USDA/EPA Working Group Update

The USDA/EPA Methyl Bromide Working Group was organized in 1993 to coordinate development and registration of methyl bromide alternatives. For the last several months, this working group has been studying the registration status of potential alternatives with the goal of working with registrants to adjust registrations to maximize their usefulness as methyl bromide alternatives.

First, the working group is working with growers and researchers to discover and evaluate the most promising alternatives, and meetings have been held to discuss critical issues and potential alternatives for strawberries, tomatoes, peppers, other fruits and vegetables, sod, nursery, floriculture, and postharvest uses. These discussions will form the basis for future work on methyl bromide alternatives.

Second, the working group is identifying data requirements, associated costs, and likely registration issues for new active ingredients that scientists have identified as potential methyl bromide alternatives; for example, methyl iodide and propargyl bromide.

The working group is talking with registrants to identify and encourage industry registration activity related to methyl bromide alternatives. DOW Agrosciences briefed EPA and USDA in late July on its strategy and research on alternatives. A follow-up meeting to coordinate research priorities between ARS researchers and DOW was held in Fresno, California, in August.

EPA’s Office of Pesticide Programs has implemented a policy that gives expedited registration review to all applications of alternatives. Given that there currently exists a 4-year backlog of registration applications, expedited review status can significantly shorten the amount of time it takes to get a registration decision. Three methyl bromide alternatives are currently undergoing active registration review and assessment: Ecofume, dazomet, and vorlex.

In addition, the Office of Pesticide Programs is reviewing reregistration issues associated with some of the more promising older chemicals such as phosphine, telone, and pebulate (Tillam) to address issues and data needs that would allow these pesticides to help replace methyl bromide uses.

Despite significant progress by the working group, there remain serious obstacles to be confronted. Many older chemicals that could potentially be expanded to cover some methyl bromide uses currently have label restrictions due to concerns about potential worker and bystander exposure, potential groundwater contamination, and potential ambient air-quality degradation. Additional data will likely be needed to rebut these concerns or demonstrate that new formulations and application methods in development can mitigate them.

Economic considerations also pose a significant obstacle. When determining what portfolio of potential new active ingredients to invest in, companies seriously weigh many factors including the net present value of future estimated income streams for each pesticide candidate, payback times, registration and production costs, potential crop damage liabilities, and other uncertainties. At present, methyl bromide alternatives do not seem to compare favorably with other more commercially viable options.

With these considerations in mind, the interagency working group is attempting to address growers’ needs by working with registrants to expand, where possible, the uses of existing pesticides to cover some methyl bromide uses. The addition of new uses for older chemicals will likely take several years to accomplish where it is possible at all.

At the same time, the working group is assessing the potential for registration of new pesticides such as methyl iodide and propargyl bromide. Developing the data necessary to register a new active ingredient typically takes 4 years, plus, under the best of circumstances, one additional year for EPA to review the data, perform the appropriate risk assessments, and make a registration decision.

Given the very short time period for the mandatory phaseout of methyl bromide—a second 25- percent reduction in use by 2001 with complete phaseout by 2005—USDA’s, EPA’s, and the industry’s best joint efforts will be required to bring alternatives to the marketplace in a timely manner in order to minimize the disruption to agriculture.

Last Updated: October 1, 1999