Wine et al. (1983) determined the rate constants of reaction (5.2) at 237−477 K by direct measurement of time decay of O(3P) using a resonance fluorescence method. These values agreed well with previous experiments, and the IUPAC subcommittee (Atkinson et al., 2004) recommends the rate constant at 298 K as k(298 K)= 8.0 10-15 cm3 molecule-1 s-1, and the Arrhenius’s formula for temperature dependence as,