At their November 1992 meeting, the parties to the Montreal Protocol listed methyl bromide as a stratospheric ozone depletor with an ozone depletion potential (ODP) of 0.7.  They agreed to freeze production levels for developed countries at 1991 levels in 1995 except for quarantine and some postharvest and preshipment uses. Since then, they have agreed to phase out methyl bromide, (except for the exceptions noted above) in developed countries by the year 2005.

The identification of methyl bromide by the Montreal Protocol brought methyl bromide under provisions of the United States Clean Air Act (CAA). The CAA requires the phase out, within 7 years, of any material listed as an ozone depletor by the Montreal Protocol.  Consequently, on November 30, 1993, the United States Environmental Protection Agency (EPA) issued a final rule under the CAA that froze production at 1991 levels in 1994, and required elimination (both production and importation) of methyl bromide by January 1, 2001.  Since there is no practical way to stockpile methyl bromide for use after that date, this rule effectively banned methyl bromide use in the United States.  In addition to requiring an earlier phase out than mandated by the Montreal Protocol, the CAA at that time made no provision for exceptions to the ban for quarantine, preshipment, or emergency uses, all of which are exempted from regulation by the Montreal Protocol.  Congress amended the CAA in October, 1998, as part of the Fiscal Year 1999 budget to make the CAA treatment of methyl bromide consistent with the Montreal Protocol phase out of 2005 including exemptions for quarantine, preshipment, and emergency uses.

Methyl bromide is a highly efficacious fumigant used on over 100 crops in forest and ornamental nurseries and on wood products.  It helps control insects, nematodes, weeds, and pathogens and is critical to important segments of American agriculture.  It is used for soil fumigation, postharvest protection, and quarantine treatments.  Approximately 80 percent of the methyl bromide produced in the United States is used to fumigate soil before planting crops, and 19 percent is used to fumigate harvested commodities during storage or in marketing channels and structures (such as flour mills and food processing plants).

Substitution of a single alternative chemical fumigant for methyl bromide is unlikely.  An array of alternative control measures will be required to substitute for the many essential uses of methyl bromide.  Such measures include combinations of fungicides, herbicides, and insecticides; possible replacement fumigants for some applications; nonchemical alternatives including cultural changes in cropping systems; and biological control and integrated pest management. Irradiation and heat treatments are being evaluated in relation to quarantine and export application.

It is clear that unless viable alternatives to methyl bromide are found, there will be significant negative impacts to United States agriculture, including the important question of competition in the world market.  Developing countries will be allowed to use methyl bromide to produce and market crops long after the cutoff date of 2005 in the United States.  The goal of the Methyl Bromide Alternatives National Program is to make available to the United States agriculture community environmentally acceptable, practical, economically feasible, and sustainable alternatives to methyl bromide.