(CNN) -- FedEx on Friday found a package containing radioactive material that went missing a day earlier at one of its shipping stations in Knoxville, Tennessee, the company said.
The package contained a radioactive rod used in CT scans, which use X-rays to create images of patients' bodies.
The shipment was lost in transit between its origination point, a hospital in North Dakota, and the equipment's manufacturer in Tennessee.
FedEx spokeswoman Sandra Munoz said the rod was enclosed in a metal cylinder that was itself enclosed in a rectangular box. That rectangular box had originally been placed in another box that had the shipping information on it.
"We are trying to track down how the package became detached from the original shipment," Munoz said.
FedEx employees found an unlabeled container Friday afternoon and opened it, revealing the metal cylinder, which remained closed.
"FedEx employees were never exposed to the radiation," Munoz said.
Earlier, Munoz had said that if the metal container were opened, there would be some exposure to radiation, but at a low concentration. "There would be some very low-level energy skin absorption there. It would take 1,000 hours of exposure to get skin blisters," she said.
CNN's Greg Morrison contributed to this report.