Safety exclusion zones for mobile masts

Safety exclusion zones for mobile masts

Jeremy Moody ,
11 Feb 2020

Jeremy Moody is the Secretary & Adviser to the Central Association of Agricultural Valuers (CAAV). Here he discusses technical aspects of masts, as well as the information landowners should expect from operators.

Negotiations over agreements for mobile phone masts can be as much about terms as about rent; indeed, the rent should be based on terms.  Alongside issues like access rights, operators are now typically proposing to cap their liability to the site provider for their use of the site and not to accept any consequential liability.

The antennae on a mast work by emitting radio waves.  While these are a less serious, “non-ionising” form of radiation, they are still governed by international guidelines from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) used to define zones around the antenna from which people should be excluded - a larger general one and a smaller one for specifically trained workers.  Their size depends on the direction and height of the antenna, the power used, and the wavelength.  To date, these zones have been limited by shielding, but it appears that this is not feasible for the wavelengths used for 5G.  A typical public exclusion zone for a 4G mast is some 19m in the direction of transmission, but a 5G one might be towards 55m.  

Operators, best placed to assess these zones, have rarely disclosed them to the site providers (or indeed other neighbours) they affect with consequences for proposed development and existing buildings and uses.  As elsewhere in the UK, Scottish Planning Policy only asks that an operator making a planning application for a mast self-certifies compliance with ICNIRP – no specific information is required.  Nothing is required for masts built under permitted development rights or where a facility is upgraded.

Landowners should expect operators to:

  • provide a scale plan showing the ICNIRP exclusion zones
  • provide further plans on any change in the use of antennae
  • accept both full liability and consequential liability  

This is most easily done in negotiating a new agreement but is nonetheless a reasonable request during the agreement by a landowner who is otherwise unaware of the assessments relevant to any future claim against him for liability.