Radiation Safety Officer (RSO)

Under US Nuclear Regulatory Commission rules (10 CFR 35.24), every licensee authorised for the medical use of byproduct material must appoint a Radiation Safety Officer (RSO) in writing, who agrees to be responsible for implementing the facility's radiation protection programme and for ensuring that radiation safety activities follow licensee-approved procedures and regulatory requirements. Management, through the RSO, remains accountable for the programme even though day-to-day duties are delegated.

The qualification pathway is set out in 10 CFR 35.900 (and its current successor, 35.50 for newer licenses): an individual can qualify either by board certification (for example the American Board of Health Physics, American Board of Radiology, American Board of Nuclear Medicine, or the Board of Pharmaceutical Specialties in Nuclear Pharmacy), or through a structured programme of at least 200 hours of classroom and laboratory training covering radiation physics and instrumentation, radiation protection, mathematics of radioactivity, radiation biology and radiopharmaceutical chemistry, plus one year of full-time supervised experience as a radiation safety technologist, or by already being an authorized user identified on the licensee's own license. A licensee may also appoint one or more Associate Radiation Safety Officers to support the RSO, though the RSO cannot delegate the ultimate authority or responsibility for the programme.

The RSO role sits alongside, and is distinct from, the Authorized User, who is the physician credentialed to prescribe and administer specific categories of radioactive drugs; a single individual can hold both roles if separately qualified for each. Agreement States (which license the majority of US medical radioactive material users) apply equivalent, NRC-compatible requirements under their own regulations.