MOLECULE

Methyl isocyanate

Isocyanatomethane or methyl isocyanate, also known as iso-cyanatomethane or methyl carbonimide, belongs to the class of organic compounds known as isocyanates. These are organic compounds containing the isocyanic acid tautomer, HN=C=O, of cyanic acid, HOCN or its hydrocarbyl derivatives RN=C=O. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Isocyanatomethane is a colorless, poisonous, lachrymatory (tearing agent), flammable liquid. It is soluble in water, but it also reacts with it. Isocyanatomethane is an intermediate in the production of carbamate pesticides (such as carbaryl, carbofuran, methomyl, and aldicarb). It has also been used in the production of rubbers and adhesives. As a highly toxic and irritating material, it is extremely hazardous to human health. Cyanide is an inhibitor of the cytochrome C oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). As a result, the electron transport chain is disrupted, and the cell can no longer aerobically produce ATP for energy. Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma, seizures, apnea, cardiac arrest and death. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Chronic inhalation of cyanide causes breathing difficulties, chest pain, vomiting, blood changes, headaches, and enlargement of the thyroid gland. Isocyanatomethane has been detected in the volatile fraction of Cannabis sativa samples, obtained from police seizures (PMID: 26657499).