The University of Iowa

Dosimeter Guideline - Personnel Using Radioactive Material in Research

The purpose of this guide is to establish a uniform protocol for the placement of radiation dosimeters throughout all departments utilizing radionuclides in research areas at the University of Iowa. The definitions below list each type of dosimeter along with the area it is to be worn and the significance of each reading.

Dosimeters are only effective for monitoring penetrating radiation and are not normally effective for monitoring uCi quantities of RAM typically used in research labs.

  • Dosimeters cannot detect radiation from low-energy beta emitters such as H-3, C-14, P-33, S-35 & Ni-63.

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)\

Dosimeter Types

P1 - Whole Body dosimeter - The P1 dosimeter provides a measurement of the deep (DDE) and shallow (SDE) radiation dose equivalent received by the whole body. A black body icon (as shown on the left) identifies the P1 whole body dosimeter. Wear this dosimeter on the torso at waist or chest level.

   U3 - Ring dosimeter – The U3 ring dosimeter provides a measurement of the of the extremity radiation dose equivalent received by the lower arm and hand. This dosimeter is to be worn under the protective latex glove on a finger of the hand likely to receive the highest radiation exposure.

State of Iowa Limits

Type of Exposure

Annual Limit

Whole Body Deep Dose Equivalent (DDE)
which includes: head, trunk, active blood forming organs & gonads
5000 mrem/year
Whole Body Shallow Dose Equivalent (SDE) which includes skin 50000 mrem/year
Lens of Eye Dose Equivalent 15000 mrem/year total
Extremities 50000 mrem/year total
Limit of person completing pregnancy declaration 500 mrem/gestation period

UI ALARA Limits (Monthly)

Area of Body

ALARA Action Level I

ALARA Action Level II

Whole Body Deep Dose Equivalent (DDE)
200 mrem
400 mrem
Whole Body Shallow Dose Equivalent (SDE)
2000 mrem 4000 mrem
Lens of Eye Dose Equivalent (LDE)
600 mrem 1200 mrem
2000 mrem 4000 mrem

PLEASE NOTE: Wearing your dosimeters in accordance with the guidelines given above is required in order to obtain an accurate assessment of your radiation dose. When not in use, store your dosimeters in an area that will not be exposed to radiation in excess of background levels. Please contact Environmental Health & Safety 335-8501 with any questions or concerns.