How Green Are Your Fireworks?

It's July Fourth again, and those displays of big bright flowers exploding in the sky will make the kids go ”ahhhhhhhh!” And for the next month or two, they'll make the fish and frogs living nearby go “ughhhhhhhh!” Since the Chinese created gunpowder a millennium ago, little has changed in its chemical makeup. The perchlorate salts potassium and ammonium, the primary oxidants used in fireworks — and roadside flares, weapons, etc. — are what make them go boom. They’re also known to inhibit the thyroid gland and cause cancer. According to a 2007 study published in the Journal of Environmental Science and Technology, “Within 14 hours after the fireworks perchlorate concentrations spiked in values ranging from 24 to 1028 times the mean baseline value.” These higher levels of perchlorate remain in the water, breaking down after 20 to 80 days. Moreover, high concentrates of carcinogenic heavy metals like strontium, barium and copper — to name a few — are used in pyrotechnic coloring agents.

Chemists are designing more earth-friendly fireworks by using compounds with high nitrogen concentrates that burn hotter and create less smoke. The result is fireworks that require less perchlorate and heavy metals. Another low-smoke producing chemical, nitrocellulose, a gun-propellant used by the military, is being employed as a replacement for perchlorate in pyrotechnics. (Read this excellent article in Chemical & Engineering News). These fireworks are typically sold for indoor pyrotechnic displays like concerts and stage shows held in Walt Disney World and Las Vegas, for example, where low-smoke productions are necessary. However, these earth-friendlier displays cost about twice as much as traditional products, and there doesn't seem to be a big push for municipalities to switch their outdoor displays over to the next generation of fireworks. Green fireworks will remain a thing of the future until concerned taxpayers push for change.