CF3OH is an atmospheric sink for hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs). Several new mechanisms, including catalyzation via H2O and OH radical, for the decomposition of CF3OH into HF and CF2O are studied using ab inito methods. The present work demonstrates that the OH radical has a strong catalytic effect on the transition state for the decomposition of CF3OH. The barrier is found to be reduced from 45.9 kcal mol(-1) for the unimolecular decomposition to 11.0 kcal mol(-1) for decomposition including H2O and OH.