A method for disinfecting a volume or surfaces bounding a volume comprising nebulisinga solution comprising a sterilizing agent in a solvent having a lower boilingpoint than the sterilizing agent, for example ultrasonic nebulization of aqueoushydrogen peroxide, to form a nebulant. The nebulant is subjected to energy ofa kind and for a duration sufficient to vaporize solvent in preference to sterilizingagent, eg heating element means, infra red, laser, microwave, RF or other radiationgenerating means； induction heating means； heat exchanger means； conductionmeans； convection means； or mechanical energy transfer means to increase theconcentration of the agent in the nebulant particles. Vaporized solvent is removedfrom the gas stream at or above atmospheric pressure and, if necessary, the nebulantis cooled to below 7O0C. The volume or surfaces are exposed to the nebulant fora time sufficient to sterilize said volume or surfaces. Also, apparatus for carryingout the method.
