Our recommendation is to reduce your exposure from wireless sources. We advocate what’s referred to as the Precautionary Principle. Basically, this means that because there’s research, lots of it actually, saying the energy that powers our cellphones (RF radiation) could be causing health concerns like tumors and cancer. We ought to take care when using our cell phones and all devices that emit RF, using them mindfully.
These stick on “blockers” don’t work. I am EHS and can tell you with certainty (because I feel the fields) that they are not blocking anything. You must use substantial materials like those used in faraday cages (silver and copper), which are now manufactured in materials and fabrics, or avoid EMF use period. Just look at military use for example. They are not using stick on blockers. Follow Ty’s advice for minimizing and avoiding EMF, and look up EMF blocking fabrics, building materials, etc… for the real blockers.

The guidelines created a measure of the rate that body tissue absorbs radiation during cell phone use called the specific absorption rate (SAR). The SAR for cell phone radiation was set at a maximum of 1.6 watts of energy absorbed per kilogram of body weight. The limit was set due to the thermal effects of cell phone radiation (all RF radiation can heat human body tissue at high enough levels) - it was not set to mitigate other biological effects cell phone radiation might have such as DNA damage or cancer.
Although common sense, spending as little time on your computer as possible, and when you’re not using it, disabling the Wi-Fi connection or even turning your computer off completely, is recommended to help keep EMF pollution to a minimum. These devices emit a constant stream of EMFs when plugged in and “synced” up to a router or other wireless device.
Use the speaker mode on the phone or a hands-free device such as a corded or cordless earpiece. This moves the antenna away from your head, which decreases the amount of RF waves that reach the head. Corded earpieces emit virtually no RF waves (although the phone itself still emits small amounts of RF waves that can reach parts of the body if close enough, such as on the waist or in a pocket). Bluetooth® earpieces have an SAR value of around 0.001 watts/kg (less than one thousandth the SAR limit for cell phones as set by the FDA and FCC).
Independently tested DefenderShield® technology uses a patent-pending sophisticated layering of separate non-toxic, human safe exotic materials processed for maximum radiation blocking efficiency. Each material has unique and targeted radiation shielding characteristics designed to work in unison to up to eliminate all radiation emissions from 0 to 10 GHz.
Hello Donna, RF Safe offers a 30 Day money back guarantee. All of RF Safe phone accessories come with a “Lifetime Discount Protection Plan”. If the case is damaged within the first year — a replacement case is always shipped to you free of charge. After the first year RF Safe offers a 50% off discount no matter how long the case was used. Even if your phone was lost or stolen, RF Safe never charges you full price for protection – Please see website for full details on all warranties — You’ll find that you’re even covered if you upgrade to a newer phone. Certainly you are never out 70 bucks! Just to note the most expensive phone case RF Safe sells is only 39.99.
Manufacturers conduct government-required certification tests using a bare phone, set to transmit at maximum power, with no accessories. The recorded maximum SAR is reported to the FCC and listed in the phone’s manual. A phone tested with accessories under the same conditions can produce a higher SAR because the materials surrounding the antenna can affect the amount of radiation that reaches and is absorbed by the user’s body. A case can influence both the overall amount of emitted radiation and how it is directed.
I hope anyone with a damaged RF safe accessory takes the time to call the phone number on the top of RF Safe’s website. The hard plastic cases in six colors with flip covers shielded by hand at RF safe are part of each cases product lifecycle – the case shown in review is a well-tested 1st gen case. Hard plastic case with shielding applied by hand.
The American Cancer Society (ACS) states that the IARC classification means that there could be some risk associated with cancer, but the evidence is not strong enough to be considered causal and needs to be investigated further. Individuals who are concerned about radiofrequency exposure can limit their exposure, including using an ear piece and limiting cell phone use, particularly among children. (5)
Rats were exposed to radiation with a frequency of 900 megahertz, typical of the cellphones in use when the study was conceived in the 90s, for about nine hours per day for two years, The New York Times reports. The lowest levels of radiation used in the study were equivalent to the maximum exposure a phone can cause and still receive federal regulatory approval; the highest levels to which the animals were exposed were four times that. 
In addition to the increased brain cancer risk, in male rats there was also “clear evidence” of a link between the radiation and malignant heart tumors and “some evidence” of a link to adrenal-gland tumors, according to the release. In mice and in female rats, however, the link between radiation and tumors was “equivocal,” or uncertain. The hierarchy, from most to least certain, of characterizations used by the NTP is: “clear evidence”; “some evidence”; “equivocal evidence”; and “no evidence.”Today’s cellphones use higher-frequency radiation that is less able to penetrate animal tissues than the radiation used in the study, the Times reports. Further, since cellphones became popular, epidemiologists have not observed an overall increase in the frequency of brain cancers known as gliomas in humans. 
The researchers found other strange effects that muddied the interpretation of the studies: The rats exposed to cellphones seemed to outlive the rats in the control group, for example. There was no clear linear relationship between higher levels of cellphone exposure and more cancer at some tissue sites, and the cancer rate in the control group was lower than it should have been at other tissue sites.
The average radiation level of a Bluetooth earpiece is 0.23 watts per kilogram (W/Kg) according to RF Safe. This is 10 to 100 times higher than the amount of radio frequency (RF) exposure needed to create “leaks” in the blood-brain barrier, allowing for toxins (not to mention the radiation itself!) to pass through into the brain. It’s best to just say NO to Bluetooth!
Third, most of the studies published so far have focused on adults, rather than children. (One case-control study looking at children and teens did not find a significant link to brain tumors, but the small size of the study limited its power to detect modest risks.) Cell phone use is now widespread even among younger children. It is possible that if there are health effects, they might be more pronounced in children because their bodies might be more sensitive to RF energy. Another concern is that children’s lifetime exposure to the energy from cell phones will be greater than adults’, who started using them at a later age.
An analysis of data from all 13 countries participating in the Interphone study reported a statistically significant association between intracranial distribution of tumors within the brain and self-reported location of the phone (7). However, the authors of this study noted that it is not possible to draw firm conclusions about cause and effect based on their findings.