Cibrianite Flux was a metal, which could make humans unconscious.
Sarah Jane Smith had two fuse rods made from Cibrianite Flux. She used fuse rods to built an energy web machine. the If two Fuse Rods were touched at the same time without protection, these fuse rods would complete an electro neurological circuit that could render a human unconscious for at least an hour. However, if the Fuse Rods were touched with gloves this would not happen. (TV: Warriors of Kudlak)