Hydrogen cyanide

"The Pikaati breathe hydrogen cyanide. The helmet flooded as soon as she activated the seal. Open that, and you could put the rest of us in danger."

- Wilhuff Tarkin, to Denetrius Vidian after Thetis Quelton commited suicide using hydrogen cyanide

Hydrogen cyanide was a gas breathed by the Pikaati species. It was extremely poisonous to humans, who could perish if they inhaled the gas.

Appearances

 * "Bottleneck"&mdash;The Rise of the Empire