N Glossary
Ammonium nitrate
Ammonium salt of nitric acid. Ammonium nitrate is typically produced in either dense, nonporous fertilizer-grade or porous explosive-grade prills.
ANFO
A blasting agent (explosive hazard classification Division 1.5) containing no essential ingredients other than prilled ammonium nitrate and fuel oil. [I]
Barn
A unit of measure of the probability of nuclear reaction based on the capture cross section.
Black powder
A deflagrating or low-explosive compound of an intimate mixture of sulfur, charcoal, and an alkali nitrate, usually potassium or sodium nitrate. [I]
Blasting agent
An explosive material that meets prescribed criteria for insensitivity to initiation. For storage, Title 27, Code of Federal Regulations, Section 55.11 defines a blasting agent as any material or mixture, consisting of fuel and oxidizer intended for blasting, not otherwise defined as an explosive—provided
NOTE: Many of the definitions appearing in this glossary are from the Institute of Makers of Explosives, Safety Library Publication No. 12, Washington, D.C., April 1997, and are indicated by the symbol [I]. Where no source is shown, the definition was crafted explicitly for this glossary by the committee.
that the finished product, as mixed for use or shipment, cannot be detonated by means of a No. 8 test blasting cap (detonator) when unconfined. For transportation, Title 49, Code of Federal Regulations, Section 173.50 defines Class 1, Division 1.5 (blasting agent) as a substance that presents a mass explosion hazard but is so insensitive that there is very little probability of initiation or of transition from burning to detonation under normal conditions in transport. [I]
Blasting cap
See Detonator. [I]
Booster
An explosive charge, usually of high detonation velocity and detonation pressure, designed to be used in the explosive initiation sequence between an initiator or primer and the main charge. [I]
Borehole
A hole drilled in the material to be blasted, for the purpose of containing an explosive charge. [I]
Bridge wire
A resistance wire connecting the ends of the leg wires inside an electric detonator and which is embedded in the ignition charge of the detonator. [I]
Bulk explosive
An unpackaged explosive, such as ANFO, that is typically shipped in trucks directly to the blasting site.
Cap
See Detonator.
Cap-Sensitive Explosive Material
An explosive material that will detonate with a No. 8 test detonator when the material is unconfined. [I]
Coincident gamma emitter
A radioactive material that, upon decay, simultaneously releases two gamma rays, thereby making it detectable by use of several counters with coincident decision logic.
Commercial explosive
An explosive designed, produced, and used for commercial or industrial applications rather than for military purposes. [I]
Curie
A unit of radioactivity equal to 3.7 × 1010 disintegrations per second.
Date-shift code
A code, required by the Bureau of Alcohol, Tobacco, and Firearms, applied by manufacturers to the outside of shipping containers and, in many instances, to the immediate containers of explosive materials to aid in their identification and tracing. [I]
Deflagration
An explosive reaction such as a rapid combustion that moves
through an explosive material at a velocity less than the speed of sound in the material. [I]
Desensitize
To make less reactive or explosive.
Detection taggant
See Marker.
Detonating cord
A flexible cord containing a center cord of high explosive that may be used to initiate other high explosives. [I]
Detonation
An explosive reaction that moves through an explosive material at a velocity greater than the speed of sound in the material. [I]
Detonator
Any device containing an initiating or primary explosive that is used for initiating detonation in another explosive material. A detonator may not contain more than 10 grams of total explosives by weight, excluding ignition or delay charges. The term includes, but is not limited to, electric blasting caps of instantaneous and delay types, blasting caps for use with safety fuses, detonating-cord delay connectors, and nonelectric instantaneous and delay blasting caps that use detonating cord, shock tube, or any other replacement for electric leg wires. Unless specifically classified otherwise, detonators are classified 1.1 (Class A explosives). [I]
Diluent
Any chemical material added to an explosive to make it less reactive.
Dolomite
A limestone rich in magnesium carbonate.
Dynamite
A high explosive used for blasting, generally consisting of nitroglycerin, nitrocellulose, ammonium nitrate, and/or sodium nitrate.
Emulsion
An explosive material containing substantial amounts of oxidizer dissolved in water droplets, surrounded by immiscible fuel, or droplets of an immiscible fuel surrounded by water containing substantial amounts of oxidizer. [I]
Explosive
Any chemical compound, mixture, or device, the primary purpose of which is to function by explosion. [I]
Explosive material
Materials including explosives, blasting agents, and detonators. The term includes, but is not limited to, dynamite and other high explosives; slurries, emulsions, and water gels; black powder and pellet powder; initiating explosives; detonators (blasting caps); safety fuse; squibs; detonating cord; igniter cord; and igniters.
A list of explosive materials determined to be within the coverage of 18 U.S.C., Chapter 40, ''Importation, Manufacture, Distribution and Storage of Explosive Materials," is issued at least annually by the Director of the Bureau of Alcohol, Tobacco, and Firearms of the Department of the Treasury. [I]
Gamma ray
Penetrating electromagnetic radiation of very short wavelength (less than 0.1 nanometer), especially that emitted by a nucleus in a transition between two energy levels.
High explosive
An explosive characterized by a very high rate of reaction, high pressure development, and the presence of a detonation wave in the explosive. [I]
Identification taggant
An additive (or "tracer element") designed to survive an explosive blast, to be recoverable at the bomb scene, and to provide pertinent information to aid law enforcement personnel in identifying the perpetrator. Explosives containing identification taggants are considered "tagged."
Improvised explosive
Explosive material that was not manufactured commercially.
Improvised explosive device
A mechanism such as a pipe bomb fabricated from explosive, commercial, or homemade materials.
Inert
Nonreactive or nondetonable.
Initiator
A detonator, detonation cord, or similar device used to start detonation or deflagration in an explosive material. [I]
Low explosive
An explosive that is characterized by deflagration or a low rate of reaction and the development of low pressure. [I]
Magazine
A building or structure used to store explosive materials.
Main explosive charge
The explosive material that performs the major work of blasting. [I]
Marker
A material (or "tracer element") added to explosives that can be sensed preblast by an associated detection instrument. Explosives that contain such a marker are considered "marked." Also known as detection taggant.
Military explosive
An explosive developed and produced for military applications. This category includes plastic and sheet explosives, explosive materials with a moldable, thermoplastic binder material.
Nonideal explosive
An explosive that releases its energy slowly following shock compression and heating. It usually exhibits thicker reaction zones and contributes a smaller fraction of its total energy toward supporting the shock wave.
Oxidizer
A chemical that yields oxygen to promote the combustion of a fuel.
Packaged explosive
An explosive material manufactured, sold, and used in the form of individual cartridges or containers.
Permissible explosive
An explosive that is approved by the Mine Safety and Health Administration for use in gassy and dusty atmospheres and must be used and stored in accordance with certain specified conditions.
Plastic explosive
A moldable explosive material that has a high detonation velocity, relative insensitivity, and high density; contains one or more of the explosive materials PETN, RDX, or sometimes TNT; and includes in the composition hydrocarbon oils, synthetic rubber compounds, or other plasticizers. Compositions such as C-4, Semtex, and others with various proprietary names are almost exclusively military explosives.
Precursor chemical
A chemical used to synthesize an explosive material via a chemical process or as a component in a mixture that enhances the destructive force.
Prill
Particle-like form of ammonium nitrate as manufactured in a gravity-fed, evaporative "prilling tower."
Prilled ammonium nitrate
Ammonium nitrate in pelleted or prilled form. [I]
Propellant
An explosive material that normally functions by deflagration and is used for propulsion purposes. [I]
Pyrotechnic composition
Any combustible or explosive composition or manufactured articles designed and prepared for the purpose of producing audible or visible effects. [I]
Sheet explosive
An explosive material with the appearance of rubbery sheets, composed of RDX or PETN with rubber-type polymers and plasticizers.
Shock wave
A transient pressure pulse that propagates at supersonic velocity.
Short ton
A unit of weight equal to 2,000 pounds, 907 kilograms, and 0.907 metric tons.
Slurry explosive
An explosive containing substantial portions of a liquid, oxidizers, and fuel, plus a thickener. [I]
Smokeless powder
A solid propellant, commonly used in small-arms ammunition, cannons, rockets, propellant-actuated power devices, and the like. It is classified as single-base (with nitrocellulose as the only active ingredient), double-base (with nitrocellulose and nitroglycerin), or triple-base (with nitrocellulose, nitroglycerin, and nitroguanidine).
Squib
A firing device that burns with an external flash. It is used for igniting black powder or pellet powder. [I]
Taggant
An additive that either (1) enhances the detectability of explosives before an explosion ("detection taggant") or (2) survives an explosion and is used to trace explosive materials to the last legal purchaser ("identification taggant"). See also Marker.
Torr
A unit of measure for pressure, approximately equal to 0.02 pounds per square inch, or 133 pascals.
Vapor pressure
The pressure exerted by the vapor phase of a chemical in equilibrium with its solid or liquid phase.
Water gel
An explosive material containing substantial portions of water, oxidizers, and fuel, plus a cross-linking agent. [I]
