Cyanide

Abstract

Cyanide (CN) exists in many different forms, such as, cyanide ion, sodium cyanide, potassium cyanide, hydrogen cyanide, and copper cyanide etc. It is a rapidly acting, potentially deadly chemical. CN can be a colorless gas, such as hydrogen cyanide or cyanogen chloride, or a crystal form such as sodium cyanide or potassium cyanide. CN has a “bitter almond” smell, but it does not always give off an odor, and the odor is not easily detectable. CN is often released from natural substances, and found in certain plants such as cassava, lima beans, and almonds. Pits and seeds of common fruits (apricots, apples, & peaches) may have quantifiable amounts of chemicals which are metabolized to cyanide, although edible parts have low amounts of CN. Cigarette smoke and the combustion products of plastics & synthetic materials can contain CN. It is an extensively used industrial chemical (paper, textiles, plastics, photographic materials, metallurgy for electroplating, metal cleaning, gold purification, and for extermination of vermin in ships and buildings). Accidental ingestion of chemicals found in acetonitrile-based products (artificial nail removers) can produce cyanide when metabolized by the body. Cyanide can interact with ∼40 metalloenzymes, but its lethal action is inhibition of cytochrome c oxidase in mitochondria, halting cellular respiration & causing hypoxic anoxia. Hydrogen cyanide, under the name Zyklon B, was used as a genocidal agent in World War II. Depending upon the level and duration of exposure, cyanide can produce (headache, nausea/vomiting, rapid breathing, rapid heart rate, restlessness, convulsions, loss of consciousness, low blood pressure, lung injury, and respiratory failure leading to death). LD50 dose in mice=3mgkg−1 when given intraperitoneally. Cyanokit (hydroxocobalmin), or the Cyanide Antidote Kit (amyl nitrite pearls vi inhalation; sodium nitrite and sodium thiosulfate administered by infusion) can be used in cyanide poisonings. Hyperbaric oxygen treatment remains controversial.