2 ms·

The acid is not the real issue. The question is how much dioxin was created, where does it end up, how much are/were people/animals exposed short term and how m

The acid is not the real issue. The question is how much dioxin was created, where does it end up, how much are/were people/animals exposed short term and how much in the long run - it accumulates in the food chain.

gruez 4y ago
> The question is how much dioxin was created Does it even generate dioxins? Somebody mentioned in a previous thread that dioxins are only produced when burning PVC (the polymer), not vinyl chloride (the precursor chemical).
- mindslight 4y ago
  In one of these threads I saw a spreadsheet of the derailed cars, and there are a bunch with dry bulk materials. These were the source of the fire that was/is burning [0], and included a few listed as containing "POLYVINYL". I couldn't really figure out what that was, whether it was PVC pellets or a different polymer or what. There was an article posted last night [1] (now flagged) talking about dioxins. It showed a picture of 2,3,7,8-TCDD [2], with two benzene rings, and talking about its longevity due to those. I've only got a rudimentary knowledge of ochem, but my first thought was wondering where those benzene rings would come from in the burning of vinyl chloride. My conclusion was that the article was conflating different types of dioxins as a single thing - if dioxins are being created by the burning of the vinyl chloride, it's likely the simpler 1,4-Dioxin [3] which according to Wikipedia "is very unstable" so probably will not last long. This is all guessing on my part, but it still feels more in depth than most of the reporting/discussion has been trying to independently analyze. [0] Which necessitated doing something about the adjacent tanks full of vinyl chloride, which are seemingly under some pressure (PRV @ 225psi) but mostly rely on keeping a lower temperature over the course of their journey (at least that's what I gathered from reading the spec sheet of a DOT-105 tank car meant for transporting vinyl chloride) [1] https://news.ycombinator.com/item?id=34800306 https://news.ycombinator.com/item?id=34800306 [2] https://en.wikipedia.org/wiki/2,3,7,8-Tetrachlorodibenzodioxin https://en.wikipedia.org/wiki/2,3,7,8-Tetrachlorodibenzodiox... [3] https://en.wikipedia.org/wiki/1,4-Dioxin https://en.wikipedia.org/wiki/1,4-Dioxin
- downvotetruth 4y ago
  https://en.wikiversity.org/wiki/WikiJournal_of_Medicine/Dioxins_and_dioxin-like_compounds:_toxicity_in_humans_and_animals,_sources,_and_behaviour_in_the_environment#Sources https://en.wikiversity.org/wiki/WikiJournal_of_Medicine/Diox... question is where the ash ended up: https://imgur.com/gallery/g83UxXI https://imgur.com/gallery/g83UxXI & given the westerly direction of the wind on the 4th - 6th most likely in the Appalachians or the Atlantic. Also, Butyl Acrylate killed the fish.

gruez 4y ago

> The question is how much dioxin was created Does it even generate dioxins? Somebody mentioned in a previous thread that dioxins are only produced when burning PVC (the polymer), not vinyl chloride (the precursor chemical).

mindslight 4y ago
In one of these threads I saw a spreadsheet of the derailed cars, and there are a bunch with dry bulk materials. These were the source of the fire that was/is burning [0], and included a few listed as containing "POLYVINYL". I couldn't really figure out what that was, whether it was PVC pellets or a different polymer or what. There was an article posted last night [1] (now flagged) talking about dioxins. It showed a picture of 2,3,7,8-TCDD [2], with two benzene rings, and talking about its longevity due to those. I've only got a rudimentary knowledge of ochem, but my first thought was wondering where those benzene rings would come from in the burning of vinyl chloride. My conclusion was that the article was conflating different types of dioxins as a single thing - if dioxins are being created by the burning of the vinyl chloride, it's likely the simpler 1,4-Dioxin [3] which according to Wikipedia "is very unstable" so probably will not last long. This is all guessing on my part, but it still feels more in depth than most of the reporting/discussion has been trying to independently analyze. [0] Which necessitated doing something about the adjacent tanks full of vinyl chloride, which are seemingly under some pressure (PRV @ 225psi) but mostly rely on keeping a lower temperature over the course of their journey (at least that's what I gathered from reading the spec sheet of a DOT-105 tank car meant for transporting vinyl chloride) [1] https://news.ycombinator.com/item?id=34800306 https://news.ycombinator.com/item?id=34800306 [2] https://en.wikipedia.org/wiki/2,3,7,8-Tetrachlorodibenzodioxin https://en.wikipedia.org/wiki/2,3,7,8-Tetrachlorodibenzodiox... [3] https://en.wikipedia.org/wiki/1,4-Dioxin https://en.wikipedia.org/wiki/1,4-Dioxin
downvotetruth 4y ago
https://en.wikiversity.org/wiki/WikiJournal_of_Medicine/Dioxins_and_dioxin-like_compounds:_toxicity_in_humans_and_animals,_sources,_and_behaviour_in_the_environment#Sources https://en.wikiversity.org/wiki/WikiJournal_of_Medicine/Diox... question is where the ash ended up: https://imgur.com/gallery/g83UxXI https://imgur.com/gallery/g83UxXI & given the westerly direction of the wind on the 4th - 6th most likely in the Appalachians or the Atlantic. Also, Butyl Acrylate killed the fish.