A stun grenade, also known as a flash grenade, flashbang, thunderflash, or sound bomb, is a less-lethal

explosive device An explosive device is a device that relies on the exothermic reaction of an explosive material to provide a violent release of energy. Applications of explosive devices include: *Building implosion (demolition) * Excavation *Explosive forming ...

used to temporarily disorient an enemy's senses. Upon detonation, they produce a blinding flash of light and an extremely loud "bang". They are often used in

close-quarters combat Close-quarters combat (CQC) or close-quarters battle (CQB) is a tactical situation that involves a physical fight with firearms involved between multiple combatants at short range. It can occur between military units, police/corrections officers ...

, door breaching, and riot control, typically to stun enemies or distract them. Stun grenades were first used by the

British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurk ...

Special Air Service The Special Air Service (SAS) is a special forces unit of the British Army. It was founded as a regiment in 1941 by David Stirling and in 1950, it was reconstituted as a corps. The unit specialises in a number of roles including counter-terro ...

counterterrorist Counterterrorism (also spelled counter-terrorism), also known as anti-terrorism, incorporates the practices, military tactics, techniques, and strategies that governments, law enforcement, business, and intelligence agencies use to combat or el ...

wing in the late 1970s, and have been used by

police The police are a constituted body of persons empowered by a state, with the aim to enforce the law, to ensure the safety, health and possessions of citizens, and to prevent crime and civil disorder. Their lawful powers include arrest and t ...

and

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...

forces worldwide since. Despite their less-lethal nature, stun grenades are still capable of causing harm, and can injure or kill when detonating in close proximity. They are also capable of sparking fires.

Effects

Nonlethal, Deny, move, disperse 140305-A-WN220-885

Stun grenades designed to produce a blinding flash of light of around 7

megacandela The candela ( or ; symbol: cd) is the unit of luminous intensity in the International System of Units (SI). It measures luminous power per unit solid angle emitted by a light source in a particular direction. Luminous intensity is analogous to ...

(Mcd) and an intensely loud "bang" of greater than 170

decibel The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...

s (dB). The flash temporarily activates all

photoreceptor cell A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiatio ...

s in the

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

, blinding it for approximately five seconds. Afterward, victims perceive an afterimage which impairs their vision. The volume of the detonation also causes temporary deafness in the victim and disturbs the fluid in the ear, causing a loss of balance.

Construction

Unlike a fragmentation grenade, stun grenades are constructed with a casing made to remain intact during detonation and avoiding

fragmentation Fragmentation or fragmented may refer to: Computers * Fragmentation (computing), a phenomenon of computer storage * File system fragmentation, the tendency of a file system to lay out the contents of files non-continuously * Fragmented distributi ...

injuries, while having large circular cutouts to allow the light and sound of the explosion through. The filler consists of a pyrotechnic metal-oxidant mix of

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

and an oxidizer such as

potassium perchlorate Potassium perchlorate is the inorganic salt with the chemical formula K Cl O4. Like other perchlorates, this salt is a strong oxidizer although it usually reacts very slowly with organic substances. This, usually obtained as a colorless, crysta ...

potassium nitrate Potassium nitrate is a chemical compound with the chemical formula . This alkali metal nitrate salt is also known as Indian saltpetre (large deposits of which were historically mined in India). It is an ionic salt of potassium ions K+ and nitrat ...

Hazards

While stun grenades are designed to limit injury to their targets, permanent hearing loss has been reported. Other injuries and deaths have also been caused by their use, usually when a grenade detonated close to a person, or due to structure fires caused by detonation. The concussive blast still has the ability to cause injuries, and the heat created may ignite flammable materials. The fires that occurred during the 1980 Iranian Embassy siege in London were caused by stun grenades coming into contact with flammable objects.

References

External links

{{commons category
FM 3-23.30 ''Grenades and Pyrotechnic Signals''
GlobalSecurity.org, 1 September 2000. Ch. 1, Sec. 10. "Stun Hand Grenades". Retrieved on 26 May 2011. British inventions

Effects

Construction

Hazards

See also

References

External links