The reactions of hydrogen atoms with the ClCF2CHF, ClC2F4, BrC2H4, BrC2F4, and BrCF2CFBr radicals have been studied at room temperature and 1 Torr pressure of Ar by an infrared chemiluminescence technique in a flow reactor. The H + CF3CH2 recombination reaction was also examined to provide a reference point to earlier experiments from this laboratory. The recombination step generates vibrationally excited molecules that undergo HX(X = Br, Cl, F) elimination at I Torr of pressure. The characteristic low vibrational excitation, approximate to 0. 15, with a monotortically declining distribution from unimolecular 1,2-HX elimination reactions versus approximate to 0.35 with an inverted distribution from disproportionation, or direct halogen atom abstraction, reactions is used as a diagnostic test for recombination versus disproportionation mechanisms. Upon the basis of the observed HBr vibrational distributions, the H + BrC2F4 reaction has a small Br atom abstraction component that is superimposed upon the HBr vibrational distribution from unimolecular HBr elimination. The other reactions proceed only by a recombination-elimination mechanism. The multiple reaction channels, including C-Br rupture and 1,1-HX elimination as well as 1,2-HX elimination, of the haloethanes are discussed. The 1, 1-HX elimination channel is important for the CF2XCF2H and CF2XCFXH molecules. The H + PBr3 reaction is discussed in an appendix.