What is SAR (Specific Absorption Rate) Rating and its Importance
To receive and operate the signals from the wireless GSM network, every mobile phone comes with the radio transmitter. For these to function with an optimum radiation, there are some standards set for the companies who manufacture them. There are a few authorities which take a control on the regulation, and these include – Federal Communications Commission (FCC) of the U.S. Government, Industry Canada of the Canadian Government (IC), and the Council of the European Union.
These authorities set the maximum measure for radiation, called as Specific absorption rate (SAR), which is a measure of the rate at which the energy is absorbed by the body when it is exposed to a Radio Frequency electromagnetic field, i.e. to the radiation which is emitted by the mobile phone. The same SAR rating is also used for the absorption of other forms of energy, i.e. ultrasound, etc.
The limits set and measurements done by the different authorities do not match, and thus they are not comparable. Here are the limits set by the authorities:
- US: Limit set by FCC/IC is 1.6W/kg, averaged over 1 gram of the actual tissue
- Europe: Limit set by Council of the European Union is 2W/kg, averaged over 10 gram of the actual tissue
- In India, the limits from Europe were taken earlier but then it shifted to the US values, and India doesn’t rely on these because there are random tests done by government-run Telecommunication Engineering Center (TEC) SAR Laboratory to check out the values on average.
SAR Limits Country Wise
|Region / Country||SAR Measurement Protocol||Reference to SAR Limit||Limit|
|US||Federal Communications Commission (FCC) Guidelines (FCC 1997)||American Standard ANSI C95.1 (ANSI 1992)||1.6 W/Kg in 1g of tissue|
|Europe||European Specification ES 59005 (1998)||ICNIRP Guidelines 1998 (ICNIRP 1998)||2.0 W/Kg in 10g of tissue|
|Australia||Australian Communications Authority (ACA) Standard (ACA RS 1999)||Australian Standard AS/NZS 2772.1||1.6 W/Kg in 1g of tissue|
SAR levels are measured at the highest power level, and thus, the actual level can keep getting lower because the mobile phones are made to work in multiple levels of power, so that they can use lower power when the GSM network towers are near and there is no need to send higher levels of radiation.
If any mobile phone comes with the SAR rating of over 1.6 in the US rating system, the phone isn’t approved for the market and thus, you will be seeing the rating of maximum 1.59 for the devices selling in US.
According to the FCC/IC, the SAR values have to be measured at two levels – hip level, head level. This is because there are many cases when people use Bluetooth headsets and carry the phone in the waist pocket while making calls, and the head level is where people usually make calls directly using the phone. The Council of European Union doesn’t measure the hip level, and takes only the ear level as the consideration for the SAR levels.
How is SAR value important for mobile phone users?
If the radiation is higher, it can cause health hazards in the long run. Not that you could be the unlucky one, but there are cases where the cell phone radiation has even caused brain tumor, thus it is good to be safe and choose a mobile phone which has the lower SAR level.
The American Cancer Society says most published studies have not found a link between cell phones and the development of tumors. The Food and Drug Administration says “the weight of scientific evidence has not linked cell phones with any health problems.”
Although there are verbal statements from opposing groups, there has been a higher demand in the west for the phones which have a lower SAR level. SAR Shield (sarshield.com) has a table of all the phones and their SAR levels, so one can check out the rating before choosing a phone, especially for the elders.
Some current and recent devices having a high SAR rating (US Rating):
- Samsung Galaxy Tab 3 7.0 – 1.59
- Samsung GT-i9300 Galaxy S III – 1.584
- Samsung Galaxy S5 – 1.58
- Blackberry 9700 Bold – 1.55
- Nokia Lumia 900 – 1.51
- Google Nexus 4 – 1.50
- Samsung Galaxy Note 3 SM-N900P – 1.50
- Motorola Droid 2 – 1.49
- Nokia Lumia 820 – 1.49
- Motorola Atrix 4G – 1.47
- Nokia 808 PureView – 1.46