The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

Experiment Hazard Class 8.2 – Sealed Sources


This hazard classification applies to all experiments involving the use of DOE exempt and non-exempt radioactive sealed sources.

Experiment Category

Experiments in this experiment hazard class are categorized as high, medium, or low risk depending upon the type of source and the manner in which the source will be used.

Experiment Hazard Control Verification Statements

Engineered Controls – None.

Procedural Controls – Sealed sources must be secured when no experimenters are present.

Design Reviews and Equipment Inspections – Sealed sources must be checked out from the Beamline Sealed Source Custodian and the location must be logged.  Sources will be deemed exempt or non-exempt as determined by RSO-HP personnel.


  • GERT (ESH 738) for exempt sealed sources.
  • ANL Radiation Worker I or II (ESH700 or ESH702) for non-exempt sealed sources depending on the associated exposure rate.  There is also a practical training requirement which is administered by RSO-HP.

Signs and Labeling – All signs and postings required for the experiment station will be supplied by RSO Health Physics.

Personal Protective Equipment – As determined in the review of the experiment.

Dosimetry and Monitoring – All users involved in the experiment may be required to wear a dosimeter during the experiment.  Dosimetry requirements are determined during the review of the experiment.

Experiment Authorization

Unless otherwise noted in the approved experiment safety plan, the PSC Deputy Associate Laboratory Director of Operations delegates the authority to authorize an experiment in this hazard class to the Beamline Sealed Source Custodian, a member of the APS Experiment Safety Review Board, and resident beamline personnel having the authority to authorize experiments as listed in the ESAF system.  Approval by both the host beamline and APS Experiment Safety Review Board are mandatory prerequisites for experiment authorization.

Hazard Control Verification

The PSC Deputy Associate Laboratory Director of Operations delegates responsibility for verifying that required controls are in place to RSO Health Physics, the experiment On-Site Spokesperson, and Beamline Management.


Contact the APS User Safety Program with any questions or if the internal links are not working properly.

Reviewed: May 8, 2020