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 Code of Federal Regulations (Last Updated: November 8, 2024)
 Title 10 - Energy
 Chapter I - Nuclear Regulatory Commission
 Part 20 - Standards for Protection Against Radiation
 Subpart O - Enforcement

  Appendix C to Part 20 - Quantities 1 of Licensed Material Requiring Labeling

Latest version.

  • Appendix C to Part 20 - Quantities1 of Licensed Material Requiring Labeling

    Radionuclide Quantity (µCi)
    Hydrogen-3 1,000
    Beryllium-7 1,000
    Beryllium-10 1
    Carbon-11 1,000
    Carbon-14 100
    Fluorine-18 1,000
    Sodium-22 10
    Sodium-24 100
    Magnesium-28 100
    Aluminum-26 10
    Silicon-31 1,000
    Silicon-32 1
    Phosphorus-32 10
    Phosphorus-33 100
    Sulfur-35 100
    Chlorine-36 10
    Chlorine-38 1,000
    Chlorine-39 1,000
    Argon-39 1,000
    Argon-41 1,000
    Potassium-40 100
    Potassium-42 1,000
    Potassium-43 1,000
    Potassium-44 1,000
    Potassium-45 1,000
    Calcium-41 100
    Calcium-45 100
    Calcium-47 100
    Scandium-43 1,000
    Scandium-44m 100
    Scandium-44 100
    Scandium-46 10
    Scandium-47 100
    Scandium-48 100
    Scandium-49 1,000
    Titanium-44 1
    Titanium-45 1,000
    Vanadium-47 1,000
    Vanadium-48 100
    Vanadium-49 1,000
    Chromium-48 1,000
    Chromium-49 1,000
    Chromium-51 1,000
    Manganese-51 1,000
    Manganese-52m 1,000
    Manganese-52 100
    Manganese-53 1,000
    Manganese-54 100
    Manganese-56 1,000
    Iron-52 100
    Iron-55 100
    Iron-59 10
    Iron-60 1
    Cobalt-55 100
    Cobalt-56 10
    Cobalt-57 100
    Cobalt-58m 1,000
    Cobalt-58 100
    Cobalt-60m 1,000
    Cobalt-60 1
    Cobalt-61 1,000
    Cobalt-62m 1,000
    Nickel-56 100
    Nickel-57 100
    Nickel-59 100
    Nickel-63 100
    Nickel-65 1,000
    Nickel-66 10
    Copper-60 1,000
    Copper-61 1,000
    Copper-64 1,000
    Copper-67 1,000
    Zinc-62 100
    Zinc-63 1,000
    Zinc-65 10
    Zinc-69m 100
    Zinc-69 1,000
    Zinc-71m 1,000
    Zinc-72 100
    Gallium-65 1,000
    Gallium-66 100
    Gallium-67 1,000
    Gallium-68 1,000
    Gallium-70 1,000
    Gallium-72 100
    Gallium-73 1,000
    Germanium-66 1,000
    Germanium-67 1,000
    Germanium-68 10
    Germanium-69 1,000
    Germanium-71 1,000
    Germanium-75 1,000
    Germanium-77 1,000
    Germanium-78 1,000
    Arsenic-69 1,000
    Arsenic-70 1,000
    Arsenic-71 100
    Arsenic-72 100
    Arsenic-73 100
    Arsenic-74 100
    Arsenic-76 100
    Arsenic-77 100
    Arsenic-78 1,000
    Selenium-70 1,000
    Selenium-73m 1,000
    Selenium-73 100
    Selenium-75 100
    Selenium-79 100
    Selenium-81m 1,000
    Selenium-81 1,000
    Selenium-83 1,000
    Bromine-74m 1,000
    Bromine-74 1,000
    Bromine-75 1,000
    Bromine-76 100
    Bromine-77 1,000
    Bromine-80m 1,000
    Bromine-80 1,000
    Bromine-82 100
    Bromine-83 1,000
    Bromine-84 1,000
    Krypton-74 1,000
    Krypton-76 1,000
    Krypton-77 1,000
    Krypton-79 1,000
    Krypton-81 1,000
    Krypton-83m 1,000
    Krypton-85m 1,000
    Krypton-85 1,000
    Krypton-87 1,000
    Krypton-88 1,000
    Rubidium-79 1,000
    Rubidium-81m 1,000
    Rubidium-81 1,000
    Rubidium-82m 1,000
    Rubidium-83 100
    Rubidium-84 100
    Rubidium-86 100
    Rubidium-87 100
    Rubidium-88 1,000
    Rubidium-89 1,000
    Strontium-80 100
    Strontium-81 1,000
    Strontium-83 100
    Strontium-85m 1,000
    Strontium-85 100
    Strontium-87m 1,000
    Strontium-89 10
    Strontium-90 0.1
    Strontium-91 100
    Strontium-92 100
    Yttrium-86m 1,000
    Yttrium-86 100
    Yttrium-87 100
    Yttrium-88 10
    Yttrium-90m 1,000
    Yttrium-90 10
    Yttrium-91m 1,000
    Yttrium-91 10
    Yttrium-92 100
    Yttrium-93 100
    Yttrium-94 1,000
    Yttrium-95 1,000
    Zirconium-86 100
    Zirconium-88 10
    Zirconium-89 100
    Zirconium-93 1
    Zirconium-95 10
    Zirconium-97 100
    Niobium-88 1,000
    Niobium-89m (66 min) 1,000
    Niobium-89 (122 min) 1,000
    Niobium-90 100
    Niobium-93m 10
    Niobium-94 1
    Niobium-95m 100
    Niobium-95 100
    Niobium-96 100
    Niobium-97 1,000
    Niobium-98 1,000
    Molybdenum-90 100
    Molybdenum-93m 100
    Molybdenum-93 10
    Molybdenum-99 100
    Molybdenum-101 1,000
    Technetium-93m 1,000
    Technetium-93 1,000
    Technetium-94m 1,000
    Technetium-94 1,000
    Technetium-96m 1,000
    Technetium-96 100
    Technetium-97m 100
    Technetium-97 1,000
    Technetium-98 10
    Technetium-99m 1,000
    Technetium-99 100
    Technetium-101 1,000
    Technetium-104 1,000
    Ruthenium-94 1,000
    Ruthenium-97 1,000
    Ruthenium-103 100
    Ruthenium-105 1,000
    Ruthenium-106 1
    Rhodium-99m 1,000
    Rhodium-99 100
    Rhodium-100 100
    Rhodium-101m 1,000
    Rhodium-101 10
    Rhodium-102m 10
    Rhodium-102 10
    Rhodium-103m 1,000
    Rhodium-105 100
    Rhodium-106m 1,000
    Rhodium-107 1,000
    Palladium-100 100
    Palladium-101 1,000
    Palladium-103 100
    Palladium-107 10
    Palladium-109 100
    Silver-102 1,000
    Silver-103 1,000
    Silver-104m 1,000
    Silver-104 1,000
    Silver-105 100
    Silver-106m 100
    Silver-106 1,000
    Silver-108m 1
    Silver-110m 10
    Silver-111 100
    Silver-112 100
    Silver-115 1,000
    Cadmium-104 1,000
    Cadmium-107 1,000
    Cadmium-109 1
    Cadmium-113m 0.1
    Cadmium-113 100
    Cadmium-115m 10
    Cadmium-115 100
    Cadmium-117m 1,000
    Cadmium-117 1,000
    Indium-109 1,000
    Indium-110 (69.1min.) 1,000
    Indium-110
    (4.9h) 1,000
    Indium-111 100
    Indium-112 1,000
    Indium-113m 1,000
    Indium-114m 10
    Indium-115m 1,000
    Indium-115 100
    Indium-116m 1,000
    Indium-117m 1,000
    Indium-117 1,000
    Indium-119m 1,000
    Tin-110 100
    Tin-111 1,000
    Tin-113 100
    Tin-117m 100
    Tin-119m 100
    Tin-121m 100
    Tin-121 1,000
    Tin-123m 1,000
    Tin-123 10
    Tin-125 10
    Tin-126 10
    Tin-127 1,000
    Tin-128 1,000
    Antimony-115 1,000
    Antimony-116m 1,000
    Antimony-116 1,000
    Antimony-117 1,000
    Antimony-118m 1,000
    Antimony-119 1,000
    Antimony-120 (16min.) 1,000
    Antimony-120 (5.76d) 100
    Antimony-122 100
    Antimony-124m 1,000
    Antimony-124 10
    Antimony-125 100
    Antimony-126m 1,000
    Antimony-126 100
    Antimony-127 100
    Antimony-128 (10.4min.) 1,000
    Antimony-128 (9.01h) 100
    Antimony-129 100
    Antimony-130 1,000
    Antimony-131 1,000
    Tellurium-116 1,000
    Tellurium-121m 10
    Tellurium-121 100
    Tellurium-123m 10
    Tellurium-123 100
    Tellurium-125m 10
    Tellurium-127m 10
    Tellurium-127 1,000
    Tellurium-129m 10
    Tellurium-129 1,000
    Tellurium-131m 10
    Tellurium-131 100
    Tellurium-132 10
    Tellurium-133m 100
    Tellurium-133 1,000
    Tellurium-134 1,000
    Iodine-120m 1,000
    Iodine-120 100
    Iodine-121 1,000
    Iodine-123 100
    Iodine-124 10
    Iodine-125 1
    Iodine-126 1
    Iodine-128 1,000
    Iodine-129 1
    Iodine-130 10
    Iodine-131 1
    Iodine-132m 100
    Iodine-132 100
    Iodine-133 10
    Iodine-134 1,000
    Iodine-135 100
    Xenon-120 1,000
    Xenon-121 1,000
    Xenon-122 1,000
    Xenon-123 1,000
    Xenon-125 1,000
    Xenon-127 1,000
    Xenon-129m 1,000
    Xenon-131m 1,000
    Xenon-133m 1,000
    Xenon-133 1,000
    Xenon-135m 1,000
    Xenon-135 1,000
    Xenon-138 1,000
    Cesium-125 1,000
    Cesium-127 1,000
    Cesium-129 1,000
    Cesium-130 1,000
    Cesium-131 1,000
    Cesium-132 100
    Cesium-134m 1,000
    Cesium-134 10
    Cesium-135m 1,000
    Cesium-135 100
    Cesium-136 10
    Cesium-137 10
    Cesium-138 1,000
    Barium-126 1,000
    Barium-128 100
    Barium-131m 1,000
    Barium-131 100
    Barium-133m 100
    Barium-133 100
    Barium-135m 100
    Barium-139 1,000
    Barium-140 100
    Barium-141 1,000
    Barium-142 1,000
    Lanthanum-131 1,000
    Lanthanum-132 100
    Lanthanum-135 1,000
    Lanthanum-137 10
    Lanthanum-138 100
    Lanthanum-140 100
    Lanthanum-141 100
    Lanthanum-142 1,000
    Lanthanum-143 1,000
    Cerium-134 100
    Cerium-135 100
    Cerium-137m 100
    Cerium-137 1,000
    Cerium-139 100
    Cerium-141 100
    Cerium-143 100
    Cerium-144 1
    Praseodymium-136 1,000
    Praseodymium-137 1,000
    Praseodymium-138m 1,000
    Praseodymium-139 1,000
    Praseodymium-142m 1,000
    Praseodymium-142 100
    Praseodymium-143 100
    Praseodymium-144 1,000
    Praseodymium-145 100
    Praseodymium-147 1,000
    Neodymium-136 1,000
    Neodymium-138 100
    Neodymium-139m 1,000
    Neodymium-139 1,000
    Neodymium-141 1,000
    Neodymium-147 100
    Neodymium-149 1,000
    Neodymium-151 1,000
    Promethium-141 1,000
    Promethium-143 100
    Promethium-144 10
    Promethium-145 10
    Promethium-146 1
    Promethium-147 10
    Promethium-148m 10
    Promethium-148 10
    Promethium-149 100
    Promethium-150 1,000
    Promethium-151 100
    Samarium-141m 1,000
    Samarium-141 1,000
    Samarium-142 1,000
    Samarium-145 100
    Samarium-146 1
    Samarium-147 100
    Samarium-151 10
    Samarium-153 100
    Samarium-155 1,000
    Samarium-156 1,000
    Europium-145 100
    Europium-146 100
    Europium-147 100
    Europium-148 10
    Europium-149 100
    Europium-150 (12.62h) 100
    Europium-150 (34.2y) 1
    Europium-152m 100
    Europium-152 1
    Europium-154 1
    Europium-155 10
    Europium-156 100
    Europium-157 100
    Europium-158 1,000
    Gadolinium-145 1,000
    Gadolinium-146 10
    Gadolinium-147 100
    Gadolinium-148 0.001
    Gadolinium-149 100
    Gadolinium-151 10
    Gadolinium-152 100
    Gadolinium-153 10
    Gadolinium-159 100
    Terbium-147 1,000
    Terbium-149 100
    Terbium-150 1,000
    Terbium-151 100
    Terbium-153 1,000
    Terbium-154 100
    Terbium-155 1,000
    Terbium-156m (5.0h) 1,000
    Terbium-156m (24.4h) 1,000
    Terbium-156 100
    Terbium-157 10
    Terbium-158 1
    Terbium-160 10
    Terbium-161 100
    Dysprosium-155 1,000
    Dysprosium-157 1,000
    Dysprosium-159 100
    Dysprosium-165 1,000
    Dysprosium-166 100
    Holmium-155 1,000
    Holmium-157 1,000
    Holmium-159 1,000
    Holmium-161 1,000
    Holmium-162m 1,000
    Holmium-162 1,000
    Holmium-164m 1,000
    Holmium-164 1,000
    Holmium-166m 1
    Holmium-166 100
    Holmium-167 1,000
    Erbium-161 1,000
    Erbium-165 1,000
    Erbium-169 100
    Erbium-171 100
    Erbium-172 100
    Thulium-162 1,000
    Thulium-166 100
    Thulium-167 100
    Thulium-170 10
    Thulium-171 10
    Thulium-172 100
    Thulium-173 100
    Thulium-175 1,000
    Ytterbium-162 1,000
    Ytterbium-166 100
    Ytterbium-167 1,000
    Ytterbium-169 100
    Ytterbium-175 100
    Ytterbium-177 1,000
    Ytterbium-178 1,000
    Lutetium-169 100
    Lutetium-170 100
    Lutetium-171 100
    Lutetium-172 100
    Lutetium-173 10
    Lutetium-174m 10
    Lutetium-174 10
    Lutetium-176m 1,000
    Lutetium-176 100
    Lutetium-177m 10
    Lutetium-177 100
    Lutetium-178m 1,000
    Lutetium-178 1,000
    Lutetium-179 1,000
    Hafnium-170 100
    Hafnium-172 1
    Hafnium-173 1,000
    Hafnium-175 100
    Hafnium-177m 1,000
    Hafnium-178m 0.1
    Hafnium-179m 10
    Hafnium-180m 1,000
    Hafnium-181 10
    Hafnium-182m 1,000
    Hafnium-182 0.1
    Hafnium-183 1,000
    Hafnium-184 100
    Tantalum-172 1,000
    Tantalum-173 1,000
    Tantalum-174 1,000
    Tantalum-175 1,000
    Tantalum-176 100
    Tantalum-177 1,000
    Tantalum-178 1,000
    Tantalum-179 100
    Tantalum-180m 1,000
    Tantalum-180 100
    Tantalum-182m 1,000
    Tantalum-182 10
    Tantalum-183 100
    Tantalum-184 100
    Tantalum-185 1,000
    Tantalum-186 1,000
    Tungsten-176 1,000
    Tungsten-177 1,000
    Tungsten-178 1,000
    Tungsten-179 1,000
    Tungsten-181 1,000
    Tungsten-185 100
    Tungsten-187 100
    Tungsten-188 10
    Rhenium-177 1,000
    Rhenium-178 1,000
    Rhenium-181 1,000
    Rhenium-182 (12.7h) 1,000
    Rhenium-182 (64.0h) 100
    Rhenium-184m 10
    Rhenium-184 100
    Rhenium-186m 10
    Rhenium-186 100
    Rhenium-187 1,000
    Rhenium-188m 1,000
    Rhenium-188 100
    Rhenium-189 100
    Osmium-180 1,000
    Osmium-181 1,000
    Osmium-182 100
    Osmium-185 100
    Osmium-189m 1,000
    Osmium-191m 1,000
    Osmium-191 100
    Osmium-193 100
    Osmium-194 1
    Iridium-182 1,000
    Iridium-184 1,000
    Iridium-185 1,000
    Iridium-186 100
    Iridium-187 1,000
    Iridium-188 100
    Iridium-189 100
    Iridium-190m 1,000
    Iridium-190 100
    Iridium-192 (73.8d) 1
    Iridium-192m (1.4min.) 10
    Iridium-194m 10
    Iridium-194 100
    Iridium-195m 1,000
    Iridium-195 1,000
    Platinum-186 1,000
    Platinum-188 100
    Platinum-189 1,000
    Platinum-191 100
    Platinum-193m 100
    Platinum-193 1,000
    Platinum-195m 100
    Platinum-197m 1,000
    Platinum-197 100
    Platinum-199 1,000
    Platinum-200 100
    Gold-193 1,000
    Gold-194 100
    Gold-195 10
    Gold-198m 100
    Gold-198 100
    Gold-199 100
    Gold-200m 100
    Gold-200 1,000
    Gold-201 1,000
    Mercury-193m 100
    Mercury-193 1,000
    Mercury-194 1
    Mercury-195m 100
    Mercury-195 1,000
    Mercury-197m 100
    Mercury-197 1,000
    Mercury-199m 1,000
    Mercury-203 100
    Thallium-194m 1,000
    Thallium-194 1,000
    Thallium-195 1,000
    Thallium-197 1,000
    Thallium-198m 1,000
    Thallium-198 1,000
    Thallium-199 1,000
    Thallium-200 1,000
    Thallium-201 1,000
    Thallium-202 100
    Thallium-204 100
    Lead-195m 1,000
    Lead-198 1,000
    Lead-199 1,000
    Lead-200 100
    Lead-201 1,000
    Lead-202m 1,000
    Lead-202 10
    Lead-203 1,000
    Lead-205 100
    Lead-209 1,000
    Lead-210 0.01
    Lead-211 100
    Lead-212 1
    Lead-214 100
    Bismuth-200 1,000
    Bismuth-201 1,000
    Bismuth-202 1,000
    Bismuth-203 100
    Bismuth-205 100
    Bismuth-206 100
    Bismuth-207 10
    Bismuth-210m 0.1
    Bismuth-210 1
    Bismuth-212 10
    Bismuth-213 10
    Bismuth-214 100
    Polonium-203 1,000
    Polonium-205 1,000
    Polonium-207 1,000
    Polonium-210 0.1
    Astatine-207 100
    Astatine-211 10
    Radon-220 1
    Radon-222 1
    Francium-222 100
    Francium-223 100
    Radium-223 0.1
    Radium-224 0.1
    Radium-225 0.1
    Radium-226 0.1
    Radium-227 1,000
    Radium-228 0.1
    Actinium-224 1
    Actinium-225 0.01
    Actinium-226 0.1
    Actinium-227 0.001
    Actinium-228 1
    Thorium-226 10
    Thorium-227 0.01
    Thorium-228 0.001
    Thorium-229 0.001
    Thorium-230 0.001
    Thorium-231 100
    Thorium-232 100
    Thorium-234 10
    Thorium-natural 100
    Protactinium-227 10
    Protactinium-228 1
    Protactinium-230 0.1
    Protactinium-231 0.001
    Protactinium-232 1
    Protactinium-233 100
    Protactinium-234 100
    Uranium-230 0.01
    Uranium-231 100
    Uranium-232 0.001
    Uranium-233 0.001
    Uranium-234 0.001
    Uranium-235 0.001
    Uranium-236 0.001
    Uranium-237 100
    Uranium-238 100
    Uranium-239 1,000
    Uranium-240 100
    Uranium-natural 100
    Neptunium-232 100
    Neptunium-233 1,000
    Neptunium-234 100
    Neptunium-235 100
    Neptunium-236 (1.15 × 105 y) 0.001
    Neptunium-236 (22.5h) 1
    Neptunium-237 0.001
    Neptunium-238 10
    Neptunium-239 100
    Neptunium-240 1,000
    Plutonium-234 10
    Plutonium-235 1,000
    Plutonium-236 0.001
    Plutonium-237 100
    Plutonium-238 0.001
    Plutonium-239 0.001
    Plutonium-240 0.001
    Plutonium-241 0.01
    Plutonium-242 0.001
    Plutonium-243 1,000
    Plutonium-244 0.001
    Plutonium-245 100
    Americium-237 1,000
    Americium-238 100
    Americium-239 1,000
    Americium-240 100
    Americium-241 0.001
    Americium-242m 0.001
    Americium-242 10
    Americium-243 0.001
    Americium-244m 100
    Americium-244 10
    Americium-245 1,000
    Americium-246m 1,000
    Americium-246 1,000
    Curium-238 100
    Curium-240 0.1
    Curium-241 1
    Curium-242 0.01
    Curium-243 0.001
    Curium-244 0.001
    Curium-245 0.001
    Curium-246 0.001
    Curium-247 0.001
    Curium-248 0.001
    Curium-249 1,000
    Berkelium-245 100
    Berkelium-246 100
    Berkelium-247 0.001
    Berkelium-249 0.1
    Berkelium-250 10
    Californium-244 100
    Californium-246 1
    Californium-248 0.01
    Californium-249 0.001
    Californium-250 0.001
    Californium-251 0.001
    Californium-252 0.001
    Californium-253 0.1
    Californium-254 0.001
    Any alpha emitting radionuclide not listed above or mixtures of alpha emitters of unknown composition 0.001
    Einsteinium-250 100
    Einsteinium-251 100
    Einsteinium-253 0.1
    Einsteinium-254m 1
    Einsteinium-254 0.01
    Fermium-252 1
    Fermium-253 1
    Fermium-254 10
    Fermium-255 1
    Fermium-257 0.01
    Mendelevium-257 10
    Mendelevium-258 0.01
    Any radionuclide other than alpha emitting radionuclides not listed above, or mixtures of beta emitters of unknown composition 0.01

    1 The quantities listed above were derived by taking 1⁄10th of the most restrictive ALI listed in table 1, columns 1 and 2, of appendix B to §§ 20.1001-20.2401 of this part, rounding to the nearest factor of 10, and arbitrarily constraining the values listed between 0.001 and 1,000 µCi. Values of 100 µCi have been assigned for radionuclides having a radioactive half-life in excess of 109 years (except rhenium, 1000 µCi) to take into account their low specific activity.

    Note: For purposes of §§ 20.1902(e), 20.1905(a), and 20.2201(a) where there is involved a combination of radionuclides in known amounts, the limit for the combination should be derived as follows: determine, for each radionuclide in the combination, the ratio between the quantity present in the combination and the limit otherwise established for the specific radionuclide when not in combination. The sum of such ratios for all radionuclides in the combination may not exceed “1” (i.e., “unity”).

    [56 FR 23465, May 21, 1991; 56 FR 61352, Dec. 3, 1991. Redesignated and amended at 58 FR 67659, Dec. 22, 1993; 60 FR 20186, Apr. 25, 1995]