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13 Fascinating Things You Never Knew About Fireworks

Fascinating behind-the-scenes facts about a Fourth of July fireworks display will help you see this annual feast for the eyes in a whole new light.

Iriga City, Philippines - December 2016: Fireworks on display for public buyingRainier Martin Ampongan/Shutterstock

The big show

Unlike backyard fireworks that happen pretty much completely randomly, major community fireworks shows take months of design and planning and require a host of people to pull off. A choreographer assembles the script for the show, and in most cases programs computers to execute the plan. The stagehands or crew carry out the directions of the production manager and choreographer and prepare to safely launch the fireworks. In some shows, an announcer will explain to the audience what is coming up. Finally, no show would be successful without the safety crew, whose sole job is to ensure that the fireworks are produced safely. These are the cities that have the most spectacular 4th of July fireworks.

Crowd watching fireworksnd3000/Shutterstock

And… action!

There’s only one person who can set the fireworks show in motion and that’s the production manager, also known as the Lead Shooter. And for good reason. “When multiple events are occurring, the production manager manages competing events,” says Dan Creagan, pyrotechnician and media coordinator for Pyrotechnics Guild International (PGI). “He or she directs the placement of the different launching mechanisms and ensures that all parties are in safety compliance.”

Fireworks - Red, White, and Blue CakeMike Randall/Shutterstock

The unknown artist

While you’re oohing and aahing, you probably don’t consider that someone actually designed the fiery spectacle, but it takes an experienced fireworker to create a larger than life, star-spangled masterpiece. After all, the entire sky is the pyrotechnician’s canvas. “The shells are the paint and the art is in the hands of the pyrotechnicians, and often a choreographer will work months to produce a unique show for an event. The shells, effects, and sound are selected to paint an ethereal picture that is pleasing,” says Creagan. “Different devices are used to have a balance of ground, mid-sky, and high altitude effects.”

Iriga City, Philippines - December 2016: Fireworks on display for public buyingRainier Martin Ampongan/Shutterstock

What’s in a firework

It’s amazing how a firework can end up looking like a chrysanthemum or smiley face when it has only three main components—an oxidizer, a fuel, and a chemical mixture to produce the color. The ingredients are placed in a small tube called an aerial shell. The explosive materials are called stars that form the colorful spheres, cubes, cylinders, and other shapes that explode into complex designs.

group of fireworks mortar tubesTooykrub/Shutterstock

The big bang

To get fireworks into the air, the aerial shells are placed in a tube called a mortar. Fireworks staff light a fast-acting fuse below the shell that contains gunpowder and the gunpowder explodes, creating a build-up of heat and gas and a whole lot of pressure. When the pressure reaches critical mass, off it goes up into the sky. But that’s not the end. Once the shell is high off the ground, another fuse inside the aerial shell that’s on a time-delay ignites, causing the bursting charge to explode and light up all those stars you see from the ground.

professianal firework set up prior to launchShaunWilkinson/Shutterstock

I ♥ U

How do the components in a cylinder end up looking like a heart, smiley face, or an acronym? Creagan says they are created in an aerial shell with embedded colored stars laid out in a pattern of the desired shape. There’s filler in between the stars that is usually a quickly burning composite that is light and doesn’t compete with the stars. The stars with greater mass travel farther than the lighter stars. “This physical trait can be taken advantage of to get the familiar flower-like display you see with a huge outer ring and progressively smaller inner rings, ending with a ‘flower’ of light at the center,” says Creagan. See if you can you guess what these firework patterns are called.

Amazing fireworks with space isolated on black background.tarapong srichaiyos/Shutterstock


A fireworks show is not just a feast for the eyes but for the ears as well, with those giant booms that follow each burst of light. The specific sounds are determined by a mix of chemical combinations within tubes. As each layer of the firework burns, it releases a gas, creating sound. For example, the hissing and sizzling sparkle sounds are from aluminum or iron flakes, and the big loud booms are generated with titanic powder. Up the boom factor with one of these splurge-worthy Fourth of July destinations.

Blue fireworks at festivalB.Zhorov/Shutterstock

Blue can be fickle

Brilliant, glowing colors come from different metal elements. When the chemicals in fireworks burn, energy is released in the form of light. The chemicals burn in different wavelengths of light depending on the metal element. For example, deep reds are the result of burning strontium and lithium compounds; barium gives off a green color, and copper produces blues. Blue, however, is a fickle hue and considered the most difficult to produce because the copper compound has to be heated just right to give off a brilliant blue color. If it burns too hot, the color is lost, and if it’s too low, there is no intensity.

Fireworks over cityscape by the beach and sea surrounding with hotels, restaurant, and service boats and cruises sign of cristmas/ New Year eve and special festival.Sujin Wutiprasert/Shutterstock

Intense energy

Most U.S. shows use up to 6-inch shells that go up to 800 feet high. “Fireworks are not extremely fast but their intense energy sends them flying quite high,” says Creagan. “We often demonstrate firing a 3-inch mortar shell through a 3/4-inch piece of plywood. The shell isn’t going extremely fast but because it has a large amount of energy it will penetrate the wood with no problem.” Since DIY fireworks also have tremendous power, it’s critical to keep hands, feet, and especially heads away from the blast-off. Find out why we set off fireworks for the Fourth of July every year.

Red, White, & Blue Fireworks reflecting in lakeSherri R. Camp/Shutterstock

Weather plays a role

For fireworks to look their best, Mother Nature needs to cooperate. “Winds tend to cause aerial fireworks to fly off course and can make for fire hazards,” Creagan says, adding that national codes dictate canceling fireworks shows when wind is high. Rain makes lighting the fireworks more difficult and can dampen visibility. Fog and still air aren’t ideal conditions either. “It makes the smoke from previous fireworks hang in the area, clouding the view.” Low-forming clouds also make it difficult for fireworks to be seen. The best canvas for fireworks is during a new moon phase, when the air is clear, so the colors really pop against a dark sky.

Young people holding fireworks at a party.Sellwell/Shutterstock

Handling fireworks

It’s not uncommon to see people in shorts and flip-flops lighting bottle rockets or waving sparklers, but the pros wear safer attire when working with commercial fireworks. “Fireworks are sensitive to impact, friction, and static electricity. All fireworkers are taught to wear non-synthetic clothes and to use safety glasses,” says Creagan. “While most modern shows are electrically fired, there are still hand lit shows being done. If hand-lighting a show, the crew must wear appropriate gear similar to a firefighter’s safety gear, complete with helmet and face shield.” As you can imagine, donning this type of gear gets pretty toasty in hot weather, which is why heat exhaustion can be a problem for fireworkers.

professional paramedics giving unconscious young woman first aidmichaeljung/Shutterstock

The ouch factor

According to the United States Consumer Product Safety Commission Fireworks Information Center, an average of 250 people go to the emergency room every day with fireworks-related injuries around the July 4th holiday. Those seemingly innocent sparklers can burn at temperatures up to 2,000 degrees, which is hot enough to melt some metals. In fact, injuries from sparklers were the cause of 900 ER-treated injuries in 2017, and bottle rockets caused 400 ER-treated injuries. According to the Fireworks Alliance, one way to protect yourself is to wear the right attire—cotton or denim clothing, long pants, eye protection, covered shoes, and also ear protection if your fireworks have a loud boom factor.

The debris caused by the explosion of the firecrackers are stacking resulted in dirty places.SOORACHET KHEAWHOM/Shutterstock

The aftermath

What happens to a firework once it explodes? Creagan explains: “Fireworks are paper paste, string, and the burning component. After a firework expends itself, the remaining debris is biodegradable paper and a small amount of carbon. According to, the U.S. Army Pyrotechnics Technology and Prototyping Division have found some alternatives that are more environmentally friendly. Although these alternatives are earmarked for military use, they could be applied to civilian fireworks in the future. The hurdle is making these fireworks as inexpensive as the commercial offerings currently used. Next, find out the 20 things you didn’t know about the Fourth of July.

Lisa Marie Conklin
Lisa Marie Conklin is a Baltimore-based writer who writes regularly about pets and home improvement for Reader's Digest. Her work has also been published in The Healthy, HealthiNation, The Family Handyman, Taste of Home, and, among other outlets. She's also a certified personal trainer and walking coach for a local senior center. Follow her on Instagram @lisamariewrites4food and Twitter @cornish_conklin.