UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
April
13,
2006
OFFICE
OF
PREVENTION
PESTICIDES
AND
TOXIC
SUBSTANCES
Memorandum
SUBJECT:
Biological
and
Economic
Analysis
of
Dichlorvos
for
Food
Storage
Areas
FROM:
Don
Atwood,
Entomologist
Biological
Analysis
Branch
TJ
Wyatt,
Economist
Economic
Analysis
Branch
Biological
and
Economic
Analysis
Division
(
7503C)

THRU:
Arnet
Jones,
Chief
Biological
Analysis
Branch
Tim
Kiely,
Acting
Chief
Economic
Analysis
Branch
Biological
and
Economic
Analysis
Division
(
7503C)

TO:
Dayton
Eckerson/
Eric
Olson,
Chemical
Review
Manager
Reregistration
Branch
1
Special
Review
and
Reregistration
Division
(
7508C)

PRP
REVIEW
DATE:
March
31,
2006
SUMMARY
Available
data
indicate
that
dichlorvos
is
the
major
insecticide
used
to
control
pests
in
food
storage
areas.
BEAD
believes
that
pyrethrin
would
be
the
insecticide
of
choice
in
the
absence
of
dichlorvos.
However,
pyrethrin
is
not
as
volatile
as
dichlorvos
and
therefore
individual
applications
of
pyrethrin
do
not
treat
equivalent
areas
as
dichlorvos.
In
addition,
1
to
4
(
average
2.5)
applications
of
pyrethrin
would
be
necessary
to
achieve
the
same
efficacy
as
currently
provided
by
dichlorvos.
Based
on
the
increased
number
of
applications,
BEAD
estimates
that
a
move
from
dichlorvos
to
pyrethrin
would
cost
an
additional
$
24
million
dollars
annually
in
the
US.
Considering
the
unique
properties
of
dichlorvos,
the
increased
number
of
applications
of
pyrethrin
required
to
achieve
equivalent
efficacy,
and
the
additional
cost
of
pyrethrin,
BEAD
concludes
that
there
is
an
important
need
for
the
use
of
dichlorvos
to
control
food
storage
pests.
2
I.
SCOPE
AND
LIMITATIONS
OF
ASSESSMENT
The
scope
of
this
assessment
is
at
the
national
level.
This
mitigation
scenario
is
in
response
to
the
health
risks
identified
by
the
Health
Effects
Division
of
the
Office
of
Pesticide
Programs.

There
are
limits
to
this
assessment.
The
primary
limit
is
the
lack
of
available
data
associated
with
usage
of
dichlorvos
in
food
storage
area.
The
assessment
relies
primarily
upon
state
insecticide
recommendations
for
stored
product
and
pantry
pests
and
usage
information
from
the
California
Department
of
Pesticide
Regulation.
In
addition,
this
assessment
relies
heavily
on
the
EPA
benefit
assessment
conducted
in
1993.
In
the
absence
of
efficacy
data
for
dichlorvos
alternatives,
this
assessment
assumes
that
alternatives
as
recommended
by
the
states
can
provide
efficacy
equivalent
to
dichlorvos.
In
addition,
fumigants
were
not
considered
in
this
assessment
as
they
are
used
to
control
infestations
rather
than
prevent
infestations
and
therefore
are
not
direct
replacements
for
dichlorvos.

II.
FOOD
STORAGE
AREA
DICHLORVOS
USAGE
Dichlorvos
for
use
in
controlling
pests
of
food
storage
areas
is
supplied
as
a
soluble
concentrate
and
generally
applied
as
space
treatment
to
prevent
pest
infestations
from
developing
(
preventative).
Current
dichlorvos
usage
data
for
this
site
is
only
available
for
California
(
Table
1).
Dichlorvos
is
the
primary
insecticide
used
for
insect
control
in
food
storage
areas,
representing
67%
of
total
area
treated
with
insecticides.

Table
1.
Insecticide
usage
in
California
Food
Processing
and
Handling
Plants
2000.

Insecticide
#
of
Applications
Area
treated
(
1,000
cu.
ft)
Area
treated
per
application
(
1,000
cu.
ft.)
%
total
area
treated
cyfluthrin
1
210
210
0.1
dichlorvos
31
133,000
4290
67.2
pyrethrin
42
64,841
1543
32.7
It
is
estimated
that
50,000
lbs
of
dichlorvos
are
used
per
year
to
control
pests
in
food
storage
areas.
At
an
application
rate
of
1
­
2
grams
per
1,000
cu
ft
and
assuming
12
applications
per
year,
it
is
estimated
that
0.9
­
1.8
billion
cu
ft
of
food
storage
area
is
treated
per
year
in
the
US.
3
III.
USE
OF
DICHLORVOS
TO
CONTROL
PESTS
OF
FOOD
STORAGE
AREAS
The
most
common
insects
infesting
food
storage
areas
are
in
the
insect
orders
Lepidoptera
(
moths)
and
Coleoptera
(
beetles).
Dichlorvos
is
used
as
a
soluble
concentrate
in
food
storage
areas
to
control
a
wide
range
of
stored
product
insects
including
but
not
limited
to;
cigarette
beetle,
warehouse
beetle,
sawtoothed
grain
beetle,
rice
weevil,
confused
flour
beetle,
cocoa
bean
moth,
Mediterranean
flour
moth,
and
Indianmeal
moth.

Food
storage
area
pests
damage
products
through
contamination
with
their
bodies
and
their
by­
products.
The
larval
stage
of
the
Indianmeal
moth
produces
frass
(
excrement)
and
webbing,
and
some
beetle
larvae
produce
secretions
that
give
food
a
disagreeable
odor
and
taste.
Setae
(
hairs)
from
the
warehouse
beetle
can
irritate
the
mouth,
throat,
and
stomach
of
people
who
eat
infested
products
and
can
be
a
choking
hazard
to
young
children
and
pets.
In
addition,
food
storage
area
pests
can
introduce
microbes
into
the
food
products
that
could
produce
mycotoxins
(
highly
carcinogenic
compounds),
especially
if
the
food
is
stored
in
warm,
humid
conditions.

A.
FOOD
STORAGE
AREA
PESTS
CONTROLLED
WITH
DICHLORVOS
1.
Flour/
grain
moths
­
The
most
common
species
of
meal
moths
found
in
the
food
storage
areas
are
the
Indianmeal
moth
and
Mediterranean
flour
moth.
All
damage
is
done
by
the
larvae,
which
attack
a
wide
range
of
products,
including
cereal
and
cereal
products,
flour,
cornmeal,
rice,
dried
fruit,
dehydrated
vegetables,
nuts,
chocolate,
candies,
and
other
confections.

2.
Weevils/
beetles
­
There
are
several
species
of
beetles
which
commonly
attack
a
wide
variety
of
foods:
the
warehouse
beetle;
the
sawtoothed
grain
beetle
and
the
merchant
grain
beetle;
the
confused
flour
beetle
and
the
red
flour
beetle;
and
the
drugstore
beetle
and
the
cigarette
beetle.

a.
Warehouse
Beetle
­
The
warehouse
beetle
feeds
on
a
wide
variety
of
foods
including
cereals,
candy,
cocoa,
cookies,
cornmeal,
fish
meal,
pet
foods,
flour,
nuts,
dried
peas
and
beans,
pastas,
potato
chips,
spices,
dead
animals,
and
dead
insects.
The
setae
of
this
beetle
are
shed
within
the
infested
food
product
and
can
be
irritating
to
the
mouth,
esophagus,
and
digestive
tract
if
they
are
ingested;
consequently
any
food
found
infested
with
this
beetle
should
be
discarded.

b.
Sawtoothed
Grain
Beetle
and
Merchant
Grain
Beetle
­
In
both
larval
and
adult
stages,
these
beetles
feed
on
all
food
of
plant
origin,
especially
grain
and
grain
products
like
flours,
meals,
breakfast
foods,
stock
and
poultry
feeds,
coconut,
nut
meats,
candies,
and
dried
fruit;
it
is
not
uncommon
to
find
these
beetles
infesting
pet
4
food,
bird
seed,
and
rodent
bait.

c.
Confused
Flour
Beetle
and
Red
Flour
Beetle
­
These
beetles
have
a
very
wide
food
range
including
cereals,
damaged
grains,
grain
products,
shelled
nuts,
dried
fruit,
chocolate,
drugs,
and
herbarium
and
museum
specimens.

d.
Cigarette
Beetle
and
Drugstore
Beetle
­
The
cigarette
beetle
feeds
on
cured
tobacco,
cigarettes,
and
cigars.
It
also
feeds
on
dried
herbs,
spices,
nuts,
cereals
and
cereal
products,
dried
fruit,
seeds,
and
animal
products
such
as
dried
fish
and
meats,
hair,
and
wool.
In
the
home
this
beetle
is
most
commonly
found
in
pet
foods,
cereals,
nuts,
and
candy.
It
may
also
infest
dried
pepper
arrangements,
wreaths,
and
spices
such
as
chili
powder
or
paprika.

The
drugstore
beetle
is
a
very
general
feeder,
attacking
a
great
variety
of
stored
foods,
seeds,
pet
foods,
spices,
and
pastry
mixes,
and
has
been
said
to
"
eat
anything
except
cast
iron."
It
gets
its
name
from
its
habit
of
feeding
on
almost
all
drugs
found
in
pharmacies.

e.
Rice/
grain
weevils
­
These
insects
generally
damage
whole
grains
or
seeds,
but
also
have
been
observed
feeding
on
nuts
and
beans.
They
generally
do
not
feed
on
flour
or
cereals
unless
it
has
become
caked.

IV.
ALTERNATIVE
INSECTICIDES
TO
DICHLORVOS
FOR
CONTROLLING
FOOD
STORAGE
AREA
PESTS
Numerous
pesticides
are
registered
to
control
pests
in
food
storage
areas
(
Table
2).
Most
registered
products
are
effective
against
both
moths
and
beetles.
Fumigants
were
not
included
as
they
are
used
to
eliminate
infestations
where
dichlorvos
is
used
to
prevent
infestations.
In
most
cases,
pesticides
will
only
provide
a
temporary
solution
for
controlling
pests
in
food
storage
areas.

Table
2.
Alternative
insecticides
available
to
control
pests
in
food
storage
areas
as
of
2003.

PEST
CLASS
ACTIVE
INGREDIENT
Biological
permethrin
Insect
Growth
Regulator
methoprene
Carbamate
propoxur
acephate
Stored
Food
Insects
Organophosphate
chlorpyrifos
5
PEST
CLASS
ACTIVE
INGREDIENT
diazinon
propetamphos
cyfluthrin
deltamethrin
allethrin
pyrethrins
tetramethrin
tralomethrin
resmethrin
phenothrin
esfenvalerate
imiprothrin
Pyrethroids
sumithrin
Sticky
traps
pheromone
bait
However,
while
there
are
a
number
of
registered
pesticides,
usage
data
from
the
California
Department
of
Pesticide
Regulation
for
2000
(
Table
1),
indicates
that
dichlorvos
and
pyrethrin
are
the
only
2
primary
insecticides
used
for
control
of
pests
in
food
storage
areas.

V.
NONCHEMICAL
CONTROL
OF
FOOD
STORAGE
AREA
PESTS
Numerous
non­
chemical
alternatives
are
available
for
control
of
pests
in
food
storage
areas.
These
include
temperature
modification
(
heat
or
cold),
atmosphere
modification,
irradiation,
electric
zappers,
traps
(
light
and
pheromone),
biological
control
(
parasites/
predators/
pathogens),
and
sanitation.
However,
the
use
of
some
of
these
alternatives
would
require
extensive
facility
modification
at
high
cost.
In
addition,
use
of
alternative
controls
is
dependent
upon
target
pest,
pest
density,
type
of
storage
facility,
and
commodity.
With
additional
research,
control
of
pests
in
food
storage
areas
could
be
achieved
using
some
of
these
nonchemical
alternatives
alone
or
in
combination.
However,
at
present,
nonchemical
alternatives
are
best
used
to
augment
conventional
pest
control
programs
using
insecticides.

VI.
BIOLOGICAL
IMPORTANCE
OF
DICHLORVOS
FOR
FOOD
STORAGE
AREA
PESTS
6
Numerous
alternative
insecticides
are
registered
to
control
pests
in
food
storage
areas.
However,
as
most
of
the
alternative
insecticides
registered
for
food
storage
area
pest
control
are
surface
sprays
as
opposed
to
a
space
spray,
they
cannot
be
considered
as
direct
replacements
for
dichlorvos.
Nevertheless,
usage
data
from
California
suggests
that
if
dichlorvos
was
unavailable,
users
would
most
likely
use
pyrethrin
to
achieve
pest
control.
According
to
professionals
and
applicators,
1
­
4
(
average
of
2.5)
applications
of
pyrethrin
might
be
needed
to
provide
the
same
level
of
control
as
1
treatment
of
dichlorvos.
This
is
the
result
of
the
unique
volatility
of
dichlorovos.
Pyrethrin
does
not
exhibit
the
same
high
vapor
pressure
and
diffusion
as
dichlorvos
and
cannot
as
effectively
treat
a
similar
area.
BEAD
concludes
that
alternative
insecticides
are
available
but
will
require
more
applications
and
additional
expense
to
achieve
the
same
level
of
control
as
currently
provided
by
dichlorvos.

VII.
ECONOMIC
IMPORTANCE
OF
DICHLORVOS
FOR
FOOD
STORAGE
AREA
PESTS
While
there
are
a
few
registered
chemicals
for
food
storage
areas,
2000
use
data
from
the
California
Department
of
Pesticide
Regulation
show
that
primarily
dichlorvos
and
pyrethrin
are
used
to
prevent
pests
in
the
food
storage
areas.
However,
pyrethrin
does
not
exhibit
the
same
high
vapor
pressure
and
diffusion
as
dichlorvos
and
does
not
as
effectively
treat
a
similar
sized
area.
Because
of
a
lack
of
comparative
efficacy
data,
we
assume
that
higher
application
frequencies
(
2.5)
of
pyrethrin
would
provide
the
same
level
of
control
as
one
application
of
dichlorvos.

A.
DATA
USED
2000
California
data
are
the
only
available
usage
data
for
dichlorvos
and
its
alternative
pyrethrin.
Available
data
show
about
463
pounds
ai
of
dichlorvos
are
used
on
nearly
133
million
cu
ft
of
treated
space,
almost
67
percent
of
the
total
cu
ft
treated
with
both
dichlorvos
and
pyrethrin
(
198
million
cu
ft).
About
53
pounds
ai
of
pyrethrin
are
used
on
almost
65
million
cu
ft
of
storage
area,
almost
33
percent
of
the
total
space
area
treated
with
both
chemicals.
According
to
expert
opinion
(
EPA
1993),
1­
4
applications
(
average
2.5)
of
pyrethrin
would
be
needed
to
replace
1
application
of
dichlorvos.

B.
COMPARATIVE
COSTS
Table
2
compares
the
major
alternative
with
dichlorvos
as
a
space
treatment.
Other
alternative
chemicals
may
be
used
as
surface
treatments
or
as
fumigants;
however,
because
dichlorvos
is
not
usually
used
as
a
surface
treatment
or
fumigant,
price
comparisons
of
these
uses
were
not
included
in
this
analysis.
7
Table
2.
Estimated
Impacts
to
Food
Storage
Areas
Of
Not
Having
Dichlorvos
Available
for
Use
To
Control
Major
Pests.

CHEMICAL
FORMULATION
APPLICATION
RATE
(
product/
1,000
ft3)
PRICE/
UNITa
Cubicb
Feet
Treated
(
000)
COST/
1,000
ft3
dichlorvos
5%
EC
(
Vap
5)
½
­
1
fl
ounce
$
24/
gallon
133,000
½
fl
oz.
rate
$
0.10
1
fl
oz.
rate
$
0.19
pyrethrin
3%
EC
(
ULD
BP
300)
1.0
fl
ounce
$
105/
gallon
65,000
$
0.82
a
California
Pesticide
Use
Summaries
Report,
University
of
California,
Division
of
Agriculture
and
Natural
Resources,
January
2003,
and
b
Rolfes,
Pat,
President,
Chem­
Tech,
Ltd.
Facsimiles
on
current
prices
for
dichlorvos
and
pyrethrin,
to
Jihad
Alsadek
of
USEPA/
OPP/
BEAD/
EAB,
February
25
and
27,
2003.

C.
UNITS
TREATED
California
data
shows
463
lb.
a.
i.
of
dichlorvos
are
applied
in
food
storage
areas.
At
a
typical
application
rate
of
1
gram
a.
i.
per
1000
cu
ft,
the
463
lb.
a.
i.
of
dichlorvos
applied
in
California
would
treat
about
211
million
cubic
feet
yearly.
According
to
expert
opinion
(
EPA
1993),
on
average
you
need
about
2.5
applications
of
pyrethrin
to
provide
the
same
control
as
1
application
of
dichlorvos.
Assuming
a
12
applications
per
year,
roughly
17
million
cu
ft
of
Food
Storage
area
are
treated
annually
in
California.
Using
the
same
application
rate
and
number
of
applications
for
national
food
storage
use
of
dichlorvos,
assuming
annual
use
of
50,000lbs,
it
is
estimated
that,
on
average,
1.5
billion
cu
ft
of
food
storage
area
are
treated
annually
with
this
insecticide.

D.
IMPACTS
OF
USING
PYRETHRIN
INSTEAD
OF
DICHORVOS
The
impacts
of
using
pyrethrin
rather
than
dichlorvos
is
roughly
$
26
million
per
year.
The
cost
per
application
(
1,000
cu
ft)
with
the
alternative
(
pyrethrin)
would
increase
about
63
cents,
for
the
1
fl
oz
rate.
If
30
applications
of
pyrethrin
replaced
12
applications
of
dichlorvos
per
year,
the
extra
cost
per
year
would
be
about
$
17
per
1,000
cu
ft
treated
(
19
cents
x
12
applications
+
82
cents
x
18
applications)
or
about
$
80,000
for
an
average
warehouse.
Expert
opinion
provided
to
the
EPA
in
1993
estimated
the
volume
of
the
dry
portion
of
an
average
grocery
warehouse
to
be
4,730,000
cu
ft.
It
is
estimated
1.5
billion
cu
ft
of
food
storage
space
receive
an
average
of
12
applications
of
dichlorvo
per
year
(
18
billion
cu
ft/
12
applications).
The
added
cost
of
1.5
billion
cu
ft
treatments
is
8
about
$
26
million.

VIII.
REFERENCES
1.
Benefit
analysis
of
dichlorvos
­
Support
Document.
1993.
US
EPA.

2.
Insecticide
Usage
Data.
2000.
California
Department
of
Pesticide
Regulation.

3.
Control
of
Household
Pests.
2006.
2006
North
Carolina
Agricultural
Chemicals
Manual
­
Chapter
V:
Insect
Control
http://
ipm.
ncsu.
edu/
agchem/
5­
22.
pdf
4.
Nebguide
­
Insect
Pests
of
Stored
Food
in
Kitchen
and
Pantry.
1996.
University
of
Nebraska
Cooperative
Extension.
G93­
1130­
A
5.
Household
Insects
­
Pantry
Pests.
Clemson
Cooperative
Extension.

6.
Pantry
Pests.
1996.
Cooperative
Extension
Service
­
University
of
Missouri­
Columbia.
Agricultural
publication
G7370.

7.
Keeping
Pests
Out
of
the
Home
with
Fewer
Pesticides
&
Using
Pesticides
Safely.
2001.
Cooperative
Extension
Service
­
University
of
Georgia.

8.
USAID
Commodities
Reference
Guide.
Section
IV:
Controlling
Damage
to
Food
Commodities.
2206.
http://
www.
usaid.
gov/
our_
work/
humanitarian_
assistance/
ffp/
crg/
sec4.
htm
9.
Pest
Management
in
Food­
Handling
and
Other
Specialized
Facilities.
http://
www.
pested.
msu.
edu/
Resources/
bulletins/
pdf/
2048/
E­
2048PestManagement_
FoodHandling.
pdf
