The chlorine and fluorine substituted ethanes number in the fifties. Including bromine and iodine as possible substituents expands the group of halogenated ethanes much further. This group includes compounds of major commercial importance such as methyl chloroform (CH3CCl3), ethylene dichloride (CH2ClCH2Cl), fluorocarbon 113 (C2Cl3F3), and fluorocarbon 114 (C2Cl2F4). Environmentally favorable new solvents and refrigerants are being sought from within this group of compounds. The spectra are strong and each is unique. See SPECTRA, chapter Q.