Endrin

Endrin is a cyclodiene insecticide used on cotton, maize, and rice. It also acts as an avicide. As a rodenticide, it is used to control mice and voles. It is a solid, cream to light tan to white, almost odorless substance. It melts and decomposes at 200 °C. It is moderately soluble in benzene and acetone, slightly soluble in alcohols, alkanes, and xylene, and almost insoluble in water. It is also known as Mendrin, and Compound 269.

The use of endrin is now banned in many countries.

The majority of use (about 80%) was as a spray to control insect pests of cotton. It was also used on rice, to some extent on sugar cane, in a limited way on grain crops and sugar beets, and in Australia on tobacco and cole crops. It was occasionally used in orchards as a control of rodents, where it is sprayed on the ground under the trees in autumn or spring, often as a solution in mineral oil. As a seed treatment, it was used for cotton seed in the United States, and for beans seeds in Australia.

Endrin is a stereoisomer of dieldrin and is structurally similar to aldrin, and heptachlor epoxide.

It is likely to adsorb onto the sediments in surface water. It can bioaccumulate in tissues, particularly fatty tissues, of organisms living in water. Some estimates indicate its half-life in soil for over 10 years. It is very toxic to aquatic organisms, namely fish, aquatic invertebrates, and phytoplankton. 

Acute endrin poisoning in humans affects primarily the nerve system. Food contaminated with endrin caused several clusters of poisonings worldwide, especially affecting children. 

In comparison with dieldrin, the degree of persistence of endrin in organisms is lower, likely due to its rapid excretion in bile. It is eliminated mostly in feces.