# Deadliest substance/thing in the world by size/weight
**URL:** https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814
**Category:** Factual Questions
**Created:** [August 17, 2012, 8:10pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814 "2012-08-17T20:10:56Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@obbn](https://boards.straightdope.com/u/obbn)
#### Post date: [August 17, 2012, 8:10pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/1 "2012-08-17T20:10:56Z")
Hello Everyone,
I was bored and started thinking what is the deadliest substance/thing that could kill a human adult that is also either very tiny. I came up with ricin, as I understand only a few grams of the stuff could be deadly, although I might be wrong. I think that was the toxin used in the spy killings when a spy stabbed someone with an umbrella tip that injected a tiny ball full of ricin.
Okay, so you get my drift. What is the smallest amount of something that can kill an adult?
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### Author:  [@chrisk](https://boards.straightdope.com/u/chrisk)
#### Post date: [August 17, 2012, 8:18pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/2 "2012-08-17T20:18:30Z")
Apparently you can die from swallowing as little as 50 nanograms of Polonium 210. [Wiki cite.](http://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvinenko#Po-210_concentration_in_the_body_of_Litvinenko)
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### Author:  [@Lobohan](https://boards.straightdope.com/u/Lobohan)
#### Post date: [August 17, 2012, 8:19pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/3 "2012-08-17T20:19:42Z")
I don’t know if this is best but Polonium is pretty toxic:
> **[Polonium](https://en.wikipedia.org/wiki/Polonium)**
>
> Polonium is a chemical element; it has symbol Po and atomic number 84. A rare and highly radioactive metal (although sometimes classified as a metalloid) with no stable isotopes, polonium is a chalcogen and chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting poloniu...
> [@](#):
>
> By mass, polonium-210 is around 250,000 times more toxic than hydrogen cyanide (the actual LD50 for 210Po is less than 1 microgram for an average adult (see below) compared with about 250 milligrams for hydrogen cyanide[53]).
I’m sure anti-matter would be more damaging.
Edit: Ninjas are also quite deadly.
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### Author:  [@Gagundathar](https://boards.straightdope.com/u/Gagundathar)
#### Post date: [August 17, 2012, 8:29pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/4 "2012-08-17T20:29:30Z")
So, the answer is ninjas injecting polonium-120 using an umbrella?
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### Author:  [@Gagundathar](https://boards.straightdope.com/u/Gagundathar)
#### Post date: [August 17, 2012, 8:33pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/5 "2012-08-17T20:33:04Z")
Seriously, though, the amount is dependent upon the time the assailant is willing to wait for the victim to succumb.
There are bioweapons with very low dosages that will cause death in 5 days or so.
Do those count?
Does the death need to occur rapidly?
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### Author:  [@cjepson](https://boards.straightdope.com/u/cjepson)
#### Post date: [August 17, 2012, 8:35pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/6 "2012-08-17T20:35:17Z")
Botulinum toxin (of which Botox is one variety) might be the winner. According to [Wiki](http://en.wikipedia.org/wiki/Botulinum_toxin):
“When introduced intravenously in monkeys, type A (Botox Cosmetic) of the toxin exhibits an LD50 of 40–56 ng, type C1 around 32 ng, type D 3200 ng, and type E 88 ng[citation needed]; these are some of the most potent neurotoxins known.”
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### Author:  [@cjepson](https://boards.straightdope.com/u/cjepson)
#### Post date: [August 17, 2012, 8:37pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/7 "2012-08-17T20:37:10Z")
> [@Gagundathar](#):
>
> Seriously, though, the amount is dependent upon the time the assailant is willing to wait for the victim to succumb.
> There are bioweapons with very low dosages that will cause death in 5 days or so.
>
> Do those count?
>
> Does the death need to occur rapidly?
Good point. Ultraviolet radiation can cause melanoma, so maybe the answer is sunlight.
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### Author:  [@Smeghead](https://boards.straightdope.com/u/Smeghead)
#### Post date: [August 17, 2012, 8:47pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/8 "2012-08-17T20:47:19Z")
Time. It’s weightless, yet it kills us all eventually.
Duuuude.
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### Author:  [@Michael63129](https://boards.straightdope.com/u/Michael63129)
#### Post date: [August 17, 2012, 8:54pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/9 "2012-08-17T20:54:11Z")
> [@cjepson](#):
>
> Botulinum toxin (of which Botox is one variety) might be the winner. According to [Wiki](http://en.wikipedia.org/wiki/Botulinum_toxin):
>
> “When introduced intravenously in monkeys, type A (Botox Cosmetic) of the toxin exhibits an LD50 of 40–56 ng, type C1 around 32 ng, type D 3200 ng, and type E 88 ng[citation needed]; these are some of the most potent neurotoxins known.”
According to the list [here](http://en.wikipedia.org/wiki/Median_lethal_dose#Examples), botulinum toxin is about 10 times more toxic than polonium, and 20,000 times more toxic than ricin, but only if the latter is injected; the oral dose is a thousand times greater still, with ionizing radiation the only thing that exceeds it (what would the weight of 3-6 Gy of radiation be? Very small in any case, especially gamma rays).
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### Author:  [@DCnDC](https://boards.straightdope.com/u/DCnDC)
#### Post date: [August 17, 2012, 8:55pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/10 "2012-08-17T20:55:54Z")
> [@Smeghead](#):
>
> Time. It’s weightless, yet it kills us all eventually.
Time may win on weight, but loses on size. It’s so big, it’s everywhere.
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### Author:  [@YogSothoth](https://boards.straightdope.com/u/YogSothoth)
#### Post date: [August 17, 2012, 9:00pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/11 "2012-08-17T21:00:43Z")
> [@Gagundathar](#):
>
> So, the answer is ninjas injecting polonium-120 using an umbrella?
Anti-matter ninjas
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### Author:  [@Chimera](https://boards.straightdope.com/u/Chimera)
#### Post date: [August 17, 2012, 9:36pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/12 "2012-08-17T21:36:07Z")
Well, unless you’re Big Jim McBob and Billy Sol Hurok, the anti-matter solution has some drawbacks.
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### Author:  [@Lobohan](https://boards.straightdope.com/u/Lobohan)
#### Post date: [August 17, 2012, 9:37pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/13 "2012-08-17T21:37:16Z")
How much damage would one microgram of antimatter cause? Would it crater a fist sized hunk of flesh? Vaporize a pile of anvils? Make newspapers smolder?
One of you physics types tell me!
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### Author:  [@Gagundathar](https://boards.straightdope.com/u/Gagundathar)
#### Post date: [August 17, 2012, 9:51pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/14 "2012-08-17T21:51:13Z")
> [@Lobohan](#):
>
> How much damage would one microgram of antimatter cause? Would it crater a fist sized hunk of flesh? Vaporize a pile of anvils? Make newspapers smolder?
>
> One of you physics types tell me!
0.00004296 megatons.
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### Author:  [@Rhaegar](https://boards.straightdope.com/u/Rhaegar)
#### Post date: [August 17, 2012, 9:51pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/15 "2012-08-17T21:51:16Z")
Ebola virus perhaps? That can’t weigh much at all, and it is pretty deadly.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [August 17, 2012, 9:51pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/16 "2012-08-17T21:51:18Z")
> [@Lobohan](#):
>
> How much damage would one microgram of antimatter cause? Would it crater a fist sized hunk of flesh? Vaporize a pile of anvils? Make newspapers smolder?
>
> One of you physics types tell me!
From wikipedia:
> [@](#):
>
> one gram of antimatter annihilating with one gram of matter produces 180 terajoules, the equivalent of 42.96 kilotons of TNT (approximately 3 times the bomb dropped on Hiroshima - and as such enough to power an average city for an extensive amount of time).
So, 1 microgram would produce an explosion equal to around 85 lbs of TNT.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [August 17, 2012, 9:52pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/17 "2012-08-17T21:52:23Z")
> [@Gagundathar](#):
>
> 0.00004296 megatons.
I think this is much too high.
As my Physics prof used to say - show your work!
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### Author:  [@grude](https://boards.straightdope.com/u/grude)
#### Post date: [August 17, 2012, 10:08pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/18 "2012-08-17T22:08:50Z")
There are supposedly some fentynal analogues that are so insanely potent even one single grain or speck touching your skin could be fatal. For a chemist to work with it requires full bunny suit with air filter, and keep a syringe full of nalaxone handy in case your suit gets breached. Thats pretty crazy.
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### Author:  [@Kkrose](https://boards.straightdope.com/u/Kkrose)
#### Post date: [August 17, 2012, 10:22pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/19 "2012-08-17T22:22:22Z")
Humans. One of us can do a lot of damage to a large group of people while theses toxins generaly affect a single individual. At least in the quantaties above.
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### Author:  [@Mosier](https://boards.straightdope.com/u/Mosier)
#### Post date: [August 17, 2012, 11:29pm UTC](https://boards.straightdope.com/t/deadliest-substance-thing-in-the-world-by-size-weight/631814/20 "2012-08-17T23:29:47Z")
A vacuum.
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