Evaluation of an Ultraviolet C (UVC) Light-Emitting Device for Disinfection of High Touch Surfaces in Hospital Critical Areas
2019 Oct; 16(19): 3572.
doi: 10.3390/ijerph16193572 / PMCID: PMC6801766 / PMID: 31554297
2. Department of Health Sciences, University of Genoa, via Pastore, 1-16132 Genoa, Italy; [email protected] (M.L.C.); [email protected] (A.M.S.)
* Correspondence: [email protected]; Tel.: +39-050-2213-590
The aim of this study was to evaluate the effectiveness on the field of an ultraviolet C (UVC) light-emitting device in reducing environmental bacterial burden and the presence of pathogens when compared to the current standard operating protocol (SOP).
Hospitals that use UV-light disinfection after cleaning and disinfection standard protocol have actually significantly mitigated infection risks associated with environmentally mediated transmission routes.
The PX-UVC device (Xenex Disinfection Services, San Antonio, TX USA) uses a xenon flash lamp to generate high-energy, broad-spectrum ultraviolet and visible light (UVC 100–280 nm, visible 380–700 nm), in microsecond bursts (pulses) at 67 Hz. No touch UV technology is dependent on the distance between the lamp and the surface being disinfected. The inverse square law states that the doubling of distance between the lamp and the surface being disinfected will quadruple the time required for disinfection.
The PX-UVC device uses 5-min disinfection cycles and multiple positions with minimal distances from high-touch surfaces. The manufacturer recommends that high-touch surfaces are within two meters of the lamp in order to achieve optimal efficacy.
For patient rooms, the device requires one 5-min disinfection cycle on each side the patient bed and one cycle in the private bathroom (if applicable). For operating theatres, the device requires one 10-min disinfection cycle on each side of the operating bed. Due to the high-intensity broad-spectrum UV light, the device is operated in unoccupied rooms.
The exposition time varied from 14 min at 46,000 µWs/cm2 to 57 min at 22,000 µWs/cm2 for the sporicidal cycle.
When the robot is operated in accordance with the procedures, the ozone produced is far below the Occupational Safety and Health Administration OSHA short-term exposure limits (0.1 ppm/8 h), however the manufacturer recommends using the robot in rooms with a system of ventilation, where possible. The robot allows access to the room (a green light turns on) after a delay that allows the ozone to dissipate. In our study, rooms were aerated after using the robot.