Kinetics of the Reaction of Hydroxyl Radicals with CH sub(2)Br sub(2) and Its Implications in the Atmosphere

The rate constants of the reaction of dibromomethane with hydroxyl radicals were measured at different temperatures using a discharge-flow-resonance fluorescence apparatus. All experiments were conducted under pseudo-first-order conditions. At a typical average tropospheric temperature of 277 K, the lifetime of CH sub(2)Br sub(2) was estimated at 1.12 10 super(-13) cm super(3)/molecule/s. The ozone depletion potential of the compound, which is defined as the integrated O sub(3)-destroying capacity of a gas emitted into the troposphere over a given timescale per unit mass related to a reference gas, was estimated at 0.13.