( CNN ) -- Following the World Health Organization 's announcement that radio frequency emissions from cell phones may increase the risk of some kinds of brain cancer , what do you need to know about the radiation coming from your phone ? How can you protect yourself ? And should RF emission information be listed on cell phone packaging , and in stores ? First things first : The WHO study did not say `` cell phones cause brain cancer . '' Rather , there is some evidence indicating a possible connection -- and while not conclusive , it warrants further study . Consequently , WHO has now categorized radio frequency electromagnetic fields as a `` group 2B '' possible human carcinogen . Here 's how Ed Yong , head of health information at Cancer Research UK , explained it in his detailed analysis of the WHO announcement : . `` Group 2B means that there is some evidence for a risk but it 's not that convincing . This group ends up being a bit of a catch-all category , and includes everything from carpentry to chloroform . '' Dr. Gupta : Cell phones , brain tumors . So it 's worth being aware of this classification -- just as you should be mindful of your intake of coffee , another group 2B carcinogen . But this announcement is not a reason to panic . Would labels help ? San Francisco has been wrestling with whether to require cell phones to be labeled for their RF emissions . Last year , the city tried to mandate cell phone radiation labeling in stores , originally to take effect February 2011 . But according to the San Francisco Chronicle , `` implementation was delayed until May 1 , then June 15 . There now is no proposed start date . '' The city backtracked on this partly out of concern over a lawsuit filed by the Cellular Telecommunications and Internet Association -- but also because officials did n't know how to ensure the accuracy of the labels . Scientists are n't sure what 's the most realistic , intuitive way to communicate cell phone RF emissions to consumers . Specific absorption rate , a measure of the rate of RF energy that your body absorbs from the phone , is the most commonly cited benchmark . For a phone to be certified by the FCC and sold in the U.S. , for example , its maximum SAR level must be less than 1.6 watts per kilogram . But Joel Moskowitz , director of the Center for Family and Community Health at University of California , Berkeley , told the Chronicle that `` specific absorption rate is n't a very useful measure because it 's the peak reading on a variety of tests conducted on cell phones to measure their radiation , but does n't indicate the average amount of radiation a user would generally be exposed to . '' He likened it to a car 's gas mileage being reported only based on driving it up a steep hill . Such a measurement could actually make a car shopper avoid a hybrid because it does n't perform well on hills , even though it would generally consume less gas . CNET recently updated its guide to cell phone radiation levels , which ranks phones according to SAR . Cell phones and radiation : The 10 highest- and lowest-emitting models . What cell phone users can do . If you are concerned that cell phones might increase your cancer risk , probably the best way to put the WHO announcement to good use is to minimize how much you hold your cell phone next to your head . More tips on minimizing cell phone radiation . Your best bet is to use a headset that physically plugs in to your phone , such as earbuds with a microphone attached . Unlike Bluetooth headsets , this entails no additional RF exposure near your head -- although it may take a moment to connect your headset to your phone . While the WHO examined only the possible risk of brain cancer , you can further reduce your cell phone RF exposure by placing your phone a few inches away from your body while using it -- such as in a purse or on the table . Or whenever possible , talk via your phone 's speaker function , or send a text message instead of placing a call . The opinions expressed in this commentary are solely those of Amy Gahran .
WHO lists radio frequency electromagnetic fields as a ` ` ' ' '' possible carcinogen . This is over - all category , and includes everything from mercury to chloroform . Scientists are n't sure how to explain cell phone RF emissions to consumers . Specific absorption rate is the most commonly cited factor .