October 2010
EPA738-F-10-001
United States
Environmental Protection
Agency
Soil Fumigant Mitigation Factsheet:
Buffer Zones
EPA is requiring important new safety measures for soil fumigant pesticides to increase
protections for agricultural workers and bystanders ~ people who live, work, or otherwise spend time
near fields that are fumigated. These measures are for the soil fumigants chloropicrin, dazomet, metam
sodium/potassium, and methyl bromide.
This fact sheet summarizes new requirements to protect fumigant handlers and other workers
from fumigant exposures. When new fumigant labels appear in the market place in 2010, fumigant
users will need to comply with new requirements. Requirements for Buffer Zone Mitigation Measures,
however, will not appear on fumigant labels until late 2011.
Buffer Zone Distances
A buffer zone provides distance between the application site (i.e., edge of field)
and bystanders, allowing airborne residues to disperse before reaching the
bystanders. This buffer will reduce the chances that air concentrations where
bystanders are located will cause acute adverse health effects.
EPA has selected buffer distances that will protect bystanders from acute
exposures, but which are not so great as to eliminate benefits of soil fumigant
use. The size of the buffer zones is based on the following factors:
• application rate;
• field size;
• application equipment and methods; and,
• credits for use of emission-reduction measures such as high-barrier
tarps and site conditions.
Buffers zone distances are scenario-based using applicable site conditions and
will be based on look-up tables on product labels. EPA is also giving "credits"
to encourage users to employ practices which reduce emissions. Credits will
reduce buffer distances. Some credits will also be available for site conditions
that reduce emissions (e.g., high organic or clay content of soils).
New Requirements for
Buffer Zones
General
To address the risk to bystanders who live and work near fumigated fields, the
Agency is requiring buffer zones. The following summarizes the buffer zone
requirements:
General
A "buffer zone" must be established around the perimeter of each
application block or greenhouse where a soil fumigant is applied. The
buffer zone must extend from the edge of the application block or
greenhouse perimeter equally in all directions.
All non-handlers including field workers, nearby residents, pedestrians,
and other bystanders must be excluded from the buffer zone during the
buffer zone period, except for people in transit (see exemptions section
below).
The "buffer zone period" starts at the moment when any fumigant
is delivered/ dispensed to the soil within the application block or
greenhouse and lasts for a minimum of 48 hours after the fumigant has
stopped being delivered/dispensed to the soil.
Soil Fumigant Mitigation: Buffer Zones
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Buffer Zone Distances
Authorized Entry to
Buffer Zones
Buffer Zone Proximity
Exemptions for Transit
Through Buffer Zones
Structures Under the
Control of Owner/
Operator of the
Application Block
Areas Not Under the
Control of Owner/
Operator of the
Application Block
Soil Fumigant Mitigation: Buffer Zones
Buffer zone distances
• Buffer zone distances must be based on look-up tables on product
labels (25 feet is the smallest distance regardless of site-specific
application parameters).
• For selective replant fumigation in an orchard using hand held
application methods (e.g., deep injection auger probes) to treat
individual tree holes, the minimum buffer zone will be 25 feet
measured from the center of each injection site (i.e., tree hole).
Authorized entry to buffer zones
• Only authorized handlers who have been properly trained and
equipped according to EPA's Worker Protection Standard (WPS) and
label requirements may be in the buffer zone during the buffer zone
period.
Buffer zone proximity
• To reduce the potential for off-site bystander exposure to peak
fumigant emissions from multiple fumigated fields, buffer zones from
multiple application blocks may only overlap under the following
conditions:
• For continuous-move center-pivot applications (metam
sodium/potassium products only), buffers may overlap only if
applications are made using low-drift systems.
• For all other application methods, buffers may overlap only if
at least 12 hours have elapsed from end of the application for
which a buffer is already in place to the start of the subsequent
application.
• The certified applicators in charge of the fumigations must
provide information to handlers who may work in the buffers
about the protective equipment, signs of exposure, and health
effects associated with each fumigant to which they may be
exposed.
Exemptions for transit through buffer zones
• Vehicular and bicycle traffic on public and private roadways through
the buffer zone is permitted
• Bus stops or other locations where persons wait for public transit are
not permitted within the buffer zone.
• See the Posting Fact Sheet for additional requirements that may apply.
Structures under the control of owner/operator of the application block
• Buffer zones may not include buildings used for storage such as sheds,
barns, garages, etc., UNLESS,
• The storage buildings are not occupied during the buffer zone
period,and
• The storage buildings do not share a common wall with an
occupied structure.
• See the Posting Fact Sheet for additional requirements that may apply.
Areas not under the control of owner/operator of the application block
• Buffer zones may not include residential areas (including employee
housing, private property, buildings, commercial, industrial, and other
areas that people may occupy or outdoor residential areas, such as
lawns, gardens, or play areas) UNLESS,
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Areas Not Under the
Control of Owner/
Operator of the
Application Block,
continued
Fumigation Restrictions
Near Difficult-to-
Evacuate Sites
• The occupants provide written agreement that they will
voluntarily vacate the buffer zone during the entire buffer
zone period, and
• Reentry by occupants and other non-handlers does not occur
until the buffer zone period has ended.
• For methyl bromide formulations with less than 20%
chloropicrin, air monitoring with direct-read instruments
shows concentrations are below action levels before reentry is
permitted.
• Buffer zones may not include agricultural areas owned/operated
by persons other than the owner/operator of the application block.
UNLESS,
• The owner/operator of the application block can ensure that
the buffer zone will not overlap with a buffer zone from any
adjacent property owners, taking into account the amended
requirements for overlapping buffers, and
• The owner/operator of the areas that are not under the control
of the applicator provides written agreement to the applicator
that they, their employees, and other persons will stay out of
the buffer zone during the entire buffer zone period.
• Buffer zones may not include publicly owned and/or operated areas
(e.g., parks, sidewalks, walking paths, playgrounds, athletic fields,
etc), UNLESS,
• The area is not occupied during the buffer zone period,
• Entry by non-handlers is prohibited during the buffer zone
period,and
• Written permission is given by the appropriate state and/or
local authorities to include public areas in the buffer zone.
• Buffer zones may include publicly owned and/or operated roads,
including rights of ways. As mentioned in the previous bullet, if a
sidewalk or permanent walking path is associated with it, written
permission must be given by the appropriate state and/or local
authorities.
Fumigation Restrictions Near Difficult-to-Evacuate Sites
• The Agency has defined "difficult-to-evacuate" sites to include
schools, state-licensed daycare centers, nursing homes, assisted living
facilities, hospitals, in-patient clinics, and prisons.
• No fumigant applications with buffer zones greater than 300 feet will
be permitted within % mile of a difficult-to-evacuate site unless the
site is not occupied during the application and the 36-hour period
following the application.
• If the fumigation buffer zone is 300 feet or less, then no fumigant
applications will be permitted within 1/8 mile of a difficult-to-
evacuate site unless the site is not occupied during the application and
the 36-hour period following the application.
For additional information, please see EPA's Web page on risk mitigation measures
for the soil fumigants, http://www.epa.gov/oppsrrd1/reregistration/soil_fumigants/.
Soil Fumigant Mitigation: Buffer Zones
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