National Management Strategy 

For Methyl Bromide

United States of America 

December 2005 
National Management Strategy Contents 

Chapter I. Introduction 1 

Chapter II. Aims of the Strategy 3 

 A. Avoid increases of MeBr 3 

 B. Encourage use of alternatives 4 

 C. Potential market penetration of alternatives 5 

 D. Promote implementation of emissions reductions measures 7 

 E. Promoting the methyl bromide phaseout, particularly with respect to R&D 8 

Chapter III. MeBr Alternatives Research Overview 11 

Chapter IV. EPA MeBr Alternatives Registration Process 18 

Chapter V. Clean Air Act Regulation of MeBr 20 

 

Chapter VI. Use Chapters 23 

 Pre-Plant Soil Uses 29 

 Post-Harvest Uses 41 

Tables 

Table 1.2006 Critical Uses and Critical Limiting Conditions 46 

Table 2. Principal Pre-plant MeBr Alternatives and their Strengths and 54 

General Limitations / Impediments to Adoption 

References to specific commercial enterprises and brand name products and services do not imply endorsement or 

approval by the United States Department of Agriculture.
Chapter I. Introduction

The United States has supported the objectives of the Montreal Protocol on Substances that 

Deplete the Ozone Layer (Protocol, or Montreal Protocol) since before the inception of this 

landmark environmental treaty in 1987. The United States developed this strategy on methyl 

bromide (MeBr) in accordance with Decision Ex. I/4 (3) which requests a Party nominating a 

Critical Use Exemption (CUE) after 2005 to provide a national management strategy on the use 

of MeBr. The information upon which this strategy was developed is the result of a 

collaborative research effort at the national, state, and local levels. The relevant provision of this 

decision taken in March 2004 requests “each Party which makes a critical-use nomination after 

2005 to submit a national management strategy for phase-out of critical uses of methyl bromide 

to the Ozone Secretariat before 1 February 2006.” 

The criteria for the critical use exemption are delineated in Decision IX/6. In that Decision, the 

Parties agreed that “a use of methyl bromide should qualify as ‘critical’ only if the nominating 

Party determines that: (i) The specific use is critical because the lack of availability of methyl 

bromide for that use would result in a significant market disruption; and (ii) there are no 

technically and economically feasible alternatives or substitutes available to the user that are 

acceptable from the standpoint of environment and public health and are suitable to the crops and 

circumstances of the nomination.“ The Critical Use Nomination for which this strategy has been 

developed involved careful review of the circumstances and research surrounding the individual 

conditions and sectors identified. 

In this document, the United States will describe the policies, procedures and regulations that are 

in place to show how, as a Party to the Montreal Protocol, we are addressing the elements in 

Decision Ex. I/4 (3), including how we: 

• Avoid increases of MeBr except under unforeseen circumstances 

• Encourage the use of alternatives 

• Provide information on the potential market penetration of alternatives 

• Promote implementation of emissions reductions measures 

• Provide a description of phase-in process once an alternative is determined to be feasible, 

in particular with respect to research programs 

Through the applications for CUEs, applicants and the United States Government (USG) have 

provided detailed information on efforts to explore and implement alternatives to MeBr for 

control of pests in pre-plant and post-harvest situations. This document is not intended to be a 

technical recitation of these submissions, but rather, is an overview for the Parties to understand 

the comprehensive analysis and regulatory scheme that has been implemented by the United 

States domestically to meet the terms of the Montreal Protocol. 

This document describes the following elements of the U.S. strategy to minimize the dependence 

on MeBr and thereby reduce its requests for MeBr for each sector for which a CUE may be 

necessary after 2007: 

• Develop information on the technical and economic feasibility of alternatives 

• Share information from research trials with MeBr users 

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• Confirm the viability of alternatives under commercial-scale conditions 

• Promote an orderly transition from MeBr to the alternative 

This document was prepared in the context of domestic efforts that have taken place in the 

United States over the last decade that have implemented viable replacements for MeBr where it 

was possible to do so. Uses for which alternatives have already been implemented have not been 

included in CUE nominations submitted by the USG. Through its assessment of the CUE 

applicant requests, the USG has reviewed the substantial problems or “limiting factors” that exist 

in transitioning the remaining critical uses to viable alternatives. These problems may be 

technology related, economically based, or may be based on regulatory constraints. The decision 

to submit Critical Use Nominations does not mean that the commitment to transition to 

alternatives is any less important; however, it is a statement of practical reality which the USG 

believes the Parties should continue to keep in mind as this Strategy is implemented. 

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Chapter II Aims of the Strategy

In developing this strategy, the USG used the following criteria described by the Parties in their 

decision taken at the First Extraordinary Meeting of the Parties. Decision Ex. I/4 (3) requests a 

Party to develop a management plan that should aim, among other things: 

(a) To avoid any increase in methyl bromide consumption except for unforeseen circumstances; 

(b) To encourage the use of alternatives through the use of expedited procedures, where possible, to develop, 

register and deploy technically and economically feasible alternatives; 

(c) To provide information, for each current pre-harvest and post-harvest use for which a nomination is planned, 

on the potential market penetration of newly deployed alternatives and alternatives which may be used in the 

near future, to bring forward the time when it is estimated that methyl bromide consumption for such uses can 

be reduced and/or ultimately eliminated; 

(d) To promote the implementation of measures which ensure that any emissions of methyl bromide are 

minimized; 

(e) To show how the management strategy will be implemented to promote the phase-out of uses of methyl 

bromide as soon as technically and economically feasible alternatives are available, in particular describing 

the steps which the Party is taking in regard to subparagraph (b) (iii) of paragraph 1 of decision IX/6 in 

respect of research programmes in non-Article 5 Parties and the adoption of alternatives by Article 5 Parties; 

A. Avoid increases of MeBr 

To avoid any increase in methyl bromide consumption except for unforeseen circumstances; 

As a broad spectrum fumigant, MeBr has been used to prepare areas for planting high value 

crops to protect against diseases, nematodes, insects, and weeds. This practice has been the 

accepted grower standard for production for over 40 years. Occasionally, remnants of a previous 

crop may also constitute an unwanted contaminant of a successive crop and become a weed. 

While most pre-plant MeBr alternatives are capable of controlling one or two classes of plant 

pests, few are effective in controlling all at the same time as effectively as MeBr. As part of the 

CUE process, the United States has identified key criteria that limit the technical and economic 

feasibility of MeBr alternatives. Table 1 includes a listing of CUE sectors and the critical 

limiting factors. Table 2 lists the principal pre-plant alternatives to MeBr that are in use in the 

United States, or have been determined as potentially suitable, along with their strengths and 

relative limitations. 

For post-harvest uses, the range of pests includes various diseases in or on commodities, adult 

insects and their immature forms (including eggs), rodents, and plant propagules (seeds, buds, 

corms, and such). 

Recognizing that the interaction of crop and pest distribution, geographic location of crop 

growing areas, and regulatory constraints on the use of alternatives is exceedingly complex, the 

USG implemented a comprehensive review of the CUE applications in 2002 utilizing over 45 

technical experts to evaluate the various requests for MeBr. After establishing that these uses 

were indeed critical in accordance with the criteria in Decision IX/6 under the circumstances that 

they were produced, an effort was undertaken by the U.S. Environmental Protection Agency 

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(USEPA) to identify the extent of the critically limiting factors. By combining available data on 

the size of crops grown between 2000 and 2001, a baseline of crop area was determined. For 

post-harvest uses, production data were analyzed to estimate the volume of commodity or facility 

treated, number of treatments, and factors impacting the relative efficiency of such uses 

including such variables as the age of facilities, suitability of equipment for various alternative 

treatments, and time constraints for treatments. 

An important way that the United States addresses the issue of avoiding increases in MeBr use is 

our policy to disallow any increases in acreage or throughput that CUE applicants might include 

in their CUE request. Requests are compared to historical use and acreage data where available 

to ensure accuracy and consistency of data. Applicant requests to increase treatment of a larger 

acreage, commodity volume, or additional facilities are disallowed by the USG unless 

corroborating information is provided indicating that our estimates of MeBr require a correction. 

An increase in MeBr need could also be justified in a case where an applicant shifted to an 

alternative, but found it necessary to submit a CUE request because the alternative consistently 

provided insufficient pest control after transition. This policy was established to limit further 

expansion within a sector using MeBr, even in the presence of critical limiting factors, as a 

means to avoid increases in MeBr usage. As a result of this policy, additional acreage or 

production volume of a commodity must be accomplished using a MeBr alternative. 

Even with the adoption of this strong domestic policy aimed at avoiding increases in MeBr use, 

unforeseen circumstances could arise that could impact estimates of actual MeBr need. These 

circumstances include the loss of a technically and economically feasible MeBr alternative due 

to changes in its state or federal regulatory status for health, environmental or safety reasons, loss 

of efficacy due to pest resistance, or an emergency, such as the introduction of an economically 

damaging pest not otherwise controlled by MeBr alternatives. There have also been cases where 

a MeBr user reduced their need for MeBr by switching to an alternative, but after suffering a 

failure of pest control from the alternative, was forced to go back to MeBr use in the following 

year. In the event of an unforeseen circumstance, it may be necessary to use MeBr for pest 

control, but all criteria of the CUE process will be examined on a case-by-case basis to avoid the 

potential for allocating more MeBr than is justified by the technical and economic circumstances 

of the particular situation. 

B. Encourage use of alternatives 

To encourage the use of alternatives through the use of expedited procedures, where possible, to develop, 

register and deploy technically and economically feasible alternatives; 

Since MeBr was listed as an ozone-depleting substance in 1995, the USG has promoted research 

on new and existing pesticidal active ingredients to determine their potential as MeBr 

alternatives. Numerous compounds have been tested as candidate alternatives in programs 

funded in part by the USG through the Agricultural Research Service (ARS), Cooperative State 

Research Education and Extension Service (CSREES), the Inter-regional Project 4 (IR-4) 

programs or private industry. It is estimated that over $400 million dollars has been spent since 

1995 by the private sector, state agricultural universities, and the USG towards development of 

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MeBr alternatives. The USG is committed to continue funding MeBr alternatives research to 

address ongoing CUE requirements, and is seeking continued funding of these programs beyond 

2006. Ongoing research supported by the U.S. Government (USG) is being conducted by the 

Agricultural Research Service (ARS) and the Cooperative State Research, Education, and 

Extension Service (CSREES). One of the programs that has been funded by ARS and CSREES 

is the IR-4 Program, which has conducted MeBr alternatives research in conjunction with 

alternatives manufacturers. Since 1997, the IR-4 MeBr alternatives program has evaluated 

iodomethane, furfural, propylene oxide (PPO), and sodium azide as potential stand-alone 

treatments, as well as fosthiazate (nematode control), trifloxysulfuron sodium and halosulfuron 

methyl (herbicides for nutsedge control) as companion treatments for other alternatives. 

Beginning in 1995, the USEPA initiated an expedited registration scheme for MeBr alternatives. 

A description of this program is found in Chapter IV. Through EPA, the USG encourages the 

registration of MeBr alternatives by expediting the regulatory review process for those products 

identified by industry as potential MeBr alternatives that were subsequently determined to 

qualify for this designation by the USEPA. Because of the considerable number of pesticide 

applications, there is typically some delay between the date of the application and time of initial 

review. Because USEPA has made MeBr replacements a priority, these applications 

immediately enter the review process, in which they are subjected to a full review to ensure 

adequate protection of human health and the environment. 

In addition, the USG recognized that the task we faced was not only to expedite the registration 

of new alternatives, but to seek a level playing field for fumigants with respect to their human 

health and environmental impacts. Some fumigants, such as MeBr, 1,3-dichloropropene, metamsodium and chloropicrin, were registered over 30 years ago at a time when the risk analysis and 

exposure methodology was different than the current review methodology. For this reason, 

USEPA initiated a comprehensive review of all pre-plant fumigants to ensure that there was no 

unintentional regulatory partiality towards these fumigants simply because they were registered a 

number of years ago. This review is ongoing, and until it comes to conclusion it is not possible 

to ascertain how it will impact the amounts and patterns of use in the United States given the 

wide range of possible regulatory constraints that could be placed on any of the fumigants under 

consideration. 

C. Potential market penetration of alternatives 

To provide information, for each current pre-harvest and post-harvest use for which a nomination is 

planned, on the potential market penetration of newly deployed alternatives and alternatives which may be 

used in the near future, to bring forward the time when it is estimated that methyl bromide consumption for 

such uses can be reduced and/or ultimately eliminated; 

The goal of the USG is to eliminate the use of MeBr where it is technically and economically 

feasible to do so. Under the terms of the Montreal Protocol, and especially Decision IX/6 

allowing for critical use exemptions, the USG has worked with affected users to seek 

alternatives. During the phase-out period of 1999-2004, users were able to reduce their reliance 

on MeBr from the 1991 baseline of over 25,000 metric tons of MeBr to approximately 10,000 

metric tons. This reduction was driven by market forces associated with the regulatory phase-out 

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of MeBr and was accomplished in part by the introduction of greater levels of chloropicrin (PIC) 

to MeBr/PIC blends by formulators, by reductions in application rates, and by the shifting of 

some uses to MeBr alternatives. Even within sectors that could accomplish some shifts, MeBr 

use remained critical as anticipated in Decision IX/6. As part of the CUE process, applicants 

have been required to identify the impediments to adoption of alternatives. 

In the United States, it is important to note that most MeBr alternatives that are registered have 

been in the market over 30 years, long before the Montreal Protocol identified MeBr as an ozone 

depleter and sought to limit its use (Table 4). As the price of MeBr has increased, the market has 

allowed for the transition of uses away from MeBr to alternatives when it was already 

technically and economically feasible. Prior to the end of the phase-out period in 2004, the 

readily-achieved transition to MeBr alternatives was accomplished. This can be determined 

indirectly as the use of MeBr continued in certain areas despite the lower cost of alternatives for 

comparable uses. (Although two or more products may be registered for control of a pest, their 

efficacy may not be equal, or perhaps, not even comparable. In an open-market situation, users 

will consider many factors such as price, timeliness and efficacy in making their selection of a 

pest control option.) Price differentials between products serve as natural incentives for 

transition away from MeBr where it is technically and economically feasible; however, lower 

input costs resulting in a high level of yield loss, quality loss, or planting delays may result in a 

negative economic result if revenue falls faster than expenses. 

Decision IX/6 allows for continued use of MeBr where no technically and economically feasible 

alternatives are available; this provision ensures that users are not forced into unsustainable 

economic losses if adequate alternatives are unavailable in the particular circumstances of the 

nomination. Through the CUE process, the USG has evaluated research data and information 

provided by users concerning the efficacy of MeBr and alternatives to determine the current 

extent to which registered alternatives may substitute for MeBr. It is extremely difficult to 

ascertain the adoption rate of newly-registered alternatives because the process of registration by 

its very nature typically imposes safety requirements such as the use of personal protective 

equipment (PPE), buffers, or regional caps that inherently limit the use of an alternative. In the 

United States, this is true both at the national, state and local levels. For example, States may 

impose more restrictive requirements than the federal government to ensure protection of human 

health and the environment. Such restrictions may hinder the adoption of a MeBr alternative. In 

fact, concerns over human health/environmental impacts in the State of California led them to 

adopt township caps on the use of a key MeBr alternative. Imposing such a cap was deemed to 

be important to environmental protection in California, but has prevented users in a number of 

sectors from phasing-in an alternative that is otherwise efficacious. For these reasons, it is not 

possible to estimate with any precision the extent of the adoption of alternatives, or the timing 

involved in it, and they must be considered on a case by case, sector by sector basis taking into 

account the circumstances of the individual nomination. 

To further complicate the status of alternatives, the pre-plant fumigant alternatives as well as 

MeBr are currently being reviewed by EPA to determine their eligibility for registration 

(iodomethane), reregistration (MeBr, metam sodium and chloropicrin) or label changes (1,3-

dichloropropene). This review is not scheduled for completion until the end of 2006. The 

review may impose additional restrictions on the use of these products beyond 2008. Any 

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changes in the use of these products, which are unknown at this time, will be factored into the 

assessment of MeBr CUE nominations as such information becomes available. 

Despite the dynamic and unpredictable nature of these circumstances, the chapters contain 

information on the individual sectors providing the best-available information impacting the 

adoption of MeBr alternatives. 

D. Promote implementation of emissions reductions measures 

To promote the implementation of measures which ensure that any emissions of methyl bromide are 

minimized; 

U.S. CUE users take important steps to reduce emissions of MeBr. In general, U.S. pre-plant 

users either use deep-shank injection to insert MeBr 12 inches under the surface of the ground, or 

apply tarps over treated areas. Both of these methods reduce emissions of MeBr. For postharvest applications, best efforts are required to improve building seals and minimize MeBr 

leakage/emissions during treatment. During the reregistration process for MeBr, the USEPA will 

evaluate research results on the use of low permeability films and other measures for their 

effectiveness in reducing emissions, and their potential for reducing rates, along with their 

technical and economic feasibility. 

As part of the domestic review of CUE applications, the USG imposed dose rate reductions 

where we believed lower doses would maintain adequate pest control. Many users moved to 

dramatically lower dosage rates, in part due to the existing U.S. regulatory approach and the 

progressive tightening of the market for available MeBr. As an example, the food processing 

facilities sector has effectively reduced dose rate to one-quarter or one-third of the approved 

label rate for routine applications. The frequency of these applications has also been cut by 

about 50%. These measures have already provided a significant benefit to ozone layer 

protection. 

Scientists of the Agricultural Research Service (ARS), the University of California, and the 

University of Florida have explored the use of emissions reducing films for pre-plant MeBr uses. 

Although earlier work focused on virtually impermeable films (VIF), regulatory restrictions 

prohibiting their use (California) and operational difficulties in adapting the films to commercial 

conditions (e.g. speed of laying film, differences in application equipment, and such) 

experienced in the United States (Florida), have resulted in growers being unable to broadly 

adopt VIF. Growers and researchers in Florida and California have continued to work with 

plastics manufacturers to find other alternatives for emissions reduction, and have in recent years 

identified several candidates, including metallized films and newer types of trilayer film, that 

may be more amenable to commercial application. Growers are conducting trials in 2005 on 

over 3000 acres to ascertain the effectiveness of such barriers. Should the results of these tests 

and trials planned for 2006 demonstrate their effectiveness, it is anticipated that this could 

benefit all fumigants by further reducing use rates and their resulting emissions. Wide-scale 

adoption of these technologies may be limited by the logistics associated with production of the 

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requisite barrier films. As research results become clearer, the direction for commercialization 

of these technologies will become apparent. 

For post-harvest sectors, increased costs for MeBr have provided market-based incentives to 

improve the sealing of structures treated with MeBr. The USG recognizes that a number of older 

buildings are inherently more difficult to seal than facilities built in recent years; however, U.S. 

MeBr label requirements compel applicators to take efforts to seal buildings, and the reduced 

costs of fumigant material provide both a regulatory and a cost incentive for sealing facilities to 

minimize MeBr emissions. Emissions have also been cut wherever possible by fumigating less 

frequently and, when fumigations are necessary, by using quantities that are less than the 

approved label rate. 

E. Promoting the methyl bromide phaseout, particularly with respect to R&D. 

To show how the management strategy will be implemented to promote the phase-out of uses of methyl 

bromide as soon as technically and economically feasible alternatives are available, in particular describing 

the steps which the Party is taking in regard to subparagraph (b) (iii) of paragraph 1 of decision IX/6 in 

respect of research programmes in non-Article 5 Parties and the adoption of alternatives by Article 5 

Parties; 

Efforts by the United States in this area include a variety of regulatory, policy, and programmatic 

activities aimed at reducing the need for MeBr. A robust and well-funded U.S. alternatives 

research program has invested hundreds of millions of dollars to find, evaluate, and facilitate the 

commercialization of alternatives. The U.S. pesticide registration process has made efforts to 

ensure that MeBr alternatives are given prioritized consideration for immediate review. The 

recent registration of sulfuryl fluoride has provided direct and measurable benefits in reducing 

the need for MeBr in certain post-harvest sectors, and several other alternatives in the 

registration queue have the potential for further benefit. The U.S. allocation rulemaking process 

includes additional restrictions, requirements, and limitations to users of MeBr from CUEs, and 

takes into account information on newly registered pesticides to further reduce the amount of 

MeBr allowed for use in the United States below the amount approved by the Parties where this 

is appropriate. 

As a non-Article 5 Party to the Montreal Protocol, the United States has had an active ongoing 

research program to support users in identifying suitable alternatives to MeBr, and then to work 

with the users and universities to identify conditions under which the research results could be 

adapted into commercial production systems. Federally funded research has been conducted by 

ARS and university scientists at locations that are typically representative of the MeBr users. A 

large portion of the national research program was devoted to long term solutions and basic 

understanding of the role of fumigants in critical crop production systems; in contrast, the 

cooperative research between growers and the Universities at the state level has been in support 

of specific commodity needs and has been more directed toward local production practices. A 

description of the overall research program is found in Chapter 3. 

Several challenges exist in adapting the findings of research trials into commercial production. 

Since 1995, products have been identified as potential MeBr replacements but due to the cost of 

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conducting required health and safety testing for registration, the product was not developed (e.g. 

propargyl bromide). In other instances, multiple steps were needed to replace a single MeBr 

application, for example where plastic was laid simultaneously (in-bed application) – such multistep approaches were determined to be technically feasible, but not economically practicable. 

As part of the CUE application process, the USG evaluates whether research data supporting a 

MeBr alternative has been demonstrated repeatedly within the same plot and at multiple 

locations, and if the alternative has been evaluated on a commercial scale under the time 

constraints experienced by the sector. Experience with VIF films, for instance, has shown that 

efforts to apply VIF at speeds necessary to maintain an effective planting schedule were not 

possible using commercial equipment. Reductions in speed resulted in significant, and costly, 

delays resulting in the potential need for large capital expenditures for additional application 

equipment. 

Factors considered in determining the technical and economic feasibility of an alternative 

include: 

• Efficacy against target pest(s) and impact on yield, quality and timeliness of harvest 

• Reliability of treatment in controlling pests 

• Direct/indirect costs of delays in making applications on treated crop (and subsequent 

crop if part of a multi-crop rotation scheme) or commodity (e.g. missed market window) 

• Costs of application for multiple products 

• Regulatory constraints on the use of alternatives 

• Soil type, geological origin, and environment 

Once these factors have been evaluated and an alternative is determined to be technically and 

economically feasible, adoption by users is not instantaneous or linear. Agricultural economists 

describe adoption rates as fitting an S-curve. Adoption of new technologies, when deemed to be 

superior to existing practice, may take 6-10 years to take a significant share of a market and 10-

15 years to achieve maximum market penetration. In the instance where a product is merely 

comparable to existing products, the time to maximum market penetration is longer under openmarket (unconstrained) conditions. The USG is cognizant of the investment that manufacturers 

have made in expanding pesticide labels or to obtain new registrations as MeBr alternative. It is 

the intent of the USG to work towards a phase-in of a MeBr alternative within eight years after 

the determination is made that it is technically and economically feasible. Such a timeframe 

represents an acceleration of the time it would normally take to phase in alternatives, but this 

amount of time is required to accommodate regulatory conditions between various states, and to 

ensure that users have ample time to adopt the technology within the confines of their specific 

operation. This phase-in schedule is accomplished by analyzing the regulatory status by 

jurisdiction, and reducing the CUE allocation in accordance with the expected phase-in level. If 

other factors are determined to impact the potential for a sector to adopt an alternative, for 

example, if there are shifts in pest spectrum that were not foreseen from the use of an alternative, 

then the phase-out schedule will be amended. 

The USG has an additional regulatory tool to implement downward corrections to the amounts 

approved by the Parties to the Montreal Protocol. This tool is the annual notice and comment 

rulemaking used to allocate amount of MeBr to critical users. When a rule is proposed, 

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stakeholders are asked to provide information that the USEPA can utilize to revise the amount of 

MeBr allocated to users. This process can accommodate information such as the registration of 

an alternative prior to a control period, but after the time that the Parties have decided on a 

nominated amount. Since the regulatory process can take up to one year, it continues to be 

important to the United States for decisions of the Parties are made a year in advance of the 

control period where the CUE allocation will be used. 

The recently published proposed rule for the 2006 MeBr allocation does this by accounting for 

the recent registration of sulfuryl fluoride in California, and the expansion of the federal 

registration to include ingredients. While this rule has not been finalized, it proposes a reduction 

in the amount of MeBr that will be allocated to users as compared to what was approved by the 

Parties. This notice and comment rulemaking process is a key element in the U.S. strategy to 

promote the phase out of MeBr by incorporating information on newly developed alternatives so 

that less MeBr will be allocated as feasible alternatives become available. While the allocation 

rule is a useful tool to apply more recent information to reduce amounts of MeBr below the 

levels authorized by the Parties, there is currently no effective method to make changes in the 

CUE in the event of changed circumstances warranting an increase in the allocated amount of 

MeBr due to changes in pest pressure, weather, or other such circumstances. 

Finally, some of the elements noted above are important parts of our overall efforts to phase out 

the use of MeBr as technically and economically feasible alternatives become available. Our 

prioritization of MeBr alternatives in our domestic registration process helps move forward the 

time at which new alternatives can be registered, thereby moving forward the time at which they 

begin to penetrate the market. Our re-review of the pre-plant fumigants will create a level 

playing field from a regulatory perspective that ensures MeBr and its alternatives are considered 

with the same methodology and analysis in developing appropriate regulations to protect human 

health and the environment. 

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Chapter III. MeBr Alternatives Research Overview

Agricultural Research Service Research and Outreach Strategy 

RESEARCH

After implementation of the U.S. Clean Air Act, as amended, and 1992 amendments to the 

Montreal Protocol, the USDA Agricultural Research Service (ARS), recognizing that the uses of 

MeBr in agriculture and forestry would be significantly reduced, initiated efforts to develop a 

research agenda. In view of the time required to produce alternative technologies and substitute 

chemicals, USDA ARS began developing a strategic plan and research agenda in February 1992 

at a workshop with partners, customers, and stakeholders that identified important areas and 

priorities to use in initiating research to find alternatives for agricultural use. Specific research 

components necessary for both pre-plant soil fumigation, post-harvest and quarantine treatments 

were discussed. In the summer of 1993 ARS provided leadership to hold a workshop to further 

examine research needs and priorities. Approximately 250 persons from government, academia, 

and the private sector attended the meeting. The workshop consisted of nine working groups that 

were organized by commodities; four considered alternatives for post-harvest commodity and 

quarantine treatment, and five considered alternatives for soil fumigation treatment. In October 

of 1993 the Crop Protection Coalition, in cooperation with the USDA, convened a conference for 

the assessment of research and Extension needs and priorities in reducing atmospheric emissions 

and finding replacements for MeBr. Following the success of this meeting, USEPA joined as a 

cosponsor in 1994 and the annual meetings have been known as the Methyl Bromide 

Alternatives Outlook (MBAO) Conference. 

Based on the output from the workshops and conference, ARS initiated research to meet the 

needs of MeBr users. In 1998 when ARS research was organized into National Programs, this 

research was incorporated into the Methyl Bromide Alternatives National Program (NP 308). 

National Programs function on a specific five-year cycle. Preparatory to beginning this cycle, 

NP 308 held two customer/stakeholder workshops to prioritize research for the next five years, 

one in December 1998 in Gainesville, FL and one in April 1999 in Monterey, CA. From these 

workshops an action plan for research was developed. The action plan continued the ARS 

strategy of using model commodities, an approach first agreed upon by researchers and 

commodity groups at the summer 1993 workshop. This plan may be accessed on the ARS web 

site: www.ars.usda.gov. An outline of the plan follows: 

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National Program 308 – Methyl Bromide Alternatives Action Plan: Components 

and Problem Areas

Component I – Pre-plant Soil Fumigation Alternatives

The following problem areas are to be considered as constituent parts that can be integrated into 

sustainable management systems. 

Problem Area Ia – Chemical Controls 

Problem Area Ib - Biorationals

Problem Area Ic – Cultural Controls

Component II – Post-harvest Commodity Treatment (Including Structural)

Problem Area II a - Methodologies to maintain quality of stored durable commodities.

Problem Area II b - Quarantine treatments for export of commodities and provision of technical 

assistance to APHIS to gain acceptance of these procedures by trading partners. 

Problem Area II c - Technology to capture/recycle methyl bromide used in post-harvest 

fumigations to reduce or eliminate emissions to the atmosphere. 

Problem Area II d - Physical or chemical detection systems for stored product and quarantine 

pests.

Problem Area II e - Replacements for fumigating food processing plants, flour and other mills, 

food storage facilities, and transportation carriers such as ships and railcars.

Problem Area II f - Emergency technology that will allow movement of commodities out of 

emergency quarantine areas caused by accidental introduction of exotic pests such as fruit flies.

Problem Area II g - Methods to prevent the spread of quarantine pests into and within the United 

States including population suppression, trapping and surveillance, and eradication.

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ARS scientists working on MeBr alternatives prepared their research projects based on the action 

plan. These projects were reviewed by a peer panel organized through the ARS Office of 

Scientific Quality Review in 2002. Once projects were approved, research was initiated. 

Currently NP 308 is preparing to undergo a peer panel assessment to evaluate whether the 

research priorities in the action plan were met and what research needs remain. This will take 

place in December 2005. In February, 2006 customer/stakeholder workshops will be held to set 

priorities for future ARS MeBr alternatives research. 

OUTREACH

Outreach is an important part of all ARS research, and the circumstances in the case of MeBr 

alternatives research necessitated working more closely with grower groups than many of the 

other ARS research programs. Outreach includes field days, on-farm demonstrations, 

presentations to grower groups, and peer-reviewed publications. ARS earmarked $500,000/year 

for seven years to support on-farm demonstration projects in California and Florida of the most 

promising alternatives. These funds supported a number of projects in conjunction with 

university and commodity organization scientists on strawberries, tomatoes, peppers and 

perennial crops. 

These are some selected examples of ARS outreach related to MeBr alternatives. 

• ARS research in Hawaii was the first in quarantine treatment research and development 

to demonstrate the use of hot-water immersion, forced hot-air technology (ARS patent), 

and high-temperature MeBr fumigation as efficacious quarantine treatments against 

tephritid fruit flies infesting fruits. This led to new quarantine treatments that expanded 

international trade in fresh fruit and vegetables. 

• ARS scientists demonstrated that resistance to root-knot nematodes controlled by the N 

gene was effective in the bell peppers "Charleston Belle" and "Carolina Wonder" when 

grown in fields highly infested with southern root-knot nematode. This information was 

transferred to plant breeders, plant pathologists, and extension personnel for use in 

developing nematode resistant hybrid bell peppers and for developing management 

methods for root-knot nematodes in pepper. 

• Research demonstrated that the mango seed weevil could be sterilized in mangoes with a 

300 Gy irradiation dose, which allows mangoes to be exported from Hawaii for the first 

time in 50 years. 

• Six commercial scale of-farm field trials demonstrated to growers the performance of 

selected herbicides, alone and in combination, when used as part of an alternative 

program based on Telone C-35® broadcast application. In addition, field days were 

conducted at multiple on-farm research sites. 

• ARS Ft. Pierce scientists participated in a grower field day explaining a long-term land 

management project targeting organic vegetable producers that needed non-chemical 

alternatives to MeBr. 

 13
• Large-scale field trials conducted in commercial tomato and pepper fields in cooperation 

with growers have validated the use of 1,3-dichloropropene and chloropicrin (Telone C35®) as a technically feasible alternative to the soil fumigation with MeBr. Trials were 

conducted using broadcast applications of Telone C-35® in combination with the 

herbicides Devrinol® and Treflan® and an additional application of chloropicrin in the 

bed. In a 50 acre trial that was conducted four consecutive years in the same field, yields 

in the fourth year under the alternative were higher than in adjacent fields fumigated with 

MeBr and the incidence of soilborne diseases was lower than in adjacent fields fumigated 

with MeBr. Additional large-scale field trials were conducted with Telone C-35® 

applied under VIF using the `Under Bed Fumigator’. 

• To facilitate sweet potato exports from Hawaii and provide an alternative quarantine 

treatment to MeBr fumigation, the U.S. Pacific Basin Agricultural Research Center in 

Hilo, in collaboration with Hawaii Pride, LLC (a local quarantine x-ray irradiation 

facility) developed dose/mortality data for West Indian sweet potato weevil and sweet 

potato vine borer, two major quarantine pests associated with sweet potatoes in the 

islands. These data resulted in USDA-APHIS approval of a 400 Gy irradiation 

quarantine treatment for Hawaii-grown sweet potatoes exported to U.S. mainland 

markets. Sweet potato exports using the new irradiation quarantine treatment, which 

began in July, 2003, have helped to increase agricultural diversity in Hawaii following 

the decline of its sugar and pineapple industries. 

• Field research and demonstration plots have been established to evaluate the yield 

potential of different strawberry cultivars (public and private cultivars) when grown in 

nonfumigated soil. Since there have not been disease problems with Verticillium wilt in 

these soils, these trials allow the evaluation of tolerance to other, nonlethal soilborne 

pathogens. Results have been made available to the California Strawberry Commission 

and local growers via field days and presentations at local commission and grower 

meetings. 

 

• Field research and demonstration plots were used to evaluate remote sensing technologies 

for assessing the efficacy of control provided by alternative fumigants. Results from this 

research (approximately 170 acres in 2003) have been made available to the scientific 

and grower community through presentations at grower field days, individual meetings 

with participating growers, and professional scientific meeting. 

 

• ARS scientists involved in MeBr alternatives research have been active participants in 

grower field days at two test plot locations, one in Watsonville that is managed by the 

California Strawberry Commission, and one in Salinas that is managed by ARS/USDA. 

The results of their research program were presented and discussed. 

• ARS worked with engineers on the design and machine performance of a commercial 

CATTS (various combinations of controlled atmospheres and elevated temperatures). 

This unit was shown to be suitable for large-scale quarantine treatments of apples, pears, 

peaches, and nectarines both in bins and in packed boxes.

 14
• Major technologies were transferred to growers in Hawaii and to fruit fly researchers 

worldwide, including the importance of sanitation, GF-120 spinosad bait sprays, male 

annihilation treatments, sterile flies, and parasitoids.

• ARS scientists at Parlier, California demonstrated that peaches and nectarines could be 

subjected to treatment with high temperatures combined with controlled atmospheres and 

maintain fruit quality. This work provided the foundation for further ongoing work in 

this area which may result in an alternative non-chemical treatment to substitute for 

MeBr fumigation. 

• Large-scale commercial tests were conducted in cooperation with the National Hay 

Association to confirm the efficacy of bale compression combined with hydrogen 

phosphide fumigation to control Hessian fly in large-size, polypropylene fabric-wrapped 

bales. The results of this test fulfilled specific requirements by the Japan Ministry of 

Agriculture, Forestry, and Fisheries for a certified treatment. Approval of the quarantine 

treatment will support a $340 million annual hay export market to Pacific Rim countries. 

• Large-scale tests of the use of ozone combined with carbon dioxide and vacuum showed 

the orange industry that bean thrips that cause rejections of lots of oranges in Australia 

could be eliminated with this treatment. This technology could save oranges from being 

rejected by allowing them to be exported under a phytosanitary certificate. 

Cooperative State Research, Education and Extension Service Research and Outreach Strategy 

RESEARCH 

The USDA Cooperative State Research, Education and Extension Service (CSREES) sponsors 

research through competitive grants. Their MeBr Transitions Integrated Grants for fiscal year 

2006 (FY06) will support the discovery and implementation of alternatives through 

commercial/field scale (not small plot) research on short to medium-term solutions to develop, 

register or apply new alternatives, or to minimize MeBr emissions. Comprehensive economic 

information on the impact of alternatives on crop yields and profitability will be required to 

assess both the economic and technical feasibility of alternatives. 

CSREES Methyl Bromide Transitions Integrated Grants for fiscal year (FY) 2006 

The Cooperative State Research, Education and Extension Service (CSREES) sponsors research 

through competitive grants. The Methyl Bromide Transitions Integrated Grants for fiscal year 

2006 (FY06) will support the discovery and implementation of alternatives through 

commercial/field scale (not small plot) research on short to medium-term solutions to develop, 

register or apply new alternatives, or to minimize MeBr emissions. Comprehensive economic 

information on the impact of alternatives on crop yields and profitability will be required to 

assess both the economic and technical feasibility of alternatives. The proposed projects will 

support practical pest management alternatives for uses which the U.S. is requesting critical use 

 15
exemptions. Proposals addressing critical use nominations for which there is not an extensive 

database, e.g. cucurbits and eggplant, are encouraged. 

• The projects will focus on commercial/field scale (not small plot/small scale) research on 

short- to medium-term solutions to develop, register and apply new alternatives or to 

minimize MeBr emissions and must be repeated for two or more research periods (years, 

crop cycles, etc). 

• Comprehensive economic information on the impact of alternatives on crop yields and 

profit margins compared with MeBr fumigation is required to provide comprehensive 

information on the impact of alternatives on crop yields and profit margins. 

• The proposed projects must address the potential application of the alternative methods 

and quantify MeBr use that might be replaced by the alternative methods or the reduction 

in MeBr emissions. 

• The proposal must include the potential timeline for replacement of the current critical 

use or application methods by the proposed alternative methods. 

• Formal extension and/or education programs to expedite adoption of proposed 

alternatives must be clearly delineated in the proposal. 

Since 2000, the CSREES Methyl Bromide Transition Program has made the following funds 

available: 

Year Available Research Funding 

million U.S. dollars 

2000 2.0 

2001 2.495 

2002 2.498 

2003 3.229 

2004 3.131 

2005 3.106 

2006 3.106* 

 * anticipated 

Since 2000, CSREES has awarded and managed 32 Methyl Bromide Transition grants (for 

abstracts, see: http://www.csrees.usda.gov/fo/fundview.cfm?fonum=1107). In addition, USDA 

CSREES has indirectly funded MeBr transition research and extension through other spending 

authorities. Expanded examples of results and impacts of CSREES funded research, extension 

and education are presented in Chapter Six, Critical Use Sectors. A review of USDA funded 

research related to MeBr alternatives is presented by the USDA CSREES Current Research 

Information System (CRIS) at http://cris.csrees.usda.gov/ . 

IR-4 METHYL BROMIDE ALTERNATIVES PROGRAM

RESEARCH

IR-4 began addressing MeBr alternatives in 1998. Under the direction of the IR-4 New 

Technology Team, work began on a project to identify safe products and new technologies that 

have potential to replace MeBr. Several MeBr alternative programs for specialty crops are 

 16
underway. These programs include soil fumigation studies in production strawberries, fresh 

market tomatoes, strawberry nurseries, and in cut flowers. IR-4's role is to form alliances with 

university and USDA scientists, grower organizations, pesticide company representatives and 

producers to conduct research leading to acceptable MeBr replacements. IR-4 has been active in 

the development of MeBr alternatives for controlling pests in stored food products including 

raisins, other dried fruits, and tree nuts. 

IR-4 is also facilitating cooperative efforts between pesticide manufacturers and university 

researchers in Florida to address the critical problems facing specialty crop producers. Research 

on metam sodium will be conducted to determine the causes of inconsistent performance under 

Florida conditions. This research, funded by the Metam Sodium Task Force, will be conducted 

by scientists at the University of Florida, Gainesville. Another project involves pesticide 

companies with selective herbicides used solely in vegetable crops. Dow AgroSciences will be 

cooperating with University of Florida weed scientists to superimpose herbicide treatments over 

Telone C-35® (1,3-D) fumigated plots and evaluate the herbicides for control of weeds not 

controlled by 1,3-D. Companies funding this research have a vested interest in registering their 

products as MeBr alternatives. IR-4 assists these companies in obtaining fast-track registration 

status for promising products by running residue (MRL) studies needed to meet registration 

requirements. 

OUTREACH 

Ongoing support for State Cooperative Extension activities is a fundamental element of the 

annual support that CSREES provides to the State Land Grant Universities. State programs have 

been developed to support the transfer of research information to growers through publications, 

meetings and field days. State, regional and national events are supported financially or in-kind 

by Cooperative Extension personnel to facilitate the dissemination of MeBr alternatives 

information to growers, applicators and pest control professionals. 

 17
Chapter IV. EPA MeBr Alternatives Registration Process

Pesticide registration is the process through which the USEPA examines the ingredients of a 

pesticide; the site or crop on which it is to be used; the amount, frequency and timing of its use; 

and storage and disposal practices. EPA evaluates the pesticide to ensure that it will not have 

unreasonable adverse effects on humans, the environment and non-target species. A pesticide 

cannot be legally used in the United States if it has not been registered with EPA's Office of 

Pesticide Programs. Most states also have state registration programs which preclude the sale, 

distribution, or use of a pesticide unless the pesticide is registered in that specific state. 

Since 1995, the EPA has made the registration of alternatives to MeBr a high registration 

priority. MeBr alternatives enter the science review process as soon as EPA receives the 

application and supporting data rather than waiting in turn for the EPA to initiate its review. 

Under the new Pesticide Registration Improvement Act, in 2006, applications for registration of 

new active ingredients must be reviewed within 24 months of the receipt of a complete 

application. Applications for registration of new uses of already-registered active ingredients 

must be reviewed within 21 months of receiving a complete application. 

An additional incentive for the pesticide industry to develop alternatives to MeBr, the Agency 

has worked to reduce the burdens on data generation, to the extent feasible, while still ensuring 

that the Agency’s registration decisions meet the Federal statutory safety standards. Where 

appropriate, the Agency has refined the data requirements for a given pesticide application, 

allowing a shorter research and development process for the MeBr alternative. Furthermore, 

Agency scientists routinely meet with prospective MeBr alternative applicants, counseling them 

through the registration process to increase the probability that the data is done right the first 

time and rework delays are minimized 

Since 1997, the United States has registered several alternatives for “niche” uses of MeBr. 

These registrations include: 

▪ 2000: Phosphine to control insects in stored products 

▪ 2001: Halosulfuron to control weeds in melons 

▪ 2001: Indian Meal Moth Granulosis Virus to control insects in stored products 

▪ 2001: 1,3-Dichloropropene to be applied via drip applications 

▪ 2002: Halosulfuron to control weeds in selected fruiting vegetables 

▪ 2003: s-Metolachlor to control weeds in tomatoes 

▪ 2003: Trifloxysulfuron-methyl to control weeds in tomatoes 

▪ 2004: Sulfuryl Fluoride to control insects in stored grains, dried fruit, nuts, and grain 

mills 

▪ 2004: Fosthiazate to control nematodes in tomatoes 

▪ 2005: Sulfuryl Fluoride to control insects in food processing facilities 

MeBr alternatives that are currently under consideration in the EPA registration process include: 

▪ Iodomethane as a pre-plant soil fumigant for tomato, strawberry, pepper, and ornmentals. 

▪ Dazomet as a pre-plant soil fumigant for strawberries and tomatoes. 

▪ Furfural as a pre-plant soil fumigant for cut flowers, propagative materials, ornamentals, 

turfgrass, golfcourses, sod farms, ad sports fields. 

 18
▪ Sodium azide as a pre-plant soil fumigant for ornamental nurseries, sod farms, and turf 

renovation on golf courses. 

It is important to note that some of the existing MeBr alternatives are undergoing evaluation by 

US EPA. EPA's goal in evaluating the soil fumigants is to ensure safety and maintain their 

benefits to agriculture. EPA plans to develop risk management decisions for five soil fumigant 

pesticides: 

• chloropicrin 

• dazomet 

• metam sodium 

• methyl bromide, and 

• a new active ingredient, iodomethane

These decisions, which are expected in late 2006, may affect the use of MeBr and these other 

alternatives. 

 19
Chapter V. Clean Air Act Regulation of MeBr

Methyl bromide was added to the Montreal Protocol on Substances that Deplete the Ozone Layer 

(Montreal Protocol) as an ozone depleting substance in 1992 through the Copenhagen 

amendment to the Protocol. The Parties agreed that each industrialized country’s level of MeBr 

production and consumption in 1991 should be the baseline for establishing a freeze in the level 

of MeBr production and consumption for industrialized countries. Through subsequent 

Decisions, the Parties have authorized critical use exemptions. 

The domestic implementation of the Montreal Protocol is through the Clean Air Act (CAA). The 

current regulatory requirements of the Stratospheric Ozone Protection Program that limit 

production and consumption of ozone depleting substances can be found at 40 CFR Part 82 

Subpart A. The regulatory program was originally published in the Federal Register on August 

12, 1988 (53 FR 30566), in response to the 1987 signing and subsequent ratification of the 

Montreal Protocol on Substances that Deplete the Ozone Layer (Protocol). The U.S. was one of 

the original signatories to the 1987 Montreal Protocol and the U.S. ratified the Protocol on April 

12, 1988. The Clean Air Act Amendments of 1990 (CAAA of 1990) were enacted and signed 

into law. They included Title VI on Stratospheric Ozone Protection, codified as 42 U.S.C. 

Chapter 85, Subchapter VI, to ensure that the United States could satisfy its obligations under the 

Protocol. EPA issued new regulations to implement this legislation and has made several 

amendments to the regulations since that time. 

Methyl bromide is controlled under the CAA as a Class I ozone depleting substance (ODS). 

Additional details about the uses of MeBr can be found in the proposed rule on the phase-out 

schedule for MeBr published in the Federal Register on March 18, 1993 (58 FR 15014) and the 

final rule published in the Federal Register on December 10, 1993 (58 FR 65018). 

At their 1995 meeting, the Parties made adjustments to the MeBr control measures and agreed to 

reduction steps and a 2010 phase-out date for industrialized countries with exemptions permitted 

for critical uses. At that time, the U.S. continued to have a 2001 phase-out date in accordance 

with the CAAA of 1990 language. At their 1997 meeting, the Parties agreed to further 

adjustments to the phase-out schedule for MeBr in industrialized countries, with reduction steps 

leading to a 2005 phase-out for industrialized countries. In October 1998, the U.S. Congress 

amended the CAA to prohibit the termination of production of MeBr prior to January 1, 2005, to 

require EPA to bring the U.S. phase-out of MeBr in line with the schedule specified under the 

Protocol, and to authorize EPA to provide exemptions for critical uses. These amendments were 

codified in Section 604 of the CAA, 42 U.S.C. 7671c. On November 28, 2000, EPA issued 

regulations to amend the phase-out schedule for MeBr and extend the complete phase-out of 

production and consumption to 2005 (65 FR 70795). 

The revised phase-out schedule was again amended to allow for an exemption for quarantine and 

preshipment purposes on July 19, 2001 (66 FR 37751) with an interim final rule and with a final 

rule (68 FR 238) on January 2, 2003. 

Starting in 2002, EPA began notifying applicants as to the availability of an application process 

for a critical use exemption to the MeBr phase-out. The Agency published a notice in the 

 20
Federal Register (68 FR 24737) announcing the deadline to apply, and directing applicants to 

announcements posted on EPA’s MeBr website at www.epa.gov/ozone/mbr. This process has 

been repeated on an annual basis since then. The critical use exemption is designed to meet the 

needs of MeBr users who do not have technically and economically feasible alternatives 

available to them. 

In response to the yearly requests for critical use exemption applications published in the Federal 

Register, applicants have provided information supporting their position that they have no 

technically and economically feasible alternatives to MeBr available to them. Applicants for the 

exemption have submitted information on their use of MeBr, on research into the use of 

alternatives to MeBr, on efforts to minimize use of MeBr and efforts to reduce emissions and on 

the specific technical and economic research results of testing alternatives to MeBr. 

On December 23, 2004 (69 FR 76982), EPA published a final rule in the Federal Register that 

established the framework for the critical use exemption; set forth a list of approved critical uses 

for 2005; and specified the amount of MeBr that could be supplied in 2005 from available stocks 

and new production or import to meet approved critical uses. In EPA’s recently published 

regulation describing the operational framework for the critical use exemption (69 FR 76982) the 

majority of critical uses for the 2005 calendar year were established. 

Similar efforts will occur for successive control periods for which a CUE nomination is made 

and approved. 

When reviewing CUE applications, the Agency has rejected increases in requested amounts 

related to increase in production area, unless that area existed before 2001/2002 and utilized 

MeBr for pest control under limiting critical conditions, but was simply not reflected in a 

previous application. 

As set out in the U.S. regulations, an approved critical user is an entity who meets the following 

requirements: 

(1) for the applicable control period, applied to EPA for a critical use exemption or is a 

member of a consortium that applied to EPA for a critical use exemption for a use and 

location of use that was included in the U.S. nomination, authorized by a Decision of the 

Parties to the Montreal Protocol, and then finally determined by EPA in a notice and 

comment rulemaking to be an approved critical use, and 

(2) has an area in the applicable location of use that requires methyl bromide fumigation 

because the entity reasonably expects that the area will be subject to a limiting critical 

condition (LCC) during the applicable control period, if an LCC is given in Appendix L. 

A “limiting critical condition” is the basis on which the critical need for MeBr is authorized. It is 

defined as “the regulatory, technical, and economic circumstances . . . that establish conditions of 

critical use of methyl bromide in a fumigation area.” 40 CFR 82.3. The limiting critical 

condition placed on a use category reflects certain regulatory, technical or economic factors that 

 21
either prohibit the use of alternatives or represent the lack of a technically or economically 

feasible alternative for that use or circumstance. 

Data submitted by the CUE applicants serve as a basis for each nomination. EPA and other 

government experts also seek data from multiple other sources, including but not limited to the 

National Agricultural Statistics Service of the U.S. Department of Agriculture, the State of 

California Department of Pesticide Regulation, and proprietary agricultural databases available 

to EPA. All of the CUE applications undergo a rigorous review by highly qualified technical 

experts. A detailed explanation of the nomination process, including the criteria used by expert 

reviewers, is available in a memo titled “2003 Nomination Process”, accessible through 

http://www.regulations.gov, Environmental Protection Agency Docket ID OAR-2005-0122, 

document number 0037. 

 22
Chapter VI. Critical Use Sectors

Fourteen sectors in the United States are currently working under Critical Use Exemptions 

(CUEs) for MeBr. Four nursery (plants for propagation) and seven crop production sectors 

comprise the pre-plant CUEs. Additionally, three general areas of commodity and facility pest 

control comprise the post-harvest CUEs. 

Pre-Plant 

Nursery Production Post-Harvest 

Forest Nursery Seedlings 

Fruit, Nut and Flower Nurseries 

Strawberry Runner 

Turfgrass Sod Nursery 

Cucurbit 

Eggplant 

Orchard Replant 

Ornamentals 

Pepper 

Strawberry Fruit 

Tomato 

Commodities 

 Walnuts 

 Dried beans 

 Dried plums 

 Figs 

 Raisins 

 Dates 

 Pistachios 

Dry Cured Pork Products 

Food Processing (Facilities) 

Phytosanitary requirements are generally quite restrictive for the nursery uses. As propagative 

plant material, they must be essentially free of foreign matter, weeds, diseases, nematodes and 

other pests. Often, alternative treatments are difficult to qualify as being as effective as MeBr. 

In some instances, market requirements are substantially similar to quarantine requirements, and 

much of the produce for local use is indistinguishable from material to be shipped under QPS 

and cannot be segregated at time of treatment. Many of the CUE requests are intended to treat 

the portion of the crop that does not strictly qualify for QPS, and for which a technically and 

economically feasible alternative treatment does not exist. 

Pre-plant production uses of MeBr that have qualified under the CUE process are generally listed 

because available alternatives do not control one or more pests faced by the growers of these 

crops. Much of the production in the southeastern United States must battle soil-borne diseases, 

nematodes and weeds, such as yellow and purple nutsedge. Although MeBr alternatives exist for 

many of the nematode and disease combinations, cost-effective control of weeds is a limiting 

factor for tomato, strawberry, pepper, curcurbit and eggplant production. Labor costs in the 

United States make hand-weeding cost prohibitive as a primary weed control technique. Handweeding of herbicide-treated plots is considered a last resort to avoid significant economic loss. 

The plasticulture system of raised-bed vegetable production developed in the 1960s and 70s has 

succeeded in minimizing the impact of weeds as long as effective nutsedge control is possible. 

Methyl bromide has provided such control. Currently available herbicides compatible with 

tomato production prevent the planting of a second crop into the bed due to phytotoxicity (i.e. 

follow-crop injury). The inability to plant a second crop dramatically impacts the economic 

viability of producing both tomatoes and other vegetable crops such as melons and other 

cucurbits in the Southeast. 

 23
In the post-harvest sector, many uses for which alternatives are labeled have successfully shifted 

from MeBr. These uses have been successful where the length of treatment time was not a 

constraint on existing facilities, and where vulnerable equipment that might be damaged by heat 

(e.g. electronic equipment) or phosphine (e.g. exposed electrical equipment) are not present. In 

instances where fumigation throughout is critical, such as during harvest, certain commodity 

processors remain dependent on MeBr to handle the high production levels necessary to keep 

pace with field-harvesting. Subsequent treatments of stored commodity at these facilities are 

often feasible with alternatives without substantial capital investment, but this is not the case for 

initial treatments when commodities are received from the field. 

For high-value commodities that are exported, internationally recognized maximum residue 

limits (MRLs) are necessary to ensure the unrestricted flow into offshore markets. The absence 

of such regulatory approvals renders treated product unacceptable. Regulatory acceptance of 

commodities treated with MeBr, have been in place for international trade for many years. The 

ability to use at least one potential MeBr alternative is dependent on sufficient countries 

recognizing the MRL as being acceptable on imported commodities. 

Over the past ten years, the United States has committed significant financial and technical 

resources to the goal of seeking alternatives to MeBr that are technically and economically 

feasible to provide pest protection for a wide variety of crops, soils, and pests, while also being 

acceptable in terms of human health and environmental impacts. To date, the U.S. Department of 

Agriculture has spent over $200 million in research and outreach related to alternatives for the 

crops on which MeBr is currently used. In addition, various farm consortia and universities have 

expended significant efforts to find alternatives. It is estimated that private research and 

development expenditures to identify MeBr alternatives have equaled or exceeded USG 

expenditures. 

The U.S. pesticide registration program has established a rigorous process to ensure that 

pesticides registered for use in the United States do not present an unreasonable risk of health or 

environmental harm. Within the program, the USG has given the highest priority to rapidly 

reviewing MeBr alternatives, while maintaining our high domestic standard of environmental 

protection. The resulting research program has taken into account these inputs, as well as the 

extensive private sector research and trial demonstrations of alternatives to MeBr. While 

research has been undertaken in all sectors, federal government efforts have been based on the 

input of experts as well as the fact that nearly 80 percent of pre-plant MeBr soil fumigation is 

used in a limited number of crops. Accordingly, much of the federal government pre-plant 

efforts have focused on strawberries, tomatoes, ornamentals, peppers and nursery crops, (forest, 

ornamental, strawberry, pepper, tree, and vine), with special emphasis on tomatoes in Florida and 

strawberries in California as model crops. 

The USDA/ARS strategy for evaluating possible alternatives is to first test the approaches in 

controlled experiments to determine efficacy, then testing those that are effective in field plots. 

The impact of the variables that affect efficacy is addressed by conducting field trials at multiple 

locations with different crops and against various diseases and pests. Alternatives that are 

effective in field plots are then tested in field scale validations, frequently by growers in their 

own fields. University scientists are also participants in this research. Research teams that 

 24
include ARS and university scientists, extension personnel, and grower representatives meet 

periodically to evaluate research results and plan future trials. 

Recently registered pesticides with registrations that make them potential methyl bromide 

alternatives are listed in Section IV of this document. EPA is currently reviewing several 

additional applications for registration as MeBr alternatives, including: 

• Iodomethane as a pre-plant soil fumigant for strawberries, tomatoes, peppers and 

ornamentals. 

• Dazomet as a pre-plant soil fumigant for strawberries and tomatoes. 

• Furfural for use in greenhouses for cut flowers, propagative materials, ornamentals, and 

other non-food/non-feed commodities; outdoors for cut flower production, production 

nurseries, residential and commercial landscapes, residential and commercial turf, golf 

courses, sod farms, and sports fields. 

• Sodium Azide is pending registration on the following use sites -- ornamental nurseries, 

sod farms, and turf renovation on golf courses. 

While these activities appear promising, it must be noted that issues related to toxicity, ground 

water contamination, and the release of air pollutants may pose significant problems with respect 

to some alternatives that may lead to use restrictions since many of the growing regions are in 

sensitive areas such as those in close proximity to residential areas. There are a wide range of 

potential restrictions at both the national and state level that can be imposed including handling 

requirements, personal protective equipment, buffer zones, limitations on use in certain soil 

types, caps on use in certain geographical areas, and other restrictions as well. Indeed, it is 

possible that a substance may not be registered if it is deemed to have severe human health or 

environmental impacts. Given the enormous range of potential outcomes for alternatives, and 

for that matter for MeBr and chloropicrin which are being re-registered, it is not possible to 

provide estimates of potential reduced need for MeBr until after the precise regulatory 

restrictions and market conditions are known. 

Ongoing research on alternative fumigants is evaluating ways to reduce emission under various 

application regimes and examining whether commonly used agrochemicals, such as fertilizers 

and nitrification inhibitors, could be used to rapidly degrade soil fumigants. 

Remaining regional-crop specific pest problems 

A number of alternatives have already been registered for use, and several additional promising 

alternatives are under review at this time. Research efforts to find new alternatives to MeBr and 

move them quickly toward registration and commercialization have allowed growers and users to 

make great progress over the last decade in phasing out many uses of MeBr. Through all of this 

research, it has become increasingly clear that no one existing alternative can replace MeBr in all 

of its uses. There are no effective alternatives for all crops, soil types and pest pressures as 

evidenced by the CUE sectors listed below. Accordingly, the USG has submitted a critical use 

nomination to address these limited needs. 

 25
General description of CUE sectors

Rigorous review by the USG narrowed the list of requested uses based on the availability of 

technically and economically feasible alternatives. The thorough and comprehensive review that 

created the U.S. nomination entailed multiple levels of analysis with teams of biologists and 

economists. In addition, the recommendations of these reviews were evaluated whether or not 

there was a critical need for MeBr, based on the criteria agreed to by the Parties of the Montreal 

Protocol. The following CUE were nominated by the USG and approved by the Parties to the 

Protocol: 

1. Pre-plant Soil Uses: Cucurbits – field; Eggplant – field; Forest nursery seedlings; Fruit, 

Nut and Flower Nurseries - Chrysanthemum cuttings, rose plants (nursery), fruit tree 

nurseries, strawberry runners; Orchard replant; Peppers – field; Strawberry fruit – field; 

Tomato – field; Turfgrass sod nurseries. 

2. Post-harvest uses: Commodities- Dried fruit, beans and nuts; Food processing facilities - 

mills and processors; Smokehouse ham; 

For each sector, there is a brief discussion of the research efforts to develop alternatives that, if 

successful, will allow the use of MeBr to be reduced over time. The section also lists what 

actions are underway to minimize the MeBr emissions. 

 26
Pre-Plant Soil Uses 

Cucurbits: (squash, melons, and cucumber) 

Key Pests are soil borne fungi Phytophthora capsici and Fusarium oxysporum, and nutsedge. 

The only currently available MeBr alternative that is technically feasible for the control of the 

first two key target pests is 1,3-D + chloropicrin. Regulatory restrictions due to concerns over 

human exposure and ground water contamination, along with the lower yields, result in 

economic infeasibility of this formulation as a practical MeBr alternative under certain 

circumstances. Key among these factors are a delay in planting up to 14 days relative to MeBr, 

due to a combination of label restrictions, low soil temperatures, as well as a mandatory 30 m 

buffer for treated fields with 1,3-D + chloropicrin near inhabited structures. Metam-sodium 

offers some control of nutsedges and nematodes; however, in areas where nutsedge infestations 

are moderate to severe and fungal pathogens are present, metam-sodium results in an estimated 

44 % yield loss relative to MeBr. Yield losses and regulatory restrictions render these promising 

MeBr alternatives technologically and economically infeasible. 

Future Plans for reducing Methyl Bromide use in Cucurbits:

1,3-D + chloropicrin, metam-sodium, furfural, propylene oxide, and sodium azide will continue 

to be the subjects of field studies of utilization and efficacy enhancement where Phytophthora 

and Fusarium fungi are the target pests. It should be kept in mind that furfural, propylene oxide, 

and sodium azide are currently unregistered for use on cucurbits, and there are presently no 

commercial entities pursuing registration in the U.S. The regulatory restrictions on 1,3-D will 

also remain as negative influences on the economics of this MeBr alternative. 

The timeline for developing the above-mentioned MeBr alternatives in Michigan (by Michigan 

State University) is as follows: 

2003 – 2005: Test for efficacy (particularly against the more prevalent Phytophthora fungi) 

2005 – 2007: Establish on-farm demonstration plots for effective MeBr alternatives 

2008 – 2010: Work with growers to implement widespread commercial use of alternatives 

demonstrated to be effective. 

Research is also under way to evaluate the feasibility and optimize the use of a 50% MeBr: 50% 

chloropicrin formulation to replace the currently used 67:33 formulation. In addition, field 

research is being conducted to optimize a combination of crop rotation, raised crop beds, black 

plastic and foliar fungicides. Use of virtually impermeable film (VIF) will also be investigated 

as a replacement for the currently used low density polyethylene (LDPE). All research is to be 

conducted by Michigan State University staff in collaboration with commercial cucurbit growers, 

and if demonstrated effective, these films could potentially reduce the future need for MeBr in 

this sector. 

In the Southeastern U.S., research has been conducted on nutsedge control with halosulfuron, 

1,3-D + chloropicrin, and metam-sodium. Future research will focus on halosulfuron and crop 

rotation for control of nutsedges. Approximately 3 to 5 years are expected as a timeframe for 

developing effective MeBr alternatives for nutsedge control in cucurbits. Research will be 

conducted in cooperation with commercial cucurbit growers, by faculty and extension staff at 

 27
various land-grant universities in the states encompassed by this region. Also, it is reasonable to 

expect that the results from Michigan research on fungicidal alternatives to MeBr will be used to 

develop options for fungal pests of southeastern U.S. cucurbits. 

Future plans to minimize MeBr use also include: 

(1) Using research and on-farm evaluations to optimize a combination of nutsedge control in 

fallow fields, crop rotation, and use of post-emergent herbicide in crops. Herbicides will include 

halosulfuron, sulfentrazone, and glyphosate. 

(2) Optimize the combined use of plastic (e.g. LDPE) tarps and drip irrigation equipment for 

applying at-plant herbicides. 

 28
Eggplant

Methyl bromide is the only fumigant that consistently provides reliable control of target weeds, 

nematodes, and pathogens. The best alternatives (e.g. 1,3-D + chloropicrin, metam sodium) are 

not as effective in controlling nutsedge and have a long waiting period for planting (28 days) that 

would disrupt planting schedules and cause growers to miss key market windows. Regulatory 

restrictions (30.4 m buffer for treated fields near inhabited structures) due to concerns over 

human exposure and ground water contamination, along with technical limitations, result in 

potential economic infeasibility of 1,3-D alone or in combination as a practical MeBr alternative. 

Future Plans for reducing Methyl Bromide use in Eggplant:

Iodomethane is under consideration as a potential MeBr replacement; it is unknown when it will 

be registered at the federal or State level, or what types of regulatory restrictions may be 

associated with its use. Given the considerable uncertainty associated with the timing and 

conditions of its registration, and the concurrent regulatory consideration of MeBr, it isn’t 

possible to determine the extent of applicability of iodomethane to this crop, or the timing of 

phase in. The economic feasibility of this product is also impossible to ascertain at this time 

because there is no market price for the material in the United States. Nevertheless, registration 

of this product may provide an important additional pest control tool to farmers that could result 

in reducing the amount of critical use MeBr needed for this sector. 

In addition, the following new long-term studies have been initiated at the Coastal Plain 

Experiment Station in Tifton, Georgia, with funding provided by USDA-CSREES, Methyl 

Bromide Transitions Grant: 

▪ Evaluation of the effects of soil conditions, particularly soil temperature and moisture, on 

nutsedge species efficacy from several fumigants. 

▪ Investigation of the impact of multiple-season adoption of MeBr alternatives in terms of 

pest species composition, including weeds, diseases, and nematodes. 

▪ Integration of multiple tactics as alternatives to MeBr for management of weeds, diseases, 

and nematodes in pepper and eggplant. 

▪ Evaluation of vegetable crop response to herbicides applied under plastic prior to crop 

transplants and characterize herbicide fate when applied in a plasticulture system between 

summer and fall crops. 

 29
Forest Seedlings

Nurseries in the U. S. are located in eight climate zones, mostly with light or medium soils. The 

majority of seedlings are species of conifers, and 30-40 species of hardwoods, such as oaks, 

hickory, poplars, and ash. Forest nurseries throughout the U. S. must contend with a variety of 

pests. Effective fumigation is primarily relied on to manage fungal pathogens and especially, 

yellow and purple nutsedges. Economic issues, such as increased application costs, have an 

impact on overall feasibility of alternatives (metam-sodium and chloropicrin) for the forest 

seedlings sector. 

Future Plans for reducing Methyl Bromide use in Forest Seedlings:

Combinations of chemicals, such as chloropicrin, metam-sodium, or 1,3-D appear to be effective 

for some nurseries in reducing pest infestations, including some weed problems. Combinations 

of these compounds and application techniques (such as deep injection) to achieve the same pest 

control efficiencies as MeBr are being studied. So far, none have proven cost effective and have 

generally resulted in an increased input of other pest control products. Physical limitations (e.g. 

low vapor pressure of metam-sodium) lead to the lack of consistency of these products. Tests 

are being conducted with iodomethane, which has potential as a MeBr replacement, although it is 

unknown when registration might occur, and what the associated regulatory conditions of that 

registration at both the federal and state levels might be. 

The use of virtually impermeable film (VIF) may offer a means of reducing MeBr use rates 

while maintaining efficacy and production goals. Work is being conducted to determine if this 

type of film is feasible in the U.S. from a technical standpoint and to determine if it is 

economically feasible; however, California does not permit the use of VIF, so it will not be 

possible to use it there. There is also interest in examining the effects of certain fertilizer salts 

(e.g. ammonium thiosulfate) which may act as barriers to volatile compounds (e.g. 1,3-D and 

MeBr) when applied to the soil surface, thus reducing emissions and improving efficacy. The 

reduction of MeBr from 98:2 to 65:35 or even 50:50, the reduction in use rate, increased periods 

of cover crop growth, use of glyphosate, and an increased use of mechanical cultivation may be 

effective in reducing weed populations, and the overall use of MeBr; however, such treatments 

need to be confirmed under commercial growing conditions. Experiments have indicated that 

some soil amendments can reduce possible adverse growth effects of some MeBr alternatives 

(e.g. dazomet). Work in Wisconsin suggested that white pine seedlings subjected to dazomet, 

but supplied with various nutrients, could reduce chlorosis sometimes observed in dazomet 

treated beds. Large scale trials will be necessary to confirm this effect. For disease control, 

studies comparing cultivation practices, such as conventional till versus no-till and organic 

amendments indicate that effects vary according to the species grown, thus each nursery may 

have to consider alternatives with species and local environmental conditions in mind, unlike the 

more consistent effects of MeBr fumigation. 

 30
Fruit, Nut and Flower Nurseries

Under California regulatory laws, nursery crops must be “free of especially injurious pests and 

disease symptoms” in order to qualify for a California Department of Food and Agriculture 

(CDFA) Nursery Stock Certificate for Interstate and Intrastate Shipments. There are no effective 

alternatives that can ensure certification. 

Future Plans for reducing Methyl Bromide use in Fruit, Nut and Flower Nurseries:

Raspberry nurseries have spent $100,000 on research, including $20,000 on screening resistance 

for Phytophthora and Verticillium, and over $60,000 over the last decade studying various 

alternatives in the Watsonville, California area. Studies are also ongoing to discover how 

application methods can improve efficacy of chemical alternatives such as 1,3-D and metamsodium, and mixes of chemicals. Moisture constraints, both too much and too little, can reduce 

efficacy of effective chemicals such as 1,3-D, especially when soil textures are not optimal for 

their physical chemistry. Iodomethane is a potential replacement for MeBr, but is not registered 

in the U.S. The use of virtually impermeable film (VIF) may offer a means of reducing fumigant 

use rates while maintaining efficacy and production goals, although VIF use is currently 

prohibited in California. There is also interest in examining the effects of certain fertilizer salts 

(e.g. ammonium thiosulfate) which may act as barriers to volatile compounds (e.g. 1,3-D and 

MeBr) when applied to the soil surface, thus reducing emissions and improving efficacy. 

Between 1999 and 2000, the California fruit, vine, and nut industries have spent $378,467 on 

numerous research projects. From 2002-2003, researchers were granted $262,002 by this 

industry to study alternatives. In addition, an equal amount of funding has been granted to these 

industries by government and universities. 

Research on MeBr alternatives has been conducted by the nursery industry since at least 1990, 

initially to find alternatives to 1,3-D, whose registration had been cancelled in California. Upon 

reinstatement of the 1,3-D registration in 1994, studies began to examine 1,3-D formulations that 

could provide acceptable nematode control under conditions (especially critical moisture 

conditions) common to commercial nursery sites that would meet certification requirements and 

reduce or replace the use of MeBr. Successful treatment with 1,3-D depends on enough surface 

moisture to retain effective fumigant concentration, but with a maximum of 12% soil moisture 

throughout the rest of the soil profile to facilitate optimal fumigant distribution. Studies with 

new emulsifiable formulations of 1,3-D and chloropicrin, such as Inline, may improve efficacy 

by improving fumigant distribution beyond the limitations currently associated with shank 

injection techniques. However, township caps, buffer zones, and limitations due to physical 

characteristics of soils are still important issues to successful nursery production. The Nursery 

Rose industry is developing technologies to improve efficacy of alternatives such as deep 

injection methods, soil moisture management by improving drip technologies, experience with 

virtually impermeable films (VIF) to increase efficacy and decrease emissions. Between 2001 

and 2003, $60,000 was devoted to nursery rose alternatives research at USDA and on-farm 

research. A rose nursery trial conducted for two years resulted in rootknot nematode control 

comparable to MeBr with the use of tarped Telone C35. However, soil moisture and township 

caps will limit use of 1,3-D, and the cost of tarping can significantly increase prices of nursery 

stock. 

 31
Orchard Replant

The Orchard Replant sector represents stone fruit, almond, and walnut orchards, and table grape 

and raisin vineyards in California. The key pest, “orchard replant problem” (or syndrome), is 

characterized by poor tree growth during the early years of establishment (rejection component) 

and in some cases a slow and detrimental decline in root health and plant growth caused 

primarily by pathogenic nematodes and fungi. A pre-plant fumigation occurs only once in the 

life of the orchard, and therefore, the most cost-effective but deep penetrating treatment is sought 

by growers. The primary alternative, 1,3-D, has regulatory restrictions on its use and application 

rate, including township caps in California, and reduced rates that are considered ineffective for 

some severe replant situations. 

Future Plans for reducing Methyl Bromide use in Orchard Replant:

The development of technologies to improve efficacy of alternatives, such as deep injection 

methods, soil moisture management by improving drip technologies, use of fallow, crop rotation, 

tolerant rootstocks, and improved experience with chemical/non-chemical combinations, is 

underway. Even where MeBr is considered critical, an improvement in efficient delivery 

techniques will result in reduction of MeBr use requirements. Considering that this sector uses 

MeBr only once in the life of the orchard, use of alternatives to replace MeBr will have to be 

considered in light of the long-term impact on tree and vine health, as well as fruit and nut 

production. There are several approaches that can help address MeBr alternatives for almonds, 

as well as walnuts, grapes, and stone fruit; use of herbicides to kill remnant roots, use of fallow 

and crop rotations, use of “virgin” soil as an amendment to possibly reduce replant problem, 

resistant rootstocks when available, irrigation regimes to improve consistency of metam-sodium, 

etc. 

 32
Ornamentals

Florida and California field grown ornamentals include bulbs, cut flowers, and cut foliage. It is a 

labor intensive industry characterized by high costs of production (land, labor, energy and other 

inputs), urban encroachment, intense cropping systems, rapidly changing market demands and 

high risk. It is plagued by a pest spectrum in the soil that includes nematodes, soil-borne 

pathogens and weeds that must be controlled without delaying production or harming the crops. 

 

Weeds, especially nutsedge, tend to be particularly difficult to control and are a limiting factor in 

replacing MeBr. Once weeds emerge, contact herbicides cannot be used without damaging the 

crop and hand weeding is cost prohibitive on a large scale. Soil persistent pre-emergent 

herbicides cannot be used without risk to the current crop or subsequent plantings. 

Comprehensive phytotoxicity studies can not be conducted due to the large number of crops, 

numerous varieties within crops, and the regular introduction of new varieties through aggressive 

breeding programs. 

MeBr has been the industry standard for soil fumigants because it works well across the entire 

pest spectrum, it works consistently and is environmentally safe on all soil types, is applied 

safely by expert applicators, is not a threat to human health and safety as currently applied, and 

leaves no residue that can interfere with the intense multi-cropping and breeding practices of the 

field grown ornamentals industry. The alternatives currently identified do not meet these 

criteria, even if they were available to and economical for ornamentals growers. MeBr use has 

declined and emissions reduced through formulation changes, tarping after application and use of 

alternative control measures. Although MeBr use has been reduced, it cannot be eliminated with 

the existing alternatives. 

Chemical alternatives include 1,3-D, chloropicrin, metam sodium and their combinations. None 

of these alternatives provide sufficient control over the entire pest spectrum when used either 

alone or in combination. All have use restrictions imposed by local, state and federal agencies 

due to environmental risks and potential human exposure. These chemicals are also undergoing 

re-registration review by U.S. EPA; registrations may be lost or additional restrictions may be 

imposed, further limiting their usefulness to growers. Non-chemical alternatives do not provide 

the level or consistency of control, are too expensive, or are not compatible with current 

production practices. As discussed previously, weed control is also a limiting factor. 

Another major factor affecting the search for MeBr alternatives is the need for flexibility in the 

types of crops produced. Growers must be able to respond to rapidly changing market demands. 

Growers must respond to peak demands, such as holidays, as well as to changing consumer 

preferences. They cannot afford planting or harvest delays, or production uncertainties due to 

unpredictable pest control. 

Future Plans for reducing Methyl Bromide use in Ornamentals:

Research efforts are difficult because this is a relatively small industry, commercial acreage 

available for testing is limited, and the crops and cropping systems are complicated, requiring 

large testing programs to be representative of the industry. Regardless, the field grown 

ornamental industry has supported public and private research and has performed in-house 

 33
testing. Research has included registered pesticides, pesticides in various stages of development 

(including biologicals), and non-pesticidal treatments. 

The research strategy of the field grown cut flower industry is to continue to investigate ways to 

use existing chemicals and non-chemical methods, as first priority. This strategy includes 

looking at different application techniques, product combinations and multi-year programs using 

existing chemicals; investigating various barrier films to use for emissions reduction, solarization 

and optimizing pesticide efficacy; and, testing biological control agents and other non-chemical 

alternatives in integrated programs when feasible. However, the industry has already devoted 

extensive, and expensive, effort and resources to these lines of investigation and the existing 

alternatives do not, singly or in combination, meet the industry’s needs. 

The next level of investigation includes testing registered products that are seeking label 

expansion into field grown ornamentals or non-registered products that fit into and are being 

developed for this market. The best example of the latter is iodomethane. However, these 

alternatives remain unproven at this time, are unregistered, and cannot be viewed at present as 

economically or technically feasible until research and commercial trials confirm their viability. 

Field grown ornamental growers will continue to look for efficacious and economical means to 

produce their crops and are committed to continuing to support efforts to find MeBr alternatives. 

Existing chemical alternatives pose greater risks than MeBr – risks of crop failure, environmental 

risks and human health risks. Continued reduction in MeBr use can not progress much further 

until viable alternatives are available. 

 34
Peppers

Key pests are soil fungi Phytophthora capsici and nutsedge. A viable alternative for susceptible 

fungi is the combination of 1,3-D + chloropicrin; however, regulatory restrictions (mandatory 30 

meter buffer) due to concerns over human exposure and ground water contamination, planting 

delays of up to 28 days, along with technical limitations, result in potential economic 

infeasibility of this formulation as a practical MeBr alternative. Also, 1,3-D, cannot be used 

when soils are very wet. The alternative for nutsedge control, metam-sodium, has resulted in 

yield losses of up to 44% compared to MeBr where weed infestations are moderate to severe. 

Future Plans for reducing Methyl Bromide use in Peppers:

Although alternatives for methyl bromide in the circumstances of the U.S. nomination remain 

technically and economically infeasible, research into MeBr alternatives is beginning to show 

some promising results and USG scientists now anticipate that transition away from MeBr will 

be possible in some cases over the next five to ten years. Some conditions in each of the 

growing areas limit the extent to which, with alternatives available in the foreseeable future, the 

transition can be completed. The future plan described for each region below are estimated 

based on the current regulatory status of methyl bromide and other alternatives. Should the 

regulatory status of these chemicals change as a part of the reregistration process, it could impact 

some of these estimates. 

In Michigan, due to the cold soil temperatures and the very short growing season, there does not, 

at present, appear to be any combination of alternatives that can replace MeBr and still allow an 

economically viable crop production. 

In California the major impediment to adoption of the preferred alternative to MeBr 

(combinations of 1,3-dichloropropene and chloropicrin) is the regulatory cap on the amount of 

1,3-D used in each township. Experiments with lower rates and less permeable tarps (currently 

not legal in California) and better understanding of the conditions of metam sodium use should 

enable approximately 75% of pepper production to replace MeBr use over the next five years. 

In Florida the major impediment to the adoption of the preferred alternative to MeBr 

(combinations of 1,3-dichloropropene and chloropicrin, sometimes followed by metam sodium) 

is the presence of heavy concentrations of nutsedge (nutgrass). An additional impediment is the 

presence of karst topography, which comprises approximately 40% of Florida agricultural land. 

This limits the use of 1,3-D. In Dade county the use of 1,3-D is not allowed by regulation. 

Experiments with metalized films in conjunction with the chemical treatments also showed 

promise although work in this area is still preliminary. Continued work in these areas is 

anticipated to allow up to 75% of Florida pepper production to replace MeBr over a period of ten 

years. 

In Georgia the major impediment to the adoption of the preferred alternative to MeBr 

(combinations of 1,3-dichloropropene and chloropicrin, sometimes followed by metam sodium) 

is the presence of heavy concentrations of nutsedge (nutgrass). An additional impediment is the 

presence of karst topography, which comprises approximately 8% of Georgia agricultural land. 

This limits the use of 1,3-D. Experiments with metalized films in conjunction with the chemical 

 35
treatments also showed promise although work in this area is still preliminary. It is anticipated 

that continued work in these areas should allow up to 80% of Georgia pepper production to 

replace MeBr over a period of seven years. 

In the southeastern U.S., comprising the States of Alabama, Arkansas, Louisiana, North 

Carolina, South Carolina, Tennessee, and Virginia, the major impediments to the adoption of the 

preferred alternative to MeBr (combinations of 1,3-dichloropropene and chloropicrin, sometimes 

followed by metam sodium) is the presence of heavy concentrations of nutsedge (nutgrass). 

Other weeds, particularly nightshade, are also present in abundance. There is scattered karst 

topography throughout the region that limits the use of mixtures containing 1,3-D. Experiments 

with metalized films in conjunction with the chemical treatments also showed promise although 

work in this area is still preliminary. Continued work in these areas is anticipated to allow up to 

85% of pepper production in the southeastern United States to replace MeBr over a period of 

seven years. 

New data on potential MeBr alternatives for use on peppers, submitted by the Georgia and 

Southeast U.S. Peppers Consortium, show that 1,3-D + chloropicrin, followed by more 

chloropicrin, was more effective than MeBr against yellow nutsedge, but less effective against 

purple nutsedge. Although this treatment performed as well as MeBr in terms of spring crop 

yield, its fall yield performance was inferior to that of MeBr. In a second treatment,1,3-D by 

itself, followed by chloropicrin, was significantly less effective than MeBr for the control of both 

purple and yellow nutsedge, but as effective as MeBr for the control of soil nematodes. In terms 

of spring and fall pepper yield, however, this treatment performed as well as MeBr. In a third 

treatment,1,3-D + chloropicrin, followed by metam sodium, was as effective as MeBr against 

yellow nutsedge, 36% less effective than MeBr against purple nutsedge, and as effective as 

MeBr for the control of soil nematodes. This treatment also performed as well as MeBr in terms 

of both spring and fall pepper yield. Although these combinations are showing promise, they 

will require further testing and validation under commercial conditions. 

Iodomethane is under consideration as a potential MeBr replacement; it is unknown when it will 

be registered at the federal or State level, or what types of regulatory restrictions may be 

associated with its use. Given the considerable uncertainty associated with the timing and 

conditions of its registration, and the concurrent regulatory consideration of MeBr, it isn’t 

possible to determine the extent of applicability of iodomethane to this crop, or the timing of 

phase-in. The economic feasibility of this product is also impossible to ascertain at this time 

because there is no market price for the material in the United States. Nevertheless, registration 

of this product may provide an important additional pest control tool to farmers that could result 

in reducing the amount of critical use MeBr needed for this sector. 

 36
Strawberries

In California, regulatory limits on the amount of 1,3-D that can be used in each township results 

in the continuing need for MeBr. In Florida and other eastern States, nutsedge is a primary pest 

on about 40 percent of the crop area, and the alternative can not be used on land that has karst 

topography. Where there is moderate to severe pest pressure, the suggested alternatives for 

strawberry fruit production fail to provide the necessary degree of pest control, or their use is not 

easily adoptable due to state-imposed restrictions. Applying alternatives is further complicated 

when plant-back restrictions prevent farmers from meeting marketing windows (e.g. winter or 

early spring) when strawberry sale prices are as much as 100% higher than during the rest of the 

year. 

Future Plans for reducing Methyl Bromide use in Strawberry:

Positive results have been observed for replacing MeBr use with options such as 1,3- D + 

chloropicrin, metam-sodium, VIF tarps, etc. Growers will achieve further reductions in MeBr 

use where nutsedge is not a primary pest (representing about 60% of the industry) by changing 

the formulation to 57:43; this change can result in a 9% reduction in MeBr use. It may be 

feasible to use 50:50 mixtures with chloropicrin under plastic mulch beds to achieve further 

reductions, but this has not yet been demonstrated under local conditions. Increasing the 

percentage of Pic can occur with the fewest obstacles to implementation and can potentially 

reduce MeBr use up to 15% by 2007. 

It is more difficult to accomplish comparable reductions by formulation changes in nutsedge 

infested regions, as experience has shown that MeBr dosages below 30.2 g/m2 do not provide 

satisfactory nutsedge control. These growers will likely implement alternative methods, such as 

VIF or high barrier films that could reduce MeBr by one third. Ongoing research will help 

define the best approach. If the use of VIF or high barrier tarps proves effective, there is 

potential to significantly reduce MeBr use. The net effect would be a 28.4% reduction by 2007. 

 37
Strawberry Nursery

Methyl bromide is needed for strawberry nursery production to produce plants free of all 

damaging diseases and nematodes to meet state and foreign certification standards, as well as 

prospective buyer expectations. In addition to these certification-related pest control concerns, 

weed control is also essential to insure maximum runner production and prevent the spread of 

noxious weeds. The available alternatives have thus far not been found to provide acceptable 

levels of control of the key pests to depths of three feet. 

Future Plans for reducing Methyl Bromide use in Strawberry Nursery Production:

Results of ongoing research suggest that there are treatments for strawberry nurseries that may 

have the potential to replace MeBr in the future. Iodomethane plus chloropicrin, chloropicrin 

followed by dazomet, and Telone C35 (1,3-D + chloropicrin) followed by dazomet are being 

investigated as potential MeBr replacements in strawberry nurseries. The industry supports 

research to identify the most effective methods to treat soil. After possibly five years of research 

trials, scale-up trials on a commercial level will be done to confirm the most effective treatments 

found in research trials. Combinations of several chemical and non-chemical controls are likely 

to be the most effective alternative to MeBr, but their ability to provide the same level of 

consistent control must be tested and demonstrated before MeBr can be replaced. 

 38
Tomatoes

The key pest pressure is moderate to high nutsedge in the Southeastern U.S. Regulatory 

constraints due to the presence of karst geology and delay in planting and harvesting (the plantback interval for 1,3-D + chloropicrin is two weeks longer than MeBr + chloropicrin) limit the 

use of alternatives. There are additional delays in areas with cold climates where the soil 

temperatures must be higher to fumigate with alternatives. Such delays result in users missing 

key market windows, and adversely affect revenues through lower prices. 

Future Plans for reducing Methyl Bromide use in Tomatoes:

Although alternatives for MeBr in the circumstances of the U.S. nomination remain technically 

and economically infeasible, research into MeBr alternatives is beginning to show some 

promising results and USG scientists now anticipate that transition away from MeBr will be 

possible in many cases over the next five to ten years. Some conditions in each of the growing 

areas limit the extent to which, with alternatives available in the foreseeable future, the transition 

can be completed. 

In Michigan, due to the cold soil temperatures and the very short growing season, there does not, 

at present, appear to be any combination of alternatives that can replace MeBr and still allow an 

economically viable crop production. 

In California, the major impediment to adoption of the preferred alternative to MeBr (metam 

sodium) is the hilly terrain in which the tomatoes are grown. (When tomatoes are grown in flat 

terrain, 1,3-D or 1,3-D and chloropicrin combinations can be used as long as the regulatory cap 

on the amount of 1,3-D used in a township is not exceeded. These areas are not part of the U.S. 

nomination.) Until the problem of uneven distribution of the pest control agent in hilly terrain is 

solved, the USG does not foresee adoption of 1,3-D or 1,3-D + chloropicrin combinations as 

alternatives. 

In the southeastern U.S., comprising the States of Alabama, Arkansas, Florida, Georgia, 

Louisiana, North Carolina, South Carolina, Tennessee, and Virginia, the major impediments to 

the adoption of the preferred alternative to MeBr (combinations of 1,3-dichloropropene and 

chloropicrin, sometimes followed by metam sodium) is the presence of heavy concentrations of 

nutsedge (nutgrass). Other weeds, particularly nightshade, are also present in abundance. There 

is scattered karst topography throughout the region, ranging from approximately 40% of Florida 

agricultural land to 8% of Georgia agricultural land, to lesser amounts in the other States. The 

presence of karst topography limits the use of mixtures containing 1,3-D. Experiments with 

metalized films in conjunction with the chemical treatments have also showed promise although 

work in this area is still preliminary. Continued work in these areas is anticipated to allow up to 

80% of tomato production in the southeastern United States to replace MeBr over a period of 

eight years. 

 39
 Turfgrass Sod Nursery

Methyl bromide is the only treatment that consistently provides effective control of off-type 

perennial grasses, as well as nutsedge and other weeds, nematodes, and insect pests. Sod 

certification programs operate on a state or regional level, some of which specifically require 

MeBr fumigation as a condition for certification. Alternatives, such as dazomet and metamsodium, are unreliable and do not provide the degree of consistent pest control needed by the 

industry to meet market demands. 

Future Plans for reducing Methyl Bromide use in Turf:

Although alternatives for MeBr in the circumstances of the U.S. nomination remain technically 

and economically infeasible, research into MeBr alternatives is beginning to show some 

promising results and USG scientists now anticipate that transition away from MeBr will be 

possible in many cases over the next five to ten years. Some conditions in each of the growing 

areas limit the extent to which, with alternatives available in the foreseeable future, the transition 

can be completed. 

Turf grass is grown primarily in California, Florida, Georgia, Alabama and Texas. The major 

impediment to the adoption of the preferred alternative to MeBr (dazomet and metam sodium) is 

the presence of high pest pressure that render the alternatives ineffective against the pests 

affecting this crop. Although alternative treatments can be foreseen as solutions to 

approximately 75% of MeBr use over the next eight to ten years, with currently available 

alternatives, it is not expected that MeBr use can be completely replaced in this sector. The 

replacement of MeBr will require the development of application technologies to better deliver 

these alternatives to soils containing target pests. Alternatives will likely require more frequent 

applications thereby increasing costs and environmental pesticide burden. 

Metam-sodium and dazomet already are used in the sod turfgrass production industry. It has not 

been determined how the 1% of total sod farm hectares that use MeBr can further reduce its use. 

Studies of high density polyethylene will be conducted to evaluate its efficacy in this sector. 

 40
Post-Harvest Uses 

Commodities

Methyl bromide is needed primarily to treat stored agricultural commodities in a very short 

period, during the peak production season, shortly after harvest before they can be stored and/or 

shipped. Methyl Bromide fumigation for commodities occurs to ensure pest-free food and meet 

the strict requirements of the Food Sanitation Regulations. Methyl bromide is typically utilized 

in processed food and feed facilities as a space fumigant for treating the facility one to three 

times per year. As the need arises, MeBr is also used for trailer fumigations of product or 

packaging material. Phosphine, alone or combined with carbon dioxide (Eco2fume®), is the 

principal chemical alternative currently available for use. Although sulfuryl fluoride has 

received a federal registration for many stored commodities, it is not registered in California 

where these uses occur. Furthermore, as many of these commodities are exported, the lack of 

internationally recognized food tolerances (i.e. maximum residue limits or MRLs) will make the 

use of sulfuryl fluoride impractical until such tolerances are granted. These sectors are already 

using phosphine alone or in combination to the extent that their processing systems and 

marketing needs allow it due to the increased time of treatment over MeBr. Complete 

replacement of MeBr by phosphine fumigation is impracticable since it takes longer than MeBr 

and is not feasible when rapid fumigations are needed such as during harvest. Also harvest of 

commodities occurs in autumn, when temperatures are falling, making temperature-dependent 

phosphine fumigation less practicable. Any additional shifting from MeBr to the slower 

phosphine fumigation would result in disruption of commodity processing during peak 

production times, lost market windows, and substantial economic losses. Adoption of not in 

kind alternatives, such as controlled atmospheres, cold, and carbon dioxide under pressure would 

require major investments for appropriate treatment units and /or retrofitting of existing 

warehouses. 

Future Plans for reducing Methyl Bromide use in Commodities:

For dried beans, walnuts, pistachios, dried fruit, and dates, alternatives are phosphine, PPO, and 

sulfuryl fluoride. It is believed that 100% of nuts and dried fruit will be able to convert to 

sulfuryl fluoride when receiving countries have established tolerances for this product on these 

food commodities. Although these tolerances (MRLs) are under consideration before CODEX, 

it is not possible to determine when the CODEX and individual country approvals may occur. 

The transition period could be as long as 10 years, to allow for the construction of fumigation 

facilities able to effectively use sulfuryl fluoride, phosphine or PPO. Also, phosphine changes 

the flavor of fresh dates and is not considered an alternative. 

 41
Dry Cured Pork

Producers of dry cured pork products (including smoked hams) experience pest pressure from 

insects. Alternatives include phosphine and heat. Heat is not viable as an alternative because of 

its effect on the final product (rancidity) and its ability to alter the character of the final product, 

producing, for example, a cooked pork product rather than a dry cured pork product with the 

attendant flavor differences. Phosphine is corrosive on certain metals and can not be used in 

mechanical and electrical areas of the facilities. Until recently, there were no registered 

alternatives in the United States for ham; however, in July of 2005, sulfuryl fluoride received a 

registration granting a food tolerance for this sector. A research effort is underway to ascertain 

its efficacy for controlling the target pests. 

Future Plans for reducing Methyl Bromide use in Dry Cured Pork:

Due to the challenges of penetrating the tissue, most available fumigants are not technically 

feasible. Experts are exploring potential candidates such as sulfuryl fluoride, but efficacy data 

are lacking under the conditions experienced in the facilities used to cure these hams. Smallscale trials cannot be conducted until a suitable compound has been identified through laboratory 

efficacy experiments. 

 42
Facilities

There are many food processing facilities in the United States for which the USG is not 

requesting MeBr use because they have been able to successfully implement alternatives. 

However, other facilities cannot adopt alternatives at this time because of structural 

configurations that make the alternatives economically infeasible. Some facilities are using both 

phosphine and heat treatments to disinfest at least portions of their plants. Facilities have been 

able to reduce the number of MeBr fumigations from an average of six times a year to an average 

of two times per year. Also, MeBr now is typically applied at 25-30 % of the approved label rate. 

The U.S. CUE nomination in this sector only includes a request for MeBr use where use of 

alternatives is limited by technical or economic constraints. Phosphine, both alone and in 

combination with carbon dioxide, is often used to treat incoming grain and some finished 

products. Unfortunately, phosphine is corrosive to copper, silver, gold and their alloys. These 

metals are critical components of both the computers that run the machines as well as electrical 

components in some of the machines in the plants. Additionally, phosphine requires more time 

to kill insect pests than MeBr, so plants will need to be shut down longer to achieve mortality, 

with associated economic losses from this downtime. There are also reports of stored product 

pests becoming resistant to phosphine. 

There are several limitations associated with the use of heat in this industry. Not all areas of a 

plant can be efficiently fumigated with heat. Some food substances, for instance cheeses, will go 

rancid with heat treatments. Not all finished food products can be heated for the length of time 

heat is required for efficient kill of pests. Achieving uniform distribution of the heat throughout 

the facility can be a significant obstacle, and reports of structural damage due to excess heat in 

facilities have been received. Incidents have been reported where heat triggered fire suppression 

water sprinkler systems. High heat can damage processing equipment not engineered for such 

temperatures and manufacturers may not warrant their equipment after exposure to high heat. 

Few facilities have the heating capacity to raise the temperature to 60-65°C (140-150°F) to 

achieve insecticidal control. Installing permanent heating capacity or bringing in temporary 

heaters is usually cost prohibitive. 

Sulfuryl fluoride (SF) received a new label in July, 2005, that clarified its use on certain raw 

agricultural commodities and processed foods. The label does not allow for direct fumigation of 

many processed foods such as pasta, breakfast cereals, and bakery mixes; or pet foods. To 

prevent excessive residues, the sulfuryl fluoride label requires that the amount of flour present 

during fumigation be minimized. This presents a technical and logistical hurdle that impacts the 

economics of a fumigation. 

Future Plans for reducing Methyl Bromide use in Facilities:

Although alternatives for MeBr in the circumstances of the U.S. nomination remain technically 

and economically infeasible, research into MeBr alternatives is beginning to show some 

promising results and USG scientists now anticipate that transition away from MeBr will be 

possible in approximately half of the flour mills and rice mills that currently use MeBr over the 

next four years. There is a newly registered alternative, sulfuryl fluoride, which shows promise 

 43
although current information indicates that this alternative is significantly more expensive than 

MeBr when used in sufficient concentration to kill all insect stages including the egg stage. 

Wider use of this alternative in other food producing facilities is limited by the need to obtain 

tolerances for all foodstuffs present in the facility being fumigated if the product is not to be 

removed prior to fumigation or discarded thereafter. 

 Older alternatives, such as phosphine and heat are not expected to completely replace MeBr 

although they are important in reducing the frequency of MeBr fumigations. 

Until recently, about 100 rice and flour mills in California and New York were unable to use 

sulfuryl fluoride due to the lack of a state registration for this product. California has now 

registered sulfuryl fluoride for use in rice and flour mills, and it is expected that approximately 

three-quarters of these mills will eventually be able to convert, over a 4 year period, to sulfuryl 

fluoride. 

The rice milling industry has spent over U.S.$500,000 on research to develop alternatives since 

1992, and plans to use additional pesticides, such as carbonyl sulfide, carbon dioxide, phosphine, 

magnesium phosphide (magtoxin®), and dichlorvos (vapona®) over the next few years. Nonchemical methods used by this sub-sector to reduce MeBr use, include heat and cold treatments, 

and many individual companies are involved in further research and testing of alternatives. 

Industry experts have been trying to determine how best to incorporate sulfuryl fluoride into their 

IPM programs since its recent registration. 

The bakery sector is implementing heat as an alternative at those facilities where heat is 

technically feasible. Currently, heat is being implemented at several facilities nationwide, but 

further trials are needed to determine the effects of heat on a long-term basis. However, older 

facilities with hardwood floors and plant electrical wiring systems are unsuitable for heat 

treatments as damage may occur. Other methods being used to reduce reliance on MeBr are: 

pest exclusion, cleaning, early detection, improved design of equipment, trapping, and other 

integrated pest management (IPM) approaches. Phosphine continues to be tested, and sulfuryl 

fluoride just received a federal registration for this use. 

The flour milling industry is committed to IPM techniques including non-chemical means in 

order to minimize reliance on any one tool. Many plants have reduced the amount of annual 

fumigations from 4-5 per year to 2-3 per year. Some of these facilities combine MeBr with 

carbon dioxide. Further, these applicants have authored a manual on IPM practices that is 

widely utilized throughout the industry and sponsor an industry conference on IPM. The 

industry continues to test high heat, phosphine, alone and in combination; and the combination of 

heat, phosphine, and carbon dioxide. In addition, industry experts have been trying to determine 

how best to incorporate sulfuryl fluoride into their IPM programs since its recent registration. 

The Pet Food Institute has invested hundreds of thousands of dollars in research on a variety of 

alternatives to MeBr, including heat treatments. Sulfuryl fluoride was tested in an inactive pet 

food facility last year as well. They have made improvements in worker training, pest 

 44
monitoring, and sanitation to greatly reduce the necessity for fumigations with MeBr, or any 

other fumigant. 

 45
TABLES

Table 1. 2006 Critical Uses and Critical Limiting Conditions 

EPA determined that the following uses with the limiting critical conditions specified below 

qualify to obtain and use critical use MeBr in 2006. However, as discussed previously, some of 

the circumstances for some of the critical use categories may have changed due to recent 

registrations of an alternative and therefore EPA has proposed a decrease in the total critical use 

exemption level for 2006 relative to what has been approved by the MOP. 

Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

PRE-PLANT USES 

Cucurbits (a) Michigan growers with a reasonable expectation that moderate to 

severe soilborne fungal disease infestation, or 

moderate to severe disease infestation could occur 

without methyl bromide fumigation; or with a need 

for methyl bromide for research purposes 

(b) Southeastern U.S. except Georgia 

limited to growing locations in 

Alabama, Arkansas, Kentucky, 

Louisiana, North Carolina, South 

Carolina, Tennessee, and Virginia 

with a reasonable expectation that one or more of 

the following limiting critical conditions either 

already exist or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, or to a lesser extent: 

fungal disease infestation and root knot nematodes; 

or with a need for methyl bromide for research 

purposes 

(c) Georgia growers with a reasonable expectation that one or more of 

the following limiting critical conditions either 

already exist or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, moderate to severe 

fungal disease infestation, or to a lesser extent: 

root knot nematodes; or with a need for methyl 

bromide for research purposes 

Eggplant (a) Florida growers with a reasonable expectation that one or more of 

the following limiting critical conditions either 

already exist or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, or moderate to severe 

nematodes, or moderate to severe disease 

infestation, or restrictions on alternatives due to 

karst geology; or with a need for methyl bromide 

for research purposes 

(b) Georgia growers with a reasonable expectation that one or more of 

the following limiting critical conditions either 

already exist or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, or moderate to severe 

nematodes, or moderate to severe pythium root and 

 46
Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

collar rots, or moderate to severe southern blight 

infestation, and to a lesser extent: crown and root 

rot ; or with a need for methyl bromide for research 

purposes 

(c) Michigan growers with a reasonable expectation that moderate to 

severe soilborne fungal disease infestation could 

occur without methyl bromide fumigation; or with 

a need for methyl bromide for research purposes 

Forest Nursery 

Seedlings 

(a) growers in Alabama, Arkansas, 

Florida, Georgia, Louisiana, 

Mississippi, North Carolina, 

Oklahoma, South Carolina, 

Tennessee, Texas and Virginia 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exist or could occur without methyl bromide 

fumigation: moderate to severe yellow or purple 

nutsedge infestation, or moderate to severe disease 

infestation 

(b) International Paper and its 

subsidiaries limited to growing 

locations in Arkansas, Alabama, 

Georgia, South Carolina and Texas 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exist or could occur without methyl bromide 

fumigation: moderate to severe yellow or purple 

nutsedge infestation, or moderate to severe disease 

infestation 

(c) Public (government owned) 

seedling nurseries in the states of 

Idaho, Illinois, Indiana, Kansas, 

Kentucky, Maryland, Missouri, 

Nebraska, New Jersey, Ohio, Oregon, 

Pennsylvania, Utah, Washington, 

West Virginia and Wisconsin 

with a reasonable expectation that one or more of 

the following limiting critical conditions either 

already exist or could occur without methyl 

bromide fumigation: moderate to severe weed 

infestation including purple and yellow nutsedge 

infestation, or moderate to severe Canada thistle 

infestation, or moderate to severe nematodes, and 

to a lesser extent: fungal disease infestation 

(d) Weyerhaeuser Company and its 

subsidiaries limited to growing 

locations in Alabama, Arkansas, 

North Carolina and South Carolina 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exist or could occur without methyl bromide 

fumigation: moderate to severe yellow or purple 

nutsedge infestation, moderate to severe disease 

infestation, and to a lesser extent: nematodes and 

worms 

(e) Weyerhaeuser Company and its 

subsidiaries limited to growing in 

Washington and Oregon 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exist of could occur without methyl bromide 

fumigation: moderate to severe yellow nutsedge 

infestation, or moderate to severe fungal disease 

infestation 

(f) Michigan growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exist or could occur without methyl bromide 

fumigation: moderate to severe disease infestation, 

moderate to severe Canada thistle infestation, 

moderate to severe nutsedge infestation, and to a 

lesser extent: nematodes 

(g) Michigan herbaceous perennials with a reasonable expectation that one or more of 

the following limiting critical conditions already 

 47
Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

growers exist or could occur without methyl bromide 

fumigation: moderate to severe nematodes, 

moderate to severe fungal disease infestation, and 

to a lesser extent: yellow nutsedge and other weeds 

infestation 

Orchard Nursery 

Seedlings 

(a) Members of the Western 

Raspberry Nursery Consortium 

limited to growing locations in 

California and Washington 

(Driscoll’s raspberries and their 

contract growers in California and 

Washington) 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe nematode 

infestation, medium to heavy clay soils, or a 

prohibition of on the use of 1,3-dichloropropene 

products due to reaching local township limits on 

the use of this alternative; or with a need for 

methyl bromide for research purposes 

(b) Members of the California 

Association of NurserymenDeciduous Fruit and Nut Tree 

Growers 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe 

nematodes, medium to heavy clay soils, or a 

prohibition of on the use of 1,3-dichloropropene 

products due to reaching local township limits on 

the use of this alternative; or with a need for 

methyl bromide for research purposes 

(c) California rose nurseries with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe 

nematodes, or user may be prohibited from using 

1,3-dichloropropene products because local 

township limits for this alternative have been 

reached; or with a need for methyl bromide for 

research purposes 

Strawberry 

Nurseries 

(a) California growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe disease 

infestation, or moderate to severe yellow or purple 

nutsedge infestation, or moderate to severe 

nematodes; or with a need for methyl bromide for 

research purposes 

(b) North Carolina, Tennessee and 

Maryland growers 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe black root 

rot, or moderate to severe root-knot nematodes, or 

moderate to severe yellow and purple nutsedge 

infestation, and to a lesser extent: crown rot; or 

with a need for methyl bromide for research 

purposes 

Orchard Replant (a) California stone fruit growers with a reasonable expectation that one or more of 

 48
Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe 

nematodes, or moderate to severe fungal disease 

infestation, or replanted (non-virgin) orchard soils 

to prevent orchard replant disease, or medium to 

heavy soils, or a prohibition on the use of 1,3-

dichloropropene products because local township 

limits for this alternative have been reached; or 

with a need for methyl bromide for research 

purposes 

Ornamentals (a) California growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe disease 

infestation, or moderate to severe nematodes, or a 

prohibition on the use of 1,3-dichloropropene 

products because local township limits for this 

alternative have been reached; or with a need for 

methyl bromide for research purposes 

(b) Florida growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe weed 

infestation, or moderate to severe disease 

infestation, or moderate to severe nematodes, or 

karst topography; or with a need for methyl 

bromide for research purposes 

Peppers (a) California growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe disease 

infestation, or moderate to severe nematodes, or a 

prohibition on the use of 1,3-dichloropropene 

products because local township limits for this 

alternative have been reached; or with a need for 

methyl bromide for research purposes 

(b) Alabama, Arkansas, Kentucky, 

Louisiana, North Carolina, South 

Carolina, Tennessee and Virginia 

growers 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, or moderate to severe 

nematodes, or moderate to severe pythium root, 

collar, crown and root rots, or the presence of an 

occupied structure within 100 feet of a grower’s 

field the size of 100 acres or less; or with a need 

for methyl bromide for research purposes 

(c) Florida growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

 49
Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

purple nutsedge infestation, or moderate to severe 

disease infestation, or moderate to severe 

nematodes, or karst topography; or with a need for 

methyl bromide for research purposes 

(d) Georgia growers with a reasonable expectation that one or more of 

the following limiting critical conditions either 

already exist or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, or moderate to severe 

nematodes, or moderate to severe pythium root and 

collar rots, or moderate to severe southern blight 

infestation, and to a lesser extent: crown and root 

rot ; or with a need for methyl bromide for research 

purposes 

(e) Michigan growers with a reasonable expectation that moderate to 

severe fungal disease infestation would occur 

without methyl bromide fumigation; or with a need 

for methyl bromide for research purposes 

Strawberry Fruit (a) California growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe black root 

rot or crown rot, or moderate to severe yellow or 

purple nutsedge infestation, or moderate to severe 

nematodes, or a prohibition of the use of 1,3-

dichloropropene products because local township 

limits for this alternative have been reached, time 

to transition to an alternative; or with a need for 

methyl bromide for research purposes 

(b) Florida growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge, or moderate to severe nematodes, 

or moderate to severe disease infestation, or karst 

topography and to a lesser extent: carolina 

geranium or cut-leaf evening primrose infestation; 

or with a need for methyl bromide for research 

purposes 

(c) Alabama, Arkansas, Georgia, 

Illinois, Kentucky, Louisiana, 

Maryland, New Jersey, North 

Carolina, Ohio, South Carolina, 

Tennessee and Virginia growers 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge, or moderate to severe nematodes, 

or moderate to severe black root and crown rot, or 

the presence of an occupied structure within 100 

feet of a grower’s field the size of 100 acres or 

less; or with a need for methyl bromide for 

research purposes 

Tomatoes (a) Michigan growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

 50
Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

either exists or could occur without methyl 

bromide fumigation: moderate to severe disease 

infestation, or moderate to severe fungal pathogens 

infestation; or with a need for methyl bromide for 

research purposes 

(b) Alabama, Arkansas, Florida, 

Georgia, Kentucky, Louisiana, North 

Carolina, South Carolina, and 

Tennessee growers 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe yellow or 

purple nutsedge infestation, or moderate to severe 

disease infestation, or moderate to severe 

nematodes, or the presence of an occupied 

structure within 100 feet of a grower’s field the 

size of 100 acres or less, or karst topography; or 

with a need for methyl bromide for research 

purposes 

(c) California growers with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe disease 

infestation, or moderate to severe nematodes; or 

with a need for methyl bromide for research 

purposes 

Turfgrass (a) U.S. turfgrass sod nursery 

producers who are members of 

Turfgrass Producers International 

(TPI) 

for the production of industry certified pure sod; 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

either exists or could occur without methyl 

bromide fumigation: moderate to severe 

bermudagrass, nutsedge and off-type perennial 

grass infestation, or moderate to severe, or 

moderate to severe white grub infestation; or with 

a need for methyl bromide for research purposes 

POST-HARVEST USES 

Food Processing (a) Rice millers in all locations in the 

U.S. who are members of the USA 

Rice Millers Association. 

with a reasonable expectation that one or more of 

the following limiting critical conditions exists: 

moderate to severe infestation of beetles, weevils 

or moths, or older structures that can not be 

properly sealed to use an alternative to methyl 

bromide, or the presence of sensitive electronic 

equipment subject to corrosivity, time to transition 

to an alternative 

(b) Pet food manufacturing facilities 

in the U.S. who are active members 

of the Pet Food Institute. (For 

today’s rule, “pet food” refers to 

domestic dog and cat food). 

with a reasonable expectation that one or more of 

the following limiting critical conditions exists: 

moderate to severe infestation or beetles, moths, or 

cockroaches, or older structures that can not be 

properly sealed to use an alternative to methyl 

bromide, or the presence of sensitive electronic 

equipment subject to corrosivity, time to transition 

to an alternative 

 51
Approved Critical 

Uses 

Approved Critical User and 

Location of Use 

Limiting Critical Conditions 

(c) Bakeries in the U.S. with a reasonable expectation that one or more of 

the following limiting critical conditions exists: 

design problems or the presence of sensitive 

electronic equipment subject to corrosivity, time to 

transition to an alternative 

(d) Members of the North American 

Millers’ Association in the U.S. 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

exists or could occur without methyl bromide 

fumigation: moderate to severe beetle infestation, 

or older structures that can not be properly sealed 

to use an alternative to methyl bromide, or the 

presence of sensitive electronic equipment subject 

to corrosivity, time to transition to an alternative 

(e) Members of the National Pest 

Management Association associated 

with dry commodity structure 

fumigation (cocoa) and dry 

commodity fumigation (processed 

food, herbs, spices, and dried milk) 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

exists or could occur without methyl bromide 

fumigation: moderate to severe beetle or moth 

infestation, or older structures that can not be 

properly sealed to use an alternative to methyl 

bromide, or the presence of sensitive electronic 

equipment subject to corrosivity, time to transition 

to an alternative 

Commodity 

Storage 

(a) California entities storing walnuts, 

beans, dried plums, figs, raisins, dates 

and pistachios in California 

with a reasonable expectation that one or more of 

the following limiting critical conditions exists: 

rapid fumigation is required to meet a critical 

market window, such as during the holiday season, 

rapid fumigation is required when a buyer provides 

short (2 days or less) notification for a purchase, or 

there is a short period after harvest in which to 

fumigate and there is limited silo availability for 

using alternatives; or with a need for methyl 

bromide for research purposes 

Dry Cured Pork 

Products 

(a) Members of the National Country 

Ham Association 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

exists or could occur without methyl bromide 

fumigation: moderate to severe red legged ham 

beetle, cheese/ham skipper, dermested beetle or 

ham mite infestation 

(b) Members of the American 

Association of Meat Processors 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

exists or could occur without methyl bromide 

fumigation: moderate to severe red legged ham 

beetle, cheese/ham skipper, dermested beetle or 

ham mite infestation 

(c) Nahunta Pork Center (North 

Carolina) 

with a reasonable expectation that one or more of 

the following limiting critical conditions already 

exists or could occur without methyl bromide 

fumigation: moderate to severe red legged ham 

beetle, cheese/ham skipper, dermested beetle or 

ham mite infestation 

 52
 53
 54

Table 2. Principal Pre-plant MeBr Alternatives and their Strengths and General Limitations / 

Impediments to Adoption 

MeBr Alternative Strength General Limitations / 

Impediments to Adoption 

Chloropicrin (PIC) Good fungicide Weak on nematodes 

Ineffective on weeds 

Metam sodium / potassium Good nematicide Marginal fungicide and herbicide 

Strong odor / large buffers 

Antagonistic to PIC 

Iodomethane Similar handling and 

application properties 

to MeBr plus PIC 

Not registered 

Cost is unknown 

Must be applied with PIC 

Longer/irregular aeration period 

required after treatment 

1,3-dichloropropene (1,3-D) Good nematicide with 

some disease control 

Subject to regulatory constraints 

on karst topography 

Subject to regulatory constraints 

in California (Township caps) 

1,3-D plus PIC Good nematicide and 

fungicide 

Ineffective alone on weeds, 

requires a compatible 

herbicide treatment 

Metam sodium / potassium 

followed by PIC 

Good nematicide and 

fungicide 

Marginally effective on weeds 

Requires separate applications to 

avoid antagonism 

Steam treatment Effective against diseases, 

nematodes and weeds 

Cost prohibitive except on raised 

beds or potted media in 

protected culture 

Solarization Effective against pests near 

the surface 

Highly variable results wherever 

rainfall occurs during 

treatment (well-suited only 

for desert climates) 

Ineffective against pests at depths 

beyond a few centimeters 

Long treatment times prevent 

planting of second crops 

(well-suited to hot/dry 

locations where only one crop 

is grown per season) 

The use of trade, firm, corporation or product names in this document does not constitute an official endorsement or 

approval by the United States Department of Agriculture of any product or service to the exclusion of others that 

may be suitable.