Category: "food" & "drink"

October 11, 2011 10:29 AM

What do various poisons and toxins taste like? What flavor is lead, for example, or strychnine? How about common deadly household chemicals like bleach, or organic toxins like mercury/methylmercury?

I saw a Law & Order: SVU about a child with pica that ate the lead paint off his father's old toy cars because it tasted like sweet and sour candy. That started me thinking about other dangerous materials. Not planning anything or writing anything, just wondering.

Bonus question: how do people know this information.

posted by 2bucksplus to Food & Drink (15 answers total)

Response by poster: Oh and if you have information on what hazardous gases smell like, that would be great too.
posted by 2bucksplus at 10:31 AM on October 11, 2011

Best answer: There's a good reason that lead(II) acetate is also known as "sugar of lead". It's been used as a sweetener at various times through history, especially to improve the saleability of low-quality wines. (There's a note on the Wikipedia page that such wine may have contributed to Ludwig von Beethoven's death.)
posted by McCoy Pauley at 10:33 AM on October 11, 2011

Many of these things aren't so poisonous that you can't taste them once. Lick a fishing weight, you won't die. Or put a drop of diluted bleach on your tongue, you'll be fine.

Obviously don't do this with more dangerous things.
posted by tylerkaraszewski at 10:36 AM on October 11, 2011

Best answer: This is information that the MSDS of a chemical usually has. Here's strychnine's (PDF). Look at section 9, physical and chemical properties. Apparently, it's odorless and bitter tasting. Often ones that have well documented smells or flavors will be elaborated on here.
posted by zug at 10:38 AM on October 11, 2011 [1 favorite]

Best answer: Common automobile antifreeze, ethylene glycol, is decidedly sweet. It attacks the kidneys, among other organs, which will lead to death if not treated in time. The sweetness is the primary reason it's so attractive to dogs and children and also why it's sometimes used as a deliberate poison in sweet drinks.
posted by tommasz at 10:42 AM on October 11, 2011

Antifreeze is apparently sweet too--there was a scandal a few years ago where wine producers were using ethylene glycol to improve poor-quality sweet wines. Er, what tommasz said.

Most acids are apparently sour--I can recall being told by the chemistry teacher that acids were sour and asking how anybody knew--apparently people did taste very dilute sulphuric acid and lived to tell the tale. Come to think of it, one of my friends told me once that he had tasted battery acid. "Cordwainer Smith" apparently used to drink dilute hydrochloric acid.

Neither of these experiments is really a good idea.
posted by Logophiliac at 10:43 AM on October 11, 2011

HS is very sulfury, like rotting eggs on the first sniff. The second sniff smells like nothing because your olfactory cells are already dead.
posted by infinitewindow at 11:04 AM on October 11, 2011

CS Gas - tear gas, odorless

I don't know if I would agree with that completely. While I wouldn't exactly say it has an odor, it's smell is sort of the anti-smell. It just whips through your sinuses negating everything in its path.

Incidentally, now that I've started doing metal casting, I now know that, in addition to the coal smoke, China smells like zinc fumes.
posted by The 10th Regiment of Foot at 11:08 AM on October 11, 2011

Best answer: The Straight Dope: "How do they know what lethal gases smell like?"
posted by Rhaomi at 11:13 AM on October 11, 2011

Anecdote: bleach tastes like lemony gut-instinct-get-this-outta-my-mouth.

(soontobe)Mother-in-law left some in a drinking glass on the windowsill - she uses it to clean blinds strings - I thought it was my drinking glass and drank a pretty sizable swig that got about halfway down before realizing that it was bleach, and as soon (or before?) my mind processed the sensation, it was coming back up, and I spent about the next twenty minutes coughing/hacking up this lemony-exactly-like-a-cleaning-agent-smells taste.

... then, as they were pretty concerned, the whole family spent some time on the internet and the situation ended with me taking a shot of olive oil so that they felt better about my not-dying-from-minor-bleach-ingestion.
posted by Seeba at 11:15 AM on October 11, 2011

Best answer: Strychnine tastes bitter, more or less like quinine (as in tonic water). I had a chemistry professor who filled a coffee mug with about 1/10th the LD50 of strychnine and then passed it around so we could all take sips from it to see what it tasted like.
posted by pombe at 11:30 AM on October 11, 2011 [1 favorite]

Best answer: Beryllium salts are, apparently, sweet. They used to taste-test for its presence.
posted by scruss at 12:20 PM on October 11, 2011

Best answer: Many bad-for-you or-otherwise-potent potables taste bitter. Some scientists think this is actually why bitter as a taste exists, evolutionarily speaking. 'Bitter' is a really rough clue that some food you are eating might be bad for you:

"Bitterness is of interest to those who study evolution, as well as various health researchers since a large number of natural bitter compounds are known to be toxic. The ability to detect bitter-tasting, toxic compounds at low thresholds is considered to provide an important protective function. Plant leaves often contain toxic compounds, yet even amongst leaf-eating primates, there is a tendency to prefer immature leaves, which tend to be higher in protein and lower in fiber and poisons than mature leaves. Amongst humans, various food processing techniques are used worldwide to detoxify otherwise inedible foods and make them palatable.

—Wikipedia

Normally, I think it sounds really dumb when people say, "blah blah blah tasting stuff isn't that big a deal, you can only taste four or five or six basic tastes!" I mean, that's like saying, "the ear can only detect increases and decreases in air pressure , so, you know, music is mostly just marketing." Or, "the color vision part of the eye has peak sensitivities around only three wavelenths of light, so, you know...seeing stuff is mostly imaginary." No one says those things, but they always try to take taste down a peg. But it does seem that some of the basic tastes supply important information about stuff you might eat: salty things contain life-sustaining salt and we see how animals use that as a guide all the time, sweet things contain valuable easily digested energy, bitter things might be poison (I have no idea where this leaves sour/acidic things, or any of the other tastes.)

Of course, this system doesn't work perfectly, or dogs would never die from licking up sweet puddles of antifreeze.

Also, continuing on the bitterness as a rough guide to poisonousness theme, I believe there are certain foods who's wild ancestors are both bitter (to the point of not being enjoyable) and poisonous, and the domesticated or adequately processed versions lose both the poison aspect and the bitter aspect. The foods I'm thinking of include almonds: 'The fruit of the wild forms contains the glycoside amygdalin, "which becomes transformed into deadly prussic acid (hydrogen cyanide) after crushing, chewing, or any other injury to the seed."' (wikipedia) and olives, although checking the wikipedia page for olives it does say that olives are too bitter to eat without processing, but that they are not actually dangerous.

The cyanide/bitter almonds connection is why the "the body smells like bitter almonds!" is is such a well-known murder mystery trope.

A big category of compounds that makes it looks like this would be a reasonable behavior to have evolved is alkaloids. Alkaloids have the following properties (quoted material from Wikipedia):

• "Alkaloids are produced by a large variety of organisms, including bacteria, fungi, plants, and animals, and are part of the group of natural products (also called secondary metabolites)."
• "Many alkaloids are toxic to other organisms..." Many others also "do something" to the body (e.g. many drugs are alkaloids).
• "Although alkaloids act on a diversity of metabolic systems in humans and other animals, they almost uniformly invoke a bitter taste."

So you've got a range of chemicals that occurs very frequently in things that are candidates for omnivores to eat and that are very frequently toxic, and they very frequently taste the same: bitter. You might wonder, how does that work? Is "bitterness" an alkaloid detector? The different tastes are detected by different mechanisms, but the bitter ones happen to be detected by G protein-coupled receptors, which basically means they are like the bottom of in-play Tetris board, and they detect pieces of molecules the way the Tetris board detects of Tetris pieces when they snap into place and the Tetris board blinks and give you points. The stick-out bits of molecules that mate with the GPCRs are called ligands. So you might think "Do alkaloids all have the same ligands? Is that how this works?" Are their different GPCRs for a big enough set of alkaloids that you get a lot of hits?" I looked this up once recently and my conclusion from a cursory poking around in Google was that biology people weren't actually totally sure yet, how all these different compounds triggered the same feeling of "tasting bitter".

This brings us to another question: "If bitter signals poison, then why are bitter foods so awesome?" I don't know. It's weird. Why is spicy food so awesome? Capsaicin binds directly to nociceptors in your mouth. People seem to really enjoy the mild dose of deadly tetrodotoxin numbing their lips when they eat fugu. You would think if there was anything people would be guaranteed to not enjoy, it would be a chemical that you put in your face, that directly plucks the wires that signal pain to your brain, and yet I was bummed when I ran out of hot sauce while eating my breakfast this morning.
posted by jeb at 12:53 PM on October 11, 2011 [5 favorites]

Jeb beat me to it. There are dozens of types of taste receptors that produce a sensation of bitterness, while there are just one or a few types of receptors corresponding to the other tastes. Bitterness receptors are probably designed to respond to a wide range of chemicals that are bioactive—in other words, chemicals that can disrupt homeostasis. That's why most drugs and toxins taste bitter.
posted by dephlogisticated at 12:57 PM on October 11, 2011

Best answer: Most acids are apparently sour--I can recall being told by the chemistry teacher that acids were sour and asking how anybody knew--apparently people did taste very dilute sulphuric acid and lived to tell the tale.
Many food items are acidic, e.g. lemons [citric acid], vinegar [acetic acid], rhubarb [oxalic acid], yogurt [lactic acid]. The strong acids could also be safely tasted simply by diluting them sufficiently. Although some acids are poisonous, and some acids are strong enough to be harmful, acidity itself is not inherently poisonous.

BTW: Vinegar was the strongest acid known to the ancient world.
posted by HiroProtagonist at 6:42 PM on October 11, 2011