California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 18 - Explosive Materials › Article 116 - Handling and Use of Explosive Materials in Blasting Operations › Section 5306 - Electric Blasting in Proximity to Radio, Television or Radar Transmitters

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) Blasting area
						warning signs shall be posted approximately 1,000 feet from the blasting area
						along all access routes. These signs shall be in accordance with all
						requirements of the California Manual on Uniform Traffic Control Devices for
						Streets and Highways, September 26, 2006, published by the State Department of
						Transportation (CA-MUTCD), Part 6, Temporary Traffic Control, Sections
						6 F.38 through 6F.41, which are
						hereby incorporated by reference.
(b) Electric blasting operations shall not be
						conducted closer to any operating mobile or fixed radio, television, or radar
						transmitter than the distances shown in the following tables:
Table 1 Recommended Table of Distances for
						  Commercial AM Broadcast Transmitters (0.535 to 1.605
						  MHz)
Transmitter
								  Power
(1)
(Watts)
Minimum Distance (Feet)
Up to
								  4,000..........................
..........................720
5,000..........................
..........................800
10,000..........................
..........................1,130
25,000..........................
..........................1,790
50,000
(2)
..........................
..........................2,500
100,000..........................
..........................3,600
500,000..........................
..........................8,000
__________
1
Power delivered to the
						  antenna.
2
50,000 watts is the present
						  maximum power of U.S. broadcast transmitters in this frequency range.
Table 2 Recommended Distances for Transmitters Up
						  to 50 MHz (Excluding AM Broadcast) Calculated for a Specific Loop Pickup
						  Configuration(1)(2)
Transmitter
								  Power
(3)
(Watts)
Minimum Distance (Feet)
100..........................
..........................790
200..........................
..........................1,120
500..........................
..........................1,770
1,000..........................
..........................2,500
1,500..........................
..........................3,070
5,000..........................
..........................5,590
50,000..........................
..........................17,700
500,000
(4)
..........................
..........................55,900
__________
(1) Based
						on the configuration with the blasting machine being the component of the
						blasting circuit closed to the transmitter, using 20.8 MHz, which is the most
						sensitive frequency.
(2) This table
						should be applied to International Broadcast Transmitters in the 10-25 MHz
						range.
(3) Power delivered to the
						antenna.
(4) Present maximum for
						International Broadcast.
Table 3 Recommended Distances of Mobile
						  Transmitters and Cellular Telephones Including Amateur and Citizens' Band
						  MINIMUM DISTANCE (Feet)
Transmitter
(1)
Power (Watts)
MF 1.7 to 3.4 MHz
								  Industrial
HF 28 to 29.7 MHz
								  Amateur
VHF 35 to 36 MHz Public Use 42 to 44 MHz
								  Public Use 50 to 54 MHz Amateur
VHF 144 to 148 MHz
								  Amateur 150.8 to 161.6 MHz Public Use
UHF 450 to 470
								  MHz Public Use Cellular Telephones Above 800 MHz
1
15
47
37
12
8
5
33
105
82
27
18
10
46
148
116
38
25
50
102
331
259
85
55
100
144
468
366
120
78
180(2)
193
627
491
161
104
200
204
661
518
170
110
250
228
739
579
190
123
500(3)
322
1,045
818
268
174
600(4)
353
1,145
897
294
190
1,000
455
1,478
1,157
379
245
1,500(5)
557
1,810
1,417
464
300
10,000(6)
1,438
4,673
3,659
1,198
775
Citizens Band, Class D Transmitters, 26,965
						  MHz (Channel 1)-27,405 MHz
						  (Channel 40)
Type
Recommended Minimum Distance
Hand-Held
Vehicle-Mounted
Double Sideband - 4 watts maximum
								  transmitter power
5 ft.
65 ft.
Single Sideband - 12 watts peak
								  envelope power
20 ft.
110 ft.
__________
(1) Power
								  delivered to antenna.
(2)
								  Maximum power for two-way mobile units in VHF (150.8 or 161.6
								  MHz range) and for two-way mobile and fixed station
								  units in UHF (450 to 460 MHz range).
(3)
								  Maximum power for major VHF two-way mobile and fixed station units in 35 to 44
								  MHz range.
(4)
								  Maximum power for two-way fixed station units in VHF (150.8 to 161.5
								  MHz range).
(5)
								  Maximum power for amateur radio mobile units.
(6)
								  Maximum power for some base stations in 42 to 44 MHz
								  band and 1.6 to 1.8 MHz band.
Table 4 Recommended Table of Distances for VHF TV
						  and FM Broadcasting Transmitters
Effective Radiated
								  Power
Minimum Distance
								  (Feet)
(Watts)
Channels
								  2 to 6
FM Radio
Channels 7 to
								  13
Up to
								  1,000
820
667
502
10,000
1,450
1,190
892
100,000(1)
2,580
2,115
1,585
316,000(2)
3,450
2,820
2,130
1,000,000
4,600
3,770
2,820
10,000,000
8,190
6,690
5,020
__________
(1)
								  Present maximum effective radiated power channels 2 to 6 and FM--100,000 watts.
(2)
								  Present maximum effective radiated power channels 7 to 13--316,000 watts.
Table 5 Recommended Table of Distances from UHF
						  TV Transmitters
Effective Radiative Power
								  (Watts)
Minimum Distance (Feet)
Up to
								  10,000..........................
..........................600
1,000,000..........................
..........................2,000
5,000,000(1)..........................
..........................3,000
100,000,000..........................
..........................6,000
__________
(1)
Present maximum power
						  channels 14 to 69--5,000,000 watts.
NOTE: RECOMMENDED TABLES OF DISTANCES
These tables of distances are designed for the
						  convenience of the licensed blaster. The selected groupings include all the
						  obvious types of RF transmitters that will be encountered around blasting
						  sites.
These tables were derived from analytical worse case
						  calculations. They are based on an assumed 40-milliwatt no-fire level of
						  commercial blasting caps. Actual field tests have shown that these tables are
						  conservative as would be expected. Because of the uncertainties involved in
						  field tests as to the efficiency of RF energy pickup and its delivery to the
						  blasting cap, we strongly recommend that these tables be followed. If these
						  tables present distances which are operationally inconvenient to use, we
						  suggest field tests be made by expert consultants and the procedures detailed
						  for providing minimum RF pickup be adhered to.
The data upon which these tables are based were derived
						  by the Franklin Institute Research Laboratories for the Institute of Makers of
						  Explosives.