β-Hexachlorcyclohexane is a byproduct of the production of insecticide lindane (γ-hexachlorocyclohexane). Technical grade hexachlorocyclohexane contains about 5-12% of technical grade hexachlorocyclohecane. Elevated levels of β-Hexachlorcyclohexane in blood was linked with risk of Alzheimer's disease and Parkinson's disease. β-Hexachlorcyclohexane is a xenoestrogen and promotes growth and invasiveness of breast tumor cell lines.