Disinfection Efficacy Analysis of an Ultraviolet-C (UVC) Device for Escalator Handrails

The global Coronavirus pandemic is of urgent concern with its high transmission rate and rapid spread throughout the world from 2019. This paper introduces an Ultraviolet-C (UVC) device to be fitted on escalators which was designed to inactivate bacteria and viruses on the surfaces of handrails during escalator operation. Through a combination method of measurement and finite element analysis (FEA) simulation, the authors accurately calculated the UVC intensity, dosage, and distribution of the UVC device on a surface. The authors also describe how the UVC device works and detail the disinfection efficacy of the device to inactivate bacteria and viruses. In this work, efficacy of the device against two bacteria (E. Coli and S. Aureus) and two corona viruses (HCoV-229E and HCoV-OC43) were tested. All tests were conducted in two modes of the UVC device: continuous mode and pulsed cyclic mode. Based on the test results and combining UVC parameters, the disinfection efficacy of the UVC device was analysed. The investigation found, i) the relationship between the disinfection efficacy and the UVC parameters of the device, ii) the relationship between the disinfection efficacies of continuous and pulsed test mode and iii) the dosage for killing 99% pathogens (D99) of the UVC device for the two bacteria and viruses based on escalator operation.