The GSMA supports an internationally harmonized approach to radiofrequency exposure standards. Countries should follow the recommendations of the WHO and the ITU and base their national requirements on the ICNIRP exposure guidelines. These guidelines have been widely adopted in Africa, Asia, Europe, Latin America and the Middle East.
Some countries have adopted restrictive limits but the current consensus of scientific reviews is that these provide no additional health benefit. Large differences between national limits and international guidelines can foster confusion for regulators and policy makers and increase public anxiety.
The ICNIRP guidelines are structured around basic restrictions, measures of RF energy absorbed by the body, and reference levels, external field levels that are more easily measured for compliance purposes. In general reference levels are used for compliance of network antennas and basic restrictions for devices used close to the body.
In cases were the source is distant from the human body free-field exposure assessment methods can be used and limits are specified in units such as volts per meter (V/m) or power density (Watts / square metre).
When the radio transmitter is used close to the head or body the method uses robot positioned measurement probes in phantom humans containing tissue simulating liquids (YouTube) and limits are specified in terms of the Specific Absorption Rate (SAR) with units of watts per kilogram (W/kg).
It is important to emphasize that exposure standards are not the same as emission standards. Exposure standards apply to locations accessible to workers or members of the general public and it is possible to achieve compliance by limiting access to areas where the exposure limits are exceeded. Emission standards are technical equipment specifications.