EPA's Safety Measures for Aluminum and Magnesium Phosphide Fumigants1
Frederick M. Fishel2
The US Environmental Protection Agency (EPA) is requiring restrictions on aluminum and magnesium phosphide products used to control burrowing rodents. The EPA's intent is to better protect people, especially children, from dangerous exposures. The new restrictions, which went into effect in spring 2010, prohibit all uses of the products around residential areas, increase buffer zones for treatment around non-residential buildings that could be occupied by people or animals, and create more protective product labeling. This publication outlines the new measures.
Aluminum and magnesium phosphide are fumigants used to control insects and rodents. They are primarily used for indoor fumigation of raw agricultural commodities, animal feeds, processed food commodities, and non-food commodities in sealed containers or structures, and for outdoor fumigation of burrows to control rodents and moles in non-domestic areas and non-cropland agricultural areas. Aluminum and magnesium phosphide are formulated as tablets, pellets, impregnated materials, and dusts. Aluminum and magnesium phosphide are restricted-use chemicals (Figure 1).
Fumigant pesticides form gases or vapors toxic to plants, animals, and microorganisms. Aluminum and magnesium phosphide products for controlling burrowing rodents are formulated as tablets and pellets that are rapidly transformed to highly toxic phosphine gas when exposed to moisture. Phosphine fumigants have been associated with accidental poisoning incidents, and their use is restricted to specially trained pesticide applicators (Figure 2).
To increase public safety by reducing potential exposure to phosphine fumigants, the EPA expanded the restrictions and is requiring clearer label directions and precautions for aluminum and magnesium phosphide products that are used in rodent burrow fumigation. Indoor use of such products has long been prohibited. The EPA has expanded and clarified the outdoor use restrictions for these products as follows:
Use is strictly prohibited around all residential areas, including single and multi-family residential properties, nursing homes, schools (except athletic fields, where use may continue), day care facilities, and hospitals.
The products must only be used outdoors for control of burrowing pests, and are for use only on agricultural areas, orchards, non-crop areas (such as pasture and rangeland), golf courses, athletic fields, parks and recreational areas, cemeteries, airports, rights-of-way, earthen dams, and other non-residential institutional or industrial sites.
Products must not be applied in a burrow system within 100 feet of a building that is or may be occupied by people or domestic animals. This buffer zone for treatment around non-residential buildings that could be occupied by people or animals has been increased from 15 feet to 100 feet.
When this product is used in athletic fields or parks, the applicator must post a sign at entrances to the treated site containing the signal word DANGER/PELIGRO, skull and crossbones, the words DO NOT ENTER/NO ENTRE, FIELD NOT FOR USE, the name and EPA registration number of the fumigant, and a 24-hour emergency response number. Signs may be removed two days after the final treatment.
When this product is used out-of-doors in a site frequented by people, other than an athletic field or park, the applicator shall post a sign at the application site containing the signal word DANGER/PELIGRO, skull and crossbones, the name and EPA registration number of the fumigant, and a 24-hour emergency response number. Signs may be removed two days after the final treatment.
Fumigant management plans must be written before all applications of phosphine products, including all burrowing pest fumigations. A fumigant management plan is a written description of the steps designed to plan for a safe, legal, and effective fumigation. The certified applicator and owner of the property to be fumigated must characterize the area to be treated and include all safety requirements in the plan before application.
Fishel, F. M. 2005. Pesticide Toxicity Profile: Phosphorous and Sulfur Fumigants. PI-73. Gainesville: University of Florida Institute of Food and Agricultural Sciences http://edis.ifas.ufl.edu/pi110 (accessed February 2013).
This document is PI228, one of a series of the Agronomy Department, UF/IFAS Extension. Original publication date May 2010. Revised February 2013 and March 2016. Reviewed March 2019. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.
Frederick M. Fishel, professor, Agronomy Department, and director, Pesticide Information Office; UF/IFAS Extension, Gainesville, FL 32611.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.
U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.