FTIR smog chamber techniques were used to measure k(Cl + CF3CFHCF2O(CH2)(3)OCF2CFHCF3) = (2.97 +/- 0.17) x 10(-12) k(OH + CF3CFHCF2O(CH2)(3)OCF2CFHCF3) = (2.45 +/- 0.14) x 10(-13), k(Cl + C4F9O(CH2)(3)OC4F9) = (1.45 +/- 0.16) x 10(-12), and k(OH + C4F9O(CH2)(3)OC4F9) = (1.44 +/- 0.10) x 10(-13) cm(3) molecule(-1) s(-1) in 700 Torr of air at 296 K. The atmospheric lifetimes of CF3CFHCF2O(CH2)(3)OCF(2)ZCFHCF(3) and C4F9O(CH2)(3)OC4F9 with respect to reaction with OH radicals are estimated to be 46 and 83 days, respectively. In 700 Torr of N2/02 diluent at 296 K, decomposition via C-C bond scission and reaction with O-2 are competing loss mechanisms for the alkoxy radicals ROCH(O-.)CH2CH2OR and ROCH2CH(O-.)CH2OR (R = C4F9, CF3CFHCF2). (c) 2006 Elsevier B.V. All rights reserved.