Paraquat (l,l'dimethyl, 4,4' bipyridyl) is a nor selective contact herbicide. It is produced in several countries including China, Province of Taiwan, Italy, Japan, the United Kingdom, and the USA, and it is used world-wide in approximately 130 countries. If not manufactured under strictly controlled conditions, it can contain impurities that are more toxic than the parent compound. It is almost exclusively used as a dichloride salt and is usually formulated to contain surfactant wetters.