α-Hexachlorocyclohexane (α-HCH) is an organochloride which is one of the isomers of hexachlorocyclohexane (HCH).

[1] It is a byproduct of the production of the insecticide lindane (γ-HCH) and it is typically still contained in commercial grade lindane used as insecticide.

Lindane, however, has not been produced or used in the United States for more than 20 years.

[1] At ambient temperatures it is a stable, white, powdery solid substance.

As of 2009, the Stockholm Convention on Persistent Organic Pollutants classified (α-HCH) and (β-HCH) as persistent organic pollutants (POPs), due to the chemical's ability to persistence in the environment, bioaccumulative, biomagnifying, and long-range transport capacity.