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That Methyl Methacrylate Tank

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Re: That Methyl Methacrylate Tank

#71

Post by __david__ »

copypaper wrote: post #22

What a disaster and complete failure on the local government in the way they handled this situation. If we ever get hit by an earthquake or other larger disaster, it's safe to assume we're all on our own. Also, as someone affected by this, it has been extremely frustrating getting updates via xitter. Do we really have no other options?

> What a disaster and complete failure on the local government in the way they handled this situation.

Can you expand on that? It seems like there wasn't a lot they could do once the tank started leaking.

Re: That Methyl Methacrylate Tank

#72

Post by _whiteCaps_ »

decimalenough wrote: post #15
h335ian wrote: post #9

By the miraculous grace of God, a crack allowed pressure to bleed & enabled our engine company to prevent thermal runaway. A BLEVE was the projected outcome, a firefighters worst nightmare - see the Kingman BLEVE - https://www.cityofkingman.gov/government/departments-a-h/fir...

BLEVE = Boiling Liquid Expanding Vapor Explosion

https://www.youtube.com/watch?v=rGWmONHipVo

MythBusters have a good BLEVE episode. Apparently Adam Savage's favourite explosion.

Re: That Methyl Methacrylate Tank

#73

Post by tjohns »

MisterTea wrote: post #18
codazoda wrote: post #12

Earlier quoted context omitted.

A contractor showed me how to fix dents in granite with superglue. It’s totally clear. The trick is to scrape it with a razor blade at a 90 degree angle (strait horizontal). The imperfections become nearly invisible.

I've been told this is a cheap way to fix small windshield cracks. Never tried it but sounds like it would work for the small spider sized and shaped cracks from small rock impacts.

This is basically what the glass repair kits sold at auto parts stores are. (They also include a suction cup with syringe, to vacuum any air bubbles out.)

Re: That Methyl Methacrylate Tank

#74

Post by cyberax »

robocat wrote: post #30
dan_sbl wrote: post #8

Earlier quoted context omitted.

I believe they tried to inject some chemicals to slow the reaction, but the pump and/or valves failed and clogged.

That is active. Something passive could be submerging the tank in a pool of water (also good for proving spill containment won't leak).

Typically you don't have enough surface area for that. The walls are thick enough that thermal conductivity into an ambient-temperature liquid alone is not going to be sufficient.

Re: That Methyl Methacrylate Tank

#75

Post by xoxxala »

decimalenough wrote: post #15
h335ian wrote: post #9

By the miraculous grace of God, a crack allowed pressure to bleed & enabled our engine company to prevent thermal runaway. A BLEVE was the projected outcome, a firefighters worst nightmare - see the Kingman BLEVE - https://www.cityofkingman.gov/government/departments-a-h/fir...

BLEVE = Boiling Liquid Expanding Vapor Explosion

My parents are retired fire-fighters. They had an American pygmy goat named Bleve. Those goats commonly have very rotund stomachs[1] that look like they are about to explode.

[1] https://commons.wikimedia.org/wiki/Category:American_Pygmy_G...

Re: That Methyl Methacrylate Tank

#76

Post by DannyBee »

KennyBlanken wrote: post #14

> The immediate danger seems to abated, fortunately, The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades? Thousands of gallons of toxic chemicals don't just disappear.

MMA is not very toxic. It has the same LD50 as vitamin C. Table salt and baking soda are twice as toxic as MMA, for example.

Additionally it is almost certainly not in vapor form at 100 degrees. In sunlight it will also polymerize to a solid pretty quickly.

As such you'd practically have to drink it inside to hit the ld50.

The explosion would be much worse than a release of liquid or vapor based MMA during the day, and here it almost certainly solidified at this point

Re: That Methyl Methacrylate Tank

#77

Post by amluto »

gus_massa wrote: post #36
KennyBlanken wrote: post #14

> The immediate danger seems to abated, fortunately, The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades? Thousands of gallons of toxic chemicals don't just disappear.

It probably polymerized completely and it's a giant block of nasty looking solid plastic, that perhaps can be lifted with a crane (with some support, in case it has cracks or something). In some plastics the monomer is toxic, but the polymerized form is safe. (I think it was use for windshields for planes, so once polymerized it was probably safe to touch at least.) In this case it was an uncontrolled reaction so I'm…

> In some plastics the monomer is toxic, but the polymerized form is safe.

This is common. Isocyanates are a common example — isocyanate monomers are nasty, and the very light ones are very nasty. They’re used to make polyurethane, polyurea and such, which are quite nontoxic in polymerized form.

In applications where the unreacted isocyanates are used by anyone other than professionals (e.g. two component varnishes), the manufacturer may go out of their way to use more expensive but less toxic variants.

Re: That Methyl Methacrylate Tank

#78

Post by amluto »

DannyBee wrote: post #76
KennyBlanken wrote: post #14

> The immediate danger seems to abated, fortunately, The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades? Thousands of gallons of toxic chemicals don't just disappear.

MMA is not very toxic. It has the same LD50 as vitamin C. Table salt and baking soda are twice as toxic as MMA, for example. Additionally it is almost certainly not in vapor form at 100 degrees. In sunlight it will also polymerize to a solid pretty quickly. As such you'd practically have to drink it inside to hit the ld50. The explosion would be much worse than a release of liquid or vapor based MMA during the day, a…

MMA can apparently cause some issues that are more subtle than death. I would MUCH rather eat 1g of vitamin C than 1g of MMA.

Also, vitamin C is not volatile, so there is no risk of inhaling it as a gas.

Re: That Methyl Methacrylate Tank

#79

Post by compass_copium »

gus_massa wrote: post #36
KennyBlanken wrote: post #14

> The immediate danger seems to abated, fortunately, The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades? Thousands of gallons of toxic chemicals don't just disappear.

It probably polymerized completely and it's a giant block of nasty looking solid plastic, that perhaps can be lifted with a crane (with some support, in case it has cracks or something). In some plastics the monomer is toxic, but the polymerized form is safe. (I think it was use for windshields for planes, so once polymerized it was probably safe to touch at least.) In this case it was an uncontrolled reaction so I'm…

Correct, PMMA is completely harmless. MMA is an incredibly common adhesive, and is in probably a dozen things in the room you are sitting in in its polymerized form.

Re: That Methyl Methacrylate Tank

#80

Post by __david__ »

KennyBlanken wrote: post #14

> The immediate danger seems to abated, fortunately, The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades? Thousands of gallons of toxic chemicals don't just disappear.

On the plus side, it's a chemical that was discovered more than a century ago so scientists have accumulated a lot of knowledge about it. So far no studies were able to link it to cancer. It also doesn't significantly build up in the body over time (like heavy metals do). It's 3x heavier than air so it shouldn't spread too far away. The main issue is they want to try to keep it from getting into storm drains or into the ground water.

I've heard from others that it's readily absorbed by water. That's bad in the ground water case, but it seems it might be a positive when trying to clean up a (contained) spill.

It appears to me to have a relatively high lethal dosage (my back of the napkin calculations are saying a 200 pound human would have to orally ingest almost a liter of it to reach the LD50 dosage--but again don't quote me on that number because I am not an expert and could have very easily messed up the math or the concept of a lethal dose).

So, while I agree there might be unknown long term issues, it does appear to be a relatively low probability of that since it seems to be on the less pernicious side.

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