A flash bang, also known as a stun grenade or diversionary device, is a non-lethal explosive designed to temporarily disorient individuals. It creates an overwhelming sensory overload through an intense flash of light and an extremely loud sound, gaining a tactical advantage by disrupting a target’s perceptions without causing severe physical harm.
Inside the Device
A flash bang typically features a sturdy, non-fragmenting casing made from materials like steel or aluminum. This design prevents the device from producing dangerous shrapnel upon detonation, a key distinction from traditional fragmentation grenades.
Inside this casing, a time-delay fuze mechanism initiates the device after a short period, commonly between one to two seconds. When activated, a percussion primer ignites a delay column, which then triggers the main pyrotechnic charge.
The pyrotechnic charge, known as “flash powder,” is composed of a metallic fuel (such as aluminum powder or magnesium) and an oxidizer (like potassium perchlorate or strontium nitrate). When ignited, these components rapidly combust, producing significant heat and light.
This rapid combustion generates a sudden expansion of hot gases, creating the deafening sound. Simultaneously, the burning metallic fuel emits an extremely bright flash. Some designs disperse the metallic powder as a cloud, creating a diffuse light source that enhances the blinding effect.
The Impact and Its Purpose
When a flash bang detonates, it unleashes a blinding flash of light, often exceeding one million candelas, with some devices producing up to 13.5 million candelas. This intense light temporarily overwhelms the eyes’ photoreceptors, causing immediate flash blindness and persistent afterimages. This visual impairment provides a momentary advantage.
Simultaneously, the device produces a deafening bang, typically ranging from 170 to 180 decibels (dB) when measured close to the point of detonation. For perspective, sounds above 150 dB can rupture eardrums. This extreme noise level can lead to temporary deafness, ringing in the ears (tinnitus), and inner ear disturbance, affecting balance and coordination.
Beyond immediate sensory overload, a flash bang also creates a psychological impact. Individuals exposed to its effects often experience shock, confusion, and disorientation. This sensory and psychological disruption makes it difficult for targets to react effectively.
Flash bangs are primarily applied in law enforcement and military operations as a tactical tool to temporarily incapacitate or distract subjects. They are used to facilitate entry into hostile environments, such as during building clearances, hostage rescues, or counter-terrorism missions. The goal is to reduce risk to personnel by disorienting individuals without causing lethal harm or significant structural damage.