Paper Title
Evaluation of Non-Touch Disinfection Potential of Ultraviolet Germicidal Irradiation in Different Operational Settings

Abstract - This paper presents a scoping assessment, highlighting the potential role of Ultraviolet germicidal irradiation (UVGI), i.e. application of short-wavelength ultraviolet (UV-C) light, to kill or inactivate microorganisms, as an alternative to conventional water-based sanitisation practice. Typical disinfection activities have been classified into three application categories – “High risk-High frequency”, “Moderate risk-Moderate frequency”, “Moderate risk-Low frequency”. Based on the evaluations of additional energy demands and the potential gains (water resource and energy savings), our study found UVGI to be the most effective for high frequency sanitisation in high-to-moderate risk applications, such as healthcare facilities, public transit, transport hubs, etc. This is mainly attributed to its short treatment time averaging 5m2/min at the UV-C exposure levels of 207 J/m2, resulting in>4log10 reduction for SARS-CoV-19 (99.99% disinfection). The corresponding water and chlorine resources saving potential is between 0.01-0.1 L and per 0.01-0.15 grams per m2 sweep area respectively, depending on the application intensity and frequency. These outcomes are extrapolated to some real-world scenarios to evaluate the trade-offs of this technology, comparing the added energy demands for operating the UVGI unit against the resource and energy savings from conventional cleaning, especially in terms of alleviating water demand. Integrating the UVGI sanitation technology with localised renewable energy generation can offer a clean and resource-efficient disinfection technology to overcome the supply chain in sanitising public assets. Keywords - Germicidal; Sanitisation; SDG; UV-C; UVGI