did you know...
How firecrackers work?

FIRECRACKERS consist of black powder or gunpowder, which is placed in a tight paper tube with a fuse. The black powder contains charcoal, sulphur and potassium nitrate. Sometimes aluminum is added instead of charcoal to brighten the explosion.

• Sparklers burn longer to produce a bright and showery light. They consist of fuel (charcoal and sulphur), oxidiser (aluminum per chlorate or barium nitrate plus aluminum per chlorate), iron or steel powder and a binder (sugar or starch). Mixed with water, these are coated on a wire. Once dried, sparklers are formed that burn from one end to another when lit. The fuel and oxidizer make it burn slowly rather than explode like a firecracker. A variety of chemicals can be added to produce colours.

• An aerial firework consists of a cylinder-shaped container, which is made of paper, a string, star-shaped sparkler material, black powder and a fuse. This container or shell is launched from a mortar tube. The black powder explodes in the tube to launch the shell. The fuse burns and the shell rises to an optimum altitude. Then the fuse ignites the contents of the shell, which then gets exploded. The explosion ignites the outer surface of stars, throwing around a bright shower of sparks.

• We should only use those crackers that produce 125 db or less of sound. Chemicals contained in crackers may produce toxic gases, which can cause a variety of respiratory diseases. UV light from crackers are harmful to eyes and carbon monoxide negatively effects the haemoglobin content in the blood.

— Compiled by Gaurav Sood