A colorless or light blue liquid or gas, a triatomic cyanide,
which is extremely flammable. HCN is an important industrial chemical
and over a million tonnes are produced yearly in the world. It is produced industrially
by reacting methane and ammonia in air at high temperature.
A wide range of combustion processes produce HCN gas in the smoke or fumes.
HCN is found naturally throughout the environment at low levels as it is released
from volcanoes and certain plants and bacteria.
Hydrogen cyanide is abundant in all kinds of astronomical environments, from dark clouds to
star-forming regions and circumstellar envelopes. The first detection of
interstellar HCN (at 88.6 GHz) and H13N (at 86.3 GHz)
was reported by Buhl & Snyder (1971, ApJ 163, L47).
Also called → hydrocyanic acid and
→ prussic acid.
See also: → hydrogen; → cyanide.
