Thread by @LysanderBoomer

Based on my preliminary research, the derailed train of Vinyl Chloride is going to be something of a short term calamity with hopefully few long term effects. Apart from the cause of the derailment most everything else makes sense.

Vinyl Chloride is a highly flammable carcinogenic and monomer used to make plastic. It's really nasty stuff, bad for you down to at least 1 PPM, but you can only smell it starting at 10 PPM. It causes Cancer, liver issues, and is mutagenic in acute and chronic exposure.

The HazMat information I found earlier today indicates that evacuation of 1 mile is standard. The fire is not to be extinguished unless the leaks can be stopped. Due to the risk of BLEVE approaching the accident was very hazardous for several reasons, even geared up.

Apparently a decision was made to vent the tanks explosively. This is preferable to an uncontrolled BLEVE. The combustion products are bad, HCL and trace amounts of Phosgene but both of these will be eliminated in the environment quickly.

Vinyl Chloride is quite reactive and will begin to polymerize in open atmosphere. This is actually good because polymerized Vinyl Chloride is relatively harmless stuff, think PVC. The environmental damage should be short lived with a fast recovery.

They basically had to blow up those tanks, there was not a good way to deal with the fire and leaks under the threat of a BLEVE.

Anyway, agree or disagree, apart from the derailment, I don't believe there is any sort of conspiracy going on here. The reason for the derailment must be investigated to rule out foul play.

Good night, folks.

I should have defined it before I used it. The term BLEVE is an acronym for Boiling Liquid Expanding Vapor Explosion, and they're mega bad news. In this case it would have been equivalent to a boiler explosion if the boiler was full of toxic flammables.

In the worst case those tanks could have had a chain of BLEVEs with an ensuing VCE Vapor Cloud Explosion, akin to a fuel air bomb. I don't know how much damage there would have been but the potential was incredible for something of that magnitude.

Apart from the obvious typos, which I am sorry for there is one more thing to clear up. Its good for Vinyl Chloride to polymerize eventually but in the presence of heavy metal that can cause the formation of explosive polymers (literal plastic explosives) which are also ungood.

I did some research earlier today. I'll qt that stuff in here so others can follow up.

https://twitter.com/LysanderBoomer/status/1624851611372617728?t=yTOguV9cONVa38c6T7SsKw&s=19

PubChem entry for Vinyl Chloride

pubchem.ncbi.nlm.nih.gov/compound/Vinyl…

PubChem Hazardous Substance Data Base entry. This is some pretty hard reading. If you didn't already believe that Vinyl Chloride was some nasty stuff. pubchem.ncbi.nlm.nih.gov/source/hsdb/169

Snippets about the environmental fate of Vinyl Chloride from the above.

A bit more on the environmental fate ibid.

Looks like whatever made it into the ground will degrade eventually, half life of around 28 days has been reported for aerobic systems. In water between 28 and 110 days as it doesn't seem to photo degrade. By photo degradation the half life is 3.8 days or so.

It has been reported that there were other chemicals involved as well. Ethylhexyl Acrylate, Glycol monobutyl ether, isobutylene. I'll do a quick gloss on those too. Remember, I'm not a trained chemist or an expert, listen to local authorities about evacuations etc.

Ethyhexyl Acrylate was indicated as the more hazardous of the lot. The Toxicity section shows some toxicity for animals etc but less than Vinyl Chloride. pubchem.ncbi.nlm.nih.gov/compound/2-Eth…

ILO entry, the working limit is 5 ppm vs 1 for Vinyl Chloride. Not good but probably not worse either.
ilo.org/dyn/icsc/showc…

Environmental fate in air it is quickly degraded but in soil and water it looks like it may take a while. It is expected to hydrolyze but may bioaccumulate in acquatic organisms. Overall it's a mixed bag.

The "glycol monobutyl ether" from the reports may be this substance, it looks like it is mildly toxic with working limit of 5 ppm. pubchem.ncbi.nlm.nih.gov/compound/8133

Toxicity information snippet

The good news for this one is that it seems to degrade in the environment pretty quickly.

It should be noted that just because something degrades, that doesn't always make it less toxic, although in the literature they don't mention anything bad happening in this respect for the chemicals in question.

I'm not trained in this stuff so YMMV.

Isobutylene was the last compound in question. PubChem entry here. pubchem.ncbi.nlm.nih.gov/compound/8255

Toxicity data snippets. This one seems pretty tame, all things considered. 200000mg/kg for toxicity in a rat study. Not good but it isn't Vinyl Chloride either.

Seemingly released as part of daily life the environmental fate is pretty tame as well.

To try to summarize this mess. The release was bad, definitely going to affect the ground and water in the immediate area for a while. It is not Chernobyl and should remain very limited in the region affected. An initial dieoff beyond the immediate area should be the worst of it.

Beyond the first weeks the main threat would be contact via drinking water. I'm not trained in this so I won't make recommendations. Keep pressure on authorities to clean and remediate the spill site and make sure domestic water sources are tested at independent labs by the city.

I should clarify this. It does not photo degrade in water but it does in the air and soil. The last two sentences could be confusing without this context. If only the media covered this story properly with editors and the ability to write longer than 120 characters...

Bit more info. EPA has released manifest of train here with status. Mostly things I already covered but there is one addition. epaosc.org/sites/15933/fi…

It appears that there were two tank cars loaded with benzene that were damaged but not breached. Finally we have confirmation that there was benzene on the train. People kept saying it but never produced any documents.

PubChem for Benzene. pubchem.ncbi.nlm.nih.gov/compound/241

Toxicity snippets for Benzene.

Ecological fate. It is a component of gasoline and biodegrades in the ground over weeks. Half life in rivers and lakes between 3 hours and 3 days. In soil it vaporizes and the vapor degrades with a half-life of around 13 days. It is highly water soluable.

Reading closely you will notice that the containers of Benzene are stated to have been empty so it is very unlikely that any large quantity was present and has escaped into the environment.