In Long Beach, playing pyrotechnician is illegal. The city prohibits the sale and use of firework products and instead encourages residents to attend local firework events if they wish to watch aerial displays.
Meanwhile, in the neighboring city of Lakewood, TNT Fireworks, one of the largest firework distributors in the country, opened up stands on July 1 to sell “safe and sane” fireworks.
These include your standard issue sparklers, Piccolo Petes, Morning Glories, Nuclear Sunrises , and other miscellaneous flashers, fizgigs, and patriotic payloads drunk dads across the nation will be igniting on July 4.
According to FireworksLand.com, “safe and sane” typically refers to firecrackers that “don’t fly or explode.” The phrase became popular in the middle of the 20th century to promote a new generation of consumer firework products.
The exact definition varies from state to state, even city to city. Generally, the phrase means that you’re paying for a few of snaps, crackles and pops accompanied by some colorful shimmer to jazz up the pavement. If you’re buying these legally in your hometown, you’re most likely safe to assume that they’re legal to light.
Quick disclaimer: “Safe and sane” in California does not extend to include rockets, missiles or M80s.
But what makes a firework go boom in the night?
Aerial fireworks have five main parts, according to Chris Woodford, a British science writer for explainthatstuff.com.
- Stick (“tail”): If you’re in the business of lighting fireworks, you want nothing less than a straight shooter. This long, wooden or plastic stick protruding from the bottom helps the firework stay true to its intended path. So this 4th of July, when you’re out enjoying the skyrockets, take a moment to salute the stick. Its what’s keeping your face from becoming a target.
- Fuse: This is what gets the charge to blow. It also ignites other, smaller fuses that make the interesting, colorful parts of the firework come to life.
- Charge (“motor”): Made of very tightly packed explosive powder, otherwise known as black powder, the charge blasts the firework up into the air at the speed of a jet fighter.
- Effect: Ignited by a slow burning, time-delayed fuse working its way up toward the head, this is what makes you cry ooh and aah. Woodford’s Firework Science notes that, “though essentially just explosives, the effects are quite different from the main charge. Each one is made up of more loosely packed, finer explosive material often fashioned into separate ‘stars,’ which make up the small, individual, colorful explosions from a larger firework.”
- Head: The head of the firework holds the effect or effects, and is collectively known as the payload. According to Woodford, most fireworks have a blunt end on the head, but “sometimes the head has a pointed ‘nose cone’ to make the firework faster and more aerodynamic and improving the chance of it going in a straight line.”
Whew! So that’s what we see from below when we watch fireworks at Disneyland or from the Queen Mary, but what makes the large booming sound that sends our pets into a frenzy?
Kathy de Antonis of the American Chemical Society explained in a 2010 edition of ChemMatters that “the loud boom that accompanies fireworks is actually a sonic boom produced by the expansion of the gases at a rate faster than the speed of sound!”