The organic compound 1,1,1-trichloroethane, also known as methyl chloroform and chlorothene, is a chloroalkane with the chemical formula CHCCl. It is an isomer of 1,1,2-trichloroethane. This colorless, sweet-smelling liquid was once produced industrially in large quantities for use as a solvent. It is regulated by the Montreal Protocol as an ozone-depleting substance and its use is being rapidly phased out.