Low Ozone Concentration and Negative Ions for Rapid SARS-CoV-2 Inactivation

Author(s): Davide De Forni, Barbara Poddesu, Giulia Cugia, Giovanni Gallizia, Massimo La Licata, Julianna Lisziewicz, James G Chafouleas, Franco Lori

Background: Ozone possesses potent anti-bacterial, anti-fungal, and anti-viral properties, but elevated levels can jeopardize human/animal health and cause long-term corrosion. To mitigate these risks, we explored the efficacy of brief exposure to low- concentration ozone for disinfecting indoor spaces without occupants or animals.

Methods: The ICON3 by O3ZONO/M2L, a novel disinfection device generating ozone and negative ions, was chosen to assess its potential in deactivating various SARS-CoV-2 viral isolates. In controlled laboratory settings, tests were conducted using an ozone- resistant airtight plastic box within a biological safety cabinet.

Results: Two strains of SARS-CoV-2 were exposed to ozone and negative ions, with virucidal activity measured through viral replication capacity and titer determination. Results indicated that low-concentration ozone (averaging 3.18 ppm post-peak) deactivated over 99% of SARS-CoV-2 within 20 minutes. Recreating similar ozone exposure with ICON3 in different volume rooms (15, 30, 60 m3) demonstrated a linear correlation between room volume and continuous ozone/ion flow duration needed to attain and sustain desired ozone levels from laboratory studies.

Conclusions: These findings suggest the potential of ICON3 for SARS-CoV-2 disinfection in unoccupied indoor environments under carefully monitored safety conditions.