10 CFR Appendix B
Quantities of Licensed Material Requiring Labeling
June 9, 2020
CFR
Open Table
Material Microcuries
Americium-241 .01
Antimony-122 100
Antimony-124 10
Antimony-125 10
Arsenic-73 100
Arsenic-74 10
Arsenic-76 10
Arsenic-77 100
Barium-131 10
Barium-133 10
Barium-140 10
Bismuth-210 1
Bromine-82 10
Cadmium-109 10
Cadmium-115m 10
Cadmium-115 100
Calcium-45 10
Calcium-47 10
Carbon-14 100
Cerium-141 100
Cerium-143 100
Cerium-144 1
Cesium-131 1,000
Cesium-134m 100
Cesium-134 1
Cesium-135 10
Cesium-136 10
Cesium-137 10
Chlorine-36 10
Chlorine-38 10
Chromium-51 1,000
Cobalt-58m 10
Cobalt-58 10
Cobalt-60 1
Copper-64 100
Dysprosium-165 10
Dysprosium-166 100
Erbium-169 100
Erbium-171 100
Europium-152 9.2 h 100
Europium-152 13 yr 1
Europium-154 1
Europium-155 10
Fluorine-18 1,000
Gadolinium-153 10
Gadolinium-159 100
Gallium-72 10
Germanium-71 100
Gold-198 100
Gold-199 100
Hafnium-181 10
Holmium-166 100
Hydrogen-3 1,000
Indium-113m 100
Indium-114m 10
Indium-115m 100
Indium-115 10
Iodine-125 1
Iodine-126 1
Iodine-129 0.1
Iodine-131 1
Iodine-132 10
Iodine-133 1
Iodine-134 10
Iodine-135 10
Iridium-192 10
Iridium-194 100
Iron-55 100
Iron-59 10
Krypton-85 100
Krypton-87 10
Lanthanum-140 10
Lutetium-177 100
Manganese-52 10
Manganese-54 10
Manganese-56 10
Mercury-197m 100
Mercury-197 100
Mercury-203 10
Molybdenum-99 100
Neodymium-147 100
Neodymium-149 100
Nickel-59 100
Nickel-63 10
Nickel-65 100
Niobium-93m 10
Niobium-95 10
Niobium-97 10
Osmium-185 10
Osmium-191m 100
Osmium-191 100
Osmium-193 100
Palladium-103 100
Palladium-109 100
Phosphorus-32 10
Platinum-191 100
Platinum-193m 100
Platinum-193 100
Platinum-197m 100
Platinum-197 100
Plutonium-239 .01
Polonium-210 0.1
Potassium-42 10
Praseodymium-142 100
Praseodymium-143 100
Promethium-147 10
Promethium-149 10
Radium-226 .01
Rhenium-186 100
Rhenium-188 100
Rhodium-103m 100
Rhodium-105 100
Rubidium-86 10
Rubidium-87 10
Ruthenium-97 100
Ruthenium-103 10
Ruthenium-105 10
Ruthenium-106 1
Samarium-151 10
Samarium-153 100
Scandium-46 10
Scandium-47 100
Scandium-48 10
Selenium-75 10
Silicon-31 100
Silver-105 10
Silver-110m 1
Silver-111 100
Sodium-24 10
Strontium-85 10
Strontium-89 1
Strontium-90 0.1
Strontium-91 10
Strontium-92 10
Sulphur-35 100
Tantalum-182 10
Technetium-96 10
Technetium-97m 100
Technetium-97 100
Technetium-99m 100
Technetium-99 10
Tellurium-125m 10
Tellurium-127m 10
Tellurium-127 100
Tellurium-129m 10
Tellurium-129 100
Tellurium-131m 10
Tellurium-132 10
Terbium-160 10
Thallium-200 100
Thallium-201 100
Thallium-202 100
Thallium-204 10
Thorium (natural)1 100
Thulium-170 10
Thulium-171 10
Tin-113 10
Tin-125 10
Tungsten-181 10
Tungsten-185 10
Tungsten-187 100
Uranium (natural)2 100
Uranium-233 .01
Uranium-234—Uranium-235 .01
Vanadium-48 10
Xenon-131m 1,000
Xenon-133 100
Xenon-135 100
Ytterbium-175 100
Yttrium-90 10
Yttrium-91 10
Yttrium-92 100
Yttrium-93 100
Zinc-65 10
Zinc-69m 100
Zinc-69 1,000
Zirconium-93 10
Zirconium-95 10
Zirconium-97 10
Any alpha emitting radionuclide not listed above or mixtures of alpha emitters of unknown composition .01
Any radionuclide other than alpha emitting radionuclides, not listed above or mixtures of beta emitters of unknown composition .1

1Based on alpha disintegration rate of Th-232, Th-230 and their daughter products.

2Based on alpha disintegration rate of U-238, U-234, and U-235.

Note: For purposes of §20.303, where there is involved a combination of isotopes in known amounts, the limit for the combination should be derived as follows: Determine, for each isotope in the combination, the ratio between the quantity present in the combination and the limit otherwise established for the specific isotope when not in combination. The sum of such ratios for all the isotopes in the combination may not exceed “1” (i.e., “unity”).

[35 FR 6425, Apr. 22, 1970, as amended at 36 FR 16898, Aug. 26, 1971; 38 FR 29314, Oct. 24, 1973; 39 FR 23991, June 28, 1974; 45 FR 71763, Oct. 30, 1980. Redesignated at 56 FR 23391, May 21, 1991, and further redesignated at 58 FR 67659, Dec. 22, 1993]


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