Home >> Science & Nature >> Science

Six Facts for Fireworks Engineering

Fireworks engineering, or pyrotechnics, is a highly regulated activity. The big aerial fireworks used in shows are called "Display Fireworks," or "1.3g Fireworks." The 1.3g classification does not refer to weight in grams, but is a designation taken from the United States Department of Transportation's "Hazardous Materials Table." It is a violation of federal, state and local laws to make display fireworks without the required permits.

Licensing
- Anyone making display fireworks must obtain a permit issued by the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE). The permit process involves a background check and a personal interview by a BATFE field agent. There are also state and local laws restricting the manufacturing and use of fireworks and requiring licensing or permits. These laws will vary from state to state.
Colors
- The blue-violet color is the most challenging because its formulation is unstable
  
  The blue-violet color is the most challenging to formulate and the most dangerous to use. Metals and metal compounds are what give fireworks color. Strontium produces red hues, sodium glows yellow, green is produced from barium, and copper produces blues and greens.
Construction
- The parts of a basic aerial firework are: the mortar, shell, stars and fuse. Fireworks consist of an outer cylinder chamber called a mortar made of plastic or metal. On the bottom of the chamber is the black powder that is used as a propellant. On top of the black powder is a hollow sphere called the "shell" made of a pasted paper material. When assembling the firework, the shell is cut in half so it can be packed with "stars" (pyrotechnic compounds). Also inside the shell is a bursting charge at the center that ignites the firework. A fuse is connected that allows for a time delay before the firework explodes.
Multi-Break Shells
- Multi-break fireworks create multiple explosions from one rocket.
  
  Multi-break shells are fireworks that burst in two or more phases. They contain stars of different colors and chemical compositions that will create different effects, such as soft or bright light and more or less sparks. Multi-break shells can either be filled with other shells or have multiple sections that are ignited with separate fuses. When one section bursts, it ignites the fuse of the second and when the second bursts it ignites the fuse of the third, and so on.
Black Powder
- Black powder is a time-honored formulation but new propellant methods are being developed
  
  Black powder is an ancient formula made of potassium nitrate, sulfur and charcoal. When the black powder is ignited, the nitrate oxidizes the sulfur and charcoal resulting in a high volume of hot gasses and glowing solid bits. Today, black powder is only used in fireworks and in historical reenactments of cannon and rifle fire.
Pollution
- Disney replaced black powder with compressed air after complaints about the smoke from neighbors.
  
  Pollution from fireworks is a problem, and pyrotechnic engineers are working to make fireworks less harmful to the environment. The problem is magnified when fireworks are set off indoors (such as at concerts) or in the same location night after night (such as at amusement parks). The chemical oxidizers, fuels, propellants, binders, and coloring agents leave behind clouds of toxic smoke and particulate matter that settle into nearby soil and water.

Science