ChEBI: Hexachlorobenzene is a member of the class of chlorobenzenes that is benzene in which all of the hydrogens are replaced by chlorines. An agricultural fungicide introduced in the mid-1940s and formerly used as a seed treatment, its use has been banned since 1984 under the Stockholm Convention on Persistent Organic Pollutants. It has a role as a persistent organic pollutant, a carcinogenic agent and an antifungal agrochemical. It is a member of chlorobenzenes and an aromatic fungicide.