UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
DATE:
11/
03/
00
SUBJECT:
Cypermethrin
and
Zeta­
Cypermethrin
­­
Conclusions
of
the
Meeting
of
Metabolism
Assessment
Review
Committee
(
10/
10/
00).

DP
Barcode:
D269584
PRAT
Case#:
191525
Submission
#:
S570509
Caswell#:
None
Chemical#:
109702,
129064
Class:
insecticide
Trade
Name:
Fury
®
1.5
EW
EPA
Reg#:
279­
3126
Fury
®
1.5
EC
279­
3125
Ammo
®
2.5
EC
279­
3027
40
CFR:
180.418
MRID:
none
TO:
George
Kramer,
Ph.
D.
Chemist
MARC
Executive
Secretary
RAB1/
HED
(
7509C)

FROM:
Yan
Donovan,
Chemist
RAB2/
Health
Effects
Division
(
7509C)

THRU:
Richard
Loranger,
Ph.
D.,
Branch
Senior
Scientist
RAB2/
Health
Effects
Division
(
7509C)
and
Christine
Olinger,
Chair
of
MARC
Health
Effects
Division
(
7509C)
2
A.
Material
Reviewed
The
Committee
reviewed
and
discussed
the
material
in
the
10/
02/
00
Issues
Memo
of
Yan
Donovan
and
Alan
Levy,
which
includes
the
new
submitted
acute
toxicity
(
oral
LD50
in
the
rat;
MRID#
44952001)
and
Mutagenicity
Assay
(
Ames
Assay;
MRID#
44952002)
studies
for
metabolite
DCVA.

B.
Conclusions
Nature
of
the
Residue
in
Plant
and
in
Animals
The
Committee
concluded
that,
for
the
case
of
cypermethrin
and
zeta­
cypermethrin
only,
the
parent
compound
is
the
only
residue
of
concern
which
needs
to
be
included
in
the
tolerance
expression
and
used
for
dietary
risk
assessment,
including
drinking
water.
Metabolite
DCVA
will
not
be
included
in
the
risk
assessment
and
therefore
can
be
waived
in
future
residue
analyses
of
samples
from
cypermethrin
and
zeta­
cypermethrin
studies.
This
decision
regarding
DCVA
does
not
extend
to
other
pyrethroids
which
generate
this
metabolite.
Each
such
insecticide
needs
to
be
examined
individually
with
respect
to
DCVA.

c.
Supporting
Reasons
The
Committee
used
the
following
conclusions/
facts
in
supporting
the
conclusion
drawn
above:

­
The
submitted
salmonella
reverse
mutation
assay
(
Ames
assay)
conducted
with
DCVA
indicated
that
the
compound
(
DCVA)
was
negative
in
the
presence
and
absence
of
metabolic
activation
in
all
five
tester
strains.
The
submitted
acute
oral
toxicity
study
in
rats
conducted
with
DCVA
concluded
that
for
metabolite
DCVA,
the
acute
oral
LD50
is
1609
mg/
kg
for
males
and
1192
mg/
kg
for
females.
These
values
are
higher
than
those
for
the
parent
compounds
(
Cypermethrin:
LD50
=
247
mg/
kg
for
males,
LD50
=
309
mg/
kg
for
females;
Zeta­
cypermethrin:
LD50
=
134.4
mg/
kg
for
males,
LD50
=
86.0
mg/
kg
for
females).
Although
these
toxicity
study
results
eased
some
of
the
toxicity
concerns
for
DCVA,
they
do
not
completely
remove
all
concerns.
The
Committee
was
concerned
with
the
presence
of
the
electrophilic
dichlorovinyl
group.
A
90­
day
study
will
be
more
helpful
to
address
the
toxicity
of
DCVA.

­
Regardless
of
the
fact
that
there
are
still
toxicity
concerns
for
DCVA,
the
residue
data
indicated
that
in
majority
of
the
crops,
parent
compound
accounts
for
at
least
3
90%
of
the
total
residue,
with
only
a
few
exceptions.
In
those
crops
where
DCVA
was
found
>
10%,
either
the
detected
DCVA
levels
are
below
the
limit
of
quantitation
(
LOQ)
or
the
maximum
animal
dietary
burden
contributions
from
DCVA
for
these
commodities
are
about
equal
to
or
less
than
the
LOQ.

­
The
DCVA
levels
in
the
animal
tissues,
liver
and
kidney
are
greater
than
those
of
the
parent.
However,
considering
that
these
are
secondary
residues
and
these
foods
contribute
little
to
the
total
dietary
exposure,
the
amount
of
DCVA
would
be
negligible
in
the
risk
assessment.

S
EFED
provided
information
which
indicates
that
at
neutral
pH,
parent
compound
is
stable.

D.
Individuals
in
Attendance
1.
Metabolism
Assessment
Review
Committee
George
Kramer,
Nancy
Dodd,
Kit
Farwell,
Cheng
Leung,
John
Doherty,
and
Alberto
Protzel.

2.
Scientists
(
non­
Committee
members)

Yan
Donovan,
Pam
Hurley,
and
Jose
Melendez
(
EFED
representative)

3.
Committee
members
in
Absentia
Sanjivani
Diwan,
Christine
Olinger,
William
Wassell
cc:
Yan
Donovan;
Reading
file.
