It has only one stable isotope, caesium-133. It is the least electronegative element, with a value of 0.79 on the Pauling scale. The most reactive of all metals, it is pyrophoric and reacts with water even at −116 ☌ (−177 ☏). Caesium has physical and chemical properties similar to those of rubidium and potassium. It is a soft, silvery-gold alkali metal with a melting point of 28.5 ☌ (83.3 ☏), which makes it one of only five elemental metals that are liquid at or near room temperature. Although the element is only mildly toxic, the metal is a hazardous material and the radioisotopes present a significant health and ecological hazard in the environment.Ĭaesium or cesium is a chemical element with symbol Cs and atomic number 55. The radioactive isotope caesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology. Since the 1990s, the largest application of the element has been as caesium formate for drilling fluids, but it has a range of applications in the production of electricity, in electronics, and in chemistry. Since then, caesium has been widely used in highly accurate atomic clocks. In 1967, acting on Einstein's proof that the speed of light is the most constant dimension in the universe, the International System of Units used two specific wave counts from an emission spectrum of caesium-133 to co-define the second and the metre. The first small-scale applications for caesium were as a "getter" in vacuum tubes and in photoelectric cells. The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the newly developed method of flame spectroscopy. Caesium is mined mostly from pollucite, while the radioisotopes, especially caesium-137, a fission product, are extracted from waste produced by nuclear reactors. The most reactive of all metals, it is pyrophoric and reacts with water even at −116 ☌ (−177 ☏). It is a soft, silvery-gold alkali metal with a melting point of 28.5 ☌ (83.3 ☏), which makes it one of only five elemental metals that are liquid at or near room temperature. The agency will continue to update this page in the event additional actions are taken related to cesium chloride.Caesium or cesium is a chemical element with symbol Cs and atomic number 55. On October 9, 2020, the FDA issued warning letters to the following companies whose dietary supplement labeling lists cesium chloride as a dietary ingredient: On February 5, 2020, the FDA warned consumers to avoid using dietary supplements containing cesium salts, including cesium chloride, due to significant safety concerns. There must be a history of use or other evidence of safety establishing that cesium chloride, when used under the conditions recommended or suggested in the product labeling, will reasonably be expected to be safe and at least 75 days before the product is introduced or delivered for introduction into interstate commerce, the manufacturer or distributor must notify the FDA of the basis on which the manufacturer or distributor has concluded that a dietary supplement containing cesium chloride will reasonably be expected to be safe.īecause neither of these conditions has been met by those marketing products that contain cesium chloride as a dietary ingredient, these products are deemed to be adulterated.Ĭesium chloride is sometimes promoted as an alternative treatment for cancer, but it has never been proven to be safe and effective to treat cancer or for any other use.Cesium chloride, and all other new dietary ingredients in the product, must have been present in the food supply as an article used in food in a form in which the food has not been chemically altered or.As a result, cesium chloride is a new dietary ingredient, and dietary supplements that contain cesium chloride must, among other requirements, satisfy one of the following: The FDA is not aware of any information demonstrating that cesium chloride was lawfully marketed as a dietary ingredient in the United States before this date. Under existing law, a “new dietary ingredient” is a dietary ingredient that was not marketed in the United States before October 15, 1994. Cesium chloride is declared as a dietary ingredient on the labeling of some dietary supplements.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |