Occupational Exposure


It is the policy of University of North Texas that exposure to ionizing radiation will be As Low As Reasonably Achievable (ALARA).

UNT set two investigation levels, ALARA 1 and ALARA 2, to establish standards for dosimetry badge monitoring, dose assessment, and investigate high radiation. If an individual exceeds an ALARA action level, the Radiation Safety Officer will report the exposure to the Radiation Safety Committee and the appropriate Principal Investigator.

Dosimetry Badge

Dosimeter (badges and rings) measure the amount of radiation received by radiation worker and ensure that radiation worker do not exceed annual occupational dose limits. Badges issued are appropriate with the type of ionizing radiation to which a worker is exposed.

Each radiation worker with the potential to exceed 10 percent of any annual exposure limit due to external radiation detectable by industry standard dosimetry will have that exposure monitored by the use of personnel dosimetry. Dosimeter should be requested from the RSO before an individual resume the use of any radiation source. Find the Dosimetry Badge Request on the Forms page under "Request for Radiation Monitoring."

Occupationally Exposed Adults

The occupational dose to individual adults (radiation workers) shall not exceed the following annual dose limits:

  1. A total effective dose equivalent (TEDE) of 5 rem; or,
  2. The sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue, other than the lens of the eye, being equal to 50 rem.
  3. A dose equivalent of 15 rem to the lens of the eye.
  4. A shallow-dose equivalent of 50 rem to the skin or any extremity.
Occupational Exposure to Pregnant Women

Pregnancy declaration is voluntary under state and federal law. The dose limit for a pregnant radiation worker is 5,000mrem per year prior to a writing and signed declaration. Upon declaration, the radiation safety officer will monitor exposure to the embryo/fetus. The dose equivalent to the embryo/fetus during the gestation period, due to the occupational exposure is 500mrem.

A pregnant radiation worker has the right to withdrawal declaration at any time and without reason, including changes in work or pregnancy status. The standard occupational dose limits for a radiation worker will be reinstated upon withdrawal. Find the Declared Pregnancy Request on the Forms page. 

Radioactive Waste Disposal

Radioactive wastes are unavoidable byproducts of any use of radioactive materials. Generated waste must be disposed in a manner that minimizes impacts on the public and safety.


All radioactive waste should be stored in appropriate labeled waste containers and secured to prevent inappropriate disposal.

Solid waste should be stored in a rigid container with lids, lined with a plastic bag. When appropriate these containers shielded to prevent unnecessary radiation exposure. Liquid waste should be stored in appropriate containers to minimize and avoid spillage. A secondary container that can hold the content is required. When appropriate these containers shielded to prevent unnecessary radiation exposure.


All radioactive waste MUST be labeled with a Caution Radioactive Material. Radioactive waste container should have this information and must be legible:

  • the  isotope
  • the Principal investigator information
  • the  type of waste

The Radiation Safety personnel must dispose of all radioactive material waste. It is the responsible of the Principal Investigator and laboratory personnel to segregate the generated waste by categories and radionuclides.

These steps should be considered during waste disposal:

  • keep waste segregated by categories and radionuclides,
  • keep waste container closed and secure at all times,
  • liquid waste must be in a chemically compatible container, sealed with a screw-on cap
  • waste should be properly tagged for disposal with the label "Hazardous Waste" or "Caution-Radioactive Materials"
  • complete the Hazardous Waste Pickup Request, located online by clicking here
  • radioactive waste is collected and disposed by the RSO
Disposal of Radiographic Equipment

Radiographic devices that is to be disposed of (not transferred) must be rendered in operable to ensure that it will not be a danger to unqualified personnel. Contact Radiation Safety for guidance in proper disposal of this equipment.