Development and verification of a test rig for inactivation of bacteria and (corona-) viruses by UVC air disinfection systems

Abstract

The ongoing coronavirus pandemic spreads through airborne transmission and is therefore difficult to contain. However, coronaviruses are highly sensitive to UVC, so UVC air disinfection systems should be able to inactivate the virus. Unfortunately, so far there are only few possibilities to test the reduction of airborne viruses or other pathogens. A special test rig, which mainly consisted of a nebulizer and an airflow system, was developed to determine the antiviral and antibacterial efficiency of UVC air disinfection systems. In the assessment of such an UVC air disinfection system with nebulized Staphylococcus carnosus and a sampling period of 30 minutes, a mean bactericidal reduction of 3.70 log10 (99.98 %) was determined. For antiviral irradiation of the coronavirus surrogate phi6 a mean viral load reduction of 1.18 log10 (93.40 %) was observed after a sampling period of 10 minutes. Therefore, mobile UVC air disinfection systems could be applied in hospitals, retirement and nursing homes.

Keywords

• sars-cov
• sars-cov-2
• coronavirus
• covid- 19
• phi6
• s. aureus
• bacteria
• staphylococcus aureus
• uvc
• uv-c
• ultraviolet
• irradiation
• inactivation
• disinfection