Specific Absorption Rate of Mobile Phones

Tue, 05/01/2021 - 15:48


We are all living in the digital era where our routine and work can be managed by a device the size of a palm - smartphones. Though mobile phones have many advantages, there is one important risk factor we need to take into consideration - the Specific Absorption Rate (SAR) commonly denoted by SAR value. The SAR value is printed in mobile phone boxes as well as on mobile phones as stickers. We can also obtain the SAR values on our phone display by dialing *#07#.

What is Specific Absorption Rate?

It is the amount of radiation (electromagnetic radiation) that will be absorbed by the human body while using a mobile phone. SAR is measured in units of W/kg of tissue.

How it is tested?

SAR value can be measured in two ways in laboratory conditions:

  1. Head measurement
  2. Body measurement 

i) Head Measurement

  • The mobile phone which has to be tested will be switched on to full power and placed against the phantom head.
  • Radio Frequency (RF) probe of the precision robots moves throughout the phantom head and measures the signal level.
  • Then the radio signal levels are converted into SAR(W/kg) by a computer.
  • With different phone positions, the test will be conducted at all operating frequencies. Once the test is completed, the maximum level measured will be recorded as the SAR value against the phantom head.

ii) Body Measurement

  • The mobile phone is placed against the phantom body and switched on to full power.
  • The remaining procedures are the same as the head measurement method.
  • The maximum level measured is recorded as the SAR value against the body.     

SOURCE: emf explained

Note: Boundary representation (BREP) phantoms are computational human models that contain exterior and interior anatomical features of a human body using boundary representation method. 


In September 2012, the Department of Telecom, Government of India issued regulations to the mobile manufacturers to ensure safety from mobile phone radiation.

  • Companies are permitted to manufacture or import mobile handsets with a  SAR value of 1.6W/kg averaging over 1 gram of human tissue in India.
  • Details about SAR value and its impact on health should be given to customers at the time of purchase. The SAR value should be displayed on the IMEI (International Mobile Equipment Identity) display.
  • The Telecommunication Engineering Centre can randomly test mobile handsets manufactured and sold in India or imported from other countries at the SAR laboratory  for compliance with the SAR limit.

Impacts of SAR On Human Body

Ongoing research on SAR states that RF radiations from cellular phones have thermal and non-thermal effects on the human tissue. Thermal effects could potentially increase body temperature and directly affect the head and the brain. Non-thermal effects could cause cellular and molecular changes in human tissue. Children and teens could be at higher risk as their brains are still developing. 

How can one reduce impact of SAR?

We can reduce the SAR impact by:

  • Using phones having low SAR Value.
  • Reducing the amount of time we carry phones in our pockets or hand.
  • Keeping the phones away when not in use, especially while sleeping.
  • Minimising phone usage among children.
  • Attending calls using headphones or speaker mode, the reason being that the impact on head tissues decreases with increase in distance between the cell phone and head.
  • Keeping calls as short as possible, especially while attending calls using handset.
  • Using pong back cases for mobiles. It will reduce the SAR by redirecting and redistributing the electromagnetic radiation from our cell phone away from our body and head.
  • Staying 12 inches away from the cell phone and 20 feet away from the WiFi will ensure that the exposure levels do not reach a significant level. 


Since consumers use mobile phones for prolonged periods of time and lack sufficient evidence about the effects of RF radiation on human health, it is important that consumers be aware of the type of device they purchase and the statutory guidelines provided by the government. 

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