These cases work by redirecting the electromagnetic radiation (EMR) that is produced by phones, away from the user. All phones produce EMR when connected to the mobile network, and the effect of this energy is measured as a Specific Absorption Rate, or SAR: a measurement describing the radiation absorbed by kilogram of tissue. Government regulations in Australia dictate that all phones in Australia must emit a SAR less than 2 W/kg under the worst case scenario, and while all phones comply, most modern phones emit, at most, only half of this safe level, or approximately 1 W/kg.
The FCC has yet to implement GAO’s recommendations to more closely reflect real-life use. For a narrow subset of smartphones – those sold with lanyards or straps – the FCC advises manufacturers to test phones at a distance of no more than 5 mm from the body (FCC 2014). Yet the FCC has done nothing to ensure more realistic testing of most other smartphones or to account for the widespread use of accessories such as cases, which many different manufacturers produce with both metallic and non-metallic components.

Who wants to make his own shielded passport or credit card sleeve? Or line a purse, wallet, cellphone case or backpack? Add a shielding liner to a pocket? Wrap a wifi node to block radiation output? Repair a fencing lame? Shield a part of a circuit board? Make an RF gasket? Shield your homeopathy bottles? Attach a ground cord to a fabric? There are hundreds of uses for this versatile shielding patch. A peel-off paper backing reveals a super strong conductive adhesive that keeps the patch where you put it. Easily cut to any shape with ordinary scissors, this metalized fabric is conductive on both sides, completely flexible with no stretch, and solid black in color. 40-50 dB from 10 MHz to 10 GHz. You get two pieces, each 5.5x8 inches. Not intended to adhere directly to skin. Do not machine wash.

We began by getting a baseline of ambient RF in the room at the location of our testing. We then recorded a baseline of the cellphone RF while on an active call with no case. And finally, we measured the reduction in that baseline (still on the active call) using a variety of different cases and RF reducing products – all at the same set distance from the phone.
There is a degree of controversy surrounding the implications of cell phone radiation, and what it means to our health. Some research has suggested that the type of radio frequencies used by cell phones can speed up the progression of cancer in laboratory test animals, but it has proven difficult to replicate these results. It is known that radiation from cell phones can affect pacemakers, but the main concern is related to the fact that most cell phone users hold the phone against their ear. If significant levels of radiation enter the tissues of the head in this way over time, some worry that this can increase the likelihood of brain tumors and related conditions.
In 2007, Dr Devra Davis founded non­profit Environmental Health Trust to provide basic research and education about environmental health hazards. Dr Davis served as the President Clinton appointee to the Chemical Safety and Hazard Investigation Board in the U.S.A. from 1994–­1999, an independent executive branch agency that investigates, prevents and mitigates chemical accidents.

The Pong Case is easy to use and snaps on to activate two built in antenna that draw away radiation. Tests performed by Pong labs and Wired magazine show that Pong cases redirect energy from the face of the cell phone or tablet toward the back of the device, reducing absorption by 67%. While one might think this would interrupt reception, the opposite occurs and reception has actually been observed to increase up to 13%. It fits most major phone brands and Pong also makes a case for the iPad (however it works a little differently and diffuses the energy instead of redirecting). The products come with a 6 month warranty and a 60 day money back guarantee. For more information, visit their website or watch these videos.
I did a lot of research prior to purchasing and came down to this one as the best/most tested and proven option. Happy with the cover. I don’t have a way to actually test the efficacy of it but it’s a quality product otherwise. I haven’t dropped it but there’s enough room around the edges that it seems like it would have a good cushion to blunt the impact when I do. I’d recommend trying it if you like the looks of It.
What the study showed: Self-reported cell phone use was not associated with an increased risk of glioma, meningioma, or non-central nervous system tumors. Although the original published findings reported an association with an increased risk of acoustic neuroma (14), this association disappeared after additional years of follow-up of the cohort (15).
And don’t get me started on the immersion headgear they are coming out with for gaming. Anyway, I figured I would get a cell phone eventually and use it just as a phone, no bells and whistles. However after this article and a podcast on privacy, where I learned your cell phone is a tracking device, this goes to the towers, I’ve decided on a Definite no.
The Ministry of Health Medical Administration circular (from 2002) addressed to hospital Directors, states that use of mobile phones and wireless handheld transceivers (walkie talkie) in the hospital, must on the one hand guarantee the patient’s wellbeing and safety, and on the other hand, allow the staff, the patients and their families to enjoy the service benefits. This circular outlines the areas where use of mobile phones is strictly forbidden and areas where use is permitted (while keeping an appropriate safety distance from areas where life-supporting equipment or systems are operated).

The cell phone industry constantly guards its financial interests, but unfortunately, an unwitting public can be harmed in the process, says Dr. Carlo. “Industry-funded studies in many cases now produce industry-desired outcomes. By tampering with the integrity of scientists, scientific systems and public information steps over the lines of propriety that are appropriate for protecting business interests—especially when the casualty of the interference is public health and safety.”
The Specific Absorption Rate that the FCC, with input from many other government institutions, decided on, is defined using an average of a 30-minute phone call with the cell phone held directly to the ear. Since modern cell phones are used in all sorts of manners, ie speakerphone, scrolling through social media, browsing the web, etc, a base had to be set.
Don’t rely on a “radiation shield” or other products claiming to block RF energy, electromagnetic fields, or radiation from cell phones. According to the U.S. Federal Trade Commission, products that interfere with the phone’s signal may force it to work harder and emit more RF energy in order to stay connected, possibly increasing your exposure. It is best to use wired solutions to reduce RF rather than rely on an untested  product.
I love this case. However, I don't understand what happens to the radiation that must collect under the case; isn't there a burst of radiation when the case is opened? I posted this question but the answers were from people who hadn't thought of that issue; they didn't have the answer, except for one who theorized that the radiation is slowly leaking out the top, bottom, and sides. I assume the case keeps radiation off the hand that holds the case with the phone in it, which is great, but I do wonder about the stored radiation when, for example, I'm listening to a podcast with the case closed, then open it later.
Several nations have advised moderate use of mobile phones for children.[45] A journal by Gandhi et al. in 2006 states that children receive higher levels of Specific Absorption Rate (SAR). When 5- and 10-year olds are compared to adults, they receive about 153% higher SAR levels. Also, with the permittivity of the brain decreasing as one gets older and the higher relative volume of the exposed growing brain in children, radiation penetrates far beyond the mid-brain.[46]
A series of studies testing different scenarios (called simulations by the study authors) were carried out using incidence data from the Nordic countries to determine the likelihood of detecting various levels of risk as reported in studies of cell phone use and brain tumors between 1979 and 2008. The results were compatible with no increased risks from cell phones, as reported by most epidemiologic studies. The findings did suggest that the increase reported among the subset of heaviest regular users in the Interphone study could not be ruled out but was unlikely. The highly increased risks reported in the Swedish pooled analysis were strongly inconsistent with the observed glioma rates in the Nordic countries (24).