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What is Cyanide?

Michael Pollick
Michael Pollick
Michael Pollick
Michael Pollick

It's easy to assume that the word "cyanide" is always synonymous with a deadly poison. Chemically speaking, however, cyanide describes a triple bond between carbon and nitrogen atoms. This carbon-nitrogen combination can be combined with metals or other elements to form any number of compounds or salts, such as potassium cyanide, sodium cyanide or hydrogen cyanide. It is also found naturally in sugars, cassava roots, large fruit pits and tobacco leaves.

Different cyanide salts are used to process film, remove gold from ore, electroplate or clean metals, and make paper or plastic. In gas form, hydrogen cyanide is used to fumigate warehouses and the cargo areas of ships. The compounds can be stored in liquid, solid or gas form. The infamous "suicide pills" used by spies were often derived from prussic acid, a solid form of the compound.

Cyanide salts can be used to process film.
Cyanide salts can be used to process film.

Perhaps its most insidious use occurred during World War II. Charged with the gruesome task of exterminating large groups of Jewish captives, German concentration camp directors ordered canisters of hydrogen cyanide, sold under the brand name Zyklon B. Victims were ordered into airtight chambers, ostensibly for showers, and the gas would be introduced through the ventilation system. There have also been claims that former Iraqi president Saddam Hussein used this gas to kill thousands of Kurds during an uprising in the late 1980s.

A small amount of hydrogen cyanide is found in the pits of nectarines and other similar fruits.
A small amount of hydrogen cyanide is found in the pits of nectarines and other similar fruits.

Because cyanide, especially hydrogen cyanide, is produced naturally, it is very difficult for humans to avoid exposure completely. It is not considered to be carcinogenic (cancer-causing) however, and the gas evaporates quickly from groundwater. Long-term exposure to smoke, as in forest fires or cigarettes, is considered dangerous, since this gas is a natural by-product of smoke production. Liquid cyanide products such as insecticides and industrial cleaners can cause localized rashes and blister on exposed skin.

Cyanide is released in cigarette smoke.
Cyanide is released in cigarette smoke.

Hydrogen cyanide gas causes death and sickness by preventing normal oxygen absorption by blood cells. As the ions block the oxygen in the blood, the heart and brain suffer major damage. If the concentration of gas is heavy enough, death will occur within minutes of exposure. Victims of cyanide poisoning can be treated at a hospital if transported in time. Lower level exposure can cause dizziness, rapid heart rate, overall weakness and breathing difficulties. Evacuation to a source of fresh air is usually the first response, followed by decontamination and oxygen treatments.

Michael Pollick
Michael Pollick

A regular AllTheScience contributor, Michael enjoys doing research in order to satisfy his wide-ranging curiosity about a variety of arcane topics. Before becoming a professional writer, Michael worked as an English tutor, poet, voice-over artist, and DJ.

Learn more...
Michael Pollick
Michael Pollick

A regular AllTheScience contributor, Michael enjoys doing research in order to satisfy his wide-ranging curiosity about a variety of arcane topics. Before becoming a professional writer, Michael worked as an English tutor, poet, voice-over artist, and DJ.

Learn more...

Discussion Comments

anon997081

anon296493 asked in Post 6

Since cyanide is also found naturally in certain fruit pits, is it unwise to eat those pits? Or is naturally occurring cyanide not as poisonous?

Answer: The cyanide in apple seeds, and various pits has been dubbed : B17 by some scientists. Not certain whether or not this makes sense to do or not as I do not fully understand the various compositions of the other B vitamins.

Regardless, the cyanide is bound to another poison, I believe it is benzyl hydroxide (I believe, I'm working off of a 6 or 7 year old memory, but I think it's that) as well as 2 molecules of glucose.

Unless it encounters one enzyme the body's cells make, it just passes harmlessly through your body and is discarded by the bowels. Interesting thing though is cancerous cells release 300X more of that one specific enzyme than normal cells. Then when it breaks that bond, the poisons kill the nearest cell, generally a cancerous cell.

But none of this answers your Q. Not certain anyone knows, although there may be better guesses than mine. I have eaten pits and apple seeds before, many, actually, just not lots at one time, but several, sure. But the almonds, I suspect, have the same or similar cyanide, benzyl hydroxide and two molecules of glucose make up in it as peach, apricot & similar pits I have eaten taste very similar. And I have eaten large quantities of almonds in one sitting. Never have felt off or queasy or anything after eating. Also, lots of foods fava beans etc. have lots of "B17" in them, so I suspect it is very safe in small amounts and fairly safe in larger ones. Gorging might be bad idea, but then you can die from drinking too much water all at once too, so, moderation, people.

anon296493

Since cyanide is also found naturally in certain fruit pits, is it unwise to eat those pits? Or is naturally occurring cyanide not as poisonous?

anon283229

Hydrogen cyanide is not actually found naturally in tobacco leaves; it forms in the smoke. Also, in wood smoke, car exhaust, probably many, many other instances where pyrolysis occurs in a low oxygen environment.

anon194759

Thank you very much, this was very interesting, not too difficult to read (I am not from an english speaking country), and really informative. Great site!

anon79671

I'm afraid the answer may be somewhat misleading and has thrown off some of my students answering questions related to cyanide poisoning.

Cyanide does bind to hemoglobin, interfering with oxygen transport to cells. However, it also disrupts mitochondria (specifically the electron transport chain) so that cells cannot produce ATP efficiently. Lack of oxygen does the same thing.

So while it does block oxygen, mitochondria are not using oxygen anyhow since cyanide has halted their function.

I'm fairly certain both factors are at work, depending on dosage of cyanide, but omitting the effect on mitochondria is incomplete for my biology students. -- J. Buegge

anon75443

Thank you very much for your very informative website. This is the second time I have been able to get an answer to my questions via your information provided here.

The history and the detailed explanations about what happens concerning cyanide in its different forms has helped me understand a lot of things that have happened, and do happen, especially when I get around people who are smoking - I may be allergic to the smoke, but it is also literally stealing the oxygen from me. Thanks again. K. Austin

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    • Cyanide salts can be used to process film.
      By: Joseph Becker
      Cyanide salts can be used to process film.
    • A small amount of hydrogen cyanide is found in the pits of nectarines and other similar fruits.
      By: stoleg
      A small amount of hydrogen cyanide is found in the pits of nectarines and other similar fruits.
    • Cyanide is released in cigarette smoke.
      By: Николай Григорьев
      Cyanide is released in cigarette smoke.
    • Cassava roots are a natural source of cyanide.
      By: Unclesam
      Cassava roots are a natural source of cyanide.
    • Hydrogen cyanide was used to kill prisoners of German concentration camps during World War II.
      By: Patryk Kosmider
      Hydrogen cyanide was used to kill prisoners of German concentration camps during World War II.
    • Nitrogen atoms triple bond with carbon atoms to form cyanide.
      By: Gman73
      Nitrogen atoms triple bond with carbon atoms to form cyanide.
    • Hydrogen cyanide is used to fumigate warehouses.
      By: Maurizio Targhetta
      Hydrogen cyanide is used to fumigate warehouses.
    • Cyanide poisoning may result in cardiac arrest.
      By: Tyler Olson
      Cyanide poisoning may result in cardiac arrest.