Chlorine trifluoride
>It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively. It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminum keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.
>Chlorine trifluoride and gases like it have been reported to ignite sand, asbestos, and other highly fire-retardant materials. It will also ignite the ashes of materials that have already been burned in oxygen. In an industrial accident, a spill of 900 kg of chlorine trifluoride burned through 30 cm of concrete and 90 cm of gravel beneath.Other than the use of nitrogen and noble gases, no known fire control/suppression methods are capable of suppressing this oxidation, so the surrounding area must be flooded with nitrogen or helium or simply kept cool until the reaction ceases
>It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively. It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminum keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.
>Chlorine trifluoride and gases like it have been reported to ignite sand, asbestos, and other highly fire-retardant materials. It will also ignite the ashes of materials that have already been burned in oxygen. In an industrial accident, a spill of 900 kg of chlorine trifluoride burned through 30 cm of concrete and 90 cm of gravel beneath.Other than the use of nitrogen and noble gases, no known fire control/suppression methods are capable of suppressing this oxidation, so the surrounding area must be flooded with nitrogen or helium or simply kept cool until the reaction ceases
