The Control of Electromagnetic Fields at Work Regulations came into force in the UK on the 1 July 2016. It aims to protect workers against adverse health effects caused by exposure to electromagnetic fields (EMF). Here, we present an introduction.
The Control of Electromagnetic Fields at Work Regulations covers electromagnetic fields with frequencies of up to 300 GHz. It refers only to risks associated with effects recognised by the International Commission of Non-Ionizing Radiation Protection (ICNIRP), i.e., short-term effects in the human body caused by the circulation of induced electrical currents and by energy absorption, as well as contact currents.
Internal induced electrical currents result from the interactions of low frequency fields with the body. These currents are measured by their intensity and density. Energy absorption is the result of exposure to fields of frequencies higher than 10 kHz and can produce a rise in temperature. This is measured in the frequency range up to 10 GHz by the specific energy absorption rate or SAR (expressed in watts per kilogram) and above that by the field incident power density.
The EMF Regulations are based on the ICNIRP recommendations. It puts forward dosimetric values within the body (Exposure Limit Values, ELVs) that cannot be exceeded. These values are based on proven adverse health effects and can only be calculated using computer simulations.
It also incorporates Action Levels (ALs) that are based on measurable values. It is important to note that Action Levels are fixed for the static fields that are found around magnets including those used in MRI equipment. ALs are not exposure limits, if they are exceeded, employers have the option to calculate the internal dose quantities for comparison with ELVs.
When carrying out their risk assessment, employers must take into account the guidelines for limiting exposures in situations where workers are at particular risk, for example, EMF exposure to pregnant women and pacemaker-wearers. Employers must also take account of indirect EMF effects, like projections of metal objects and the initiation of electro-explosives.