Page
1
of
7
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
Date:
March
20,
2006
Subject:
Risk
Mitigation
Options
for
Methyl
Bromide's
Uses
in
Enclosures,
Chambers,
and
Structural
Food
Processing/
Storage
Facilities
in
Support
of
the
Reregistration
Eligibility
Decision
(
RED)

From:
Steven
Weiss,
Chemical
Review
Manager
Special
Review
Branch,
Special
Review
and
Reregistration
Division
(
7508C)

To:
Methyl
Bromide
Docket
(
EPA­
HQ­
OPP­
2005­
0123)

Background
The
Environmental
Protection
Agency
(
EPA)
is
opening
Phase
5
of
the
Public
Participation
Process
for
methyl
bromide's
uses
in
enclosures,
chambers,
and
structural
food
processing/
storage
facilities.
The
term
"
commodity
uses"
will
be
used
to
refer
to
these
uses
in
the
rest
of
this
document.
This
document
outlines
the
risk
management
options
EPA
is
considering
to
address
risks
that
have
been
identified
in
the
revised
risk
assessment
for
commodity
or
structural
uses.
EPA
seeks
public
comment
on
these
options,
particularly
comments
addressing
the
costs,
feasibility,
and
effectiveness
at
reducing
risks.
The
Agency
plans
to
release
a
revised
assessment
(
Phase
5)
for
methyl
bromide's
other
uses
(
e.
g.
pre­
plant
soil
uses)
later
this
year.

On
August
3,
1996,
the
Food
Quality
Protection
Act
of
1996
(
FQPA)
was
signed
into
law.
This
Act
amends
FIFRA
and
the
Federal
Food
Drug
and
Cosmetic
Act
(
FFDCA)
to
require
reassessment
of
all
existing
tolerances
for
pesticides
in
food.
In
reassessing
these
tolerances,
the
Agency
must
consider,
among
other
things,
aggregate
risks
from
non­
occupational
sources
of
pesticide
exposure.
When
a
safety
finding
has
been
made
that
aggregate
risks
are
below
EPA's
level
of
concern
and
the
Agency
concludes
that
there
is
a
reasonable
certainty
of
no
harm
from
aggregate
exposure,
the
tolerances
are
considered
reassessed.
In
this
document,
the
Agency
is
asking
for
cost
and
benefits
information
in
order
to
develop
a
risk
management
decision
that
both
meets
the
FQPA
standard
for
tolerance
reassessment
and
provides
for
feasible
and
practical
product
use.

Summary
of
Risks
A
full
discussion
of
the
direct
risks
associated
with
the
commodity
uses
of
methyl
bromide
is
included
in
"
Methyl
Bromide:
Phase
5
Health
Effects
Division
(
HED)
Human
Health
Risk
Assessment
For
Commodity
Uses"(
Jeff
Dawson,
March
10,
2006,
DP
Barcode:
D304623).
This
Page
2
of
7
document
is
included
in
the
Methyl
Bromide
Docket
(
EPA­
HQ­
OPP­
2005­
0123).
Risks
resulting
from
dietary
exposure
to
methyl
bromide
are
well
below
EPA's
level
of
concern;
therefore,
no
risk
mitigation
measures
are
necessary
to
address
dietary
exposure
and
risk.

Acute
risks
to
bystanders,
people
who
may
be
near
facilities
during
and
after
methyl
bromide
commodity
fumigations,
may
be
of
concern
depending
on
a
number
of
factors.
Some
of
these
factors
include
proximity
to
the
facility,
size
and
type
of
facility,
rates
of
methyl
bromide
used,
and
method
and
duration
of
aeration
following
treatment.
Also,
risks
to
workers
involved
in
methyl
bromide
commodity
fumigations
may
be
of
concern,
as
are
risks
to
workers
involved
in
non­
fumigation
activities
at
facilities
where
fumigations
take
place.
Furthermore,
EPA's
Office
of
Atmospheric
Programs
(
OAP)
has
estimated
the
number
of
UV­
related
skin
cancer
incidence
and
deaths
based
on
the
methyl
bromide's
commodity
uses
due
to
ozone
depletion.
OAP's
assessment
is
included
in
the
docket
along
with
HED's
assessment.
EPA
is
seeking
comments
on
ways
to
mitigate
these
risks
by
reducing
methyl
bromide
release
into
the
atmosphere.

Introduction
to
Bystander
Risk
Management
Options
In
general,
the
closer
bystanders
are
to
methyl
bromide
commodity
fumigation
facilities
the
higher
their
potential
risk.
The
State
of
California
has
developed
guidance
to
aid
California
County
Agricultural
Commissioners
in
regulating
methyl
bromide
commodity
fumigations,
and
since
the
early
1990s
a
major
element
of
California's
regulatory
approach
is
the
use
of
buffer
zones
to
protect
bystanders.
Enclosure
operators
and/
or
pest
control
businesses
in
California
must
obtain
a
site­
specific
permit
to
fumigate
commodities
with
methyl
bromide.
As
part
of
this
permitting
process,
county
agricultural
commissioners
define
buffer
zones
during
treatment
and
aeration
periods
of
the
fumigation
process
based
on
site­
specific
surveys
provided
by
enclosure
operators
and/
or
pest
control
businesses.
Only
persons
supervising
or
performing
fumigation
activities
are
permitted
in
the
treatment
and
aeration
buffer
zones.
All
other
people
including
residents
and
workers
must
be
excluded
from
these
zones.
Permits
for
repeat
applications
are
not
required
unless
conditions
at
the
specific
sites
have
changed.
Look­
up
tables
which
define
buffer
distances
are
based
on
amount
of
methyl
bromide
released
during
treatment
and
aeration
periods
along
with
the
volume
fumigated
in
a
24­
hour
period.
Conditions
of
the
permit
depend
on
enclosure
types
(
pressure
tested,
retention
tested,
or
untested)
and
aeration
method
(
standard
stack,
minimum
stack,
or
no
stack).
Site
conditions
are
also
a
factor
regarding
the
size
of
buffers.
The
less
methyl
bromide
that
is
leaked
or
released
during
treatment
and
aeration
results
in
smaller
buffer
zones.
Similarly,
higher
stack
heights
result
in
smaller
buffers.
California's
most
recent
methyl
bromide
commodity
fumigation
guidelines
include:
(
1)
the
suggested
permit
conditions
for
methyl
bromide
commodity
fumigation;
(
2)
work
site
plan;
(
3)
final
permit
conditions;
and
(
4)
a
reference
manual.
These
items
can
be
found
at:
http://
www.
cdpr.
ca.
gov/
docs/
enfcmpli/
penfltrs/
penf2001/
2001048.
htm.

California's
approach
for
managing
risks
associated
with
commodity
fumigation
appears
to
be
effective
and
feasible.
EPA
recognizes
that
there
are
costs
associated
with
these
measures.
The
Agency
would
like
comments
on
risk
mitigation
options
outlined
below
which
are
based
in
part
on
California's
methyl
bromide
commodity
fumigation
guidelines.
The
Agency
acknowledges
that
risks
are
highly
site­
specific
and
there
is
a
great
variety
of
sizes
and
types
of
fumigation
facilities.
Risk
management
that
is
flexible
enough
to
allow
for
site­
specific
characteristics
may
also
increase
complexity
and
increase
the
need
for
highly
skilled,
well
trained
applicators.
Furthermore,
the
Agency
recognizes
that
flexibility
also
may
increase
burden
on
local,
state
and/
or
federal
regulators.
Page
3
of
7
Risk
Management
Options
For
the
following
17
options
and
any
other
options
you
would
like
to
suggest,
please
provide
comments
for
the
following
general
questions
and
specific
questions
listed
under
each
mitigation
option:

 
What
type
of
fumigation
operation
do
your
comments
address?
 
What
is
the
feasibility
of
implementing
this
option
on
a
national
level?
 
What
are
the
costs
associated
with
this
option?
 
How
effectively
does
this
option
mitigate
the
risks
resulting
from
methyl
bromide
use?

1)
Application
Site­
specific
Fumigation
Management
Plans:
The
Agency
sees
risk
reduction
value
in
encouraging
fumigators
to
anticipate,
recognize,
and
evaluate
the
factors
that
could
lead
to
methyl
bromide
exposure.
The
Agency
believes
that
a
potentially
valuable
supplement
to
other
requirements
is
a
comprehensive
site­
specific
plan.

2)
Buffer
Zones:
The
Agency
believes
that
establishing
zones
around
an
enclosure
or
structure
during
treatment
and
aeration
is
an
effective
mitigation
option
for
managing
the
risks
from
inhalation
exposure
to
both
workers
involved
in
the
fumigation
process
and
bystanders
in
areas
around
enclosures.
The
distance
or
size
of
the
buffer
zones
would
be
based
on
several
factors
that
include
loss/
emission
rates,
enclosure
types,
and
stack
height.
The
Agency
believes
that
in
addition
to
establishing
buffer
distances
based
on
these
factors,
it
may
be
prudent
to
establish
a
minimum
buffer
distances
for
all
applications.

How
would
buffer
zones
change
fumigation
schedules
and
capacity,
and
what
would
the
associated
costs
be?
Please
provide
information
on
the
cost
of
moving
commodities
or
fumigation
facilities
to
different
sites
if
adequate
buffers
cannot
be
achieved
at
current
sites.
If
product
must
be
stored
before
or
after
fumigation
due
to
changes
in
fumigation
schedule
and
capacity,
what
are
the
storage
costs?
Which
ports
have
or
do
not
have
sufficient
space
available
to
increase
buffer
zones?
Please
provide
the
cost
of
acquiring
additional
property
that
would
allow
for
increased
buffers.
Please
describe
when
a
buffer
is
not
feasible.
If
fumigation
with
methyl
bromide
is
not
feasible,
what
is
the
next
best
alternative
and
what
is
the
cost
difference?
Please
identify
the
type
of
fumigation
operation
your
comments
address.

3)
Stacks:
The
Agency
believes
that
enclosures
or
structures
equipped
with
vertical
stacks
at
sufficient
heights
can
significantly
reduce
the
size
of
buffer
zones
compared
to
the
size
that
would
be
necessary
if
methyl
bromide
were
discharged
at
ground
level
during
aeration.
The
Agency
is
aware
that
the
initial
costs
of
retrofitting
enclosures
with
fixed
stacks
or
purchasing
mobile
stacks
may
be
substantial
but
notes
that
the
use
of
stacks
in
cases
where
larger
buffers
would
not
be
feasible
would
enable
facilities
to
continue
with
applications
rather
than
rerelocating
or
making
other
major
modifications
to
their
enclosures.

Please
provide
the
type
of
fumigation
operation,
the
types
of
stacks
used
(
mobile,
fixed,
stack
height,
and
air
flow
capacity)
and
the
cost
of
purchase,
installation,
use,
and
maintenance.
How
do
the
use
of
stacks
affect
fumigation
schedules?
What
are
the
resulting
costs?

At
present,
the
Agency
has
information
that
stack
costs
are
approximately
$
1000
per
stack,
including
tubing
and
brackets,
but
has
no
information
on
the
cost
of
their
installation,
use,
and
maintenance.
Page
4
of
7
Please
provide
the
type
of
fumigation
operation,
the
types
of
fans
used,
the
number
of
each
fan
required,
the
cubic
feet
of
air
moved
per
minute,
and
the
cost
of
purchase,
installation,
and
maintenance.

At
present,
the
Agency
believes
that
fan
costs
are
approximately
$
850
per
10,000
cubic
foot
of
air
moved
per
minute,
but
has
no
information
on
the
cost
of
their
use,
installation,
and
maintenance.

4)
Enclosure
Performance
Criteria:
The
Agency
believes
that
several
performance
measures
relating
to
enclosure
or
structure
type
could
affect
the
size
of
buffer
zones.
The
gas
tightness
of
the
structure
or
enclosure,
type
of
aeration
method
(
air
exchanges
per
hour,
exit
velocity
from
stacks)
and
the
flexibility
to
control
temperature
within
the
enclosure
(
lower
temperatures
require
higher
application
rates)
could
also
affect
the
duration
of
aeration
periods
and
buffer
sizes.
Furthermore,
tighter
enclosures
use
less
methyl
bromide
which
will
also
mitigate
risks
associated
with
ozone
depletion
(
e.
g.
UV­
related
skin
cancer).
The
Agency
is
aware
that
in
many
cases
costs,
logistics,
and
the
nature
of
commodities
being
treated
would
inhibit
the
likelihood
of
upgrading
the
performance
level
of
enclosure
systems.

Is
it
possible
to
make
fumigation
structures
more
air
tight?
If
so,
what
are
the
costs
of
modifying
structures,
chambers,
and
tarps
to
limit
gas
loss
(
e.
g.,
using
heavy
canvas
or
thicker
tarps)?
What
is
the
cost
of
building
new
fumigation
systems
that
use
the
best
available
technology
to
limit
gas
loss?
Please
provide
the
type
of
fumigation
operation.

5)
Recovery/
Destruction
Systems:
Eliminating
the
need
to
vent
methyl
bromide
out
of
the
enclosure
by
recovering
the
gas
or
converting
the
methyl
bromide
into
an
inert
material
that
can
be
safely
disposed
of
or
used
for
other
purposes
could
drastically
reduce
or
eliminate
buffer
zones
(
if
certain
performance
criteria
were
met).
Furthermore,
if
such
systems
are
used,
less
methyl
bromide
will
be
emitted
and
therefore
reduce
the
risks
associated
with
ozone
depletion
that
occurs
from
methyl
bromide
entering
the
stratosphere
(
e.
g.
UV­
skin
related
skin
cancers).

Information
on
the
cost
of
equipment,
installation,
operation,
and
cost
to
remove
recovered
methyl
bromide
(
MeBr)
or
waste
products
would
be
very
useful.
Because
the
size
and
amount
of
MeBr
used
in
the
enclosure
or
structure
can
have
a
significant
impact
on
costs
or
efficacy
please
provide
information
on
the
type
of
enclosure
and
size:
small=
5,000
cubic
feet
(
ft3)
or
20
pounds
(
lbs)
of
MeBr;
medium
=
100,000
ft3
or
400
lbs
of
MeBr;
large
=
1,000,000
ft3
or
2,000
lbs
of
MeBr.

6)
Limitation
of
Use
by
Amount
and
Time:
The
Agency
believes
that
limiting
the
amount
of
methyl
bromide
used
at
a
worksite
and
volume
fumigated
in
a
24­
hour
period
would
reduce
risks
at
greater
maximum
distances
where
off­
site
concentration
would
be
of
concern
(
lookup
tables
for
buffer
size
would
be
determined
by
loss
rates
and
volume
fumigated).
For
example,
California's
suggested
permit
conditions
limits
the
total
amount
of
methyl
bromide
to
1000
pounds
and
25,000
ft3
of
volume
treated
in
a
24
hour
period
at
a
specific
location.
United
States
Department
of
Agriculture's
Animal
and
Plant
Health
Inspection
Service
(
APHIS)
provides
usage
data
that
includes
total
amount
of
methyl
bromide
and
volume
treated
in
a
24
hour
period
for
APHIS­
supervised
facilities
(
this
document
is
included
in
the
docket).

How
would
limits
on
total
pounds
of
methyl
bromide
used
per
day
impact
commercial
postharvest
fumigation
of
commodities,
structures,
and
pre­
shipment
and
quarantine
Page
5
of
7
commodities?
If
a
fumigation
cannot
be
done
in
one
event
due
to
such
limits,
what
are
the
costs
associated
with
multiple
fumigations.
What
problems
might
result?

7)
Timing
of
Applications
or
Aeration:
Generally,
the
less
stable
atmosphere
during
daylight
hours
dilutes
and
dissipates
methyl
bromide
more
rapidly
than
to
more
stable
night
time
conditions.
California's
suggested
permit
conditions
require
aeration
to
start
during
daylight
hours
unless
enclosures
have
stacks
that
meet
specific
height
requirements.

8)
Sensitive
Sites:
The
Agency
believes
that
it
may
be
prudent
to
require
additional
protective
measures
for
schools,
hospitals,
and
other
sensitive
sites,
including
a
prohibition
on
fumigations
or
aeration
while
people
are
present.

9)
Minimum
Aeration
Times:
Methyl
bromide
absorbed
within
the
commodity
can
continue
to
off­
gas
for
a
long
time.
The
rate
of
off­
gassing
depends
on
how
tightly
methyl
bromide
binds
to
the
commodity.
The
amount
of
air
which
passes
through
the
enclosure
or
structure
has
a
minimal
effect
on
the
rate
of
off­
gassing.
Current
EPA
labels
require
aeration
until
concentration
reaches
5
parts
per
million
(
ppm)
or
less
and
permit
active
or
passive
aeration
methods.
A
minimum
time
is
not
listed.
The
Agency
believes
that
a
minimum
time
period
for
aeration
may
reduce
exposures
for
workers
reentering
enclosures.

10)
Permits:
California's
permitting
system
for
commodity
fumigation
is
based
on
a
comprehensive
state­
wide
program
that
relies
heavily
on
County
Agricultural
Commissioners
who
review
and
issue
permits
for
applications.
The
Agency
is
aware
that
few
states
have
such
a
regulatory
network
in
place
to
efficiently
administer
a
program
such
as
California's.
However,
the
Agency
does
recognize
the
value
of
such
a
system
at
ensuring
compliance
with
label
requirements
and
enforcing
against
misuse.
Therefore,
the
roles
and
responsibilities
for
local,
state,
federal
and
public
stakeholders
would
need
to
be
defined
to
ensure
that
commodity
fumigations
are
conducted
in
compliance
with
the
new
labels
(
e.
g.
review
of
site
plans,
determining
buffers,
record
keeping,
etc.).

11)
Record
Keeping/
Reporting
/
Tracking:
There
are
currently
no
requirements
on
EPA
labels
for
site
operators
to
keep
records
of
equipment
testing
or
applications
made.
California's
suggested
permit
conditions
require
that
records
of
performance
testing
be
kept
for
at
least
2
years.
Reporting
and
tracking
of
site
plan
information
will
likely
be
major
tool
for
federal,
state,
and
local
regulators
to
ensure
compliance
with
labeling
and
regulations
associated
with
commodity
fumigations.

12)
Training
and
Certification:
As
part
of
the
Agency's
Certification
and
Training
Regulations,
EPA
requires
pesticide
applicators
to
meet
certain
training
and/
or
testing
requirements
before
they
use
or
supervise
the
use
of
pesticides
labeled
"
restricted
use."
Currently
these
regulations
do
not
require
any
training
specifically
on
the
safe
handling
of
fumigants
used.
The
Agency
believes
that
a
formal
training
program
may
be
an
effective
way
to
maximum
compliance
with
labeling
requirements
and
more
importantly,
minimize
the
risk
from
worker
and
bystander
inhalation
exposure
associated
with
commodity
fumigations.
The
Agency
also
recognizes
that
many
of
the
hazards
associated
with
commodity
fumigations
are
very
unique.
A
possible
option
would
be
to
establish
a
commodity/
structural
fumigator
training
and
certification
category
under
the
Agency's
Certification
and
Training
Regulations
based
on
training
programs
already
being
used
by
APHIS,
state
agencies,
and
industry.
Page
6
of
7
13)
Maximum
Application
Rates:
Current
EPA
registered
labels
specify
maximum
application
rates
for
various
commodities.
Application
rate
for
commodity
uses
range
from
1
to
20
lbs
active
ingredient
(
ai)
per
1000
cubic
feet
with
most
occurring
in
the
1
to
9
lbs
ai
per
1000
cubic
feet
range.
Lower
rates
that
are
still
efficacious
would
reduce
exposure
to
methyl
bromide
and
indirect
effects
from
ozone
depletion
(
e.
g.
UV­
related
skin
cancer).
However,
the
Agency
is
aware
that
there
may
be
issues
other
than
efficacy,
such
as
resistance,
that
the
Agency
needs
to
consider
if
rates
are
lowered.

For
example,
many
fresh
and
processed
foods
and
nuts
are
fumigated
at
average
rates
below
4
lbs
ai
per
1000
cubic
feet,
many
food
processing
facilities
use
rates
below
2
lbs
ai
per
1000
cubic
feet,
and
the
highest
use
rates
of
15
lbs
ai
per
1000
cubic
feet
are
for
logs.

14)
Alternatives:
Using
an
alternative
material
or
method
that
result
in
lower
risks
while
maintaining
sufficient
efficacy
is
also
a
preferred
mitigation
option
which
also
mitigates
effects
on
ozone.
Please
comment
on
whether
other
pesticides
or
non­
chemical
treatments
not
identified
in
the
Agency's
analysis
exist
which
can
be
used
commercially
to
control
pests
that
are
controlled
by
fumigation
with
methyl
bromide.

Since
the
initiation
of
the
Methyl
Bromide
Critical
Use
Exemption
process
under
the
Montreal
Protocol,
the
Biological
and
Economic
Analysis
Division
of
the
Office
of
Pesticide
Programs,
in
conjunction
with
the
Office
of
Air
and
Radiation,
has
developed
the
United
States
nomination
for
critical
use
exemptions
from
the
phaseout
of
methyl
bromide.
These
technical
documents
discuss
in
detail
the
benefits
of
methyl
bromide
and
alternatives.
The
most
recent
documents
for
commodities
and
structures
may
be
located
at:

http://
www.
epa.
gov/
ozone/
mbr/
CUN2008/
CUN2008_
Commodities.
pdf
and
http://
www.
epa.
gov/
ozone/
mbr/
CUN2008/
CUN2008_
PostHarvest.
pdf
As
part
of
this
assessment
the
Biological
and
Economic
Analysis
Division
has
assumed
that
there
are
currently
no
alternatives
for
international
quarantine
uses
because
those
uses
require
a
CODEX
Alimentarius
Commission
standard
for
the
165
member
countries.

15)
Integrated
Pest
Management
(
IPM):
Many
facilities
such
as
food
processing
or
storage
operations
are
fumigated
at
regular
intervals
regardless
of
pest
pressures
as
a
preventive
measure.
The
Agency
believes
that
an
effective
IPM
program
that
includes
diagnostic
analysis
and
treatment
thresholds
may
result
in
a
reduction
of
the
frequency
of
treatments
and
the
amount
of
methyl
bromide
used.

16)
Air
Monitoring/
Modeling
Data:
One
option
that
would
increase
flexibility
would
be
to
allow
facilities
the
option
of
using
smaller
buffer
zones
than
what
is
required
on
labels
if
sitespecific
air
monitoring
and
modeling
shows
that
methyl
bromide
concentrations
are
below
the
Agency's
level
of
concern
at
the
particular
distance
monitored.
This
monitoring
and
modeling
would
need
to
reflect
worst
case
weather
conditions.

17)
Notification/
Posting:
EPA
believes
that
workers
not
involved
in
the
fumigation
and
others
who
may
be
present
near
treatment
facilities
could
take
steps
to
protect
themselves
if
they
are
aware
of
potential
risks
associated
with
commodity
or
structural
fumigations
that
are
occurring
near
them.
This
can
be
accomplished
by
requiring
the
posting
of
signs
as
well
as
other
communication
methods
(
e.
g.
verbal
notification).
Page
7
of
7
Comments
Please
submit
comments
to
the
public
docket
on
the
web
at
http://
www.
regulations.
gov/.
When
submitting
comments,
please
identify
the
question(
s)
to
which
you
are
responding
and
include
discussions,
explanations,
and
references
where
possible.
