The Minnesota Historical Society’s Local History Services helps Minnesotans preserve and share their history. This blog is a resource of best practices on the wide variety of museum, preservation, conservation, funding, and non-profit management topics. We’re here to help.
I recently had an interesting question sent to my inbox about the safety of uranium-containing glass in a museum collection.
“So, I read The Radium Girls and had watched that webinar on hazards in museum collections. Yep, I put two and two together and bought a black light flashlight. Snapped these pictures and wondered, is it safe to keep them on display or any precautions?”
Uranium glass fluoresces bright green under ultraviolet light. Photo courtesy of Lindsay Marshall, Lake of the Woods Historical Society.
Here was my response:
Great question, and love the black light photos! (As an extra safety precaution on top of everything else, I recommend wearing UV-protecting eyewear when using a blacklight – polycarbonate safety glasses are one good option). These objects are really cool and I bet people would love to learn more about them.
The only real way to know how much precaution to take with any radioactive artifact is to measure the radiation coming off it using a Geiger counter. You might be able to partner with local health & safety officials to test the radioactivity of the glass. I don’t know if you’ve used a Geiger counter before, but it’s totally non-invasive, non-destructive testing.
Radiation is considered in “doses”, as in – how much radiation per year can I safely be exposed to? You can take one 'big' dose of radiation once per year and be safe, or you can get small exposures to radiation more frequently, and be at the same risk level. The risk is much less for a visitor who comes in occasionally and doesn’t spend all that much time near the radioactive glass compared to a collections worker who is working directly with these objects every day.
One way to mitigate risk is to limit the amount of time you spend with a radioactive object. Other ways to mitigate risk are to increase distance and barriers between you and the objects – good practice would be to always handle this glassware while wearing nitrile gloves; and to display it behind glass in a display case rather than on open display.
The good news is that the amount of uranium in glassware (or Fiestaware) is quite low – often as low as 0.5% of the weight of the object. They don’t emit much radiation. So it’s safe to have these kinds of objects in museum collections, although I recommend taking precautions like those I mentioned above.
For those who want to do more research, these are all great resources:
Managing Small Radioactive Collections in the UK: Experiences from the Polar Museum, Cambridge
Uranium Glass in Museum Collections
Uranium in a Cupboard Near You!
Seeing More: glow-in-the-dark glass
EPA: Radioactivity in Antiques
Radium Girls: The dark times of luminous watches
MN Department of Health: Radiation Control