Abstract: The present invention discloses an activated biocidal aqueous solution containing hydrogen peroxide (activated peroxide solution) obtainable by subjecting an initial solution of hydrogen peroxide in water to a non-thermal electrical discharge process, such as a glow discharge plasma or a corona discharge. The resulting activated peroxide solution containing 0.05 to 20% (w/w) hydrogen peroxide has a pH in the range of 2 to 4, an oxidation-reduction potential (ORP) in the range of 400 to 600 mV, and the solution when having a peroxide content in the range of 0.05% to 0.5% (w/w) has a conductivity in the range of 100 to 500 ?Siemens/cm, the solution when having a peroxide content in the range of 0.1% to 5% (w/w) has a conductivity in the range of 100 to 450 ?Siemens/cm, and the solution when having a peroxide content in the range of 5% to 20% (w/w) has a conductivity in the range of 100 to 350 ?Siemens/cm.