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Limit values for static and low frequency fields

  • The 26th Ordinance Implementing the Federal Immission Control Act (Ordinance on electromagnetic fields – Verordnung über elektromagnetische Felder zum Bundes-Immissionsschutzgesetz – 26 BImSchV) sets limits to protect the public against health hazards due to electric and magnetic fields from direct current and low frequency systems.
  • Low frequency installations shall not exceed the limits in places intended for non-temporary presence of humans when operated at maximum capacity. The same is required for direct current installations in places intended for long-term, or temporary presence of humans.
  • According to the present state of knowledge, compliance with these limits will ensure health protection of the public even under permanent exposure.

The 26th Ordinance Implementing the Federal Immission Control Act (Ordinance on electromagnetic fields – Verordnung über elektromagnetische Felder zum Bundes-Immissionsschutzgesetz – 26 BImSchV) sets limits to protect the public against health hazards due to electric and magnetic fields from direct current and low frequency systems.

The Twenty-sixth Ordinance Implementing the Federal Immission Control Act

The Ordinance has been in force since 1997 and was amended in August 2013. It is based on recommendations of the German Commission on Radiological Protection (Deutsche Strahlenschutzkommission, SSK) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP).

The recommendations of the above commissions rest on scientific evidence of health relevant biological effects that may be produced by electric and magnetic fields.

The 26th BImSchV applies to all stationary low frequency and direct current installations

The 26th BImSchV applies to all stationary low frequency and direct current installations for electric power transformation and distribution operated at voltages exceeding 1000 (for stationary low frequency) or 2000 (for direct current installations) Volts. This includes high-voltage lines, traction current lines, electrical substations, transformer stations and power conversion systems (for high-voltage direct-current transmission, HVDC transmission).

The 26th BImSchV does not apply to domestic electric appliances and power lines. However, the limit values set by the Ordinance may be used to evaluate the risk with regard to potential effects of static and low frequency fields from domestic electric appliances and power lines.

Low frequency installations shall not exceed the limits in places intended for non-temporary presence of humans when operated at maximum capacity. The same is required for direct current installations in places intended for long-term, or temporary presence of humans.

Since its amendment, the 26th BlmSchV contains limits covering both the whole low frequency range (1 Hertz to 9 Kilohertz) and static magnetic fields for the first time. The previous ordinance only covered fields from the traction power lines and overhead lines as well as fields from the 50-Hz-power supply grid.

Limit values for low frequency and direct current power installations laid down in the 26th Ordinance Implementing the Federal Immission Control Act (Ordinance on electromagnetic fields – Verordnung über elektromagnetische Felder zum Bundes-Immissionsschutzgesetz – 26 BImSchV)
Frequency f
(Hertz)
Electric field strength E
(kilovolt per metre)
Magnetic flux density B
(microtesla)
0-5001)
1 - 8540.000/f2)
8 - 2552)5.000/f
25 - 5052003)
50 - 400250/f200
400 - 3.000250/f80.000/f
3.000 - 10.000.0000,08327
  1. Since the 26th BImSchV was amended, immissions from high voltage direct current (HVDC) transmission installations have been regulated by law. The limit was selected so as to avoid interference with implanted medical devices such as cardiac pacemakers by static magnetic fields.
  2. For rail power systems (frequency 16,7 Hertz) the amendment involves a reduction of the limit values of electric field strength to a current value of 5 kilovolts per metre from a former value of 10 kilovolts per metre.
  3. Low frequency installations with a frequency of 50 Hz (i.e. public electricity supply installations) must not exceed half the limit value of magnetic flux density. The former limit of 100 microtesla, which was applicable prior to the amendment, remains valid for these systems.

Limit values help safeguard public health

According to the present state of knowledge, compliance with these limits will ensure health protection of the public even under permanent exposure.

State of 2023.01.30

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