Vol. XXVI - No. 1
Spring 2010
New Bystander Risk Mitigation Measures For Soil Fumigants
By Dr. Bob Bruss
Risk Assessment and Environmental Fate
Team Manager, NCDA&CS
The EPA released final Reregistration Eligi¬
bility Decisions (REDs) in 2009 for many
soil fumigants that will have a significant
impact on production practices for several
key crops in North Carolina including
tobacco, peanuts, strawberries, tomatoes
and forestry seedlings. The new safety
measures for soil fumigant pesticides are
intended to increase exposure protection
for agricultural workers and bystanders -
people who live, work, or otherwise spend
time near fields that are fumigated. The
2009 REDs apply to products than contain
the following fumigant active ingredients:
• Chloropicrin
• Dazomet
• Metam sodium/potassium (including
methyl isothiocyanate or MITC)
• Methyl bromide
lodomethane is a fairly new soil fumigant
that was first registered in 2007. Although
iodomethane was not included in the re¬
cent REDs, the EPA provided the registrant
with guidance on expected standards for
bystander protection. Thus, iodomethane
products already have labels with mitiga¬
tion measures similar to the new require¬
ments for the older compounds. Products
that contain only 1 ,3-dichloropropene are
not subject to implementation of the new
RED requirements at this time. In 1998,
1 ,3-dichloropropene went through the
reregistration process and it will be up for
registration review in 2013.
The high pest control benefits of fumi¬
gants results in widespread use and po¬
tential scenarios for bystander exposure.
As gases, fumigants move from the soil
to the air at the application site and may
pose risks to workers. Bystanders, who
are not involved in the fumigant applica¬
tion but who live, work, or are otherwise
located in nearby areas, may also be
exposed to airborne fumigants that move
off the application site. Bystanders include
agricultural workers in nearby fields who
are not involved with the fumigant ap¬
plication. The incident rate of exposure
to bystanders, although relatively rare in
North Carolina, shows that fumigants have
the potential to move off-site for periods
of several hours to days after application
at concentrations which could be detri¬
mental to human health. These effects
may range from mild and reversible eye
irritation to more severe adverse health
conditions, depending on the fumigant
and level of exposure.
As a result, EPA is requiring a suite of
complementary mitigation measures to
protect handlers, reentry workers, and
bystanders from risks resulting from expo¬
sure to the soil fumigants. These measures
are designed to work together to address
all risks, with special focus on the acute
human inhalation risks that have been
identified in the revised risk assessments
for these fumigants. The risk mitigation
measures include:
Buffer Zones - Areas around treated
fields that prohibit entry for 48 hours after
application unless individuals are wearing
personal protective equipment (PPE) that
meets clearly defined specifications. The
size of the buffer zone depends on the size
of the fumigated area, the application rate
of the fumigant, the application method
and the use of emission-control measures
such as tarps. Detailed product labels
will contain tables that list buffer zone
distances based on these critical param¬
eters. The buffer distance value obtained
from the table may be reduced further
based on credits for certain environmental
parameters such as high clay content, high
organic matter or low soil temperatures at
application.
Difficult-to-Evacuate Sites (DES) - Soil
fumigation will not be allowed within Vs to
'A mile of certain locations such as schools,
state-licensed daycare centers, nursing
homes, hospitals and prisons jf the facili¬
ties are occupied during the application
and the 36 hour period following the ap¬
plication. Fumigations that require a buffer
zone of 300 ft. or less will only have a DES
restriction of Vs mile, while fumigant ap¬
plication parameters that mandate a larger
Please see Risk Mitigation,
page 7
INSIDE
• Rule to Protect the Carolina
Heel splitter Freshwater Mussel in
Union County . 2
• New Regulations in Effect for
Pesticide Containment
Structures . 3
• Potential Requirement for NPDES
Permits for Pesticide Applications
in, over, and near
Waters of the United States . 4
• Pesticide Disposal Assistance
Program Helps North Carolina
Citizens with Pesticide Waste
Problems . 5
• Temik on Tobacco Phase-Out . 6
• Quarantine area for the imported
fire ant expanded . 8
• N.C. Pesticide Board Adopts New
Pesticide Regulations . 9
• New Record Keeping Requirements
For Commercial Applicators
And Public Operators Applying
Restricted Use Pesticides . 9
• New Bulk Storage Regulations ....11
• New Record Keeping Requirements
For Aerial Applicators . 12
• North Carolina Pesticide Board
Actions . 14
