/
kg/
day
Reproductive
Toxicity
study
in
rats
LOAEL
=
15
based
on
decreased
body
weight
in
adult
males,
decreased
body
weight
and
brain
weight
in
offspring
Incidental
Oral
Short
Term
(
1­
30
days)
NOAEL
=
30
mg/
kg/
day
MOE=
1000
FQPA
SF
=
1
Developmental
Toxicity
study
in
rabbits
LOAEL=
45
mg/
kg
based
clinical
signs
and
mortality
in
does
starting
on
GD
6
or
7
Incidental
Oral
Intermediate
or
Long
Term
(
30
days
to
6
months)
LOAEL
=
15
mg/
kg/
day
MOE
=
3000
FQPA
SF
=
1
Reproductive
Toxicity
study
in
rats
LOAEL
=
15
based
on
decreased
body
weight
in
adult
males,
decreased
body
weight
and
brain
weight
in
offspring
Dermal
Short
Term
(
1­
30
days)
NOAEL
=
30
mg/
kg/
day
MOE=
1000
Developmental
Toxicity
study
in
rabbits
LOAEL=
45
mg/
kg
based
clinical
signs
and
mortality
in
does
starting
on
GD
6
or
7
Table
2
Summary
of
Toxicological
Doses
and
Endpoints
for
Chemical
for
Use
in
Human
Risk
Assessments
Exposure
Scenario
Dose
Used
in
Risk
Assessment,
UF
Special
FQPA
SF
and
Level
of
Concern
for
Risk
Assessment
Study
and
Toxicological
Effects
Page
5
of
14
Dermal
Intermediate
or
Long
Term
(
30
days
to
6
months)
LOAEL
=
15
mg/
kg/
day
MOE
=
3000
Reproductive
Toxicity
study
in
rats
LOAEL
=
15
based
on
decreased
body
weight
in
adult
males,
decreased
body
weight
and
brain
weight
in
offspring
Inhalation
Short­
Term
(
1
­
30
days)
NOAEL
=
30
mg/
kg/
day
MOE=
1000
Developmental
Toxicity
study
in
rabbits
LOAEL=
45
mg/
kg
based
clinical
signs
and
mortality
in
does
starting
on
GD
6
or
7
Inhalation
Intermediate
or
Long
Term
(
30
days
to
6
months)
LOAEL
=
15
mg/
kg/
day
MOE
=
3000
Reproductive
Toxicity
study
in
rats
LOAEL
=
15
based
on
decreased
body
weight
in
adult
males,
decreased
body
weight
and
brain
weight
in
offspring
Cancer
(
oral,
dermal,
inhalation)
Classification:
Not
determined
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
3.0
Use
Profile
While
a
number
of
conazole
fungicides
are
registered
for
agricultural
use
sites,
this
assessment
is
limited
to
T­
D
fungicides
that
have
current
or
proposed
registrations
for
residential
uses.
Residential
T­
D
fungicide
uses
include
treatment
of
ornamentals,
treatment
of
wood
that
could
be
used
in
construction
of
decks
and
playground
equipment,
and
treatment
of
lawns.
Lawn
treatment
is
believed
to
represent
the
highest
residential
risk
potential,
and
therefore,
this
assessment
has
been
limited
to
lawn
care
(
turf)
products.
The
following
table
lists
a
number
of
the
T­
D
fungicides
for
which
there
are
currently
registered
or
proposed
turf
uses,
along
with
readily­
available
use
information
and
characteristics
that
are
pertinent
to
the
assessment
of
risks
from
such
uses.

Table
3.
T­
D
Fungicide
Exposure­
Relevant
Characteristics
Page
6
of
14
T­
D
Fungicide
Max.
Single
Application
Rate
(
lb
ai/
acre)
1,2,4­
T/
Parent
Molecular
Weight
Ratio
Mammalian
Metabolic
Conversion
Rate
to
1,2,4­
T
(%)
Max.
Soil
Conversion
Rate
to
1,2,4­
T
(%)
Dermal
Absorption
Factor
(%)

Myclobutanil*
1.761
0.241
10
181
141
Propiconazole*
1.761
0.201
5
23.61
501
Triadimefon*
2.751
(
5.42)
0.241
22
30.71
81
Paclobutrazol*
0.5
0.241
0
2.61
DG
Cyproconazole*
DG
DG
DG
DG
DG
Fenbuconazole*
DG
DG
DG
DG
DG
Tebuconazole**
1.371
0.22
5.4
91
71
Triticonazole**
1.14
0.221
15
6.61
36
Tetraconazole**
1.4
0.191
77
6.61
DG
Bromuconazole**
DG
DG
DG
DG
DG
1.
USTTF.
1,2,4­
Triazole
Aggregate
Exposure
Assessment.
May
20,
2005.
2.
"
Bayleton
50%
WP
Fungicide"
(
reg.
no.
264­
737).
Assumed
to
be
applied
by
PCO's
only.
Therefore,
this
rate
is
only
used
for
postapplication
risk
estimates.
*
Currently
registered
for
use
on
residential
lawns.
**
Proposed
for
use
on
residential
lawns.
DG
=
Data
Gap.
Information
has
not
yet
been
obtained.

4.0
Residential
(
Non­
Occupational)
Exposures
and
Risks
There
is
a
potential
for
1,2,4­
T
exposure
to
homeowners
during
the
application
of
T­
D
fungicide
products
on
lawns
(
turf),
and
from
subsequent
activities
in
such
treated
areas.
As
a
result,
risk
assessments
have
been
completed
for
both
residential
handler
and
postapplication
scenarios.

Toddlers
can
be
exposed
directly
to
1,2,4­
T
by
ingesting
soil
where
T­
D
fungicides
have
been
sprayed,
and
subsequently
undergone
environmental
degradation
to
1,2,4­
T.
Indirect
exposure
of
toddlers
to
1,2,4­
T
can
occur
dermally
from
contact
with,
and
absorption
of
T­
D
fungicide
residues
on
treated
turf,
with
subsequent
internal
metabolism
to
1,2,4­
T.
Indirect
exposure
also
can
occur
through
incidental
ingestion
of
parent
residues
from
hand­
to­
mouth
and
object­
tomouth
activities
on
T­
D
fungicide
treated
turf,
with
subsequent
internal
metabolic
breakdown
to
1,2,4­
T.
Likewise,
indirect
1,2,4­
T
exposure
can
occur
to
adults
from
internal
metabolic
conversion,
following
direct
dermal
and
inhalation
of
T­
D
fungicides
during
application
to
home
lawns,
and
via
the
dermal
route
alone
from
subsequent
contact
with
those
treated
lawns.

1,2,4­
T
exposure
is
determined
by
certain
key
characteristics
specific
to
the
parent
T­
D
fungicide
from
which
it
is
formed.
These
characteristics
can
be
different
for
each
parent
T­
D
fungicide,
and
include
application
rate,
environmental
and
metabolic
conversion
rates,
molecular
weight
ratio
and
dermal
absorption
factors.
The
USTTF
calculated
the
route­
specific
risks
for
individual
registered
and
proposed
turf­
use
T­
D
fungicides,
using
an
average
metabolic
conversion
rate,
empirically
derived
turf
transferrable
residue
(
TTR)
data
(
where
available),
dermal
absorption
data
(
where
available),
and
standard
values
and
procedures
from
the
US
EPA
Draft
Standard
Page
7
of
14
Operating
Procedures
for
Residential
Exposure
Assessment.
The
USTTF
then
used
results
from
the
T­
D
fungicide
with
the
highest
total
toddler
postapplication
exposure
(
i.
e.,
dermal
plus
incidental
oral)
in
its
aggregate
assessment
of
turf­
use
T­
D
fungicides.

HED
has
assessed
the
currently
registered
turf­
use
T­
D
fungicide
that
results
in
the
highest
1,2,4­
T
exposure
(
i.
e.,
triadimefon),
as
well
as
the
highest
1,2,4­
T
exposure
resulting
from
a
hypothetical
T­
D
fungicide
that
is
characterized
by
the
maximum
exposure
input
characteristics
found
among
all
registered
and
proposed
turf­
use
T­
D
fungicides
(
see
shaded
values
in
Table
3
for
highest
input
variables).
This
latter
is
intended
to
cover
any
future
proposed
turf­
use
T­
D
fungicides
that
may
present
a
greater
exposure
potential
than
those
currently
under
consideration.

4.1
Residential
Handler
Exposures
and
Risks
4.1.1
Handler
Exposure
Scenarios
Non­
occupational
exposure
is
likely
during
the
handling
of
T­
D
fungicides
in
the
treatment
of
residential
lawns,
which
would
include
the
following
major
residential
exposure
scenarios:

(
1)
M/
L/
A
Liquids:
hose­
end
sprayer;
(
2)
M/
L/
A
Liquids:
low­
pressure
handwand;

4.1.2
Data
and
Assumptions
For
Residential
Handler
Exposure
Scenarios
The
following
assumptions
and
factors
are
specific
to
the
residential
assessment:

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

C
Homeowner
handler
assessments
are
completed
based
on
individuals
wearing
shorts
and
short­
sleeved
shirts.

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

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

C
The
Agency
based
calculations
on
what
would
reasonably
be
treated
by
homeowners
such
as
the
size
of
a
lawn,
or
the
size
of
a
garden.

C
A
70
kg
body
weight
is
used
for
adults
because
the
toxicity
endpoint
is
not
genderspecific

4.1.3
Residential
Handler
Exposure/
Risk
Estimates
Residential
handlers
may
be
exposed
dermally
and
by
inhalation
during
mixing,
loading
and
application
of
T­
D
fungicides
for
short­
term
durations.
Because
a
common
toxicity
endpoint
was
identified
for
both
dermal
and
inhalation
routes,
a
combined
risk
from
both
routes
of
exposure
is
Page
8
of
14
assessed.
Results
from
these
risk
calculations
for
residential
handlers
are
seen
in
Table
4
below.

Note:
Proprietary
data
from
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
have
been
used
in
this
assessment.
The
chemical
review
manager
is
encouraged
to
pursue
data
compensation
in
the
event
the
registrant
in
not
a
member
of
this
task
force.
Page
9
of
14
Table
4.
Non­
Occupational
Handler
Exposure
and
Risk
Estimates
for
T­
D
Fungicides
(
Triadimefon)

Exposure
Scenario
Personal
Protective
Equipment
Exposure
Route
Application
Rate
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Absorption
Rate
(%)
Amount
Treated
per
day
Unit
Exposure
(
mg/
lb
ai)
Data
Confidence
Daily
Dose1
(
mg/
kg/
day)
MOE
2
Total
Daily
Dose
(
mg/
kg/
day)
Total
MOE3
M/
L/
A
Liquids:

hoseend
sprayer
short
sleeves
short
pants
no
gloves
Dermal
2.75
lb
ai/
A
0.24
22
8
0.5
acre
114
High
0.00091
33,000
0.00093
32,000
Inhalation
100
0.0164
High
0.000017
1.8E+
6
M/
L/
A
Liquids:

lowpressure
handwand
short
sleeves
short
pants
no
gloves
Dermal
2.75
lb
ai/
A
0.24
22
8
0.023
acre
(
1000
ft2)
565
Low
0.00021
140,000
0.00021
140,000
Inhalation
100
0.00385
Medium
0.00000018
1.7E+
8
1
Daily
Dose
=
[
Application
Rate
*
MW
Ratio
*
Metabolic
Rate
*
Absorption
Rate
*
Amount
Treated
*
Unit
Exposure)]/
Body
Weight
(
70
kg)

2
MOE
=
NOAEL/
Daily
Dose.
The
dermal
and
inhalation
NOAEL
=
30
mg/
kg/
day,
was
used
for
all
calculations.
The
LOC
=
1000.

3
Total
MOE
=
NOAEL/(
dermal
daily
dose
+
inhalation
daily
dose)

4
Unit
exposure
values
taken
from
ORETF
study
(
OMA004),
"
Mixer/
Loader/
Applicator:
Hose­
end
Sprayer.
Mix
your
own."

5
Unit
exposure
values
taken
from
ORETF
study
()
MA005),
"
Resident
Mixer/
loader/
applicator
­
Handheld
Pump
Sprayer:
Fruit
Trees
and
Ornamentals."

Table
4a.
Non­
Occupational
Handler
Exposure
and
Risk
Estimates
for
T­
D
Fungicides
(
Screening
Level)

Exposure
Scenario
Personal
Protective
Equipment
Exposure
Route
Application
Rate
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Absorption
Rate
(%)
Amount
Treated
per
day
Unit
Exposure
(
mg/
lb
ai)
Data
Confidence
Daily
Dose1
(
mg/
kg/
day)
MOE
2
Total
Daily
Dose
(
mg/
kg/
day)
Total
MOE3
M/
L/
A
Liquids:

hoseend
sprayer
short
sleeves
short
pants
no
gloves
Dermal
2.75
lb
ai/
A
0.24
77
50
0.5
acre
114
High
0.019
1600
0.02
1500
Inhalation
100
0.0164
High
0.000058
520,000
M/
L/
A
Liquids:

lowpressure
handwand
short
sleeves
short
pants
no
gloves
Dermal
2.75
lb
ai/
A
0.24
77
50
0.023
acre
(
1000
ft2)
565
Low
0.0047
6400
0.0047
6400
Inhalation
100
0.00385
Medium
0.00000064
4.7E+
7
1
Daily
Dose
=
[
Application
Rate
*
MW
Ratio
*
Metabolic
Rate
*
Absorption
Rate
*
Amount
Treated
*
Unit
Exposure)]/
Body
Weight
(
70
kg)

2
MOE
=
NOAEL/
Daily
Dose.
The
dermal
and
inhalation
NOAEL
=
30
mg/
kg/
day,
was
used
for
all
calculations.
The
LOC
=
1000.

3
Total
MOE
=
NOAEL/(
dermal
daily
dose
+
inhalation
daily
dose)

4
Unit
exposure
values
taken
from
ORETF
study
(
OMA004),
"
Mixer/
Loader/
Applicator:
Hose­
end
Sprayer.
Mix
your
own."

5
Unit
exposure
values
taken
from
ORETF
study
()
MA005),
"
Resident
Mixer/
loader/
applicator
­
Handheld
Pump
Sprayer:
Fruit
Trees
and
Ornamentals."
Page
10
of
14
4.1.4
Summary
of
Risk
Concerns
and
Data
Gaps
for
Residential
Handlers
Residential
handler
risks
from
exposure
to
1,2,4­
T
do
not
exceed
HED's
LOC
for
lawn
use
of
triadimefon.
Likewise,
the
screening
level
assessment,
using
a
composite
of
high­
end
exposure
input
values,
results
in
risks
that
do
not
exceed
HED's
LOC.
Dermal
absorption
factors
used
in
this
assessment
were
taken
from
the
USTTF
Aggregate
Risk
Assessment.

4.2
Residential
Postapplication
Exposures
and
Risks
Individuals
of
varying
ages
can
potentially
be
exposed
from
activities
on
treated
turf.
Potential
routes
of
exposure
include
dermal
(
adults
and
toddlers)
and
incidental
ingestion
(
toddlers
only).
It
is
believed
that
most
residential
uses
of
T­
D
fungicides
will
result
in
short­
term
(
1
to
30
days)
postapplication
exposures.
The
likelyhood
of
routine
lawn
mowing
is
believed
to
mitigate
against
the
possibility
of
intermediate­
term
(>
30
days
to
180
days)
exposures.
Because
of
the
conservative
values
and
methodology
used,
the
residential
postapplication
assessment
is
not
believed
to
underestimate
risks.

The
HED
Standard
Operating
Procedures
for
Residential
Exposure
Assessments
(
Draft,
December
18,
1997)
were
used
as
a
guideline
for
performing
the
residential
postapplication
assessment.
Also
used
in
the
assessment
were
interim
changes
to
these
SOPs
which
were
adopted
by
the
HED
Exposure
Science
Advisory
Council
regarding
standard
values,
including,
for
turf
transferrable
residues,
turf
transfer
coefficients
and
hand­
to­
mouth
activities
(
Policy
11,
February
22,
2001).
The
exposure
and
risk
estimates
for
the
four
residential
exposure
scenarios
are
assessed
for
the
day
of
application
(
day
"
0")
because
it
is
assumed
that
adults
and
toddlers
could
contact
the
lawn
immediately
after
application.
On
the
day
of
application,
it
was
assumed
that
5
percent
of
the
application
rate
is
available
from
the
turfgrass
as
transferrable
residue
(
20
percent
for
object­
to­
mouth
activities).

4.2.1
Residential
Postapplication
Exposure
Scenarios
Assessment
of
residential
postapplication
exposure
was
performed
using
the
same
approach
as
was
used
for
handler
exposure
above.
The
assessment
was
performed
for
the
T­
D
fungicide,
triadimefon,
and
for
a
hypothetical
worst­
case
turf­
use
T­
D
fungicide
(
i.
e.,
one
which
results
in
the
highest
1,2,4­
T
exposure
from
using
the
maximum
input
variables
from
current
and
proposed
turf­
use
T­
D
fungicides).

4.2.2
Residential
Postapplication
Exposure/
Risk
From
Turf
A
summary
of
the
estimated
exposures
and
risks,
along
with
the
algorithms
used
for
each
turf
exposure
scenario
are
presented
below
in
Tables
5a
­
5d
for
triadimefon,
and
Tables
6a
­
6d
for
the
screening
level
assessment.
Page
11
of
14
Table
5a.
Dermal
Exposure
and
Risk
for
Adults
and
Children
from
Treated
Lawns
(
Triadimefon)

Subgroup
exposed
Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Turf
Transferrable
Residue
at
Day
"
0"

(
ug/
cm2)
1
Dermal
Transfer
Coefficient
(
cm2/
hr)
Exposure
Time
(
hrs/
day)
Absorption
Factor
Body
Weight
(
kg)
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Daily
Dose2
(
mg/
kg/
day)
MOE3
Adult
5.4
0.05
2.94
14,500
2
8%
70
0.24
22
0.0051
5900
Children
5.4
0.05
2.94
5200
2
8%
15
0.24
22
0.0086
3500
1
Turf
Transferrable
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Turf
Transferrable
Residue
x
Absorption
Factor
x
1E­
3
mg/
ug
x
Dermal
Transfer
Coefficient
x
Exposure
Time
x
MW
ratio
x
Metab.
Conv.
Rate)/
Body
weight
3
MOE
=
Dermal
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.

Table
5b.
Oral
Hand­
to­
mouth
Exposure
and
Risk
for
Children
from
Treated
Lawns
(
Triadimefon)

Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Turf
Transferrable
Residue
at
Day
"
0"

(
ug/
cm2)
1
Exposure
Time
(
hrs/
day)
Extraction
by
saliva
Hand
Surface
Area
(
cm2/
event)
Frequency
(
events/
hr)
Body
Weight
(
kg)
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Daily
Dose2
(
mg/
kg/
day)
MOE3
5.4
0.05
2.94
2
0.5
20
20
15
0.24
22
0.0041
7300
1Turf
Transferrable
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Turf
Transferrable
Residue
x
Extraction
by
Saliva
x
Hand
Surface
Area
x
Frequency
x
1E­
3
mg/
ug
x
Exposure
Time
x
MW
ratio
x
Metab.
Conv.
Rate)/
Body
Weight.

3
MOE
=
Oral
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.

Table
5c.
Oral
Object­
to­
mouth
(
Turfgrass)
Exposure
and
Risk
for
Children
from
Treated
Lawns
(
Triadimefon)

Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Grass
Residue
at
Day
"
0"

(
ug/
cm2)
1
Surface
Area
Mouthed
(
cm2/
day)
Body
Weight
(
kg)
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Daily
Dose2
(
mg/
kg/
day)
MOE3
5.4
0.2
11.8
25
15
0.24
22
0.001
30,000
1Grass
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Grass
residue
x
Surface
Area
Mouthed
x
1E­
3
mg/
ug
x
MW
ratio
x
Metab.
Conv.
Rate)/
Body
Weight.

3
MOE
=
Oral
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.

Table
5d.
Exposure
and
Risk
for
Children
from
Ingestion
of
Soil
from
Treated
Lawns
(
Triadimefon)

Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Soil
Residue
at
Day
"
0"

(
ug/
g)
1
1,2,4­
T
to
Parent
MW
Ratio
Max.
Soil
Conversion
Rate
to
1,2,4­
T
(%)
Ingestion
Rate
(
mg/
day)
Body
Weight
(
kg)
Daily
Dose2
(
mg/
kg/
day)
MOE3
5.4
1
39.4
0.24
30.7
100
15
0.000019
1.6E+
6
1
Soil
residue
(
ug/
g)
=
[
Application
Rate
(
lbs
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
x
0.67
cm3/
g
soil]

2
Daily
Dose
=
[
Soil
residue
(
ug/
g)
x
Soil
Conversion
Rate
(%)
x
MW
ratio
x
Ingestion
rate
(
mg/
day)
x
1E­
6
g/
ug]
/
[
Body
Weight
(
kg)]

3
MOE
=
Oral
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.
Page
12
of
14
Table
6a.
Dermal
Exposure
and
Risk
for
Adults
and
Children
from
Treated
Lawns
(
Screening
Level)

Subgroup
exposed
Applic.
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Turf
Transferrable
Residue
at
Day
"
0"
(
ug/
cm2)
1
Dermal
Transfer
Coefficient
(
cm2/
hr)
Exposure
Time
(
hrs/
day)
Absorp.

Factor
Body
Weight
(
kg)
1,2,4­
T
to
Parent
MW
Ratio
Metab.
Conversion
Rate
(%)
Daily
Dose2
(
mg/
kg/
day)
MOE3
Adult
5.4
0.05
2.94
14,500
2
50%
70
0.24
77
0.11
270
Children
5.4
0.05
2.94
5200
2
50%
15
0.24
77
0.19
160
1
Turf
Transferrable
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Turf
Transferrable
Residue
x
Absorption
Factor
x
1E­
3
mg/
ug
x
Dermal
Transfer
Coefficient
x
Exposure
Time
x
MW
ratio
x
Metab.
Conv.
Rate)/
Body
weight
3
MOE
=
Dermal
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.

Table
6b.
Oral
Hand­
to­
mouth
Exposure
and
Risk
for
Children
from
Treated
Lawns
(
Screening
Level)

Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Turf
Transferrable
Residue
at
Day
"
0"

(
ug/
cm2)
1
Exposure
Time
(
hrs/
day)
Extraction
by
saliva
Hand
Surface
Area
(
cm2/
event)
Frequency
(
events/
hr)
Body
Weight
(
kg)
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Daily
Dose2
(
mg/
kg/
day)
MOE3
5.4
0.05
2.94
2
0.5
20
20
15
0.24
77
0.014
2100
1Turf
Transferrable
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Turf
Transferrable
Residue
x
Extraction
by
Saliva
x
Hand
Surface
Area
x
Frequency
x
1E­
3
mg/
ug
x
Exposure
Time
x
MW
ratio
x
Metab.
Conv.
Rate)/
Body
Weight.

3
MOE
=
Oral
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.

Table
6c.
Oral
Object­
to­
mouth
(
Turfgrass)
Exposure
and
Risk
for
Children
from
Treated
Lawns
(
Screening
Level)

Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Grass
Residue
at
Day
"
0"

(
ug/
cm2)
1
Surface
Area
Mouthed
(
cm2/
day)
Body
Weight
(
kg)
1,2,4­
T
to
Parent
MW
Ratio
Metabolic
Conversion
Rate
(%)
Daily
Dose2
(
mg/
kg/
day)
MOE3
5.4
0.2
11.8
25
15
0.24
77
0.0036
8300
1Grass
Residue
(
ug/
cm2)
=
Application
rate
(
lb
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
2
Daily
Dose
=
(
Grass
residue
x
Surface
Area
Mouthed
x
1E­
3
mg/
ug
x
MW
ratio
x
Metab.
Conv.
Rate)/
Body
Weight.

3
MOE
=
Oral
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.

Table
6d.
Exposure
and
Risk
for
Children
from
Ingestion
of
Soil
from
Treated
Lawns
(
Screening
Level)

Application
Rate
(
lb
ai/
A)
Fraction
of
ai
Available
Soil
Residue
at
Day
"
0"
(
ug/
g)
1
1,2,4­
T
to
Parent
MW
Ratio
Max.
Soil
Conversion
Rate
to
1,2,4­
T,
or
[
Metab.
Conv
Rate]
(%)
Ingestion
Rate
(
mg/
day)
Body
Weight
(
kg)
Daily
Dose2
(
mg/
kg/
day)
MOE3
5.4
1
39.4
0.24
30.7
100
15
0.000019
1.6E+
6
1
Soil
residue
(
ug/
g)
=
[
Application
Rate
(
lbs
ai/
A)
x
Fraction
of
ai
Available
x
4.54E+
8
ug/
lb
x
2.47E­
8
A/
cm2
x
0.67
cm3/
g
soil]

2
Daily
Dose
=
[
Soil
residue
(
ug/
g)
x
Soil
Conversion
Rate
(%)
x
MW
ratio
x
Ingestion
rate
(
mg/
day)
x
1E­
6
g/
ug]
/
[
Body
Weight
(
kg)]

3
MOE
=
Oral
NOAEL
(
30
mg/
kg/
day)
/
Daily
Dose.
LOC
=
1000.
Page
13
of
14
4.2.2.1
Summary
of
Residential
Postapplication
Exposure/
Risk
From
Turf
The
MOEs
for
postapplication
exposure
to
the
T­
D
fungicide
turf
product,
triadimefon
are
all
$
1000
for
individual
routes
of
exposure,
and
therefore
do
not
exceed
HED's
level
of
concern.
FQPA
requires
residential
exposures
that
could
reasonably
be
expected
to
occur
on
the
same
day
be
combined
and
compared
to
the
appropriate
toxicity
endpoint.
Likewise,
if
individual
routes
of
exposure
(
e.
g.,
toddler
dermal
and
incidental
ingestion
by
hand­
to­
mouth,
object­
to­
mouth
and
soil
ingestion
activities)
are
combined,
the
MOE
is
2200,
and
therefore
does
not
exceed
HED's
LOC.

The
MOEs
for
postapplication
exposure
to
a
hypothetical
screening
level
T­
D
fungicide
are
less
than
1000
for
the
dermal
route
of
exposure
(
e.
g.,
adult
dermal
MOE
=
270;
toddler
dermal
MOE
=
160),
and
therefore
exceed
HED's
LOC.

The
exposure
estimates
generated
are
based
on
some
upper­
percentile
(
i.
e.,
maximum
application
rate)
and
some
central
tendency
(
i.
e.,
surface
area,
hand­
to­
mouth
activity,
and
body
weight)
assumptions
and
are,
therefore,
considered
to
be
representative
of
central
to
high­
end
exposures.
The
uncertainties
associated
with
this
assessment
stem
from
the
use
of
an
assumed
amount
of
pesticide
available
from
turf,
and
assumptions
regarding
transfer
of
chemical
residues,
and
handto
mouth
activity.

5.0
Recreational
T­
D
fungicides
may
be
used
on
turf
at
recreational
use
sites,
and,
therefore
may
result
in
postapplication
exposure
to
adults
and
children
involved
in
recreational
activities.
Exposures
to
adults
and
children
from
the
use
of
T­
D
fungicides
at
recreational
use
sites
are
assumed
to
be
the
same
as
those
assessed
for
residential
use
sites,
and
therefore,
a
separate
recreational
exposure
assessment
was
not
included.
Results
from
the
residential
turf
exposure
assessment
are
considered
upper
percentile
risk
estimates.
Therefore,
it
is
not
expected
that
the
high­
end
residential
exposure
scenario
would
occur
on
the
same
day
as
a
high­
end
recreational
exposure
scenario.
Exposure
from
these
two
exposure
scenarios
are
not
aggregated.
Rather,
the
residential
risk
estimate
should
serve
as
a
high­
end
estimate
for
both
residential
and
recreational
exposure
6.0
Spray
Drift
While
the
drifting
of
agricultural
spray
applications
of
T­
D
fungicides
to
nearby
residential
settings
is
possible,
the
T­
D
funcgicide
turf
uses
addressed
in
the
above
residential
risk
assessment
are
considered
to
be
conservative,
worst
case
scenarios,
that
would
cover
any
potential
1,2,4­
T
risks
from
agricultural
spraying
operations.
Page
14
of
14
Spray
drift
is
always
a
potential
source
of
exposure
to
residents
nearby
to
spraying
operations.
This
is
particularly
the
case
with
aerial
application,
but,
to
a
lesser
extent,
could
also
be
a
potential
source
of
exposure
from
the
groundboom
application.
The
Agency
has
been
working
with
the
Spray
Drift
Task
Force,
EPA
Regional
Offices
and
State
Lead
Agencies
for
pesticide
regulation
and
other
parties
to
develop
the
best
spray
drift
management
practices.
The
Agency
is
now
requiring
interim
mitigation
measures
for
aerial
applications
that
must
be
placed
on
product
labels/
labeling.
The
Agency
has
completed
its
evaluation
of
the
new
data
base
submitted
by
the
Spray
Drift
Task
Force,
a
membership
of
U.
S.
pesticide
registrants,
and
is
developing
a
policy
on
how
to
appropriately
apply
the
data
and
the
AgDRIFT
computer
model
to
its
risk
assessments
for
pesticides
applied
by
air,
orchard
airblast
and
ground
hydraulic
methods.
After
the
policy
is
in
place,
the
Agency
may
impose
further
refinements
in
spray
drift
management
practices
to
reduce
off­
target
drift
and
risks
associated
with
aerial
as
well
as
other
application
types
where
appropriate.
