Many vintage glassware items are not microwave safe; Depression glass can shatter in the microwave, according to the National Depression Glass Association.
So keeping in mind that most vintage glassware is not microwave safe due to the glass itself, let’s take a look at if there is any interaction between the Uranium and the microwave.
Uranium Glass in the Microwave
If your Uranium glass is newer and the glass itself is microwave-safe, Dr. Lyle Burgoon, regulatory toxicologist, is not concerned about putting Uranium glass in a microwave. He explains that the microwave should not change the dose of Uranium or the likelihood of breakage (assuming the glass is microwave-safe).
Bruce Heinmiller, Certified Health Physicist, also explained in an email that “there is no risk from putting a glass plate containing Uranium in a microwave oven.”
How Microwaves Interact with Uranium
I asked Bruce Heinmiller if there is any interaction between the Uranium and the microwave waves. He explained further:
“Uranium is mildly radioactive as a result of it having an unstable nucleus (all of its isotopes are radioactive), and irradiating it with microwaves has no effect on this radioactivity.
Glass containing enough Uranium will fluoresce with exposure to ultraviolet (UV) radiation, a property attributable to Uranium’s electron arrangement; UV has enough quantum energy to excite some of Uranium’s electrons above their ground state, and light is emitted as they return to the ground state. Although UV and microwaves are both electromagnetic radiation, microwaves have very low quantum energy, an energy insufficient to cause this fluorescence.
If there’s any interaction between uranium and microwave radiation it would be either reflection or absorption of the microwaves. The probability of this would depend on the amount and chemistry of the Uranium, but I expect it to be very low. Microwaves are reflected from metal surfaces and are absorbed by polar molecules such as water molecules. Dipole rotational motion results from this absorption and quickly results in the substance containing the polar molecules to be heated.
I’m not aware of glass plates containing Uranium having enough microwave absorption to heat it up significantly compared to substances being heated with it, but I did try it myself. I microwaved a glass of water on top of a Uranium glass plate. This resulted in hot water, but the uranium plate remained at room temperature, aside from some local heat conducted from the glass to the portion of the plate immediately under the glass.
Any risk from use of a microwave oven does not depend on whether or not the container in the oven contains uranium.”
Corinne Segura is a Building Biologist Practitioner with 8 years of experience helping others create healthy homes.