Paraquat

Paraquat (trivial name; ), or N,N′-dimethyl-4,4′-bipyridinium dichloride (systematic name), also known as methyl viologen, is a toxic organic compound with the chemical formula [(C6H7N)2]Cl2. It is classified as a viologen, a family of redox-active heterocycles of similar structure. It is one of the most widely used herbicides worldwide. It is quick-acting and non-selective, killing green plant tissue on contact. Paraquat is highly toxic to humans and other animals. The toxicity and lethality depends on the dose and how the herbicide is absorbed by the body. In humans, paraquat damages the mouth, stomach, and intestines if it is ingested orally. Once absorbed in the body, paraquat causes particular damage to the lungs, kidneys, and liver. Paraquat's lethality is attributed to its enhancing production of superoxide anions and human lung cells can accumulate paraquat. Paraquat exposure has been strongly linked to the development of Parkinson's disease. Paraquat may be in the form of salt with chloride or other anions; quantities of the substance are sometimes expressed by cation mass alone (paraquat cation, paraquat ion). The name is derived from the para positions of the quaternary nitrogens.