Unitecl States Prevention, Pesticides
Environmental Protection and Toxic Substances May 2009
Agency (7508P)
Amended Reregistration Eligibility
Decision for Dazomet
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Amended Dazomet RED
ListB
Case No. 2135
Approved by:
Richard P. Keigwin, Jr., Director
Special Review and Reregistration Division
Date:
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Glossary of Terms and Abbreviations
AGDCI
ai
aPAD
BCF
CFR
cPAD
CSF
CSFII
DCI
DEEM
DFR
DNT
EC
EDWC
EEC
EPA
EUP
FDA
FIFRA
FFDCA
FQPA
GLN
IR
LCso
LD
50
LOC
LOAEL
MATC
mg/kg/day
mg/L
MOA
MOE
MRID
Agricultural Data Call-In
Active Ingredient
Acute Population Adjusted Dose
Bioconcentration Factor
Code of Federal Regulations
Chronic Population Adjusted Dose
Confidential Statement of Formulation
USDA Continuing Surveys for Food Intake by Individuals
Data Call-In
Dietary Exposure Evaluation Model
Dislodgeable Foliar Residue
Developmental Neurotoxicity
Emulsifiable Concentrate Formulation
Estimated Drinking Water Concentration
Estimated Environmental Concentration
Environmental Protection Agency
End-Use Product
Food and Drug Administration
Federal Insecticide, Fungicide, and Rodenticide Act
Federal Food, Drug, and Cosmetic Act
Food Quality Protection Act
Guideline Number
Index Reservoir
Median Lethal Concentration. A statistically derived concentration of a
substance that can be expected to cause death in 50% of test animals. It is
usually expressed as the weight of a substance per weight or volume of
water, air, or feed, e.g., mg/1, mg/kg, or ppm.
Median Lethal Dose. A statistically derived single dose that can be
expected to cause death in 50% of the test animals when administered by
the route indicated (oral, dermal, inhalation). It is expressed as a weight
of substance per unit weight of animal, e.g., mg/kg.
Level of Concern
Lowest Observed Adverse Effect Level
Maximum Acceptable Toxicant Concentration
Micrograms Per Gram
Micrograms Per Liter
Milligram Per Kilogram Per Day
Milligram Per Liter
Mode of Action
Margin of Exposure
Master Record Identification Number. EPA's system for recording and
tracking studies submitted.
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MUP
NOAEL
OPP
OPPTS
PAD
PCA
PDF
PHED
PHI
ppb
PPE
ppm
PRZM/EXAMS
RAC
RED
REI
RfD
RQ
SCI-GROW
SAP
SF
SLC
TGAI
USDA
USGS
UF
UV
WPS
Manufacturing-Use Product
No Observed Adverse Effect Level
EPA Office of Pesticide Programs
EPA Office of Prevention, Pesticides, and Toxic Substances
Population Adjusted Dose
Percent Crop Area
USDA Pesticide Data Program
Pesticide Handler's Exposure Data
Pre-harvest Interval
Parts Per Billion
Personal Protective Equipment
Parts Per Million
Tier II Surface Water Computer Model
Raw Agriculture Commodity
Reregi strati on Eligibility Decision
Restricted Entry Interval
Reference Dose
Risk Quotient
Tier I Ground Water Computer Model
Science Advisory Panel
Safety Factor
Single Layer Clothing
Technical Grade Active Ingredient
United States Department of Agriculture
United States Geological Survey
Uncertainty Factor
Ultraviolet
Worker Protection Standard
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Table of Contents
Abstract 9
I. Introduction 10
II. Chemical Overview 14
A. Chemical Identity 14
B. Use and Usage Profile 15
C. Regulatory History 17
III. Dazomet Risk Assessments 17
A. General Overview of Soil Fumigants 17
1. Human Health Risk 17
2. Environmental Fate, Ecological Effects and Risks 20
3. Benefits 23
4. 2008 RED Mitigation Impacts 24
B. Antimicrobial Risk 26
IV. Risk Management and Reregistration Decision 27
A. Determination of Reregistration Eligibility 27
B. Public Comments and Responses 28
C. Regulatory Position 29
1. Regulatory Rationale 30
a. Dazomet Soil Uses 30
i. Rate Reduction and Use Sites 30
ii. Human Health Risk Management 30
aa. Bystander Risk Mitigation 32
1. Buffer Zones 32
2. Restriction for Schools and Other Difficult to Evacuate Sites 53
3. Posting 54
bb. Occupational Risk Mitigation 56
1. Handler Definition 56
2. Handler Requirements 57
3. Dermal Protection for Handlers 59
4. Respiratory Protection for Handlers 59
5. Tarp perforation and removal 67
6. Entry Prohibitions 70
cc. Other Risk Mitigation 75
1. Restricted Use Classification 75
2. Good Agricultural Practices 77
3. Fumigant Management Plans (FMPs) 80
4. Site Specific Response and Management 87
5. Notice to State Lead Agencies 94
6. Soil Fumigation Training for Applicators and Training Information for Other Handlers
95
7. Community Outreach and Education Programs 100
iii. Environmental Risk Management 105
2. Endocrine Disrupter Effects 108
3. Endangered Species Considerations 109
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D. Conclusion 109
V. What Registrants Need to Do 109
A. Manufacturing Use Products 110
1. Additional Generic Data Requirements 110
2. Labeling for Manufacturing-Use Products 116
B. End-Use Products 116
1. Additional Product-Specific Data Requirements 117
2. Labeling for End-Use Products 117
Appendix A(l). Dazomet (PC Code 035602) Soil Fumigant Uses Eligible for Reregistration
118
Appendix A(2). Dazomet (PC Code 035602) Antimicrobial Uses Eligible for Reregistration
119
Appendix B. Table of Generic Data Requirements and Studies Used to Make the
Reregistration Decision 128
Appendix C. Technical Support Documents 129
Appendix D. Bibliography 132
Appendix E. FMP Template 133
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Dazomet Reregistration Eligibility Decision Team
Office of Pesticide Programs:
Health Effects Risk Assessment
Charles Smith, Risk Assessor
Anna Lowit, Toxicology
Sherri Kinard, Residue Chemistry
Ruth Allen, Epidemiology
Judy Facey, Toxicology
Shalu Shelat, Risk Assessor
Biological and Economic Analysis Assessment
TJ Wyatt, Senior Agricultural Economist
Jonathan Becker, Senior Science Advisor
Bill Chism, Senior Agronomist
David Donaldson, Agricultural Economist, Team Leader
Colwell Cook, Entomologist
Nicole Zinn, Biologist
Stephen Smearman, Economist
Leonard Yourman, Plant Pathologist
John Faulkner, Economist
Nikhil Mallampalli, Entomologist
Sunil Ratnayake, Botanist
Environmental Fate and Effects Risk Assessment
Mah Shamim, Branch Chief
FaruqueKhan, Senior Fate Scientist
James Felkel, Wildlife Biologist
Gabriel Rothman, Environmental Scientist
Registration Support
Mary Waller, Product Manager
Tamue Gibson, Product Reviewer
Kathy Monk, Senior Advisor
Antimicrobial Risk Assessment Team
Heather Garvie, Chemical Review Manager
Diane Isbell, Reregistration Team Leader
Cassi Walls, Ph.D., Chemist
Timothy Dole, Industrial Hygienist
Rick Petrie, Senior Agronomist, Team Leader
Office of General Council:
Andrea Medici
Office of Enforcement and Compliance:
David Stangel
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Risk Management
Andrea Carone, Chemical Review Manager
Steven Weiss, Industrial Hygienist, Chemical Review
Manager
Susan Bartow, Chemical Review Manager
Dirk Helder, Chemical Review Manager
Karen Santora, Chemical Review Manager
Dana Friedman, Chemical Review Manager
Cathryn O'Connell, Team Leader
Eric Olson, Team Leader
John Leahy, Senior Advisor
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Abstract
This document presents the Environmental Protection Agency's (hereafter referred to as
EPA or the Agency) amended decision regarding the reregi strati on eligibility of the registered
soil and antimicrobial uses of dazomet. This follows the 105-day public comment period on the
Reregi strati on Eligibility Decision provided for stakeholders to have the opportunity to review
and provide comments on issues related to the implementation of the risk mitigation measures.
The Agency's risk conclusions for dazomet have not changed. In addition, all measures
established in the July 2008 RED to reduce risks to bystanders and workers will still be required.
However, the Agency has determined that certain modifications in how and when some measures
will be implemented are appropriate. Products containing dazomet uses are eligible for
reregi strati on provided that: (1) current data gaps are addressed; (2) the risk mitigation measures
identified in the document are adopted; and (3) labels are amended to implement these measures.
Generally, registered dazomet uses fall into two basic categories, soil fumigation or
antimicrobial use. Soil fumigation includes use on golf greens and tees, nonbearing crops, turf
sites, ornamental sites, field nurseries, compost piles, potting soils, and strawberries and
tomatoes in California only. Antimicrobial uses include: 1) as a treatment during the production
of pulp and paper; 2) as a material preservative treatment paper coatings, non-food adhesives,
epoxy flooring compounds, slurries, and high viscous suspensions; 3) as a biocide treatment used
during petroleum operations; 4) as a biocide treatment to recirculating cooling water systems;
and 5) as a remedial wood treatment to utility poles.
Concurrent to EPA's review of the soil fumigant uses of dazomet, EPA assessed the risks
and developed risk management decisions for four other soil fumigant pesticides, including:
chloropicrin, metam sodium/potassium, methyl bromide, and a new active ingredient,
iodomethane. Risks of a fifth soil fumigant, 1,3-dichloropropene (1,3-D), were also analyzed
along with the other soil fumigants for comparative purposes; its risk management decision was
completed in 1998. The Agency evaluated these soil fumigants concurrently to ensure that
human health risk assessment approaches are consistent, and that risk tradeoffs and potential
economic impacts were considered appropriately in reaching risk management decisions. This
review is part of EPA's program to ensure that all pesticides meet current health and safety
standards.
EPA has identified potential human health risks of concern associated with the registered
soil fumigant uses of dazomet from acute inhalation exposure to handlers, bystanders, and
workers. To reduce these exposures and to address risks of concern, EPA is requiring a number
of mitigation measures, such as buffer zones, posting, handler protection, restrictions on the
timing of tarp perforation and removal operations, extending the entry prohibitions, restricted use
classification (for soil uses only), mandatory good agricultural practices (GAPs), site-specific
fumigant management plans (FMPs), emergency preparedness and response, notice to state and
tribal lead agencies, training for applicators and handlers, and required community outreach and
education programs. In addition the registrants have agreed to reduce the maximum rate from
530 Ibs ai/A to 425 Ibs ai/A for incorporated applications except golf course greens/tees and turf
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renovation (which will remain at 530 Ibs ai/A) which will directly reduce the potential risks to
both humans and non-target organisms. The ecological risk assessment identified potential acute
risks of concern for birds and mammals that could be exposed to unincorporated dazomet
granules.
The Agency also has identified potential human health risks of concern associated with the
registered antimicrobial uses of dazomet. To reduce these exposures, the Agency is requiring a
number of mitigation measures, including additional PPE for handlers engaged in these
applications: pulp and paper use, cooling tower use, and metering pumps. For the epoxy flooring
uses, the labels must be amended to reduce the amount of dazomet formulated in end use
products.
I. Introduction
This amends and supersedes the document, "Reregi strati on Eligibility Decision for
Dazomet," published by the U.S. Environmental Protection Agency (hereafter, EPA) on July 16,
2008. That day EPA opened a 60-day public comment period on the implementation aspects of
the risk mitigation measures that were required as conditions of reregi strati on eligibility under
FIFRA. EPA received requests to extend the comment period from the Methyl Bromide Industry
Panel (MBIP), California Specialty Crops Council, the Chloropicrin Manufacturers' Task Force
(CMTF), the National Association of Manufacturers (NAM), the American Nursery and
Landscape Association (ANLA), the California Strawberry Nurserymen's Association, the
Agricultural Retailers Association, the American Forest and Paper Association, and McDermott,
Will, and Emery LLP, on behalf of the Minor Crop Farmer Alliance (MCFA). In response to
these requests, on August 29, 2008, EPA published a notice in the Federal Register extending the
comment period for an additional 45 days. The comment period closed on October 30, 2008.
EPA has completed its review of public comments as well as new scientific data and other
information provided and determined that all measures established in the July 2008 RED to
reduce risks to bystanders and workers will still be required. The Agency has determined that
certain modifications in how and when some measures will be implemented are appropriate. The
public comments and EPA's responses, as well as other supporting documents, may be found in
the public docket for dazomet at EPA-HQ-2005-0128. EPA has determined that the
modifications described herein will achieve the same protection goals for persons potentially
exposed to dazomet but with a greater likelihood of compliance, fewer impacts on the benefits of
dazomet use, and with less uncertainty regarding the protectiveness of the required measures.
Please see table 1 for modifications from the 2008 RED to the 2009 amended soil fumigant
REDs.
Table 1. Modifications from 2008 to 2009 Amended Soil Fumigant REDs
Buffer Zones
2008 REDs
Buffer zones based on
available data
2009 Amended REDs
New chloropicrin data support smaller
buffers and increased confidence in safety
New dazomet data support larger buffers
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Buffer Credits
Structures within
Buffer Zones
Rights of Way
Buffer Overlap
Restriction for
Difficult to Evacuate
Sites
Posting
Handler Protection
Respiratory
Protection
Tarp perforation and
removal
Entry Prohibitions
2008 REDs
Credits allowed based on
available data; capped at
50%
Monitor with devices
before reentry
Permission from local
authorities must be granted
if buffers extend onto
rights of way
Buffers may not overlap
1/4 mile restriction around
hard to evacuate areas
including day care centers,
nursing homes, schools;
was to be in effect for the
duration of the buffer zone
period
Posting required at buffer
zones points of entry,
where people are likely to
approach, and areas
between these locations
Described tasks that may
only be performed by
handlers and situations
when 2 handlers were
required to be present
while in the buffer zone
Required monitoring
devices to trigger
additional measures
Perforating tarps restricted
to mechanical means only
Entry for non-handlers is
prohibited for the duration
2009 Amended REDs
New data support additional credits and an
increase in the cap to 80% for chloropicrin
and methyl bromide, 80% for metam
sodium and metam potassium, and 40%
for dazomet.
Monitor for sensory irritation before
reentry
Permission from local authorities is only
required when a sidewalk or permanent
walkway is present
Buffers may overlap; separate applications
by 12 hours and increase emergency
preparedness and response measures
Maintain 1/4 mile restriction but allow a
reduced restricted area of 1/8 mile for
applications with smaller buffers (300 feet
or less); is to be in effect during the
application for 36 hours following the
application
The posting requirement is retained but no
longer requires areas between the entry
areas to be posted
Information required on the signs has been
simplified to encourage reuse of signs
Tasks that may only be performed by
handlers have been updated and clarified
The situations have been clarified
requiring one handler supervised by a
certified applicator to be present based on
the chemical properties of the different soil
fumigants, and current label statements
Allow sensory irritation properties to
trigger additional measures for MITC and
chloropicrin
Monitoring with devices is still required to
remove respirators
Monitoring with devices required for
methyl bromide formulations with <20%
chloropicrin
Perforating tarps by hand is allowed for
areas less than 1 acre in size and for flood
prevention activities
No major changes
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2008 REDs
2009 Amended REDs
of the entry restricted
period, until tarps have
been removed, or if 14
days has passed
Restricted Use
Classification
The soil fumigant uses of
dazomet, metam-sodium
and metam potassium, and
MITC use for remedial
treatment of wood poles
and timbers are required
to be classified as restricted
use
No change
Good Agricultural
Practices
(GAPs)
Certain GAPs required for
all fumigant applications
Some clarifications and refinements have
been made based on stakeholder comments
Fumigant
Management Plans
(FMPs)
FMPs required to be
completed before fumigant
application begins and
post-application summary
report required following
the application
No major changes. Based on comments an
example of an FMP has been included to
illustrate how the required information
may be presented effectively
Emergency Response
and Preparedness
If neighbors are near
buffers they must be
provided with information
or buffer zones must be
monitored every 1-2 hours
over 48 hours with
monitoring devices
Same basic measures
Monitoring required only during peak
emission times of the day; irritation
detection acceptable for MITC and
chloropicrin in lieu of devices; methyl
bromide requires devices
Notice to SLAs
Applicators required to
provide notice to the
appropriate state/tribal lead
agency before fumigating
to facilitate compliance
assistance and assurance
States may determine if they wish to
receive this information
All states required to include strategies for
compliance assistance and assurance for
soil fumigation in their cooperative
agreements
Applicator Training
Certified applicators
required to receive
registrant soil-fumigant
training every year
Certified applicators required to receive
registrant soil-fumigant training every
three years
Community Outreach
and Education
Registrants required to
develop and implement
community outreach &
education programs along
with information for first
responder in high fumigant
use areas
Same basic requirement
The Agency is providing information on
where registrants are required to focus
these efforts
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With regard to implementation timing, EPA has determined that most measures can be
efficiently implemented via revised product labels by the 2010 use season. Other measures, in
particular those related to buffer zones, will present greater compliance challenges and will
require additional time for EPA to conduct the necessary outreach, and communication activities
with states, tribes, other regulatory partners, fumigant users, and other stakeholders to facilitate
transition. EPA has determined that these measures will be implemented via revised product
labels by the 2011 use season. As a result, all measures described in this amended RED that are
necessary for reregi strati on eligibility will appear on product labels by 2011. The table below
shows the measures that will be implemented in 2010 and the additional measures that will be
implemented in 2011.
Table 2. Implementation Schedule for Soil Fumigant Risk Mitigation Measures
Risk Mitigation Measure
Restricted Use
New Good Agricultural Practices
Rate reductions
Use site limitations
New handler protections
Tarp cutting and removal restrictions
Extended worker reentry restrictions
Training information for workers
Fumigant Management Plans
First responder and community outreach
Applicator training
Compliance assistance and assurance measures
Restrictions on applications near sensitive areas
Buffer zones around all occupied sites
Buffer credits for best practices
Buffer posting
Buffer overlap prohibitions
Emergency preparedness measures
Currently
2010
o
0
o
o
2011
o = under development
= adopt completely
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended in 1988
to accelerate the reregistration of products with active ingredients registered prior to November
1, 1984. The amended Act calls for the development and submission of data to support the
reregi strati on of an active ingredient, as well as EPA's review of all submitted data.
Reregi strati on involves a thorough review of the scientific database underlying a pesticide's
registration. The purpose of the Agency's review is to reassess the potential risks arising from
the currently registered uses of the pesticide; to determine the need for additional data on health
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and environmental effects; and to determine whether or not the pesticide meets the "no
unreasonable adverse effects" criteria of FIFRA.
Dazomet is used as a non-selective soil fumigant with fungicidal, herbicidal, and
nematicidal properties. It is also used as an algaecide, bacteriostat, fungicide, microbiocide,
mildewcide in a number of antimicrobial use sites. When dazomet is applied, it is quickly
broken down into several degradates; the major degradate being methyl isothiocyanate (MITC).
The Agency made its reregi strati on eligibility determination based on the required data, the
current guidelines for conducting acceptable studies to generate such data, and published
scientific literature. The Agency has found that currently registered uses of dazomet are eligible
for reregi strati on provided the mitigation and labeling outlined in this amended RED are
implemented.
This document presents the Agency's reregi strati on eligibility decision for the supported
soil and antimicrobial uses of dazomet. The document consists of five sections. Section I
contains the regulatory framework for reregi strati on and a synopsis of modifications from the
July 2008 RED. Section II provides a profile of the use and usage of the chemical. Section III
provides a general fumigant overview and also summarizes dazomet's risk assessments as well
as benefit and impact assessments. Section IV presents the Agency's reregi strati on eligibility
and risk management decisions. Section V summarizes label changes necessary to implement
the risk mitigation measures outlined in Section IV. Unless otherwise noted, all Agency
references in this document are available for review in the dazomet docket (EPA-HQ-OPP-2005-
0128) atwww.Regulations.gov.
II. Chemical Overview
A. Chemical Identity
When dazomet is applied to soil, either to the surface or incorporated, it quickly breaks
down. The major degradate is MITC, but formaldehyde, monomethylamine, hydrogen sulfide
and (in acid soils) carbon disulfide, are also formed. All of these degradates are gases or volatile
liquids which diffuse through the spaces in the soil, killing living organisms with which they
come in contact. This reregi strati on eligibility decision considers risks of exposure of dazomet
and the major degradate, MITC, as a result of dazomet applications. Table 3 provides a
summary of the dazomet and MITC nomenclature.
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Table 3: Dazomet and MITC Nomenclature
Properties
Chemical Structure
Chemical Group
Common Name
Molecular formula
Molecular Weight
CAS No.
PC Code
Case Number
Dazomet
rV
^N^^S
Dithiocarbamate
Dazomet
C5H10N2S2
MITC
/N^.
H3C ^C=S
sothiocyanate
Methyl isothiocyanate
C2H3NS
162.28 73.12
533-74-4 556-61-6
035602 068103
2135 |Not Applicable
B. Use and Usage Profile
Soil Uses
Pesticide Type:
Target pests:
Use patterns:
Formulations:
Methods of
Application:
Broad spectrum soil fumigant with herbicidal, nematicidal, and
fungicidal properties
Weeds, nematodes and various soil-borne pathogens
Golf greens/tees, nonbearing crops (such as orchard crops,
berries, and flower bulbs), turf sites (establishing or renovating),
ornamental sites (establishing or renovating), field nurseries
(establishing or renovating), greenhouses, compost piles,
potting soils, and strawberries and tomatoes in California only
Granular
Tractor drawn spreaders and handheld equipment such as belly
grinders and push-type spreaders
Application Rates: Maximum application rate for incorporated applications is 530
Ibs ai/acre and for surface applications is 265 Ibs ai/acre
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Technical
registrant:
Annual Usage:
Certis USA, LLC
Approximately 15,000 pounds of dazomet are used annually1 as
a soil fumigant.
Pesticide Type:
Target pests:
Use patterns:
Formulations:
Methods of
Application:
Application Rates:
Technical
registrant:
Antimicrobial Uses
Algaecide, bacteriostat, fungicide, microbiocide, mildewcide
Fungi, bacteria, mildew, algae
Dazomet may be used in a variety of ways including: 1) as a
treatment during the production of pulp and paper; 2) as a
material preservative treatment for paper coatings, non-food
adhesives, epoxy flooring compounds, slurries, and high
viscous suspensions; 3) as a biocide treatment used during
petroleum operations; 4) as a biocide treatment to recirculating
cooling water systems; and 5) as a remedial wood treatment to
utility poles.
Pelleted/tableted, liquid (soluble concentrate and flowable
concentrate) solutions, water soluble packaged solids, ready to
use solutions
Open pour (for both solid and liquid formulations), metering
pump, and water-soluble packaged solid mixing
Rates vary by application use site and method. Maximum rates
are included in Table 4.1 of the Revised Occupational and
Residential Antimicrobial Exposure Assessment (Walls, C.
2/14/08)
BASF
USDA Agricultural Chemical Usage 2003 Nursery and Floriculture Summary, September 2004,
http://usda.mannlib.cornell.edu/MannUsda/viewDocumentInfo.do?documentID= 1001.
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C. Regulatory History
Dazomet, (PC code 035602) and the sodium salt, tetrahydro-3,5-dimethyl-2H-l,3,5-
thiadiazine-2-thione (PC Code 035607) are included in pesticide reregistration case number
2135. Currently, there are 22 products registered containing dazomet and there are no active
products registered containing the sodium salt.
Dazomet has both agricultural and antimicrobial uses. Dazomet was first registered in
the United States in 1967 as an algaecide, a bacteriostat, and a microbiocide in a variety of
commercial and industrial applications such as pulp and paper mills, cooling tower waters, and
non-food adhesives.
In the late 1980s pre-plant soil uses of dazomet were registered. Dazomet is registered
for use on non-bearing orchard crops, ornamentals, and turf to control plant pathogens,
nematodes, and weeds. Unlike other soil fumigants, dazomet is applied as a dry granule and
incorporated into the soil or applied to the soil surface and watered into the soil to activate it.
A Phase IV data call-in (DCI) was issued for dazomet in January 1991 and included data
requirements for ecotoxicity, toxicology, and environment fate. A follow-up DCI was issued in
May of 1992 that included data requirements for neurotoxicity and the nature of residue in
plants. Dazomet was also included in the October 1995 agricultural reentry data call-in.
III. Dazomet Risk Assessments
A. General Overview of Soil Fumigants
Soil fumigants are pesticides that form gasses when applied to soil. Once in the soil, the
fumigants work by controlling pests that can disrupt plant growth and crop production. Soil
fumigants play a very important role in agriculture, but they also have the potential to pose risk
concerns to people involved in application of the chemicals (handlers), workers who re-enter
fumigated fields (workers), and people who may be near the treated area (bystanders).
1. Human Health Risk
When dazomet is applied and mixes with moist soil, it is quickly broken down into
several products. One of these products is MITC that accounts for most of the fumigant activity.
The main risk of concern for handlers, workers, and bystanders associated with the soil uses of
dazomet is from acute inhalation exposure to MITC as a result of fumigant off-gassing.
Dazomet handlers also are at risk from direct fumigant exposure during applications. The term
handler refers to persons involved in the application of dazomet. For soil applications, handlers
also include persons involved in perforating and removing of tarps. The term worker in this
document refers to persons performing non-handler tasks within the application block, after the
fumigation process has been completed, such as planting. The term bystander refers to any
person who lives or works in the vicinity of a fumigation site.
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In addition to soil use, dazomet is also used as an antimicrobial pesticide in the following
ways: 1) as a treatment during the production of pulp and paper; 2) as a material preservative
treatment for coatings, adhesives, epoxy flooring compounds, slurries, and high viscous
suspensions; 3) as a biocide treatment used during petroleum operations; 4) as a biocide
treatment to recirculating cooling water systems; and 5) as a remedial wood treatment to utility
poles.
Estimating exposure to fumigants is different from non-fumigant pesticides due to
fumigants' volatility, and thus, this increased ability to move off site during and after application.
For example, pesticide spray drift is the physical movement of pesticide particulate or droplets
from the target site during the application and soon thereafter. In the case of soil fumigants, the
pesticide moves as a gas (not as paniculate or droplets) and movement off-site can occur for an
extended period after application. Importantly, fumigants have a well-documented history of
causing large-scale human exposure incidents up to several thousand feet from treated fields.
Assessing fumigant exposure takes into account the size of the fumigated field, the amount of
fumigant applied, and the rate at which the fumigant escapes from the treated field.
The term "flux rate" or "emission rate" defines the rate at which a fumigant off-gasses
from a treated field. Many factors influence the rate of emissions from treated fields. Factors
such as the application method, soil moisture, soil temperature, organic matter levels, water
treatments, the use of tarps, biological activity in the soil, soil texture, weather conditions, soil
compaction, and others influence the amount of fumigant that comes off the field and is available
to move off-site to areas where bystanders may be located.
The human health risk assessment indicates that acute inhalation exposures to MITC
concentrations of 22 ppb or greater for a 1 to 8 hour time period for non-occupational
(residential) bystanders and occupational handlers could pose risks of concern. The 22 ppb
concentration is based on a reversible endpoint from a human eye irritation and odor threshold
study for acute exposures to MITC. The lowest observable adverse effect level (LOAEL) was
800 ppb, and the human concentration (HC) based on the no observable adverse effect level
(NOAEL) from this study is 220 ppb. The NOAEL of 220 ppb being used by EPA is similar to a
benchmark concentration level of 200 ppb submitted by the group Toxicology Excellence in
Risk Assessment (TERA) on behalf of the metam sodium registrants. The benchmark
concentration analysis thus supports the Agency's toxicity endpoint. Since the study is a human
exposure study for acute eye exposures to MITC, the standard 10X for animal to human
extrapolation is not needed. A 10X uncertainty factor for intraspecies variability was included,
which when applied to the HC, results in the target concentration for acute inhalation exposures
of 22 ppb.
California Pesticide Illness Surveillance Program data from 1992-2003 confirm that eye
effects from MITC exposure as seen in this human study provide a sensitive endpoint for
regulating acute inhalation exposures. In many incident cases, people complain of eye effects.
However, many reported cases also report systemic or respiratory effects without eye irritation.
Compared to eye irritation, the systemic and respiratory effects are more serious in nature.
Unfortunately, the available toxicity data in animals or humans do not allow a quantitative
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comparison of the dose response curves of the eye, systemic, and respiratory effects to determine
at the exact doses of which those effects occur. However, the Agency believes eye irritation
provides a surrogate for other toxic effects and thus makes this the appropriate endpoint to
regulate. To ensure that this endpoint is protective of any effects from repeated and longer term
exposures, EPA is requiring data to evaluate developmental, reproductive, chronic, and cancer
hazards and has encouraged the registrants to purse additional studies to characterize the dose
response curves of different target organs.
The Agency has not revised the 10X human variability uncertainty factor for MITC and
the MITC-generating compounds. Agency scientists have carefully reviewed comments
provided by the Metam Alliance and TERA that claim a mode of action (MOA) evaluation for
MITC and the relative sensitivities of the eyes and lungs to MITC, support an uncertainty factor
less than 10X. Upon request by the Metam Alliance, Agency scientists have evaluated the
registrant's scientific position [see regulations.gov, docket number: EPA-HQ-OPP-2005-0125].
While Agency scientists acknowledge that data are available to formulate a hypothesis for a
MO A, currently available data are insufficient to support the key events of the proposed MO A
and also to refute other scientifically plausible hypotheses (a step critical in a MOA framework
analysis). Moreover, there remains uncertainty with respect to the dose response relationship for
sensitive measures of respiratory effects. Thus, given gaps in the existing data for MITC, the
Agency is unable to determine, according to existing guidance, that the uncertainty factor can be
reduced. If, in the future, additional data are provided, the Agency will re-evaluate the scientific
basis for MITC's human variability uncertainty factor.
In assessing risks from dazomet, the Agency considered multiple lines of evidence, using
the best available information from monitoring studies, modeling tools, and from incidents.
Monitoring: For the human health risk assessments completed for dazomet and the other
soil fumigants within the group, several field-scale monitoring studies were considered.
These studies quantify dazomet concentrations in and around fields at various times and
distances during and after applications. Many of these data indicate that there can be
risks of concern associated with dazomet use at a broad range of distances from treated
fields. However, these data are limited in their utility because they provide results only
for the specific conditions under which the study was conducted.
Modeling: Models enable the use of data from monitoring studies to estimate
concentrations and potential risks under a wide range of conditions and use patterns.
EPA used the Version 2.1.4 of the Probabilistic Exposure and Risk model for Fumigants
(also called the PERFUM model) to evaluate potential risks at distances around treated
fields. PERFUM incorporates actual weather data and flux distribution estimates, and
then accounts for changes and altering conditions. Analyses based on a variety of model
outputs were used to compare the potential risks at a range of distances. The PERFUM
model and users manual are public domain and can be downloaded at
http ://www. exponent, com/perfum/.
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Bystander, handler, and worker incident reports: Incidents for the soil fumigants
generally occur at a low frequency relative to the total number of fumigant applications
performed annually. However, when incidents occur, there are often many people
involved. Incidents involving handlers and workers tend to occur more often than
incidents with bystanders.
Reconstructing incidents to examine the exact factors which led to the incident can be
difficult, especially when bystanders are involved since all the factors that contributed to
the incident may not have been documented. Some of the factors that have been linked to
incidents in the past have included equipment failure, handler accidents, applicator failure
to adhere to label recommendations and/or requirements, and temperature inversions.
Bystander incidents have occurred both close to fumigated fields and up to two miles
away from the fumigated field, although these types of incidents have not been reported
specifically for dazomet.
Based on these lines of evidence and as described in more detail in the risk assessments,
EPA has determined that dazomet risks to handlers, workers, and bystanders are of concern
given current labels and use practices. The human health risk assessments indicate that
inhalation exposures to bystanders who live and work near agricultural fields where dazomet
fumigations occur have the potential to exceed the Agency's LOG without additional mitigation
measures. There are also risks of concern for occupational handlers involved in dazomet
applications and for workers who may re-enter treated area shortly after fumigation or tarp
perforation has been completed.
For more information about the specific information in the Agency's human health risk analysis
for dazomet, refer to the documents listed below, all of which can be found in the dazomet
docket # EPA-HQ-OPP-2005-0128 at http://www.regulations.gov:
Dazomet: Updated Final Revised HED Chapter of the Reregistration Eligibility
Decision Document (RED). fShelat, S. et al., Dated April 30, 2009)
Methyl Bromide (PC Code 053201), Chloropicrin (PC Code 081501), Dazomet
(PC Code 035602), Metam Sodium and Potassium (PC Codes
039003 & 039002), MITC (PC Code 068103), DP Barcode 362369, Updated
Health Effects Division Recommendations for Good Agricultural
Practices and Associated Buffer Credits (Dated May 14, 2009)
MITC 1 OX placeholder
Dazomet: Updated Final Revised HED Chapter of the Reregistration Eligibility
Decision Document (RED). (Smith, C. et al., Dated June 2008)
Mode of Action, Eye Irritation, and the Intra-Species Factor: Comparison of
Chloropicrin and MITC. (Lowit, A. and Reaves, E., Dated June 25, 2008)
2. Environmental Fate, Ecological Effects and Risks
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The Agency's environmental fate and ecological effects risk assessments indicate that
there are some concerns for non-target organisms that may be exposed to fumigants. Exposure
to terrestrial organism such as birds and mammals could occur two ways, as either oral exposure
to dazomet granules or by the inhalation route of exposure to the breakdown product MITC.
Potential exposure to aquatic organisms may occur from surface runoff/leaching and/or
volatilization and deposition of MITC in water bodies.
Hazard
Dazomet is considered moderately toxic on an acute oral basis to both birds (LDso = 424
mg/kg) and mammals (LD50 = 415 mg/kg). MITC is considered highly toxic on an acute oral
basis to mammals (LD50 = 55 mg/kg), and moderately toxic via the inhalation route. Acute oral
and inhalation toxicity data with MITC are needed for birds.
MITC is considered very highly toxic to both fish (lowest LC50 = 51.2 ppb) and aquatic
invertebrates (lowest LCso = 55 ppb).
Exposure
Terrestrial (Dazomet and MITC)
Direct exposure of mammals and birds to dazomet granules was estimated using the
model T-REX, Version 1.2.3 (T-REX, 2005). T-REX was run for tomato and strawberry crops
(also applicable to turf, ornamental and other pre-plant incorporated uses) for a single application
of dazomet applied at the maximum rate of 530 Ib a.i./A. In addition, exposure of terrestrial
animals to the volatile degradation product MITC was evaluated using a preliminary LDso/square
foot risk screening method. The Industrial Source Complex Short Term (ISCST3) model
together with information about MITC emissions from a treated field was used to evaluate the
range of MITC concentrations which might be found under different conditions of application
rate, weather, source size and shape (e.g., field size in acres) and distance from the treated field.
Aquatic (MITC)
For exposure to fish and aquatic invertebrates, EPA considers surface water only, since
most aquatic organisms are not found in ground water. The aquatic exposure assessment for
MITC relied on Tier II aquatic models. The Pesticide Root Zone Model (PRZM version 3.1.2
beta) simulates fate and transport on the agricultural field, while the water body is simulated with
Exposure Analysis Modeling System (EXAMS version 2.98.04). Simulations are run for
multiple (usually 30) years and the reported EECs represent the values that are expected once
every ten years based on the thirty years of daily values generated during the simulation.
PRZM/EXAMS simulates a 10 hectare (ha) field immediately adjacent to a 1 ha pond, 2
meters deep with no outlet. The location of the field is specific to the crop being simulated using
site specific information on the soils, weather, cropping, and management factors associated with
the scenario. The crop/location scenario in a specific state is intended to represent a high-end
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vulnerable site on which the crop is normally grown. Based on historical rainfall patterns, the
pond receives multiple runoff events during the years simulated. PRZM has limited capabilities
in capturing the amount of a volatile chemical in air, water and sediment. The estimated
concentrations of chemicals like MITC in surface water bodies may be upper bound.
To simulate field application of dazomet, multiple scenarios were selected representing
proposed dazomet usage areas based on geography and weather. PRZM and EXAMS models and
relevant scenarios were used to estimate MITC estimated exposure concentrations (EECs) in
surface water based on label information for dazomet application to tomatoes, strawberries, turf
and ornamental trees at the highest application rate. The scenario with the highest concentration
of MITC from dazomet applications was the California strawberry scenario.
Risk
Terrestrial Risk (Dazomet and MITC)
Available dazomet toxicity studies allow the assessment of acute oral exposure of birds
and mammals. Inhalation toxicity studies for MITC are only available for mammals. There are
currently no studies available to estimate chronic terrestrial risks.
The Agency's levels of concern are exceeded for acute oral consumption of dazomet
granular product for both mammal and bird species that are not Federally-listed as endangered or
threatened as well as for 'listed' species. However, for mammal inhalation exposure to MITC all
of the estimated risks are below the Agency's LOG for both listed and non-listed species. The
inhalation effects observed at levels higher than would be expected under normal use and
assessed in mammals included both metaplasia of respiratory epithelium and lethality. There
were no data available to assess inhalation risk to birds, and additional data is required. At the
present time there are no registrant-submitted toxicity studies, or studies published in the open
literature, that evaluate the toxicity of dazomet or MITC to terrestrial plants.
Aquatic Risk (MITC)
None of the estimated acute fish or aquatic invertebrate risks were above the Agency's
LOG for freshwater non-listed or listed species. However, no MITC studies are available for
marine/estuarine organisms. For chronic risk from MITC the only data available to evaluate
chronic effects on aquatic organisms are for freshwater invertebrates, which predict risks below
the Agency's LOG. However, no MITC data are available to evaluate the chronic effects on
freshwater and estuarine/marine fish, or estuarine/marine invertebrates. All of the estimated
risks for aquatic plants were below the Agency's levels of concern.
Due to the current data gaps for dazomet and MITC, the Agency is requiring additional
eco-toxicity studies for both terrestrial and aquatic organisms. For more information on the
Agency's environmental fate and ecological effects risk analysis:
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Revised Environmental Fate and Ecological Risk Assessment For Dazomet. (Khan. F.
and Felkel, 1, Dated April 8, 2008)
3. Benefits
Soil fumigation can provide benefits to both food consumers and growers. For
consumers it means more fresh fruits and vegetables can be cheaply produced domestically year-
round because severe pest problems can be efficiently controlled. Growers benefit because crops
grown in fumigated soil produce fewer blemished products, which translates into an increase in
marketable yields. Fumigation can also provide benefits to growers by increasing crop
management flexibility. This includes shorter crop rotational intervals (i.e., less time when fields
are left fallow), improved ability to meet quarantine requirements (which are imposed when
states or other jurisdictions require a pest-free harvested product), and consistent efficacy against
critical pests. The magnitude of benefits depends on pest pressure, which varies over space and
time, and the availability and costs associated with the use of alternatives.
There are a number of benefits assessments that have been completed by the Agency to
estimate the value of these chemicals to various industries, which are listed below.
EPA-HQ-OPP-2005-0123-0321, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Metam-Sodium, and Methyl Bromide in Eggplant Production
EPA-HQ-OPP-2005-0123-0322, Assessment of the Benefits Soil Fumigants (Methyl
Bromide, Chloropicrin, Metam-Sodium, Dazomet) Used by Forest Tree Seedling
Nurseries
EPA-HQ-OPP-2005-0123-0323, Assessment of the Benefits of Soil Fumigation with
Methyl Bromide, Chloropicrin, Dazomet, Metam Potassium andMetam Sodium for Use
in Raspberry Nurseries, Fruit and Nut Deciduous Tree Nurseries, and Rose Bush
Nurseries in California
EPA-HQ-OPP-2005-0123-0324, Assessment of the Benefits of Soil Fumigation with
Chloropicrin andMetam-sodium In Onion Production
EPA-HQ-OPP-2005-0123-0325, Assessment of the Benefits of Soil Fumigation with
Methyl Bromide, Chloropicrin and Metam-sodium In Grape Production
EPA-HQ-OPP-2005-0123-0326, Assessment of the Benefits of Soil Fumigation with
Methyl Bromide, Chloropicrin and Metam-sodium In Tree Nut Production
EPA-HQ-OPP-2005-0123-0327, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, and Methyl Bromide In Pome Fruit Production
EPA-HQ-OPP-2005-0123-0328, Assessment of the Benefits of Soil Fumigation with
Methyl Bromide, Chloropicrin, andMetam Sodium In Stone Fruit Production
EPA-HQ-OPP-2005-0123-0329, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, and Metam-Sodium in Bell Pepper Production
EPA-HQ-OPP-2005-0123-0330, Assessment of the Benefits of Soil Fumigation with
Metam-sodium in Potato Production
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EPA-HQ-OPP-2005-0123-0331, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, andMetam-sodium In Strawberry Production
EPA-HQ-OPP-2005-0123-0332, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, Metam-sodium, andDazometln Strawberry Nursery
Runner Production
EPA-HQ-OPP-2005-0123-0333, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide and Metam-sodium In Sweet Potato Production
EPA-HQ-OPP-2005-0123-0334, Assessment of the Benefits of Soil Fumigation with
Chloropicrin In Tobacco Production
EPA-HQ-OPP-2005-0123-0335, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, and Metam-sodium in Tomato Production
EPA-HQ-OPP-2005-0123-0336, Assessment of the Benefits of Soil Fumigation with
Metam Sodium in Carrot Production
EPA-HQ-OPP-2005-0123-0337, Assessment of the Benefits of Soil Fumigation with
Metam Sodium in Peanut Production
EPA-HQ-OPP-2005-0123-0338, Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, Metam Sodium andDazomet in Ornamental Production
EPA-HQ-OPP-2005-0123-0339, Summary of the Benefits of Soil Fumigation with Methyl
Bromide in Crop Production
EPA-HQ-OPP-2005-0123-0340, BEAD's Planned Impact Assessments on Agricultural
Sites with Significant Use of Soil Fumigants
4. 2008 RED Mitigation Impacts
Requirements in the July 2008 RED
The July 2008 RED acknowledged that even with the use of credits, there could be
significant economic impacts to some growers who may not be able to accommodate large
buffers based on their current application practices. However, the Agency believed that the
options provided in the scalable buffer approach in the fumigant REDs would allow growers the
flexibility to modify their practices to achieve smaller buffers; for example, by treating smaller
application blocks, switching to a lower emission application method, or by switching to an
alternative fumigant that would require smaller buffers. Therefore, the Agency concluded that
growers would be able to alter their fumigation applications, given the flexibility designed into
the system, in a manner that would enable growers to minimize the impact on production. The
Agency noted, however, that the buffers would significantly impact some growers by delays in
planting due to longer fumigation operations, additional planning, and more trips to the field for
planting and other operations if fumigating in smaller blocks resulted in staggered operations. It
was determined that some of these costs could be substantial in some production scenarios.
Comments on the July 2008 RED
The July 2008 RED requested commenters to submit a description of fumigation
practices and provide maps of their property illustrating locations of fields, offices, residences,
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roads, and property lines so that the Agency could better understand the impacts of the mitigation
plan. In response, various stakeholders, including several forest seedling nursery operations,
submitted detailed information. From an analysis of the information submitted, including an
analysis of a nursery and options they would have for compliance, the Agency concludes that it
had overestimated the ease with which many growers and fumigators would be able to comply
with the buffer requirements as presented in the July 2008 RED, and that potential impacts
would be much greater than previously anticipated for some types of production.
From the Agency's analysis, the primary driver of the impacts is the size of the buffer
zones, which will require many growers to divide their fields into smaller fumigation blocks to
achieve smaller buffer zone distances. Two other contributing factors are the prohibition on
buffers overlapping in space and time and the duration of the buffer zone. As discussed above,
the Agency has provided flexibility on overlapping buffers. Nevertheless, the analysis indicates
that the buffer system identified in the July 2008 RED can be less flexible than expected for
certain scenarios and the associated field topography, field infrastructure, and need for a
consistent orientation in the application of a fumigant, which constrain how a field may be
divided. Together, these requirements could result in the loss of part of a grower's field that can
be effectively fumigated. Further, there may be substantial delays in completing fumigations and
multiple trips to a field with fumigation equipment may often be necessary. Not only could there
be delays in production activities in these instances, but it may also be difficult to maintain
proper soil moisture over the period that multiple blocks would be fumigated. Soil moisture has
been identified as a critical element in controlling emissions. Some growers will face numerous
scheduling conflicts if they rely on commercial applicators, and the Agency estimates that
growers would be more likely to conduct their own fumigations. In addition, repeated trips to
the field to fumigate small blocks will increase costs, a further incentive for growers to conduct
their own fumigations.
The Agency does agree that compliance with buffer zone requirements as outlined in the
July 2008 RED would be a significant challenge for applicators and growers. However, field
flux studies, monitoring data, modeling analyses and information from incidents involving
fumigants continues to support a conclusion that dazomet off-gasses and moves away from
treated fields at concentrations that have the potential to cause adverse effects. Therefore, the
Agency still believes that buffer zones that exclude bystanders are a critical aspect of mitigating
risks from dazomet.
In addition to these impacts, if emergency preparedness and response requirements were
triggered due to proximity of neighbors, for example, the requirement in the July 2008 RED to
monitor the buffer zone for its duration was estimated to impose the highest direct costs. The
Agency estimates that the cost of sampling tubes alone could range from $1000 to over $3000
for a field or enterprise, not including the cost of labor. These costs would fall
disproportionately on growers with small acreage. As an alternative, growers could notify their
neighbors of their intent to fumigate. However, the Agency understands and appreciates the
many comments indicating that notification may not be an attractive option due to the potential
for neighbors to attempt to impede or block fumigant applications.
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Finally, the Agency concludes that the development and implementation of workable
fumigation strategies, considering buffer and other requirements, will require substantial new
information and management skills on the part of growers and applicators. While the Agency's
risk management approach provides flexibility to the grower, providing a reasonable period of
time for growers to adapt would reduce impacts.
Based on this new information and EPA's analyses, the Agency has identified
modifications to the mitigation which will maintain the important protections necessary for the
health and safety of workers and bystanders, but will increase the ability of fumigant users to
comply by reducing impacts associated with the mitigation. This includes allowing buffer zone
overlap and changes in monitoring requirements. In addition, due to new data that have been
submitted to the Agency and buffer zones distances for some scenarios have been refined.
Although many aspects of the RED mitigation will appear on labels in 2010, the Agency will not
require buffers until the 2011 growing season.
B. Antimicrobial Risk
In addition to the use of fumigants to sterilize soil before planting, there are a number of
antimicrobial uses that the Agency has assessed in this RED. Dazomet may be used as an
antimicrobial chemical in the following ways: 1) as a treatment during the production of pulp
and paper; 2) as a material preservative treatment for paper coatings, non-food adhesives, epoxy
flooring compounds, slurries, and high viscous suspensions; 3) as a biocide treatment used
during petroleum operations; 4) as a biocide treatment to recirculating cooling water systems;
and 5) as a remedial wood treatment to utility poles.
All of the occupational handler risks were below the Agency's LOG except for some
scenarios with the following uses: preservation of epoxy flooring compounds, pulp and paper
slimicide use, and microbe control in large water cooling systems.
For more information on these antimicrobial uses:
Dazomet Antimicrobial Risk Mitigation Paper. (Garvie, H., Dated June 2008)
Dazomet: Revised Occupational and Residential Exposure Assessment of Antimicrobial
Uses for the Reregistration Eligibility Decision (RED) Document. (Walls, C., Dated June
2008)
Dazomet: Dietary Risk Assessment of Antimicrobial Uses for the Reregistration
Eligibility Decision (RED) Document. (Walls, C., Dated March 2007)
Environmental Fate and Ecological Risk Assessment for the Reregistration of Dazomet
(035602) andMITC (068103) -Antimicrobial Uses. (Petrie, R., Dated April 2007)
Please refer to the RED Appendix for the complete document citations, which are also
available in the dazomet docket (OPP-2005-0128) at www.regulation.gov.
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IV. Risk Management and Reregistration Decision
A. Determination of Reregistration Eligibility
Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission of
relevant data concerning an active ingredient, whether or not products containing the active
ingredient are eligible for reregi strati on. The Agency has previously identified and required the
submission of the generic (i.e., active ingredient-specific) data to support reregi strati on of
products containing dazomet. The Agency has completed its assessment of the residential,
occupational, and ecological risks associated with the use of pesticides containing the active
ingredient dazomet.
In Phase 5, the Agency published a risk mitigation options paper.2 This document
detailed potential mitigation options and sought public comment on these options. The following
is the list of mitigation options discussed in the Agency's paper:
Buffer zones;
Sealing methods;
Timing of applications;
Application block size limitations;
Respiratory protection;
Tarp perforation/removal procedures;
Entry-restricted period;
Application method/practice restrictions;
Fumigant management plans (FMPs);
FMP certification;
Responsible parties;
Record keeping/reporting/tracking;
Restricted Use Pesticide Classification;
Notification and posting;
Good agricultural practices;
Fumigant manuals; and
Stewardship programs.
Based on a review of the dazomet database and public comments on the Agency's
assessments for dazomet, the Agency had sufficient information on the human health and
ecological effects of dazomet to make decisions as part of the reregi strati on process under
FIFRA in July 2008. The Agency determined in the 2008 Dazomet RED that dazomet products
are eligible for reregi strati on provided that (i) required product specific data are submitted, (ii)
the risk mitigation measures outlined in this document are adopted, and (iii) label amendments
2 EPA-HQ-OPP-2005-0128-0031, Risk Mitigation Options to Address Bystander and Occupational Exposures from
Soil Fumigant Applications
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are made to implement these mitigation measures, as outlined in Chapter V. Appendix A
summarizes the uses of dazomet that are eligible for reregi strati on.
The Agency's decision takes into account the best available information on the potential
risks and benefits of dazomet use. In reaching its reregi strati on decision and developing the
dazomet mitigation proposal, EPA considered a range of factors, including: characteristics of
bystander and other populations exposed to dazomet; hazard characteristics of dazomet and
MITC; available information on levels of exposure, feasibility, cost, and effectiveness of various
risk mitigation options; incident information; public comments; potential impacts of mitigation
on growers ability to produce crops; availability of efficacious alternatives; comparative risks of
alternative control methods; and the uncertainties and assumptions underlying the risk and
benefit assessments.
A substantial amount of research is currently underway or is expected to begin in the near
term to (1) address current data gaps, and (2) refine understanding of factors that affect fumigant
emissions. Additionally, a number of new methods and technologies for fumigation are
emerging. EPA plans to move the soil fumigants forward in Registration Review, from 2017 to
2013, which will allow EPA to consider new data and information relatively soon, determine
whether the mitigation included in this decision is effectively addressing the risks as EPA
believes it will, and to include other soil fumigants which are not part of the current review.
The Registration Review process for dazomet and the other soil fumigants will also
include a comprehensive endangered species assessment. Once that endangered species
assessment is completed, further changes to dazomet labels may be necessary.
B. Public Comments and Responses
The Phase 3 public comment period on the preliminary risk assessments and related
documents for dazomet lasted from July 13 through October 12, 2005. EPA-HQ-OPP-2005-
0128-0062 contains the Agency responses to Phase 3 public comments related to dazomet uses.
EPA revised its risk assessments and developed benefits and risk mitigation options during
Phase 4. The Phase 5 public comment period on revised risk assessments, benefits analysis, and
risk management options took place from May 2 to November 3, 2007. Comments on issues
which were significant to many stakeholders and directly influenced EPA's decisions are
highlighted in this document as well as EPA's responses to those comments. The following
documents include EPA's responses to comments related to dazomet which may be found in the
dazomet docket.
The Health Effects Division's Response to Comments on EPA 's Phase 5
Reregistration Eligibility Decision Document for Dazomet. (Smith, C., Dated June
2008)
Response to Phase 5 Public Comments on the Phase 4 Dazomet Environmental
Fate and Ecological Risk Assessment. (Khan, F., and Felkel, J., Dated April 2,
2008)
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Response to Phase 5 BEAD Related Public Comments Received on the
Reregistration of Chloropicrin, Dazomet, Metam Potassium, Metam Sodium, and
Methyl Bromide. (Donaldson, D. et al., Dated June 2008)
Review of Stakeholder Submitted Impact Assessments of Proposed Fumigant
Buffers, Comments on Initial Buffer Zone Proposal, and Case Studies of the Impact
of a Flexible Buffer System for Managing By-Stander Risks ofFumigants. (Wyatt,
T., et al, Dated June 2008)
Phase 6 Response to Substantive Public Comments on Antimicrobials Division's
Occupational and Residential Assessments for the Reregistration Eligibility
Decision (RED) Documents for the following chemicals: Methylisothiocyanate
(MITC), Metam Sodium, Dazomet, and Chloropicrin. (Walls, C., Dated February
14, 2008)
SRRD 's Response to Phase 5 Public Comments for the Soil Fumigants. (Dated July
2008)
The Agency also opened a 60-day public comment period following the publication of
the dazomet RED on July 16, 2008. The Agency received requests to extend the comment
period, so in response to these requests, on August 29, 2008, EPA published a notice in the
Federal Register extending the comment period for an additional 45 days. The comment period
closed on October 30, 2008. The Agency has reviewed these public comments as well as new
scientific data and other information provided and determined that all measures established in the
July 2008 RED to reduce risks to bystanders and workers will still be required. The Agency has
determined that certain modifications in how and when some measures will be implemented are
appropriate. The following documents include EPA's responses to comments on the dazomet
RED which may be found in the dazomet docket:
Further Response to Public Comments on the 7/9/08 Completed Dazomet RED.
(Dated March 3, 2009)
Methyl Bromide, 1,3-Dichloropropene, Chloropicrin, Dazomet, Metam
Sodium/Potassium, MITC: Health Effects Division (HED) Component of Agency
Response To Comments On 2008 Reregistration Eligibility Documents (Dated May
14, 2009)
Response to BEAD Related Public Comments Received on the Reregistration
Eligibility Decision for Chloropicrin, Dazomet, Metam Potassium, Metam Sodium,
and Methyl Bromide (DP# 363545; Dated May 14., 2009)
Analysis of Soil Fumigant Risk Management Requirements using Geographic
Information Systems: Case Studies based on a Forest Seedling Nursery (DP#
363546; Dated May 13, 2009)
SRRD's Response to Post-RED Comments for the Soil Fumigants (Dated May 20,
2009)
C. Regulatory Position
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1. Regulatory Rationale
The Agency has determined that dazomet is eligible for reregi strati on provided the risk
mitigation measures outlined in this document are adopted and label amendments are made to
reflect these measures. EPA has determined that the modifications to the measures outlined in
the July 2008 RED, described herein, will achieve the same protection goals for persons
potentially exposed to dazomet but with a greater likelihood of compliance, fewer impacts on the
benefits of dazomet use, and with less uncertainty regarding the protectiveness of the required
measures. The following is a summary of the rationale for managing risks associated with the
use of dazomet. Where labeling revisions are warranted, specific language is set forth in the
summary table in Section V of this document.
a. Dazomet Soil Uses
i. Rate Reduction and Use Sites
Rate
The current maximum application rates for dazomet are 530 Ibs ai/A for incorporated
applications and 265 Ibs ai/A for surface applications. According to the dazomet soil use
registrant, Certis, USA LLC, the actual use rate of dazomet is usually much lower for most uses
of dazomet. The turf and ornamental use rarely requires the maximum rate, except for golf
course or turf renovation. For crop uses, the rate generally ranges from 200-300 Ibs ai/A,
although there are some cases where an application up to 400 Ibs ai/A is needed. Therefore, the
registrant has agreed to lower the maximum use rate of dazomet to 425 Ibs ai/A for all registered
uses except for golf course/turf renovation. The maximum rate for golf course/turf renovation
will remain at 530 Ibs ai/A.
Use Sites
Although current labels include instructions for dazomet's use in greenhouses, the
Agency was not aware of greenhouse use occurring prior to the 2008 RED and prohibited all
dazomet use in greenhouses. The Agency received a comment citing dazomet's use in
greenhouses, and in light of this additional information, use in greenhouses is being retained
provided the risk mitigation measures outlined in this document are adopted and label
amendments are made to reflect these measures. Please refer to Table 6 for information
regarding greenhouse buffer zones.
ii. Human Health Risk Management
For details on the dazomet human health risk assessment for soil uses, please refer to the
Human Health Risk Assessments referenced in Section III of this document. These documents
are also available in the public docket EPA-HQ-OPP-2005-00128, located on-line in the Federal
Docket Management System (FDMS) at http://www.regulations.gov.
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Dietary Risk
Based on the currently registered use patterns for dazomet, dietary exposure, including
exposure from drinking water, is not expected and no dietary risk mitigation is warranted for
dazomet at this time.
Bystanders, Workers, and Handlers
The human health risk assessments indicate that inhalation exposure to bystanders who
live and work near agricultural fields, nurseries, golf courses, and other areas where dazomet
fumigations occur, and to handlers involved in the application of dazomet have the potential to
exceed the Agency's LOG without additional mitigation measures.
To reduce the potential for exposure to bystanders, handlers, and workers and to address
subsequent risks of concern, EPA is requiring a number of mitigation measures which include:
Reducing maximum application rates;
Clarifying use sites;
Buffer zones;
Dermal protection for handlers;
Respiratory protection for handlers;
Restrictions on the timing of perforation and removing of tarps;
Posting;
Good agricultural practices;
Fumigant management plans;
Site specific response and management; and
Notice to state lead agencies.
The Agency also believes that registrant developed and implemented training and
community outreach and education programs, will help reduce risk. Additionally, EPA will
continue to work with registrants to identify additional measures that could be implemented as
part of product stewardship. These additional measures should include efforts to assist users'
transition to the new label requirements.
Some of the required mitigation measures only address one group of potentially exposed
individuals (i.e., bystanders, handlers, or workers), while other measures will help reduce risk to
more than one group. All mitigation measures are designed to work together to reduce
exposures, enhance safety, and facilitate compliance and enforcement. The Agency has based its
risk mitigation decision on a flexible approach which EPA believes will be protective and allow
users to make site-specific choices to reduce potential impacts on benefits of the use. While
some of these measures, buffer zones for example, can be used to estimate MOEs, others such as
emergency preparedness and response and community education will contribute to bystander
safety, but are difficult to express in terms of changes to quantitative risk estimates such as
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MOEs. However, EPA has determined that these measures, working together, will prevent
unreasonable adverse effects to human health.
aa. Bystander Risk Mitigation
Bystanders are persons who live and/or work near fumigated fields and are potentially
exposed to fumigant emissions that travel off-site. In some cases the bystanders are workers
performing agricultural tasks in nearby fields. If they are employed by the grower who has
control of the fumigated field, they are more likely to be aware that a fumigant application has
occurred.
Bystander risks for people that live near treated fields differ from other human health
risks evaluated under FIFRA, for example residential and worker reentry risks. Unlike
residential exposures resulting from use of products to control pests in and around the home,
non-occupational bystanders receive no direct benefit from the pesticide which was applied
elsewhere. These bystanders have not made a decision to purchase a pest control product or
service, and as a result they have little access to information about the product (e.g., hazards,
safety information, first aid, etc.) or symptoms of exposure. Additionally, non-occupational
bystander exposures to fumigants are largely involuntary and unanticipated. In this regard non-
occupational bystander exposure is similar to dietary exposure in that people consuming foods or
drinking water expect to be safe from possible adverse effects associated with pesticide residues
that could be present in their food and drinking water.
Unlike workers, non-occupational bystanders typically receive no safety information or
training related to the pesticide to which they may be exposed. Whereas workers are generally
expected to play an active role in protecting themselves from pesticide risk, no such expectation
exists for non-occupational bystanders. Workers who experience symptoms of pesticide
exposure are also more likely to link their symptoms to the pesticide and take steps to receive
appropriate treatment. Conversely, bystanders are much less likely to attribute adverse effects to
pesticide exposures or to have access to information needed to take appropriate steps to mitigate
the effects of the exposure. Thus, EPA's mitigation includes elements for site specific response
and management, notice to state lead agencies, training, and community outreach and education,
as well as labeling changes.
1. Buffer Zones
The human health risk assessments indicate bystanders may be exposed to MITC air
concentrations, following dazomet applications, which exceed the Agency's level of concern
based on current label requirements. In general, the risk from inhalation exposures decreases as
the distance from the field where bystanders are located increases. Because of this relationship,
the Agency has determined that a buffer zone must be established around the perimeter of each
application block where dazomet is applied. The Agency acknowledges that buffer zones alone
will not mitigate all risks or eliminate incidents caused by equipment failure, human error,
adverse weather (e.g., temperature inversions), or other events. The Agency however does
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believe that buffer zones along with other mitigation measures required by this decision
described below will mitigate risks so that bystanders will not experience unreasonable adverse
effects.
Buffer Zone Requirements
General Requirements in the July 2008 RED
The 2008 dazomet RED described general buffer zone requirements for dazomet and
other soil fumigants. This included the definition of a buffer zone, the requirement to exclude
non-handlers from the buffer zone during the buffer-zone period, and the definition of the
application block.
The RED also did not allow buffer zones to overlap and fumigations were prohibited
within 0.25 miles of difficult to evacuate sites such as schools, state licensed day care centers,
nursing homes, and hospitals, if occupied during the buffer zone period. Exemptions for
vehicular and bicycle traffic were allowed on roadways through the buffer zone. However, bus
stops or other locations where persons wait for public transit were not permitted within the buffer
zone. Structures within the buffer zone were also not allowed to be occupied during the buffer
zone period and air samples were required before bystanders could enter the structure following
expiration of the buffer-zone period. In addition, before a buffer zone could extend onto
adjacent private or public property, the applicator needed to obtain written permission from the
owner/operator or local authority to allow the buffer zone to extend onto the property. This was
to ensure that non-handlers would not enter the buffer zone and that buffer zones did not overlap.
Comments on the July 2008 RED
During the post-RED comment period, the Agency received many comments from
stakeholders concerning the buffer zone requirements. Many comments stated that the large
buffer zone distances would make fumigation infeasible and the mitigation options were not
flexible enough to allow some fumigations to occur; however other comments expressed concern
that buffers EPA specified would not be large enough to protect bystanders.
The Agency also received numerous comments that buffer zone duration will present
severe hardship for growers. Many commenters expressed concern that the buffer zone overlap
restriction would have the unintended consequence of forcing some applications to occur during
less-than-optimal weather and soil conditions, because the restriction could preclude nearby
application blocks from being treated when weather and soil conditions would be optimal for
reducing emissions. Hence, subsequent fumigations in adjacent fields would have an increased
chance of occurring when weather and soil conditions are more conducive to off-gassing.
Examples cited by commenters where this situation could occur include the Southeast and
Pacific Northwest where optimal soil moisture conditions occur during a limited time period.
The commenters felt that while the buffer zone is in effect, properly trained and equipped
handlers should be allowed to enter adjacent application blocks to make applications. Several
commenters felt that providing an exception to this prohibition would make buffers more
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workable, reduce delays, allow a more efficient use of equipment and labor, allow growers
additional flexibility to achieve compliance with buffer requirements, and potentially reduce risk
if applications could be made under more favorable soil and weather conditions. In addition,
some comments suggested that allowing adjacent application blocks to be treated would not
increase risk to bystanders since the Agency's mitigation measures encourage users to split
application blocks into smaller treatment areas which result in less fumigant being applied, less
exposure, and less potential risk.
Some commenters also asked for clarification on various aspects of the buffer zone
requirements, and some asked that EPA provide additional increments for acreages and
application rates for buffer zone tables. In addition, many commenters stated that buffer zone
credits should be greater for the use of tarps and for certain environmental conditions. A number
of comments indicated that obtaining written permission from local authorities for buffers to
extend over roads and rights-of-way would be extremely difficult, and that neighbors may not
provide permission. EPA also received additional field emissions (flux) data for some
fumigants, as well as additional information regarding factors that affect fumigant emissions.
Based on EPA's review of the comments, and new data and information, the Agency has
determined that certain amendments to the buffer zone requirements are appropriate. EPA
believes these amendments will maintain the important protections for bystanders but will
increase the feasibility of compliance with buffers and will reduce potential impacts of buffers on
the beneficial uses of soil fumigants. The Agency does agree that compliance with buffer zone
requirements as outlined in the July 2008 RED would be a significant challenge for applicators
and growers. However, field flux studies, monitoring data, modeling analyses, and information
from incidents involving fumigants continue to support a conclusion that dazomet off-gasses and
moves away from treated fields at concentrations that have the potential to cause adverse effects.
Therefore, the Agency still believes that buffer zones that exclude bystanders are a critical aspect
of mitigating risks from the use of dazomet. The Agency believes the modifications to the buffer
requirements, specified below, will increase compliance feasibility and encourage further
adoption of emission reduction application techniques, while still protecting human health and
the environment.
Amended RED Requirements
EPA has determined that no changes to several aspects of the general buffer zone
requirements from the 2008 RED are appropriate. This includes
the definition and duration of a buffer zone;
the requirement to exclude field workers, nearby residents, pedestrians, and other
bystanders from the buffer zone during the buffer zone period (except for transit);
- the definition of the application block;
the minimum buffer of 25 feet and maximum buffer of /^ mile.
the requirement limiting entry into buffer zones to handlers who have been properly
trained and equipped according to EPA's Worker Protection Standard;
the exemption for transit through buffer zones;
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the prohibition on including in buffer zones bus stops or other locations where
persons wait for public transit;
- the prohibition against including in buffer zones buildings under the control of the
owner/operator of the application block 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;
- the prohibition against including in buffer zones residential areas that are not under
the control of the owner/operator unless occupants agree in writing that they will
voluntarily vacate the buffer zone until the buffer zone period expires;
- the prohibition against including in buffer zones agricultural areas that are not under
the control of the owner/operator unless the owner/operator of the other area provides
written agreement that they, their employees, and other persons will not enter the
buffer zone; and
- the prohibition against including in buffer zones publicly owned and/or operated
areas such as parks, sidewalks, walking paths, playgrounds, and athletic fields
without first obtaining written permission from local authorities.
EPA has determined that certain other amendments to the July 2008 RED requirements
are appropriate; these are discussed in greater detail below. The amended buffer zone
requirements are summarized at the end of this section.
Buffer Zone Proximity - Exception to Allow Buffer Zone Overlap
The Agency is concerned that emissions from multiple fields located close to one another
could be higher than air concentrations from individually treated fields. As a result, bystanders
outside of buffers for individual application blocks could be exposed to concentrations of
concern particularly if peak concentrations from multiple application blocks in proximity to each
other coincide. To reduce the potential for off-site movement of fumigant emissions beyond
buffer zones for multiple fumigated fields, the July 2008 RED prohibited buffer zones from
multiple application blocks from overlapping, including application blocks fumigated by other
property operators.
EPA has considered the comments submitted and has determined that allowing an
exception to the buffer zone overlap prohibition, under the conditions specified below, is
reasonable and will not demonstrably alter the protection goals provided to bystanders in the July
2008 RED. EPA has determined that buffer zones from nearby application blocks may overlap
one another provided at least 12 hours have elapsed from the end of one application until the
start of the next application. By separating the application times by at least 12 hours the
fumigant emission peaks are less likely to occur at the same time, which would sufficiently
reduce potential exposure outside buffer zones and meets the Agency's protection goals.
The Agency is maintaining the requirement for buffer zones around each application
block to be in effect for 48 hours, as well as the requirement that only properly trained and
equipped handlers are allowed to enter into buffers zones.
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To clarify, below are conditions when buffer zones may or may not overlap:
A buffer zone may NOT overlap buffer zones from other application blocks that
are already in effect UNLESS a minimum of 12 hours has elapsed from the time
the first application ends until the second application begins.
EPA has determined that when fumigators exercise the exception to allow buffers to
overlap, the emergency preparedness and response measures described later in this document
must be implemented if there are homes, businesses, or property not within the control of the
fumigator within 300 feet of the buffer zone.
To ensure handlers are aware that they are working in an existing buffer from an
overlapping buffer zone area, the labels will require the certified applicator, before beginning the
application, to determine whether the application block or its resulting buffer will overlap with a
buffer that is already in effect. If so, the certified applicator must inform handlers of this and the
health effects, early signs of exposure, and respiratory protection and PPE requirements for
products applied in both the application block in which they are working and the other
application block. The Agency is requiring that all treatment areas and buffers be clearly posted
with proper signage to ensure handlers entering a treatment area are aware of previous treatments
and the existence of buffers associated with that treatment. In addition, certified applicators must
obtain permission from other landowners when buffers extend onto other lands. This provides
an additional mechanism to ensure handlers are aware when they are working in a buffer zone
and that they have the necessary information regarding health effects, warning properties, and
respiratory/PPE requirements for all products they may be exposed to.
Areas not under the control of owner/operator of the application block
For areas not under the control of the owner/operator of the application block, the
requirements remain unchanged except (1) air samples do not need to be taken to allow
occupants to reenter buildings or homes after the buffer zone period has expired, and (2) buffer
zones may include publicly owned and/or operated roads, including rights of ways, without first
obtaining written permission from local authorities; however, if a sidewalk or permanent walking
path is associated with the road or right-of-way, written permission must be given by the
appropriate state and/or local authorities.
In summary, areas of a buffer zone not under the control of the owner/operator of the
application block, 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 the occupants provide written
agreement that they will voluntarily vacate the buffer zone during the entire buffer zone period.
The Agency determined that the concentrations of the fumigants 48 hours after completion of the
application were likely to be below the Agency's level of concern, and that the warning
properties of MITC would alert persons reentering these sites if concentrations had not yet
36
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dissipated were of concern. Therefore, monitoring of buildings and outdoor areas after
termination of the buffer zone is not necessary and will no longer be required.
Buffer zones may still 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. In
addition, the applicator must still receive written permission from the owner/operator of areas
that are not under the control of the applicator stating that the owner, their employees, and other
persons other than handlers, consistent with buffer overlap provisions, will stay out of the buffer
zone during the entire buffer zone period. The goal of this agreement is to ensure that a property
owner of an agricultural field adjacent to an area that will be treated with a fumigant is aware
when the fumigation will occur. This will allow the applicator to post on the adjacent property
and take other required safety measures to ensure that persons on the property will not be
exposed to a fumigant at levels above the Agency's level of concern. Informing the property
owner of the adjacent field will enable them to take any appropriate safety measure The Agency
believes that requiring the applicator to obtain written permission will be an enforceable measure
that will meet the goal of protecting workers and bystanders on adjacent properties that fall
within a buffer zone.
In addition, buffer zones still may include publicly owned and/or operated areas such as
parks, sidewalks, walking paths, playgrounds, and athletic fields only if the area is not occupied
during the buffer zone period and entry by non-handlers is prohibited during the buffer zone
period. Written permission from the appropriate state and/or local authorities to include those
public areas in the buffer zone is also still required.
However, for roads and rights-of-ways, EPA has determined that these may be included
in buffers, subject to local laws and regulations, as long as it is posted according to the
requirements of this amended RED. If, as discussed above, the road or right-of-way has an
associated sidewalk or permanent walking path, then written permission would also be required
to include the area in the buffer zone. The Agency believes that if a town or county has invested
resources into building a sidewalk or establishing a walking path, it is reasonable to anticipate
pedestrian traffic at that location. In such circumstances EPA believes a local authority would be
best positioned to make a determination about the practicality of preventing non-handlers from
entering the buffer zone. EPA acknowledges that laws and regulations vary from jurisdiction to
jurisdiction and that the requirement to post points of entry into buffer zones may necessitate
additional steps on the part of fumigant applicators before a road or right-of-way can be included
in a buffer.
Buffer zone distances
The Agency has received additional flux studies from the California Department of
Pesticide Regulation, and the dazomet buffer zones have been revised to reflect this new data as
well as other information received during Phase 5 comment period. Buffer zones have increased
for surface applications of between 132 Ibs ai/A and 265 Ibs ai/A only.
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PERFUM Model Inputs
The major input parameters for the modeling were: application rates, application block
sizes, application method emission profiles, weather conditions, and the target air concentration
(based on acute inhalation endpoint and uncertainty factors). The following summarizes the key
points for each of these input parameters.
Rates
The maximum rates for soil applications of dazomet are 425 Ibs ai/A for incorporated
applications and 265 Ibs ai/A for surface applications. Since there is limited use information on
typical dazomet rates, a range of rates was modeled. The rates used in the model included the
maximum, along with rates at 75%, 50%, and 25% of the maximum for both surface and
incorporated applications.
Rates for bedded or strip applications (Ib ai per treated area) were converted to broadcast
equivalent application rate to determine the minimum buffer zone distance. In Figures 1 and 2
(shown below), the dashed line represents the perimeter of the field, the shaded area is the
portion of the field that is treated, and the un-shaded area is the untreated portion of the field.
Assuming both fields are 10 acres, and only 50% of field in Figure 2 is fumigated, the rate per
treated acre is 400 Ibs ai/A for both Figure 1 and 2. The broadcast rate for Figure 1 is 400 Ib
ai/A but the effective broadcast equivalent rate for Figure 2 is 200 Ibs ai/A. Labels may express
rates as Ibs per treated acre under the application instructions but they must identify buffer zone
distances based on the broadcast or effective broadcast equivalent rates.
1111
Figure 1. Broadcast Application Figure 2. Bedded Application
Block Sizes
The Agency has limited information available on the size of application blocks treated in
a given day but according to the registrants, dazomet is generally applied to a smaller number of
acres than other fumigants, typically from 5 to 20 acres. The modeling did consider block sizes
up to 40 acres per day for dazomet, and so based on the registrant comment the application block
size will be limited to 40 acres for dazomet.
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The application block size pertains to size of the field and not the size of the area treated.
The area inside the dashed lines in both Figures 1 and 2 is the application block. In this example
the application block size for both figures is 10 acres. For both figures, 10 acres would be used
to determine the buffer zone distance.
During the post-RED comment period, the Agency received comments requesting buffer
zone distances for additional acreage increments for small fields. In response, the Agency
determined buffer distances for smaller block sizes (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 acres).
Although the Agency added additional acreage and rate increments, not all increments may be
captured by the tables presented. If the tables do not capture a specific acreage or rate, round up
to the nearest acre or rate. For example, when applying to a 9.5 acre field, round up to 10 acres.
In the 2008 RED, the Agency had calculated all dazomet buffer zones based on a square
application block. The Agency received comments regarding the buffer zone calculations for the
use of dazomet on golf course fairways, as a rectangular applicator block is more representative
of how fairways are treated. The Agency agrees that fairways should be calculated using a
rectangular application block because it is more representative of the typical treatment for
specific use-site. The Agency has thus calculated the buffer zones for golf course fairways
taking into account this additional information, and more information on these buffers is located
in the section on buffer zone distances.
Emission Studies
The Agency's risk assessment for the RED includes modeling of the two main ways that
dazomet is applied, surface or soil-incorporated. Details of these emission studies can be found
in Appendix D of the Dazomet: Final Revised HED Chapter of the Reregistration Eligibility
Decision Document (RED dated April 2009).
Weather
It is estimated that the major use of dazomet is in California and Washington. Some use
in Michigan and Florida (or elsewhere in those regions) is also estimated. As a result, weather
data for the following locations were included in this assessment: Bakersfield, CA; Ventura, CA;
Flint, MI; Tallahassee, FL; Bradenton, FL; and Yakima, WA. Each modeling run used five years
of weather (i.e., 1,825 potential application days) for each weather data set. Generally, Ventura,
and Bradenton weather data result in the largest buffer zone distances, Bakersfield, Tallahassee,
and Yakima data fall in the middle, and Flint data resulted in the smallest buffers.
Target Air Concentration
As described in the Human Health Risks section of Chapter III, the 22 ppb target air
concentration is based on a reversible sensitive endpoint from a human eye irritation and odor
threshold study for acute exposures to MITC, with a 10X uncertainty factor for intraspecies
extrapolation. The lowest observable adverse effect level (LOAEL) was 800 ppb and the human
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concentration (HC) based on the no observable adverse effect level (NOAEL) from this study is
220 ppb.
PERFUM Model Outputs
The PERFUM model outputs are presented in percentiles for "whole field" and the
"maximum distance" distributions. The model also provides outputs as distributions of air
concentrations from which MOEs can be estimated. The following summarizes the key points
for each of these output parameters.
The maximum distance distribution is a compilation of the farthest predicted buffer
distances (i.e., the farthest downwind points) over 5 years of weather. The whole field
distribution differs because it includes all points around the perimeter for the same period.
Another way to consider the difference between the distributions is that maximum distance
results are a subset of the whole field results and that maximum distances allow for more
resolution at the upper percentiles of this distribution. Version 2.1.4 of PERFUM also allows for
direct consideration of air concentrations at various distances around treated fields. These air
concentrations and MOEs were also considered in the decision making process.
An analysis based on a variety of PERFUM outputs was used in the buffer distance
determinations. This involved consideration of not only the typical maximum and whole-field
results, which are predictions of the distances at which a target concentration of concern (i.e., the
human concentration adjusted by applicable uncertainty factors) is achieved at varying
percentiles of exposure. In addition, a complementary approach, which determined the
percentiles of exposure for maximum and whole-field buffers at predetermined buffer distances,
was employed. Air concentration data were also used to calculate risk estimates (i.e., MOEs) at
predefined buffer distances and varied percentiles of exposure.
This overall approach allowed the Agency to utilize more of the information available
from PERFUM so that a more comprehensive view of the risks could be considered. Buffer
distances indicated by this type of analysis along with information from monitoring studies and
incidents were valuable in determining buffer distances to manage potential risks from dazomet
use when coupled with other mitigation measures.
Buffer Zone Distances
The Agency has developed buffer zones distances based on application rate and
application block size (rounding up to nearest rate and block size). These distances are
summarized in Tables 4, 5, 6, and 7.
For each of the soil emission studies, distances were first chosen for the rates identified in
the risk assessment as the 100%, 75%, 50%, and 25% of the maximum rates for each application
method, as shown by the bolded red font in the table. For example, for surface applications the
rates were 265 Ibs ai/A, 200 Ibs ai/A, 132 Ibs ai/A, and 66 Ibs ai/A; and for incorporated
applications the rates were 530 Ibs ai/A, 400 Ibs ai/A, 265 Ibs ai/A, and 132 Ibs ai/A. For golf
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course fairways, buffers were calculated for rectangular application blocks of 1 and 5 acres. For
greenhouse applications, buffers were calculated for structures sizes between 5,000 and 50,000
square feet. For all other applications, application block sizes of 5, 20, and 40 acres were used in
the buffer zone calculations. Distances for the other rates in the buffer zone tables were scaled
by assuming a linear relationship between the 100%, 75%, 50%, and 25%, and maximum rates
(e.g., distance at 37.5% rate = [distance at 25% rate + distance at 50% rate]/2 ) with some
adjustments for whole numbers. This scaling was necessary to provide an incremental spread of
rates. It should be noted that the distances in the lookup tables are not model outputs, although
the model outputs were used for their development.
Minimum and Maximum Buffer Zone Distances
For dazomet, the largest buffer distance is 1140 for applications of 265 Ibs ai/A for
greenhouses of 50,000 square feet. Applications to larger block sizes and higher rates will be
prohibited for dazomet. Comments from the registrants indicate that dazomet users do not apply
to large areas at the very highest rates on current labels. A minimum buffer zone of 25 feet will
be required regardless of site-specific application parameters. In some instances the PERFUM
model predicts that the risks reach the target at the edge of the field, but the Agency believes that
a 25 foot minimum buffer is a good agricultural practice. While modeling may support no buffer
in some cases, a minimum buffer is being required because of variability in emission rate over a
field and other factors not accounted for in the modeling.
Additional buffer tables for use of dazomet in greenhouses and for golf course use have
been added below since the 2008 RED.
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Table 4: Buffer zone distances (in feet) for all dazomet soil applications except golf course fairways and greenhouses
Application Rates for incorporated applications (Ibs ai/acre)
Block
Size
(acres)
40
30
20
15
10
9
8
7
6
5
4
3
2
1 or less
425
864
692
520
400
280
256
232
208
184
160
150
140
120
110
400
770
605
440
343
247
230
210
190
170
150
135
117
100
75
390
750
588
426
333
240
222
204
186
168
147
130
113
96
72
380
730
571
412
323
233
215
197
179
161
144
127
110
92
69
370
710
554
398
312
227
210
193
176
159
141
123
106
88
66
360
690
537
384
302
220
204
188
172
156
138
120
102
84
63
350
670
520
370
292
213
198
182
166
151
135
117
99
80
60
340
650
503
356
281
207
192
177
162
147
132
113
95
76
57
330
630
487
343
271
200
186
171
157
143
128
109
91
72
54
320
610
470
330
261
193
180
167
153
139
124
105
87
68
51
310
590
454
317
251
186
173
160
147
134
120
101
82
64
48
300
565
435
305
242
179
167
155
142
129
116
97
78
60
45
290
545
417
288
229
171
159
147
135
123
112
93
75
56
42
280
524
400
275
219
164
153
142
131
119
108
89
70
52
39
270
505
383
260
208
156
146
136
125
115
104
85
66
48
36
265
500
375
250
200
150
140
130
120
110
100
82
64
44
33
260
490
368
245
193
141
130
119
110
99
89
72
56
40
30
250
471
353
234
182
130
120
109
99
89
78
64
50
36
25
240
452
338
223
171
119
109
98
89
78
67
55
43
32
25
Application Rates for incorporated applications (Ibs ai/acre)
Block
Size
(acres)
40
30
20
15
10
9
8
230
433
323
212
160
108
99
88
220
414
308
201
149
97
89
78
210
395
293
190
138
86
76
65
200
375
281
187
133
79
68
57
190
357
268
179
127.7
76.33
65
55
180
339
255
171
122
73.7
63
53
170
321
242
163
117
71
61
51
160
303
229
154
111
68
59
49
150
285
215
145
105
65
56
47
140
267
202
136
99
62
54
45
132
250
188
125
92
58
51
44
130
250
188
125
92
58
49
41
120
218
164
110
82
53
45
38
110
186
141
95
72
48
41
35
100
154
117
80
62
43
38
33
90
122
94
65
52
38
34
30
80
90
70
50
42
33
31
28
70
58
47
35
32
28
28
27
66
25
25
25
25
25
25
25
42
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7
6
5
4
3
2
1 or less
78
67
56
47
38
28
25
68
57
45
39
32
25
25
54
44
34
31
29
25
25
46
38
25
25
25
25
25
44
35
25
25
25
25
25
43
34
25
25
25
25
25
42
33
25
25
25
25
25
41
32
25
25
25
25
25
39
31
25
25
25
25
25
38
31
25
25
25
25
25
37
30
25
25
25
25
25
35
30
25
25
25
25
25
33
29
25
25
25
25
25
31
28
25
25
25
25
25
30
28
25
25
25
25
25
28
27
25
25
25
25
25
27
26
25
25
25
25
25
26
26
25
25
25
25
25
25
25
25
25
25
25
25
Table 5: Buffer zone distances (in feet) for all dazomet soil applications except golf course fairways and greenhouses
A
Block
Size
(acres)
40
30
20
15
10
9
8
7
6
5
4
3
2
1 or less
265
675
560
450
420
390
360
330
300
270
240
176
112
47
35
260
669
546
429
400
371
342
313
284
255
223
164
105
45
34
250
663
532
408
379
350
321
292
263
234
206
152
98
42
34
240
657
518
387
359
331
303
275
247
219
189
140
91
41
33
230
651
504
366
338
310
282
254
226
198
172
128
84
39
32
220
645
490
345
318
291
264
237
210
183
155
116
77
38
31
pplication Rates for surface applications (Ibs ai/acre)
210
639
477
323
297
271
245
219
193
167
138
104
70
36
31
200
630
465
300
274
248
222
196
170
144
120
91
62
35
31
190
576
425
275
248
221
197
172
151
127
106
82
57
33
29
180
522
385
250
222
194
172
148
132
110
92
73
51
32
28
170
467
345
225
196
167
147
124
113
93
78
64
46
29
27
160
414
305
200
170
140
122
100
94
76
64
55
40
28
27
150
360
265
175
144
113
97
76
75
59
50
46
35
27
26
140
306
225
150
118
86
72
52
56
42
36
37
30
26
26
132
250
188
125
92
58
51
44
38
31
25
25
25
25
25
130
250
188
125
92
58
51
44
38
31
25
25
25
25
25
120
218
164
110
81.67
53.33
47
41
35
30
25
25
25
25
25
110
186
141
95
72
48
43
38
34
29
25
25
25
25
25
100
154
117
80
62
43
41
38
33
29
25
25
25
25
25
90
122
94
65
52
38
36
33
30
27
25
25
25
25
25
80
90
70
50
42
33
31
29
28
26
25
25
25
25
25
70
58
47
35
32
28
27
27
26
26
25
25
25
25
25
66
25
25
25
25
25
25
25
25
25
25
25
25
25
25
43
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Table 6: Buffer zone distances (in feet) for dazomet greenhouse applications
Structure Size
5000 square feet
10000 square feet
15000 square feet
20000 square feet
25000 square feet
30000 square feet
35000 square feet
40000 square feet
45000 square feet
50000 square feet
265 Ibs ai/A (100%)
240
360
450
540
630
720
810
855
900
1140
200 Ibs ai/A (75%)
180
300
330
450
540
570
650
720
760
810
132 Ibs ai/A (50%)
120
210
270
330
390
450
585
540
600
630
66 Ibs ai/A (25%)
45
90
110
170
210
240
270
300
330
360
Table 7: Buffer zone distances (in feet) for dazomet golf course fairways applications
Application Rates for incorporated applications (Ibs ai/acre)
Block
Size
(acres)
5
4
3
2
1 or less
530
25
25
25
25
25
400
25
25
25
25
25
390
25
25
25
25
25
380
25
25
25
25
25
370
25
25
25
25
25
360
25
25
25
25
25
350
25
25
25
25
25
340
25
25
25
25
25
330
25
25
25
25
25
320
25
25
25
25
25
310
25
25
25
25
25
300
25
25
25
25
25
290
25
25
25
25
25
280
25
25
25
25
25
270
25
25
25
25
25
265
25
25
25
25
25
260
25
25
25
25
25
250
25
25
25
25
25
240
25
25
25
25
25
44
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The buffer zone distances shown in Table 7 are based on PERFUM modeling runs that
are representative of golf course fairways where the width of the application block is 15% of the
length of the application block. This ratio was proposed by the dazomet registrants as a typical
representation of golf course fairways. The Agency understands that golf course fairway width
to length ratios can vary significantly. Given these potential variations, the Agency believes that
applicators can use the rectangular buffer zones shown in Table 6 if the width of the application
block is less than or equal to 20% of the length of the application block. Examples have been
provided below:
For an application block 550 feet long by 110 feet wide:
110 feet / 550 feet = 0.20 x 100 = 20%, so the buffers in table 6 can be used
For an application block 700 feet long by 175 feet wide:
700 feet /175 feet = .25 x 100 = 25%, so the buffers in table 6 cannot be used;
The buffers in table 4 must be used instead.
The buffer zone distances were not based on the selection of a specific percentile or
distribution from the PERFUM modeling results. Rather, EPA used a weight of evidence
approach to set the buffers which included consideration of the hazard profile of MITC,
information from incident reports, monitoring data, stakeholder comments along with
comprehensive analysis of results from PERFUM modeling and consideration of results using
other models (e.g., the Fumigant Emissions Modeling System or FEMS). Each model was
reviewed by the FIFRA Scientific Advisory Panel (SAP) in 2004 during the August and
September meetings (http://www.epa.gov/oscpmont/sap/meetings/2004/index.htm). The
analysis of PERFUM results considered distances at various percentiles of the whole field and
maximum distance distributions, and predicted MOEs for various distances. The risk assessment
characterizes additional types of analysis that were performed. EPA's goal for risk management
was to achieve buffer distances where associated risks were at or above target concentration
levels at high percentiles of exposure. The following characterizes the risks associated with the
buffer zone distances summarized in Table 8:
This table shows the various buffer distances for each rate and block size. It also shows
the percentile for the whole and maximum distribution for each distance, as well as the
MOE at the 95th percentile air concentration of PERFUM2.
The target MOE for dazomet is 10, and the MOEs at these distances range from about 7
up to 20. Although the target air concentration is not below our LOG at all the distances,
at the lowest MOE of 7, the predicted air concentration would be 28 times lower than the
lowest observable adverse effect level (LOAEL) that is the level where the eye irritation
effects were first observed in the human study.
Two registrant-submitted studies were used to calculate the buffers in the RED, and this
data indicated little apparent difference in risk between the surface and incorporated
application methods when similar rates were compared.
Flux data for surface applications was submitted by CDPR during the comment period,
and the Agency has incorporated this new data in calculating the surface application
45
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buffer distances. The new surface application buffer zone distances were calculated using
the CDPR data because it is more conservative, and the buffer zones for the higher
surface application rates have changed as a result. Since the Agency did not receive any
new data for the incorporated application method, buffer zone distances for this method
have not changed since the RED.
The use of GAPs, FMPs, and other mitigation measures required by this decision will
contribute to an additional decrease in risk (see GAP and FMP sections).
Example
Table 8 shows the required buffer zone distances and corresponding PERFUM modeling
results for the soil uses of dazomet (excluding fairway and greenhouse applications) using both
the maximum distribution and the whole field distribution to the target concentration based on an
MOE of 10, as well as the MOE from the air concentration outputs from PERFUM at the 95th
percentile. The weather data selected here are from Ventura, CA, since only California has
agricultural uses registered which typically involve larger application blocks than dazomet's
other soil uses.
Focusing on the incorporated application method in the top row, using a 265 Ibs ai/A rate
on a 40 Acre block size, the buffer zone required for that application is 500 feet. The blocks
referenced in this example are shaded in gray in Table 8.
At this distance using the PERFUM model to predict both the whole field and maximum
distributions the results indicate 91st percentile for whole field and 57th percentile for
maximum, as shown in the next two columns in the table.
o The risk level corresponding to this buffer zone distance at the 91st percentile
whole field distribution is equivalent to saying a person at any location on the
perimeter of the buffer zone during the 24 hour period following the fumigation
of a specific field during a 5-year period would have at least a 91 percent chance
of having of an exposure below the LOG (i.e., MOE of ^10).
o The risk level corresponding to the buffer zone distances at the 57th percentile
maximum distribution is equivalent to saying a person at the location on the
perimeter of the buffer zone where the maximum concentration occurs during the
worst case 24 hour period following the fumigation of a specific field during a 5-
year period would have a 57 percent chance of having of an exposure below the
LOG (i.e., MOE of ^ 10) for these typical use scenarios.
Using the PERFUM 2 model outputs of air concentrations to predict MOEs at the 95th
percentile, at 500 feet for these application parameters, the MOE is about 9 which is not
significantly below the target MOE of 10.
46
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Table 8: Dazomet's Buffers and Risk Estimates
Incorporated applications
Block
Size
(acres)
40
20
5
530lbsai/A(100%)
Max incorporated rate
Buffer
Distance
(feet)
1080
650
200
Percentile
using
PERFUMat
MOEof 10
Whole
93
93
92
Max
46
43
44
MOEat
95th
percentile
of
PERFUM2
7
7
7
400 Ibs ai/A (75%)
Buffer
Distance
(feet)
770
440
150
Percentile
using
PERFUMat
MOEof 10
Whole
93
93
92
Max
50
49
74
MOEat
95th
percentile of
PERFUM2
7
7
8
265 Ibs ai/A (50%)
Buffer
Distance
(feet)
500
250
100
Percentile
using
PERFUMat
MOEoflO
Whole
91
91
96
Max
57
53
63
MOEat
95th
percentile
of
PERFUM2
9
8
11
132 Ibs ai/A (25%)
Buffer
Distance
(feet)
250
125
25
Percentile
using
PERFUMat
MOEoflO
Whole
96
98
99
Max
72
73
98
MOEat
95th
percentile
of
PERFUM2
11
12
19
Surface applications
Block
Size
(acres)
40
20
5
265lbsai/A(100%)
Max surface rate
Buffer
Distance
(feet)
675
450
240
Percentile
using
PERFUMat
MOEof 10
Whole
90
90
93
Max
23
25
38
MOEat
95th
percentile
of
PERFUM2
7
7
7
200 Ibs ai/A (75%)
Buffer
Distance
(feet)
630
300
120
Percentile
using
PERFUMat
MOEoflO
Whole
93
90
90
Max
45
30
30
MOEat
95th
percentile of
PERFUM2
7
7
7
132 Ibs ai/A (50%)
Buffer
Distance
(feet)
250
125
25
Percentile
using
PERFUMat
MOEoflO
Whole
89
88
87
Max
38
33
37
MOEat
95th
percentile
of
PERFUM2
7
7
7
66 Ibs ai/A (25%)
Buffer
Distance
(feet)
25
25
25
Percentile
using
PERFUMat
MOEoflO
Whole
90
93
99
Max
61
72
91
MOEat
95th
percentile
of
PERFUM2
8
10
14
Ventura Weather Data is used to calculate all the numbers in this table since it was one of the worst weather scenarios and for the agricultural uses of dazomet
there is more use in California than Florida.
Shaded areas represent the numbers explained in the example above.
All values are approximate.
47
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The Agency believes that the buffer zone distances described above, combined with other
risk mitigations described herein, will provide protection against any unreasonable adverse
effects.
Amended General Buffer Zone Requirements
The following describes the general buffer zone requirements, as amended, for dazomet:
"Buffer zone" is an area 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 transit (see
exemptions section).
The "buffer zone period" starts at the moment when any fumigant is delivered/dispensed to
the soil within the application block and lasts for a minimum of 48 hours after the fumigant
has stopped being delivered/dispensed to the soil.
An "application block" is a field or portion of a field treated with a fumigant in any 24-hour
period. See exception provided in the "Buffer zone proximity" section below.
Buffer zone proximity
To reduce the potential for off-site movement from multiple fumigated fields, buffer zones
from multiple dazomet application blocks may not overlap UNLESS:
o A minimum of 12 hours have elapsed from the time the earlier application(s) for
which a buffer is in place end(s) until the latter application begins, and
o Emergency preparedness and response measures specified later in this document
have been implemented if there are any homes, businesses, or property not within
the control of the fumigator within 300 feet of each buffer zone.
Buffer zone distances
Buffer zone distances must be based on look-up tables on product labels. Twenty-five feet is
the minimum buffer 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), 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.
48
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Exemptions for transit through buffer zones
Vehicular and bicycle traffic on public and private roadways through the buffer zone is
permitted. "Roadway" means that portion of a street or highway improved, designed or
ordinarily used for vehicular travel, exclusive of the sidewalk or shoulder even if such
sidewalk or shoulder is used by persons riding bicycles. In the event a highway includes two
or more separated roadways, the term "roadway" shall refer to any such roadway separately.
(This definition is based on the definition of roadway in the Uniform Vehicle Code prepared
by the National Committee on Uniform Traffic Laws and Ordinances. See
http://www.ncutlo.org/ for more details)
Bus stops or other locations where persons wait for public transit are not permitted within the
buffer zone.
See the Posting Section of this document 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,
1. The storage buildings are not occupied during the buffer zone period, and
2. The storage buildings do not share a common wall with an occupied structure.
See the Posting Section of this document 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,
1. The occupants provide written agreement that they will voluntarily vacate the buffer zone
during the entire buffer zone period, and
2. Reentry by occupants and other non-handlers must not occur until,
0 The buffer zone period has ended, and;
0 Sensory irritation is not experienced
Buffer zones may not include agricultural areas owned/operated by persons other than the
owner/operator of the application block, UNLESS,
1. 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, except as provided for
above, and
2. The owner/operator of the adjacent areas (i.e., areas that are not under the control of the
owner/operator of the application block) 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 must not include roads and rights of way UNLESS,
1. The area is not occupied during the buffer zone period, and
2. Entry by non-handlers is prohibited during the buffer zone period.
49
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3. Applicators must comply with all local laws and regulations.
For all other publicly owned and/or operated areas such as parks, side walks, walking paths,
playgrounds, and athletic fields, buffer zones must not include these areas UNLESS,
1. The area is not occupied during the buffer zone period,
2. Entry by non-handlers is prohibited during the buffer zone period, and
3. Written permission to include the public area in the buffer zone is granted by the
appropriate state and/or local authorities responsible for management and operation of the
area.
4. Applicators must comply with all local laws and regulations..
Restriction for Schools and Other Difficult-to-Evacuate Sites
"Difficult-to-evacuate" sites include schools (preschool to grade 12), state licensed day care
centers, nursing homes, assisted living facilities, hospitals, in-patient clinics, and prisons.
No fumigant application with a buffer zone greater than 300 feet is permitted within 1A mile
(1320 feet) of the sites listed above unless the site is not occupied during the application and
the 36-hour period following the application.
No fumigant application with a buffer zone of 300 feet or less is permitted within 1/8 mile
(660 feet) of the sites listed above unless the site is not occupied during the application and
the 36-hour period following the application.
Buffer Zone Reduction Credits
In preparing for the July 2008 RED, the Agency undertook a significant effort to evaluate
available empirical data results, modeling, and scientific studies reported in the literature
regarding the factors and control methods that may reduce emissions from soil fumigants. For
details on the Agency's analysis, please see the June 9, 2008 memo, "Factors Which Impact Soil
Fumigant Emissions - Evaluation for Use in Soil Fumigant Buffer Zone Credit Factor
Approach,"3 in the dazomet docket. The Agency also coordinated and led a discussion on this
issue at the 2006 and 2007 Methyl Bromide Alternatives Outreach (MBAO) Conferences with
leading researchers and other stakeholders. A general description of the MBAO sessions can be
found at http://mbao.org.
Based on the Agency's analysis of the current data, the Agency developed dazomet
buffer zone reduction credits for: soils with high organic matter, and for soils with high clay
content. The Agency believes that in addition to reducing bystander risk and the size of buffer
zones, these credits have the potential to also decrease application rates. Applicators will be
required to document any information about buffer zone credits that apply in the Fumigant
Management Plan (FMP).
Soil Conditions
Factors Which Impact Soil Fumigant Emissions - Evaluation for Use in Soil Fumigant Buffer Zone Credit Factor
Approach, June 9, 2008, DP Barcode: 306857
50
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Soil conditions like the amount of organic matter and type of soil do have an impact on
fumigant emissions. However, soil conditions differ from other credits because they are
essentially beyond a grower's ability to change. Although a grower may not be able to
manipulate organic matter or soil type, the Agency's factors document indicates that soil
conditions can reduce fumigant emissions, and is offering credits for these conditions. EPA
acknowledges that some variability in soil characteristics within a given field is likely. If users
are unsure whether the fields they intend to treat meet the criteria for a credit, they may consult
with their local agriculture extension office or soil conservation district for assistance in
determining soil characteristics.
The Agency's factors document not only reviews available literature regarding soil
conditions, but also describes modeling exercises that estimate the impact of organic matter and
soil type using Chain_2D. Chain_2D is a first principles model that takes into consideration
factors such as boundary layers or moisture that could impact fumigant emissions. The Agency
used Chain_2D as modified by Dow AgroSciences' Steve Cryer and Ian van Wesenbeek in the
sensitivity analysis4 Cryer and van Wesenbeek modified the original source code to create a
more usable graphical user interface; this included incorporating a new air/soil boundary
condition proposed by Wang in 19985. See the Agency's factors analysis for further details
about the CHAIN_2D model6.
Based on the review of available literature and modeling with the CHAIN_2D model,
EPA believes 10 percent buffer zone credits are appropriate if the application block contains soil
with organic matter of greater than 3 percent and/or for clay content of at least 27 percent.
CHAIN_2D that shows the impact of changes in organic content is not fumigant specific.
The Agency's Chain_2D sensitivity analysis suggests that organic matter can have a
small impact on emissions. There is generally a high correlation between the organic matter
content of the soils and the dissociation constant (K d) value. Increasing K d value by 10 or 25
percent generally reduced emissions by 10 or 20 percent. Decreasing the Kd value by 10 or 25
percent increased emissions by 10 or 20 percent (see figures 147 to 154 of the factors analysis
for further details).
Generally, clay loam and sandy clay loam soils tended to show significantly lower
emissions than other soil types, sometimes showing 50 percent lower reductions. Conversely,
loamy sand and loam soils tended to show higher emissions than other soil types (see figures 167
to 174 of the factors analysis for further details).
4 Cryer, S.A. (2007) Air/Soil Boundary Conditions For Coupling Soil Physics and Air Dispersion Modeling.
Unpublished report of Dow AgroSciences LLC (Report # DN241493)
Wang, D; Yates, S.R.; Jury, W.A. (1998) Temperature Effect on Methyl Bromide Volatilization: Permeability of
Plastic Cover Films. J. Environ. Qual. 27, 821-827.
6 Factors Which Impact Soil Fumigant Emissions - Evaluation for Use in Soil Fumigant Buffer Zone Credit Factor
Approach, June 9, 2008, DP Barcode: 306857
51
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Since the 2008 RED, information from the Chloropicrin Task Force has been submitted
and has allowed the Agency to reevaluate credits for soil organic matter. From these studies the
Agency has determined that soils with between 1% and 2% organic matter will get a 10% credit,
soils with between 2% and 3% organic matter will get a 20% credit, and greater than 3%, a 30%
credit. No credit will be given for soils with less than 1% organic matter. The credit for clay
content of greater than 27% will remain at 10%.
Dazomet buffer zone credits are additive and as since only the organic content and clay
content credits apply for dazomet, buffer zone credits will not exceed 40 percent (e.g., 40
percent credit would apply for using > 3 percent organic content and >27 percent clay content).
For example, if an application block is 10 acres and the applicator is planning to make an
incorporated application of 230 Ibs of dazomet per acre, the buffer distance from the look up
tables is 108 feet. If after the applicator tests the soil and determines the soil contains greater
than 27 percent clay content, then the buffer zone may be reduced by 10 percent. By calculating
10 percent of 108 feet (108 feet x 10% = 10.8 feet buffer credit) and then subtracting the original
buffer distance by the credit (108 feet - 10.8 feet = about 97 feet) the final buffer distance
required is 97 feet.
Other Buffer Zone Credits Considered
Currently the dazomet label allows for use of tarps when making applications, but there is
little information to suggest that growers are currently using tarps with dazomet. Since there is
no information available about how dazomet reacts with tarps, and since other data for metam
sodium suggests that standard tarps may not be very effective in trapping MITC vapors, there is
no tarp credit for dazomet at this time. If additional tarps or other emission factor data become
available to show the emissions from dazomet applications are decreased, the Agency will
consider adding those to the dazomet label. More information on the type of data the Agency is
looking for can be found in the Health Effects Division Recommendations for Fumigant Data
Requirements (J. Dawson, C. Smith, dated June 2008).
EPA (through OPP's Environmental Stewardship Branch) has co-funded a grant with
USDA-ARS for several flux studies in the southeastern U.S. These studies would provide (1)
field data on the emission reduction potential of certain low permeability barrier films to support
possible, additional, buffer reduction credits as well as to (2) help develop an affordable and
reliable hybrid field/lab test to evaluate the many barrier films available to growers. EPA has
also prepared a document to describe possible research and study designs to reduce uncertainties
in understanding emission factors in the context of different films and seals, agricultural
practices, and environmental conditions.7 These studies are scheduled to be completed in 2009
and data from these studies will be submitted to the Agency for review.
Other factors such as soil moisture content, field preparation, water sealing, and
application depth could not be used to justify credits based on the available data. However, EPA
7 Health Effects Division Recommendations for Fumigant Data Requirements. June 2008. DP Barcode 353724
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has established mandatory good agricultural practices (GAPs) for these conditions. See the GAP
section of this document for further discussion. If additional data on such emission reduction
methods becomes available, EPA will consider developing further credits.
2. Restriction for Schools and Other Difficult to Evacuate Sites
Certain types of sites are difficult to evacuate should an incident occur. EPA determined
that additional measures to reduce the potential need to evacuate these types of sites were
necessary to reduce risk of exposure to occupants and address potential challenges associated
with an accident. There were many comments on this measure including: requests to delete this
requirement; suggestions to reduce the size of the restricted area; a proposal to use a scalable
approach to calculate the distance; requests to define and refine the places included on this list so
that facilities such as research universities were excluded; suggestions to shorten the duration of
the requirement so applicators may be able to take advantage of weekends to fumigate; questions
about how to determine where these sites are located, and other suggestions to change the
required measures.
Based on a review of the comments, the Agency has retained this mitigation measure to
ensure the protection goals are still achieved and encourage lower-emission application methods.
This mitigation measure has been refined such that compliance is more effective in achieving the
protection goal. Modifications to this requirement include: shortening the duration of the
restriction so weekends may be used to fumigate near schools and day care centers; clarifying the
types of schools that are covered by this requirement; removing the term "elder care facilities"
from the list since many of the same facilities are included in the terms, " assisted living
facilities, nursing homes, and in-patient clinics;" and reducing the restricted area from 1/4 mile to
1/8 mile for application blocks with less than 300 foot buffers. The 1/8 mile (660 feet) distance
is more than twice the required buffer distance and remains protective of people who may be
difficult to evacuate while reducing the potential challenges of complying with the restrictions
for some users who may be fumigating in close proximity to these types of institutions. EPA has
determined that these modifications achieve the same protection goals as the 2008 RED but
provide additional clarity and flexibility that will enhance users' ability to practically and
effectively comply with the requirements. EPA also believes that reducing the restricted area for
blocks with buffers less than 300 feet will provide an incentive for some users to adopt lower-
emission application methods or practices. The revised measures are summarized below.
"Difficult-to-evacuate" sites include schools (preschool to grade 12), state licensed day
care centers, nursing homes, assisted living facilities, hospitals, in-patient clinics, and
prisons.
No fumigant application with a buffer zone greater than 300 feet is permitted within 1/4
mile (1320 feet) of the sites listed above unless the site is not occupied during the
application and the 36-hour period following the start of application.
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No fumigant application with a buffer zone of 300 feet or less is permitted within 1/8
mile (660 feet) of the sites listed above unless the site is not occupied during the
application and the 36-hour period following the start of application.
3. Posting
Posting is an effective means of informing workers and bystanders about areas where
certain hazards and restrictions exist. Current soil fumigant labels require treated areas to be
posted and handlers are required to wear specific PPE when they are in a treated area. For buffer
zones to be effective risk mitigation, bystanders, including agricultural workers in nearby areas,
need to be informed of the location and timing of the buffer zone to ensure they do not enter
designated areas.
In addition to alerting bystanders, posting a buffer zone will help handlers determine
where and when they are required to use PPE. As described in the Handler Section, handlers
working in treated areas or buffers during the buffer zone period must use label-specified PPE
and meet other requirements under the Worker Protection Standard (WPS). Therefore, EPA has
determined that to ensure the protectiveness of buffer zones for bystanders and handlers, the
perimeter of the fumigant buffer zones must be posted.
Comments received in response to the July 2008 RED decisions recommended some
changes to the posting requirements to make them easier to understand and implement. Based on
EPA's review and consideration of these comments, EPA has slightly revised the posting
requirements and provided additional clarification as described below.
EPA had included two exceptions for the buffer zone posting requirement. The first
exception did not require posting in situations where the land 300 feet from the edge of the
buffer was under the control of the property operator. Based on comments that this measure was
too complicated and confusing this exception has been removed. There were also comments that
the examples provided in the description of a physical barrier may lead to misinterpretation of
the requirement. EPA agrees and believes that a performance standard is a more effective means
of communicating the requirement. Therefore, to reduce the potential for confusion, the
examples have been removed.
In the 2008 RED, signs were required to be posted at usual points of entry and likely
routes of approach to buffer zones. If there were no usual points of entry or likely routes of
approach, then posting was required in the corners of buffer zones, and between the corners, so
signs could be viewed from one another. Many comments expressed concern over the burden
and potential confusion with the number of signs that may need to be posted and how many signs
may need to be posted depending on the configuration of the field. EPA agrees that signs posted
in areas where there is low likelihood of workers or others approaching or accessing the buffer
provide little risk reduction, but can add substantially to the challenges of compliance. As a
result, the Agency has revised the criteria for location of signs since the areas that are of most
concern are those where people are most likely to enter (e.g., roads, footpaths, etc.), and at likely
routes of approach such as the perimeter of a buffer that faces a housing development.
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Comments also indicated that the requirement to include certain application-specific
information on the posted signs would make reuse of the signs more difficult and would also
substantially increase the amount of time needed to prepare signs before posting. These
comments stated that the primary purpose of signs is to communicate to bystanders the buffer
zone locations. EPA generally agrees with these comments; therefore certain application-
specific details on the posted signs, like the date and time of the fumigation and buffer zone
restrictions, have also been reduced to allow the signs to be reused more easily.
Comments also stated that the posting example included in the 2008 RED was confusing.
Since the posting restrictions have been simplified by removing the distance criteria, the example
has been removed from this document. There were no substantive comments suggesting a
change to the exception for posting multiple contiguous blocks and no changes have been made
in this Amendment.
The revised posting requirements are listed below and have been included in the revised
label table.
Requirements
Posting of a buffer zone is required unless there is a physical barrier that prevents
bystander access to the buffer zone.
Buffer zone posting signs must:
o Be placed at all usual points of entry and along likely routes of approach from areas
where people not under the land operator's control may approach the buffer zone.
o Some examples of points of entry include, but are not limited to, roadways,
sidewalks, paths, and bike trails.
o Some examples of likely routes of approach are the area between a buffer zone and a
roadway, or the area between a buffer zone and a housing development.
Buffer zone posted signs must meet the following criteria:
o The printed side of the sign must face away from the treated area toward areas from
which people could approach.
o Signs must remain legible during entire posting period and must meet the general
standards outlined in the WPS for text size and legibility (see 40 CFR ง170.120).
o Signs must be posted before the application begins and remain posted until the buffer
zone period has expired.
o Signs must be removed within 3 days after the end of the buffer zone period.
o Registrants must provide generic buffer zone posting signs which meet the criteria
above at points of sale for applicators to use. The Agency is requiring registrants to
submit proposals for these materials through the data call-ins that will accompany this
RED.
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Exception: If multiple contiguous blocks are fumigated within a 14-day period, the entire
periphery of the contiguous blocks' buffer zones may be posted. The signs must remain posted
until the last buffer zone period expires and signs may remain posted up to 3-days after the
buffer zone period for the last block has expired.
Additional requirements for treated-area posting:
The treated area posted signs must remain posted for no less than the duration of the entry
restricted period after treatment.
Treated area signs must be removed within 3 days after the end of the entry-restricted
period.
Signs must meet the general standards in the WPS for placement, text size, and location
(40CFRง170.120).
Contents of Signs
The treated area sign (currently required for
fumigants) must state the following:
~ Skull and crossbones symbol
- "DANGER/PELIGRO,"
~ "Area under fumigation, DO NOT
ENTER/NO ENTRE,"
~ "Dazomet fumigant in USE,"
~ the date and time of fumigation,
~ the date and time entry prohibition is lifted
~ Name of this product, and
~ name, address, and telephone number of the
certified applicator in charge of the fumigation.
The buffer zone sign must include the
following:
Do not walk sign
- "DO NOT ENTER/NO ENTRE,"
~ "Dazomet OR [Name of product] Fumigant
BUFFER ZONE,"
~ contact information for the certified
applicator in charge of the fumigation
bb. Occupational Risk Mitigation
1. Handler Definition
Based on stakeholder comments provided during the Phase 5 comment period, the July
2008 RED clarified fumigation tasks that meet EPA's definition of handler activities, as
currently defined in the Worker Protection Standard (WPS) and on fumigant labels. During the
post-RED comment period the Agency received some comments from stakeholders who were
concerned that the Agency was redefining handlers. It was not the Agency's intention to change
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the current definition. As a result, the Agency has slightly changed the language from the July
2008 RED so it is clear that the Agency is just clarifying the existing definition and not writing a
new definition. Below is the revised language.
The following activities are prohibited from being performed in the fumigant
application block or surrounding buffer zone during the buffer zone period by anyone
other than persons who have been appropriately trained and equipped as handlers in
accordance with the requirements in the WPS (40 CFR Part 170), from the start of the
application until the entry-restricted period ends. Those activities include those persons:
Participating in the application as supervisors, loaders, drivers, co-pilots, shovelers,
shovel ditchers, or as other direct application participants (note: the application starts
when the fumigant is first introduced into the soil and ends after the fumigant has stopped
being delivered/dispensed to the soil);
Using devices to take air samples to monitor fumigant air concentrations;
Persons cleaning up fumigant spills (this does not include emergency personnel not
associated with the fumigation application);
Handling or disposing of fumigant containers;
Cleaning, handling, adjusting, or repairing the parts of fumigation equipment that may
contain fumigant residues;
Installing, repairing, or operating irrigation equipment in the fumigant application block
or surrounding buffer zone during the buffer zone period;
Entering the application site or surrounding buffer zone during the buffer zone period to
perform scouting or crop advising tasks;
Installing, perforating (cutting, punching, slicing, poking), removing, repairing, or
monitoring tarps:
o until 14 days after application is complete if tarps are not perforated and removed
during those 14 days, or
o until tarp removal is complete if tarps are both perforated and removed less than
14 days after application; or
o until 48 hours after tarp perforation is complete if they will not be removed within
14 days after application.
In addition to the above, persons outside the perimeter of the buffer zone who monitor
fumigant air concentrations must also be trained and equipped as handlers in accordance
with the requirements in the Worker Protection Standard (40 CFR Part 170).
2. Handler Requirements
Since many incidents are caused by human error and equipment failure, EPA believes the
presence of on-site trained personnel would help to reduce these risks. To address these risks,
the July 2008 RED required that (1) a certified applicator must supervise all fumigant handlers
during the entire period that the person is performing a fumigant handling task within the treated
field or within the buffer zone, (2) the person monitoring another handler could also be engaged
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in fumigant handling tasks during the monitoring period, and (3) the certified applicator
supervising dazomet applications could perform all tasks without anyone supervising them.
In addition to certified applicator supervision, in the July 2008 RED, the Agency required
that a minimum of two WPS-trained handlers remain on site when handlers are fixing tarps,
moving irrigation equipment, and/or performing other handler tasks as defined above. This
mitigation measure was put in place to address the possibility that handlers could be overcome
with the vapors and have difficulty leaving the area while they are performing these tasks. The
Agency is removing this handler requirement for the MITC generating chemicals since the
hazard profiles are not the same for all the soil fumigants. With MITC-generating compounds,
EPA believes eye or sensory irritation would likely be felt in sufficient time for a handler to
leave the area or put on a respirator, before more serious effects occur. With chloropicrin, in
contrast, as indicated by precautionary statements on current labels, a handler may be overcome
more quickly, justifying the presence of another person to provide assistance if needed.
During the post-RED comment period the Agency received many comments that stressed
the difficulty implementing a requirement that mandates certified applicators to maintain visual
contact with handlers. The commenters also indicated that for longer applications this
requirement would be significant burden. Other stakeholders stated that the Agency needs to
modify the requirement to ensure that the certified applicator is on site while others believe EPA
should require that all handlers are certified applicators, which would eliminate the need for
direct handler supervision.
The Agency has considered the comments and has revised the certified applicator
requirement by specifying different requirements for different applications. EPA believes that
these revisions accomplish the same goal as the July 2008 RED mitigation while reducing the
burden on users. The revised language is:
For ground-rig applications (e.g., shank, rototiller, and spray blade), from the start of the
application until the fumigant has stopped being delivered/dispensed into the soil (e.g.,
soil is sealed) the certified applicator must be at the fumigation site and must directly
supervise all persons performing handling activities.
For fumigant handling activities that take place after the fumigant has been
delivered/dispensed into the soil until the entry restricted period expires, the certified
applicator must communicate in writing to the site owner/operator and other handlers
information necessary to comply with the label and the FMP (e.g., emergency response
plans and procedures).
The July 2008 RED also required that certified applicators supervising the application
completed a registrant administered dazomet training program within the preceding 12 months
before they applied a dazomet product. The Agency is still requiring certified applicators to
complete the registrant training; however, the Agency is now requiring the certified applicators
successfully complete the training every three years. Please see the Soil Fumigation Training for
Applicators and Other Handlers section for further.
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3. Dermal Protection for Handlers
The dazomet dermal risk assessment indicated potential risks of concern for handlers for
some scenarios. For handlers loading and applying dazomet for tractor drawn spreaders, there
were potential risks for short term exposures assuming applications to 80 acres per day.
According to information from the registrant in the phase 3 comments, dazomet is not typically
applied to large acreages, but more typically applied to blocks 5-20 acres in size. The Agency is
prohibiting applications to block sizes over 40 acres, so the short term concerns for dermal risk
to handlers loading and applying with tractor drawn spreaders does not present unreasonable
adverse effects.
For intermediate term dermal risk, there are potential risk concerns for loaders and
applicators, with MOEs below 100, the intermediate dermal LOG. MOEs for loaders range from
13 for handlers wearing baseline PPE, up to 650 for handlers using closed systems. For
applicators, there is only data for handlers applying with closed cabs, and the MOE is 52 for a 40
acre field. Due to the amount of dazomet applied, and the small area it is typically applied to, it
is not likely a single handler will be exposed to the amount assumed in the risk assessment over
the intermediate time frame of 1 to 6 months. Current dazomet labels require handlers to wear
double layers (coveralls over short-sleeved shirt and short pants) and chemicals resistant gloves
to protect from dermal exposures. The Agency does not calculate risks with this level of PPE
since there is no data to assess coveralls over short-sleeved shirt and short pants. However, since
the current labels require this level of protection, the short-term risks were acceptable and the
amount of dazomet exposure assumed in the intermediate term assessment are higher than would
be expected based on dazomet's use patterns, the Agency is requiring all handlers to wear double
layers consisting of coveralls over short-sleeved shirt and short pants with gloves. In addition,
handlers will have an option to reduce the dermal protection if application equipment (i.e.,
enclosed cabs) that provides dermal protection is used.
For hand held applications there are potential dermal risks of concern when making
applications with baseline PPE. The registrants have indicated that they will not be continuing to
support applications with hand held equipment, and labels will be amended to prohibit hand held
equipment.
4. Respiratory Protection for Handlers
The Agency's human health risk assessment for dazomet indicates that inhalation risks
for many handler tasks exceed the Agency's LOG for the acute exposure to the parent (dazomet)
and MITC. In the 2008 Dazomet RED, the Agency required handlers potentially exposed to
MITC vapors from dazomet applications to either wear at least a half-face respirator during the
handling activity, or follow the monitoring program detailed below. In addition, the Agency
required that for some handling tasks, respirators were required to be worn at all times due to the
short duration of the task and the potentially high concentration of MITC exposure. The certified
applicator supervising the fumigant application must ensure that any handler who enters the
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buffer zone (including tractor drivers, loaders, irrigators, tarp cutters, removers, etc.) is either
wearing respiratory protection or is following the handler monitoring requirements, with
respirators immediately available to each handler.
During the post-RED comment period, the Agency received several comments on the
Respiratory Protection for Handlers section. For MITC, comments focused on the feasibility of
using colormetric tubes, due to the current sensitivity and accuracy of the tubes; the cost of the
tubes; and the Agency's trigger level of 100 ppb, which some commenters questioned, given that
the Agency's level of concern for acute MITC exposures is 22 ppb. Some comments also
suggested that rather than wear respirators, fumigators should have the option of ceasing the
application until air concentrations of MITC are less than the action level.
After reviewing the comments, the Agency has determined that respiratory protection is
still needed to mitigate risks to dazomet handlers if concentrations of MITC reach a certain level;
however, EPA is revising the required procedures for determining when respirators must be used
due to technological limitations of currently available monitoring devices that are appropriate for
field use. EPA believes that while colorimetric tubes are likely to be reliable at higher
concentrations and when used in more static conditions (e.g., a warehouse or laboratory), under
the dynamic conditions characteristic of outdoor field fumigation, currently available devices
provide somewhat less reliable information about concentrations relative to EPA's action level,
which is below the levels for which the devices are rated.
The Agency is aware of several commercial systems for monitoring MITC, including
colormetric tubes from the following manufacturers: Sensidyne and Dragaer. While these tubes
have detection limits of at least 100 ppb, based on commenters' experience and the accuracy of
the tubes (e.g., some tubes have a standard deviation plus or minus 20-30%), the Agency
believes it is possible that handlers will experience sensory irritation before the monitoring
device shows a level of concern. As such, the Agency does not believe that initial monitoring to
trigger the use of respirators significantly reduces handler risks. EPA is also concerned that
monitoring with devices that are not reliable could cause handlers to believe that concentrations
are below the action level despite other indications (eye irritation). As a result, the Agency is
removing the initial monitoring requirement. In addition, EPA is aware that monitoring with
these devices adds significant costs to fumigations. For additional details please see the
following document: Analysis of Soil Fumigant Risk Management Requirements using
Geographic Information Systems: A Case Study for the Forest Seedling Industry, dated May 13,
2009, located in the dazomet docket..
EPA does believe, however, that monitoring devices that are currently available will
generally be reliable at higher concentrations of MITC and that there is high value in air
monitoring using currently available devices in certain situations. As a result, EPA is
maintaining the requirement for colorimetric tube monitoring once use of respirators has been
triggered and respirators are being worn. This will enable handlers to detect concentrations that
would exceed the upper working limit of the respirator. Additionally monitoring will still be
required to help enable handlers to determine if concentrations have decreased and whether it is
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safe to either remove respirators or to resume the application if the fumigator has opted to cease
the application rather than wear respirators.
The Agency is modifying the procedures for respiratory protection because of
technological limitations of currently available devices. However, the Agency does believe that
quantitative air monitoring would enhance worker safety if the appropriate technology were
available. Some equipment manufacturers have indicated interest in developing devices that
would be more functional and reliable for field fumigation applications (e.g., badge-type
monitors). EPA encourages such efforts and plans to stay abreast of developments and
improvements in monitoring devices and will consider this issue again in registration review or
sooner should such monitors become available in the short term.
Since the Agency has removed the initial monitoring requirement, regulating at an action
level of 100 ppb is no longer appropriate since this level was based on the detection limit of the
currently available MITC monitoring tubes. Due to the reliability issue previously, instead, the
Agency is using an action level of 600 ppb which corresponds to early signs of exposure and
effects are non-severe and reversible at this level. .The Agency believes that this level is
effective as a warning for handlers of when concentrations are reaching the point where steps are
needed to protect fumigant handlers.
Respiratory Requirements
The following procedures must be followed for all agricultural pre-plant soil applications
of dazomet. In addition to the respiratory protection requirements, the Agency believes that
GAPs, FMPs, and other mitigation measures will reduce inhalation risks from MITC to levels
below the EPA's level of concern.
If at any time any handler experiences sensory irritation (tearing, burning of the eyes or
nose) then either:
o An air-purifying respirator (APR) must be worn by all handlers who remain in the
application block and surrounding buffer zone, or
o Operations must cease and handlers not wearing respiratory protection must leave
the application block and surrounding buffer zone.
Handlers can remove respirators or resume operations if two consecutive breathing-zone
samples taken at the handling site at least 15 minutes apart show that levels of MITC
have decreased to less than 600 ppb, provided that handlers do not experience sensory
irritation. Samples must be taken where the irritation is first experienced.
When respirators are worn, then air monitoring samples must be collected at least every 2
hours in the breathing zone of a handler performing a representative handling task.
If at any time: (1) a handler experiences any sensory irritation when wearing a respirator,
or (2) an air sample is greater than or equal to 6000 ppb, then all handler activities must
cease and handlers must be removed from the application block and surrounding buffer
zone. If operations cease the emergency plan detailed in the FMP must be implemented.
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Handlers can resume work activities without respiratory protection if two consecutive
breathing-zone samples taken at the handling site at least 15 minutes apart show levels of
MITC have decreased to less than 6000 ppb, provided that handlers do not experience
sensory irritation.
During the collection of air samples an air-purifying respirator must be worn by the
handler taking the air samples. Samples must be taken where the irritation is first
experienced.
Work activities may resume if the following conditions exist provided that the
appropriate respiratory protection is worn:
o Two consecutive breathing zone samples for MITC taken at the handling site at
least 15 minutes apart must be less than 600 ppb,
o Handlers do not experience sensory irritation while wearing the APR, and
o Cartridges have been changed.
o During the collection of air samples an air-purifying respirator must be worn by
the handler taking the air samples. Samples must be taken where the irritation is
first experienced.
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Figure 3 provides an illustration of the requirements when handlers cease operations.
Handler activity begins. Handlers
are NOT wearing APRs.
^
r
Sensory Irritation
T
r
Certified applicator in charge
decides to cease operations rather
than continue with respirators.
i
r
Handlers must stop work and
leave application block and buffer
zone.
i
r
If 2 samples taken at least 15
minutes apart (by a handler
wearing an APR) show
concentrations are less than 600
ppb and NO sensory irritation,
then
i
r
Resume operations.
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Figure 4 provides an illustration of the requirements when handlers put on a respirator.
Handler activity begins. Handlers
are NOT wearing APRs.
Sensory Irritation
Certified applicator in charge
decides to continue operations.
All handlers in the application
block and buffer zone put on an
APR. Air monitoring program
begins.
Feel irritation through APR, OR
monitoring indicates
concentrations above 6000 ppb.
Handlers must stop work and
leave application block and buffer
zone.
If, 2 consecutive samples taken at
least 15 minutes apart, by a
handler wearing an APR are
above 600 ppb BUT below 6000
ppb, no sensory irritation is felt,
and the cartridge is changed, then
Resume operations wearing an
APR. Air monitoring continues.
If 2 consecutive samples taken at
least 15 minutes apart, by a
handler wearing an APR, are less
than 600 ppb and NO sensory
irritation, then
Resume operations without an
APR or remove respirator.
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Respiratory Protection Equipment
In the July 2008 RED, the Agency required handlers to wear an air purifying respirator
approved for MITC with a protection factor (PF) of 10. For additional clarity, even though
currently there are no air-purifying respirator cartridges certified by the Mine Safety and Health
Administration-National Institute for Occupational Safety and Health (MSHA-NIOSH) for
protection against MITC, NIOSH/OSHA does recommend respirators with organic vapor
cartridges for MITC use, and the Agency is requiring half-face respirators with organic-
cartridges be used when a respirator is necessary; the Agency will consider other APR-cartridges
combinations provided written certification of their efficacy against MITC is provided to the
Agency. The EPA assumes that half-face respirators have a protection factor of 10, therefore, the
respiratory protection will only be protective up to MITC concentrations of 6000 ppb, and if
concentrations exceed 6000 ppb (or if eye irritation occurs), operations must cease. At air
concentrations greater than 6000 ppb, the respirator is not designed to protect handlers from
inhaling more than 600 ppb of MITC. Therefore, the handler must continue to monitor once
respirators are donned. If concentrations of MITC exceed 6000 ppb or if eye irritation occurs,
then the operations must cease until levels of MITC are measured to be below 600 ppb from
consecutive air samples.
The Agency did receive comments regarding the cartridge recommendations, the
recommended equipment, and the assumed respirator protection factor. All of these comments
are addressed in detail in the following document located in the dazomet docket: Methyl
Bromide, 1,3-Dichloropropene, Chloropicrin, Dazomet, Metam Sodium/Potassium, MITC:
Health Effects Division (HED) Component of Agency Response To Comments On 2008
Reregistration Eligibility Documents (Dated May 14, 2009). The Agency would like to clarify
issues regarding the respiratory protection cartridges and respirators. Comments suggested that
the Agency require organic-vapor cartridges. This was the Agency's intention in the July 2008
RED. Others commented on the use of full-face respirators and goggles. The Agency is still
recommending the use of organic-vapor cartridges when protection is required.
Respirator fit testing, training, and medical qualification
As detailed in the July 2008 RED, the respirator protection factor described above in the
Respiratory Protection Equipment section is based on the following assumptions: 1) the
respirator is fit-tested, 2) proper respirator training occurs, and 3) an annual medical evaluation
and clearance is completed. Without these requirements, it is unclear whether the reduction in
inhalation exposure that is assumed by the protection factor will be achieved. In order to ensure
that the respiratory protection EPA is assuming is being achieved in the field, respiratory
requirements will include fit testing, respirator training, and annual medical evaluation.
During the post-RED comment period, the Agency received a variety of comments
ranging from full support of the requirement, to comments about the cost and time burden
associated with the requirement. The Agency also received several comments regarding the
details of this requirement, for example who conducts the fit-testing and medical exam and what
the medical exam entails. Detailed responses to the general requirements are included in the
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following document: SRRD 's Response to Post-RED Comments for the Soil Fumigants, dated
May 20, 2009 located in the dazomet docket.
While EPA recognizes that there is a cost associated with the fit-testing, training, and
medical exam requirement the Agency still believes that respirator fit-testing, training, and
medical exams are a necessary part of the mitigation package. Since the Agency is now offering
a cease operations option where handlers can leave the application block and surrounding buffer
zone in lieu of putting on an air-purifying respirator, the Agency is only requiring that handlers
who wear a respirator are fit-tested, trained, and medically examined. The Agency believes that
this revision will reduce the cost associated with this requirement while still keeping the same
level of protection for the handlers that wear respirators. The following language must be added
to product labels:
"Employers must also ensure that any handler who uses a respirator is:
Fit-tested and fit-checked using a program that conforms to OSHA's requirements (see
29CFR Part 1910.134)
Trained using a program that confirms to OSHA's requirements (see 29CFRPart 1910.134)
Examined by a qualified medical practitioner to ensure physical ability to safely wear the
style of respirator to be worn. A qualified medical practitioner is a physician or other
licensed health care professional (PLHCP) who will evaluate the ability of a worker to wear a
respirator. The initial evaluation consists of a questionnaire that asks about medical
conditions (such as a heart condition) that would be problematic for respirator use. If
concerns are identified, then additional evaluations, such as a physical exam, might be
necessary. The initial evaluation must be done before respirator use begins. Handlers must
be reexamined by a qualified medical practitioner at least annually or if their health status or
respirator style or use-conditions change."
Respirator availability
The handler employer must confirm and document in the FMP that enough air-purifying
respirators and cartridges are available for each handler that wears an air-purifying respirator.
The Agency is requiring that at minimum two handlers have the appropriate respirator and
cartridges available and that these handlers are fit-tested, trained, and medically examined.
Tarp Repair
The July 2008 RED required handlers to wear APRs if they perform tarp repair
operations before the entry-restricted period has ended. The requirements were different from
other handling activities because the duration of tarp repair activities was believed to be shorter
than other handling tasks and therefore tarp repair activities would not trigger the initial
monitoring requirement. Upon consideration of comments the Agency received on this
requirement, EPA has determined that respiratory protection for tarp repair activities should be
handled consistently with other handler activities, i.e., handlers repairing tarps are not required to
wear respirators unless sensory irritation is experienced. Additionally, the Agency believes that
tarp repair like other handling activities described above would benefit from the development of
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sensitive monitoring devices to reliably inform handlers if and when concentrations are above
the action level for respiratory protection. EPA will reevaluate this measure during Registration
Review or sooner if such devices are available in the short term.
5. Tarp perforation and removal
The Agency's risk assessment indicates that there is a risk concern for handlers during
the perforation (cutting, poking, punching, or slicing) and removal of tarps, and notes potential
for increased risk when high barrier tarps are used. To address these risks EPA required the
following mitigation in the July 2008 RED:
Tarps cannot be perforated until a minimum of 5 days (120 hours) after fumigation was
complete.
Tarps cannot be removed until 24 hours after tarp perforation is complete.
If tarps are not removed after perforation, planting cannot start until 48 hours after
perforation is complete.
If tarps are left intact for at least 14 days after the fumigation is complete then planting
can take place as tarps are being perforated.
Broadcast tarps could be removed before 5 days if adverse weather compromised the
integrity of the tarp provided that at least 48 hours had passed since the fumigation was
completed, the buffer zone was extended until 24 hours after the tarp removal was
complete, and untreated areas in the application block are not treated for at least 24 hours
after tarp removal is complete.
Tarp perforation must be done using mechanical methods.
Each broadcast tarp panel must be perforated using a lengthwise cut.
During the post-RED comment period the Agency received comments on the tarp
perforation and removal requirements. In particular the Agency received comments on: the
adequacy of the 5 day requirement for high barrier tarps to protect workers; the feasibility of
leaving tarps down for 5 days in areas that use seepage irrigation; the difficulty implementing the
24 hour period between tarp perforation and removal; and concerns regarding the weather
condition exceptions, mechanical perforation, and broadcast panel perforation.
There is some uncertainty regarding potential risks if high barrier tarps are perforated
after 5 days. This is because worker exposure data used in the risk assessments are generally
based on what has been the industry standard tarping technology, i.e., low or high density
polyethylene tarps, typically with higher application rates and no significant emphasis on using
the GAPs as defined in the RED. Data indicate that high barrier tarps are effective measures to
reduce fumigant emissions (see Methyl Bromide (PC Code 053201), Chloropicrin (PC Code
081501), Dazomet (PC Code 035602), Metam Sodium and Potassium (PC Codes 039003 &
039002), MITC (PC Code 068103), Updated Health Effects Division Recommendations for
Good Agricultural Practices and Associated Buffer Credits located in the dazomet docket).
While this reduction decreases the risk to bystanders, it could increase the risk to handlers
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perforating or removing tarps because more fumigant could be trapped between the soil surface
and the tarpcurrently California Department of Pesticide Regulation (CDPR) prohibits the use
of methyl bromide with certain high barrier tarps due to worker concerns.
Based on CDPR's prohibition and stakeholder's comments, EPA considered requiring a
longer interval such as 10 days before allowing high barrier tarps to be perforated. However,
EPA was concerned that adding such a requirement could discourage fumigators from using high
barrier tarps which potentially allow for lower application rates and reduce bystander risk
associated with offgassing. New studies currently underway which involve use of high barrier
tarps may enable EPA to refine estimates of handler risk in the future. EPA will consider these
data during Registration Review, or sooner as the information becomes available.
Since the Agency has designed the mitigation measures to work together and believes
that measures to address handler risks are likely to protect these handlers when the reduced rates
are considered in conjunction with other measures such as respiratory protection, GAPs, FMPs,
and training, EPA is not increasing the number of days before high barrier tarps can be
perforated.
In the comment period EPA learned from stakeholders that leaving the tarps on for 5 days
would pose problems for current flood prevention activities. According to the comment, for
flood prevention fields must be properly drained. In order to ensure proper drainage tarps must
be manually cut, soil removed, and then tarps retucked. The Agency understands that the 5 day
requirement before tarps can be perforated and the restriction on manual tarp perforation would
be difficult for this situation and the Agency has added language to address this situation.
During earlier comment periods EPA heard from various stakeholders that windy
conditions sometimes caused tarps to blow off fields and create other hazards, e.g., to motorists
on nearby roadways. As a result, in the July 2008 RED the Agency provided an exception to
allow tarps to be removed after 48 hours under adverse weather conditions. During the post-
RED comment period EPA received comments that this exception did not fully address the issue
since the mitigation required waiting a minimum of 48 hours after fumigation but tarps could
blow of fields sooner than that. Commenters also said waiting 24 hours between tarp perforation
and removal and the requirement to cut every broadcast tarp panel added to the potential for tarps
to blow off fields and create other hazards: once tarps are cut they are prone to blowing off
when windy conditions occur. To decrease the potential of tarps blowing off, commenters also
suggested that the Agency add flexibility to the 24 hour requirement by giving tarp removers the
option to remove tarps 2 hours after tarp perforation if monitoring indicated levels below the
Agency's LOG. Commenters also suggested that every 1-3 tarp panels should be cut based on
the professional judgment of the handler.
Upon review of the comments the Agency agrees that the mitigation should be revised
somewhat to allow for tarp removal at any time if the tarp is no longer performing its intended
function and it is creating other types of risk. Therefore, EPA is revising the exception outlined
in the RED to address these comments. EPA notes that handlers undertaking these tasks must
follow the respiratory protection procedures detailed in Section 4 (Respiratory Protection for
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Handlers); this change still provides handler protection while reducing the unintended
consequences of tarps creating other hazards.
The Agency believes cutting every panel allows the fumigant trapped beneath each panel
to off-gas before the tarp is removed. If each panel is not cut, it is not likely that necessary off-
gassing can take place to reduce risks to handlers removing tarps. The Agency understands that
the main concern for not cutting every panel is due to the potential for tarps to blow off and has
determined that this concern is best addressed by modifying the 24-hour wait period. Tarps may
be removed 2 hours after tarp perforation is complete provided that tarp removers follow the
procedures set forth in the (cite respiratory protection section); therefore the risk to handlers will
not increase as a result of this modification. EPA considered the suggestion to monitor before
tarp removal begins; however, because of technical limitations with current technology the
Agency did not include monitoring as part of the mitigation. As with the respiratory protection
section, the Agency sees the value in a monitoring program if reliable and accurate devices are
available and will consider monitoring during Registration Review or sooner if information
becomes available.
The Agency received comments supporting the requirement for mechanical tarp
perforation, though other commenters stated that for some situations mechanical cutting is not
feasible. Examples cited included at the start of a row when a mechanical device such as an
ATV will be used to cut the tarps on the field, during flood prevention activities, and for small
fields. Based on comments, EPA believes these are necessary short-duration activities. Provided
the respiratory protection procedures for handlers are followed, these activities would not
increase the risk to handlers. With regard to small fields where mechanical cutting is not
feasible, the Agency considered the duration of the activity and the respiratory protection
considerations and will permit manual perforation only for application blocks that are 1 acre or
less in size.
As a result of the Agency's review and consideration of comments, the following
summarizes the revised mitigation measures to address inhalation risks from tarp perforation and
removal activities:
As described in the Handler Definition section of this document, tarp perforators and
removers are considered handlers for a specified duration and every handler must adhere
to the respiratory protection procedures outlined in the Respiratory Protection section of
this document.
Tarps must not be perforated until a minimum of 5 days (120 hours) have elapsed after
the fumigant injection into the soil is complete (e.g., after injection of the fumigant
product and tarps have been laid or after drip lines have been purged and tarps have been
laid), unless a weather condition exists which necessitates the need for early perforation
or removal See Early Tarp Removal for Broadcast Applications Only and Early Tarp
Perforation for Flood Prevention Activities sections below.
If tarps will be removed before planting, tarp removal must not begin until at least 2
hours after tarp perforation is complete.
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If tarps will not be removed before planting, planting or transplanting must not begin
until at least 48 hours after the tarp perforation is complete.
If tarps are left intact for a minimum of 14 days after fumigant injection into the soil is
complete, planting or transplanting may take place while the tarps are being perforated.
Each tarp panel used for broadcast fumigation must be perforated.
Tarps used for fumigations may be perforated manually ONLY for the following
situations:
o At the beginning of each row when a coulter blade (or other device which
performs similarly) is used on a motorized vehicle such as an ATV.
o In fields that are 1 acre or less.
o During flood prevention activities
In all other instances tarps must be perforated (cut, punched, poked, or sliced) only by
mechanical methods.
Tarp perforation for broadcast fumigations must be completed before noon, (seepage
irrigation exception)
For broadcast fumigations tarps must not be perforated if rainfall is expected within 12
hours.
Early Tarp Removal for Broadcast Applications Only:
o Tarps may be removed before the required 5 days (120 hours) if adverse weather
conditions have compromised the integrity of the tarp, provided that the
compromised tarp poses a safety hazard. Adverse weather includes high wind,
hail, or storms that blow tarps off the field and create a hazard, e.g., tarps blowing
into power lines and onto roads. A compromised tarp is a tarp that due to an
adverse weather condition is no longer performing its intended function and is
creating a hazard.
o If tarps are removed before the required 5 days have elapsed due to adverse
weather, the events must be documented in the post fumigation summary section
oftheFMP.
Early Tarp Perforation for Flood Prevention Activities
o Tarp perforation is allowed before the 5 days (120 hours) have elapsed if rain
necessitates field drainage.
o Tarps must be immediately retucked and packed after soil removal.
6. Entry Prohibitions
Current dazomet labels allow reentry to the treated field by workers 24 hours after
application. The risk assessment indicates that risks could exceed EPA's LOG for workers
entering fields at this time period. In addition, stakeholder comments prior to the July 2008 RED
indicated that non-handler entry to perform post-application (i.e., non-handler) tasks is generally
not needed for at least 10 to 14 days following the completion of the application.
Due to the volatile nature of MITC and the potential for exposure to unprotected workers,
in the July 2008 RED the Agency restricted entry into the treated area by anyone other than a
properly trained and protected handler. This restriction differs from Restricted Entry Intervals
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(REIs) that is currently required for most conventional pesticides where dermal exposure is the
primary pathway of exposure. Under the Worker Protection Standard (WPS), exceptions allow
certain tasks to take place before the REI has expired as long as dermal contact with treated
surfaces will be limited; however for fumigants where inhalation exposure is the primary risk
concern, entry to a treated area is further restricted.
During the post-RED comment period the Agency received some comments that
expressed concern that extending the entry-restricted period for fumigants could prevent certain
important activities from taking place, contrary to the comments received during earlier
comment periods. Based on discussions with stakeholders, EPA's review of public comments,
and the risks identified in EPA's risk assessment, EPA does not believe any change to the entry-
restricted period is warranted. EPA's review of comments indicates that extending the entry-
restricted period to protect workers will not have a substantial impact on agricultural operations.
Therefore, the Agency is not making any changes to this section of the July 2008 RED. The
mitigation is listed below.
EPA believes that risks will not exceed the Agency's LOG provided entry (including
early entry that would otherwise be permitted under the WPS) by any person - other than a
correctly trained and PPE-equipped handler who is performing a handling task - is prohibited
from the start of the application until:
5 days (120 hours) after application has ended for untarped applications (Figure 5), or
After tarps are perforated and removed if tarp removal is completed less than 14 days
after application (Figure 6), or
48 hours after tarps are perforated if they will not be removed prior to planting (Figure 7),
or
5 days (120 hours) after application is complete if tarps are not perforated and removed
until 14 days after the application is complete (Figure 8).
Figures 5, 6, 7, and 8 provide illustrations of tarp perforation/removal and entry prohibition
mitigation required for various dazomet applications. The intervals depicted are the minimum
that must be followed.
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FigureS. Untarped Applications
5 days (120 hours)
48 hours
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Figure 6. Tarp Broadcast Applications (tarps removed before planting)
5 days (120 hours)
Tarp
Perforation
Begins
Tarp
Perforation
Ends
2 hours
Tarp
Removal
Begins
Tarp
Removal
Ends
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Figure 7. Tarp Bed Applications (Tarps not removed before planting)
5 days (120 hours)
Tarp
Perforation
Begins
Tarp
Perforation
Ends
48 hours
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Figure 8. Tarp Bed/Broadcast Applications (Tarps are not perforated until 14 days after
application)
5 days (120 hours)
14 days
cc. Other Risk Mitigation
Below are requirements for FMPs, GAPs, emergency preparedness and response, notice
to state lead agencies, training, and community outreach and education that the Agency
concludes are needed to mitigate risks and the likelihood of incidents caused by human error,
equipment failure, and weather events such as temperature inversions.
1. Restricted Use Classification
All soil fumigant products containing methyl bromide, 1,3-dichloropropene (1,3-D),
iodomethane, and chloropicrin are currently classified as RUPs. Soil fumigant products
containing dazomet and metam sodium/potassium are currently unclassified. However, MITC,
the byproduct of dazomet and metam sodium/potassium, has characteristics that meet the criteria
for restricted use for both human hazard criteria (as specified in 40 CFR 152.170(b)) and from
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other evidence (as specified in 40 CFR 152.170(d)) including the use history and incident data
from exposure to MITC.
Human Hazard Criteria
The acute toxicity profile of MITC shows it is more acutely toxic (toxicity categories are
all I or II) than dazomet (mostly toxicity categories III and IV. While the product toxicity of
dazomet does not meet the hazard criteria for classification as restricted use, the degradate
product of MITC, that both handlers and bystanders can be exposed to, does meet the criteria.
Other Evidence
If any soil fumigant is not applied correctly, bystanders may be exposed to concentrations
that exceed levels of concern and that could cause significant adverse effects. There is a history
of incidents involving fumigants in which multiple bystanders experienced illness/injury despite
being several hundred to several thousand feet from the treated area. The application of soil
fumigants can pose risk for several hours from the time of application to several days after
application. Depending on the situation, worker and/or area air monitoring may be required to
ensure that exposure limits are not exceeded. Special equipment is often needed to apply soil
fumigants safely and accurately (e.g., compaction rig, tarp equipment, and self-contained
breathing apparatus). To apply soil fumigants safely and ensure bystanders and applicators are
not adversely affected, handlers also need specialized competencies.
In sum, dazomet meets the standard for restricted use because:
The application of fumigants involves complex operations requiring specialized training
and/or experience.
Fumigant label directions call for specialized apparatus and protective equipment that is
not available to the general public.
A minor failure to follow label directions may result in severe adverse effects.
Even if directions for use are followed, use may result in discernible adverse effects, of
both direct and indirect nature, on non-target organisms.
Therefore, the Agency has determined that all dazomet soil fumigant products must be classified
as restricted use. Label requirements will include the following, which is also contained in Table
9. This requirement has not changed from the July 2008 RED.
Requirement on Labels
"Restricted Use Pesticide Due to acute inhalation toxicity to humans."
"For retail sale to and use by Certified Applicators or persons under their direct supervision and
only for those uses covered by the Certified Applicator's certification."
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In order to ensure that a certified applicator is at the application site, the label will also
state, "the certified applicator supervising the application must be at the fumigant application site
and able to maintain visual contact with every handler participating in the application starting
when the fumigant is first introduced into the soil and ending after the fumigant has stopped
being delivered/dispensed to the soil and the soil is sealed."
2. Good Agricultural Practices
Since the application methods and work practices of fumigators have direct impacts on
the amount of fumigant applied and emitted, the Agency determined that labeling should require
proven practices that will reduce risks to handlers, bystanders, and the environment. Registrants,
applicators, growers, and other stakeholders have consistently reported to the Agency that GAPs
are a key mitigation measure to reduce the amount of fumigants applied and fumigant emissions.
The purpose of this section in the July 2008 RED was to specify good agricultural
practices (GAPs) that were required for soil applications of dazomet. The practices specified
contribute to reducing emissions and thereby are expected to reduce potential for worker and
bystander exposures.
The Agency received comments regarding the GAPs outlined in the July 2008 RED.
These comments addressed a range of topics:
making the GAPs voluntary rather than mandatory label requirements,
buffer zone credits associated with GAP implementation,
wind speed requirements and the description of inversion conditions,
crop residue requirements,
application equipment requirements,
soil moisture and temperature requirements,
flexibility in the event that new GAPs are developed,
enforceability of GAPs,
university research exemptions, and
These comments are addressed in detail in the Special Review and Reregi strati on
Division's response to comments document. Based on the comments, the Agency has revised
some of the GAPs.
The GAPs outlined in the RED and this RED amendment have been shown to reduce
emissions and bystander exposures and will continue to be mandatory label requirements. Buffer
zone credits have been reanalyzed and additional credits have been calculated for various GAPs
depending on the soil fumigant used (see buffer zone credit section).
The Agency has clarified the language regarding inversions and wind speed
requirements. The Agency agrees that erosion control is an important consideration. However,
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removing the crop residue prior to fumigation is important to limit the natural "chimneys" that
will occur in the soil when crop residue is present. These "chimneys" allow the soil fumigants to
move through the soil quickly and escape into the atmosphere. This may create potentially
harmful conditions for workers and bystanders and will limit the efficacy of the fumigant. To
accommodate both of these important considerations (erosion control and human health
protection), the Agency encourages that the field be cleared of crop residue as close to the timing
of the fumigation as possible to limit the length of time that the soil would be exposed to
potentially erosive weather conditions.
The following are mandatory GAPs that already appear on dazomet product labels. Some
of the measures have been updated to clarify the language and be consistent among the fumigant
chemical product labels.
Do not use dazomet when the soil temperature is extremely high (over 90ฐ F at 2"deep).
Do not apply dazomet if ambient air temperature exceeds 103ฐ F.
Do not apply within 3-4 feet of growing plants or closer than the drop line of trees and
large shrubs. If slopes are treated with this product, take precautions to prevent the
chemical from washing downward to growing plants.
The area intended for treatment should be in seedbed condition with a fine tilth, free of
clods. Do not apply dazomet to dry or improperly tilled soil. Repeated cultivation before
treating will improve control of perennial weeds. Ditching around the site will prevent
weed seeds, nematodes, and fungi from washing into the treated area and contaminating
it.
For optimal effect, the soil to be fumigated must have sufficient moisture for good plant
growth (at least 50% field capacity) for 5-14 days (depending on temperature) before the
treatment.
After application, the soil must be kept uniformly moist for 5-7 days. As soon as possible
after incorporation, the soil must be sealed to retain the concentration of gases in the soil
which can be achieved by:
o Compacting the soil surface after incorporation with a roller attached behind the
compacting implement.
o Moistening the surface after incorporation so a crust forms.
o Lightly moistening the soil on the third and fourth days after treatment in case the
weather dries out the soil surface to avoid surface cracks.
o In difficult situations best results may be obtained by tarping the treated area.
Do not store dazomet in an open spreader overnight.
Do not apply dazomet when wind may cause granules to drift from target area.
Do not apply dazomet through any type of irrigation equipment.
Before using dazomet be aware that the three most critical factors for a successful
fumigation program are: soil preparation, soil temperature, and soil moisture.
Weather Conditions
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The Agency is concerned with off gassing occurring during temperature inversion. In
many reported incidents, a temperature inversion is often given as a potential contributing factor.
To address this concern in the 2008 RED, the Agency prohibited applications during periods of
temperature inversion, or when the wind speed is less than 2 mph, which can sometimes be an
indication an inversion is occurring. In addition, the Agency provided additional information on
the label as guidance to applicators in determining if an inversion exists.
The Agency received many comments related to the inversion label language including:
concern that some of the characteristics of inversion conditions (like misty conditions or clear
skies at night) do not always indicate the presence of an inversion: relying on a weather forecast
to predict inversions is unreliable and not enforceable: and that prohibiting application during
inversions does not address concerns of inversions during the off-gassing period.
Based on these comments the Agency has revised the "weather conditions" section of the
GAPs that relates to temperature inversions to clarify that parts of the weather conditions that are
requirements and those that are included to help guide the applicator to identify temperature
inversions. The measures have also been updated to prohibit application only if temperature
inversion conditions are forecasted to persist for more than 18 of the 48 hours after the start of
the application since this will filter out conditions when diurnal temperature inversions may
occur, though even diurnal temperature inversions could contribute to exposures to fumigant
concentrations outside buffers. As such, EPA believes that the measures described below in the
emergency preparedness and response section of this document are important to address potential
risks associated with shorter-term diurnal inversions. The Agency is also changing the wind
speed requirement so winds may either be 2 mph at the start of application or be forecasted to
reach 5 mph during the application. These changes are designed to prevent applications when
inversion conditions are predicted to occur after the application has begun, since this is the time
when the peak off-gassing is expected to occur. In summary, EPA has determined that
applicators must (1) check the weather forecast and make a decision whether to proceed with a
planned fumigation, based on conditions that are predicted, (2) only begin a fumigant application
if wind speed is a minimum of 2 mph at the start of the application or forecasted to reach at least
5 mph during the application, and (3) not fumigate if there will be a persistent low-level local
inversion or an air stagnation advisory is in effect. EPA believes advisory language providing
more detailed information on how to identify inversions and adverse weather conditions will
increase the likelihood that applicators will proceed with applications only when weather
conditions are or are forecast to be favorable for safe fumigations. See below and the label table
in Section V of this document for label statements.
Stakeholders also questioned where the inversion conditions must exist and to what
extent the temperature inversion must exist that would prevent an application. The Agency has
provided additional temperature inversion details and has added a prohibition for application
during an air-stagnation advisory. Air-stagnation advisories are issued through the National
Weather Service and usually capture long periods of air stillness that may remain in an area from
one to several days. EPA has determined that these modifications achieve the same goals as the
2008 RED since they provide additional clarity that will enhance users' ability to practically
comply with the requirements. The revised statements are stated below.
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Prior to fumigation the weather forecast for the day of the application and the 48-hour period
following the fumigation must be checked to determine if unfavorable weather conditions
exist or are predicted and whether fumigation should proceed.
Wind speed at the application site must be a minimum of 2 mph at the start of the application
or forecasted to reach at least 5 mph during the application.
Do not apply if a shallow, compressed (low-level) temperature inversion is forecast to persist
for more than 18 consecutive hours for the 48-hour period after the start of application, or if
there is an air-stagnation advisory in effect for the area in which the fumigation is planned.
Detailed local forecasts for weather conditions, wind speed, and air stagnation advisories
may be obtained on-line at: http://www.nws.noaa.gov. For further guidance, contact your
local National Weather Service Forecasting Office.
Unfavorable Weather Conditions
Unfavorable weather conditions block upward movement of air, which results in trapping
fumigant vapors near the ground. The resulting air mass can move off-site in unpredictable
directions and cause injury to humans, animals or property. These conditions typically exist
prior to sunset and continue past sunrise and persist as late as noontime. Unfavorable
conditions are common on nights with limited cloud cover and light to no wind and their
presence can be indicated by ground fog or smog and can also be identified by smoke from a
ground source that flattens out below a ceiling layer and moves laterally in a concentrated
cloud.
All measurements and other documentation planned to ensure that the mandatory label
requirements are achieved must be recorded in the FMP and/or the post application summary
report.
3. Fumigant Management Plans (FMPs)
As noted elsewhere in this document, soil fumigation is a complex site-specific activity.
Failure to adhere to label requirements and procedures for safe use has led to accidents affecting
workers involved in fumigations as well as bystanders. Information from various sources shows
that health and safety plans, FMPs in this context, typically reduce workplace injuries and
accidents by prescribing a series of operational requirements and criteria. In fact plans like these
are widely implemented in a variety of industries and are recommended as standard approaches
for occupational health and safety management by groups such as American Industrial Hygiene
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Association8 (i.e., through "Administrative" and "Workplace" controls). The Centers for Disease
Control provides guidance for developing health and safety plans in agricultural settings.9 The
effectiveness of similar plans has also been evaluated in the literature. Examples include
"lookback" reviews conducted by the Occupational Safety and Health Administration (OSHA)
which essentially implemented standards in various industries then reviewed their effectiveness
in this process as they are required to determine whether the standards should be maintained
without change, rescinded or modified. OSHA is required by Section 610 of the Regulatory
Flexibility Act (5 U.S.C. 610) and Executive Order 12866 to conduct the "lookback" reviews.
These reviews are conducted to make the subject final standards more effective or less
burdensome in achieving their objectives, to bring them into better alignment with the objectives
of Executive Order 12866, and to make them consistent with the objectives of the Regulatory
Flexibility Act. Two examples of "lookback" reviews that support the use of FMPs for soil
fumigant health and safety management include: ethylene oxide use as a fumigant/sterilant, and
grain handling facilities requirements.10
In the July 2008 RED, EPA required FMPs to be completed before a fumigant
application occurs. EPA concluded that FMPs will reduce potential risks to bystanders as well as
handlers by requiring that applicators have carefully planned, in writing, each major element of
the fumigation. In this context, an FMP is a set of performance criteria for each application,
including how the fumigator intends to comply with label requirements. As added benefits, the
Agency determined that FMPs would ensure directions on the product labels were followed and
that the conditions under which fumigation occurred were documented. EPA also concluded that
FMPs would help ensure an appropriate response by the applicator or others involved in the
application should an incident occur since a proper and prompt response would reduce the
potential risk to bystanders from potential high exposure situations (e.g., readily available first
responder contact information could reduce response times to impacted bystanders and carefully
thought out emergency response plans can help ensure appropriate actions are taken in case of
unforeseen events).
The July 2008 RED provided a list of each major element FMPs would need to address.
These included general site and applicator information, application procedures, and a description
of how the fumigator planned to comply with label requirements for GAPs, buffer zones,
monitoring, worker protection, posting, and providing notification to the state or tribal lead
agency. FMPs also were required to include plans for communication between the applicator
and others involved in the fumigation, documentation, and handling emergency situation.
Additionally, EPA required that applicators complete a post fumigation summary that described
any deviations from the FMP, measurements taken to comply with GAPs, and information about
8 Ignacio and Bullock (2006) A Strategy For Assessing and Managing Occupational Exposures (Third Edition),
American Industrial Hygiene Association, AIHA Press 2700 Prosperity Avenue, Suite 250 Fairfax VA 22031 (ISBN
1-931504-69-5)
9 Karsky (2002) Developing a Safety and Health Program to Reduce Injuries and Accident Losses, Centers For
Disease Control National Ag Safety Database, available at http://www.cdc.gov/nasd/docs/d001501-
dOO 1600/dOO 1571/dOO 1571 .html
10 United States Department of Labor, Occupational Safety and Health Administration (2008) Lookback Reviews
available at http://www.osha.gov/dea/lookback.html
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any problems such as complaints or incidents that occurred as a result of the fumigation. The
RED also specified requirements for record keeping and that FMPs must be provided, upon
request, to enforcement officials and handlers involved in the fumigation.
According to stakeholder comments in earlier comment periods, much of the information
required for the site-specific FMP was already being documented by users, and most industry
stakeholders supported mandatory FMPs provided they are not too restrictive or complex and do
not result in an excessive administrative burden.
During the post-RED comment period, EPA received several comments regarding FMPs.
Several comments from industry and user stakeholders expressed concern that FMP
requirements would increase paperwork burden without providing significant risk reduction,
though others supported FMPs provided they did not result in an excessive administrative
burden. A number of comments suggested that the level of detail EPA had required was too
great and could result in voluminous, resource-intensive plans. Some of these comments
suggested that a checklist format would be more efficient and far less burdensome. Some
comments expressed reservations about the ability of FMPs to enhance compliance with label
requirements. Some commenters were concerned about the feasibility of providing a copy of the
FMP to on-site handlers or enforcement personnel, though others said that copies of the FMP
should be provided to workers in areas adjacent to the application block.
Following EPA's review of the post-RED comments, the Agency still believes that
FMPs will reduce potential risks to bystanders as well as handlers and are a key component of
the package of measures to reduce risks. EPA believes that FMPs will also enhance
compliance by requiring that applicators verify and document compliance with the label
requirements during and after application events are completed. In cases where errors may
have occurred, a post-application summary may also prevent similar problems from occurring
during future applications. However, in response to comments, the Agency has somewhat
modified the list of elements that must be addressed in the FMP (as described below) to make
it more streamlined and thus less burdensome to applicators and growers. In addition, the
Agency has developed a sample template in which many of the elements are covered in
checklist format, which fumigators have the option of downloading and modifying to meet the
needs of their specific fumigation situations. See
[http://www.epa.gov/pesticides/reregistration/soil_fumigants/]. EPA will also continue to work
with stakeholders to refine the FMP template and potentially develop others so it is a more
useful tool for ensuring the safe application of dazomet.
The Agency estimates that, if a certified applicator decides not to use the FMP template
and decides to prepare a narrative FMP, a carefully designed FMP could take several days to
develop the first time. Subsequent FMPs should require substantially less time to develop
because much of the information can be reused from the initial plan. In addition, an enterprise
fumigating multiple application blocks as part of a larger fumigation may format their FMP in a
manner whereby all of the information that is common to all the application blocks is captured
once, and any information unique to a particular application block or blocks is captured in
subsequent, separate sections.
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Amended FMP Requirements
Consistent with the July 2008 RED, the Agency is not requiring FMPs to be submitted to
state or local agencies. They must, however be maintained by the applicator and grower (if the
grower is not the applicator) for a period of 2 years.
The Agency agrees with comments that having both the applicator and the
owner/operator provide copies of the FMP to handlers is unnecessarily duplicative and that
providing each worker with a hardcopy of the FMP wastes paper. The Agency also agrees that it
is not necessary for the FMP to be provided to the workers in areas adjacent to the application
block. Workers in adjacent areas will be notified of the fumigation by buffer posting
requirements and, in the case of neighbors whose land is part of a buffer zone, the adjoining
neighbor has responsibility for workers in areas adjacent to the application for which permission
was granted to use as part of a fumigation buffer. The Agency has revised the following
requirement that was included in the 2008 RED, "Once the application begins, the certified
applicator and owner/operator of the application block must provide a copy of the FMP to
handlers involved in the fumigation, workers in adjacent areas to the application block, and
federal/state/local enforcement personnel, upon request." The RED Amendment requires the
certified applicator to make a copy of the FMP available for viewing by handlers involved in the
fumigation. The certified applicator or the owner/operator of the application block must provide
a copy of the FMP to any federal, state, tribal, or local enforcement personnel who request the
FMP. In the case of an emergency, the FMP must be made available when requested by
federal/state/local emergency response and enforcement personnel.
The Agency agrees with comments that the term "etc." complicates enforcement
activities and has removed that term from the label tables.
Each site-specific FMP must contain the following elements:
ปปป Applicator information (name, phone number, license number, employer name, employer
address, date of completing registrant dazomet training program)
*ป* General site information
> Application block location, address, or global positioning system (GPS) coordinates
> Name, address, and, phone number of owner/operator of the application block
> Map, aerial photo, or detailed sketch showing field location, dimensions, buffer zones,
property lines, roads, rights-of-ways, sidewalks, permanent walking paths, bus stops,
water bodies, wells, nearby application blocks, surrounding structures (occupied and non-
occupied), locations of posted signs for buffers, and sites requiring 1A or Vs mile buffer
zones (e.g., schools, state licensed day care centers, nursing homes, assisted living
facilities, hospitals, in-patient clinics and prisons) with distances from the application site
labeled
ปปป General application information (target application date/window, brand name of fumigant,
EPA registration number)
*ป* Tarp Information and procedures for repair, perforation and removal (if tarp is used)
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> Brand name, lot number, thickness
> Name and phone number of person responsible for repairing tarps
> Schedule for checking tarps for damage, tears, and other problems
> Maximum time following notification of damage that the person(s) responsible for tarp
repair will respond
> Minimum time following application that tarp will be repaired
> Minimum size of damage that will be repaired
> Other factors used to determine when tarp repair will be conducted
> Name and phone number of person responsible for cutting and/or removing tarps (if other
than certified applicator)
> Equipment/methods used to cut tarps
> Schedule and target dates for cutting tarps
> Schedule and target dates for removing tarps
Soil conditions (description of soil texture in application block, method used to determine
soil moisture)
Weather conditions (summary of forecasted conditions for the day of the application and the
48-hour period following the fumigant application)
> Wind speed
> Inversion conditions (e.g., shallow, compressed (low-level) temperature inversion)
> Air stagnation advisory
Buffer zones
> Application method
> Application rate from lookup table on label (Ib ai/A)
> Application block size from lookup table on label (acres)
> Credits applied
> Buffer zone distance
> Description of areas in the buffer zone that are not under the control of the
owner/operator of the application block
Respirators and other personal protective equipment (PPE) for handlers (handler task,
protective clothing, respirator type, respirator cartridge type, respirator cartridge replacement
schedule, eye protection, gloves, other PPE)
Emergency procedures (evacuation routes, locations of telephones, contact information for
first responders, local/state/federal contacts, key personnel and emergency
procedures/responsibilities in case of an incident, equipment/tarp/seal failure, complaints or
elevated air concentration levels outside buffer zone suggesting potential problems, or other
emergencies).
Posting procedures (person(s) who will post signs, location of posting signs, procedures for
sign removal)
Site-specific response and management (if applicable)
> Fumigant site monitoring
Description of who, when, where, and procedures for monitoring buffer zone
perimeter
> Response information for neighbors
List of residences, businesses, and neighboring property owners informed
Name, address, and phone number of person doing notification
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Method of sharing information
*ป* State and tribal lead agency notification (If state and/or tribal lead agency requires notice,
provide a list of contacts that were notified and date notified.)
ปปป Plan describing how communication will take place between applicator, land owner/operator,
and other on-site handlers (e.g., tarp cutters/removers, irrigators) for complying with label
requirements (e.g., buffer zone location, buffer zone start/stop times, timing of tarp cutting
and removal, PPE).
> Name and phone number of persons contacted
> Date contacted
*ป* Authorized on-site personnel
> Names, addresses and phone numbers of all handlers
> Employer name, addresses, and phone numbers for all handlers
> Tasks that each handler is authorized and trained to perform
> Date of PPE training for each handler
> For handlers designated to wear respirators when respiratory protection is required
(minimum of one handler), date of medical qualification to wear a respirator and date of
fit testing for respirator.
ปปป Air monitoring
> For buffer zone monitoring:
Name, address, and phone number of handler to perform monitoring activities
Location and timing of monitoring for the buffer zone
> For handlers without respiratory protection:
If sensory irritation is experienced, indicate whether operations will be ceased or
operations will continue with respiratory protection
If intend to cease operations when sensory irritation is experienced, provide the name,
address, and phone number of the handler that will perform monitoring activities
prior to operations resuming
> For handlers with respiratory protection:
Representative handler tasks to be monitored
Monitoring equipment to be used and timing of monitoring
ปปป Good Agricultural Practices (GAPs)
> Description of applicable mandatory GAPs (registrants may also include optional GAPs)
> Measurements and documentation to ensure GAPs are achieved (e.g., measurement of
soil and other site conditions)
ปปป Description of hazard communication. (The buffer zone around the application block has
been posted in accordance with the label. Pesticide product labels and material safety data
sheets are on-site and readily available for employees to review.)
*ป* Record keeping procedures (the owner/operator of the application block as well as the
certified applicator, must keep a signed copy of the site-specific FMP and the post
application summary for 2 years from the date of application).
For situations where an initial FMP is developed and certain elements do not change for
multiple fumigation sites (e.g., applicator information, authorized on-site personnel, record
keeping procedures, emergency procedures) only elements that have changed need to be updated
in the site-specific FMP provided the following:
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The certified applicator supervising the application has verified that those elements are
current and applicable to the application block before it is fumigated and has documented
the verification in the site-specific FMP.
Recordkeeping requirements are followed for the entire FMP (including elements that do
not change)
Once the application begins, the certified applicator must make a copy of the FMP
available for viewing by handlers involved in the fumigation. The certified applicator or the
owner/operator of the application block must provide a copy of the FMP to any federal, state,
tribal, or local enforcement personnel who request the FMP. In the case of an emergency, the
FMP must be made available when requested by federal/state/local emergency response and
enforcement personnel.
Within 30 days of completing the application portion of the fumigation process, the
certified applicator supervising the application must complete a post fumigation application
summary that describes any deviations from the FMP that have occurred, measurements taken to
comply with GAPs as well as any complaints and/or incidents that have been reported to
him/her.
Specifically, the Post-Application Summary must contain the following elements:
ปปป Actual date of the application, application rate, and size of application block fumigated
*ป* Summary of weather conditions on the day of the application and during the 48-hour period
following the fumigant application
ปปป Tarp damage and repair information (if applicable)
> Location and size of tarp damage
> Description of tarp/tarp seal/tarp equipment failure
> Date and time of tarp repair
ปปป Tarp removal details (if applicable)
> Description of tarp removal (if different than in the FMP)
> Date tarps were cut
> Date tarps were removed
ปปป Complaint details (if applicable)
> Person filing complaint (e.g., on-site handler, person off-site)
> If off-site person, name, address, and phone number of person filing complaint
> Description of control measures or emergency procedures followed after complaint
ปปป Description of incidents, equipment failure, or other emergency and emergency procedures
followed (if applicable)
*ป* Details of elevated air concentrations monitored on-site (if applicable)
> Location of elevated air concentration levels
> Description of control measures or emergency procedures followed
> Air monitoring results
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When sensory irritation experienced:
Date and time of sensory irritation
Handler task/activity
Handler location where irritation was observed
Resulting action (e.g., cease operations, continue operations with respiratory
protection)
When using a direct read instrument:
Sample date and time
Handler task/activity
Handler location
Air concentration
Sampling method
ปปป Date of sign removal
ปซป Any deviations from the FMP
In addition to recordkeeping requirements from 7 CFR part 110 "Recordkeeping
Requirements for Certified Applicators of Federally Restricted Use Pesticides", this decision
requires that both the applicator and owner/operator of the application block keep a signed copy
of the site-specific FMPs and the post-application summary record for 2 years from the date of
application.
Applicators and other stakeholders have the flexibility to use EPA's templates, prepare
their own FMPs templates, or use other commercially available software with certain elements
listed above in check-list and/or fill in the blank format. Below are examples of other FMP
templates available on the internet for structural fumigations that may be useful to users when
developing FMPs for dazomet soil applications:
http://www.cardinalproproducts.com/Misc/FMP%20Version%203 .pdf
http://www.pestcon.com/techlibrary/fum_mgmt_plan.doc
http://www.agr. state.ne.us/division/bpi/pes/fumigation_plan.pdf
http://www.agr.state.ne.us/division/bpi/pes/fumigation_plan2.pdf
http://nmdaweb.nmsu.edu/pesticides/Management%20Plans%20Required%20for%20Fu
migations.html
The Agency has provided a template in located in the appendix of this document.
4. Site Specific Response and Management
EPA believes measures for ensuring preparedness for situations when accidents or
emergencies occur are an important part of the suite of measures necessary to address risks posed
by fumigants. Therefore, EPA is requiring such measures at the community level in the form of
educational materials for first responders, and measures for specific sites to ensure early
detection and quick and appropriate response to situations as they arise.
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Although EPA believes buffers and other mitigation will prevent many future incidents, it
is likely that some incidents will still occur due to accidents, errors, and/or unforeseen weather
conditions such as diurnal inversions.. Early detection and appropriate response to accidental
chemical releases is an effective means of reducing risk, as well as addressing the source of the
release. Reducing risks associated with incidents that may occur in the future is a key part of
EPA's soil fumigant decisions. By combining buffers with GAPs, FMPs, and effective
emergency response, EPA is able to reach a "no unreasonable adverse effects" finding under
FIFRA.
To ensure that appropriate response mechanisms are in place in the event of a fumigant
exposure incident, EPA is requiring that registrants provide training information, in the context
of their community outreach and education programs to first responders in high-fumigant use
areas and areas with significant interface between communities and fumigated fields. In
addition, for situations in which people, homes, or other structures are in close proximity to
buffer zones, applicators must either monitor buffer zone perimeters or, alternatively, provide
emergency response information directly to neighbors. Each element is discussed in more detail
below.
First Responder Education
EPA is requiring registrants through their community outreach and education programs
(see the Community Outreach and Education Section), to ensure that emergency responders have
the training and information that they need to effectively identify and respond to fumigant
exposure incidents. EPA believes this will help ensure, in the case of a fumigant accident or
incident that first responders recognize the exposure as fumigant related and respond
appropriately. Additional details are included in the Community Outreach and Education
Section of this document.
Emergency Preparedness and Response Considerations for the 2008 RED
Prior to the 2008 RED the EPA received comments from many stakeholders about the
Agency's emergency preparedness and response option. Users have commented that notification
is burdensome and that it is unnecessary if buffer zones are also required. However, community
groups have commented on the importance of bystanders being informed when fumigations are
occurring, since this group of pesticides, compared to other pesticides, has a greater potential to
move off site and affect people not involved in the application. State regulators have different
views on this requirement. Some support the sharing of information with neighbors, and some
states have notification requirements for fumigations with certain products or for certain
application methods. In addition, some states require notification to chemically sensitive
individuals in proximity to pesticide applications. Others also had concerns about the
enforceability of this type of measure and the possible burden on the states to enforce a
notification requirement.
California currently requires notification of persons within 300 feet of a methyl bromide
buffer zone. California strawberry growers consider the 300 foot notification area for methyl
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bromide applications to be an extension of the buffer zone. In areas where a large number of
people would need to be notified about a planned methyl bromide application, strawberry
growers indicated that they would rather not use methyl bromide because some communities
could mobilize to prevent the fumigation from taking place. Some stakeholders also commented
that it would be protective and less burdensome if EPA required the user to monitor fumigant air
concentrations at the edge of the buffer for 24 hours after the application to ensure the fumigant
does not move beyond the buffer at concentrations that exceed EPA's level of concern. If
concentrations of concern were detected, the user would be required to implement the emergency
response measures specified in the fumigant management plan.
EPA has concluded that bystanders could take steps to protect themselves if they had
basic information about fumigations and the appropriate steps to take if they experienced
symptoms of exposure. In a number of fumigant incidents that have occurred, the magnitude and
severity of the incident could have been significantly reduced if people had such information.
Similarly, having on-site monitoring will enable site managers to take remedial action (i.e.,
activate the control plan in the FMP) to lower emissions sooner, also resulting in fewer and less
severe exposures. And, if necessary, site managers would activate the emergency response
elements of the FMP.
Providing communities with information about local chemical releases is an important
part of emergency preparedness programs and is recognized as an effective means of addressing
risk at the local level. Some states, like Florida and Wisconsin, have requirements for providing
information to chemically-sensitive individuals about chemicals used nearby so they can take
steps to protect themselves from potentially harmful exposures (see http://edis.ifas.ufl.edu/pi004
and http://www.legis.state.wi.us/rsb/code/atcp/atcp029.pdf). The requirements in Florida do not
apply to agricultural chemical applications. Wisconsin also requires fumigators applying metam
sodium products through chemigation to provide written notice to the county public health
agency and to every individual or household within 1A miles of the chemigation application site
(see http://www.legis.state.wi.us/rsb/code/atcp/atcp030.pdf). EPA agrees that information about
how to recognize and address exposures can help citizens reduce potential risk.
EPA understands that difficult challenges exist when agricultural land borders urban or
suburban communities. While EPA's decisions for the fumigants will not alleviate challenges
that already exist, EPA is allowing options for ensuring emergency preparedness in an effort to
lessen potential impact on growers, while maintaining the Agency's protection goals.
EPA is not requiring a specific method of providing the information to neighbors, but
rather that it be done in a way that effectively communicates, in a manner the recipients will
understand. Some methods may not result in documentation that would be retained. To address
concerns about enforcement, EPA is requiring that information on how and when the emergency
response information was delivered, and to whom, be included in the FMP.
Emergency Preparedness and Response Revisions
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To reduce risks to people who may be near a buffer zone (e.g., at their home or working
in a nearby field) in the July 2008 RED EPA required applicators to either monitor buffer zone
perimeters or, alternatively, provide emergency response information directly to neighbors. This
measure is intended to ensure protection in places people may be found. Whether measures are
required depends on the size of the buffer zone and how close land (e.g., residential properties
and businesses) not within the control of the owner/operator of the application block may be to
the buffer zone.
The Agency received many comments about the Emergency Preparedness and Response
requirements that suggested the requirements were too complex and confusing. To address these
concerns, EPA has revised the structure and content of the requirements in the RED Amendment
to improve clarity. As was outlined in the 2008 RED, it is important to note that site-specific
Emergency Preparedness and Response measures are only required if there are people, homes or
businesses within a certain specified distance from the edge of the buffer zone.
Some comments were received that questioned the rationale behind scaling the
Emergency Preparedness and Response measures. EPA believes that scaling the size of the
Emergency Preparedness and Response area will be protective. Generally the larger the buffer
distance the higher the application rate or the size of the treated area may be, which translates to
a greater total amount of fumigant being applied and potentially higher exposure in the area
surrounding the application block. The buffer distances for triggering the Emergency
Preparedness and Response requirements are scaled to allow the amount of fumigant used (a
surrogate for potential exposure) to determine the applicable distance for implementing this
requirement. When the area is scaled to the size of the buffer, small buffers which generally
result from applications to small areas, at low application rates, and/or using low-emission
application techniques, will have small or no areas to monitor or inform, while larger
applications will have larger areas to monitor or inform. In addition, to create additional
incentive to achieve the smallest buffer possible, EPA has included an exception for application
blocks so fields with the smallest required buffer (25 feet) which would not be subject to this
requirement, since they are most likely using lower application rates, applying to smaller areas,
and/or using lower emission application methods. Based on changes to the buffer zone section
regarding overlapping buffer zones, any buffer zone that overlaps with another buffer zone must
use the maximum distance in the Emergency Preparedness and Response measures to determine
if monitoring or providing information to neighbors is needed. None of the other distances have
changed.
Many stakeholders also expressed concern over the potential burden the 2008 RED
requirements may have on applicators and growers. Specifically, the frequency and cost of
monitoring using sampling devices such as colorimetric tubes were of concern. Several of these
comments noted concerns with the reliability of such devices at low concentrations.
Stakeholders felt the inherent warning properties of chloropicrin and MITC (i.e., eye irritation)
were better indicators of exposure than available devices. Additionally, several stakeholders
indicated that monitoring is most appropriate and effective at dawn and dusk, the times of day
when off-site movement of concentrations is most likely. Based on these comments, the Agency
has revised the requirement so monitoring is required during those periods when risk of high
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concentrations of fumigant moving beyond buffers is greatest (i.e., at dawn and dusk). As a
precaution, monitoring is also required once during the night and during the day.
Additionally, as noted above in the respiratory protection section of this document, due to
limitations on currently available technology for monitoring, use of sampling devices such as
colorimetric tubes will not be required at this time. EPA believes that currently available devices
are likely to be more reliable at fumigant concentrations which exceed EPA's action level
concentrations. In fact, some of these action levels are at or near the detection limits for the
devices available for some fumigants. Additionally, colorimetric devices provide snapshot
measurements. In conditions that are likely to be more static (e.g., monitoring an indoor
fumigation such as a grain mill or warehouse) it is likely that minute to minute changes in
conditions would not be as great as those anticipated for the more dynamic conditions
characteristic of outdoor field fumigation where exposure concentrations could shift because of
weather changes or stratification in soil conditions across a single field.
While the Agency is modifying the procedures for monitoring buffer zones because of
technological limitations of currently available devices for MITC and chloropicrin that are not
practical or reliable for field use, the Agency does believe that quantitative air monitoring would
enhance safety if the appropriate technology were available as it is for methyl bromide. Some
equipment manufacturers have indicated interest in developing devices that would be more
functional and reliable for field fumigation applications (e.g., badge-type monitors). EPA
encourages such efforts and plans to stay abreast of developments and improvements in
monitoring devices and will consider this issue again in Registration Review or sooner should
such monitors become available in the short term. In the interim, buffer monitoring for the
MITC generating chemicals and chloropicrin will rely on sensory indicators (e.g., eye and/or
nose irritation) to trigger a response instead of using tubes. Monitoring tubes are still required
for measuring products that contain more than 80% methyl bromide.
Finally some comments provided suggestions to increase flexibility in how a grower may
comply with these measures as well as the effectiveness of the option to provide information to
neighbors. EPA agrees with the importance of users being able to comply with these measures
and has modified some aspects of the requirements for this option to reduce the number of
notices an applicator may need to provide to a given neighbor. Also, to enhance the
effectiveness of the information neighbors would receive, EPA is requiring that the information
is provided close to when the application is planned to take place and early enough for neighbors
to make use of the information. EPA believes these modifications will enhance compliance and
effectiveness of the information if the emergency response criteria are met and applicators
exercise this option.
Emergency Preparedness and Response Requirements
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When are Emergency Preparedness and Response Measures Needed?
If the buffer zone is:
25 feet < Buffer < 100 feet
100 feet < Buffer < 200 feet
200 feet < Buffer < 300 feet
Buffer > 300 feet or buffer zones
overlap
AND There is land (e.s. residential properties
and businesses) NOT in the control of the
property operator within this distance
from the edge of the buffer zone:
50 feet
100 feet
200 feet
300 feet
Then either monitoring of the buffer zone perimeter or providing emergency response
information to neighbors is required.
If the buffer zone is 25 feet, the minimal buffer zone size, then the Emergency
Preparedness and Response requirements are not applicable. Also, if all of the land within 300
feet of the edge of the buffer zone is under the control of the property operator, then no site
monitoring or informing neighbors would be required regardless of the size of the buffer zone.
Fumigation Site Monitoring
EPA has determined that monitoring of the buffer zone perimeter for fumigants moving
beyond buffers is an effective approach to protecting bystanders. Under this approach, if the
person monitoring the buffer perimeter experiences eye or nasal irritation, an early sign of
exposure to concentrations that exceed the Agency's action level, then the emergency response
plan specified in the FMP must be implemented. If other problems occur, such as a tarp coming
loose, then the appropriate control plan must be activated. Because data indicate that peak
concentrations sometimes occur on the second day following applications, and the greatest
potential for concentrations outside buffers may be observed at dawn and dusk, EPA has decided
that this monitoring must be done at least three times per day during the full buffer zone period at
dawn, dusk, and once during the night and during the day, to ensure concentrations do not
exceed the action level which will be specified on product labels.
Specific requirements include:
Monitoring must take place beginning on the day the application begins until the buffer zone
period expires.
Monitoring must be conducted by a certified applicator or someone under his/her supervision.
Monitoring for air concentrations above the action level for the fumigant, as determined by
sensory irritation, must take place in areas between the buffer zone perimeter and residences
or other occupied areas that trigger this requirement.
The person monitoring for perceptible levels must start monitoring approximately 1 hour
before sunset of the day the application begins and continue once during the night, once at 1
hour after sunrise, and once during the day until the end of the buffer zone period.
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If at any time the person monitoring the air concentrations experiences sensory irritation,
then the emergency response plan stated in the FMP must be immediately implemented.
If other problems occur, such as a tarp coming loose, then the appropriate control plan must
be activated.
The location and any results of the air monitoring must be recorded in the FMP.
While protective, this site monitoring might be burdensome for users fumigating in areas
with few people. Therefore, EPA is allowing users the alternative option of providing
emergency response information directly to neighbors.
Response Information for Neighbors
As an alternative to on-site monitoring, the certified applicator supervising the fumigation
(or someone under his/her direct supervision) would need to ensure that residences, businesses,
or other sites that meet the criteria outlined below have been provided the required information
below at least one week prior to the fumigant application in a specified field. If after four weeks,
the fumigation has not yet taken place, the information must be delivered again.
Information that must be provided includes:
o The general location of the application block,
o Fumigant(s) applied including the active ingredient, name of the fumigant
products(s), and the EPA Registration number,
o Contact information for the applicator and property owner/operator,
o Time period in which the fumigation is planned to take place (must not range
more than 4 weeks),
o Early signs and symptoms of exposure to the fumigant(s) applied, what to do, and
what emergency responder phone number to call who to call if you believe you
are being exposed (911 in most cases), and.
o How to find additional information about fumigants.
The method for distributing information to neighbors must be described in the FMP and
may be accomplished through mail, telephone, door hangers, or through other methods that can
be reasonably expected to effectively inform people at residences and businesses within the
required distance from the edge of the buffer zone.
To clarify this measure, the following example is provided:
IF the buffer zone is 125 feet, then these requirements apply to residences within 100 feet of the
buffer zone. Either the applicator must monitor the area between the dotted house and the buffer zone
or residents of the dotted house must be provided emergency response information.
The location of the cross-hatched house would not prompt any action.
Figure 9. Example Site Map for Informing Neighbors
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If there are no residences or other occupied structures within 300 feet of the edge of the
buffer zone, or if the buffer distance is the minimum of 25 feet, neither site monitoring nor
providing information to neighbors is required.
5. Notice to State Lead Agencies
Ensuring fumigant users understand and comply with the new label requirements is an
important component of the fumigant risk mitigation package since these requirements are
designed to mitigate risks of concern for bystanders, handlers, and workers. Knowledge of the
location and timing of fumigant applications allows enforcement officials to focus their
compliance assistance and inspection efforts around periods when, and places where,
fumigations are expected to occur. Therefore, in the July 2008 RED, the Agency required written
notification of the appropriate state or tribal lead agency prior to fumigant applications.
Following publication of the July 2008 REDs, the Agency received feedback from some
states that were interested in receiving the notice because it would enhance their ability to
provide technical assistance and assure compliance. However, the Agency also received
comments from states that were concerned about the notification requirement largely due to
resource constraints. Some states also indicated that they are already well-informed about when
and where fumigations take place, and receiving specific notice of applications would create a
paperwork burden rather than aid their compliance assistance and assurance programs. Some
states recommended that, in lieu of receiving notice of fumigations, states could modify their
cooperative agreements with EPA to incorporate specific strategies for assuring compliance with
the new fumigant labels. States also suggested that rather than providing notice directly to states,
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fumigators could enter application information into a registrant-developed and maintained
database. They suggested this would be an appropriate mechanism because it would standardize
and streamline the process for applicators to provide the required information, and states could
access and utilize information more quickly, with greater ease, and using fewer state resources.
Based on consideration of public comments, the Agency still believes that compliance
assistance and assurance is a critical component of the soil fumigant mitigation. EPA agrees that
some states already have mechanisms in place to provide them with information needed to assist
and assure compliance with new fumigant requirements, but other states are in need of additional
information to accomplish this objective. The Agency also believes that all states in which
fumigants are used will need to modify their cooperative agreements, to some extent, to
incorporate strategies for compliance assistance and assurance to aid the transition from current
labels to labels that reflect the new mitigation.
While the Agency will continue to work with all state and tribal lead agencies on efficient
ways to obtain the information needed to plan and implement compliance assistance and
assurance activities, the Agency is currently retaining the notification requirement only for state
and tribal lead agencies that choose to be notified of fumigant applications. The Agency plans
to provide a website listing these state and tribal lead agencies and how and when these agencies
want applicators to provide to them the following information:
Applicator and property owner/operator contact information (name, telephone number,
and applicator license number)
Location of the application block(s)
Name of fumigant(s) products(s) applied including EPA Registration number
Time period in which fumigation may occur
The Agency will work with all states to amend their cooperative agreements to include
strategies for compliance assistance and assurance, which will be particularly important over the
next several years as the new mitigation measures are implemented. For states that do not
choose to be notified of fumigant applications, modification of their cooperative agreements
must include the methods these agencies will use to survey fumigation application periods and
locations.
6. Soil Fumigation Training for Applicators and Training Information for Other Handlers
Soil fumigation is an inherently complex activity involving specialized equipment and
application techniques. Additionally, the mitigation measures required as part of these decisions
will introduce new requirements in the form of more detailed instructions and restrictions on soil
fumigations. Failure to adequately manage fumigant applications increases risks to handlers
involved in the fumigation, nearby workers, and other bystanders. Incident data show that a
number of fumigant incidents are the result of misapplications, failure to follow label
requirements and other safety precautions, and other errors on the part of fumigant applicators.
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Although states have certification programs, some of which include a specific category or
subcategory for soil fumigation, there currently is not a consistent standard across states and
regions where soil fumigation is done. Additionally, the federal certification program currently
has no category for soil fumigation, and while EPA is considering the development of a category
for soil fumigation, the potential changes to the federal certification program and worker safety
regulations to include a soil fumigation category are not anticipated in the near future.
EPA believes that training is an effective way to increase applicators' skill and
knowledge so they are better prepared to effectively manage the complexities and risks
associated with soil fumigation. Further, training is a means of ensuring fumigators are able to
understand and comply with revised fumigant labeling. Therefore, EPA determined that training
designed to establish a national baseline for safe fumigant use, developed and implemented by
registrants, will help enhance fumigators' ability to adequately manage the complexities of soil
fumigation and enhance compliance with fumigant product labeling. EPA also determined that
providing additional safety information to other fumigant handlers will help them understand and
adhere to practices that will help handlers protect themselves from risks of exposure.
Soil Fumigation Training Considerations
In comments on fumigant risk management options, stakeholders were broadly
supportive of additional training for applicators and handlers. During the Phase 5 and post-RED
comment periods, the majority of stakeholders, including growers, community groups, farm
workers, states, and registrants expressed strong support for increased training for applicators
and other handlers. Several comments noted that fumigant incidents affecting both fumigant
workers and bystanders could have been prevented or mitigated if applicators had better training
about correct practices and procedures.
The Agency agrees that additional training for fumigant applicators and handlers will
help educate and inform these workers, thus decreasing the likelihood of both incidents and
noncompliance. EPA believes fumigant-specific training for applicators and additional training
information for handlers also will help reduce the magnitude and frequency of exposure
incidents and, coupled with the other mitigation measures described in this decision, will address
risks of unreasonable adverse effects from the use of soil fumigants.
It is important to note that training developed and provided by registrants as required by
this RED is separate and distinct from state certification programs. EPA encourages registrants,
in developing their training proposals, to work with states where their products are used to
identify opportunities to build on and complement state programs. However, the training
programs required as part of this decision are intended to be separate from the state certification
process and will be developed and administered by registrants. Individual state regulatory
agencies have the option of working with registrants on these activities, but are not required to
do so. It is important to note that some fumigant registrants have already developed soil
fumigant training programs that will serve as a good basis for this expanded effort.
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As noted above, several states have high-quality certification programs for fumigators
that include exams to test the competency of fumigators. EPA recognized that for applicators to
become certified in those states, they must acquire the knowledge and skill necessary to pass the
exam. But several stakeholders commented that training opportunities are varied across the
country, and the scope and detail of information provided in available training is not consistent.
EPA is also concerned that information in existing programs will need to be substantially
updated as a result of new requirements associated with this decision and the label changes
which will implement it. Although EPA is considering revisions to the federal certification and
training program in the future to include a soil fumigation category/subcategory, EPA believes
that registrants have access to resources and materials to best develop and deliver training in the
interim.
EPA stresses that registrant training programs will be separate from the state certification
process and will be developed and administered by registrants in coordination with EPA. EPA
will, however, work with state organizations and training experts to explore opportunities for the
registrant programs to supplement any existing state programs to provide additional training
resources for fumigators working in those states. EPA will also work with state lead agencies
and extension programs to review training program proposals, the content for the programs and
materials, and proposed vehicles for delivery.
During the post-RED comment period, the Agency received comments from several
states asking that the applicator training requirements be coordinated with existing state
certification and training programs. The Agency agrees that for states that have existing soil
fumigation certification programs that address the same training elements required of the
registrant soil fumigant training programs, as outlined in this section of the RED addendum,
applicators should be able to complete the state certification program in lieu of completing the
registrant soil fumigation training. For the state soil fumigation certification program to qualify,
both EPA and the state must agree that the program satisfies the applicator training elements
required in the RED.
Pesticide labels will state that the certified applicator supervising that application must
have successfully completed, within the last 36 months, a dazomet training program made
available by the registrant. The Fumigant Management Plan must document when and where the
training program was completed. This requirement for registrant-provided applicator training
does not supersede or fulfill state requirements, unless the state has expressly acknowledged that
the registrant training may substitute for state requirements.
Training for Applicators Supervising Fumigations
The July 2008 RED required registrants to develop and implement training programs for
applicators in charge of soil fumigations on the proper use of and best management practices for
soil fumigants. During the public comment period on the proposed mitigation measures and the
post-RED comment period, stakeholders were broadly supportive of additional training for
fumigators, but concerns were raised with regard to implementation of the training. The Agency
also received comments from state representatives and pesticide applicator training
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organizations, such as the Association of American Pesticide Control Operators, American
Association of Pesticide Safety Educators, and Certification & Training Assessment Group,
expressing concern over EPA's decision to implement the training via labeling and raising
questions over compliance and state enforcement of such a requirement and the potential for
conflict or redundancy with state certification and training programs. Various stakeholders
recommended that, rather than a label-mandated training requirement, the Agency, instead,
should require registrants to develop and implement training for soil fumigant applicators as a
condition of registration.
The Agency's goal in requiring soil fumigation training for applicators is to ensure that
all applicators in charge of soil fumigations understand the safe use of soil fumigants and in how
to apply products in compliance with new product labeling, including provision required by the
RED. Given the unique properties of soil fumigants and their application and safety procedures
compared with other agricultural and non-agricultural pest control practices, the inherent
complexities involved in soil fumigant applications, and the additional complexities that will
arise with the implementation of the REDs, the Agency feels that additional training, beyond that
available currently, will be needed. The states that currently have certification programs that
include soil fumigation categories will not have requirements pertaining to the new mitigation
and their programs will need to be modified. EPA agrees that making the required training
programs a condition of registration is an important means of ensuring that such training is
ultimately developed and implemented. However, it would not ensure that all individuals in
charge of soil fumigant applications avail themselves of the training. The Agency believes that
making successful completion of the training a condition of use is also important to achieve this
goal. Therefore, EPA has decided that development and delivery of training will be included in
the DCI that accompanies this RED and successful completion of the training will remain a
condition of use.
Each registrant must develop and implement training programs for applicators in charge
of soil fumigations on the proper use of and best practices for soil fumigants. In addition,
registrants will be required to submit proposals for these programs as data requirements that will
accompany this RED. EPA will review each program and determine whether it adequately
addresses the requirements specified in the DCI. The proposal must address, among other
elements, both the content and the format for delivering training. The Agency acknowledges the
value of hands-on training in the field, but recognizes that may not be feasible in all instances.
The Agency welcomes and is actively seeking participation from state lead agencies and
extension programs in the evaluation of the registrant training proposals and materials that are
submitted.
The training programs must address, at a minimum, the following elements: (1) how to
correctly apply the fumigant, including how to comply with new label requirements; (2) how to
protect handlers and bystanders; (3) how to determine buffer zone distances; (4) how to develop
a FMP and complete the post-fumigation application summary; (5) how to determine when
weather and other site-specific factors are not favorable for fumigant application; and (6) how to
comply with required GAPs and how to document compliance with GAPs in the FMP. In
addition, based on comments received during the post-RED comment period, the Agency is
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adding a seventh training elementtraining programs must also include information on how to
develop and implement emergency response plansto ensure that applicators are prepared in the
event that a problem develops during or shortly after the fumigant application. EPA is also
requiring registrants to incorporate a mechanism for evaluating the effectiveness of their training
programs at conveying the required information to participants and for determining whether
participants have successfully completed the training program.
To assist states in enforcing these training requirements, the registrants will be required to
(1) develop a database to track which certified applicators have successfully completed the
training, (2) make this database available to state and/or federal enforcement entities upon
request, and (3) provide documentation (e.g., a card) to each training participant who
successfully completes the training. This documentation shall include the applicator's name,
address, license number, and the date of completion. Applicators must provide to federal, state,
or local enforcement personnel, upon request, this documentation that verifies successful
completion of the appropriate training program(s).
In the July 2008 RED, the Agency required applicators supervising fumigations to
complete the training annually. During the post-RED public comment period, the Agency
received comments from various stakeholders indicating that the substance and content of
training would not change significantly from year to year, and that an annual training
requirement for applicators would be excessive and burdensome to both applicators and
registrants and was unnecessary. As a result of these comments, the Agency has decided to
require applicators supervising fumigations to have successfully completed the program within
the preceding 36 months and to document when and where the training program was completed
in their FMPs. This may be accomplished, for example, by simply attaching a copy of the
training documentation provided by the registrant to the FMP. The registrant also must be able
to provide to federal, state, or local enforcement personnel, upon request, the names, addresses,
and certified applicator license numbers of persons who successfully completed the training
program, as well as the date of completion.
Based on questions received during the post-RED comment period, the Agency is
clarifying that the applicator training requirements are active ingredient-specific rather than
product-specific. That is, applicators who apply more than one of the soil fumigant active
ingredients (i.e., methyl bromide, chloropicrin, metam sodium/potassium, or dazomet) will be
required to complete training for each soil fumigant active ingredient they apply, but not for each
different product containing the same active ingredient(s). Further, EPA encourages the soil
fumigant registrants to jointly develop programs to reduce the redundancy of this training
requirement. For example, a substantial portion of the required training is universal to all soil
fumigants. Therefore modules addressing the information common to all could be generic and
each fumigator would participate in those modules, while separate modules addressing active
ingredient-specific content could be provided to those fumigators supervising applications with
those active ingredients only. Documentation provided to trainees could indicate the active
ingredient modules completed. While EPA sees efficiencies in such an approach, it will be the
registrants' choice as to how they will comply with the requirement to develop and implement
training programs.
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Training Materials for Handlers
EPA is requiring registrants to prepare and disseminate training information and
materials for other fumigant handlers, i.e., those working under the supervision of the certified
applicator in charge of fumigations. The Agency is requiring registrants to submit proposals for
these materials through the data call-ins that will accompany this RED. EPA will review these
materials to determine whether they adequately address the requirements specified in the DCI.
The Agency welcomes and is actively seeking participation from state lead agencies and
extension programs in the evaluation of these handler training materials.
The training materials must address, at minimum, the following elements: (1) what
fumigants are and how they work, (2) safe application and handling of soil fumigants, (3) air
monitoring and respiratory protection requirements for handlers, (4) early signs and symptoms of
exposure, (5) appropriate steps to take to mitigate exposures, (6) what to do in case of an
emergency, and (7) how to report incidents. Registrants must provide this training information
through channels open to the public (e.g., via a website). Pesticide labels will require that
applicators supervising fumigations provide this training information to handlers under their
supervision before they perform any fumigant handling task, or they must ensure that handlers
have been provided the required information within the preceding 12 months. The label will also
require that the training information be provided in a manner that the handler can understand.
Applicators supervising fumigations must ensure the FMP includes how and when the required
training information was provided to the handlers under their supervision.
"The certified applicator must provide fumigant safe handling information to each
handler involved in the application in a manner that they can understand prior to
performing any fumigant handling task or confirm that each handler participating in the
application has received fumigant safe handling information in the past 12 months."
During the post-RED comment period, no substantive comments were received that
resulted in changes to the RED requirements for training materials for handlers, as a result, these
requirements are identical to those published in the July 2008 RED. However, during the
comment period, the Agency received comments indicating that there was some confusion about
whether fumigant handlers working under the supervision of the certified applicator would be
required to be trained, i.e., participate in a training program developed by the soil fumigant
registrant(s), or whether handlers would need only to be provided with training information and
materials. The Agency wishes to clarify that handler participation in a registrant training
program, per se, is not required. As noted above, applicators supervising a soil fumigation will
be required to provide the registrant-developed, EPA-approved training information to handlers
in a manner that they can understand prior to performing any fumigant handling task, or
applicators must ensure that the handler has been provided the required information within the
proceeding 12 months.
7. Community Outreach and Education Programs
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EPA understands from public comments, site visits, and stakeholder meetings, conducted
as part of the soil fumigant review, that there is often a fundamental lack of information and
communication about soil fumigants within communities where soil fumigation occurs, which
has raised health and safety concerns among community members. This lack of information and
communication has led to inappropriate responses in cases where fumigants have moved off site
and into communities. This also has led, in some cases, to unwarranted concern and anxiety
among communities about the risks associated with the use of fumigants. The Agency believes
that outreach and education to communities where soil fumigation occurs is an important
component of the overall package of measures to address bystander risk. Community outreach
will address the risk of acute bystander exposure by informing community members in high-use
areas about buffer zones and their characteristics and purpose, the meaning of posted warning
signs, the importance of not entering buffer zones, how to recognize early signs of fumigant
exposure, and how to respond appropriately in case of an incident.
In the July 2008 RED, the Agency required registrants to develop and implement
community outreach and education programs to address these needs. At a minimum, these
programs were to include the following elements: (1) what soil fumigants are and how they
work, (2) what buffer zones are, (3) early signs and symptoms of exposure, (4) appropriate steps
to take to mitigate exposures, (5) what to do in case of an emergency, and (6) how to report an
incident as well as a plan for evaluating the effectiveness of these programs. Few details on how
the programs would be implemented were provided in the RED. Rather, during the post-RED
comment period, the Agency sought feedback from the registrants and other stakeholders on how
best to design and target programs to community members in high-use areas. The Agency
encouraged the registrants to work with existing community resources, such as community
health networks, for disseminating information and implementing community outreach
programs.
During the post-RED comment period, the Agency received some comments from
stakeholders that suggested that having registrants develop and implement a community outreach
and education program is unnecessary and likely to needlessly raise heath and safety concerns
among community members, and such a requirement could draw scarce resources from other
registrant stewardship efforts. As noted previously, the Agency believes that providing basic
information about soil fumigants and buffer zones as well as information on what to do in the
event that an incident occurs to communities in high fumigant use areas is an important
component of the overall package of risk mitigation measures to address bystander risk. EPA's
community outreach requirements do not preclude other voluntary stewardship programs or
activities targeted to community members or the applicator/grower community, but rather are
meant to help ensure that community members in high fumigant usage areas are informed about
soil fumigant safety and better able to respond appropriately if an incident were to occur.
Few recommendations and no specific proposals for these programs were received during
the post-RED comment period. Therefore, the Agency is identifying minimum requirements that
each registrant must fulfill when developing its community outreach programs in response to a
DCI that will be issued. The Agency remains open to considering additional registrant outreach
program elements that address the same needs and goals as the program requirements described
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below in their response to the DCI. EPA notes that registrants have suggested that programs
focusing on specific target audiences, such as staff and managers of migrant health care and day
care facilities, prison officials, and school nurses and principals, may be more effective in
providing useful information in a meaningful way than broadcast messages to entire
communities. Registrants have indicated that they will provide proposals for such programs in
late May 2009. EPA looks forward to these proposals and will consider the extent to which they
contribute to meeting the goals of the community outreach programs required by the RED.
In the absence of acceptable alternative proposals, registrants will be required to provide
information to communities in the form of monthly public service announcements (PSAs)
distributed via local radio stations or newspapers in high-use fumigant areas during the
fumigation season(s) in those areas. As per the requirements included in the July 2008 RED, at a
minimum, registrants must include the following information in their community outreach
messages: (1) what soil fumigants are and how they work, (2) what buffer zones are, (3) early
signs and symptoms of exposure to MITC, (4) appropriate steps to take to mitigate exposures to
MITC, (5) what to do in case of an emergency, and (6) how to report an incident as well as a
plan for evaluating the effectiveness of these programs. Based on comments, EPA has decided
that information on the meaning of posted warning signs is also important to help ensure the
signs convey the needed information about the importance of staying out of buffer zones and
treated areas.
The Agency is requiring registrants to implement their outreach programs in communities
located in areas where there is high soil fumigant use. For the purposes of the RED addendum,
high-use areas are considered at the county level. To identify these areas, the Agency is
proposing a process for identifying high-use areas in the subsection following the section on
information for first responders. However, the Agency is willing to consider alternative
proposals for identifying high soil fumigant-use areas, based on additional data sources and
alternate approaches identified by the registrant(s) and other stakeholders.
Information for First Responders
In the July 2008 RED, the Agency required registrants to ensure that first responders in
areas with high fumigant usage have the training and information that they need to effectively
identify and respond to fumigant exposure incidents. Specifically, the registrants were required
to provide information and/or training to first responders, which at a minimum, included the
following elements: (1) how to recognize the early signs and symptoms of fumigant exposure,
(2) how to treat fumigant exposures, and (3) how fumigant exposure differs from other pesticide
exposure. In addition, the registrants were required to provide material safety data sheets to first
responders for both the fumigant applied (e.g., dazomet) as well as the active compound
generated (e.g., MITC). Few details on how the education programs would be implemented were
provided in the RED. Rather, during the post-RED comment period, the Agency sought feedback
from the registrants and other stakeholders on how best to design and target programs to first
responders in high-use areas. The Agency encouraged the registrants to work with state and local
emergency response coordinators to identify needs and opportunities to supplement any
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information already included in state and local training for first responders about soil fumigants
specifically.
During the post-RED comment period, the Agency received comments from several
registrants indicating that rather than requiring registrants to implement face-to-face training
programs, the Agency should consider allowing the required first responder training information
to be conveyed via written materials to state and local emergency response agencies, which
would provide these agencies the ability to incorporate this information into their existing
training programs. Other comments indicated that even if training programs were developed, it
would be difficult to ensure participation of first responders. The Agency's goal for the first
responder training program is to ensure that first responders in high use fumigant areas have
access to the information that they need to be able to quickly and effectively identify an exposure
that is fumigant related and respond appropriately. The Agency agrees that this goal can be met
by requiring the soil fumigant registrants to develop informational materials on the soil
fumigants and distribute this information to first responders (i.e., police, fire, rescue, emergency
medical services, and others who respond to "911" calls) in high soil fumigant-use areas. This
would then provide the first responder entities the ability to incorporate this information into
their existing first responder training programs as they best see fit. This recommendation has
been incorporated into the RED amendments for the soil fumigants.
The Agency is willing to consider additional registrant proposals so long as they address
the same needs and achieve the same goals as the program requirements described below. At a
minimum, registrants will be required to develop and disseminate chemical-specific soil
fumigant training materials to first responders i.e., police, fire, rescue, emergency medical
services, and others who respond to "911" calls) operating in high fumigant-use areas. As a data
requirement in the DCIs that will accompany the REDs, registrants must submit proposals
detailing how they will (1) identify the first responder entities in high soil fumigant-use areas to
which they will disseminate the training materials, and (2) provide materials to the first
responders in these areas. Additionally registrants must provide draft copies of the training
materials for EPA review and approval. As per the requirements included in the July 2008 RED,
at a minimum, the materials must convey the following information to first responders: (1) how
to recognize the early signs and symptoms of dazomet fumigant exposure, (2) how to treat
dazomet fumigant exposures, and (3) how dazomet fumigant exposures differ from other
pesticide exposures as well as (4) copies of material safety data sheet(s) for the fumigant applied
as well as for the active compound generated, if applicable. Training materials can take a number
of forms, including: brochures, fact sheets, CDs, videos, web-based training materials, etc., as
long as these materials incorporate, at a minimum, the information requirements identified
above.
The Agency is requiring registrants to target their first responder training information to
those communities located in high soil fumigant-use areas. For the purposes of the RED, high-
use areas are considered at the county level. To identify these areas, the Agency is proposing the
following process. However, the Agency is willing to consider alternative proposals in the
registrants' response to the DCIs for identifying and targeting high-use soil fumigant areas, based
on additional data sources and alternate approaches identified by the registrant(s).
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Process for Identifying High-Use Fumigant Areas:
Identifying high-use areas for dazomet is a two-step process because reliable fumigant
use data is not available at the county level from either publicly available data sources or EPA
proprietary data sources. First, the states with high use of dazomet have been identified by the
Agency using EPA proprietary data. Second, the high-use counties for dazomet within those
states must be identified. The second step, identifying high-use counties, will be the registrant's
responsibility, using the process defined below.
Step 1: Identifying States with High Use of Dazomet: The Agency is defining states with
high usage of dazomet as those states where, on average, more than 100,000 Ibs of
dazomet are applied annually. To determine those states where, on average, more than
100,000 Ibs of dazomet has been applied annually, the Agency obtained data on the
average number of pounds of dazomet applied in all states across a ten-year period
(1999-2008) using EPA proprietary data. To view the Agency's analysis of this data,
please see the Biological and Economic Analysis Division's memo, "Process for
Defining High-Use Fumigant Areas at State and County Levels" dated May 14, 2009 and
supporting documentation located in the dazomet docket at EPA-HQ-OPP-2005-0128.
Step 2: Identifying Counties with High Use of Dazomet: For each of the high-use states
that the Agency identified in Step 1, the registrants will be required to identify the
counties where use of dazomet may be high. Because county-level fumigant usage data is
not publicly available and EPA proprietary data are not appropriate for this level of
specificity, crop acreage should be used as a surrogate indicator for fumigant usage. Crop
acreage can be obtained for major use sites of dazomet from the publicly available 2007
USD A Census of Agriculture. Crop acreages for each of the major use sites for dazomet
should be obtained for each the major use sites for dazomet and then summed by county.
All counties making up at least the top 90% of acreage in a state are considered high-use
areas. Registrants will be required to target each of these high-use counties for
community outreach programs.
For the purposes of this analysis, the Agency defines a "major use site" as any crop that has
more than 5% crop treated annually or more than 100,000 Ib of dazomet applied annually. Given
the low usage rates of dazomet at this time, the requirement for community outreach and first
responder training programs will not likely be triggered. However, the Agency could review this
issue during registration review to determine of dazomet usage has changed, such that
community outreach and first responder training programs are determined to be necessary.
Example Identifying High-Use Fumigant Areas for Metam Sodium in California:
To help explain the process for identifying high-use fumigant areas for dazomet the
Agency is providing the following example, which identifies the high-use counties for the soil
fumigant, metam sodium, usage in California.
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Step 1: Identify States with High Use of Metam Sodium:
o Based on its analysis of proprietary data, the Agency has identified the following
high-use states for metam sodium: California, Washington, Idaho, Oregon,
Wisconsin, Michigan, Florida, Minnesota, North Carolina, Virginia, Arizona,
Nevada, Georgia, Colorado, and North Dakota. This example will focus only on
identifying the counties in California with high use of metam sodium. The same
process would be applied to other high-use states.
Step 2: Identify the Counties in California with High Use of Metam Sodium:
o EPA has identified the following as the major use sites of metam
sodium/potassium: artichokes, cabbage, cantaloupes, carrots, onions, peanuts,
peppers, potatoes, spinach, squash, tomatoes, and watermelons.
o Using the 2007 USDA Census of Agriculture, registrants will need to obtain
harvested crop acreage data for each of the 12 major use sites for metam sodium
identified above for each county in California. (An example of this analysis is
provided as a supporting document to the Biological and Economic Analysis
Division's memo "Process for Defining High-Use Fumigant Areas at State and
County Levels" dated May 14, 2009 and supporting documentation located in the
dazomet docket at EPA-HQ-OPP-2005-0128)
o Registrants will then need to sum the total number of combined crop acres for
these major use sites for each county in California and then select all the counties
that make up at least the top 90% of acreage in the county. [An example of this
analysis is also provided as a supporting document to the Biological and
Economic Analysis Division's memo "Process for Defining High-Use Fumigant
Areas at State and County Levels" dated May 14, 2009 and supporting
documentation located in the dazomet docket at EPA-HQ-OPP-2005-0128)
As with the training for fumigant applicators and handlers and the community outreach
program that the Agency is requiring, the first responder training requirements are intended to be
part of the registrants' long-term product stewardship. The Agency encourages registrants to
work with appropriate state emergency response entities in these areas to ensure that the
appropriate first responder entities are being targeted and that the information being provided to
first responders is both useful and presented appropriately.
iii. Environmental Risk Management
In the July 2008 RED, EPA addressed the concerns about both aquatic and terrestrial
risks are discussed in Section III.C. The July 2008 RED also stated that EPA believed that
mitigation measures detailed in the Human Health Risk Mitigation Section would also reduce
ecological risks. The Agency stated that although buffer zones and GAPs do not directly reduce
the potential risk to ecological organisms, these mitigation measures do provide an incentive to
reduce fumigant application rates and individual treatment areas which in turn will contribute to
lower exposure and risks for non-target organisms.
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The July 2008 RED discussed exposure to terrestrial organisms such as birds and
mammals, which could occur two ways, as either oral exposure to dazomet granules or by the
inhalation route of exposure to the breakdown product MITC. Potential exposure to aquatic
organisms may occur from surface runoff/leaching and drift (wind) of MITC.
The risk assessment also identified potential acute risks of concern for birds and
mammals, since it is assumed they could be exposed to unincorporated dazomet granules. There
are uncertainties about the aquatic risks since there are no toxicity data available. Additional
eco-toxicity data are required for both dazomet and MITC.
Since dazomet is applied as a granular and watering in is required in order to activate the
product, the amount of dazomet granular left on the soil surface to which birds and mammals
could have access is not estimated in this assessment. It is likely the amount of dazomet actually
available to birds and mammals is less than assumed in the risk assessment due to watering in.
In addition, the registrants will lower the maximum rate for dazomet from 530 to 425 Ibs
a.i./A for all use sites, except for golf-course renovation. This rate reduction will also reduce the
potential for effects on non-target organisms. In addition, the structure of the buffer zones
required in this decision encourages growers to use the lowest rate and block size feasible in
order to establish the smallest possible buffer zone distance for an application. Although this
mitigation measure does not directly reduce the potential risk to ecological organisms, it does
provide an incentive to reduce fumigant application rates and individual treatment areas which in
turn will contribute to lower exposure and risks for non-target organisms.
The July 2008 RED noted that based on the fate parameters of MITC, it should not
persist in terrestrial environments because of volatilization and degradation and the available
non-targeted monitoring data does not detect MITC in the ground-water samples within the U.S.
However, MITC is highly soluble in water and has a low adsorption to soil which suggests that
there is a potential of leaching to shallow groundwater under flooded and saturated conditions.
Also, if intense rainfall or continuous irrigation occurs there is potential for MITC to move to
surface water. Due to the importance of adequate soil moisture as described in the GAP section
and the knowledge that volatilization is dazomet's most important route of dissipation, EPA
required the following language in the July 2008 RED taking these factors into consideration:
"While dazomet and its major degradate MITC have certain properties and characteristics in
common with chemicals that have been detected in groundwater (MITC is highly soluble in
water and has low adsorption to soil), volatilization is this chemical's most important route of
dissipation."
While the Agency believes that volatilization is this chemical's most important route of
dissipation, it is being removed from the groundwater statement because volatilization is
addressed in other areas of the mitigation package. The new language will state, "Dazomet has
certain properties and characteristics in common with chemicals that have been detected in
groundwater (dazomet is highly soluble in water and has low adsorption to soil)."
106
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The July 2008 RED also included language required for both tarped and non-tarped
dazomet applications to minimize potential for leaching or runoff. During the post-RED
comment period commenters stated that the following language was not clear or enforceable:
"For untarped applications of dazomet, potential leaching into groundwater and runoff into
surface water can be reduced by avoiding applications when heavy rainfall is forecasted to occur
within 24 hours."
EPA would like to clarify that the statement was meant to be advisory and not
mandatory. However in an effort to clarify the requirement the Agency has revised the July
2008 RED language as follows, "For untarped applications, leaching and runoff may occur if
there is heavy rainfall after soil fumigation." The revised statement is based on information
presented in a 2007 article by Zhang and Wang11.
b. Dazomet Antimicrobial Uses
The Agency received comments on the RED for antimicrobial uses of dazomet. A
summary of the risk mitigation measures for the antimicrobial uses of dazomet is presented
below; for further information on the antimicrobial risk assessment and mitigation, please see
these documents in the dazomet docket:
Dazomet: Revised Occupational and Residential Exposure Assessment of
Antimicrobial Uses for the Reregistration Eligibility Decision (RED) Document.
(Walls, C., Dated June 4, 2008)
Risk Mitigation Measures and Updated Label Language for the Antimicrobial Uses
of Dazomet (PC Code 035602) for the Reregistration Eligibility Decision Document.
(Garvie, H., Dated June 2 2008)
All of the dazomet antimicrobial uses are for occupational applications. These uses
include: 1) a treatment during the production of pulp and paper; 2) a materials preservative
treatment for paper coatings, non-food adhesives, epoxy flooring compounds, slurries, and high
viscous suspensions; 3) a biocide treatment used during petroleum operations; 4) a biocide
treatment used in recirculating cooling water systems; and 5) a remedial wood treatment to utility
poles.
Risks of Concern
All of the occupational handler inhalation, dermal and total MOEs were above the target
MOE of 100 (short-term and intermediate-term) except for the following scenarios:
11 Zhang, Y. and Wang, D .2007. Emission, distribution, and leaching of methyl isothiocyanate and chloropicrin
under different surface containments. Chemosphere, 2007 Jun; 68(3): 445-454.
107
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Intermediate-term dermal exposure resulting from the preservation of epoxy
flooring compounds via solid open pour methods: MOE = 58
Intermediate-term total exposure resulting from the preservation of epoxy flooring
compounds via solid open pour methods: MOE = 55
Intermediate-term dermal exposure resulting from pulp and paper slimicide use
via solid open pour methods: MOE = 79
Intermediate-term total exposure resulting from pulp and paper slimicide use via
solid open pour methods: MOE = 74
Intermediate-term inhalation exposure resulting from the maintenance dose of
microbe control in large water cooling system via metering pump: MOE = 98
Intermediate-term total exposure resulting from the maintenance dose of microbe
control in large water cooling system via metering pump: MOE = 55
Risk Mitigation Measures
For epoxy flooring open pour scenario- labeling language must state that the product
is not to exceed 3,500 ppm (maximum application rate of .35%) by weight of material
treated.
For the pulp and paper solid open pour scenario - update PPE language to state that
long sleeve coveralls will be required in addition to wearing long sleeved shirt, long
pants, shoes, socks, goggles or face shield and chemical resistant gloves.
For the cooling tower use: update personal protective equipment (PPE) language to
state that chemical resistant gloves are necessary, in addition to goggles or face
shield.
For all scenarios that use metering pumps, chemical resistant gloves must be used.
Additional label instructions for pole treatment use requiring that pre-drilled holes are
plugged immediately after application and instructions that holes are not to be drilled
through seasoning checks.
The data requirements for dazomet's antimicrobial use and label changes are found in Section V.
2. Endocrine Disrupter Effects
EPA is required under the FFDCA, as amended by FQPA, to develop a screening
program to determine whether certain substances (including all pesticide active and other
ingredients) "may have an effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or other such endocrine effects as the Administrator may designate. "
Following the recommendations of its Endocrine Disrupter Screening and Testing Advisory
Committee (EDSTAC), EPA determined that there were scientific bases for including, as part of
the program, androgen and thyroid hormone systems, in addition to the estrogen hormone
system. EPA also adopted EDSTAC's recommendation that the Program include evaluations of
potential effects in wildlife. When the appropriate screening and/or testing protocols being
considered under the Agency's Endocrine Disrupter Screening Program (EDSP) have been
108
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developed and vetted, dazomet may be subjected to additional screening and/or testing to better
characterize effects related to endocrine disruption.
3. Endangered Species Considerations
The Agency has not conducted a risk assessment that supports a complete endangered
species determination. The ecological risk assessment planned during registration review will
allow the Agency to determine whether dazomet use has "no effect" or "may affect" federally
listed threatened or endangered species (listed species) or their designated critical habitats.
When an assessment concludes that a pesticide's use "may affect" a listed species or its
designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service
and/or National Marine Fisheries Services (the Services), as appropriate.
D. Conclusion
The Agency has determined that products containing dazomet are eligible for
reregi strati on provided the risk mitigation measures outlines above are adopted and label
amendments are made to reflect these measures. Where labeling revisions are warranted,
specific language is set forth in Section V of this document.
V. What Registrants Need to Do
EPA recognizes that the extent of the mitigation needed for dazomet and the other soil
fumigants will require continued coordination among state regulatory agencies, EPA, registrants,
growers and other stakeholders to ensure that all provisions of the RED are understood, that data
are developed and evaluated expeditiously, and that bystander and worker protection measures
are implemented as soon as practicable.
When the soil fumigant REDs were issued in July, 2008, EPA specifically requested
comment on the mechanisms and timing of implementing the provisions of the REDs. After
considering stakeholder comments largely focused on the challenges of implementing many new
measures simultaneously, EPA has developed the following schedule:
July 2008 Dazomet RED issued
October 2008 Comment period closed
May 2009 EPA responds to comments, amends RED as appropriate
Mid 2009 EPA issues product and generic DCIs
September 1, 2009 Registrants must submit revised labels to EPA, reflecting phase one of
the mitigation measures as outlined in Table 2: restricted use, GAPs, rate
reductions, limitations on use sites, new handler protection measures, tarp
cutting and removal restrictions, extended worker re-entry restrictions,
training information for workers, and relevant portions of the FMP
requirements.
December, 2009 EPA reviews/approves new labeling for 2010 use season
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During 2009-10
September 1, 2010
2009-2012
2013
Labeling
EPA works with registrants, states and stakeholders to develop and begin
implementation of first responder and community outreach, applicator
training, and compliance assistance and assurance measures.
Registrants must submit revised labels to EPA reflecting all remaining
mitigation measures outlined in Table 2 including:
applicator training, restrictions on applications near sensitive sites, buffer
zones, buffer credits, buffer zone posting and buffer overlap prohibitions
and exceptions, and the full FMP requirements.
Registrants develop data per DCIs
EPA begins Registration Review for dazomet and other fumigants
Registrants must submit labeling reflecting phase one mitigation measures by September
1, 2009. All measures will need to be reflected on labels submitted to EPA by September 1,
2010. Because of the relatively large amounts of product shipped under a single label, e.g., 50
gallon drums and railroad tank cars, changes to fumigant labeling can be adopted relatively
quickly. Therefore, the Agency anticipates that labeling approved late in 2009 would begin to
appear on products used for the 2010 fumigation season.
A. Manufacturing Use Products
1. Additional Generic Data Requirements
The generic data base supporting the reregi strati on of dazomet for the eligible uses has
been reviewed and determined to be substantially complete. However, data to characterize the
hazard of MITC, the degradate of dazomet, are not available and are necessary to confirm the
reregi strati on eligibility decision documented in this RED.
Data requirements for all dazomet uses
OPPTS
Guideline
Number
870.6200
870.3550
870.3800
870.5550
870.4200
i
%
%'&
Q*
Neurotoxicity Screening Battery - Inhalation
(MITC)
Developmental Toxicity Screening Test -
Inhalation (MITC)
Reproduction and Fertility Effects - Inhalation
(MITC)
Unscheduled DNA Synthesis in Mammalian
Cells in Culture (MITC)
Chronic/Carcinogenicity Rats - Inhalation
8,
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t
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TOX
TOX
TOX
TOX
TOX
110
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870.4200
(MITC)
Chronic/Carcinogenicity Mice
(MITC)
- Inhalation
TOX
870.6200 - Neurotoxicity Screening Battery
Acute neurotoxicity study in rat via the inhalation route with pathological evaluation of
the complete respiratory tract. The Agency is using single day, acute exposures in its
consideration of buffer zones following applications of dazomet. The toxicology data available
to inform this decision are limited to an eye irritation study in human subjects and an acute
inhalation study in rats. The purpose of the acute study in rats was to determine the LC50, not
for use in hazard identification for human health risk assessment. The Agency can not evaluate
the dose response relationship of irritation and systemic effects to the nose and lungs using these
studies. This information on the respiratory tract is critical for the risk assessment as the relative
sensitivity of eye irritation and more serious health outcomes is unknown. The Agency is open
to discussing MITC-specific changes to the standard neurotoxicity screening battery to ensure
that the appropriate target organs are evaluated and that relevant dose-response data would be
generated.
870.3550 - Developmental Toxicity Screening Test - Inhalation
This inhalation developmental toxicity study in rat is being requested to further
characterize the toxicity profile of this compound via the inhalation route. MITC has been
shown to travel off fields to residential areas. As such, it is appropriate to evaluate the effects of
MITC on pregnant females and their fetuses.
870.3800 - Reproduction and Fertility Effects
Two generation reproduction study in rats via inhalation with pathological evaluation of
the complete respiratory tract in offspring is needed for MITC. This inhalation reproductive
toxicity study is being requested to further characterize the toxicity profile of this compound via
the inhalation route. MITC has been shown to travel off fields to residential areas. As such, it is
appropriate to evaluate the effects of MITC on reproductive performance and to pups directly
exposed to MITC via the inhalation route. The Agency is open to discussing with the registrant
the potential for performing the new enhanced 1-generation reproductive study instead of the
standard 2-generation study.
870.5550 - Unscheduled DNA Synthesis in Mammalian Cells in Culture
This study is required to complete the genetic toxicity testing battery for MITC.
870.4200 - Chronic/Carcinogenicity in Rats and Mice
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Carcinogenicity studies for MITC per se are not available; therefore, the carcinogenic
potential of MITC cannot be determined at this time. Although there are not expected to be
exposures of six months or longer in duration in a given year, since the same fields are often
treated every year, there is potential for exposure to occur annually for many years. Moreover,
metaplasia of the respiratory epithelium, a lesion often associated cancer, was observed after
only 28 days of exposure in the subchronic inhalation study in rats with MITC. As such EPA is
requiring inhalation carcinogenicity studies with MITC in rats and mice.
Data requirements for dazomet's soil uses
OPPTS
Guideline
Number
835.8100
Special
850.2300
850.1075
850.1025
850.1035
850.4225
850.4250
850.4400
850.3020
Special
Special
Special
Special
1
%
S'l
C3 a)
Q rt
Field Volatility from Soil
Avian Acute Inhalation, MITC
Avian Reproduction, Dazomet (bobwhite quail
and mallard)
Acute Marine/Estuarine Fish, MITC
Acute Marine/Estuarine Mollusk, MITC
Acute Marine/Estuarine Shrimp, MITC
Seedling Emergence - Tier II, MITC.
Vegetative Vigor - Tier II, MITC
Aquatic Plant Growth - Tier II, MITC (3
remaining species)
Honeybee Acute Contact, MITC
Community Outreach and Education Program
Training for Applicators Supervising
Fumigations
Training Materials for Handlers
Buffer Zone Posting Signs
I
(73
ORE
ECO
ECO
ECO
ECO
ECO
ECO
ECO
ECO
ECO
Special
Special
Special
Special
835.8100 - Field Volatility from Soil
Volatility studies are required for dazomet's soil uses to determine flux for modeling
purposes of the breakdown products of dazomet, including formaldehyde.
Special - Avian Acute Inhalation, MITC
The current estimate of avian risk is based largely on the mammal assessment. This
study will enable an inhalation risk assessment specific to birds. This is critical, since avian
exposure to MITC is expected to be largely via inhalation.
850.2300 - Avian Reproduction (bobwhite quail and mallard duck), Dazomet
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These studies are needed to assess potential reproductive effects in birds from exposure
to the parent dazomet in the granular formulation. Neither of the existing studies is able to
provide an overall NOAEL/LOAEL needed for risk assessment. There were problems with
mixing of the diet in both studies and the mallard study had unacceptably high embryo mortality
in the controls between day 21 and hatch. The studies indicate the possibility of severe
reproductive effects, particularly in the mallard study, which included effects prior to those
identified in the controls.
850.1075 - Acute Marine/Estuarine Fish. MITC
The aquatic risk assessment of dazomet use is based on exposure to MITC. Given the
use patterns evaluated, marine/estuarine species could also be exposed. This study will enable a
risk assessment for marine/estuarine species exposure.
850.1025 - Acute Marine/Estuarine Mollusk. MITC
The aquatic risk assessment of dazomet use is based on exposure to MITC. Given the
use patterns evaluated, marine/estuarine species could also be exposed. This study will enable a
risk assessment for marine/estuarine species exposure. It will also improve certainty with the
endangered species risk assessment, as this test species may be more representative of
endangered freshwater mussels than the freshwater Daphnia.
850.1035 - Acute Marine/Estuarine Shrimp. MITC
The aquatic risk assessment of dazomet use is based on exposure to MITC. Given the
use patterns evaluated, marine/estuarine species could also be exposed. This study will enable a
risk assessment for marine/estuarine species exposure.
850.4225 - Seedling Emergence - Tier IL MITC
Dazomet is used in part due to the phytotoxicity of MITC at the application site. This
study will enable the assessment of risk to non-target terrestrial plants off-site. The protocol
should be modified to test using air concentrations of MITC.
850.4250 - Vegetative Vigor - Tier IL MITC
Dazomet is used in part due to the phytotoxicity of MITC at the application site. This
study will enable the assessment of risk to non-target terrestrial plants off-site. The protocol
should be modified to test using air concentrations of MITC.
850.4400 - Aquatic Plant Growth - Tier IL MITC
Only one of five tests currently available (on duckweed) is considered to be Acceptable
(Core) (MRID #45919422). The submission of data for remaining test species under this
guideline will reduce uncertainty and improve the assessment of risk to aquatic plants. For
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example, the blue-green alga and green alga studies are 72-hour OECD studies that are only
accepted as Tier I screening studies.
850.3020 - Honeybee Acute Contact MITC
Although there is honeybee data for dazomet indicating that it is relatively non-toxic to
honey bees, there is a concern that MITC could be more toxic to bees. Therefore, honeybee
acute contact data is required for MITC.
Special Study - Training for Applicators Supervising Fumigations
EPA has determined that training, developed and implemented by registrants to foster
product stewardship, will help reduce potential risks associated with failure to adequately
manage the complexities of fumigation, and ensure compliance with fumigant product labeling.
Additionally, EPA believes that providing safety information to other fumigant handlers will
help them understand and adhere to practices that will help handlers protect themselves from
fumigant exposure.
Registrants are required to develop and implement training programs for applicators in
charge of soil fumigations on the proper use of and GAPs for soil fumigants. EPA is requiring
registrants to submit proposals for these programs. The training programs must address, at
minimum, the following elements: how to correctly apply the fumigant; how to protect handlers
and bystanders; how to determine buffer zone distances; how to develop a FMP and complete the
post fumigation application summary; how to determine when weather and other site-specific
factors are not favorable for fumigant application; how to comply with required GAPs and
document compliance in the FMP. The training program must be made available to applicators
at least annually. The registrant shall provide documentation, such as a card or certificate, to
each applicator who successfully completes the training. This documentation shall include the
applicator's name, address, license number, and the date of completion.
The registrant must be able to provide to federal, state, or local enforcement personnel,
upon request, the names, addresses, and certified applicator license numbers of persons who
successfully completed the training program, as well as the date of completion. Applicators
supervising fumigations must have successfully completed the program within the preceding 36
months and must document when and where the training program was completed in the FMP.
The registrants will be required to (1) develop a database to track which certified applicators
have successfully completed the training and (2) make this database available to state and/or
federal enforcement entities upon request. In addition, the applicator must provide to Federal,
State, or local enforcement personnel, upon request, documentation that verifies completion of
the appropriate training program(s).
Training programs must also include information on how to develop and implement
emergency response plans to ensure that applicators are prepared in the event that a problem
develops during or shortly after the fumigant application. EPA is also requiring registrants to
incorporate a mechanism for evaluating the effectiveness of their training programs at conveying
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the required information to participants and for determining whether participants have
successfully completed the training program.
Special Study - Training Materials for Handlers
EPA has determined that registrants must prepare and disseminate training information
and materials for other fumigant handlers, i.e., those working under the supervision of the
certified applicator in charge of fumigations. The training materials must address, at minimum,
the following elements: (1) what fumigants are and how they work, (2) safe application and
handling of soil fumigants, (3) air monitoring and respiratory protection requirements for
handlers, (4) early signs and symptoms of exposure, (5) appropriate steps to take to mitigate
exposures, (6) what to do in case of an emergency, and (7) how to report incidents. Registrants
must provide this training information through channels open to the public (e.g., via a website).
Pesticide labels will require that applicators supervising fumigations provide this training
information to handlers under their supervision before they perform any fumigant handling task,
or they must ensure that handlers have been provided the required information within the
preceding 12 months. The label will also require that the training information be provided in a
manner that the handler can understand. Applicators supervising fumigations must ensure the
FMP includes how and when the required training information was provided to the handlers
under their supervision.
Special Study - Buffer Zone Posting Signs
EPA has determined that registrants must prepare and disseminate generic buffer zone
posting signs which meet the following criteria: (1) signs must remain legible during the entire
posting period (2) signs must meet the general standards outlined in the WPS for text size and
legibility (see 40 CFR ง170.120). The requirements for the contents of the sign are as follows
The treated area sign (currently required for
fumigants) must state the following:
~ Skull and crossbones symbol
- "DANGER/PELIGRO,"
~ "Area under fumigation, DO NOT
ENTER/NO ENTRE,"
~ "Dazomet fumigant in USE,"
~ the date and time of fumigation,
~ the date and time entry prohibition is lifted
~ Name of this product, and
~ name, address, and telephone number of the
certified applicator in charge of the fumigation.
The buffer zone sign must include the
following:
Do not walk sign
-- "DO NOT ENTER/NO ENTRE,"
~ "Dazomet OR [Name of product] Fumigant
BUFFER ZONE,"
~ contact information for the certified
applicator in charge of the fumigation
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Registrants must capture all of the information above, excluding the contact information
for the certified applicator in charge of fumigating. However, registrants must provide
appropriate space on the sign, and the sign must be made of material appropriate for applicators
to write in this information on the buffer zone posting signs. Registrants must provide buffer
zone posting signs at the point of sale for applicators to use. EPA is requiring registrants to
submit proposals that must address their strategy for development and dissemination of the
buffer zone posting signs.
Data requirements for dazomet's antimicrobial uses
Chemical Manufactures Association (CMA) unit exposure data to be called in:
GLN 875.1200 - dermal indoor exposure
GLN 875.1400 - inhalation indoor exposure
GLN 875.1600 - applicator exposure monitoring data reporting
GLN 875.1700 - product use information
Because dazomet degrades into MITC, the Agency needs MITC air concentration monitoring
data for all enclosed facilities that utilize dazomet. The guideline numbers are as follows:
GLN 875.2500 - inhalation exposure study
GLN 875.2700 - product use information
GLN 875.2800 - description of human activity
GLN 875.2900 - post-application data reporting and calculations
Residue data are needed to support the dazomet antimicrobial use in pulp and paper
manufacturing. The purpose of this confirmatory study is to demonstrate that the paper
manufacturing processes remove any residual dazomet and MITC - GLN 860.1520
Avian acute oral LDso data using technical MITC to bobwhite quail or mallard duck - GLN
850.2100
Acute estuarine fish LCso data using technical MITC - GLN 850.1075
Acute mysid shrimp using technical MITC - GLN 850.1035
Acute bivalve embryo larvae using technical MITC to Eastern oyster - GLN 850.1055
2. Labeling for Manufacturing-Use Products
To ensure compliance with FIFRA, manufacturing use product (MUP) labeling must be
revised to comply with all current EPA regulations, PR Notices, and applicable policies.
B. End-Use Products
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1. Additional Product-Specific Data Requirements
Section 4(g)(2)(B) of FIFRA calls for the Agency to obtain any needed product-specific
data regarding the pesticide after a determination of eligibility has been made. The Registrant
must review previous data submissions to ensure that they meet current EPA acceptance criteria
and if not, commit to conduct new studies. If a registrant believes that previously submitted data
meet current testing standards, then the study MRID numbers must be cited according to the
instructions in the Requirement Status and Registrants Response Form provided for each
product. The Agency intends to issue a separate product-specific data call-in (PDCI), outlining
specific data requirements.
2. Labeling for End-Use Products
In order to be eligible for reregi strati on, registrants must amend all product labels to
incorporate the risk mitigation measures outlined in Section IV.
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Appendix A
Appendix A(l). Dazomet (PC Code 035602) Soil Fumigant Uses Eligible for Reregistration
Use Site
Formulation
Method of
Application
Maximum Application Rate
Use Limitations
Soil
Nonbearing crops (such as
orchard crops, berries, and
flower bulbs), ornamental
sites (establishing or
renovating), field nurseries
(establishing or renovating),
compost piles, potting soils,
and strawberries and
tomatoes in California only
Golf greens/tees, turf sites
(establishing or renovating),
Greenhouses
Granular
Granular
Granular
Tractor drawn
spreader
Tractor drawn
spreader
Tractor drawn
spreader/
mechanical
spreader
425 Ibs ai/A for incorporated
applications.
265 Ibs ai/A for surface
applications.
530 Ibs ai/A for incorporated
applications.
265 Ibs ai/A for surface
applications.
265 Ibs ai/A for surface
applications.
Application with hand-held applications is
prohibited.
See the label table in Section V for additional use
restrictions.
Application with hand-held applications is
prohibited.
See the label table in Section V for additional use
restrictions.
Application with hand-held applications is
prohibited.
See the label table in Section V for additional use
restrictions.
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Appendix A(2). Dazomet (PC Code 035602) Antimicrobial Uses Eligible for Reregistration
Use Site
Formulation
Method of
Application
Application Rate/ No. of
applications
Use Limitations
Materials Preservatives
Slurries and high viscosity
suspensions (starches, non-
food use adhesives, clay
slurries, glues, coatings for
paper and resin emulsions)
Slurries and high viscosity
suspensions (starches, non-
food use adhesives, clay
slurries, and coatings for
paper)
Ready to use
solution
1706-193
Soluble
concentrate
1448-104
33753-25
Flowable
concentrate
67869-25
Soluble
concentrate
67869-46
Formulation
Intermediate
1448-98
Ready to use
solution
1448-103
1448-395
1706-193
9386-3
Pump or Gravity
feed
Pump or Gravity
feed
Pump or Gravity
feed
Pump or Gravity
feed
Pump or Gravity
feed
Add 0.03-0.50% by weight
based on the total
formulation. Actual use
levels should be determined
by a test of the system.
Add 0.01-0. 11% by weight
based on the total
formulation. Actual use
levels should be determined
by a test of the system.
Add 0.5-2.5% by weight of
the suspension or dispersion.
Actual use levels should be
determined by a test of the
system.
Add at concentration of 250
ppm to 5000 ppm to water
Add 0.04-0.5 % by weight
based on the total
formulation. Actual use
levels should be determined
by a test of the system.
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Use Site
Formulation
Method of
Application
Application Rate/ No. of
applications
Use Limitations
9386-28
Ready to use
solution
74655-1
Pump or Gravity
feed
Add 1.67-2.5 pounds per
1000 gallons of material to be
preserved. Actual use levels
should be determined by a
test of the system.
Formulation
Intermediate
1448-98
Slurries and high viscosity
suspensions (starches, non-
food use adhesives, clay
slurries, coatings for paper,
and glues)
Soluble
concentrate
1706-195
Pump or Gravity
feed
Add 0.04-0.1% by weight
based on the total
formulation. Actual use
levels should be determined
by a test of the system.
Paper and pulp mill Slime
control
Ready to use
solution
1448-103
1448-395
9386-3
9386-28
Pump or Gravity
feed
Intermittent method: Add 12-
20 oz per ton (dry basis) of
pulp or paper for two hours
every 8 hours.
Continuous method: Add 5-
15 oz per ton (dry basis) of
pulp or paper on a continuous
basis.
Badly fouled systems may require cleaning before
initial treatment.
Ready to use
solution
1706-193
Pump or Gravity
feed
Add 5-36 oz per ton of
finished product on a
continuous basis. Actual use
levels should be determined
by a test of the system.
Shock dosages are to be avoided. Badly fouled
systems may require cleaning before initial
treatment.
120
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Use Site
Formulation
Method of
Application
Application Rate/ No. of
applications
Use Limitations
Ready to use
1706-195
Pump or Gravity
feed
0.083-0.415 Ibs. per 1000
gallons of treated water.
Actual use levels should be
determined by a test of the
system.
Flowable
concentrate
67869-25
Pump or Gravity
feed
Add 0.5-2.5% by weight of
the suspension or dispersion.
Actual use levels should be
determined by a test of the
system.
Badly fouled systems may require cleaning before
initial treatment.
67869-46
Pump or Gravity
feed
Add concentrations of 250-
4000 ppm into make up water
during the grind during the
manufacturing process
Ready to use
solution
74655-1
Pump or Gravity
feed
If system is noticeably fouled,
add product at the rate of 0.5
to 3.0 pounds per ton of pulp
or paper product. Additions to
additive system should be
made directly at the rate of
0.2 to 4.0 pounds (24 to
480ppm) per 1000 gallons.
Add product at the rate of
0.5-2.0 pounds per ton of
pulp or paper produced. Treat
the system as needed to
maintain control. Additions
to the additive system may be
reduced to 0.2 to 2.0 pounds
(24 to 240 ppm) per 1000
gallons.
Badly fouled systems may require cleaning before
initial treatment.
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Use Site
Construction Products:
Caulking material, Concrete
additives, concrete and
masonry additives
Coatings for paper
Epoxy Flooring Compounds
Formulation
Soluble
concentrate:
67869-46
Soluble
concentrate:
67869-46
Ready to use
solution
1448-104
Formulation
Intermediate
1448-98
Method of
Application
Incorporation
Incorporation
Solid open pour
Water-soluble
packaged solids
Application Rate/ No. of
applications
Can be fed at concentration of
250 to 6000 ppm either
directly to the finished
product or to one of the raw
materials
Add at concentration of 250
to 4000 ppm into the makeup
water during the grind during
the manufacturing process
0.59% a.i. by weight (0.6%
product by weight of material
treated X 98% a.i. in product)
Use Limitations
Industrial Processes and Water Systems
Recirculating cooling water
systems
Ready to use
solution
1448-103
1448-395
9386-3
9386-28
Soluble
concentrate
Pump or Gravity
feed
Pump or Gravity
feed
Add 3.25-6.5 ounces of
product to 1000 gallons of
water to produce a 30-60ppm
concentration initially. Add
0.5-3.25 ounces of product to
1000 gallons of water to
produce a 5-30ppm
concentration to maintain
control.
Add 16 ounces of product per
each 5,000-16,000 gallons of
122
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Use Site
Recirculating cooling water
systems
Formulation
1448-104
Formulation
Intermediate
1448-98
Method of
Application
Application Rate/ No. of
applications
water in system initially to
produce a concentration of
7.5-15ppm. Add 16 ounces
of product per each 15,000-
96,000 gallons of water in
system to produce a
concentration of 1.25-7. 5ppm
to maintain control.
Use Limitations
123
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Use Site
Oilfield water treatment and
water floods
Formulation
Ready to use
solution
1448-103
1448-395
9386-3
9386-28
Soluble
concentrate
33753-25
Method of
Application
Open Pour
Open Pour
Application Rate/ No. of
applications
Add 2. 1 pounds of product to
1000 gallons of drilling fluid
to produce a 2500ppm
concentration initially. Add
0.30 pounds of product to
1000 gallons of drilling fluid
to produce a 350ppm
concentration to maintain
control.
Add 1.67 pounds of product
to 1000 gallons of drilling
fluid to produce a 200ppm
concentration initially. Add
1.25 pounds of product to
1000 gallons of drilling fluid
Use Limitations
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Use Site
Soluble
Oilfield Drilling Muds and
work over or completion
fluids
Formulation
concentrate
1448-104
Soluble
concentrate
1448-104
9386-13
33753-25
Ready to use
solution
1448-103
9386-3
Method of
Application
Open Pour
Application Rate/ No. of
applications
to produce a 150ppm
concentration to maintain
control.
Add 5.22 pounds of product
to 1000 gallons of drilling
fluid to produce a 625ppm
concentration initially. Add
0.73 pounds of product to
1000 gallons of drilling fluid
to produce an 88ppm
concentration to maintain
control.
For water soluble packaging:
One pound per 191 gallons
initially then one pound per
1363 gallons to maintain
control.
Add 175- 182 pounds of
product to 1000 barrels of
drilling fluid to produce a
500-520ppm concentration.
For best results add product
in a thin stream to the pit
while drilling fluid is
circulating.
Add 75 pounds of product to
1000 barrels of drilling fluid
to produce a 2080-2500ppm
concentration. For best
results add product in a thin
stream to the pit while
drilling fluid is circulating.
Use Limitations
125
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Use Site
Formulation
Ready to use
solution
1448-395
9386-28
Method of
Application
Application Rate/ No. of
applications
Add 75 pounds of product to
1000 barrels of drilling fluid
to produce a 2080ppm
concentration. For best
results add product in a thin
stream to the pit while
drilling fluid is circulating.
Use Limitations
Wood Preservatives
Utility Poles, pilings,
timbers, solid and laminated
wood products.
Pelleted solid
7969-162
71406-5
1448-104
Applied in
treatment holes
drilled into wood
product to be
treated
Drill three 7/8 in. diameter by
14 in. long holes at a steep
angle (45 deg or greater) in a
spiral patter starting at ground
line. Apply 70 grams of end
use product into each hole.
Do not overfill treatment
hole. Add liquid accelerant if
desired to treatment hole.
Plug treatment hole with a
tight fitting treated wooden
dowel, removable plastic plug
or other suitable cap.
For wood in ground contact, the first hole should
start at or slightly below ground line and should
be arranged in a spiral pattern covering the
treatment zone with about 6" to 12" vertically
between holes.
An accelerant of a 1% solution of copper
napthenate in mineral spirits may be added to
treatment holes after application of the product
and is designed to speed up the decomposition and
release of the active fumigant inside the wood
product. Keep accelerant away from product
except when in treatment holes, which should be
plugged immediately after they combine.
Not to be used indoors or underneath indoor
structures.
Technical Registrations
Chemical:
7969-161
N/A
N/A
For use in the formulation of dazomet end-use
registrations only.
For use in the formulation of microbiocides and
wood protectants only.
126
Technical
-------
Use Site
Formulation
Method of
Application
Application Rate/ No. of
applications
Use Limitations
Technical
chemical:
9386-10
N/A
N/A
Technical
chemical:
67869-18
N/A
N/A
For use in the formulation of dazomet end-use
registrations only
For use in the formulation of dazomet end-use
registrations only
For use in the following Industrial Process Water
Systems: pulp and paper mill systems.
For Material Preservations of slurries and high
viscosity suspensions (starches, non-food
adhesives, clay slurries, glues, coatings for paper,
and resin emulsions)
127
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Appendix B. Table of Generic Data Requirements and Studies Used to Make the
Reregistration Decision
This section is currently not available.
128
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Appendix C. Technical Support Documents
Additional documentation in support of this RED is maintained in the OPP docket,
located in room S-4400, One Potomac Yard (South Building), 2777 S. Crystal Drive,
Arlington, VA 22202. It is open Monday through Friday, excluding legal holidays, from 8:30
am to 4 pm. All documents, in hard copy form, may be viewed in the OPP docket room or
downloaded or viewed via the Internet at the following site: http://www.regulations.gov
These documents include:
Health Effects Support Documents
Methyl Bromide, 1,3-Dichloropropene, Chloropicrin, Dazomet, Metam
Sodium/Potassium, MITC: Health Effects Division (HED) Component of Agency
Response To Comments On 2008 Reregi strati on Eligibility Documents, May 14, 2009
Dazomet: Third Revision of the HED Human Health Risk Assessment. April 30, 2009
Dazomet: Updated Final Revised HED Chapter of the Reregi strati on Eligibility Decision
Document (RED). Smith, C. et al.; D354014; June 24, 2008.
Mode of Action, Eye Irritation, and the Intra-Species Factor: Comparison of Chloropicrin
and MITC. Lowit, A. and Reaves, E.; D293356; TXR 0054860; June 25, 2008.
The Health Effects Division's Response to Comments on EPA's Phase 5 Reregi strati on
Eligibility Decision Document for Dazomet. Smith, C.; D306858; June 18, 2008.
Environmental Fate and Ecological Effects Support Documents
Further Response to Public Comments on the 7/9/08 Completed Dazomet RED,
Rothman, G. and Felkel, J. March 3, 2009
Revised Environmental Fate and Ecological Risk Assessment For Dazomet. Khan. F.
and Felkel, J.; D306855; April 8, 2008.
Response to Phase 5 Public Comments on the Phase 4 Dazomet Environmental Fate and
Ecological Risk Assessment. Khan, F., and Felkel, J.; D306854; April 2, 2008.
Biological and Economical Analysis Support Documents
Response to BEAD Related Public Comments Received on the Reregi strati on Eligibility
Decision for Chloropicrin, Dazomet, Metam Potassium, Metam Sodium, and Methyl
Bromide (DP# 363545) May 14, 2009.
Analysis of Soil Fumigant Risk Management Requirements using Geographic
Information Systems: Case Studies based on a Forest Seedling Nursery (DP#363546).
May 13, 2009.
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Process for Defining High-Use Fumigation Areas at the State and County Levels
(DP#364647) May 14, 2009.
Assessment of the Benefits Soil Fumigants (Methyl Bromide, Chloropicrin, Metam-
Sodium, Dazomet) Used by Forest Tree Seedling Nurseries. (Chiri, D. and Donaldson, D.
Dated April 19, 2007) EPA-HQ-OPP-2005-0125-0044
Assessment of the Benefits of Soil Fumigation with Methyl Bromide, Chloropicrin,
Dazomet, Metam Potassium and Metam Sodium for Use in Raspberry Nurseries, Fruit
and Nut Deciduous Tree Nurseries, and Rose Bush Nurseries in California. (Faulkner, J.,
and Yourman, L., Dated April 20, 2007) EPA-HQ-OPP-2005-0125-0045
Assessment of the Benefits of Soil Fumigation with Chloropicrin, Methyl Bromide,
Metam-sodium, and Dazomet In Strawberry Nursery Runner Production. (Yourman, L.,
and Smearman, S., Dated April 19, 2007) EPA-HQ-OPP-2005-0125-0054
Assessment of the Benefits of Soil Fumigation with Chloropicrin, Methyl Bromide,
Metam Sodium and Dazomet in Ornamental Production. (Chiri, A., and Wyatt, T., Dated
April 18, 2007)EPA-HQ-OPP-2005-0128-0060
Response to Phase 5 BEAD Related Public Comments Received on the Reregi strati on of
Chloropicrin, Dazomet, Metam Potassium, Metam Sodium, and Methyl Bromide.
(Donaldson, D. et al., Dated June 2008)
Review of Stakeholder Submitted Impact Assessments of Proposed Fumigant Buffers,
Comments on Initial Buffer Zone Proposal, and Case Studies of the Impact of a Flexible
Buffer System for Managing By-Stander Risks of Fumigants. (Wyatt. T., et al, Dated
June 2008)
Antimicrobial Assessment Support Documents
Dazomet Antimicrobial Risk Mitigation Paper. Garvie, H., Dated June 2, 2008.
Dazomet: Revised Occupational and Residential Exposure Assessment of Antimicrobial
Uses for the Reregi strati on Eligibility Decision (RED) Document. Walls, C.; D Dated
June 2008.
Dazomet: Dietary Risk Assessment of Antimicrobial Uses for the Reregistration
Eligibility Decision (RED) Document. (Walls, C., Dated March 2007)
Environmental Fate and Ecological Risk Assessment for the Reregistration of Dazomet
(035602) andMITC (068103) -Antimicrobial Uses. (Petrie, R., Dated April 2007)
Phase 6 Response to Substantive Public Comments on Antimicrobials Division's
Occupational and Residential Assessments for the Reregistration Eligibility Decision
130
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(RED) Documents for the following chemicals: Methylisothiocyanate (MITC), Metam
Sodium, Dazomet, and Chloropicrin. Walls, C.; February 14, 2008.
Buffer Zone Credits Support Document
Methyl Bromide (PC Code 053201), Chloropicrin (PC Code 081501), Dazomet (PC
Code 035602), Metam Sodium and Potassium (PC Codes 039003 &039002), MITC (PC
Code 068103), DP Barcode 362369, Updated Health Effects Division Recommendations
for Good Agricultural Practices and Associated Buffer Credits. May 14, 2009
Factors Which Impact Soil Fumigant Emissions - Evaluation for Use in Soil Fumigant
Buffer Zone Credit Factor Approach. Dawson, J. and Smith, C.; D306857; June 9, 2008.
Risk Management Support Documents
SRRD's Response to Post-RED Comments for the Soil Fumigants. Rice, M. and
McNally, R; May 2009.
SRRD's Response to Phase 5 Public Comments for the Soil Fumigants. Rice, M. and
McNally, R.; July 2008.
Risk Mitigation Options to Address Bystander and Occupational Exposures from Soil
Fumigant Applications. EPA-HQ-OPP-2005-0128-0031.
131
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Appendix D. Bibliography
This section is not currently available.
132
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Appendix E. FMP Template_(template uses MeBr soil applications as an example)
133
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Certified Applicator Supervising the Fumigation
Name and phone number: License number:
Employer name and address:
General Site Information
D Commercial applicator
D Private applicator
Date of completing registrant
training program:
Application block location, address, or global positioning system (GPS) coordinates:
Name, address, and phone number of owner/operator of application block:
General Application Information
Tarps (check here if section is not applicable D )
Lot#:
Name and phone number of contact person responsible for repairing tarps:
EPA Registration Number:
Thickness:
Schedule for checking tarps for damage, tears, and other problems:
Maximum time following notification of damage that the person(s) responsible for tarp repair will respond:
Minimu
Other factors used to determine when tarp repair will be conducted:
Equipm
Schedul
m size of damage that will be repaired:
ent/methods used to cut tarps:
e and target dates for removing tarps:
134
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Soil Conditions
Description of method us
Weather Conditions
ed to determine soil moisture level:
Summary of the weather forecast for the day of the application and the 48-hour period following the fumigant application (may attach a copy
of printed forecast to FMP):
Buffer Zones
Application method:
D Bedded
D Broadcast
D Hot gas - outdoor
D Hot gas - greenhouse
D Hand held probes
Block size
from lookup
table on label
(acres):
List and describe areas in the buffer zone that are not under the control of owner/operator of the
Buffer zone
distance:
ft
application block:
Personal Protective Equipment for Handlers
Handler Task Clot
Emergency Response Plan
Respirator Type, Filter Cartridge Eye
ling Type and Change-out Schedule Protecti
on Gloves Other
Description of evacuation routes:
Locations of telephones:
Contact information for first responders:
Local/state/federal contacts: Ot
ler contact information for emergencies:
Emergency procedures/responsibilities in case of an incident, equipment/tarp/seal failure, odor complaints or elevated air concentration levels
outside buffer zone suggesting potential problems, or other emergencies).
135
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Posting Signs
Name and phone number of person that is doing posting:
Location of posting signs:
Procedures for posting and sign removal:
Site Specific Response and Management D Fumigation Site Monitoring or DResponse Information for Neighbors
If Response Information for Neighbors has been selected, completed the following:
If buffer zone is 25-100 ft: D Neighbors within 50 ft of buffer zone D No neighbors within 50 ft of buffer zone
D Neighbors within 100 ft of buffer zone D No neighbors within 100 ft of buffer zone
D Neighbors within 200 ft of buffer zone D No neighbors within 200 ft of buffer zone
D Neighbors within 300 ft of buffer zone D No neighbors within 300 ft of buffer zone
D Neighbors within 300 ft of buffer zone D No neighbors within 300 ft of buffer zone
If buffer zone is 100-200 ft:
If buffer zone is 200-300 ft:
If buffer zone is > 300 ft:
If buffer zones overlap
List of residences and businesses informed (neighboring property owners):
Name, address, and phone number of person providing information:
Method used to provide information:
Notice to State Lead Tribal Agencies
Date notified:
Communication Between Applicator, Land Owner/Operator, and Other On-site Handlers
Plan for communicating to the land owner/operator and all on-site handlers (e.g., tarp cutters/removers, irrigators) requirements to comply
with label including location and start/stop times of buffer zones; timing of tarp cutting/removal, and PPE:
Names and phone numbers of persons contacted:
Date contacted:
136
-------
Comments/notes:
137
-------
Site Map
Location of application block:
Application block Buffer zone
_งJ Bus stop I^งJ Water body l_2ฃj Daycare facility
| NH
Nursing home
Map Legend
Property lines ~~~ Roads
|Sch I
I School
Right-of-way
J Nearby application block
Walkway, sidewalk, path
I Inpatient clinic I " I Prison ^Q' Well
Assisted living facility
138
-------
Handler Information
Handler Name, Address, and Phone
Number
Employer Name, Address, and Phone
Number
Tasks They are Trained and
Authorized to Perform
DateofPPE
Training
Date of
Medical
Qualification to
Wear a
Respirator
Date of Fit
Testing for
Respirator
139
-------
Air Monitoring Plan
For Buffer Zone Monitoring: (check here if section is not applicable D )
Name of handler
performing monitoring
activities
Handler address
Handler phone
number
Location of monitoring
Timing
For Handlers without Respiratory Protection: (check here if section is not applicable D )
If sensory irritation is experienced: D Intend to cease operations D Intend to continue operations with respiratory protection
If intend to continue operations with respiratory protection, complete section for Handlers with Respiratory Protection below.
Monitoring equipment:
For Handlers with Respiratory Protection: (check here if section is not applicable D )
Representative Handler Tasks to be Monitored
Monitoring Equipment
Timing
140
-------
Air Monitoring Plan for Methyl Bromide Formulation with < 20% Chloropicrin
For Buffer Zone Monitoring: (check here if section is not applicable D )
Name, address, and phone number of person(s) to perform sampling:
Area or Structure to be Monitored Before Reentry is Permitted
Monitoring Equipment
Timing
For Handlers with Respiratory Protection:
Representative Handler Tasks to be Monitored
Monitoring Equipment
Timing
141
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Methyl Bromide FMP Check List
General Site Information
A map, aerial photo, or detailed sketch is attached to this FMP that shows each of the following with distances from the application site
labeled: field location, application block dimensions, buffer zones, property lines, roads, bus stops, water bodies, wells, rights-of-ways,
nearby application blocks, surrounding structures, and sites requiring 1A and 1A mile buffer zones.
Supervision of Handlers
An on site certified applicator will directly supervise the handlers participating in the application starting when the fumigant is first
introduced into the soil and ending after the fumigant has stopped being delivered/dispensed to the soil and the soil is sealed.
After the application is complete, and before leaving the application block, the certified applicator has provided the owner/operator and
handlers with written information necessary to comply with the label and procedures outlined in the FMP.
Fumigant safe handling information has been provided to each handler involved in the application or confirm that each handler
participating in the application has received fumigant safe handling information in the past 12 months.
For all fumigation handling tasks, at least 2 WPS-trained handlers must be present.
Weather Conditions
Wind speed at the application site is a minimum of 2 mph at the start of the application or forecasted to reach at least 5 mph during the
application.
A shallow, compressed (low-level) temperature inversion is not forecast to persist for more than 18 consecutive hours during the 48-hour
period after the application.
An air-stagnation advisory is not in effect for the area where the application site is located.
If air temperatures have been above 100 degrees F in any of the 3 days prior to application, then soil temperature will be measured and
recorded in the post application summary report.
Soil Conditions
The soil has been properly prepared and the surface has been checked to ensure that it is free of clods that are golf ball size or larger.
The area to be fumigated has been tilled to a depth of 5 to 8 inches.
Field trash has been properly managed (e.g., residue from a previous crop has been worked into the soil to allow for decomposition prior
to fumigation, little or no crop residue is present on the soil surface, and crop residue that is present does not interfere with the soil seal).
The soil temperature at the depth of injection ^ 90 degrees F at the beginning of the application.
The soil moisture at 9 inches below the surface is sufficient (field capacity is 50 to 80 percent).
Trash pulled by the shanks to the ends of the field will be covered with tarp or soil before making the turn for the next pass.
Shank Applications (check here if section is not applicable D )
For tarped-broadcast and -bedded applications, injection points will be at least 8 inches from the nearest final soil/air interface.
For tarped-bedded applications, the injection depth will not be as deep as the lowest point of the tarp (i.e., the lowest point of the tuck).
For untarped-bedded applications, the injection points will be at least 12 inches from the nearest final soil/air interface.
For untarped-broadcast applications, the injection points will be at least 18 inches from the nearest final soil/air interface.
For broadcast untarped applications, a disc or similar equipment will be used to uniformly mix the soil to at least a depth of 3 to 4 inches
to eliminate the chisel or plow traces and will following elimination of the chisel trace, the soil surface will be compacted with a
cultipacker, ring roller, and roller in combination with tillage equipment.
For performed bed applications, the soil will be sealed by disruption of the chisel trace using press sealers, bed shapers, cultipackers, or
by re-shaping (e.g., relisting, lifting, replacing) the beds immediately following injection.
For beds formed at the time of application, the soil will be sealed by disrupting the chisel trace using press sealers, or bed shapers.
For shanked bedded and broadcast applications, tarps will be installed immediately after fumigant is injected into the soil.
Applicators have been trained and instructed not to apply or allow fumigant to drain onto the soil surface.
For each injection line a check valve been located as close as possible to the final injection point, or applicators will drain/purge the line
of any remaining fumigant prior to lifting injection shanks from the ground.
Applicators have been trained and instructed not to lift injection shanks from the soil until the shut-off valve has been closed and the
fumigant has been depressurized (passively drained) or purged (actively forced out via air compressor) from the system.
Brass, carbon steel, or stainless steel fittings must be used throughout application rigs.
Polyethylene tubing, polypropylene tubing, Teflonฎ tubing or Teflonฎ -lined steel braided tubing have been used for all low pressure
lines, drain lines, and compressed gas or air pressure lines and is all other tubing Teflonฎ -lined steel braided.
Application equipment been inspected to ensure that application rigs do not contain galvanized, PVC, nylon, or aluminum pipe fittings.
All rigs include a filter to remove any particulates from the fumigant, and a check valve to prevent backflow of the fumigant into the
pressurizing cylinder or the compressed air system.
All rigs include a flowmeter or a constant pressure system with orifice plates to insure the proper amount of fumigant is applied.
Applicators have been trained and instructed to ensure that positive pressure is maintained in the cylinder at not less than 200 psi during
the entire time it is connected to the application rig, if a compressed gas cylinder is used. (This is not required for a compressed air
system that is part of the application rig because if the compressor system fails the application rig will not be operable).
Application rigs are equipped with properly functioning check valves between the compressed gas cylinder or compressed air system and
the fumigant cylinder.
Applicators have been trained and instructed to always pressurize the system with compressed gas or by use of a compressed air system
before opening the fumigant cylinder valve.
142
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Before using a fumigation rig for the first time, or when preparing it for use after storage, applicators have been trained and instructed to:
0 Check the filter, and clean or replace the filter element as required.
0 Check all tubes and chisels to make sure they are free of debris and obstructions.
0 Check and clean the orifice plates and screen checks, if installed.
0 Pressurize the system with compressed gas or compressed air, and check all fittings, valves, and connections for leaks using soap
solution.
Applicators have been trained and instructed to:
0 Install the fumigant cylinder, and connect and secure all tubing. Slowly open the compressed gas or compressed air valve, and
increase the pressure to the desired level. Slowly open the fumigant cylinder valve, always watching for leaks.
0 When the application is complete, close the fumigant cylinder valve and blow residual fumigant out of the fumigant lines into the
soil using compressed gas or compressed air. At the end of the application, disconnect all fumigant cylinders from the application
rig. At the end of the season, seal all tubing openings with tape to prevent the entry of insects and dirt.
ฐ Calibrate all application equipment and ensure that all control systems must be working properly.
Hot Gas Applications (check here if section is not applicable D )
Tarps have been installed prior to starting the application.
All delivery tubes have been placed under the tarp in such a way that they do not move during the application of methyl bromide.
The fumigant will be introduced from outside of the greenhouse.
All fittings, connections, and valves have been checked for leaks prior to fumigation and if cylinders are replaced during the fumigation
process, the connections and valves were checked for leaks prior to continuing the job.
Tree Replant (non-shank) Application (check here if section is not applicable D )
For each individual tree-site, the tree stump and primary root system have been removed and the tree hole has been backfilled with soil
before application.
The fumigant will be injected at a depth of at least 18 inches into the soil.
The wand will be cleared using nitrogen or compressed air before removing it from the soil and after the wand is cleared and removed
from the soil, the injection hole will be covered with soil and tamp or the soil will be compacted over the injection hole.
Buffer Zones
There are no difficult to evacuate sites within 1A (or Vs) miles of the application block that will be occupied during the buffer zone period.
There are no bus stops or other locations where persons wait for public transit within the buffer zone.
There are no buildings used for storage such as sheds, barns, garages, within the buffer zone that are occupied or that share a common
wall with an occupied structure.
For areas in the buffer zone that are not under the control of owner/operator of the application block, written agreement has been
obtained from occupants that they will voluntarily vacate the buffer zone during the entire buffer zone period.
For nearby agricultural areas that are in the buffer zone the owner/operator of that property provided written agreement that they, their
employees, or other persons will stay out of the buffer zone during the entire buffer zone period.
For publicly owned and/or operated areas (e.g., parks, rights of way, side walks, walking paths, playgrounds, athletic fields) written
permission has been given to include the public area in the buffer zone from the appropriate local and/or state officials.
Buffer Zones Overlap (check here if section is not applicable D )
A minimum of 12 hours has elapsed from the time the 1st application ends until the 2nd application begins.
If a structure exists within 300 feet of the buffer zone, appropriate emergency preparedness and response procedures are followed.
Certified applicator has informed handlers of the overlapping buffers and associated health protection requirements.
Personal Protective Equipment for Handlers
At least 1 air rescue device (e.g., SCBA) is on-site in case of an emergency.
All of the handler's PPE has been cleaned and maintained as required by the WPS for Agricultural Pesticides.
Hazard Communication
The application area buffer zone has been posted in accordance with the label.
Pesticide product labels and material safety data sheets are on-site and readily available for employees to review.
Recordkeeping
The owner/operator of the application block has been informed that he/she as well as the certified applicator must keep a signed copy of
the site-specific FMPs and the post-application summary record for 2 years from the date of application.
I have verified that this site-specific FMP reflects current site conditions and product label directions before beginning the
fumigation.
Signature of certified applicator supervising the fumigation Date
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Post-Application Summary
General Application Information
Size of application block:
Weather Conditions
Summary of the weather on the day of the application:
Summary of the weather during the 48-hour period following the fumigant application:
Soil Conditions (check here if section is not applicable D )
Soil temperature if air temperatures were above 100 degrees F in any of the 3 days prior to the application:
Tarp Damage and Repair (check here if section is not applicable D )
Location and size of tarp damage:
Description of tarp/tarp seal/tarp equipment failure:
Date and time of tarp repair:
Additional comments or other deviations from FMP (if applicable):
Tarp Removal (check here if section is not applicable D )
Description of tarp removal (if different than in the FMP):
Date tarps were removed:
Odor Complaints (check here if section is not applicable D )
Person filing odor complaint:
D On-site handler
D Person off-site
If off-site person, name, address, and phone number of person filing odor complaints:
Description of control measures or emergency procedures followed after odor complaint:
Additional comments:
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Description of Incidents (check here if section is not applicable D )
Date and time:
Description of emergency procedures followed:
Additional comments:
Elevated Air Concentration Levels (check here if section is not applicable D )
D On-site
D Outside buffer zone
Location of elevated air concentration levels:
Date and time:
Description of elevated air concentration levels: (provide air monitoring results on next page)
Description of control measures or emergency procedures followed:
Description of deviations from FMP (if applicable):
Posting Signs
Date of sign removal:
Description of deviations from FMP (if applicable):
Other
Additional comments/notes:
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Air Monitoring Results
When Respiratory Protection is Not in Use - Sensory Irritation Experienced (check here if section is not applicable D )
Date and Time
Handler Task/ Activity
Handler Location Where
Irritation Was Observed Resulting Action
D Cease operations
D Respiratory protection
D Cease operations
D Respiratory protection
D Cease operations
D Respiratory protection
D Cease operations
D Respiratory protection
D Cease operations
D Respiratory protection
Comments
When Respiratory Protection is in Use - Direct Read Instrument Air Monitoring (check here if section is not applicable D )
Sample Type
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
DArea
DBreathing Zone
D Structure
Sample
Number
Sample
Date/Time
Handler
Task/Activity
(not
applicable for
structural
monitoring)
Handler
Location/
Structure
Location
Air
Concentration
Sampling
Method
Comments (e.g.,
sensory irritation
experienced while
wearing
respirator)
I have verified that this post application summary reflects the actual site conditions during the fumigation and an accurate
description of deviations from the FMP (if applicable).
Signature of certified applicator supervising the fumigation
Date
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