Synergistic Effects of Low-Level UV and Hydrogen Peroxide in Reducing Airborne Influenza A (H1N1) ^†

Introduction: Influenza A (H1N1) is a highly contagious respiratory virus transmitted via droplets and aerosols, representing a major public health challenge. This study evaluated the effectiveness of a novel air decontamination technique based on the synergistic use of low-level ultraviolet (UV) light and hydrogen peroxide (H₂O₂). Separately, these components show limited antiviral efficacy, but when combined, they generate reactive oxygen species that are approximately ten times more powerful than traditional disinfection methods. The process accelerates the decomposition of harmful viral particles, leaving behind only water and oxygen. Methodology: Experiments were conducted in a 28.5 m³ environmental chamber under controlled temperature and humidity. Six decay tests were performed: three control runs and three active runs with the UV–H₂O₂ system operating. Airborne Influenza A (H1N1) was aerosolised and sampled at multiple time points. Viral RNA concentrations were quantified using real-time qPCR. Results: Control runs showed stable airborne virus concentrations with a natural decay of only 22.9%. In contrast, the UV–H₂O₂ technique achieved rapid and consistent viral reduction, reaching 95.4% within 50–60 min in two test runs, and 95.6% in a third run with reduced UV exposure. Importantly, no harmful ozone generation was detected. Conclusion: The combined low-level UV and H₂O₂ technique provides a highly effective, safe, and sustainable approach for reducing airborne viral loads, demonstrating its strong potential to enhance indoor air quality and mitigate infectious disease transmission.