Hexafluorine
Hexafluorine was a gas, deadly to Humans.

In 2153, while aboard the Vulcan  combat cruiser Seleya, Captain Jonathan Archer, Lieutenant Malcolm Reed, Sub-Commander T'Pol, and Private F. Hawkins barricaded themselves in the ship's auxiliary control room.

The Vulcan crewmembers, affected by the exposure of trellium, flooded the room with hexafluorine and forcing the away team to escape. ()

de: Hexafluor
Chemical compounds