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# Study Confirms Cell Phone Magnetic Interference
- URL: https://www.fdaweb.com/study-confirms-cell-phone-magnetic-interference/
- Published: 2021-08-27T12:00:00.000Z
- Updated: 2026-09-14T17:12:12.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5150033

A new study by FDA researchers supports an agency recommendation earlier this year that 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, especially pacemakers and cardiac defibrillators. The [study](https://www.heartrhythmjournal.com/article/S1547-5271%2821%2901859-2/fulltext?ref=fdaweb.com#%20), published by the Heart Rhythm Society, found that the iPhone 12 and Apple Watch 6 models tested have static magnetic fields, and if placed within close proximity, the fields are high enough to place implanted cardiac devices into magnet mode.  

In May, FDA issued a [safety advisory](https://www.fda.gov/radiation-emitting-products/cell-phones/magnets-cell-phones-and-smart-watches-may-affect-pacemakers-and-other-implanted-medical-devices?ref=fdaweb.com) notes that some consumer electronic devices (cell phones, smart watches) may contain high field-strength magnets, and recent studies have shown that the magnets may cause certain implanted devices to switch to “magnet mode” and suspend normal operations until the magnet is moved away. The advisory says that many implanted medical devices have patient labeling that cautions patients to keep all cell phones and smart watches at least six inches from the implanted device. “When near high strength magnets, devices with a magnetic safe mode could stop working or change how the device works,” it says. “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.”