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User Guideā€”Research Using Radionuclides


Radioactive material is commonly used in research. In biomedical research, incorporating radioactive materials into cells and other biological material allows for location and measurement of sites of interest. Sealed nuclear sources are used in analytical equipment such as gas chromatographs and liquid scintillation counters. Use of any form of radioactive material is subject to the provisions of the University Radiation Safety Program.

Training Requirements

Any individual who will be handling or otherwise using radioactive material must attend a training lecture offered by the Radiation Safety Office (RSO). The lecture covers:

  • Regulatory requirements for the use of radioactive material
  • Concepts of ionizing radiation and radiation dose
  • Basic principles of radiation protection
  • Health effects from exposure to ionizing radiation
  • Applicable radiation safety policies and procedures

The lecture is offered at least once each month. Individuals should register in advance using the Isotope Research Training form.

Dosimetry Requirements

The regulations require that personal dosimetry be issued to all individuals who may receive 10 percent of the annual allowable exposure. Most research will not result in this level of exposure. Therefore, for researchers, dosimetry is issued on an individual basis based upon the specific radionuclide and quantity being used. Criteria for Dosimetry

Policies and Procedures



Equipment Repair or Disposal

All laboratory equipment which is either labeled with a "Caution Radioactive Materials" label or is suspected to have come in contact with loose radioactive material (refrigerators, freezers, water baths, centrifuges, etc.), should be considered potentially contaminated and must be monitored for contamination by RSO personnel before being removed from the laboratory for disposal, repair, modification, calibration, storage, or use elsewhere.

Food in Radiation Laboratories

Eating, drinking, smoking, storage/preparation of food, and application of cosmetics are not permitted in radiation laboratories. This policy is not unique to the University of Pittsburgh. It is designed to minimize the risks of ingesting potentially harmful agents into the body.

The presence of coffee mugs, soft drink containers, food in refrigerators or cold rooms, coffee makers, and some microwave ovens is considered evidence that eating and drinking may be occurring in an area. Therefore, the Radiation Safety Office staff has been instructed to confiscate and dispose of any such materials found in a designated radiation laboratory, regardless of value.

Security of Radioactive Material


Regulations pertaining to the security of radioactive materials require that "The licensee shall secure from unauthorized removal or access licensed materials that are stored in controlled or unrestricted areas," and that "the licensee shall control and maintain constant surveillance of licensed material that is in a controlled or unrestricted area and that is not in storage."


Radioactive materials are to be stored in a manner that will minimize the risk of breakage, leakage or theft. The use and storage of radioactive materials must either be under the constant surveillance and immediate control of a radiation worker or secured from unauthorized removal and access. These requirements apply to stock solutions, sealed sources, materials in process, and radioactive waste.


In accordance with the above policy the following shall be implemented:

  • Radioactive materials must be used and/or stored in posted rooms listed on the Authorized User's application.
  • Radioisotope laboratories are to be locked when unoccupied if there are unsecured sources of radioactive material.
  • Material may be secured in a locked container such as a cabinet, refrigerator, shield, hood, or storage box.
  • Any individual who is unknown to laboratory occupants or who is unfamiliar with the work practices in your laboratory should be "challenged" upon entry into areas in which materials are unsecured.


Small quantities of materials (liquid scintillation vials, gamma counting samples, etc.) in the process of being assayed in nuclear counting laboratories, are exempt. However, these materials are not exempt from proper handling and waste disposal procedures.

Spills and Emergencies

In case of a spill of radioactive material, the following procedures should be performed:

  1. Alert others in the laboratory that a spill has occurred.
  2. Contain and minimize the spread of contamination by covering the spill with absorbent material such as paper towels, padding, Kimwipes, etc. Cordon off the suspected area of contamination, or seal off the laboratory if the radioactive material is volatile.
  3. Contact the Radiation Safety Office (412-624-2728) as soon as possible.
  4. Taking the necessary precautions to limit exposure, determine the extent of contamination by monitoring the area with the appropriate survey instrument and/or by performing a smear survey.
  5. To clean up the spill: Decontaminate the area in convenient sectors by starting from the outer edge with a wiping and scrubbing motion and working in towards the center. Use a commercial decontamination product or a soap-and-water cleaning solution on paper towels or pads. Other additives such as alcohol or EDTA may also be used, depending on the chemical form of the contamination. Sodium bicarbonate should be used with radio-iodine spills to buffer the pH and reduce the volatilization of iodine gas.
  6. Package the contaminated waste from the clean up in a yellow bag and re-survey the area to make sure that there is no residual contamination.
  7. The Radiation Safety Office will assist in the monitoring, clean up, and survey operations.

In case of personnel contamination, the following procedures should be performed:

  1. Immediately remove any contaminated clothing or shoes, exercising caution not to spread or track the contamination further.
  2. Wash contaminated areas of skin with soap and water. Do not use hot water and do not use abrasive scrubbing, as this will only increase the passage of radioactive material through the skin.
  3. Call the Radiation Safety Office (412-624-2728) to evaluate the exposure.

Survey Instrument Calibration and Repair

Portable survey instruments are required for laboratories using medium-to-high-energy radionuclides. The University license requires that instruments be calibrated at least annually. The Radiation Safety Office has the capability to perform calibrations. Instruments are tracked using a database. When due for calibration, they will be picked up from the laboratory, calibrated, and returned within a reasonable time. Loaner instruments may be provided for continuous use.

Should an instrument require repairs, the RSO will estimate the costs and contact the Authorized User for authorization to proceed with repairs.

Personnel Radiation Monitoring Requirements

External Monitoring

The following table summarizes the various types of radiation work performed under the University of Pittsburgh licenses. For each type of work, the type of monitoring (if any) is indicated.

For radioisotope users, dosimetry is required for the handling of material in quantities equal to or greater than the indicated activity. For example, a radiation worker handling 5 mCi or more of Cr-51 is required to wear both ring and whole body dosimeters; however, a worker handling less than 5 mCi is not required to wear dosimetry. It is also required that all workers who have been issued dosimetry wear it at all times when handling isotopes, regardless of the activity level.

Type of Radiation Work Activity level for
Ring dosimeter
Activity level for
Whole Body Dosimeter
Radioisotopes (For isotopes not listed, contact RSO for guidance)
Photon Emitters
Group 1 -
Na-22, Sc-46, Fe-59, Co-60, Sr-85, Nb-95
1 mCi 5 mCi
Group 2 -
Cr-51, Co-57, I-125, I-131, Ce-141, In-111
5 mCi 5 mCi
Beta Emitters
Emax < 500 Kev
H-3, C-14, S-35, Ca-45, Ni-63, P-33
Not required Not required
Emax > 500 Kev
P-32, Cl-36

1 mCi

5 mCi
Sealed sources or gamma irradiators

Not required

Not required
Analytical X-Ray equipment Yes As Required by RSO
Clinical or research X-Ray equipment As Required by RSO Yes
Particle accelerator As Required by RSO Yes

Use of Radioactive Materials in Animals

The use of radioactive material in animals requires protocol approval from the IACUC and observance of the following Radiation Safety Office guidelines.

If the study is an acute study, the IACUC may allow it to be performed in the research laboratory. It is the responsibility of the Authorized User to make certain his or her associates and employees understand and exercise the necessary safety precautions, handling procedures, clean-up responsibilities, and waste-disposal methods.

If the study requires use of radiolabeled animals in institutionally managed facilities, then the responsibility for animal care may be shared between the investigator and animal facility personnel. This division of responsibility must be developed cooperatively, before the study begins.

The following are some guidelines for the use of radioactive materials in animals:

  1. The administration of radioactive materials to/into animals and the subsequent dissection of those animals should be performed in trays lined with absorbent padding.
  2. Cages that house animals containing radioactive materials should be labeled with the name of the radionuclide, activity per animal, date of administration, and Authorized User's name.
  3. Volatile and readily dispersible radioactive material should be administered in a fume hood. Subsequent work with the animal may also be best handled within the fume hood.
  4. Animal carcasses and tissues containing radioactive material should be placed in a yellow plastic bag. Do not include any other materials such as pads, tubing, needles, instruments, etc., with the carcass. The bags can then be taken to a radioactive waste storage area during scheduled hours or by special arrangement. Radioactive animals and tissues should be kept refrigerated or frozen before delivery to RSO personnel.
  5. Animal excreta may be disposed of through the sanitary sewer in accordance with the applicable limits for liquid waste (30 uCi/day).
  6. Any material returned to the institutional animal care facility, such as cages, must be decontaminated prior to return.