Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In the United States, the person within an organization responsible for the safe use of radiation and radioactive materials as well as regulatory compliance. An organization licensed by the Nuclear Regulatory Commission to use radioactive materials must designate a Radiation Safety Officer in writing. The Radiation Safety Officer is responsible for recommending or approving corrective actions, identifying radiation safety problems, initiating action, and ensuring compliance with regulations. The Radiation Safety Officer (hereafter referred to as the RSO) is also responsible for assisting the Radiation Safety Committee in the performance of its duties and serving as its secretary.