Lindane

A pesticide, which also has numerous other evocative trade names, e.g. Agrocide, Arbitex, Hexicide, and Omnitox; its chemical name is gamma-1,2,3,4,5,6-hexachlorocyclohexane, and its molecular formula is C₆H₆Cl₆.

A lot of people, e.g. Friends of the Earth International, want it banned for health and environmental reasons. Its use is being phased out in the first world, but continues in the developing world, according to http://www.pan-uk.org/banlindane. It is suspected of being carcinogenic to humans.

To throw in a bit of chemistry: Lindane is an organic compound containing six atoms each of carbon, hydrogen and chlorine. It is formed by the chlorination of benzene, making use of a chain reaction which begins with the splitting of chlorine molecules by ultraviolet radiation. The delocalised electron system of the benzene ring is destroyed as the six atoms of chlorine are added, one to each carbon. 1,2,3,4,5,6-hexachlorocyclohexane is thus a halogenated cycloalkane rather than an aromatic compound. Hexachlorocyclohexane exists as a number of structural isomers, of which Lindane, the gamma-isomer, is the only one with significant pesticidal properties.

The displayed formula of gamma-1,2,3,4,5,6-hexachlorocyclohexane, Lindane, is:

                  H   Cl
                   \ /
             Cl     C     H
               \  /   \  /
            H - C       C - Cl
                |       |
           Cl - C       C - H
               /  \   /  \
              H     C     Cl
                   / \
                 Cl   H

With thanks to eeyore14.