EWG is calling on the FCC to update its testing guidelines to take account of the widespread use of smartphone cases. Such action is critical because mounting scientific studies have raised serious questions about the safety of cell phone radiation exposure over the short and long term. In the absence of meaningful action by the Commission, EWG offers consumers tips on how to reduce their exposure to cell phone radiation.
When you make a phone call, just flip the shielded front cover down when you put the phone against your head. It’s that simple. By keeping the shielded front cover closed while against any part of your body, a barrier is created to protect from a broad spectrum of potentially harmful cell phone radiation emissions, yet won’t affect signal quality. You can use your cell phone with a higher sense of safety by simply keeping the shielded flip cover between your body and radiation-emitting source.

Cooper's prototype arrived on the market a decade later at the staggering price of $3,995. Designed by Rudy Krolopp, it was known as the Motorola DynaTAC 8000X, or simply "the brick.” Featuring 20 large buttons and a long rubber antenna, it measured about 11 inches high, weighed almost 2 pounds, provided one hour of battery life and could store 30 phone numbers.
I don't know why, but I recently had a concern about the fact I keep my smartphone in my pocket for a good part of the day. Was this a "smart" idea, or was there a potential problem with phone radiation? To address this concern, I searched for answers on the Internet. There were a lot of contraptions, many of which seemed to be too good to be true. The one that looked the most promising was Blocsock, not cheap at $24 for the high-end model with the pouch, but it did say it blocked 96% of the cell phone radiation from your body by having special radiation-blocking material on one side, with the side facing away from your body regular material so the phone could still communicate with the outside world. Cheap eBay knockoffs had material on both sides, meaning when you put your phone in them, your phone could't communicate with the outside world! Others did not have the testing results that assured how well the blocking material worked. There is a very detailed SAR test report validating the Blocsock, which I found at sustainablemobile.com. You can Google it. It is a very exhaustive testing report!

The owner of a damaged case are always encouraged send it in for a replacement and when available a 2nd generation final production case is always sent. As demand increases for a particular color and model — silicon cases are made with RF Safe’s peel-n-shield embedded inside the flip cover. The 2nd Gen cover also includes room for a credit card but this is discouraged because excessive conductive RFID material that pushes the shielding at an angle from a phones surface can compromise shielding effectiveness.

Unfortunately, regulatory boards do not require third-party phone accessory manufacturers to consider how their product will work in tandem with the smartphone. Neither do governments require smartphone manufacturers to conduct extensive research on whether their SAR will still meet the FCC’s allowable radiation exposure limits when their devices are using a phone case or other 3rd party accessories.
Your phone sends radiofrequency, or RF, waves from its antenna to nearby cell towers, and receives RF waves to its antenna from cell towers when you make a call or text or use data. The frequency of a cell phone’s RF waves falls between those emitted by FM radios and those from microwave ovens, all of which are considered “non-ionizing” forms of radiation. That means that—unlike radiation from a nuclear explosion, a CT scan, or a standard X-ray—the radiation from your phone does not carry enough energy to directly break or alter your DNA, which is one way that cancer can occur. (FM radios and microwaves don’t raise alarms, in part because they aren’t held close to your head when in use and because microwave ovens have shielding that offers protection.)
The guidelines recommend keeping phones away from the body when they’re not in use—in a backpack, for example, rather than a pocket—and sleeping with phones away from the bed. People may also choose to use speakerphone or a headset to make calls, rather than holding the phone to their heads. (They should remove their headsets when they’re not in use, though, as these devices also emit small amounts of RF frequency.)
I debated whether to give it 3 or 4 stars: on features, speed of delivery, and quality of construction, it definitely deserves 4 stars. If I can measure and verify the emf reduction, then I will change the rating to 5 stars. Since the whole point of using it is to block excess em radiation, I can't really give it 5 stars without more proof that it really does so.

EWG also reviewed data in the FCC filings on tests of battery life during a continuous call, measured on an iPhone 4 without a case and on the same phone with an Incipio Le Deux case. This case was chosen because it contains metallic parts (a stainless steel back plate). The presence of metallic components influences the phone’s radiation properties, as the FCC acknowledges (FCC 2001; FCC 2014). Under the test conditions with constant signal strength, an iPhone 4 without a case had 85 percent of battery capacity after a one-hour call and 70 percent after two hours. When the test was repeated with the Incipio Le Deux case, the phone had only 65 percent of battery capacity after a one-hour call and only 10 percent after two hours (Pong 2012).

The energy of electromagnetic radiation is determined by its frequency; ionizing radiation is high frequency, and therefore high energy, whereas non-ionizing radiation is low frequency, and therefore low energy. The NCI fact sheet Electromagnetic Fields and Cancer lists sources of radiofrequency radiation. More information about ionizing radiation can be found on the Radiation page.