The COVID-19 pandemic has made the general public more understanding of threats viruses pose. With that threat comes the interest in how long pathogens are able to survive on surfaces, in the hopes that people are able to minimize potential exposures. Hypochlorous Acid (HOCl) is effective against a wide range of microorganisms. This research will determine the efficacy of HOCl for eliminating the H1N1 Virus, which is responsible for a highly contagious respiratory disease, and identify the survival rate on various surfaces.
To identify the reduction rate of H1N1, a plaque assay technique was utilized to calculate the PFU of virus plated on polylactic acid, polystyrene and aluminum at different timeframes. In relation to time, drying in a room temperature was more susceptible to viruses surviving than at 4°C, despite the variance in surfaces. After 48 hours drying, none of the condition can reach 4 log reduction, not nearly enough to be considered antiviral (requires at least 4-log or 99.99%) (Figure 1). Therefore, the addition of HOCl was deemed necessary to increase the log reduction of H1N1 on various surfaces. the HOCl chlorine concentration was tested at 350 and 510 ppm (low and high). The samples contain with virus were fogged with HOCI at different time with a 5 mins interval of rest. The results show that even fogging with low concentration of HOCl, 10 mins fogging with 5 mins resting could eliminate more than 99.99% of H1N1 virus.(Figure 2) These preliminary results provide promising evidence that makes HOCl fogging, a cheap and readily available substance, a potential method of disinfecting with high efficacy.

Drying test on surface

Fogging results with time

Qianhui Hong

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