Paraquat (PQ)

Paraquat is one of the most widely used herbicides in the world. Paraquat, a viologen, is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings and animals. Research has shown that it is linked to development of Parkinson's disease. The name is derived from the para positions of the quaternary nitrogens. Paraquat is used as a quaternary ammonium herbicide, one of the most widely used herbicides in the world. It is quick-acting, non-selective, and kills green plant tissue on contact. It is redistributed within the plant, but does not harm mature bark. Herbicides are used to protect crops by controlling a wide range of annual and certain perennial weeds that would otherwise compete with the crop for water, nutrients, and light. Pure paraquat, when ingested, is highly toxic to mammals, including humans; potentially leading to acute respiratory distress syndrome (ARDS).