What is the most dangerous chemical that you know about

[Slam_Jones]

Stap with the water we get it kills so does everything ever try naming something that doesn't kill?

Anything can kill if you have enough of it

[wx7]

Oxygen.

It's what keeps mankind alive.

Philosophical, isn't it?

[KSACheese]

Carbon Dioxide. It causes the greenhouse effect, which envelops all of Venus (possibly ruining a past-perfect world), and is a cause of The Great Dying, in which roughly 90% of marine organisms and around 70% of all terrestrial organisms.

I don't really know, to be honest, I'm not big on chemistry.

[KerikBalm]

Has to be Hydrogen Dioxide. 100% of people who come in contact with it eventually die.

... I'll show myself out now

Please do, you didn't even get the name right (unless that was part of the joke?) what you described is HO2 not H2O

Anyway, as far as the LD-50, extremely pure water still has a really high LD-50... sure... too much pure water can upset your salt balance.. but... yea, you can drink a several liters and be fine.

There are things with orders of magnitude upon orders of magnitudes lower LD-50s...

But how to compare that with extremely reactive chemicals....

Even N2 can be a dangerous asphyxiant if it is purified and stored in a small place.

The lab here was recently evacuated because of an ammonia leak from some coolant system... there's so much stuff that isn't good for you...

[magnemoe]

My parents once used an industrial cleaning solvent before painting the walls of the house, I was reading the warnings. Yes it was dangerous to health, that was no surprise.

Will damage glass and aluminium made me do an fast trip to an friend 5 km upwind

[Ethanadams]

everything in cigarettes

[WestAir]

Gasoline.

It lets the ego-blimp in the Ford F-150 next to me plow down the freeway at 90 mph with no regard to the harsh realities of Fnet=m(a).

[Nothalogh]

Pentaborane is my personal favorite; it features extreme acute toxicity (on par with some nerve agents) with delayed symptom onset, is highly flammable (and usually pyrophoric due to residual impurities), and it reacts with chlorinated hydrocarbon solvents (among many other things) to form poorly-characterized shock-sensitive explosives.

It was briefly considered (along with diborane and several alkylated boranes) as a rocket and jet engine fuel.

Source: "The Green Flame: Surviving Government Secrecy" by Andrew Dequasie. American Chemical Society, December 1991. ISBN13: 978-0841218574

Gotta love boron zip fuels

[GreenWolf]

There's a few that make the list. Just about any fluorine compound that's not a salt. Anything with large numbers of nitrogen bonds. The pure forms of alkali metals and halogen gases.

However, the most dangerous chemical that I, personally, have worked with is probably HF (hydrofluoric acid).

[SSR Kermit]

Didn't see it mentioned, but ethylphosphinate is probably one of the worst chemicals created ever created by man. Also known as VX nerve agent; unlike most other compounds mentioned, it has no use other than as a weapon of mass destruction.

[GDJ]

The most toxic stuff I've had to personally deal with:

Condensate (crude oil additive)

Benzene

Hydrazine

Hydrogen Peroxide (90% concentration)

Ammonia

Lithium

Caesium (accidental low level exposure. I'm fine, so no worries okay?)

Edited October 6, 2015 by GDJ

[Layereddiagram]

Amatoxin.

Its not as acutely toxic as some things listed here, but it is still pretty toxic.

Pair that with its delayed effects that don't even start to appear for several hours and by the time they do, your DNA is already irreversibly damaged.

[peadar1987]

Worst stuff I've had to deal with?

Spent nuclear fuel rods. Screamingly radioactive, acutely and chronically toxic (not that that even matters!), and very, very hot to boot.

Luckily they were inside a spent fuel flask, and I was decontaminating the outside of it for transport. I've also seen them merrily giving off Cherenkov radiation at the bottom of a spent fuel pond. I wouldn't fancy being much closer than that!

[sgt_flyer]

well - randall wrote a what-if once about spent nuclear fuel pools

https://what-if.xkcd.com/29/

So, even swimming on the surface of this kind of pool would be quite safe (at least from the radiations - from the security teams, that would be another story )

[cantab]

Cherenkov Radiation, incidentally, is freaking awesome. It's basically a sonic boom for light.

[PB666]

well - randall wrote a what-if once about spent nuclear fuel pools

https://what-if.xkcd.com/29/

So, even swimming on the surface of this kind of pool would be quite safe (at least from the radiations - from the security teams, that would be another story )

Well its almost i possible to keep the fissile products out of the water so if you coinicidentally gulped the water you could get a nasty amount of Sr. I would be willing to bet the water is saturated with strontium carbonate, unless they dose the water with CaOH2. Which would drive dissolved divalent cations to the metal and walls of the unit.

[NuclearNut]

Well its almost i possible to keep the fissile products out of the water so if you coinicidentally gulped the water you could get a nasty amount of Sr. I would be willing to bet the water is saturated with strontium carbonate, unless they dose the water with CaOH2. Which would drive dissolved divalent cations to the metal and walls of the unit.

NOTE:Spellcheck is your best friend.

Anyway, begone grammar pedantry, welcome engineering pedantry. I would like to have some data regarding that if you have any. From what I understand fuel rods are designed to minimize leakage (including xenon, but that is due to other reasons) due to corrosion reasons in the reactor core itself, which is quite a bit hotter and has a faster water flow rate than the coolant pools. Considering the pools are open air that would, presumably, result in quite a bit of radioactive material in the air where the people are, which needless to say would not be a good thing. Thus I believe they chemically process the water, just like the coolant water inside the core itself.

Please, correct me if I am wrong.

----EDIT-9:42-10/7/2015----

Cherenkov Radiation, incidentally, is freaking awesome. It's basically a sonic boom for light.

Seconded. Cherenkov radiation is absolutely awesome, and beautiful to look at, especially how it fades off into oblivion from it's soft blue color.

Edited October 8, 2015 by NuclearNut
Added

[PB666]

NOTE:Spellcheck is your best friend.

Anyway, begone grammar pedantry, welcome engineering pedantry. I would like to have some data regarding that if you have any. From what I understand fuel rods are designed to minimize leakage (including xenon, but that is due to other reasons) due to corrosion reasons in the reactor core itself, which is quite a bit hotter and has a faster water flow rate than the coolant pools. Considering the pools are open air that would, presumably, result in quite a bit of radioactive material in the air where the people are, which needless to say would not be a good thing. Thus I believe they chemically process the water, just like the coolant water inside the

Well im sitting on the sofa with Assembly language Step by Step, The C programming Language and an Ipad with no spell checker. If reading a whole book about C does not ruin your English syntax then you are truely multilingual. lol. I just saw the same code written in hexadex and C, remarkably the hexadecimal code was easier to understand, ;^). The problem with I pad is that when you move your fingers rapidly close to target letters, even without contact they add characters.

Ok, but the divalents should not be able to evaporate off a still pond surface, There is extensive chelation between the oxygen of adjacent water molecules and the outer electron shells increasing the effective molecular weight. The only real way to make them accumulate is to add a monvalent acid like hydrochloric. In the basic form with CO2 present they will be pretty much in a powdery film at the bottom of the pond. According to the folks that studied radiation in farmers around chernobyl, the true and significant danger came from burning chaff, the radioactivity was not bad, but chaff contains associated dirt from roots and that contained strontium isotopes that was only volatlie in the context of a highly convective fire, and breathing was the way in. So its not actually easy to get strontium isotope into the body, its not easy to build up a concentration at higher pHs but if somene were to go suitless diving to the bottom and started taking in water they could get dosed with isotope. If they did that repeatedly I suspect they might start to see bone specific radioactivity. So the little graphic showing the danger dose zone, but the rods could be on one side and the diver could be handing off the bottom and stirring up radioactive carbonates on the other side, simply because thats where the carbonates settle.

Whether or not strontium leaches out from the pellets depends on the coating, but i would suspect that fission results in decreased density of the products, so that there would be a tendency for the pellets to expand and present fissures. This does not also mean they will leak, but near boiling water at high pressure is rather corrosive itself over long periods.

Edited October 8, 2015 by PB666

[peadar1987]

The fuel elements do indeed leak. It's not unknown for newer ones to bubble Xenon at a visible rate.

If this was allowed to build up in the ponds, the radiation dose would be very nasty. However, the water is completely cycled every, if I remember correctly, every 24 hours through a huge bunch of filters, and there is a brisk breeze from the air purification system as well. The actual dose from air or water is very low. As Randall says in his article, divers can, and do, swim in the ponds for maintenance (the boric acid gives them a lovely blue/green colour, and the fuel elements keep them toasty warm, I'm told it's actually quite pleasant!)

Now the filters that the water is run through? Those things are really unpleasant. They're filled with a concentrated, foul-smelling, toxic, insanely radioactive sludge. I'm not sure which I like least about that stuff, the radiation poisoning, or the smell!

[PB666]

The fuel elements do indeed leak. It's not unknown for newer ones to bubble Xenon at a visible rate.

If this was allowed to build up in the ponds, the radiation dose would be very nasty. However, the water is completely cycled every, if I remember correctly, every 24 hours through a huge bunch of filters, and there is a brisk breeze from the air purification system as well. The actual dose from air or water is very low. As Randall says in his article, divers can, and do, swim in the ponds for maintenance (the boric acid gives them a lovely blue/green colour, and the fuel elements keep them toasty warm, I'm told it's actually quite pleasant!)

Now the filters that the water is run through? Those things are really unpleasant. They're filled with a concentrated, foul-smelling, toxic, insanely radioactive sludge. I'm not sure which I like least about that stuff, the radiation poisoning, or the smell!

The boric acid is to absorb neutrons, the sulfides come from the redution of sulfates, though, the source of which is not apparent, the radioactivity should create reducing conditions in the pond due to heat and conversion from more stable metals to fast oxidizable metals. If you want to keep the smell down the boric acid is a problem so they would need to add a base. Sulfide has a pka in the eightish range so you kind of want the pH around 9 or so. A base above 9.5 would constantly absorb CO2 from the surrounding air and raise carbonate concentation, basic sulfides are attraced to metals like iron and will preciptiate. Once the filters are pulled into the air the higher pCO2 will cause them to start smelling.

Having thought about the metallic strontium, even with one outer shell electron would not be a good thing. Since hypochlorite or hydrogen peroxide would not neccesarily be stable or a good thing, sulfate is a stable situational oxidant that could be added to prevent reduced strontium from producing H2 gas, therefore its probably added to prevent this from happening.

Edited October 8, 2015 by PB666

[lajoswinkler]

The most toxic stuff I've had to personally deal with:

Condensate (crude oil additive)

Benzene

Hydrazine

Hydrogen Peroxide (90% concentration)

Ammonia

Lithium

Caesium (accidental low level exposure. I'm fine, so no worries okay?)

Crude oil additive - yuck.

Benzene - silent killer, avoid it as much as you can.

Hydrazine - no, thanks.

90% hydrogen peroxide - not exactly poisonous as it will turn you into smoldering goo first.

Ammonia - it's difficult to poison yourself with it.

Lithium - not poisonous. Just corrosive and harmful.

Caesium - same as lithium, only way more corrosive and reactive.

well - randall wrote a what-if once about spent nuclear fuel pools

https://what-if.xkcd.com/29/

So, even swimming on the surface of this kind of pool would be quite safe (at least from the radiations - from the security teams, that would be another story )

Yeah, that last claim of his was so stupid. It would not happen for several reasons.

[peadar1987]

Yeah, that last claim of his was so stupid. It would not happen for several reasons.

My last claim?

[sgt_flyer]

I think he meant about what randall wrote in his what if article that if you wanted to try to get inside the pool for a swim you'll die long before reaching it - from severe lead poisoning gunshot wounds - though, it was still a fun comment (guess randall's way of mixing a bit of humor with facts is what made these series so appreciated )

Guess that'll depend in which country you try something like that, but you'll still be intercepted (and most likely a bit roughed up by the security teams - unless you try to continue at all costs) long before entering any critical buildings, before being put into police custody. (Not taking into account the various security doors etc in your way - with keycards, guardposts controlling an airlock etc)

Edited October 8, 2015 by sgt_flyer

[lajoswinkler]

Yeah I meant what Randall said about them firing at someone going for a swim/dive the pool. Not only it can cause a serious radiological disaster (regular bullets can't reach the rods, though, so it's useless) if it hits a critical piece of equipment, but also a human being can't possibly damage the rods. The assemblies have at least 100 kg and are made out of zirconium which is not something one can tamper with easily. What would a man do? Try to lift them as he's holding his breath, bathing in such doses that they will actually kill him in few minutes? Yeah, right.

It would be a murder and a totally unnecessary one.

[peadar1987]

I think he meant about what randall wrote in his what if article that if you wanted to try to get inside the pool for a swim you'll die long before reaching it - from severe lead poisoning gunshot wounds - though, it was still a fun comment (guess randall's way of mixing a bit of humor with facts is what made these series so appreciated )

Guess that'll depend in which country you try something like that, but you'll still be intercepted (and most likely a bit roughed up by the security teams - unless you try to continue at all costs) long before entering any critical buildings, before being put into police custody. (Not taking into account the various security doors etc in your way - with keycards, guardposts controlling an airlock etc)

Depends how persistent you were, I suppose. I'm not really allowed to discuss security at the plant I worked in, but there is a double barbed wire fence before you even get into the licensed site, patrolled by armed guards with dogs, that's the bit everyone can see. Several layers of security inside the plant as well. A friend of mine had armed security down on him within a minute after he accidentally opened a door he wasn't supposed to. Another friend had been offered a job, and drove out to have a look at the plant the week before he was due to start. An unknown car in the carpark, among hundreds of others, was enough to get an SMG pointed at him.

They are extremely security conscious. We were specifically told that, in the event of a terrorist attack on the plant, stopping the terrorists would be considered a higher priority than avoiding civilian casualties. The guards' orders were to shoot through plant workers if necessary.