Smoke grenade

A smoke grenade is a canister-type grenade used as a signaling device, target or landing zone marking device, or as a screening device for unit movements.

Smoke grenades generally emit a far larger amount of smoke than smoke bombs, which are a type of fireworks typically started with an external fuse rather than a pin and are more complex. Smoke grenades often cost around US$40 compared to smoke bombs, which can often cost just a few cents.

Typical design consists of a sheet steel cylinder with four emission holes on top and one on the bottom to allow smoke release when the grenade is ignited. The filler consists of 250 to 350 grams of colored smoke composition (mostly potassium chlorate, lactose, and a dye) in virtually any color. The reaction is exothermic and though they remain intact, smoke grenade casings will often remain scalding hot for some time even after the grenade is no longer emitting smoke. Although modern smoke grenades are designed not to directly emit fire or sparks, they remain a fire hazard and are capable of igniting dry vegetation or flammable substances if used injudiciously.

Another type of smoke grenade is the bursting variation. These are filled with white phosphorus (WP), a pyrophoric agent which is spread quickly into a cloud by an internal bursting charge. White phosphorus burns with a brilliant yellow flame, while producing copious amounts of white smoke (phosphorus pentoxide). This type of smoke grenade is favored for its ability to produce a very dense and nearly instantaneous cloud of white concealment smoke as compared to the more common solid-filler grenades which expel a slower stream of smoke over a period of roughly 1 minute. For this reason they are favored for use in onboard grenade launching attachments on armored vehicles, which require extremely fast concealment in the event they are targeted by laser guided anti-tank missiles and need to rapidly retreat.

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