The reflectivity of material lining the inside of a disinfection chamber can have a dramatic effect on the ultraviolet-C (UV-C) radiation dose received across all sides of a contaminated object. Because minimum UV-C dosages are required to reliably inactivate microorganisms, it is crucial for the disinfection chamber to have either multiple UV-C sources or a highly reflective internal surface. This article describes an experimental comparison of four different materials, polytetrafluoroethylene (PTFE), acrylonitrile butadiene styrene, silver gloss self-adhesive aluminum, and Rosco matte black Cinefoil, to determine their efficacy as UV-C reflectors by using a custom-designed testing apparatus utilizing a UV-C radiation-emitting diode alongside photochromic UV-C indicators, allowing for a full 360° analysis of a target object and its received UV-C dose. Results determined that UV-C radiation received at the photochromic indicators varied greatly among the chosen materials, with PTFE providing the most uniform levels of radiation across all sides of the test object.
Keywords: disinfection; light-emitting diodes; photochromic; polytetrafluoroethylene; reflectivity; scattering; ultraviolet-C.