The reflected shock tube technique with multipass absorption spectrometric detection of OH-radicals at 308 nm, corresponding to a total path length of similar to 2.8 m, has been used to study the reaction CH3 + O-2 - CH2O + OH. Experiments were performed between 1303 and 2272 K, using ppm quantities of CH3I (methyl source) and 5-10% O-2, diluted with Kr as the bath gas at test pressures less than 1 atm. We have also reanalyzed our earlier ARAS measurements for the atomic channel (CH3 + O-2 -> CH3O + O) and have compared both these results with other earlier studies to derive a rate expression of the Arrhenius forrn. The derived expressions, in units of cm(3) molecule(-1) s(-1), are k = 3.11 X 10(-13) exp(-4953 K/T) over the T-range 1237-2430 K, for the OH-channel, and k = 1.253 x 10(-11) exp(-14241K/T) over the T-range 1250-2430 K, for the O-atom channel. Since CH2O is a major product in both reactions, reliable rates for the reaction CH2O + O-2 -> HCO + HO2 could be derived from [OH](t) and [0], experiments over the T-range 1587-2109 K. The combined linear least-squares fit result, k = 1.34 x 10(-8) exp(-26883 KIT) cm(3) molecule(-1) s(-1), and a recent VTST calculation clearly overlap within the uncertainties in both studies. Finally, a high sensitivity for the reaction OH + O-2 -> HO2 + O was noted at high temperature in the O-atom data set simulations. The values for this obtained by fitting the O-atom data sets at later times (similar to 1.2 ms) again follow the Arrhenius form, k = 2.56 x 10(-10) exp(-24145 K/T) cm(3) molecule(-1) s(-1), over the T-range, 1950-2100 K.