Document ID: EPA-HQ-OPP-2005-0123-0236
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-08-09T04:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON
D.
C.,
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
SUBJECT:
Qualitative
Assessment
of
the
Impact
of
Changes
in
the
Use
of
Methyl
Bromide
in
Structural
and
Food
Processing
Facilities
in
Support
of
the
Reregistration
Eligibility
Decision
(
RED)

FROM:
Jonathan
Becker,
Senior
Science
Advisor
William
Chism,
Senior
Agronomist
Colwell
Cook,
Biologist
Monisha
Kaul,
Biologist
Biological
Analysis
Branch
Biological
and
Economic
Analysis
Division
(
7503P)

David
Donaldson,
Economist
Elisa
Rim,
Economist
T
J
Wyatt,
Agricultural
Economist
Economic
Analysis
Branch
Biological
and
Economic
Analysis
Division
(
7503P)

THRU:
Arnet
Jones,
Chief,
Biological
Analysis
Branch
Istanbul
Yusuf,
Acting
Chief,
Economic
Analysis
Branch
Biological
and
Economic
Analysis
Division
(
7503P)

TO:
John
Leahy,
Senior
Policy
Analyst
Eric
Olson,
Team
Leader
Steven
Weiss,
Chemical
Review
Manager
Special
Review
and
Registration
Division
(
7508P)

PRODUCT
REVIEW
PANEL
DATE:
July
26,
2006
Page
2
SUMMARY
As
part
of
the
reregistration
of
methyl
bromide,
the
Biological
and
Economic
Analysis
Division
(
BEAD)
assessed
the
potential
impacts
of
risk
mitigation
and
enforcement/
compliance
options.
These
options
were
outlined
in
the
Environmental
Protection
Agency
(
EPA)
Federal
Register
Notice
of
March
29,
2006.
This
document
addresses
the
potential
impacts
to
fumigations
of
structures
and
food
processing
facilities.
Other
assessments
address
the
impacts
on
quarantine
commodities,
non­
quarantine
commodities,
and
dry­
cured
pork.

BEAD
does
not
expect
substantial
impacts
to
result
from
lowering
the
air
concentration
limit
of
occupational
exposure
from
five
(
5)
parts
per
million
(
ppm)
to
one
(
1)
ppm
as
a
8­
hour
TWA,
provided
facilities
have
the
option
to
utilize
air
purifying
respirators
to
protect
employees
when
air
concentrations
are
between
these
points.
BEAD
also
does
not
expect
substantial
impacts
if
EPA
were
to
require
Fumigation
Management
Plans
and
other
actions
that
focus
on
compliance
and/
or
enforcement.

BEAD
believes
that
a
treatment
buffer
greater
than
20
to
30
feet
or
an
aeration
buffer
larger
than
200
to
250
feet
would
be
infeasible
for
most
facilities.
Facilities
located
in
rural
areas
may
be
able
to
accommodate
larger
treatment
and
aeration
buffers
without
substantial
impacts
on
their
operations.
BEAD
estimates
the
majority
(
72%)
of
the
structures
/
food
processing
facilities
to
be
greater
than
500,000
cubic
feet.
Under
the
99
whole
field
standard,
the
calculated
treatment
buffers
for
a
500,000
cubic
foot
facility,
assuming
the
greatest
gas
retention
and
a
1­
lb
application
rate,
is
280
feet.
Treatment
buffers
will
be
greater
for
larger
volumes,
higher
rates
and
lower
gas
retention.
The
calculated
aeration
buffers
for
large
facilities
range
from
90
to
over
2,680
feet.
These
buffers,
therefore,
are
likely
to
impose
some
impacts
on
medium
to
large
facilities
located
in
urban
areas
and
possibly
large
facilities
located
in
rural
areas.

It
appears
that
using
various
other
risk
mitigation
options,
including
rate
reduction,
fumigating
smaller
volumes,
improvements
in
sealing
techniques,
active
aeration
with
fans
and
stacks,
and/
or
capture
and
destruction
technology
may
help
to
reduce
the
size
of
the
buffer
zones.
BEAD
believes
that
most
facilities,
even
the
larger
ones,
would
be
able
to
accommodate
aeration
buffers
using
a
combination
of
options,
such
as
active
aeration
and
stacks.
Portable
stacks
appear
particularly
effective,
although
they
may
not
be
feasible
for
larger
facilities.
This
conclusion
is
based
on
the
assumption
that
the
99
percentile
whole
field
buffer
is
the
regulatory
basis.
However,
there
appear
to
be
few
feasible
options
to
reduce
the
treatment
buffers
and
few
facilities
are
likely
to
be
able
to
comply
with
those
estimated
in
this
document.
Site­
specific
modeling
may
result
in
smaller
buffers
that
still
meet
safety
standards.

If
facilities
are
unable
to
meet
the
buffer
requirements,
even
with
the
adoption
of
other
measures,
they
would
be
unable
to
use
methyl
bromide.
Since
2005,
production
of
methyl
bromide
is
only
permitted
under
the
Montreal
Protocol
for
certain
uses,
including
those
that
have
been
designated
as
a
critical
need.
EPA
and
USDA
have
evaluated
exemption
requests
based
on
current
conditions
and
found
that
there
are
no
alternatives
that
are
technically
and
economically
feasible
to
the
use
of
methyl
bromide
in
this
sector
(
USA,
2006a,
2006b).
If
medium
to
large
food
processing
facilities
cannot
feasibly
implement
the
required
treatment
zone,
even
with
the
additional
mitigation
options,
they
may
have
to
cease
operations.
This
could
have
detrimental
Page
3
effects
on
U.
S.
producers
of
grains
and
other
raw
materials,
on
consumers
of
these
products,
and
on
the
local
economies.
BEAD
does
not
have
adequate
data
about
the
specific
site
characteristics
of
these
facilities
to
quantify
the
distribution
and
magnitude
of
these
impacts.

BACKGROUND
Methyl
bromide
is
an
odorless,
colorless
gas
that
is
widely
used
as
a
soil
and
structural
fumigant
to
control
a
range
of
insect,
fungal
and
weedy
pests.
Under
the
Federal
Insecticide,
Fungicide,
and
Rodenticide
Act
(
FIFRA),
the
Office
of
Pesticide
Programs
(
OPP)
is
presently
making
a
determination
of
methyl
bromide's
eligibility
for
reregistration.
In
this
process,
OPP
is
assessing
the
risks
and
benefits
of
methyl
bromide
use
to
control
pests
in
food
processing
and
storage
facilities.

The
Montreal
Protocol
on
Ozone
Depleting
Substances
Methyl
Bromide
has
been
identified
as
an
ozone
depleting
substance
under
the
Montreal
Protocol
on
Ozone
Depleting
Substances
to
which
the
United
States
is
a
party.
The
Montreal
Protocol
is
an
international
treaty
developed
to
protect
the
earth
from
the
detrimental
effects
of
ozone
stratospheric
depletion.
Initially
signed
in
1987
by
the
United
States
and
26
other
countries,
there
are
now
189
signatories
to
the
treaty.
The
Parties
to
the
Montreal
Protocol
have
agreed
to
specific
reduction
steps
that
lead
to
the
phaseout
of
production
and
use
of
ozonedepleting
substances,
including
methyl
bromide.
The
Protocol
required
an
incremental
reduction
in
methyl
bromide,
leading
to
a
complete
phase
out,
in
industrialized
nations,
by
January
1,
2005.
Developing
countries
are
to
phase
out
use
by
January
1,
2015.

However,
there
are
some
cases
where
there
are
no
available
alternatives
that
are
technically
and
economically
feasible
and
acceptable
from
a
public
health
standpoint.
The
treaty
allows
for
exemptions
to
the
phase
out
for
critical
uses,
quarantine
and
preshipment
uses,
and
emergency
uses.
Critical
uses
are
those
situations
where
there
are
no
technically
and
economically
feasible
alternatives
and
market
disruptions
would
occur
if
methyl
bromide
were
not
available.
They
are
reviewed
in
EPA's
Methyl
Bromide
Critical
Use
Exemption
(
CUE)
process.
Quarantine
and
preshipment
uses
of
methyl
bromide
are
often
required
by
national
and
international
law
to
prevent
the
introduction
of
exotic
pests
into
new
areas.
Unanticipated
emergency
use
of
methyl
bromide,
for
example
to
address
public
health
problems,
is
authorized
by
the
Montreal
Protocol,
if
there
are
no
technically
and
economically
feasible
alternatives
and
the
quantity
used
does
not
exceed
20
metric
tons.

The
uses
addressed
in
this
document
have
received
critical
use
exemptions
under
the
Montreal
Protocol
for
the
years
2005,
2006,
and
2007.
A
critical
use
exemption
for
2008
is
currently
being
evaluated
by
the
Parties
to
the
Montreal
Protocol.
These
represent
situations
of
severe
or
unique
pest
problems
for
which
the
available
alternatives
are
not
feasible
and
will
result
in
severe
market
disruptions
if
methyl
bromide
is
not
available.

The
Parties
to
the
Protocol
approve
an
amount
of
methyl
bromide
that
is
allocated
for
soil
and
non­
soil
uses.
That
amount
is
the
maximum
amount
that
can
be
used
from
newly
produced
methyl
bromide
or
from
critical
use
stockpiles.
Entities
that
are
users
of
"
critical
use"
methyl
Page
4
bromide
do
not
have
access
to
the
general
use
methyl
bromide
stockpiles
(
i.
e.,
those
methyl
bromide
stocks
generated
before
January
1,
2005).
This
sets
an
upper
limit
on
the
amount
of
methyl
bromide
for
structures,
commodities,
and
dry­
cured
hams,
and
consequently,
on
the
total
volume
that
can
be
fumigated
in
any
one
year.
Individual
entities
are
not
allocated
a
specific
quantity
of
methyl
bromide.

Risks
of
Concern
As
part
of
OPP's
determination
of
methyl
bromide's
eligibility
for
reregistration,
OPP
conducted
risk
assessments
for
methyl
bromide
use
in
enclosures,
chambers,
and
food
processing/
storage
facilities.
There
are
no
aggregate
dietary
and
water
risks
of
concern.
However,
there
are
risks
of
concern
associated
with
the
use
of
methyl
bromide
for
occupational
exposure
during
both
treatment
and
aeration
and
for
bystanders
during
aeration
(
EPA
2006).
Occupational
exposure
may
occur
to
fumigant
applicators
during
and
immediately
after
treatment
and
to
certain
employees
at
the
treated
sites,
especially
those
handling
treated
commodities.
Bystanders
refer
to
site
employees
and
people
unaffiliated
with
the
treated
site
who
are
present
in
the
general
vicinity.
EPA's
Office
of
Air
and
Radiation
has
also
assessed
the
potential
impacts
on
the
incidents
of
skin
cancer
due
to
stratospheric
ozone
depletion
caused
by
the
use
of
methyl
bromide
for
non­
soil
fumigations.

OPP
is
evaluating
various
means
of
managing
the
risks
of
concern
from
occupational
and
bystander
exposure.
In
determining
an
appropriate
risk
management
strategy,
OPP
considers
a
number
of
factors
including
efficacy
of
the
measures,
enforceability,
the
impact
on
users
of
methyl
bromide
and
the
extent
to
which
these
measures
can
also
contribute
to
reduction
in
ozone
depletion.
This
document
presents
OPP's
evaluation
of
various
risk­
reduction
strategies
according
to
these
factors.
However,
because
of
the
great
diversity
in
sites
being
treated
with
methyl
bromide,
OPP
has
limited
ability
to
make
quantitative
evaluations.

RISK
MANAGEMENT
STRATEGIES
Bystander
and
Occupational
Exposure
during
Treatment
and
Aeration
Broadly
speaking,
there
are
three
risk
management
strategies
for
addressing
bystander
risk
to
be
considered.
Within
these
broad
strategies
some
or
all
of
the
17
different
options
suggested
by
EPA
(
2006)
for
public
comment
may
be
included.
The
broad
strategies
are
adoption
of
a
performance
standard,
command
and
control,
and
a
hybrid
approach
that
sets
certain
minimum
requirements
but
permits
flexibility
to
accommodate
site­
specific
characteristics.
EPA
believes
the
third
option
best
addresses
all
the
factors
to
be
considered.

Performance
Standard:
EPA
sets
maximum
air
concentrations
at
reference
points;
sets
criteria
for
determining
reference
point;
sets
criteria
for
monitoring;
establishes
penalties
for
exceedences.

Under
this
approach,
EPA
would
establish
performance
standards
to
limit
exposure
to
methyl
bromide
during
treatment
and
during
post­
treatment
aeration.
Essentially,
this
would
entail
defining
how
appropriate
reference
points
(
potential
bystanders)
would
be
chosen,
setting
a
Page
5
maximum
air
concentration
at
those
reference
points,
and
establishing
criteria
for
monitoring
at
the
reference
points.
Fumigators
would
be
responsible,
via
whatever
means
available,
including
those
suggested
by
EPA
(
2006),
to
insure
that
air
concentrations
of
methyl
bromide
do
not
exceed
limits.
EPA
would
also
establish
methods
to
ensure
compliance.

The
main
advantage
of
this
strategy
is
that
it
provides
maximum
flexibility
to
methyl
bromide
users
to
meet
the
safety
standard
and,
therefore,
minimizes
the
impacts
on
the
regulated
community.
That,
in
turn,
means
that
it
would
have
the
least
impact
of
the
three
options
on
the
total
amount
of
methyl
bromide
used
and
released
into
the
atmosphere.

The
primary
disadvantage
of
this
strategy
is
the
basic
question
of
whether
it
can
be
implemented
effectively.
Unless
the
number
and
location
of
bystanders
is
limited
and
well­
defined,
extensive
monitoring,
both
horizontally
and
vertically,
around
the
treated
facility
would
be
necessary
to
insure
that
the
statutory
requirement
of
reasonable
certainty
of
no
harm
is
met.
Further,
because
compliance
would
depend
on
post­
treatment
penalties
for
exceedances,
the
reporting
and
oversight
requirements
on
the
fumigator
and
state
and
local
regulators
would
be
burdensome.

EPA
does
not
believe
a
pure
performance
standard
can
be
reliably
implemented
in
a
costeffective
manner.

Single
Approach:
Buffer
Zones:
The
second
strategy
represents
the
opposite
end
of
the
spectrum,
where
EPA
would
establish
a
command
and
control
strategy
to
encompass
all
sites.
The
most
likely
option
for
addressing
bystander
risk
would
be
to
require
treatment
and
aeration
buffer
zones
that
would
be
dependent
on
the
amount
of
methyl
bromide
used
in
a
24­
hour
period
that
would
result
in
a
reasonable
certainty
of
no
harm
for
all
possible
fumigation
scenarios.
To
account
for
all
situations,
the
buffer
zone
would
have
to
be
substantial.

This
strategy
would
be
relatively
easy
to
enforce
because
it
would
depend
on
so
few
factors.
With
minimal
effort
by
EPA
and
State
and
local
regulators,
EPA
could
also
be
assured
that
all
use
of
methyl
bromide
would
meet
the
statutory
safety
requirement
 
in
fact,
most
uses
would
substantially
surpass
what
would
be
necessary
to
meet
the
requirements.
This
strategy
would
also
result
in
the
greatest
decrease
in
the
total
amount
of
methyl
bromide
used
and
released
into
the
atmosphere
of
the
three
strategies
because
many
facilities
would
be
unable
to
comply
with
a
large
buffer
zone
and
would
have
to
use
alternative
pest
control
methods
or
cease
operation.

However,
the
inability
of
many
facilities
to
comply
with
this
strategy
would
lead
to
large
impacts
on
methyl
bromide
users.
As
explained
in
this
document
and
the
U.
S.
nomination
of
critical
use
exemptions
to
the
Montreal
Protocol,
use
of
methyl
bromide
remains
necessary
in
many
situations.
Without
methyl
bromide,
there
would
be
serious
disruptions
in
global
and
interstate
trade
and
many
items
would
be
unable
to
meet
federal
health
requirements
for
safe
and
unadulterated
food
products.
Consumers
could
face
substantially
higher
costs
for
goods
and
some
goods
would
probably
not
be
available
year
around.

EPA
does
not
believe
such
a
simplistic
strategy
would
be
a
cost­
effective
means
of
insuring
the
safe
use
of
methyl
bromide.
Page
6
Flexible
Approach:
Buffer
Zones
as
a
Function
of
Other
Mitigation
Actions:
The
third
strategy
combines
the
flexibility
of
the
performance
standard
with
the
relative
simplicity
of
clear,
minimum
standards.
Some
of
the
options
suggested
by
EPA
(
EPA
2006)
could
be
used
in
concert
to
achieve
the
statutory
human
health
requirement.
The
basic
requirement
would
be
for
a
buffer
zone,
but
the
size
of
the
buffer
would
depend
on
the
use
of
other
risk
management
options.
EPA's
concept
is
for
two
buffers:
a
treatment
buffer
during
fumigation
and
an
aeration
buffer
following
treatment
as
the
gas
is
vented.
The
size
of
each
buffer
would
be
positively
related
to
the
amount
or
rate
of
methyl
bromide
used
and
the
size
of
the
facility/
enclosure
fumigated.
Reductions
in
any
of
these
factors
would
permit
a
smaller
required
buffer.
The
size
of
the
treatment
buffer
would
be
negatively
related
to
the
retention
of
gas
in
the
fumigated
enclosure.
The
tighter
the
enclosure,
the
less
gas
would
escape
and
the
smaller
the
treatment
buffer.
The
size
of
the
aeration
buffer
would
be
negatively
related
to
the
relative
height
of
the
point
methyl
bromide
is
vented
(
a
stack)
and
the
speed
of
aeration
(
i.
e.,
as
defined
by
air
exchange
rate),
which
improves
mixing
and
reduces
air
concentrations.
Increases
in
either
of
these
factors
would
permit
a
smaller
buffer
for
bystanders.

As
with
the
first
possible
strategy,
this
approach
can
reduce
the
cost
of
complying
with
the
regulation
by
providing
different
facilities
the
ability
to
reduce
bystander
exposure
according
to
the
specific
characteristics
of
the
site.
The
clear,
minimum
requirements
make
it
relatively
easy
to
enforce
and
insure
that
the
safety
standards
will
be
achieved.
Some
reductions
in
the
total
amount
of
methyl
bromide
will
likely
occur,
contributing
to
reductions
in
ozone
depletion.

The
strategy
will
entail,
however,
some
costs
to
the
regulated
community
and
to
consumers
of
treated
commodities.
Some
facilities
may
have
to
alter
their
fumigation
practices
or
invest
in
mitigation
measures.
Despite
its
relative
flexibility,
some
facilities
may
not
be
able
to
meet
the
requirements
with
the
use
of
methyl
bromide.
They
will
be
obligated
to
use
other
pest
control
measures
or
will
be
unable
to
operate.
Some
of
these
impacts
will
be
passed
on
to
consumers.
This
document
describes
in
more
detail
the
extent
of
EPA's
information
regarding
these
impacts.

Occupational
Exposure
Fumigators
and
employees
who
handle
treated
commodities
soon
after
treatment
may
also
be
exposed
to
levels
of
methyl
bromide
exceeding
EPA's
level
of
concern.
Current
practice
is
that
levels
of
methyl
bromide
are
monitored
and
if
concentrations
are
greater
than
five
(
5)
ppm,
respirators
must
be
worn.
Immediately
after
treatment,
enclosures
are
often
actively
aerated
to
lower
concentrations.
Treatment
buffers
may
also
be
enforced.

EPA's
current
plan
is
to
lower
the
permissible
concentration
limit
to
one
(
1)
ppm
(
8­
hr
TWA).
Levels
above
this
limit
will
require
the
use
of
respirators.
Use
of
respirators
may
be
burdensome
for
employees,
especially
in
hot
conditions,
but
should
not
otherwise
significantly
affect
applicators
or
the
operation
of
the
facilities
since
it
is
common
practice.
Facilities
would
have
the
option
of
increasing
aeration
time
to
avoid
the
use
of
respirators,
but
where
that
would
impinge
on
the
movement
of
commodities,
respirators
can
be
used.
Page
7
Enforcement/
Compliance
Mechanisms
The
Agency
is
also
considering
several
mechanisms
to
aid
in
enforcement
and
compliance.
Chief
among
these
would
be
a
requirement
to
prepare
and
follow
a
Fumigation
Management
Plan
(
FMP).
The
FMP
would
detail
how
a
specific
fumigation
would
comply
with
the
label
restrictions,
including
the
establishment
of
buffer
zones
and
the
factors
that
determined
the
size
of
the
buffers.
EPA
envisions
certification
so
that
the
FMP
conforms
to
the
label
requirements.

Currently,
most
fumigations
already
follow
some
kind
of
plan,
although
all
plans
would
now
have
to
be
brought
into
compliance
with
the
new
requirements
of
use.
Therefore,
BEAD
anticipates
few
impacts
on
applicators
or
facilities
in
preparing
the
FMP.
Once
prepared
for
a
fixed
facility,
the
plan
may
need
few
modifications
for
repeated
fumigations.
The
certification
of
the
FMP
may
entail
added
cost
to
the
fumigation,
but
currently
BEAD
cannot
predict
that
cost.

Other
compliance
mechanisms
include
record
keeping
requirements
and
posting
notices
of
fumigation,
both
on
treated
commodities
and
to
the
general
public
prior
to
the
treatment
of
facilities
or
commodities.
Record
keeping
requirements
may
not
entail
significant
added
costs,
since
most
fumigations
are
already
closely
monitored.
Notices
that
a
structure
is
to
be
treated
should
also
not
impose
substantial
costs.

INDUSTRY
OVERVIEW
Since
2002,
EPA's
Methyl
Bromide
Critical
Use
Exemption
process
reviews
and
nominates
various
structures
or
food
facilities
for
continued
use
of
methyl
bromide.
The
following
information
is
based
on
industry
applications
for
a
Critical
Use
Exemption
and
EPA
proprietary
data.

The
Critical
Use
Exemption
structures/
food
facilities
include
flour
and
rice
mills,
pet
food
manufacturers,
bakeries
and
other
food
processing
facilities.
Specific
associations
have
submitted
Critical
Use
Exemption
applications,
but
when
methyl
bromide
is
allocated
to
these
uses,
all
facilities
in
these
industries
will
have
the
right
to
purchase
methyl
bromide
from
that
allocation.
These
industries
combined
generate
over
$
12
billion
in
annual
sales
revenue.
These
facilities
may
account
for
up
to
90%
or
more
of
domestic
production
and
manufacturing.
Food
processing
is
a
value­
added
activity
that
involves
capital­
intensive
specialty
equipment
and
facilities.
Post
harvest
food
storage
is
an
integral
part
of
operations
because
in
many
cases
the
production
season
is
separated
from
the
peak
demand
season.
Therefore
it
is
imperative
for
these
industries
to
fumigate
in
order
to
maintain
the
product's
integrity
and
quality.
Page
8
North
American
Millers
Association:
This
industry
trade
association
represents
46
members
operating
169
mills
in
38
states
and
accounts
for
approximately
90%
of
the
milling
capacity
in
the
U.
S.
They
represent
wheat
flour,
corn,
rye,
and
oat
millers.
This
is
one
of
the
oldest
industries
in
the
U.
S.
with
flour
mills
dating
back
to
at
least
1836.
They
operate
on
a
domestic
and
global
scale
with
much
global
competition
in
the
marketplace
with
relatively
inelastic
demand.
The
industry
generates
gross
revenues
of
approximately
$
8.3
billion
in
annual
sales.
The
representative
facility
generates
gross
revenues
of
about
$
49
million
in
annual
sales
with
a
gross
margin
(
gross
revenue
minus
cost
of
goods
sold)
of
about
24%
and
a
net
profit
margin
(
gross
margin
minus
total
expenditures)
of
about
3%.

Pet
Food
Institute:
This
industry
trade
group
represents
53
dog
and
cat
food
manufacturing
plants
or
approximately
97%
of
the
dog
and
cat
food
manufacturers
in
the
U.
S.
They
operate
on
a
domestic
and
global
scale
with
much
global
competition
in
the
marketplace.
They
generate
gross
revenues
of
approximately
$
1.5
billion
in
annual
sales.
The
representative
facility
generates
gross
revenues
of
about
$
28
million
in
annual
sales
with
a
gross
margin
of
about
57%
and
a
net
profit
margin
of
about
13%.

Rice
Millers'
Association:
This
industry
trade
association
represents
32
rice
milling
facilities
and
accounts
for
almost
all
of
the
rice
milling
capacity
in
the
U.
S.
with
mill
members
in
Arkansas,
California,
Florida,
Louisiana,
Mississippi,
Missouri,
and
Texas.
This
is
one
of
the
oldest
agricultural
industries
in
the
U.
S.
dating
back
to
at
least
1685
and
on
of
the
oldest
trade
associations
dating
back
to
1899.
They
operate
on
a
domestic
and
global
scale
with
much
global
competition
in
the
marketplace
with
relatively
inelastic
demand.
Almost
50%
of
the
U.
S.
rice
crop
is
exported
to
over
100
countries
supplying
approximately
13%
of
global
trade.
The
industry
generates
gross
revenues
of
approximately
$
1.7
billion
in
annual
sales.
The
representative
facility
generates
gross
revenues
of
about
$
27
million
in
annual
sales
with
a
gross
margin
of
about
33%
and
a
net
profit
margin
of
about
4%.

Bakeries:
This
industry
trade
group
represents
6
bakery
facilities.
They
operate
on
a
domestic
and
global
scale
with
much
global
competition
in
the
marketplace.
The
group
generates
gross
revenues
of
approximately
$
621
million
in
annual
sales.

National
Pest
Management
Association:
This
association
represents
pest
control
entities
engaging
in
post
harvest
fumigation
of
commodities
such
as
spices,
cocoa
beans,
cheese,
as
well
as
the
commodities
listed
above.
These
commodities
are
produced
and
processed
in
a
number
of
other
food
processing
facilities.

SITE
DESCRIPTIONS
Purpose
of
Fumigation
Food
processing
facilities
and
mills
are
under
intense
pressure
from
many
insect
pests.
Some
of
the
major
pests
are
listed
in
Table
1.
Insect
pests
will
infest
the
ingredients
and
the
product
manufactured,
as
well
as
invading
the
equipment
and
structure
itself.
Insect
pests
leave
their
excrement,
body
parts,
and
exuviae
which
violate
US
Food
and
Drug
Administration
regulations
(
FDA
regulations
can
be
found
at:
http://
www.
cfsan.
fda.
gov/~
dms/
dalbook.
html
and
Page
9
http://
www.
fda.
gov/
opacom/
laws/
fdcact/
fdcact4.
htm).
In
addition
several
insect
pests
pose
health
hazards
either
because
they
can
cause
choking
in
small
children
or
because
they
can
cause
allergic
reactions.
Structural
fumigations
target
the
facilities
and
do
not
generally
target
the
commodities,
although
some
product
may
be
present
during
fumigation.

TABLE
1:
KEY
PESTS
TARGETED
BY
METHYL
BROMIDE
IN
STRUCTURES
Genus
and
Species
of
Major
Pests
Common
Name
Tribolium
confusum
Confused
flour
beetle
Tribolium
castaneum
Red
flour
beetle
Trogoderma
variable
Warehouse
beetle
Lasioderma
serricorne
Cigarette
beetle
Sitophilus
oryzae
Rice
weevil
Plodia
interpunctella
Indianmeal
moth
Oryzaephilus
mercator
Merchant
grain
beetle
Cryptolestes
pusillus
Flat
grain
beetle
Source:
USA,
2006a,
2006b
Structural/
Food
Processing
Plants
Structural/
food
processing
facilities
are
highly
variable
in
their
sizes
and
shapes.
The
sites
are
typically
more
than
500,000
cubic
feet
(
cu
ft)
in
size,
but
may
be
considerably
smaller
and
some
may
be
over
5
million
cubic
feet
(
Table
2).
Many
of
the
structures
were
built
100
years
ago
and
have
had
many
additions
over
the
years.

TABLE
2.
STRUCTURAL
/
FOOD
PROCESSING
FACILITY
SIZE
Number
of
Facilities
in
Each
Size
Category
1
(
cu
ft)
Small
Medium
Large
CUE
Site
<
50,000
50,001
to
500,000
>
500,0012
over
1
million
Median
Volume
(
cu
ft)

Flour
Mills
3
18
52
18
1,126,000
Pet
Food
Processors
3
7
24
17
860,000
Rice
Mills
0
2
8
4
538,000
Bakeries
1
0
0
10
975,000
Other
Food
Processors
2
12
7
0
1,420,000
TOTAL
9
39
91
49
47%
25%
%
Of
TOTAL
5%
23%
72%
Source:
USA,
2006a,
2006b
1
Numbers
do
not
include
all
the
facilities
that
use
methyl
bromide
as
part
of
the
Critical
Use
Exemption
process
but
are
representative
of
the
size
distribution
2
This
category
does
not
mean
that
the
facility
is
greater
than
500,001
but
less
than
1
million
cubic
feet.
It
means
that
the
facility
is
greater
than
500,001
cubic
feet.
Due
to
the
format
of
the
category,
most
of
the
facilities
that
fall
into
this
category
do
not
specify
the
exact
size
of
the
facility.
Therefore
the
1
million
to
5
million
cubic
feet
category
and
over
5
million
cubic
feet
category
may
have
a
larger
percentage
of
facilities
in
those
categories.

Food
processing
facilities
are
located
throughout
the
U.
S.
Mills
and
food
processing
facilities
are
usually
located
near
transportation
facilities
such
as
railroad
terminals,
ports
or
intersections
of
major
highways.
These
locations
are
also
attractive
to
other
manufacturing
facilities
are
Page
10
frequently
located
in
or
near
urban
centers.
Table
3
presents
the
number
of
U.
S.
structural
and
food
processing
plant
facilities
and
estimates
of
location
in
urban
settings
for
the
three
groups
for
which
we
have
facility
information.
BEAD
identified
the
location
of
each
facility
and
compared
it
to
areas
defined
as
Urbanized
Area
or
Urban
Cluster
by
the
2000
U.
S.
Census
(
www.
census.
gov).
An
Urbanized
Area
consists
of
contiguous
census
blocks
and
block
groups
of
at
least
1,000
persons
per
square
mile
that
together
encompass
a
population
of
at
least
50,000
people.
An
Urban
Cluster
consists
of
contiguous
census
blocks
and
block
groups
that
together
encompass
between
2,500
and
50,000
people.

TABLE
3:
NUMBER
OF
STRUCTURAL
/
FOOD
PROCESSING
FACILITIES
Total
in
U.
S.
Facilities
with
Street
Addresses
In
Urban
Areas
Not
in
Urban
Areas
Facility
Sites
Unit:
Number
of
Facilities
Flour
Mills
340
146
114
32
Rice
Mills
76
21
12
9
Bakeries
2,616
244
222
22
Total
3,274
411
348
63
Source:
2002
Economic
Census
data.
Available
online
at
http://
www.
census.
gov/
prod/
www/
abs/
manuind2002
html
Flour
Mills:
Based
on
currently
available
information,
there
are
approximately
340
flour
mill
facilities
in
the
U.
S.
(
Table
3).
In
general,
these
facilities
are
located
primarily
on
the
East
Coast
and
in
the
Midwest
(
Figure
1).
BEAD
estimates
that
at
least
78%
(
114
of
146)
of
these
facilities
are
located
in
urban
centers.
At
least
22%
(
32
of
146)
are
located
in
more
rural
areas.

Rice
Mills:
Based
on
currently
available
information,
there
are
approximately
76
rice
mill
facilities
in
the
U.
S.
(
Table
3).
In
general,
these
facilities
are
located
in
the
southern
part
of
the
United
States,
primarily
Louisiana,
Arkansas
and
Texas
(
Figure
2).
BEAD
estimates
that
at
least
57%
(
12
of
21)
of
these
facilities
are
located
in
urban
centers.
At
least
43%
(
9
of
21)
are
located
in
more
rural
areas.

Bakeries:
Based
on
currently
available
information,
there
are
approximately
2,616
bakery
facilities
in
the
U.
S.
(
Table
3).
In
general,
these
facilities
are
located
primarily
on
the
East
Coast
and
in
the
Midwest
(
Figure
3).
BEAD
estimates
that
at
least
91%
(
222
of
244)
of
these
facilities
are
located
in
urban
centers.
At
least
9%
(
22
of
244)
are
located
in
more
rural
areas.
Page
11
FIGURE
1.
U.
S.
MAP
OF
FLOUR
MILL
FACILITIES
IN
URBAN
AREAS
Urban
Facilities
Non­
Urban
Facilities
Urban
Areas
Flour
Mills
and
Urban
Areas
Page
12
FIGURE
2.
U.
S.
MAP
OF
RICE
MILL
FACILITIES
IN
URBAN
AREAS
Urban
Facilities
Non­
Urban
Facilites
Urban
Areas
Rice
Mills
and
Urban
Areas
FIGURE
3.
U.
S.
MAP
OF
COMMERCIAL
BAKERY
FACILITIES
IN
URBAN
AREAS
Commercial
Bakeries
and
Urban
Areas
Urban
Facilities
Non­
Urban
Facilites
Urban
Area
Page
13
Use
and
Usage
of
Methyl
Bromide
Methyl
bromide
is
one
of
the
most
widely
used
fumigants
to
control
insect
pests
in
structural
food
processing
and
storage
facilities.
It
is
inexpensive,
broad
spectrum,
kills
insect
eggs,
and
is
efficacious
at
a
wide
range
of
temperatures.

Table
4
provides
estimates
of
methyl
bromide
use
in
2004,
according
to
the
U.
S.
Critical
Use
Exemption
request
to
the
parties
of
the
Montreal
Protocol
(
USA,
2006a,
2006b).
The
amount
of
annual
methyl
bromide
usage
in
the
structural
and
food
processing
sector
ranges
from
approximately
1,885,000
pounds
in
2000
to
about
1,492,000
pounds
in
2004.
Application
rates
range
from
less
than
1.0
to
2.0
pounds
active
ingredient
per
1,000
cubic
feet
with
the
average
application
rate
of
1.25
pounds
per
1,000
cubic
feet.
For
the
2008
calendar
year,
about
958,000
pounds
of
methyl
bromide
were
nominated
by
the
U.
S.
for
use
in
this
sector.

TABLE
4:
METHYL
BROMIDE
USE
INFORMATION
FOR
STRUCTURAL
/
FOOD
PROCESSING
FACILITIES
CUE
Site
Average
Use
Rate
(
lbs/
1,000
cu
ft)
Treatment
Time
(
hours/
fumigatio
n)
Aeration
Time
(
hours/
fumigatio
n)
2004
Use
(
pounds)

Flour
Mills
1.2
24
24
750,000
Pet
Food
Manufacturers
1.1
24
24
69,000
Rice
Mills
1.5
24
24
321,000
Bakeries
1.0
24
24
47,000
Other
Food
Processing
1.25
Variable
Variable
305,000
Total
1,492,000
Source:
United
States
of
America,
2006a,
2006b.

Although
fumigations
occur
anytime
a
pest
population
explosion
occurs,
food­
processing
plants
in
warmer
climates
will
usually
be
fumigated
prescriptively
with
methyl
bromide
twice
a
year.
These
occur
just
prior
to
the
summer
and
at
summer's
end,
essentially
just
prior
to
and
immediately
after
very
warm
temperatures
that
increase
insect
pressure.
Fumigations
of
structures
typically
take
advantage
of
3­
day
holiday
weekends
when
the
facility
would
normally
be
closed
and
no
employees
would
be
present.

IMPACTS
OF
BUFFER
ZONES
ON
FACILITIES
Fumigated
facilities
are
very
diverse
and
will
have
varying
capacity
for
establishing
buffer
zones.
Those
in
urban
areas
especially
may
be
very
constrained
by
space.
Even
if
site­
specific
information
were
available,
it
would
be
very
difficult
to
determine
feasible
distances.
This
assessment
is,
by
necessity,
very
qualitative.
There
may
also
be
differing
capacity
to
enforce
a
buffer
zone
during
fumigation
(
treatment
buffer)
and
during
venting
(
aeration).

Imagine
a
facility
that
occupies
a
square
city
block.
Blocks
are
approximately
0.1
mile
or
about
500
feet.
If
this
facility
could
vent
methyl
bromide
near
the
center
of
the
space,
it
would
have
an
inherent
aeration
buffer
of
about
250
feet.
Some
of
the
largest
facilities
may
occupy
more
area,
(
see
Table
2).
Therefore,
BEAD
believes
that
a
500­
foot
buffer
is
the
maximum
any
facility
Page
14
could
accommodate,
most
would
struggle
to
achieve
a
250­
foot
buffer
and
the
smaller
facilities
may
be
able
to
maintain
a
buffer
of
about
100
feet.
Any
aeration
buffer
larger
than
these
distances
would
require
the
facility
to
undertake
additional
mitigation
measures.
If
those
measures
would
not
reduce
the
aeration
buffer
below
the
maximum,
the
facility
would
be
unable
to
use
methyl
bromide.

However,
during
treatment,
gas
may
leak
from
any
point
in
the
facility,
not
just
from
the
center.
Therefore,
an
enforceable
treatment
zone,
measured
from
the
edge
of
the
building,
may
be
much
smaller.
In
fact,
in
some
cases
the
edge
of
the
building
may
be
near
the
property
line.
For
the
purpose
of
this
assessment,
BEAD
assumes
that
a
zone
of
10
to
50,
about
one­
tenth
of
the
aeration
zone,
may
be
possible
for
a
facility,
depending
on
the
size.

Calculated
Buffers
The
Agency
used
the
PERFUM
air
model
to
estimate
buffer
distances
(
EPA,
2006).
Two
buffers
were
calculated
 
a
treatment
buffer
(
which
accounts
for
the
amount
of
methyl
bromide
leaking
from
the
structure
during
fumigation)
and
an
aeration
buffer
(
which
accounts
for
the
amount
of
methyl
bromide
vented
at
the
completion
of
the
treatment).

The
estimation
of
these
buffers
depend
on
a
number
of
input
parameters
to
the
model
such
as
atmospheric
conditions,
application
rate,
chamber/
enclosure
conditions
(
e.
g.,
gas­
tightness),
fumigated
volume,
the
use
of
stacks,
building
effects,
and
the
rate
and
type
of
aeration.
The
tables
of
buffer
distances
identify
the
various
combinations
of
these
input
factors.

The
PERFUM
model
generates
distributions
of
buffers.
Two
distributions
of
buffers
were
developed
from
the
model
 
a
"
maximum
buffer"
distance
and
the
"
whole
field
buffer"
distance.
Three
values
are
presented
in
this
document
 
the
95th
percentile
of
the
maximum
buffer
distribution
(
abbreviated
herein
as
"
95
max"),
the
99th
percentile
of
the
whole
field
buffer
distribution
("
99
whole")
and
the
99.9th
percentile
of
the
whole
field
buffer
distribution
("
99.9
whole").
For
more
detail
on
the
models
and
the
results,
please
refer
to
EPA's
risk
assessment
(
EPA,
2006).

Estimates
of
the
buffer
zones
are
taken
from
the
PERFUM
model
used
by
EPA
for
the
risk
assessment
(
EPA,
2006).
We
consider
volumes
ranging
from
5,000
cubic
feet,
representing
fumigation
of
a
part
of
a
facility,
up
to
1,000,000
cubic
feet,
representing
a
large
size
facility.
Note
that
the
majority
of
facilities
exceed
500,000
cubic
feet
(
Table
2).
Rates
of
1
and
2
pounds
methyl
bromide
per
1,000
cubic
feet
are
considered.
We
also
look
at
the
effect
of
the
gas
tightness
of
the
enclosure.
Low
loss
rates,
5
to
10%
per
24­
hour
period,
represent
new,
wellsealed
steel
or
concrete
facilities
while
higher
loss
rates,
25
to
50%
per
24
hours,
are
more
representative
of
older
buildings
and
wood
construction.
In
contrast,
the
California
regulatory
buffer
system
assumes
that
3%
of
the
concentration
is
lost
per
hour
unless
specifically
measured.
This
implies
that
a
12­
hour
treatment
would
lose
36%
of
the
fumigation
rate
while
a
24­
hour
treatment
would
lose
72%
of
the
application
rate.
Page
15
Treatment
Buffers
Table
5
presents
estimated
treatment
buffer
for
different
percentile
of
exposures:
95
max,
99
whole,
and
99.9
whole.

Treatment
buffers
under
the
99
whole
would
be
unlikely
to
impose
impacts
on
small
facilities
or
partial­
facility
fumigations
of
5,000
to
10,000
cubic
feet,
even
at
typical
rates
of
less
than
2
pounds
per
1,000
cubic
feet.
Medium
to
large
facilities,
however,
are
likely
to
find
treatment
buffers
burdensome
for
fumigations,
even
if
the
buildings
are
reasonably
well­
sealed.
Structures
in
this
industry
larger
than
250,000
cubic
feet,
which
account
for
at
least
three­
fourths
of
the
structures
(
Table
2),
are
not
likely
to
find
treatment
buffers
feasible
without
further
mitigation
efforts.
Buffers
associated
with
other
regulatory
standards
would
be
infeasible
except
for
the
smaller,
tightest
facilities
at
low
rates.

TABLE
5.
ESTIMATED
METHYL
BROMIDE
FUMIGATION
TREATMENT
BUFFER
DISTANCES
Treatment
Buffer
(
feet)
Site
(
cubic
ft)
Rate
(
lbs/
1000
ft3)
Loss
During
Treatment
(%)
95
max
99
whole
99.9
whole
5%
0
0
0
10%
0
0
0
5,000
1
25%
0
0
0
5%
0
0
0
10%
0
0
0
25%
100
0
99
1
40%
200
50
190
10%
70
0
70
10,000
2
50%
460
150
430
5%
180
30
170
10%
410
150
380
1
25%
830
300
760
5%
410
150
380
100,000
2
50%
3,430
1,150
3,280
5%
430
150
400
10%
780
300
710
1
25%
1,450
530
1,350
250,000
2
5%
780
300
710
5%
680
280
640
500,000
1
10%
1,190
480
1,120
5%
1,070
480
1,010
1,000,000
1
10%
1,810
740
1,690
Source:
EPA
2006.
Note:
BEAD
anticipates
that
some
minimum
buffer
zone
would
be
established
for
situations
listed
as
zero.
California
currently
has
a
10­
foot
minimum.

Other
mitigation
options
that
would
permit
smaller
treatment
zones
are
limited.
BEAD
has
identified
three
ways
that
a
facility
may
reduce
the
required
buffer:
(
1)
reduce
the
use
rate
(
amount
of
methyl
bromide
per
1,000
cubic
feet),
(
2)
partition
the
facility
and
fumigate
smaller
volumes
and
(
3)
improve
the
gas
retention
of
the
structure.
Page
16
Rate
Reductions:
Reducing
the
rate
may
not
be
practical
in
many
situations
because
certain
pests
will
not
be
destroyed
at
the
lower
rates.
Moreover,
this
option
may
not
be
sufficient
to
obtain
a
feasible
treatment
buffer.
As
shown
in
Table
5,
a
250,000
cubic
feet
facility
that
loses
only
5%
of
the
gas
over
24
hours
can
reduce
the
treatment
buffer
from
300
ft
with
2
pounds
methyl
bromide
1,000
cubic
feet
to
150
ft
with
1
pound
methyl
bromide
per
1,000
cubic
feet.
However,
that
still
exceeds
the
likely
maximum
feasible
treatment
buffer.

Partitioning
Structures:
Many
facilities
already
only
fumigate
portions
of
the
facility
and,
so
long
as
the
buffer
is
measured
from
the
source
of
methyl
bromide,
this
practice
may
help
to
reduce
the
necessary
buffer
size.
However,
many
facilities,
particularly
mills,
have
limited
ability
to
partition
the
building.
Mills
have
multiple
stories
to
allow
for
all
of
the
steps
necessary
in
converting
raw
grain
into
a
finished
product.
These
include
both
fine
cleaning
and
the
repeated
grindings
and
siftings
necessary
to
produce
flour
and
other
food
products
appropriate
to
the
final
use.
A
second
consequence
is
the
multiple
connections
(
chutes)
between
the
stories
in
a
facility
needed
to
move
the
intermediate
products
to
the
next
processing
point
and
to
remove
unwanted
material
to
waste
areas.
For
both
of
these
reasons
it
is
difficult
to
segregate
areas
of
a
facility
and
careful
sealing
is
required.

Further,
partitioning
a
facility
may
have
limited
effect
on
the
buffer.
The
size
of
the
buffer
is
not
directly
proportional
to
the
size
of
the
facility.
As
shown
in
Table
5,
the
treatment
buffer
for
a
500,000
cubic
feet
facility
is
480
ft
for
a
10%
loss
per
24
hours.
Dividing
that
facility
in
half,
to
two
250,000
cubic
feet
fumigations,
would
only
reduce
the
treatment
buffer
to
300
ft,
less
than
a
40%
reduction.
Similarly,
halving
a
1
million
cubic
feet
facility
with
a
10%
loss
rate
reduces
the
treatment
buffer
from
740
ft
to
480
ft,
a
35%
reduction
in
distance.

Finally,
partitioning
a
structure
and
fumigating
over
several
days
could
be
costly.
Typically,
facilities
fumigate
when
the
plant
will
be
closed
anyway,
but
extending
the
period
of
downtime
is
costly
in
terms
of
lost
production.

Improving
Gas
Retention:
Newly
constructed
facilities
are
likely
to
have
been
constructed
in
a
manner
that
would
lower
fumigant
loss
rates
during
treatment.
However,
it
may
be
very
difficult
for
older
facilities
to
improve
gas
retention
without
complete
and
costly
renovation.
With
very
large
structures,
there
are
likely
technical
limits
to
the
ability
to
avoid
losses,
even
with
newer
materials
and
construction
methods.
However,
this
may
be
the
most
direct
way
of
meeting
the
requirements
of
treatment
buffers
while
maintaining
operation.

Aeration
Buffers
Table
6
presents
the
estimated
aeration
zone
for
facilities
with
no
active
ventilation
system
("
passive"
aeration)
for
different
regulatory
standards:
95
max,
99
whole,
and
99.9
whole
(
see
EPA
2006
for
details
about
the
interpretation
of
these
regulatory
standards).
This
may
be
a
restrictive
assumption
as
facilities
likely
have
some
ventilation
system
that
may
be
capable
of
venting
methyl
bromide.
However,
anecdotal
evidence
suggests
to
BEAD
that
many
facilities
simply
open
windows
or
doors
and
allow
the
gas
to
escape.
Page
17
BEAD
believes
the
maximum
aeration
buffer
for
most
facilities
will
be
around
200­
250
ft,
roughly
half
a
city
block.
This
represents
the
likely
limit
of
the
property
and
beyond
this
range,
facilities
would
probably
not
be
able
to
exert
control
to
impose
a
buffer
zone.
Table
6
suggests
that
only
the
smallest
facilities
would
find
these
buffers
feasible.
Buffers
are
beyond
the
maximum
for
facilities
of
100,000
or
more,
which
account
for
nearly
90%
of
these
structures
(
Table
2).

TABLE
6.
ESTIMATED
METHYL
BROMIDE
FUMIGATION
AERATION
BUFFER
DISTANCES
Aeration
Buffer
(
feet)
Site
(
cubic
ft)
Rate
(
lbs/
1000
cu
ft)
Air
Exchange
(
cu
ft/
min)
[
exchanges/
min]
Stack
Type
1
95
max
99
whole
99.9
whole
Passive
270
90
250
Minimum
100
0
80
5,000
1
2,500
[
0.5]
Portable
0
0
0
Passive
270
90
250
Minimum
130
0
130
1
5,000
[
0.5]
Portable
0
0
0
Passive
460
150
430
Minimum
220
90
200
10,000
2
5,000
[
0.5]
Portable
0
0
0
Passive
1,940
680
1,860
Minimum
360
210
350
50,000
[
0.5]
Portable
0
0
0
Minimum
590
300
560
1
5,000
[
0.05]
Portable
200
0
200
Passive
2,990
1,020
2,860
Minimum
1,040
380
910
50,000
[
0.5]
Portable
270
0
250
Minimum
1,500
500
1,430
100,000
2
5,000
[
0.05]
Portable
610
230
530
Passive
3,430
1,150
3,280
Minimum
840
280
740
125,000
[
0.5]
Portable
0
0
0
25
ft
940
430
890
1
12,500
[
0.05]
Portable
580
280
560
Passive
>
4,730*
1,690
>
4,730*
25
ft
1,170
430
960
125,000
[
0.5]
Portable
480
0
430
25
ft
2,530
780
2,330
250,000
2
25,000
[
0.1]
Portable
1,550
580
1,270
Passive
>
4,730*
1,740
>
4,730*
25
ft
510
250
460
250,000
[
0.5]
Portable
250
0
220
500,000
1
100,000
[
0.2]
Portable
1,610
380
1,460
Passive
>
4,730*
2,680
>
4,730*
25
ft
580
380
550
500,000
[
0.5]
Portable
380
0
330
1,000,000
1
200,000
[
0.2]
Portable
1,890
560
1,600
Source:
EPA
2006.
1
Minimum
stack
is
10
feet
above
the
highest
building
within
200
feet.
*
Aeration
buffer
greater
than
4,730
feet,
the
maximum
the
model
can
calculate.
Page
18
BEAD
has
identified
four
ways
that
a
facility
may
reduce
the
required
aeration
buffer:
(
1)
Reduce
the
rate
(
amount
of
methyl
bromide
per
1,000
cubic
feet),
(
2)
fumigate
smaller
volumes,
(
3)
install
an
active
aeration
system
including
stacks
or
other
venting
systems,
and
(
4)
install
a
capture
and
destruction
system.

Rate
Reductions:
Reducing
the
application
rate
may
not
be
practical
in
many
situations
because
certain
pests
will
not
be
destroyed
at
the
lower
rates.

Fumigate
Smaller
Volumes:
Fumigating
in
smaller
units
may
also
present
logistical
problems,
depending
on
the
facility.

Table
6
also
presents
estimated
aeration
buffers
when
active
air
exchange
and
ventilation
stacks
are
employed.
Many
facilities
probably
employ
some
kind
of
active
aeration
that
could
be
used
to
vent
methyl
bromide.
However,
a
venting
stack
some
distance
above
ground
may
not
be
so
common.
A
50­
foot
portable
stack,
upon
which
the
risk
assessment
is
based,
combined
with
active
air
exchange,
has
substantial
impact
on
the
estimated
aeration
buffer
for
smaller
facilities.
Such
a
system,
which
requires
that
methyl
bromide
be
drawn
from
the
building
to
a
vent
a
minimum
of
25
feet
away,
or
far
enough
to
eliminate
building
effects,
may
not
be
practical
for
a
medium
to
large
facility.
However,
such
facilities
can
decrease
the
aeration
zone
by
venting
the
gas
through
a
stack.
Air
exchange
systems
also
have
a
substantial
effect
on
the
aeration
buffer.
However,
BEAD
does
not
know
what
exchange
rate
larger
facilities
can
reasonably
be
expected
to
achieve.

Active
Aeration
Systems:
The
cost
to
improve
the
active
aeration
of
fumigated
facilities
is
not
known
but
some
representative
costs
are
available.
Information
submitted
through
the
public
comment
process
indicates
that
the
cost
of
a
50­
foot
soft
portable
stack,
including
ducts
and
fittings,
is
approximately
$
1,000,
and
adding
a
stack
to
a
100,000
cubic
foot
warehouse
would
cost
approximately
$
30,000.
The
comments
did
not,
however,
indicate
the
height
or
airflow
capacity
of
these
stacks.
Fan
costs
range
from
$
500
to
$
850
and
range
in
capacity
from
10,000
to
40,000
cubic
feet
per
minute,
but
often
require
special
engineering
and
design
that
can
multiply
the
cost
(
EPA,
2006).

Multiple
fans
increase
air
exchange
in
an
additive
fashion,
therefore
larger
facilities
may
achieve
sufficient
air
flow
through
a
large
enough
stack
to
reduce
the
aeration
buffer
to
a
feasible
distance.
A
factor
in
determining
the
viability
of
such
an
investment
is
that
many
facilities
fumigate
infrequently.

Capture
and
Destruction
Technology:
A
capture
and
destruction
system
"
scrubs"
the
exhaust
stream
to
remove
methyl
bromide.
These
systems
appear
to
be
aimed
primarily
at
commodity
treatments,
including
sealed
and
tarped
enclosures.
It
is
not
clear
to
what
extent
they
would
be
feasible
for
structures.
However,
it
may
be
assumed
that
they
could
be
used
in
conjunction
with
or
in
place
of
a
portable
stack.
Even
if
some
proportion
of
the
methyl
bromide
could
be
captured,
the
estimated
aeration
buffer
could
be
reduced
substantially.
Further,
these
systems
reduce
the
amount
of
methyl
bromide
released
into
the
atmosphere
and
could
have
an
impact
on
ozone
depletion.
Page
19
Alternatives
to
Methyl
Bromide
There
are
other
fumigants
that
are
available
for
use
in
the
post­
harvest
sector.
Phosphine
is
often
used
when
time
is
not
critical,
because
it
usually
takes
longer
for
a
fumigation.
In
addition,
phosphine
is
corrosive
to
certain
metals
and
has
temperature
constraints.
Sulfuryl
fluoride
was
registered
in
January
of
2004
in
the
U.
S.
and
in
California
in
May
of
2005,
for
use
in
mills
of
cereal
grains,
dried
fruits,
and
tree
nuts.
Use
sites
were
extended
in
July
of
2005
by
the
Federal
government,
but
not
by
California.
Research
is
ongoing
to
determine
its
capability
to
replace
methyl
bromide
in
all
its
critical
uses.
However,
there
have
been
some
export
issues
that
the
registrant
is
trying
to
solve.
Sulfuryl
fluoride
is
currently
undergoing
review
by
the
Codex
Alimentarius
Commission
to
establish
maximum
residue
levels
(
MRL)
from
the
use
of
quarantine
fumigations
and
by
the
Committee
for
the
Agreement
on
the
Application
of
Sanitary
and
Phytosanitary
Measures
to
set
standards
for
its
use.
If
approved
by
Codex
MRL's
would
be
established
for
foods
such
as:
dried
fruits
and
tree
nuts,
bran,
cereal
grains,
and
flour
(
e.
g.
maize,
rye,
and
wheat).

Other
options
for
controlling
pests
in
the
post­
harvest
sector
include
(
but
are
not
limited
to):
manipulations
of
temperature,
such
as
heat
or
cold;
controlled
atmospheres,
such
as
ozonation,
carbon
dioxide;
and
increased
sanitation,
especially
micro­
sanitation.
Research
is
continuing
in
this
field
to
identify
both
technically
and
economically
feasible
alternatives
to
methyl
bromide.
However,
at
this
time,
these
alternatives
are
not
technically
and
economically
feasible
for
the
uses
considered
here
or
are
prohibitively
expensive
(
United
States
of
America,
2006a,
2006b)

CONCLUSION
BEAD
does
not
expect
substantial
impacts
to
result
from
lowering
the
air
concentration
limit
of
occupational
exposure
from
five
(
5)
parts
per
million
(
ppm)
to
one
(
1)
ppm
as
a
8­
hour
TWA,
provided
facilities
have
the
option
to
utilize
air
purifying
respirators
to
protect
employees
when
air
concentrations
are
between
these
points.
BEAD
also
does
not
expect
substantial
impacts
if
EPA
were
to
require
Fumigation
Management
Plans
and
other
actions
that
focus
on
compliance
and/
or
enforcement.

BEAD
believes
that
a
treatment
buffer
greater
than
20
to
30
feet
or
an
aeration
buffer
larger
than
200
to
250
feet
would
be
infeasible
for
most
facilities.
Facilities
located
in
rural
areas
may
be
able
to
accommodate
larger
treatment
and
aeration
buffers
without
substantial
impacts
on
their
operations.
BEAD
estimates
the
majority
(
72%)
of
the
structures
/
food
processing
facilities
to
be
greater
than
500,000
cubic
feet.
Under
the
99
whole
field
standard,
the
calculated
treatment
buffers
for
a
500,000
cubic
foot
facility,
assuming
the
greatest
gas
retention
and
a
1­
lb
application
rate,
is
280
feet.
Treatment
buffers
will
be
greater
for
larger
volumes,
higher
rates
and
lower
gas
retention.
The
calculated
aeration
buffers
for
large
facilities
range
from
90
to
over
2,680
feet.
These
buffers,
therefore,
are
likely
to
impose
some
impacts
on
medium
to
large
facilities
located
in
urban
areas
and
possibly
large
facilities
located
in
rural
areas.

It
appears
that
using
various
other
risk
mitigation
options,
including
rate
reduction,
fumigating
smaller
volumes,
improvements
in
sealing
techniques,
active
aeration
with
fans
and
stacks,
and/
or
capture
and
destruction
technology
may
help
to
reduce
the
size
of
the
buffer
zones.
Page
20
BEAD
believes
that
most
facilities,
even
the
larger
ones,
would
be
able
to
accommodate
aeration
buffers
using
a
combination
of
options,
such
as
active
aeration
and
stacks.
Portable
stacks
appear
particularly
effective,
although
they
may
not
be
feasible
for
larger
facilities.
This
conclusion
is
based
on
the
assumption
that
the
99
percentile
whole
field
buffer
is
the
regulatory
basis.
However,
there
appear
to
be
few
feasible
options
to
reduce
the
treatment
buffers
and
few
facilities
are
likely
to
be
able
to
comply
with
those
estimated
in
this
document.
Site­
specific
modeling
may
result
in
smaller
buffers
that
still
meet
safety
standards.

If
facilities
are
unable
to
meet
the
buffer
requirements,
even
with
the
adoption
of
other
measures,
they
would
be
unable
to
use
methyl
bromide.
Since
2005,
production
of
methyl
bromide
is
only
permitted
under
the
Montreal
Protocol
for
certain
uses,
including
those
that
have
been
designated
as
a
critical
need.
EPA
and
USDA
have
evaluated
exemption
requests
based
on
current
conditions
and
found
that
there
are
no
alternatives
that
are
technically
and
economically
feasible
to
the
use
of
methyl
bromide
in
this
sector
(
USA,
2006a,
2006b).
If
medium
to
large
food
processing
facilities
cannot
feasibly
implement
the
required
treatment
zone,
even
with
the
additional
mitigation
options,
they
may
have
to
cease
operations.
This
could
have
detrimental
effects
on
U.
S.
producers
of
grains
and
other
raw
materials,
on
consumers
of
these
products,
and
on
the
local
economies.
BEAD
does
not
have
adequate
data
about
the
specific
site
characteristics
of
these
facilities
to
quantify
the
distribution
and
magnitude
of
these
impacts.

REFERENCES
CDPR
(
California
Department
of
Pesticide
Regulation),
1994.
Suggested
Permit
Conditions,
Methyl
Bromide
Commodity
Fumigation.
State
of
California
Environmental
Protection
Agency,
August
8.

CAL
DPR.
2006.
California
Department
of
Pesticide
Regulation
Pesticide
Use
Reporting
(
PUR)
data
base.
Available
at
http://
www.
cdpr.
ca.
gov/
docs/
pur/
purmain.
htm
EPA.
2006.
Methyl
Bromide:
Phase
5
health
Effects
Division
(
HED)
Human
Health
Risk
Assessment
for
Commodity
Uses.
March
10,
2006.

EPA.
2006.
U.
S.
Environmental
Protection
Agency,
Office
of
Pesticide
Programs,
Docket
on
Methyl
Bromide
Risk
Assessment
for
Fumigant
Pesticide.
Docket
No.
EPA­
HQ­
OPP­
2005­
0123.
Available
at
http://
www.
regulations.
gov
.

EPA
Proprietary
Data,
2003.
Industrial
Economics,
Incorporated
report
entitled:
"
Financial
Profiles
and
Alternative
Costs
Report
2002
Methyl
Bromide
Critical
Use
Exemption
Application
from
Post­
Harvest/
Structure
Users
for
U.
S.
Environmental
Protection
Agency
Office
of
Pesticide
Programs
(
7503C)".

U.
S.
Census.
2002.
Meat
Processed
from
Carcasses:
2002
Economic
Census.
Manufacturing,
Industry
Series.
Available
at:
http://
www.
census.
gov/
prod/
ec02/
ec0231i311612.
pdf
U.
S.
Census
Bureau.
2000.
Urban
and
Rural
Classification.
Available
at
http://
www.
census.
gov/
geo/
www/
ua/
ua_
2k.
html
Page
21
United
States
of
America.
2006a.
Methyl
Bromide
Critical
Use
Nomination
for
Post
Harvest
Use
for
NPMA
(
Submitted
in
2006
for
2008
Use
Season).
Located
at:
http://
www.
epa.
gov/
ozone/
mbr/
2008_
nomination.
html
United
States
of
America.
2006b.
Methyl
Bromide
Critical
Use
Nomination
for
Post­
Harvest
Use
in
Structures
 
Food
Processing
Plants
(
Submitted
in
2006
for
2008
Use
Season).
Located
at:
http://
www.
epa.
gov/
ozone/
mbr/
2008_
nomination.
html