9.1 Personal Dosimeters

Personal monitoring devices used to record occupational radiation exposures are supplied and processed through a commercial dosimeter service accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) of the National Institute of Standards & Technology.  The administration and management of the personnel monitoring program is provided by EHS.  Copies of dosimetry reports are provided to each dosimeter account and are maintained on file at EHS.  

Personal dosimeters are assigned to individuals based upon regulatory requirements and their potential occupational exposure to penetrating radiation. Dosimeters are not effective for measurement of exposure from H-3, C-14, P-33, S-35, and Ni-63.  Dosimeters are normally exchanged on a monthly basis.  Temporary dosimeters are available for interim issue until permanent dosimeter assignment is established.  EHS’s dosimetry request and change forms are available online at the EHS website.  For questions on dosimeter usage, call EHS at 335-8518.

Types of Dosimeters

Whole body dosimeters provide measurement of penetrating and non-penetrating radiation.  Penetrating radiation is designated on reports as “DDE” for deep dose equivalent, and includes exposure to the whole body (head, trunk, active blood-forming organs, and reproductive organs).   Non-penetrating radiation is designated on reports as “SDE” for shallow dose equivalent, and includes exposure to the skin and extremities.  Lens of the eye dose equivalent is designated as “LDE.” 

Ring dosimeters provide measurement of radiation exposure to the extremities (hands and forearms).

Dosimeter Requirements for Personnel Using Radioactive Materials in Research Laboratories:

Whole body and ring dosimeters are required for individuals who routinely work with > 1 mCi quantities of:

  • Beta emitters with average energies > 250 keV  (P-32)
  • Gamma emitters with max. energies > 20 keV  (Cr-51)

Returning Dosimeters

Monthly dosimeters must be received by EHS by no later than the 10th day of the month following the wear period.  If dosimeters are received late or lost three or more times during a 12-month period, one of two things will happen, depending on your status as a dosimeter participant:

  1. Required Participants – The department of an individual who is required to have dosimetry based on his/her job duties will be assessed an administrative fee.  This will continue for each subsequent lost or late dosimeter until the participant has less than three late or missing dosimeters during the preceding 12 month period.
  2. Elective Participants - Dosimeter service will be canceled following the third late or lost dosimeter.  Individuals wishing to reinstate dosimeter services, are required to contact EHS and pay an administrative reinstatement fee.