A two-part sterilant system comprises: (a) a first part comprising a first reagent in an aqueous medium having a first foam promoter dissolved therein and contained in a first dispenser whereby it may be dispensed as a first foam; and (b) a second part which comprises a second reagent in an aqueous medium having a second foam promoter dissolved therein and contained in a second dispenser whereby it may be dispensed as a second foam; wherein the first reagent and the second reagent will react to provide a sterilizing composition when the first foam is mixed with the second foam.