Chlormephos (chemical formula: C5H12ClO2PS2) is an organothiophosphate insecticide.

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S.

Emergency Planning and Community Right-to-Know Act (42 U.S.C.

11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.

[1] Chloromephos exhibits its toxic effects via the inhibition of the enzyme acetylcholinesterase, this is the same mechanism of action as the notorious chemical weapons known as V-series nerve agents.