Tibanna
Tibanna gas is a main export of Cloud City on Bespin. It is briefly mentioned in The Empire Strikes Back, when Solo discovers that Calrissian is now running Cloud City, but its use was never revealed in the movie. The novels eventually explained it as a blaster gas, used in many small-arms laser weapons, and in the first Rogue Squadron game for the Nintendo 64, Tibanna gas was noted as being used in the blasters of Imperial TIE Fighters as well as Rebel Fighters. Tibanna gas in a cooled, liquid form is also used as a coolant in hyperdrive engines, and its sale and distribution is regulated by the Imperial Mining guild. Semi-legal operators of illicit spacecraft seek out sources of Tibanna gas that are not regulated by Imperial authorities, so as to keep their operations secret. However, it is flammable, and must be handled with care.
Read more about this topic: List Of Star Wars Substances