Read the “fine print” from the manufacturer’s instruction manual which tells users to put a distance between the phone and your head and body. These fine print warnings range  from a few millimeters to almost an inch. The fine print warnings on other wireless devices (such as Wi-Fi routers, wireless printers, home cordless phone base stations and baby monitors) generally state the distance should be at least 20 cm, or about 8 inches. If people are closer than the manufacturer stated separation distance, then they can be exposed to RF levels that violate the US government FCC limits for this radiation.
Launched at the U.S. Food and Drug Administration’s request 10 years ago, the NTP study dosed rats and mice of both sexes with RF radiation at either 1.5, 3 or 6 watts of radiation per kilogram of body weight, or W/kg. The lowest dose is about the same as the Federal Communications Commission’s limit for public exposure from cell phones, which is 1.6 watts W/kg. The animals were exposed nine hours a day for two years (about the average life span for a rat), and the exposures were cranked up steadily as the animals grew, so the absorbed doses per unit body weight remained constant over time.

Independently tested DefenderShield technology uses a patent-pending sophisticated layering of separate non-toxic, human safe 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.

It'd be wrong to say that there is no evidence of harm at all. In fact, the re-classification by the IARC came about in the first place because the Working Group contributing to the Interphone study acknowledged "limited evidence" of an increase in glioma (a type of tumour, commonly found in the brain) among phone users in one of the studies. In this study, which concluded in 2004, researchers found that participating phone owners who had used their handsets for calls for more than 30-minutes a day, over a period of ten years, had an increase incidence of glioma.
That mystery probably stokes fears about cellphone radiation instead of soothing them, though — in part because of how we in the media cover the rare and frightening. We’ve seen the same thing with fear over nuclear power plants, according to a paper published in Science in the 1980s by psychologist Paul Slovic. “Because nuclear risks are perceived as unknown and potentially catastrophic, even small accidents will be highly publicized and may produce large ripple effects,” Slovic wrote.

SafeSleeve products are not tested by an FCC-approved lab. They have grossly mislead consumers. They only had tested one piece of material they claim is in their products. The consumer is given no proof that any of SafeSleeve products reduce any type of radiation. Do not bother testing their products with an RF meter because accurate testing requires a special lab that costs thousands of dollars. That’s why SafeSleeve has never had their products tested.
The only sure way is to stop using a cell phone. Most people however would prefer to play safe by simply reducing their exposure to radio frequency radiation. Bluetooth devices emit only 10% of the radiation of a cell phone. A hands-free set enables the user to keep the phone away from the head but usually leaves the phone near some other part of the body. It is safe to say that in the event that radio frequency radiation causes damage, you would like to protect other parts of your body. Therefore the only way to reduce your risk is to reduce the radio frequency radiation your body absorbs. SAR Shield reduces radio frequency radiation by up to 89%. 
When it comes to ionizing radiation — which we’re exposed to in X-rays, in CT scans, and during air travel — we know it’s powerful enough to damage the DNA, and that repeated DNA damage over time can cause cancer. That’s why, for example, you’re not supposed to get too many X-rays in your lifetime. (In case you were wondering, there’s no precise number on how many X-rays are too many — but the Food and Drug Administration suggests keeping track and avoiding any that seem unnecessary.)
The government’s policies must change. Cell phone users should make their voices heard to prompt the FCC and manufacturers of cell phones and cases to ensure that these accessories never increase and, to the extent possible, decrease, users’ radiation exposure. At minimum, the FCC must take cell phone cases into consideration when it updates its standards to ensure that the use of a case will not expose people to more radiation than its legal SAR limit.  
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.
During the years 1996-1999, due to the sharp increase in mobile phone use, several expert committees convened worldwide to discuss the question whether the radiowave radiation that is emitted from the mobile phone is harmful to health. Their conclusion was that existing scientific knowledge is insufficient to determine the existence or absence of harm to health.
Can cellphone radiation cause cancer in humans? There’s no scientific consensus on this issue, but there is “some evidence” that exposure to radiation equivalent to that emanating from 1990s-era cellphones is associated with brain tumors in male rats, according to results of a US National Toxicology Program (NTP) study released last week (November 1). 
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).