Our Glo Germ Oil contains proven safe ingredients which simulate the presense of real germs, 5 micros in size. Glo Germ Oil will illuminate bright orange under UV light, showing where actual germs would reside. Glo Germ Oil works best in applications where greater accuracy is required. It is more difficult to remove than our oil. Place a few drops of the oil on palms of hands and rub together, including bthe back of hands. Scrape fingernails on pals to "infect" germs under the nails. Place hands under a UV light to view the "germs." Follow with normal hand washing, then test again with UV light to inspect how well the hands were washed.