Explosives can be defined as a single chemical compound or a mixture of substances. It may be solid-liquid or gaseous, capable of exerting a sudden and intense pressure on its surroundings when it is initiated by heat, friction, or percussion.
Explosives are classified into two categories, low explosives and high explosives, respectively. This classification is based on the speed and chemical composition of the explosives.
- These kinds of explosives are also known as deflagrating explosives. These types of explosives only explode and do not detonate.
- Few examples of low explosives include gunpowder, nitrocellulose, cordite.
- These kind of explosives requires heat, flash, or friction for their initiation.
- Deflagrating explosives produce relatively low pressure.
- These explosives are also known as detonating explosives. They produce high pressure upon detonating.
- High explosives require a detonation wave as an impulse for their initiation.
- They are used where shattering effects are required.
- Few examples of high explosives include boosters, detonators, dynamite, etc.
- High explosives are further classified into two categories: primary high explosive and secondary high explosive.
The features of primary high explosive and secondary high explosives are:-
|Primary High Explosives||Secondary High Explosives|
|These are extremely sensitive to heat, mechanical shocks, friction.||These are not readily detonated by heat, friction, flame, or shock.|
|These explosives detonate violently instead of burning.||These explosives burn if ignited in small quantity, and detonate only under the shock waves of an exploding primary high explosives.|
|They are generally used to initiate secondary high explosives and used as a main ingredient of percussion caps or detonators.||They are used as booster charges or main bursting charges.|
|Commonly used primary high explosives are Mercury Fulminate, Lead Azide, Lead Styphnate, tetrazene, etc.||These are military explosives and commonly used are TNT, RDX, etc.|
Few other types of explosives which do not fall under the categories mentioned above are as follows.
These are sold under several trade names; different products are being marketed for a particular use and location.
These generally contain nitro-glycerine mixed with either nitrocellulose or ammonium nitrate and other inert substances. They are put in the cylindrical-shaped waterproofed paper and stamped with the maker’s name.
Examples include gelatin dynamite, ammonia dynamite.
These bombs are generally explosives confined in a case and fitted with a suitable initiating device. They are typically made with a malicious intention to cause injury to life or property.
These are the secondary high explosives. military explosives and include the following:
- TNT (tri-nitro toluene)
- RDX (cyclo tri methylene tri- nitrate)
- PETN (Pentaerythritol tetranitrate)
The explosion is very rapid combustion in the absence of atmospheric oxygen. The explosive substance rapidly decomposes into large quantities of gas at a speed of 400 to 1000 meters per second.
Knowledge of explosives, explosion devices, and the sophistication of explosive materials used is essential for the law enforcement agency to take adequate measures to safeguard citizens’ lives and property.