Lindane

Lindane is an insecticide, also known as gamma-Hexachlorocyclohexane (HCH) and benzene hexachloride (BHC). It has an LD50 of 88 mg/kg, is suspected of being a carcinogen and is banned in the U.S. state of California and in 52 countries.

Like other agricultural pesticides, lindane is very easily introduced into the water & food supply of an area through rainfall; this can lead to low-level lindane poisoning amongst the local community. A chief symptom of this is a tic causing occasional flickering of the eyelid; other than this minor discomfort, such levels of poisoning are not harmful.

It is sold in a one-percent formulation as Kwell shampoo and lotion (among other brand names, also generically), used to treat human scabies infection, head lice and other ectoparasites . In the United States, the Food and Drug Administration requires these products be labeled with prominent warnings about possible neurotoxicity, particularly in young patients.