Sodium cyanide is harmful because it interferes with the body’s ability to use oxygen. According to the Center for Disease Control, sodium cyanide releases a highly toxic chemical asphyxiant known as hydrogen cyanide gas. This gas retards the body’s ability to use oxygen properly, which leads to fatalities.
Sodium cyanide is fatal if it is inhaled, swallowed or absorbed through the skin, and if it comes in contact with the skin or eyes, it causes burns. Because sodium cyanide is extremely toxic, even a small dose of 5 kilograms is considered fatal.
Sodium cyanide affects the entire body, especially the organs that are sensitive to low oxygen, such as the brain, heart, blood vessels and lungs. This means that people with chronic diseases of the respiratory tract, kidneys, skin or thyroid are at a much greater risk of developing toxic cyanide effects if they are exposed.
In addition, sodium cyanide is highly reactive to water and acids, even weak acids like soda pop. When it reacts with these agents, it releases the fatal and extremely flammable hydrogen cyanide gas. It also reacts violently with magnesium, fluorine, nitric acid, nitrates and nitrites. According to the CDC, even carbon dioxide from the air is acidic enough to release hydrogen cyanide gas when it comes in contact with sodium cyanide.