UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
PC
Code:
127201
DPBarcode:
D364167
SUBJECT:
EFED
Response
to
Bayer's
Comments
on
the
Triadimenol
Drinking
Water
Assessment
FROM:
James
Breithaupt
Environmental
Risk
Branch
II
Environmental
Fate
and
Effects
Division
(
7507C)

TO:
Susan
Lewis,
RM
51/
John
Pates
Jr.,
CRM
Special
Registration
and
Review
Division
(
7505
C)

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

DATE:
February
7,
2006
In
response
to
the
triadimenol
drinking
water
assessment
(
D312519,
2/
9/
05),
Bayer
requested
a
clarification
of
why
EFED
provided
two
sets
of
chronic
Estimated
Exposure
Concentrations
(
EECs)
for
triadimenol
in
surface
water.
For
non­
cancer
risk
assessment,
EFED
normally
provides
the
upper
10th
percentile
annual
mean
value
from
PRZMEXAMS
over
a
30­
year
period.
For
cancer
risk
assessment,
EFED
provides
the
mean
of
all
EECs
from
PRZM­
EXAMS
over
a
30­
year
period.
Table
1
below
provides
the
EECs
from
the
drinking
water
memorandum
dated
February
9,
2005.
Because
no
changes
to
the
drinking
water
assessment
were
necessary,
EFED
did
not
revise
the
original
memorandum.
If
there
are
any
questions,
please
contact
Jim
Breithaupt
at
703­
305­
5925
or
by
email
at
breithaupt.
james@
epa.
gov
.
Table
1.
Tier
II
surface
water
EEC's
using
PRZM­
EXAMS
for
drinking
water
for
triadimenol
for
use
on
crops
as
a
seed
treatment
EECs
(
ng/
L),
parts­
per­
trillion
Crop
Peak
4­
day
21­
day
60­
day
90­
day
Annua
l
Mean
Overal
l
mean
Wheat
(
for
wheat,
barley,
oats,
and
rye)
393
389
367
329
308
194
128
Corn
95
94
87
75
68
34
22
Cotton
133
128
114
87
73
27
14
