Pyrotechnics Keep Getting Greener

Fireworks are beautiful, but their color-burning components—often perchlorate-based mixtures—are less than environmentally friendly. Scientists, including Jesse J. Sabatini of the Army’s Picatinny Arsenal, in New Jersey, have been working to develop less polluting compounds for pyrotechnics used by the military and for public display. For example, scientists recently synthesized high-nitrogen nitri­minotetrazolate salts, which served as perchlorate replacements in pyrotechnic mixtures. But the high-nitrogen salts were not commercially available. In addition, producing a specific firework color required synthesizing a custom salt: for example, a strontium compound for red and a barium compound for green. Now, Sabatini and colleague Jared D. Moretti have discovered that a readily available and cheap nitrogen-rich compound, anhydrous 5-aminotetrazole (5-ATZ), can be used as a perchlorate replacement in both red and green flares (Chem.—Eur. J. 2013, DOI: 10.1002/chem.201300779). Sabatini and Moretti prepared a number of 5-ATZ-containing mixtures, which included magnesium and barium or strontium nitrate. Two mixtures, one producing green flame and one producing red, performed as well as perchlorate-containing mixtures and showed “excellent stability,” the researchers write. They envision that 5-ATZ could serve as a foundation for cost-effective red and green light-emitting pyrotechnic devices.