Radiation Producing Machines

The University of California, San Francisco Office of Environmental Health and Safety (EH&S) operates a Radiation Producing Machine Program. There are a variety of radiation producing machines that are used on campus for research and both diagnostic and therapeutic purposes in the medical centers. The purpose of the program is to ensure the safety of campus staff and researchers when using machines which produce ionizing radiation. The components of the program include:

  • Registration of radiation producing machines with the State of California.
  • Radiation safety tests of the machines as specified in the California Code of Regulations Title 17.
  • Shielding specification (plans review).
  • Shielding determination.
  • Investigation of incidents or injuries.
  • Training of staff as needed or requested.


The Office of Environmental Health and Safety is the office of record for the registration with the State of California for the Radiation Producing Machines. Any acquisition, transfer or removal of radiation producing machines should be made known to EH&S by contacting the program specialists at 476-5303 (UCSF East Campuses) or 502-7666 (UCSF West Campuses). Machines that produce ionizing radiation which require registration include:

  • Diagnostic radiographic / fluoroscopic machines for clinical or research applications.
  • Computed tomographic machines.
  • Bone mineral densitometers.
  • Irradiators.
  • Cabinet x-ray machines for irradiation / imaging of samples.
  • Particle accelerators.
  • Analytical x-ray diffraction devices.
  • Electron microscopes.


Radiation Safety testing of radiation producing machines is performed at acquisition, relocation, after major repair or maintenance, and on an annual basis. When a machine has a significant repair or maintenance performed (change of tube, generator, collimators, etc.) contact EH&S to schedule the safety testing at 476-5303 (UCSF East Campuses) or 502-7666 (UCSF West Campuses). Radiation safety testing of radiation producing machines includes:

  • The measurement of the x-ray potential energy versus the selected energy.
  • Timer accuracy.
  • Linearity of exposure.
  • Skin entrance exposure / rate of exposure.
  • Reproducibility of exposure.
  • Photo-timer operation.
  • Filtration.
  • Beam limitation accuracy.
  • Proper labels and postings.
  • Scatter radiation exposure measurements.

EHS Categories

Radiation Safety