Exposure to ionizing radiation, such as from x-rays, is known to increase the risk of cancer. However, although many studies have examined the potential health effects of non-ionizing radiation from radar, microwave ovens, cell phones, and other sources, there is currently no consistent evidence that non-ionizing radiation increases cancer risk in humans (2).

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.

If not, then how can the seller claim that the reported effects on cell cultures, muscle strength testing, plants, skin heating, or other biological effects are due to electromagnetic changes (see http://www.cellphone-health.com/mret-howitworks.htm for example)? Electromagnetic field characteristics are well known and easy to measure. If there is truly an electromagnetic change, that change will be easy to detect and measure.
Dr Devra Davis is an internationally recognised expert on electromagnetic radiation from mobile phones and other wireless transmitting devices. She is currently the Visiting Professor of Medicine at the Hebrew University Hadassah Medical School, and Visiting Professor of Medicine at Ondokuz Mayis University, Turkey. Dr Davis was Founding Director of the Center for Environmental Oncology at The University of Pittsburgh Cancer Institute —­ the first institute of its kind in the world, to examine the environmental factors that contribute to the majority of cases of cancer.
But manipulation by the industry had begun almost immediately at the start of research. While Dr. Carlo and his team had never defined their research as being done to prove the safety of cell phones, the industry internally defined it as an insurance policy to prove that phones were safe. From the outset, what was being said by the cell phone industry in public was different from what was being said by the scientists behind closed doors.
Transmitters, including cell phones, emit radio signals on more than the assigned frequency. These other signals on other frequencies are “harmonics” and/or “noise” and/or “dirty” signals from less than optimal transmitters, antennae, and/or resonating frequencies emitted from metallic objects in close proximity to the transmitter, like the other components of the cell phone.
We purchased a cell phone case directly from SafeSleeve. Once received, we attempted to determine how much radiation protection is actually possible from the product. What we learned is that NONE of the products SafeSleeve sells are actually tested by an FCC approved lab. Their advertising is very misleading! The testing results they use as "proof" that their products are tested was a single test done ONLY on a piece of material they claim is used inside their products. NONE OF THEIR PRODUCTS HAVE EVER BEEN TESTED BY AN FCC APPROVED TESTING LAB. We read the test report from SafeSleeve's website and called the testing lab listed on the report who verified this information. We also called an independent, FCC approved cell phone testing lab and they explained the same thing. We were informed that radiation comes from all sides and edges of a cell phone, so when you use the SafeSleeve cell phone case, you are NOT being protected. SafeSleeve cell phone cases offer you no more protection than using a cell phone without a case. To protect yourself from cell phone radiation, you still need to use hold the phone at least 6-8 inches from your body, use the speaker for conversations, text more than talk, and don't use or carry your cell phone against your body. We attempted to have the SafeSleeve cell phone case tested and were informed that to have it properly tested would require paying thousands of dollars in a lab equipped for such testing; using an RF meter or similar device to test a cell phone case will not provide meaningful or accurate results. If SafeSleeve were an honest company, they would have each of their products tested in an FCC approved lab, the same type of lab that cell phones are tested in. However, SafeSleeve is not willing to spend the money. If you don't believe us, call an FCC approved cell phone testing lab and ask a few questions. In the meantime, don't waste your money on SafeSleeve products. Note: SafeSleeve attempts to protect themselves by not listing any business phone number or business address on their website. Any questions/complaints you may have with SafeSleeve are strictly handled via email. They refused our request to speak to a "real person" regarding our questions or issues with their products. Does the word SCAM apply here? We think so.
Parents and consumer advocacy groups occasionally capture attention for voicing concerns about cellphones and other types of non-ionizing radio-frequency radiation exposure, such as the energy emitted from wifi routers in schools. In some cases, they have exaggerated what we know about the risks to kids, and rarely note that cellphones are also just one of many radiation sources we all live with. (Even the Earth itself, the air we breathe, and the sun and stars in our galaxy constantly give off radiation.)
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.
The frequency of radiofrequency electromagnetic radiation ranges from 30 kilohertz (30 kHz, or 30,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Electromagnetic fields in the radiofrequency range are used for telecommunications applications, including cell phones, televisions, and radio transmissions. The human body absorbs energy from devices that emit radiofrequency electromagnetic radiation. The dose of the absorbed energy is estimated using a measure called the specific absorption rate (SAR), which is expressed in watts per kilogram of body weight.