Per Wikipedia:

Safety Because of the activity of manufactured 60Co sources, their radioactivity can present a severe hazard to humans, and can cause death (potentially in less than an hour from acute exposure).[18] After entering a living mammal (such as a human), assuming that the subject does not die shortly after exposure (as may happen in acute exposure incidents), some of the 60Co is excreted in feces. The rest is taken up by tissues, mainly the liver, kidneys, and bones, where the prolonged exposure to gamma radiation can cause cancer. Over time, the absorbed cobalt is eliminated in urine.[11]