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California State University, Long Beach
College of Natural Sciences and Mathematics

Minimum Training for Radioisotope Lab Personnel


CSULB Radiation Safety Manual

The State of CA Health Department, Radiologic Health Branch (RHB) has issued a license to this campus allowing us to use certain types and quantities of radioactive materials; the manual is part of that license. Each radiation worker must read the manual and know where it is in her/his workplace. Each Professor that uses radioactive materials has been issued an individual license by campus Radiation Safety. Each radiation worker must practice excellent recordkeeping and know the correct procedures for radioactive materials acquisition, handling, labeling, storage, disposal, spill clean-up, and radioisotope contamination control and monitoring. Gross errors on your part can cause your professor to lose her/his license, and could even result in the loss of the campus license! Each radioisotope worker must be given a copy of the condensed "Manual Highlights" document and a copy of the "Fetal Health Policy" as appropriate.

Department of Radiologic Health Workplace Information Poster

All isotope users must be familiar with this poster and its location. It is posted in most labs and is also displayed on the official College of Natural Sciences Bulletin Board (PH2 first floor).

Biological Effects of Ionizing Radiation

  1. Natural, medical and radiation worker exposure. Your DOSE is the amount of radiation your body has absorbed. Dose is measured in millirems (or milliSieverts).
  2. Damage mechanism of ionizing radiations. Immediate/acute effects vs. chronic/delayed effects.
  3. Contamination vs. irradiation: getting it on your hands vs. just having it shine out at you!
  4. External dose: from irradiation (from working in a radiation field).
  5. Internal dose: from ingestion, inhalation, or absorption via eyes/contaminated skin. Know the target organs; e.g. 35S goes to the testes, 125I goes to the thyroid. The chemical form makes a difference in the target and in the degree of hazard, e.g. 3H bound to a DNA precursor vs. bound to a sugar.
  6. Total dose: affected by both the radioactive AND biological half-life if ingestion occurs.
    • radioactive halflife: 14C is 5,730 yrs; 3H is 12 yrs; 35S is 3 months; 125I is two months; 32P is 2 wks; all others > 3 months.
    • biological halflife: Time it takes for half to be excreted. It can be a long time! 30% of 32P is retained until isotope is decayed; 10% of 35S is retained until decayed, etc.
  7. Bioassay procedures: thyroid monitoring, urinalysis, whole body count.
  8. Read the "Isotope Information" section of the white Rad Notebook!
  9. Remember to minimize exposure!

Basic Radiation Safety/Health Physics

  1. Types of radiation: Alpha, Beta, Gamma, Neutron, X-Ray. Know the type you have in your workplace.
  2. Amount of radioactive material (activity) is expressed as millicuries or microcuries (or Bequerels).
  3. Personal protective equipment (PPE) and its limitations; gloves, labcoat, goggles etc.
  4. Use and limitations of the various radiation detection instruments available in the lab and from Radiation Safety. Use them each time you work with radioactive material! Know what isotopes you have in your lab, and how to detect them (geiger counters, gamma detectors)!
    • Low energy isotopes: 3H, 14C, 35S, 109Cd. These shine out less than 2 feet!
    • Penetrating isotopes: 32P, 65Zn, 60Co, 125I. These shine out several feet or more!
    • The survey meter with the pancake probe (geiger counter) is:
      • VERY sensitive for 32P, 65Zn and 60Co;
      • NOT very sensitive for the low-energy isotopes 14C, 35S; and
      • BLIND to 3H, 125I and 109Cd.
    • The survey meter with the cylindrical probe (gamma detector) is:
      • VERY sensitive for 125I;
      • NOT very sensitive for 109Cd; and
      • BLIND to all others listed above.
  5. Exposure minimization techniques: TIME, DISTANCE, SHIELDING. For example: Spill of 1mCi 32P dry – 2 million mrem/hr on contact; 200,000 mrem/hr at 1 cm; 2000 mrem/hr at 1 cm and in 1 ml water; 0.03 mrem/hr at 10 cm and in 25 mls of water in a glass container.
  6. ALARA (As Low As Reasonably Achievable) = Your mantra! If you can reduce exposure, you must do it!


  1. Requirements for and limitations of film badges/ring badges (no badges for low-energy isotopes, no badges for the use of <1mCi of other isotopes)
  2. Apply for badge if needed when you take the Rad Test - one week prior to planned use.

CSULB Radiation Safety Manual -- APPENDIX II(a) revised (Formerly distributed as "Radiation Safety Memo 10")