University Grants Commission (UGC) has issued guidelines to varsities on use and safe disposal of radioactive elements, nearly eight months after origin of Cobalt-60, which lead to the death of a man here, was traced to Delhi University's chemistry department.UGC sources told PTI that various universities and colleges have been asked to follow the set guidelines on usage of radioactive elements without fail.Under these guidelines, universities and colleges have been asked to seek permission from Atomic Energy Regulatory Board (AERB) on purchase of radioactive substance, details on its use, formation and solutions in case of an emergency among others. They are also directed to maintain proper disposal mechanism for liquid radioactive substance.