This invention relates to an aqueous composition and a process for killing spores. The process may comprise contacting the spores with the aqueous composition for a sufficient period of time to effect a desired reduction (e.g., at least a 4 log reduction) in the number of spores capable of returning to vegetative growth. The aqueous composition may comprise water, an antimicrobial agent (e.g., peracetic acid) and a peroxide (e.g., hydrogen peroxide). The process may be a two-step process involving the use of a first aqueous composition, which may comprise water and the peroxide, and a second aqueous composition which may comprise water and the antimicrobial agent.
