1
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
PC
Code:
109901
DPBarcode:
328531
SUBJECT:
Response
to
Bayer
Public
Comments
Regarding
the
Environmental
Fate
And
Effects
Division
Triadimefon
Risk
Assessment
FROM:
Fred
Jenkins,
MS
Jonathan
Angier,
PhD
Environmental
Risk
Branch
II
Environmental
Fate
and
Effects
Division
(
7507C)

TO:
John
Pates
Jr.
Special
Registration
and
Review
Division
(
7505
C)

THRU:
Tom
Bailey,
PhD
Branch
Chief
Environmental
Risk
Branch
II
/
EFED
(
7507C)

DATE:
June
1,
2006
In
response
to
the
phase
3
Bayer
public
comments
submitted
about
the
revised
EFED
ecological
risk
assessment
(
dated
January,
9
2006),
EFED
has
prepared
the
attached
responses
to
comments.
2
Tier
2
Drinking
Water
Assessment
for
Triadimefon
and
its
Major
Degradate
Triadimenol
(
Aug.
31,
2005),
page
4
and
Triadimefon
­
Preliminary
Human
Health
Risk
Assessment
(
Revised),
February
9,
2006,
Section
5.7.1,
page
49­
51
of
102.

Surface
Water
Modeling
EPA:
"
A
default
Percent
Cropped
Area
(
PCA)
factor
of
0.87
(
87%
percent
has
been
applied
to
all
the
scenarios
except
turf,
for
which
100%
of
area
is
considered
(
no
adjustment)."

Bayer
Response:
The
high
drinking
water
concentrations
from
turf
uses
of
triadimefon
are
a
direct
result
of
the
assumption
that
100%
of
a
surface
drinking
water
system
(
SDWS)
watershed
is
covered
with
golf
courses,
and
consequently
100%
of
a
SDWS
watershed
is
treated
with
the
compound.
This
assumption
is
extremely
conservative.
Studies
conducted
by
Bayer
CropScience
to
calculate
the
percent
of
golf
course
areas
within
56
SDWS
watersheds
in
Florida,
North
Carolina,
and
South
Carolina
(
MRID
465637­
01;
Bayer
Report
04RAOAY001)
showed
that
golf
course
areas
represented
between
0%
and
5.8
%
of
SDWS
watershed
(
i.
e.
maximum
PCA
of
5.8%).
Moreover,
Bayer
is
in
the
process
of
determining
the
PCA
factors
of
recreational
grasses
for
the
1606
SDWS
watersheds
which
were
used
by
the
USGS
for
WARP
modeling.
To
date,
Bayer
has
received
data
from
USGS
on
947
of
the
SDWS
watersheds,
and
the
results
indicate
PCA
factors
ranged
from
0%
to
7.7%.
Therefore,
a
turf
PCA
factor
of
7.7%
is
more
appropriate
for
the
evaluation
of
drinking
water
exposure
and
risk.

The
7.7%
PCA
can
be
used
to
recalculate
the
drinking
water
expected
concentrations
as
follows
(
EPA
derived
values
for
Florida
turf
with
3
applications,
times
0.077):
°
Acute:
7.76
ppb
°
Chronic
1
in
10
year:
1.92
ppb
°
Chronic
30­
year
mean:
1.00
ppb
Considering
that
triadimefon
has
agricultural
uses,
which
could
contribute
to
the
load
within
a
watershed,
Bayer
has
evaluated
a
combination
of
sales
data
for
the
turf
uses,
and
Doanes
use
data
for
the
agricultural
uses.
This
comparison
indicates
that
agricultural
uses
are
minimal,
representing
less
than
5%
of
the
total
triadimefon
used.
To
confirm
these
data,
Bayer,
in
conjunction
with
USGS,
is
calculating
the
seasonal
use
rates
for
the
1606
SDWS
based
on
2005
sales
data
(
all
uses).
The
results
are
expected
to
show
a
significantly
lower
use
than
the
conservative
estimate
of
100%
of
the
watershed.

Thus,
the
PCA
factor
should
be
considered
in
the
drinking
water
risk
assessments,
to
3
provide
a
more
realistic
measure
of
the
potential
exposure
of
triadimefon
and
triadimenol.
The
additional
information
regarding
PCA
factors
for
the
remaining
watersheds,
and
the
use
data
per
watershed
will
be
provided
to
the
agency
as
soon
as
it
is
available.

Agency
Response
We
have
performed
multiple
alternate
model
runs
with
varying
amounts
of
Triadimefon
applied,
varying
numbers
of
applications,
and
various
PCAs
and
other
adjustment
factors
(
e.
g.,
Golf
Course
Adjustment
Factors
 
GCAFs).
When
appropriate
GCAFs
are
applied,
EEC
numbers
drop
considerably.
The
100%
cropped
area
with
no
further
adjustments
only
applies
to
non­
golf
course
turf
uses.
While
assuming
100%
cropped
area
may
indeed
be
overly
conservative,
we
currently
do
not
have
sufficient
quality
data
to
confidently
make
any
other
assumption;
a
Scientific
Advisory
Panel
(
SAP)
on
this
subject
has
basically
said
as
much.
At
present,
the
lowest
PCAs
applied
to
any
crop
are
still
substantially
higher
(
20%)
than
that
proposed
by
Bayer
for
turf
usage
(
7.7%).
We
would
have
to
see
some
very
compelling
and
extensive
evidence
to
support
this
assertion.

Tier
2
Drinking
Water
Assessment
for
Triadimefon
and
its
Major
Degradate
Triadimenol
(
Aug.
31,
2005),
page
5,
and
Triadimefon
­
Preliminary
Human
Health
Risk
Assessment
(
Revised),
February
9,
2006,
Section
5.7.1,
page
51
of
102.

Ground
Water
Monitoring
EPA:
"
The
most
recent
studies
show
maximum
concentrations
of
approximately
25
ppb
for
turf
application
in
New
Jersey
(
MRID
45544202)
and
1.67
ppb
for
turf
application
in
California
(
MRID
455I44202,
45688801
&
46097201)."

Bayer
Response:
The
referenced
concentrations
are
total
residues
(
triadimefon
plus
all
degradates),
and
this
should
be
clarified.
The
maximum
concentrations
of
triadimefon
plus
triadimenol
in
the
New
Jersey
ground
water
monitoring
study
was
6.58
ppb
(
0.21
ppb
triadimefon,
6.37
ppb
triadimenol),
and
it
should
also
be
noted
that
these
residues
dissipated
quickly
in
the
groundwater,
and
therefore
greatly
overestimate
chronic
concentrations.
The
maximum
concentrations
of
triadimefon
plus
triadimenol
in
the
California
groundwater
monitoring
study
was
0.52
ppb
(
0.16
ppb
triadimefon,
0.36
ppb
triadimenol),
and
showed
no
indication
of
persistence
in
the
groundwater.
Use
of
these
values
provides
a
proper
comparison
to
the
SCIGROW
results,
which
represent
concentrations
of
triadimefon
plus
triadimenol.

Agency
Response
The
sentence
just
prior
to
this
in
the
document
specifies
that
these
are
total
residues
 
it
should
not
be
necessary
to
repeat
this
in
every
sentence.
The
values
cited
in
the
Drinking
Water
Assessment
(
DWA)
were
taken
from
Agency­
approved
studies
and
represent
`
high­
end'
monitoring
data.
The
most
recent
Bayleton
Prospective
Groundwater
4
Monitoring
Study
for
Fresno,
CA
(
Bayer
Study
Number
BL212402)
yielded
maximum
triadimefon
+
triadimenol
residues
at
0.52
ppb;
nevertheless,
the
relationship
between
the
monitoring
data
concentrations
and
concentrations
predicted
by
SciGrow
remains
similar.
In
any
event,
it
is
the
surface
water
concentrations
that
are
of
greater
concern.

I.
EXECUTIVE
SUMMARY
Bayer
Response:
The
executive
summary
of
the
Environmental
Fate
and
Effects
Chapter
should
be
revised
to
take
into
consideration
the
many
mitigating
factors
that
can
be
used
in
a
refined
assessment
for
triadimefon
and
that
are
included
in
the
following
response.

Page
10:
Uncertainties
and
Data
Gaps
EPA:
EPA
notes
that
one
of
the
greatest
uncertainties
in
the
risk
assessment
concerns
the
major
degradate
of
triadimefon,
triadimenol.
Bayer
Response:
Some
of
the
uncertainty
associated
with
triadimenol
and
the
terrestrial
risk
assessment
can
be
addressed
by
examining
the
wheat
metabolism
study
(
Bayer
Report
number
80293).
The
wheat
metabolism
study
examined
the
time
course
of
the
parent
and
metabolite
over
a
4
week
period.
The
peak
parent
was
observed
in
day
0
for
both
trials.
The
peak
triadimenol
occurred
on
day
14.
The
calculated
half­
lives
for
the
parent
and
total
residue
range
from
6.3
to
8.3
days
and
12.8
and
24.8
days,
respectively.
Therefore
the
screening
level
risk
assessment
takes
into
account
the
potential
exposure
to
the
metabolite
in
a
highly
conservative
manner.
Furthermore,
residue
decline
trial
for
wheat
(
Bayer
report
number
100111)
demonstrated
a
significantly
shorter
total
residue
half­
life
(
3.5
days),
which
may
be
a
more
appropriate
half­
life
to
use
in
the
terrestrial
risk
assessment.

Agency
Response:

The
soil
half­
life
study
submitted
to
the
Agency
(
MRID
4224104)
indicates
that
triadimefon
is
very
persistent
(
240
day
half­
life)
in
the
terrestrial
environment
(
specifically
in
soils).
Bayer
asserts
that
a
half­
life
value
of
1.5
to
3.5
days
in
wheat
is
most
appropriate
to
use
as
a
terrestrial
exposure
value.
However,
this
value
does
not
account
for
the
significant
disparity
with
the
results
of
the
soil
half­
life
study.
Given
the
large
disparity
and
uncertainty
between
the
Bayer
asserted
wheat
residue
half­
life
of
1.5
to
3.5
days
and
the
soil
half­
life
of
240
days,
the
Agency
calculated
the
risk
quotients
based
on
the
Agency
default
foliar
half­
life
value
of
35
days.
5
III.
Analysis
A.
Expanded
Use
Characterization
Page
29:
Table
6
EPA:
EPA
notes
that
the
current
label
for
triadimefon
use
on
golf
course
turf
does
not
state
a
maximum
number
of
applications
per
season
or
a
maximum
total
seasonal
applications
rate.
EPA
states
that
2
applications
of
the
profession
care
lawn
and
turf
label
allows
2
applications
of
1.36
lb
ai/
A.

Bayer
Response:
BCS
concurs
that
the
golf
course
turf
label
does
not
currently
state
that
a
maximum
number
of
applications
or
total
seasonal
application
rate.
However,
BCS
is
prepared
to
add
to
the
label
a
maximum
number
of
applications
of
3
for
the
golf
course
use
pattern,
and
a
maximum
total
seasonal
application
of
8.1
lb
ai/
A.
For
curative
control
of
southern
blight,
the
profession
care
lawn
and
turf
label
allows
3
applications
of
1.36
lb
ai/
A,
with
a
30
day
interval.

Agency
Response
The
current
label
for
triadimefon
use
on
golf
course
turf
did
not
specify
a
maximum
number
of
applications
per
season
or
a
maximum
total
seasonal
applications
rate.
Thus,
EFED'S
revised
ecological
risk
assessment
(
dated
1/
19/
06)
evaluated
a
range
of
different
scenarios
for
turf
application
rates.
These
scenarios
of
application
rates
ranged
from
1
to
26
applications
of
either
1.36,
1.31,
or
2.7
lbs.
a.
i./
acre
with
intervals
of
either
7,
14,
28,
30,
or
60
days.
There
are
bird
and
mammal
Agency
level
of
concern
(
LOC)
exceedances
throughout
the
entire
range
of
application
rates.
In
particular,
there
are
bird
and
mammal
LOC
exceedances
which
would
result
from
Bayer's
proposals
to
add
to
the
label
which
include:
1)
a
maximum
number
of
applications
of
3
for
the
golf
course
use
pattern
for
a
maximum
total
seasonal
application
of
8.1
lbs.
a.
i./
acre
(
equivalent
to
3
applications
of
2.7
lbs.
a.
i./
acre)
and
2)
a
professional
care
lawn
and
turf
maximum
use
rate
that
allows
3
applications
of
1.36
lbs.
a.
i./
acre,
with
a
30
day
interval
for
curative
control
of
southern
blight.
Tables
1­
3
illustrate
these
use
rates
and
their
resulting
LOC
exceedances
for
birds
and
mammals.

Tables
1­
3
also
include
risk
quotient
calculations
with
a
range
of
interval
times
(
7,
14,
30,
and
60
days
for
interval
times)
between
applications
for
the
Bayer
proposed
maximum
seasonal
application
amount
of
8.1
lbs.
a.
i./
acre
(
equivalent
to
3
applications
of
2.7
lbs.
a.
i./
acre).
The
Agency
took
this
measure
because
Bayer
did
not
specify
an
interval
time
between
applications
for
this
application
rate.
6
There
would
be
no
LOC
exceedances
for
fish,
aquatic
invertebrate,
and
aquatic
plants
for
Bayer's
newly
proposed
turf
maximum
application
rates
of
either:
1)
3
applications
for
the
golf
course
use
pattern
for
a
maximum
total
seasonal
application
of
8.1
lbs.
a.
i./
acre
or
2)
a
professional
care
lawn
and
turf
maximum
use
rate
that
allows
3
applications
of
1.36
lbs.
a.
i.
/
A,
with
a
30
day
interval
for
curative
control
of
southern
blight.

Table
1.
Avian
dietary­
based
acute
and
chronic
risk
quotients
for
selected
uses
of
nongranular
triadimefon
(
based
on
LC50
of
8392
mg/
kg
diet
and
NOAEC
of
20
mg/
kg
diet)
based
on
upperbound
Kenega
values.
Use
(
Application
Rate)
Food
Item
Upper
Bound
EEC
(
mg/
kg)
Acute
dietary
Based
RQ
(
EEC/
LC50)
Chronic
Dietary
based
RQ
(
EEC/
NOAEC)
Short
Grass
1703.21
0.20
85.16
Tall
Grass
780.64
0.09
39.03
Broadleaf
plants/
sm
Insects
958.06
0.11
47.9
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
7
day
interval)

Fruits/
pods/
seeds/
lg
insects
106.45
0.01
5.32
Short
Grass
1511.27
0.18
75.56
Tall
Grass
692.67
0.08
34.63
Broadleaf
plants/
sm
Insects
850.09
0.10
42.50
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
14
day
interval)

Fruits/
pods/
seeds/
lg
insects
94.45
Below
LOC
4.72
Short
Grass
1203.21
0.14
60.16
Tall
Grass
551.47
Below
LOC
27.57
Broadleaf
plants/
sm
Insects
676.80
Below
LOC
33.84
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
30
days
interval)

Fruits/
pods/
seeds/
lg
insects
75.20
Below
LOC
3.76
Short
Grass
905.66
0.11
45.28
Tall
Grass
415.10
Below
LOC
20.75
Broadleaf
plants/
sm
Insects
509.44
Below
LOC
25.47
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
60
days
interval)

Fruits/
pods/
seeds/
lg
insects
56.60
Below
LOC
2.83
Short
Grass
606.06
Below
LOC
30.30
Tall
Grass
277.78
Below
LOC
13.89
Broadleaf
plants/
sm
Insects
340.91
Below
LOC
17.05
Turf
(
1.36
lbs.
a.
i./
A,
3
applications
30
day
interval)

Fruits/
pods/
seeds/
lg
insects
37.88
Below
LOC
1.89
7
Table
2.
Mammalian
dose­
based
acute
risk
quotients
for
selected
uses
of
non­
granular
triadimefon
(
based
on
triadimenol
LD50
OF
689
mg/
kg
in
rats)
based
on
upper­
bound
Kenega
values
Mammalian
Dose­
based
Acute
Risk
Quotients
Use
(
Application
Rate)
Body
Weight
Adjusted
LD50
Short
Grass
Tall
Grass
Broadleaf
Fruits/
pods/
large
insects
Seeds
15
1514
1.07
0.49
0.60
Below
LOC
Below
LOC
35
1225
0.92
0.42
0.52
Below
LOC
Below
LOC
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
7
day
interval)
1000
530
0.49
0.23
0.28
Below
LOC
Below
LOC
15
1514
0.95
0.44
0.54
Below
LOC
Below
LOC
35
1225
0.81
0.37
0.46
Below
LOC
Below
LOC
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
14
day
interval)
1000
530
0.44
0.20
0.25
Below
LOC
Below
LOC
15
1514
0.76
0.35
0.43
Below
LOC
Below
LOC
35
1225
0.65
0.30
0.36
Below
LOC
Below
LOC
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
30
days
interval)
1000
530
0.35
0.16
0.20
Below
LOC
Below
LOC
15
1514
0.57
0.26
0.32
Below
LOC
Below
LOC
35
1225
0.49
0.22
0.27
Below
LOC
Below
LOC
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
60
days
interval)
1000
530
Below
LOC
Below
LOC
15
1514
0.38
0.17
0.21
35
1225
0.33
0.15
0.18
Turf
(
1.36
lbs.
a.
i./
A,
3
applications
30
day
interval)
1000
530
0.17
Below
LOC
Below
LOC
Below
LOC
Below
LOC
8
Table
3.
Mammalian
dietary­
based
chronic
risk
quotients
for
selected
uses
of
non­
granular
triadimefon
(
based
on
triadimefon
rat
NOEAL
of
50
mg/
kg
diet)
based
on
upper­
bound
Kenega
values
Risk
Quotients
for
each
mammalian
food
item
Use
(
Application
Rate)

Short
Grass
Tall
Grass
Broadleaf
Fruits/
pods/
large
insects/
Seeds
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
7
day
intervals)
34.06
15.61
19.16
2.13
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
14
day
intervals)
30.23
13.85
17.00
1.89
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
30
days
intervals)
24.06
11.03
13.54
1.50
Turf
(
2.7
lbs.
a.
i./
A,
3
applications,
60
days
intervals)
18.11
8.30
10.19
1.13
Turf
(
1.36
lbs.
a.
i./
A,
3
applications
30
day
interval)
12.12
5.56
6.82
0.76
9
B.
Exposure
Characterization
Page
37.
Table
12
and
associated
EEC's
in
subsequent
tables
and
text
EPA:
EPA
used
various
turf
exposure
scenarios
to
calculate
the
aquatic
EEC's.
These
scenarios
are
summarized
in
Table
12.

Bayer
Response:
As
noted
earlier,
BCS
agrees
with
the
Agency
that
the
golf
course
labels
did
not
adequately
specify
the
number
of
applications
or
the
total
seasonal
maximum
application
rates.
However,
BCS
is
prepared
to
amend
the
label
to
specify
a
maximum
of
3
applications
per
season
for
a
total
seasonal
application
of
8.1
lb
ai/
A.
In
order
to
adequately
characterize
the
potential
risk
for
aquatic
organisms,
the
proposed
use
pattern
should
be
modeled
with
PRZM/
EXAMS.
A
similar
statement
can
be
made
for
the
exposure
scenarios
for
terrestrial
vertebrates
(
pages
42
 
Table
14).

Agency
Response:

There
would
be
no
LOC
exceedances
for
fish,
aquatic
invertebrate,
and
aquatic
plants
for
Bayer's
newly
proposed
turf
maximum
application
rates
of
either:
1)
3
applications
for
the
golf
course
use
pattern
for
a
maximum
total
seasonal
application
of
8.1
lbs.
a.
i./
acre
or
2)
a
professional
care
lawn
and
turf
maximum
use
rate
that
allows
3
applications
of
1.36
lbs.
a.
i./
acre,
with
a
30
day
interval
for
curative
control
of
southern
blight.

Pages
38
 
39
EPA:
EPA
calculated
the
potential
environmental
exposure
for
terrestrial
organisms.
Bayer
Response:
Wheat
residue
trials
were
conducted
for
triadimefon
(
Bayer
report
number
100111)
which
demonstrate
a
rapid
decline
of
the
parent
and
total
residues
for
triadimefon
on
wheat
forage.
Four
trials
were
conducted;
the
forage
residue
data
for
3
of
the
trials
provide
a
half­
life
of
1.0
to
2.3
days
for
the
parent,
and
a
half­
life
of
1.5
to
3.5
days
of
the
total
residue,
which
would
include
the
triadimenol
metabolite.
The
data
from
the
fourth
decline
trial
were
not
useful.
If
a
half­
life
of
1
to
3.5
days
were
used
in
the
calculation
of
the
terrestrial
EECs,
the
exposure
would
be
reduced
by
as
much
as
53%.
Given
that
these
trials
included
an
examination
for
triadimenol
residues,
some
of
the
uncertainty
associated
with
potential
exposure
to
the
metabolite
is
addressed.
The
half­
life
for
the
total
residue
was
not
significantly
greater
than
the
half­
life
for
the
parent
material
alone.
EPA
should
consider
using
these
residue
trials
in
a
refinement
of
the
terrestrial
risk
assessment.
10
Agency
Response:

The
soil
half­
life
study
submitted
to
the
Agency
(
MRID
4224104)
indicates
that
triadimefon
is
very
persistent
(
240
day
half­
life)
in
the
terrestrial
environment
(
specifically
in
soils).
Bayer
asserts
that
a
half­
life
value
of
1.5
to
3.5
days
in
wheat
is
most
appropriate
to
use
as
a
terrestrial
exposure
value.
However,
this
value
does
not
account
for
the
significant
disparity
with
the
results
of
the
soil
half­
life
study.
Given
the
large
disparity
and
uncertainty
between
the
Bayer
asserted
wheat
residue
half­
life
of
1.5
to
3.5
days
and
the
soil
half­
life
of
240
days,
the
Agency
calculated
the
risk
quotients
based
on
the
Agency
default
foliar
half­
life
value
of
35
days.

C.
Ecological
Effects
Characterization
Page
51.
Chronic
toxicity
to
Birds
Page
9
of
15
EPA:
In
the
bobwhite
quail
study
(
MRID
110431),
the
NOAEC
was
determined
to
be
20
ppm
ai
based
on
an
increase
in
cracked
eggs
and
decreases
in
the
number
of
fertile
eggs,
viable
embryos,
hatchlings,
and
14­
day
survivors.
The
primary
effect
of
triadimefon
on
avian
reproduction
seems
to
be
the
number
of
fertile
eggs
and
viable
14­
day
old
survivors.
Both
of
these
endpoints
demonstrated
an
83%
decrease
at
the
highest
dose
of
500
ppm.
7The
LOAEC
was100
ppm
ai.
The
other
bobwhite
quail
study
(
MRID
42342301)
was
classified
as
supplemental
because
of
problems
with
the
incubator
causing
cracked
eggs
in
the
control
dose.
A
mallard
duck
study
(
MRID
42342302)
demonstrated
a
NOAEC
at
the
highest
concentration
tested
of
780
ppm
ai.
There
were
no
effects
of
triadimefon
exposure
on
mortality,
behavior,
or
reproductive
performance
at
this
concentration.
A
second
mallard
duck
study
(
MRID
248117)
was
classified
as
supplemental
because
of
poor
reproductive
success
of
the
control
(
poor
hatchling
survival
rates
in
the
controls).

Bayer
Response:
BCS
disagrees
with
the
selection
of
the
NOAEC
derived
form
the
avian
reproduction
studies.
The
first
bobwhite
quail
study
was
conducted
in
1982,
prior
to
the
implementation
of
GLP.
The
second
bobwhite
quail
study
was
conducted
in
1992
under
GLP.
The
first
bobwhite
quail
study
had
an
unexplained
increase
in
the
number
of
cracked
eggs.
However
the
number
of
cracked
eggs
was
not
related
to
the
eggshell
thickness,
the
primary
indicator
for
egg
quality.
While
there
was
an
increase
with
increasing
concentration,
there
was
not
dose
response
relationship.
The
percent
cracked
eggs
per
hen
were
4.4,
7.7,
12.9
and
13.8
in
the
control,
20,
100
and
500
ppm
groups,
respectively.
As
noted
in
the
report
and
in
the
US
EPA
rejection
rate
analysis,
there
are
a
number
of
reasons
why
eggs
may
crack
(
egg
handling
by
birds,
egg
handling
by
study
personnel,
and/
or
cage
related
cracking),
and
without
an
indication
of
an
effect
on
egg
shell
thickness,
there
is
insufficient
evidence
to
implicate
triadimefon
as
the
cause
of
11
cracking
(
particularly
in
these
older
studies.
A
study
conducted
by
Toll
et
al.
(
1990)
examined
the
number
of
cracked
eggs
in
the
control
groups
of
95
studies.
Toll
et
al.
reported
eggs
cracked
in
control
groups
averaged
7.4%
and
ranged
from
0
­
24%.
The
numbers
of
cracked
eggs
observed
in
the
triadimefon
study
were
within
the
historical
control
data
at
the
time
the
study
was
conducted.
The
only
other
significant
difference
noted
in
the
report
were
the
percent
fertile
eggs
of
the
number
of
eggs
laid.
However
the
primary
driver
for
this
finding
is
the
number
of
cracked
eggs.
When
the
percent
fertile
eggs
of
the
number
of
eggs
set
(
which
corrects
for
the
number
cracked)
then
there
were
no
significant
differences
in
the
fertility
of
the
eggs.
While
EPA
contends
that
the
primary
effect
in
the
study
was
on
egg
fertility
and
hatchling
survival,
neither
of
these
endpoints
was
statistically
different
from
the
control
when
the
percentages
were
based
upon
the
number
of
eggs
set.
EPA
also
made
the
statement
that
these
endpoints
resulted
in
an
83%
decrease
in
the
high
dose
group.
This
statement
is
not
accurate;
the
percent
reduction
compared
to
the
control
group
was
12%
for
the
fertile
eggs
of
eggs
set
and
11%
of
14­
day
survivor
of
hatchling
(
neither
being
statistically
different).
Even
if
you
were
to
erroneously
compare
the
number
of
14­
day
survivors
between
the
control
and
highest
treatment
group,
the
reduction
is
31%
BUT
this
number
does
not
account
for
the
differences
in
the
number
of
eggs
laid
or
the
differences
observed
in
the
number
of
eggs
set
due
to
cracked
eggs.
A
second
bobwhite
quail
study
was
conducted
in
1992
under
GLP
conditions.
Unfortunately
in
this
second
study
a
malfunction
occurred
with
the
incubator
that
caused
the
loss
of
three
weeks
of
eggs,
resulting
in
the
study
being
classified
as
supplemental.
In
the
review
of
the
study
EPA
contends
that
there
is
too
much
uncertainty
that
the
eggs
produced
at
the
beginning
of
the
study
(
when
the
malfunction
occurred)
are
comparable
to
eggs
produced
later
in
the
study,
and
hence
the
2
triadimefon
studies
are
not
comparable.
There
is
no
evidence
in
avian
reproduction
studies
that
egg
quality
decreases
under
the
duration
of
the
normal
bobwhite
quail
reproduction
study.
In
the
second
bobwhite
quail
study
with
triadimefon,
9
weeks
of
data
were
available
for
analysis
and
over
500
eggs
were
produced
in
each
of
the
control
and
treatment
groups.
The
test
levels
in
the
second
study
were
50,
200
and
600
ppm.
As
noted
in
the
report,
there
were
no
significant
differences
noted
between
the
triadimefon
treatment
groups
and
the
control
in
any
of
the
reproductive
or
growth
parameters.
While
the
report
concluded
that
no
statistical
differences
in
the
number
of
eggs
cracked,
EPA
in
their
review
of
the
study
noted
a
significant
difference
between
the
control
and
the
200
ppm
treatment
group.
This
difference
(
whether
it
is
statistically
different
or
not)
was
not
treatment
related.
The
percent
eggs
cracked
of
eggs
laid
per
hen
were:

Mean
Percent
Standard
Deviation
Control
3.6
5.3
50
ppm
2.7
2.5
200
ppm
4.4
3.9
600
ppm
4.2
5.4
12
There
was
only
a
minor
difference
noted
between
the
control
group
and
the
200
ppm
treatment
group.
There
was
no
dose­
response
relationship
between
the
treatment
groups
and
the
number
of
eggs
cracked.
The
standard
deviations
clearly
indicate
a
wide
overlap
between
the
control
and
all
of
the
treatment
groups.
The
percent
cracked
eggs
falls
well
within
the
historical
control
data
of
Toll
et
al.
(
1990)
and
is
well
below
the
acceptable
limits
of
cracked
eggs
in
the
controls
as
noted
in
the
rejection
rate
analysis.
Additionally,
in
the
study
there
were
no
statistical
differences
in
egg
shell
thickness
or
egg
shell
strength,
indicating
egg
quality
was
comparable
between
all
groups.
The
NOAEC
from
this
test
is
600
ppm
(
nominal
concentration)
or
587
ppm
(
mean
measured
concentration).
If
the
2
studies
are
examined
in
total,
there
is
a
compelling
argument
that
triadimefon
has
minimal
effect
on
bobwhite
quail
reproduction
or
growth.
While
the
first
study
may
have
had
an
unexplained
difference
in
the
number
of
cracked
eggs,
it
is
not
at
all
clear
that
his
was
related
to
the
exposure
to
triadimefon.
Without
any
concurrence
of
an
effect
on
egg
shell
thickness
or
egg
shell
strength,
and
nor
could
a
second
study
repeat
the
finding,
the
number
of
cracked
eggs
observed
in
the
first
bobwhite
quail
study
was
nuisance
variable,
that
is
not
relevant
to
the
risk
assessment.
The
risk
assessment
for
triadimefon
should
consider
600
ppm
(
nominal
or
587
ppm
measured)
as
the
NOAEC
for
the
compound.

Citations:
Toll,
P.
A.,
J.
B.
Beavers,
and
D.
W.
Fletcher.
1990.
Biological
Significance
of
Cracked
Eggs
In
Avian
Reproduction
Studies.
Society
Environmental
Toxicology
and
Chemistry
Eleventh
Annual
Meeting,
Arlington,
Virginia.
November
11­
15,
1990.

Agency
Response
In
regards
to
risk
quotient
calculations,
it
is
the
Agency's
policy
that
for
screening
level
risk
assessments
the
most
sensitive
acute
and/
or
chronic
endpoint
is
selected
from
the
available
test
data
and
is
used
in
the
risk
assessment.

The
Bobwhite
Quail
reproductive
toxicity
study,
MRID
110431,
was
reviewed
by
the
Agency.
The
Agency
review
determined
that
the
study
was
acceptable
and
that
it
produced
a
NOEAC
of
20
ppm
for
the
number
of:
eggs
cracked
fertile
eggs,
viable
3­
week
embryos,
hatchlings,
and
14
day
survivors.
The
study
results
illustrated
a
clear
dose
response
for
each
of
the
affected
entities
(
Table
1).
The
20
ppm
NOAEC
produced
in
this
study
was
the
most
sensitive
reproductive
toxicity
endpoint
among
all
available
avian
reproductive
studies.
Thus,
in
accordance
with
Agency
policy,
EFED
used
the
endpoint
to
calculate
reproductive
risk
to
Avian
Species.
13
Table
1.
Summary
of
Affected
Reproductive
Entities
in
the
Bobwhite
Quail
Reproductive
Toxicity
Test
MRID
110431
Results
Reproductive
Endpoint
Significantly
Affected
Control
20
ppm
100
ppm
500
ppm
Eggs
Cracked
63
101
184
205
Fertile
Eggs
1138
1042
937
941
Viable
3­
Week
Embryos
1060
972
897
877
Hatchlings
635
724
570
488
14­
Day
Survivors
595
613
472
411
Page
52.
Chronic
toxicity
to
mammals
EPA:
Similar
to
the
acute
data,
mammalian
chronic
data
obtained
from
the
Agency's
HED
are
substituted
for
wild
mammalian
testing.
HED
reproductive
and
developmental
toxicity
values
are
reported
in
Appendix
C.
These
studies
provide
adequate
toxicity
data
on
chronic
developmental
and
reproductive
effects
of
triadimefon.
Chronic
triadimefon
studies
using
laboratory
rats
show
decreased
pup
weights
and
viability
in
the
F1
and
F2
generations
and
decreased
litter
size
in
the
F2
generation
(
MRID
00155075,
92188019,
9
2188320),
with
an
offspring
NOAEL
of
50
ppm
ai.
Bayer
Response:
BCS
has
fully
examined
the
available
chronic
toxicity
data
for
rats,
and
strongly
believes
the
NOAEC
for
ecological
risk
assessment
is
300
ppm
ai
(
NOAEL
=
15
mg/
kg/
day).
Two
rat
reproduction
studies
are
available.
The
first
study
with
3
treatment
groups
(
50,
300
and
1800
ppm)
and
a
control
group
was
conducted
for
3
generations
in
1979
(
rated
as
acceptable/
nonguideline
by
the
EPA
reviewers).
The
second
study
with
2
treatment
groups
(
50,
and
1800
ppm)
and
a
control
group
was
conducted
for
2
generations
in
1984
(
also
rated
as
acceptable/
nonguideline
by
the
EPA
reviewers).
Both
studies
demonstrate
that
exposure
to
1800
ppm
triadimefon
had
significant
effects
on
the
growth
and
reproduction
of
rats.
BCS
agrees
that
the
parental/
reproductive
LOAEC
was
1800
ppm
(
90
mg/
kg/
day).
Since
no
parental/
reproductive
effects
were
observed
in
the
300
ppm
treatment
group
(
1979
study),
the
parental/
reproductive
NOAEC
is
300
ppm
(
15
mg/
kg/
day),
as
concluded
by
the
EPA
reviewers.
The
EPA
reviewers
state
that
the
offspring
NOAEC
is
50
ppm
(
2.5
mg/
kg/
day);
however
consideration
must
be
given
to
the
relevance
and
potential
long­
term
impact
of
an
endpoint
in
determining
the
ecologically
relevant
NOAEC.
BCS
believes
the
14
relevant
NOAEC
is
300
ppm.
In
the
first
study
with
the
3
triadimefon
treatment
groups,
the
only
difference
observed
in
the
300
ppm
treatment
group
was
related
to
body
weight
development
during
lactation.
In
2
of
the
6
litters
produced
(
the
2
Page
12
of
15
litters
from
the
second
mating
of
the
F1
and
F2
generations;
i.
e.,
F2b
and
F3b
litters)
had
a
slight
decrease
in
body
weight
during
the
lactation
period.
However
these
slight
differences
may
not
be
ecologically
relevant
given
that
the
F2b
generation
were
reared
until
maturity
and
mated.
As
the
development
of
these
animals
progressed,
there
were
no
further
effects
noted
on
the
growth
or
development
and
no
effects
were
observed
on
the
reproduction
of
these
animals.
Therefore
any
effect
observed
on
body
size
during
lactation
was
slight
and
transient.
Additionally,
the
exposure
that
caused
this
effect
occurred
over
a
constant
and
very
long
exposure
period,
and
the
offspring
produced
in
the
second
mating
are
based
on
aging
parental
animals,
which
may
have
an
impact
on
the
study.
In
conclusion,
the
ecologically
relevant
NOAEC
that
should
be
used
for
the
ecological
risk
assessment
is
300
ppm
(
15
mg/
kg/
day).

Agency
Response
In
regards
to
risk
quotient
calculations,
it
is
the
Agency's
policy
that
for
screening
level
risk
assessments
the
most
sensitive
acute
and/
or
chronic
endpoint
is
selected
from
the
available
test
data
and
is
used
in
the
risk
assessment.

Therefore
in
accordance
with
Agency
policy
for
calculating
the
triadimefon
mammalian
chronic
toxicity
risk
quotient
the
Agency
has
selected
the
mammalian
chronic
toxicity
NOEAL
endpoint
of
50
ppm
produced
in
multigeneration
rat
study,
MRID
00155075.
The
results
of
this
study
demonstrated
a
parental
NOAEC
of
50
ppm
for
decreases
in
litter
size,
number
of
pups
produced,
fertility,
body
weight,
and
decrease
in
ovary
size.
The
results
of
this
study
also
produced
an
offspring
NOAEC
of
50
ppm
for
decreases
in
pup
weights,
pup
viability,
and
decreases
in
litter
size.
Based
on
the
evidence
produce
in
this
study
showing
multiple
adverse
reproductive
effects,
EFED
presumes
that
the
adverse
effects
demonstrated
in
this
study
may
represent
biologically
significant
effects
that
may
adversely
impact
the
reproductive
success
of
wild
mammals
exposed
to
triadimefon.
This
presumption
is
may
especially
be
applicable
to
endangered
mammalian
species
populations
that
may
already
be
stressed.

The
results
of
the
study
demonstrated
more
adversely
affected
factors
and
a
more
sensitive
NOAEL
value
than
the
only
other
available
multigeneration
rat
reproductive
toxicity
study,
MRID
00032541.
This
study
produced:
1)
a
parental
NOAEL
of
300
ppm
based
on
decreased
fertility,
body
weights,
body
weight
gains,
and
litter
size,
and
2)
an
offspring
NOAEL
of
300
ppm
based
on
decreases
in
pup
body
weight
and
pup
weight
gains.
Consequently,
because
this
study
produced
a
less
sensitive
NOAEL
than
the
previously
mentioned
rat
multigenerational
study
(
MRID
00155075),
the
Agency
did
not
use
the
less
sensitive
results
of
this
study
to
calculate
the
chronic
risk
quotient
calculations
for
mammals.
15
IV.
RISK
CHARACTERIZATION
Pages
56
 
60
and
Tables
20
 
22.
EPA:
EPA
provides
a
concise
summary
of
the
RQs
and
LOC
exceedences
for
the
freshwater
risk
assessment.
Bayer
Response:
BCS
does
not
disagree
with
the
presentation
of
the
RQs
and
LOC
exceedences
presented.
However
as
noted
above,
a
useful
scenario
to
present
would
be
for
the
golf
course
turf
with
3
applications
at
2.7
lb
ai/
A
(
total
seasonal
application
of
8.1
lb
ai/
A).
This
is
a
reduction
in
23
applications
of
the
worst­
case
scenario
conducted
by
the
reviewers.
For
the
fish
and
invertebrate
acute
and
chronic
risk
quotients
(
Tables
20
and
21),
the
only
LOC
exceedences
were
for
turf
scenarios
that
had
13
or
more
applications.
Given
that
the
acute
RQ
for
13
applications
of
2.7
lb
ai/
A
was
0.07
(
only
a
slightly
above
the
endangered
species
LOC),
when
the
exposure
scenario
is
reduced
by
another
10
applications,
there
would
no
longer
be
any
LOC
exceedences.
Similarly
the
chronic
RQ
for
13
applications
of
2.7
lb
ai/
A
was
2.3;
the
reduction
of
the
number
of
applications
to
3
would
result
in
a
RQ
well
below
the
chronic
LOC.
For
the
risk
quotients
for
aquatic
non­
vascular
plants,
the
only
LOC
exceedences
were
for
turf
scenarios
with
13
or
more
applications.
The
RQ
for
the
turf
scenario
with
13
applications
of
2.7
lb
ai/
A
was
1.5.
As
mentioned
above,
when
the
number
of
applications
is
reduced
to
3,
the
RQ
will
be
well
below
the
endangered
species
LOC.

Agency
Response
The
Agency
is
in
agreement
that
there
would
be
no
LOC
exceedances
for
fish,
aquatic
invertebrate,
and
aquatic
plants
for
Bayer's
newly
proposed
turf
maximum
application
rates
of
either:
1)
3
applications
for
the
golf
course
use
pattern
for
a
maximum
total
seasonal
application
of
8.1
lbs.
a.
i./
acre
or
2)
a
professional
care
lawn
and
turf
maximum
use
rate
that
allows
3
applications
of
1.36
lbs.
a.
i./
acre,
with
a
30
day
interval
for
curative
control
of
southern
blight.

However,
the
Agency
deems
it
not
necessary
to
amend
the
current
Agency
`
s
ecological
risk
assessment
to
reflect
this
particular
application
rate
because
the
current
Agency's
ecological
risk
assessment
already
reflects
a
large
range
of
various
turf
application
rates
ranging
from
a
total
seasonal
application
of
70
lbs.
a.
i./
acre
(
26
applications
of
2.7
lbs.
a.
i./
acre)
to
a
total
seasonal
application
of
2.6
lbs.
a.
i./
acre
(
2
applications
of
1.3
lbs.
a.
i./
acre).
Within
that
range
of
application
rates,
the
Agency
LOC
exceedances
for
16
aquatic
organisms
begin
at
a
maximum
seasonal
rate
of
35
lbs.
a.
i./
acre
(
13
applications
of
2.7
lbs
a.
i./
acre.).

1.
Non­
target
Terrestrial
Animals
Pages
60­
66
Page
13
of
15
EPA:
EPA
present
the
risk
assessment
for
birds
and
mammals
using
the
endpoints
described
in
Ecological
Effects
Characterization
section.
A
discussion
of
the
RQs
and
LOCs
follow.
Bayer
Response:
Similar
to
the
discussion
for
the
aquatic
risk
assessment,
a
golf­
course
assessment
for
3
applications
of
2.7
lb
ai/
A
should
be
performed.
This
would
result
in
a
significant
reduction
in
the
acute
and
chronic
RQs
for
both
birds
and
mammals,
compared
to
the
26
application
scenario.
As
discussed
above,
the
appropriate
endpoint
(
NOAEL)
for
the
chronic
avian
risk
assessment
is
600
ppm
(
587
ppm
measured),
based
on
the
hazard
characterization
using
the
complete
set
of
data
available
for
triadimefon.
This
would
result
in
a
30
fold
decrease
in
the
RQs
for
the
chronic
avian
risk
assessment;
a
significant
reduction
in
the
potential
risk.
Similarly,
the
appropriate
endpoint
for
the
chronic
mammalian
risk
assessment
is
300
ppm
(
15
mg/
kg/
day).
This
would
result
in
a
6
fold
decrease
in
the
RQs
for
the
chronic
mammalian
risk
assessment,
a
significant
reduction
in
the
potential
risk.

The
golf
course
turf
use
pattern
represents
the
worst­
case
scenario
for
birds
and
wild
mammals.
In
assessing
the
potential
risk
under
this
scenario,
there
are
many
mitigating
factors
that
reduce
the
exposure/
and/
or
risk:
°
The
screening
level
assessment
assumes
a
mammal
or
bird
consumes
100%
of
diet
from
treated
field
(
or
food
items),
a
highly
conservative
assumption
that
is
not
realistic.
For
reasons
explained
below:
It
is
highly
unlikely
that
a
bird
and
mammal
will
consume
100%
of
their
diet
on
treated
food
items
that
maintain
a
constant
concentration
over
a
very
long
period
of
time
with
a
golf
course
use
pattern.
°
Golf
courses
are
highly
managed
areas.
While
watering­
in
of
the
compound
is
not
a
requirement,
frequent
irrigation
of
the
course
occurs.
This
irrigation
will
decrease
the
potential
exposure
of
triadimefon
on
the
relevant
avian
and
mammalian
food
items.
°
As
noted
on
the
label,
application
of
triadimefon
should
occur
when
the
turf
is
established
and
growing.
The
rapid
growth
of
the
turf
during
the
growing
season
will
have
a
dilution
effect
on
the
residues
of
triadimefon
in/
on
the
food
items.
Therefore
the
triadimefon
exposure
will
decrease
over
time
as
the
plant
grows.
°
Golf
courses
are
also
mowed
frequently.
As
the
plant
is
cut
and
new
growth
occurs,
the
potential
exposure
to
triadimefon
is
significantly
reduced
over
time
°
Triadimefon
is
not
applied
to
the
entire
golf
course
acres;
it
is
primarily
applied
to
tees,
greens
and
fairways,
which
encompass
approximately
28%
of
17
the
acres.
Therefore
triadimefon
will
generally
not
be
applied
to
the
primary
Page
14
of
15
wildlife
habitat
and
nor
would
100%
of
the
diet
be
receiving
a
direct
overspray
of
the
product.
In
conclusion,
the
screening
level
risk
assessment
for
the
golf
course
use
pattern
is
highly
conservative.
The
agronomic
practices
associated
with
golf
courses,
significantly
reduces
the
potential
risks
for
birds
and
mammals.

Agency
Response
In
response
to
the
Bayer's
proposal
to
use
Chronic
NOEAL
of
600
ppm
for
birds
and
300
ppm
for
mammals,
the
Agency
has
determined
(
as
previously
explained
in
above
Agency
responses)
that
in
accordance
with
Agency
policy
the
results
of
the
study
that
produces
the
most
sensitive
chronic
NOEAL
endpoint
must
be
used
to
calculate
chronic
risk
quotients
for
birds
and
mammals.
Thus,
the
Agency
used
the
chronic
toxicity
NOAEL
of
20
ppm
for
birds
and
50
ppm
for
mammals
(
MRIDs
110431
and
00155075).

The
current
label
for
triadimefon
use
on
golf
course
turf
did
not
specify
a
maximum
number
of
applications
per
season
or
a
maximum
total
seasonal
applications
rate.
Thus,
EFED'S
revised
ecological
risk
assessment
(
dated
1/
19/
06)
evaluated
a
range
of
different
scenarios
for
turf
application
rates.
These
scenarios
of
application
rates
ranged
from
1
to
26
applications
of
either
1.36,
1.31,
or
2.7
lbs.
a.
i./
with
intervals
of
either
7,
14,
28,
30,
or
60
days.
There
are
bird
and
mammal
Agency
level
of
concern
(
LOC)
exceedances
throughout
the
entire
range
of
application
rates.
In
particular,
there
are
bird
and
mammal
LOC
exceedances
which
would
result
from
Bayer's
proposals
to
add
to
the
label
which
include:
1)
a
maximum
number
of
applications
of
3
for
the
golf
course
use
pattern
for
a
maximum
total
seasonal
application
of
8.1
lbs.
a.
i./
acre
(
equivalent
to
3
applications
of
2.7
lbs.
a.
i./
acre)
and
2)
a
professional
care
lawn
and
turf
maximum
use
rate
that
allows
3
applications
of
1.36
lbs.
a.
i./
A,
with
a
30
day
interval
for
curative
control
of
southern
blight.
Tables
1­
3
illustrate
these
use
rates
and
their
resulting
LOC
exceedances
for
birds
and
mammals.

Tables
1­
3
also
include
risk
quotient
calculations
with
a
range
of
interval
times
(
7,
14,
30,
and
60
days
for
interval
times)
between
applications
for
the
Bayer
proposed
maximum
seasonal
application
amount
of
8.1
lbs.
a.
i./
acre
(
equivalent
to
3
applications
of
2.7
lbs.
a.
i./
acre).
The
Agency
took
this
measure
because
Bayer
did
not
specify
an
interval
time
between
applications
for
this
application
rate.

In
response
s
to
Bayer's
comment
about
the
assumption
about
terrestrial
organism's
diet
and
exposure
on
a
golf
course
the
Agency
concludes
the
following.
In
accordance
with
Agency
policy
in
all
screening­
level
assessments,
the
organisms
are
assumed
to
consume
100%
of
their
diet
as
one
food
type,
thereby
eliminating
the
need
at
the
screening
level
for
evaluating
mixtures
of
dietary
items
(
i.
e.
items
off
the
golf
course).
18
Risk
Description
Pages
72
and
74:
Risk
to
Terrestrial
Organisms
and
Plants
­
Spray
Drift
EPA:
EPA
used
the
AgDrift
model
to
calculate
the
distance
from
the
edge
of
the
field
required
to
bring
spray
drift
below
the
LOC.
Bayer
Response:
The
use
of
AgDrift
to
calculate
the
distance
to
achieve
drift
below
the
LOC
must
be
done
with
extreme
caution,
and
may
not
be
appropriate
use
of
the
tool.
The
spray
deposition
is
to
wildlife
food
items
is
not
equivalent
to
the
deposition
that
was
measured
to
develop
the
model.
The
AgDrift
model
was
developed
under
scenarios
to
bare
ground,
which
is
not
the
case
for
any
of
the
scenarios
modeled.
For
example,
the
golf
course
scenario
is
not
bare
ground,
and
it
is
well
known
that
golf
courses
will
have
vegetation
(
trees,
shrubs,
etc.)
that
will
intercept
drift.
Therefore
AgDrift
will
grossly
overestimate
the
deposition
distance.
In
addition,
the
droplet
spectrum
in
a
drift
event
will
be
different
than
the
spectrum
from
a
direct
application
event
to
a
wildlife
food
item.
These
differences
in
spectrum
will
result
in
difference
in
coverage
of
the
item
upon
which
deposition
as
occurred.
Deposition
onto
a
food
item
will
be
less
from
a
drift
event;
therefore
the
AgDrift
model
will
overestimate
the
residues
on
the
wildlife
food
item.
Drift
onto
a
plant
will
occur
primarily
on
the
surface
of
the
plant,
and
may
not
occur
at
the
base
of
the
plant
where,
for
example,
a
small
mammal
would
forage.
For
the
insectivorous
animals,
the
insect
food
items
will
be
immigrating
and
emigrating
from
any
one
area,
and
therefore
to
assume
that
100%
of
the
insects
have
equivalent
residues
is
not
appropriate.
Additionally,
drift
onto
many
insects
will
be
low
given
the
potential
for
drift
interception
to
occur
by
surrounding
plants.
In
conclusion,
the
use
of
AgDrift
to
determine
these
differences
may
not
provide
a
meaningful
tool
for
interpreting
risks
to
birds
and
mammals.
19
Agency
Response
For
screening
terrestrial
risk
assessments
for
listed
species,
a
generic
bird
or
mammal
is
assumed
to
occupy
either
the
treated
field,
or
adjacent
areas
receiving
pesticide
a
rate
commensurate
with
the
treatment
rate
on
the
field.
Spray
drift
model
predictions
suggest
that
this
assumption
leads
to
an
overestimation
of
exposure
to
species
that
do
not
occupy
the
treated
field.
AgDrift
estimated
drift
to
areas
removed
from
the
fields
(
below)
indicates
that
off
site
drift
is
but
a
fraction
of
on­
field
treatment
rate.

Spray
Droplet
Size
AgDrift
Model
Drift
Point
Estimate
0
to
990
from
field
(
Tier
1)

Very
fine­
fine
50%
to
4%
Fine
to
medium
50%
to
1%
Medium
to
coarse
50%
to
0.5%
Coarse
to
very
coarse
50%
to
0.3%

For
screening
risk
assessment
purposes,
the
actual
habitat
requirements
of
any
particular
terrestrial
species
are
not
considered,
and
it
is
assumed
that
species
occupy,
exclusively
and
permanently,
the
treatment
area
being
modeled.
This
assumption
leads
to
a
maximum
level
of
exposure
in
the
risk
characterization.
To
the
extent
that
a
species
does
not
reside
exclusively
and
permanently
in
treated
areas,
exposure
will
be
less,
and
presumably
significantly
less.

Page
82:
Risk
to
Terrestrial
Organisms
and
Plants
EPA:
EPA
calculated
the
probability
of
an
acute
event
at
the
highest
application
rate.
Bayer
Response:
While
it
has
been
acknowledged
that
the
golf
course
label
has
not
specified
and
the
number
of
applications,
the
presentation
of
26
applications
will
grossly
overestimate
the
potential
toxicity
of
the
compound,
which
has
low
acute
toxicity.
20
Agency
Response
The
current
label
for
triadimefon
use
on
golf
course
turf
did
not
specify
a
maximum
number
of
applications
per
season
or
a
maximum
total
seasonal
applications
rate.
Thus,
EFED'S
revised
ecological
risk
assessment
(
dated
1/
19/
06)
evaluated
a
range
of
different
scenarios
for
turf
application
rates.
These
scenarios
of
application
rates
ranged
from
1
to
26
applications
of
either
1.36,
1.31,
or
2.7
lbs.
a.
i./
with
intervals
of
either
7,
14,
28,
30,
or
60
days.
There
are
bird
and
mammal
Agency
level
of
concern
(
LOC)
exceedances
throughout
the
entire
range
of
application
rates.
In
particular,
there
are
bird
and
mammal
LOC
exceedances
which
would
result
from
Bayer's
proposals
to
add
to
the
label
which
include:
1)
a
maximum
number
of
applications
of
3
for
the
golf
course
use
pattern
for
a
maximum
total
seasonal
application
of
8.1
lbs.
a.
i./
acre
(
equivalent
to
3
applications
of
2.7
lbs.
a.
i./
acre)
and
2)
a
professional
care
lawn
and
turf
maximum
use
rate
that
allows
3
applications
of
1.36
lbs.
a.
i./
A,
with
a
30
day
interval
for
curative
control
of
southern
blight.
Tables
1­
3
illustrate
these
use
rates
and
their
resulting
LOC
exceedances
for
birds
and
mammals.

Tables
1­
3
also
include
risk
quotient
calculations
with
a
range
of
interval
times
(
7,
14,
30,
and
60
days
for
interval
times)
between
applications
for
the
Bayer
proposed
maximum
seasonal
application
amount
of
8.1
lbs.
a.
i./
acre
(
equivalent
to
3
applications
of
2.7
lbs.
a.
i./
acre).
The
Agency
took
this
measure
because
Bayer
did
not
specify
an
interval
time
between
applications
for
this
application
rate.

APPENDIX
3
 
Triadimefon
and
Triadimenol
Toxicity
Data
Page
176
 
Mammals,
Acute
and
Chronic
EPA:
EPA
provides
the
summary
of
the
mammalian
toxicity
data.
Bayer
Response:
As
discussed
earlier,
EPA
should
present
the
results
from
both
of
the
rat
reproduction
studies.

Agency
Response
In
regards
to
risk
quotient
calculations,
it
is
the
Agency's
policy
that
for
screening
level
risk
assessments
the
most
sensitive
acute
and/
or
chronic
endpoint
is
selected
from
the
available
test
data
and
is
used
in
the
risk
assessment.

Therefore
in
accordance
with
Agency
policy
for
calculating
the
triadimefon
mammalian
chronic
toxicity
risk
quotient
the
Agency
has
selected
the
mammalian
chronic
toxicity
NOEAL
endpoint
of
50
ppm
produced
in
multigeneration
rat
study,
MRID
00155075.
The
results
of
this
study
demonstrated
a
parental
NOAEC
of
50
ppm
for
decreases
in
litter
size,
number
of
pups
produced,
fertility,
body
weight,
and
decrease
in
ovary
size.
The
results
of
this
study
also
produced
an
offspring
NOAEC
of
50
ppm
for
decreases
in
pup
weights,
pup
viability,
and
decreases
in
litter
size.
Based
on
the
evidence
produce
in
this
study
showing
multiple
adverse
reproductive
effects,
EFED
presumes
that
the
adverse
effects
demonstrated
in
this
study
may
represent
biologically
significant
effects
that
may
adversely
impact
the
reproductive
success
of
wild
mammals
exposed
to
21
triadimefon.
This
presumption
is
may
especially
be
applicable
to
endangered
mammalian
species
populations
that
may
already
be
stressed.

The
results
of
the
study
demonstrated
more
adversely
affected
factors
and
a
more
sensitive
NOAEL
value
than
the
only
other
available
multigeneration
rat
reproductive
toxicity
study,
MRID
00032541.
This
study
produced:
1)
a
parental
NOAEL
of
300
ppm
based
on
decreased
fertility,
body
weights,
body
weight
gains,
and
litter
size,
and
2)
an
offspring
NOAEL
of
300
ppm
based
on
decreases
in
pup
body
weight
and
pup
weight
gains.
Consequently,
because
this
study
produced
a
less
sensitive
NOAEL
than
the
previously
mentioned
rat
multigenerational
study
(
MRID
00155075),
the
Agency
did
not
use
the
less
sensitive
results
of
this
study
to
calculate
the
chronic
risk
quotient
calculations
for
mammals.
