Request
for
Additional
Information
and
Suggestions
for
the
Reregistration
of
Imazapyr
Phase
3
Public
Comment
Period
December
21,
2005
___________________________________________________________________________

Request
for
Data
and
Mitigation
Proposals
All
elements
of
the
U.
S.
Environmental
Protection
Agency's
(
EPA)
risk
assessments
and
supporting
documents
are
open
for
public
comment.
EPA
is,
however,
particularly
seeking
use
and
usage
information,
data
refinement,
and/
or
mitigation
proposals
to
address
the
risk
estimates
presented
in
the
Agency's
risk
assessments.

Imazapyr
is
an
herbicide
used
for
the
control
of
a
broad
range
of
weeds
and
provides
residual
control
of
a
wide
variety
of
annual
and
perennial
weeds.
For
the
uses
of
imazapyr
including
corn;
forestry
sites;
rights­
of­
way;
fence
rows;
hedge
rows;
drainage
systems;
outdoor
industrial
areas;
outdoor
buildings
and
structures;
domestic
dwellings;
paved
areas;
driveways;
patios;
parking
areas;
walkways;
various
water
bodies
(
including
ponds,
lakes,
streams,
swamps,
wetlands,
and
stagnant
water);
and,
urban
areas
being
considered
for
reregistration,
EPA
is
seeking
the
following
types
of
information:

°
Is
there
any
additional
information
that
may
help
the
Agency
make
a
more
informed
ecological
risk
assessment
for
non­
target
terrestrial
plants,
aquatic
vascular
plants,
and
potential
risks
to
endangered
species
(
aquatic
vascular
plants,
terrestrial
and
semi­
aquatic
monocots
and
dicots)?
°
Are
there
any
suggestions
for
mitigation
proposals
for
uses
where
the
ecological
risks
are
a
concern
to
the
Agency
including:
risks
to
non­
target
terrestrial
plants
and
aquatic
vascular
plants,
and
potential
risks
to
endangered
species
(
aquatic
vascular
plants,
terrestrial
and
semi­
aquatic
monocots
and
dicots)?
°
What
are
the
costs
and
efficacy
of
using
alternative
methods
to
control
the
target
weeds?
°
What
are
the
cultural
practices
designed
to
minimize
the
impact
on
the
environment,
particularly
practices
that
may
help
protect
aquatic
vascular
plants,
and
monocot
and
dicot
seedling
emergence
and
vegetative
vigor?
°
Is
there
data
available
to
determine
chronic
effects
to
estuarine/
marine
fish
and
invertebrates,
and
reproductive
effects
to
avian
species?

Risk
Estimates
of
Concern
Human
Health
Assessment
Imazapyr
is
of
low
toxicity
via
the
oral,
dermal,
and
inhalation
routes
of
exposure.
There
are
no
human
health
risks
of
concern
resulting
from
the
use
of
imazapyr.

Ecological
Assessment
Risks
of
concern
associated
with
the
use
of
imazapyr
are
to
non­
target
terrestrial
plants
and
aquatic
vascular
plants,
and
potential
risks
to
endangered
species
(
aquatic
vascular
plants,
terrestrial
plants
growing
in
dry
and
semi­
aquatic
habitats,
and
endangered
species
which
depend
on
these
plants).
Imazapyr
use
on
non­
cropped
areas
and
on
Clearfield
corn
applied
at
the
labeled
concentration
rates
as
a
liquid
spray
for
ground
or
aerial
applications
as
well
as
a
granular
formulation
to
forestry
areas
presents
a
risk
to
non­
target
plants
located
adjacent
to
treated
areas.

For
the
non­
cropped
uses
at
both
the
high
and
low
application
rates
by
ground
and
aerial
spray,
risks
of
concern
include
non­
endangered
terrestrial
plants
located
adjacent
to
treated
areas,
in
semi­
aquatic
areas,
and
as
a
result
of
runoff
and
spray
drift.
For
the
granular
forestry
uses
at
both
the
high
and
low
application
rates,
risks
of
concern
include
both
the
non­
endangered
and
the
endangered
monocots
and
dicots
located
adjacent
to
treated
areas,
in
semi­
aquatic
areas,
and
as
a
result
of
runoff.
For
the
Clearfield
corn
use
by
both
ground
and
aerial
spray,
risks
of
concern
include
non­
endangered
monocots
and
dicots
located
in
semi­
aquatic
areas
and
endangered
terrestrial
plants
in
adjacent
semi­
aquatic
and
dryland
areas
and
the
endangered
species
which
depend
on
these
plants.
For
labeled
uses
of
imazapyr
applied
by
ground
and
aerial
spray,
for
the
granular
application,
and
for
direct
application
to
water
(
1.5
lbs
ai/
acre),
risks
of
concern
include
both
non­
endangered
and
endangered
aquatic
vascular
plants
inhabiting
a
treated
water
body,
or
surface
waters
adjacent
to
a
treated
field
and
endangered
species
which
depend
on
these
plants
(
as
outlined
in
the
Transmittal
of
the
Ecological
Risk
Assessment
for
Imazapyr).
