Bilenium was a chemical compound that was the byproduct of the breakdown of ferrazene, along with tarrisite. Ships' sensors regularly scanned for all three compounds on Galaxy-class starships.

In 2368, Geordi La Forge queried the USS Enterprise-D's computer about whether this substance was present on the starship; it was not. (TNG: "Violations")

Community content is available under CC-BY-NC unless otherwise noted.