Table 1 - Nationally Tracked Source Thresholds
| 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 |