Toxic Tuesdays

CHEJ highlights several toxic chemicals and the communities fighting to keep their citizens safe from harm.


Cyanide is a chemical usually found in compounds with other chemicals. Cyanide compounds can be found in some bacteria, fungi, algae, and the seeds of stone fruits. One of the most dangerous cyanide compounds is hydrogen cyanide, a colorless gas that smells like almonds. It is used in industrial processes such as electroplating, metallurgy, metal mining, plastics production, organic chemical production, and photographic developing. Hydrogen cyanide can enter the air surrounding industrial settings where it is used. It can also be produced by combustion engines, tobacco smoke, and the burning of acrylonitrile plastics. (CHEJ has previously written about acrylonitrile here). Because acrylonitrile is used in many consumer plastics, building fires are one of the most common ways people are exposed to hydrogen cyanide.

Breathing hydrogen cyanide for even short amounts of time is incredibly dangerous and can lead to death. When cyanide enters the body it stops cells from being able to produce energy, interfering with many life-sustaining functions of the brain and heart. Early symptoms of cyanide exposure occur within minutes and include headache, dizziness, elevated heart rate, shortness of breath, and vomiting. This can then progress to seizures, decreased heart rate, low blood pressure, coma, heart attack, and death. People who survive exposure can have lifelong neurological impairments. Factory workers who inhaled low levels of hydrogen cyanide over years have reported trouble breathing, chest pain, vomiting, and headaches. Exposure to other cyanide-containing compounds results in the same health effects. Because of the extreme toxicity of cyanide exposure, the use of cyanide-containing compounds and the use of compounds that can produce cyanide when burned should be restricted in order to protect public health.

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