10.7 HIERARCHY OF CONTROL MEASURES
Once RF risks have been assessed, controls must be implemented to eliminate the hazard or minimize the risk so far as reasonably practicable and to ensure that applicable exposure limits are not exceeded. The hierarchy of controls gives priority to measures that remove the hazard or reduce exposure without depending on a person's continuing behavior.
RPS S-1 lists the control priorities as elimination, substitution, engineering controls, administrative controls, personal issue RF alarms, and other appropriate personal protective equipment. Measures higher in the hierarchy are usually more reliable and should receive greater consideration. Lower-order measures remain important, but generally supplement rather than replace higher-order controls.
In practice, several controls are often combined, and their implementation, maintenance, verification, training, and review requirements should be documented.
10.7.1 Elimination
Elimination is the most effective option because it removes the RF hazard from the installation or eliminates RF exposure during the task.
The transmitter may be essential to the service, but exposure can often be eliminated for a particular activity by changing when, where, or under what source state the work is performed.
Examples include:
- removing obsolete or unnecessary RF-generating equipment from service;
- de-energizing, isolating, and verifying the relevant transmitter before access;
- performing the task during a confirmed outage rather than while the source is active;
- relocating the task so that personnel do not enter the affected RF field; or
- designing routine inspection and servicing so that entry into an RF hazard area is not required.
Controls are still required to maintain and verify the eliminated condition, particularly where another person or remote system could re-energize the source.