How do Indoor Fireworks Work?

“Wow… this ain’t good,” Jack Russell commented, noting his surroundings as they became engulfed by flames. A tragedy unfolded over the next 5 minutes as the inferno ran its course, fueled by flammable polyurethane soundproofing and the wooden superstructure of the nightclub. In the end, 100 of the 462 people in the overcrowded building perished; 230 sustained injuries. The cause? An indoor fireworks display that ignited a spark—and led to catastrophe.

Pyrotechnics have long been used to add a magical touch to festive occasions. Proximate pyrotechnics, including indoor fireworks, are custom-designed for use at wedding ceremonies and live music performances. Their use requires special training in addition to professional pyrotechnics expertise. If handled properly, the use of indoor fireworks can enhance the viewing experience for an audience that may be mere feet away.

Fireworks are effectively applications of chemistry. Both the visual element and the explosion are created simultaneously by packing a fuel such as black powder (a mixture of charcoal and sulfur) with an oxidizer (commonly potassium nitrate) and a binder (such as a sugar or starch) in a container capable of withstanding heat. A metallic powder of iron, steel, aluminum, zinc, or magnesium is used to create the effect of colored sparks often used to form a design. Finally, a fuse or electronic timing device is used to set off the display in a coordinated manner appropriate for the associated event or act. Indoor fireworks are constructed and operated in the same way, but with technical and legal limitations intended to promote safety. So what happened on that fateful night of February 20, 2003? The cause was not some intrinsic danger in the formulation of the fireworks, but rather negligence on the part of the club owner, who skimped out on fire-retardant sound proofing. Fireworks don’t kill—people do.