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

Experiment Safety Overview

Safety review is managed through the online Experiment Safety Assessment Form (ESAF). An ESAF is connected to a specific proposal and scheduled beam time request (BTR). These forms are also an important part of scientific record keeping and accountability at the APS. On the ESAF, the user declares

  • Who will be involved (on-site and off)
  • What they will do
  • What the hazards are

Useful Links


Life Cycle of an ESAF

The following describes how the ESAF is used within the overal experiment process. You can also see this information in flowchart form.

  1. Creation from a beam time request (BTR): In the APS User Portal, you select the BTR for which you want to create an ESAF. The system extracts certain information from the proposal/BTR into the new form.
  2. Editing the ESAF: You edit the autofilled information (especially the information on experimenters); identify an on-site spokesperson; and provide procedure, sample, and hazard information. Please use the ESAF Instruction Guide for complete detail on how to fill out an ESAF. (Information on APS hazard classes and resources for material safety data sheets, along with APS contacts, are available on the Safety and Training page.)  
  3. Review: The APS safety staff and beamline representatives review and approve the ESAF. They will communicate with the on-site spokesperson about changes as necessary.
  4. Training: You ensure that all team members complete required training, as indicated on the ESAF.
  5. Experiment start: At the beamline, the APS Floor Coordinator asks the on-site spokesperson to sign an Experiment Authorization to confirm that the information provided in the ESAF is accurate. The Floor Coordinator will then verify the hazards and training on the Experiment Hazard Control Plan and checklist and both documents will be physically posted at the beamline. This marks the official start time of the experiment. The experiment cannot begin until these documents are posted.
  6. Experiment end: When you are finished, the Floor Coordinator removes the posted documents. This marks the official end time of the experiment.
  7. Official record: Data from the ESAF are recorded in the Experiments database, the official record of APS beamtime usage. This ESAF ceases to be active.
  8. Feedback: The proposal spokesperson receives a feedback form (End of Experiment Form [EEF]) found in My APS Portal
  9. Return visit: For your next visit, you will probably need to create a new ESAF on a new beam time request. You can copy and edit an earlier ESAF. If everything is the same (including experimenters and contact details), you can reuse an ESAF for up to one year.
How to Avoid Problems
  • Identify your team accurately and completely. For greater accuracy, use the "Find" option to automatically fill the form with a user's official profile data. Note: An ESAF is visible only to those people whose badge number is given in the form.
  • Submit the form at least 14 days in advance for onsite access review and 7 days in advance for remote/mail experiments or as early as possible if any nonstandard activities are involved.
  • Before traveling to APS, check the training section of the ESAF to make sure all team members have completed the required training and have approved APS Site Access. Team members can access the training through their account in the My User Portal.
More Information about the ESAF system: Please contact



To comment on the contents, please contact or 630-252-9090.