Bactericidal, fungicidal, and antiviral activity of highly purified hypochlorous acid water.

This study demonstrates that high-purity hypochlorous acid water (HP-HAW) produced via reverse osmosis (RO) membrane filtration exhibits rapid, broad-spectrum antimicrobial and antiviral activity, comparable to that of hypochlorous acid water (HAW) prepared without RO membrane treatment. Common vegetative bacteria, dermatophytes, and Candida albicans were completely inactivated within 10 s, indicating excellent performance for routine disinfection. HP-HAW also showed moderate efficacy against Mycobacterium abscessus but limited activity against M. avium, M. kansasii, and spore-forming bacteria. Filamentous fungi such as Aspergillus niger were more resistant than the other fungal species tested, requiring longer exposure. Strong antiviral activity was observed against adenoviruses, influenza virus, norovirus, and others, although some enteroviruses (e.g., coxsackievirus A6 and B5) were resistant. Overall, HP-HAW demonstrates promising disinfectant properties comparable to those of HAW without RO membrane filtration; however, its limited efficacy against certain pathogens should be considered for practical applications.