Fireworks - Pyrotechnic Compounds

Pyrotechnic Compounds

Colors in fireworks are usually generated by pyrotechnic stars—usually just called stars—which produce intense light when ignited. Stars contain five basic types of ingredients.

• A fuel which allows the star to burn
• An oxidizer— a compound which chemically oxidizes the fuel, necessary for combustion
• Color-producing chemicals
• A binder which holds the compound together.
• A chlorine donor which provides chlorine to strengthen the color of the flame. Sometimes the oxidizer can serve this purpose.

Some of the more common color-producing compounds are tabulated here. The color of a compound in a firework will be the same as its color in a flame test (shown at right). Not all compounds that produce a colored flame are appropriate for coloring fireworks, however. Ideal colorants will produce a pure, intense color when present in moderate concentration.

The brightest stars, often called Mag Stars, are fueled by aluminum. Magnesium is rarely used in the fireworks industry due to its lack of ability to form a protective oxide layer. Often an alloy of both metals called magnalium is used.

Many of the chemicals used in the manufacture of fireworks are non-toxic, while many more have some degree of toxicity, can cause skin sensitivity, or exist in dust form and are thereby inhalation hazards. Others, such as barium chloride are poisons if directly ingested or inhaled.