We are a nation grown numb to the seemingly endless fine print that accompanies our purchases. But every now and then a product is sold with a warning that should command attention. Consider the little-noticed bit of legalese that comes in the safety manual for Apple's iPhone 4: "When using iPhone near your body for voice calls or for wireless data transmission over a cellular network, keep iPhone at least 15 mm (5/8 inch) away from the body, and only use carrying cases, belt clips, or holders that do not have metal parts and that maintain at least 15 mm (5/8 inch) separation between iPhone and the body," the warning reads.
Similar warnings against carrying cellular and smart phones in a closely sewn pocket show up throughout the industry. The safety manual for Research in Motion's BlackBerry 9000 phone tells users that they may violate Federal Communications Commission (FCC) guidelines for radio-frequency energy exposure by carrying the phone outside a holster and within 0.98 inches (2.5 cm) of their body. The safety manual of the Motorola W180 phone tells users to always keep the active device one full inch away from their body, if not using a company-approved "clip, holder, holster, case or body harness."
Skeptics of the safety of cellular phones have seized upon these warnings as evidence that the ubiquitous devices may be exposing Americans to far more radiation than regulators measure. "Nobody is watching," says Devra Davis, the author of a new book called Disconnect: The Truth About Cell Phone Radiation, What the Industry Has Done to Hide It, and How to Protect Your Family. "Is the law broken if something is so complicated that nobody notices?"
The answer, like the fine-print warnings themselves, is complicated, and likely has as much to do with corporate concerns over legal compliance as it does with health, given the current body of scientific knowledge. "The companies want to legally protect themselves," says Robert Cleveland Jr., a former FCC official who worked on setting the current cellular-phone radio-frequency standard.
The warnings stem from an odd quirk in federal testing procedures designed to ensure the safety of cellular phones. In 2001, the FCC released a set of guidelines for manufacturers that required all cell phones sold in the U.S. to emit a specific absorption rate (SAR) of not more than 1.6 watts of radio-frequency energy per kilogram of body tissue, a standard deemed safe given the state of scientific knowledge about thermal harm from radio-frequency waves. The standard was considered a so-called worst-case scenario, accounting for the energy emitted when the phone was transmitting at full power all of its various signals such as Bluetooth, wi-fi and cellular.
But the FCC testing regulations notably chose not to simulate a situation in which the phone was broadcasting at full power while inside a shirt or pants pocket flush against the body, an odd oversight given the known habits of many cellular-phone users. As a matter of physics, radio-frequency energy generally increases sharply as distance is reduced. "The exposure is definitely related to distance," says Cleveland.
According to the 2001 FCC guidelines, testing of the device in a "body-worn" configuration should be done with the device in a belt clip or holster. If a belt clip or holster was not supplied with the phone, the FCC told testers to assume a separation distance of between 0.59 inches and 0.98 inches (1.5 cm to 2.5 cm) from the body during a test.
"Clearly if it's tested in a holster, it's only guaranteed to be compliant if it's used with a holster," says one current FCC official familiar with these issues, who asked not to be identified by name. "Clearly a lot of people weren't aware of this, and it probably does need to be addressed." Some phones come with a holster included, while others, including Apple's iPhone 4, are not sold with holsters.