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
for
Plant
Protection
and
Quarantine
(
PPQ)
Purposes
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,
Biological
and
Economic
Analysis
Division
(
BEAD)
assessed
the
potential
impacts
of
risk
mitigation
and
enforcement/
compliance
options.
These
options
were
outlined
in
the
EPA
Federal
Register
Notice
of
March
29,
2006.
This
document
addresses
the
potential
impacts
to
Plant
Protection
and
Quarantine
(
PPQ)
fumigations
of
quarantine
commodities.
Information
on
quarantine
uses
other
than
PPQ
is
not
available
to
the
EPA.
Other
assessments
address
the
impacts
on
non­
quarantine
commodities,
dry­
cured
pork
and
structural
uses.

Methyl
bromide
is
an
important
tool
for
guaranteeing
that
commerce
can
flow
through
U.
S.
ports
without
the
risk
of
introducing
exotic
pest
species.
Federal
law
prohibits
the
introduction
of
these
species
and
dictates
treatment
regimes
for
their
control,
which
frequently
involve
fumigation
with
methyl
bromide
BEAD
does
not
expect
significant
impacts
to
result
from
lowering
the
air
concentration
limit
of
occupational
exposure
from
five
(
5)
parts
per
million
(
ppm)
as
a
ceiling
limit
to
one
(
1)
ppm
as
a
8­
hour
time
weighted
average
(
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
significant
impacts
if
EPA
were
to
require
Fumigation
Management
Plans
(
FMP)
and
other
actions
that
focus
on
compliance
and/
or
enforcement.

It
appears
that
the
treatment
and
aeration
buffers
provided
in
this
document
would
be
feasible
for
many
APHIS
facilities.
This
conclusion
is
based
on
the
assumption
that
the
99
percentile
whole
field
buffer
is
used
for
regulatory
decision
making.
There
are
some
facilities
that
will
need
to
modify
their
current
practices
using
a
combination
of
the
mitigation
options
described
in
order
to
meet
the
buffer
requirements.
These
facilities
may
have
to
invest
in
additional
equipment
to
reduce
the
aeration
and
treatment
buffers.

There
are
some
facilities
that
will
need
to
modify
their
current
practices
to
meet
these
proposed
buffer
requirements.
There
are
several
ways
to
meet
these
requirements;
for
example,
sitespecific
modeling
can
be
used
by
the
facilities
to
select
methods
to
implement
that
would
result
in
the
reduction
of
buffers.
In
most
cases,
facilities
could
potentially
achieve
the
greatest
buffer
reduction
by
using
a
combination
of
methods.
Treatment
buffers
may
be
reduced
by
methods
such
as
improved
gas
retention,
lower
rates
or
treating
smaller
volumes
of
commodities.
Aeration
buffers
may
be
reduced
by
methods
such
as
improved
ventilation
systems
(
greater
air
exchanges
per
minute,
taller
stacks),
lower
rates,
treating
smaller
volumes,
or
installing
a
capture
and
destruction
system.
BEAD
anticipates
that
using
a
combination
of
these
mitigation
options
most
facilities
will
be
able
to
meet
the
buffer
requirements.
However,
these
changes
will
entail
some
costs.

However,
if
PPQ
facilities
cannot
meet
the
buffer
requirements,
even
with
the
adoption
of
additional
equipment,
they
would
not
be
able
to
use
methyl
bromide.
Therefore,
if
buffers
are
infeasible,
some
facilities
may
have
to
cease
operation.
This
may
impact
producers
and
consumers,
as
well
as
the
local
economy.
BEAD
does
not
have
adequate
data
about
the
specific
site
characteristics
of
these
facilities
to
quantify
the
distribution
and
magnitude
of
these
impacts.
Page
3
However,
BEAD
anticipates
that
by
using
a
combination
of
mitigation
options
most
facilities
will
be
able
to
meet
the
buffer
requirements.

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,
the
Office
is
assessing
the
risks
and
benefits
of
methyl
bromide
use
in
quarantine
pest
control.

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.

Once
the
Parties
to
the
Protocol
have
approved
an
amount
of
methyl
bromide,
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
bromide
do
not
have
access
to
the
general
use
methyl
bromide
stockpiles
(
i.
e.,
those
methyl
bromide
stocks
generated
before
January
1,
2005).
This,
therefore,
sets
an
upper
limit
on
the
amount
of
methyl
bromide
that
can
be
used
for
structures,
commodities,
and
dry­
cured
hams,
and
consequently,
on
the
total
volume
that
can
be
fumigated
in
any
one
year.
Because
of
its
importance
for
quarantine
pest
control,
quarantine
use
of
methyl
bromide
is
exempted
from
the
Clean
Air
Act
and
the
Protocol.
Under
this
exemption,
quarantine
and
pre­
shipment
(
QPS)
use
of
methyl
bromide
is
defined
as:
"
treatments
to
prevent
the
introduction,
establishment
and/
or
spread
of
quarantine
pests
or
to
ensure
their
official
control "
Page
4
Quarantine
uses
of
methyl
bromide
addressed
in
this
document
are
in
place
to
prevent
movement
of
exotic
pest
species
from
the
U.
S.
to
our
trading
partners,
to
protect
the
U.
S.
from
introduction
of
pests
from
other
countries,
to
prevent
the
interstate
movement
of
pests,
and
to
prevent
intrastate
movement
of
pests.

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
qualitative
extent
to
which
these
measures
can
also
contribute
to
reduction
in
ozone
depletion.
This
document
presents
OPP's
evaluation
of
various
riskreduction
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
(
EPA
2006)
suggested
by
EPA
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
(
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
exceedences,
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
single
approach
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.
The
air
exchange
rate
can
also
be
manipulated
instead.

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.

Enforcement/
Compliance
Mechanisms
Page
7
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.
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
appropriate
size.
EPA
envisions
certification
so
that
the
FMP
conforms
to
the
label
requirements.

Currently,
APHIS
fumigations
already
follow
a
fumigation
plan,
although
all
plans
would
now
have
to
be
brought
into
compliance
with
the
new
requirements
of
use.
Once
prepared
for
a
fixed
facility,
the
plan
would
need
few
modifications
for
repeated
fumigations.
Therefore,
BEAD
anticipates
few
impacts
on
applicators
or
facilities
in
preparing
the
FMP.
The
certification
of
the
FMP
may
entail
added
cost
to
the
fumigation,
but
BEAD
has
no
way
of
predicting
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
would
not
entail
significant
added
costs,
since
APHIS
fumigations
are
already
closely
monitored
and
documented.
Notices
that
a
commodity
has
been
treated
should
also
not
impose
significant
costs.

SITE
DESCRIPTIONS
Quarantine
fumigations
can
occur
at
a
number
of
locations,
primarily
in
port
or
airport
facilities
but
also
at
packing
sheds
and
other
points
of
shipment.
A
wide
variety
of
items
are
fumigated
including
perishable
and
non­
perishable
commodities
and
durable
goods.

The
information
provided
in
this
document
generally
concerns
the
Plant
Protection
and
Quarantine
(
PPQ)
used
by
the
US
Department
of
Agriculture's
Animal
Plant
Health
Inspection
Service
(
USDA
APHIS),
based
on
information
provided
by
them
(
USDA.
2005).
Information
on
the
quarantine
use
of
methyl
bromide
outside
the
control
of
PPQ
is
not
available
to
the
EPA.

Purpose
of
Fumigation
Quarantine
requirements
are
used
to
prevent
movement
of
pests
from
the
U.
S.
to
our
trading
partners,
to
protect
the
U.
S.
from
introduction
of
pests
from
other
countries,
to
prevent
the
interstate
movement
of
pests
(
federal
domestic
quarantines
and
state
exterior
quarantines),
and
to
prevent
intrastate
movement
of
pests
(
state
interior
quarantines).
Quarantine
requirements
are
dynamic,
changing
as
pest
outbreaks
occur,
new
pests
are
identified,
and
new
trading
partnerships
develop.

The
USDA
APHIS
fumigations
fulfill
numerous
phytosanitary
requirements
under
the
Plant
Protection
Act.
These
requirements
are
codified
in
Title
7
of
the
Code
of
Federal
Regulations,
Parts
300­
399.
Required
treatments
are
available
in
the
APHIS
treatment
manual
(
see:
http://
www.
aphis.
usda.
gov/
ppq/
manuals/).
Quarantine
fumigation
treatments
are
designed
to
allow
the
movement
of
commodities
that
might
accidentally
aid
in
the
movement
of
quarantined
organisms
to
areas
where
they
don't
presently
exist.
Methyl
bromide
fumigation
is
required
by
many
countries
as
a
condition
for
the
importation
of
certain
crops
that
could
carry
new
pests
into
Page
8
their
country.
Interstate
trade
also
requires
the
use
of
methyl
bromide
if
state
regulations
mandate
shipments
be
free
of
pests.
Without
methyl
bromide,
APHIS
has
indicated
that
a
variety
of
food
and
nonfood
commodities
would
not
be
allowed
to
enter
the
country,
and
domestic
producers
may
have
difficulty
exporting
their
commodities.

USE
AND
USAGE
OF
METHYL
BROMIDE
APHIS
sites
are
primarily
located
in
port
and
airport
facilities
where
both
imported
and
exported
commodities
and
goods
must
be
fumigated.
At
least
75%
of
these
are
located
in
urban
areas;
the
location
of
the
rest
could
not
be
determined1.
APHIS
has,
however,
indicated
that
144
of
152
port
sites
have
residential
or
business
areas
closer
than
3300
feet.
FIGURE
1.
U.
S.
MAP
OF
PLANT
PROTECTION
AND
QUARANTINE
PORTS
FACILITIES
IN
URBAN
AREAS
APHIS
PPQ
Ports
and
Urbanized
Areas
or
Urban
Clusters
Urban
Facilities
Urban
Area
APHIS
fumigations
encompass
the
range
of
conditions
from
vacuum
fumigation
chambers
to
simple
tarp
enclosures.
Goods
may
be
fumigated
in
the
shipping
containers
or
as
loose
cargo
(
break
bulk)
in
existing
or
temporary
enclosures,
including
warehouses.
Table
1
presents
the
range
of
enclosures
and
sizes
of
fumigated
enclosures
at
APHIS
supervised
sites.

1
BEAD
identified
the
location
of
each
facility
and
compared
it
to
areas
defined
as
Urbanized
Area
or
Urban
Cluster
by
the
2000
US
Census
(
www.
census.
gov).
An
Urbanized
Area
consists
of
contiguous
census
blocks
and
block
groups
of
at
least
1,000
persons/
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.
Page
9
TABLE
1.
ENCLOSURE
VOLUMES
AT
APHIS
SUPERVISED
FUMIGATION
SITES,
2005.

Enclosure
Type
Average
Volume
(
cu
ft)
Minimum
Volume
(
cu
ft)
Maximum
Volume
(
cu
ft)
Chambers
1,970
100
32,300
Container
(
No
Tarp)
10,030
140
89,040
Container
(
Tarp)
8,440
250
120,000
Dumpster
(
Tarp)
4,130
1,360
137,280
Structure
18,640
60
109,200
Bulk
Items
(
Tarp)
16,900
50
137,280
Source:
USDA,
2005.

APHIS
use
of
methyl
bromide
on
imported
and
on
exported
commodities
accounts
for
approximately
1,000,000
pounds
of
methyl
bromide
annually
(
Table
2).
Approximately
47%
of
methyl
bromide
PPQ
use
is
for
imports
and
52%
is
for
exports.
The
top
ten
APHIS
use
sites
account
for
over
95%
of
the
total
pounds
used.
Table
2
provides
descriptive
data
on
commodity
and
methyl
bromide
use
for
all
APHIS
sites.

Table
2.
Quarantine
Use
of
Methyl
Bromide
by
the
United
States
in
2005
Commodity
MeBr
(
lb)
Totals
Fruits
&
vegetables
(
mostly
Chilean)
445,584
Propagative
plant
material
3,778
Cut
flowers
and
greenery
12,551
Tile,
marble,
etc
21,522
Guar
gum
5,130
Bamboo
6,222
Wood
2,778
Cotton
3,317
Post
Harvest
Imports
Miscellaneous
1,194
502,075
Cherries
to
Japan
(
Washington
State)
59,855
Solid
wood
packing,
etc
100,119
Logs
(
primarily
to
Europe)
324,672
Post
Harvest
Exports
Miscellaneous
California
exports
70,077
554,722
Texas
1,551
Post
Harvest
Interstate
Florida
6,128
7,678
Grand
Total
1,064,476
Source:
U.
S.
A.
2005.
Quarantine
and
Preshipment
Report.

About
half
of
the
methyl
bromide
is
used
on
imported
fruits
and
vegetables,
which
mostly
come
from
Chile.
The
majority
of
APHIS­
supervised
export
treatments
consist
of
oak
logs
destined
for
the
European
Union.
These
treatments
are
required
by
the
importing
country,
not
by
APHIS.

Table
3
presents
information
about
typical
fumigation
rates
and
the
frequency
of
their
application.
About
75%
of
APHIS
fumigations
are
at
rates
of
4
lbs
of
methyl
bromide
per
1,000
cubic
feet
(
cu
ft)
or
less,
which
are
mainly
for
fruits,
vegetables
and
packing
materials.
Other
typical
rates
are
5
lbs
of
methyl
bromide
per
1,000
cubic
feet
primarily
for
wood
products;
8
lbs
Page
10
of
methyl
bromide
per
1,000
cubic
feet
for
invasive
snails
on
imported
tiles;
and
15
lbs
of
methyl
bromide
per
1,000
cubic
feet
for
oak
log
export
treatments.

TABLE
3.
FREQUENCY
OF
METHYL
BROMIDE
RATES
IN
APHIS
FUMIGATIONS,
2005.
Rate
(
lb
per
1000
cu
ft)
Frequency
per
Year
Frequency
(%)
Methyl
Bromide
(
lbs)
Methyl
Bromide
Pounds
(%)
Less
than
or
equal
to
4.0
7,950
76
466,893
73
Greater
than
4.0
to
9.0
1,970
19
48,748
8
Greater
than
9.0
to
15.0
570
5
123,255
19
Source:
Wood,
2006.
Note
that
Table
2
is
from
a
different
source
and
differ
from
thos
in
Table
3.
cu
ft
=
cubic
feet
Table
4
presents
information
from
the
10
highest
APHIS
methyl
bromide
use
sites.
The
table
indicates
the
total
amount
of
methyl
bromide
used
in
2005,
average
daily
use,
and
treatment
durations.

TABLE
4.
APHIS,
PPQ
USE
INFORMATION,
FUMIGATIONS
OF
IMPORTED
AND
EXPORTED
COMMODITIES,
2005
1
Station
ID
Total
Gas
Used
(
lb)
Average
Use
(
lb/
day)
Average
No.
Fumigations
/
day
Average
Duration
of
Treatment
(
hr)
Max
Use
Single
Fumigation
(
lb/
day)
Max
No.
Fumigations
/
day
Maximum
Treatment
Duration
(
hrs)
Site
1
184,243
841
3.69
2.1
512
14
16
Site
2
97,405
1,432
4.15
53.9
502
9
72
Site
3
88,758
292
5.92
5.6
240
21
72
Site
4
78,658
495
2.48
2.4
577
9
7
Site
5
69,226
1236
2.79
50.0
1099
6
72
Site
6
43,650
128
13.21
5.1
270
141
72
Site
7
15,428
86
2.12
27.5
165
7
72
Site
8
14,318
97
8.69
16.0
16
21
16
Site
9
13,793
85
2.54
16.0
186
8
74
Site
10
13,622
100
2.93
48.9
388
8
72
Source:
USDA,
2005.
1
Data
reported
is
for
365
day
time
period,
but
average
and
maximum
values
in
the
table
represent
days
when
fumigation
occurred,
e.
g.,
a
total
of
184,243
lbs
of
methyl
bromide
were
used
in
Site
1
in
219
days
and,
on
days
when
fumigations
occurred,
there
were
an
average
of
4
fumigations
using
841
lbs
of
methyl
bromide.

Typical
Use
Scenarios
Perishable
commodities,
wood
products
and
tile,
and
logs
are
some
example
categories
of
PPQ
fumigated
products.
In
order
to
narrow
the
focus
of
this
assessment,
the
following
provides
typical
use
patterns,
including
enclosure
size
and
fumigation
rate
for
these
categories.
The
patterns
are
based
on
average
use
by
port
where,
to
be
conservative,
the
average
use
pattern
with
the
highest
values
has
been
selected.
Maximum
values
were
also
taken
from
this
port
to
represent
a
non­
typical
use
pattern
that
occurred
over
the
reporting
period
(
fiscal
year
2005).
The
information
is
summarized
in
Table
5.

Fumigation
of
perishable
commodities
(
primarily
grapes
and
asparagus)
accounts
for
about
75%
of
total
number
of
fumigations.
The
rate
most
typical
of
perishable
commodity
fumigation
is
1
lb
per
1,000
cubic
feet
for
asparagus
and
grapes.
Perishable
commodities
are
fumigated
for
2
to
4
hours.
Site
1
is
the
largest
user
of
methyl
bromide
for
fumigation
of
perishable
commodities,
Page
11
accounting
for
about
half
of
all
use.
Typical
fumigation
enclosure
sizes
in
Site
1
are
57,000
cubic
feet
per
fumigation
with
3
to
4
fumigations
occurring
in
a
typical
day.
The
maximum
enclosure
size
in
Site
1
in
2005
was
128,000
cubic
feet,
the
maximum
number
of
fumigations
per
day
was
14,
and
the
maximum
amount
of
methyl
bromide
used
in
a
single
day
was
about
4,250
lbs,
according
to
APHIS
data.

Wood
products
and
tiles
account
for
about
20%
of
total
number
of
fumigations.
Rates
for
wood
products
and
tile
range
from
5
lbs
per
1,000
cubic
feet
(
wood
products)
to
8
lbs
per
1,000
cubic
feet
(
tiles).
Wood
products
and
tiles
are
fumigated
for
16
hours.
Based
on
available
information,
Site
9
is
used
here
to
represent
typical
methyl
bromide
use
patterns.
Typical
enclosure
sizes
in
Site
9
are
approximately
2,500
cubic
feet
per
fumigation
with
8
to
9
fumigations
occurring
in
a
typical
day.
The
maximum
enclosure
size
in
Site
9
in
2005
was
5,000
cubic
feet,
the
maximum
number
of
fumigations
per
day
was
21,
and
the
maximum
amount
of
methyl
bromide
used
in
a
single
day
was
about
270
lbs,
according
to
APHIS
data.

Logs
account
for
about
5%
of
total
number
of
fumigations.
The
log
fumigation
rate
is
15
lbs
per
1,000
cubic
feet.
Logs
are
fumigated
for
72
hours.
Site
2
is
the
largest
user
of
methyl
bromide
for
fumigation
of
logs,
accounting
for
over
half
of
log
fumigations.
Typical
log
fumigation
enclosure
sizes
in
Site
2
are
30,000
cubic
feet
per
fumigation
with
about
4
fumigations
occurring
in
a
typical
day
that
fumigations
occur
(
note
that
this
may
account
for
multi­
day
fumigations
that
overlap).
The
maximum
enclosure
size
in
Site
2
in
2005
was
45,000
cubic
feet,
the
maximum
number
of
fumigations
per
day
was
9,
and
the
maximum
amount
of
methyl
bromide
used
in
a
single
day
was
about
7,500
lbs,
according
to
APHIS
data.

TABLE
5.
TYPICAL
FUMIGATION
SCENARIOS
FOR
QUARANTINE
USE
OF
METHYL
BROMIDE.

Site
Rate
(
lb/
1000
cu
ft)
Treatment
Duration
(
hr)
Enclosure
Size
(
cu
ft)
Fumigations
per
Day
2
50,000
average
3
to
4
typical
Perishable
Commodities
1
4
100,000
high
14
high
5
2,500
average
8
to
9
typical
Wood
Products
and
Tile
8
16
5,000
high
21
high
30,000
average
4
typical
Logs
15
72
45,000
high
9
high
Source:
USDA,
2005.

CURRENT
PPQ
BUFFER
AND
VENTILLATION
SYSTEMS
Buffers
are
already
required
for
all
APHIS
supervised
fumigations
and
are
based
on
air
concentration
monitoring
data.
PPQ
requires
a
30
foot
buffer
during
treatment,
and
a
200
foot
buffer
during
the
first
10
minutes
of
aeration,
when
the
majority
of
fumigant
is
expelled.
These
values
were
put
in
place
after
PPQ
used
monitoring
data
to
determine
that
the
ambient
air
concentrations
never
exceed
5
ppm,
and
in
fact
are
often
below
the
level
of
detection
of
air
monitoring
devices
(
1
ppm)
at
these
distances.
California
requires
that
fumigation
enclosures
be
aerated
using
a
stack
and
mandates
that
the
stack
height
be
a
minimum
of
10
feet
higher
than
the
nearest
building
within
200
feet.
Aeration
is
at
ground
level
for
most
other
states.
APHIS
uses
active
ventilation.
Aeration
for
fresh
fruits
and
vegetables
is
no
longer
than
4
hours,
due
to
the
necessity
of
moving
perishable
items
quickly.
Aeration
of
non­
perishable
commodities
can
last
from
2
to
72
hours.
APHIS
PPQ
requires
that
the
fumigators
wear
SCBA
gear
within
the
30
foot
Page
12
buffer
during
treatment
and
the
200
foot
buffer
during
aeration.
APHIS
notes
that
California
regulations
allow
passers­
by
to
move
through
a
1,000
foot
buffer
without
SCBA
gear
or
air
purifying
respirators.

IMPACTS
OF
BUFFER
ZONES
ON
FACILITIES
Ports
and
fumigation
facilities
are
very
diverse
and
will
have
varying
capacity
for
establishing
buffer
zones.
Most
are
in
urban
areas
and
are
constrained
by
limited
space,
for
which
there
are
several
competing
uses.
If
site­
specific
information
were
available
describing
individual
ports
and
space
constraints,
it
would
still
be
very
difficult
to
determine
feasible
distances.
This
assessment
is,
by
necessity,
very
qualitative.
There
may
also
be
differing
capacity
to
maintain
a
buffer
zone
during
fumigation
(
treatment)
and
during
venting
(
aeration).

In
order
to
assess
the
impacts
of
the
proposed
risk
mitigation,
estimated
treatment
and
aeration
buffer
zones
are
presented
below.
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
10,000
cubic
feet,
representing
a
fumigation
of
several
pallets
or
multiple
trailers,
up
to
100,000
cubic
feet,
representing
a
warehouse
fumigation
or
multiple
fumigations
in
adjacent
enclosures.
These
buffers
represent
individual
fumigation
facilities
and
not
a
port
facility
as
a
whole.

Fumigation
rates
of
1
and
4
lb
methyl
bromide/
1,000
cubic
feet
are
considered
to
represent
perishable
commodities
and
packing
materials.
The
4­
lb
rate
is
excessive,
but
data
were
readily
available
from
the
EPA
risk
assessment.
A
rate
of
9
lb/
1,000
cubic
feet
is
used
to
represent
fumigation
of
durable
goods,
such
as
wood
and
tile,
and
a
rate
of
15
lb/
1,000
cubic
feet
is
used
to
assess
the
impacts
on
treatments
of
logs.
We
also
look
at
the
effect
of
the
gas
tightness
of
the
enclosure.
Low
loss
rates,
1
to
5%
per
24­
hour
period,
represent
well­
sealed
or
vacuum
chambers
while
higher
loss
rates,
10
to
25%
per
24
hours,
are
more
representative
of
tarped
enclosures2.

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
chamber
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
(
held
constant),
application
rate,
chamber/
enclosure
conditions
(
e.
g.,
gastightness
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.

2
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
applied
fumigant
while
a
24­
hour
treatment
would
lose
72%
of
the
applied
fumigant.
According
to
APHIS,
supervised
fumigation
facilities
use
the
highest
quality
tarps
and
enclosures
and
have
little
gas
leakage.
Page
13
The
APHIS
PPQ
practice
when
venting
is
to
use
portable
tubing
to
an
area
adjacent
to
the
treated
structure,
typically
within
200
feet
away
from
the
building
or
to
a
stack
in
California.
This
is
the
scenario
presented
in
the
BEAD
PPQ
tables
and
assumes
a
50
foot
stack
placed
away
from
any
adjacent
building's
downwash
affects.
The
last
scenario
is
PPQ
ground
level
stack
where
aeration
is
with
a
mobile
ground
level
source
not
near
a
building.
This
represents
an
APHIS
PPQ
practice
where
venting
is
through
portable
tubing
where
the
output
is
laid
on
the
ground
in
an
area
adjacent
to
a
treated
structure,
typically
within
200
feet.

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).

Treatment
Buffers
Table
6
presents
estimated
treatment
buffers
for
perishable
products.
Due
to
the
short
duration
of
fumigation
(
4
hr),
we
only
examine
loss
rates
of
10%
or
below.
This
assumes
that
the
majority
of
the
escaping
gas
is
lost
within
the
first
hour
of
treatment,
in
contrast
to
the
treatment
zones
for
higher
rates.
Page
14
TABLE
6.
ESTIMATED
PPQ
TREATMENT
BUFFER
ZONES
FOR
PERISHABLE
GOODS
Buffer
(
ft)
Rate
(
lb/
1000
cu
ft)
Loss
During
Treatment
(%)
95
max
99
whole
99.9
whole
Enclosure
Size
10,000
ft3
1%
0
0
0
5%
0
0
0
1.0
10%
0
0
0
1%
0
0
0
5%
90
0
90
4.0
10%
200
50
190
Enclosure
Size
50,000
ft3
1%
0
0
0
5%
0
0
0
1.0
10%
130
0
120
1%
0
0
0
5%
380
130
360
4.0
10%
680
250
640
Enclosure
Size
100,000
ft3
1%
0
0
0
5%
180
30
170
1.0
10%
410
150
380
1%
120
0
100
5%
710
260
660
4.0
10%
1,110
400
1,060
Source:
EPA
2006.
Note:
Buffers
are
based
on
a
4
hr
fumigation.
There
will
likely
be
a
minimum
buffer
enforced.
California
currently
has
a
10­
foot
minimum.

Table
7
presents
potential
treatment
zones
for
durable
products,
estimated
for
different
percentile
of
exposures
(
see
EPA
2006
for
details
about
the
interpretation
of
these
regulatory
standards).
BEAD
believes
the
estimated
treatment
zones
reflect
an
assumption
that
the
escaping
gas
is
lost
steadily,
but
slowly,
throughout
the
treatment
period,
similar
to
the
California
scheme.

TABLE
7.
ESTIMATED
PPQ
TREATMENT
BUFFER
ZONES
FOR
DURABLE
GOODS
Buffer
(
feet)
Rate
(
lb/
1000
cu
ft)
Loss
During
Treatment
(%)
95
max
99
whole
99.9
whole
Enclosure
Size
10,000
cu
ft
1%
0
0
0
10%
0
0
0
9.0
25%
0
0
0
Enclosure
Size
25,000
cu
ft
5%
0
0
0
10%
0
0
0
15.0
25%
300
80
280
Enclosure
Size
50,000
cu
ft
5%
0
0
0
10%
0
0
0
15.0
25%
297
83
281
Source:
EPA
2006.
Note:
Buffers
are
based
on
a
24
hr
fumigation.
There
will
likely
be
a
minimum
buffer
enforced.
California
currently
has
a
10­
foot
minimum.
Page
15
The
treatment
buffer
zones
for
perishable
commodities
(
Table
6)
are
much
larger
than
those
for
durable
goods
(
Table
7)
because
of
differences
in
treatment
times
(
4
versus
24
hours)
and
estimates
of
emission
rates
from
the
different
commodities.
The
risk
assessment
covers
these
differences
(
EPA
2006).
The
implication
of
this
difference
is
that
treatment
buffer
differences
may
be
too
large
if
a
4
hour
emission
estimate
is
used
as
in
Table
6
or
of
an
acceptable
distance
if
a
24
hour
emission
estimate
is
used
as
in
Table
7.

The
treatment
buffer
zones
listed
in
Tables
6
and
7
for
the
99
whole
field
buffers
are
larger
than
the
current
treatment
buffer
that
APHIS
maintains.
The
relevant
treatment
buffer
and
any
potential
impacts
will
depend
on
the
proximity
to
adjacent
structures,
the
size
and
loss
rate
of
the
enclosure
and
the
fumigation
rate
used.
The
mitigation
options
that
would
permit
smaller
treatment
zones
are
limited.
Essentially,
facilities
would
have
to
reduce
application
rates,
fumigate
in
smaller
amounts,
and/
or
increase
the
gas­
tightness
of
their
enclosures.

Rate
Reductions:
Rate
reduction
is
particularly
impractical
in
PPQ
use
of
methyl
bromide.
Rates,
as
well
as
fumigation
time,
are
determined
by
target
pest,
temperature,
and
commodity
to
be
fumigated
through
extensive
efficacy
testing
and
negotiation
with
U.
S.
trading
partners.
Agreed
upon
treatment
practices
are
codified
in
the
Code
of
Federal
Regulation.
Fumigators
are
required
to
follow
these
standards
for
the
fumigation
to
be
certified
by
APHIS.

Fumigate
Smaller
Volumes:
Fumigation
of
smaller
volumes
(
leading
to
a
reduced
amount
of
methyl
bromide
used)
may
be
possible
is
some
cases,
but
would
likely
lead
to
substantial
impacts
on
APHIS
systems
because
it
would
significantly
increase
the
time
to
treat
commodities.
The
primary
impact
would
arise
from
cost
of
storage,
the
potential
need
to
construct
additional
fumigation
facilities,
loss
of
perishable
commodities,
and
possible
disruptions
in
trade.

Comments
received
from
Royal
Fumigation
Inc.
(
comment
number
0204.1)
during
the
Phase­
5
public
comment
period
indicated
that
storage
costs
for
dry
commodities
per
container
run
from
$
15
to
$
30
per
day
and
that
storage
costs
of
refrigerated
commodities
are
significantly
higher.
They
also
stated
that
each
day
of
waiting
for
fumigation
reduces
value
of
grapes
by
$
1
per
crate,
where
the
value
of
grapes
ranges
from
$
7
to
$
28
per
crate.

Improving
Gas
Retention:
BEAD
does
not
have
data
regarding
the
feasibility
of
improving
the
retention
capability
of
large
chambers.
There
may
be
technical
limitations
to
achieving
loss
rates
of
less
than
5%
with
larger
enclosures.

Aeration
Buffers
Table
8
presents
the
estimated
aeration
buffers
for
representative
PPQ
fumigations.
BEAD
assumes
that
all
APHIS
facilities
currently
actively
vent
methyl
bromide
following
fumigation.
Active
aeration
is
in
accordance
with
the
APHIS
treatment
manual,
and
prevents
the
damage
of
perishable
commodities
while
allowing
cargo
through
the
port
as
fast
as
possible.
Currently,
APHIS
maintains
an
aeration
buffer
of
200
feet
and
has
indicated
that
larger
buffers
would
hinder
their
activities.
Page
16
TABLE
8.
ESTIMATED
PPQ
AERATION
BUFFERS
ZONES.
Buffer
(
ft)
Rate
(
lb/
1000
cu
ft)
Air
Exchange
(
cu
ft/
min)
[
exchanges/
min]
95
max
99
whole
99.9
whole
Perishable
Goods
and
Packing
Materials:
Enclosure
Size
10,000
cu
ft
500
[
0.05]
170
90
170
1.0
5,000
[
0.5]
40
0
40
500
[
0.05]
450
250
430
4.0
5,000
[
0.5]
170
90
150
Perishable
Goods
and
Packing
Materials:
Enclosure
Size
50,000
cu
ft
2,500
[
0.05]
460
250
450
1.0
25,000
[
0.5]
0
0
0
2,500
[
0.05]
2,080
630
1,870
4.0
25,000
[
0.5]
550
250
380
Perishable
Goods
and
Packing
Materials:
Enclosure
Size
100,000
cu
ft
5,000
[
0.05]
690
380
660
1.0
50,000
[
0.5]
0
0
0
5,000
[
0.05]
3,420
960
4,750
4.0
50,000
[
0.5]
840
380
790
Durable
Goods:
Enclosure
Size
10,000
cu
ft
9.0
5,000
[
0.5]
0
0
0
Durable
Goods:
Enclosure
Size
10,000
cu
ft
15.0
5,000
[
0.5]
20
0
30
Durable
Goods:
Enclosure
Size
50,000
cu
ft
2,500
[
0.05]
330
180
310
15.0
25,000
[
0.5]
0
0
30
Source:
EPA
2006.
Note:
4
hr
model
used
for
1
to
4
lb
rates
and
24
hr
model
used
for
9
and
15
lb
rate.
There
will
likely
be
a
minimum
buffer
enforced.
California
currently
has
a
10­
foot
minimum.

The
aeration
buffers
presented
for
the
99
whole
field
are
larger
than
those
currently
in
effect
for
APHIS
fumigations.
The
relevant
aeration
buffer
and
any
potential
impacts
will
depend
on
the
proximity
to
adjacent
structures,
the
size
and
aeration
rate
of
the
enclosure
and
the
fumigation
rate
used.
Air
exchange
rates
up
to
50,000
cubic
feet/
min
are
likely
already
in
place
and
the
large
fumigations
of
perishable
commodities
would
not
use
the
4­
lb
rate
for
which
we
have
estimates
of
the
buffer.
Other
mitigation
options
may
help
to
reduce
the
aeration
buffer.
Assuming
that
active
aeration
systems
are
already
in
use,
BEAD
has
identified
four
ways
that
quarantine
fumigators
may
reduce
the
required
aeration
buffer:
(
1)
reduce
the
rate
(
amount
of
methyl
bromide
/
1,000
cubic
feet),
(
2)
fumigate
smaller
volumes,
(
3)
install
additional
aeration
equipment,
and
(
4)
install
a
capture
and
destruction
system.
The
first
two
were
discussed
above
and
may
have
limited
utility.

Active
Aeration
Systems:
The
cost
to
improve
the
active
aeration
of
PPQ
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
Page
17
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.
Some
of
the
early
systems
encountered
difficulties
and
have
not
been
commercially
accepted.
Newer
systems
are
available
that
have
been
designed
to
overcome
these
difficulties.
These
systems
could
reduce
aeration
buffers
if
the
EPA
regulatory
scheme
permits
captured
methyl
bromide
to
be
subtracted
from
total
quantity
used
when
calculating
the
buffer.

There
are
a
number
of
companies
that
are
marketing
or
have
previously
marketed
methyl
bromide
capture
and
destruction
systems;
BEAD
obtained
information
from
two
of
them.
The
cost
of
a
capture
and
destruction
system
for
a
small
system
(
a
few
pallets)
at
approximately
$
5
per
pound
of
methyl
bromide
scrubbed
or
$
50
per
fumigation
cycle
and
for
a
large
system
(
trailer)
at
$
3.50
per
pound
or
$
1,800
per
cycle.

Alternatives
to
Methyl
Bromide
Methyl
bromide
is
a
required
fumigant
for
many
quarantine
treatments
(
USA
2005).
However,
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
(
SPS
Agreement)
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).
Research
is
ongoing
to
determine
its
capability
to
replace
methyl
bromide
in
all
its
critical
uses.

CONCLUSION
Methyl
bromide
is
an
important
tool
for
guaranteeing
that
commerce
can
flow
through
U.
S.
ports
without
the
risk
of
introducing
exotic
pest
species.
Federal
law
prohibits
the
introduction
of
these
species
and
dictates
treatment
regimes
for
their
control,
which
frequently
involve
fumigation
with
methyl
bromide
BEAD
does
not
expect
significant
impacts
to
result
from
lowering
the
air
concentration
limit
of
occupation
exposure
from
five
(
5)
ppm
as
a
ceiling
limit
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
significant
impacts
if
EPA
were
to
require
FMPs
and
other
actions
that
focus
on
compliance
and/
or
enforcement.
Page
18
BEAD
believes
the
current
APHIS
treatment
buffer
of
30
feet
and
aeration
buffer
of
200
feet
is
near
the
maximum
feasible
because
of
the
proximity
of
these
facilities
to
urban
areas.
It
appears
that
the
treatment
and
aeration
buffers
provided
in
the
document
would
be
feasible
for
many
APHIS
facilities.
This
conclusion
is
based
on
the
assumption
that
the
99
percentile
whole
field
buffer
is
used
for
regulatory
decision
making.
And
that
the
model
has
correctly
accounted
for
the
different
treatment
timings
and
emission
rate
(
4
versus
24
hour)
since
the
treatment
duration
can
have
a
significant
effect
on
the
treatment
buffer.
There
are
some
facilities
that
will
need
to
modify
their
current
practices
using
a
combination
of
the
mitigation
options
described
in
order
to
meet
the
buffer
requirements.
These
facilities
may
have
to
invest
in
additional
equipment
to
reduce
the
aeration
and
treatment
buffers.

There
are
some
facilities
that
will
need
to
modify
their
current
practices
to
meet
these
proposed
buffer
requirements.
There
are
several
ways
to
meet
these
requirements;
for
example,
sitespecific
modeling
can
be
used
by
the
facilities
to
select
methods
to
implement
that
would
result
in
the
reduction
of
buffers.
In
most
cases,
facilities
could
potentially
achieve
the
greatest
buffer
reduction
by
using
a
combination
of
methods.
Treatment
buffers
may
be
reduced
by
methods
such
as:
improved
sealing
techniques,
improvements
in
the
treatment
enclosures,
or
treating
smaller
volumes
of
commodities.
Aeration
buffers
may
be
reduced
by
methods
such
as:
improved
ventilation
systems
(
greater
air
exchanges
per
minute,
taller
stacks),
less
methyl
bromide
used
through
fumigating
at
the
lowest
permissible
rate,
treating
smaller
volumes,
fumigating
at
a
lower
concentration
for
a
longer
time,
building
additional
fumigation
facilities
at
a
site
further
away
from
bystanders,
or
building
a
capture
and
destruction
system.
BEAD
anticipates
that
using
a
combination
of
these
mitigation
options
most
facilities
will
be
able
to
meet
the
buffer
requirements.
However,
these
changes
will
entail
some
costs.

However,
if
PPQ
facilities
cannot
meet
the
buffer
requirements,
even
with
the
adoption
of
additional
equipment,
they
would
not
be
able
to
use
methyl
bromide.
Therefore,
if
buffers
are
infeasible,
some
facilities
may
have
to
cease
operation.
This
may
impact
producers
and
consumers,
as
well
as
the
local
economy.
BEAD
does
not
have
adequate
data
about
the
specific
site
characteristics
of
these
facilities
to
quantify
the
distribution
and
magnitude
of
these
impacts.
However,
BEAD
anticipates
that
by
using
a
combination
of
mitigation
options
most
facilities
will
be
able
to
meet
the
buffer
requirements.

REFERENCES
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
.

U.
S.
Census
Bureau.
2000.
Urban
and
Rural
Classification.
Available
at
http://
www.
census.
gov/
geo/
www/
ua/
ua_
2k.
html
United
States
of
America.
2005.
Quarantine
and
Preshipment
(
QPS)
­
supplement
to
document
filed
in
May
2005
in
accordance
with
Decision
XVI/
10.
Document
filed
as
part
of
the
Montreal
Protocol
on
Ozone
Depleting
Substances.
\
Page
19
United
States
Department
of
Agriculture.
2005.
Additional
Data
from
the
U.
S.
Department
of
Agriculture
Animal
and
Plant
Health
Inspection
Service
in
Response
to
the
Methyl
Bromide
Interim
Registration
Eligibility
Document
(
OPP­
2005­
0123):
Use
of
Methyl
Bromide
under
APHIS
Supervision,
Submitted
December
29,
2005
USDA.
2006.
PPQ
Cites
Directory.
Available
online
at
http://
www.
aphis.
usda.
gov/
ppq/
permits/
plantproducts/
cites/
list.
pdf
Wood,
S.,
2006,
Director,
Treatment
Quality
Assurance
Unit,
APHIS,
Presentation
to
EPA.
