CFR › Title 10 › Part 71 › §71.6310 CFR §71.63Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkShipments containing plutonium must be made with the contents in solid form, if the contents contain greater than 0.74 TBq (20 Ci) of plutonium.