Negative air ionisation and the production of hydrogen peroxide

The aim of this study was to investigate the possibility of producing low concentrations of hydrogen peroxide (H2O2) in indoor air, when using an extra high-tension, direct-current, negative voltage generator. A specially designed interactive gas-phase reactor (IGPR) was used to assess in real time, the concentration of gaseous H2O2 in indoor air (with varying relative humidity levels), exposed to negative ionisation. The air in the IGPR was ionised by corona discharge from a carbon fibre thread emitter, charged with a variable negative voltage (−7.5–0 kV). Small negative air ion concentrations measured within the IGPR ranged from 0–21,000 ions cm−3 of air. H2O2 concentrations ranged from 0.46 μg l−1 in ordinary air (RH 40%) to 936 μg l−1 in wet air (RH 96%). This study demonstrates that it is possible to produce and measure in real time, low concentrations of gaseous H2O2 in indoor air, exposed to negative air ionisation.