A. Radio, television and radar transmitters create fields of electrical energy in the air surrounding their antennas that can, under exceptional circumstances, detonate electric blasting caps. Electrical blasting operations or storage of electrical detonators shall be prohibited in the vicinity of radio frequency transmitters except where the following clearances can be observed:
Amplitude Modified (AM) Transmitters
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
5 - | 2 | 100 | |
25 - | 50 | 150 | |
50 - | 100 | 220 | |
100 - | 250 | 350 | |
250 - | 500 | 450 | |
500 - | 1,000 | 650 | |
1,000 - | 2,500 | 1,000 | |
2,500 - | 5,000 | 1,500 | |
5,000 - | 10,000 | 2,200 | |
10,000 - | 25,000 | 3,500 | |
25,000 - | 50,000 | 5,000 | |
50,000 - | 100,000 | 7,000 | |
Frequency Modulated (FM) Mobile Transmitters
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
1 - | 10 | 5 | |
10 - | 30 | 10 | |
30 - | 60 | 15 | |
60 - | 250 | 30 | |
250 - | 600 | 45 | |
Very High Frequency (VHF)
Television and FM Broadcasting
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
1 - | 10 | 5 | |
10 - | 100 | 20 | |
100 - | 1,000 | 60 | |
1,000 - | 10,000 | 200 | |
10,000 - | 100,000 | 600 | |
100,000 - | 1,000,000 | 2,000 | |
Ultra High Frequency (UHF)
Television Transmitters
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
Transmitter Power (Watts)
| Minimum Distance (Feet)
| ||
1 - | 10 | 2.5 | |
10 - | 100 | 8 | |
100 - | 1,000 | 25 | |
1,000 - | 10,000 | 80 | |
10,000 - | 100,000 | 250 | |
100,000 - | 1,000,000 | 800 | |
1,000,000 - | 5,000,000 | 2,000 | |
B. When necessary to perform blasting distances less than those shown in tables, detonating fuse shall be used with a nonelectric cap or primer. (Ord. A-348, 6-4-1979)