San Francisco’s Board of Supervisors has approved a new law requiring cell phone retailers to post the amount of radiation emitted by each phone they sell. This is a first-of-its-kind ordinance that requires stores to disclose the phones’ specific absorption rate, or SAR. Violators would face fines of up to $500. Critics say this is an example of a city responding to unfounded concern over radiation from phones. But advocates say they hope the labels will dissuade consumers from buying higher-radiation phones until the science is clearer.