Since there are no known risks from exposure to RF emissions from wireless
express cards, there is no reason to believe that accessories that claim to shield the
head from those emissions reduce risks. Some products that claim to shield the
user from RF absorption use special express card cases, while others involve
nothing more than a metallic accessory attached to the express card. Studies have
shown that these products generally do not work as advertised. Unlike “hand-free”
kits, these so-called “shields” may interfere with proper operation of the express
card. The express card 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
express card users from radiation with making false and unsubstantiated claims.
According to FTC, these defendants lacked a reasonable basis to substantiate their
claim.
What about wireless express card interference with medical equipment?
Radio frequency energy (RF) from wireless express cards 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 teleexpress cards. 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 express card EMI. FDA has tested wireless express cards 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 express cards so that no interference
occurs when a person uses a compatible express card 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 express cards for possible interactions
with other medical devices. Should harmful interference be found to occur, FDA will
conduct testing to assess the interference and work to resolve the problem.
Additional information on the safety of RF exposures from various sources can be
obtained from the following organizations:
FCC RF Safety Program:
http://www.fcc.gov/oet/rfsafety/
Environmental Protection Agency (EPA):
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