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Implementation of Risk Mitigation Measures for Soil Fumigant Pesticides

Soil Fumigant Pesticides

Current as of April 2010

Fumigant Management Plan templates are now available for methyl bromide and will be available soon for other soil fumigants.

EPA is requiring important new safety measures for soil fumigant pesticides to increase protections for agricultural workers and bystanders – people who live, work, or otherwise spend time near fields that are fumigated. These measures are included in Amended Reregistration Eligibility Decisions (REDs) for the soil fumigants:

On this page you will find information on EPA’s implementation of a suite of complementary measures in the Agency's multifaceted regulatory approach to minimize risks of these pesticides. Taken together, these measures are expected to directly reduce exposures and risks, improve safety and reduce the potential for accidents, foster compliance and reduce misuse, and enhance enforcement, while maintaining important benefits.

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Amended Soil Fumigant REDs

In May 2009, after consulting with stakeholders and obtaining extensive public input, EPA issued Amended Reregistration Eligibility Decisions (REDs) for the soil fumigant pesticides, including final new safety measures for soil fumigant pesticides to increase protections for agricultural workers and bystanders. Implemented over the next two years, these measures will work together to establish a baseline for safe use of the soil fumigants throughout the United States, reducing fumigant exposures and significantly improving safety.

Many of the new safety measures were announced in July 2008 when EPA issued risk management Reregistration Eligibility Decisions (REDs) for the soil fumigants. During the next year, the Agency took significant public comment on implementation of these measures, including public meetings and visits with many agricultural, farm worker, and public health constituents. In the May 2009 Amended REDs, all measures to reduce risks are still required, however, some aspects of these measures were adjusted based on input from stakeholders and on new scientific data that reduce the uncertainties in the Agency’s assessments and improved information on certain technological capabilities. These modifications will achieve the same level of protection for people potentially exposed to the fumigants, while resulting in greater compliance and fewer impacts on the benefits of soil fumigant use.

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Risk Mitigation Measures for Soil Fumigants

EPA is requiring a suite of complementary mitigation measures to protect handlers, reentry workers, and bystanders from risks resulting from exposure to the soil fumigant pesticides. These measures are designed to work together to address all risks, but focus on the acute human inhalation risks that have been identified in the revised risk assessments for these fumigants.

Most of the measures summarized here apply to all of the soil fumigants (for example, fumigant management plans).  See fact sheets explaining implementation of these general risk mitigation measures. However, some measures are specific to individual fumigants (for example, buffer distances). The fumigant-specific measures are explained in detail chemical-specific Amended REDs.

Measures include:

Buffer Zones: (Fact Sheet) EPA is requiring fumigant users to establish a buffer zone around treated fields to reduce risks from acute inhalation exposure to bystanders. A buffer zone provides distance between the application site (i.e., edge of field) and bystanders, allowing airborne residues to disperse before reaching the bystanders. This buffer will reduce the chances that air concentrations where bystanders are located will cause acute adverse health effects.

EPA has selected buffer distances that will protect bystanders from exposures that could cause adverse effects, but that are not so great as to eliminate benefits of soil fumigant use. The size of the buffer zones is based on the following factors:

Buffer zone distances are scenario-based using applicable site conditions and will be provided in look-up tables on product labels. EPA is also giving "credits" to encourage users to employ practices that reduce emissions (for example, use of high-barrier tarps). Credits will reduce buffer distances. Some credits will also be available for site conditions that reduce emissions (e.g., high organic or clay content of soils).

Posting Requirements: (Fact Sheet) For buffer zones to be effective as risk mitigation, bystanders need to be informed about the location and timing of the fumigation to ensure they do not enter areas designated as part of the buffer zone. EPA is requiring that buffer zones be posted at usual points of entry and along likely routes of approach to the buffer unless:

  1. a physical barrier prevents access to the buffer, or
  2. all of the area within 300’ of the buffer is under the control of the owner/operator.

The signs must include a “do not walk” symbol, fumigant product name, and contact information for the fumigator.

Agricultural Worker Protections: (Fact Sheet) Persons engaged in any of a number of activities that are part of the fumigation process are considered “handlers.”  Handler activities include operating fumigation equipment, assisting in the application of the fumigant, monitoring fumigant air concentrations, and installing, repairing, perforating, and removing tarps.

Applicator and Handler Training Programs: EPA is requiring fumigant registrants to develop and implement training programs for applicators in charge of soil fumigations on proper use and good agricultural practices so these applicators are better prepared to effectively manage fumigant operations. The registrants also must prepare and disseminate training information and materials for fumigant handlers (those working under the supervision of the certified applicator in charge of fumigations). Providing safety information to other fumigant handlers will help them understand and adhere to practices that will protect them from risks of exposure. The training materials must include elements designed to educate workers regarding work practices that can reduce exposure to fumigants, and thereby improve safety for workers and bystanders.

Good Agricultural Practices: Current fumigant labels recommend practices that help reduce off-gassing and improve the safety and effectiveness of applications.  The Agency has determined that including certain practices on labels as requirements rather than recommendations will minimize inhalation and other risks from fumigant applications.  Several fumigant products already incorporate some of these measures on their labels.  Examples of good agricultural practices include proper soil preparation/tilling, ensuring optimal soil moisture and temperature, appropriate use of sealing techniques, equipment calibration, and weather criteria.

Application Method, Practice, and Rate Restrictions: The Agency is restricting certain fumigant application methods and practices for which data are not currently available to determine appropriate protections, or that lead to risks that are otherwise difficult to address. These include certain untarped applications for some fumigants. EPA is also lowering maximum application rates to reflect those rates needed for effective use, thereby reducing the potential for inhalation exposure and risk.

Restricted Use Pesticide Classification: All soil fumigant products containing methyl bromide, 1,3-dichloropropene, iodomethane, and chloropicrin are currently restricted use pesticides, but many soil fumigant products containing metam sodium/potassium and dazomet are not restricted use pesticides.  The Agency has determined that all of the soil fumigants undergoing reregistration meet the criteria for restricted use.  Therefore, EPA will reclassify metam sodium/potassium and dazomet as restricted use pesticides.

Site-Specific Fumigant Management Plans (FMPs): (Fact Sheet; 2010 FMP template for methyl bromide (10 pp, 217 KB, About PDF); 2011 FMP template for methyl bromide (14 pp, 270 KB, About PDF)) Soil fumigations are complex processes involving specialized equipment to properly apply volatile and toxic pesticides. EPA's risk mitigation allows for site-specific decisions to address the specific conditions where the fumigant is applied. To address this complexity and flexibility, EPA is requiring that fumigant users prepare a written, site-specific fumigant management plan before fumigations begin. Written plans and procedures for safe and effective applications will help prevent accidents and misuse and will capture emergency response plans and steps to take in case an accident occurs.

FMPs will be a resource for compliance assurance; fumigators will capture in the FMP how they are complying with label requirements. FMPs will help ensure fumigators successfully plan all aspects of a safe fumigation, and will be an important tool for federal, state, tribal, and local officials to verify compliance with labeling.

Elements that must be included in soil Fumigant Management Plans are:

The certified applicator supervising the fumigation must verify in writing that the FMP is current and accurate before beginning the fumigation. A post-fumigation summary report describing any deviations that may have occurred from the FMP will also be required within 30 days of the end of the application.

The fumigator and the owner/operator of the fumigated field must keep the FMP and post-fumigation summary report for two years and make them available upon request to federal, state, tribal, and local enforcement officials.

Emergency Preparedness and Response Requirements: (Fact Sheet) Although buffers and other mitigation will prevent many future incidents, it is likely that some incidents will still occur due to accidents, errors, and/or unforeseen weather conditions. Early detection and appropriate response to accidental chemical releases is an effective means of reducing risk. Preparedness for these types of situations is an important part of the suite of measures necessary to avoid risks posed by fumigants.

Compliance Assistance and Assurance Measures: Assuring compliance with new label requirements is an important part of the package of mitigation measures. Some states have mechanisms in place to obtain information needed to assist and assure compliance with new fumigant requirements. Therefore, in states that wish to receive this information, fumigators must notify State and Tribal Lead Agencies for pesticide enforcement about applications they plan to conduct. This information will aid those states in planning compliance assurance activities. EPA will work with all the states to amend their cooperative agreements with the Agency to include strategies for assuring compliance with new fumigant labels. States that do not choose to receive notification will need to document in their cooperative agreements their methods of identifying fumigant application periods and locations.

Community Outreach and Education Programs: EPA is requiring fumigant registrants to develop and implement community outreach programs to ensure that information about fumigants and safety is available within communities where soil fumigation occurs. Outreach and information will address the risk of bystander exposure by educating community members about fumigants, buffer zones, how to recognize early signs of fumigant exposure, and how to respond appropriately in case of an incident.

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Next Steps

Implement Fumigant Mitigation Measures:To achieve new protections, EPA is moving expeditiously to implement the mitigation measures in the soil fumigant Amended REDs. As indicated in the Timeline and the Implementation Schedule , many mitigation measures will appear on fumigant product labels in 2010, and all measures will be implemented by late 2011. EPA will continue to work closely with stakeholders to ensure that they understand the new requirements and how they will be phased in.

Registration Review: A substantial amount of research is currently under way or is expected to begin in the near term to address current data gaps and to refine understanding of factors that affect fumigant emissions. Additionally, new technologies to reduce emissions are emerging. EPA has moved the soil fumigants forward in Registration Review from 2017 to 2013. This will allow EPA to consider new data and technologies sooner, determine whether the mitigation included in this decision is effectively addressing the risks as EPA believes it will, and to include other soil fumigants that are not part of the current review.

Timeline for Next Steps:

Implementation Schedule for Soil Fumigant Risk Mitigation Measures
Risk Mitigation Measure Currently 2010 2011
Restricted Use (metam sodium/potassium and dazomet only)
New Good Agricultural Practices  
Rate reductions  
Use site limitations  
New handler protections  
Tarp cutting and removal restrictions  
Extended worker reentry restrictions  
Training information for workers  
Fumigant Management Plans  
First responder and community outreach  
Applicator training  
Compliance assistance and assurance measures  
Restrictions on applications near sensitive areas  
Buffer zones around all occupied sites  
Buffer credits for best practices  
Buffer posting  
Buffer overlap prohibitions  
Emergency preparedness measures  
ø = methyl bromide and chloropicrin are currently RUPs
° = under development/partial implementation
• = adopt completely

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Fumigant Properties and Uses

Soil fumigants are pesticides that, when applied to soil, form a gas to control pests that live in the soil and can disrupt plant growth and crop production. The fumigants are either volatile chemicals that become gases at relatively low temperatures, around 40 degrees Fahrenheit, or they are chemicals that react to produce such a gas (e.g., dazomet and metam sodium converting to methyl isothiocyanate or MITC). Soil fumigants are used on many high value crops, including vegetables, fruits, nuts, forest seedlings, ornamentals, and nursery crops, to control a wide range of pests including nematodes, fungi, bacteria, insects, and weeds.

Agricultural Benefits and Human Health Risks

Because of the broad range of pests controlled, soil fumigants are used as part of the production of a wide variety of crops and provide high benefits for many growers. As gases, however, fumigants move from the soil to the air at the application site and may pose risks to workers. Bystanders, who are not involved in the fumigant application but who live, work, or are otherwise located in nearby areas, may also be exposed to airborne fumigants that move off the application site. Bystanders include agricultural workers in nearby fields who are not involved with the fumigant application.

Incidents of bystander exposure demonstrate that fumigants have the potential to move off site at concentrations that produce adverse health effects in humans, over periods of several hours to days after application. These health effects may range from mild and reversible eye irritation to more severe and irreversible effects, depending on the fumigant and the level of exposure.

Group Review

EPA reviewed chloropicrin, dazomet, metam sodium/potassium, and methyl bromide and the soil fumigants 1,3-dichloropropene (Telone®) and iodomethane (methyl iodide) as a group. The Agency completed a RED for 1,3-dichloropropene in 1998. Iodomethane was registered in October 2007. The Agency will reexamine the mitigation required for iodomethane to ensure consistency with other currently registered fumigants. By considering the soil fumigants as a group, the Agency has ensured that similar risk assessment tools and methods were used for all, and risk management approaches were consistent. EPA plans to consider the soil fumigants together again during Registration Review, beginning in 2013.

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For More Information:

Soil Fumigant Dockets: EPA’s soil fumigant decision documents and related information is available in the following individual fumigant dockets at Regulations.gov.

Soil Fumigant Amended REDs:

Mitigation Measure-Specific Fact Sheets:

Other Soil Fumigants:

EPA Soil Fumigant Contacts:

Susan Bartow (bartow.susan@epa.gov)
Methyl Bromide Chemical Review Manager
703) 603-0065

Andrea Carone (carone.andrea@epa.gov)
Chloropicrin Chemical Review Manager
1,3-Dichloropropene Chemical Review Manager
(703) 308-0122

Dana Friedman (friedman.dana@epa.gov)
Dazomet, Metam Sodium/Potassium and Methyl Isothiocyanate (MITC)Chemical Review Manager
(703) 347-8827

Mary Waller (waller.mary@epa.gov)
Iodomethane Product Manager
(703) 308-9354

John Leahy (leahy.john@epa.gov)
Senior Advisor
(703) 305-6703

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