According to the Cellular Telecommunications Industry Association (CTIA), SAR or specific absorption rate is "a way of measuring the quantity of radiofrequency (RF) energy that is absorbed by the body." For a phone to pass FCC certification, that phone's maximum SAR level must be less than 1.6W/kg (watts per kilogram). The SAR level listed in our chart represents the maximum SAR level with the phone next to the ear, a level obtained through required FCC tests.
It's important to note that in publishing this list are we in no way implying that cell-phone use is or isn't harmful to your health. The jury is still out, research is ongoing, and we will continue to monitor its results. For more information on safety issues, readers should go to WOW-Com's Guide to Wireless Industry Health Questions.