EXEMPT CONCENTRATIONS

Subpart 1. Parent isotope. Many radioisotopes disintegrate into isotopes that are also radioactive. In expressing the concentrations in subpart 3, the activity stated is that of the parent isotope and takes into account the daughters. Subp. 2. Combination of isotopes. For purposes of part 4731.3025 , where a combination of isotopes is involved, the limit for the combination should be derived as follows: determine for each isotope in the product the ratio between the concentration present in the product and the exempt concentration established in subpart 3 for the specific isotope when not in combination. The sum of the ratios may not exceed one. Concentration of isotope A in product Concentration of isotope B in product __________________________ + __________________________ ≤ 1 Exempt concentration of isotope A Exempt concentration of isotope B Subp. 3. Exempt concentrations. Column I Column II Element (atomic number) Isotope Gas concen- tration µCi/ml 1 Liquid and solid concen- tration µCi/ml 2 _ Antimony (51) Sb 122 3 x 10 -4 Sb 124 2 x 10 -4 Sb 125 1 x 10 -3 Argon (18) A 37 1 x 10 -3 A 41 4 x10 -7 Arsenic (33) As 73 5 x 10 -3 As 74 5 x 10 -4 As 76 2 x 10 -4 As 77 8 x 10 -4 Barium (56) Ba 131 2 x 10 -3 Ba 140 3 x 10 -4 Beryllium (4) Be 7 2 x 10 -2 Bismuth (83) Bi 206 4 x 10 -4 Bromine (35) Br 82 4 x 10 -7 3 x 10 -3 Cadmium (48) Cd 109 2 x 10 -3 Cd 115m 3 x 10 -4 Cd 115 3 x 10 -4 Calcium (20) Ca 45 9 x 10 -5 Ca 47 5 x 10 -4 Carbon (6) C 14 1 x 10 -6 8 x 10 -3 Cerium (58) Ce 141 9 x 10 -4 Ce 143 4 x 10 -4 Ce 144 1 x 10 -4 Cesium (55) Cs 131 2 x 10 -2 Cs 134m 6 x 10- 2 Cs 134 9 x 10 -5 Chlorine (17) Cl 38 9 x 10 -7 4 x 10 -3 Chromium (24) Cr 51 2 x 10 -2 Cobalt (27) Co 57 5 x 10 -3 Co 58 1 x 10 -3 Co 60 5 x 10 -4 Copper (29) Cu 64 3 x 10 -3 Dysprosium (66) Dy 165 4 x 10 -3 Dy 166 4 x 10 -4 Erbium (68) Er 169 9 x 10 -4 Er 171 1 x 10 -3 Europium (63) Eu 152 (T/2=9.2 hrs) 6 x 10 -4 Eu 155 2 x 10 -3 Fluorine (9) F 18 2 x 10 -6 8 x 10 -3 Gadolinium (64) Gd 153 2 x 10 -3 Gd 159 8 x 10 -4 Gallium (31) Ga 72 4 x 10 -4 Germanium (32) Ge 71 2 x 10 -2 Gold (79) Au 196 2 x 10 -3 Au 198 5 x 10 -4 Au 199 2 x 10 -3 Hafnium (72) Hf 181 7 x 10 -4 Hydrogen (1) H 3 5 x 10 -6 3 x 10 -2 Indium (49) In 113m 1 x 10 -2 In 114m 2 x 10 -4 Iodine (53) I 126 3 x 10 -9 2 x 10 -5 I 131 3 x 10 -9 2 x 10 -5 I 132 8 x 10 -8 6 x 10 -4 I 133 1 x 10 -8 7 x 10 -5 I 134 2 x 10 -7 1 x 10 -3 Iridium (77) Ir 190 2 x 10 -3 Ir 192 4 x 10 -4 Ir 194 3 x 10 -4 Iron (26) Fe 55 8 x 10 -3 Fe 59 6 x 10 -4 Krypton (36) Kr 85m 1 x 10 -6 Kr 85 3 x 10 -6 Lanthanum (57) La 140 2 x 10 -4 Lead (82) Pb 203 4 x 10 -3 Lutetium (71) Lu 177 1 x 10 -3 Manganese (25) Mn 52 3 x 10 -4 Mn 54 1 x 10 -3 Mn 56 1 x 10 -3 Mercury (80) Hg 197m 2 x 10 -3 Hg 197 3 x 10 -3 Hg 203 2 x 10 -4 Molybdenum (42) Mo 99 2 x 10 -3 Neodymium (60) Nd 147 6 x 10 -4 Nd 149 3 x 10 -3 Nickel (28) Ni 65 1 x 10 -3 Niobium (Columbium) (41) Nb 95 1 x 10 -3 Nb 97 9 x 10 -3 Osmium (76) Os 185 7 x 10 -4 Os 191m 3 x 10 -2 Os 191 2 x 10 -3 Os 193 6 x 10 -4 Palladium (46) Pd 103 3 x 10 -3 Pd 109 9 x 10 -4 Phosphorus (15) P 32 2 x 10 -4 Platinum (78) Pt 191 1 x 10 -3 Pt 193m 1 x 10 -2 Pt 197m 1 x 10 -2 Pt 197 1 x 10 -3 Potassium (19) K 42 3 x 10 -3 Praseodymium (59) Pr 142 3 x 10 -4 Pr 143 5 x 10 -4 Promethium (61) Pm 147 2 x 10 -3 Pm 149 4 x 10 -4 Rhenium (75) Re 183 6 x 10 -3 Re 186 9 x 10 -4 Re 188 6 x 10 -4 Rhodium (45) Rh 103m 1 x 10 -1 Rh 105 1 x 10 -3 Rubidium (37) Rb 86 7 x 10 -4 Ruthenium (44) Ru 97 4 x 10 -4 Ru 103 8 x 10 -4 Ru 105 1 x 10 -3 Ru 106 1 x 10 -4 Samarium (62) Sm 153 8 x 10 -4 Scandium (21) Sc 46 4 x 10 -4 Sc 47 9 x 10 -4 Sc 48 3 x 10 -4 Selenium (34) Se 75 3 x 10 -3 Silicon (14) Si 31 9 x 10 -3 Silver (47) Ag 105 1 x 10 -3 Ag 110m 3 x 10 -4 Ag 111 4 x 10 -4 Sodium (11) Na 24 2 x 10 -3 Strontium (38) Sr 85 1 x 10 -3 Sr 89 1 x 10 -4 Sr 91 7 x 10 -4 Sr 92 7 x 10 -4 Sulfur (16) S 35 9 x 10 -8 6 x 10 -4 Tantalum (73) Ta 182 4 x 10 -4 Technetium (43) Tc 96m 1 x 10 -1 Tc 96 1 x 10 -3 Tellurium (52) Te 125m 2 x 10 -3 Te 125m 6 x 10 -4 Te 127 3 x 10 -3 Te 129m 3 x 10 -4 Te 131m 6 x 10 -4 Te 132 3 x 10 -4 Terbium (65) Tb 160 4 x 10 -4 Thallium (81) Tl 200 4 x 10 -3 Tl 201 3 x 10 -3 Tl 202 1 x 10 -3 Tl 204 1 x 10 -3 Thulium (69) Tm 170 5 x 10 -4 Tm 171 5 x 10 -3 Tin (50) Sn 113 9 x 10 -4 Sn 125 2 x 10 -4 Tungsten (Wolfram) (74) W 181 4 x 10 -3 W 187 7 x 10 -4 Vanadium (23) V 48 3 x 10 -4 Xenon (54) Xe 131m 4 x 10 -6 Xe 133 3 x 10 -6 Xe 135 1 x 10 -6 Ytterbium (70) Yb 175 1 x 10 -3 Yttrium (39) Y 90 2 x 10 -4 Y 91m 3 x 10 -2 Y 91 3 x 10 -4 Y 92 6 x 10 -4 Y 93 3 x 10 -4 Zinc (30) Zn 65 1 x 10 -3 Zn 69m 7 x 10 -4 Zn 69 2 x 10 -2 Zirconium (40) Zr 95 6 x 10 -4 Zr 97 2 x 10 -4 Beta- or gamma- emitting radioactive material not listed above with half-life less than three years 1 x 10 -10 1 x 10 -6 1 Values are given only for those materials normally used as gases. 2 µCi/gm for solids.