Roman candle (firework)

A Roman candle is a traditional type of firework that ejects one or more stars or exploding shells.

[1] They are banned in Finland[2] and the Netherlands,[3] and illegal to possess or set off in the U.S. states of California,[4] Delaware,[5] Florida,[6] Maryland,[7] Massachusetts,[8] Minnesota,[9] New Jersey,[10] New York,[11] North Carolina,[12] Oregon,[13] and Rhode Island.

Because the star fits loosely in the tube, the fire spreads around it and ignites the lift charge.

For example, when potassium perchlorate (KClO4) is used as an oxidizer, chemical reactions involving the dissociated elements of the perchlorate—potassium and chlorine ions—create barium compounds which emit green light (especially BaCl2).

The potassium compounds formed by this reaction emit mostly near-infrared light, and so they do not affect the color of the star in a significant way.