Electron Microscope Radiation Safety Education

Radiation Safety Requirements for Use of Electron Microscopes

What are the radiation safety concerns?

The radiation safety concerns are related to the electrons that are backscattered from the sample, as well as X-rays produced in the process. Most modern electron microscopes are extremely well shielded and do not produce exposure rates greater than background. However, electron microscopes are radiation-generating devices and are required to be register with the Pennsylvania State Department of Environmental Health and Safety Bureau of Radiation Protection.  It is also important that the integrity of the shielding is maintained, that all existing interlocks are functioning, and that workers are aware of radiation safety considerations.

Rules for Safe Use

  1. Applicability

    • The rules in this section apply to electron microscopes. These requirements are in conformity with the Pennsylvania Code Title 25 Environmental Protection Chapter 227 Sections 227.31, 227.32 and 227.33.

  2. Registration

    • Penn State is required to register your electron microscope with the State of Pennsylvania. The state as well as EHS maintains an inventory of X-ray producing equipment at Penn State University. EHS notifies the state of all changes to the inventory. Please notify EHS if you install, move or dispose of an electron microscope.

  3. Posting

    • No radiological area posting is required for electron microscopes.

    • Pennsylvania Department of Environmental Protection Bureau of Radiation Safety form 2900-FM-RP0003 "Notice to Employees"

  4. Warnings and Labels

    • A label bearing the statement: "CAUTION: THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED" shall be posted on the electron microscope.

  5. Training

    • Individuals who wish to operate electron microscopes are required to read this Electron Microscope (EM) document (https://ehs.psu.edu/radiation-protection/electron-microscope-radiation-safety-education) and then verify that they have completed the reading by going to the EHS Course Registration page, log in if necessary, and click on “Enroll” for |Electron Microscope (EM) Safety Education” under "Radiation Safety". Those who have taken the Radiation Producing Equipment Safety Education do not need to take the EM specific training. Both the Electron Microscope (EM) Education and the Radiation Producing Equipment education are a one time only class and do not require a refresher. However, all individuals should receive hands-on instruction and training (e.g. working with experienced users, reading the manufacturer's operation manual) before independently using the equipment.

  6. Operating Procedures

    • Operating procedures/instruction manuals should be available to all users.

    • Radiation safety interlocks, if present, must remain operational unless approved by the RSO.

  7. Radiation Limits

    • Radiation emitted from electron microscopes shall not exceed a dose equivalent rate (averaged over 10 square centimeters) of 0.5 mrem (5 µSv)/hr at 5 cm from any accessible surface of the equipment.

    • All miscellaneous X-ray producing equipment (electron microscopes) must contain sufficient shielding, and be located and operated so exposure rates in unrestricted areas do not exceed 2 mrem/hr or 100 mrem/yr.

  8. Personnel Monitoring

    • Personnel monitoring is not required for users of electron microscopes.

  9. Notifications & Emergency Procedures

    • The Radiation Safety Office must be notified (865-6391) if any modifications are made to the interlocks or any other safety devices or in the event of an emergency involving the equipment.

  10. Inspections & Recordkeeping

    • Safety evaluations (including radiation surveys) should be performed initially when equipment is installed and after equipment has had maintenance, modification or has been moved.

    • The Radiation Safety Office will keep inventory and survey information on file in their offices.