Switzerland is, as far as we know, along with Italy one of the few countries in the world to have set national limits at power frequencies based on a precautionary approach to childhood cancer.
The limits were set by an Ordinance of December 1999. It came into force 1 Feb 2001 and existing installations have three years to meet its requirements.
The basic limits are similar to many other countries – 5 kV/m and 100 µT. But in addition, for “sensitive use locations” only (basically rooms in buildings regularly occupied for significant periods of time, children’s playgrounds etc), overhead lines and underground cables greater than 1 kV, substations, and railways have a limit of 1 µT. However, exemptions are granted for new installations if all technically and operationally feasible and financially viable measures have been taken, and some old installations are granted exemptions provided some even more basic conditions are met.
Thus, this is undoubtedly an instance of precautionary limits, but applying only in specified areas, mainly to new equipment, and with exemptions.
see also the source documents
