Introduction to RF Radiation Safety / 9 / 9.4 / 9.4.2

9.4.2 Relationship To The Icnirp Guidelines

RPS S-1 is based on the 2020 ICNIRP Guidelines for frequencies from 100 kHz to 300 GHz. Its exposure quantities and limits are aligned with the ICNIRP framework for protecting against direct nerve stimulation at the lower end of the range and excessive heating across the RF range.

The two documents consequently use the same central protection logic: mandatory restrictions are linked to substantiated adverse health effects, practical reference levels are derived from those restrictions, and occupational and general-public exposure are treated differently because their conditions of awareness and control differ.

RPS S-1 is not merely a republication of ICNIRP. ICNIRP supplies the scientific guidance; RPS S-1 places that guidance within an Australian standard and adds requirements for compliance verification, workplace risk management, controlled areas, public protection, records, and incident response.

9.4.3 Basic Restrictions, Reference Levels, And Averaging

The basic restrictions are the mandatory exposure limits. Depending on frequency and duration, they use induced electric-field strength, whole-body average SAR, local SAR, absorbed power density, specific energy absorption, and absorbed energy density. They address whole-body exposure, localized exposure, sustained exposure, and brief exposure.

RPS S-1 adopts the same temporal structure as the ICNIRP Guidelines. Whole-body average SAR and corresponding whole-body reference levels are averaged over 30 minutes; localized SAR, absorbed power density, localized reference levels, and limb current are averaged over 6 minutes; and brief localized exposure above 400 MHz is subject to time-dependent energy restrictions for intervals greater than zero and shorter than 6 minutes. These requirements appear in the sustained- and brief-exposure basic restrictions and the corresponding whole-body, localized, and brief-exposure reference levels.

For each applicable exposure quantity and spatial or temporal averaging condition, compliance may be shown against either the basic restriction or its corresponding reference level; both need not be assessed. Compliance with a reference level demonstrates compliance with the corresponding basic restriction. Exceeding a reference level instead triggers a more detailed assessment and does not, by itself, establish that a basic restriction has been exceeded.

The averaging conditions form part of each limit. RPS S-1 distinguishes whole-body and local exposure, extended and brief exposure, spatial peaks and spatial averages, and the different assessment rules applicable in the far field, radiating near field, and reactive near field. Simultaneous frequencies must be combined using the standard's summation rules.

AS/NZS 2772.2 provides general methods for temporal sampling, instrument time averaging, treatment of duty cycle and modulation, extrapolation, uncertainty assessment, post-processing, and reporting. However, the 2016 edition predates ICNIRP 2020 and RPS S-1 and consequently does not independently reproduce all current temporal and brief-exposure requirements. When AS/NZS 2772.2 is used to verify compliance, the exposure quantities, 30-minute and 6-minute averaging conditions, brief-exposure integration requirements, and other compliance criteria specified by RPS S-1 take priority wherever the documents differ.