Variable toxicity. A very dangerous fire hazard when exposed to heat or flame. Severe explosion hazard when shocked or exposed to heat or flame. See also various fulminates and EXPLOSIVES, HIGH.

The fulminates are a group of explosives that are very sensitive to heat, impact, and friction when dry. They should be kept moist until ready for use. If compressed beyond 25,000 psi they become what is known as “deadpressed,” i.e., not capable of being exploded by flame. Fulminates are subject to deterioration when stored in hot climates. They decompose completely and violently when detonated. They can be ignited with a flame or “spit,” with a fuse, or with an electrically heated wire. They are widely used as initiators or primers for detonation of high explosives or the ignition of powder. They are commonly used in combination with substances that provide a more prolonged blow and a bigger flame than fulminates alone. In the reinforced type of detonator, fulminates are made more effective by the addition of a more sensitive and powerful high explosive such as tetryl. This material is generally used in the manufacture of caps and detonators for initiating explosions for military, industrial, and sporting purposes.

All precautions required for protection of magazines apply to storage of these materials. They should not be handled when frozen. Wet fulminate of mercury or wet floor coverings containing small quantities of fulminates may be burned on windrows of flammable material. Nonexplosive products are formed by neutralizing fulminates with cold sodium thiosulfate. All floors, tables, and walls where the dry fulminates have been used should be washed with this solution. In the manufacture of mercury fulminate, the fumes given off are toxic and flammable. Care is required to prevent fulminate dust from being carried off in the exhaust system: deposits thus made have caused explosions. Careful attention should be given to cleanliness as foreign or gritty materials in the product may cause an unexpected explosion. The floors on which fulminates are used should be covered with 1/16-inch cloth-inserted rubber packing or its equal. All cracks and crevices should be covered. The walls of these rooms should be covered with glazed, waterproof material. Frequent washing with neutralizing solution is necessary. In manufacture, the fulminate is dried on muslin squares on a drying table. Drying tables may be heated with hot water or the dry house may be heated with an air blower system to between 50 and 60°. Primer caps and detonators loaded with fulminate of mercury are less sensitive than the dry bulk material but must be handled with great care. Fires involving these assemblies should be treated the same as for the bulk material. They will explode as soon as fire reaches them. Stocks in an assembly or loading room should be kept as small as possible. Examples of fulminates commonly used in the explosive industry are mercury fulminate, copper fulminate, and silver fulminate.