ELF SHIELDING

Legislation, Regulations and Recommendations

Exposure of the general public

About protection from exposure to electromagnetic field in Europe and outside Europe the situation is not homogeneous. Regarding Europe, in 1999, the Council of the European Union published a recommendation (1999/519/EC, further called 'the Recommendation') on the limitation of exposure of the general public to EMF (0 hertz to 300 GHz). The Recommendation contains reference levels for the strength of EMF at the various frequencies.

The limits in both the Recommendation and the Directive are derived from the 1998 Guidelines for limiting exposure to time-varying EMF by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), as reported in Table 6.

ICNIRP has published new guidelines for EMF with frequencies between 1 Hz and 100 kHz in 2010, but these have not yet led to changes in EU legislation.

Because the Recommendation is not legally binding, EMF policy in member states can be divided into three different approaches.

In the first group of member states the Recommendation has been transposed in binding national legislation. This means that the basic restrictions and reference levels must be applied. Member states in this group are the Czech Republic, Estonia, Greece, Hungary, Luxembourg, Portugal and Romania.

Luxembourg also has a ministerial recommendation not to create any new living spaces in the immediate vicinity of overhead power lines (within 20 metres for 65 kV lines and 30 metres for 100 to 220 kV powerlines).

Finally, in Germany and Slovakia the reference levels in the Recommendation are applied without reference to basic restrictions.

In the second group of member states, the national limits based on the European Recommendation or ICNIRP are not binding, there are more lenient limits or there is no regulation. Member states in this group are Austria, Cyprus, Denmark, Finland, Ireland, Latvia, Malta, Netherlands and United Kingdom. In some of these countries, a precautionary policy has been advised, to which electricity companies and government can voluntarily conform (see below). Spain has no federal legislation for exposure of the general public to EMF of 50 Hz, but some regional governments prohibit construction of new power lines near homes, schools and public spaces.

In the third group of member states, there are stricter basic restrictions and/or reference levels based on the precautionary principle. A brief summary is therefore given per member state:

Belgium: The federal limit on electric field strength since 1987 equals the reference level in the Recommendation. In Flanders, a Decision on indoor environments is in force since 2004 which limits the magnetic flux density in homes and buildings accessible to the public to 10 μT.

Denmark: The Danish National Board of Health recommended in 1993 not to build new homes or children's institutions close to power lines or new power lines close to homes or children's institutions. The exact distance was left to pragmatic considerations. The Danish electricity sector and local government have agreed that measures at reasonable cost to reduce the magnetic field must be investigated if the average exposure per year is higher than 0.4 μT. Like the National Board of Health advice, the agreement applies only to new developments.

Italy: The basic limits for magnetic flux density are identical with the reference levels in the Recommendation. An 'attention value' of 10 μT applies to existing situations with exposure for more than 4 hours in homes, playgrounds and schools. A 'quality goal' of 3 μT is applied to new construction of homes, playgrounds or schools near power lines, primary or secondary substations or vice versa.

Another important restriction to magnetic field at low frequency has been introduced in France since 2013. The “Ministère de l’Ecologie du Dévelopement Durable et de l’Energie” has published indications regarding the maximum level of magnetic flux density in sensitive area as hospitals, maternity, nurseries, kindergartens, primary schools, etc..

Such value is 0.4 μT as average value in 24 hours. In order to satisfy this limit a distance of compliance (“bordure de zone de prudence”) associated to 1 μT as to be guarantee for new plant installation as aerial and buried cable, substation, etc.

Netherlands: The Ministry of Infrastructure and the Environment has recommended that local authorities and grid companies avoid creating new situations with long-term stay of children in areas close to overhead high-voltage power lines with annually averaged magnetic flux density greater than 0.4 μT. This advice was given because of epidemiological studies that found an association between residence near overhead power lines and childhood leukaemia.

Poland: A limit of 75 μT for the magnetic field are applied to areas with homes, hospitals, schools and kindergartens.

Slovenia: A limit of 10 μT is applied for new or modified sources near homes, schools, kindergartens, hospitals, sanatoria, playgrounds, parks, recreational areas, public buildings and buildings with a tourist destination.

Serbia: A limit of 40 μT is applied for sources near homes, schools, kindergartens, hospitals, playgrounds, parks, recreational areas, public buildings etc.

Sweden: In conjunction with the Environmental code and legislation of 1998, guidance for policy makers has been published which explains how the precautionary principle is to be applied to electric and magnetic fields of 50 Hz. For existing situations, exposure to a magnetic flux density that differs strongly from natural background (0.1 μT of the reference level in the Recommendation) must be reduced when possible at reasonable cost and with reasonable consequences. For new situations, an effort has to be made to reduce the exposure when designing and constructing sources.

Different approaches to limiting exposure to power frequency EMF also exist outside Europe.

In Russia, general rules for the protection are set in a 1999 framework law. The public exposure limit for the magnetic fields is 10 μT.

In Switzerland, an Ordinance on Non-ionising Radiation has been in force since 1999. Exposure limits identical to the reference levels in the European Recommendation apply to all areas accessible to the public. A stricter, precautionary limit on magnetic flux density of 1 μT is applied to new installations, unless the owner can prove that the phase order has been optimised and all technically possible and economically viable measures to reduce exposure have been taken. For existing installations, the phase order has to be optimised when the precautionary limit on magnetic flux density is exceeded.

In the United States, no federal legislation is in force. In some states (Colorado, Connecticut, Hawaii, Maryland, Ohio), variations on the 'prudent avoidance' principle have been adopted. This means that exposure of the public to EMF of 60 Hz must be limited at reasonable cost. In other states, fixed limits for the electric or magnetic field of power lines are set, varying from 20 μT to 240 μT (Florida, Minnesota, Montana,New Jersey, New York, Oregon).

International Standards

The protection of the population (which also includes workers not occupationally exposed) and occupationally exposed workers was the subject of guidelines by ICNIRP (International Commission on Non-Ionizing Radiation Protection). The levels established by said commission were included in the various European directives after 2004 (directive 2004/40/EC) up to the current directive of 2013 (2013/35/EU), which was transposed in Italy via Legislative Decree 159 dated 1 August 2016. This decree, which came into force from 02/09/2016 modified Title VIII part IV of Legislative Decree 81/08.

The tables below show the 2010 ICNIRP limits (those currently in force according to law 81: “Consolidated act regarding safety” limited to protection of professionally exposed workers.

Table 8. ICNIRP (2010) Reference levels for occupational exposure to timevarying electric and magnetic fields (unperturbed rms values).

Frequency range E-field strength E (kV/m) Magnetic field strength H (A/m) Magnetic flux density B (T)
1 Hz - 8 Hz 20 1.63 x 105 / f2 0.2 / f2
8 Hz - 25 Hz 20 2 x 104 / f 2.5 x 10-2 / f
25 Hz - 300 Hz 5 x 102 / f 8 x 102 1 x 10-3
300 Hz - 3 kHz 5 x 102 / f 2.4 x 105 / f 0.3 / f
3 kHz - 10 MHz 1.7 x 10-1 80 1 x 10-4

Note:

- f in Hz.

- See separate sections below for advice on non sinusoidal and multiple frequency exposure.

- To prevent indirect effects especially in high electric fields see chapter on “Protective measures.”

- In the frequency range above 100 kHz, RF specific reference levels need to be considered additionally.

Table 9. ICNIRP (2010) Reference levels for general public exposure to timevarying electric and magnetic fields (unperturbed rms values).
Frequency range E-field strength E (kV/m) Magnetic field strength H (A/m) Magnetic flux density B (T)
1 Hz - 8 Hz 5 3.20 x 104 / f2 4 x 10-2 / f2
8 Hz - 25 Hz 5 4 x 103 / f 5 x 10-3 / f
25 Hz - 50 Hz 5 1.6 x 102 2 x 10-4
50 Hz - 400 Hz 2.5 x 102 / f 1.6 x 102 2 x 10-4
400 Hz - 3 kHz 2.5 x 102 / f 6.4 x 104 / f 8 x 10-2 / f
3 kHz - 10 MHz 8.3 x 10-2 21 2.7 x 10-5

Note:

- f in Hz.

- See separate sections below for advice on non sinusoidal and multiple frequency exposure.

- In the frequency range above 100 kHz, RF specific reference levels need to be considered additionally.

• Electronic equipment

Current regulation, in addition to establishing exposure limits for people, also sets out protection values for electronic equipment.

CEI EN 61000-4-8 requires that equipment not be exposed to fields with magnetic induction above 3,75 µT.