What makes a firework, work?

Class B explosives are used in all firework displays and work by using a complicated mixture of chemicals.Potassium nitrate is used as the oxidizer and sulfur or charcoal as the fuel.These fireworks are far more powerful than the roadside varieties that are only classified as Class C.Of course what the crowd wants to see is color.What gives the sky sparklers their amazing color is a different composition of chemicals.Vivid blues need copper oxide while stand out reds require strontium chloride and brilliant yellows need Calcium Nitrate. The mixtures are then loaded into shells that range from one to four inches.Because of the explosive power Class Bs can only be sold to licensed pyrotechnicians who must meet a range of Pennsylvania regulations.