Consumer Update on Wireless Phones
U.S. Food and Drug Administration
1. Do wireless phones pose a health hazard?
The available scientific evidence does not show that any health problems are associated with
using wireless phones. There is no proof, however, that wireless phones are absolutely safe.
Wireless phones emit low levels of radio frequency energy (RF) in the microwave range while
being used. They also emit very low levels of RF when in the stand-by mode. Whereas high levels
of RF can produce health effects (by heating tissue), exposure to low level RF that does not
produce heating effects causes no known adverse health effects. Many studies of low level RF
exposures have not found any biological effects. Some studies have suggested that some
biological effects may occur, but such findings have not been confirmed by additional research.
In some cases, other researchers have had difficulty in reproducing those studies, or in
determining the reasons for inconsistent results.
2. What is FDA's role concerning the safety of wireless phones?
Under the law, FDA does not review the safety of radiation-emitting consumer products
such as wireless phones before they can be sold, as it does with new drugs or medical
devices. However, the agency has authority to take action if wireless phones are shown
to emit radio frequency energy (RF) at a level that is hazardous to the user. In such a case,
FDA could require the manufacturers of wireless phones to notify users of the health
hazard and to repair, replace or recall the phones so that the hazard no longer exists.
Although the existing scientific data do not justify FDA regulatory actions, FDA has urged the
wireless phone industry to take a number of steps, including the following:
Support needed research into possible biological effects of RF of the type emitted by
Design wireless phones in a way that minimizes any RF exposure to the user that is not
necessary for device function; and
Cooperate in providing users of wireless phones with the best possible information on
possible effects of wireless phone use on human health.
FDA belongs to an interagency working group of the federal agencies that have responsibility
for different aspects of RF safety to ensure coordinated efforts at the federal level. The following
agencies belong to this working group:
National Institute for Occupational Safety and Health
Environmental Protection Agency
Federal Communications Commission
Occupational Safety and Health Administration
National Telecommunications and Information Administration
The National Institutes of Health participates in some interagency working group activities,
FDA shares regulatory responsibilities for wireless phones with the Federal Communications
Commission (FCC). All phones that are sold in the United States must comply with FCC safety
guidelines that limit RF exposure. FCC relies on FDA and other health agencies for safety
questions about wireless phones. FCC also regulates the base stations that the wireless phone
networks rely upon. While these base stations operate at higher power than do the wireless
phones themselves, the RF exposures that people get from these base stations are typically
thousands of times lower than those they can get from wireless phones. Base stations are thus
not the subject of the safety questions discussed in this document.
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3. What kinds of phones are the subject of this update?
The term wireless phone refers here to hand-held wireless phones with built-in antennas, often
called cell mobile or PCS phones. These types of wireless phones can expose the user to
measurable radio frequency energy (RF) because of the short distance between the phone and
the user’s head. These RF exposures are limited by Federal Communications Commission safety
guidelines that were developed with the advice of FDA and other federal health and safety
agencies. When the phone is located at greater distances from the user, the exposure to RF is
drastically lower because a person's RF exposure decreases rapidly with increasing distance
from the source. The so-called cordless phones; which have a base unit connected to the
telephone wiring in a house, typically operate at far lower power levels, and thus produce RF
exposures far below the FCC safety limits.
4. What are the results of the research done already?
The research done thus far has produced conflicting results, and many studies have suffered
from flaws in their research methods. Animal experiments investigating the effects of radio
frequency energy (RF) exposures characteristic of wireless phones have yielded conflicting
results that often cannot be repeated in other laboratories. A few animal studies, however, have
suggested that low levels of RF could accelerate the development of cancer in laboratory
animals. However, many of the studies that showed increased tumor development used animals
that had been genetically engineered or treated with cancer-causing chemicals so as to be pre-
disposed to develop cancer in the absence of RF exposure. Other studies exposed the animals to
RF for up to 22 hours per day. These conditions are not similar to the conditions under which
people use wireless phones, so we don’t know with certainty what the results of such studies
mean for human health.
Three large epidemiology studies have been published since December 2000. Between them, the
studies investigated any possible association between the use of wireless phones and primary
brain cancer, glioma, meningioma, or acoustic neuroma, tumors of the brain or salivary gland,
leukemia, or other cancers. None of the studies demonstrated the existence of any harmful
health effects from wireless phone RF exposures. However, none of the studies can answer
questions about long-term exposures, since the average period of phone use in these studies was
around three years.
5. What research is needed to decide whether RF exposure from
wireless phones poses a health risk?
A combination of laboratory studies and epidemiological studies of people actually using
wireless phones would provide some of the data that are needed. Lifetime animal exposure
studies could be completed in a few years. However, very large numbers of animals would be
needed to provide reliable proof of a cancer promoting effect if one exists. Epidemiological
studies can provide data that is directly applicable to human populations, but 10 or more years
follow-up may be needed to provide answers about some health effects, such as cancer. This is
because the interval between the time of exposure to a cancer-causing agent and the time tumors
develop - if they do - may be many, many years. The interpretation of epidemiological studies is
hampered by difficulties in measuring actual RF exposure during day-to-day use of wireless
phones. Many factors affect this measurement, such as the angle at which the phone is held, or
which model of phone is used.
6. What is FDA doing to find out more about the possible health effects
of wireless phone RF?
FDA is working with the U.S. National Toxicology Program and with groups of investigators
around the world to ensure that high priority animal studies are conducted to address important
questions about the effects of exposure to radiofrequency energy (RF).
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FDA has been a leading participant in the World Health Organization International
Electromagnetic Fields (EMF) Project since its inception in 1996. An influential result of this
work has been the development of a detailed agenda of research needs that has driven the
establishment of new research programs around the world. The Project has also helped develop
a series of public information documents on EMF issues.
FDA and the Cellular Telecommunications
Internet Association (CTIA) have a formal
Cooperative Research and Development Agreement (CRADA) to do research on wireless phone
safety. FDA provides the scientific oversight, obtaining input from experts in government, industry,
and academic organizations. CTIA-funded research is conducted through contracts to
independent investigators. The initial research will include both laboratory studies and studies
of wireless phone users. The CRADA will also include a broad assessment of additional research
needs in the context of the latest research developments around the world.
7. How can I find out how much radio frequency energy exposure I can
get by using my wireless phone?
All phones sold in the United States must comply with Federal Communications Commission
(FCC) guidelines that limit radio frequency energy (RF) exposures. FCC established these
guidelines in consultation with FDA and the other federal health and safety agencies. The FCC
limit for RF exposure from wireless telephones is set at a Specific Absorption Rate (SAR) of 1.6
watts per kilogram (1.6 W/kg). The FCC limit is consistent with the safety standards developed
by the Institute of Electrical and Electronic Engineering (IEEE) and the National Council on
Radiation Protection and Measurement. The exposure limit takes into consideration the body’s
ability to remove heat from the tissues that absorb energy from the wireless phone and is set well
below levels known to have effects.
Manufacturers of wireless phones must report the RF exposure level for each model of phone to
the FCC. The FCC website (http://www.fcc.gov/oet/rfsafety) gives directions for locating the
FCC identification number on your phone so you can find your phone’s RF exposure level in the
8. What has FDA done to measure the radio frequency energy coming
from wireless phones?
The Institute of Electrical and Electronic Engineers (IEEE) is developing a technical standard for
measuring the radio frequency energy (RF) exposure from wireless phones and other wireless
handsets with the participation and leadership of FDA scientists and engineers. The standard,
Recommended Practice for Determining the Spatial-Peak Specific Absorption Rate (SAR) in the
Human Body Due to Wireless Communications Devices: Experimental Techniques, sets forth
the first consistent test methodology for measuring the rate at which RF is deposited in the
heads of wireless phone users. The test method uses a tissue-simulating model of the human
head. Standardized SAR test methodology is expected to greatly improve the consistency of
measurements made at different laboratories on the same phone. SAR is the measurement of the
amount of energy absorbed in tissue, either by the whole body or a small part of the body. It is
measured in watts/kg (or milliwatts/g) of matter. This measurement is used to determine
whether a wireless phone complies with safety guidelines.
9. What steps can I take to reduce my exposure to radio frequency
energy from my wireless phone?
If there is a risk from these products--and at this point we do not know that there is--it is
probably very small. But if you are concerned about avoiding even potential risks, you can take
a few simple steps to minimize your exposure to radio frequency energy (RF). Since time is a key
factor in how much exposure a person receives, reducing the amount of time spent using a
wireless phone will reduce RF exposure.
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If you must conduct extended conversations by wireless phone every day, you could place more
distance between your body and the source of the RF, since the exposure level drops off
dramatically with distance. For example, you could use a headset and carry the wireless phone
away from your body or use a wireless phone connected to a remote antenna.
Again, the scientific data do not demonstrate that wireless phones are harmful. But if you are
concerned about the RF exposure from these products, you can use measures like those described
above to reduce your RF exposure from wireless phone use.
10. What about children using wireless phones?
The scientific evidence does not show a danger to users of wireless phones, including children
and teenagers. If you want to take steps to lower exposure to radio frequency energy (RF), the
measures described above would apply to children and teenagers using wireless phones.
Reducing the time of wireless phone use and increasing the distance between the user and the
RF source will reduce RF exposure.Some groups sponsored by other national governments have
advised that children be discouraged from using wireless phones at all. For example, the
government in the United Kingdom distributed leaflets containing such a recommendation in
December 2000. They noted that no evidence exists that using a wireless phone causes brain
tumors or other ill effects. Their recommendation to limit wireless phone use by children was
strictly precautionary; it was not based on scientific evidence that any health hazard exists.
11. What about wireless phone interference with medical equipment?
Radio frequency 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
accompanied 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 to
assess the interference and work to resolve the problem.
12. Where can I find additional information?
For additional information, please refer to the following resources:
FDA web page on wireless phones
Federal Communications Commission (FCC) RF Safety Program
International Commission on Non-Ionizing Radiation Protection
World Health Organization (WHO) International EMF Project
National Radiological Protection Board (UK)
July 18, 2001
For updates: http://www.fda.gov/cdrh/phones
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