Recent Study on SAR

How important is SAR value ?

ABSTRACT

In modern society people are frequently exposed to different types of radiations and this exposure comes from different sources. It could be related to everyday life (televisions, mobile phones, computer devices, occupational equipment). SAR is a measure of the rate at which energy is absorbed per unit mass by a human body when exposed to a radio frequency. FCC approval means that the device should never exceed the maximum levels of consumer RF exposure permitted by federal guidelines. The National Frequencies Agency (ANFR) publishes an interim report of DAS (Specific Absorption Rate) checks carried out on 46 mobile phones in 2021. There are Mobile phones available in France and India but don’t comply with the relevant standards.

India has adopted one of the most stringent electromagnetic field (emf) exposure norms in the world. Unlike previous technologies, the current 5G in the 3.5 GHz band requires the phone to use two networks simultaneously, the 4G network and the 5G network. Measures have been taken by the department of telecommunications, Government of India to keep a regulatory check on the exposure. Exposure to very high RF intensities can result in heating of biological tissue and an increase in body temperature.

What is SAR?

Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed per unit mass by a human body when exposed to a radio frequency (RF). It is defined as the power absorbed per mass of tissue and has units of watts per kilogram (W/kg).

What SAR shows?

The FCC requires the cell phone manufacturers to conduct their SAR testing to include the most severe, worst-case (and highest power) operating conditions for all the frequency bands used in the USA for that cell phone. The SAR values recorded on the FCC’s authorization and in the cell phone manual to demonstrate compliance with Commission rules indicate only the highest single measurement taken for each frequency range that the particular model uses.

How to Check the Radiation Level (SAR) of Your Phone?

  • Check Radiation level (SAR) of your Smartphone by USSD code *#07#.
  • Check the user guide of mobile phone.
  • Checking phone’s settings.

What SAR Does Not Show?

The SAR value used for FCC approval does not account for the multitude of measurements taken during the testing. Moreover, cell phones constantly vary their power to operate at the minimum power necessary for communications; operation at maximum power occurs infrequently.

Consequently, cell phones cannot be reliably compared for their overall exposure characteristics on the basis of a single SAR value for several reasons

(Each of these examples is based on a reported SAR value for cell phone A that is higher than that for cell phone B):

  • Cell phone A might have one measurement that was higher than any single measurement for cell phone B. Cell phone A would, therefore, have a higher reported SAR value than cell phone B, even if cell phone B has higher measurements than A in most other locations and/or usage configurations. In such a case, a user generally would receive more RF energy overall from cell phone B.
  • Cell phone A might communicate more efficiently than cell phone B, so that it operates at lower power than cell phone B would under comparable conditions. Consequently, a user would receive more RF energy overall from cell phone B.

The highest value from cell phone A might come from a position which the user seldom or never employs to hold a phone, whereas that user might usually hold a phone in the position that resulted in the highest value for cell phone B. Therefore, the user would receive the highest RF exposure that cell phone B delivers but would not receive the highest RF exposure that cell phone A delivers.

What is FCC approval?

FCC approval means that the device will never exceed the maximum levels of consumer RF exposure permitted by federal guidelines, but it does not indicate the amount of RF exposure consumers experience during normal use of the device. While only the maximum SAR values are used for FCC approval, all test reports submitted by the manufacturer are available in full for public inspection on the Commission’s website.

FCC – defined SAR values for the Grants of Equipment Authorization
Maximum Cellular/PCS Head SAR value 1.03W/kg
Maximum WLAN Head SAR value 0.37W/kg
{Max + max] Simultaneous head SAR value 1.15W/kg
Maximum Cellular/PCS Body SAR value 0.68W/kg
Maximum WLAN Body SAR value 0.05W/kg
{Max + max] Simultaneous Body SAR value 0.73W/kg
Maximum Product Specific (Wireless Router) SAR value 1.31W/kg
Maximum Simultaneous SAR value 1.36W/kg

Regarding 5G terminals:

Unlike previous technologies, the current 5G in the 3.5 GHz band requires the phone to use two networks simultaneously, the 4G network and the 5G network. This linked mode of operation, known as “Non-Standalone (NSA)”, could be analysed in the new SAR measurement laboratory of the ANFR.

The first checks carried out as part of the market surveillance show that the additional contribution of 5G is very low and only appears when the 4G and 5G antennas in the phone are co-located. Average increase of 0.4% for trunk SAR and 1.8% for limb SAR were thus observed.

Concerning the two non-compliant terminals, the list of which and the details of the measures are recalled in the appendix, the highest levels of “trunk SAR” and “member SAR” were 2.86 W/Kg and 5.26 W/Kg. These phones have been the subject of a software update to reduce the power of the phone and thus lower the level of SAR below the thresholds of 2 and 4 W/Kg.

 

INTERIM REPORT OF DAS-FRANCE:

The National Frequencies Agency (ANFR) publishes an interim report of DAS (Specific Absorption Rate) checks carried out on 46 mobile phones collected from points of sale in France since the start of 2021.

Among these, 13 5G phones have been checked and appeared to comply with the regulations. Of the 46 telephones sampled, two of them exceeded the regulatory limit and were already the subject of a communication during the implementation of software updates by their manufacturers.

As part of its mission to control public exposure to electromagnetic waves and market surveillance, the ANFR publishes the results of the SAR measurements it performs on mobile phones marketed in France to ensure their compliance with European regulations. The DAS makes it possible to quantify the energy transported by electromagnetic waves and absorbed by the human body. This publication contributes to public information on exposure due to mobile phones.

As requested by Cédric O, Secretary of State in charge of the Digital Transition of Electronic Communications, the ANFR is strengthening its controls in 2021, with 140 terminals planned in the long term, including 5G smartphones.

Since the start of the year, the ANFR has collected 99 models of telephones sold in France, representing more than 77% of telephone sales in France. 46 telephones have already been the subject of SAR measurements (trunk and limb), 44 of them have been measured with a SAR in accordance with the regulations, that is say less than 2 W/Kg for the SAR trunk and 4 W/Kg for the DAS member.

The other two phones were measured at levels exceeding these values.

Regarding the 44 compliant terminals:  

  • The average value of the “trunk SAR” measured is 979 W/kg,

the levels varying from 0.439 to 1.80 W/kg;

  • The average value of the “limb SAR” measured is 263 W/kg,

the levels varying from 1.3 to 3.89 W/kg;

MOBILE PHONES THAT ARE AVAILABLE IN FRANCE AND DON’T COMPLY WITH THE RELEVANT STANDARDS

 

List of mobile phones with a non-compliant “trunk” SAR

Telephone SAR “trunk” measured Manufacturer’s decision “Trunk” SAR measured after update
EssentialB Heyou 60 2.86 W / Kg Software update 1.11 W / Kg
EssentialB Heyou 40 2.54 W / Kg Software update 1.29 W / Kg

  

List of Mobile phones with a non-compliant “member” SAR

Telephone SAR “member” measured Manufacturer’s decision SAR “member” measured after update
EssentialB Heyou 60 5.26 W / Kg Software update 2.92 W / Kg
EssentialB Heyou 40 4.02 W / Kg Software update 2.22 W / Kg

  

EXPOSURE NORMS IN INDIA:

India has adopted one of the most stringent Electro Magnetic Field (EMF) exposure norms in the world. The measures taken by the Department of Telecommunications, Government of India, are:

EMF Radiation Norms:

Mobile Towers

  • EMF exposure limit (Base Station Emissions) is lowered to 1/10th of the existing ICNIRP exposure level effective from 1st 2012. India now has one of the most stringent EMF exposure norms in the world.
  • Telecom Enforcement Resource & Monitoring (TERM) Cells of DOT have been entrusted with the job of conducting audit on the self-certification furnished by the Service Providers. TERM Cell shall carry out test audit up to 10% of the BTS site on random basis and on all cases where there is a public complaint.
  • Telecom Engineering Centre (TEC) has revised the Test Procedure for measurement of EMF for verification of EMF compliance for BTS towers in accordance with new standards effective from 1st 2012.
  • For non‐compliance of EMF standards, a penalty of 5 lakh is liable to be levied per BTS per Service Provider.

Mobile Handsets –

  • India has adopted the most stringent international norms for mobile handsets.
  • All the new designs of mobile handsets shall comply with the SAR values of 1.6W/kg averaged over 1 gram of human tissue w.e.f. 1st2012.
  • The mobile handsets with existing designs which are compliant with 0W/kg averaged over 10 gram of human tissue, continued to co‐exist up to 31st August 2013.
  • From 1st 2013, only the mobile handsets with revised SAR value of 1.6 W/kg would be permitted to be manufactured or imported in India.
  • Specific Absorption Rate (SAR) value information display on the mobile handsets like IMEI (International Mobile Equipment Identity) display. The information on SAR values to be made available to the consumer at the point of sale.
  • Mobile handset manufactured and sold in India or imported from other countries shall be checked on random basis for compliance of SAR limit after TEC SAR Laboratory is set up by end of year 2012. Test results from International accredited labs shall be acceptable in the interim period.
  • All cell phone handsets sold in the market in India shall comply with relevant standards and shall be available in hand free mode.

MOBILE PHONES THAT ARE AVAILABLE IN INDIA AND DON’T COMPLY WITH THE RELEVANT STANDARDS

PHONES AVAILABLE IN INDIA SAR MEASURED SAR LIMITS(W/KG) RELEASE DATE
Xiaomi Black shark 2 1.92 1.6 June 2019
OnePlus 5T 1.68 1.6 Nov 2017
Xiaomi Mi A1 1.75 1.6 Sep 2017

  

Effects on health:

  • Biological effects can result from exposure to RF energy.  Biological effects that result from heating of tissue by RF energy are often referred to as “thermal” effects.  It has been known for many years that exposure to very high levels of RF radiation can be harmful due to the ability of RF energy to heat biological tissue  This is the principle by which microwave ovens cook food.
  • Exposure to very high RF intensities can result in heating of biological tissue and an increase in body temperature.  Tissue damage in humans could occur during exposure to high RF levels because of the body’s inability to cope with or dissipate the excessive heat that could be generated.
  • Two areas of the body, the eyes and the testes, are particularly vulnerable to RF heating because of the relative lack of available blood flow to dissipate the excess heat load.

REFERENCES: 

1) SAR WHAT IT MEANS TO YOU – FEDERAL COMMUNICATION COMMISION

https://www.fcc.gov/consumers/guides/specific-absorption-rate-sar-cell-phones-what-it-means-you

2) RADIO FREQUENCY SAFETY – FCC

https://www.fcc.gov/general/radio-frequency-safety-0

3) NATIONAL FREQUENCIES AGENCY

 https://www.anfr.fr/toutes-les-actualites/actualites/publication-des-premiers-controles-de-das-de-telephones-5g-commercialises-en-france/

4) SPECIFIC ABSORPTION RATE – GOVERNMENT OF INDIA

https://dot.gov.in/sites/default/files/Specific_absorption.pdxf

Author:

Jaishree B
Technical Engineer
Livesafe