Hexachlorobenzene (HCB)

Hexachlorobenzene is a chlorocarbon with the molecular formula C6Cl6. It is a fungicide formerly used as a seed treatment, especially on wheat to control the fungal disease bunt. It has been banned globally under the Stockholm Convention on persistent organic pollutants. Hexachlorobenzene is an animal carcinogen and is considered to be a probable human carcinogen.This material has been classified by the International Agency for Research on Cancer (IARC) as a Group 2B carcinogen (possibly carcinogenic to humans). Animal carcinogenicity data for hexachlorobenzene show increased incidences of liver, kidney and thyroid cancers. Chronic oral exposure in humans has been shown to give rise to a liver disease, skin lesions with discoloration, ulceration, photosensitivity, thyroid effects, bone effects and loss of hair.