Vinyl Chloride Disaster: 2/19 Followup

Questions, clarifications and developments about the vinyl chloride spill and fire.

I might have been mistaken to say that my warning was unlikely to reach everyone that needed it. Over 1M views inside 24 hours. That was surprising, and I’m glad at least a few of you have might have heeded it. The disaster is continuing to unfold and progress, and I’m still following the developments as they occur on Twitter.

There have been a few notable criticisms and dismissals from various people of varying expertise. Myself, I’d be inclined to trust the scientist that’s spent her whole career studying vinyl chloride. I would love to have been wrong, but thus far it’s progressing pretty much as I expected, albeit a little more slowly - which is also par for the course at this point. I did make one mistake that needs to be corrected, but my warnings still stand.

Let’s get into it.

1. It was “only” 100,000 gallons of VC, not millions?

Information has been extremely limited and conflicting, as is usually the case with a disaster of this magnitude, that’s also being actively covered up by the powers that be. It was not just 100,000 gallons, but that number is not too far off, and lower than “up to 2.5 million.”

Five of the derailed cars contained vinyl chloride; a very recently filed lawsuit accused Norfolk Southern of (allegedly) spilling 1.1 million pounds of the chemical. Exact information is still difficult to come by, but seeing as lawsuits tend to have a pretty high standard, let’s go with that and do the math.

Vinyl chloride has a density of 911 kg/m³. 1.1 million pounds is exactly 500,000 kilograms: 500,000 / 911 = 548 cubic meters. One cubic meter is 264 gallons, so multiplying 548 cbm by 264 gal/cbm gives us 144,895 gallons. It seems unlikely that there was precisely 500,000 kilograms of it, so perhaps the lawyers are also just guesstimating.

That is a lot closer to 100K than 2M, though. The maximum capacity of the five DOT-111 rail cars is up to 150,000 gallons, combined, so it adds up. I overstated the amount of vinyl chloride that was released.

I’ll ascribe that to being somewhat rushed, and reviewing significantly conflicting sources of information, while trying to warn 250 million people of a rapidly proliferating, deadly chemical spill, and I apologize.

So, that might be some good news.

Is it?

Not really.

2. It’s being spread across the entire eastern seaboard, and the LD50 is only X. That’s only Y per square foot, which isn’t dangerous.

There’s two flawed assumptions here. One, that it will be evenly spread, and two, that the LD50 metric is even applicable to vinyl chloride.

LD50 is a measure of a given chemical or drug’s lethality. Specifically, it is the dose at which half the testing population is killed by it; Lethal Dose 50%. It’s usually a very important measure: that figure contributes to the calculation of the therapeutic window for any given drug. When a drug is said to have a narrow therapeutic window, it means that the difference between the therapeutic dose and the lethal or injurious dose is uncomfortably small, and a slight overdose may injure or kill.

LD50 is completely irrelevant in this case.

Vinyl chloride is not a drug. It is a toxic industrial chemical. Aside from its own direct, and not insignificant toxicity, the metabolite chloroethylene oxide attacks DNA. Specifically, it alkalizes our deoxyribonucleic acid, binding to the N7 position of guanine. The relatively small spill at Camp Lejeune poisoned over a million people: some had short-term effects, whilst the effects on others have taken years or decades to materialize. According to a highly specialized expert - and basic common sense, with a basic understanding of DNA - there is absolutely no safe dose for exposure. Once chloroethylene oxide and chloroacetaldehyde are produced in the liver, it goes straight to work attacking DNA. Many cancers, and conditions completely unrelated to cancer, can be caused by even a single mutated, damaged or missing base pair; a lot more than that will be damaged by even an infinitesimally small dose.