Radionuclides

Commonly Used in Research

Please forward all questions and comments regarding the following information to Radiation Safety at 6-7055.

Calcium-45

(CA-45)

Physical Data:

Pure Beta Emitter
  • Beta Energy
258 keV (max.)
77.2 keV (avg.)
  • Radioactive Half-Life
  • Effective Half-Life
  • Biological Half-Life
  • Max. beta range in air
  • Approximately 50% transmission rate through dead layer of skin
162.61 days
162 days
1.8 x 104 days
47.91 cm

 

 

 

 

 

 


 

Radiological Data:

  • Critical organ: bone
  • Internal exposure through ingestion, inhalation, or absorption are primary concerns
  • Dose rate to the basal cells from skin contamination is approx. 2850 mr/hr µCi per cm2

Shielding:

  • None required

Survey Instrumentation:

  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 750
    • LS efficiency: 100%
  • Geiger - Mueller counter (efficiency low)

 

Regulatory Compliance:
  • ALI
2000 µCi: (by ingestion)
8000 µCi:  (by inhalation)
  • DAC
4 x 10 -7 µCi/mL

Special Considerations:
In general, Calcium-45 does not require any special precautions over and above those necessary for any beta-emitting radionuclide of this energy of emissions. The majority of Calicum-45 is deposited in the bone and is retained with a long biological half-life.

Carbon-14

Physical Data: 

Pure Beta Emitter
  • Beta Energy
156.5 keV (max.)
49.47 keV (avg.)
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
  • Max. beta range in air
  • Max. beta range in water
  • Max. beta range in plastic
5730 years
12 days
40 days (unbound) 12 days (bound)
21.9 cm
0.28 mm
0.25 mm

Radiological Data:

  • 1% of beta particles energy transmitted through dead layer of skin
  • Critical organ: fat tissue
  • Internal exposure is primary concern

Shielding:

  • None required (plastic can be used for beta removal)

Survey Instrumentation:

  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 670
    • LS efficiency: 96%
  • Thin window G-M survey meter

 

Regulatory Compliance:
  • ALI
2400 µCi: (by ingestion)
2000 µCi:  (by inhalation)
  • DAC
1 x 10 -6 µCi/mL

Special Considerations:
There is a possibility that some organic compounds can be absorbed through gloves. Care needs to be taken not to generate carbon dioxide, which could be inhaled. Urinalysis is recommended after a spill or suspected intake.

Chromium-51


Physical Data:

  • Principal mode of decay: Electron capture
  • Principal emissions:
  Intensity
  • Gamma Energy
320 keV 10.08%

          X-ray

5.2 keV 22.3%
  • Radioactive Half-Life
27.7 days  
  • Biological Half-Life
18 days total body
1,000 days, bone
 

Radiological:

  • Critical organ: bone (5%), liver (25%)

Dose rate:

  • 100 cm from 1µCi - 0.023 mr/hr
  • 10 cm from 1µCi - 2.3 mr/hr
  • 1 cm from 1µCi - 230 mr/hr

Shielding:

  • 1/4 in lead > 1µCi
  • 1/2 in lead > 10µCi

Survey Instrumentation:

  • NaI Scintillation Counter
  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 400
    • LS efficiency:  37%

 

Regulatory Compliance:
  • ALI
40,000 µCi: (by ingestion)
50,000 µCi:  (by inhalation)
  • DAC
2 x 10 -5 µCi/mL

Special Considerations:
In general, Chromium-51 does not require special precautions over and above those necessary for any radionuclide of this energy of emissions. Chromium-51 in the form of chromate is not selectively absorbed by any organ in the body.

Hydrogen-3

(H-3) (Tritium)


Physical Data:

Pure Beta Emitter
  • Beta Energy
18.6 keV (max.)
5.69 keV (avg.)
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
  • Max. beta range in air
  • Max. beta range in water
12.3 years
12 days
12 days
0.6 cm
6 x 10-4 cm

 

 

 

 

 

 

 


Radiological:

  • 0% of beta particle energy transmitted through dead layer of skin
  • Critical organ: body water or tissue
  • Internal exposure through ingestion, inhalation, or adsorption are primary concerns

Shielding:

  • None required

Survey Instrumentation:

  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 400
    • LS efficiency: 65%

 

Regulatory Compliance:
  • ALI
8 x 104 µCi: (by ingestion)
8 x 104 µCi:  (by inhalation)
  • DAC
2 x 10 -5 µCi/mL

Special Considerations:
Tritium, because of its low beta energy, cannot be monitored directly, so special care is needed to keep the working environment clean. Regular monitoring by counting swipes is recommended in areas where Tritium is used. 

Iodine-125


Physical Data:
  • Gamma Energy
  • X-ray Energy
  • Radioactive Half-Life
  • Effective Half-Life
  • Biological Half-Life
35 keV
27-32 keV
59.6 days
42 days
120-138 days

 

 

 

 

 


Radiological Data:

  • Critical organ: thyroid
  • Internal exposure through inhalation, ingestion, or absorption are primary concerns

Shielding:

  • Lead 1/32 in for >1 mCi

Dose Information (assume point source):

  • 100 cm from 1mCi - 0275 mr/hr
  • 10 cm from 1mCi - 27.5 mr/hr
  • 1 cm from 1mCi - 2750 mr/hr

Survey Instrumentation:

  • NaI scintillation probe
  • Liquid scintillation counter (LSC)
    • Ls window: 0 to 850
    • LS efficiency: 78%

 

Regulatory Compliance:
  • ALI
400 µCi: (by ingestion)
600 µCi:  (by inhalation)
  • DAC
3 x 10 -8 µCi/mL

Special Considerations:
Volatilization of iodine is the most significant problem with this isotope. Simply opening a vial of sodium [I-125] iodide at high radioactive concentration can cause minute droplets of up to 100Bq to become airborne. Solutions containing iodide ions should not be made acidic nor stored frozen: both lead to formation of volatile elemental iodine. As some iodocompounds can penetrate surgical rubber gloves, it is advisable to wear two pairs, or polyethylene gloves over rubber. In the event of suspected or actual significant contamination of personnel, the thyroid should be blocked by administration of stable iodine as, for example, tablets of potassium iodate (170mg) or potassium iodide (130mg). To render any spilled iodine-125 chemically stable, the area of the spill should be treated with alkaline sodium thiosulfate solution before commencing decontamination.

Iodine-131

(131I)


Physical Data:
    Intensity
  • Beta Energy
  • Gamma
806 keV (max.)
365 keV
89.3%
81.2%
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
8 days
80.4 days, thyroid
7.3 days
 

 

 

 

 

 

 

 

 


Radiological Data:

  • Dose rate at:
    • 100 cm from 1 µCi, 0.03 mr/hr
    • 10 cm from 1 µCi, 28.3 mr/hr
    • 1 cm from 1 µCi, 2829.4 mr/hr
  • Dose rate to basal cells from skin contamination - 5030 mr/hr per µCi per cm2

Shielding:

  • 1/3 inch lead for <5 µCi
  • 1 inch lead for >5 µCi

Survey Instrumentation:

  • Geiger-Mueller Counter
  • NaI (Sodium Iodide) detector
  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 700
    • LS efficiency: 70%

Phosphorus-32

Physical Data: 

Pure Beta Emitter
  • Beta Energy
1710.3 keV (max.)
694.9 keV (avg.)
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
  • Max. beta range in air
  • Max. beta range in water
  • Max. beta range in plastic
14.26 days
1155 days
14.1 days (bone) 13.5 days (whole body)
611 cm (20 feet)
0.76 cm (0.29 in)
0.61 cm (0.24 in)

Radiological Data:

  • Critical organ: bone (30%), body tissues (70%)
  • Internal and external exposure hazard
  • Dose rate to basal cells from skin contamination - 6240 mr/hr per µCi per cm2

Shielding:

  • 1 cm plastic
  • Do not use lead as primary shielding layer due to Bremstrahlung effect (may use lead behind plastic to shield X-rays).

Survey Instrumentation:

  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 1000
    • LS efficiency: 100%
  • G-M Detector

 

Regulatory Compliance:
  • ALI
600 µCi: (by ingestion)
900 µCi:  (by inhalation)
  • DAC
2 x 10 -5 µCi/mL

Special Considerations:
P-32 is the highest energy radionuclide commonly encountered in research laboratories and requires special care. Avoid exposure, do not hold tubes containing even small quantities of P-32 any longer than necessary. Use a stand or holder if quantities greater than a few tens of Mbq (=1mCi) are used, and finger dosmeters should be worn. The use of lead-impregnated rubber gloves also is recommended. Even with low-density materials (plastics), the absorption of beta particles gives rise to relatively high-energy Bremstrahlung, which may require some lead shielding when quantities greater than a few hundred Mbq are being handled.

Phosphorus-33


Physical Data:
  • Beta Energy
249 keV (max.)
85 keV (avg.)
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
  • Fraction transmitted through dead layer of skin - 51%
25.4 days
19 days
24.9 days

Radiological Data:

  • Critical organ: bone marrow (30%), total body tissues (70%)
  • Internal exposure is primary concern
  • Dose rate to basal cells from skin contamination - 3270 mr/hr per µCi per cm2

Shielding:

  • 32 mm of lucite (plexiglass) for stock solutions

Survey Instrumentation:

  • Thin window G-m survey meter
  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 750
    • LS efficiency: 100%

 

Regulatory Compliance:
  • ALI
4000 µCi: (by ingestion)
6000 µCi:  (by inhalation)
  • DAC
3 x 10 -6 µCi/mL

Rubidium-86

(Rb-86)


Physical Data:

Gamma Energy
Beta Energy

Radioactive Half-Life
Effective Half-Life
Biological Half-Life
Maximum Beta range in air
Maximum Beta range in tissue
Maximum Beta range in plastic

1077 keV
698 keV (9%) [maximum] 233 keV [average]
1774 keV (91%) [maximum] 709 keV [average]
18.7 days
13 days
45 days
10 m
0.8 cm
0.66 cm

 

 

 

 

 

 


 

Radiological Data:

Critical organ: bone (ingestion); Bone surface Bone surface, Lung (inhaled)
External Exposure and Internal exposure through inhalation, ingestion, or absorption are primary concerns.
Dose rate to basal cells from skin contamination – 8,447 mR/hr per µCi per cm2

Shielding:

Photons: Lead 0.02” HVL or 0.08” TVL
Betas: 0.30”  or 1 cm plexiglass
Do not use lead as primary shielding layer due to Bremstrahlung effect.  (may use lead behind plastic to shield x-rays)  

Dose Information (assume point source):

100 cm from 1mCi – 0.539 mR/hr
10 cm from 1mCi – 53.9 mR/hr
1 cm from 1mCi - 539 mR/hr

Survey Instrumentation:

NaI scintillation probe
G-M Detector
Liquid scintillation counter (LSC)

Ls window:  0 to 1000
LS efficiency:  100 %

Regulatory Compliance:

ALI

500 µCi: (by ingestion)
800 µCi:  (by inhalation)

DAC

3 x 10 -7 µCi/mL


Special Considerations:
DOSIMETRY AND BIOASSAY REQUIREMENTS:
Rb-86 is one of the highest energy (Beta or Gamma emitting) radionuclides encountered in UM research laboratories, although not routinely, and requires special care. Avoid exposure, do not hold tubes containing even small quantities of Rb-86 any longer than necessary. 

Use a stand or holder if quantities greater than a few tens of Mbq (=1 mCi) are used, and finger dosimeters should be worn. 

Film badges and dosimeter rings are required if 1 millicuries or more are being handled at any one time or millicurie levels are handled on a frequent (daily) basis.

Urine assays may be required after spills or contamination incidents. Avoid skin contamination (absorption), ingestion, inhalation, and injection (all routes of intake).

Store 86Rb (including waste) behind lead shielding (½+ inch thick); lead bricks may be necessary. Survey (with GM meter) to check adequacy of shielding (accessible dose rate < 2 mR/hr; should be background).

Use shielding to minimize exposure while handling 86Rb.

Use tools to handle 86Rb sources and contaminated objects; avoid direct hand contact. Near 86Rb sources, the beta dose rate can be much higher than the gamma dose rate.

Rubidium is an alkali earth metal; elemental form reacts (chemically) violently with water.

Sodium-22

(22Na)


 Physical Data: 
    Intensity
  • X-ray
  • Gamma
  • Position
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
511 keV
1275 keV
545 keV
2.6 years
10 days (tissue)
500 days (bones)
327.5 days
180%
100%
90%

Radiological Data:

  • Dose rate at:
    • 100 cm from 1 µCi - 1.34 mr/hr
    • 10 cm from 1 µCi - 134 mr/hr
    • 1 cm from µCi 13,400 mr/hr
  • Dose rate to the basal cells from skin contamination 5020 mr/hr µCi per cm2

Shielding:

  • Lead bricks

Survey Instrumentation:

  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 900
    • LS efficiency: 100%
  • Geiger - Mueller Counter

Sulfur-35

(35S)


Physical Data:

Pure Beta Emitter
  • Beta Energy
166.8 keV (max.)
48.63 keV (avg.)
  • Radioactive Half-Life
  • Biological Half-Life
  • Effective Half-Life
  • Max. beta range in air
  • Max. beta range in water
  • Max. beta range in plastic
87.51 days
90 days
44.3 days (bone) 13.5 days (whole body)
0.32 mm 
10.2 in
0.25 mm

   


Radiological Data:

  • 12% of beta particles energy transmitted through dead layer of skin
  • Critical organ: male gonads
  • Internal exposure through ingestion, inhalation, or absorption are primary concerns
  • Dose rate to basal cells from skin contamination - 1040 mr/hr per µCi per cm2

Shielding:

  • None required

Survey Instrumentation:

  • Liquid Scintillation Counter (LSC)
    • LS window: 0 to 700
    • LS efficiency: 97%
  • Thin window G-M survey meter 
Regulatory Compliance:
  • ALI
1 x 104 µCi: (by ingestion)
6 x 10-6  µCi:  (by inhalation)
  • DAC
2 x 10 -8 µCi/mL

Special Considerations:
Note that organic compounds are often strongly retained and no limits of exposure have been set for them. Care also needs to be taken not to generate sulphur dioxide or hydrogen sulphide, which could be inhaled. Radiodysis of S35 amino acids during storage and use may lead to the release of S35 labeled volatile impurities. Although the level of these impurities is small, contamination of the internal surfaces of storage and reaction vessels may occur. Vials should be opened and used in ventilated electrons.