Beginning in December, cell-phonemakers will put this SAR number somewhere inside the booklet that explains how to use the phone. Higher-powered phones will have SARs approaching the maximum, while phones with lower SARs will necessarily have less power.

For handheld cellular telephones, at least 5 [sic] factors must be taken into account in determining whether transmitter falls within guidelines: (1) Power output of antenna. (2) Frequency in which transmitter operates (higher frequency ones would be required to operate with lower power outputs). (3) Distance of transmitter from people, as well as area, density and location of tissue that receives RF radiation (referred to by scientists as specific absorption rate — SAR). (4) Average time of use of transmitter.