In a secret bunker on the German-Polish border

Nazi agents were overseeing the production of a recently discovered chemical

they'd code-named "Substance N"

It boiled when they exposed it to air,

It exploded when it touched water, it was lethal when inhaled,

and when it decomposed it spit out deadly hydrofluoric acid.

When loaded into a flamethrower and ignited it could burn at

temperatures over 2400°C

The plan was to arm troops with "Substance N"

and use it to melt allied bunkers into hot porridge

But then after studying it for a while even the German soldiers were like

"Whoa." experiments with "Substance N" were discontinued because

the Nazis decided it was to dangerous to work with.

Should give you some kind of sense of what we're dealing with

here when we talk about the most dangerous chemicals in the world.

I'm talking about things that explode when you touch them,

things so poisonous that if even a millionth of a gram went up your nose, it would end up killing you

things that could even disable you because of their totally, debilitatingly, horrifying smell,

and yes, chemicals so severe, that even the Nazis thought they were crazy.

Let's start with what the Germans had in that secret weapons bunker

They originally planned to produce 90 tons of the stuff every month

but only made about 30 tons throughout the whole war

what they'd concocted was chlorine trifluoride,

the most vigorous fluorinating agent known to humanity

fluorinating agents rip other molecules apart to replace their hydrogen atoms with fluorine

the result is what chemists called a 'violently exothermic reaction',

in this case known as a fluorine fire

it's much more dangerous to handle than even fluorine gas,

which as anyone with a degree in chemistry could tell you

is not a sentence that you get to say very often

it's also a better oxidizer than oxygen

oxidizers are compounds that steal electrons from other chemicals in a reaction

and they are what make combustion possible.

chlorine trifluoride is so good at this, that it can burn stuff that sane people might think of as non flammable, like

bricks or asbestos or things that have already been burned

oxidizers are also used to ignite rocket fuel and in

the very short time that us rocket scientists thought about using this stuff as a propellant,

they quickly learned that this idea was bad

and the early 1950s, the first time that US scientists tried to ship chlorine trifluoride in bulk

the steel tank cracked and a full ton of it spilled out

it burned so hot that the chemical ate through an entire concrete floor

and then a meter of dirt and gravel beneath that

One eye-witness described the spill only by saying

"The concrete...was on fire!"

Chlorine trifluoride is still manufactured and is used by semi-conductor companies to clean their equipment

to within an inch of its life.

The good news is that you can store it safely in a regular steel drum

as long as it's air-tight and you're really, really careful,

because, it instantly scorches the inside lining of the container

leaving behind a nonreactive plating of metallic fluoride.

Nonreactive is not a word that we're gonna need when discussing the next chemical on our list

"Azidoazide azide", the most explosive chemical compound ever created

This twitchy little compound is a part of a class of chemicals known as

"High nitrogen energetic materials"

And it does what it does because nitrogen just wants to be left alone

A nitrogen atom bonded with another nitrogen atom is one of the most stable molecules on earth

Their electrons form an extremely strong triple bond with each other,

which, in nature can usually only be broken by a molecule being hit by lightning

The strength of that bond means that when two nitrogen atoms snap together,

they release a tremendous amount of energy.

So if you look in a molecule of AA.. We're gonna call it AA cause Azidoazide Azide is hard

You can see how it gets its bang.

It has 14 nitrogen atoms and because of the way the molecule was structured,

None of them are in a triple bond.

Instead, they're stuck in a loosely bound high-energy state

and are dying to move to a more stable lower energy state

which means releasing a lot of pent-up energy in the process.

As a result, AA is both highly reactive and heck-a explosive.

How sensitive is this stuff? Well, it's actually hard to say, because it's too sensitive

even to measure how sensitive it is.

A team of German chemists created it in 2010 with the help of the US army,

in an effort to develop more energetic compounds.

And their first report on the discovery,

they said, and I quote, "The sensitivity of C2N14 is beyond our capabilities of measurement...

...even the smallest possible loadings in shock & friction-tests led to explosive decomposition."

To give you a list of how touchy this stuff is,

here's a list of things that make Azidoazide explode:

moving it, touching it,

dispersing it in solution, leaving it undisturbed on a glass plate,

exposing it to bright light, exposing it to x-rays,

putting it in a spectrometer, turning on the spectrometer,

and my favourite: ABSOLUTELY NOTHING!!!

They had it in a shock-proof explosive case, in a dark climate controlled room...

and it blew up!

I think somebody said something mean about it somewhere, and it was like:

(Censored Bleep)

The lead scientists on the team that synthesized it called it: "A very exciting discovery."

If I worked with Azidoazide Azide, waking up every morning,

and seeing that I still had all my fingers would be a very exciting discovery.

Next up, let's talk about Dimethylcadmium

This is an organometallic compound,

which means it it has a molecule in which carbon has bonded with a metal

In this case, that metal is Cadmium,

a pretty nasty customer all on its own

So far we've talked about chemicals that explode

or cover everything in unquenchable fire

And don't get me wrong; Dimethylcadmium, it does that too

But that is not what makes it so dangerous

It is, in all likelihood, gram-for-gram the most toxic chemical in the world

It has both acute and chronic effects

Which means it will kill you now AND later

It was first prepared by a pioneer of metal organic chemistry

A fellow named Erich Krause who was from, yes, Germany

It was 1917

To give you a sense of how Krause rolled

he died in his lab at the age of 37 after accidentally inhaling a bunch of chlorine

but before that happened he managed to report his discovery of Dimethylcadmium

When you breathe it in it is absorbed instantly into your bloodstream,

where it basically serves as a kind of chemical chauffeur for toxic compounds of cadmium

to travel all around your body

Because it's so effective at exploiting your bloodstream it quickly effects your most blood-infused organs

Like lungs and your kidneys and liver, creating compounds that rip electrons off the atoms of your cells

But if you manage to survive your first few hours after Dimethylcadmium exposure,

don't get your hopes up. It's also extremely carcinogenic,

So it will take you down with cancer just to spite you

This stuff is so potent that, as an airborne vapor

just a few millionths of a gram per cubic meter of air meets the legal safety limits

But if you spill it, how are you going to clean it up?

Water?

Well, when it reacts with water it produces both lots of heat and lots of hydrogen gas

Which is flammable so, yeah, it explodes in water

Maybe you could sweep it up?

Eeuhh friction makes it ignite

Might wanna just try waiting for it to decompose?

Well, it will do that

It'll form a crust of dimethyl cadmium peroxide, which is a friction-sensitive explosive

So you're just one shoe-scuff away from "KABLAMMO"

And on top of it all

the chemical has an odor that has been described as foul, unpleasant, metallic, and disagreeable

But that's nothing compared to our next chemical:

Thioacetone

It won't explode, or start fires, or even give you cancer

Compared to other chemicals on the list it's like a cute little fluffy bunny

If that cute little fluffy bunny had the MOST UNGODLY STINK YOU CAN IMAGINE

That's right, Thioacetone takes the prize for The World's Smelliest Chemical

It's a thiol, an organic compound in which a carbon atom is bonded to a sulfur-hydrogen pair

They're all gross

A skunk's spray uses two different thiols to eye-watering effect

Most sulfur-containing compounds are released by rotting meat

which is a reason why we would want to be very good at being able to detect them

and also not think that it smells...Good

But when it comes to bad smells

Thioacetone takes the stinky, seriously unappetizing cake

You can smell one drop of this substance, almost instantly, from half a kilometer away

In the 1960s a vial of the stuff fell off a shelf in a research lab

People were chucking their cookies in buildings 200 meters away

But the greatest example of thioacetone's silent-but-deadly strength comes from the German city of Freiburg

where in 1889 chemists at a soap factory were, reportedly, working on a larger molecule

known as tri-thioacetone, which is used as a flavoring and a fragrance

But, when they broke it apart into thioacetone workers started falling ill

Spontaneous outbreaks of vomiting were reported in the surrounding neighborhoods

It led to the evacuation of the whole city

There might be a lot to learn about thioacetone and thiols in general

but, understandably, scientists are not really rushing to look into it

And finally, there's the strongest corrosive agent in the world

The most dangerous acid ever devised by humanity

Fluoroantimonic acid

Because what list of dangerous chemicals would be complete

without a super acid

What makes an acid an acid is its ability to donate a proton to another molecule nearby it

And a proton is just a hydrogen atom that's lost its electron

This process is called Protonation

And an acid's strength is determined by how willing it is to give up that proton

A weak acid, acetic acid for example

Which is just the undiluted form of vinegar

will drag its feet about protonating other molecules

Most of it will just sit there doing nothing

But a strong acid like sulfuric acid'll punch that proton in the air like a beach volleyball at spring break

And remember from Substance N how crazy fluorine is

Well, fluoroantimonic acid is ten quadrillion times stronger than sulfuric acid

This molecule is begging for an excuse to fly apart

Once it's lost its hydrogen atoms

the remaining atoms of fluorine and another element, antimony

tear through everything else around them, ripping electrons off nearby molecules

and leaving just organic goo in their wake

Especially exciting is that fluorine really likes to bond with calcium

So once the acid tears through the fatty organic tissues of your skin and muscles

the fluorine will burn through your bones

The only way to store fluoroantimonic acid is in Teflon containers

Teflon, by the way, is held together by carbon-fluorine bonds

which are the single strongest bond in organic chemistry

We don't actually know a lot about this acid because it's so hard to do experiments with it

You can't put it in a syringe or on a slide

It eats through glass like it's cotton candy

You can't put it under a fume hood - it'll eat the fume hood

All you can really do is, just like, look at it

Ideally from...

...very far away

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