10 C.F.R. § 20 app E to Part 20
Current through September 30, 2024
The Terabecquerel (TBq) values are the regulatory standard. The curie (Ci) values specified are obtained by converting from the TBq value. The curie values are provided for practical usefulness only and are rounded after conversion.
| Radioactive material | Category 1 (TBq) | Category 1 (Ci) | Category 2 (TBq) | Category 2 (Ci) |
| Actinium-227 | 20 | 540 | 0.2 | 5.4 |
| Americium-241 | 60 | 1,600 | 0.6 | 16 |
| Americium-241/Be | 60 | 1,600 | 0.6 | 16 |
| Californium-252 | 20 | 540 | 0.2 | 5.4 |
| Cobalt-60 | 30 | 810 | 0.3 | 8.1 |
| Curium-244 | 50 | 1,400 | 0.5 | 14 |
| Cesium-137 | 100 | 2,700 | 1 | 27 |
| Gadolinium-153 | 1,000 | 27,000 | 10 | 270 |
| Iridium-192 | 80 | 2,200 | 0.8 | 22 |
| Plutonium-238 | 60 | 1,600 | 0.6 | 16 |
| Plutonium-239/Be | 60 | 1,600 | 0.6 | 16 |
| Polonium-210 | 60 | 1,600 | 0.6 | 16 |
| Promethium-147 | 40,000 | 1,100,000 | 400 | 11,000 |
| Radium-226 | 40 | 1,100 | 0.4 | 11 |
| Selenium-75 | 200 | 5,400 | 2 | 54 |
| Strontium-90 | 1,000 | 27,000 | 10 | 270 |
| Thorium-228 | 20 | 540 | 0.2 | 5.4 |
| Thorium-229 | 20 | 540 | 0.2 | 5.4 |
| Thulium-170 | 20,000 | 540,000 | 200 | 5,400 |
| Ytterbium-169 | 300 | 8,100 | 3 | 81 |
10 C.F.R. 20 app E to Part 20