Most of the ingredients in normal paints (binders, additives and pigments) absorb the deeper ultraviolet wavelengths in UV-C simply due to their molecular structure.  UV-C is a very short wavelength of light that is absorbed by many types of molecules including many carbon bonds present in living things and in polymers and paints. The germicidal properties of UV-C are due to UV-C being absorbed by DNA’s molecular structure, which leads to bond-breaking and DNA errors that render microbes unable to replicate.  A typical paint or plastic material will absorb about 95% of light at 254 nanometers (the most common germicidal UV-C wavelength).  To develop patent pending Lumacept™ we had to essentially re-write the book on coating formulation,  to provide interior latex coatings with high UV-C reflectivity.