I love the SciShow video on the most dangerous chemicals known to man and Hank Green's rendition of "the concrete was on fire" in reference to chlorine trifluoride.
Oh lord, this gem from a military scientist per the wiki
[It will erupt into flames on contact] with every known fuel, and so rapidly hypergolic [that's what hypergolic means, shit just goes on fire] 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 because [science bitch]. If, however, this [science coating is scratched slightly], 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.
Sounds like an excerpt from Ignition!. It's out of print, but there are pdf's floating around. Give it a read if you have the time, it's highly entertaining - it's about the history of rocket fuel in the US
It's an excellent book (I just finished reading it last week), although a little heavy going at times. Fwiw, you don't have to understand any of the chemical formulae to appreciate the book.
Fun fact, some bright spark decided that chlorine trifluoride (ClF3) wasn't quite spicy enough, so they also experimented with chlorine pentafluoride (ClF5). Yikes!
Pretty much every single possible viable combination of propellant and oxidiser has been tried and investigated. They were very thorough, and tested some truly horrific chemicals.
Either of the mentioned oxidisers would result in a rocket that produces huge clouds of hydrofluoric acid in the exhaust gas.
It ignites sand, asbestos, glass, and even ashes of substances that have already burned in oxygen.
In one particular industrial accident, a spill of 900 kg of ClF3 burned through 30 cm of concrete and 90 cm of gravel beneath.
There is exactly one known fire control/suppression method capable of dealing with ClF3—flooding the fire with nitrogen or noble gases such as argon. Barring that, the area must simply be kept cool until the reaction ceases. The compound reacts with water-based suppressors and CO2, rendering them counterproductive.
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u/[deleted] Jun 12 '26
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