Before 1943, the colorant was uranium oxide, with the uranium content being about 0.7% U-235 and the remainder U-238. Between 1943 and 1959 under license by the AEC, the Laughlin company begain producing a red glaze dinnerware. The colorant then used technical grade uranium U-308 with the uranium content being made up of about 0.2% U-235 and the remainder U-238.

In a study done at Perdue University, the radiation from the uranium oxide was measured. They calculated the exposure to the plates, bowls, and cups as if a person was holding a 13″ chop plate strapped to their chest for twenty-four hours. This resulted in an exposure of twenty milliroentgens per day. Safe levels for humans working with radiation is twenty milliroentgens per day. In comparison,a dental x-ray produces 910 mR per film. Therefore, Radioactive red fiestaware is safe to use. Also, there is no danger from the fired-on glazes.

After a Televison station caused a scare in 1977, fiestaware was tested and the FDA reported that daily use of fiestaware for serving food does not pose a hazard. It did warn that to be on the safe side, food should not be stored on the dishes. Also, it concluded that the glaze or decal is no hazard. Check out these great videos with fiestaware and a geiger counter!