Yes, UV-C light has been tested at many institutions and on a product-by-product basis, observing the effectiveness of UV light on killing microorganisms. UV light has been used since the late 1880’s to kill microorganisms so it has had centuries of domestic use. There has also been plenty of research on its potential harmful effects to humans which research suggests seem to be minimal if non-at all, if not exposed for long, sustained periods. However you should not look directly at UV light – as you would not look directly at the sun.
DentaDenta UV has been tested and seen to kill 99.9% of bacteria, germs and microbes.