Implementation of Risk Mitigation Measures for Soil Fumigant Pesticides
Este Web page está disponible en español
Current as of December 1, 2008
Pesticide Soil Fumigant Chemicals
EPA Pesticide Program Update, 8/29/08
EPA News Release, 7/10/08
Mitigation Measure-Specific Fact Sheets
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 risk management Reregistration Eligibility Decisions (REDs) for the soil fumigants:
- chloropicrin
- dazomet
- metam sodium/potassium (including methyl isothiocyanate or MITC)
- methyl bromide
Although these soil fumigant decisions are final, EPA requested public comment on implementation of the risk mitigation measures by October 30, 2008 - August 29, 2008, FR Notice; July 16, 2008, FR Notice. The Agency is considering comments and new information received, at present.
On this page you will find information on a suite of complementary measures in EPA'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.
Background
Fumigant Properties and Uses
Soil fumigants are pesticides which, 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 crops, primarily potatoes, tomatoes, strawberries, carrots, and peppers, to control a wide range of pests including nematodes, fungi, bacteria, 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 which 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. The newly registered fumigant iodomethane will be reexamined later this year to determine whether new mitigation or restrictions are necessary. 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. As discussed further below, EPA plans to consider the soil fumigants together again during Registration Review, beginning in 2013.
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 summarized in chemical-specific RED fact sheets.
Measures include:
- Buffer zones (see related fact sheet)
- Posting requirements (see related fact sheet)
- Agricultural worker protections (see related fact sheet)
- Applicator and handler training programs
- Good agricultural practices
- Application method, practice, and rate restrictions
- Restricted use pesticide classification
- Site-specific fumigant management plans (see related fact sheet)
- Emergency preparedness and response requirements (see related fact sheet)
- Notice to state and tribal lead agencies
- Community outreach and education programs
Buffer Zones: 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:
- application rate;
- field size;
- application equipment and methods; and,
- emission-control measures (e.g., tarps).
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: 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:
- a physical barrier such as a fence prevents access to the buffer, or
- 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, date and time of the fumigation, date and time the buffer restrictions expire, fumigant product name, and contact information for the fumigator.
Agricultural Worker Protections: Persons engaged in any of a number of activities which 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.
- fit-tested to ensure respirators will provide the protection they are designed to provide;
- trained in how to properly use a respirator; and
- determined to be physically fit enough to wear the respirator to ensure they have no health problems such as a heart condition which could make use of the respirator dangerous.
- a minimum interval of 5 days between application and tarp perforation;
- a minimum interval of 24 hours between perforation and tarp removal;
- use of respiratory protection; and,
- use of mechanical devices (e.g., using all-terrain vehicles with cutting implements attached).
Respiratory Protection: Many current labels require handlers to use respirators when air concentrations in the area where they are working reach certain action levels, but do not require monitoring to determine if the action levels have been reached. New labels will require monitoring at regular intervals so handlers will know whether respirators are needed.
In most cases inhalation risks can be mitigated with the use of air purifying respirators equipped with approved respirator cartridge filters. However, for scenarios involving very high air concentrations where these respirators do not provide adequate protection, EPA is requiring handlers stop work and leave the area until corrective action has been taken to address the source of the high air concentration, for example, to repair a tarp which has been damaged or displaced.
During the corrective action, a self-contained breathing apparatus (SCBA) may be required to adequately reduce the risks to those handlers. To resume work activities, air monitoring must show concentrations are less than limits identified on labels. Handlers repairing tarps before re-entry prohibitions have ended must use respirators.
Additionally, EPA is requiring that handlers be:
Tarp Perforation and Removal: Fumigant gases become trapped under tarps and can be released when the tarp is perforated (i.e., cut, punched, poked) and removed (for application methods in which tarps are removed before planting). Handlers perforating and removing tarps may be exposed to air concentrations of concern. To reduce these exposures, the Agency is requiring the following:
Entry Prohibitions: Current labels allow worker reentry into fumigated fields two to five days after applications are complete. However, there are risks of concern for workers reentering even after 48 hours. Stakeholder comments indicate that reentry for non-handler tasks is generally not needed for several days after the application is complete. EPA is extending the time that agricultural workers (i.e., non-handlers) are prohibited from entering the treated area. The entry prohibited period depends on the method of application, but generally the minimum period for worker reentry will be five days or until after tarps are perforated and removed.
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 programs 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, 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): 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:
- general site information,
- applicator information,
- application procedures,
- measurements taken to verify compliance with good application practices,
- how buffers were determined,
- worker protection information,
- procedures for air monitoring,
- posting,
- training of applicators supervising fumigations,
- communication among key parties,
- hazard communication,
- record keeping,
- site-specific response and management activities,
- emergency plans,
- procedures for controlling fumigant releases in case of problems during or after the application.
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: 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.
First Responder Education: EPA is requiring registrants to provide, through their community outreach programs, training and information to first responders in high fumigant use areas and areas with significant interface between communities and fumigated fields. These measures will ensure that emergency responders are prepared to effectively identify and respond to fumigant exposure incidents.
Site-Specific Response and Management Activities: EPA is requiring that applicators provide for on-site monitoring of buffer zone perimeters in areas where homes, schools, and other sensitive sites are present. If measured concentrations anywhere along the buffer perimeter reach a level of concern specified on product labels, or if the person monitoring the air concentrations experiences eye irritation, then the emergency response plan stated in the Fumigant Management Plan must be implemented. This monitoring must be done during the full buffer zone time period.
As an alternative to on-site monitoring, fumigant users may provide emergency response information directly to neighbors. In this case, the certified applicator supervising the fumigation, or someone under his/her direct supervision, must ensure that nearby residents and business owners/operators have been provided the response information at least 48 hours prior to fumigant application. The method for distributing information to neighbors must be described in the Fumigant Management Plan.
Notice to State and Tribal Lead Agencies: Assuring compliance with new label requirements is an important part of the package of mitigation measures. Therefore, before the application, fumigators must notify State and Tribal Lead Agencies for pesticide enforcement about applications they plan to conduct. This information will aid states in planning compliance assurance activities.
Community Outreach and Education Programs: EPA is requiring fumigant registrants to develop and implement community outreach programs, including programs for first responders, 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.
Next Steps
Final Decision for Comment: After consulting with stakeholders and obtaining public input through the Agency's pesticide public participation process, EPA has made final decisions on the soil fumigants. Although the decisions are final, due to the broad scope and complexity of the decisions, EPA requested input on implementation approaches during an extended public comment period that ended October 30, 2008 - August 29, 2008, FR Notice; July 16, 2008, FR Notice. At present, EPA is considering new information received during the comment period and may refine plans for implementation of the risk mitigation measures, as needed.
Registration Review: A substantial amount of research is currently underway or is expected to begin in the near term to (1) address current data gaps, and (2) refine understanding of factors that affect fumigant emissions. Additionally, new technologies to reduce emissions are emerging. EPA plans to move 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:
- July 2008 – Federal Register Notice opens 60-day comment period
- Fall 2008 – Comment period closes
- Late 2008 to Early 2009 – EPA considers comments, develops responses
- Early 2009 – EPA issues RED amendments if needed and issues product specific and generic data call-ins (DCIs)
- 2009 – Registrants begin implementing training and community outreach and education programs
- Late 2009 – Product data and revised labels submitted to EPA
- 2010 – EPA reviews, approves new soil fumigant labels
- 2010 to 2011 – New labels begin appearing in the field
- 2013 – EPA begins reevaluation of soil fumigants under the Registration Review program
Cómo enviar comentarios
For More Information:
Soil Fumigant Dockets: REDs, RED fact sheets, and supporting information for these decisions are available in the following individual soil fumigant dockets at Regulations.gov.
- EPA-HQ-OPP-2005-0123 for Methyl Bromide
- EPA-HQ-OPP-2005-0124 for 1,3-Dichloropropene
- EPA-HQ-OPP-2005-0125 for Metam Sodium/Potassium and Methyl Isothiocyanate (MITC)
- EPA-HQ-OPP-2005-0128 for Dazomet
- EPA-HQ-OPP-2007-0350 for Chloropicrin
Fumigant REDs and RED Fact Sheets: Are also available on the Pesticide Reregistration Status Web page.
-
Chloropicrin
- RED (PDF) (128 pp, 1.7 MB, About PDF)
- RED Fact Sheet (PDF) (7 pp, 75.63k, About PDF)
- RED (PDF) (114 pp, 955 kB, About PDF)
- RED Fact Sheet (PDF) (7 pp, 71.9k, About PDF)
- RED (PDF) (142 pp, 2.3 MB, About PDF)
- RED Fact Sheet (PDF) (8 pp, 76k, About PDF)
- RED (PDF) (117 pp, 1.7 MB, About PDF)
- RED Fact Sheet (PDF) (8 pp, 75k, About PDF)
- RED (PDF) (203 pp, 3.2 MB, About PDF)
- Revised RED Fact Sheet
Mitigation Measure-Specific Fact Sheets:
- Buffer zones
- Posting requirements
- Agricultural worker protections
- Site-specific fumigant management plans
- Emergency preparedness and response requirements
EPA Soil Fumigant Contacts:
Steven Weiss (weiss.steven@epa.gov)
Methyl Bromide Chemical Review Manager
703) 308-8293
Andrea Carone (carone.andrea@epa.gov)
Chloropicrin Chemical Review Manager
1,3-Dichloropropene Chemical Review Manager
(703) 308-0122
Dirk Helder (helder.dirk@epa.gov)
Metam Sodium/Potassium Chemical Review Manager
(208) 378-5749
Heather Garvie (garvie.heather@epa.gov)
Methyl Isothiocyanate (MITC) Chemical Review Manager
(703) 308-0034
Cathryn OConnell (oconnell.cathryn@epa.gov)
Dazomet Chemical Review Manager
(703) 308-0136
John Leahy (leahy.john@epa.gov)
Senior Advisor
(703) 305-6703