UVC for surface disinfection, particularly in health care settings, has been applied to reduce the number of microorganisms on surfaces. Surfaces can be irradiated with fixed or portable in-room UVC fixtures that serve as part of the room’s disinfection methodology. Application of UVC to any surface is based on the UV dose delivered to the surface. The dose (μJ/cm2) of UVC needed to disinfect a surface depends on the selected target and desired disinfection level. Different microorganisms require various levels of UVC
energy for to be killed or dis-activated.
UVC irradiates all line-of-sight objects and into shadowed areas (e.g., tables, chairs, surgical equipment, objects) through reflection, so the desired level of disinfection can be achieved, even on surfaces which are not directly irradiated. UVC surface disinfection should only be applied as an adjunct to normal surface cleaning procedures of the facility. No living organisms, including animals and plants, should be in the room when UVC is used.
The germicidal performance of UVC devices are depending on the device’s power output, distance between the unit to each surface, and irradiation time. A device with higher UVC irradiation power (μ W/cm2) will generate more UVC energy (μJ/cm2) on a given surface, within a specific time frame. Therefore, the duration of UVC irradiation that requires to kill or dis activate germs depend on the dose (μJ/cm2) delivered to a surface. Room size and space function are critical measures in selecting any stationary or portable UVC germicidal device.