Specific Absorption Rate (SAR)
The amount of radiofrequency (RF) energy absorbed into human tissue by a radio transmitter (e.g. when using a mobile phone). The higher the SAR rating, the more radiation is emitted by the mobile phone. The SAR value will depend heavily on the geometry of the part of the body that is exposed, and on the exact location and geometry of the source of the RF energy.
Various governments have defined safety limits for exposure to RF energy produced by mobile devices:
- European Union: 2 W/kg, averaged over 10 grams of tissue.
- United States: 1.6 watts per kilogram (W/kg) averaged over 1 gram of tissue.
