Clorium is a fairly common element, but it is one of the Six Forbidden Cargos for Leviathan biomechanoids. For the biomechanical vessels, clorium is a numbing agent. To most humanoid species, however, clorium servea as something with which to season and preserve food. It is known by numerous names across the Milky Way, including "onlux" on Denea and "table salt" (or "sodium chloride") on Earth.
Clorium is seen in Farscape.