Navigation and service

Other applications

  • In addition to the widespread sources of electric and magnetic fields such as household appliances, electrical installations and power supply systems, there are a number of other special applications that give rise to static or low-frequency fields in their surroundings.
  • For example, these special applications include electric cars, electronic article surveillance systems or even magnetic resonance imaging (MRI) scanners

Electric cars

A comparatively new technology with rapidly increasing popularity is, for example, electrically powered moto vehicles. The field strengths of low-frequency magnetic fields in several purely electric cars or cars with hybrid-electric propulsion have been measured and evaluated in a research project commissioned by the BfS. The full final report from 2009 of the research project is published in the Digital Online Repository and Information System (DORIS) of the BfS. An update of the project with a selection of the vehicles currently on the market is expected to be available in 2024.

Electronic article surveillance systems

Electronic article surveillance systems in stores are intended to prevent the theft of goods. They currently use many different technologies, which operate by means of either low-frequency magnetic fields or high-frequency electromagnetic fields (see article “Electronic article surveillance systems”).

Magnetic resonance imaging (MRI)

Magnetic resonance imaging is a diagnostic imaging procedure that uses static magnetic fields, magnetic field gradients, and high-frequency electromagnetic fields.

Electro- and magnetic field therapy

Electrotherapy involves the use of low-frequency alternating current primarily for the purposes of pain relief and the stimulation of muscles and circulation. The current is generally administered via electrodes that adhere to the skin.

In magnetic field therapy, the currents are not applied via electrodes but rather induced in the body by an alternating magnetic field. This form of therapy is used for pain relief, to stimulate circulation, to improve wound and bone healing, and to exert a positive influence on nerve regeneration, but it is not effective in all patients. The possible mechanism of action is unknown, and a causal relationship with the magnetic fields is disputed.

Magnetic field therapy equipment is freely available on the market, but the benefits of these devices are questionable. Medically necessary treatment must only ever be delivered under medical supervision.

Magnetic blankets, plasters and cushions and other “magnetic remedies”

Various therapeutic effects are attributed to static magnetic fields. According to information from the manufacturers, a wide range of complaints can be tackled using magnetic plasters, cushions, blankets, bracelets or belts. These products all have one thing in common: they use static magnetic fields with flux densities of between 0.03 and 0.3 tesla at their immediate surface. At a distance of three to four millimetres, the fields strength values are just a multiple of that. At a distance of a few centimetres, the field is already weaker than the Earth’s natural magnetic field.

The known biological effect thresholds for static magnetic fields are orders of magnitude above these levels, and so the effectiveness of these “magnetic remedies” is questionable from a scientific perspective. In any case, the known mechanisms of action of magnetic fields offer no explanation for the reported positive effects.

Nevertheless, for people with certain models of cardiac pacemaker, interference cannot be completely ruled out. The doctor treating the patient must assess the risk of interference on a case-by-case basis.

Namensschild mit Dauermagnet Namensschild mit DauermagnetNamensschild mit Dauermagnet

Permanent magnets

Wearing small permanent magnets on the body, such as in the form of magnetic fasteners for name badges, is generally harmless to health. Such applications only result in very localised exposure to weak, static magnetic fields. The exposure resulting from normal use of magnetic clips of this kind is well below the known biological effect thresholds.

However, one cannot rule out the possibility of interference with certain models of cardiac pacemaker by small permanent magnets. From a magnetic flux density of approximately 1 millitesla (mT), it is also possible for these magnets to affect magnetic cards, credit cards or watches, among other things. It is therefore advisable not to use badges of this kind directly on top of an implanted pacemaker and not to store sensitive magnetic cards in jacket pockets.

State of 2022.10.08

How do you rate this article?

Site information and functions

© Bundesamt für Strahlenschutz