given amount of electrical energy than does incandescent lighting. Terbium is also used to detect endospores, as it acts as an assay of dipicolinic acid based on photoluminescence. Precautions Terbium has no known biological role. As with the other lanthanides, terbium compounds are of low to moderate toxicity, although their toxicity has not been investigated in detail. Based on the toxicity of terbium chloride to mice, it is estimated that the ingestion of 500 grams or more could be fatal to a human (c.f. lethal dose of 300 grams of common table salt for a 100 kilogram human). The insoluble salts are non-toxic. See also Terbium compounds List of elements facing shortage References External links WebElements.com – Terbium It's Elemental – Terbium Chemical elements Chemical elements with hexagonal close-packed structure Ferromagnetic materials Lanthanides Reducing agents