UL’s laboratory in Carugate (Italy) has recently received a new accreditation that lets the laboratory team of experts test plastic materials in accordance to the standard IEC 60335-1 Annex T. The UL professionals can now conduct aging tests on selected plastic materials to verify any change of the material properties before and after exposure to UVC light. By doing so, the technicians verify that the exposure to UVC light has not modified the electrical or the mechanical characteristics of the material and it can be safely used if exposed to UVC light. Due to the sanitizing properties of UVC radiation, more and more organizations are using UVC light in the fight against coronavirus, and the number of products using UVC light has increased exponentially (for example robotic sterilizers, portable or stationary air filtering appliances, water treatment devices, handheld UV sterilizers). However, as UL explains, if UVC light can help fight Covid-19, it also presents health risks if it is improperly contained. Similar to UVC’s harmful effect on people, UVC affects plastic, too. Products requiring the use of plastic may become brittle with a visible color change on the material’s surface. In technical terms, UV radiation causes photooxidative degradation, which leads to a break of the polymer chains and deterioration of its mechanical properties. Additionally, plastic that has been damaged by UVC light can quickly lose its electrical and mechanical properties. For some plastics, UVC damage can lead to complete component failure altogether. “While there is evidence that UVC light may help fight Covid-19 – Davide Atzeni, UL operations manager, said – it’s also important to consider the long-term safety of products continuously exposed to UVC rays. This new testing capability will help both manufacturers and end users be and feel safer”.