The Cl atom initiated oxidation of C6F13CH2OH, C6F13CHO, and C3F7CHO was investigated at 298 K and 1000 mbar pressure of air in a photoreactor using in situ Fourier transform infrared (FTIR) analysis. The rate coefficient for the reaction Cl + C6F13CH2OH (reaction 2) was measured using a relative method: k(2) = (6.5 +/- 0.8) x 10(-13) cm(3) molecule(-1) s(-1). C6F13CHO was detected as the major primary product, while CO and CF2O were found to be the major secondary products. A fitting procedure applied to the concentration-time profiles of C6F13CHO provided a production yield of (1.0 +/- 0.2) for this aldehyde in reaction 2, and the rate coefficient for the reaction Cl + C6F13CHO (reaction 4) was k(4) (2.8 +/- 0.7) x 10(-12) cm(3) molecule(-1) s(-1). A high CO yield observed in the oxidation of C6F13CH2OH, (52 +/- 1)%, is attributed to the Cl atom initiated oxidation of C6F13CHO. High CO yields, (61 +/- 2)% and (85 +/- 5)%, were also measured in the Cl atom initiated oxidation Of C3F7CHO in air and nitrogen, respectively. These high CO yields suggest the occurrence of a decomposition reaction of the perfluoroacyl, C6F13CO, and C3F7CO radicals to form CO which will compete with the combination reaction of these radicals with oxygen to form perfluoroacyl peroxy radicals in the presence of air. The latter radicals CnF2n+1CO(O)(2) (n = 6-12), through their reaction with HO2 radicals, are currently considered as a possible source of persistent perfluorocarboxylic acids which have been detected in the environment. The consequences of the present results would be a reduction of the strength of this potential source of carboxylic acids in the atmosphere.