Some people are concerned that radio frequency energy from cell phones will cause cancer or other serious health hazards. Based on the evaluation of the currently available information, the FDA believes that the weight of scientific evidence has not linked exposure to radio frequency energy from cell phone use with any health problems at or below the radio frequency exposure limits set by the FCC.

Key points:

• Cell phones emit low levels of radio frequency energy, a type of non-ionizing radiation.
• The available scientific data on exposure to radio frequency energy show no categorical proof of any adverse biological effects other than tissue heating.
• Public health data show no association between exposure to radio frequency energy from cell phone use and health problems.

Cell Phones and Radio Frequency Energy

Cell phones emit low levels of non-ionizing radiation when in use. The type of radiation emitted by cell phones is also referred to as radio frequency (RF) energy. As stated by the National Cancer Institute, "there is currently no consistent evidence that non-ionizing radiation increases cancer risk in humans. The only consistently recognized biological effect of radiofrequency radiation in humans is heating."

See Radio Frequency Energy and Cell Phones for the basics on radio frequency energy and non-ionizing radiation.

Scientific Consensus on Cell Phone Safety

Scientific studies: The FDA’s physicians, scientists, and engineers regularly analyze scientific studies and publications for evidence of health effects of exposure to radio frequency energy from cell phones. The weight of nearly 30 years of scientific evidence has not linked exposure to radio frequency energy from use of cell phones to health problems, such as cancer.

Public health data: The FDA also monitors and analyzes public health data on cancer rates in the U.S. population. The data clearly demonstrate no widespread rise in brain and other nervous system cancers in the last 30 years despite the enormous increase in cell phone use during this period. In fact, the rate of brain and other nervous system cancers diagnosed in United States has decreased for the last 15 years or so.

Radio frequency energy (RF) from cell phones can potentially interact with some electronic medical devices. This type of interference is called electromagnetic interference (EMI).

Precautions for Pacemaker Wearers

Based on current research, cell phones do not seem to pose a significant health problem for pacemaker wearers. Nevertheless, people with pacemakers may want to take some simple precautions to be sure that their cell phones don't cause a problem, including:

• Hold the phone to the ear opposite the side of the body where the pacemaker is implanted to add some extra distance between the pacemaker and the phone.
• Avoid placing a turned-on phone next to the pacemaker implant. For example, don’t carry the phone in a shirt or jacket pocket directly over the pacemaker.

In the unlikely event that EMI occurs, it could affect a pacemaker in one of three ways:

• Stopping the pacemaker from delivering the stimulating pulses that regulate the heart's rhythm.
• Causing the pacemaker to deliver the pulses irregularly.
• Causing the pacemaker to ignore the heart's own rhythm and deliver pulses at a fixed rate.

Testing and Evaluating Potential Cell Phone Interference

Because of concerns that EMI could potentially affect some electronic medical devices, the FDA took a lead role in developing detailed test methodologies to measure EMI of implanted cardiac pacemakers and defibrillators from cell phones. This test method is now part of an international standard (ISO 14117) and is utilized for testing and evaluation of potential EMI from cell phones minimizing risk to patients worldwide.

The FDA continues to monitor the use of cell phones for possible interactions with other electronic medical devices and will develop new assessment methods to help ensure minimal to no impact on the function of these devices by EMI.

Some consumer electronic devices, such as certain cell phones and smart watches, include high field strength magnets. Recent studies have shown that consumer electronic devices with high field strength magnets may cause certain implanted medical devices to switch to “magnet mode” and suspend normal operations until the magnet is moved away from the medical device.

Many implanted medical devices are designed with a “magnet mode” to allow for safe operation during certain medical procedures such as undergoing an MRI scan. These safety features are typically engaged by physicians with the use of a high field strength magnet that is placed near the implanted device placing it into a “magnet mode.” Removal of the magnetic field causes the device to return to normal operation.

Precautions for Patients with Pacemakers and Other Implanted Medical Devices

The FDA recommends patients keep any consumer electronic devices that may create magnetic interference, including cell phones and smart watches, at least six inches away from implanted medical devices, in particular cardiac defibrillators. Many implanted medical devices have FDA-approved information written for patients (patient labeling), which cautions patients to keep all cell phones and smart watches at least six inches from the implanted medical device.

People with implanted medical devices may want to take some simple precautions, including:

• Keep the consumer electronics, such as certain cell phones and smart watches, six inches away from implanted medical devices.
• Do not carry consumer electronics in a pocket over the medical device.
• Check your device using your home monitoring system, if you have one.
• Talk to your health care provider if you are experiencing any symptoms or have questions regarding magnets in consumer electronics and implanted medical devices.

When near high strength magnets, devices with a magnetic safe mode could stop working or change how the device works. For example, a cardiac defibrillator may be unable to detect tachycardia events. Or it may change the operational mode of the devices such as turning on asynchronous (i.e., two or more events not happening at the same time) mode in a pacemaker.

Cardiac implanted electronic devices are intended to support heart rhythm disorders, such as slow or fast heart rates. When the device stops working, a patient may experience dizziness, loss of consciousness or even death if therapy is not delivered when lifesaving shocks are required.

It is important to emphasize the following: to avoid interference between cell phones and smart watches and your heart device, keep them at least six inches (15 centimeters) away from implanted medical devices. Also, do not place cell phones, smart watches, and other consumer electronics close to your implanted medical device.

The FDA is aware of published articles which describe the effect that sufficiently strong magnetic fields can turn on the magnetic safe mode when in close contact. The FDA also conducted its own testing on some products that use the high field strength magnet feature and have confirmed the magnetic field is both consistent with the publications and strong enough to turn on the magnetic safety mode of the medical devices in question. The FDA believes the risk to patients is low, and the agency is not aware of any adverse events associated with this issue at this time.

The FDA continues to monitor all relevant scientific information about this ongoing issue and will continue to take appropriate action, including informing the public and providing additional information, if the need arises based on its risk analysis.

Before you buy a cell phone, you should try different brands and models to see which phone works best for you.

People who wear hearing aids or have implanted hearing devices may experience some difficulties when trying to use cell phones. Some cell phones can cause radiofrequency interference with hearing aids, so the user hears high-pitched whistling sounds, buzzes, or static.

Fortunately, the compatibility of cell phones and hearing aids is improving. Some phones have lower radiofrequency emissions or use different technologies that can reduce the unwanted effects on hearing aids. The FCC now requires cell phone manufacturers to test and rate their wireless handsets’ hearing aid compatibility using the American National Standards Institute (ANSI) C63.19 standard. These ratings give an indication of the likelihood a cell phone may interfere with hearing aids; the higher the rating, the less likely the cell phone-hearing aid combination will experience undesired interference. Hearing aid users should read and understand these ratings when choosing a cell phone.f

Radiation is energy that comes from a source and travels through space. For example, an electric heater operates by heating metal wires and the wires radiate that energy as heat (infrared radiation).

Radio frequency radiation is a type of electromagnetic radiation, which is a combination of electric and magnetic fields that move through space together as waves. Electromagnetic radiation falls into two categories:

Generally, when people hear the word radiation, they’re thinking of ionizing radiation, like X-rays and gamma rays. Ionizing radiation carries enough energy to break chemical bonds, knock electrons out of atoms, and cause direct damage to cells in organic matter. In fact, ionizing radiation carries more than a billion times more energy than does non-ionizing radiation. A little ionizing radiation can be used to produce x-ray images for diagnosis. A lot of ionizing radiation is needed to kill cancer cells in radiation therapy.

By contrast, non-ionizing radiation does not have enough energy to break chemical bonds or strip electrons from atoms. Scientific consensus shows that non-ionizing radiation is not a carcinogen and, at or below the radio frequency exposure limits set by the FCC, non-ionizing radiation has not been shown to cause any harm to people.

Cell phones emit low levels of non-ionizing radiation while in use. The type of radiation emitted by cell phones is also referred to as radio frequency (RF) energy. As stated by the National Cancer Institute, "there is currently no consistent evidence that non-ionizing radiation increases cancer risk in humans. The only consistently recognized biological effect of radiofrequency radiation in humans is heating."

The scientific evidence indicates radio frequency (RF) exposures that are at or below current U.S. safety limits do not cause health problems. There is no established health benefit from reducing an individual’s RF exposure from cell phones. Nevertheless, some people still have concerns about RF energy, and there are some simple actions that could help reduce an individual’s RF energy exposure from cell phones.

Generally, wireless products emit the most RF energy when you are using them to talk to someone. The closer the device is to you, the more energy you will absorb.

Steps to Reduce Radio Frequency (RF) Exposure

• Reduce the amount of time spent using your cell phone.
• Use speaker mode, head phones, or ear buds to place more distance between your head and the cell phone.
• Avoid making calls when the signal is weak as this causes cell phones to boost RF transmission power.
• Consider texting rather than talking - but don’t text while you are driving.

Claims About Cell Phone Accessories

Manufacturers of certain cell phone accessories may claim that an accessory shields the user from emissions or prevents health problems caused by radio frequency radiation. The FDA does not regulate such products and, given the weight of scientific evidence to show that cell phones are safe for use, the Agency considers these claims to be bogus.

Claims to shield the phone’s user from RF radiation: 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 and may interfere with proper operation of the phone.

Claims to "prevent adverse health effects caused by RF radiation:" The manufacturers of these products claim their products have astonishing effects. Claims of protective effects cannot be proven because radio frequency energy from cell phones does not cause health problems. Claims about disease prevention may make the item an illegally marketed medical device. There are no direct protective effects from the use of these products. At best, they are harmless, and, at worst, they might prevent your phone from finding signal when you most need to make a call for your safety.

Examples of specific unprovable and misleading cellphone accessory claims include:

• "[the product’s] frequencies create fields that counter the cell phone radiation’s effect on the body."
• "Circuits mirror the structure of the earth’s electromagnetic field and amplify your resonance with the Earth.";
• "Shield yourself from harmful frequencies [… with an] inductor coil, which suppresses these frequencies."

Current scientific evidence does not show a danger to any users of cell phones from radio frequency (RF) energy, including children and teenagers. There are also simple steps that anyone, including children and teenagers, can take if they would like to reduce RF exposure.

• Reduce the amount of time spent using the cell phone.
• Use speaker mode, head phones, or ear buds to place more distance between the head and the cell phone.
• Avoid making calls when the signal is weak as this causes cell phones to boost RF transmission power.
• Consider texting rather than talking — but don’t text while driving.

A large epidemiological study of the effects of cell phones in young adults aged between 10 and 24 was completed across 14 countries in Europe (the MOBI-KIDS study). The case-controlled study was conducted "to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people." The subjects (899 with brain tumors and 1,910 age matched controls) were between age 10 and 24 and the vast majority were described as regular cell phone users. The study concluded that there was no evidence of a link between cell phone use and brain tumors in young people.

Most of us depend on cell phones every day. Some people wonder if cell phones can cause health problems. Here’s what you should know about cell phones and your health.

Can using a cell phone cause cancer?

There is no scientific evidence that provides a definite answer to that question. Some organizations recommend caution in cell phone use. More research is needed before we know if using cell phones causes health effects.

Do cell phones give off (emit) radiation?

Yes – cell phones and cordless phones use radiofrequency radiation (RF) to send signals. RF is different from other types of radiation (like x-rays) that we know can be harmful. We don’t know for sure if RF radiation from cell phones can cause health problems years later. The International Agency for Research on Cancer (IARC) has classified RF radiation as a “possible human carcinogen.” (A carcinogen is an agent that causes cancer.)

Should people stop using cell phones?

At this time we do not have the science to link health problems to cell phone use. Scientific studies are underway to determine whether cell phone use may cause health effects. It is also important to consider the benefits of cell phones. Their use can be valuable in an urgent or emergency situation – and even save lives.

If you are worried about cell phone use, follow the tips below.

Cell phone tips

To reduce radio frequency radiation near your body:

• Get a hands-free headset that connects directly to your phone.
• Use speaker-phone more often.
• In the past, RF interfered with the operation of some pacemakers. If you have a pacemaker and are concerned about how your cell phone use may affect it, contact your health care provider.

What research is being done to learn more about cell phones and health?

Scientists are continuing to study the possible health effects of cell phone use. For example, the World Health Organization (WHO) is currently looking into how cell phones may affect:

• Some types of tumors (a lump or growth)
• Our eyes
• Sleep
• Memory
• Headaches