Use
URANIUM HEXAFLUORIDE in which the uranium has been depleted of the isotope U-235. Naturally occurring uranium contains 0.7% U-235 and 99.3% U-238 (lower radioactivity). Thus, a depleted uranium material with some U-235 removed by the enrichment process is less radioactive. Emits fumes of highly toxic metallic uranium and uranium fluorides when heated to decomposition [Lewis, 3rd ed., 1993, p. 1301]. Reacts vigorously with aromatic hydrocarbons (benzene, toluene, xylenes), undergoes a violent reaction with water or alcohols (methanol, ethanol) [Bretherick, 5th ed., 1995, p. 1439]. Reacts with most metals.