Quoted from “Yellow-Green Vaseline – The Magic Glass” by Jay Glickman: First of all, the coloring agent used in glass is not the unstable and radioactive element uranium, but the more stable compound URANIUM DIOXIDE. Secondly, this uranium compound is only 1% to 2% per volume of the glass. Finally, and most importantly, it is the medium, glass itself, which contributes to the safety of Vaseline Glass. Glass, being a solid, is a barrier or shield to radiation. Glass is actually used in radiation rooms for such purposes. The bottom line is that there is an insignificant amount of radiation emission from Vaseline glass roughly equivalent in distance to source as TV and microwave-oven emissions. If you are interested in further information on Vaseline Glass, we would highly recommend the book “Yellow-Green Vaseline – A Guide To The Magic Glass” written by Jay L. Glickman. It contains a wealth of information as well as full color pictures of over 100 pieces of Vaseline glass