Setting exposure guidelines and product safety standards for radio-frequency exposure at frequencies above 6 GHz: brief review

Two international guidelines/standards for human protection from electromagnetic fields are on-going revision. Most attention has been paid to the revisions above 3 or 10 GHz where the new fifth generation wireless communication system will be deployed soon. The frequency of 3 or 10 GHz is the transition frequency at which the metric of the basic restriction is changed from the specific absorption rate to the power density. Rationales for the metrics above 3 or 10 GHz were not well established when the current guidelines/standards were published. In this review, we focused on three issues to be considered in the next revision of the exposure guidelines: (i) the averaging area of the power density, (ii) the transition frequency at which the metric is changed from the specific absorption rate to the power density, and (iii) the exposure averaging time. In addition, some remarks and trends on related product safety will also be reviewed and discussed briefly.