Radio frequency emissions FAQ

Frequently asked questions about radio frequency (RF) emissions

Key points

  • All wireless phones have a field of low-level radio frequency energy surrounding them.
  • The strength of the radio wave is dependent upon, among other things, the distance between the mobile phone and the nearest antenna. In general, the further the distance, the more strength is needed to reach the antenna.
  • To date, there have been hundreds of studies conducted investigating the effect of wireless devices on a user's health. Currently, the weight of scientific evidence does not support a causal relationship between adverse health effects and mobile phone usage.
  • The FCC, the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA), and the World Health Organization (WHO) are actively involved in monitoring and investigating issues related to RF exposure.
  • The current exposure limit and FCC standard for a wireless device is 1.6 watts per kilogram (W/kg).

Frequently asked questions

Federal Communications Commission (FCC): Since 1996, the FCC requires all wireless communications devices sold in the United States to meet its minimum guidelines for safe human exposure to RF energy. These guidelines and rules are based upon standards developed by the Institute of Electrical and Electronics Engineers (IEEE), the National Council on Radiation Protection and Measurements (NCRP), as well as input from other federal agencies, including the Environmental Protection Agency (EPA), Food and Drug Administration (FDA), the National Institute for Occupational Safety and Health (NIOSH), and the Occupational Safety and Health Administration (OSHA). These guidelines specify exposure limits in terms of Specific Absorption Rate (SAR). The SAR measures the rate of electromagnetic frequency (EMF) energy absorbed by the body.
The guidelines stipulate the following:
All mobile and portable transmitting devices are subject to routine environmental evaluation for radio frequency exposure prior to equipment authorization or use.
SAR limit on wireless devices is 1.6 watts per kilogram (W/kg).
  Food and Drug Administration (FDA): In partnership with the FCC, the FDA sets policies and procedures in place for wireless phones in the United States. The FDA continuously monitors the effects of RF energy on health. The FDA believes that the weight of scientific evidence available does not show any association between exposure to RF from cell phones and adverse health outcomes.
  Environmental Protection Agency (EPA): Wireless technology has become an increasingly controversial topic, as the use of technology continues to increase. However, the RF energy generated by wireless technology is nonionizing, meaning experts say it is not strong enough to affect the structure of the atoms it contacts. The EPA has concluded that there is not enough evidence to suggest that there is any cause and effect relationship between RF energy and cancer. If you are interested in seeking more information on radiation, the EPA has dedicated a website to radiation, including the most common forms individuals are exposed to daily.
  World Health Organization (WHO): There are a number of studies that have investigated the effects of RF energy on health over the past two decades. However, these studies contain an inadequate amount of evidence to establish a causal relationship between RF exposure and adverse health effects. According to the WHO, short-term tissue heating is the only interaction between RF energy and the human body that occurs. In May of 2011, the International Agency for Research on Cancer (IARC) classified RF energy as being possibly carcinogenic to humans, meaning there is limited evidence to say RF energy causes cancer in humans, and less than sufficient evidence of RF energy causing cancer in experimental animals. Other everyday items joining RF energy in this category include coffee, pickles, talc-based powder and gasoline exhaust.
It is important to note that today's 3G and 4G phones emit less radio frequency energy than their counterparts that were used more than a decade ago. Furthermore, according to the WHO, any large risks associated with exposure to RF should have been detected in the studies that have been conducted to date. Time trend studies monitoring occurrences of brain cancer have not shown trends or evidence affected by mobile phone use. This also pertains to leukemia, lymphoma and other adverse health effects.
One area of interest to some consumers is the potential interference between mobile phones and electronic devices used for medical purposes, such as cardiac pacemakers. RF emissions from mobile phones may interact with some other electronic devices, so the FDA helped develop a test to ensure that pacemakers and defibrillators are protected from electromagnetic interference (EMI) from mobile phones. The test is now part of a standard sponsored by the Association for the Advancement of Medical Instruments.
The FDA continues to monitor for any potential interactions between mobile phones and other medical devices. Should potentially harmful interactions be found, the FDA will conduct testing to assess the interference and work to help resolve the issue. Consumers looking for additional information about potential EMI between mobile phones and electronic medical equipment can visit the FDA's website: Interference with Pacemakers and Other Medical Devices. (– link to:
Based on current research, the FDA suggests that mobile phones do not pose a significant risk for the vast majority of pacemaker wearers. The FDA offers some simple precautions that pacemaker wearers may follow:
  • Hold the mobile phone to the ear opposite the side of the body where the pacemaker is implanted to add separation between the pacemaker and the mobile phone.
  • Avoid placing a mobile phone near the pacemaker such as in a shirt or jacket pocket near the pacemaker.  
The amount of RF emissions absorbed by the body is referred to as the Specific Absorption Rate (SAR). SAR values can vary from mobile phone to mobile phone. The SAR value for each wireless phone is based on controlled laboratory conditions and reflects the maximum SAR value consumers would experience during a phone call, which could be lower during actual use. All wireless devices marketed in the United States must have a SAR value at or below the maximum defined by industry standards and adopted by the FCC, (link to: which is 1.6 watts per kilogram (W/kg), averaged over one gram of tissue.
Manufacturers of wireless phones are required to report the SAR value for each model of phone to the FCC. On the FCC website, consumers can locate information on their phone’s SAR value. The FCC explains where to find your phone's identification number, in turn allowing you to find your phone's SAR value through an online directory.
You may consider increasing the distance between the wireless device and your body; this includes texting rather than talking, and using the speakerphone. To maintain compliance with FCC radio frequency exposure guidelines, if you wear a handset on your body, use a Sprint-supplied or Sprint approved carrying case, holster or other body worn accessory. (Remember: If you choose to text, do not text while driving.)
Hands-free equipment: The intensity of the RF signal is reduced when distance from the mobile phone to the body is increased. Hands-free kits may include a variety of components such as headsets, belt clips and holsters. Sprint offers various hands-free kits for convenience and comfort and for use in states where the law may require hands free device use while driving. For more information on Sprint products and services, including accessories available for each handset, please visit
According to the FDA, products that claim to shield users from RF emissions generally do not work as advertised. Some of the so-called "shields" use special mobile phone cases, while others involve a metal accessory attached to the mobile phone. Unlike hands-free kits, these "shields" may interfere with the proper operation of the mobile phone and can actually cause the device to increase power output to compensate for the loss of signal.
All wireless phones sold by Sprint in the United States meet FCC standards. These requirements have been created to limit an individual's exposure to radio frequency energy. The FCC requires that wireless phones have a Specific Absorption Rate (SAR) level no greater than 1.6 watts per kilogram (W/kg). This limit is considered a safe level for mobile handsets.
The existing exposure limit values were created based on more than 30 years of in-depth research on electromagnetic exposure. This research has concluded that the only demonstrated effect of being exposed to this type of radio frequency energy is an increase in the temperature of biological tissue. The World Health Organization (WHO) introduced a maximum exposure level that included a large margin of safety. In the United States, the FCC has adopted its own limit. In 1991-92, the Institute of Electrical and Electronics Engineers (IEEE) and the American National Standards Institute (ANSI) joined in updating ANSI's 1982 standard for safety levels with respect to human exposure to radio frequency (RF) signals. More than 120 scientists, engineers and physicians from universities, government health agencies and industries developed this updated standard after reviewing the available body of research. In 1993, the FCC adopted this updated standard in a regulation. In August 1996, the FCC adopted a hybrid standard and the guidelines published by the National Council of Radiation Protection and Measurements (NCRP).
The FCC has guidelines in place for the maximum permissible exposure (MPE) allowable to the general public from the RF emissions of wireless telecommunications facilities. The FCC's guidelines are based on the recommendations of industry expert organizations. The MPE limit contained in the guidelines is much more conservative than the RF emissions levels normally encountered at the base of an antenna tower or within the vicinity of other low-powered transmitters.
RF emissions from an antenna are normally directed toward the horizon in a narrow pattern. As one moves away from the antenna, the power density of the antenna decreases rapidly. As a result, ground level exposure is much lower than the exposure that would be encountered if an individual were very close to the antenna or directly in front of its main transmission beam. To be exposed to RF emissions levels approaching the FCC's maximum permitted amounts, an individual would have to remain in front of the transmitting beam and within a few feet of the antenna for several minutes or longer. The exposure levels encountered at the base of an antenna are about a thousand times less than the FCC limit. Subsequently, the FCC has concluded that the possibility that a member of the general public would encounter RF levels in excess of the FCC guidelines is extremely remote.
The FCC requires all wireless telecommunications carriers and equipment manufacturers to comply with the FCC's rules and regulations regarding RF emissions and equipment authorization. The FCC has broad enforcement authority, which includes substantial fines and forfeitures. Sprint designs, constructs and operates our wireless telecommunications facilities in accordance with FCC rules and regulations related to RF emissions, and requires that our equipment manufacturers also be in compliance with these rules and regulations. The RF power that is transmitted from each antenna depends on the number of transmitters and the power of each transmitter. The FCC's Maximum Permissible Exposure limit for cellular and PCS wireless telecommunications facilities is 0.575 milliwatts per square centimeter (mW/cm2).
Information drawn from the Federal Communications Commission

Statistics drawn from the Federal Communications Commission
Signals that reach the ground from wireless telecommunications towers are very weak. These emissions equate to roughly one percent of the limit value established by the World Health Organization (WHO). Radio waves from the antenna will be found in the direction where the antenna is pointing. The FCC states that the maximum power radiated in any direction does not normally exceed 50 watts. Emissions from an antenna travel in a horizontal pattern, parallel to the ground. This pattern closely resembles the shape created by a fan or a beam of light from a flashlight; the energy is more condensed directly in front of the antenna, and its strength and density disperse as you move further away. As a result, there are very few emissions directly below the tower. The exposure level below an antenna is only about one percent of the safe limit value.
Information drawn from the Federal Communications Commission
The output power from an antenna in the Sprint network varies depending on the type of antenna and configuration of the cell sites where the antenna is deployed. The output power from all antennas in the Sprint network is within FCC guidelines. The FCC guidelines recommend a maximum permissible exposure level to be 580 microwatts per square centimeter. This limit is greater than what is normally found near the base of cellular or PCS sites.
Information and statistics drawn from the Federal Communications Commission
Sprint holds multiple FCC licenses for several frequency bands, which may or may not involve separate antennas. Moreover, in some cases several operators will want to install antennas at the same location. Each operator will then be using its own antennas. When Sprint deploys cell sites, analyses are conducted to ensure that each of the cell sites is compliant with FCC Maximum Permissible Exposure limits. When we have a cell site where the general population may be in close proximity to an antenna, such as on a rooftop, we take radio frequency emission measurements at the site to ensure compliance with FCC limits. The same requirements apply regardless of whether a cell site has one or more antennas.
Should children's use of mobile phones be restricted?
Research does not show that children's use of wireless phones involves added health risks. Current safety recommendations protect all individuals, including children. It is, however, not possible to provide irrefutable evidence that mobile phone use is 100 percent risk free. Even though the research in this field is at an advanced stage, most of the new research is conducted in specialized areas. Until conclusive results are established, national and international health institutions have adopted a precautionary approach to children's use of mobile phones.
If you are concerned about reducing exposure to radio frequency energy:
  • Use a headset or other hands-free equipment.
  • Avoid long calls.
  • Send an SMS or MMS rather than calling.
Mobile phones do provide important safety benefits to children, as they can use them in times of disaster or emergency situations. Sprint encourages parental supervision of children's use of wireless phones and offers technology and guidance for parents and guardians. Click here for more information.(link to: People > Communities > Internet Safety)
Information drawn from the National Cancer Institute
The human body largely consists of liquids. Emissions from radio waves will cause a temperature increase in these liquids, known as thermal heating; the degree of that increase is dependent on the intensity and frequency of the radio waves. The frequency and intensity of radio waves from cell phones are very low, so even at the maximum effect the radio waves will never raise the temperature of the human body by more than 0.1 degree Celsius. This increase in temperature cannot be registered by human beings.
On the other hand, batteries and other electronic components in a mobile phone may heat up depending on type and duration of use. Mobile phones have been constructed to prevent overheating by monitoring temperature and taking action by slowing down or turning off to prevent damage to the device and user. Furthermore, when you hold any warm object to your ear, you will feel a warm sensation. This warming is caused by the pressure being placed against your ear. The additional pressure alters the bloodstream around the ear and causes the blood volume to increase. This is why your skin turns red when something is pressed against it. Since your blood temperature is higher than the temperature of your skin at the surface, it will feel like a slight increase in temperature in your ear. This heat is not created by the radio frequency energy.
Information from the International Agency for Research on Cancer, World Health Organization
There have been instances where people reported various health problems such as headaches, aching muscles or skin irritation, and they attributed those symptoms to radio frequency exposure. There is a type of sensitivity described as a form of allergy, known as electromagnetic hypersensitivity, and various kinds of equipment have been hypothesized as possible sources of these ailments, including, for example, power lines, PCs or television screens, electronic cookers, or mobile phones. A small number of individuals suffering from this condition are affected to an extent of having to take measures to adapt their lifestyle.
While some individuals report a variety of health problems, research and blind tests have failed to establish any connection between the reported afflictions and exposure to radio frequency energy. For more information on hypersensitivity please see the following:
World Health Organization (WHO) fact sheet for electromagnetic hypersensitivity

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