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from those emissions reduce risks. Some products that claim to shield the user 

from RF absorption use special phone cases, while others involve nothing more 

than a metallic accessory attached to the phone. Studies have shown that these 

products generally do not work as advertised. Unlike “hands-free” kits, these 

so-called “shields” may interfere with proper operation of the phone. The phone 

may be forced to boost its power to compensate, leading to an increase in RF 

absorption. In February 2002, the Federal Trade Commission (FTC) charged two 

companies that sold devices that claimed to protect wireless phone users from 

radiation with making false and unsubstantiated claims. According to FTC, these 

defendants lacked a reasonable basis to substantiate their claim.

Radiofrequency energy (RF) from wireless phones can interact with some 

electronic devices. For this reason, FDA helped develop a detailed test method to 

measure electromagnetic interference (EMI) of implanted cardiac pacemakers 

and defibrillators from wireless telephones.  

This test method is now part of a standard sponsored by the Association for 

the Advancement of Medical instrumentation (AAMI). The final draft, a joint 

effort by FDA, medical device manufacturers, and many other groups, was 

completed in late 2000. This standard will allow manufacturers to ensure that 

cardiac pacemakers and defibrillators are safe from wireless phone EMI. FDA 

has tested hearing aids for interference from handheld wireless phones and 

helped develop a voluntary standard sponsored by the Institute of Electrical and 

Electronic Engineers (IEEE). This standard specifies test methods and performance 

requirements for hearing aids and wireless phones so that no interference occurs 

when a person uses a “compatible” phone and a “compatible” hearing aid at the 

same time. This standard was approved by the IEEE in 2000. FDA continues to 

monitor the use of wireless phones for possible interactions with other medical 

devices. Should harmful interference be found to occur, FDA will conduct testing