In Germany, the limits for static, low frequency, and radiofrequency fields are regulated by law by the 26. BlmSchV (Ordinance on Electromagnetic Fields). The regulation applies only to fixed installations (such as mobile phone base stations or power lines).
Three different fields of application are defined in the regulation:
The regulations for these fields of application refer to two separate tables with reference levels (cf. Reference levels) for the low-frequency and the high-frequency ranges (see tables). Exceptions, such as the allowed short-term exceedance of the limits, are also defined in the regulations.
Devices with wireless applications used in everyday life, domestic electrical installations, or household appliances are not included. In these cases, regulations for the safety of devices and products such as DIN standards have to be applied. They are harmonized across Europe and refer essentially to the international guidelines of the ICNIRP and the EU , (cf. Limit values).
There is an overlap of frequency ranges in the tables in the transition range from 3 kHz to 10 MHz. It takes into account that the irritant effect on the nervous system or the heating effect on the body tissue (or a combination of both) must be considered (see chapter Basic restrictions). This is based on the ICNIRP limits of 1998 and the amended version for the frequency range 1 Hz - 100 kHz from 2010. Consequently, for high-frequency systems in the range between 9 kHz and 10 MHz both tables apply, depending on the case considered. In addition, for high-frequency systems summation effects have to be considered (i.e. contributions from other fixed installations, or if the output sum from several smaller systems reaches 10 W or more).
Further notes on the implementation of the 26. BlmSchV with further explanations, definitions and specific rules have been developed by the German Länder Committee for Immission Control (LAI).
A special rule is applied for power supply systems working with a frequency of 50 Hz. Here, half of the limit for the magnetic flux density must not be exceeded. Thus, as before the amendment of the 26. BlmSchV of 2013, in Germany a limit of 100 µT still applies – and not the limit of 200 µT, as recommended by the ICNIRP. The limit for the electric field strength is 5 kV/m (cf.Low frequency (0.1 Hz–1 kHz), fig. “Thresholds for the magnetic flux density and electric field strength”). For low-frequency systems, which were built before August 22, 2013, short-term exceedance of the limits (not more than by 100 percent with a duration of not more than 5 percent of a day) and small-scale exceedance of the limit for the electric field strength (not more than by 100 percent outside of buildings) are allowed. The revised 26. BlmSchV provides a minimizing principle. For newly built low-frequency and DC power systems, the emissions must be kept as low as possible. New power lines with voltages of 220 kV and above are not allowed to span buildings or parts of buildings that are intended for permanent residency any longer. In this sense, the General administrative regulation for the implementation of the council regulation on electromagnetic fields (26th BImSchVVwV) specifies the requirements for extremely low frequency and DC systems when they are installed and significantly modified in order to minimize the electrical and magnetic fields emitted from these systems.
For DC power systems (0 Hz), including high-voltage direct current transmission systems (HVDC), the limit of 500 µT for the magnetic flux density is set in a way that interference to cardiac implants by static magnetic fields can be excluded. No limit exists in Germany for the electric field strength of static fields.
The regulations in the 26. BImSchV provide limits for the operation of mobile base stations, but not for the use of mobile phones. The safe use of mobile phones is ensured by product standards which are internationally recognized (see below). All manufacturers must comply with these standards.
From the reference levels in the table the following limits for the different mobile networks can be derived:
In the case of base stations (far field situation) compliance with the reference levels guarantees compliance with the ICNIRP basic restriction for the corresponding frequency ranges, i.e. an average whole-body SAR of 0.08 W/kg (see chapter Basic restrictions).
Due to the relatively strong local exposure, the application of reference levels is not suitable for the safety assessment of mobile phones (see chapter Reference levels). Therefore, the product standards for mobile phones (e.g. IEC/EN 62209-1, IEC/EN 62209-2, European standard EN 50360 , IEEE 1528-2013) refer directly to compliance with the basic restrictions given in the ICNIRP guidelines (cf. Basic restrictions). Thus, in the relevant frequency ranges of mobile phone operation the local SAR is applied:
The establishment of the aforementioned SAR limits is based on the following facts:
For medical reasons, it is assumed that a longer-term increase in core body temperature by more than 1 °C can cause adverse health effects. Short-term local heating (e.g. when drinking hot beverages) or short-term increases in core body temperature in the range of 1 °C (e.g. during exercise), however, are harmless and can be regulated by the body of a healthy person. In this respect, the head is particularly sensitive and therefore has to be protected (e.g. by wearing headgear when exposed to heat in the blazing sun). From experiments and calculations it is well known that the energy absorption in the body, induced by radiofrequency electromagnetic fields at a SAR of 4 W/kg, results in an increase in core body temperature of about 1 °C within about 30 minutes, if the fields are uniformly applied to the whole body. For precautionary protection of the general public, the recommended basic restriction value was set with a safety factor of 50 below this SAR value, i.e. 0.08 W/kg in the case of whole body exposure. This value is relevant for uniform exposure in the far field of a radiofrequency field source, e.g. in the field emitted by a mobile phone base station. At non-uniform local exposure, as in the case of mobile phone use, excessive local temperature increase in body parts must be excluded. So, in the sensitive area of the head, but also in the trunk, a SAR of 0.02 W per 10 g of body tissue (equivalent to 2 W/kg) should not be exceeded. In the less sensitive limbs 0.04 W per 10 g of body tissue (equivalent to 4 W/kg) are allowed. By averaging over 6-minute periods, as fixed in the guidelines, the distribution of locally generated heat in the body with time is taken into account.