United
States
Prevention,
Pesticides
EPA­
738­
F­
05­
007
Environmental
Protection
And
Toxic
Substances
September
2005
Agency
(
7508C)

R.
E.
D.
FACTS
Ametryn
Pesticide
Reregistration
All
pesticides
sold
or
distributed
in
the
United
States
must
be
registered
by
EPA,
based
on
scientific
studies
showing
that
they
can
be
used
without
posing
unreasonable
risks
to
people
or
the
environment.
Because
of
advances
in
scientific
knowledge,
the
law
requires
that
pesticides
which
were
first
registered
before
November
1,
1984,
be
reregistered
to
ensure
that
they
meet
today's
more
stringent
standards.

In
evaluating
pesticides
for
reregistration,
EPA
obtains
and
reviews
a
complete
set
of
studies
from
pesticide
producers,
describing
the
human
health
and
environmental
effects
of
each
pesticide.
To
implement
provisions
of
the
Food
Quality
Protection
Act
of
1996,
EPA
considers
the
special
sensitivity
of
infants
and
children
to
pesticides,
as
well
as
aggregate
exposure
of
the
public
to
pesticide
residues
from
all
sources,
and
the
cumulative
effects
of
pesticides
and
other
compounds
with
common
mechanisms
of
toxicity.
The
Agency
develops
any
mitigation
measures
or
regulatory
controls
needed
to
effectively
reduce
each
pesticide's
risks.
EPA
then
reregisters
pesticides
that
meet
the
safety
standard
of
the
FQPA
and
can
be
used
without
posing
unreasonable
risks
to
human
health
or
the
environment.

When
a
pesticide
is
eligible
for
reregistration,
EPA
explains
the
basis
for
its
decision
in
a
Reregistration
Eligibility
Decision
(
RED)
document.
This
fact
sheet
summarizes
the
information
in
the
RED
document
for
reregistration
case
2010,
ametryn.

Use
Profile
Ametryn
is
an
herbicide
used
to
control
broadleaf
and
grass
weeds
in
fields
planted
with
field
corn,
popcorn,
pineapple,
and
sugarcane.
There
is
only
one
formulation,
an
80%
water
dispersible
granule.
Ametryn
is
applied
mainly
by
groundboom
but
also
by
aerial
application
in
Florida.

Regulatory
History
Ametryn
was
first
registered
as
a
pesticide
in
the
U.
S.
in
1964.
Several
Generic
Data
Call­
Ins
(
DCIs)
were
issued
that
required
a
full
range
of
testing
on
ametryn's
chemistry,
toxicology,
and
environmental
fate.

Currently,
only
one
ametryn
end
use
product
is
registered.
EPA
has
received
requests
for
voluntary
cancellation
of
all
other
products.

Human
Health
Acute
Toxicity
2
Assessment
Ametryn
has
been
shown
to
have
low
acute
dermal,
oral,
and
inhalation
toxicity.
It
is
classified
as
a
Toxicity
Category
III
for
oral
ingestion
and
dermal
toxicity
and
Category
IV
for
inhalation
toxicity.
Ametryn
is
non­
irritating
to
the
eye
(
Category
III)
and
skin
(
Category
IV)
and
did
not
demonstrate
sensitization.
The
category
ratings
are:

Category
I
=
very
highly
or
highly
toxic
Category
II
=
moderately
toxic
Category
III
=
slightly
toxic
Category
IV
=
practically
non­
toxic
Based
on
the
available
data,
acute
and
chronic
toxicity
is
expected
to
be
low.
Cancer
is
not
expected
to
be
a
concern
as
tumors
only
occurred
in
oncogenicity
studies
when
the
maximum
dose
tolerated
was
exceeded.

Dietary
Exposure
and
Risk
People
may
be
exposed
to
residues
of
ametryn
through
the
diet.
Established
tolerances
or
maximum
residue
limits
for
field
corn,
popcorn,
pineapple,
and
sugarcane
(
please
see
40
CFR
§
180.258)
have
been
reassessed
and
set
at
lower
levels.
All
other
tolerances
are
to
be
revoked.
No
new
tolerances
were
established
for
ametryn.

EPA
has
assessed
the
dietary
risk
(
food
and
drinking
water)
posed
by
ametryn.
Acute
and
chronic
dietary
(
food
only)
risk
from
ametryn
from
all
sources
are
low
and
below
the
Agency's
level
of
concern.
Estimated
concentrations
of
ametryn
and
its
metabolites,
in
groundwater
and
surface
water
sources
of
drinking
water,
are
low
resulting
in
risks
below
EPA's
level
of
concern.

Occupational
and
Residential
Exposure
and
Risk
Based
on
current
use
patterns,
occupational
handlers
(
mixers,
loaders,
and
applicators)
may
be
exposed
to
ametryn
during
normal
use.
Estimated
risk
to
handlers
with
baseline
personal
protective
equipment
(
pants,
long
sleeve
shirt,
shoes,
and
socks)
are
low
and
not
of
concern.
Post
application
exposure
is
not
expected
for
the
registered
use
patterns
of
ametryn.
Also,
there
are
no
residential
uses
of
ametryn
and
no
anticipated
exposures
in
or
around
homes
and
recreational
areas.

FQPA
Considerations
EPA
has
determined
that
the
reduced
tolerances
for
ametryn,
with
amendments
and
changes
as
specified
in
the
RED,
meet
the
safety
standards
under
the
FQPA
amendments
to
§
408(
b)(
2)(
C)
of
the
FFDCA,
and
that
there
is
a
reasonable
certainty
of
no
harm
for
infants
and
children.
3
EPA
considered
the
aggregate
exposure
from
food
and
drinking
water
(
there
are
no
residential
uses)
and
determined
that
the
risks
were
well
below
the
Agency's
level
of
concern.

EPA
reduced
the
ametryn
FQPA
safety
factor
to
1X
based
on
the
following:
(
1)
there
are
no
concerns
and
no
residual
uncertainties
with
regard
to
developmental
toxicity
studies
and
the
reproduction
study;
(
2)
there
were
no
indications
of
immunotoxicity
or
direct
neurotoxicity
in
the
standard
studies,
(
3)
the
good
quality
of
the
dietary
exposure
data
(
crop
field
trial
data);
and
(
4)
the
conservatism
in
the
drinking
water
models
which
are
also
considered
adequately
protective
to
infants
and
children.

EPA
has
determined
that
there
is
no
known
mechanism
of
toxicity
that
would
support
grouping
ametryn
with
chloro­
s­
triazines
(
atrazine,
simazine,
propazine
and
their
chloro­
s­
triazine
metabolites)
for
a
cumulative
risk
assessment.
Ametryn
has
a
different
functional
group
attached
to
the
triazine
ring,
i.
e.,
thiomethyl
versus
chloro.
Moreover,
ametryn
does
not
exhibit
the
same
toxicity
profile
as
the
chloro­
s­
triazines.
Further,
the
Agency
has
found
no
information
indicating
ametryn
shares
a
common
mechanism
of
toxicity
with
other
substances,
nor
does
ametryn
appear
to
produce
a
toxic
metabolite
produced
by
other
substances.

Environmental
Assessment
For
terrestrial
species,
short­
term
or
acute
ametryn
risks
are
low
to
mammals,
birds,
and
non­
target
insects.
However,
the
screening­
level
ecological
risk
assessment
for
terrestrial
species
indicates
some
exceedance
of
the
chronic
levels
of
concern
(
LOCs),
especially
to
mammals
that
rely
on
grasses
and
broadleaf
plants/
insects
for
their
diet
and
birds
that
rely
on
short
grasses.
In
aquatic
species,
acute
and
chronic
risks
are
low,
with
the
exception
of
the
chronic
risk
for
estuarine/
marine
invertebrates.

Consistent
with
its
chemical
use
as
an
herbicide,
ametryn
is
toxic
to
plants,
including
dicots
which
are
much
more
sensitive
to
ametryn
than
monocots.
The
LOCs
for
dicot
plants
are
exceeded
for
uses
of
ametryn
in
all
exposure
scenarios
(
adjacent
areas,
semi­
aquatic,
and
spray
drift).
The
LOCs
for
monocots
exceed
for
almost
all
uses
in
adjacent
area
and
semi­
aquatic
exposure
scenarios.
Similarly,
for
aquatic
plants,
although
based
on
limited
data,
the
LOCs
are
exceeded
for
both
vascular
and
non­
vascular
plants
for
uses
of
ametryn.

Risk
Mitigation
To
lessen
the
environmental
risks
posed
by
ametryn,
EPA
is
requiring
the
following
risk
mitigation
measures:

N
reduce
the
maximum
single
application
rate
and
maximum
annual
rate
for
all
remaining
crops;

N
limit
aerial
application
to
sugarcane
in
Florida
only;

N
eliminate
use
on
bananas,
plantain,
and
non­
cultivated
areas;
and
4
N
measures
to
control
spray
drift
to
reduce
the
risk
of
ametryn
to
non­
target
organisms.

Additional
Data
Required
EPA
is
requiring
several
general
and
confirmatory
data
requirements
for
ametryn.
These
include
product
and
residue
chemistry
studies,
environmental
fate
and
effects
studies,
and
a
mutagenicity
study.
EPA
will
be
calling
in
one
new
study,
a
modified
foliar
dissipation
study
to
determine
ametryn's
half­
life
on
leaves.
For
a
complete
listing
of
required
studies
with
corresponding
guideline
number,
see
Section
V.
of
the
ametryn
RED
document.

Product
Labeling
Changes
Required
The
remaining
ametryn
end­
use
product
must
comply
with
EPA's
pesticide
product
labeling
requirements
summarized
in
the
RED.
For
a
comprehensive
list
of
labeling
requirements,
please
see
Section
V.
of
the
ametryn
RED
document.

Regulatory
Conclusion
EPA
has
determined
that
all
products
containing
ametryn
as
the
sole
active
ingredient
are
eligible
for
reregistration,
provided
changes
specified
in
the
ametryn
RED
are
incorporated
into
the
label.

For
More
Information
EPA
is
making
the
Reregistration
Eligibility
Decision
(
RED)
document
and
all
supporting
documents
for
ametryn
available,
as
announced
in
a
Notice
of
Availability
published
in
the
Federal
Register
September
21,
2005.
To
obtain
a
copy
of
the
RED
document,
please
contact
the
Pesticide
Docket,
Public
Information
and
Records
Integrity
Branch,
Information
Technology
and
Resource
Management
Division
(
7502C),
Office
of
Pesticide
Programs
(
OPP),
US
EPA,
Washington,
DC
20460,
telephone
703­
305­
5805.
Please
refer
to
EPA
Docket
number
OPP­
2004­
0411.

Electronic
copies
of
the
RED
and
this
fact
sheet
are
available
on
the
Internet.
See
http://
www.
epa.
gov/
pesticides/
reregistration/
status.
htm.

For
more
information
about
EPA's
pesticide
reregistration
program,
the
ametryn
RED,
or
reregistration
of
individual
products
containing
ametryn,
please
contact
the
Special
Review
and
Reregistration
Division
(
7508C),
OPP,
US
EPA,
Washington,
DC
20460,
telephone
703­
308­
8000.

For
information
about
the
health
effects
of
pesticides,
or
for
assistance
in
recognizing
and
managing
pesticide
poisoning
symptoms,
please
contact
the
National
Pesticide
Information
Center
(
NPIC).
Call
toll­
free
1­
800­
858­
7378,
from
6:
30
am
to
4:
30
pm
Pacific
Time,
or
9:
30
am
to
7:
30
pm
Eastern
Standard
Time,
seven
days
a
week.
The
NPIC
internet
address
is
http://
npic.
orst.
edu.
