Methyl Bromide

The following fact sheet is part of a series relating to chemicals that may be used in Federal Anthrax decontamination efforts. EPA has approved these pesticides against anthrax only for use by authorized personnel according to the specific requirements of the applicable crisis exemption and approved decontamination plans. These chemicals are not intended for use by the general public.

• What is Methyl Bromide?
• Antimicrobial Pesticides
• EPA's Registration of Pesticides
• Registered Uses for Methyl Bromide
• FIFRA Section 18 Emergency Exemption
• Determination of Safety and Efficacy for Crisis Exemption for Methyl Bromide
• Use of Methyl Bromide in Anthrax Decontamination under the Crisis Exemption
• More Information on Antimicrobial Pesticides

What is Methyl Bromide?

Methyl bromide is a broad spectrum pesticide used to control insects, weeds, rodents, and pathogens. A colorless, odorless gas at room temperature, methyl bromide is normally applied as a liquid under pressure that vaporizes upon release at the point of application.

The use of methyl bromide as a pesticide is currently being phased out both in the United States and all other countries. Through various scientific assessments, atmospheric scientists have concluded that use of methyl bromide contributes to the destruction of the ozone layer. Complete phase out of methyl bromide is scheduled for 2005, with certain preshipment, quarantine, and emergency uses exempted.

Antimicrobial Pesticides

Antimicrobial pesticides are substances used to control harmful microorganisms including bacteria, viruses or fungi on inanimate objects and surfaces primarily in indoor environments. Types of antimicrobial products have traditionally included sanitizers, disinfectants, and sterilants.

• A "sanitizer" is a substance that significantly reduces the bacterial population in the inanimate environment, but does not destroy or eliminate all bacteria or other microorganisms.



• A "disinfectant" is a substance that destroys or eliminates a specific species of infectious or other public health microorganism, but not necessarily bacterial spores, in the inanimate environment.



• A "sterilant" is a substance that destroys or eliminates all forms of microbial life in the inanimate environment, including all forms of vegetative bacteria, bacterial spores, fungi, fungal spores, and viruses.

EPA's Registration of Pesticides

Before a pesticide can be marketed and used in the United States, EPA must evaluate the pesticide to ensure that it meets Federal safety standards for human health and the environment. Such evaluation is particularly important for antimicrobial pesticides (sanitizers, disinfectants, and sterilants) used to reduce or eliminate microbial contamination. Once EPA determines that a pesticide meets federal safety standards, the Agency grants a license or "registration" permitting its distribution, sale, and use according to approved label instructions.

Before EPA grants registration for a pesticide product, the Agency will review efficacy and safety data to ensure that, when used according to the specific instructions of the label, the product is effective and does not pose any unreasonable adverse effect on human health or the environment. The label provides specific safety precautions and use directions for handling or using the product. EPA has concluded that methyl bromide products registered to date have met federal standards for environmental and human health safety.

Registered Uses for Methyl Bromide

• Soil fumigant: Methyl bromide gas may be injected into the soil, before a crop is planted, which effectively sterilizes the soil, killing the vast majority of soil organisms. In the United States, methyl bromide is used mostly on strawberries (18% of U.S. total) and tomatoes (23% of U.S. total), consuming about 7,000 tons (14,000,000 pounds) annually. Methyl bromide is used on other crops as a soil fumigant including tobacco, peppers, grapes, and nut and vine crops.



• Commodity treatment: Methyl bromide gas also can be used for post harvest pest control and can be injected into a chamber or under a tarp containing commodities such as grapes, raisins, cherries, nuts, and imported materials. Some commodities are treated several times during both storage and shipment.



• Structural pest control treatment: Methyl bromide gas is used to fumigate buildings for termites, warehouses and food processing facilities for insects and rodents, aircraft for rodents, and ships (and other transportation vehicles) for various pests.



• Quarantine Uses: USDA's Animal Plant and Health Inspection Service uses methyl bromide (APHIS) to treat imported commodities as required by quarantine regulations.



• Phase Out: Under the Montreal Protocol on Substances that Deplete the Ozone Layer and under the Clean Air Act, production of methyl bromide is scheduled to be eliminated by 2005.

FIFRA Section 18 Emergency Exemption

Under Section 18 of FIFRA, the EPA "may exempt any Federal or State agency from any provision of this Act if the Administrator determines that emergency conditions exist which require such exemption." Normally, a federal or state agency would submit an application for a FIFRA exemption to EPA for review and approval. If the EPA approves the request, it would issue either a specific or a public health exemption, as appropriate. However, if the emergency is of such urgency that a federal or state agency does not have enough time to submit an application for exemption and wait for EPA's approval, then the federal or state agency may issue a crisis exemption, which is effective for 15 days. In order for the crisis exemption to be extended beyond 15 days, the federal or state agency must submit an application for exemption to EPA.

In order to handle all anthrax contamination cases as quickly as possible, the Agency has decided to issue all crisis exemptions itself. To obtain a crisis exemption from EPA for the unregistered use of a pesticide against anthrax, a State or Federal agency must submit a written request describing the antimicrobial product(s) to be used; how, when and where they will be used; the data demonstrating efficacy of the product for the intended purpose; and how human health and safety will be protected. Prior to issuing the exemption, EPA will perform a multi-disciplinary risk assessment of the requested use, relying on data that have been supplied for the pesticide.

If, during this review, EPA notes any adverse human health or environmental concerns, EPA may deny the exemption request. If, however, EPA believes that the proposed use of an antimicrobial product will be effective and will protect human health and the environment, EPA will issue a crisis exemption. Moreover, if EPA determines that use of the product is needed beyond the 15-day use period, EPA will complete an application for a public health exemption on behalf of the requesting entity, which allows the crisis exemption to continue in effect until it is either withdrawn or EPA issues a public health exemption.

Determination of Safety and Efficacy for Crisis Exemption for Methyl Bromide

EPA reviewed data related to safety and effectiveness and issued a crisis exemption to conduct limited testing to determine whether methyl bromide may be used for anthrax decontamination. Based on a review of the laboratory efficacy data to support the crisis exemption request, EPA has determined that methyl bromide has the potential to be effective for use in a decontamination program. In addition, EPA believes that this limited testing is needed to evaluate the efficacy feasibility of applying methyl bromide in buildings.

Based on this review, EPA issued a crisis exemption for the limited sale, distribution, and use of methyl bromide ["Meth-O-Gas" (EPA Registration Number 5785-11)] for use in a vacant mobile home by the University of Florida and Cobra Termite Control for testing purposes only. EPA has determined that the public health threat posed by the anthrax incidents constitutes a public health emergency of such immediacy that normal processing and review of a conventional public health exemption under FIFRA is neither prudent nor practical. Under this crisis exemption, only this specific product - for testing purposes only - may be sold or distributed to the University of Florida and Cobra Termite Control.

Use of Methyl Bromide in Anthrax Decontamination under the Crisis Exemption

Applications of the pesticide product mentioned above under the crisis exemption will be limited to use in a vacant mobile home on the premises of the University of Florida. Applications must be conducted according to all use directions, safety precautions, and environmental monitoring as specified in "Methyl Bromide Field Test Procedures" (2/4/2002) and "UF MeBr Efficacy Test Buffer Zone Determination," as approved by EPA.

More Information on Antimicrobial Pesticides

• Background on EPA's Antimicrobial Pesticide Regulatory Program
  

If you have general questions about the federal pesticide program browse the Web site, or contact EPA's pesticides office:

• Office of Pesticide Programs (OPP)

Tel: 703-305-5017
Fax: 703-305-5558
E-mail: opp-web-comments@epa.gov

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