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 Pyrotechnics is the science of materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke and/or sound. Pyrotechnics include not only the manufacture of fireworks but items such as safety matches, oxygen candles, explosive bolts and fasteners, and components of the automotive airbag. Pyrotechnic devices combine high reliability with very compact and efficient energy storage, in the form chemical energy which is converted to expanding hot gases either through deflagration or detonation. The controlled action of a pyrotechnic device (initiated by any of several means, including an electrical signal, optical signal or mechanical impetus) makes possible a wide range of automated and/or remote mechanical actions; for example, the deployment of safety equipment and services, precisely timed release sequences, etc. The majority of the technical pyrotechnic devices use propellants in their function, a minority use materials that are classified as primary or secondary explosives to obtain very fast and powerful mechanical (mostly cutting) actions; for example cable cutters, exploding bolts, or similar pyrotechnic fasteners. Individuals responsible for the safe storage, handling, and functioning of pyrotechnic devices are referred to as pyrotechnicians.
[edit] Proximate pyrotechnicsExplosions, flashes, smoke, flames, fireworks or other propellant driven effects used in the entertainment industry are referred to as pyrotechnic special effects, theatrical effects, or proximate pyrotechnics. Proximate refers to the pyrotechnic device's location relative to an audience. In the majority of jurisdictions, special training and licensing must be obtained from local authorities to legally prepare and use proximate pyrotechnics.  Many musical groups use pyrotechnics to enhance their live shows. Some of the earliest bands to use pyrotechnics were Pink Floyd, Queen, and KISS. The band Rammstein uses a large variety of pyrotechnics, from flaming costumes to face-mounted flamethrowers. Also Nightwish and Lordi are known for their vivid pyrotechnics. Many professional wrestlers have also used pyrotechnics as part of their entrances to the ring. Modern pyrotechnics are, in general, divided into categories based upon the type of effect produced or manufacturing method. The most common categories are:
 A basic theatrical effect, designed to create a jet or fountain of sparks, is referred to as a gerb. A gerb consists of a sufficiently strong and non-flammable container to hold the pyrotechnic compound. Typical pyrotechnic formulations consist either of flammable materials such as nitrocellulose and/or blackpowder or a mixture of a fuel and oxidizer blended in situ. A plug placed at one end of the container with a small orifice, called a choke, constricts the expulsion of the ignited pyrotechnic compound, increasing the size and aggressiveness of the jet.  Various ingredients may be added to pyrotechnic devices to provide colour, smoke, noise or sparks. Special additives and construction methods are used to modify the character of the effect produced, either to enhance or subdue the effect; for example, sandwiching layers of pyrotechnic compounds containing potassium perchlorate, sodium salicylate or sodium benzoate with layers that do not creates a fountain of sparks with an undulating whistle. In general, such pyrotechnic devices are initiated by a remotely controlled electrical signal that causes an electric match, or e-match, to produce ignition. The remote control may be manual, via a switch console, or computer controlled according to a pre-programmed sequence and/or a sequence that tracks the live performance via stage cues. [edit] Display pyrotechnicsMain article: Firework  Display pyrotechnics, also known as commercial fireworks, are pyrotechnic devices intended for use outdoors, where the audience can be further away, and smoke and fallout is less of a concern. Generally the effects, though often similar to proximate pyrotechnics, are of a larger size and more vigorous in nature. It will typically take an entire day to setup a professional fireworks display. The size of these fireworks can range from 50 mm (2") to over 600 mm (24") diameter depending on the type of effect and available distance from the audience. In most jurisdictions, special fireworks training and licensing must be obtained from local authorities to legally prepare and use display pyrotechnics. [edit] Consumer pyrotechnicsConsumer pyrotechnics are devices readily available for purchase to the general public without special licensing or training. These items are considered relatively low hazard devices but, like all pyrotechnics, can still be hazardous and should be stored, handled and used appropriately. Some of the most common examples of consumer pyrotechnics encountered include recreational fireworks (including whistling and sparking types), model rocket motors, highway and marine distress flares, sparklers and caps for toy guns. Pyrotechnics are also indirectly involved in other consumer products such as powder actuated nail guns, ammunition for firearms, and modern fireplaces. Some types, including bird scarers, shell crackers, whistle crackers and flares, may be designed to be fired from a 12-gauge pistol or rifle. [edit] SafetyPyrotechnics are dangerous and must be handled and used properly. Recently, several high profile incidents involving pyrotechnics have re-enforced the need to respect these explosives at all times[citation needed]. Proximate pyrotechnics is an area of expertise that requires additional training beyond that of other professional pyrotechnics areas and the use of devices specifically manufactured for indoor, close proximity use. [edit] Homemade devices A common low-budget pyrotechnic flash pot is built using modified screw-in electric fuses in a common light fixture. Homemade devices commonly fail to include the appropriate safety features and can provide numerous hazards, including:
Proper commercial flash pots include safety features such as warning pilot lamps, preignition grounding, and safing circuits. They also use isolated and low-voltage power sources, and have keyed power connections to help prevent accidental ignition. [edit] Pyrotechnic incidentsMichael Jackson had suffered from injuries sustained when a pyrotechnic went wrong during filming for a Pepsi advertisement on January 27, 1984, when they went off too early and caused him to suffer from burns to his hair and scalp. In 2003, improper use of pyrotechnics caused a fire in a Rhode Island nightclub called The Station. The Station nightclub fire was started when the fireworks the band Great White were using accidentally ignited flammable soundproofing foam. The pyrotechnics in question were not appropriate. The foam caused combustion to spread rapidly and the resulting fire led to 100 deaths, apparently because their quick escape was blocked by ineffective exit doors. While the type of foam used and the lack of a sprinkler system were important factors in the fire, the Great White fire could have been prevented had those involved paid attention to standard safety practices around the use of pyrotechnics.[citation needed] A similar pyrotechnic-induced fire in 2004 destroyed the Republica Cromagnon nightclub in Buenos Aires, Argentina, killing 194 people. [edit] External links
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