Alkyl halides can be effectively scrubbed from gas streams containing them by passing the gas streams through dispersers having a very small pore size into an aqueous scrubbing liquid containing a nucleophile such as thiosulfate. Optionally, the addition of a water-soluble organic compound to the scrubbing liquid may increase the rate of destruction of the alkyl halide. Alkyl halides such as methyl bromide can be effectively scrubbed from enclosed spaces containing the halide, for example in enclosures used for fumigation.