Vapor pressure data below the normal boiling point are presented for ternary mixtures that are prepared from the following chemicals: perfluoro[methylethyl ether] (RE-218), pentafluorodimethylether (RE-125), 1, 1, 1-trifluorodimethylether (RE-143a), dimethylether (RE-170), 1,1,1,2-tetrafluoroethane (R-134a), 1,1,1-trifluoroethane (R-143a), 1,1-difluoroethane (R-152a), fluoroethane (R-161), and difluoromethane (R-32). Liquid-liquid phase separation in the binary mixtures RE-218/RE-170 and RE-218/R-161 is eliminated with the ternary mixtures, RE-218/RE-143a/RE-170 and RE-218/R-134a/R-161. A sufficient amount of vapor pressure data was obtained for these ternary mixtures to calculate vapor-liquid phase relations using van Laar equations for ternary mixtures. Vapor pressure data are also reported for a number of ternary mixtures containing RE-125. Liquid density data and the critical parameters are reported for the equimolar mixtures, RE-218/R-134a/R-161, RE-125/R-32/R-152a, and RE-125/R-32/R-134a, which are judged to have a high potential as R-22 alternatives based on their boiling point and critical temperature. (C) 2004 Elsevier B.V. All rights reserved.