Home › Campaigns › Protect from Fumigants

Fumigant Pesticides Review

The Fumigant Cluster Assessment Decision

As part of the re-registration of older pesticides mandated by the Food Quality Protection Act, the U.S. Environmental Protection Agency (EPA) conducted a simultaneous review of several soil fumigant pesticides in a process that they call the "Fumigant Cluster Assessment." Fumigants are gases or highly volatile liquids or solids that are injected or dripped into soil to sterilize a field before planting. They are also used to fumigate stored foods, greenhouses and imported goods

On May 27th, 2009 U.S. EPA announced their final decision on the fumigant cluster assessment. This comes nearly a year after the July 10th, 2008 decision which appeared to be final, but was forced to be revisited by intense lobbying from agricultural and chemical manufacturing interests. The decision affects all the fumigants but Telone, which was reviewed in 1998. EPA will revisit all the registered fumigants again in 2013.

 


Source: U.S. EPA [6]


EPA's July 2008 and May 2009 decisions include many "mitigations" that PANNA believes will substantially reduce, but not eliminate, fumigant poisonings. Among the most significant are:

  • buffer zones around fumigated fields
  • posting at the edge of the buffer zones
  • notification of state agencies (or tribal agencies) in advance of fumigation
  • strengthened worker protections

Some of these were weakened in the May 2009 decisions. In the case of chloropicrin, the buffer zones around fumigated fields were reduced (although in the case of metam sodium, they were increased). Buffer zones are now allowed to cross roads, meaning that people using those roads will be entering into a region that is unsafe to remain in. Fortunately, posting is still required, and therefore people entering into the buffer zone will have a good chance of recognizing what is happening, and at least go through quickly or decide to take some other route. Notification of state agencies (or tribal agencies) was gravely weakened. It is now only required if the state specifies that it wants to be notified. In the case of worker protection, an example of weakening between the July 2008 and May 2009 decisions is that tarp removal is now allowed to occur within two hours of tarp-cutting, instead of 24 hours.

Although the mitigations are very welcome, evidence from models and poisoning incidents suggests that the buffer zones EPA has chosen are not sufficiently large to eliminate fumigant poisonings. For example, in the Yerington, Nevada poisoning in the fall of 2007, over 120 workers in a neighboring field were poisoned despite being 1/3 of a mile from the fumigated field. Officials investigating the incident cleared the grower of wrongdoing and instead blamed a weather inversion. Furthermore they characterized this as a rare occurrence. In fact, weather inversions are a frequent occurrence in the evenings in agricultural valleys, and they are a factor in many of the fumigant mass poisonings that have been investigated. EPA has attempted to address this by imposing restrictions on the weather conditions under which fumigants can be applied.

When accidents do happen, there is often a lack of understanding as to the probable cause. Posting at the edge of the buffer zones will help with this in two ways: (1) it will help keep people out of the buffer zones, which could have no demarcation at all if it weren't for this mitigation, and (2) it will help people living and working near fields be informed and be prepared. Notification complements posting and notification can help enforcement officials and emergency personnel monitor compliance and respond to accidents.

The worker protections include adding tarp cutters to the "fumigant handler" category, extending the re-entry interval to five days, and strengthening the procedures for the use of masks. These measures will significantly reduce worker exposure and injuries.

EPA's decision is the culmination of a five-year process involving many people and organizations. Communities and farmworkers who live and work near fumigated fields and advocates on their behalf can be proud that many of the measures that they know are critical to caring for people's health and safety found their way into EPA's final decision

More details on EPA's fumigant cluster assessment decision, can be found in PANNA's newsroom and on EPA's website. For those interested in the process leading up to the decision, addtional information follows.

Process Leading up to the Final Decision

 

EPA is evaluating these pesticides as a group because they share common issues related to exposure and toxicity. [1] A new fumigant, methyl iodide, see article, is also being registered.

This has been a six-phase process with multiple comment periods.

You can view the documents that the EPA produced and the comments submitted on each fumigant in the "dockets":

To help cut through all the large amounts of paperwork and detail, the EPA held stakeholder meetings in different regions of the country — one in Ft. Myers, Florida on June 6, 2007 and one in Richland, Washington, on May 22, 2007. In addition, in California, EPA staff attended meetings hosted by California's Department of Pesticide Regulation and by stakeholders. They also toured the parts of the San Joaquin Valley to meet community membersthat had been poisoned in large fumigant drift incidents, and to understand conditions first-hand.

EPA's fumigant cluster assessment process has two main opportunities for public comment:

  • Phase 3, the "preliminary risk assessment," in which EPA's preliminary assessment of industry's toxicology and exposure assessment studies.
  • Phase 5, the "revised risk assessment" and "risk mitigations," in which EPA addresses comments from Phase 3 and asks for feedback on mitigation measures.
  • After Phase 5, there was a comment period intended to address implementation issues, but which resulted in the revisions to the "final" decision detailed above.

Phase 3 Comments

Phase 3 opened on July 13, 2005. EPA publish edits assessment of use patterns, toxicity data, exposure data, and existing alternatives for the five fumigant pesticides. These documents remain in the above dockets.

PANNA and many other organizations jointly submitted comments on the Phase 3 preliminary risk assessments. Methyl bromide "commodity" fumigation comments were also needed, and PANNA submitted comments on those too:

Exactly how much of a difference extensive technical comments make is open to debate. During the entire process, there has been a tendency in EPA's analyses to whittle away at established "safety factors" and to proceed to the next step of the process despite the identification of severe problems in the current step. For example, the exposure modeling shows that for a small but significant percentage of fumigations, the buffer zones EPA has been considering will not be large enough to keep toxic concentrations of fumigants out of communities that border fields. This is a fundamental failure in protecting public health, and so far, it has not been adequately addressed. Worker exposure is in a similarly problematic state.

Phase 5 Comments

Phase 5 of the process ended on November 3rd, 2007. PANNA was one of 30 organizations that collaborated on submission of detailed comments on the revised risk assessments:

Without these analyses, we would have far less understanding of the facts and no case in the public record.

However, technical comments by themselves are clearly not enough to make significant change. The case that has been made carries the weight of many allied organizations. It is supported by over 12,000 signers of a petition to EPA organized through PAN's Action Alert page and by the United Farm Workers. It is on the radar screen of legislative staff at the federal level. It is being considered by state regulators and local activists who have their own say in how fumigants are used in their regions, independent of U.S. EPA's decision. The issue is in the media, thanks in part to repeated accidents that poison so many people simultaneously that they deserve — and occasionally get — front-page coverage.

Titanic forces pitting the drive for ever-cheaper commodities against public health, worker protection and environmental sustainability are clashing. The close of the Phase 5 comment period is a time to take stock and strategize for the health of people that live and work near fumigated fields, and for the quality and sustainability of the food supply.

Final Comments

EPA published the "final" re-registration documents for methyl bromide, metam salts, dazomet, and chloropicrin in July of 2008. EPA indicated that it anticipated that it would make only minor amendments to the final re-registrations. The comment period closed on October 30, 2008. PANNA and many partner organizations submitted comments to the docket on the mitigation measures proposed by EPA.

How Fumigants Are Used

Fumigants are a class of highly volatile pesticides used to sterilize soil before planting. Highly toxic as well (see Toxicity of Soil Fumigants below), fumigants are designed to target a variety of insects, nematodes, fungi, and weeds and are applied more intensively than other pesticides. Application rates for soil fumigants are 50–400 pounds per acre compared to typical rates of 1–5 pounds per acre for other pesticides. Off-site drift is inevitable with fumigants because of these high application rates and the fact that these pesticides are gases or are very volatile liquids or solids that break down into gases after application.


Source: U.S. EPA [6]

A sprinkler application of metam sodium puts substantial amounts of fumigant into the air.

Fumigants are applied by injection into the soil, by sprinkler application or via drip tape. After application, fields may be covered with a plastic tarp or a layer of water to “water in” the fumigant and slow its release from the field. Neither of these measures is fully effective in preventing fumigant drift, which can pose risks to workers and nearby communities for several days and up to several weeks after the application. Five major fumigant drift incidents have occurred in California since 1999, with each incident resulting in hundreds made ill and forced to flee their homes to escape the incoming toxic cloud.


Source: PAN Archive

Methyl bromide is applied via soil injection followed by tarping the field to slow the release of the fumigant from the soil.


Source: PAN Archive

Application of Telone by a shank injection process. Note the shanks below the platform on which the worker is sitting in the top picture. The fumigant is released through these shanks when the platform is lowered, as in the bottom picture.

Fumigant Use Remains High

Crops for which soil fumigant use is heavy include strawberries, potatoes, tobacco, tomatoes, carrots, and peanuts, among others. These pesticides are also used in commodity fumigations to treat seeds, stored grains and fruits, and imported food and timber products and account for about 10% of total pesticide use in the U.S.[6] In California, where fumigant use has been tracked since the 1980s, total reported use of all fumigants has remained relatively constant over time (see Figure 1), although the pounds applied for each fumigant has changed. These use patterns suggest that most farmers are not changing their basic approach and continuing their reliance on pre-plant fumigation for soil pest control. Find out more about the history of fumigant use.

Economically viable non-chemical alternatives are available and already in use by organic and other sustainable agricultural practitioners. These alternatives include use of resistant cultivars, cultural methods such as crop rotation and use of cover crops as well as physical methods such as soil solarization (download PANNA's Technical Comment letter for more detail on alternatives). Providing research and incentives for widespread adoption of these methods should be a high priority for the U.S. Department of Agriculture and the EPA.

In California where pesticide use is tracked through a use reporting system, fumigant use has remained relatively constant over the years, although the mix of fumigants has changed.


Source: PANNA plot using CA DPR Pesticide Use Reporting data.

Fumigant use in California has remained relatively constant over the last 15 years.

In the U.S., fumigant use is especially heavy in just a few regions, including California and the Northwest and the Southeast, especially Florida. The U.S. EPA has published maps of estimated use for each fumigant pesticide currently in use, which we have reproduced here. EPA's full report on use patterns can be found in reference [7].


Source: U.S. EPA [7]


Source: U.S. EPA [7]


Source: U.S. EPA [7]


Source: U.S. EPA [7]


Resources

1 .Soil Fumigant Cluster Assessment Underway, U.S. EPA.

2. Fumigant Bystander Exposure Model Review, Meeting Minutes from August 24-27, 2004 and September 9-10, 2004 U.S. EPA Scientific Advisory Panel Meeting.

3. Preliminary Risk Assessment for Metam Sodium, U.S. EPA, E-Docket # OPP-2004-0159.

4. Guadalupe Hernandez, comment to U.S. EPA on Docket Control Number OPP-00730A, January 14, 2002; see fuller description of the incident in S. E. Kegley, A. Katten, M. Moses, Secondhand Pesticides: Airborne Pesticide Drift in California, Pesticide Action Network, California Rural Legal Assistance Foundation and Pesticide Education Center (San Francisco: 2003), p. 15.

5. Summary of 1990-2000 VOC Emissions Inventory Data, Version 01.12, memorandum from F. Spurlock to J. Sanders, California Department of Pesticide Regulation, February 4, 2002.

6. This percentage is calculated based on national fumigant use (127 million pounds) and toal use of all pesticides (1,203 million pounds) reported in reference 7, including sulfur and petroleum oils, which is same as the basis for the percentages reported in California. Because reference 7 sums pesticide use both with and without sulfur and petroleum oils, this number can also be calulated using the sum without sulfur and petroleum oils (888 million pounds), which results in fumigant use accounting for 14% of the total U.S. pesticide use.

7. J. Becker, W. Chism, M. Kaul, D. Donaldson, T. Kiely, Overview of the Use and Usage of Soil Fumigants, U.S. EPA, June 15, 2005.

See the complete list ofresources about pesticide drift.

‹ Fumigant History: Still Poison After All These YearsupToxicity of Fumigants ›

Back to top