dano84096 It absolutely damages organic molecules such as DNA, that's what makes it work. Glass, and metals are not rapidly affected. Most types of glass will absorb this light and protect whatever is on the other side (such as Organic LED displays). However, this spectrum of UV light also creates ozone which readily oxidizes many more organic molecules and unprotected metals such as copper. Between the harsh UV and the ozone, bacteria and viruses can be killed rather quickly. But continued long-term use will cause cumulative damage to other materials such as the natural rubber in some elastics, and degradation of some fabrics, but this takes much much longer. Just like a car's paint will fade after 20 years of full sunlight exposure, it takes a long time for non-organic materials to be affected.