PDFWAC 246-221-236

Nationally tracked source thresholds.

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
Cesium-137
100
2,700
1
27
Curium-244
50
1,400
0.5
14
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
[Statutory Authority: RCW 70.98.050 and 70.98.080. WSR 09-06-003, § 246-221-236, filed 2/18/09, effective 3/21/09.]