- Exposure limit values to avoid health and sensory effects, and
- Action levels to ensure, by simplified assessment, the compliance with the exposure limit values at the workplaces.
The protection of workers in Germany is mainly regulated by the Electromagnetic fields Accident prevention regulation (BGV B11) from June 1, 2001. Here, four different exposure areas are defined, in which higher exposures are permitted than those defined in the 26. BlmSchV for the general public:
- Exposure area 2 (all publicly accessible areas of the company, which are not assigned to one of the other exposure areas)
- Exposure area 1 (controlled areas and areas where the permissible exposure values of Exposure area 2 will be exceeded temporarily)
- Area of increased exposure (controlled areas where the permissible exposure values of Exposure area 1 are exceeded)
- Danger area (controlled areas where the permissible exposure values of the area of increased exposure are exceeded)
The employers must also take special measures to protect carriers of active and passive physical aids (e.g. pacemakers or metallic implants) from health hazards.
As an example, the reference levels in the different frequency ranges are summarized for Exposure area 1 in the following table.In the frequency range from 10 MHz to 110 MHz, high-frequency currents may be injected in the human body, which may lead to the basic restrictions (SAR values in this case) being exceeded in the limbs. For this reason, in addition to the field strengths shown in the “Reference levels” table, a limit for currents through the limbs is defined in the BGV B11. The permissible value for injected high-frequency currents is 100 mA for Exposure area 1.
There are specific limits for the permissible contact currents and contact voltages in the frequency range from 0 Hz to 1 MHz (see following table; this applies to all Exposure areas).For pulsed fields, a special assessment procedure applies; this is described in Annex 2 of the BGV B11. For workplaces at plants or devices with strong static magnetic fields, e.g. in the case of magnetic resonance imaging, specific limits according to the following table apply:All regulations defined in the Accident prevention regulation BGV B11 will be replaced in the future by new laws, regulations or administrative provisions, because the above-mentioned EU Directive 2013/35/EU is to be implemented into national law by all EU Member States by July 1, 2016. The appropriate implementation is currently being developed in Germany.