The organic compound 1,1,1-trichloroethane is a chloroalkane. This colourless, sweet-smelling liquid was 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. 1,1,2-Trichloroethane, or 1,1,2-TCA, is an organochloride solvent with the molecular formula C2H3Cl3. It is a colorless, sweet-smelling liquid that does not dissolve in water, but is soluble in most organic solvents. It is used as a solvent and as an intermediate in the synthesis of 1,1-dichloroethane. TCA is a central nervous system depressant and inhalation of vapors may cause dizziness, drowsiness, headache, nausea, shortness of breath, unconsciousness, or cancer.