What’s in a firework?

Virginia Zantow

Other than heat and mosquitoes, the most distinguishing thing about the Fourth of July is undoubtedly the fireworks show.

A mixture of artistry, chemistry and a little danger, fireworks are fairly simple in design, though the basic elements of their composition vary widely in order to create the diversity of effects that light up the night sky.

Thomas Daniels, assistant professor of electrical and computer engineering, has been shooting fireworks with Aerial FX in St. Joseph, Mo., for the past few years.

“Most of the things you see in the sky in a typical professional fireworks shoot are called aerial shells or mortar shells,” Daniels said.

“Basically what they are is a spherical device that gets shot out of a tube. There’s a little bit of black powder on the bottom that shoots it almost like a bullet out of a gun, and that shoots it up out of the air.”

Inside of the sphere, a unique arrangement of tiny “stars” determines the pattern that viewers see in the sky.

Mark-Stephen Woodburn, of Stumptown, an Iowa-based pyrotechnics club that teaches and certifies people who wish to learn how to shoot fireworks professionally, said the stars consist of two chemicals: a fuel and an oxidizer.

The different chemicals used for each of these yield different firework colors. The most common oxidizer used in professional fireworks displays, he said, is sodium bichlorate.

Woodburn said the combination of a fuel and an oxidizer is the most basic description of a firework.

Daniels said a time fuse attached to the fireworks burns for approximately 3 seconds once the firework is set off, and when it reaches a height of 300 feet or so, it explodes, lighting the stars as they fall in a pattern.

Not all fireworks have stars – some, known as “salutes,” merely go off with a “bang!” and leave nothing but a mark of smoke in the sky.

“People either love those or they hate them,” Daniels said.

Daniels said, incidentally, he loves them; they are very powerful, he said.

The size of each firework shell varies, Daniels said, from those with 2.5-inch diameters to larger shells, with diameters as long as 12 inches or more.

“We’ve shot shells 16 inches in diameter in the past,” he said.

In Iowa, a person needs to have a license in order to shoot off fireworks, or be involved in a company or organization that has a license.

To those interested in becoming certified to shoot off fireworks, Daniels recommended contacting a company or individual selling professional fireworks and asking about getting certified.

Another possible option would be to contact Stumptown and inquire about their training programs. More information about this organization can be found at www.stumptownshooters.org.