APPENDIX 5
RADIOTOXICITY OF RADIOISOTOPES*



Table 1
Radiotoxicity of the
Individual Radionuclides
Permissible Level of Activity
for Normal Chemical Operations
5 MBq (135 µCi)
500 MBq (13.5 mCi)
** 5 GBq (135 mCi)
50 GBq (1.35 Ci)
* Radiotoxicity is defined as potential toxicity following ingestion, inhalation and absorption.
** Except for Mo/99mTc generators and 99mTc eluate, for which the permissible activity is 100 GBq (3Ci)



Table 2
Relative Radiotoxicity* and Physical Half Life
of Some Radioisotopes
Very High Radiotoxicity
 .
Very High Radiotoxicity
Actinium 227 21.2 years Plutonium 240 6,760 years
Americium 241 458 years Plutonium 241 13 years
Americium 243 7,650 years Plutonium 242 3.8x105 years
Californium 249 360 years Polonium 210 138 days
Californium 250 10 years Protactinium 231 3.2x104 years
Californium 252 2.6 years Radium 223 11.7 days
Curium 242 163 days Radium 226 1,620 years
Curium 243 32 years Radium 228 6.7 years
Curium 244 17.6 years Thorium 227 18.2 days
Curium 245 9,320 years Thorium 228 1.9 years
Curium 246 5,480 years Thorium 230 7.6x104 years
Lead 210 21 years Uranium 230 20.8 days
Neptunium 237 2.1x106 years Uranium 232 73.6 years
Plutonium 238 89 years Uranium 233 1.6x105 years
Plutonium 239 2.4x104 years Uranium 234 2.5x105 years
*   Appendix I, "Safety Code; Laboratory Facilities for Handling Radioisotopes" Bulletin
RPB-SC-12, Health and Welfare Canada 1976

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High Radiotoxicity
 .
High Radiotoxicity
Actinium 228 6.1 hours Iodine 131 8.0 days
Antimony 124 60 days Iodine 133 21 hours
Antimony 125 2.7 years Iridium 192 74 days
Astatine 211 7.2 hours Lead 212 10.6 hours
Barium 140 12.8 days Manganese 54 314 days
Berkelium 249 314 days Protactinium 230 17 days
Bismuth 207 30 years Radium 224 3.6 days
Bismuth 210 5.0 days Ruthenium 106 1.0 years
Cadmium 115m 43 days Scandium 46 84 days
Calcium 45 165 days Silver 110m 249 days
Cerium 144 285 days Sodium 22 2.6 years
Cesium 134 2.1 years Strontium 89 50 days
Cesium 137 30 years Strontium 90 28 years
Chlorine 36 3x105 years Tantalum 182 115 days
Cobalt 56 77 days Tellurium 127m 105 days
Cobalt 60 5.3 years Tellurium 129m 33 days
Europium 152 13 years Terbium 160 73 days
Europium 154 16 years Thorium 234 24.1 days
Hafnium 181 45 days Thulium 170 127 days
Indium 114m 50 days Uranium 236 2.4x107 years
Iodine 124 4.2 days Yttrium 91 59 days
Iodine 125 57 days Zirconium 95 65 days
Iodine 126 132.2 days Thallium 204 3.8 years



Moderate Radiotoxicity
 .
Moderate Radiotoxicity
Antimony 122 2.8 days Osmium 191 15 hours
Argon 41 1.8 hours Osmium 193 32 hours
Arsenic 73 76 days Palladium 103 17 days
Arsenic 74 18 days Palladium 109 13.5 hours
Arsenic 76 26.5 hours Phosphorus 32 14.3 days
Arsenic 77 39 hours Phosphorus 33 25.3 days
Barium 131 11.6 days Platinum 191 3.0 days
Beryllium 7 53 days Platinum 193 500 years
Bismuth 206 6.2 days Platinum 197 2.0 hours
Bismuth 212 60.6 minutes Potassium 42 12.4 hours
Cadmium 109 1.3 years Potassium 43 22 hours
Cadmium 115 2.3 days Praseodymium 142 19.2 hours
Calcium 47 4.5 days Praseodymium 143 13.7 days
Carbon 14 5730 years Promethium 147 2.5 years
Gerium 141 32.5 days Promethium 149 53 hours
Cerium 143 33 hours Protactinium 233 27.4 days
Cesium 131 9.7 days Radon 220 56 seconds
Cesium 136 13 days Radon 222 3.8 days
Chlorine 38 37 minutes Rhenium 183 70 days
Chromium 51 27.8 days Rhenium 186 90 hours
Cobalt 57 267 days Rhenium 188 17 hours
Cobalt 58 71 days Rhodium 105 36 hours
Copper 64 12.9 hours Rubidium 86 18.7 days
Dysprosium 165 2.3 hours Ruthenium 97 2.9 days
Dysprosium 166 80 hours Ruthenium 103 40 days
Erbium 169 9.4 days Ruthenium 105 4.4 hours
Erbium 171 7.5 hours Samarium 151 90 years
Europium 152m 9.2 hours Samarium 153 46.7 hours
Europium 155 1.7 years Scandium 47 3.4 days
Fluorine 18 111 minutes Scandium 48 44 hours
Gadolinium 153 200 days Selenium 75 120 days
Gadolinium 195 18 hours Silicon 31 2.6 hours
Gallium 72 14.1 hours Silver 105 40 days
Gold 196 6.2 days Silver 111 7.5 days
Gold 198 64.8 hours Sodium 24 15 hours
Gold 199 3.15 days Strontium 85 64 days
Holmium 166 9x104 years Strontium 91 9.7 hours
Indium 115m 4.4 hours Sulfur 35 87 days
Iodine 130 12.5 hours Technetium 96 43 days
Iodine 132 2.3 hours Technetium 97m 91 days
Iodine 134 53 minutes Technetium 97 2.6x106 years
Iodine 135 6.7 hours Technetium 99 2.1x105 years
Iridium 190 12 days Tellerium 125m 58 days
Iridium 194 19 hours Tellerium 127 9.3 hours
Iron 52 8.3 hours Tellerium 129 67 minutes
Iron 55 2.7 years Tellerium 131m 1.2 days
Iron 59 45 days Tellerium 132 78 hours
Krypton 85m 4.4 hours Thallium 200 26 hours
Krypton 87 78 minutes Thallium 201 73 hours
Lanthanum 140 40.2 hours Thallium 202 12 days
Lead 203 52 hours Thorium 231 25.6 hours
Lutetium 177 6.8 days Thulium 171 1.9 years
Manganese 52 5.7 days Tin 113 118 days
Manganese 56 2.6 hours Tin 125 9.4 days
Mercury 197m 24 hours Tungsten 181 130 days
Mercury 197 65 hours Tungsten 185 74 days
Mercury 203 47 days Tungsten 187 24 hours
Molybdenum 99 66 hours Vanadium 48 16.1 days
Meodymium 147 11.1 days Xenon 135 9.2 hours
Neodymium 149 1.8 hours Ytterbium 175 4.2 days
Neptunium 239 2.4 days Yttrium 90 64.2 hours
Nickel 63 92 years Yttrium 92 3.5 hours
Nickel 65 2.6 hours Yttrium 93 10.1 hours
Niobium 93m 3.7 years Zinc 65 245 days
Niobium 95 35 days Zinc 69m 14 hours
Osmium 185 94 days Zirconium 97 17 hours



Slight Radiotoxicity
 .
Slight Radiotoxicity
Argon 37 34.3 days Rhodium 103m 57 minutes
Cesium 134m 2.9 hours Rubidium 87 5x1010 years
Cesium 135 2x106 years Samarium 147 1.1x1011 years
Cobalt 58m 9 hours Strontium 85m 70 minutes
Germanium 71 11 days Technetium 96m 52 minutes
Hydrogen 3 12.3 years Technetium 99m 6.0 hours
Indium 113m 1.7 hours Thorium 232 1.4x1010 years
Iodine 129 1.6x107 years Natural Thorium  
Krypton 85 10.4 years Uranium 235 7x108 years
Nickel 59 8x104 years Uranium 238 4.5x109 years
Niobium 97 72 minutes Natural Uranium  
Osmium 191m 14 hours Xenon 131m 12 days
Oxygen 15 2 minutes Xenon 133 5.3 days
Platinum 193m 4.4 days Yttrium 91m 50 minutes
Platinum 197m 82 minutes Zinc 69 55 minutes
Rhenium 187 4x1010 years