Review Sar Values Radiation Levels Bluetooth Headsets

SAR (specific absorption rate) measure how much electromagnetic radiation human tissue can absorb using a mobile phone. In the USA all cell phones must comply to the Federal Communications Commission (FCC) and have a SAR limit of 1.6 W/kg in 1 g of tissue. In Europe according to European Union Council SAR limit is set for 2.0 W/kg in 10 g of tissue.




Controversial studies published in 2002 in Finland and Sweden have claimed to found a link between radiation from mobile phones and adverse effect on overall health on mice. The scientist said that they need more research to give a real correlation between headaches, fatigue, and loss of concentration and mobile phone waves.

The level of radiation of a Bluetooth headset is lower than that of a mobile phone. Under normal circumstances a modern Bluetooth headset emits only 10% of the power of an average phone. Still, using a Bluetooth remains a good practice for safe driving and also for protecting you from the radiation level of your cell phone even if this is in the standards set by regulatory organization around the globe.  Bluetooth headsets sends out weak radio signals to connect to your phone. Some worry that this radiation could cause health problems, but the Bluetooth signal is extremely low at 1 miliWatt compared to cell phone that can emit up to 3 watts.

SAR is a measurement of the worst case of heating effect on a single gram of living tissue (studies were conducted on mice at level of radiation way much higher than the modern cell phone can emit). That heat is dispersed throughout the head and body. Over a period of one hour the maximum concentrated energy at a maximum SAR value of 1,6 watts/kg can heat up a few grams of tissue 1.3 degrees Celsius. The average human body has over 50,000 grams of mass so the heat would disperse much faster.
Test result documents submitted by Apple to FCC shows difference in the iPhone 3G’s tested radiation emission relative to its predecessors. This phone comply to FCC rule having a SAR value lower than the standard 1.6 W/kg on any given measure.
Part 22 (824 – 849 MHz): 3G – Head: 0.506 W/kg, Body: 1.03 W/kg. 3G S – Head: 0.57 W/kg, Body: 0.67 W/kg.
Part 24 (1850 – 1910 MHz): 3G – Head: 1.38 W/kg, Body: 0.521 W/kg. 3G S – Head: 1.19 W/kg, Body: 0.33 W/kg
Part 15 (2400 – 2483.5 MHz): 3G – Head: 0.779 W/kg, Body: 0.088 W/kg. 3G S – Head: 0.52 W/kg, Body: 0.06 W/kg.
From this numbers we can conclude that the iPhone 3Gs compared with the iPhone 3G puts out lower maximum radiation levels when broadcasting in the 1850-1910 and 2400-2483.5 MHz frequency ranges, higher when near the head in 824-849 MHz, and lower near the body in that range.

A good modern Bluetooth headset beside a lower SAR indicator must have built in noise cancelation, long autonomy, the possibility to interact with different models of cell phones and don’t forget the obvious part, must be very small and discrete.