Definition
A highly toxic chemical compound containing a carbon-nitrogen group that blocks the body's cells from using oxygen, even when oxygen is present in the blood. In aviation, cyanide is most relevant as a product of combustion released when cabin materials, plastics, or upholstery burn during an in-flight or post-crash fire.
Plain English
A poison that stops your body's cells from being able to use the oxygen they receive. It is one of the dangerous gases produced when aircraft interior materials catch fire.
Context Anchor
Seen in aeromedical discussions of histotoxic hypoxia, especially when studying smoke, fire, poisoning, or toxic fumes.
Derivation
From the Greek 'kyanos,' meaning dark blue. The name comes from Prussian blue, the pigment from which the compound was first isolated. The link to aviation is indirect, but it explains why the word looks unrelated to its toxic effect.
Why Pilots Care
Inhalation of cyanide from aircraft fires or smoke can cause rapid incapacitation by inducing histotoxic hypoxia even when oxygen supply is adequate.
Grounding Statement
Even with full lungs of air, cyanide prevents cells from accepting the oxygen, so the body suffocates from the inside.
Intuition Check
Do not think of cyanide as simply “bad air” or low oxygen. The danger is that the body may be unable to use oxygen that is already present.
Example Sentence 1
Smoke from burning cabin plastics can contain cyanide, which is one reason pilots are trained to don oxygen masks immediately at the first sign of fire.
Example Sentence 2
The handbook lists cyanide poisoning as one trigger for histotoxic hypoxia during flight.