Time-temperature Thresholds and Safety Factors for Thermal Hazards from Radiofrequency Energy above 6 GHz

Abstract

Overview

This review critically examines the revised exposure limits for radiofrequency (RF) radiation above 6 GHz, as established by the International Commission on Nonionizing Radiation Protection (ICNIRP 2020) and the Institute of Electrical and Electronics Engineers (IEEE C95.1-2019). It provides an updated comprehension of the thermal hazards associated with RF energy, particularly in the millimeter wave (mm-wave) band spanning 30-300 GHz.

Findings

• It compares thermal damage and pain data from RF energy exposure to that from infrared energy and other heat sources.
• Estimates safety factors included in the IEEE and ICNIRP RF exposure limits.
• Identifies the benchmarks for thermal damage, such as minimal epithelial damage to the cornea and first-degree burns on the skin observable within 48 hours post-exposure.

Conclusion

The findings indicate that exposure levels significantly above the current ICNIRP and IEEE limits would be necessary to cause thermally hazardous effects to skin and cornea, which are the tissues most susceptible to RF energy in the specified frequency range. Nevertheless, it is important to note the limitations of available data and models which could affect the accuracy of these conclusions and underscore the need for caution in RF exposure.