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Comment by wlesieutre | Hacker News Reader

Headline doesn't provide any context, this is a chemical plant near Houston that makes organic peroxides. With 6 feet of flooding and loss of power it's probably going to blow up.

News outlets have more info: http://abcnews.go.com/US/risk-chemical-plant-explosion-houst...

Anyone in a 1.5 mile radius has been instructed to evacuate.

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I don't know a ton about chemistry so I did a bit of looking. The trouble with organic peroxides is that the oxygen bonds are unstable and decompose easily. There are compounding effects:

    1) The higher the temperature, the faster the decomposition
    2) Decomposition releases energy, driving the temperature up

There's a threshold called the "Self Accelerating Decomposition Temperature" at which point the released energy can't flow into the environment as fast as it's being produced, causing a runaway reaction. Didn't find specific temperatures, but they're cold enough to require refrigeration. Without power to run that, the stored peroxides will definitely become unstable and explode.

The facility in question on Google Maps - https://www.google.com/maps/place/Arkema+Inc./@29.9494556,-9...

Thankfully not much around it within 1.5 mi.

The blast zone of Hiroshima was less than 1.5 miles. What on earth were they storing there?

I don't think Hiroshima's blast zone includes a safety margin.

The article mentions the plant manufactures organic peroxides. I'm not sure how it would compare but, for example, the PEPCON disaster[1] (which involved ammonium perchlorate) caused severe damage within a 1.5 mile radius, with damage extending all the way out to 10 miles.

[1] https://en.wikipedia.org/wiki/PEPCON_disaster#Damage_assessm...

Ammonium perchlorate is a different beast. Organic peroxides are unstable as hell but as explosives their thermodynamics kind of suck. Their chemical reactivity also makes them difficult to store. TATP is popular with terrorists because it is easy to synthesize but sad material otherwise to an explosives engineer. Ammonium perchlorate, on the other hand, is right up near the top when it comes to explosive inorganic oxidizers, well-balanced and tons of potential energy. There are stronger inorganics (like hydrazine nitrate) but you never see that in industrial chemistry.

The only organic peroxide I can think of that was ever a legitimate high-power explosive was HMTD, used as a primary in strong detonators, and its chemistry was a bit like swapping peroxide for the nitro in RDX (the explosive used in C4 plastic explosives).

I don't think it's this specific peroxide, but TATP is "acetone peroxide". Supposedly pretty powerful as an explosive. Probably also lots of debris to fly around, nasty clouds of burning chemical laden smoke, plus some margin for safety.

Powerful oxidizers. The PEPCON disaster in 1988 was a different oxidizer, ammonium perchlorate: https://en.wikipedia.org/wiki/PEPCON_disaster

Derek Lowe has a good post on some very strong peroxides: http://blogs.sciencemag.org/pipeline/archives/2014/10/10/thi...

Of course quantity matters. But messing about with strong oxidizers is scary. The article doesn't say which organic peroxide it is, and that matters a lot too.

Edit: Given the list of products made at the site[1] (PVC, acrylic paints, etc) it might be MEKP[1]. That's quite a strong explosive.

[1] https://web.archive.org/web/20170830090410/http://www.arkema... [2] https://en.wikipedia.org/wiki/Methyl_ethyl_ketone_peroxide

Uf, ammonium perchlorate is literally rocket fuel, they use it in the SRBs and for a lot of amateur rocketry.

Yes, and TATP is a high explosive. MEKP is almost as powerful (5200m/s detonation velocity vs 5300m/s for TATP) but much more useful commercially. It's a precursor for all sorts of plastics.

It's not rocket fuel itself, it's an oxidizer. Storing it in aluminum bins as PEPCON did strikes me as quite risky, since aluminum powder with such an oxidizer would make a good solid rocket fuel or explosive. As a kid, friends and I used to make our own fireworks with ammonium nitrate fertilizer. These days if you buy much of that and aren't a farmer you'll likely get a visit from serious men in dark suits.

The Hiroshima bomb only weighed about 10,000lb.

I suspect this site has a LOT more material than that.

Nuclear bombs don't have a monopoly on large explosions - their claim to fame is how light the bomb can be, not how large the explosion.

>Nuclear bombs don't have a monopoly on large explosions

I get what you mean in relation to the Hiroshima bomb, but they do have a monopoly at some value of "large". All of the bombs exploded in WWII added up to about a 3 megaton TNT equivalent. There have been single thermonuclear weapons with roughly 10x that amount or more.

Apples to oranges. The radius you read about for a nuke is the distance within which most things were destroyed. The number in this article is the distance beyond which nothing is expected to be hurt.

Why was the word "exploding" muted in that video? Is that a normal thing?

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