Potassium cyanide (KCN) is a highly toxic, white crystalline powder used in various industrial processes, including gold mining, electroplating, and organic synthesis. It releases hydrogen cyanide gas when it comes into contact with acids or water, posing severe risks if inhaled or ingested. Potassium cyanide is infamous for its rapid, potentially lethal effects on the human body, as it disrupts the cellular respiration process by inhibiting enzymes crucial for oxygen use. Handling potassium cyanide requires strict safety protocols, including protective equipment and proper ventilation. Due to its toxicity, it is regulated and should only be handled by trained professionals in controlled environments.