Chapter 50: Non-ionizing Radiation

Overview (1)

SLAC conducts research and development programs that involve sources of radio frequency (RF) non-ionizing electromagnetic radiation (NIR). (In this chapter RF will refer to frequencies in the range from 3 kilohertz (kHz) to 300 gigahertz (GHz)). Devices that may produce RF radiation include high-power amplifiers such as klystrons, high-energy electron and positron beams traveling through beam chambers, telecommunications equipment, and induction heaters and ultrasonic cleaners.

With the exception of some telecommunication equipment, the high-power RF systems in use at SLAC are designed to deliver the RF fields they generate to accelerating structures via waveguides or coaxial cables. When functioning properly, these systems emit no hazardous levels of NIR. Other devices at SLAC, such as modulators, produce large electromagnetic transients in the RF spectrum, but the energy they emit is well below the threshold at which it would become a hazard.

Central to meeting the safety goals and requirements of this chapter is the development of a radio frequency safety program (RFSP) for each installation that has the potential to exceed the action level determined by the adopted Institute of Electrical and Electronics Engineers (IEEE) Standard C95.1-2005, "IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz" (IEEE Std C95.1-2005). The RFSP must be approved by the Non-ionizing Radiation Safety Committee (NIRSC) and the RFSP becomes the vehicle to ensure that hazard mitigation and communication are achieved. This chapter provides guidance for developing such a program.

This chapter is a general interpretation of relevant laws and standard and does not address all conceivable situations. Contact the NIRSC for any specific situations and for exceptions to the requirements found in this document.

Hazards/Impacts (1.1)

The potential hazards associated with exposure to RF fields are electro-stimulation of nerves in the frequency range of 3 kHz to 5 megahertz (MHz) and thermal heating of body tissues in the frequency range of 100 kHz to 300 GHz.

Scope (2)

This chapter establishes requirements for controlling the exposure of both SLAC personnel and the public to non-ionizing electromagnetic radiation and fields in the RF portion of the spectrum (3 kHz to 300 GHz). These requirements apply to all SLAC personnel, subcontractors, visiting scientists, users, and any other persons who conduct operations in which they may be exposed to such energy sources.

This chapter covers only the RF portion of the NIR spectrum. For NIR safety concerning lasers, see Chapter 10, "Laser Safety". For other NIR safety issues consult the SLAC Environment, Safety, and Health Division.

Exemptions (2.1)

All systems with RF sources are subject to NIRSC review, except for such consumer items as microwave ovens and cell phones, which are regulated under federal RF emissions standards.

Implementation (8)

The requirements of this chapter will be implemented according to Non-ionizing Radiation: Implementation Plan [pdf].

continue to Standards (3)

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