Flashbang Grenade: Among the First Modern ‘Non-Lethal’ Weapons Ever Developed

Photo Credit: Mass Communication Specialist Seaman Martin Carey / U.S. Navy / Wikimedia Commons / Public Domain
Photo Credit: Mass Communication Specialist Seaman Martin Carey / U.S. Navy / Wikimedia Commons / Public Domain

Stun devices are among the most important non-lethal tools at a soldier’s disposal. They have the ability to disorient a target without causing harm, allowing the person(s) who deployed them a few extra seconds to get in position and gain the upper hand. Among the first to be created was the flashbang, a grenade that evolved from the increasing number of terrorist attacks that were occurring in the 1970s.

What is a flashbang grenade?

Also known as a stun grenade, thunderflash, sound bomb and flash grenade, the flashbang is among the earliest “non-lethal” weapons to be developed. Constructed from an aluminum or steel casing that’s built to remain intact, it uses a mixture of chemicals (typically potassium nitrate or potassium perchlorate) to create a reaction designed to stun targets.

Two US Marines aim their weapons at an open doorway while an explosion occurs inside the building
Two US Marines with 2nd Battalion, 1st Marine Division prepare to clear a building after throwing a flashbang grenade, Marine Corps Base Camp Pendleton, California. (Photo Credit: Lance Cpl. Joshua Murray / Wikimedia Commons / Public Domain)

The flashbang disorients targets in two ways. The first is through a flash of light measuring several million candela, which is caused by the ignition of a magnesium-based charge. Capable of blinding a person for around five seconds, it’s followed by an afterimage that temporarily impairs one’s vision. There have also been reports of pain, due to potential harm to the retina, but none of these effects are permanent.

As CEENTA ophthalmologist Ernest Bhend, MD explains, “Flashbang grenades will cause an effect called ‘flash blindness’ which is due to overloading the light receptors in the eye and causing a significant afterimage. The effect is temporary and reversible. The intense light can cause pain, but should not cause permanent damage to your eyes.”

The second way in which the device causes disorientation is the loud “bang” it produces, which typically measures around 170 decibels. This causes ear ringing and temporary deafness, as well as an inner ear imbalance. While flashbangs are designed to limit injury to targets, there have been reports of permanent hearing loss, due to how loud they are.

Close-up of a Ukrainian Interior Troops officer with stun grenades and tear gas strapped to his uniform
Interior Troops officer fully armed with tear gas kits and stun grenades during clashes in Kyiv, Ukraine, 2014. (Photo Credit: Mstyslav Chernov / Unframe / Wikimedia Commons CC BY-SA 3.0)

While considered a non-lethal weapon, serious injuries aren’t uncommon and deaths have occurred. This is typically due to the proximity of the target to the detonation or structure fires caused by the grenades going off.

Developed for the Special Air Service

Flashbang grenades were first developed in the late 1970s for use by the British Army’s Special Air Service (SAS). The special forces unit had created a Counter Terrorist Wing in response to the increasing number of terrorist attacks, and asked engineers with Royal Ordnance Enfield to develop a new stun device for use in hostage situations.

The idea for the device was that those involved in such criminal acts would see the grenade enter the room and assume it was going to explode in a violent and deadly blast. This would cause them to hesitate, allowing the team time to enter the location and launch their assault.

Sgt. Jason Christy and Staff Sgt. Stephen Crowe duking while an M84 stun grenade detonates inside a cargo container
Sgt. Jason Christy and Staff Sgt. Stephen Crowe practice throwing an M84 stun grenade. (Photo Credit: Melissa Buckley / Fort Leonard Wood Public Affairs Office / Wikimedia Commons / Public Domain)

A scientist working with the British government on top-secret chemical and biological warfare research suggested adding a 4.5-gram mixture of magnesium and potassium perchlorate to the grenade, which would create an amplified “bang” and flash. The result was the G60.

Over the years, the flashbang has been adopted across the world, largely for use in hostage and urban tactical situations. Members of the SAS, in particular, have gradually become conditioned to the effects of the devices through their training and are equipped with a number of tools to protect themselves in the field. These included tinted eyepieces and respirators, as well as ear defenders that minimize the sound of the blast.

There are various types of flashbangs

Since their development in the 1970s, a number of flashbang grenades have been produced, largely for use by the military and law enforcement. The US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has classified them as a destructive weapon and, as such, they’re largely unavailable for commercial sale.

The current-issued grenade equipped by the US military and Special Weapons and Tactics (SWAT) teams is the M84, which is capable of producing a “bang” of between 170-180 decibels and a flash of over one million candela. As with other flashbangs, those within five feet of the detonation site will suffer immediate blindness, inner ear disruption, deafness, tinnitus, confusion, disorientation and a loss of balance.

While the M84 is incapable of igniting material that’s typically flammable, the same can’t be said for liquids and vapors.

Mass Communication Specialist 1st Class James E. Foehl aiming his gun while Max Joseph prepares to toss a flashbang grenade
Mass Communication Specialist 1st Class James E. Foehl, assigned to Fleet Combat Camera Group Pacific, provides cover while the Director of Tactical Firearms Training Team Max Joseph tosses a flashbang grenade into a shoot house during Quick Shot 2010. (Photo Credit: Mass Communication Specialist Seaman Martin Carey / U.S. Navy / Wikimedia Commons / Public Domain)

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Flashbangs have also evolved for use in crowd control scenarios, with the ability to detonate multiple times. They typically contain irritants, such as CS or CN tear gas, and some can be deployed aerially, with the ability to fly between 20-30 feet.

Clare Fitzgerald

Clare Fitzgerald is a Writer and Editor with eight years of experience in the online content sphere. Graduating with a Bachelor of Arts from King’s University College at Western University, her portfolio includes coverage of digital media, current affairs, history and true crime.

Among her accomplishments are being the Founder of the true crime blog, Stories of the Unsolved, which garners between 400,000 and 500,000 views annually, and a contributor for John Lordan’s Seriously Mysterious podcast. Prior to its hiatus, she also served as the Head of Content for UK YouTube publication, TenEighty Magazine.

In her spare time, Clare likes to play Pokemon GO and re-watch Heartland over and over (and over) again. She’ll also rave about her three Maltese dogs whenever she gets the chance.

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