Hydrogen cyanide is a colorless gas or liquid with a faint, bitter almond odor. Sodium cyanide and potassium cyanide are both colorless solids that have a slight odor of bitter almonds in damp air.
Cyanides are both man-made and naturally occurring substances.
They are found in a number of foods and plants and are produced by certain bacteria, fungi, and algae. Most of the cyanide found in the environment comes from industrial processes. Hydrogen cyanide is used mainly in the production of organic chemicals. Cyanide salts are used primarily in electroplating and metal treatment. Cyanide gained public attention when it was found to have caused the deaths of seven people who swallowed capsules contaminated with it.