A flash photolysis-resonance fluorescence technique was used to study the rate constant for the reaction of OH radicals with dimethyl carbonate over the temperature range 252-370 K. The rate constant exhibited a weak temperature dependence, increasing at both low and high temperature from a minimum value of approximately 3.1 × 10^-13 cm³ molecule^-1 s^-1 near room temperature. Pulse radiolysis/transient UV absorption techniques were used to study the ultraviolet absorption spectra and kinetics of CH₃OC(O)OCH₂ and CH₃OC(O)CH₂O₂ radicals at 296 K. Absorption cross sections of CH₃OC(O)OCH₂ and CH₃OC(O)OCH₂O₂ at 250 nm were (3.16 ± 0.34) × 10^-18 and (3.04 ± 0.43) × 10^-18 cm² molecule^-1, respectively. Rate constants measured for the self-reactions of CH₃OC(O)OCH₂ and CH₃OC(O)OCH₂O₂ radicals and reactions of CH₃OC(O)OCH₂O₂ radicals with NO and NO₂ were (5.6 ± 1.1) × 10^-11, (1.27 ± 0.21) × 10^-11, (1.2 ± 0.2) × 10^-11, and (1.2 ± 0.2) × 10^-11 cm³ molecule^-1 s^-1, respectively. The rate constant for reaction of F atoms with dimethyl carbonate was determined by a pulse radiolysis absolute rate technique to be (6.1 ± 0.9) × 10^-11 cm³ molecule^-1 s^-1. A FTIR smog chamber system was used to show that, in 760 Torr of air at 296 K, CH₃OC(O)OCH₂O radicals are lost via three competing processes: 42 ± 15% via reaction with O₂, 14 ± 2% via H atom elimination, and 44 ± 10% via decomposition and/or isomerization. Relative rate techniques were used to measure rate constants for the reactions of F atoms with CH₃OC(O)OCH₃, (6.4 ± 14) × 10^-11 cm³ molecule^-1 s^-1, and Cl atoms with CH₃OC(O)OCH₃, CH₃OC(O)OCH₂Cl, CH₃OC(O)OCHO, and HC(O)OC(O)OCHO, (2.3 ± 0.8) × 10^-12, (4.6 ± 2.8) × 10^-13, (1.7 ± 0.1) × 10^-13, and (1.7 ± 0.1) × 10^-14 cm³ molecule^-1 s^-1, respectively. Results are discussed in the context of the atmospheric chemistry of CH₃OC(O)OCH₃.