Relative rate experiments performed in a photochemical reactor at 293 +/- 0.5 K and a total air pressure of 980 mbar were used to determine k(CH3C(O) OCH3 + Cl) = (1.93 +/- 0.27) x 10 (12) cm(3) molecule (1) s (1) and k(CH3C(O) OCH3 + OH) = (3.18 +/- 0.13) x 10 (13) cm(3) molecule (1) s (1). The product branching ratio for the Cl-initiated oxidation of CH3C(O) OCH3 was investigated at 293 +/- 0.5 K and 980 mbar N-2, air, or O-2, in the presence and absence of NO. Products observed were CH3C(O) OCHO, CH3C(O) OH, HC(O) OH, CO, and CO2. The product branching ratios were dependent on NO, but not on the oxygen partial pressure. (C) 2009 Elsevier B. V. All rights reserved.