How do they do that?
Fireworks are launched in a cartridge known as an aerial shell. The shell is made from treated cardboard or heavy paper, filled with a black powder made from sulfur, charcoal, and 75% potassium nitrite, (also known as gun powder or flash powder) and a mixture known as stars.
The stars are made of combustible materials, chemicals, and metal salts. It is the chemical makeup of each star that determines the color and the shape of the sparkler. For example, strontium carbonate (SrCO3) is used to create red, metals such as aluminum or magnesium are used to create white, and copper chloride (CuCl) is used to create blue. There is great attention to detail in selecting the compounds that make up the star; the composition must be stable and safe for storage, yet produce the desired effect.
Safety: Number One Priority
Fireworks are launched from steel tubes buried in sand. A lift charge ignites to create pressure from heated, trapped gas in the bottom of the launch tube, propelling the firework as high as 1,000 feet into the air. The time-delayed fuse begins burning as the shell is launched into the air. It must be carefully constructed to detonate the black powder at just the right moment; when the shell is at its highest altitude. When the fuse burns into the shell, it ignites the black powder causing the shell to explode. The explosion ignites the stars and throws them in all directions, generating a shower of sparkling light.
Safety is the highest priority in the fireworks industry. Manufacturers and fireworks exhibitors are aware of all possible ignition sources around the display area. Oil from nearby machinery can combine with the firework chemicals, creating an explosive gas. A sharp blow or static electricity can also detonate a firework shell. Personnel that handle the fireworks must undergo extensive training and are required to follow detailed safety practices.
As a consumer or spectator of firework displays, safety should be taken seriously. In 2013, three deaths were directly related to fireworks and about 8,600 consumers were injured, according to the most recent statistics from the Consumer Product Safety Commission. Keep the following safety tips in mind when viewing or handling fireworks:
For more information on firework safety, visit the National Council on Fireworks Safety.
Our team at Wilson Insurance Services, Inc. wishes you and your family a very happy Fourth of July weekend!