We couldn't find one legit EMF expert online or anywhere else that would recommend a radiation blocking case or anti-radiation case. Not the Environmental Health Trust or Magda Havas, or Joel Moskowitz, in fact his site, safeEMR cautions against scams and claims for radiation protection.  So if a so-called "EMF expert" is recommending any kind of anti-radiation case, they probably aren't that much of an expert. 

Then there is non-ionizing radiation, which encompasses the vast majority of light we are exposed to: visible light from lightbulbs, infrared light from an oven and from people, gigahertz light from our wifi, megahertz light to/from our cell phones, and radio waves hitting our car radio. They are not harmful in small doses because one photon does not have enough energy to ionize atoms and/or break apart molecules. In very large doses, non-ionizing radiation can be harmful. For example, a visible light laser with sufficient power (at least several hundred times more than a legal laser pointer) which is concentrated in a small enough spot will burn your skin and do worse things to your eye if it gets in there. And those of us who are old enough, remember the gerbil-in-a-microwave flash animations which went viral 17 years ago [1] as a humorous (but not exactly factual) representation of what would happen if you microwaved a live rodent.
Dr Davis holds a B.S. in physiological psychology and an M.A. in sociology from the University of Pittsburgh, 1967. She completed a PhD in science studies at the University of Chicago as a Danforth Foundation Graduate Fellow, 1972 and a M.P.H. in epidemiology at the Johns Hopkins University as a Senior National Cancer Institute Post-­Doctoral Fellow, 1982. She has authored more than 200 publications and has been published in Lancet and Journal of the American Medical Association as well as the Scientific American and the New York Times.
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.
Today’s report, the final one, was about a decade in the making and is the last of several versions that have been released since preliminary results were presented in May 2016. It represents the consensus of NTP scientists and a group of external reviewers, according to the release. In the future, the NTP plans to conduct studies in smaller exposure chambers and to use biomarkers such as DNA damage to gauge cancer risk. These changes in the experimental setup should mean that future studies will take less time.
According to Dr. Devra Davis, who wrote Disconnect: The Truth About Cell Phone Radiation, cell phones are dangerous because they emit erratic signals capable of disrupting resonance and DNA repair. As long as your cellular phone is on, it sends out radiation intermittently. Even if you don’t take your phone out of your pocket all day, it continues to expose you to radiation. Dr. Joseph Mercola, founder of Mercola.com recently wrote an excellent article on the dangers of cell phones and provided common sense ways we can protect ourselves and our family from the electromagnetic radiation it emits.
I liked the way Blocsock implemented this protection and the quality of the product construction, combined with the validated test results, so I recently ordered ones for the rest of my family. I think Blocsock is the BMW-class of what I could find for products that protect against cell phone radiation. My wife has a larger Droid phone and it fits in the case (just barely though)! I hope the makers consider making a larger model for all the new, larger smartphones that recently came out with the larger screen sizes. Again, check to make sure your phone fits, which a friendly message to the company will answer if you are not sure.
Since 2011 RF radiation has been classified as a Group 2B “possible” human carcinogen by the International Agency on Cancer (IARC), an agency of the World Health Organization. Based on the new animal findings, and limited epidemiological evidence linking heavy and prolonged cell phone use with brain gliomas in humans, Fiorella Belpoggi, director of research at the Ramazzini Institute and the study’s lead author, says IARC should consider changing the RF radiation designation to a “probable” human carcinogen. Even if the hazard is low, billions of people are exposed, she says, alluding to the estimated number of wireless subscriptions worldwide. Véronique Terrasse, an IARC spokesperson, says a reevaluation may occur after the NTP delivers its final report.
The study also found that about 5 to 7 percent of the male rats exposed to the highest level of radiation developed certain heart tumors, called malignant schwannomas, compared to none in the control group. Malignant schwannomas are similar to acoustic neuromas, benign tumors that can develop in people, in the nerve that connects the ear to the brain.
With the background levels of information-carrying radio waves dramatically increasing because of the widespread use of cell phones,Wi-Fi, and other wireless communication, the effects from the near and far-fields are very similar. Overall, says Dr. Carlo, almost all of the acute and chronic symptoms seen in electrosensitive patients can be explained in some part by disrupted intercellular communication. These symptoms of electrosensitivity include inability to sleep, general malaise, and headaches. Could this explain the increase in recent years of conditions such as attention-deficit hyperactivity disorder (ADHD), autism, and anxiety disorder?
In addition, cellphones potentially harm our health in ways that have nothing to do with cancer. The effect on sperm is concerning to Moskowitz, the director of the Center for Family and Community Health at the Berkeley School of Public Health, and he noted that our current cellphone regulations also don’t account for these potential effects. Plus, we still don’t know what steady exposure to this kind of radiation from devices means for kids.
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.