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Unconfirmed reports that a fireworks depot fire caused a secondary benzene explosion. src: https://twitter.com/mattparlmer/status/1290679715892690945 https://tw

Unconfirmed reports that a fireworks depot fire caused a secondary benzene explosion. src: https://twitter.com/mattparlmer/status/1290679715892690945 https://twitter.com/mattparlmer/status/1290679715892690945

madaxe_again 6y ago
That sounds plausible - it won’t be fireworks alone, black powder won’t make that kind of bang. Ammonium nitrate would fit the bill, too, which is the sort of thing you often have in warehouses or bulk carriers in quantities that would make an explosion of that order. Honestly, it’s somewhat amazing that this kind of thing doesn’t happen far more often than the ~1 incident per year, globally.
- Jtsummers 6y ago
  A friend of mine worked in EOD (explosive ordinance disposal) and related fields. I got to talk with him once about all this. One of the primary thing that reduces the rate of accidents is people following the rules. Basically, there are rules that say, based on mass, how far apart different things need to be from each other. It also varies by the kind of explosive (as different explosives have different triggers like heat or concussion). [0] is like the tables he showed me (his were more complex and dealt with specifically named explosives, not the broader categories this one describes). [0] https://www.atf.gov/explosives/table-distances https://www.atf.gov/explosives/table-distances
- reducesuffering 6y ago
  Quite prescient. Early reports from Lebanon's Interior Minister seemed to implicate ammonium nitrate.[0] [0]https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-lebanon-capital-beirut-live-updates-200804163620414.html https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-...
macintux 6y ago
I’ve also seen reports of grain silos in the area being destroyed; grain is an astonishingly powerful explosive.
- throwaway0a5e 6y ago
  Grain is a pretty poor explosive because the upper and lower explosive limits are so close (yes I know that's not traditionally a metric we use for solids), it needs an oxidier and the volume of byproduct for volume of input is relatively low. But large amounts of grain and oxygen are often found together in confined spaces so that makes it more explosive in practice than most things that people who work in offices and don't deal in bulk goods come into contact with.
  - throwaway_pdp09 6y ago
    Can you elaborate what "upper and lower explosive limits" are, please. Also I don't understnd how it could be explosive at all, sudden oxidation of large (that is, low surface area to volume), non-dry particles seems unlikely. Flour etc. may be another matter, but a blast like this... flour?
    - throwaway0a5e 6y ago
      >upper and lower explosive limits concentration of the fuel in otherwise normal atmospheric air required to go whoosh (or bang, which is basically just a really fast woosh or one that's constrained by something). Too much fuel, too rich, no woosh. Too little fuel, too lean, no woosh. Lower and upper explosive limits are generally used to refer to gas mixtures though you can use them for solids but the units will be different. Solids we think of as explosive when not fishing around for virtue points on the internet generally contain their own oxygen supply so lower and upper explosive limit doesn't apply. >sudden oxidation of large (that is, low surface area to volume), non-dry particles seems unlikely. Flour etc. may be another matter, but a blast like this... flour? Yeah, no way that secondary explosion is flour or grain. I'd put my money on some sort of industrial chemical that contains its own oxidizer. Explosions that use atmospheric oxygen look different and rarely manage to be able to build up that kind of shock-wave if not constrained by something (like a building). There should be videos of natural gas explosions on YouTube that illustrate the difference.
    - TimSchumann 6y ago
malandrew 6y ago
I've seen one report that cites the Lebanese government that it was sodium nitrate seized from a ship that was temporarily stored there and was slated to be moved.

madaxe_again 6y ago

That sounds plausible - it won’t be fireworks alone, black powder won’t make that kind of bang. Ammonium nitrate would fit the bill, too, which is the sort of thing you often have in warehouses or bulk carriers in quantities that would make an explosion of that order. Honestly, it’s somewhat amazing that this kind of thing doesn’t happen far more often than the ~1 incident per year, globally.

Jtsummers 6y ago
A friend of mine worked in EOD (explosive ordinance disposal) and related fields. I got to talk with him once about all this. One of the primary thing that reduces the rate of accidents is people following the rules. Basically, there are rules that say, based on mass, how far apart different things need to be from each other. It also varies by the kind of explosive (as different explosives have different triggers like heat or concussion). [0] is like the tables he showed me (his were more complex and dealt with specifically named explosives, not the broader categories this one describes). [0] https://www.atf.gov/explosives/table-distances https://www.atf.gov/explosives/table-distances
reducesuffering 6y ago
Quite prescient. Early reports from Lebanon's Interior Minister seemed to implicate ammonium nitrate.[0] [0]https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-lebanon-capital-beirut-live-updates-200804163620414.html https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-...

macintux 6y ago

I’ve also seen reports of grain silos in the area being destroyed; grain is an astonishingly powerful explosive.

throwaway0a5e 6y ago
Grain is a pretty poor explosive because the upper and lower explosive limits are so close (yes I know that's not traditionally a metric we use for solids), it needs an oxidier and the volume of byproduct for volume of input is relatively low. But large amounts of grain and oxygen are often found together in confined spaces so that makes it more explosive in practice than most things that people who work in offices and don't deal in bulk goods come into contact with.
- throwaway_pdp09 6y ago
  Can you elaborate what "upper and lower explosive limits" are, please. Also I don't understnd how it could be explosive at all, sudden oxidation of large (that is, low surface area to volume), non-dry particles seems unlikely. Flour etc. may be another matter, but a blast like this... flour?
  - throwaway0a5e 6y ago
    >upper and lower explosive limits concentration of the fuel in otherwise normal atmospheric air required to go whoosh (or bang, which is basically just a really fast woosh or one that's constrained by something). Too much fuel, too rich, no woosh. Too little fuel, too lean, no woosh. Lower and upper explosive limits are generally used to refer to gas mixtures though you can use them for solids but the units will be different. Solids we think of as explosive when not fishing around for virtue points on the internet generally contain their own oxygen supply so lower and upper explosive limit doesn't apply. >sudden oxidation of large (that is, low surface area to volume), non-dry particles seems unlikely. Flour etc. may be another matter, but a blast like this... flour? Yeah, no way that secondary explosion is flour or grain. I'd put my money on some sort of industrial chemical that contains its own oxidizer. Explosions that use atmospheric oxygen look different and rarely manage to be able to build up that kind of shock-wave if not constrained by something (like a building). There should be videos of natural gas explosions on YouTube that illustrate the difference.
  - TimSchumann 6y ago

malandrew 6y ago

I've seen one report that cites the Lebanese government that it was sodium nitrate seized from a ship that was temporarily stored there and was slated to be moved.