A Smartphone User Guide: Specific Absorption Rate(SAR)


It’s 2018 and the following information may not be new to the eyes of a person who takes an extra mile to read whatever that is packaged with that new smartphone, but to a person who doesn’t do so, it’s worth a while to take note of one the notes that comes with every gadget provided by the manufacturer and this is the user guide. A user guide is defined as a technical communication document intended to give assistance to people using a particular equipment and in this case a smartphone. But again, we shall not look at the whole user guide document, that’s a lot of work to write on right now, we shall look at the specific absorption rate(SAR) and ascertain the safety of your phone!

A few months ago, I purchased a Nokia 6 and as i was going through the user guide, the following statement under a subtitle ‘ Certification information (SAR)’ caught my attention…

”This mobile device meets guidelines for exposure to radio waves as set forth by the Council of Europe(CE) and the Federal Communications Commission(FCC)”.

This implies that there are set standards which your mobile handset should meet before it is approved to be safe for use and among them include the amount of radio waves it exposes to you. These are better explained in what is known as specific absorption rate(SAR).

By definition, specific absorption rate is a measure of the rate at which energy is absorbed by the human body when exposed to a radio frequency(RF) electromagnetic field. It is measured in watts/Kilogram(W/Kg). Since we are here to make use of a user guide, I will quote the information contained on the user guide for the Nokia 6.

Referring to the European RF exposure standards, it is quoted that ‘your mobile device is a radio transmitter and receiver and therefore it is designed not to exceed the limits for exposure to radio waves recommended by international guidelines which were developed by the independent scientific organisation and include safety margins designed to assure protection of all persons, regardless of age and health.’ Here the SAR limit for mobile devices is 2.0W/Kg.

Referring to the FCC RF Exposure standards, the SAR limit set by the FCC is 1.6W/Kg.

Whatever the case, no device is approved to be used on either the European or US markets until it passes through these regulatory bodies to approve its safety, meaning that if you ever buy a phone and its safety isn’t mentioned anywhere through out the user guide, please return it and reclaim your money.

How are specific absorption rate(SAR) values determined?

Well, as i said earlier, SAR is a unit of measurement employed by the exposure standard for wireless handsets. The tests are performed in specific positions and locations for example at the ear and worn on the body. For typical body-worn operations, the handset is kept 1.0 cm from the body, and so to maintain this only accessories that are compliant should be used. During general use ,the reported SAR values is usually below those that are given by each manufacturer in their respective user guides and hence there is no cause for alarm, and the reason is very clear ,the operating power of any mobile device is automatically decreased when full power is not needed for the call as this minimizes interference on the network as well as optimizing system efficiency in one way or the other.

SAR values are always low when power output from the phone is low. However, many manufacturers produce device models with different versions, for example Nokia 6 has a chinese variant (TA-1033) and an international variant (TA- 1021) and this means that each of these variants has its SAR value. Also components and changes in the design of the phone may occur over time and some changes could affect the SAR values. It’s however, not exactly known if the older the phone gets, the more or less it exposes you to radio waves(more research is needed here).

Lastly but not the least, according to the World Health Organisation(WHO), current scientific information does not indicate the need for any special precautions when using mobile devices.


If you are in need of reducing exposure to radio waves, limit the usage of your device(which is practically impossible in this era) or start using a hands-free accessory to keep the device away from your head and body.

In a nut shell, every genuine device has an electronic label for certification information and you can access it from your device by selecting settings > About phone > Certification. (Credit: Nokia 6 accessibility is used as an example).