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16.08.2022 00:39

SAR coefficient – what is it? Is it dangerous?

Science Smartphones and Tablets

SAR coefficient – what is it and what does it mean? Is a high rate dangerous to your health?

When you want to buy a phone, you check all the information about a given model, brand, its specifics or functions. You verify whether the phone has a suitable amount of memory, screen resolution, quality of graphics or cameras, as well as whether it has all the functions that interest you. Of course, you should pay attention to many different quality parameters, but the safety of using the devices is also important. However, there is little interest in whether a given phone is safe for you. One of the parameters allowed to assess this is the SAR coefficient. What is it and what does it mean? Is a high rate dangerous to your health?

Related: Camera phones – TOP 10 smartphones for photography

What is SAR (specific absorption rate)?

Specific Absorption Rate (SAR) shows the amount of radio wave energy absorbed by the human body when using a mobile phone. It indicates the specific rate of energy absorption by the tissues of our body. In short, it is the electromagnetic radiation factor of mobile phones. SAR measurements are made by using special antennas, which are placed in the human head model, and by placing a mobile phone to them while using and reaching the high power of the phone. The result is given in Watts per kilogram of body weight.

what is SAR
Can our smartphones be dangerous to us?

Currently, every mobile phone manufacturer is required to perform SAR measurements for each new model before it is released to the market. Only smartphone models that do not exceed the permissible standards are allowed for sale. However, it is worth remembering that you do not have to use the phone strictly to be exposed to radiation. It is enough to keep the mobile phone turned on and close to you, especially to your head. Just looking at the screen absorbs radiation through your eyes and face, and even when you keep your phone in your pocket, you absorb radiation in a different part of your body.

Can a high SAR be dangerous?

Scientists conducting research on cell phone radiation do not agree as to whether the radiation emitted by cell phones is harmful and what effects it can cause on the body. Various research results are easy to find – suggesting that radiation can cause cancer or cause DNA degeneration, and suggesting that there is no harm. However, prolonged exposure to such radiation can cause health problems.

For example, it has been proven that an eye near a device with a SAR exceeding 100 Watts per kilogram can heat up to 40 degrees Celsius, which is already above the protein curling value. So it’s easy to guess that it will damage your eyesight. However, the requirement for phone manufacturers to limit the SAR value is much, much lower, and means that scientists cannot conduct adequate research. All that remains for them is to study the long-term effects of waves, and that takes a long time.


Standards of the SAR coefficient

The minimum value of the SAR coefficient allowing Smartphones for sale is defined by legal regulations. The current SAR limit for head and body weight in Europe is 2 W/kg body weight, and in the US it is just 1 W/kg body weight. This SAR value must not be exceeded or the phone will not be approved for sale or use by humans.

If, when checking the coefficient for our smartphone, we notice that the SAR is 1.6 W/kg of body weight, it means that it is safe. If the SAR is 2 then it can be considered that the phone is safe, but the best value of the coefficient should be below 2. However, despite the correct SAR value, it is worth avoiding prolonged use of the phone just in case and choose mobile phones with the lowest SAR coefficient.

Which companies’ phones have the lowest SAR values?

If you are really concerned about your Smartphone’s radiation and its negative impact on health and life, you should definitely choose a phone whose SAR value is between 0.2 and 0.5 W/kg of body weight. Which brands record such results?


Samsung is the undisputed leader among smartphone brands in terms of the SAR rate, both in terms of flagship models, such as Samsung Galaxy, and cheaper mobile phones of this company. The lowest SAR values ​​are recorded by Samsung from the Note series with a result of 0.21 or 0.19. Samsung Galaxy has a slightly worse result. The Galaxy S10 has a radio wave emission level of 0.26 and the Galaxy A8 achieves the results of 0.24 W/kg of body weight. These are primarily the head coefficients.

Why is Samsung achieving such spectacular SAR results? Because a dozen or so years ago, this company reprogrammed its antennas for just low radiation. However, there is no shortage of opinions that Samsung has specially reprogrammed the antennas to obtain good test results, while in fact they do not care so much about the lowest values ​​of this factor.


Nokia, or in fact HMDD Global, is another phone manufacturer that cares about low SAR values. For example, the Nokia 6 smartphone has a radio wave absorption coefficient of 0.21 W/kg of body weight, while the Nokia 8 has a result of 0.22. However, not all phones of this company enjoy such a low rate. For example, the Nokia 2.1 model already has a SAR of 0.7. However, this is not a very high factor anyway. Up to 2 Watts is still very far.


LG is the third manufacturer of mobile phones to keep the SAR of its smartphones as low as possible. For example, the LG G8X has a coefficient of 0.27 W/kg body weight, the LG G7 0.24 W/kg body weight, and the LG Q7 Plus has SAR values ​​of 0.37. As in the case of Nokia, the SAR values ​​of individual phone models can be checked on the manufacturer’s website. However, navigation can be problematic, because instead of names, the smartphones of this brand have code numbers here.

Brands with the highest SAR

Unfortunately, there are a few brands that achieve a high SAR, although of course they are within the regulated standards. Otherwise, the smartphones of these brands would not be allowed for sale at all. Unfortunately, these companies also include two of the most popular on the market. I am talking about Apple iPhones, as well as the Chinese brand Xiaomi, which triumphs by selling phones at a much lower price, whose quality does not differ from the most popular smartphones, e.g. Samsung. In addition to these two companies, the coefficients in the upper limit of the norm are recorded by even less known models, such as the OnePlus or Google Pixel.

Does SAR matter nowadays?

Unfortunately, it is easy to see that hardly anyone nowadays pays attention to the SAR value when choosing a new mobile phone for themselves. It’s not that people aren’t worried about their health. Many people are still unaware of the existence of such a factor, and for those who are aware, it is enough to know that every mobile phone approved for sale meets the legal requirements for the radiation standard. In addition, people who have heard about this factor certainly also know that there is no confirmation in the studies of the harmfulness of this radiation for humans.

People definitely prefer to pay attention to technical issues when choosing a phone. More important is the amount of RAM, built-in memory, type and power of the processor, camera parameters, graphics, screen resolution or functions that the phone has. People are guided by what they need the most phone for and choose the one that is best for chatting, texting, browsing the web and keeping accounts on social networks, listening to music, watching movies or even TV on a smartphone, operating various applications or just playing. Only then do we consider safety issues, including the SAR coefficient. This is indicated by the huge popularity of Xiaomi iPhones and smartphones.

How to protect yourself from phone radiation?

Although all phone models meet the acceptable SAR limits, it is worth remembering that judicious use of the phone can help you protect yourself against the possible effects of radiation. It is not known what the effects of long-term exposure may be, so be careful. First of all, try not to spend most of your day in front of the screen (this will avoid overexposure) and check the SAR value of the phone model you are interested in before buying it.

In addition, try not to use the phone while it is currently being charged. It is also not worth keeping the phone near your head and body when you are not using it. Many people carry smartphones in their pants pockets. Most people only have vibrations set that they can sense just with their phone in their pocket. However, it is best to carry the phone in a purse instead of against the body. In addition, many people have also learned to sleep with smartphones – we still browse the Internet before going to sleep, and the first thing we do after waking up is reach for the phone. In addition, we use it as an alarm clock or a watch. However, let’s try to keep it on the bedside table, and not in the bed next to the pillow.

Telephones with the lowest and highest SAR values

​​The results for the following cell phone models are obtained from the German radiation protection authority. The Office tested a total of over 3,000 smartphone models. The full reports can be found on the website of the office, but here we list the models with the lowest and the highest SAR coefficients.

Models with the lowest SAR

The models with the lowest radiation coefficient include:

  • Samsung Galaxy Note 8 – 0.17 W/kg
  • ZTE Axon Elite – 0.18 W/kg
  • LG G7 – 0.24 W/kg
  • Samsung Galaxy A8 – 0.24 W/kg
  • Samsung Galaxy S8 + – 0.26 W/kg
  • Samsung Galaxy S7 Edge – 0.26 W/kg
  • HTC U11 life – 0.28 W/kg
  • LG Q6 / Q6 + – 0.28 W/kg
  • Samsung Galaxy S9 + – 0.29 W/kg
  • Motorola Moto G5 Plus – 0.30 W/kg
  • Motorola Moto Z – 0.30 W/kg

Smartphones with the highest SAR value

The following smartphones have the highest SAR values:

  • Xiaomi Mi A1 – 1 , 75 W/kg
  • OnePlus 5T – 1.68 W/kg
  • Xiaomi Mi Max 3 – 1.58 W/kg
  • OnePlus 6T – 1.55 W/kg
  • HTC U12 life – 1.48 W/kg
  • Xiaomi Mi Mix 3 – 1 , 45 W/kg
  • Google Pixel 3 XL – 1.39 W/kg
  • OnePlus 5 – 1.39 W/kg
  • iPhone 7 – 1.38 W/kg
  • Sony Xperia XZ1 Compact – 1.36 W/kg
  • HTC Desire 12/12 + – 1.34 W/kg
  • Google Pixel 3 – 1.33 W/kg
  • OnePlus 6 – 1.33 W/kg
  • iPhone 8 – 1.32 W/kg

As you can see, especially the SAR values ​​for the models Xiaomi mobile phones reach the upper limit of the norm. And the norm enforced in the United States is significantly exceeded here. However, this does not prevent this brand from celebrating triumphs and great popularity. Xiaomi devices are characterized by low prices with comparable quality to other top brands.


So the popularity is absolutely not surprising. Overall, when it comes to SAR values, you can feel safe. The results of laboratory tests are also worth taking a bit of a grain of salt. They are often overestimated because the radiation factor value is determined only after activating the highest power level of the phone. In fact, it is rare for a cell phone to reach its highest power output for normal human use.



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