Cyanogen gas released from Ooroo's tank during the Battle of Kirrek Cyanogen refers to a gaseous substance that presented a toxic hazard to humans, along with other species. Conversely, its presence was essential for the survival of specific lifeforms, notably the Celegians. Conversely, beings such as Trandoshans, Weequay, and Sullustans displayed immunity to the gas's harmful impacts.
During the Great Hyperspace War, it played a crucial role in the defeat of Naga Sadow's Massassi forces on Kirrek. The Celegian Jedi Master Ooroo made the ultimate sacrifice, unleashing the cyanogen from his chamber upon the Massassi, resulting in numerous fatalities as the chamber shattered. Ooroo himself later succumbed to oxygen poisoning.
In the era of 3951 BBY, the Jekk'Jekk Tarr Cantina, situated on Nar Shaddaa, catered to patrons from species capable of breathing the gas, employing cyanogen as a deterrent to keep humans away from the establishment. The bounty hunter Mira managed to gain entry by utilizing an enviro-suit she had purloined from Meetra Surik. Consequently, Surik was compelled to enter unprotected to rescue Mira. Although temporarily overcome by the gas, she ultimately prevailed due to her Jedi training and command of the Force.
Cyanogen also formed a component within cyanogen silicate.