What is the most dangerous chemical that you know about

[clivman]

Unsymmetrical Dimethyl Hydrazine and Dinitrogen Tetroxide, this was used by the US as well in the Titan rockets

Wasn't it in The Martian as well?

[Nothalogh]

Wasn't it in The Martian as well?

http://static5.businessinsider.com/image/5575b2af6bb3f7b822e1f014/oxygen-explosion-martian.gif

He only called it Hydrazine in the book, and said it was used with a catalyst, not with a reactant

[cantab]

Sarin doesn't count becuase it's not toxic to things that don't have nerves. It won't kill a single-celled organism.

While it was never explicitly stated, I interpret "most dangerous" as meaning dangerous to people.

Sarin still doesn't count to me though. The Tokyo subway attackers carried it around with plastic bags, poked holes in them, and walked away. Sarin's certainly highly lethal, but I feel a real "most dangerous" candidate would have leaked through the plastic, blown up when poked, or otherwise found a way to kill the terrorists who carried it around.

[Ethanadams]

Colbalt

ever hear of a dirty bomb? Colbalt would be one of the top contenders

[kerbiloid]

The most toxic and dangerous are dioxins.

The most deadly is water. Every year it kills many thousands of people. There is no another such deadly substance.

Doesn't count, because you'll die if you DON'T drink it, too.

Seriously, WATER DOES NOT BELONG IN THIS THREAD. STAHP.

You see! Water kills not only by presence, but even with absence! Absolute evil.

[RainDreamer]

Whatever that created the kerbals.

[sgt_flyer]

Whatever that created the kerbals.

Welll - here's a breakdown of the composition of what created the kerbals

https://en.m.wikipedia.org/wiki/Composition_of_the_human_body

And indeed, the full complete thing proved that it can be quite deadly. But i doubt it can be simpky considered as a 'dangerous chemical'

[MalfunctionM1Ke]

Dimethylmercury is extremely toxic and dangerous to handle. Absorption of doses as low as 0.1 mL can result in severe mercury poisoning.

The toxicity of dimethylmercury was highlighted with the death of the inorganic chemist Karen Wetterhahn of Dartmouth College in 1997, 10 months after spilling no more than a few drops of this compound on her latex-gloved hand; the barrier was immediately compromised and within a few seconds it was absorbed into the back of her hand, quickly circulating and resulting in her later death (+10 months)

https://en.wikipedia.org/wiki/Dimethylmercury

Common symptoms of mercury poisoning include peripheral neuropathy, presenting as paresthesia or itching, burning, pain, or even a sensation that resembles small insects crawling on or under the skin (formication); skin discoloration (pink cheeks, fingertips and toes); swelling; and desquamation (shedding or peeling of skin).

Edited October 5, 2015 by MalfunctionM1Ke

[p1t1o]

Dimethylmercury is extremely toxic and dangerous to handle. Absorption of doses as low as 0.1 mL can result in severe mercury poisoning.

The toxicity of dimethylmercury was highlighted with the death of the inorganic chemist Karen Wetterhahn of Dartmouth College in 1997, 10 months after spilling no more than a few drops of this compound on her latex-gloved hand; the barrier was immediately compromised and within a few seconds it was absorbed into the back of her hand, quickly circulating and resulting in her later death (+10 months)

https://en.wikipedia.org/wiki/Dimethylmercury

Common symptoms of mercury poisoning include peripheral neuropathy, presenting as paresthesia or itching, burning, pain, or even a sensation that resembles small insects crawling on or under the skin (formication); skin discoloration (pink cheeks, fingertips and toes); swelling; and desquamation (shedding or peeling of skin).

I work in safety documentation in the chemical industry, when it comes to recommending gloves for particular materials we hae some simple guidelines to help us make a selection - one of which is never choose latex because it hardly stops anything. You sometimes see them in biological labs as microorganisms are too large to penetrate and that kind of science uses a lot of water-based solutions, but even then, they are quite easy to puncture/tear...

The most common type of glove you find in a given laboratory are made of nitrile rubber and would probably have saved her life.

Most dangerous chemicals i have come across in my job are actually the toxins you get in bad/tainted shellfish...

[lajoswinkler]

Absorption of doses as low as 0.1 mL can result in severe mercury poisoning.

This severely underestimates the toxicity of it and it's a dangerous myth. She might've spilled that amount (drops IIRC), but the amount that leaked through the latex glove and went inside the skin and then killed her after a long time are probably nanolitres or less. She probably didn't even feel there's something wet inside the glove as it was microscopic. Dimethylmercury has almost 100% absorption rate in organisms. The reason why it's so difficult to poison yourself with metallic mercury (unless you're really being stupid with it, or living in a place where you have chronic exposure to fumes) is because its absorption rates are very, very tiny. Very little clings to you, and most of that will get purged out fast.

Ions of mercury are way worse, but organomercury compounds, especially dimethylmercury, chemically cling to your body like white on rice. Almost 100% absorption, almost 100% retention, therefore almost 0% excretion.

It's so incredibly poisonous that even a whiff of it in the air, so that you could feel the smell of it, is lethal. Granted, it takes months to kill you and it's perfectly safe in a sealed ampoule.

[cantab]

Exposure is barely noticeable, and it's one of a number of poisons that by the time you show symptoms it's too late to treat. Nasty, nasty stuff.

[Ethanadams]

Anything in big enough quantity

[Woksaus]

Containers for chemicals are usually labeled with an chemicals hazards identification system. There are several of these, including the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and the NPFA-704 system (also known as the fire diamond). For the GHS system, the more labels a chemical container has, the more dangerous the chemical that is within.

The NFPA uses a different classification system. Their label is composed of four diamonds: a blue one (health hazards), a red one (flammability), a yellow one (chemical reactivity) and a white one (oxidizer / reacts with water / asphyxiant). For a chemical, each diamond has a certain number in (ranging from 0 to 4), indicating how dangerous it is. For example, BLUE 0 poses no health risks, while BLUE 4 can cause death after a very short exposure time. From this logic, we can assume that the most dangerous chemical would have a 4/4/4 W Ox classification:

The chemical with the closest rating I can find is tert-butylhydroperoxide, but the problem with this classification system is that it's generally only used for commercially available chemicals. So if you want to go for the really nasty stuff, a lot of the above options are pretty high up there.

As a chemist, compounds containing fluorine make me nervous, especially fluorinating agents.

[Ethanadams]

White phosphorus is nasty it burns really hot its smoke is toxic and it's nearly impossible to smother phosphorus that's on fire

[Gaarst]

Botulinum Toxin (known as Botox) is pretty bad also, with a LD50 of 1-2 ng/kg. Most lethal toxin known according to Wikipedia.

[Ethanadams]

Botox the thing that freezes your muscles and make you look fake I'm mean younger?

[Ignath]

Botox the thing that freezes your muscles and make you look fake I'm mean younger?

Yep, that one.

https://en.wikipedia.org/wiki/Botulinum_toxin

From the Wikipedia article:

"Botulinum toxin type A and B is used in medicine for, among others, upper motor neuron syndrome, focal hyperhidrosis, blepharospasm, strabismus, chronic migraine and bruxism. It is also widely used in cosmetic treatments. The U.S. Food and Drug Administration requires a boxed warning stating that when locally administered the toxin may spread from the injection site to other areas of the body, causing symptoms similar to those of botulism. The warning was the result of deaths associated with its uses.[4][5] The commercial form is marketed under the brand name Botox, among others."

[malte]

There is a whole bunch of really nasty chemicals, but the most toxic propellant I work with is hydrazine

[Fail-Man 3D]

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

Edited October 5, 2015 by Fail-Man 3D
Fix touchscreen typo

[PB666]

I figure I would tag this on to this thread, since water is considered highly dangerous to some people, I supposed if you consider water

:Frozen and shot as a bullet

:In a storm surge of a hurricane (not factoring that it was the wind that blew the storm surge)

:In a tsunamic (not factoring that it was a subduction fault rupture that caused the tsunami, or a major volcanic event - like Mt. Santorini explosion)

:In a swimming pool for some one who doen't know how to swim

We can also say air is deadly

:Such as during a volcanic eruption

:As the blast wave front in a bombing

:As when you fall through it and go splat because you don't have a parachute (despite the fact that vacuum is more deadly

:As when you breath to much of it, as in nitrogen embolism or Oxygen toxicity.

Of course going by that logic we can also say a vacuum is more deadly than oxygen or water.

:High vacuum kills within seconds.

:Falling through a vacuum has not terminal velocity.

:blastwaves propogate further and maintain deadly contact velocities over greater distances.

So now that we have gotten rid of this foolishness. Reductio ad absurbum style - less so a violation of common sense than in most cases.

So if we look at risks and dangers and we see that there are many interconnected risk. Education is by far the best deterrent to risk of any origin (for example the most educated people tend to have the least problem with sugar diabetes). In risk management there is a word called situational awareness, for example if you are working around a cobalt irradiator, its a good idea to know that it can be lethal, and it is best to take note any unusual behavior. If you have a beach house in a typhoon zone, its best to check the weather report more often and follow the guidance carefully. If you live in a war zone then have a complex risk aversion strategy that may involve kin-selection. Education also helps discern killers by there nature (a hand grenade, etc) from things that are lethal only in rare situations (like water, that beam above your head in your house, or an incoming asteroid). For example if you asked an extremely educated person what chemical statistically is most likely to kill you as a result of all it direct and indirect affects (due to overconsumption, for example) that substance would be dextrose. IOW through a process of statistically mediated risk aversion we can see in a process of exclusion; which things will increase or decrease life expectancy with exposure above an optimum - multiplied by its likelihood of exposure. Botox is not a likely risk, but cigarettes are given there is a risk of physical addiction, sugar is also a risk, etc.

[Pixel of Life]

The most hazardous material I have personally worked with is nitromethane (CH3NO2). The kind of stuff used with model planes, cars etc. that have internal combustion engines.

[Slam_Jones]

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

... I'll show myself out now

[Ethanadams]

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

- - - Updated - - -

Also anything is the poisoners corridor on the periodic table

[lajoswinkler]

White phosphorus is nasty it burns really hot its smoke is toxic and it's nearly impossible to smother phosphorus that's on fire

It's pretty easy. Cover it with moist sand. It cools the melt and prevents oxygen to reach it.

[TheMoonRover]

Any anti particle will react with an regular particle. It does NOT matter what element it is!

Fair point.

Although having exactly identical/opposite structures has got to help if you're trying to destroy everything.

At a fundamental level particles would only annihilate with their corresponding antiparticles, for example an up quark and a positron (anti-electron) would not annihilate. But for atoms you are correct.