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    How do fireworks work?


    Fireworks are explosions of numerous small pellets of black powder called stars. The main ingredient in fireworks is black powder, which explodes when ignited (lit on fire). In addition to black powder, firework stars contain different chemicals or metals to create certain colors. The stars are intentionally arranged to create various firework shapes or images.

The fireworks we enjoy at large celebrations are called aerials. To assemble aerial fireworks, trained professionals called pyrotechnicians first make stars by mixing black powder with different chemicals or metals. When reacting with heat from exploding black powder, the chosen additive produces a certain color. For instance, mixing copper into a star will produce a blue firework. The stars are then arranged inside a cardboard or plastic container called a shell. How the pellets are arranged within the shell determines the shape of the firework. Lastly, fuses are attached to or embedded within the shell and everything is wrapped in paper.

Pyrotechnicians don’t just make the fireworks; they also supervise every aspect of firework shows. It can take several days to several weeks designing, preparing, and setting up a 20 minute show. To set up an aerial fireworks display, pyrotechnicians prepare the launch site with short metal pipes called mortars. Each shell is placed in a mortar on top of more black powder called the lift charge. The professionals then attach one end of a wire fuse to the lift charge. The other end of the wire fuse is connected to a control panel. When prompted by a computer or trained operator, the panel sends an electric jolt to the shell which ignites the lift charge to create an explosion. This explosion launches the shell into the air and lights the shell’s fuse. When the lit fuse reaches the stars in the shell, they explode into the air in the designed shape. The heat from these explosions reacts with the chemicals mixed within each star, and we see the vivid colors and shapes of the fireworks in the nighttime sky.

Pyrotechnicians carefully measure black powder, chemicals, fuses and other supplies to build fireworks that work properly. These professionals make precise calculations to ensure that each firework projects to the correct altitude (height) and explodes at the right time and in the right location. The next time you enjoy an aerial fireworks show hopefully you can appreciate the exact science that becomes a beautiful celebration of chemistry and physics.

Standard DisclaimerRelated Web Sites
  • Fireworks! External Link - This article from the October 2010 issue of ChemMatters Magazine (American Chemical Society) targets high school students and provides fireworks facts and images as well as an interview with a pyrotechnic chemist. (PDF, 650 KB)
  • How Are Fireworks Made? External Link- This website from Wonderopolis has a read-aloud feature, vocabulary, videos, and additional resources to learn even more about the science of fireworks.
  • How Do Fireworks Work? External Link - Video from National Geographic: 1 minute, 20 seconds.
  • Nova Online: Fireworks! External Link - This website, from the PBS science series, has videos, games, interviews and more resources to reveal the science behind fireworks. Also includes a Teacher’s Guide.
  • Promoting Safe and Responsible Use of Consumer
    External Link - The National Council on Fireworks Safety offers fireworks safety tips for you and your pets!

Library of Congress Web SiteFurther Reading
  • Cobb, Vicki.  Fireworks.  Minneapolis, Millbrook Press, c2006.  48 p.  (Juvenile)
  • Davis, Gary W. (Gary William).  From rock to fireworks: a photo essay.  New York, Children's Press, c1997.  32 p.  (Juvenile)
  • Firestone, Mary.  Pyrotechnician.  Philadelphia, Chelsea House Publishers, c2006.  69 p.  (Juvenile)
  • Rau, Dana Meachen.  Fireworks.  New York, Marshall Cavendish Benchmark, c2011.  24 p.   (Juvenile)
  • Rocker, Megan.  How it happens at the fireworks factory.  Minneapolis, Clara House Books, c2004.  32 p.  (Juvenile)
  • Thomas, Isabel.  Fireworks!   Chicago, Raintree, c2007.
    32 p.  (Juvenile)

SearchFor more print resources...
Search on "fireworks," "explosives," or "pyrotechnists" in the Library of Congress Online Catalog.

Photo: closeup of a Chinese shell
Example of shell used in fireworks display.  From the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention website.


Poster with colored fireworks with the names and atomic numbers of metals used in fireworks
"Common metals added to fireworks to create color."  From the NASA website.


Drawing of a cutaway image of a fireworks shell with text How do Fireworks Work enlarge View Larger
Courtesy of Jessica Law.


Photo: fireworks going off behind the Martin Luther King Jr. Memorial
Fireworks behind the Martin Luther King, Jr. Memorial in Washington, D.C. From the National Park Service website.


Photo: different colored aerial fireworks
Aerial fireworks. From the Occupational Safety and Health Administration, U.S. Department of Labor website.


World’s Fair. Fireworks over water I. New York, 1939, or 1940.  Prints and Photographs Division, Library of Congress

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 August 14, 2017
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