I have heard conflicting reports on whether it is possible to block the type of radiation emitted from cell phones, for example by consumer products/shields such as http://www.amazon.com/Phone-Anti-Radiation-Phones-inches-Black/dp/B006TGAQNA/ref=sr_1_1?ie=UTF8&qid=1439351881&sr=8-1&keywords=cell+phone+radiation+case.

Is it theoretically possible and what is the mechanism of such shielding?

Edit based on comments: I realize that it is not clear whether radiation from cell phones is harmful, I have seen studies suggesting that it is harmful but it is not clear that they do not have methodologic flaws, but regardless, that is not the question, the question is whether it is possible to block such radiation, what is the mechanism, and are consumer devices such as the one posted above plausible in their efficacy?

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    The problem with this is that the radiation is the means of communication that the phone uses. You could presumably block all of it with a Faraday Cage, but that leaves you with a phone incapable of communicating with the outside world. Aug 12, 2015 at 4:41
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    Oh, by the way, that only applies to electromagnetic radiation (micro and radio waves). I'm not aware of any other type of radiation emitted (or received) by cellphones, though. Aug 12, 2015 at 4:48
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    There's no consensus that mobile phones (Cell phones to you yanks) emit any harmful radiation whatsoever. Aug 12, 2015 at 8:26
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    @RensvanderHeijden The display emits additional electromagnetic radiation in the visible light spectrum ;). I suggest a sheet of plastic, paper or cloth to block this. In a pinch you can use your hand. Aug 12, 2015 at 9:46
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    Yes, you could put it in a Faraday cage. But then it wouldn't connect to a network. The "radiation" they emit is radio waves and there's no proof that they are any health risk at all.
    – GordonM
    Aug 12, 2015 at 11:39

1 Answer 1


Per the FTC, there is no scientific proof that so-called shields significantly reduce exposure from these electromagnetic emissions. "In fact, products that block only the earpiece or another small portion of the phone are totally ineffective because the entire phone emits electromagnetic waves. What's more, these shields may interfere with the phone's signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation."

The 2011 IARC group 2B classification of cell phone radiation as a possible carcinogen was based on the limited evidence from human studies and limited evidence from animal studies. Suggestions per FTC to limit exposure to cell phone electromagnetic emissions:

" 1. Increase the distance between your phone and your head by using a hands-free device, like an earpiece that is wired to the phone, or using the speakerphone feature.

  1. Consider texting more and limiting your cell phone use to short conversations. Wait for a good signal. When you have a weak signal, your phone works harder, emitting more radiation. Phones also give off more radiation when transmitting than when receiving, so tilt the phone away from your head when you're talking, and bring it back to your ear when you're listening."
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    You could, however, stop the radiation of the phone by switching it off, or, if you really need to communicate, by using a landline phone with a loooong cable to the next landline socket...
    – Alexander
    Jun 16, 2016 at 9:49

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