ABSTRACT

Methyl bromide is currently in widespread use as a fumigant. The environmental effects of using methyl bromide are being scrutinized by international, Federal, and State agencies. The United States Environmental Protection Agency (EPA), based on its evaluation of data concerning the ozone depletion potential of methyl bromide, published regulations in the Federal Register on December 10, 1993 (58 FR 65018-65082). That rule froze methyl bromide production in the United States at 1991 levels and required the phasing out of domestic use of methyl bromide by the year 2001. The EPA revised the accelerated phase-out regulations that govern the production, import, export, transformation and destruction of substances that deplete the ozone layer under authority of Title VI of the Clean Air Act Amendments of 1990 (CAA) and established a 25 percent reduction in the 1991 baseline levels of production allowances and consumption allowances for methyl bromide (class I, Group VI controlled substance) for the 1999 and 2000 control periods (Federal Register, June 1, 1999, 64 FR 29240–29245). This rule also allows the EPA to amend these regulations through notice and comment rule-making for a complete phase-out of production and consumption with processes for special exemptions permitted under the Montreal Protocol by the beginning of January 1, 2005. The EPA plans to publish a proposal that will describe a process for exempting quantities of methyl bromide used in the U.S. for quarantine and pre-shipment from the reduction steps in the phase-out schedule.

The Agriculture, Rural Development, Food and Drug Administration, and Related Agencies Appropriations Act, 1999 provides a quarantine-use exemption for the production, importation, consumption of methyl bromide to fumigate commodities entering or leaving the United States for purposes of complying with APHIS regulations. The EPA has also indicated that it will work closely with USDA, State agricultural departments, and other stakeholders to define the pre-shipment and quarantine uses of methyl bromide that will be exempt from the phase-out. The EPA’s proposal assumes the continued availability of methyl bromide for use as a fumigant for at least the next few years. Nonetheless, the Animal and Plant Health Inspection Service (APHIS) of the United States Department of Agriculture (USDA) is studying the effectiveness and environmental acceptability of alternative treatments to prepare for the eventual unavailability of methyl bromide fumigation.

The APHIS has been exploring alternatives to methyl bromide to remain in compliance with the regulations promulgated by the EPA. Researchers with the Agriculture Research Service of USDA and several academic institutions around the world are actively engaged in finding solutions to combat agriculture pests. Radiation treatment of many traded commodities 40represents a viable alternative to methyl bromide fumigation and has been found to be one of the best quarantine treatments in reducing and combating the entry of harmful pests into the United States. Scientists are actively investigating the tolerance doses for a number of tropical fruits, and the minimum doses for several pests of quarantine importance. This paper discusses the status, benefits and risks of irradiation over methyl bromide fumigation for controlling insects that infest plant and products.