- •Preface
- •Contents
- •1. Introduction
- •2. Sources
- •3. Radiofrequency radiation
- •3.1. Electromagnetic radiation
- •3.2. Quantities and units of exposure
- •4. Exposure and energy absorption
- •5. Radiofrequency biological effects
- •5.1. Whole-body response
- •5.2. Localized responses
- •5.2.1. Reproductive system
- •5.2.2. Teratogenic effects
- •5.2.3. Effects on the eye
- •5.2.4. RF burns and operator hand numbness
- •5.2.5. Carcinogenesis
- •5.3. Conclusion
- •6. Occupational exposure standards and guidelines
- •6.1. ICNIRP guidelines
- •7. Exposure assessment
- •7.1. Measurement of RF fields
- •7.2. Measurement of induced currents
- •8. Control technology and radiation protection programme
- •8.1. General obligations and duties
- •8.1.1. Role of competent authorities
- •8.1.2. Responsibility of the employer
- •8.1.3. Duties of the worker (user)
- •8.1.4. Responsibility of manufacturers
- •8.2. Work practice controls
- •8.2.1. Maintenance procedures
- •8.2.2. Operator procedures
- •8.2.3. Identification of RF hazard areas
- •8.3. Design and installation considerations
- •8.3.1. Shielding
- •8.3.2. Installation details
- •8.3.2.1. Installations near pipes
- •8.3.2.2. Grounding
- •8.4. Medical surveillance
- •8.4.1 Normal conditions
- •8.4.2 Abnormal conditions
- •1. Basic principles
- •Current paths
- •Resistance
- •2. Shielding design and construction
- •Characteristics and selection of shielding materials
- •Joints
- •Ports or slot openings in shielding
- •Doors and removable panels
- •Vestibules (shielding tunnels)
- •High frequency power connections
- •3. Summary of control technology
- •Capacitors
- •Inductors
- •Resonant conductors
- •Waveguides
- •References
8
Control technology and radiation protection programme
To minimize the risk of adverse health effects, RF fields as well as induced and contact currents must be in compliance with the applicable guidelines. Reduction and control of exposure can be accomplished through the implementation of appropriate administrative and work practice controls, and/or proper design, construction and installation of RF heaters. RF shielding is emphasized because it is typically both practical and effective (Murray et al., 1992; Ruggera and Schaubert, 1982). Its ease of construction, low cost, versatility, minimal operator involvement, and protective value have been proved through years of experience.
8.1. General obligations and duties
8.1.1. Role of competent authorities
To avoid duplication of effort, there should be cooperation among the competent or regulatory authorities whose scope of function includes protection against potential hazards of RF heaters. These competent authorities should adopt the necessary regulations and establish inspection systems to ensure compliance with applicable safety guidelines.
8.1.2. Responsibility of the employer
It is the responsibility of an employer utilizing RF heaters to implement and enforce, as part of its comprehensive safety and health programme, an RF protection programme which assures the safety of employees from RF hazards. The RF protection programme shall include:
(a)utilization of RF heaters which meet applicable RF and other safety standards when new and during the time of use, including after any modifications made by the employer;
(b)RF hazard identification and periodic surveillance by a competent person (i.e. safety officer) who can effectively assess RF exposures;
(c)implementation of controls to reduce RF exposures to levels in compliance with applicable guidelines, including rules regarding safe work practice procedures;
(d)RF safety and health training to ensure that all employees and supervisors understand the RF hazards to which they may be exposed and the means by which the hazards are controlled;
(e)employee involvement in the structure and operation of the programme and in decisions that affect their safety and health, to make full use of their insight and to encourage their understanding and commitment to the safe work practices established;
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