Although they are normally used to provide cover to soldiers in combat, smoke grenades are also used as an important form of communication on the battlefield.

Smoke Screens
Smoke grenades and canisters are most often used to provide a “smoke screen” for soldiers and vehicles that are moving in a combat zone. The smoke can be used to hide soldiers, jeeps, tanks, ships, even aircraft that are taking off or landing in an area under enemy fire. Current smoke grenades also block infrared sensors and laser targets from locking onto soldiers and vehicles.

Artillery and mortars can be used to fire smoke grenades and provide needed cover on the battlefield. Smoke canisters used by the U.S. military include M18 and M40 grenades. These grenades are made of a steel cylinder with holes on the top and bottom that release smoke when ignited. Smoke grenades are considered non-lethal by the U.S. military. However, once ignited, smoke grenades are scalding hot and should not be touched by bare hands.

Coloured Smoke used for Communications
In addition to providing cover in combat situations, smoke grenades are also used to communicate on the battlefield. Many smoke grenades contain dye that produces coloured smoke when ignited. Smoke can come in a variety of colours that include red, purple, orange, yellow, blue, green, gray, white and black.

On the battlefield, the coloured smoke can be used to identify landing zones for airplanes and helicopters, designate friendly troops, and signal the location of enemy targets. These markers are important to soldiers under fire and combat stress, and can help minimize mistakes made in battle.

Health and Environmental Considerations
In 2005, the U.S. military replaced the sulphur that had been used in smoke grenades with a sugar formulation. This change made the smoke produced by the grenades healthier and easier on soldiers who came into contact with it.The new design of the smoke grenades also removed some dyes that were potentially harmful to the environment.