Most poisonous thing

This isn’t true at all.

Beryllium Oxide in its dust form has an LD50 to 0.5 to 5 mg/kg.

I knew someone was going to point that out as soon as I read the post back through :p. It does tend to get used rather loosely by lazy scientists to just mean lethal dose when it shouldn’t.

My point was that human LD50 records tend to either be based on a very random patchwork of incidents or an extrapolation from other primates. Given both this and the fact that the exposure environment and access to medical intervention tend to vary by compound, it’s very difficult to make statements about relative toxicity of compounds based on published human LD50 values that are within a order of magnitude or so of each other.

Just highlighting that plutonium is toxic if you swallow it, although less so than arsenic, for example. It’s also radioactive, carcinogenic if inhaled, can pose a risk of criticality, and it’s heavy as hell if you drop it on your foot. Plus you will draw the attention of government agents if you have any. Just stay away from it. It’s bad stuff.

Well, the most poisonous native thing growing in north america is probably the fool’s webcap. There have been reports of fatal poisonings from merely tasting it and spitting it out. Destroying angels and deathcaps get a lot of publicity, but you need to eat quite a bit more of them to die.

Nobody mentioned hydrogen sulfide? Just a whiff will kill you, and its easy enough to accidentally ingest some crude oil that contains a lethal dose.

And if you survive, your lifetime tolerance goes down.

Just making a post about plutonium on a public message board can draw the attention of jack-booted thugs.

There’s also dimethyl mercury. In a notable case, a small amount killed someone right through her protective equipment. Procedures for handling it were revised as a result of this accident, but, more to the point, most authorities now discourage using it at all.

Maybe. What exactly do you think they are going to do after they get here and ascertain that the thread isn’t “can someone hook me up with 7kg of plutonium, need answer fast”?

Or do you think everyone gets an annual allowance of times that they are allowed to discuss things that have national security implications in a none security relevant context, before they go on the no flight list? :stuck_out_tongue:

I don’t see anything suggesting that in Wikipedia:

Really? Wikipedia mentions claims to this effect, but states that a citation is required. I had previously understood (on the authority of several respected mycologists) that any fungus could be tasted with impunity, as long as it was just a very small piece, spat out and followed by further salivating and spitting.

Wikipedia never worked on an oil rig. If you do, you are required to take an H2S safety course and get certified.

One of the things they drum into you is that it is heavier than air and can be dissolved in various substances, so walking through the wrong mud puddle can jar it loose. You’ll drop like a stone if its concentrated enough.

Here is a chart. http://www.safetydirectory.com/hazardous_substances/hydrogen_sulfide/fact_sheet.htm

Those are pretty rarefied concentrations. The stuff is bad news.

I was taught that if you do succumb and are revived(or are even just exposed to high levels), you then have a life time lower tolerance, and beyond a certain point you will be barred from entering oil lease sites.

Ah-ha! “Legator and Singleton (1997) reported that permanent central nervous system damage can occur at concentrations common at industrial facilities, asphalt sites, and livestock operations.” from http://ohsonline.com/Articles/2007/10/Human-Health-Effects-from-Exposure-to-LowLevel-Concentrations-of-Hydrogen-Sulfide.aspx?Page=2

So the means by which it damages can be permanent, so on subsequent exposures, less of the same would be needed to kill you.

That is probably correct. However, I’m not so confident that I’d try it out!

It’s nasty stuff all right. I’d always been taught that hydrogen sulfide was about on par with hydrogen cyanide.

The issue is that it’s detectable via smell at very low levels (I believe that it’s actually released by old style ammonium sulfide stink bombs), and when increased steadily will become physically intolerable well below the toxic levels, it’s therefore not regarded as dangerous by a lot of people who have encountered it only through chemistry lessons because of that. But your sense of smell is rapidly lost (potentially in seconds) at high concentrations which makes it easy for poisoning to go unnoticed.

I don’t remember anything about the reduced tolerance thing, and a search for “hydrogen sulfide lifetime tolerance” didn’t show anything relevant in the first few hits other than this thread.

Are you sure that the reference wasn’t to shorter term issues? Enzymes do often take a fair amount of time to recover to normal levels after major poisoning events.

There is a paper here that Google search tells me contains the text “time to apparent recovery, e.g. some blood enzymes returned to normal only. 2 months after the H2S poisoning (101, 102)”
but I’m not in a position to get the actual paper, so you might want to check it out if you have literature access.

It’s certainly going to have the capacity to cause permanent nervous system damage, anything that screws with mitochondria is going to have the capacity to do that. I wouldn’t expect such damage to increase it’s chance of killing you next time, although I’d be surprised if we understood the nervous system well enough for anyone to be able to give you a definitive no on that.

The toxin is Ricin and when injected is very toxic - so toxic that the KGB used it successfully as an assassination weapon - check out Georgi Markov.

Si

Right. In the field it can jump from barely irritable to fatal levels in seconds. I can see that being much less likely in a lab.

Possibly. I will see if I can find my old text book. I do remember being told you could be blacklisted from work, and there is an effective blacklist system in place.

For instance, if you were a big enough jerk to people they’ll blacklist you, and if your employer attempts to use you on jobs, they will get blacklisted too.

Yeah, they might be erring on the side of caution. For instance, if you have a hearing impairment, they will ask you to get medical proof that you dont have a perforated ear drum as H2S poisoning can bypass PPE(air masks) that way.

What would be a lethal dose of anti-matter?

Seems like just enough to blow your head off would do the trick. Anyone know off hand the mass/energy equivalent of a few M-80s?

Even few people eat antimatter than they do lava. See the OP.

Bullshit. If that were true, nobody would survive their first boiled egg fart. Every spring, children would be lying on church lawns dead after easter egg hunts. (Certainly it is lethal at high enough concentrations, but I wouldn’t call that a “whiff”).
The one interesting thing about HS is that it doesn’t smell at lethal concentrations.

Cad Jnr was asking for the answer. Is there a consensus on which food (not refined chemical) will kill you the fastest?