Reactions of Cl atoms with CH₃OC(O)H (1) and CH₃CH₂OC(O)H (2) have been studied using the Discharge Flow-Mass Spectrometric (DF-MS) method. The study has been carried out at 1 Torr total pressure under pseudo-first-order conditions in the temperature range 253 K to 333 K to approach the tropospheric temperature profile. The measured room temperature rate coefficients are k(1) = (1.01 ± 0.15) × 10⁻¹² cm³ molecule⁻¹ s⁻¹ and k(2) = (8.78 ± 1.22) × 10⁻¹² cm³ molecule⁻¹ s⁻¹ (errors are 2σ) and the fitted Arrhenius expressions, k(1) = (1.7 ± 1.4) × 10⁻¹¹ exp −(810 ± 250)/T cm³ molecule⁻¹ s⁻¹ and k(2) = (5.5 ± 4.8) × 10⁻¹¹ exp −(556 ± 268)/T cm³ molecule⁻¹ s⁻¹ (errors are 2σ). The reactions proceed through the abstraction of an H atom to form HCl and the corresponding radical. At 298 K and 1 Torr, yields on HCl of 0.95 ± 0.09 (error is 2σ) for reaction (1) and 0.96 ± 0.11 (error is 2σ) for reaction (2) have been measured. The tropospheric lifetimes are calculated and discussed.