Cyanide Gas

This page is a basic fact sheet about Cyanide Gas (Hydrogen Cyanide - HCN).

A Random Quote:
Disease can never be conquered, can never be quelled by emotion's wailful screaming or faith's cymballic prayer. It can only be conquered by the energy of humanity and the cunning in the mind of man. In the patience of a Curie, in the enlightenment of a Faraday, a Rutherford, a Pasteur, a Nightingale, and all other apostles of light and cleanliness, rather than of a woebegone godliness, we shall find final deliverance from plague, pestilence, and famine.
Sean O'Casey (1884-1964), Irish dramatist. Inishfallen, Fare Thee Well, vol 1., title chapter (1949).

Characteristics
Toxicology
Symptoms
Cautions
First-aid and therapy
Neutralization and decontamination

Characteristics		Basic characteristics: melting point: -15C boiling point: 26C less dense than air (rises upwards) volatility at 20C: 891,000 mg/m3 (milligrams per cubic meter) odour: like bitter almonds vapor evaporates very rapidly and is detectable in the open air for only a few minutes stabilizers may be added to reduce the speed of evaporation: stannic chloride and chloroform ("Vincennite"); or arsenic trichloride ("Manganite") miscible with water and slowly decomposes industrial chemical

Toxicology		Properties include: casualty dosage (unmasked): 2-5000 mg-min /m3 (milligrams per minute per cubic meter) lethal dosage 2-5000 mg-min/m3 size of the casualty and lethal dosages vary widely according to the exposure time effects not apparent until lethal doses are achieved readily absorbed into circulation through lungs central nervous system toxicant

Symptoms		Symptoms include: at low concentration (effects prolonged for one or more hours) immediate and progressive sensation of warmth prostration nausea and vomiting headache difficulty in breathing unconsciousness asphyxial convulsions at high concentration sudden loss of consciousness death from respiratory arrest causes a "tobacco reaction": people who inhale small amounts and then begin to smoke may experience a flat metallic taste

Cautions		Important precautions include: effects follow extremely rapid course if high concentrations are achieved the gas has a tendency to inflame when disseminated by explosive burst charcoal filters can become saturated with cyanide more readily than with other chemical agents protection required: gas masks fitted with canisters containing silver oxide

First-aid and therapy		Therapeutic course: initial treatment involves administration of artificial respiration and oxygen subsequent treatment aimed at dissociating cyanide from cytochrome oxidase molecule; therapies include administration of sodium thiosulfate (to aid activity of rhodanese), sodium nitrite (to produce methemoglobin) or cobalt (to form complex with cyanide) antidotes should be administered as soon as possible

Neutralization and decontamination

None necessary (because the gas disperses rapidly, leaving no residue.)