Shock sensitivity is a comparative measure of the sensitivity to sudden compression (by impact or blast) of an

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

. Determination of the shock sensitivity of a material intended for practical use is one important aspect of

safety testing of explosives The safety testing of explosives involves the determination of various properties of the different energetic materials that are used in commercial, mining, and military applications. It is highly desirable to measure the conditions under which exp ...

. A variety of tests and indices are in use, of which one of the more common is the Rotter Impact Test with results expressed as FoI ( Figure of Insensitivity.) At least four other impact tests are in common use, while various "gap tests" are used to measure sensitivity to blast shock.

Sensitivities vary widely

A few materials such as nitrogen triiodide cannot be touched at all without

detonating Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with s ...

, and so are of purely academic interest. Some other compounds with a high sensitivity to shock, such as nitroglycerin and acetone peroxide, may detonate from a firm jolt and so cannot be legally transported in pure form. Acetone peroxide is often used by amateurs and terrorists as a means to detonate other explosives as well as acting as the main blasting agent, often resulting in injuries or death to those who underestimate its sensitivity. A number of methods are known to desensitize nitroglycerine so that it can be transported for medical uses, and it is also incorporated into other less sensitive explosives, such as

dynamite Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay), and Stabilizer (chemistry), stabilizers. It was invented by the Swedish people, Swedish chemist and engineer Alfred Nobel in Geesthacht, Northern Germa ...

s and

gelignite Gelignite (), also known as blasting gelatin or simply "jelly", is an explosive material consisting of collodion-cotton (a type of nitrocellulose or guncotton) dissolved in either nitroglycerine or nitroglycol and mixed with wood pulp and saltpe ...

s. Many practical commercial materials of intermediate sensitivity, such as gelignites and

water gel explosive A water-gel explosive is a fuel sensitized explosive mixture consisting of an aqueous ammonium nitrate solution that acts as the oxidizer. Water gels that are cap-insensitive are referred to under United States safety regulations as blasting agent ...

s, can be safely handled as they will not explode from casual shocks such as being dropped or lightly knocked by a tool. However, they may explode if struck forcefully by a metal tool, and would certainly explode in the barrel if they were used in an artillery

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

. Reliable initiation of such materials requires the small explosion of a detonator. Apart from this another explosive material such as Armstrong's mixture is also used in commercial markets and even sold to the public in the form of

fireworks Fireworks are a class of Explosive, low explosive Pyrotechnics, pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a l ...

cap gun A cap gun, cap pistol, or cap rifle is a toy gun that creates a loud sound simulating a gunshot and smoke when a small percussion cap is ignited. Cap guns were originally made of cast iron, but after World War II were made of zinc alloy, and mo ...

s and

party poppers A party popper is a handheld pyrotechnic device commonly used at parties. It emits a loud popping noise by means of a small friction-actuated explosive charge that is activated by pulling a string. The explosive charge comes from a very small amo ...

. Still less sensitive materials such as

blasting agent An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...

s like

ANFO ANFO ( ) (or AN/FO, for ammonium nitrate/fuel oil) is a widely used bulk industrial explosive. It consists of 94% porous prilled ammonium nitrate (NH4NO3) (AN), which acts as the oxidizing agent and absorbent for the fuel, and 6% number 2 fue ...

, are so insensitive that the impulse from the detonator must be amplified by an

explosive booster {{unreferenced, date=August 2011 An explosive booster is a sensitive explosive charge that acts as a bridge between a (relatively weak) conventional detonator and a low-sensitivity (but typically high-energy) explosive such as TNT. By itself, the ...

charge to secure reliable detonation. Some

polymer bonded explosive Polymer-bonded explosives, also called PBX or plastic-bonded explosives, are explosive materials in which explosive powder is bound together in a matrix using small quantities (typically 5–10% by weight) of a synthetic polymer. PBXs are normall ...

s — especially those based on

TATB TATB, triaminotrinitrobenzene or 2,4,6-triamino-1,3,5-trinitrobenzene is an aromatic explosive, based on the basic six-carbon benzene ring structure with three nitro functional groups (NO2) and three amine (NH2) groups attached, alternating aroun ...

— are designed for use in

insensitive munitions Insensitive munitions are munitions that are designed to withstand stimuli representative of severe but credible accidents. The current range of stimuli are shock (from bullets, fragments and shaped charge jets), heat (from fires or adjacent ther ...

, which are unlikely to detonate even if struck by another explosive weapon. Explosives {{Chem-stub