is an organochlorine insecticide
that was widely used until the 1970s, when it was banned in most countries. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides became notorious as persistent organic pollutants
Aldrin is produced by combining hexachlorocyclopentadiene
in a Diels-Alder reaction
to give the adduct.
<br style="clear:left;"/>Aldrin is named after the German chemist Kurt Alder
, one of the coinventors of this kind of reaction. An estimated 270 million kilograms of aldrin and related cyclodiene pesticides were produced between 1946 and 1976.
In soil, on plant surfaces, or in the digestive tracts of insects, aldrin oxidizes to the epoxide dieldrin
, which is more strongly insecticidal
Environmental impact and regulation
Like related polychlorinated pesticides, aldrin is highly lipophilic. Its solubility in water is only 0.027 mg/L, which exacerbates its persistence in the environment. It was banned by the Stockholm Convention on Persistent Organic Pollutants
. In the U.S., aldrin was cancelled in 1974. The substance is banned from use for plant protection by the EU