ALUMINUM PHOSPHIDE-BASED FUMIGANTS\u00a0AS AN IGNITION SOURCE IN AGRICULTURAL\u00a0COMMODITY STORAGE STRUCTURE FIRES<\/p>\n
John L. Schumacher, MChE, PE, CFI, CFPS
\nZachary J. Jason, PE, CFEI
\nAdvanced Engineering Investigations Corporation, USA<\/p>\n
Presented at\u00a0International Symposium on Fire Investigation<\/a>, 2012<\/p>\n ABSTRACT<\/p>\n Raw agricultural commodities, such as corn, soybean, rice and wheat, are typically stored in bins and silos\u00a0prior to shipment. During storage, it is often necessary to protect the commodities from damage by insects and\u00a0pests. A common protection method utilized is the addition of solid fumigant pellets or tablets to the commodity.<\/p>\n One of the most common solid fumigants employed is a blend of aluminum phosphide, ammonium carbamate and\u00a0other inert ingredients. Aluminum phosphide reacts with atmospheric water and moisture in the commodity based\u00a0on the following equation:<\/p>\n AlP + 3H2O = Al(OH)3 + PH3 + Heat<\/p>\n The reaction yields phosphine gas (PH3), which is highly toxic to insects, pests and humans. The reaction is\u00a0exothermic, which means heat is generated alongside the other products. Phosphine gas has a lower flammable limit\u00a0(LFL) of about 1.8% gas in air and can ignite spontaneously at concentrations above the LFL. The ammonium\u00a0carbamate is added to the mixture to reduce the potential fire hazard by generating ammonia and carbon dioxide,\u00a0which act as inerting gases. The carbon dioxide reduces the tendency of phosphine to auto-ignite in air. The\u00a0decomposition reaction is as follows:<\/p>\n NH2COONH4 = 2NH3 + CO2<\/p>\n Improper application of the fumigant tablets or pellets can lead to fires. This paper provides basic product\u00a0information, and discusses the chemistry, application methods, previous testing, and ignition scenarios associated\u00a0with solid fumigants containing aluminum phosphide. A case study of a fire that occurred in a metal grain bin\u00a0containing wheat will be presented.<\/p>\n Presented at\u00a0International Symposium on Fire Investigation<\/a>, 2012<\/p>\n","protected":false},"excerpt":{"rendered":" ALUMINUM PHOSPHIDE-BASED FUMIGANTS\u00a0AS AN IGNITION SOURCE IN AGRICULTURAL\u00a0COMMODITY STORAGE STRUCTURE FIRES John L. Schumacher, MChE, PE, CFI, CFPS Zachary J. Jason, PE, CFEI Advanced Engineering Investigations Corporation, USA Presented at\u00a0International Symposium on Fire Investigation, 2012 ABSTRACT Raw agricultural commodities, such as corn, soybean, rice and wheat, are typically stored in bins and silos\u00a0prior to shipment. … Continue reading Aluminum Phosphide-Based Fumigants as an Ignition Source<\/span>