Updated at 23 Jun 2026
The EMF-Portal explores electromagnetic fields across various frequency ranges, highlighting their perceptibility, biological effects, and interaction mechanisms. It covers static, low, intermediate, and radiofrequency fields, focusing on phenomena like nerve stimulation, heating, and interactions with implants.
The electromagnetic spectrum encompasses various frequency ranges that differ significantly in terms of perceptibility and biological effects. Humans perceive electric fields indirectly, for example through static discharges when taking off a sweater. Magnetic fields are felt through the forces exerted by permanent or electromagnets. Electromagnetic fields can also produce thermal effects, such as the heating of food in microwave ovens. The penetration of these fields into biological tissue and their effects depend on frequency, field strength, the tissue’s reflection and absorption properties, resonance phenomena, and grounding. The biological mechanisms of action vary depending on the frequency range. Direct effects include, for example, nerve stimulation or tissue heating, while indirect effects include, for instance, interference with electronic implants or static discharges. The EMF Portal distinguishes four frequency ranges: static fields (0 Hz), low-frequency fields (0.1 Hz to 1 kHz), fields in the intermediate frequency range (1 kHz to 10 MHz), and high-frequency fields (10 MHz to 300 GHz). Static electric fields cause charge shifts and can lead to perceptible effects such as hair movement or spark discharges. Static magnetic fields can interact with charges moving within the body and, starting at approximately 0.5 mT, influence electronic and metallic implants, although significantly higher field strengths of up to about 10 T are used in magnetic resonance imaging. Low-frequency fields generate induced electric fields and currents that can cause irritating effects on excitable cells (such as nerves and muscles) and affect electronic implants. In the intermediate frequency range, low- and high-frequency effects combine; as frequency increases, the thermal effect increases. High-frequency fields primarily cause a thermal effect through the excitation of molecular motion and electrical charges, which is perceptible as frictional heat. This differentiated classification allows for a better understanding of the diverse biological effects of electromagnetic fields.
