Bicuprodyanide is a neural toxin that is deadly to alien races with an oxygen transported metabolism that is bicupric-based, such as Andorians or Bolians. In 2374, Vash had an accomplice inject her with a dart containing bicuprodyanide to stall an investigation by the crew of Deep Space 9 into the Pah-wraith Red Orbs of Jalbador. (DS9 - Millennium novel: The Fall of Terok Nor)