What Are Common Sources and Causes of Cyanide Poisoning?

Common sources of cyanide poisoning include:

Fires: Smoke inhalation during the burning of common substances such as rubber, plastic, and silk can create cyanide fumes and cause cyanide poisoning.

Photography, chemical research, synthetic plastics and fibers, metal processing, fumigation and pesticides, mining, and electroplating industries use hydrogen cyanide. Potassium cyanide is used in gold and silver extraction, chemical analysis, to make other chemicals, and as an insecticide.

Plants: Mostly from the family Rosaceae, seeds and pits from plants such as apricot, bitter almond, cherry laurel, plum, peach, pear, and apple contain cyanogenic glycosides. A type of potato called cassava can also cause cyanide poisoning. Fortunately, only chronic or massive ingestion of any of these plants or pits can cause serious cyanide poisoning.

Laetrile, a compound that contains amygdalin (a chemical found in the pits of raw fruits, nuts, and plants) has been purported as a cancer treatment worldwide. One of the side effects of laetrile is cyanide poisoning. The Food and Drug Administration (FDA) has not approved laetrile as a cancer treatment in the United States. The drug is also made and used as a cancer treatment in Mexico under the name "laetrile/amygdalin."

Certain chemicals, after ingestion, can be converted by the body into cyanide and cause cyanide poisoning. Most of these chemicals have been removed from the market, but some old artificial nail polish removers, solvents, and plastics manufacturing solutions can contain these substances.

Cigarette smoke is the most common source of cyanide exposure for most people. Cyanide is naturally found in tobacco, and smokers can have more than 2.5 times the mean whole blood cyanide level of nonsmokers, though this is generally not enough to cause poisoning.

Those most at risk of cyanide poisoning are those who work in industries that use this chemical and people who intentionally try to kill themselves. Those who attempt suicide by using cyanide pills or capsules may believe it is a quick and painless death, however, cyanide burns the stomach and prevents the body from using oxygen, causing a painful death.

For most people, cyanide only causes poisoning if a fire occurs or if some of the compounds mentioned above are accidentally ingested.